JPWO2019171427A1 - Compressor - Google Patents

Abstract

The compressor mainly supports a compression mechanism unit arranged in a closed container, an electric motor unit that drives the compression mechanism unit, a drive shaft that transmits the driving force of the electric motor unit to the compression mechanism unit, and an upper portion of the drive shaft. A bearing, an auxiliary bearing that supports the lower part of the drive shaft, a radial receiving surface that is provided on the auxiliary bearing and slidably supports the radial surface of the drive shaft, and a thrust that slidably supports the thrust surface of the drive shaft. It has a bearing surface. The thrust surface and the thrust receiving surface have a contact point where the thrust surface and the thrust receiving surface are in contact with each other on a curved surface, and a gap which continuously increases radially outward from the contact point.

Description

The present invention relates to a compressor used as one of the components of a refrigeration cycle device.

One of the components of a refrigeration cycle device such as an air conditioner, a compression mechanism unit having swing scrolls and fixed scrolls that mesh with each other, an electric motor unit that drives the compression mechanism unit, and a compression mechanism unit that drives the electric motor unit. There is a scroll compressor with a drive shaft that transmits to. The drive shaft is rotatably supported by main bearings and auxiliary bearings provided above and below the electric motor unit. When the drive shaft is rotationally driven by the electric motor unit, the swing scroll installed on the eccentric shaft portion at the upper end of the drive shaft revolves. As a result, the refrigerant is compressed in the compression chamber provided between the swing scroll and the fixed scroll in the compression mechanism unit. When the refrigerant is compressed by the compression mechanism, a gas load in the radial direction acts on the drive shaft, and this gas load is supported by the main bearing and the auxiliary bearing. Further, the auxiliary bearing supports the rotation of the drive shaft and also supports the vertical downward own weight of the drive shaft.

In such a scroll compressor, ball bearings are adopted as auxiliary bearings for the purpose of simultaneously supporting both the radial load (hereinafter referred to as radial load) and the thrust direction load (hereinafter referred to as thrust load). (See, for example, Patent Document 1).

However, ball bearings are expensive and have various problems such as poor long-term reliability because the inner ring and the rolling ball and the outer ring and the rolling ball come into contact with each other at points to support the load. As a countermeasure against this, there is a scroll compressor in which a slide bearing is applied to an auxiliary bearing (see, for example, Patent Document 2).

In the scroll compressor described in Patent Document 2, the auxiliary bearing which is a slide bearing is composed of a radial bearing and a thrust bearing which individually support a radial load and a thrust load. Then, the thrust surface provided at the lower end of the drive shaft is received by the thrust receiving surface provided on the auxiliary bearing, and the radial surface provided on the auxiliary shaft portion of the drive shaft is received by the radial receiving surface provided on the auxiliary bearing. ..

JP-A-04-241786 Japanese Patent No. 4356375

Generally, a compressive load and a centrifugal force act on the drive shaft of a scroll compressor during operation, and a large load acts in the radial direction. Therefore, the axis of the drive shaft bends while being inclined with respect to the central axis of the compressor. The central axis of the compressor refers to an axis extending in the vertical direction. The main shaft portion and the sub shaft portion of the drive shaft rotate while tilting with respect to the main bearing and the sub bearing, respectively. When a ball bearing is adopted as the auxiliary bearing of the scroll compressor as in Patent Document 1, the inclination of the drive shaft is absorbed by the clearance of the rolling ball and the inner ring and the clearance of the rolling ball and the outer ring, so that the drive shaft It is easy to secure the parallelism between the bearing and the auxiliary bearing. However, ball bearings are inferior in terms of cost and long-term reliability as described above.

Adopting a plain bearing as an auxiliary bearing as in Patent Document 2 has advantages in cost and long life, but the drive shaft that rotates while tilting hits the thrust receiving surface on one side, and the local Hertz stress is high. Therefore, there is a problem that the sliding state on the thrust receiving surface becomes severe. However, Patent Document 2 does not consider the problem of one-sided contact with respect to the thrust receiving surface.

The present invention has been made in view of such a point, and provides a compressor capable of ensuring a good sliding state of the thrust receiving surface in a compressor using a slide bearing as an auxiliary bearing. The purpose.

The compressor according to the present invention includes a compression mechanism unit arranged in a closed container, an electric motor unit that drives the compression mechanism unit, a drive shaft that transmits the driving force of the electric motor unit to the compression mechanism unit, and an upper portion of the drive shaft. The main bearing that supports the drive shaft, the sub-bearing that supports the lower part of the drive shaft, the radial receiving surface that is provided on the sub-bearing and slidably supports the radial surface of the drive shaft, and the thrust surface of the drive shaft are slidable. The thrust receiving surface is provided with a thrust receiving surface, and between the thrust surface and the thrust receiving surface, a contact point where the thrust surface and the thrust receiving surface are in contact with each other on a curved surface and a contact point continuously outward in the radial direction from the contact point. It has an increasing gap.

According to the present invention, a good sliding state of the thrust receiving surface can be ensured.

It is a vertical cross-sectional view which shows typically the cross-sectional structure of the scroll compressor which concerns on Embodiment 1 of this invention. It is a figure which shows the main part of the scroll compressor which concerns on Embodiment 1 of this invention. It is explanatory drawing of the bending state in the ZX cross section of the drive shaft of the scroll compressor which concerns on Embodiment 1 of this invention, and the arrangement position in the circumferential direction of a radial oil groove. It is explanatory drawing of the bending state in the YY cross section of the drive shaft of the scroll compressor which concerns on Embodiment 1 of this invention, and the arrangement position in the circumferential direction of a radial oil groove. It is explanatory drawing of the load acting on the drive shaft of the scroll compressor which concerns on Embodiment 1 of this invention, and the action direction of a load. It is a figure which shows the modification 1 of the scroll compressor which concerns on Embodiment 1 of this invention. It is a figure which shows the modification 2 of the scroll compressor which concerns on Embodiment 1 of this invention. It is a figure which shows the modification 3 of the scroll compressor which concerns on Embodiment 1 of this invention. It is a figure which shows the main part of the scroll compressor which concerns on Embodiment 2 of this invention, and is the schematic diagram which shows the lower end part enlarged from the auxiliary bearing. It is a figure which shows the main part of the scroll compressor which concerns on Embodiment 3 of this invention, and is the schematic diagram which shows the lower end part enlarged from the auxiliary bearing.

Hereinafter, a scroll compressor will be described as an example of the compressor according to the embodiment of the present invention with reference to the drawings. Here, in the following drawings including FIG. 1, those having the same reference numerals are the same or equivalent thereto, and are common to the whole texts of the embodiments described below. The form of the component represented in the entire specification is merely an example, and is not limited to the form described in the specification.

Embodiment 1.
FIG. 1 is a vertical cross-sectional view schematically showing a cross-sectional configuration of a scroll compressor according to a first embodiment of the present invention. In FIG. 1, the thrust load is represented by an arrow a and the radial load is represented by an arrow b. FIG. 2 is a diagram showing a main part of the scroll compressor according to the first embodiment of the present invention. In FIG. 2, (a) is a schematic view showing an enlarged lower end portion of the auxiliary bearing of the drive shaft, and (b) is a schematic view of the shape of the thrust surface of the drive shaft viewed from directly below. Further, in FIG. 2, the arrow indicates the flow of the lubricating oil.

The scroll compressor 100 is mounted as one of the refrigerating devices constituting a refrigerating cycle device such as a refrigerator, a freezer, a vending machine, an air conditioner, a refrigerating device or a water heater.

The scroll compressor 100 includes a compression mechanism unit A housed in a closed container 13, an electric motor unit B, and a drive shaft 6 for transmitting the driving force of the electric motor unit B to the compression mechanism unit A. As shown in FIG. 1, the compression mechanism portion A is arranged on the upper side of the closed container 13, and the electric motor portion B is arranged on the lower side of the closed container 13. Then, when the drive shaft 6 is rotationally driven by the electric motor unit B, the volume of the compression chamber 5 described later formed in the compression mechanism unit A is reduced, and the refrigerant in the compression chamber 5 is compressed.

Further, a refrigerant suction pipe 15 for sucking the refrigerant and a refrigerant discharge pipe 16 for discharging the refrigerant are connected to the closed container 13. The closed container 13 is a pressure vessel, which forms the outer shell of the scroll compressor 100. The bottom of the closed container 13 is an oil storage space 14 for storing lubricating oil. The lubricating oil stored in the oil storage space 14 is sucked up by the oil pump 9 provided at the lower end of the drive shaft 6 and supplied to each sliding portion of the drive shaft 6 and the compression mechanism portion A. .. The refueling route will be described later.

Hereinafter, each component will be described.

