JP2021134743A - Scroll type fluid machine - Google Patents

Abstract

To improve lubrication performance of a crank chamber in a scroll type fluid machine.SOLUTION: In a scroll type compressor as a scroll type fluid machine, an oil passage for injecting a lubricant separated by an oil separator, toward an annular step portion 220E of a front housing 220 receiving thrust force of a turning scroll, is formed on an upper portion of a fixed scroll, and a suction portion P1 sucking a gas refrigerant in a direction along an inner peripheral surface of the front housing 220 while crossing the lubricant injected from the oil passage, is formed on the housing. Further, a first lubricant supply passage 220F extended from an inner peripheral end portion toward an outer peripheral end portion is formed on the step portion 220E opposed to the oil passage, and a second lubricant supply passage 220H extended from the inner peripheral end portion toward the outer peripheral end portion, is formed on the step portion 220E at a downstream side with respect to the first lubricant supply passage 220F along a circulating direction of the gas refrigerant sucked from the suction port P1.SELECTED DRAWING: Figure 3

Description

The present invention relates to a scroll type fluid machine that compresses or expands a compressible fluid by changing the volume of a compression chamber partitioned by a fixed scroll and a swirl scroll.

A scroll-type compressor, which is an example of a scroll-type fluid machine, changes the volume of a compression chamber by revolving around the axis of a fixed scroll, and sucks in a gaseous refrigerant, which is an example of a compressible fluid. It is configured to compress and discharge. In the scroll type compressor, the lubricating oil contained in the gaseous refrigerant lubricates the crank chamber in which the crank mechanism for revolving the swivel scroll around the axis of the fixed scroll is housed. Specifically, as described in Japanese Patent Application Laid-Open No. 2000-80995 (Patent Document 1), the gas refrigerant is separated from the gaseous refrigerant by an oil separator from the tip opening of the oil passage extending from the back surface of the fixed scroll to the tip surface. The lubricating oil is injected, and the lubricating oil is supplied to the crank chamber through a receiving groove formed on the inner surface of the housing facing the lubricating oil.

Japanese Unexamined Patent Publication No. 2000-80995

However, a part of the lubricating oil injected from the opening at the tip of the oil passage is flowed in the downstream direction by the gaseous refrigerant sucked from the suction port formed in the vicinity thereof, and is not received by the receiving groove, but is not received by the receiving groove, and is not received by the receiving groove. There was a risk that the absolute amount of lubricating oil supplied to the vehicle would decrease. If the absolute amount of lubricating oil supplied to the crank chamber is reduced, the lubrication performance of the crank chamber is deteriorated.

Therefore, an object of the present invention is to provide a scroll type fluid machine having improved lubrication performance of a crank chamber.

Scroll-type fluid machines are made from housings, fixed scrolls fixed to the housing, swivel scrolls revolving around the axis of the fixed scrolls, and compressible fluids compressed or expanded by the fixed scrolls and swivel scrolls. It is equipped with an oil separator that separates the lubricating oil. Then, an oil passage for injecting lubricating oil separated from the compressible fluid by an oil separator is formed at the upper part of the fixed scroll toward the annular thrust receiving surface of the housing that receives the thrust force of the swivel scroll, and the housing is formed. In addition, a suction port is formed to suck the compressible fluid in the direction along the inner peripheral surface of the housing while intersecting with the lubricating oil injected from the opening of the oil passage. Further, a first groove extending from the inner peripheral end portion to the outer peripheral end portion is formed on the thrust receiving surface facing the opening of the oil passage, and the compressible fluid sucked from the suction port on the thrust receiving surface. A second groove extending from the inner peripheral end to the outer peripheral end is formed downstream of the first groove along the flow direction.

According to the present invention, the lubrication performance of the crank chamber can be improved with respect to the scroll type fluid machine.

It is sectional drawing which shows an example of the scroll type compressor. It is a perspective view which shows an example of the oil passage formed in a fixed scroll. It is a front view which faces the step part of a housing.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the attached drawings.
As the scroll type fluid machine, either a compressor or an expander can be used, but here, a scroll type compressor will be described as an example.

