JP2012225226A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll compressor in which flowing out of lube oil from an oil sump is prevented when the operation of the compressor is stopped.SOLUTION: In the scroll compressor, a flow control valve (6) introduces the lube oil pressure of an oil storage part (53) and any one of the suction pressure and intermediate pressure of the lube oil pressure between both scrolls, as pilot pressure. When the operation of the scroll compressor (100) is stopped, the flow control valve (6) closes a part of an oil feed path leading from the oil storage part (53) to a fixed scroll (22), and when the scroll compressor (100) is operated, the flow control valve (6) opens a part of the oil feed path when the pressure difference between the pressure of the oil storage part (53) and the suction pressure or intermediate pressure is a preset value or more.

Description

  The present invention relates to a scroll compressor that prevents lubricating oil from flowing out of an oil reservoir when operation is stopped.

  In the conventional scroll compressor as seen in Patent Document 1, lubricating oil is mixed in the refrigerant, and when the compressed refrigerant temporarily stays in the discharge chamber, the lubricating oil is separated from the refrigerant. The separated lubricating oil is stored in an oil reservoir and supplied to a sliding portion such as a scroll or a back pressure chamber for receiving the thrust force of the orbiting scroll through an oil supply passage. In such a conventional scroll compressor, when the oil supply passages are in communication with each other when the compressor is stopped, the oil suddenly flows out from the oil reservoir into the container. For this reason, there is a possibility that a shortage of oil supply occurs due to a decrease in the lubricating oil in the lubricating oil reservoir.

  Patent Document 2 discloses a conventional technique that prevents the lubricating oil from flowing out of the oil sump when the operation is stopped. This prior art is characterized in that a bypass hole is provided in an oil supply hole of a rotating shaft driven by an electric motor, and a lid is provided at the outlet of the bypass hole. The lid is a weight body attached to the elastic body, and is configured such that the weight body as the lid opens the bypass hole outlet when the centrifugal force is not applied when the operation is stopped. When the operation is stopped, the lid is opened, and high-pressure gas refrigerant with a discharge pressure is introduced into the oil supply hole to prevent the lubricating oil from flowing out of the oil reservoir. In this conventional technology, a weight body and an elastic body are added to the rotating shaft, so that the structure and assembly adjustment are complicated, and reliability and productivity are poor. There was a problem that the efficiency of the system decreased.

JP 2008-309150 A Japanese Patent No. 4232349

  In view of the above problems, the present invention provides a scroll compressor that prevents lubricating oil from flowing out of an oil sump when operation is stopped.

  In order to solve the above-mentioned problems, the invention of claim 1 includes a compression mechanism (2) having a turning scroll (21) and a fixed scroll (22), and compressing the working fluid, and housing the compression mechanism (2). A pressure vessel (1) that is provided on the discharge side of the compression mechanism portion (2), and stores an oil storage portion (53) that stores lubricating oil separated from a working fluid, and the lubricating oil in the oil storage portion (53) is supplied to the pressure vessel (1) In the scroll compressor provided with the oil supply passage for circulating the inside of the pressure vessel using the pressure difference in the inside, and the flow rate adjusting valve (6), the flow rate adjusting valve (6) is the oil storage part. The lubricating oil pressure of (53) and either the suction pressure or the intermediate pressure of the lubricating oil pressure between the scrolls are introduced as pilot pressures, and when the operation of the scroll compressor (100) is stopped, the flow rate adjusting valve ( 6) is the oil storage part (53) Part of the oil supply passage leading to the fixed scroll (22) is closed, and during operation of the scroll compressor (100), the flow rate adjusting valve (6) is connected to the pressure of the oil storage section (53), The scroll compressor is characterized in that a part of the oil supply passage is opened at a predetermined value or more by a differential pressure from the suction pressure or the intermediate pressure.