[Compression mechanism A]
The compression mechanism unit A has a function of compressing the refrigerant sucked from the refrigerant suction pipe 15 and discharging the refrigerant to the outside of the closed container 13 via the discharge port 4 and the refrigerant discharge pipe 16 described later. The compression mechanism unit A is mainly composed of a fixed scroll 1, a swing scroll 2, and an Oldham joint 25. The fixed scroll 1 is composed of a base plate 1a and a spiral protrusion 1b provided on the lower surface of the base plate 1a. The fixed scroll 1 is fixed to the upper end portion of the main frame 8a fixed to the inner peripheral surface of the closed container 13. The fixed scroll 1 may be fixed with a fastening member such as a bolt.

Like the fixed scroll 1, the swing scroll 2 is also composed of a base plate 2a and a spiral protrusion 2b provided on the upper surface of the base plate 2a. An eccentric hole 2c is formed in the vicinity of the center of the lower bottom surface of the base plate 2a of the swing scroll 2, and the swing bearing 17 is press-fitted into the eccentric hole 2c. An eccentric shaft 6a provided at the upper end of the drive shaft 6 is slidably connected to the swing bearing 17. The oscillating scroll 2 revolves with respect to the fixed scroll 1 without rotating with respect to the fixed scroll 1 by the old dam joint 25 provided between the oscillating scroll 2 and the main frame 8a. Further, a swing thrust bearing 18 is provided on the lower surface side of the swing scroll 2, that is, between the swing scroll 2 and the main frame 8a.

The fixed scroll 1 and the swing scroll 2 are provided in the closed container 13 so that the spiral protrusions mesh with each other. Then, the compression chamber 5 whose volume changes relatively is formed by the engagement of the spiral protrusions of the fixed scroll 1 and the swing scroll 2 with each other. A suction port 3 for guiding the refrigerant sucked into the closed container 13 from the refrigerant suction pipe 15 to the compression chamber 5 is formed on the outer peripheral portion of the compression chamber 5, and the refrigerant flows into the compression chamber 5 through the suction port 3. Inhaled. Then, the refrigerant is compressed in the compression chamber 5, and the compressed refrigerant is discharged from the discharge port 4 formed in the central portion of the fixed scroll 1. The refrigerant discharged from the discharge port 4 is discharged to the outside of the closed container 13 via the refrigerant discharge pipe 16.

[Mainframe 8a]
The main frame 8a fixes the fixed scroll 1 at the upper end thereof, and slidably supports the swing scroll 2 from below via the swing thrust bearing 18. The main frame 8a is mounted in the closed container 13 so that the outer peripheral surface is in contact with the inner peripheral surface of the closed container 13. Further, a through hole is formed in the vicinity of the central portion of the main frame 8a to allow the drive shaft 6 to pass through, and in this through hole, a main bearing 19 that rotatably supports the main shaft portion 6b described later of the drive shaft 6. Is provided. That is, the main frame 8a also has a function of rotatably supporting the drive shaft 6 via the main bearing 19.

[Subframe 8b]
The subframe 8b is fixed to the inner surface of the side wall of the closed container 13 below the electric motor portion B. The subframe 8b constitutes the housing 8 together with the main frame 8a. The subframe 8b is composed of a tubular portion 8ba and a flange portion 8bb extending outward from the lower end portion of the tubular portion 8ba.

Further, a through hole through which the drive shaft 6 penetrates is formed in the vicinity of the central portion of the subframe 8b, and a cylindrical auxiliary bearing 11 is provided in the through hole. The auxiliary bearing 11 is a radial bearing that rotatably supports the auxiliary shaft portion 6c described later of the drive shaft 6 and supports a load in the radial direction. Further, the auxiliary bearing 11 is composed of a slide bearing commonly called "metal".

In addition to the radial load, the subframe 8b also receives a thrust load generated by the weight of the drive shaft 6 and the magnetic force of the rotor. This thrust load is received by the upper surface cover 9c of the oil pump 9 described later, which is arranged below the subframe 8b, and the upper surface of the upper surface cover 9c is the thrust receiving surface 12.

That is, the scroll compressor 100 of the first embodiment supports the radial load acting on the drive shaft 6 by the auxiliary bearing 11, and receives the thrust load by the thrust receiving surface 12 provided on the upper surface cover 9c of the oil pump 9. It is composed. The scroll compressor 100 of the first embodiment is characterized by a structure that maintains a good sliding state of the thrust receiving surface 12. This structure will be described later.

[Motor unit B]
The electric motor unit B has a function of driving the swing scroll 2 in order to compress the refrigerant by the compression mechanism unit A. The electric motor unit B is arranged between the main frame 8a and the subframe 8b. The electric motor unit B is mainly composed of an electric motor 10 having a rotor 10a and a stator 10b. The rotor 10a is fixed to the peripheral surface of the drive shaft 6, and is rotationally driven by starting energization of the stator 10b. The stator 10b is fixed to the inner peripheral surface of the closed container 13 by shrink fitting or the like, surrounds the rotor 10a through a gap, and rotates the rotor 10a.

[Drive shaft 6]
The drive shaft 6 transmits the rotation of the rotor 10a of the electric motor unit B to the swing scroll 2 of the compression mechanism unit A. The drive shaft 6 includes an eccentric shaft 6a, a spindle portion 6b fixed to the rotor 10a of the electric motor portion B, a sub shaft portion 6c, and a pump insertion shaft 6d whose diameter is smaller than that of the sub shaft portion 6c. have. The eccentric shaft 6a is provided eccentrically with respect to the axial center of the drive shaft 6, and is slidably connected to the swing bearing 17 as described above. Further, the spindle portion 6b is provided with a balancer 26a on the upper side of the rotor 10a and a balancer 26b on the lower side of the rotor 10a.

Further, the drive shaft 6 has a refueling vertical hole 7a extending in the central portion of the drive shaft 6 in the axial direction, an eccentric shaft refueling horizontal hole 7b, a spindle refueling horizontal hole 7c, and a radial refueling horizontal hole extending in the radial direction from the refueling vertical hole 7a. 7d and a thrust refueling horizontal hole 7e are formed. More specifically, the eccentric shaft refueling horizontal hole 7b is formed on the eccentric shaft 6a, the spindle refueling horizontal hole 7c is formed on the main shaft portion 6b, the radial refueling horizontal hole 7d is formed on the sub shaft portion 6c, and the thrust refueling horizontal hole 7e is a pump. It is formed on the insertion shaft 6d.

Further, an axial oil groove 7f extending in the axial direction is formed on the outer peripheral surface of the auxiliary shaft portion 6c of the drive shaft 6, and the radial oil supply horizontal hole 7d communicates with the oil supply vertical hole 7a.

The bottom surface of the sub-shaft portion 6c has a hollow disk shape, and is a thrust surface 6f formed by an orthogonal surface extending radially outward from the upper end of the pump insertion shaft 6d. The weight and magnetic force of the drive shaft 6 act downward on the axis of the compressor, and the drive shaft 6 rotates while being pressed against the thrust receiving surface 12.

A radial oil groove 7g extending in the radial direction from the inner peripheral end to the outer peripheral end is formed on the thrust surface 6f. Further, the outer diameter side corner portion of the lower end of the sub-shaft portion 6c, in other words, the radial outer end portion of the thrust surface 6f is a curved surface having a radius of curvature Rs1 in order to relax the contact angle with the thrust receiving surface 12 during rotation. The chamfered portion (fillet) 6e is formed. The arc range of the chamfered portion (fillet) 6 is formed in an angle range smaller than 90 degrees.

[Material hardness of the auxiliary bearing 11 of the auxiliary shaft portion 6c]
Generally, the main shaft portion 6b and the sub shaft portion 6c of the drive shaft 6 are hardened and used by quenching the base carbon steel. The portion indicated by the dot in FIG. 2A indicates the quenching portion of the sub-shaft portion 6c. On the other hand, since the thrust surface 6f is used without being cured, it is necessary to keep a distance from the hardened portion of the auxiliary shaft portion 6c. A metal metal having excellent lubricity is usually used for the radial receiving surface 11a of the auxiliary bearing 11. An aluminum alloy or a copper alloy is used for the inner peripheral surface of the radial receiving surface 11a that slides on the radial surface, and receives the hard auxiliary shaft portion 6c. On the other hand, the thrust receiving surface 12 has a fine surface roughness, and a hardened hard steel material is used, and the thrust receiving surface 12 does not wear even when a load is received from the rotating thrust surface 6f.

[Oil pump 9]
The oil pump 9 includes a movable portion 9a having an inner rotor 9aa and an outer rotor 9ab, a main body 9b, and a top cover 9c that covers the movable portion 9a, and is fixed to the subframe 8b at the main body 9b with screws 24. ing. The upper surface of the upper surface cover 9c is a thrust receiving surface 12 as described above, and the oil pump 9 is attached to the subframe 8b so as to maintain the squareness accuracy and sufficient rigidity between the thrust receiving surface 12 and the auxiliary bearing 11. It is fixed and integrated.

