JP7051005B2 - Compressor - Google Patents

Description

The present invention relates to a compressor used in, for example, a refrigerating device or an air conditioner.

Conventionally, as shown in Patent Document 1, a closed container in which oil is stored at the bottom, an electric motor that generates a rotational force in the closed container, a drive shaft having an oil supply passage inside, and rotation of the drive shaft A compressor having a compression mechanism for compressing a fluid and supplying oil by a differential pressure between the bottom of the closed container and the compression mechanism is known (see, for example, Patent Document 1).

Further, as a compressor using another refueling method, there is a compressor provided with a positive displacement refueling pump at the lower end of the drive shaft (see, for example, Patent Document 2). In Patent Document 2, the refueling pump is driven by the rotation of the drive shaft, and the oil stored in the bottom of the closed container is supplied to the suction side space of the compression mechanism portion via the refueling passage provided in the drive shaft. ing.

Japanese Patent Application Laid-Open No. 2003-227480 Japanese Unexamined Patent Publication No. 2002-98055

Since the compressor described in Patent Document 1 is a differential pressure refueling method in which refueling is performed by the differential pressure between the high pressure in the closed container and the low pressure of the compression mechanism portion, it is difficult to refuel in the operation range of low differential pressure. ..

In the compressor described in Patent Document 2, since refueling is performed by a positive displacement refueling pump, the refueling amount depends on the rotation speed. Therefore, a sufficient amount of refueling can be secured during high-speed operation in which the drive shaft rotates at high speed. Further, during low-speed operation in which the drive shaft rotates at a low speed, the amount of refueling is lower than that during high-speed operation, but during low differential pressure and low-speed operation, the amount of refueling is compared with the amount of refueling at low differential pressure by the differential pressure refueling method. Stable refueling can be performed. However, the amount of refueling during high differential pressure and low speed operation is reduced as compared with the amount of refueling during high differential pressure by the differential pressure refueling method, which may cause poor lubrication of the sliding portion.

The present invention is for solving the above-mentioned problems, and an object of the present invention is to provide a compressor capable of ensuring high differential pressure and refueling amount at low speed operation and improving reliability. do.

The compressor of the present invention is a closed container having an oil storage space for storing oil, a compression mechanism unit that is housed in the closed container and compresses the working gas flowing into the closed container, and a shaft that drives the compression mechanism unit. The oil is supplied from the drive shaft in which the oil supply flow path is formed, the oil supply pump that is driven by the rotation of the drive shaft and supplies the oil accumulated in the oil reservoir space to the oil supply flow path of the drive shaft, and the oil supply flow path. A bearing that supports the rotation of the drive shaft is provided, and the gap between the bearing and the drive shaft is a bearing flow path through which oil flows. A groove for expanding the clearance flow path is provided in the middle, and the clearance flow path portion provided with the groove is set to be smaller than the flow path resistance of the bearing flow path.

In the compressor according to the present invention, the flow path resistance of a part of the clearance flow path in the refueling pump is set to be smaller than the flow path resistance of the bearing flow path. As a result, the pressure difference between the inlet and outlet of the bearing flow path can be secured at the time of high differential pressure, the oil flow in the bearing flow path due to the differential pressure can be formed, and the differential pressure lubrication can be performed. Since differential pressure refueling can be performed by adjusting the flow path resistance in this way, the refueling amount can be secured even during low-speed operation where the amount of refueling from the refueling pump is insufficient and even when the differential pressure is high, and reliability is achieved. The sex can be improved.

It is a vertical cross-sectional schematic diagram which shows the compressor which concerns on Embodiment 1. FIG. It is a vertical cross-sectional schematic diagram which shows an example of the structure of the refueling pump which concerns on Embodiment 1. FIG. It is sectional drawing which shows an example of the refueling pump which concerns on Embodiment 1. FIG. It is a schematic diagram which simplified the oil flow path of the comparative example. It is a schematic diagram which simplified the oil flow path which has the feature of Embodiment 1. FIG. It is a figure which shows the relationship between the lubrication amount and the rotation speed of the compressor which concerns on Embodiment 1. FIG.

Embodiment 1.
FIG. 1 is a schematic vertical sectional view showing a compressor according to the first embodiment. Hereinafter, the configuration of the compressor 100 will be described with reference to FIG. The compressor 100 of FIG. 1 is a so-called vertical scroll compressor, which compresses and discharges a working gas such as a refrigerant. The compressor 100 includes a closed container 1, a compression mechanism unit 2, an electric motor 16, and a drive shaft 19. In FIG. 2, the solid arrow in the closed container 1 indicates the flow of oil, and the white arrow indicates the flow of working gas.

The closed container 1 is formed in a cylindrical shape, for example, and has pressure resistance. A suction pipe 7 for taking the working gas into the closed container 1 is connected to the side surface of the closed container 1, and a discharge pipe 11 for discharging the compressed working gas from the closed container 1 to the outside is connected to the other side surface. It is connected. A check valve 9 and a spring 10 are arranged inside the suction pipe 7. The check valve 9 is urged by the spring 10 in the direction of closing the suction pipe 7 to prevent the backflow of the working gas.

