CN1431402A - Enclosed compressor and freezer using such compressor - Google Patents

Abstract

The present invention provides a highly reliable hermetic compressor or refrigeration device that can use hydrocarbon refrigerants. The hermetic compressor has an airtight container, a motor part and a cylinder housed in the airtight container, a suction pipe that penetrates the airtight container and is connected to the cylinder, and sucks the working fluid into the cylinder through the inside, and is arranged in the cylinder to carry out the operation fluid. A compressed piston, a discharge pipe that discharges the operating fluid from the cylinder through a closed container, and a device that regulates the pressure of the space in the closed container to be higher than the pressure inside the suction pipe and lower than the pressure in the discharge pipe.

Description

Hermetic compressor and refrigerating device using the compressor

technical field

The present invention relates to a hermetic compressor capable of using a hydrocarbon refrigerant as a refrigerant of a refrigerating cycle, and a refrigerating apparatus such as a refrigerator and an air conditioner provided with a refrigerating cycle having the hermetic compressor.

Background technique

In a conventional compressor having a rolling piston in a hermetic container, vanes for dividing into a low-pressure chamber for sucking refrigerant gas into a cylinder chamber and a high-pressure chamber for compressing the sucked refrigerant gas are in contact with a roller ( Roll the outer periphery of the piston) to make the drum rotate, and the blades reciprocate repeatedly in the state of contacting the drum. In such a compressor, the compressed refrigerant gas is temporarily discharged into the space in the airtight container. This refrigerant gas is set to a saturation pressure at the condensation temperature of the refrigeration cycle, that is, a pressure close to the discharge gas pressure.

On the other hand, in recent years, in order to suppress global warming, a refrigeration cycle that does not use chlorofluorocarbons called chlorofluorocarbons, etc. It is thought to cause damage to the ozone layer. Such candidate refrigerants for defreonization include hydrocarbon refrigerants such as propane (R290) and isobutane (R600a).

Since these hydrocarbon refrigerants are flammable by their nature, there is a high risk of explosion and explosion when used in large quantities. In order to reduce this risk, it is best to reduce the amount of refrigerant used by the equipment as much as possible. In addition, since these refrigerants have the property that the amount of refrigerant dissolved in the oil increases when the atmospheric pressure of the lubricating oil is higher, the pressure in the airtight container of the compressor that accumulates the lubricating oil is generally set to be higher. In a rolling piston type rotary compressor having a pressure (e.g. equivalent to the discharge gas pressure of the compressor) and integral rollers and vanes, a large amount of refrigerant is required, and there is a problem in using such a type of refrigerant.

In such a rolling piston compressor in which the roller and the vane are integrated, in order to push the vane to the roller, the elastic force of the spring that applies elastic force to the vane in the direction of the roller and the energy supplied to the container of the chamber that accommodates the vane are used to push the vane to the roller. The pressure of the high-pressure lubricating oil is often applied to the back side of the vane when viewed from the cylinder side. Even if the compressor rotates at a high speed and the inertial force of the blades increases, the front ends of the blades are prevented from leaving the drum. In addition, in the above-mentioned compressor, the pressure inside the drum is about the same as the pressure in the airtight container.

In this case, the space including the suction chamber and the compression chamber formed by the outer periphery of the drum and the inner wall of the cylinder that compresses the suction refrigerant, that is, the oil supply to the operation chamber is supplied from the operation outside to the operation chamber. . Specifically, since the inside of the drum is at high pressure (about the same pressure as the discharge gas pressure of the compressor), the lubricating oil (refrigerator oil) supplied to the inside of the drum passes through it under the action of the differential pressure between the inside of the drum and the working chamber The gap between the roller and the sliding portion of its bearing member leaks in. That is, lubricating oil stored in a high-pressure airtight container flows into the cylinder from a part of the operating chamber under low suction pressure, that is, a small gap that constitutes the suction chamber, and seals and lubricates various parts in the cylinder. .

When it is desired to reduce the amount of refrigerant dissolved in lubricating oil so that the inside of the airtight container is at a low pressure (the same level as the suction gas pressure of the compressor), the inside of the drum is at a low pressure, and the pressure ratio inside the drum is the same as that in the compression chamber outside the drum. The pressure is low (roughly the same as the suction chamber). Therefore, in such a configuration, it is difficult to sufficiently supply oil from the inner side of the drum from the differential pressure from the inner side of the drum to the compression chamber and the suction chamber.

The oil supply technology of the suction chamber of the rolling piston type rotary compressor in which the pressure of the space in the airtight container is set to a pressure lower than the discharge pressure of the refrigerant is described in, for example, Japanese Patent Application Laid-Open No. 6-213183 (Prior Art ). Among them, an oil capillary is provided with one side opening to the inside of the suction member portion of the compression unit and the other end opening to the oil accumulated at the bottom of the airtight container. According to this configuration, a negative pressure generated near the end of the capillary of the suction portion due to the driving of the compressor generates a pressure difference with the inside of the airtight container, and oil is supplied to the suction portion through the capillary from the differential pressure.

The prior art described above does not consider a solution applicable to a system in which the rotational speed of the compressor is changed in accordance with the refrigeration load. The reason for this will be described below.

That is, when the rotation speed of the compressor is changed, the discharge amount per unit time changes, and the flow velocity of the suction gas refrigerant changes. At this time, the negative pressure used in the above-mentioned prior art can be considered to be approximately proportional to the square of the flow velocity of the suction gas refrigerant. The amount of oil supplied to the suction portion through the capillary is also approximately proportional to the square of the flow velocity of the suction gas refrigerant.

On the other hand, if the pressure conditions are the same, the pressure difference per unit time listed below is the pressure difference between the suction chamber and the compression chamber, the pressure difference between the suction chamber and the closed container, and the pressure difference between the compression chamber and the leakage from the operating chamber. The pressure difference with the airtight container is the same regardless of the rotation speed of the compressor. Therefore, the supply amount of lubricating oil per unit time for sealing the sliding part gap of the operating chamber is substantially constant and sufficient regardless of the rotation speed of the compressor.

However, when considering an actual refrigerating cycle using a compressor, as the rotation speed of the compressor increases, the refrigerating capacity of the refrigerating cycle increases, so the temperature difference between the condensing temperature and the evaporating temperature increases. Therefore, the pressure difference between the discharge pressure and the suction pressure of the compressor also increases, so the leakage caused by the pressure difference between the pressure of the operating chamber and the space in the closed container is in the direction of increasing, but the increase of the compressor speed brings The increase of the incoming refrigerant circulation makes the absolute leakage smaller, and the relative leakage has little influence on the refrigerant circulation.

That is, when considering the application to the actual refrigeration cycle, it is considered that the supply amount of lubricating oil per unit time required to seal the sliding portion of the operating chamber does not change much with respect to the fluctuation of the compressor rotation speed.

According to the above study, in the above-mentioned prior art, the amount of lubricating oil supplied varies greatly with the increase and decrease of the rotational speed of the compressor, so it is considered that the performance and reliability of the compressor are impaired. However, for this problem, no consideration is given. That is, in the prior art described above, it is not considered to appropriately adjust the oil supply to the inner side of the compression chamber according to the rotational speed.

For example, if the oil supply amount is made to correspond to a certain rotational speed of the compressor, the oil supply amount will be insufficient when rotating at a lower speed than that, and the oil supply amount will be too large when rotating at a high speed. If the supply amount of lubricating oil is set corresponding to the low-speed rotation speed side, the supply amount of lubricating oil becomes excessive as the rotation speed increases. When the supply amount of lubricating oil is set corresponding to the high rotation speed side, the supply amount in the low rotation speed region becomes too low.

Insufficient oil supply leads to insufficient sealing of the operating chamber, increased leakage of gas refrigerant, and decreased volumetric efficiency of the compressor. At the same time, friction and wear caused by direct contact of sliding parts occur, and the reliability of the compressor decreases. When the oil supply amount is too large, the suction gas is heated by the oil having a higher temperature than the suction gas, and the specific volume increases, which reduces the volumetric efficiency.

In addition, as mentioned above, the oil supply to the working chamber composed of the inner wall of the cylinder of the compressor maintained at high pressure in the airtight container, the roller and the blades is to make the oil inside the roller slide through the roller due to the differential pressure between the inner side of the roller and the working chamber. The internal gap leaks in. Therefore, the amount of oil supplied to the actuator chamber varies with the differential pressure between the high pressure and the actuator chamber pressure determined by the operating conditions or the gap size of the sliding part. In addition, the lower limit of the gap size of the sliding part is limited by the surface roughness of the parts, machining accuracy, etc., so it is impossible to control the minimum amount of oil required to achieve the best performance.