FIG. 1 shows an example of the scroll type compressor 100.
The scroll type compressor 100 is incorporated into, for example, a refrigerant circuit of a vehicle air conditioner, sucks low-pressure gas refrigerant (compressible fluid) from the refrigerant circuit, compresses it, and discharges high-pressure gas refrigerant to the refrigerant circuit. The scroll type compressor 100 includes a housing 200, a compression mechanism 300 for compressing a low-pressure gaseous refrigerant, and a driving force transmission mechanism 400 for transmitting a rotational driving force to the compression mechanism 300 from the outside. Here, a predetermined amount of lubricating oil for lubricating the moving parts of the compression mechanism 300 and the driving force transmission mechanism 400 is stored in the lower part of the housing 200.

The housing 200 includes a front housing 220 that houses a compression mechanism 300 and a driving force transmission mechanism 400, and a rear housing 240 that is joined to the open end of the front housing 220.

The outer peripheral surface of the front housing 220 is formed in a stepped cylindrical shape whose outer diameter is reduced in four steps as the distance from the joint surface with the rear housing 240 increases. Here, the cylindrical shape may be such that it can be visually recognized as a cylindrical shape, and for example, a reinforcing rib, a mounting boss, or the like may be provided on the outer peripheral surface thereof (the shape is the same below). Further, the inner peripheral surface of the front housing 220 is formed in a stepped cylindrical shape whose outer diameter is reduced in four stages as the distance from the joint surface with the rear housing 240 increases. Therefore, the front housing 220 has a similar shape to its outer peripheral surface and inner peripheral surface, and is formed in a cylindrical shape having substantially the same outer shell thickness as a whole and having a diameter reduced in four stages. Further, a suction port P1 for sucking low-pressure gaseous refrigerant from the refrigerant circuit is formed at a predetermined position on the peripheral wall of the front housing 220. The details of the suction port P1 will be described later.

In the following description, for convenience of explanation, regarding the stepped cylindrical inner peripheral surface of the front housing 220, from the large diameter portion to the small diameter portion, the first inner peripheral surface 220A, the second inner peripheral surface 220B, and the third inner surface are described. It will be referred to as a peripheral surface 220C and a fourth inner peripheral surface 220D.

The rear housing 240 has a hemispherical shape in which the central portion thereof bulges outward as the distance from the joint surface with the front housing 220 increases. Therefore, the rear housing 240 cooperates with the compression mechanism 300 to form a discharge chamber H1 having a predetermined volume. Further, the rear housing 240 incorporates a centrifugal oil separator OS that separates the lubricating oil from the gaseous refrigerant in the discharge chamber H1. Further, a discharge port P2 is formed at a predetermined position on the peripheral wall of the rear housing 240 to discharge the high-pressure gas refrigerant from which the lubricating oil has been separated by the oil separator OS to the refrigerant circuit.

The front housing 220 and the rear housing 240 can be separated by a plurality of bolts 500, which can be mentioned as an example of a fastener, in a state where the open end of the front housing 220 and the open end of the rear housing 240 are joined. It has been concluded.

The compression mechanism 300 is arranged in a cylindrical space partitioned by the first inner peripheral surface 220A of the front housing 220. The compression mechanism 300 includes a fixed scroll 320 arranged so as to close the opening on the large diameter side of the front housing 220, and a ring-shaped step portion that transitions from the first inner peripheral surface 220A to the second inner peripheral surface 220B. It is configured to include a swivel scroll 340 arranged between the 220E and the fixed scroll 320. Here, the stepped portion 220E of the front housing 220 is given as an example of the thrust receiving surface.

The fixed scroll 320 includes a disk-shaped bottom plate 322 fitted to the open end of the first inner peripheral surface 220A of the front housing 220, an involute-shaped wrap 324 extending from one surface of the bottom plate 322 toward the swivel scroll 340, and the like. have. Further, the fixed scroll 320 has a thin ring shape that extends outward from the outer peripheral surface of the bottom plate 322 at the opening end of the first inner peripheral surface 220A and is sandwiched between the joint surfaces of the front housing 220 and the rear housing 240. Further has a flange 326 of. The outer peripheral edge of the flange 326 is formed in a shape that follows the outer shape of the open end of the front housing 220, and through holes through which the shaft portion of the bolt 500 can penetrate are formed at a plurality of positions on the plate surface thereof. Therefore, the fixed scroll 320 is sandwiched between the joint surface between the front housing 220 and the rear housing 240 via its flange 326 to close the opening end on the large diameter side of the front housing 220 and the rear housing 240. The discharge chamber H1 is partitioned in cooperation with. A gasket (not shown) is arranged between the flange 326 of the fixed scroll 320 and the rear housing 240.