The closed container 1 has a high-pressure gas atmosphere 6 in the closed container 1. The closed container 1 has an oil storage space 5 at the bottom for storing refrigerating machine oil (hereinafter referred to as oil). The oil reservoir space 5 is located in the high-pressure gas atmosphere 6, and is located below the subframe 37 that supports the lower end of the drive shaft 19, below the auxiliary bearing 27, below the lower end of the drive shaft 19, and the like. Is. The compression mechanism unit 2, the electric motor 16, and the drive shaft 19 are housed in the closed container 1.

In the closed container 1, the guide frame 30 is fixed to the closed container 1 at the upper part of the electric motor 16, and the subframe 37 holding the drive shaft 19 is fixed to the closed container 1 at the lower part of the electric motor 16. The compliant frame 31 is housed on the inner peripheral side of the guide frame 30. An upper fitting cylindrical surface 30a is formed on the fixed scroll 4 side of the inner peripheral surface of the guide frame 30. The upper fitting cylindrical surface 30a is engaged with the upper fitting cylindrical surface 35a formed on the outer peripheral surface of the compliant frame 31. A space is formed in a part of the circumferential direction between the upper fitting cylindrical surface 30a and the upper fitting cylindrical surface 35a to form the compliant frame upper space 32a.

On the other hand, a lower fitting cylindrical surface 30b is formed on the motor 16 side of the inner peripheral surface of the guide frame 30, and the lower fitting cylindrical surface 30b is a lower fitting formed on the outer peripheral surface of the compliant frame 31. It is engaged with the combined cylindrical surface 35b. An upper annular seal member 36a and a lower annular seal member 36b are arranged at two locations on the outer peripheral surface of the compliant frame 31. The inner surface of the guide frame 30 and the outer surface of the compliant frame 31 are partitioned by an upper annular seal member 36a and a lower annular seal member 36b.

A compliant frame lower space 32b is provided between the upper annular seal member 36a and the lower annular seal member 36b. The upper annular seal member 36a and the lower annular seal member 36b are arranged at two locations on the outer peripheral surface of the compliant frame 31 in FIG. 1, but the positions of the seal members are not limited to the example of FIG. .. For example, the upper annular seal member 36a and the lower annular seal member 36b may be arranged at two locations on the inner peripheral surface of the guide frame 30.

The compliant frame 31 is formed with a gas introduction flow path 14 that communicates the thrust surface 33 and the compliant frame lower space 32b. The gas introduction flow path 14 is provided in the compliant frame 31 so as to communicate with the extraction hole 3e formed in the base plate 3a of the rocking scroll 3 described later. Further, a flow path 14a is formed between the guide frame 30 and the inner wall of the closed container 1. The flow path 14a is a flow path through which the high-pressure working gas flowing out from the discharge hole 4c formed in the base plate 4a of the fixed scroll 4 described later passes.

An intermediate pressure space 38, which is an intermediate pressure space having a pressure lower than the discharge pressure and a pressure higher than the suction pressure, is formed inside the compliant frame 31. Further, an intermediate pressure adjusting valve space 39d is formed in the compliant frame 31, and an intermediate pressure adjusting valve 39a for adjusting the pressure of the intermediate pressure space 38 and an intermediate pressure adjusting valve are formed in the intermediate pressure adjusting valve space 39d. The presser 39b is arranged. The intermediate pressure adjusting spring 39c is shortened from its natural length and housed in the intermediate pressure adjusting valve space 39d. Further, the compliant frame 31 is formed with a through flow path 39e that communicates the intermediate pressure space 38 and the intermediate pressure adjusting valve space 39d.

Further, the intermediate pressure regulating valve space 39d and the compliant frame upper space 32a communicate with each other. Further, the compliant frame upper space 32a is formed so as to communicate with the inside of the old dam ring 40. Therefore, the intermediate pressure space 38 and the reciprocating sliding surface 41 of the old dam ring 40 communicate with each other via the through flow path 39e, the intermediate pressure adjusting valve space 39d, and the compliant frame upper space 32a.

The compression mechanism unit 2 compresses the low-pressure working gas sucked into the closed container 1 from the suction pipe 7 to a high pressure, and the rocking scroll 3 and the fixed scroll 4 arranged above the rocking scroll 3 And have. The fixed scroll 4 is fixed to a guide frame 30 fixedly supported by the closed container 1 with bolts (not shown) or the like.

The fixed scroll 4 has a base plate 4a and a spiral body 4b formed on one surface of the base plate 4a. The swing scroll 3 has a base plate 3a and a spiral body 3b formed on one surface of the base plate 3a. The fixed scroll 4 and the swing scroll 3 are arranged in the closed container 1 by combining the spiral body 4b and the spiral body 3b so as to face each other. The spiral body 4b and the spiral body 3b are combined in opposite phases, and a compression chamber 12 is formed between the spiral body 4b of the fixed scroll 4 and the spiral body 3b of the swing scroll 3.

A pair of fixed side old dam ring grooves 15a are formed in a straight line on the outer peripheral portion of the fixed scroll 4. In the fixed-side oldham ring groove 15a, two pairs of fixed-side keys 42a of the oldam ring 40 are installed so as to be reciprocally slidable. A discharge hole 4c for discharging the high-pressure working gas compressed by the compression mechanism part 2 is formed in the central portion of the base plate 4a, and a discharge hole 4c for preventing the backflow of the working gas is formed on the discharge hole 4c. The valve 43 is arranged.