The upper surface cover 9c is made of an annular member, and a through hole 23 is formed in the central portion. The pump insertion shaft 6d of the drive shaft 6 is inserted into the upper end opening formed by the through hole 23 and the space following the through hole 23. The circumference of the upper end opening of the through hole 23 is a chamfered portion 12e formed by a curved surface having a radius of curvature Rp0 so as not to come into contact with the pump insertion shaft 6d. The upper surface cover 9c is arranged below the sub-shaft portion 6c and corresponds to the outer member of the present invention. Further, the lower end opening 9d of the oil pump 9 is immersed in the lubricating oil of the oil storage space 14.

In the oil pump 9, the movable portion 9a operates as the drive shaft 6 rotates, and the lubricating oil stored in the oil storage space 14 is sucked up from the lower end opening 9d and supplied to various parts of the compression mechanism portion A. The various parts of the compression mechanism portion A correspond to various bearings such as a swing bearing 17, a swing thrust bearing 18, a main bearing 19, an auxiliary bearing 11, and a thrust receiving surface 12, and a sliding portion of an old dam joint 25. The lubricating oil sucked up by the oil pump 9 is supplied to the swing bearing 17 and the main bearing 19 from the oil supply vertical hole 7a through the eccentric shaft oil supply horizontal hole 7b and the spindle oil supply horizontal hole 7c. Further, a part of the lubricating oil that has flowed out from the upper outlet of the lubrication vertical hole 7a or the eccentric shaft lubrication horizontal hole 7b is supplied to the sliding portion of the swing thrust bearing 18 and the old dam joint 25. Further, the lubricating oil sucked up by the oil pump 9 is supplied to the auxiliary bearing 11 from the oil supply vertical hole 7a via the radial oil supply horizontal hole 7d, and is supplied to the thrust receiving surface 12 from the oil supply vertical hole 7a via the thrust lubrication horizontal hole 7e. Will be done. Refueling the thrust receiving surface 12 is a characteristic part of the first embodiment, and will be described again below.

[Thrust surface 6f, thrust receiving surface 12]
The thrust receiving surface 12 of the upper surface cover 9c has a flat surface 12b on the inner side in the radial direction and an inclined surface 12d on the outer side in the radial direction of the flat surface 12b that gently inclines downward toward the outside. The flat surface 12b is a surface perpendicular to the radial receiving surface 11a, which is the inner peripheral surface of the auxiliary bearing 11, and has a uniform height. The flat surface 12b of the thrust receiving surface 12 is connected so as to be in contact with the chamfered portion 12e having a radius of curvature Rp0 at the inner peripheral end, and is connected so as to be in contact with the inclined surface 12d with a radius of curvature Rp1 at the end point 12c of the flat surface. With this configuration, between the thrust surface 6f and the thrust receiving surface 12, a contact point 12f in which the thrust surface 6f and the thrust receiving surface 12 come into contact with each other on a curved surface, and a contact point 12f continuously from the contact point 12f toward the outside in the radial direction. An increasing gap 20 is formed.

Under the maximum load condition, the drive shaft 6 is tilted from 1/1000 [rad] to 2/1000 [rad] in the compressive load direction. If the inclination angle of the inclined surface 12d is designed to be the same level as the inclination of the drive shaft 6 under the maximum load condition, the thrust surface 6f is gently in contact with the thrust receiving surface 12 under the strictest operating condition. It will rotate in a normal state, and the wear state can be alleviated.

As the auxiliary shaft portion 6c of the drive shaft 6 is tilted, the position of the contact point 12f that slides on the thrust receiving surface 12 moves in the radial direction from the inner peripheral side to the outer peripheral side.

Here, the inclination of the drive shaft 6 during operation will be described.
1) First, when the radial load acting on the drive shaft 6 is very small and the thrust surface 6f and the flat surface 12b of the thrust receiving surface 12 are substantially parallel, the entire flat surface 12b receives the thrust load acting on the drive shaft 6. The thrust load acting on the drive shaft 6 usually corresponds to the own weights of the drive shaft 6, the rotor 10a, the balancer 26a and the balancer 26b, and the magnetic force in the downward direction of the thrust.

2) Next, when the compression operation starts, a radial load acts, the drive shaft 6 bends and deforms, the thrust surface 6f tilts, and the curved surface near the outside of the flat surface end point 12c of the thrust receiving surface 12 (radius of curvature Rp1). The drive shaft 6 rotates while making contact with.

3) When the load becomes larger and the compressive load and centrifugal force increase, the drive shaft 6 bends and deforms, the thrust surface 6f tilts further, and the thrust surface 6f gently contacts the thrust receiving surface 12. Rotate.

4) Finally, under the maximum load condition, when the drive shaft 6 is greatly flexed and deformed and the thrust surface 6f is tilted from the flat surface 12b of the thrust receiving surface 12, the curved surface (curvature) of the chamfered portion 6e on the outer peripheral portion of the thrust surface 6f The radius Rs1) rotates while making one-sided contact with the inclined surface 12d of the thrust receiving surface 12. In this case, by increasing the radius of curvature Rs1 of the chamfered portion 6e, it is possible to prevent the chamfered portion 12e from hitting the thrust receiving surface 12 on one side and increasing the local Hertz stress.

For example, from the equation of Hertz stress when a cylinder with radius of curvature 1 and a cylinder with radius of curvature 2 contact with each other at length L, Hertz stress ∝ (load) × (Young's modulus) × L × {1 / (radius of curvature 1) ² + (radius of curvature 2) ² }
Is established.

The radius of curvature Rs1 of the chamfered portion 6e is
Rp0 <Rs1 <Rp1
It is necessary to design Rs1 to be at least larger than Rp0 and close to Rp1.
The general R chamfer (fillet) is about R0.2 to R2, whereas the radius of curvature Rs1 of the chamfered portion 6e is large within the design allowable range, and is usually R3 or more.

Further, in the first embodiment, the sliding portion on which the sub-shaft portion 6c and the upper surface cover 9c slide is formed by separating the radial outer side of the thrust receiving surface 12 from the thrust surface 6f as an inclined surface 12d. The flat surface 12b is used instead of the entire thrust receiving surface 12. Therefore, the outer peripheral position of the sliding portion can be moved inward in the radial direction as compared with the case where the entire thrust receiving surface 12 is a flat surface 12b without forming the inclined surface 12d. Therefore, the maximum sliding speed can be suppressed.

Further, after the break-in operation, the angle of the flat surface end point 12c, which is the boundary between the flat surface 12b and the inclined surface 12d, is removed. Therefore, the contact angle between the thrust surface 6f and the thrust receiving surface 12 at the end point 12c of the flat surface becomes gentle, and the contact surface pressure of the sliding portion can be relaxed.

[Other configurations]
An oil return pipe 29 extending in the axial direction of the drive shaft 6 is arranged between the main frame 8a and the stator 10b, and an oil return hole 29a penetrating the stator 10b so as to extend in the axial direction is formed. .. The oil return pipe 29 and the oil return hole 29a have a function of returning the lubricating oil used in the compression mechanism unit A to the oil storage space 14. Note that FIG. 1 shows an example in which only one oil return pipe 29 and one oil return hole 29a are provided, but the present invention is not limited to this. For example, two or more oil return pipes 29 and oil return holes 29a may be provided.

As described above, in the scroll compressor 100, the compression mechanism unit A is arranged in the upper part of the closed container 13, and the electric motor part B is arranged in the lower part, and the driving force of the electric motor part B is applied to the compression mechanism part A via the drive shaft 6. Is transmitted to the swing scroll 2 of the above, and the swing scroll 2 is rotationally driven. The type of lubricating oil is not particularly limited as long as it can be used as a lubricating oil for the compression mechanism portion A. For example, PAG (polyalkylene grecol) or POE (polyester ester) may be used as the lubricating oil. Further, the type of the refrigerant is not particularly limited.

[Operation description]
The operation of the scroll compressor 100 will be described below.
When the stator 10b constituting the electric motor 10 is energized, the drive shaft 6 starts rotating together with the rotor 10a. When the drive shaft 6 starts rotating, the swing scroll 2 connected to the eccentric shaft 6a revolves while being prevented from rotating by the Oldham joint 25. As a result, the compression chamber 5 moves toward the center while gradually reducing its volume. As a result, the pressure of the refrigerant sucked into the compression chamber 5 from the suction port 3 is gradually increased. Then, the refrigerant whose pressure has increased is discharged to the outside of the machine through the discharge port 4 and the refrigerant discharge pipe 16, and is pressure-fed to the refrigerant pipe (not shown) connected to the refrigerant discharge pipe 16.

Since the refrigerant in the closed container 13 is discharged to the outside in this way, the pressure inside the closed container 13 becomes negative. Therefore, the refrigerant from the refrigerant pipe (not shown) outside the machine is sucked into the closed container 13 through the refrigerant suction pipe 15. Then, the refrigerant sucked into the closed container 13 is sucked into the compression chamber 5 from the suction port 3 after cooling the electric motor 10.