For this reason, when it is desired to prevent the friction and wear of the above-mentioned components, a large amount of oil is excessively supplied beyond the amount of oil required to seal the compression chamber, and the large amount of oil leaked into the operating chamber heats the suction gas to increase the specific volume. Large volume efficiency is reduced, and the gas refrigerant in the compression process is heated by a large amount of high-temperature oil, which has the problem of reducing the overall adiabatic efficiency.

In addition, if the pressure in the airtight container is lowered, it is necessary to increase the sealing distance of the leakage path for oil supply to the seal in the operating chamber and the sliding surface. In this way, the size of the device is increased, and at the same time, the inflow of lubricating oil from the gap due to the differential pressure cannot be sufficiently performed, and there is a problem that it is difficult to ensure the reliability of the cylinder sliding surface.

Contents of the invention

An object of the present invention is to provide a highly reliable hermetic compressor or refrigerating apparatus that can use a hydrocarbon refrigerant.

In order to achieve the above object, the compressor has an airtight container, a motor part and a cylinder housed in the airtight container, a suction pipe that passes through the airtight container and is connected to the air cylinder so that the working fluid is sucked into the air cylinder through the inside, and is arranged on the airtight container. A piston that compresses the working fluid in the cylinder, a discharge pipe that discharges the working fluid from the airtight container through the cylinder, and the pressure in the space in the airtight container is higher than the pressure inside the suction pipe and higher than the pressure in the discharge pipe. A device for regulating the pressure at a low level.

In addition, in order to achieve the above object, the refrigerating device has a hermetic compressor, a condenser, an evaporator, and a refrigerant pipe; Piston, discharge pipe, and discharge port; the suction pipe passes through the above-mentioned airtight container, is connected to the above-mentioned cylinder, and allows the above-mentioned working fluid to be sucked into the cylinder through the inside; the piston is arranged in the above-mentioned cylinder and connected to the rotary shaft of the above-mentioned motor ground rotation, to compress the above-mentioned working fluid; the discharge pipe passes through the above-mentioned airtight container from the above-mentioned cylinder, and discharges the above-mentioned working fluid; The agent pipe allows the above-mentioned working fluid to flow from the above-mentioned discharge pipe to the above-mentioned condenser, and makes the above-mentioned working fluid flow from the above-mentioned evaporator to the above-mentioned suction pipe; wherein, the pressure of the space in the above-mentioned airtight container is adjusted so that Either of the pressure of the above-mentioned working fluid to the above-mentioned discharge port.

Description of drawings

Fig. 1 is a longitudinal sectional view showing a general configuration of a hermetic rotary compressor according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view of A-A in Fig. 1 .

FIG. 3 is a longitudinal sectional view showing the structure of the pressure regulating device of the compressor shown in FIG. 1 .

Fig. 4 is a longitudinal sectional view showing the configuration of another example of the pressure regulating device for the compressor shown in Fig. 1 .

FIG. 5 is a graph showing changes in the pressure in the container and the pressure in the compression chamber of the compressor shown in FIG. 1 with respect to changes in the rotation angle of the cylinder.

6 is a schematic diagram showing the configuration of a refrigeration cycle including a compressor that sets the pressure in a hermetic container higher than the suction pressure and lower than the discharge pressure, according to a second embodiment of the present invention.

Fig. 7 is a diagram showing a general configuration of an air conditioner using the refrigeration cycle shown in Fig. 6 .

Fig. 8 is a cross-sectional view showing a structure for adjusting the pressure in a hermetic container of a compressor according to a third embodiment of the present invention.

FIG. 9 is a diagram illustrating the arrangement positions of communication holes shown in FIG. 8 .

FIG. 10 is a diagram illustrating the arrangement positions of communication holes shown in FIG. 8 .

Fig. 11 is a longitudinal sectional view showing a general configuration of a compressor according to yet another embodiment of the present invention.

Fig. 12 is a longitudinal sectional view showing the general structure of a compressor according to yet another embodiment of the present invention.

Fig. 13 is a graph showing changes in the pressure in the container and the pressure in the compression chamber of the compressor shown in Fig. 12 with respect to changes in the rotation angle of the cylinder.

Fig. 14 is a longitudinal sectional view showing the general structure of a compressor according to yet another embodiment of the present invention, and a schematic diagram showing the configuration of a refrigeration cycle to which the compressor is connected.

Fig. 15 is a longitudinal sectional view showing a general structure of a refrigerator using the refrigeration cycle of Fig. 14 .

Fig. 16 is a graph showing changes in the pressure in the container and the pressure in the compression chamber of the compressor shown in Fig. 14 with respect to changes in the rotation angle of the cylinder.

Detailed ways

Next, an embodiment of the present invention will be described with reference to FIGS. 1-16.

(Example 1)

FIG. 1 shows a horizontal compressor 110 used in a refrigeration cycle, which has a compression mechanism unit and a motor unit in its airtight container 6 . In this embodiment, the compressor is a single cylinder, and the piston 8 rotating in the cylinder 1 compresses the refrigerant which is the working fluid of the refrigeration cycle.

The motor unit of this compressor has a stator 7 fixed in the airtight container 6 by heat fitting or the like, and a rotor 5 attached to the drive shaft 4 and rotating inside the stator 7 .

The compressor unit is connected to the drive shaft 4 of the motor unit, and the rotation of the drive shaft 4 drives the piston (roller) 8 arranged in the cylinder 1 to rotate and reciprocate along the cylinder inner peripheral surface 1a. In the present embodiment, the piston 8 inside the cylinder 1 having a substantially cylindrical shape has a substantially cylindrical roller portion 8a of the piston 8 and a cylinder extending integrally with the roller portion 8a from the cylindrical surface of the roller portion 8a. Plate-like blade portion 8b. The eccentric part 4a provided in the part corresponding to the cylinder 1 of the drive shaft 4 is fitted in the inner periphery of the roller part 8a. The roller portion 8 a is configured to be rotatable around the eccentric portion 4 a of the drive shaft 4 .

As shown in FIG. 2, on the outside of the cylindrical inner peripheral surface 1a of the cylinder 1, a cylindrical hole portion 1b having a central axis substantially parallel to the central axis of the 1a is provided and a part thereof communicates with the inner periphery of the cylinder. Surface 1a. Also, on the opposite side (outer side) to the central axis of the cylinder 1 relative to the hole 1b, there is a cylindrical hole 1c similarly communicating with the hole 1b. The blade part 8b is inserted and housed in the space formed by connecting the hole part 1b and the hole part 1c. In the hole portion 1b, a sliding member 9 is assembled so as to sandwich the blade portion 8b and to slidably contact the plate-shaped flat portion of the blade portion 8b and the inner surface of the hole portion 1b.

On both sides of the cylinder 1, bearing members supporting the drive shaft such as the main bearing 2 and the sub bearing 3 are arranged in connection with the outer peripheral members of the cylinder 1, and the drive shaft 4 penetrating the cylinder 1 is supported by the bearing portions 2a and 3a. For this reason, the central axis of the drive shaft 4 is set to coincide with the central axis of the inner peripheral surface 1 a of the cylinder 1 .

According to the above configuration, the drive shaft 4 is rotated by the rotation of the rotor 5 of the motor part, thereby the piston 8 is rotationally driven in the cylinder 1, and the cylinder inner peripheral surface 1a and the piston 8 rotate while sliding (or maintaining a small gap). relative movement. In addition, as described above, the vane portion 8b is arranged inside the hole portion 1b and the hole portion 1c provided in communication with the cylinder 1, and moves relative to the central axis of the eccentric portion 4a by the movement of the piston 8 generated with the rotation of the drive shaft 4. Towards reciprocating motion. When this reciprocating motion is performed, the reciprocating motion and the turning motion of the sliding member 9 with respect to the blade portion 8b are made to support the blade portion 8b accordingly. This movement causes the piston 8 to reciprocate while rotating around the inner peripheral surface 1 a of the cylinder 1 .

The seal between the blade portion 8b and the holes 1b, 1c (that is, the blade chamber which is the space where these blade portions 8b reciprocate and rotate) is maintained by inserting the sliding member 9 and occupying the space between the hole portion 1b and the blade portion 8b. . In this way, the compression chamber 10 as a closed space and the suction chamber 11 as a suction space for the refrigerant are formed by the cylinder 1, the piston 8, the main bearing 2, the sub-bearing 3, and the sliding member 9, and are repeatedly rotated as the drive shaft 4 rotates. Volume increase or decrease.

The refrigerant inside the refrigeration cycle is sucked into the airtight container 6 from the suction pipe 12 penetrating the airtight container 6 . The suction pipe 12 is connected from the outside of the airtight container 6 to the compression mechanism part inside, and to the refrigerant pipe outside the container. After entering the suction chamber 11 through the suction passage 13, it is compressed. The compressed refrigerant is discharged from a discharge hole 3b formed in the subbearing 3 to a discharge chamber 3c formed by the subbearing 3 and the discharge cover 14 through a discharge valve (not shown) formed in the bearing. After that, it is discharged out of the airtight container 6 from the discharge pipe 15 penetrating the airtight container 6 .

