Compressor and method for manufacturing compressor

Abstract

To provide a compressor capable of reducing a thrust load generated due to a dead weight of a rotational shaft, and a method for manufacturing a compressor.SOLUTION: A compressor comprises a rotational shaft 30 that drives a compression mechanism 20 by rotating around a central axis X extending in a vertical direction, and an oil supply pump 60 that is provided below the rotational shaft 30 and discharges lubricant toward a lower end of the rotational shaft 30. The rotational shaft 30 has lubricant flow paths 42, 44a, 51a that guide the lubricant discharged from the oil supply pump 60 from the lower end to the upper side. The lubricant flow paths 42, 44a, 51a are provided with at least one orifice restriction 51b that imparts pressure loss to the circulating lubricant.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a compressor and a method for manufacturing a compressor. [Background technology]

[0002] For example, Patent Document 1 describes a method in which an oil supply pump is driven by a rotating shaft that rotates a compression mechanism, and lubricating oil discharged from the oil supply pump is supplied to a bearing that supports the rotating shaft through an oil flow passage formed inside the rotating shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-7382 A Summary of the Invention [Problem to be solved by the invention]

[0004] In such a compressor, if an excessive thrust load is generated due to the weight of the rotating shaft, there is a concern that the efficiency of the compressor itself will decrease due to friction loss occurring between the end face of the rotating shaft and the sliding surface of the thrust bearing, and that long-term reliability will decrease due to excessive wear occurring on the end face of the rotating shaft and / or the sliding surface of the thrust bearing. Furthermore, if the degree of wear is severe, there is a concern that operation will be stopped due to seizure of the end face of the rotating shaft and / or the sliding surface of the thrust bearing.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a compressor and a method for manufacturing a compressor that can reduce the thrust load generated by the weight of the rotating shaft. [Means for solving the problem]

[0006] In order to solve the above problems, the compressor and the manufacturing method of the compressor according to the present disclosure employ the following measures. A compressor according to one embodiment of the present disclosure includes a rotating shaft that drives a compression mechanism by rotating about a central axis that extends in a vertical direction, and an oil feed pump that is provided below the rotating shaft and discharges lubricating oil toward a lower end of the rotating shaft, the rotating shaft having a lubricating oil flow passage that guides the lubricating oil discharged from the oil feed pump from the lower end upward, and the lubricating oil flow passage is provided with at least one restriction that imparts a pressure loss to the circulating lubricating oil.

[0007] A method for manufacturing a compressor according to one embodiment of the present disclosure is a method for manufacturing a compressor, the compressor comprising: a rotating shaft that drives a compression mechanism by rotating about a central axis extending in a vertical direction; and an oil feed pump provided below the rotating shaft and discharging lubricating oil toward a lower end of the rotating shaft, the rotating shaft having a lubricating oil flow passage that guides the lubricating oil discharged from the oil feed pump from the lower end upward, the lubricating oil flow passage having at least one throttle that imparts a pressure loss to the circulating lubricating oil, and the magnitude of the upward force acting on the rotating shaft during operation of the compressor is adjusted by adjusting the opening area of ​​the throttle. Effect of the Invention

[0008] According to the present disclosure, it is possible to reduce the thrust load generated by the weight of the rotating shaft. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a partial longitudinal cross-sectional view of a compressor according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an enlarged view of the vicinity of the fuel pump and the lower part of the rotating shaft. [Diagram 3] FIG. 3 is a diagram in which the fuel pump is omitted from FIG. 2. [Figure 4] FIG. 11 is a vertical sectional view of a bearing according to a modified example. [Diagram 5] FIG. 11 is a partial vertical cross-sectional view of a compressor according to a modified example. [Figure 6] 4 is a graph showing the relationship between the flow rate of lubricating oil, the discharge pressure of an oil supply pump, and the rotation speed of a rotating shaft. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a compressor according to an embodiment of the present disclosure will be described with reference to the drawings.