  Thereby, it is possible to prevent the lubricating oil from flowing out of the oil sump when the operation is stopped, without reducing the efficiency of the compressor. In addition, there is no dead volume where compressed refrigerant gas flows into the flow rate adjustment valve, and refrigerant gas is prevented from entering the flow rate adjustment valve and oil supply passage, thus stabilizing the operation of the flow rate adjustment valve. Can be done. Therefore, the operation of the flow rate adjusting valve with high reliability and the oil supply to the oil supply passage can be performed.

  According to a second aspect of the present invention, in the first aspect of the invention, during the operation of the scroll compressor (100), the flow rate adjusting valve (6) controls a partial flow rate of the oil supply passage according to the differential pressure. It is characterized by controlling. Thereby, the amount of oil supply can be automatically increased / decreased according to the fluctuation | variation of the rotation speed of a compressor.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the flow regulating valve (6) has an upper chamber (71), a lower chamber (72), and a rod (64) on the lower side, 71) a piston (65) for separating the upper pilot chamber (71-1) and the lower pilot chamber (71-2), and a communication hole provided between the upper chamber (71) and the lower chamber (72) (74) and when the upper pilot chamber (71-1) and the lower chamber (72) are at equal pressure, the valve seat (63) below the communication hole is moved to a spring ( 62), and the lubricating oil pressure of the oil storage section (53) is introduced as a pilot pressure into the upper pilot chamber (71-1), and the lower pilot chamber (71- In 2), either the suction pressure or the intermediate pressure is set as the pilot pressure. In response to the pressure difference between the upper pilot chamber (71-1) and the lower pilot (71-2), the rod (64) moves through the communication hole (74) to move the valve body. (61) is pressed, and the amount of restriction between the rod (64) and the valve seat (63) is varied to control the flow rate of a part of the oil supply passage.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the scroll compressor is a vertical type.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to third aspects, the scroll compressor is a horizontal type.

The invention according to claim 6 is the invention according to any one of claims 1 to 5, characterized in that the working fluid is carbon dioxide (CO ₂ ).

  In addition, the code | symbol attached | subjected above is an example which shows a corresponding relationship with the specific embodiment as described in embodiment mentioned later.

It is sectional drawing which shows the scroll compressor 100 in one Embodiment of this invention. (A) is sectional drawing which shows the flow regulating valve at the time of a stop, (b) is sectional drawing which shows the flow regulating valve at the time of an operation | movement, (c) is an enlarged view of the A section of (b). It is.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. About each embodiment, the same code | symbol is attached | subjected to the part of the same structure, and the description is abbreviate | omitted.

FIG. 1 is a cross-sectional view showing a scroll compressor 100 according to an embodiment of the present invention. The present invention is not limited to this example, and can be applied to a scroll type compressor having other structures except for the main part related to the flow rate adjusting valve 6.
The scroll compressor 100 in this embodiment is a hermetic electric compressor in which the electric motor unit 3 and the compression mechanism unit 2 are accommodated in the pressure vessel 1. The electric motor unit 3 includes a stator and a rotor fixed to the shaft 4 that is rotationally driven by the electric motor unit 3.

  The compression mechanism unit 2 includes a movable scroll 21 that revolves by a crank mechanism 41 supported by a main bearing 43, and a fixed scroll 22 that is disposed opposite to the movable scroll 21 and forms an operation chamber 27. The shaft 4 is supported substantially vertically by the auxiliary bearing 44 and the main bearing 43. The movable scroll 21 has a substantially disc-shaped movable side plate, a movable side vortex standing in an involute curve shape from the end surface of the movable side plate toward the fixed scroll 22, and a cylindrical shape from the end surface opposite to the movable side vortex. The boss part is provided. The fixed scroll 21 includes a fixed side plate and a fixed side spiral formed by a spiral groove provided on the end surface of the fixed side plate on the movable scroll 21 side. A thrust bearing is disposed on the side of the movable scroll 22 where the boss is provided.

