JP6917845B2 - Scroll type fluid machine - Google Patents

Description

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

As an example of the scroll type fluid machine, as described in Japanese Patent Application Laid-Open No. 2004-300974 (Patent Document 1), a scroll type compressor having a fixed scroll and a swivel scroll that are meshed with each other is known. In the scroll type compressor, the swivel scroll revolves around the axis of the fixed scroll by the drive unit including the drive shaft, thereby changing the volume of the compression chamber partitioned by the fixed scroll and the swivel scroll to release the gaseous refrigerant. Compress and discharge.

One end of the drive shaft extends through a housing containing a fixed scroll and a swivel scroll, and is rotatably supported by the housing via a rolling bearing such as a roller bearing. The other end of the drive shaft is rotatably supported by the housing via rolling bearings such as roller bearings and needle bearings. In this case, a lip seal is provided between the outer peripheral surface of one end of the drive shaft and the inner peripheral surface of the housing to prevent the gaseous refrigerant containing the lubricating oil from leaking to the outside.

Japanese Unexamined Patent Publication No. 2004-300974

By the way, in a scroll type compressor, for example, for the purpose of improving high-speed performance, impact resistance, quietness, etc., it is considered to use a slide bearing instead of a rolling bearing that supports the other end of the drive shaft. ing. However, if a slide bearing is used instead of the rolling bearing, it becomes difficult for the gaseous refrigerant containing the lubricating oil to flow in the axial direction through the slide bearing, so that the lip seal located downstream thereof may be insufficiently lubricated. there were.

Therefore, an object of the present invention is to provide a scroll type fluid machine capable of ensuring lubrication of a lip seal located downstream of a drive shaft even if the drive shaft is freely rotationally supported by a slide bearing.

Therefore, a scroll unit that compresses or expands the fluid, a drive shaft that transmits rotational driving force to the scroll unit, and a housing that accommodates the drive shaft freely can be provided, and one end of the drive shaft penetrates the housing. The scroll-type fluid machine that projects and seals the through portion of the housing with a lip seal is provided with a sliding bearing that freely supports the other end of the drive shaft. Further, on the support surface of the housing that supports the thrust force of the scroll unit, a first supply passage for supplying the fluid sucked from the suction port formed on the peripheral wall of the housing to the slide bearing side and a supply passage to the slide bearing side are supplied. A first return passage for returning the fluid to the suction port side is formed. Further, the fluid supplied to the slide bearing side through the first supply passage is supplied to the lip seal side and the second supply passage to the press-fit portion of the housing into which the slide bearing is press-fitted, and to the lip seal side. A second return passage for returning the fluid to the slide bearing side is formed. The first return passage and the second return passage are formed at positions deviated from each other in the circumferential direction of the drive shaft.

According to the present invention, in the scroll type fluid machine, even if the drive shaft is rotatably supported by the slide bearing, the lubrication of the lip seal located downstream thereof can be ensured.

It is sectional drawing which shows an example of the scroll type compressor. It is a perspective view of the 1st Embodiment which shows the main part of the front housing. It is a top view of the 1st Embodiment which shows the main part of the front housing in which the main bearing was press-fitted. It is a perspective view of the 1st Embodiment which shows the main part of the front housing in which the main bearing was press-fitted. It is a perspective view which shows the outer shape of the front housing of 1st Embodiment. It is a top view of the 2nd Embodiment which shows the main part of the front housing in which the main bearing was press-fitted. It is a perspective view of the 2nd Embodiment which shows the main part of the front housing in which the main bearing was press-fitted. It is a top view explaining the operation of 2nd Embodiment. It is a top view of the 3rd Embodiment which shows the main part of the front housing in which the main bearing was press-fitted. It is a perspective view of the 3rd Embodiment which shows the main part of the front housing in which the main bearing was press-fitted.

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 a scroll type compressor 1 mounted in the engine room of a vehicle.
The scroll type compressor 1 is incorporated into, for example, a refrigerant circuit of a vehicle air conditioner, and compresses and discharges a gaseous refrigerant (fluid) sucked from the low pressure side of the refrigerant circuit. Lubricating oil is sealed inside the scroll type compressor 1, and the lubricating oil lubricates the bearing and the sliding portion and seals the sliding surface.