[0011] [Compressor Overview] 1, the compressor 1 is a device used in an air conditioner to compress a refrigerant that is a gas such as carbon dioxide (hereinafter also referred to as a "CO2 refrigerant"). Note that the type of refrigerant is not limited to this. The compressor 1 includes a housing 10, a rotary compression mechanism 20 (hereinafter referred to as the "compression mechanism 20") provided inside the housing 10, a rotating shaft 30 that transmits driving force from a drive unit (not shown) to the compression mechanism 20, and an oil supply pump 60 provided below the rotating shaft 30.

[0012] The housing 10 has a cylindrical main housing 11 that extends in the vertical direction, a lower housing 12 that closes the opening at the lower end of the main housing 11, and an upper housing (not shown) that closes the opening at the upper end of the main housing 11. The lower housing 12 has legs 12 a that are placed on an installation surface, and is attached to the main housing 11 with bolts 14 . An enclosed space is formed inside the housing 10 defined by the main housing 11, the lower housing 12 and the upper housing.

[0013] The rotating shaft 30 extends vertically along the central axis X inside the housing 10 . The rotating shaft 30 is a member for transmitting the driving force from the driving portion to the compression mechanism 20 . The outer peripheral surface of the upper part of the rotating shaft 30 is supported in the radial direction by a bearing (not shown). The outer peripheral surface of the lower part of the rotating shaft 30 is supported in the radial direction by a radial bearing 70. The lower end surface of the rotating shaft 30 is supported in the thrust direction by a thrust plate 62 (i.e., the thrust plate 62 functions as a thrust bearing). Note that the compressor 1 may be provided with bearings other than these to support the rotating shaft 30. The rotating shaft 30 has a main shaft 40 and a pump shaft 50 attached to the lower part of the main shaft 40 . The rotating shaft 30 defines lubricating oil passages 42, 44a, 51a, and is configured to supply lubricating oil discharged from an oil supply pump 60 to the compression mechanism 20, the radial bearing 70, etc. through the lubricating oil passages 42, 44a, 51a.

[0014] The detailed configuration of the oil supply pump 60, as well as the detailed configurations of the rotating shaft 30 and the lubricating oil passages 42, 44a, and 51a will be described later.

[0015] The drive unit that drives the rotary shaft 30 is, for example, an electric motor, which is disposed above the compression mechanism 20 and around the rotary shaft 30 and rotates the rotary shaft 30 about the central axis X. The electric motor has a rotor fixed to the outer peripheral surface of the rotating shaft 30, and a stator that faces the rotor in the radial direction with a gap between the rotor's outer peripheral surface and is fixed to the inner wall of the main housing 11 of the housing 10 by shrink fitting or the like.

[0016] The compression mechanism 20 is provided inside the housing 10 . The compression mechanism 20 includes a rotor 21 fixed to an eccentric portion 41 of the rotary shaft 30, and a cylindrical cylinder 22. The eccentric portion 41 is a portion formed on the main shaft 40 of the rotating shaft 30, and is eccentric with respect to the central axis X which is the rotation axis of the rotating shaft 30.

[0017] The rotor 21 is an annular member, and is inserted into and fixed to the eccentric portion 41 . The rotor 21 is housed in an inner region (region surrounded by an inner circumferential surface) of the cylinder 22, and defines a compression chamber C1 together with the cylinder 22. A refrigerant is supplied from outside the cylinder 22 to this compression chamber C1.

[0018] The compressor 1 may include a compression mechanism other than the compression mechanism 20. For example, a scroll compression mechanism driven by the rotary shaft 30 may be provided above the compression mechanism 20. In this case, the compressor 1 becomes a two-stage compressor in which the compression mechanism 20 (rotary compression mechanism 20) serves as a low-pressure compression mechanism and the scroll compression mechanism serves as a high-pressure compression mechanism.

[0019] [About the fuel pump] As shown in FIG. 2, an oil supply pump 60 is provided below the rotating shaft 30 and the radial bearing 70. The oil supply pump 60 is attached to, for example, a radial bearing 70 and the cylinder 22 by bolts (not shown). The oil supply pump 60 is configured to suck in the lubricating oil from the oil reservoir 13 located at the bottom of the housing 10 and discharge the lubricating oil toward the bottom end surface of the rotating shaft 30 .