The suction and discharge of these refrigerants are carried out with the swing of the piston 8 . That is, the suction of the refrigerant is performed by rotating (swinging) the piston 8 once around the drive shaft 4 to increase the volume of the suction chamber 11 . Then, by rotating (swinging) the piston 8 around the drive shaft 4, the volume of the closed space partitioned by the outer circumference of the piston 8, the inner peripheral surface 1a of the cylinder, the main bearing 2, the sub bearing 3, and the sliding member 9 is reduced, so , which becomes the compression chamber 10 in which the refrigerant in the space is compressed. By reducing the volume of the compression chamber 10, the refrigerant in the chamber is compressed and discharged from the discharge hole 3b.

In this embodiment, the piston 8 in which the roller portion 8a and the vane portion 8b of the piston 8 are integrally formed is swung. When the roller part and the vane part are formed separately, it is necessary to press the vane to the roller part by high pressure to ensure the sealing of the compression chamber. Therefore, in the past, the pressure in the container was increased, and the lubricating oil in the lubricating oil tank 16 was supplied at high pressure. to the blade room etc. And in the present embodiment that constitutes like this, do not have such necessity, can make the airtight container 6 of compressor be relatively low pressure.

The discharge chamber 3c functions as a muffler by changing the cross-sectional area of the flow path, and also functions as an oil separator for separating oil and gas refrigerant by changing the direction of the flow path. Metal mesh or steel wool can also be placed in the discharge chamber to make it easier to catch oil droplets. The oil separated and accumulated in the concave portion of the discharge chamber returns to the bottom of the airtight container through the capillary 60 .

Next, the structure of the lubricating oil supply of this embodiment will be described.

In this embodiment, oil supply to the compression mechanism and the drive shaft is performed by applying pressure to the lubricating oil by the movement of the vane portion 8b. As mentioned above, the front-end|tip of the vane part 8b moves in the hole part 1c, and the rocking motion of the piston 8 is comprised so that it may not interfere with the vane part 8b.

The hole part 1c is immersed in the lubricating oil tank 16 in the airtight container 6, and the hole part 1c is located below the oil surface. One side of the hole portion 1c communicates with the suction port 17 and an oil passage through which sucked oil flows to the side of the hole portion 1c. In addition, the other side communicates with the oil discharge port 18 and the oil passage through which the discharged oil passes. The lubricating oil 16 is sucked from the suction port 17 toward the hole 1c by the movement of the vane portion 8b. In addition, the lubricating oil in the hole portion 1 c is extruded from the discharge port 18 to the direction of the oil supply pipe 19 through the oil passage. At this time, the suction port 17 and the discharge port 18 are respectively formed in the direction from the lubricating oil tank 16 to the hole 1c and the direction from the hole 1c to the oil supply pipe 19 minus the channel area, and function as so-called fluid diodes.

For this reason, the lubricating oil in the hole 1 c is formed so that it is difficult to flow toward the lubricating oil groove 16 and is formed to flow easily toward the oil supply pipe 19 by the movement of the vane portion 8 b. Lubricating oil flows into the shaft end side of the drive shaft 4 from the oil supply pipe 19 . Then, it flows into the bearing portion (eccentric portion) in the piston roller portion 8a from the helical groove 20a formed in the portion of the drive shaft 4 supported by the sub-bearing 3 . Then, it flows into the helical groove 20b formed in the portion supported by the main bearing 2 on the surface of the drive shaft 4 .

Moreover, the lubricating oil which flowed into the inside of the roller part 8a lubricates the surface of the drive shaft 4 and the bearing part in the roller part 8a, and flows to the motor part side. In this way, lubricating oil is supplied to the rotating parts of the drive shaft 4, the piston 8, and the cylinder 1. Then, the lubricating oil supplied to the helical groove 20b flows out from the end of the helical groove 20b on the main bearing 2 side into the airtight container 6, cools the rotor 5 and the stator 7 of the motor part, and returns to the lubricating oil 16.

In addition, the refrigerant gas in the cylinder 1 sometimes flows into the inside of the roller portion 8a from the gap between the piston 8 and the cylinder 1, and then flows into the sliding surface between the roller portion 8a of the piston and the eccentric portion 4a. At this time, if there is gas on the sliding surface, the roller portion 8a and the drive shaft 4 are likely to stick, so it is necessary to escape the gas.

In this embodiment, air holes 4 b , 4 c communicating from the eccentric portion 4 a to the end of the drive shaft 4 are formed in the drive shaft 4 . The lubricating oil and refrigerant gas on the sliding surface are separated into refrigerant gas with a relatively small specific gravity and lubricating oil with a relatively small specific gravity by the centrifugal force of the rotation of the drive shaft 4, and the refrigerant gas flows into the inner side of the drive shaft 4, It flows out into the airtight container 6 through the vent hole.

In addition to the refrigerant gas from the vent holes 4b and 4c, the gas refrigerant leaking from the gap between the components constituting the compression chamber raises the pressure in the airtight container 6 higher than the pressure in the suction pipe 12 .

Next, the oil supply to the operating chamber of the present embodiment will be described. In this embodiment, a device is provided for causing a predetermined difference between the pressure in the suction pipe 12 and the pressure in the airtight container 6 . That is, in this embodiment, there is provided a device that makes a difference between the suction pressure of the working chamber constituted by the inner wall of the cylinder and the piston (roller and vane) and the pressure of the space in the container.

Fig. 3 is a structural view of the differential pressure valve of the device for producing a difference between the pressure in the suction pipe and the pressure in the closed container according to the present invention. In this figure, the valve 51 is a valve arranged to close the opening provided in the discharge cover 14 . The valve 51 is provided in the sub-bearing 3 and is provided in the valve chamber 50 communicating with the above-mentioned opening. In addition, the valve 51 is biased in a direction to block the opening by a coil spring 52 positioned by a retainer 54 inside the valve chamber 50 .

In addition, a communication passage 53 is formed to communicate with the valve chamber 50 and the inside of the suction pipe 12 . The valve chamber 50 is configured such that the cross-sectional area in the refrigerant flow direction is larger than that of the communication passage, and the influence of the flow velocity of the refrigerant in the suction pipe 12 is reduced.

The pushing force generated by the coil spring 52 is Fk+Fs (Fk: spring force, Fs: force applied to the valve 51 by the gas in the valve chamber 50) as shown in the figure. If the pressure Pi in the airtight container 6 When the force Fg acting on the opening (area A) of the passage connecting the discharge cover 14 and the valve chamber 50 is not greater than Fk+Fs, the valve 51 remains closed. If Fg>Fk+Fs, then the valve 51 is pushed open to connect the inside of the airtight container 6 with the inside of the valve chamber 50 , and therefore communicate the suction pipe 12 with the inside of the airtight container 6 .

When the pressure in the airtight container 6 exceeds the predetermined value Pi, the valve 51 is opened to communicate with the suction pipe 12 with a low opening pressure, so that the pressure in the container can be set to Pi again. In this way, the compressor of the present embodiment sets the pressure difference between the pressure in the airtight container 6 and the pressure in the suction pipe 12, and the pressure in the airtight container is adjusted to be higher than the pressure in the suction pipe (the pressure of the suction gas). A pressure lower than the pressure in the discharge pipe (discharge gas pressure).

Fig. 4 is a sectional view showing another configuration of the differential pressure valve. This figure shows a variant of the means for developing the pressure shown in Figure 3, the example shown in Figure 3 using a helical spring 52 and a valve 51, and the example shown in Figure 4 using a leaf spring 51'. In the example of Fig. 4, the pushing force of Fk+Fs is also exerted on the leaf spring 51' by the leaf spring. When the force Fg>Fk+Fs generated by the pressure Pi in the airtight container 6, the leaf spring is pushed to the valve chamber On the 50 side, the inside of the suction pipe 12 is communicated with the inside of the airtight container 6 through the valve chamber 50 and the communication channel 53 .

Thus, in this embodiment, the pressure in the airtight container becomes an intermediate pressure higher than the pressure in the suction pipe by a predetermined value by the action of the valve device.

In the above embodiments, a passage is formed between the valve chamber 50 and the airtight container 6, and a device for regulating the gas flow between the valve chamber 50 and the container is provided. As these devices, valves 51 and 51' that operate in the valve chamber 50 are provided. In addition, the size of the pressure difference can be determined according to the strength and rigidity of the coil spring 52 and the plate spring 51' that apply elastic force to the valve, and the above-mentioned passage that communicates with the space in the valve chamber 50 of the discharge cover 14 and the space in the airtight container 6. The area A of is adjusted to any size. In addition, the shape of the path of the gas refrigerant flowing from the space in the container to the suction pipe can also be selected according to the requirements of the device by setting an intermediate chamber for storing gas on the path, changing the cross-sectional area in the flow direction, and so on. Corresponds to specifications and pressures, etc.