Further, as the drive shaft 6 rotates, the inner rotor 9aa of the oil pump 9 rotates, and the outer rotor 9ab also rotates accordingly, so that the lubricating oil in the oil storage space 14 is supplied to the oil supply vertical hole by the pumping action of the oil pump 9. It is sucked upward through 7a. The sucked-up lubricating oil is distributed to each of the auxiliary bearing 11, the main bearing 19, and the swing bearing 17, and lubricates each of these bearings. Lubricating oil that has passed through the swing bearing 17 is supplied to the swing thrust bearing 18 and the Oldham joint 25 to lubricate these sliding portions. Further, the lubricating oil supplied to the Oldham joint 25 is returned to the oil storage space 14 via the oil return pipe 29.

[Deformation of tubular portion 8ba of subframe 8b]
The auxiliary bearing 11 supports a radial load generated by operating the scroll compressor 100. The tubular portion 8ba of the subframe 8b provided with the auxiliary bearing 11 is thinner in the radial direction than the flange portion 8bb, and is a thin-walled flexible structure portion. By forming the tubular portion 8ba into a thin-walled flexible structure portion in this way, the tubular portion 8ba elastically deforms following the inclination of the drive shaft 6 and suppresses one-sided contact of the drive shaft 6 with the radial receiving surface 11a. It is possible. Since FIG. 2 is a schematic view, the tubular portion 8ba is shown to be thicker than the flange portion 8bb, although it is shown to be thicker, but in reality, it is elastically deformable. Is formed in.

[Radial load and thrust load]
A radial load acts on the auxiliary bearing 11 as the scroll compressor 100 operates. That is, a fluctuating load synchronized with the rotation of the drive shaft 6 is applied to the auxiliary bearing 11 in the radial direction. The auxiliary bearing 11 is composed of a slide bearing as described above. Since ball bearings and the like are not used for the auxiliary bearing 11 in this way, long-term reliability can be ensured to prevent seizure of the drive shaft 6, and increase in wear and friction loss can be suppressed for stable start-up. You can get sex.

Further, as the scroll compressor 100 operates, a thrust load acts on the thrust receiving surface 12 of the top cover 9c. That is, the own weight of the drive shaft 6 is applied vertically downward to the thrust receiving surface 12 as a thrust load. In order to keep the thrust surface 6f of the auxiliary shaft portion 6c of the drive shaft 6 and the thrust receiving surface 12 of the upper surface cover 9c in a good sliding state, it is necessary to always secure a stable oil level on the thrust receiving surface 12. is necessary.

Therefore, in the first embodiment, the inclined surface 12d is provided on the outer peripheral side of the thrust receiving surface 12, and is between the bottom surface of the auxiliary bearing 11 and the inclined surface 12d and is a region outside the radial direction of the thrust receiving surface 12. An oil reservoir space 22 is formed in a region further outside the thrust receiving surface 12. Since oil flows into the oil reservoir space 22 from the oil seal portion 11d on the lower end side of the radial receiving surface 11a, the head pressure of the oil stored up to the upper end 22b always causes the thrust receiving surface 12 from the outer peripheral side to the sliding surface. Stable oil is supplied. On the other hand, stable oil is always supplied from the inner peripheral side of the thrust receiving surface 12 to the sliding surface through the radial oil groove 7g from the thrust oil supply lateral hole 7e of the pump insertion shaft 6d. Hereinafter, a refueling route for ensuring a stable oil level on the thrust receiving surface 12 will be described in detail. Here, in order to form a space to be the oil reservoir space 22, the region outside the thrust receiving surface 12 in the radial direction is set as an inclined surface 12d, but the region is not limited to the inclined surface 12d and is higher than the height position of the flat surface 12b. It may be a flat surface formed at a low position.

[Regarding the refueling route to the thrust receiving surface 12]
A part of the lubricating oil sucked up by the oil pump 9 flows into the outer peripheral side of the pump insertion shaft 6d, and is discharged to the outside in the radial direction of the drive shaft 6 by centrifugal force. That is, the lubricating oil that has flowed into the outer peripheral side of the pump insertion shaft 6d rises the gap between the pump insertion shaft 6d and the movable portion 9a of the oil pump 9, and further raises the gap between the pump insertion shaft 6d and the top cover 9c. To do. Then, the lubricating oil that has risen in the gap between the pump insertion shaft 6d and the upper surface cover 9c reaches the thrust receiving surface 12. Further, a part of the lubricating oil that has been boosted by the oil pump 9 and has flowed into the refueling vertical hole 7a is also discharged radially outward by centrifugal force from the thrust refueling horizontal hole 7e formed in the pump insertion shaft 6d, and the thrust receiving surface 12 To reach. Specifically, the thrust lubrication horizontal hole 7e is formed in the pump insertion shaft 6d so as to communicate with the lubrication vertical hole 7a below the thrust surface 6f and extend in the radial direction of the drive shaft 6 to allow the lubricating oil to be applied to the thrust surface. It is supplied between 6f and the thrust receiving surface 12.

Then, the lubricating oil that has reached the thrust receiving surface 12 flows through the radial oil groove 7g formed on the thrust surface 6f from the inner peripheral end to the outer peripheral end, and flows into the oil reservoir space 22. The flow path cross-sectional area obtained by cutting the radial oil groove 7 g in the axial direction is larger than the flow path cross-sectional area obtained by cutting the annular gap between the pump insertion shaft 6d and the upper surface cover 9c in the direction orthogonal to the axial direction. It is formed small. Therefore, the lubricating oil in the annular gap between the pump insertion shaft 6d and the upper surface cover 9c is concentrated in the radial oil groove 7g, and the inside of the radial oil groove 7g is filled with the lubricating oil. It has become. Then, since the radial oil groove 7g goes around in the circumferential direction by rotating the drive shaft 6, the lubricating oil spreads over the entire area of the thrust receiving surface 12.

Further, the lubricating oil supplied from the oil supply vertical hole 7a to the radial oil supply horizontal hole 7d is supplied from the axial oil groove 7f to the gap between the outer peripheral surface of the sub-shaft portion 6c and the radial receiving surface 11a. Then, the lubricating oil supplied to the gap between the outer peripheral surface of the auxiliary shaft portion 6c and the radial receiving surface 11a spreads over the entire area of the radial receiving surface 11a of the auxiliary bearing 11 and lubricates the auxiliary bearing 11.

Here, of the regions facing the auxiliary bearing 11 on the outer peripheral surface of the auxiliary shaft portion 6c, the region S1 above the axial oil groove 7f has a longer axial length than the lower region S2. .. The gap between each of the regions S1 and S2 and the auxiliary bearing 11 is an oil seal portion due to the retention of lubricating oil. Since the region S1 has a longer axial length than the region S2, the axial length of the upper oil seal portion 11c is longer than the axial length of the lower oil seal portion 11d. Therefore, the amount of lubricating oil supplied from the radial oil supply lateral hole 7d to the axial oil groove 7f flows out from the upper end side of the auxiliary bearing 11 and leaks into the closed container 13, and the lubricating oil is accumulated in the oil reservoir space 22. I am doing it. In this way, the lubricating oil is abundant in the oil reservoir space 22 so that the thrust surface 6f and the thrust receiving surface 12 can be maintained in a good sliding state.

As described above, the lubricating oil from the refueling vertical hole 7a via the thrust refueling horizontal hole 7e and the lubricating oil from the refueling vertical hole 7a via the radial refueling horizontal hole 7d merge into the oil reservoir space 22. Then, the lubricating oil merged in the oil reservoir space 22 passes through the oil discharge flow path 21 formed of grooves and holes formed on the mounting surfaces of the subframe 8b with the oil pump 9 and enters the oil storage space 14. Be returned. The upstream end of the oil discharge flow path 21 opens to the lower end 22a of the oil reservoir space 22, and the discharge hole 21a at the downstream end opens downward to the outer surface of the main body 9b of the oil pump 9. The discharge hole 21a is an outlet of the oil discharge flow path 21 and is located below the oil reservoir space 22. Then, the lubricating oil in the oil reservoir space 22 is discharged to the outside of the subframe 8b through the oil discharge flow path 21. Reference numeral 22b in FIG. 2A is the upper end of the oil reservoir space 22, and the upper end 22b is arranged above the radial oil groove 7g.

Here, when the oil reservoir space 22 is defined again, as shown in FIG. 2, the auxiliary bearing 11 is provided inside the cylindrical portion 8ba of the subframe 8b, so that the auxiliary bearing 11 has at least the thickness of the auxiliary bearing 11. A cylindrical space is formed below. This space becomes a part of the oil storage space 22.

Further, in FIG. 2, in the inner peripheral surface 22c of the tubular portion 8ba of the subframe 8b, the region facing the sub-shaft portion 6c of the drive shaft 6 and located below the sub-bearing 11 is located in the region portion. A wall surface portion 22d recessed outward in the radial direction is formed. As described above, by further providing the wall surface portion 22d on the inner peripheral surface 22c of the tubular portion 8ba of the subframe 8b, the oil storage space 22 is further expanded. Further, by providing the wall surface portion 22d, the lower end portion of the sub-shaft portion 6c of the drive shaft 6 that rotates while tilting comes into contact with the thrust receiving surface 12 or the radial receiving surface 11a, and the sub-shaft portion 6c and the thrust receiving surface receive. The risk of damage to the surface 12 or the radial receiving surface 11a can be reduced.

