JPH0565882A - Scroll type compressor - Google Patents

Abstract

(57) [Abstract] [Purpose] At the same time, the same amount of gas is derived from the two compression spaces, and without causing tilt of the orbiting scroll blade, pressure is applied to the back side of the orbiting scroll blade end plate portion to achieve seal reliability. (EN) Provided is a scroll type compressor which improves the efficiency, simplifies the release mechanism and improves the release efficiency. [Structure] The orbiting scroll vanes 13 or fixed scroll vanes 14 have end plates 13b, 14b having compression chambers 15 of the same pressure,
A pair of introduction holes 20a, 20b opening at 15 are provided, these introduction holes are communicated with each other within the plate thickness of the end plate portion, and a communication passage 21 for allowing the pressure in the compression space to act on the back side of the orbiting scroll blade end plate portion 13b is provided. The release mechanism 22 is provided for guiding a part of the gas in the middle of compression, which is guided through the communication path during operation, to the gas suction side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type compressor used in, for example, a refrigeration cycle apparatus to compress a refrigerant gas.

[0002]

2. Description of the Related Art Among compressors for a refrigerant gas used in a refrigeration cycle apparatus, scroll compressors are often used, which are capable of efficient compression and reduce the number of parts by eliminating a valve mechanism. There is a tendency.

The structure of the scroll compressor is, for example, housed in a hermetically sealed case with its axis oriented vertically.
A rotary shaft whose upper and lower parts are rotatably supported, a scroll compression mechanism unit provided at one end of the rotary shaft for sucking and compressing a refrigerant gas, and an electric motor unit provided at the other end for rotationally driving the rotary shaft. Composed.

The scroll compression mechanism portion has a boss portion that eccentrically engages with the rotating shaft, and is composed of a combination of an orbiting scroll blade that can freely orbit and a fixed scroll blade that is fixedly connected to a support frame.

These orbiting scroll blades and fixed scroll blades each consist of a spirally formed blade portion and an end plate portion integrally formed with this blade portion, which mesh with each other and are surrounded by them. A compression chamber, which is a compression space, is formed.

Along with the orbiting movement of the orbiting scroll blade, the refrigerant gas is sucked into the compression chamber on the outer peripheral side. This compression chamber gradually narrows its volume and moves to the center. When the compression chamber moves to the center, it is compressed to a predetermined pressure and discharged to the outside from a gas discharge passage provided in the orbiting scroll blade.

[0007]

The scroll compressor having the above-mentioned structure and operation has some problems. For example, sufficient consideration must be given to the sealing property at the sliding contact portion between the tip end of the fixed scroll blade and the orbiting scroll blade and the bottom surface of the end plate portion.

That is, the gas compressed in the compression chamber exerts an axial force on the orbiting scroll blade. Therefore, a force is applied in a direction in which the tip ends of the scroll blades and the end plate portion of the scroll blades are separated from each other, and the sealing property of this portion is impaired.

As a measure for maintaining the sealing property, there is a structure in which an intermediate pressure is introduced on the rear side of the end plate portion of the orbiting scroll blade.
Specifically, an intermediate pressure hole, which is a pore that opens from the compression chamber to the back side of the orbiting scroll blade end plate portion, is formed.

A part of the gas being compressed in the compression chamber is
The pressure is introduced from the compression chamber to the rear side of the orbiting scroll blade end plate portion through the intermediate pressure hole to apply an intermediate pressure to the orbiting scroll blade.

Conventionally, however, one intermediate pressure hole is usually provided, and a position almost close to the axial center is selected in order to reduce the occurrence of tilt of the orbiting scroll blade even slightly.

This position is also in a state just before the gas to be compressed reaches a predetermined high pressure, and there is a disadvantage that the compressor must continue extra compression work until then.

On the other hand, in the case of an ordinary rotary compressor, for example, the operating compression ratio changes according to the operating conditions and is always automatically adjusted to the optimum state. The structure is such that it operates at a constant compression ratio irrespective of load fluctuations such as the discharge pressure and suction pressure of the refrigeration cycle. It is connected.

For example, when the suction pressure is high and the operation compression ratio of the refrigeration cycle is extremely small, the gas pressure generated in the compression chamber becomes extremely large, and stress is exerted on the blades of the scroll blades and the portions related to the blades. Increase and adversely affect reliability.

In such a state, by providing a so-called release mechanism for returning a part of the gas in the compression chamber directly to the gas suction side, the gas pressure in the compression chamber can be reduced and the problem can be almost solved.