In the base plate 3a of the swing scroll 3, a tubular boss portion 3c is formed on the surface side facing the surface on which the spiral body 3b is formed. A swing bearing 26 is provided on the inner surface side of the boss portion 3c. The swing shaft 21 of the drive shaft 19 is inserted into the swing bearing 26, and the swing scroll 3 revolves due to the rotation of the swing shaft 21.

The compliant frame 31 is located below the base plate 3a of the oscillating scroll 3, and the oscillating scroll 3 is supported by the oscillating scroll 3 so as to be able to revolve. An old dam ring 40 oscillatingly supported by the compliant frame 31 is provided between the oscillating scroll 3 and the compliant frame 31 in order to give an oscillating motion while preventing the oscillating scroll 3 from rotating. Has been done. A pair of swing-side oldham ring grooves 15b are formed in a straight line on the outer peripheral portion of the swing scroll 3. The rocking side old dam ring groove 15b has a phase difference of about 90 degrees from the fixed side old dam ring groove 15a, and two pairs of rocking side keys 42b of the old dam ring 40 are installed so as to be reciprocally slidable. ..

In the base plate 3a of the rocking scroll 3, a slidable thrust surface 3d is formed on the outer peripheral portion of the surface on which the boss portion 3c is formed so as to be slidable with the thrust surface 33 of the compliant frame 31. A reciprocating sliding surface 41 is formed on the outer peripheral portion of the thrust surface 33 of the compliant frame 31, and the rocking side key 42b of the old dam ring 40 slides reciprocatingly. Here, the outer peripheral space of the base plate (hereinafter, the suction side space 8) outside the spiral body 4b of the fixed scroll 4 and the spiral body 3b of the swing scroll 3 becomes a low pressure space of the suction gas atmosphere which is the suction pressure. There is.

The electric motor 16 rotates and drives the drive shaft 19, and has an electric motor rotor 16a and an electric motor stator 16b. The rotation speed is variable and a rotational force is generated. The motor rotor 16a is fixed to the drive shaft 19 by shrink fitting or the like, and the motor stator 16b is fixed to the closed container 1 by shrink fitting or the like. A glass terminal (not shown) is connected to the motor stator 16b, and the glass terminal is connected to a lead wire (not shown) for obtaining electric power from the outside. Then, when the electric power is supplied to the motor stator 16b, the drive shaft 19 and the motor rotor 16a rotate with respect to the motor stator 16b. A balance weight 18a and a balance weight 18b are fixed to the motor rotor 16a and the drive shaft 19 in order to balance the entire rotation system in the compressor 100.

The drive shaft 19 can be rotated by the main bearing 25a and the auxiliary bearing 25b provided on the inner peripheral surface of the compliant frame 31 and the auxiliary bearing 27 provided in the subframe 37 fixedly supported by the closed container 1. Is supported by. The main bearing 25a, the auxiliary bearing 25b, and the auxiliary bearing 27 are configured with a bearing structure made of a slide bearing such as a copper-lead alloy, and rotatably support the drive shaft 19. Although FIG. 1 illustrates a case where the main bearing 25a, the auxiliary bearing 25b, and the auxiliary bearing 27 are made of a slide bearing, the drive shaft 19 may be pivotally supported by another known bearing structure.

The drive shaft 19 transmits the rotational force generated by the electric motor 16 to the compression mechanism unit 2. The drive shaft 19 has a spindle 20 joined to the motor rotor 16a and a swing shaft 21 provided above the spindle 20. The central axis of the swing shaft 21 is eccentric from the central axis of the main shaft 20 portion. The swing shaft 21 is engaged with a swing bearing 26 provided on the inner surface side of the boss portion 3c of the swing scroll 3.

An oil supply passage 23, a supply passage 24a, and a supply passage 24b are formed inside the drive shaft 19. The oil supply passage 23 is formed so as to extend axially from the inside of the drive shaft 19 from the lower end portion of the drive shaft 19 toward the upper end portion. The supply path 24a and the supply path 24b are formed so as to extend in the radial direction (X-axis direction) inside the drive shaft 19 and lead to the refueling path 23.

A refueling pump 50 is attached to the lower end of the drive shaft 19. The refueling pump 50 sucks the oil stored in the oil reservoir space 5 of the closed container 1 and supplies it to the refueling passage 23 in the drive shaft 19. The oil supplied to the oil supply passage 23 is supplied to each sliding portion such as the main bearing 25a, the auxiliary bearing 25b, the auxiliary bearing 27, and the swing bearing 26.

The refueling pump 50 is composed of, for example, a rotary positive displacement pump. The refueling pump 50 is operated by the rotation of the drive shaft 19. The refueling pump 50 has a characteristic that the amount of oil supplied to the refueling passage 23 at a higher pressure increases as the rotation speed of the drive shaft 19 increases. The structure of the refueling pump 50 will be described later.