The scroll type compressor 1 includes a rear housing 2 and a front housing 4 that form a housing, and the scroll unit 6 is housed in the front housing 4. Then, the rear housing 2, the flange portion 29 of the fixed scroll 24 constituting the scroll unit 6, and the front housing 4 are fastened and joined by a plurality of bolts 5.

In the internal space of the front housing 4, the drive shaft 8 is arranged so as to extend in the longitudinal direction (axial direction) of the front housing 4. The drive shaft 8 includes a large-diameter shaft portion 10 located on the scroll unit 6 side, a small-diameter shaft portion 12 located at an end opposite to the scroll unit 6 and penetrating the front housing 4 and projecting to the outside. have. The large-diameter shaft portion 10 of the drive shaft 8 is rotatably supported by the front housing 4 via the main bearing 14, and the small-diameter shaft portion 12 thereof is rotatably supported by the front housing 4 via the ball bearing 16. There is. Therefore, the drive shaft 8 is freely rotatably supported with respect to the front housing 4.

Here, the main bearing 14 is composed of an oil-impregnated plain bearing made of a porous sintered metal. The main bearing 14 has a cylindrical shape, the outer peripheral surface thereof is press-fitted into the press-fitting portion of the front housing 4, and the large-diameter shaft portion 10 of the drive shaft 8 is rotatably supported by the inner peripheral surface thereof. .. The clearance (radial clearance) between the main bearing 14 and the drive shaft 8 is set to the minimum.

Further, a lip seal 59 is attached to the penetrating portion 4A of the front housing 4 through which the small diameter shaft portion 12 of the drive shaft 8 penetrates. The tip of the lip seal 59 is slidably pressed against the outer peripheral surface of the drive shaft 8 to prevent the gaseous refrigerant containing the lubricating oil from leaking to the outside through the penetrating portion 4A.

Further, a drive pulley 20 having a built-in electromagnetic clutch 18 is attached to the protruding end of the small diameter shaft portion 12. The drive pulley 20 is rotatably supported by the front housing 4 via a bearing 22. The rotation of the drive pulley 20 can be transmitted to the drive shaft 8 via the electromagnetic clutch 18. That is, when the electromagnetic clutch 18 is connected while the engine is being driven, the drive shaft 8 rotates integrally with the drive pulley 20.

The scroll unit 6 has a fixed scroll 24 in which a flange portion 29 is sandwiched between the rear housing 2 and the front housing 4, and a swivel scroll 26 assembled so as to mesh with the fixed scroll 24. .. The fixed scroll 24 has a disk-shaped substrate 25 and a spiral-shaped wrap 27 erected on one surface of the substrate 25. On the peripheral surface of the substrate 25, an in-row portion 28 that is inserted into the inner peripheral surface of the front housing 4 and is integrated with each other, and a flange portion 29 that projects outward from the rear housing 2 side of the in-row portion 28 are formed. There is.

Then, in the fixed scroll 24, the inlay portion 28 of the substrate 25 is inserted and fitted into the front housing 4, and in this state, the flange portion 29 comes into contact with the open end portion of the front housing 4. The member designated by reference numeral 37 in FIG. 1 is an O-ring that seals between the in-row portion 28 and the front housing 4.

The swivel scroll 26 has a disk-shaped substrate 30 and a spiral-shaped lap 33 that is erected on one surface of the substrate 30 and meshes with the lap 27 of the fixed scroll 24. Then, when the lap 27 of the fixed scroll 24 and the lap 33 of the swivel scroll 26 mesh with each other, the tip end portion of the lap 33 slidably abuts on one surface of the substrate 25 of the fixed scroll 24, and the tip end portion of the lap 27 comes into contact with each other. It slidably abuts on one surface of the substrate 30 of the swivel scroll 26.

The swivel scroll 26 revolves around the axis of the fixed scroll 24 by being rotationally driven by the drive shaft 8. When the swivel scroll 26 revolves and swivels, the lap 27 of the fixed scroll 24 and the lap 33 of the swivel scroll 26 mesh with each other to form a compression chamber 35 for compressing the gaseous refrigerant containing the lubricating oil. NS. At this time, the volume of the compression chamber 35 increases or decreases as the revolving scroll 26 moves with respect to the fixed scroll 24.