A throttle flow path 21b that gives an appropriate flow path resistance is formed in the middle of the oil discharge flow path 21, and the throttle flow path 21b is formed so that the lubricating oil is once filled in the oil reservoir space 22. It is possible to store it. Further, when wear debris is generated on the radial receiving surface 11a or the thrust receiving surface 12, it is necessary to discharge the wear debris to the oil storage space 14 without accumulating the wear debris in the oil storage space 22. That is, it is necessary to discharge the wear debris from the oil reservoir space 22 through the oil discharge flow path 21. Therefore, it is preferable that the cross section of the throttle flow path 21b is a flow path cross section in which the depth and the width are set to about 0.2 mm to 1 mm, respectively.

[Axial positional relationship between the radial oil groove 7 g and the oil reservoir space 22]
The radial oil groove 7g is formed on the thrust surface 6f as described above, but in order to keep the thrust surface 6f and the thrust receiving surface 12 in a good oil lubrication state, the inside of the radial oil groove 7g is lubricated. It needs to be filled with oil. If the upper surface of the lubricating oil collected in the oil reservoir space 22 is located below the bottom of the concave groove forming the axial oil groove 7f, the inside of the radial oil groove 7g is not filled with the lubricating oil. Therefore, the upper surface of the oil collected in the oil reservoir space 22 is configured to be located above the bottom of the concave groove forming the axial oil groove 7f. Specifically, the volume of the oil sump space 22 and the throttle flow path 21b may be designed in relation to the amount of oil flowing into the oil sump space 22.

[Position of radial oil groove 7g in the circumferential direction]
The radial oil groove 7g is formed at one location on the thrust surface 6f, and the arrangement position in the circumferential direction on the thrust surface 6f is set in consideration of the bending direction of the drive shaft 6. Hereinafter, the arrangement position of the radial oil groove 7g in the circumferential direction will be described with reference to FIGS. 3 and 4. Further, prior to the description of FIGS. 3 and 4, first, the load acting on the drive shaft 6 and the acting direction of the load will be described with reference to FIG.

FIG. 5 is an explanatory diagram of a load acting on the drive shaft of the scroll compressor according to the first embodiment of the present invention and a direction of action of the load.
For the Y-axis, the direction connecting the axis of the drive shaft 6 to the axis of the eccentric axis 6a (hereinafter referred to as the eccentric direction) is defined as + when the drive axis 6 is viewed in a plane from the axial direction. The Z-axis is the axis of the drive shaft 6 and the upward direction is +. The X-axis is a coordinate axis orthogonal to the Y-axis and the Z-axis. The drive shaft 6 rotates counterclockwise in the θ (−X) direction when viewed from above, but receives a gas load in the + X direction on the opposite side. In FIG. 5, Fx works mainly in the + X direction with a gas load required for compressing the refrigerant gas in the compression chamber 5. Further, F _1x is a load acting on the main bearing 19 in the X-axis direction. F _1y is a load acting on the main bearing 19 in the Y-axis direction. F _2x is a load acting on the auxiliary bearing 11 in the X-axis direction. F _2y is a load acting on the auxiliary bearing 11 in the Y-axis direction.

Further, since a moment that tends to tilt the entire drive shaft 6 by centrifugal force acts on the drive shaft 6 in the eccentric (+ Y) direction, balancers 26a and balancers 26b are attached above and below the rotor 10a so as to cancel this. There is. The F _{BW 1} is a load due to the centrifugal force acting on the drive shaft 6 by the balancer 26a. F _{BW 2} is a load due to the centrifugal force acting on the drive shaft 6 by the balancer 26b.

FIG. 3 is an explanatory view of a bending state of the drive shaft of the scroll compressor according to the first embodiment of the present invention in the ZX cross section and the arrangement position of the radial oil groove in the circumferential direction. In FIG. 3, (A) shows a case where the gas load acting on the drive shaft 6 is in a low load operation, and (B) shows a case where the gas load is in a high load operation. Further, in each of (A) and (B), (a) is a diagram showing a bending state of the drive shaft 6 in the ZX cross section, and (b) is a plan view of the drive shaft 6 seen from above. The figure which showed the load acting on the shaft 6, (c) is the explanatory view of the position in the circumferential direction of the radial oil groove 7g seen from the bottom. Further, in FIG. 3, the arcuate double-line arrow indicates the rotation direction of the drive shaft 6.

Centrifugal force Fc acts on the drive shaft 6 in the + Y direction due to eccentric rotation of the swing scroll 2 or the like. However, when the structure in which the centrifugal force Fc is received by the spiral protrusion (tooth tip wrap) 1b of the fixed scroll 1 is adopted, the centrifugal force Fc does not act on the drive shaft 6. Here, first, in the ZX cross section where the centrifugal force can be ignored, the gas load Fx required for compressing the refrigerant gas in the compression chamber 5 acts as the main load in the + X direction on the drive shaft 6, and the main shaft portion 6b A reaction force corresponding to this acts on the sub-shaft portion 6c. There is a diameter gap (usually about 1/1000 of the shaft diameter) between the main bearing 19 and the main shaft portion 6b and between the sub-bearing 11 and the sub-shaft portion 6c to enable fluid lubrication. Therefore, the drive shaft 6 is bent and deformed, and in the main bearing 19, the main shaft portion 6b approaches in the + X direction, and in the sub bearing 11, the entire shaft inclines so that the sub shaft portion 6c approaches in the −X direction. The axis 6h of the sub-shaft portion 6c also tilts with respect to the axis (Z-axis) 6g of the compressor. As a result, during the low load operation shown in FIG. 3A, the thrust surface 6f rises in the negative direction of the X axis with respect to the thrust receiving surface 12 and tilts so as to press the positive direction of the X axis.

Further, during high load operation, as shown in FIG. 3B, the drive shaft 6 is greatly bent and deformed as compared with low load operation. Therefore, the thrust surface 6f of the sub-shaft portion 6c is tilted so as to lift the + direction of the X-axis with respect to the thrust receiving surface 12 and press the-direction of the X-axis. When the radial oil groove 7g is pressed against the thrust receiving surface 12, the surface pressure is locally increased near the edge of the radial oil groove 7g, and the wear is likely to occur. Therefore, it is preferable to arrange the radial oil groove 7g so as to avoid the ± X direction so that the vicinity of the radial oil groove 7g does not hit the thrust receiving surface 12 on one side. On the other hand, on the radial receiving surface 11a of the auxiliary bearing 11, the auxiliary shaft portion 6c approaches the −X direction and a load is applied, so that the axial oil groove 7f is provided on the + X side (counter-load side).

Next, FIG. 4 is an explanatory diagram of a bending state of the drive shaft of the scroll compressor according to the first embodiment of the present invention in the YY cross section and the arrangement position of the radial oil groove in the circumferential direction. In FIG. 4, (A) shows the time of low speed operation, and (B) shows the time of high speed operation. Further, in each of (A) and (B), (a) is a diagram showing a bending state of the drive shaft 6 in the YY cross section, and (b) is a plan view of the drive shaft 6 seen from above. The figure which showed the load acting on the shaft 6, (c) is the explanatory view of the position in the circumferential direction of the radial oil groove 7g seen from the bottom. Further, in FIG. 4, the arcuate double-line arrow indicates the rotation direction of the drive shaft 6.

When a centrifugal force Fc acts on the drive shaft 6 due to eccentric rotation of the swing scroll 2 or the like, a large load is locally applied to the spiral protrusion (tooth tip wrap) 1b or the like of the fixed scroll 1, or the drive shaft tilts. There are problems such as the rotor swinging around. Therefore, as a mechanism for relaxing the load due to the centrifugal force Fc, a balancer 26a and a balancer 26b are attached above and below the rotor 10a to balance the force and the moment acting on the YZ cross section of the drive shaft 6. At this time, the inclination angle of the drive shaft 6 that bends and tilts while being deformed changes depending on the presence or absence of the centrifugal force Fc, but the auxiliary shaft portion 6c tilts with almost the same tendency.

Since the centrifugal force F _BW1 of the balancer 26a on the upper side of the rotor 10a acts in the −Y direction and the centrifugal force F _BW2 of the balancer 26b on the lower side acts in the −Y direction, the auxiliary shaft portion 6c on the radial receiving surface 11a of the auxiliary bearing 11 At the bottom, tilt in the -Y direction to get closer. As a result, in both the low-speed operation of FIG. 4A and the high-speed operation of FIG. 4B, the thrust surface 6f is lifted in the + direction of the Y-axis with respect to the thrust receiving surface 12, and presses the-direction of the Y-axis. Lean to. Therefore, it is preferable to arrange the oil groove 7g in the radial direction so as to avoid the −Y direction so that the vicinity of the oil groove 7g does not hit the thrust receiving surface 12 on one side.