Next, the operation of the compressor 100 will be described with reference to FIG. First, the check valve 9 overcomes the spring force of the spring 10 by the low-pressure (suction pressure) working gas that has flowed into the suction pipe 7, and is pushed down to the valve stop (not shown). After that, the working gas flows into the suction side space 8 in the closed container 1.

On the other hand, the drive shaft 19 rotates by supplying electric power from the inverter device (not shown) to the electric motor 16. The swing shaft 21 rotates due to the rotation of the drive shaft 19, and the swing scroll 3 swings. At this time, the working gas is sucked into the compression chamber 12.

Then, the working gas is boosted from low pressure to high pressure by the geometric volume change of the compression chamber 12, and is discharged from the discharge hole 4c. The working gas discharged from the discharge hole 4c passes through the flow path 14a and is discharged to the outside from the discharge pipe 11 provided on the side surface of the closed container 1 with the inside of the closed container 1 as a high-pressure gas atmosphere 6.

The working gas of the intermediate pressure during compression in the compression mechanism unit 2 is guided from the extraction hole 3e of the base plate 3a to the compliant frame lower space 32b via the gas introduction flow path 14. The intermediate pressure is a pressure equal to or higher than the suction pressure and lower than the discharge pressure. The compliant frame lower space 32b is a space sealed by the upper annular seal member 36a and the lower annular seal member 36b. Therefore, the compliant frame 31 floats in the axial direction due to the working gas of the intermediate pressure introduced in the compliant frame lower space 32b.

The intermediate pressure Pm1 of the intermediate pressure space 38 is "a predetermined pressure α determined by the elastic force of the intermediate pressure adjusting spring 39c and the area exposed to the intermediate pressure of the intermediate pressure adjusting valve 39a" and "the suction side space 8". It is the sum of the pressure Ps and Ps + α. Further, the intermediate pressure Pm2 of the compliant frame lower space 32b is the product of "a predetermined magnification β determined by the position of the communicating compression chamber 12" and "the pressure Ps of the suction side space 8", and is Ps × β. It becomes.

The intermediate pressure Pm1 and the intermediate pressure Pm2 act downward on the compliant frame 31, and the high pressure Pd due to the high pressure gas atmosphere 6 acts upward on the lower end surface 34 of the compliant frame. The upward load acting on the compliant frame 31 due to the pressure Pd is larger than the downward load acting on the compliant frame 31 due to the intermediate pressure Pm1 and the intermediate pressure Pm2. Therefore, the compliant frame 31 floats in the axial direction along the inner peripheral surface of the guide frame 30.

As a result, the swing scroll 3 also floats via the thrust surface 33, so that the gap between the tip of the spiral body of each of the fixed scroll 4 and the swing scroll 3 forming the compression chamber 12 and the base plate becomes small. As a result, the high-pressure working gas is less likely to leak from the compression chamber 12, and a highly efficient compressor can be obtained.

On the other hand, when the pressure inside the compression chamber 12 becomes abnormally high during startup or liquid compression, the gas load in the axial direction acting on the swing scroll 3 becomes excessive. Then, the swing scroll 3 pushes down the compliant frame 31 via the thrust surface 33. That is, a relatively large gap is generated between the tip of each spiral body of the fixed scroll 4 and the swing scroll 3 and the base plate. With this gap, it is possible to suppress an abnormal increase in pressure in the compression chamber 12, and it is possible to obtain a highly reliable compressor without damage to the sliding portion.

Next, the flow of oil will be described with reference to FIGS. 1 to 3.
When the drive shaft 19 rotates with the rotation of the motor rotor 16a, the inside of the closed container 1 is filled with the gas compressed by the compression mechanism unit 2 to create a high-pressure gas atmosphere 6. Since the oil reservoir space 5 exposed to the high-pressure gas atmosphere 6 and the suction side space 8 of the compression mechanism unit 2 are communicated with each other by the oil supply passage 23 of the drive shaft 19, the oil in the oil reservoir space 5 is caused by the differential pressure. It is sucked up. This oil is supplied from the oil supply passage 23, the supply passage 24a and the supply passage 24b to the main bearing 25a, the auxiliary bearing 25b, the auxiliary bearing 27 and the swing bearing 26, respectively. The oil supplied to the auxiliary bearing 27 is returned to the oil reservoir space 5 at the bottom of the closed container 1 after lubricating the auxiliary bearing 27. An annular shape is formed between the main bearing 25a and the main shaft 20, between the auxiliary bearing 25b and the main shaft 20, between the auxiliary bearing 27 and the main shaft 20, and between the swing bearing 26 and the swing shaft 21, respectively. A gap is formed, and this annular gap is a bearing flow path through which oil passes.

The oil that has passed through the oil supply passage 23 and rises and is lubricated to the main bearing 25a is further guided to the intermediate pressure space 38 after lubricating the main bearing 25a. After passing through the main bearing 25a, the oil supplied to the boss portion 3c of the swing scroll 3 lubricates the swing bearing 26, is depressurized in the process, becomes an intermediate pressure, and is eventually guided to the intermediate pressure space 38. The oil guided to the intermediate pressure space 38 overcomes the spring force of the intermediate pressure adjusting spring 39c when passing through the through flow path 39e, pushes up the intermediate pressure adjusting valve 39a, and once discharges to the compliant frame upper space 32a. Will be done. After that, this oil is discharged inside the Oldam ring 40 and supplied to the suction side space 8.