The swivel scroll 340 has a disc-shaped bottom plate 342 arranged at a position facing the step portion 220E of the front housing 220, and an involute-shaped wrap 344 extending from one surface of the bottom plate 342 toward the fixed scroll 320. There is. The bottom plate 342 has an outer diameter smaller than that of the bottom plate 322 of the fixed scroll 320, and the thin ring-shaped thrust plate 510 is provided so that the outer peripheral portion of the other surface transmits the thrust force to the step portion 220E of the front housing 220. It is in contact with the step portion 220E via. The thrust plate 510 is fixed to the stepped portion 220E of the front housing 220.

The fixed scroll 320 and the swivel scroll 340 are meshed with each other so that the side walls of the laps 324 and 344 are partially in contact with each other in a state where the circumferential angles of the laps 324 and 344 are deviated from each other. At this time, a tip seal (not shown) may be attached to the tip of the lap 324 of the fixed scroll 320 to ensure airtightness with one surface of the bottom plate 342 of the swivel scroll 340. On the other hand, a tip seal (not shown) may be attached to the tip of the lap 344 of the swivel scroll 340 to ensure airtightness with one surface of the bottom plate 322 of the fixed scroll 320. Therefore, in the compression mechanism 300, a compression chamber H2 that sucks in and compresses the gaseous refrigerant, which is a crescent-shaped closed space, is partitioned between the fixed scroll 320 and the swivel scroll 340.

At the center of the bottom plate 322 of the fixed scroll 320, a discharge hole 322A for discharging the gaseous refrigerant compressed by the compression chamber H2 to the discharge chamber H1 is formed. On the other surface of the bottom plate 322 facing the discharge chamber H1, the flow of the gas refrigerant from the compression chamber H2 to the discharge chamber H1 is permitted, but the flow of the gas refrigerant from the discharge chamber H1 to the compression chamber H2 is blocked, for example. A check valve 328 consisting of a reed valve is attached.

A concave groove 322B is formed on the outer peripheral surface of the bottom plate 322 of the fixed scroll 320 over the entire circumference thereof, and an O-ring 322C for ensuring airtightness with the front housing 220 is fitted therein. Further, a concave groove 240A is formed on the open end surface of the rear housing 240 over the entire circumference thereof, and an O-ring 240B for ensuring airtightness with a gasket (not shown) is fitted therein.

The driving force transmission mechanism 400 includes a driving shaft 410, a crank pin 420, an eccentric bush 430, a balancer weight 440, an electromagnetic clutch 450, and a pulley 460.

The drive shaft 410 has a stepped cylindrical shape having a small diameter portion 410A and a large diameter portion 410B, and the tip portion of the small diameter portion 410A protrudes outward from the small diameter side end portion of the front housing 220, and the drive shaft 410 is attached to the front housing 220. It is housed freely in rotation. Specifically, the small diameter portion 410A of the drive shaft 410 is rotatably supported by a ball bearing 520 with respect to the opening side end portion of the fourth inner peripheral surface 220D of the front housing 220. Further, the large-diameter portion 410B of the drive shaft 410 is rotatably supported by a roller bearing 530 with respect to the third inner peripheral surface 220C of the front housing 220. The small-diameter portion 410A of the drive shaft 410, which is located between the ball bearing 520 and the large-diameter portion 410B, is the fourth inner circumference of the front housing 220 by, for example, a sealing member 540 such as a mechanical seal or a lip seal. Airtightness with the surface 220D is ensured. The drive shaft 410 is not limited to rolling bearings such as ball bearings 520 and roller bearings 530, and may be rotatably supported by cylindrical slide bearings.