[0020] The oil supply pump 60 is, for example, a rotary displacement pump. In this embodiment, the oil supply pump 60 is a trochoid pump, and has a pump case 61 , a thrust plate 62 , an outer rotor 63 and an inner rotor 64 .

[0021] The pump case 61 is an inverted hat-shaped disk-shaped member centered on the central axis X. A generally U-shaped recess 61a extending downward from the upper surface is provided in the central region of the pump case 61, and a thrust plate 62 is attached to the upper surface of the pump case 61 so as to close the recess 61a. An outer rotor 63 and an inner rotor 64 are housed in the space defined by the pump case 61 and the thrust plate 62. The outer rotor 63 is fixed to the pump case 61. Meanwhile, a part of the tip portion 52 of the pump shaft 50 of the rotating shaft 30 (a part penetrating the thrust plate 62) is inserted into the inner rotor 64 along the central axis X. An intake port 61b is formed in the lower part of the pump case 61. The intake port 61b communicates the oil storage section 13 located below the pump case 61 with a space in which the outer rotor 63 and the inner rotor 64 are housed. An exhaust port 62a is formed in the thrust plate 62. The exhaust port 62a communicates with a space in which the outer rotor 63 and the inner rotor 64 are housed and a space in which the lower end of the rotating shaft 30 (main shaft 40) is disposed (a space surrounded by a sliding surface 71 of the radial bearing 70).

[0022] In the oil supply pump 60 configured as above, the inner rotor 64 is driven by the rotation of the rotary shaft 30 (pump shaft 50) caused by the operation of the compressor 1. As a result, the lubricating oil in the oil storage section 13 is sucked in through the intake port 61b, and pressure is applied to the lubricating oil by the outer rotor 63 and the inner rotor 64, and the pressurized lubricating oil is discharged from the exhaust port 62a toward the lower end surface of the rotating shaft 30.

[0023] [Rotating shaft and lubricating oil flow path] First, the configurations of the rotating shaft 30 and the lubricating oil passages 42, 44a, and 51a will be described. As shown in FIGS. 1 and 2, the rotating shaft 30 has a main shaft 40 and a pump shaft 50.

[0024] The main shaft 40 extends vertically along the central axis X, and has a main shaft passage 42 (lubricant passage), a fitting hole 43, and a pocket 44 formed internally and vertically connected to each other. The main shaft passage 42 is a space (passage) extending vertically along the central axis X. The fitting hole 43 is a space whose inner diameter is larger than the inner diameter of the main shaft passage 42, and its upper end communicates with the lower end of the main shaft passage 42. A main body 51 of a pump shaft 50 is fitted into the fitting hole 43 and fixed thereto. The pocket 44 is a space whose inner diameter is larger than the inner diameter of the fitting hole 43 and the outer diameter of the pump shaft 50, and its upper end communicates with the lower end of the fitting hole 43 and its lower end is open toward the thrust plate 62. The inner region of the pocket 44 (the region surrounded by the inner circumferential surface) accommodates part of the body portion 51 and part of the tip portion 52 of the pump shaft 50. The inner region of the pocket 44 is defined as a pocket flow path 44a (lubricating oil flow path).

[0025] The pump shaft 50 extends vertically along a central axis X, and has a main body portion 51 and a tip portion 52 connected to the lower end of the main body portion 51. The main body 51 is a cylindrical part fitted into the fitting hole 43 of the main shaft 40, has a constant outer diameter, and has a pump shaft flow path 51a (lubricating oil flow path) therein and at least one (two in Figures 1 and 2) orifice restrictor 51b (restriction) on the peripheral wall. The tip portion 52 is a solid portion that penetrates the thrust plate 62 and is inserted into the inner rotor 64 of the oil supply pump 60 , and has an outer diameter smaller than that of the main body portion 51 . The pump shaft passage 51a is a space (passage) extending vertically along the central axis X, and has an upper end communicating with a lower end of a main shaft passage formed in the main shaft . The orifice restrictor 51b is a restrictor hole that extends along a direction substantially perpendicular to the central axis X and penetrates the peripheral wall of the main body 51, and connects the pump shaft passage 51a to the pocket passage 44a formed in the main shaft 40.