In order to revolve and swivel the swivel scroll 26, the boss 32 projecting from the other surface of the substrate 30 of the swivel scroll 26 and the large-diameter shaft portion 10 of the drive shaft 8 are a crank pin 34, an eccentric bush 36, and a needle bearing 38. They are interconnected via. A counterweight 40 is attached to the eccentric bush 36. A drive shaft 8 having a large-diameter shaft portion 10 and a small-diameter shaft portion 12, a crank pin 34 rotating together with the drive shaft 8, an eccentric bush 36, and a counterweight 40 constitute a drive portion 15 for driving the swivel scroll 26. There is.

Inside the front housing 4, a ring-shaped support surface 31 that supports the thrust force of the scroll unit 6 is formed. An annulus-shaped thrust plate 42 is supported on the support surface 31. The thrust plate 42 is arranged between the other surface of the substrate 30 of the swivel scroll 26 and the support surface 31 of the front housing 4, and supports the swivel scroll 26 so that it can revolve and swivel. That is, the support surface 31 and the thrust plate 42 of the front housing 4 serve as thrust support portions that support the swivel scroll 26 so that it can revolve and swivel.

A discharge chamber 44 is formed between the fixed scroll 24 and the end wall 43 of the rear housing 2. The substrate 25 of the fixed scroll 24 is formed with a discharge hole 45 for communicating the compression chamber 35 and the discharge chamber 44. A discharge valve 46 that opens and closes the discharge hole 45 is arranged in the discharge chamber 44. Further, the rear housing 2 is formed with a discharge port 51 that opens into the discharge chamber 44.

In FIG. 1, the member with reference numeral 61 is an attachment portion formed on the outer surface of the front housing 4, and the member with reference numeral 62 is an attachment formed on the outer surface of the end wall 43 of the rear housing 2. It is a department. The scroll type compressor 1 is attached to a predetermined location (mounting location) in the engine room by bolts via these mounting portions 61 and 62.

A low pressure is applied to the peripheral surface of the front housing 4 on the scroll unit 6 side of the drive shaft 8 so as to straddle the thrust plate 42 and the substrate 30 at a position where the outer periphery of the substrate 30 of the thrust plate 42 and the swivel scroll 26 is desired. A suction port 49 for introducing a gaseous refrigerant is formed. The center line C1 of the suction port 49 is offset from the thrust plate 42 toward the scroll unit 6 by a predetermined distance. Therefore, the cross-sectional area of the flow path of the suction port 49 is larger on the scroll unit 6 side indicated by reference numeral 49A than on the drive unit 15 side indicated by reference numeral 49B across the thrust plate 42.

By the way, when a cylindrical slide bearing is used as the main bearing 14 for freely rotating the large-diameter shaft portion 10 of the drive shaft 8 with respect to the front housing 4, a gas containing lubricating oil sucked from the suction port 49 is used. The flow rate of the refrigerant supplied to the lip seal 59 through the main bearing 14 is reduced. Therefore, as in each embodiment described below, the supply passage for supplying the gaseous refrigerant containing the lubricating oil sucked from the suction port 49 to the lip seal 59 and the lubricating oil supplied to the lip seal 59 are included. Lubrication of the lip seal 59 is ensured by providing a return passage for returning the gaseous refrigerant to the suction port 49 side.

[First Embodiment]
2 to 4 show a first embodiment of a supply passage and a return passage.
A first supply passage 47 extending in the radial direction from the outer peripheral end to the inner peripheral end of the support surface 31 is formed at a predetermined position on the support surface 31 of the front housing 4 facing the suction port 49. Further, at a predetermined position on the support surface 31 of the front housing 4 opposite to the first supply passage 47 sandwiching the drive shaft 8, a first portion extending in the radial direction from the outer peripheral end to the inner peripheral end thereof. A return passage 48 is formed. Therefore, the first supply passage 47 supplies the gaseous refrigerant containing the lubricating oil sucked from the suction port 49 formed on the peripheral wall of the front housing 4 to the main bearing 14 side. The first return passage 48 returns the gaseous refrigerant containing the lubricating oil supplied to the main bearing 14 side to the suction port 49 side.