  The crank mechanism 41 is configured by an eccentric shaft and a boss portion of the movable scroll 21 that are integrally provided at an end portion of the shaft 4 on the compression mechanism portion side. The eccentric part is provided so as to be eccentric by a predetermined amount e from the axial center of the main bearing 43 and the auxiliary bearing 44. This eccentricity e is the revolution radius of the movable scroll 32. An Oldham coupling (not shown) is disposed on the back side of the movable scroll 21 to prevent the movable scroll 21 from rotating. Thereby, only the revolution of the movable scroll 21 is permitted. The compression mechanism unit 2 has a plurality of working chambers 27 formed by meshing the movable-side spiral and the fixed-side spiral to reduce the volume of the fixed-side spiral by reducing the volume of the movable scroll 21 with respect to the fixed scroll 22. The refrigerant supplied from the suction port 26 communicating with the outermost peripheral side is compressed. As described above, the compression mechanism unit 2 includes the orbiting school 21 and the fixed scroll 22, and compresses the working fluid when the orbiting scroll 21 revolves by the rotation of the shaft 4 having the eccentric shaft.

Here, the function of the present embodiment for preventing the lubricating oil from flowing out of the oil reservoir when the operation is stopped will be described.
Before describing the function of the present embodiment, the phenomenon in which the lubricating oil flows backward from the oil reservoir will be described in the case where the flow rate adjustment valve 6 of the present embodiment is not provided. During operation, the working fluid sucked from the suction port 26 is compressed by the compression mechanism 2, and then the compressed working fluid and lubricating oil are discharged to the discharge port 23 and the reed valve 23 ′ (23 ″ is a stopper). Then, it passes through the discharge pipe 24 and flows into the oil separator 5. The lubricating oil is separated from the working fluid by the cylindrical portion 52 and temporarily stored in the oil storage portion 53.

  On the other hand, the high-pressure working fluid is discharged from the outlet 55 of the oil separator 5 and is sent to a condenser or the like in the refrigeration cycle. The lubricating oil returned to the oil storage section 53 in the compressor 100 is directly connected to the oil supply path 68 from the oil supply pipe 54 (explained as having no flow rate adjusting valve 6), and the intermittent oil supply mechanism 31 (see Patent Document 1). Through the oil supply passage 24, the space 45 is reached. Thereafter, lubricating oil is supplied to the main bearing 43 and the auxiliary bearing 44 through an oil supply passage 42 provided at the center of the shaft 4. The lubricating oil that has lubricated the main bearing 43 and the sub-bearing 44 is sucked into the working chamber 27 of the compression mechanism section 2 together with the working fluid sucked from the suction port 26 through the oil supply passage 25.

Next, when the compressor stops operating, the discharge port 23 is closed by the reed valve 23 ', so that the working chamber 27 (the same applies to the motor chamber) becomes equal to the suction pressure. For this reason, the lubricating oil flows backward from the oil storage portion 53 to which the discharge pressure is applied (there is no flow rate adjusting valve 6), and the lubricating oil in the oil storage portion 53 is rapidly reduced.
In this embodiment, in order to prevent the backflow phenomenon of the lubricating oil as described above, a flow rate adjusting valve 6 as described below is installed. 2A is a cross-sectional view showing the flow rate adjusting valve at the time of stop, FIG. 2B is a cross-sectional view showing the flow rate adjusting valve at the time of operation, and FIG. It is an enlarged view.
This embodiment will be described with reference to FIG. 1 in which the flow rate adjusting valve 6 is installed and FIG. 2 in which the detailed flow rate adjusting valve 6 is shown.

  The compressed working fluid and lubricating oil pass through the discharge port 23, pass through the discharge pipe 24, and flow into the oil separator 5. The lubricating oil is separated from the working fluid in the cylindrical portion 52, temporarily stored in the oil storage portion 53, and returned to the compressor 100 through the oil supply pipe 54. The working fluid is discharged from the outlet 55 of the oil separator 5. The lubricating oil that has returned to the oil storage section 53 in the compressor 100 flows into the flow rate adjusting valve 6, passes through the oil supply passage 66 (see FIG. 2), and is formed by a gap between the rod 64 and the inner diameter side of the valve seat 63. The pressure is reduced by the throttle portion and flows into the eccentric bearing 41 and the oil supply passage 42 in the bearing 4 through the oil supply passages 68 and 24. Thereafter, the main bearing 43 and the auxiliary bearing 44 flow in. The lubricating oil that has lubricated the bearing is sucked into the working chamber 27 of the compression mechanism section 2 together with the working fluid sucked from the suction port 26 through the oil connection passage 25.