Further, a part of the oil is supplied from the intermediate pressure space 38 to the thrust surface 3d, then supplied to the reciprocating sliding surface 41, and flows into the suction side space 8. The oil that has flowed into the suction side space 8 is sucked into the compression mechanism portion 2 together with the low-pressure working gas. The sucked oil enables normal operation by sealing and lubricating the gaps between the fixed scroll 4 and the swing scroll 3 constituting the compression mechanism unit 2.

As described above, when the refueling pump 50 is a positive displacement refueling pump 50, the amount of oil supplied to the suction side space 8 of the compression mechanism unit 2 and each sliding portion increases during high-speed operation, and oil is supplied during low-speed operation. It has the property that the amount decreases. Therefore, if the rotation speed of the drive shaft 19 is too low, the amount of oil supplied to each sliding portion may be insufficient, which may lead to deterioration of reliability such as deterioration of lubrication state or occurrence of seizure.

Therefore, in the first embodiment, the shortage of refueling at a low rotation speed is improved by devising the flow path resistance of the oil flow path from the refueling port 54b of the refueling pump 50 to the bearing portion. Hereinafter, the structure of the refueling pump 50 will be described first.

FIG. 2 is a schematic vertical sectional view showing an example of the structure of the refueling pump according to the first embodiment. FIG. 3 is a schematic cross-sectional view showing an example of the refueling pump according to the first embodiment. The refueling pump 50 will be described with reference to FIGS. 2 to 3.
The refueling pump 50 is a so-called trochoid pump, and has an outer rotor 51, an inner rotor 52, a housing 53 for accommodating the outer rotor 51 and the inner rotor 52 inside, and a suction pipe 56. The lower end of the suction pipe 56 is immersed in the oil reservoir space 5.

As shown in FIG. 3, the outer rotor 51 is housed in the housing 53 in a state where the center of the outer rotor 51 is eccentric with respect to the center of the drive shaft 19. Further, a plurality of teeth formed by a trochoid curve are formed on the inner peripheral surface of the outer rotor 51.

The inner rotor 52 is housed in the outer rotor 51. A plurality of teeth formed by a trochoid curve are formed on the outer peripheral surface of the inner rotor 52, and the number of teeth of the inner rotor 52 is, for example, one less than the number of teeth of the outer rotor 51. A shaft hole 52a is formed in the center of the inner rotor 52, and the drive shaft 19 is inserted into the shaft hole 52a.

A fluid chamber 57 is partitioned between the outer rotor 51 and the inner rotor 52. The volume of the fluid chamber 57 expands or contracts in accordance with the rotation of the outer rotor 51 and the inner rotor 52. The refueling pump 50 sucks in oil at a rotation angle position where the fluid chamber 57 expands, and discharges oil at an angle position where the fluid chamber 57 contracts.

The housing 53 has a concave box portion 54 having an open upper surface and an upper surface cover 55 covering the upper surface opening of the box portion 54. The housing 53 is attached to the subframe 37 and supports the drive shaft 19 in the axial direction on the upper end surface. An oil supply port 54b for supplying oil into the fluid chamber 57 is formed through the bottom surface portion 54a of the box portion 54. The upper end of the suction pipe 56 is connected to the fuel filler port 54b so that the oil from the suction pipe 56 flows into the housing 53. Further, an arc-shaped oil inflow path 54c communicating with the oil supply port 54b is formed in the bottom surface portion 54a of the box portion 54. Further, in the bottom surface portion 54a of the box portion 54, an oil drain port 54d for discharging oil from the fluid chamber 57, an arc-shaped oil outflow path 54e communicating with the oil drain port 54d, and an oil outflow extending in the radial direction. An oil outflow passage 54f is formed so as to communicate the passage 54f with the oil supply passage 23 of the drive shaft 19.

With the above configuration, when the drive shaft 19 rotates and the inner rotor 52 rotates, the oil in the oil reservoir space 5 due to the volume change of the fluid chamber 57 is discharged into the suction pipe 56 and the oil supply port 54b as shown by the solid line arrow in FIG. And is sucked into the fluid chamber 57 through the oil inflow passage 54c. The oil sucked into the fluid chamber 57 is discharged from the oil drain port 54d to the oil outflow passage 54e, and is supplied to the oil supply passage 23 of the drive shaft 19 through the oil outflow passage 54f. The above is the main flow of the oil flow in the refueling pump 50.

A rotor accommodating space is formed in the housing 53, and the height of the rotor accommodating space is higher than the heights of the outer rotor 51 and the inner rotor 52. Therefore, the rotor accommodating space has a clearance in a state where the outer rotor 51 and the inner rotor 52 are accommodated. In FIG. 2, the portion shown by the dotted line is the clearance, and this clearance portion is also a flow path (hereinafter referred to as a clearance flow path 58), and the clearance flow path 58 is the flow of oil in the oil supply pump 50. Sidestreams other than the mainstream flow.