The first supply passage 47 is composed of a concave groove whose depth gradually increases and its width gradually narrows from the outer peripheral end to the inner peripheral end of the support surface 31. Further, the first return passage 48 is composed of a concave groove having a substantially constant width in which the depth gradually increases from the outer peripheral end to the inner peripheral end of the support surface 31. That is, since the inlet side of the gaseous refrigerant containing the lubricating oil is large in the first supply passage 47 and the first return passage 48, the gaseous refrigerant can smoothly flow into the first supply passage 47 and the first return passage 48.

In the process in which the scroll unit 6 sucks, compresses, and discharges the gaseous refrigerant, there is a place where the thrust force acting on the thrust plate 42 and the support surface 31 from the swivel scroll 26 is maximized. Therefore, it is desirable that the first supply passage 47 and the first return passage 48 are formed so as to avoid the portion where the thrust force is maximized.

Further, a second supply passage 63 extending along the axial direction of the main bearing 14 is formed at a predetermined portion of the press-fitting portion of the front housing 4 into which the main bearing 14 is press-fitted. Here, the first supply passage 47 and the second supply passage 63 are formed on a straight line passing through the axis of the drive shaft 8 when viewed from a direction perpendicular to the cross section of the drive shaft 8. Further, in a state where the press-fitting portion of the front housing 4 and the housing including the rear housing 2 and the front housing 4 are fixed to the engine room, the main bearing 14 is located below the axial center of the drive shaft 8 in the vertical direction. A second return passage 64 extending along the axial direction is formed. Therefore, the second supply passage 63 supplies the gas refrigerant containing the lubricating oil supplied to the main bearing 14 side via the first supply passage 47 to the lip seal 59 side. The second return passage 64 returns the gaseous refrigerant containing the lubricating oil supplied to the lip seal 59 side through the second supply passage 63 to the main bearing 14 side.

The second supply passage 63 and the second return passage 64 are composed of recesses having substantially the same width in which the depth gradually becomes shallower from the scroll unit 6 side toward the lip seal 59 side. This is because the front housing 4 has a large diameter on the scroll unit 6 side and a small diameter on the through portion 4A side, and the outer peripheral surface of the portion where the main bearing 14 is press-fitted has a conical shape. This is to fit the shape. Then, as shown in FIG. 5, the outer peripheral surface of the front housing 4 located outside the radius of the second supply passage 63 and the second return passage 64 is along the axial direction (longitudinal direction) of the front housing 4. Reinforcing ribs 66 extending so as to extend are formed so as to project. By forming the reinforcing rib 66 on the outer peripheral surface of the front housing 4, it is possible to prevent the thickness of the outer wall of the portion where the second supply passage 63 and the second return passage 64 are located from becoming thin, and to prevent the thickness of the outer wall of the front housing 4 from becoming thin. Strength can be ensured.

In the second supply passage 63 and the second return passage 64, the scroll unit 6 sucks, compresses, and discharges the gaseous refrigerant as much as possible in the same manner as the first supply passage 47 and the first return passage 48. In the stroke, it is desirable to avoid the portion where the thrust force acting on the thrust plate 42 and the support surface 31 from the swivel scroll 26 is maximized.

Next, the operation of the scroll type compressor 1 will be described.
When the electromagnetic clutch 18 is operated in a state where the rotational driving force of the engine (not shown) is transmitted to the drive pulley 20, the drive shaft 8 rotates integrally with the drive pulley 20. When the drive shaft 8 rotates, the rotational driving force is transmitted to the swivel scroll 26 of the scroll unit 6 via the crank pin 34, the eccentric bush 36, and the needle bearing 38, and the swivel scroll 26 does not rotate and is the shaft of the fixed scroll 24. Revolve around the heart. When the swivel scroll 26 revolves around, a gaseous refrigerant containing lubricating oil is sucked into the suction port 49 of the front housing 4. Since the thrust plate 42 is provided, the gaseous refrigerant sucked from the suction port 49 is divided into the scroll unit 6 side and the drive unit 15 side. At this time, as described above, the cross-sectional area of the flow path of the suction port 49 is larger on the scroll unit 6 side (49A) than on the drive unit 15 side (49B) across the thrust plate 42, so that the scroll unit 6 side. The amount of the gas refrigerant divided into the drive unit 15 is larger than that of the gas refrigerant divided into the drive unit 15.