A cylindrical crank pin 420 extending from the large-diameter portion 410B of the drive shaft 410 toward the compression mechanism 300 is erected at a position eccentric from the axial center of the end surface in the axial direction. An eccentric bush 430 having a cylindrical outer shape is fixed to the outer peripheral surface of the crank pin 420 in a relative rotatable and eccentric state. The outer peripheral surface of the eccentric bush 430 is press-fitted into the inner peripheral surface of the annular boss portion 342A extending from the other surface (rear surface) of the bottom plate 342 of the swivel scroll 340 toward the small diameter side of the front housing 220. It is rotatably supported via a plain bearing 550. Further, a balancer weight 440 is attached to the outside of the radius of the boss portion 342A of the swivel scroll 340 in consideration of the weight of the swivel portion in order to reduce the vibration caused by the revolution of the swivel scroll 340.

As a rotation prevention mechanism for preventing the rotation of the rotation scroll 340, a plurality of rotation prevention pins 560 extending from the step portion 220E of the front housing 220 toward the rotation scroll 340 are press-fitted and fixed. The plurality of rotation prevention pins 560 are arranged equidistantly and equidistantly with respect to the axis of the drive shaft 410. In the scroll type compressor 100 shown in FIG. 1, four rotation prevention pins 560 are press-fitted and fixed to the stepped portion 220E of the front housing 220, but the number thereof can be arbitrary. Further, a plurality of through holes through which the rotation prevention pin 560 penetrates are formed on the plate surface of the thrust plate 510.

Circular holes 342B extending from the other surface of the bottom plate 342 toward one surface at a plurality of locations facing the rotation prevention pin 560 protruding from the step portion 220E of the front housing 220 on the other surface of the bottom plate 342 of the swivel scroll 340. Are formed respectively. The tips of the plurality of rotation prevention pins 560 are fitted so as to revolve around the axis of the circular hole 342B of the swivel scroll 340 while being inscribed in the circular hole 342B. Therefore, the swivel scroll 340 revolves around the axis of the fixed scroll 320 in a state where its rotation is prevented.

The tip of the drive shaft 410 is connected to a pulley 460 that is rotated by external power via an electromagnetic clutch 450 that is idlely attached to the outer peripheral surface of the small diameter portion of the front housing 220. Therefore, when the electromagnetic clutch 450 is operated, the pulley 460 and the drive shaft 410 are connected, and the drive shaft 410 is rotated by the rotational force of the pulley 460. On the other hand, when the operation of the electromagnetic clutch 450 is stopped, the pulley 460 and the drive shaft 410 are disconnected, and the rotation of the drive shaft 410 is stopped. By appropriately controlling the electromagnetic clutch 450 in this way, the operation of the scroll type compressor 100 can be controlled. The power from the outside can be, for example, an engine output, an electric motor output, or the like.

Next, the operation of the scroll type compressor 100 will be described.
When the drive shaft 410 is rotated by external power, the rotational force is transmitted to the swivel scroll 340 via the crank pin 420 and the eccentric bush 430, and the shaft center of the fixed scroll 320 is prevented from rotating while the swivel scroll 340 is prevented from rotating. Revolve around. As a result, the volume of the compression chamber H2 of the compression mechanism 300 changes, and the low-pressure gaseous refrigerant sucked into the internal space from the suction port P1 of the front housing 220 is guided to the central portion while being compressed by the compression chamber H2. .. The gaseous refrigerant guided to the central portion of the compression mechanism 300 is discharged to the discharge chamber H1 via the discharge hole 322A and the check valve 328 formed in the bottom plate 322 of the fixed scroll 320. The high-pressure gaseous refrigerant discharged into the discharge chamber H1 is separated into a gaseous refrigerant and a lubricating oil by the oil separator OS.

Then, the gaseous refrigerant from which the lubricating oil is separated is discharged to the refrigerant circuit via the discharge port P2 formed in the rear housing 240. On the other hand, as shown in FIG. 2, the lubricating oil separated from the gaseous refrigerant is the tip of the oil passage 324A extending from the other surface (back surface) of the bottom plate 322 to the tip surface of the lap 324 at the upper part of the fixed scroll 320. It is injected from the opening (opening) toward the step portion 220E of the front housing 220. The stepped portion 220E of the front housing 220 receives the lubricating oil injected from the opening of the oil passage 324A and is partitioned by the second inner peripheral surface 220B of the front housing 220, that is, a driving force transmission mechanism. A concave groove-shaped first lubricating oil supply path 220F (first groove portion) is formed to supply lubricating oil to the crank chamber in which the 400 crankpin 420, the eccentric bush 430, and the like are arranged.

