JPS647258Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention can be applied to gases such as air and refrigerants (hereinafter referred to as
Regarding a scroll compressor suitable for use in compressing air), the compressed gas in the middle of compression is guided into the crank chamber, and the orbiting scroll and the fixed scroll are compressed by pressing the orbiting scroll toward the fixed scroll. The present invention relates to a scroll compressor that performs axial sealing between the compressor and the compressor.

Conventionally, a fixed scroll is fixedly attached to a casing, a discharge port is provided at the center of the fixed scroll, and a suction port is provided at a peripheral position away from the discharge port, and a drive shaft is provided in the casing to rotate the drive shaft. An orbiting scroll that rotates while overlapping with the fixed scroll is rotatably provided on the drive shaft, a crank chamber is formed between the back surface of the orbiting scroll and the casing, and the orbiting scroll rotates with respect to the fixed scroll. 2. Description of the Related Art A scroll compressor is known in which a back pressure introduction hole is formed in an orbiting scroll for guiding compressed fluid in a compression chamber formed while the scroll rotates to the crank chamber.

To compress the air, the air sucked in from the suction port is sealed inside the airtight space formed between the fixed scroll and the orbiting scroll as a compression chamber, and the compression chamber is reduced as the orbiting scroll revolves. The structure is such that the air is compressed and discharged from the discharge port. In order to prevent the orbiting scroll from being displaced by pressure in the axial direction due to air compressed in the compression chamber, and from being unable to maintain the airtightness of the compression chamber, a back pressure is introduced into the orbiting scroll. A portion of the compressed air in the middle of compression is guided from the hole to the crank chamber as back pressure, thereby canceling out the axial pressing force applied to the orbiting scroll and sealing the scroll.

By the way, as mentioned above, in the system in which a part of the compressed air is introduced into the crank chamber and the orbiting scroll is pressed against the fixed scroll to seal the scrolls, for example, the machining accuracy of the fixed scroll and the orbiting scroll is insufficient. If the pressure is sufficient, the airtightness between the scrolls is incomplete and the back pressure introduction hole becomes a restriction at the time of starting the compressor, causing leakage between the scrolls before the crank chamber pressure rises sufficiently. A levitation phenomenon may occur in which the pressure in the compression chamber rises to nearly the same pressure as the pressure near the discharge port, causing the orbiting scroll to float up. When such a floating phenomenon occurs, the pressure in the crank chamber escapes back to the suction port through the gap between the outer circumference of the orbiting scroll and the fixed scroll, resulting in the orbiting scroll remaining floating at any time. Become.

By the way, this type of compressor supplies oil to the bearings to lubricate the bearings and the Oldham joints that make up the anti-rotation mechanism, and this oil is supplied from the crank chamber through the gap between the fixed scroll and the orbiting scroll. Since the oil enters the compression chamber and is discharged together with the compressed air, even if the machining accuracy of the fixed scroll and the orbiting scroll is somewhat insufficient as mentioned above, there is no oil present on the sliding surfaces between the scrolls. death,
During normal startup when the sealing effect of this oil is sufficiently performed, the above-mentioned floating phenomenon of the orbiting scroll does not occur. However, if there is no oil on the sliding surfaces between the scrolls and the oil film is broken, such as after stopping operation for a long time, a floating phenomenon occurs.

However, in the prior art described above, when a floating phenomenon occurs, it is necessary to supply enough oil to the sliding surfaces of the fixed scroll and the orbiting scroll, stop the compression operation, and restore the close contact between the scrolls. After securing it I rebooted. However, this type of system has the disadvantage that starting the compressor is troublesome and is not suitable for automatic operation. Furthermore, it also had the disadvantage of causing damage due to lack of lubrication of the Oldham joint, which serves as a mechanism to prevent rotation, and shaft slack.

The present invention improves the drawbacks of the prior art described above, and supplies a large amount of oil to the sliding surface between the fixed scroll and the orbiting scroll when the crank chamber pressure is lower than a predetermined pressure, such as immediately after the start of compression operation. In particular, the present invention provides a scroll compressor whose startup is stabilized.

In order to achieve the above object, the feature of the configuration adopted in the present invention is that an oil supply groove is formed on the sliding surface between the flange part of the fixed scroll and the end plate of the orbiting scroll, and the oil supply groove and the discharge An oil supply pipe is provided between the oil separator that separates oil from the gas and supplies the oil in the oil separator to the oil supply groove. The present invention is provided with a throttle valve mechanism that throttles the flow rate of oil flowing through the oil supply pipe when the oil supply pipe reaches the oil supply pipe.