[0026] To summarize the above, a lubricating oil passage is formed in the rotating shaft 30 to guide the lubricating oil discharged from the oil supply pump 60 from the lower end upward, and the lubricating oil passage has the pocket passages 44a, the pump shaft passage 51a and the main shaft passage 42, and the orifice restriction 51b is provided in the lubricating oil passage.

[0027] Next, the flow of lubricating oil will be explained (see the arrows in Figure 2 for the flow of lubricating oil). As described above, when the oil supply pump 60 is driven, the lubricating oil drawn up from the oil reservoir 13 is discharged toward the lower end surface of the rotating shaft 30 . The discharged lubricating oil flows into the pocket flow passages 44 a on the outer side of the pump shaft 50 and into the gap between the lower end face of the main shaft 40 and the thrust plate 62 .

[0028] The lubricating oil that has flowed into the pocket flow passage 44a flows into the pump shaft flow passage 51a via the orifice throttle 51b. At this time, a pressure loss occurs (is given) in the lubricating oil flowing through the orifice throttle 51b. The lubricating oil that has flowed into the pump shaft passage 51a flows into the main shaft passage .

[0029] On the other hand, the lubricating oil that has flowed into the gap between the lower end surface of the main shaft 40 and the thrust plate 62 applies an upward force to the rotating shaft 30 . Here, the lower end surface of the main shaft 40 refers to the surface of the main shaft 40 that faces the thrust plate 62 and is formed in an annular shape around the pocket 44 .

[0030] The lubricating oil is supplied to the compression mechanism 20 and the radial bearing 70 while flowing through the lubricating oil flow path. Specific examples include the following: That is, as shown in FIG. 1, lubricating oil is supplied from the pump shaft flow passage 51a to the radial bearing 70 via an oil supply port 51c formed in the peripheral wall of the main body 51 of the pump shaft 50 and an oil supply passage 45 formed in the main shaft 40 at a position corresponding to the oil supply port 51c. Furthermore, the lubricating oil is supplied from the main shaft passage 42 to the compression mechanism 20 via an oil supply passage 46 formed in the main shaft 40 at a position corresponding to the eccentric portion 41 .

[0031] The lubricating oil discharged from the oil supply pump 60 is not only used to lubricate the compression mechanism 20 and the radial bearing 70 , but also applies an upward force to the rotating shaft 30 . This reduces the thrust load generated by the weight of the rotating shaft 30, and in some cases, the rotating shaft 30 can be lifted.

[0032] The upward force acting on the rotating shaft 30 can be adjusted by the magnitude of the pressure loss imparted to the lubricating oil by the orifice restriction 51b. In other words, by setting the opening area of ​​the orifice restriction 51b to a desired value when manufacturing the compressor 1, a desired pressure loss can be imparted to the lubricating oil, and thus the magnitude of the upward force acting on the rotating shaft 30 can be set when manufacturing the compressor 1. When there are multiple orifice throttles 51b, the total opening area of ​​these throttle throttles 51b is set.

[0033] Here, the inventors have found that the rotating shaft 30 can be levitated by setting the opening area A as shown in formula (1).

number

[0034] Where: r o : Outer diameter (mm) of the lower end surface of the main shaft 40 formed in an annular shape around the pocket 44 r i : Inner diameter (mm) of the lower end surface of the main shaft 40 formed in an annular shape around the pocket 44 ρ: Density of lubricant (g / cm^3) Q: Flow rate of lubricating oil passing through the orifice 51b (m^3 / s) F s : Load on rotating shaft 30 (N) c: Flow coefficient (0.25~0.8) It is. In addition, r o and r i See Figure 3 for more information.

[0035] Conversely, by setting the opening area A to a value equal to or greater than the right-hand side of formula (1), it is possible to prevent the rotation shaft 30 from being levitated. Needless to say, even if the rotating shaft 30 does not float, an upward force is acting on the rotating shaft 30.