Then, the gaseous refrigerant separated to the scroll unit 6 side is sucked into the compression chamber 35 located outside the radius of the scroll unit 6 (suction stroke). As the swivel scroll 26 revolves around the axis of the fixed scroll 24, the volume of the compression chamber 35 gradually decreases toward the center, and the gaseous refrigerant sucked into the compression chamber 35 is compressed (compression). Itinerary). The high-pressure gaseous refrigerant compressed in this way is discharged from the scroll type compressor 1 from the compression chamber 35 via the discharge hole 45, the discharge valve 46, the discharge chamber 44, and the discharge port 51.

On the other hand, the gaseous refrigerant diverted to the drive unit 15 side flows into the first supply passage 47, passes through the first supply passage 47 and passes through the first supply passage 47 as shown by the broken line arrow in FIG. It is supplied to the crank chamber), that is, the main bearing 14 side. The gaseous refrigerant supplied to the crank chamber lubricates the sliding portions such as the crank pin 34 and the eccentric bush 36 with the lubricating oil contained therein.

A part of the gaseous refrigerant supplied to the crank chamber flows into the second supply passage 63 as shown by the broken line arrow in FIG. 1, passes through the inside thereof, and becomes the main bearing 14 and the lip seal 59. It is supplied to the inside of the front housing 4 (lip chamber) located between the two. Then, the gaseous refrigerant supplied to the lip chamber lubricates the sliding portion of the lip seal 59 with the lubricating oil contained therein, and then passes through the second return passage 64 to the crank chamber, that is, the suction port 49. Returned to the side. Further, the lubricating oil contained in the gaseous refrigerant passing through the second supply passage 63 and the second return passage 64 and the gaseous refrigerant passing around the main bearing 14 is absorbed from the surface by the main bearing 14 made of the oil-impregnated slide bearing. Therefore, the sliding portion of the large-diameter shaft portion 10 of the drive shaft 8 is also lubricated.

Since the first return passage 48 and the second return passage 64 are formed at positions shifted in the circumferential direction of the drive shaft 8, the gaseous refrigerant returned to the crank chamber has the crank pin 34, the eccentric bush 36, and the like. It circulates around the needle bearing 38, the counter weight 40, and the like, and lubricates these sliding portions. Then, the gaseous refrigerant flowing around the crank pin 34 and the like flows into the first return passage 48, passes through the inside thereof, and is returned to the scroll unit 6 side, that is, the suction port 49 side. The gaseous refrigerant returned to the scroll unit 6 side is sucked into the compression chamber 35 located outside the radius of the scroll unit 6, and is compressed and discharged through the suction stroke and the compression stroke as described above.

Here, since the second return passage 64 is formed below the axial center of the drive shaft 8 in the vertical direction in the fixed state of the housing, gravity is used to provide the lubricating oil contained in the gaseous refrigerant. The mixed sludge can be easily discharged. The sludge discharged from the second return passage 64 can be collected and removed by, for example, a filter built in the scroll type compressor 1, a filter arranged in the refrigerant circuit, or the like.

[Second Embodiment]
6 and 7 show a second embodiment of the supply and return passages.
The scroll type compressor 1 according to the second embodiment has only the formation position of the second return passage 64 formed in the press-fitting portion of the front housing 4 into which the main bearing 14 is press-fitted, as compared with the first embodiment. Is different. Since the other configurations other than the second return passage 64 are the same as those in the first embodiment, the description thereof will be omitted for the purpose of eliminating duplicate explanations (the same shall apply hereinafter). If necessary, refer to the description of the first embodiment above (the same applies hereinafter).

In a state where the press-fitting portion of the front housing 4 and the housing including the rear housing 2 and the front housing 4 are fixed to the engine room, the axial direction of the main bearing 14 is above the vertical direction passing through the axial center of the drive shaft 8. A second return passage 64 is formed along the line. Therefore, in the second return passage 64, as in the first embodiment, the gaseous refrigerant containing the lubricating oil supplied to the lip seal 59 side via the second supply passage 63 is sent to the main bearing 14 side. return.

In this way, the gaseous refrigerant returned to the crank chamber via the second return passage 64 is, for example, on the upstream side in the rotation direction when the counterweight 40 rotates in the direction shown in FIG. Since it is returned to the scroll unit 6 side through the first return passage 48 located, the staying time in the crank chamber is extended. Since the staying time of the gaseous refrigerant in the crank chamber is long, the lubrication efficiency of the sliding portions of the crank pin 34, the eccentric bush 36, the needle bearing 38, and the counterweight 40 can be improved. When the rotation method of the counterweight 40 is reversed, the above action and effect can be exhibited by forming the second return passage 64 downward as shown in FIGS. 2 to 4.