FIG. 5 shows the pressure difference in the airtight container and the pressure difference in the operating chamber in relation to the supply amount of the oil inside the drum when it leaks into the operating chamber through the gap of the sliding part of the drum. If attention is paid to the gas inhaled at a certain moment, the rotary compressor performs the suction stroke in one revolution of the crank, and performs the compression stroke and discharge stroke in the remaining one revolution. When the rotation angle of the crank is 360° as the crank angle at which the compression stroke starts (the suction stroke ends), a rotation angle of 0° indicates the start of the suction stroke, and a rotation angle of 720° indicates the end of the discharge stroke.

The solid line shows the pressure of the suction chamber and the compression chamber, the dotted line shows the pressure of the closed container, and the shaded line shows the pressure difference. The conditions here are those of a compressor for a refrigerator with refrigerant R134a, a suction pressure of 101 kPa, and a discharge pressure of 837 kPa. In FIG. 5( a ) of the present embodiment, the differential pressure valve is set such that the pressure of the airtight container, which is the intermediate pressure, is about 100 kPa higher than the suction pressure. In FIG. 5( b ), which is a conventional example of a high-pressure airtight container, the area of the shaded portion showing the differential pressure is larger than that in FIG. 5( a ). In a high-pressure airtight container, excessive supply of a large amount of oil degrades compressor performance (volume efficiency, total insulation efficiency). In this embodiment, by appropriately setting the differential pressure, the amount of oil that is beneficial to performance can be adjusted. That is, in the conventional rotary compressor in which the inside of the airtight container is substantially at the discharge pressure, the refrigerating machine oil is supplied from the roller portion 8a into the operating chamber before the compression chamber becomes at the discharge pressure. However, when the airtight container has an appropriate intermediate pressure and the pressure in the compression chamber is higher than the intermediate pressure, the supply of refrigerating machine oil from the roller portion 8a to the compression chamber decreases, and the refrigerating machine oil may migrate to the roller portion 8a conversely.

As mentioned above, according to the specifications of the device, the suction pressure and the internal pressure of the airtight container are maintained at any set difference, and the change in the amount of oil supplied to the operating chamber caused by the change in the rotation speed of the compressor is reduced. Variations in the amount of oil discharged from the compression chamber due to changes in the rotational speed of the compressor are also suppressed. Therefore, the oil to be separated by the discharge chamber 3c functioning as an oil separator is substantially constant per unit time regardless of the number of rotations of the compressor.

In actual refrigerators, the temperature inside the refrigerator is generally maintained as constant as possible, and the ambient temperature is also room temperature. Therefore, the pressure conditions of the compressor during operation rarely change greatly. Therefore, the pressure difference between the discharge chamber 3c and the airtight container 6 at both ends of the capillary 60 that returns the oil separated by the discharge chamber 3c to the bottom of the airtight container 6 will not change greatly. The throttling amount of the capillary tube 60 in this example can return approximately the same amount of oil as the amount of oil supplied to the actuating chamber to the bottom of the airtight container 6 irrespective of operating conditions such as the rotational speed of the compressor. Therefore, it is possible to reduce the lack of oil accumulated in the bottom of the airtight container due to the imbalance between the amount of oil supplied to the operating chamber and the amount of oil returned to the bottom of the airtight container, and sticking caused by insufficient oil supply to the sliding part. Damage to the extent that the reliability of compressors and refrigerators is impaired.

In this way, by maintaining the suction pressure and the pressure in the airtight container at predetermined values, the oil supply amount per unit time supplied to the operating chamber can be optimally varied with changes in the compressor rotational speed. The supply amount is reduced to approach the minimum required amount, so the performance and reliability degradation caused by excessive supply of lubricating oil in the past can be suppressed.

In addition, by suppressing fluctuations in the amount of oil supplied to the operating chamber, fluctuations per unit time in the oil discharged from the compression chamber together with the gas refrigerant are also reduced. For this reason, fluctuations in the oil return amount per unit time from the oil separator are also reduced, and throttling design for oil return becomes easy.

In addition, since the pressure in the airtight container is set to the pressure obtained by adding a predetermined differential pressure to the suction pressure, the amount of refrigerant dissolved in the lubricating oil can be reduced. Therefore, the refrigeration cycle using hydrocarbon refrigerants favorable.

(Example 2)

Next, another embodiment of the present invention will be described with reference to FIG. 6 and FIG. 7 . In this embodiment, the differential pressure valve is adjusted according to the information of the refrigeration cycle to form the pressure in the closed container that is optimal for the operating conditions of the refrigeration cycle. The basic structure of the compressor is the same as that shown in Fig. 1 and Fig. 2 of the first embodiment, so the same symbols are used for the same parts, and their descriptions are omitted.

In Fig. 6, the compressor 110a has a pressure regulating valve 70 and a pressure regulating pipe 71 for adjusting the pressure difference between the suction pipe 12 and the airtight container 6. When the pressure regulating valve 70 is opened, the suction pipe 12 and the airtight container are connected. 6. When the pressure regulating valve 70 is closed, the suction pipe 12 and the airtight container 6 are blocked.

The separation of the oil contained in the compressed gas refrigerant is performed by the oil separator 73 unlike the first embodiment. The oil separator 73 has a container equipped with an inflow pipe 73a, a gas outflow pipe 73b, and an oil outflow pipe 73c, rotates gas refrigerant flowing in from the inflow pipe 73a into the container, and separates oil from the gas by density difference. The gas refrigerant flows out from the gas outflow pipe 73b, and when a certain amount of oil is accumulated in the container, the needle valve 74 is opened by the action of the float 75, flows out from the oil outflow pipe 73c, and passes through the oil return pipe 72 installed in the airtight container 6 of the compressor. Return to the airtight container 6.

The four-way valve 76 for switching between cooling and heating operations, the outdoor heat exchanger 77, the indoor heat exchanger 78, the expansion valve 79, and the connecting pipes 80a and 80b are connected to form a refrigeration cycle for cooling and heating operations. Fans 81, 82 are outdoor and indoor fans respectively.

FIG. 7 is a schematic diagram of an air conditioner using the refrigeration cycle of FIG. 6 . The indoor unit 112 is installed inside the building 150, and the outdoor unit 113 is installed outside. The indoor heat exchanger 78, the fan 82, etc. are built in the indoor unit 112. Moreover, the compressor 110a, the outdoor heat exchanger 77, the fan 81, etc. are built in the outdoor unit 113. As shown in FIG.

Room temperature sensor 120, indoor heat exchanger temperature sensor 121, outside air temperature sensor 122, outdoor heat exchanger temperature sensor 123, compressor surface temperature sensor 124, and airtight container internal pressure sensor 125 are used to detect the temperature and pressure of each part. In addition, inverters 131, 132, and 133 serving as rotation speed control devices that control and drive the rotation speeds of the indoor side control device 130a, the outdoor side control device 130b, and the fan and compressor control the respective corresponding parts.

The control devices 130a and 130b detect commands from the remote controller 140 to set the room temperature and set the air volume, and issue commands to the valves 76 and 79 and the inverters 131 to 133 based on deviations from the room temperature sensor 120 and the like.

By assuming the temperature of the temperature sensor of the heat exchanger serving as the evaporator among the heat exchangers 77 and 78 as the saturation temperature of the refrigerant, the corresponding saturation pressure is obtained, and subtracted from it is the temperature from the heat exchanger to the compressor suction pipe. The suction pressure when the compressor is running can be obtained by calculating the pressure loss of the pipes. In addition, by assuming the temperature of the temperature sensor of the heat exchanger that becomes the evaporator among the heat exchangers 77 and 78 as the saturation temperature of the refrigerant, the The corresponding saturation pressure is added to the pressure loss in the piping from the compressor discharge pipe to the heat exchanger to obtain the discharge pressure. Since piping pressure loss is related to gas density, flow rate, etc., it can also be used as a function of saturation pressure, compressor speed, etc. These calculations are performed by the control unit.

Inverter-driven air conditioners operate in response to heat loads related to the temperature difference between indoor and outdoor air, so the discharge pressure and suction pressure of the compressor vary greatly compared to refrigerators whose internal temperature and ambient temperature vary little. . Therefore, the amount of oil required to seal the leakage of the actuator chamber associated with the pressure difference between the discharge pressure and the suction pressure varies greatly depending on the operating conditions. The oil used for sealing and maintaining the working chamber is approximately equal to the pressure inside the drum and the airtight container, so the oil inside the drum leaks through the gap of the sliding part of the drum under the differential pressure between the inside of the drum and the working chamber.