[0036] According to this embodiment, the following effects are obtained. The lubricating oil discharged from the oil supply pump 60 can apply an upward force to the rotating shaft 30 . This reduces the thrust load generated by the weight of the rotating shaft 30, and in some cases, the rotating shaft 30 can be lifted.

[0037] In addition, since the lubricating oil passage is provided with at least one orifice restrictor 51b that imparts pressure loss to the flowing lubricating oil, by adjusting the pressure loss caused by the restrictor, it is possible to adjust in advance the discharge pressure of the lubricating oil that will be applied to the lower end surface of the rotating shaft 30. In other words, by adjusting the pressure loss caused by the restrictor, it is possible to adjust the magnitude of the upward force acting on the rotating shaft 30. This makes it possible to set, for example, whether or not an upward force strong enough to lift the rotating shaft 30 is applied to the rotating shaft 30, i.e., whether or not the rotating shaft 30 is lifted during operation of the compressor 1. This makes it possible to ensure the reliability of the rotating shaft and reduce sliding loss.

[0038] Furthermore, since the oil supply pump 60 is a rotary displacement pump that is driven by the rotary shaft 30, there is no need to provide a separate drive source for the oil supply pump 60.

[0039] [Variations] As shown in FIGS. 4 and 5, a spiral groove 72 may be provided on a sliding surface 71 of a radial bearing 70 that faces the outer circumferential surface of the rotating shaft 30 (main shaft 40). The spiral groove 72 is a spiral groove formed from the lower end to the upper end of the radial bearing 70 and revolving around the central axis X.

[0040] Between the outer circumferential surface of the rotating shaft 30 (main shaft 40) and the spiral groove 72, a gap is defined as a flow path. However, the lubricating oil does not always flow through this flow path (hereinafter referred to as the "discharge flow path"). For example, when the lower end of the spiral groove 72 is located above the lower end surface of the rotating shaft 30 (spindle 40), the lower end of the spiral groove 72 is blocked by the rotating shaft 30 unless the lower end surface of the spindle 40 moves above the lower end of the spiral groove 72 as a result of the rotating shaft 30 floating up. On the other hand, when the lower end surface of the spindle 40 moves above the lower end of the spiral groove 72 as a result of the rotating shaft 30 floating up, the lower end of the spiral groove 72 is exposed in the region between the lower end surface of the spindle 40 and the thrust plate 62, and the lubricating oil that has entered this region flows into the discharge flow path (see the arrows in Figures 4 and 5 for the flow of the lubricating oil).

[0041] In summary, the discharge passage opens when the rotating shaft 30 floats by a predetermined amount or more, and discharges the lubricating oil from the region between the lower end surface of the main shaft 40 and the thrust plate 62 to outside the region. The outside of the region is, for example, the portion between the upper end surface of the radial bearing 70 and the rotor 21 of the compression mechanism 20.

[0042] The amount of levitation of the rotating shaft 30 required to open the discharge flow path can be adjusted by the position of the bottom end of the spiral groove 72. Specifically, the higher the bottom end of the spiral groove 72 is located, the greater the amount of levitation required of the rotating shaft 30, and vice versa. The final floating amount of the rotating shaft 30 is determined by the balance between the pressure loss due to the orifice restrictor 51b, the pressure loss due to the lubricating oil flowing into the discharge passage, and the weight of the rotating shaft 30 itself. Furthermore, the groove that defines the discharge flow passage between the outer circumferential surface of the rotating shaft 30 (main shaft 40) and the groove does not have to be spiral. The grooves may also be formed in the main shaft 40 .

[0043] This modified example provides the following advantages. When the rotating shaft 30 moves upward, i.e., when the rotating shaft 30 floats, a portion of the lubricating oil is discharged from the area between the lower end surface of the main shaft 40 and the thrust plate 62 through the discharge passage, and the discharge pressure of the lubricating oil applied to the lower end of the rotating shaft 30 is reduced. Therefore, the upward force acting on the rotating shaft 30 is automatically alleviated, and the rotating shaft 30 can be prevented from floating up too far.