The refueling pump 50 pumps a sufficient amount of oil from the oil reservoir space 5 during high-speed operation, but the pumping force becomes small and the amount of refueling decreases during low-speed operation. Especially in the operating range of high differential pressure with a high compression load, it is necessary to secure a large amount of lubrication because a large amount of lubrication is required to lubricate the sliding parts. I am concerned.

Therefore, in the first embodiment, differential pressure refueling is performed by adjusting the flow path resistance to secure a high differential pressure and a refueling amount during low-speed operation. As the adjustment of the flow path resistance, the flow path resistance of a part of the clearance flow path 58 is set to be smaller than the flow path resistance of the bearing flow path. As a specific structure for setting the flow path resistance of a part of the clearance flow path 58 to be smaller than the flow path resistance of the bearing flow path, in the first embodiment, the clearance flow path 58 is inserted in the middle of the clearance flow path 58. A groove 59 is provided to expand the flow path of the above.

In FIGS. 2 and 3, the groove 59 shows an example of being formed on the inner peripheral surface of the shaft hole 52a formed in the inner rotor 52, but the formation position of the groove 59 is not limited to this position, and the shaft hole is not limited to this position. It may be formed on the outer peripheral surface of the drive shaft 19 facing the inner peripheral surface of 52a. As another example, the groove 59 has a first end surface 51a in the axial direction of the outer rotor 51, a surface 53g of the housing 53 facing the first end surface 51a in the axial direction, and a second end surface in the axial direction of the inner rotor 52. It may be formed on either end surface 52b or the surface 53g of the housing 53 facing the second end surface 52b in the axial direction. The groove 59 may be provided so as to expand the flow path of the clearance flow path 58.

In this way, by setting the flow path resistance of a part of the clearance flow path 58 to be smaller than the flow path resistance of the bearing flow path 22, it is possible to secure a high differential pressure and a refueling amount during low-speed operation. This point will be described below with reference to a simplified schematic diagram of the structure of the characteristic portion of the first embodiment.

FIG. 4 is a schematic diagram of a simplified oil flow path of the comparative example, and is an explanatory diagram of the relationship between the flow path resistance and the pressure difference. FIG. 5 is a simplified schematic diagram of the oil flow path having the characteristics of the first embodiment, and is an explanatory view of the relationship between the flow path resistance and the pressure difference.
The oil flow path 101a and the oil flow path 101b have a clearance flow path 58, an oil supply passage 23, and a bearing flow path 22, and the inlet side has a high pressure and the outlet side has an intermediate pressure. The bearing flow path 22 will be described later. The flow path resistance of the clearance flow path 58 is R1, the flow path resistance of the oil supply passage 23 is R2, and the flow path resistance of the bearing flow path 22 is R3, and there is a relationship of R1>R3> R2.

The oil flow path 101b of FIG. 5 has a portion of R4 in which the clearance flow path 58 is expanded and the flow path resistance is smaller than that of R1 in the middle of the clearance flow path 58. The flow path resistance R4 is a flow path resistance that is a part of the clearance flow path 58. The portion of the flow path resistance R4 corresponds to the clearance flow path portion in which the groove 59 is formed. The flow path resistance R4 has a relationship of R4 <R3.

In the oil flow path 101a of the comparative example of FIG. 4, since the resistance R1 of the clearance flow path 58 is larger than the resistance R3 of the bearing flow path 22, it is difficult for oil to flow into the clearance flow path 58. In the bearing flow path 22, the inlet side communicating with the oil supply passage 23 has a high pressure, the outlet side has an intermediate pressure, and there is a pressure difference, and the flow path resistance is smaller than that of the clearance flow path 58, so that the oil flowing through the bearing flow path 22 The amount is larger than the amount of oil flowing through the clearance flow path 58. Therefore, the pressure of the oil supply passage 23 located between the clearance flow path 58 and the bearing flow path 22 gradually decreases from the high pressure to the same intermediate pressure as the outlet of the bearing flow path 22, and finally the clearance flow path 58 of the clearance flow path 58. The pressure also drops to the intermediate pressure. As a result, there is no pressure difference at the inlet / outlet of the oil flow path 101a, and differential pressure lubrication is not performed.

From another point of view, the amount of refueling by differential pressure refueling is determined by the differential pressure at the inlet and outlet of the flow path having the highest flow path resistance, and the differential pressure refueling is performed by the differential pressure. In the oil flow path 101a of the comparative example of FIG. 4, the flow path having the highest flow path resistance is the clearance flow path 58, but since the inside of the oil flow path 101a is filled with high-pressure oil, the clearance flow path 58 Both entrances and exits are high pressure, no pressure difference occurs, and differential pressure lubrication is not performed.

On the other hand, the oil flow path 101b of the first embodiment of FIG. 5 has a flow path resistance R4 having a flow path resistance smaller than that of the bearing flow path 22 in the middle of the clearance flow path 58. The flow path resistance of a part of the clearance flow path 58 is set to be smaller than the flow path resistance of the bearing flow path 22. By adjusting the flow path resistance in this way, the pressure difference between the inlet and outlet of the bearing flow path 22 is maintained at the time of high differential pressure, and this pressure difference forms an oil flow from the high pressure side to the intermediate pressure side in the bearing flow path 22. Will be done. By forming the oil flow due to the differential pressure in the bearing flow path 22, the oil flow is also formed in the oil supply passage 23 and the clearance flow path 58 communicating with the bearing flow path 22. As described above, in the oil flow path 101b of the first embodiment of FIG. 5, the oil flowing into the clearance flow path 58 due to the pressure difference between the inlet and outlet of the bearing flow path 22 passes through the oil supply passage 23 and then the bearing flow. Differential pressure refueling, which is supplied to the road 22, is performed.