As described above, as described with reference to FIGS. 3 and 4, a gas load, which is a main load, and a centrifugal force act on the drive shaft 6, and the thrust surface 6f is tilted. However, radial oil is used under all operating conditions. It is in the + direction of the Y-axis, that is, in the eccentric direction that the groove 7g is hard to hit one side. Therefore, it is preferable to arrange the radial oil groove 7g in the eccentric direction (+ Y direction).

Further, under the strictest high-speed and high-load operating conditions, as shown in FIGS. 3 (B) and 4 (B), in addition to the gas load Fx, which is the main load, the centrifugal force of the balancer 26a on the upper side of the rotor is always present. The centrifugal force F _BW2 of 26b of the balancer under the rotor always acts in the −Y direction with the F _BW1 acting in the + Y direction. The resultant force Fr of the gas load Fx and the centrifugal force F _BW1 acts in an angular direction slightly deviated clockwise (counter-rotating direction) when viewed from above from the + X axis, and the drive shaft 6 bends and deforms, so that the thrust surface The angle at which 6f hits one side and the direction of the secondary shaft radial load also work slightly differently. Considering this, as described in (c) of FIG. 3 (B) and (c) of FIG. 4 (B), the position of the radial oil groove 7 g on the thrust surface 6f is in the + direction (eccentricity) of the Y axis. Even better durability can be obtained by arranging the oil at an angle α offset in the counterclockwise direction (counterclockwise rotation direction) when viewed from below. The angle α is an acute angle range of 0 deg or more and 45 deg or less.

(The invention's effect)
According to the first embodiment, there is a gap 20 between the thrust surface 6f and the thrust receiving surface 12 that continuously increases from the contact point 12f toward the outer side in the radial direction. Further, an oil reservoir space 22 is provided on the outer peripheral side of the thrust surface 6f, and after the lubricating oil is supplied to the thrust receiving surface 12 through the radial oil groove 7 g and the gap 20, the oil is stored in the oil reservoir space 22. Has a configuration that is By providing the oil reservoir space 22 in this way, it is possible to constantly secure the flow of the lubricating oil between the thrust surface 6f and the thrust receiving surface 12. As a result, a good oil lubrication state and a sliding state can be ensured on the thrust receiving surface 12, and abnormal wear of the drive shaft 6 and seizure of the drive shaft 6 can be suppressed. As described above, in the first embodiment, the compressor is provided by a relatively simple means that only provides a gap and an oil reservoir space 22 that increase in the radial direction outward between the thrust surface 6f and the thrust receiving surface 12. It is possible to improve the life and reliability.

Further, by providing the throttle flow path 21b in the middle of the oil discharge flow path 21, it is possible to make it easy to temporarily hold the lubricating oil in the oil reservoir space 22, and to provide good oil lubrication of the thrust receiving surface 12. Effective to get.

Further, as a specific configuration of the oil reservoir space 22, the thrust receiving surface 12 may have an inclined surface 12d that inclines downward in the radial direction rather than the inner side in the radial direction. Can be configured.

Further, since the oil reservoir space 22 is provided on the radial outside of the thrust receiving surface 12, the radial position of the sliding portion where the thrust surface 6f and the thrust receiving surface 12 come into contact with each other can be moved inward. Therefore, the sliding speed at the flat surface end point 12c, which is the contact point, can be reduced during high-load and high-speed operation, which is a severe sliding condition in which the inclination angle of the drive shaft 6 becomes large. Alternatively, the contact angle can be kept small.

Further, since the circumference of the upper surface opening of the through hole 23 of the upper surface cover 9c is a chamfered portion 12e formed by a curved surface, it is possible to avoid contact with the pump insertion shaft 6d when the drive shaft 6 is rotated.

Further, since the radial outer end of the thrust surface 6f of the drive shaft 6 is a chamfered portion 6e formed of a curved surface, the contact angle with the thrust receiving surface 12 can be relaxed, and good sliding can be achieved. You can keep the state.

The compressor is not limited to the structure shown in FIGS. 1 to 5, and various modifications can be implemented as follows, for example, as long as the gist of the present invention is not deviated.

<Modification 1 of the first embodiment>
FIG. 6 is a diagram showing a modified example 1 of the scroll compressor according to the first embodiment of the present invention, and is a schematic view in which the lower end portion of the auxiliary bearing of the scroll compressor is enlarged.
The modified example 1 is different from the basic configuration shown in FIG. 2 in that the thrust lubrication horizontal hole 7e of the pump insertion shaft 6d is eliminated. Further, the thrust receiving surface 12 is also in a state of being hardened by quenching, and the distance between the thrust receiving surface 12 and the quenching portion of the sub-shaft portion 6c (radial surface) is closer than that of the basic configuration shown in FIG. Further, the space of the oil storage space 22 is also different from the basic configuration shown in FIG. 2 in that the volume is small because the inner wall surface 22ca has no dent as shown in FIG.

Under high-speed, high-load operating conditions, the thrust surface 6f tilts significantly and comes into contact with and slides on the chamfered portion (fillet) 6e having a large radius of curvature. Even when the thrust oil supply side hole 7e is removed from the pump insertion shaft 6d in this way, oil flows into the oil reservoir space 22 from the oil seal portion 11d on the lower end side of the radial receiving surface 11a. Therefore, the head pressure of the oil stored up to the upper end 22b makes it possible to supply abundantly stable oil to the outside of the thrust receiving surface 12 at all times. On the other hand, the lubricating oil leaking from the oil pump 9 is supplied from the inner peripheral side of the thrust receiving surface 12 to the chamfered portion 6e through the radial oil groove 7g through the gap between the pump insertion shaft 6d and the through hole 23. It is possible to do. However, the latter oil supply amount due to oil pump leakage decreases as the head becomes smaller as the number of revolutions decreases, so there is a limit to the low speed possible range.

As described above in FIG. 2, when the thrust lubrication horizontal hole 7e is provided in the pump insertion shaft 6d, the thrust receiving surface 12 is constantly supplied with lubricating oil abundantly through the radial oil groove 7g of the thrust surface 6f by the centrifugal pump action. It is an effective configuration for stable supply. However, except for the problem at the time of low-speed operation, the same effect can be obtained in the present modification 1.

<Modification 2 of the first embodiment>
FIG. 7 is a diagram showing a modified example 2 of the scroll compressor according to the first embodiment of the present invention, and is a schematic view in which the lower end portion of the auxiliary bearing of the scroll compressor is enlarged.
Modification 2 differs from the basic configuration shown in FIG. 2 in the following two points. That is, one is that there is no inclined surface 12d on the thrust receiving surface 12 side, and the flat surface 12b is extended to the end on the outer side in the radial direction. The other is that the radius of curvature Rs1 of the chamfered portion 6e at the radial outer end of the thrust surface 6f is made larger than that in FIG. 2 to form the oil reservoir space 22. The thrust receiving surface 12 is also in a state of being hardened by quenching, the distance between the thrust receiving surface 12 and the quenching portion of the sub-shaft portion 6c is close, and the space of the oil reservoir space 22 is smaller than that in FIG.

In FIG. 2, the flat surface end point 12c of the thrust receiving surface 12 was the contact point with the thrust surface 6f. On the other hand, in the modified example 2, since the entire thrust receiving surface 12 is made a flat surface, when the drive shaft 6 is tilted, a point on the thrust receiving surface 12 that comes into contact with the chamfering start position 6ea of the chamfered portion 6e is formed. The contact point is 12f. Therefore, by increasing the radius Rs of the chamfered portion 6e, the contact point 12f is located inside the thrust receiving surface 12 in the radial direction as compared with the case where the radius Rs is small, so that the sliding speed at the contact point 12f can be reduced. it can. Further, by increasing the radius Rs of the chamfered portion 6e, even if the entire thrust receiving surface 12 is a flat surface 12b, the contact angle can be relaxed as compared with the case where the radius Rs is small.

Further, in the second modification, the circle whose radius is the line segment perpendicularly drawn from the contact point 12f to the axis of the drive shaft 6 (hereinafter referred to as the contact sliding circle) is larger than the movable portion 9a when viewed in the axial direction. It is composed. With this configuration, the following effects can be obtained. That is, the upper surface cover 9c has a so-called cantilever shape in which the outer peripheral portion is supported by the main body 9b and the inner peripheral portion side is not supported and is in a floating state. Therefore, if the contact sliding circle is inside the movable portion 9a of the oil pump 9, the drive shaft 6 may push down the inner peripheral portion side of the upper surface cover 9c, and the upper surface cover 9c may bend. .. However, by making the contact sliding circle larger than the movable portion 9a, there is an effect that the upper surface cover 9c can be prevented from bending.