However, in the scroll compressor, a pair of gas suction sides are formed at symmetrical positions due to its structure, and at the same time, the compressed gas is sucked and compressed in the two compression chambers.

Therefore, it is conceivable that the release mechanism is also provided in a dedicated form in each compression chamber, and at the same time, the same amount of gas must be released. Even if there is a slight release gap, the orbiting scroll wing tilts.

As a result, there is a possibility that a portion locally and strongly slidingly contacts the fixed scroll blade, resulting in wear or damage. The release mechanism itself has a relatively complicated structure, and at the same time, accurately releasing the same amount of gas requires extremely difficult adjustment.

The present invention has been made under such circumstances, and an object thereof is to simultaneously introduce the same amount of gas from the compression space of the same pressure and to cause the orbiting scroll blade to tilt. Another object of the present invention is to provide a scroll type compressor that exerts a pressure on the rear surface side of the orbiting scroll blade end plate portion to improve the seal reliability, and simplifies the release mechanism and improves release efficiency by accurate release.

[0020]

In order to achieve the above object, the present invention has an eccentric part of a rotary shaft that is driven to rotate, and a swirl scroll blade composed of an end plate part and a wing part is movably engaged with the eccentric part. In a structure in which a fixed scroll blade composed of an end plate portion and a blade portion is meshed with an orbiting scroll blade, and a compressed gas is sucked and compressed in a compression space formed between these,
The end plate portion of the orbiting scroll vane or fixed scroll vane is provided with a pair of introduction holes that open to the bottom of the compression space vane of the same pressure, and these introduction holes are communicated with each other by a communication passage to reduce the pressure in the compression space. The scroll compressor is characterized by including a release mechanism that acts on the rear side of the end plate portion and guides a part of the gas in the middle of compression to the gas suction side through a communication path during the release operation.

[0021]

The pair of compression spaces of the same pressure are always in communication with the introduction hole and the communication passage. Therefore, the same amount of gas is simultaneously guided from the two compression spaces to the rear surface side of the orbiting scroll blade end plate portion through the communication passage to exert a pressure. If the release mechanism is opened during the release operation, the same amount of gas can be released simultaneously from the two compression spaces via the communication passage, and the release mechanism only needs to be provided in one set, and fine adjustment is not necessary.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, reference numeral 1 is a vertically elongated hermetic case, a part of which is omitted, and a supporting frame 2 is provided at a lower portion of the hermetic case 1, and a main bearing is attached to the supporting frame 2. 3 is supported. An auxiliary bearing (not shown) is provided on the upper portion of the inner peripheral surface of the closed case 1.

A rotary shaft 6 is rotatably supported between the main bearing 3 and the sub bearing. That is, the rotating shaft 6 has its axial direction oriented in the vertical direction, and the lower end portion thereof is the main bearing 3
And the upper end is pivotally supported by the auxiliary bearing.

An upper portion of the rotary shaft 6 is a main shaft portion 6a having a small diameter, and an electric motor portion 7 which is partially omitted is provided here. The electric motor unit 7 includes a rotor 8 fitted to the rotary shaft 6.
An inverter type of which the operating frequency can be controlled is adopted, which is composed of the stator 9 and the stator 9 which is fitted into the closed case 1 and has a small gap with the peripheral surface of the rotor 8.

Below the main shaft portion 6a of the rotary shaft 6 is an eccentric portion 6b in which an eccentric hole 10 is provided from the lower end surface. The scroll compression mechanism portion 12 is connected to the eccentric portion 6b.

The scroll compression mechanism portion 12 is composed of a combination of an orbiting scroll blade 13 having a boss portion 13c which engages with the eccentric hole 10 so as to freely orbit, and a fixed scroll blade 14 connected and fixed to the support frame 2. Become.

The orbiting scroll blade 13 and the fixed scroll blade 14 are each formed in a spiral shape.
a, 14a and end plates 13b, 14b integrally formed with the wings 13a, 14a, and mesh with each other.
In addition, the compression chamber 15 which is a compression space surrounded by these is formed.

A discharge port 16 is provided on the end plate portion 13b of the orbiting scroll vane 13 facing the center of the compression chamber 15, and the discharge port 16 further has the boss portion 13c.
The gas discharge passages 17 provided in the above are communicated. Gas discharge path 1
7 communicates with a gas guide passage 18 that is provided continuously with the eccentric hole 10 of the rotary shaft 6.