Here, in the bearing flow path 22, among the annular gaps between each bearing and the drive shaft 19, "an annular gap between the main bearing 25a and the drive shaft 19" and "between the swing bearing 26 and the drive shaft 19". The "annular gap" corresponds to, and the "annular gap between the auxiliary bearing 25b and the drive shaft 19" and the "annular gap between the auxiliary bearing 27 and the drive shaft 19" do not correspond. The "annular gap between the auxiliary bearing 25b and the drive shaft 19" and the "annular gap between the auxiliary bearing 27 and the drive shaft 19" are due to the high pressure at both the oil inlet and outlet. Therefore, a part of the flow path resistance of the clearance flow path 58 is the respective flow of the "annular gap between the main bearing 25a and the drive shaft 19" and the "annular gap between the swing bearing 26 and the drive shaft 19". It is set smaller than the road resistance.

FIG. 6 is a diagram showing the relationship between the refueling amount and the rotation speed of the compressor according to the first embodiment. In FIG. 6, the solid line shows the first embodiment. For comparison, FIG. 6 shows the relationship between the amount of refueling in the conventional differential pressure refueling and the rotation speed N for each of the cases of high differential pressure and low differential pressure, and in the conventional positive displacement pump refueling. It shows the relationship between the amount of refueling and the number of revolutions.

In the case of conventional differential pressure refueling, the refueling amount is A1 at high differential pressure and sufficient refueling can be performed, but at low differential pressure, the refueling amount A2 is smaller than the refueling amount A1, and the refueling amount is unsatisfactory. Will be enough.

In the case of conventional positive displacement pump refueling, the refueling amount is determined by the rotation speed of the drive shaft 19. Therefore, as the rotation speed N increases, the amount of refueling also increases, and during high-speed operation, the amount of refueling becomes A1 or more, and sufficient refueling can be performed. However, at low speed operation, the amount of refueling is less than the amount of refueling A1, which is insufficient.

In the case of the first embodiment, since the refueling pump 50 is provided, the refueling amount increases to the right as in the conventional positive displacement pump refueling during high-speed operation, and a sufficient refueling amount can be secured. During low-speed operation, the amount of refueling is lower than that during high-speed operation, but the amount of refueling by pump refueling can be obtained, and the amount of refueling by differential pressure refueling by adjusting the flow path resistance described above can be obtained. Therefore, as shown by the arrow in FIG. 6, the refueling amount increases in the low speed operation as compared with the case of the conventional positive displacement pump refueling alone, and the refueling amount A1 at the time of high differential pressure can be secured. As described above, in the first embodiment, it has the characteristics of both pump lubrication and differential pressure lubrication, and it is possible to secure the lubrication amount at the time of high differential pressure and low speed operation. As a result, it is possible to suppress poor lubrication of the sliding portion during high differential pressure and low speed operation, and it is possible to improve reliability.

As described above, the compressor 100 of the first embodiment has a high-pressure gas atmosphere inside due to the compression mechanism unit 2 that compresses the working gas from low pressure to high pressure and the working gas compressed by the compression mechanism unit 2. Both have a closed container 1 having an oil reservoir space 5 for storing oil, and a drive shaft 19 which is a shaft for driving the compression mechanism portion 2 and in which an oil supply flow path is formed. The compressor 100 is further driven by the rotation of the drive shaft 19 to supply the oil accumulated in the oil reservoir space 5 to the oil supply flow path of the drive shaft 19, and the oil is supplied from the oil supply flow path to the drive shaft. It is provided with a bearing that supports 19 rotations. The gap between the bearing and the drive shaft 19 is a bearing flow path 22 through which oil flows, and a part of the flow path resistance of the clearance flow path 58 in the oil flow path in the oil supply pump 50 causes the bearing. It is set to be smaller than the flow path resistance of the flow path 22.

As a result, the pressure difference between the inlet and outlet of the bearing flow path 22 is maintained at the time of high differential pressure, and the oil flow due to the differential pressure is formed in the bearing flow path 22, so that the oil also flows in the oil supply passage 23 and the clearance flow path 58. Flow is formed and differential pressure refueling is performed. By this differential pressure refueling, it is possible to secure the refueling amount at the time of high differential pressure and low speed operation. As a result, it is possible to suppress poor lubrication of the sliding portion during high differential pressure and low speed operation and improve reliability.

In the first embodiment, a groove 59 for expanding the clearance flow path 58 is provided in the middle of the clearance flow path 58, and the clearance flow path 58 portion provided with the groove 59 is the flow path of the bearing flow path 22. This is the part where the flow path resistance is smaller than the resistance.