<Modification 3 of Embodiment 1>
FIG. 8 is a diagram showing a modified example 3 of the scroll compressor according to the first embodiment of the present invention. 8A is a schematic view of the lower end portion of the auxiliary bearing of the scroll compressor enlarged from the auxiliary bearing, and FIG. 8B is a view of the annular steel plate which is the thrust receiving surface of the third modification from directly above.
The modified example 3 is different from the modified example 2 in the following points. The difference is that 12 g of an annular steel plate having a thin thickness and a fine surface roughness is used as the thrust receiving surface 12. The annular steel plate 12 g is used by being placed on the upper surface cover 9c of the oil pump 9. In addition, "thinness" means, for example, a thickness of 1 mm or less, and "fine surface roughness" means, for example, a surface roughness of z1 or less. As the annular steel sheet 12 g, a commercially available hardened thin sheet steel material such as a PK steel sheet having a thickness of 0.5 mm can be used. The annular steel plate 12 g corresponds to an example of the annular member of the present invention, and is finished by polishing the surface of the hardened steel strip.

The annular steel plate 12g has ear-shaped protrusions 12ga protruding outward on a part of the outer circumference of the circle, and ear-shaped protrusions 12ga are formed on the notched portion of the main body 9b of the oil pump 9. It is inserted and fixed so that it does not rotate.

In the third modification, by using the annular steel plate 12g, the annular steel plate 12g follows the behavior of the thrust surface 6f, so that the slidability is improved. Further, by using a commercially available hardened thin steel plate as 12 g of the annular steel plate, there is an advantage that the processing can be simplified.

Embodiment 2.
FIG. 9 is a diagram showing a main part of the scroll compressor according to the second embodiment of the present invention, and is a schematic view showing an enlarged lower end portion of the auxiliary bearing.
In the second embodiment, as compared with the basic configuration shown in FIG. 2, the formation position of the radial oil groove 7g is changed from the thrust surface 6f side to the thrust receiving surface 12 side, and the number of radial oil grooves 7g is changed. The difference is that the number is increased to a plurality, preferably three or more. Further, the thrust receiving surface 12 side is formed only by the flat surface 12b orthogonal to the axis 6g of the compressor, and has no inclined surface 12d. Instead, the thrust surface 6f side is different in that it is formed by an inclined surface 6fa inclined from an orthogonal plane with the axis 6g (compressor axis reference). The thrust surface 6f inclines upward from the axial center 6g toward the outer side in the radial direction. By designing the inclination angle of the thrust surface 6f to be the same as the inclination angle θs of the axial center 6h of the auxiliary shaft portion 6c bent by high load and high-speed operation, the contact angle between the thrust surface 6f and the thrust receiving surface 12 Can be kept small. The "inclination angle of the axis center 6 g bent by high load and high speed operation" is about 1/1000 to 2/1000 rad.

In the configuration in which the radial oil groove 7g is formed on the thrust surface 6f as shown in FIG. 2, the position of the radial oil groove 7g is rotated by the rotation of the drive shaft 6 to generate a centrifugal pump action, and the thrust receiving surface is generated. It had the effect of spreading the lubricating oil over the entire surface of 12. On the other hand, in the configuration in which the radial oil groove 7g is formed on the thrust receiving surface 12 as in the second embodiment, the position of the radial oil groove 7g does not rotate, so that the lubricating oil in the radial oil groove 7g is used. It is difficult to flow and spread to the thrust receiving surface 12. Therefore, in the second embodiment, the number of radial oil grooves 7g is increased to a plurality of the same to reduce the flow path resistance, so that the effect of spreading the lubricating oil over the entire surface of the thrust receiving surface 12 can be obtained.

However, the flow path cross-sectional area of the radial oil groove 7g is smaller than the flow path cross-sectional area of the flow path formed by the annular gap between the pump insertion shaft 6d and the upper surface cover 9c. As a result, the lubricating oil flowing through the radial oil groove 7g overflows to the upper surface side of the thrust receiving surface 12, and the thrust surface 6f rotates to spread over the entire surface, so that the lubricated state can be kept good.

Further, by providing the inclined surface 6fa, the contact point 12f is located inward in the radial direction as compared with the case where the thrust surface 6f and the thrust receiving surface 12 are both flat surfaces without providing the inclined surface 6fa. Therefore, it is possible to reduce the sliding speed at the contact point 12f and relax the contact angle at the contact point 12f.

When the radial oil groove 7g is formed at the thrust surface 6f as described above in FIG. 2, the lubricating oil can be abundantly supplied to the thrust receiving surface 12 by centrifugal action. However, even if the radial oil groove 7g is formed at the thrust receiving surface 12 as in the second embodiment, if the radial oil groove 7g is appropriately designed, an effect similar to that of the first embodiment can be obtained.

Further, at least one of both ends of the drive shaft 6 of the radial receiving surface 11a of the auxiliary bearing 11 in the axial direction is formed with a curved surface. As a result, damage due to contact between the end portion formed by the curved surface and the drive shaft 6 can be suppressed. Note that FIG. 9 shows a configuration in which both ends of the drive shaft 6 of the radial receiving surface 11a of the auxiliary bearing 11 in the axial direction are formed with curved surfaces.

Embodiment 3.
FIG. 10 is a diagram showing a main part of the scroll compressor according to the third embodiment of the present invention, and is a schematic view showing an enlarged lower end portion of the auxiliary bearing.
In addition to the radial load, the subframe 8b also receives a thrust load generated by the weight of the drive shaft 6 and the magnetic force of the rotor. In FIG. 2, this thrust load is received by the upper surface cover 9c of the oil pump 9 arranged below the subframe 8b, and the upper surface of the upper surface cover 9c is the thrust receiving surface 12. The third embodiment is different in that the thrust load is received by the bottom plate 8bc fixed to the bottom of the subframe 8b with bolts 40, and the upper surface of the bottom plate 8bc is the thrust receiving surface 12. The shape of the thrust receiving surface 12 is almost the same as that in FIG. The shape of the thrust surface 6f is the same as that in FIG.

The bottom plate 8bc is an annular circular base plate having a through hole formed in the central portion, and the outer diameter of the bottom plate 8bc is larger than the outer diameter of the tubular portion 8ba of the subframe 8b. A plurality of bolt holes are formed in the bottom plate 8bc, and the bottom plate 8bc is fixed to the subframe 8b by passing the bolts 40 through the bolt holes and screwing them into the screw holes provided in the subframe 8b. .. Further, the pump insertion shaft 6d is longer than FIG. 2 by the thickness of the bottom plate 8bc. The bottom plate 8bc corresponds to an example of the annular member of the present invention.

According to the third embodiment, since the thrust receiving surface 12 is formed by the bottom plate 8bc which is different from the top cover 9c of the oil pump 9, the material and thickness of the bottom plate 8bc are not restricted by the design of the oil pump 9. Can be selected. Therefore, it is easy to increase the surface hardness and bending strength of the thrust receiving surface 12 without being restricted by the design of the oil pump 9.

Further, the characteristic configurations of each of the first embodiment, the first modified example to the third modified example, the second embodiment and the third embodiment may be appropriately combined as long as the gist of the present invention is not deviated. For example, the configuration in which a plurality of radial oil grooves 7g are provided on the thrust receiving surface 12, which is a characteristic configuration of the second embodiment, is not limited to the configuration in which the inclined surface 6fa is provided on the thrust surface 6f. .. For example, the inclined surface 12d shown in FIG. 2 may be combined with the configuration provided on the thrust receiving surface 12. Further, a configuration in which the radius of curvature Rs1 of the chamfered portion 6e of the modified example 2 is increased may be combined with the second embodiment. Further, 12 g of the annular steel plate of the modified example 3 may be combined with the second embodiment and the third embodiment.

Further, in the above-described first to third embodiments, the sub-bearing 11 and the sub-frame 8b are separately configured, but the sub-bearing 11 and the sub-frame 8b are integrally configured, and the integrated constituent member is a radial of the sub-shaft portion 6c of the drive shaft 6. It may be an auxiliary bearing that supports the surface.

Further, in the first to third embodiments, the member on which the thrust receiving surface is formed is the upper surface cover 9c of the oil pump 9, the annular steel plate 12g, or the bottom plate 8bc fixed to the bottom of the subframe 8b, which is radial. It was formed separately from the auxiliary bearing 11 on which the receiving surface 11a is formed. However, as described above, the auxiliary bearing 11 is integrated with the subframe 8b, and the member on which the thrust receiving surface is formed is also integrated, and the integrated constituent member is a radial of the auxiliary shaft portion 6c of the drive shaft 6. It may be an auxiliary bearing that supports the surface and the thrust surface.

Further, in the above description, the configuration in which the compressor is a scroll compressor has been described, but the present invention is not limited to this, and other types of compressors such as a rotary compressor may be used.