  The flow rate adjusting valve 6 has an upper chamber 71, a lower chamber 72, and a rod 64 below, and a piston 65, an upper chamber 71 and a lower portion that separate the upper chamber 71 into an upper pilot chamber 71-1 and a lower pilot chamber 71-2. When the communication hole 74 provided between the chamber 72 and the upper pilot chamber 71-1 and the lower chamber 72 are at equal pressure, they are seated on the valve seat 63 below the communication hole by the spring 62 in the lower chamber 72. A valve body 61 is provided. In the upper pilot chamber 71-1, the lubricating oil pressure of the oil reservoir 53 is introduced as a pilot pressure, and either the suction pressure or the intermediate pressure is introduced as a pilot pressure in the lower pilot chamber 71-2.

  In accordance with the pressure difference between the upper pilot chamber 1-1 and the lower pilot 71-2, the rod 64 moves through the communication hole 74 and presses the valve element 61, so that a gap between the rod 64 and the valve seat 63 is reached. The flow amount of the oil supply passage between the oil storage section and the orbiting scroll 21 is controlled by varying the throttle amount. Since the increase in the discharge pressure is an increase in the internal pressure applied to the working chamber, the flow rate adjustment valve 6 is naturally controlled so as to increase the flow rate of the oil supply passage in accordance with the increase in the differential pressure.

The operation of the flow control valve 6 is as follows.
(A) When stopped The valve body 61 is pressed against the valve seat 63 by a spring 62 and is closed. Since the valve body 61 and the piston 65 are connected by a rod 64, and the oil supply passages 66 and 68 and the pressure guiding pipe 67 are equalized (equal pressure), only the force of the spring 62 acts on the valve body 61. do not do.
(B) During operation The lubricating oil pressure (substantially the discharge pressure) of the oil storage section 53 acts on the oil supply passage 66 and the pressure guide pipe 67, and the suction pressure (or intermediate pressure) acts on the oil supply passage 68. In advance, the valve force during which the valve body 61 is intended to be seated on the valve seat 63 is set smaller than the force that the differential pressure between the discharge pressure and the suction pressure during the operation acts on the piston 65. The body 61 moves away from the valve seat 63 and the lubricating oil flows. The flow rate of the lubricating oil is controlled by a clearance restriction between the rod 64 and the valve seat 63. The rod 64 may be straight. In this case, the flow rate increases as the differential pressure increases. If the taper becomes thinner as it reaches the lower part, the amount of the narrowing gap between the rod 64 and the valve seat 63 can be changed more greatly.

  The feature of the present invention is to prevent the lubricating oil from flowing out of the oil sump when the operation is stopped, without reducing the efficiency of the compressor. In this regard, as one of the features of the present invention, the flow rate adjusting valve 6 introduces the lubricating oil pressure of the oil storage portion 53 as a pilot pressure. In the development process of the present invention so far, it has been considered that the pilot pressure is directly introduced from the discharge port 23 to act as the differential pressure of the flow rate adjusting valve 6. Could occur.

  That is, when the pilot pressure is directly introduced from the discharge port 23, the upper pilot chamber 71-1 is formed as a closed dead volume before the reed valve 23 ', and re-expansion here causes a decrease in performance. In addition, when it is directly introduced from the discharge port 23, not only the lubricating oil but also the working fluid, that is, the refrigerant gas may be mixed, and the operation of the flow rate adjusting valve may become unstable. Furthermore, if refrigerant and refrigerant gas are mixed, the sealing performance of the piston 65 may be deteriorated, and gas may leak into the oil supply passage, resulting in performance degradation. If the flow rate adjusting valve 6 introduces the lubricating oil pressure of the oil storage section 53 as a pilot pressure, such a problem will not occur, and the highly reliable operation of the flow rate adjusting valve 6 and the oil supply to the oil supply passage can be performed. It can be carried out.