On the other hand, at the bottom of the orbiting scroll blade end plate portion 13b, lower end openings of the pair of introduction holes 20a, 20b are opened, and the upper end openings of the respective introduction holes 20a, 20b are
It communicates with the communication passage 21 provided along the thickness of the end plate portion 13b.

That is, the scroll compression mechanism section 12
A feature is that a pair of compression chambers 15, 15 that are compression spaces of the same pressure are formed, and the introduction holes 20a, 20b are
It must be provided at a position communicating with the compression chambers 15, 15 on the relatively low pressure side. The communication passage 21 has one introduction hole 2
0b extends along the plate thickness of the end plate portion 13b and has an open end opening to the peripheral surface.

On the other hand, in the fixed scroll blade end plate portion 14b, the release mechanism 2 which connects the compression chamber 15 having the one introduction hole 20b and the suction side of the compressed gas to each other as necessary.
Two are provided.

The release mechanism 22 is constructed as shown in FIG. That is, the fixed scroll blade end plate portion 14
A release hole 23 is provided in b in the vertical direction. The release hole 23 has a small diameter on the blade bottom opening side, a medium diameter immediately below the blade bottom, and a large diameter at most of the rest.

A release valve 24 is housed in the release hole 23. The release valve 24 is accommodated in the large diameter portion of the release hole 23 together with the spring 25 and is slidably fitted within the range of the large diameter portion, and its head slides on the small diameter portion of the release hole 23. Can be freely fitted to open and close the opening on the blade bottom side.

The lower portion of the release valve 24 has a small diameter, and has a length protruding from the large diameter portion of the release hole 23 to the outside. The protrusion is slidably and airtightly fitted to the valve receiver 26. The valve receiving member 26 is also attached to the lower surface side of the fixed scroll blade end plate portion 14b via a fixing member (not shown) to close the large diameter portion of the release hole 23.

An escape hole 32 communicates with a part of the large diameter portion of the release hole 23. The escape hole 32 opens at the blade bottom outside the outer peripheral surface of the fixed scroll blade portion 14a. From this, with the vertical displacement of the release valve 24,
The communication surface of the release hole 23 of the escape hole 32 is opened and closed.

The release mechanism 2 constructed in this way
Since it is 2, in the normal state where the release action does not occur,
As shown in FIG. 3A, the release valve 24 presses and urges against the elastic force of the spring 25, and the head portion of the release valve 24 closes the opening of the small diameter portion of the release hole 23 on the blade bottom side. , The compression capacity does not change.

If the pressing biasing force to the release valve 24 is removed, the elastic force of the spring 25 acts to push down the release valve 24 to open the release hole 23 on the blade bottom side and escape as shown in FIG. The hole 32 opening is opened,
The compression chamber 15 communicates with the gas suction side outside the fixed scroll vane portion 14a through the release hole 23 and the relief hole 32.

The action of applying and removing the pressing biasing force to the release valve 24 may be operated by the differential pressure between the pressure of the compression chamber 15 and the pressure of the outer peripheral portion of the fixed scroll blade 14, or the suction of the compressor. The pressure or discharge pressure may be guided and controlled, or a solenoid valve may be connected and operated.

As shown in FIG. 1 again, a gap is formed between the rear side of the end plate portion 13b of the orbiting scroll blade 13 and the lower surface of the main bearing 3, and the thrust ring 28 is interposed between them. There is.

The thrust ring 28 is located at a position where the gap between the main bearing 3 and the peripheral surface and the back surface of the orbiting scroll blade end plate portion 13b is partitioned into the inner and outer peripheral sides. The outer peripheral side is the communication passage 21.
From the place where it communicates with the open end of the intermediate pressure chamber 40
Call. The inner peripheral side is referred to as a high pressure chamber 50 that communicates with the inside of the closed case 1 through a gap between the main bearing 3 and the eccentric portion 6b. In the figure, 29 is an intermediate pressure chamber 40 on the outer peripheral side of the thrust ring 28.
3 is an Oldham ring provided between the rear side of the end plate portion 13b and the support frame 2.

A suction pipe 30 communicating with an evaporator (not shown) of the refrigeration cycle apparatus is provided penetrating a side portion of the closed case 1, and its orbiting end has an orbiting scroll blade 13 and a fixed scroll blade 14. It faces the outer peripheral side of the compression chamber 15, which is the meshing space of the.

On the other hand, a discharge pipe (not shown) communicating with the condenser of the refrigeration cycle apparatus is connected to the upper end of the closed case 1. This discharge pipe communicates with the inside of the closed case 1.