Since the other operations and effects of the scroll type compressor 1 are the same as those in the first embodiment, the description thereof will be omitted. If necessary, refer to the description of the operation and effect of the first embodiment above (the same applies hereinafter).

[Third Embodiment]
9 and 10 show a third embodiment of the supply passage and the return passage.
The scroll type compressor 1 according to the third embodiment has a second return passage formed in the press-fitting portion of the front housing 4 for press-fitting the main bearing 14, as compared with the first and second embodiments described above. Only the formation positions of 64 and the number thereof are different.

In a state where the press-fitting portion of the front housing 4 and the housing including the rear housing 2 and the front housing 4 are fixed to the engine room, the axial direction of the main bearing 14 is in both the vertical direction passing through the axial center of the drive shaft 8. Second return passages 64 are formed, respectively. Therefore, in the second return passage 64, as in the first embodiment, the gaseous refrigerant containing the lubricating oil supplied to the lip seal 59 side via the second supply passage 63 is sent to the main bearing 14 side. return. Here, one of the two second return passages 64 formed in the press-fitting portion of the front housing 4 sends the gaseous refrigerant supplied to the lip seal 59 side via the second supply passage 63 to the main bearing 14 side. An example of a third return passage for returning is given.

In this way, the action and effect of the second return passage 64 in the first and second embodiments are slightly weakened, but both actions and effects can be exhibited. Further, since the second supply passage 63 and the two second return passages 64 are formed in the press-fitting portion of the front housing 4, the press-fitting portion is compared with the configuration in which the two passages are formed in the press-fitting portion. Even if the main bearing 14 is press-fitted into the main bearing 14, it is possible to prevent the roundness of the press-fitting portion from being lowered. In order to effectively exert this action and effect, it is desirable to form the second supply passage 63 and the two second return passages 64 at equal intervals.

Although various modified examples have been described with respect to the above-described embodiment, new modified examples can be created by arbitrarily combining them or 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.

1 Scroll type compressor (scroll type fluid machine)
2 Rear housing 4 Front housing 4A Penetration part 6 Scroll unit 8 Drive shaft 14 Main bearing (plain bearing)
31 Support surface 47 First supply passage 48 First return passage 49 Suction port 59 Lip seal 63 Second supply passage 64 Second return passage

Claims (5)

A scroll unit that compresses or expands a fluid, a drive shaft that transmits a rotational driving force to the scroll unit, and a housing that freely accommodates the drive shaft are provided, and one end of the drive shaft penetrates the housing. In a scroll-type fluid machine that projects and seals the penetrating portion of the housing with a lip seal.
A plain bearing that freely supports the other end of the drive shaft is provided.
On the support surface of the housing that supports the thrust force of the scroll unit, a first supply passage that supplies the fluid sucked from the suction port formed on the peripheral wall of the housing to the slide bearing side, and the slide bearing side. A first return passage for returning the fluid supplied to the suction port side is formed.
A second supply passage for supplying the fluid supplied to the slide bearing side through the first supply passage to the press-fit portion of the housing into which the slide bearing is press-fitted, and the lip-seal side. A second return passage for returning the fluid supplied to the slide bearing side is formed.
The first return passage and the second return passage are formed at positions displaced in the circumferential direction of the drive shaft.
Scroll type fluid machine. The first supply passage and the second supply passage are formed on a straight line passing through the axis of the drive shaft when viewed from a direction perpendicular to the cross section of the drive shaft.
The scroll type fluid machine according to claim 1. The first supply passage and the first return passage are formed on opposite sides of the drive shaft.
The scroll type fluid machine according to claim 1 or 2. The second return passage is formed in at least one of the vertical directions passing through the axis of the drive shaft in the fixed state of the housing.
The scroll type fluid machine according to any one of claims 1 to 3. A third return passage for returning the fluid supplied to the lip seal side to the slide bearing side via the second supply passage is further formed in the press-fitting portion.
The scroll type fluid machine according to any one of claims 1 to 4.

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