Here, as shown in FIG. 3, the first lubricating oil supply passage 220F is the inner peripheral end of the step portion 220E at a position connecting the axial center of the drive shaft 410 and the portion facing the opening of the oil passage 324A. It is formed from the portion toward the outer peripheral end portion. The first lubricating oil supply passage 220F may extend from the inner peripheral end portion of the step portion 220E to at least a position facing the opening of the oil passage 324A. The width and depth of the first lubricating oil supply path 220F can be appropriately determined in consideration of, for example, the maximum injection amount of the lubricating oil injected from the opening of the oil passage 324A.

Therefore, the lubricating oil injected from the opening of the oil passage 324A of the fixed scroll 320 is the first formed in the stepped portion 220E of the front housing 220 while mixing with a part of the gaseous refrigerant sucked from the suction port P1. It is supplied to the crank chamber through the lubricating oil supply path 220F. The gaseous refrigerant containing the mist of lubricating oil supplied to the crank chamber lubricates moving parts such as the crankpin 420, the eccentric bush 430, the roller bearing 530, the seal member 540, and the slide bearing 550.

As shown in FIG. 3, the lubricating oil that lubricates the movable portion of the crank chamber passes through the lubricating oil discharge passage 220G formed at a predetermined position of the step portion 220E of the front housing 220, and is the first inner circumference of the front housing 220. It is returned to the bottom of the cylindrical space partitioned by the surface 220A. The lubricating oil returned to the lower part of this space is mixed with the gaseous refrigerant sucked from the suction port P1 of the front housing 220 and used for lubricating the compression mechanism 300.

By the way, as shown in FIG. 1, the suction port P1 of the front housing 220 uses a part of the gaseous refrigerant sucked from the suction port P1 so as to guide the lubricating oil separated by the oil separator OS to the crank chamber. , Is formed at a position straddling the other surface (rear surface) of the swivel scroll 340. Further, since the suction port P1 needs to mainly guide the gaseous refrigerant to the space near the outer peripheral end of the fixed scroll 320 and the swivel scroll 340, as shown in FIG. 3, the first inner peripheral surface 220A of the front housing 220 It extends in the direction along the line, that is, in the tangential direction thereof. In short, the suction port P1 sucks the gaseous refrigerant in the direction along the first inner peripheral surface 220A of the front housing 220 while intersecting with the lubricating oil injected from the opening of the oil passage 324A. Therefore, most of the gaseous refrigerant sucked from the suction port P1 flows along the first inner peripheral surface 220A of the front housing 220.

Since the flow direction of the gaseous refrigerant sucked from the suction port P1 is along the first inner peripheral surface 220A of the front housing 220, at least a part of the lubricating oil injected from the opening of the oil passage 324A of the fixed scroll 320 It is flowed in the downstream direction by the gaseous refrigerant and is not supplied to the crank chamber via the first lubricating oil supply path 220F. For this reason, the absolute amount of lubricating oil supplied to the crank chamber is reduced, and there is a risk that the lubrication of the moving parts thereof will be insufficient.

Therefore, in the step portion 220E of the front housing 220, downstream from the first lubricating oil supply path 220F along the flow direction of the gaseous refrigerant sucked from the suction port P1, the outer circumference from the inner peripheral end portion of the step portion 220E. A concave groove-shaped second lubricating oil supply path 220H (second groove) extending toward the end is further formed. The second lubricating oil supply passage 220H may extend from the inner peripheral end portion of the step portion 220E to at least a position facing the opening of the oil passage 324A. Further, the width and depth of the second lubricating oil supply path 220H are the same as those of the first lubricating oil supply path 220F, in consideration of, for example, the maximum injection amount of the lubricating oil injected from the opening of the oil passage 324A. It can be decided as appropriate. The second lubricating oil supply passage 220H may be formed at a position where the lubricating oil injected from the opening of the oil passage 324A is carried farthest along the flow of the gaseous refrigerant.