Therefore, the electric motor 7 is energized to turn the rotary shaft 6
When is driven to rotate, the orbiting scroll vanes 13 engaged with each other via the eccentric hole 10 make an orbiting motion, and the refrigerant gas, which is a low-pressure compressed gas, is sucked into the compression chamber 15 from the suction pipe 30 and compressed.

With the orbiting movement of the orbiting scroll blade 13, the compression chamber 15 gradually narrows its volume and moves to the center. When the compression chamber 15 moves to the center, the refrigerant gas rises to a predetermined pressure, faces the discharge port 16, and is guided to the gas discharge passage 17 from here. Further, it is guided to the gas guide flow path 18 and the closed case 1
It is released inside and fills up.

The high-pressure gas rises to the upper part inside the sealed case 1 through the clearance between the rotor 8 and the stator 9 of the electric motor section 7 and the escape hole (not shown) provided in the stator 9, and finally the upper end of the case 1 is reached. It is discharged from the discharge pipe of the section to the condenser of the refrigeration cycle.

During such a compression operation, the same amount of a part of the partially compressed gas is simultaneously introduced from the pair of low pressure side compression chambers 15 and 15 at the same time so as to communicate with each other.
0b to the communication passage 21 and again to the communication passage 2
1 through the introduction holes 20a and 20b to the compression chambers 15 and 15
Return to.

Therefore, the same pressure is always ensured in each compression chamber 15, 15. The gas in the middle of compression is guided to the intermediate pressure chamber 40 from the open end of the communication passage 21, and applies intermediate pressure to the circumferential surface and the back surface side of the orbiting scroll blade end plate portion 13b.

The intermediate pressure applied to the peripheral surface of the end plate portion 13b is
Although it does not have any effective action on the orbiting scroll blade 13, the intermediate pressure applied to the back side presses the entire orbiting scroll blade 13 in the axial direction.

That is, while the intermediate pressure chamber 40 is filled with gas, pressure acts on the rear surface side of the orbiting scroll blade end plate portion 13b to ensure the sealing performance with the fixed scroll blade 14.

When the compression ratio is changed according to the load, the release mechanism 22 is operated to open the release hole 23.
In FIG. 2, the diagram at the crank angle of 0 ° shown at the left uppermost position shows the refrigerant gas suction completion states of the chamber a and the chamber b formed on the most gas suction side and having the same pressure.

In the following, the orbiting scroll blade 13 is shown along the arrow.
Makes a swirling motion, and the blade portion 13a changes the position of the fixed scroll blade 14 with respect to the blade portion 14a. Since the release mechanism 22 is operated, the wing portion 13a is 0 ° to 60 °.
At the displaced position, that is, up to a crank angle of 60 °,
The gas in chamber b is released directly from the release hole 23 to the gas suction side.

Further, a part of the gas in the chamber a is released directly from the release hole 23 to the gas suction side, and the remaining gas is guided to the introduction hole 20a, the communication passage 21 and the introduction hole 20b in order, and then temporarily enters the chamber b. After entering, it is further released to the gas suction side through the release hole 23.

When the crank angle is up to 120 °, b
The gas in the chamber is directly guided to the release hole 23, and the gas in the chamber a is all guided through the introduction hole 20a, the communication passage 21 and the introduction hole 20b in order, and is released to the gas suction side through the chamber b and the release hole 23.

At the position where the crank angle is 180 °, the situation is the same as when the crank angle is 120 °. At the position where the crank angle is 240 °, the release hole 23 disappears and the release action is once terminated. Further, the intake of the refrigerant gas to the suction sides of both ends is started.

At the crank angle of 300 °, the state immediately before forming the compression chamber on the suction side is obtained. Each conduction hole 20a, 2
The open end of 0b is closed by the end surface of the fixed scroll blade 14a, and the compression action after release in the chambers a and b is performed. The position of the crank angle of 360 ° is the same as the crank angle of 0 ° described above, and the same operation is repeated again.

Since the release operation is performed in this way, the compression ratio can be changed according to the load even though the compressor is a scroll type compressor, the stress on the blades 13a and 14a is reduced, and the compression performance is improved. To do. Further, not only the operation compression ratio of the refrigeration cycle is changed, but also the capacity is changed, which is advantageous for low speed operation and continuous operation.

In the above embodiment, the pair of introduction holes 20a and 20b are formed in the end plate portion 13b of the orbiting scroll blade 13.
Further, the communication passage 21 is provided and the release mechanism 22 that operates against the elastic force of the spring 25 is provided, but the structure is not limited to this type.