In the present embodiment, then, by appropriately adjusting the pressure inside the closed container corresponding to the operating conditions, oil supply in an amount favorable for performance can be performed. In addition, for example, the "pressure difference between the pressure in the airtight container and the suction pressure" that should be set is stored in advance as a function or data of the "difference between the discharge pressure and the suction pressure" and the "rotational speed of the compressor". As described above, the suction pressure, discharge pressure, and the rotational speed of the compressor calculated based on the detection values of the heat exchanger temperature sensors 121 and 123, etc., issue commands to the pressure regulating valve 70 as a compression regulating device, and adjust the operation so that it becomes The desired pressure inside the airtight container (detected by the pressure sensor 125).

These storage devices are installed in the control devices 130a, 130b and can be removed and replaced, and storage devices and control devices corresponding to different conditions and models can also be used. In addition, the stored data may be stored as a combination of each data, or may be stored as the above-mentioned function, and the operation amount of the pressure regulating device may be calculated in the control device using the detected predetermined data, and issued as a command.

According to the above structure and function, it is possible to appropriately adjust the amount of oil supplied to the operating chamber depending on the operating conditions, and to reduce the fluctuation of the oil supply due to the fluctuation of the rotation speed of the compressor, and to suppress the performance caused by excessive oil supply. Decline in reliability due to drop and insufficient fuel supply.

(Example 3)

Next, another embodiment of the present invention will be described with reference to FIG. 8 , FIG. 9 , FIG. 10 , and FIGS. 1 and 2 .

The feature of this embodiment is that a hole connecting the compression chamber of the compression unit and the airtight container is provided at a certain interval during one revolution of the compressor, instead of the differential pressure valve shown in Fig. 3 and Fig. 4 of the first embodiment. The basic structure of the compressor is the same as that shown in Fig. 1 and Fig. 2 of the first embodiment, and its description is omitted.

An example of this is disclosed in Japanese Patent Application Laid-Open No. 55-107093. In this example, an opening for communicating the compressor part with the inside of the airtight container is provided in the scroll compressor to form a suction pressure in the airtight container. The intermediate pressure from the discharge pressure is different from the purpose and function of the rotary compressor of this embodiment. In the scroll compressor disclosed in the above-mentioned publication, by making the internal pressure of the airtight container an intermediate pressure, a pressing force acting in a direction opposite to the axial force acting on the orbiting scroll member acts. In addition, in the scroll compressor of the above-mentioned publication, the bottom of the airtight container and the suction pipe are connected by a capillary tube, and oil is supplied from the suction pipe to the compressor part by the difference between the internal pressure (intermediate pressure) of the airtight container and the suction pressure. On the other hand, in the rotary compressor of this embodiment, the oil is supplied to the operation chamber through the gap of the roller sliding portion.

In FIG. 8 , a hole 100 is opened in the end plate on the main bearing side of the compression unit, and is a hole communicating with the inner space of the airtight container. The hole 100 communicates with the compression chamber according to the rotation angle of 540° (180°) and its nearby rotation angle, and is blocked by the end face of the roller in other intervals. The hole 100 is provided separately from the discharge hole of the refrigerant gas, so that the operating chamber in the cylinder and the space in the airtight container can be communicated only at any time and time in the compression process.

The compression chamber pressure Pc is (Vc/Vs)k times the suction pressure Ps (Vs: excluded volume, Vs: compression chamber volume, k: adiabatic index), for example, in the case of R134a, the suction pressure of the refrigerator compressor is 101kPa, Then the pressure in the compression chamber with a rotation angle of 540° is about 230kPa (refer to FIG. 5 ). Therefore, only at the turning angle of 540° and its vicinity, the space in the compression chamber and the airtight container is communicated, so that when the pressure in the compression chamber at the turning angle of 540° and its vicinity is differential pressure and the pressure in the airtight container , the gas comes through the communication hole 100, and in a steady state, the pressure in the airtight container can be maintained at a pressure about 130kPa higher than the suction pressure. In this way, as in the first embodiment, oil can be supplied to the actuating chamber by the differential pressure.

Next, arrangement positions of the communication holes 100 will be described with reference to FIGS. 9 and 10 . Here, the case where the compression chamber communicates with the inner space of the airtight container in the range of the rotation angle of 495° to 585° will be described. The hatched part of Fig. 9 (a) shows the area of the suction chamber (suction process) formed in the range of the rotation angle of 0° to 360° and the compression chamber (compression, compression) formed in the range of the rotation angle of 360° to 495°. discharge process) area. This area includes the inner circumference of the cylinder, the circle with the radius of (piston roller part outer radius - eccentricity) (circumference part shown by the dotted line), the outer circumference of the piston roller part at the rotation angle of 495°, and other trajectory circumferences of the piston. Composition of living area. The hatched portion in FIG. 9( b ) shows the region of the compression chamber formed in the range of the swivel angle of 495° to 585°. This area is surrounded by the inner circumference of the cylinder, the outer circumference of the piston roller at a rotation angle of 495°, a circle with a radius of (outer radius of the piston roller - eccentricity) (circumferential part shown by a dotted line), and blades, etc. Area. In addition, the hatched portion in FIG. 9( c ) shows the region of the compression chamber formed in the range of the swivel angle of 585° to 720° (0°). This area includes the area surrounded by the inner circumference of the cylinder, the outer circumference of the cylinder portion of the piston at a rotation angle of 585°, the blade portion, and the like.

In order to connect the compression chamber and the inner space of the airtight container only in the interval of the rotation angle of 495°～585°, it can be used in the part of the oblique line in Fig. 9(b) that does not intersect with the oblique line of (a) and (c). The end plate on the main bearing side is provided with a communicating hole. This region is indicated by oblique lines in FIG. 10 .

This area includes a circle with a radius of (piston roller part outer radius - eccentricity) (circumferential part shown by a dotted line), the trajectory of the roller-vane connection part with a rotation angle of 495° to 540°, and the position at the rotation angle of 495° The area surrounded by the outer circumference of the piston cylinder. The end plate portion of the main bearing corresponding to the inner side of the circle with the radius of (piston cylinder portion outer radius - eccentricity) does not always communicate with the compression chamber, so the hatched portion including this portion can also be used as shown in the figure. Communication holes 100 are provided. In addition, the shape of the hole 100 arbitrarily has a shape such as a length and a cross-sectional area in accordance with the determined specifications and the size of the pressure, similarly to FIGS. 3 and 4 .

In this embodiment, in the compression process of pressure increase, the opening of the passage connecting the compression chamber and the container is provided on the inner wall surface of the cylinder only during the predetermined time and the rotation angle, so that the pressure in the container can be made higher than the suction pressure. High arbitrary size, or set lower than the discharge pressure. With the same structure, at any position and interval of the piston roller in the process from the suction of the refrigerant to the compression and discharge, the space in the operating chamber and the airtight container is communicated, and the refrigerant gas is circulated, so that the airtight container can be closed. Set to any pressure from suction to discharge. In this way, the amount of lubricating oil supplied to the operating chamber can be appropriately adjusted according to the desired pressure difference between the suction pressure and the discharge pressure.

In this embodiment, communication holes are provided in the main bearing end plate as means for maintaining the pressure in the airtight container of the compressor at an intermediate pressure, so that the cost can be reduced compared with the differential pressure valve of the first embodiment.

(Example 4)

Next, another embodiment of the present invention will be described with reference to FIG. 11. FIG.

Fig. 11 is a longitudinal sectional view of a compressor according to a fourth embodiment of the present invention, and the compressor is a rolling piston type double-cylinder rotary compressor. In the embodiments up to Embodiment 3, the compressor using the rolling piston has an integral structure of the roller part and the vane part. The difference between these embodiments and this embodiment is that the piston in the cylinder is composed of the roller part and the vane part. composed of separate parts.

FIG. 11 shows a horizontal compressor 110b used in a refrigeration cycle, and has a compression mechanism unit and a motor unit in the airtight container 6 . In this embodiment, the compressor is a double cylinder, and the refrigerant in the refrigeration cycle is compressed by the roller pistons 27a, b rotating in the cylinders 22a, 22b. The compression mechanism part is connected to the drive shaft 4 of the motor part, and the rotation of the drive shaft 4 causes the pistons (rollers) 27a, b disposed in the cylinder to rotate along the inner peripheral surfaces 22c, d, and are reciprocally driven. Example is the same.

Also in this embodiment, the inner peripheral sides of the roller pistons 27a, b are fitted into the eccentric portions 26a, b provided on the drive shaft 4 corresponding to the cylinders. The roller pistons 27 a, b are configured to be rotatable about the eccentric portion 4 a of the drive shaft 4 .