In this way, by simply providing the groove 59 in the clearance flow path 58, the flow path resistance of a part of the clearance flow path 58 can be set to be smaller than the flow path resistance of the bearing flow path 22.

In the first embodiment, the refueling pump 50 is a trochoid pump including an outer rotor 51 and an inner rotor 52. The inner rotor 52 is formed with a shaft hole 52a into which the drive shaft 19 is inserted, and a groove 59 is formed on the inner peripheral surface of the shaft hole 52a or the outer peripheral surface of the drive shaft 19 facing the inner peripheral surface. There is.

In this way, the formation position of the groove 59 can be set on the inner peripheral surface of the shaft hole 52a or the outer peripheral surface of the drive shaft 19 facing the inner peripheral surface.

In the first embodiment, the refueling pump 50 is a trochoid pump including an outer rotor 51, an inner rotor 52, and a housing 53 for accommodating the outer rotor 51 and the inner rotor 52. The first end surface 51a in the axial direction of the outer rotor 51, the surface of the housing 53 facing the first end surface 51a in the axial direction, the second end surface 52b in the axial direction of the inner rotor 52, and the second end surface 52b. A groove 59 is formed on one of the surfaces of the housing 53 facing in the axial direction.

In this way, the groove 59 is formed at the first end surface 51a in the axial direction of the outer rotor 51, the surface of the housing 53 facing the first end surface 51a in the axial direction, and the axial first end surface of the inner rotor 52. It can be either the two end surfaces 52b or the surface of the housing 53 that faces the second end surface 52b in the axial direction.

1 Sealed container, 2 Compression mechanism, 3 Swing scroll, 3a bearing, 3b spiral, 3c boss, 3d thrust surface, 3e air extraction hole, 4 fixed scroll, 4a bearing, 4b spiral, 4c discharge hole, 5 Oil reservoir space, 6 High pressure gas atmosphere, 7 Suction pipe, 8 Suction side space, 9 Check valve, 10 Spring, 11 Discharge pipe, 12 Compression chamber, 14 Gas introduction flow path, 14a flow path, 15a Fixed side old dam ring Groove, 15b Swing side Oldam ring groove, 16 motor, 16a motor rotor, 16b motor stator, 18a balance weight, 18b balance weight, 19 drive shaft, 20 spindle, 21 swing shaft, 22 bearing flow path, 23 refueling Road, 24a supply path, 24b supply path, 25a main bearing, 25b auxiliary bearing, 26 swing bearing, 27 auxiliary bearing, 30 guide frame, 30a upper fitting cylindrical surface, 30b lower fitting cylindrical surface, 31 compliant frame, 32a compliant frame upper space, 32b compliant frame lower space, 33 thrust surface, 34 compliant frame lower end surface, 35a upper fitting cylindrical surface, 35b lower fitting cylindrical surface, 36a upper annular sealing member, 36b lower annular sealing member. Seal member, 37 subframe, 38 intermediate pressure space, 39a intermediate pressure adjustment valve, 39c intermediate pressure adjustment spring, 39d intermediate pressure adjustment valve space, 39e through flow path, 40 old dam ring, 41 reciprocating sliding surface, 42a fixed side key , 42b rocking side key, 43 discharge valve, 50 refueling pump, 51 outer rotor, 51a first end face, 52 inner rotor, 52a shaft hole, 52b second end face, 53 housing, 53g surface, 54 box part, 54a Bottom, 54b refueling port, 54c oil inflow port, 54d oil drain port, 54e oil outflow path, 54f oil outflow path, 55 top cover, 56 suction pipe, 57 fluid chamber, 58 clearance flow path, 59 groove, 100 compressor , 101a oil flow path, 101b oil flow path.

Claims (3)

A closed container with an oil storage space for storing oil,
A compression mechanism unit that is housed in the closed container and compresses the working gas that flows into the closed container.
A shaft that drives the compression mechanism, and a drive shaft on which a refueling flow path is formed,
A refueling pump that is driven by the rotation of the drive shaft and supplies the oil accumulated in the oil reservoir space to the refueling flow path of the drive shaft.
It is provided with a bearing that is supplied with oil from the oil supply flow path and supports the rotation of the drive shaft.
The gap between the bearing and the drive shaft is a bearing flow path through which the oil flows, and the clearance flow path is provided in the middle of the clearance flow path in the oil flow path in the oil supply pump. A compressor in which an expanding groove is provided, and the clearance flow path portion provided with the groove is set to be smaller than the flow path resistance of the bearing flow path. The refueling pump is a trochoid pump including an outer rotor and an inner rotor.
The inner rotor is formed with a shaft hole into which the drive shaft is inserted.
The compressor according to claim 1 , wherein the groove is formed on the inner peripheral surface of the shaft hole or the outer peripheral surface of the drive shaft facing the inner peripheral surface. The refueling pump is a trochoid pump including an outer rotor, an inner rotor, and a housing for accommodating the outer rotor and the inner rotor.
The groove has a first end surface in the axial direction of the outer rotor, a surface of the housing facing the first end surface in the axial direction, a second end surface in the axial direction of the inner rotor, and the first end surface. 2. The compressor according to claim 1 , which is formed on either end surface or the surface of the housing facing the axial direction.

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