For example, as shown in FIG. 4, a pair of introduction holes 120a, 120a,
The upper end opening of 120b is provided in the blade bottom, and the lower end openings of the respective introduction holes 120a, 120b communicate with the communication passage 121 provided along the thickness of the end plate portion 14b.
(The same parts as those in the above-mentioned embodiment are designated by the same reference numerals, and a new description will be omitted.)

One end of the communication passage 121 has an end plate portion 14b.
Of the orbiting scroll blade end plate portion 13b, and is bent upward along the wall thickness of the supporting frame 2 on the outer peripheral side of the peripheral edge of the orbiting scroll blade end plate portion 13b, and further in the horizontal direction within the wall thickness of the supporting frame 2. The opening is formed so as to face the intermediate pressure chamber 40 between the thrust ring 28 and the Oldham ring 29.

The other end of the communication passage 121 has an end plate portion 14b.
And extends directly along the thickness of the plate and directly communicates with the suction pipe 30 connected thereto. Between the suction pipe 30 and the communication portion of the other introduction hole 13b, a communication passage 121 is simply formed.
Release mechanism 12 for opening and closing, for example, a valve structure
Two are provided.

Even with such a construction, a part of the gas in the middle of compression from the compression chambers 15 and 15 having the same pressure is simultaneously discharged at the same amount from the respective introduction holes 120a and 120b communicating with each other, and the communication passage 121 is formed. To the intermediate pressure chamber 40 to exert a pressure on the rear surface side of the end plate portion 13b of the orbiting scroll blade 13 and press this in the axial direction to secure the sealing property with the fixed scroll blade 14.

The release mechanism 122 having a valve structure is also used.
Similarly, it is possible to change the compression ratio according to the load by directly opening the gas in the middle of compression, which is conducted through the communication passage 121, to the suction pipe 30 by opening.

The present invention is not limited to the above-described embodiments, but can be variously modified without departing from the scope of the present invention, and is not only used as a scroll type compressor in a refrigeration cycle apparatus. However, it can also be used for other purposes.

[0065]

As described above, according to the present invention, in the end plate portion of the orbiting scroll blade or the fixed scroll blade,
A pair of introduction holes that open to the blade bottom of the compression space of the same pressure are provided, and the pressure in the compression space acts on the rear surface side of the orbiting scroll blade end plate by the communication passage that connects these introduction holes within the plate thickness of the end plate part. Since a release mechanism that guides part of the compressed gas to the gas suction side during operation is provided during operation, the orbiting scroll blade does not tilt, improving seal reliability and simplifying the release mechanism. It has the effect of improving the release efficiency by adopting an accurate release.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a scroll compressor according to an embodiment of the present invention with a part thereof omitted.

FIG. 2 is a view for sequentially explaining the release action of the embodiment.

FIG. 3A is a diagram illustrating a state of the release mechanism during normal operation. (B) is a figure explaining the state at the time of the release action of a release mechanism.

FIG. 4 is a vertical cross-sectional side view showing a part of a scroll type compressor, showing another embodiment.

[Explanation of symbols]

6b ... Eccentric part, 6 ... Rotating shaft, 13b ... End plate part, 13a
... Wing portion, 13 ... Orbiting scroll blade, 14b ... End plate portion, 1
4a ... Wing portion, 14 ... Fixed scroll blade, 15 ... Compression chamber,
20a, 20b ... Introduction hole, 21 ... Communication passage, 22 ... Release mechanism.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Morishima 336 Tatehara, Fuji City, Shizuoka Prefecture Toshiba Corporation Fuji Factory

Claims (1)

[Claims] 1. An orbiting scroll blade having an eccentric portion at one end, which is rotatably driven, an orbiting scroll blade which is engaged with the eccentric portion of the rotating shaft, and has an end plate portion and a wing portion capable of orbiting movement, and the orbiting scroll blade. In a scroll compressor including a fixed scroll blade composed of an end plate portion and a blade portion that sucks and compresses a gas to be compressed into a compression space that is meshed with and formed between them, the orbiting scroll blade or the fixed scroll blade A pair of inlet holes provided in the end plate portion of the same pressure and opening to the blade bottom of the compression space, a communication passage that communicates these inlet holes with each other and causes the pressure in the compression space to act on the rear side of the orbiting scroll blade end plate portion, and the release operation A scroll compressor characterized by further comprising a release mechanism for guiding a part of the gas being compressed to the gas suction side through the communication passage.