As shown in FIG. 11, the vane parts 28a, b are accommodated and assembled in the vane chambers provided outside the cylinders 22a, b in communication with them, and elastic forces are applied from the opposite side to the roller pistons 27a, b by springs 29a, b, and pushed to roller. In addition, similarly to the above-mentioned embodiment, the bearing members supporting the drive shaft such as the main bearing 24 and the sub bearing 25 are arranged on both sides of the cylinder in connection with the outer peripheral members of the cylinder, and are supported by the bearing portions 24a, 25a and pass through the cylinders 22a, b. The drive shaft 26. For this reason, the central axis of the drive shaft 26 is set to coincide with the central axis of the cylindrical inner peripheral surfaces 22c, d of the cylinders 22a, b, and as the drive shaft 4 rotates, the rotary drive in the cylinder 1 The roller pistons 27a, b slide (or maintain a small gap) on the inner peripheral surface and rotate to perform relative motion, and at the same time, the vane parts 28a, b are maintained in the radial direction (the direction of the drive shaft 26) of the roller provided in communication with the cylinder. Push to the state of the roller to reciprocate. When performing this reciprocating movement, the blades slide against the radial movement of the drum on the contact surfaces pushed against the drum. Thus, the suction chamber which forms the compression chamber which is a closed space and the suction space of refrigerant|coolant by these structures repeats volume increase and decrease with rotation of a drive shaft.

In the configuration of this embodiment, the refrigerant circulating in the refrigeration cycle with compressed gas is sucked into the airtight container 6 from the suction pipe 12 passing through the airtight container 6, and enters the suction chambers of the cylinders 22a and 22b through the suction passage. is compressed. The compressed refrigerant is discharged from the discharge holes 30a, b formed in the sub-bearing 25 through the discharge valve formed in the bearing to the discharge chambers 32a, b formed by the sub-bearing 25 and the discharge covers 31a, b. The refrigerant discharged to the discharge chamber 32a flows out to the discharge chamber 32b through the passage connecting the discharge chambers 32a and b, and then is discharged to the outside of the airtight container 6 through the discharge pipe 15 penetrating the airtight container 6 . Below the discharge pipe 15 of the discharge chamber 32b, there is provided a space for storing lubricating oil contained in the discharged refrigerant gas, and the lubricating oil accumulated in this space flows out to the lubricating oil groove through the capillary tube 60 communicated with the opening provided at the lower part of the discharge chamber 32b. 16.

The oil supply structure of the lubricating oil in this embodiment is also performed in the same manner as in the above-mentioned embodiment. The lubricating oil sucked into the vane chamber from the oil suction port 33 by the reciprocating action of the vane parts 28a, b applies pressure to the lubricating oil sucked into the vane chamber through the passage 19. The front end of the drive shaft 26. At this time, the suction port 33 is formed so as to reduce the passage area in the direction from the hole 1c to the fuel supply pipe 19, and functions as a so-called fluid diode. In addition, lubricating oil is supplied from the spiral groove 20 formed in the part of the drive shaft 26 to the bearing part (eccentric part) in the piston cylinder part and the bearing parts of the main and sub bearings 24 and 25, and at the same time, the passage provided in the shaft makes The point that the gas generated in the bearing part of the eccentric part flows out toward the motor part is also the same as in the above-mentioned embodiment.

In addition, the pressure in the airtight container 6 is raised higher than the pressure in the suction pipe 12 by the gas refrigerant leaking through the gap between the components constituting the compression chamber in addition to the refrigerant gas from the above-mentioned vent hole. This embodiment is also provided with a device for causing a predetermined difference between the pressure in the suction pipe 12 and the pressure in the airtight container 6 . The effect of providing the means for arbitrarily generating the pressure in the suction pipe 38 (pressure in the suction chamber) and the pressure in the airtight container 6 described in the above-mentioned embodiment can be similarly obtained in this embodiment.

In the present embodiment, the pressure in the container is set lower than that in the case where the pressure in the airtight container 6 is equal to the pressure in the discharge pipe as in the prior art. Therefore, in the past, relatively high pressure was applied to the lubricating oil, sent to the vane chamber, and the vane was pushed against the roller. Therefore, in order to suppress the local large surface pressure between the roller and the vane, adhesion, wear, and In order to prevent damage, a large amount of lubricating oil needs to be supplied to the working chamber, and in this embodiment, since the force pushing the blades to the roller is relatively low, the amount of lubricating oil supplied can also be reduced.

The supply amount of lubricating oil required for sealing the working chamber and lubricating the roller/vane can be appropriately adjusted according to, for example, the strength of the spring that applies elastic force to the valve, the area and shape of the communication passage, as described above. In addition, since the pressure in the container can be lower than that of the compressor of the prior art, it is also possible to reduce the dissolved amount and reduce the amount of refrigerant when using hydrocarbon refrigerants, so that the refrigeration cycle and other functions can be improved. The safety and reliability of refrigeration and air conditioning equipment.

(Example 5)

Next, still another embodiment of the present invention will be described with reference to FIGS. 12 to 13 .

The compressor shown in FIG. 12 is a compressor having two compression units using swing pistons, and relates to a so-called two-stage compressor that supplies refrigerant compressed in one compression unit to the other compression unit and compresses it again. . Fig. 13 is a graph showing the difference in pressure between the space in the airtight container and the operating chamber as the rotational position of the piston changes. As means for adjusting the pressure in the airtight container, the valve device shown in FIG. 3 and FIG. 4 , the communication hole shown in FIG. 8 , and the like can be used.

The compressor 110c of this embodiment generally has three pressure stages: low pressure (lower suction pressure), intermediate pressure higher than the low pressure (lower discharge pressure, higher suction pressure), and higher pressure than the intermediate pressure (higher discharge pressure). In this embodiment, the pressure in the airtight container of the compressor is not one of the three pressures, but the pressure in the airtight container can be arbitrarily set to benefit the performance.

In Fig. 12, the gas refrigerant in the refrigeration cycle is sucked into the airtight container 6 from the first suction pipe 36 penetrating the airtight container 6, and is first compressed in the first cylinder 1' constituting the first compression unit. The compressed gas refrigerant flows out from the discharge hole 30b to the first discharge pipe 37 through the discharge chamber 32b. That is, the first stage of compression is performed by the first compression unit. Thereafter, the refrigerant is discharged out of the airtight container 6 through the first discharge valve 37 passing through the airtight container 6 .

The gas refrigerant discharged out of the airtight container 6 is cooled by the ambient air through the intercooler 38 , and then sucked into the airtight container 6 again through the second suction pipe 39 penetrating the airtight container 6 . The gas refrigerant sucked into the suction pipe 39 is compressed a second time inside the second cylinder 1″ constituting the second-stage compression unit, and flows out from the discharge hole 30a to the second discharge pipe 40 through the discharge chamber 32a. That is, the second stage compression, and the refrigerant is then discharged from the discharge pipe 40 to the outside of the airtight container 6 .

At this time, the pressure in the airtight container is maintained at a pressure higher than the suction pressure of the first cylinder 1' but lower than the discharge pressure of the refrigerant by the device for setting the pressure in the airtight container detailed in Embodiments 1 and 2. In the case of the valve device shown in FIG. 3 and FIG. 4 , the inside of the first suction pipe 36 and the inside of the airtight container 6 are connected through the valve. In addition, in the case of the communication hole shown in FIG. 8, it is provided so as to communicate with the operation chamber of the compression unit on the lower side (first stage) formed by the first cylinder 1' and the like and a predetermined section in the airtight container.

In this embodiment, in order to achieve high performance, the compression work of the low-stage side and the high-stage side are set equal to the displacement of the low-stage compression unit and the high-stage compression unit, and the compression ratio of the low-stage side is equal to the Compression ratios are about the same on the advanced side.

FIG. 13 shows the variation of the pressure in the working chamber and the pressure in the airtight container with the crank angles of the first stage (lower stage) compression unit and the second stage (higher stage) compression unit of the two-stage compressor. The solid line shows the pressure of the suction chamber and the compression chamber, the dotted line shows the pressure of the closed container, and the oblique line shows the pressure difference. The conditions are those of a compressor for a refrigerator with refrigerant 134a, a low-stage suction pressure of 101 kPa, and a high-stage discharge pressure of 837 kPa. At this time, the pressure ratios of the low-stage side and the high-stage side are substantially the same, and the discharge pressure of the low-stage side and the suction pressure of the high-stage side are 291 kPa.