With this configuration, when the pressure inside the crank chamber is low, such as at the beginning of startup, the throttle valve mechanism opens, supplies a large amount of oil in the oil separator to the oil supply groove, and the oil film seals the engine. To smoothly seal the sliding surfaces of a fixed scroll and an orbiting scroll to quickly perform rated compression operation.

The present invention will be described below along with embodiments shown in the drawings.

The figure is an overall configuration diagram of the present invention.A casing 1 has a bearing part 1A and a cylindrical part 1B having a larger diameter than the bearing part 1A that forms a crank chamber (described later).The cylindrical part 1B has a fixed scroll 2. is fixedly installed. The fixed scroll 2 includes an end plate 2A,
Spiral-shaped wrap portion 2B erected on the mirror plate 2A
and a flange portion 2C fixed to the cylindrical portion 1B.
The wrap portion 2B is formed into a curve close to an involute or a rivet. Further, the flange portion 2 of the fixed scroll 2
A suction port 3 is formed near C, and a mirror plate 2
A discharge port 4 is formed at the center of A.

A drive shaft 5 is provided on the same axis _O1 as the fixed scroll 2, and the drive shaft 5 is rotatably supported by the bearing portion 1A of the casing through bearings 6, 6. A revolving scroll 7 is rotatably supported by the drive shaft 5 through a bearing 8, and the axis _O2 of the revolving scroll 7 is at a distance δ from the axis _O1 of the drive shaft 5.
Here,
The orbiting scroll 7 is composed of a head plate 7A and a spiral wrap portion 7B erected on the head plate 7A, the wrap portion 7B being formed into an involute or a curve close to an involute. The wrap portion 7B is attached to the wrap portion 2B of the fixed scroll 2 so as to overlap with it at a predetermined angle, and the spaces between the wrap portions 2B, 7B are sealed spaces to form a plurality of compression chambers 9, and the head plate 7A and the flange portion 2C of the fixed scroll 2 form a sliding surface 10 so as to slide against each other.

Reference numeral 11 denotes a crank chamber consisting of a sealed space formed between the casing 1 and the back surface of the orbiting scroll 7. In order to guide a part of the compressed air in the compression chamber 9 into the crank chamber 11, an end plate of the orbiting scroll 7 is used. 7
One or two back pressure introduction holes 12 are formed in A. Note that there is a suction port 3 in the crank chamber 11.
In order to introduce a pressure that is higher than the pressure of , and lower than the discharge pressure of the discharge port 4, the back pressure introduction hole 12 opens into the compression chamber 9 at an intermediate portion between the suction port 3 and the discharge port 4,
During compression operation, the pressure inside the crank chamber 11 is equal to the pressure in the compression chamber 9 located at the intermediate position, thereby applying a pressing force to the orbiting scroll 7.

13 is an Oldham joint as a rotation prevention mechanism provided in the crank chamber 11;
3 is an Oldham ring 13A, and cross-shaped grooves 13 formed at multiple locations on the Oldham ring 13A.
B, and a concave groove 13B installed in the orbiting scroll 7.
The shaft 13C is fitted into the shaft 13C. Therefore, when the drive shaft 5 is rotated, the orbiting scroll 7 is guided by the Oldham joint 13 and revolves around the axis O ₁ of the drive shaft 5 with a radius δ.

Further, 14 is a flange portion 2 of the fixed scroll 2.
An annular oil supply groove is formed in C so as to open toward the sliding surface 10, and the oil supply groove 14 is connected to an oil supply pipe described later through an oil passage 15 formed in the fixed scroll 2. Note that the oil supply groove 14 is not limited to one groove, and may be a plurality of annular grooves.

Next, 16 is an air pipe whose one end is connected to the discharge port 4 and the other end is connected to an air tank or pneumatic equipment (none of which is shown). An oil separator 17 is provided to separate mixed oil, and the next stage of the oil separator 17 is a valve that opens when the internal pressure of the oil separator 17 reaches a predetermined set pressure, for example, 3 kg/cm ² . A normally closed pressure regulating valve 18 is provided. Therefore, during compression operation, the pressure inside the air pipe 16, oil separator 17, etc. is equal to or higher than the opening pressure of the pressure regulating valve 18.