In this way, even if the lubricating oil injected from the opening of the oil passage 324A is flowed downstream by the gaseous refrigerant sucked from the suction port P1, at least a part of the lubricating oil is flown from the first lubricating oil supply passage 220F. It is received by the second lubricating oil supply passage 220H formed downstream, and is supplied to the crank chamber through this passage. Therefore, the absolute amount of the lubricating oil supplied to the crank chamber is increased, and the lubrication performance of the crank chamber is improved, so that the reliability of the scroll type compressor 100 can be improved, for example.

Further, the step portion 220E of the front housing 220 extends along an arc having a radius from the center of the step portion 220E to a portion facing the opening of the oil passage 324A, that is, extends in the radial direction of the step portion 220E. A concave groove-shaped communication passage 220I (third groove portion) is formed so as to communicate the lubricating oil supply passage 220F of 1 and the second lubricating oil supply passage 220H. In this way, even if the lubricating oil injected from the opening of the oil passage 324A is flowed downstream from the first lubricating oil supply passage 220F by the flow of the gaseous refrigerant sucked from the suction port P1, this is a continuous passage. It is received by the 220I, flows into the first lubricating oil supply path 220F or the second lubricating oil supply path 220H along the lower wall thereof, and is supplied to the crank chamber.

Therefore, by forming at least the second lubricating oil supply passage 220H in addition to the first lubricating oil supply passage 220F in the step portion 220E of the front housing 220, the oil is injected from the opening of the oil passage 324A of the fixed scroll 320. The absolute amount of lubricating oil supplied to the crank chamber increases, and the lubrication performance of the crank chamber can be improved. Further, by further forming a communication passage 220I in addition to the second lubricating oil supply path 220H in the step portion 220E of the front housing 220, the absolute amount of the lubricating oil supplied to the crank chamber can be further increased. ..

Regarding the above-described embodiment, the scroll type compressor 100 may have an electric motor built in the housing 200. Further, the oil separator OS is not limited to the centrifugal separation type, and may be, for example, a type in which the lubricating oil is separated from the gaseous refrigerant by a labyrinth passage.

With respect to the above embodiment, a new modification can be created by arbitrarily combining the technical ideas explained therein or by rearranging a part thereof. Therefore, it should be understood that the present invention is not limited to the contents described in the above-described embodiment, but includes technical ideas that can be easily recalled by those skilled in the art.

100 Scroll type compressor (Scroll type fluid machine)
200 Housing 220 Front housing 220E Steps (thrust receiving surface)
220F First lubricating oil supply path (first groove)
220H Second lubricating oil supply path (second groove)
220I continuous passage (third groove)
320 Fixed scroll 324A Oil passage 340 Swing scroll 400 Driving force transmission mechanism P1 Suction port OS Oil separator

Claims (3)

With the housing
With a fixed scroll fixed to the housing,
A swivel scroll that is revolved around the axis of the fixed scroll,
An oil separator that separates the lubricating oil from the compressible fluid compressed or expanded by the fixed scroll and the swivel scroll.
With
An oil passage for injecting lubricating oil separated from the compressible fluid by the oil separator is formed above the fixed scroll toward the annular thrust receiving surface of the housing that receives the thrust force of the swivel scroll. ,
A suction port is formed in the housing for sucking a compressible fluid in a direction along the inner peripheral surface of the housing while intersecting with the lubricating oil injected from the opening of the oil passage.
A first groove extending from the inner peripheral end portion toward the outer peripheral end portion is formed on the thrust receiving surface facing the opening of the oil passage.
A second groove extending from the inner peripheral end toward the outer peripheral end is formed on the thrust receiving surface downstream of the first groove along the flow direction of the compressible fluid sucked from the suction port. Was done
Scroll type fluid machine. On the outer peripheral portion of the thrust receiving surface, a third groove portion extending in the radial direction of the thrust receiving surface is formed so as to communicate the first groove portion and the second groove portion.
The scroll type fluid machine according to claim 1. The first groove portion and the second groove portion receive the lubricating oil injected from the opening of the oil passage formed in the fixed scroll, and drive the swivel scroll to revolve around the axis of the fixed scroll. Supply to the crank chamber where the force transmission mechanism is housed,
The scroll type fluid machine according to claim 1 or 2.

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