As in the prior art, as the pressure of the airtight container shown in Fig. 13(b), when the high-level suction pressure is used, for the low-level compression unit, the difference between the high-level suction pressure 291kPa and the pressure of the operating chamber (suction chamber, compression chamber) The pressure difference (hatched portion) becomes the driving force, and the oil inside the drum is supplied to the first air cylinder 1' through the gap of the sliding portion of the drum to seal the working chamber. As for the oil for sealing the working chamber of the high-stage compression unit, the oil discharged from the low-stage compression unit together with the gas refrigerant is supplied to the working chamber through the suction pipe of the high-stage compression unit.

At this time, in Fig. 13(b), the excess oil required beyond the minimum limit is supplied, and the refrigerant is heated by a large amount of high-temperature oil, and when the volumetric efficiency and total insulation efficiency of the compressor decrease, in this embodiment , as shown in Figure 13(a), by setting the pressure in the airtight container to a value lower than the high-level suction pressure, the oil supply amount can be optimized and the performance can be improved. In this case, even if the rotational speed of the compressor increases or decreases, fluctuations in the amount of lubricating oil supplied to the first cylinder 1' can be reduced, thereby suppressing reduction in efficiency of the compressor due to oversupply of lubricating oil, and improving performance. In addition, the lubricating oil flowing into the second cylinder is performed by the lubricating oil supplied to the first cylinder and circulated in the refrigerant gas. The difference between the pressure in the suction pipe 36 leading to the first cylinder 1' and the pressure in the airtight container 6 can be adjusted and set in consideration of the amount supplied to the second cylinder.

Conversely, in the case of FIG. 13(b), when the oil supply to the actuating chamber is insufficient, the pressure in the airtight container can be set higher than the high-stage suction pressure.

(Example 6)

Next, still another embodiment of the present invention will be described with reference to FIGS. 14 to 15 .

The compressor shown in Fig. 14 is a rotary compressor using the swing piston described above. However, in this embodiment, there is a valve switching device in the middle of the cycle, and it is possible to switch between compression performed by one compression chamber and compression performed by two compression chambers. The compressor of this embodiment also has a device for regulating the inside of the airtight container, and has a configuration to generate a pressure difference of an arbitrary value between the pressure in the suction pipe of the operating chamber and the pressure in the space in the container. As the means for adjusting the pressure, any of the means described in the above-mentioned embodiments can also be used.

In Fig. 14, the general structure of the refrigeration cycle of this embodiment includes a compressor 110d having two cylinders, a condenser 62, an evaporator 64a for a freezer compartment, an evaporator 64b for a refrigerator compartment, and connecting them to make the refrigerant The refrigerant tubes that circulate inside it. In addition, blowing fans 66 , 67 , and 68 for blowing air are disposed in the condenser 62 and the evaporator 64 , respectively. Thus, in this embodiment, the refrigerant compressed by the compressor 110d flows out from the discharge pipe 40, is sent to the condenser 62, and then is divided into the evaporator 64a for the freezer compartment and the evaporator 64b for the refrigerator compartment. The refrigerant flowing out of these evaporators flows into the compressor again through the refrigerant pipe to be compressed, forming a cycle.

The compressor 110d of the present embodiment has two cylinders 1', 1", which have suction pipes 36, 39 and 37, 40 for sucking and discharging refrigerant gas, respectively. The cylinders compressed by the first cylinder 1' can be compressed by these cylinders. The final refrigerant gas is sent to the second cylinder 1" for compression again, which is the so-called two-stage compression.

For this reason, the flow of refrigerant formed by the refrigerant pipe connected to the discharge pipe 37 of the first cylinder 1' is divided into two directions, one of which passes through the refrigerant path connecting the discharge pipe 40 of the second cylinder and the condenser 62 and the unit. The valve 61b is connected by a refrigerant pipe, and the other side is connected by a refrigerant pipe through the intercooler 38 in the refrigerant path connecting the refrigerating chamber evaporator 64b for the freezing chamber and the suction pipe 39 of the second cylinder 1″. A solenoid valve 65 b that regulates the flow of the refrigerant is disposed between the branch portion and the intercooler 38 .

In addition, the refrigerant pipe connected to the condenser 62 and the refrigerant flowing from the condenser is branched into two pipes, one of which is connected to the evaporator 64a for the freezer compartment and the other is connected to the refrigerating compartment through the capillary tubes 63a and b respectively. Use evaporator 64b. That is, the capillary tube 63a for the freezer compartment and the capillary tube 63b for the refrigerator compartment are arranged between the branch portion of the refrigerant tube and each evaporator, and are arranged in contact with each other, for example, to exchange heat with the refrigerant tube through which the refrigerant flowing out of the evaporator flows. . Moreover, the electromagnetic valve 65a which can adjust the flow of refrigerant|coolant is provided between the said branch part and the capillary tube 63b for refrigerator compartments.

In addition, a refrigerant path is provided by the refrigerant pipe so that the refrigerant flowing out of the evaporator 64a for the freezing room flows into the suction pipe 36 of the first cylinder 1', and at the same time, the refrigerant flowing out of the evaporator 64b for the refrigerating room flows into the suction pipe 36 of the first cylinder 1'. A refrigerant pipe is branched so that the refrigerant path to the suction pipe 39 of the second cylinder flows in through the check valve 61 a.

In such a structure, the flow of the refrigerant is regulated by the actions of the check valves 61a, b and the solenoid valves 65a, b, and the compression of the refrigerant in the first and second cylinders 1', 1" of the compressor can be controlled at The above-mentioned two-stage compression operation is switched between the parallel compression in which the refrigerant is compressed in parallel in two cylinders. That is, it can be switched to the flow path of the refrigerant in which the flow path from the condenser 62 In the branch flow, the refrigerant evaporated by the evaporator 64a for the freezer flows into the suction pipe 36, and at the same time, the refrigerant evaporated by the evaporator 65a for the refrigerator is compressed in the first cylinder, and flows out from the discharge pipe 37. After the refrigerant merges, it flows into the suction pipe 39 of the second cylinder, and after being compressed, it flows out from the discharge pipe 40; in addition, it can also be switched to such a refrigerant flow path, in which the refrigerant flows from the condenser 62 The refrigerant that has flowed out and been evaporated in the evaporator 64a for the freezing compartment branches into the suction pipes 36 and 39 of the first and second cylinders, is compressed, and then flows out through the discharge pipes 37 and 40 .

In FIG. 15, the refrigerator of this embodiment has the refrigerating cycle shown in FIG. 14, and has a configuration suitable therefor. Refrigerator main body 200 has a plurality of storage compartments inside, and has refrigerator compartment 203A, vegetable compartment 203B, and freezer compartments 202A and 202B in the upper and lower stages from the top. A plurality of evaporators are arranged in the refrigerator 200, and the evaporator 64a for the freezer compartment is arranged at the rear of the upper freezer compartment 202A, and the evaporator 64b for the refrigerator compartment is arranged at the rear of the vegetable compartment 203B. Fans 67, 68 for supplying air flow to the device.

The air cooled by these evaporators by the rotation of the fans has a circulation path that is supplied to the storage compartment through different paths, flows out of the storage compartment, and then returns to the evaporator. That is, there is a circulation path of cooling by the evaporator 64a for the freezer, flowing out into the freezer 202A, B by the fan 67, and then returning to the evaporator 64a from the rear of the lower freezer 202B, and cooling by the evaporator 64b. It is supplied to the refrigerator compartment 203A by the fan 68, cools the refrigerator compartment 203A, flows into the vegetable compartment 203B, and becomes a circulation path of the cold airflow returning to the evaporator 64b from the rear of the container in the vegetable compartment. In order to isolate these cold airflows, the partition wall which has a heat insulating material is arrange|positioned between freezer compartment 202A and vegetable compartment 203B.

Also, compressor 110d, condenser 62, condenser fan 66, and electromagnetic valves 65a, b are arranged behind the freezer compartment at the bottom of the rear side of refrigerator 200. In addition, the refrigerator of this embodiment has a control device 231 for adjusting the operation of the refrigeration cycle shown in FIG. 14 . This control device receives the outputs of the temperature sensor 218 for detecting the temperature in the freezing chamber, the temperature sensor 219 for detecting the temperature of the freezing chamber and the vegetable compartment, and the temperature sensors 220 and 221 for detecting the temperature of the evaporator, and variably adjusts the compressor 110d. The frequency converters 232, 233, 234, 235 of the rotating speeds of the electric motor, the condenser fan 66, and the evaporator fans 67, 68 send instructions to adjust the cooling capacity in the box. In addition, a command to adjust the operation of the solenoid valves 65a and b is issued to switch the flow of the refrigerant and switch between the two-stage compression and parallel compression operations of the compressor 110d. In addition, operation of the defrost heaters 216 and 217 for each evaporator is commanded, and the evaporator is heated to perform defrosting.