Further, reference numeral 19 denotes an oil supply pipe whose one end is connected to the oil reservoir in the oil separator 17 and the other end is connected to the oil passage 15, and a throttle valve mechanism 20 is provided in the middle of the oil supply pipe 19. . That is, the throttle valve mechanism 2
0 indicates a pressure-responsive valve 21 provided in the middle of the oil supply pipe 19 and a branch pipe 22 branched from the oil supply pipe 19.
and a fixed aperture 23 provided in the middle of the diaphragm. The pressure-responsive valve 21 includes a valve body 21A inserted in the middle of the oil supply pipe 19, a cylinder 21B provided in the valve body 21A, and a valve body 21D seated on and off the valve seat 21C of the valve 21A.
One end is fixed to the valve body 21D and the other end is fixed to the cylinder 2.
Valve rod 21F fixed to piston 21E in 1B
and a spring 21G stretched between one side of the piston 21E and the valve body 21A to bias the valve body 21D in the valve opening direction. 24 is a pilot pipe, one end of which communicates with the crank chamber 11 via a vent hole 25 formed in the cylindrical portion 1B of the fixed scroll 1, and the other end communicates with the intake/discharge port 21H formed in the cylinder 21B. connected to
The internal pressure of the crank chamber 11 is used as pilot pressure to act on the other side surface of the piston 21E.

The present invention is constructed as described above, but when the motor (not shown) is rotated, the rotation is caused by the drive shaft 5,
It is transmitted to the orbiting scroll 7 via the bearing 8, and the orbiting scroll 7 performs a relative circular motion about the axis _O1 with respect to the fixed scroll 2. The air sucked from the suction port 3 is then compressed into a compression chamber 9.
The liquid is gradually compressed inside, and after being raised to a predetermined pressure, it is discharged from the discharge port 4. Furthermore, this compressed air is supplied to an oil separator 17 via an air pipe 16, and oil in the compressed air is removed. When the pressure inside the oil separator 17 becomes higher than the set pressure of the pressure regulating valve 18, the pressure regulating valve 18 opens and clean compressed air is supplied to the air tank and the like.

As mentioned above, when the orbiting scroll 7 performs a circular motion due to the start of compression operation, the compressed air from the discharge port 4 is immediately supplied to the oil separator 17, and at this time, the pressure regulating valve 18 is closed until a predetermined set pressure is reached. Since the oil separator 17 has a small volume while the valve is closed, the internal pressure of the oil separator 17 also rises immediately, and the oil inside is pumped through the oil supply pipe 19, the pressure-responsive valve 21, and the throttle 2.
3, supplied to the oil supply groove 14 via the oil passage 15;
The sliding surface 10 is lubricated to perform a sealing action with an oil film. At this time, the pressure-responsive valve 21 is connected to the fixed throttle 23.
For example, if the aperture area is set to 10 times, the aperture 23
10 times the amount of oil can be obtained compared to the case where only oil is used, and the sealing action can be performed effectively.

In addition, the compressed air in the compression chamber 9 is supplied to the back pressure introduction hole 12.
The pressure is applied to the back surface of the orbiting scroll 7 to press the orbiting scroll 7 toward the fixed scroll 2 and seal the scrolls 2 and 7.

Then, the pressure inside the crank chamber 11 is a predetermined pressure,
For example, when the pressure rises to the same pressure as the compression chamber 9 in which the back pressure introduction hole 12 is bored, this pressure increases
5. Pressure-responsive valve 21 via pilot piping 24
act on the piston 21E, displacing the piston 21E to the left in the figure against the spring 21G, and displacing the piston 21E to the left in the figure.
D is seated on the valve seat 21C. As a result, during rated operation, the oil flowing inside the oil supply pipe 19 is limited to the fixed throttle 23, reducing the amount of oil, and due to the presence of excess oil in the oil supply groove 14, the orbiting scroll 7 is activated by this hydraulic pressure. This prevents oil from floating or leaking into the crank chamber 11 from increasing mechanical loss.

By the way, as mentioned above, if the machining accuracy of the fixed scroll 2 or the orbiting scroll 7 is insufficient, for example, there may be problems such as between the respective lap portions 2B, 7B, between the respective lap portions 2B, 7B and the end plates 2A, 7A, etc. Airtightness between each part becomes insufficient. As a result, the back pressure introduction hole 12 becomes a restriction at the beginning of the start-up of the compressor, and due to the time delay, the pressure inside the crank chamber 11 does not rise sufficiently. The pressure rises to nearly the same pressure as the pressure near the discharge port 4, and the orbiting scroll 7 floats up.