1 Fixed scroll, 1a base plate, 1b spiral protrusion, 2 swing scroll, 2a base plate, 2b spiral protrusion (tooth tip wrap), 2c eccentric hole, 3 suction port, 4 discharge port, 5 compression chamber, 6 drive shaft, 6a eccentric shaft, 6b main shaft, 6c sub-shaft, 6d pump insertion shaft, 6e chamfer, 6ea chamfering start position, 6f thrust surface, 6fa inclined surface, 6g compressor shaft center, 6h sub-shaft center, 7a refueling vertical hole, 7b refueling horizontal hole, 7c refueling horizontal hole, 7d refueling horizontal hole, 7e refueling horizontal hole, 7f axial oil groove, 7g radial oil groove, 8 housing, 8a main frame, 8b subframe, 8ba tubular part (sub bearing) Metal), 8bb flange, 8bc bottom plate, 9 oil pump, 9a movable part, 9aa inner rotor, 9ab outer rotor, 9b body body, 9c top cover, 9d lower end opening, 10 electric motor, 10a rotor, 10b stator, 11 auxiliary bearing , 11a radial bearing, 11c oil seal, 11d oil seal, 12 thrust bearing, 12b flat surface, 12c flat end, 12d inclined surface, 12e chamfer, 12f contact point, 12g annular steel plate, 12ga protrusion, 13 closed container, 14 oil storage space, 15 refrigerant suction pipe, 16 refrigerant discharge pipe, 17 swing bearing, 18 swing thrust bearing, 19 main bearing, 21 oil discharge flow path, 21a discharge hole, 21b throttle flow path, 22 Oil reservoir space, 22a lower end, 22b upper end, 22c inner peripheral surface, 22ca wall surface, 23 through hole, 24 screws, 25 old dam joint, 26a balancer, 26b balancer, 29 oil return pipe, 29a oil return hole, 40 volts, 100 scrolls Compressor, A compression mechanism, B electric motor.

The compressor according to the present invention includes a compression mechanism unit arranged in a closed container, an electric motor unit that drives the compression mechanism unit, a drive shaft that transmits the driving force of the electric motor unit to the compression mechanism unit, and an upper portion of the drive shaft. The main bearing that supports the drive shaft, the auxiliary bearing that supports the lower part of the drive shaft, the radial receiving surface that is provided on the auxiliary bearing and slidably supports the radial surface of the drive shaft, and the thrust surface of the drive shaft are slidable. It is connected to the thrust receiving surface supported by the thrust bearing, the subframe arranged in the closed container and provided with the auxiliary bearing, and the pump insertion shaft formed on the drive shaft at the lower part of the auxiliary bearing, and the closed container is connected by the rotation of the drive shaft. It is equipped with an oil pump that sucks up the lubricating oil in the internal oil storage space, and between the thrust surface and the thrust bearing surface, there is a contact point where the thrust surface and the thrust bearing surface meet on a curved surface, and the outside in the radial direction from the contact point. possess a gap increases continuously towards the, between the thrust surface and the thrust receiving surface, radial oil grooves extending in a radial direction of the drive shaft is provided, it sucked up by an oil pump diameter Lubricating oil that has passed through the directional oil groove is stored in the oil reservoir space formed on the radial outer side of the thrust bearing surface, and the oil pump is attached to the subframe, and the subframe and oil Grooves and holes formed in one or both of the mounting surfaces of the pump and the pump form an oil drainage channel that drains the lubricating oil in the oil reservoir space from the outlet into the oil storage space. A throttle flow path that serves as a flow path resistance is formed on the way .

Claims (20)

The compression mechanism located inside the closed container,
The electric motor unit that drives the compression mechanism unit and
A drive shaft that transmits the driving force of the electric motor unit to the compression mechanism unit, and
The main bearing that supports the upper part of the drive shaft and
An auxiliary bearing that supports the lower part of the drive shaft,
A radial receiving surface provided on the auxiliary bearing and slidably supporting the radial surface of the drive shaft,
A thrust receiving surface that slidably supports the thrust surface of the drive shaft is provided.
Between the thrust surface and the thrust receiving surface, there is a contact point where the thrust surface and the thrust receiving surface are in contact with each other on a curved surface, and a gap that continuously increases radially outward from the contact point. Compressor. The compressor according to claim 1, wherein an oil reservoir space for storing lubricating oil is formed on the radial outer side of the thrust receiving surface. The closed container has an oil storage space inside and
An oil pump is provided which is connected to a pump insertion shaft formed on the drive shaft at the lower part of the auxiliary bearing and sucks up lubricating oil in the oil storage space by rotation of the drive shaft.
A radial oil groove extending in the radial direction of the drive shaft is provided between the thrust surface and the thrust receiving surface.
The compressor according to claim 2, wherein the lubricating oil sucked up by the oil pump and passed through the radial oil groove is stored in the oil reservoir space. A subframe arranged in the closed container and provided with the sub-bearing is provided.
The oil pump is attached to the subframe, and grooves and holes formed in one or both of the mounting surfaces of the subframe and the oil pump provide lubricating oil for the oil reservoir space. The compressor according to claim 3, wherein an oil discharge flow path for discharging from an outlet is formed in the storage space, and a throttle flow path serving as a flow path resistance is formed in the middle of the oil discharge flow path. The compressor according to claim 4, wherein the outlet of the oil discharge flow path is arranged below the oil reservoir space, and the upper end of the oil reservoir space is arranged above the radial oil groove. The drive shaft is provided with an eccentric shaft eccentric from the axis of the drive shaft at the upper end.
The aspect according to any one of claims 3 to 5, wherein the radial oil groove is formed so as to extend in an eccentric direction which is a direction connecting the axial center of the eccentric shaft from the axial center of the drive shaft. Compressor. The compressor according to claim 6, wherein the radial oil groove is arranged on the thrust surface of the drive shaft in a range of 0 deg or more and 45 deg or less in the rotation direction of the drive shaft from the eccentric direction. 3. A claim 3 in which an annular member having a through hole into which the pump insertion shaft is inserted is arranged below the thrust surface, and the thrust receiving surface is formed on the upper surface side of the annular member. The compressor according to any one of claims 7. The compressor according to claim 8, wherein the annular member is an outer member of the oil pump. The compressor according to claim 8, wherein the annular member is a bottom plate fixed to the lower side of a subframe provided with the auxiliary bearing. Any one of claims 8 to 10, wherein the radial outer side of the thrust receiving surface of the annular member is formed by an inclined surface that inclines downward toward the outside to form the oil reservoir space. The compressor described in the section. The compressor according to any one of claims 8 to 11, wherein the inner peripheral portion of the thrust receiving surface formed by the through hole on the upper surface side of the annular member is a chamfered portion having a radius of curvature Rp0. .. The compressor according to claim 8, wherein the annular member is a product obtained by polishing the surface of a hardened steel strip. The compressor according to any one of claims 3 to 13, wherein a plurality of radial oil grooves are formed on the thrust receiving surface. One of claims 2 to 6, wherein the radial outer side of the thrust surface of the drive shaft is formed by an inclined surface that inclines upward as it goes outward to form the oil reservoir space. The compressor described in. A chamfered portion is formed on the radial outer peripheral portion of the thrust surface of the drive shaft in contact with the thrust receiving surface at the contact point, and the radius of curvature Rs1 of the chamfered portion is in an arc angle range smaller than 90 degrees. The compressor according to any one of claims 1 to 15 formed. The radius of curvature Rs1 of the chamfered portion of the radial outer peripheral portion of the thrust surface is
The compressor according to claim 16, which is larger than the radius of curvature Rp0 on the inner peripheral side of the thrust receiving surface, that is, has a relationship of Rs1> Rp0. The drive shaft
A refueling vertical hole extending in the axial direction of the drive shaft and through which lubricating oil flows,
A thrust lubrication horizontal hole is formed below the thrust surface, which communicates with the lubrication vertical hole and extends in the radial direction of the drive shaft, and supplies the lubricating oil between the thrust surface and the thrust receiving surface. The compressor according to any one of claims 1 to 17. The drive shaft
A radial refueling horizontal hole that communicates with the refueling vertical hole above the thrust surface and extends in the radial direction of the drive shaft to supply the lubricating oil between the radial surface and the radial receiving surface.
An axial oil groove, which is formed on the outer peripheral surface of the drive shaft and extends in the axial direction of the drive shaft, is formed so as to communicate with the radial oil supply lateral hole.
The axial oil groove faces the radial receiving surface, and among the regions facing the radial receiving surface on the outer peripheral surface of the drive shaft, the region above the axial oil groove is the lower region. The compressor according to claim 18, wherein the length of the drive shaft in the axial direction is formed longer than that of the compressor. The compression mechanism located inside the closed container,
The electric motor unit that drives the compression mechanism unit and
A drive shaft that transmits the driving force of the electric motor unit to the compression mechanism unit, and
The main bearing that supports the upper part of the drive shaft and
An auxiliary bearing that supports the lower part of the drive shaft,
A thrust receiving surface that slidably supports the thrust surface of the drive shaft,
It is provided with a radial receiving surface that slidably supports the radial surface of the drive shaft.
The drive shaft
A refueling vertical hole extending in the axial direction of the drive shaft and through which the lubricating oil flows,
A thrust refueling horizontal hole that communicates with the refueling vertical hole below the thrust surface and extends in the radial direction of the drive shaft to supply the lubricating oil between the thrust surface and the thrust receiving surface is formed. Compressor.

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