In this embodiment, an operation panel 236 is provided on the door of the refrigerator compartment 203A so that the operation of the refrigerator 200 can be adjusted arbitrarily by the user, and an operation command can be issued to the control device 231 by the operation of the panel 236 . In addition, the cooling operation in each storage room of the refrigerator 200, the flow of the switched refrigerant, and the operation of the compressor 110d are performed by the operation of the solenoid valves 65a and 65b.

For example, when the temperatures in both the freezer compartment and the refrigerator compartment are higher than the preset temperature at the start of the cooling operation, the control device 231 judges that both storage compartments need to be cooled, and operates the solenoid valves 65a and b together to open the position. . In this case, the refrigerant from condenser 62 branches and flows into freezer compartment evaporator 64a and refrigerator compartment evaporator 64b to cool the freezer compartment and the refrigerator compartment. The refrigerant from the evaporator 64 a for freezing chamber flows into the first cylinder 1 ′ from the suction pipe 36 , is compressed, and is discharged from the discharge pipe 37 .

The refrigerant from the refrigerating chamber evaporator 64b merges with the refrigerant from the discharge pipe 37, and flows into the second cylinder 1" from the suction pipe 39 to be compressed. That is, the refrigerant passing through the freezing chamber evaporator 64a is The cylinder 1' and the second cylinder 1" perform multiple compressions.

When only the freezer compartment is higher than the preset cooling start temperature, or when the cooling operation of the freezer compartment is forcibly instructed by an instruction from the operation panel 236, an operation for cooling only the freezer compartment alone is performed. In this case, the solenoid valve 65a is closed, and a command is issued from the control device to open the solenoid valve 65b. In this way, the refrigerant from the condenser 62 flows only into the evaporator 64a for the freezer compartment, and the refrigerant flowing out from the evaporator 64a is branched to the first and second cylinders 1', 1", and flows in from the suction pipes 36, 39 in parallel. Compression. That is, the refrigerant from the evaporator 64a for the freezer is compressed in parallel by the cylinders, discharged separately, and then flows into the condenser 62 after being merged. Thus, the parallel compression operation is performed.

In this embodiment, the pressure in the airtight container 6 is also adjusted to be higher than the pressure in the suction pipe of the first cylinder and higher than the pressure in the discharge pipe by the device for setting the pressure in the airtight container described in detail in the first and second embodiments. The pressure inside the tube is low pressure. The pressure in the discharge pipe may be the case of the first cylinder or the case of the second cylinder, and in the case of the second cylinder, it is substantially equal to the saturated pressure of the refrigerant at the inlet of the condenser. This embodiment has means for setting the pressure in the airtight container to an intermediate value of these pressures.

In the case of the differential pressure valve shown in FIGS. 3 and 4 , the inside of the first suction pipe 36 is connected to the inside of the airtight container 6 through the differential pressure valve. In addition, in the case of the communication hole shown in FIG. 8, it is provided so as to connect the compression chamber formed by the first cylinder 1' and the inside of the airtight container in a predetermined section. In this way, the pressure in the airtight container 6 is maintained at a predetermined pressure higher than the suction pressure of the suction pipe 36 together with the above-mentioned two-stage compression and parallel compression.

In the case of two-stage compression, the oil separated from the discharge chamber 32b on the side of the first cylinder 1' is located below the opening of the discharge pipe 37 disposed in the discharge chamber 32b and communicates with the opening provided in the discharge chamber 32b. The pressure difference between the two ends of the capillary 60a, that is, the pressure difference between the discharge chamber 32b and the airtight container 6 is small, so it is not easy to return to the airtight container 6 and stored in the discharge chamber 32b. The gases flow together through the first discharge pipe 37 .

The oil flowing out of the first cylinder 1' side from the low-stage compression unit (refrigerant from the evaporator 64a for freezing compartment is subjected to first-stage compression) is supplied to the high-stage compression unit (from the evaporator 64a for freezing compartment) together with the gas refrigerant. The refrigerant is compressed in the second stage of the second cylinder 1"), and the sealing effect of the working chamber is performed. The oil discharged from the advanced compression unit is separated from the refrigerant gas stored under the container in the discharge chamber 32a, and is further The difference between the high-level discharge pressure and the pressure inside the airtight container 6 is returned to the inner bottom of the airtight container 6 through the capillary 60b.

For the separation of oil in the case of performing single-stage compression in parallel, the oil separated by each discharge chamber 32a, 32b is returned to the bottom of the closed container 6 through the capillary 60a, 60b by the difference between the discharge pressure and the pressure in the closed container. .

At this time, in both the two-stage compression and the parallel compression, the oil separated in the discharge chamber 32a is returned to the airtight container 6 through the capillary 60b. The oil supply amount to the operating chamber related to the oil return amount of the discharge chamber 32a during the second-stage compression is related to the differential pressure indicated by the shaded portion of the low-stage compression unit in FIG. 16( a ). In addition, the oil supply amount to the operating chamber related to the oil return amount of the discharge chamber 32a at the time of single-stage compression is related to the differential pressure indicated by the shaded part of the high-stage compression unit in (b). In both the two-stage compression and the single-stage compression, the pressure inside the airtight container is set to a specified pressure higher than the suction pressure. Therefore, the oil return amount of the discharge chamber 32a and the differential pressure at the two ends of the capillary are substantially equal during the two-stage compression and the single-stage compression, and one throttling amount can correspond to the two-stage compression and the single-stage compression.

In addition, before and after switching between the two-stage compression and the single-stage compression, since the pressure inside the airtight container can be maintained at a substantially constant pressure, it is possible to prevent the refrigerant dissolved in the oil from foaming due to pressure changes in the airtight container.

As described above, according to the present invention, it is possible to provide a high performance and high reliability hermetic compressor capable of handling hydrocarbon refrigerants.

Claims (10)

1. A hermetic compressor comprising: an airtight container, an electric motor part housed in the airtight container, a cylinder having a piston that compresses a working fluid inside, and being connected to the air cylinder through the airtight container and actuated A suction pipe that guides the fluid to the cylinder, a discharge pipe that passes through the airtight container and discharges the working fluid from the cylinder, and a pressure in the airtight container that is higher than the pressure inside the suction pipe and lower than the pressure in the discharge pipe An adjustment unit that performs adjustments. 2 . The hermetic compressor according to claim 1 , wherein the adjustment unit operates when the pressure in the airtight container is higher than the pressure of the working fluid flowing in the suction pipe by a predetermined value. 3 . 3. The hermetic compressor according to claim 1, wherein there is an actuation chamber composed of the cylinder, the piston, and an end plate closing them, and when the pressure in the airtight container is higher than the pressure in the actuation chamber When the predetermined pressure is high, the adjustment unit operates. 4. The hermetic compressor according to claim 1, wherein a plurality of said cylinders are provided, and when the working fluid discharged from one cylinder is sucked into the other cylinder, the adjustment unit adjusts the volume of the space in the airtight container. The pressure is adjusted to be between the pressure in the discharge pipe of the other cylinder and the pressure in the suction pipe of the one cylinder. 5 . The hermetic compressor according to claim 1 , wherein the regulating unit has a passage connecting the space in the hermetic container and the suction pipe, and a valve disposed on the passage. 6. The hermetic compressor according to claim 3, further comprising a passage connecting said operating chamber and a space inside said airtight container, and an opening provided in said operating chamber and connected to said passage. 7. The hermetic compressor according to claim 6, wherein when the compression process is performed in the operation chamber, the opening portion opens into the operation chamber as the piston rotates. 8. The hermetic compressor according to claim 1, wherein the piston, which is arranged in the cylinder and integrally has a substantially cylindrical roller and a plate-shaped vane, is rotated by the electric motor accompanied by oscillation. , thereby compressing the above-mentioned working fluid. 9. A refrigeration device having: a hermetic compressor, a condenser, an evaporator, a refrigerant pipe, and an adjustment mechanism; A cylinder of a piston that compresses the working fluid, a suction pipe that passes through the sealed container and is connected to the cylinder and guides the working fluid to the cylinder, a discharge pipe that passes through the sealed container and discharges the working fluid from the cylinder, and An adjustment unit that adjusts the pressure in the airtight container to be higher than the pressure inside the suction pipe and lower than the pressure in the discharge pipe; the condenser condenses the working fluid discharged from the discharge pipe through the refrigerant pipe; the evaporator The device evaporates the liquid refrigerant into gas; the refrigerant pipe allows the working fluid that has undergone heat exchange in the evaporator to flow to the suction pipe; the adjustment mechanism makes the pressure in the airtight container of the above-mentioned hermetic compressor more than the The pressure in the discharge pipe is lower and higher than the pressure in the above-mentioned suction pipe. 10. The refrigeration device according to claim 9, wherein the adjustment mechanism adjusts the pressure in the airtight container based on a detection result of a temperature sensor detecting a temperature of an operating fluid in the condenser or the evaporator.

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