In the above description, the scroll compressor 100 has been described as a vertical type, but is not limited thereto, and may be a horizontal type. In this case, since the oil storage part 53 is formed below, the flow rate adjusting valve 6 is installed in the vicinity thereof. Further, the outlet of the oil supply passage 68 of the flow rate adjusting valve 6 is the sliding contact surface of the fixed scroll (22) and the orbiting scroll (21) close to the suction port, but is not necessarily limited to this. You may install in an intermediate part (middle between the suction side and the discharge port). Furthermore, you may provide an exit in the thrust bearing side which supports a turning scroll (21). The scroll compressor of the present invention may be applied to a refrigerant compressor, and the present invention can be applied to a refrigeration cycle using a CO ₂ refrigerant.

DESCRIPTION OF SYMBOLS 1 Pressure vessel 2 Compression mechanism part 6 Flow control valve 21 Orbiting scroll 22 Fixed scroll 53 Oil storage part 65 Piston 71 Upper chamber 72 Lower chamber 74 Communication hole

Claims (6)

A compression mechanism (2) having a turning scroll (21) and a fixed scroll (22) for compressing the working fluid, a pressure vessel (1) for accommodating the compression mechanism (2), and the compression mechanism (2). An oil storage part (53) that is provided on the discharge side and stores the lubricating oil separated from the working fluid, and the lubricating oil in the oil storage part (53) is passed through the pressure container using the differential pressure in the pressure container (1). In a scroll compressor having an oil supply passage for circulation and a flow rate adjustment valve (6),
The flow rate adjustment valve (6) introduces the lubricating oil pressure of the oil storage section (53) and either the suction pressure or the intermediate pressure of the lubricating oil pressure between the scrolls as a pilot pressure,
When the operation of the scroll compressor (100) is stopped, the flow rate adjustment valve (6) closes a part of the oil supply path from the oil storage section (53) to the fixed scroll (22),
During the operation of the scroll compressor (100), the flow rate adjusting valve (6) is set to a value greater than or equal to a preset value by a differential pressure between the pressure of the oil storage section (53) and the suction pressure or the intermediate pressure. A scroll compressor characterized in that a part of an oil supply passage is opened.   2. The scroll compressor according to claim 1, wherein when the scroll compressor is operated, the flow rate adjusting valve controls a flow rate of the oil supply passage according to the differential pressure. The flow rate adjusting valve (6)
Upper chamber (71),
Lower chamber (72),
A piston (65) having a rod (64) below and separating the upper chamber (71) into an upper pilot chamber (71-1) and a lower pilot chamber (71-2);
When the communication hole (74) provided between the upper chamber (71) and the lower chamber (72), and the upper pilot chamber (71-1) and the lower chamber (72) are of equal pressure, A valve body (61) seated by a spring (62) in the lower chamber (72) is provided on the valve seat (63) below the communication hole,
In the upper pilot chamber (71-1), the lubricating oil pressure of the oil storage section (53) is introduced as a pilot pressure, and either the suction pressure or the intermediate pressure is introduced into the lower pilot chamber (71-2). Is introduced as a pilot pressure,
In response to the pressure difference between the upper pilot chamber (71-1) and the lower pilot (71-2), the rod (64) moves through the communication hole (74) to move the valve body (61). 3. The scroll compression according to claim 1, wherein the flow rate of the oil supply passage is controlled by pressing and changing a throttle amount between the rod (64) and the valve seat (63). Machine.   The scroll compressor according to any one of claims 1 to 3, wherein the scroll compressor is of a vertical type.   The scroll compressor according to any one of claims 1 to 3, wherein the scroll compressor is a horizontal type. The scroll compressor according to claim 1, wherein the working fluid is carbon dioxide (CO ₂ ).

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