However, in the present invention, when compression operation is started, the pressure inside the oil separator 17 increases, and a large amount of oil in the oil separator 17 is supplied to the oil supply groove 14 via the pressure-responsive valve 21 and the fixed throttle 23. Therefore, the sliding surface 10 can be sealed by the oil film, and the sliding surface 10 can be kept sufficiently airtight. Therefore, even if the orbiting scroll 7 rises as described above, the sliding surface 10 is still sealed.
The pressure inside the crank chamber 11 escapes to the suction port 3 again, and the problem that the pressure inside the crank chamber 11 does not rise at any time does not occur. Therefore, even if the back pressure introduction hole 12 acts as a throttle and the supply time of compressed air supplied into the crank chamber 11 is prolonged, the crank chamber 11 becomes at the same pressure as the compression chamber 9 over time, and the rotation The scroll 7 is pressed against the fixed scroll 2, and the sealing between the scrolls 2 and 7 can be automatically performed. When the pressure inside the crank chamber 11 reaches a predetermined pressure, the pressure-responsive valve 21 is closed, and rated operation can be performed while supplying oil to the oil supply groove 14 only from the fixed throttle 23.

In the above embodiment, the throttle valve mechanism 20 was described as being composed of a pressure-responsive valve 21 and a fixed throttle 23, but it may also be constructed as a variable throttle valve that operates using the internal pressure of the crank chamber 11 as pilot pressure. It is something.

The scroll compressor according to the present invention, as described in detail above, supplies a large amount of oil to the sliding surfaces of the fixed scroll and the orbiting scroll at the initial stage of startup of the compressor to perform a sealing action with an oil film. As a result, even if the machining accuracy of each scroll is poor, it is possible to prevent an accident in which the pressure in the crank chamber is sucked into the suction port again, and as time passes, the pressure in the crank chamber increases and the orbiting scroll is replaced with a fixed scroll. Rated compression operation can be performed in the pressed state. In addition, since only a small amount of oil is supplied to the oil supply groove during rated compression operation, there are problems such as the orbiting scroll being lifted up by the oil pressure, or the crank chamber being filled with oil, causing mechanical loss due to oil resistance. This has effects such as being able to prevent defects.

[Brief explanation of the drawing]

The figure is an overall configuration diagram of a scroll compressor according to the present invention. 1...Casing, 2...Fixed scroll, 2
C...Flange portion, 3...Suction port, 4...Discharge port, 5...Drive shaft, 7...Orbiting scroll, 9...
... Compression chamber, 10 ... Sliding surface, 11 ... Crank chamber, 12 ... Back pressure introduction hole, 13 ... Oldham joint, 14 ... Oil supply groove, 16 ... Air piping, 17 ...
... Oil separator, 18 ... Pressure regulating valve, 19 ... Oil supply pipe, 20 ... Throttle valve mechanism, 21 ... Pressure responsive valve, 22 ... Branch pipe, 23 ... Fixed throttle, 24 ...
...Pilot piping.

Claims (1)

[Scope of utility model registration request] A casing consisting of a bearing portion and a cylindrical portion having a larger diameter than the bearing portion, a spiral wrap portion erected on the end plate, and a flange portion provided on the outer circumferential side of the wrap portion that is connected to the cylindrical portion of the casing. a fixed scroll fixed to a fixed scroll; a drive shaft rotatably supported by a bearing portion of the casing; a drive shaft located within a cylindrical portion of the casing and rotatably mounted on the drive shaft;
an orbiting scroll having a wrap portion erected on the end plate that overlaps with the wrap portion of the fixed scroll to form a plurality of compression chambers; and an orbiting scroll formed between the back side of the end plate of the orbiting scroll and the cylindrical portion of the casing. a back pressure introduction hole that is bored in the end plate of the orbiting scroll and introduces a part of the gas compressed in the compression chamber as back pressure into the crank chamber; In a scroll compressor comprising an oil separator that separates oil from compressed gas that is compressed while the gas rotates and is discharged to the outside, the sliding movement between the flange portion of the fixed scroll and the end plate of the orbiting scroll An oil supply groove is formed on the surface, and an oil supply pipe is provided between the oil supply groove and the oil separator to supply oil in the oil separator to the oil supply groove, and the crank is connected to the oil supply pipe in the middle of the oil supply pipe. A scroll compressor characterized by being provided with a throttle valve mechanism that throttles the flow rate of oil flowing through the oil supply pipe when the indoor pressure reaches a predetermined pressure.