[0044] FIG. 6 shows a comparison between a graph showing the relationship between the lubricating oil flow rate Q1, the flow rate Q2, the discharge pressure of the oil supply pump 60, and the rotation speed of the rotating shaft 30 when the lubricating oil is discharged through the discharge passage, and a graph showing the relationship between the lubricating oil flow rate Q1, the discharge pressure of the oil supply pump 60, and the rotation speed of the rotating shaft 30 when the lubricating oil is not discharged through the discharge passage. Here, the flow rate Q1 is the flow rate of the lubricant flowing through the lubricant flow passage. The flow rate Q2 is the flow rate of the lubricant flowing through the discharge flow passage. Therefore, if there is no discharge of the lubricant through the discharge flow passage, the flow rate Q2 can be ignored. 6, it can be seen that when the discharge passage is open, the rate of increase in the flow rate Q1 and the rate of increase in the discharge pressure of the oil supply pump 60 associated with an increase in the rotation speed of the rotating shaft 30 are gentler than when the discharge passage is not open. In other words, the upward force acting on the rotating shaft 30 is mitigated.

[0045] In the above embodiment, the orifice restrictor 51b is used as the restrictor, but the type of the restrictor is not limited to this. Furthermore, the location where the throttle is provided is not particularly limited as long as it is somewhere in the lubricating oil flow path.

[0046] The compressor and the method for manufacturing the compressor according to the present embodiment described above can be understood, for example, as follows. The compressor according to the first aspect of the present disclosure includes a rotating shaft (30) that drives a compression mechanism (20) by rotating about a central axis (X) that extends in the vertical direction, and an oil feed pump (60) that is provided below the rotating shaft and discharges lubricating oil toward a lower end of the rotating shaft, the rotating shaft having a lubricating oil flow path (42, 44a, 51a) that guides the lubricating oil discharged from the oil feed pump from the lower end upward, and the lubricating oil flow path is provided with at least one throttle (51b) that imparts a pressure loss to the circulating lubricating oil.

[0047] The compressor according to this aspect includes a rotating shaft and an oil pump that discharges lubricating oil toward the lower end of the rotating shaft, so that the discharged lubricating oil can apply an upward force to the rotating shaft, thereby reducing the thrust load generated by the weight of the rotating shaft and, in some cases, lifting the rotating shaft. In addition, the rotating shaft has a lubricating oil passage that guides the lubricating oil discharged from the oil supply pump from the lower end upward, and the lubricating oil passage is provided with at least one throttle that imparts pressure loss to the flowing lubricating oil, so that the discharge pressure of the lubricating oil that will be loaded on the lower end of the rotating shaft can be adjusted in advance by adjusting the pressure loss caused by the throttle. That is, the magnitude of the upward force acting on the rotating shaft can be adjusted. This makes it possible to set, for example, whether or not an upward force that is strong enough to lift the rotating shaft is applied to the rotating shaft, that is, whether or not the rotating shaft is lifted during the operation of the compressor. Therefore, it is possible to ensure the reliability of the rotating shaft and reduce sliding loss.

[0048] The compressor according to a second aspect of the present disclosure, in the first aspect, includes a radial bearing (70) provided on the lower part of the rotating shaft and having a sliding surface (71) facing an outer peripheral surface of the rotating shaft, and a groove (72) is formed in the sliding surface, and the groove defines a discharge flow path between the outer peripheral surface of the rotating shaft and the rotating shaft, for discharging a portion of the lubricating oil discharged from the oil feed pump to the outside of a region between the lower end surface of the rotating shaft and the oil feed pump when the rotating shaft moves upward by a predetermined amount or more.

[0049] According to the compressor of this aspect, a radial bearing having a sliding surface facing the outer circumferential surface of the rotating shaft is provided, and a groove is formed on the sliding surface, and the groove defines a discharge flow path between the outer circumferential surface of the rotating shaft, through which a part of the lubricating oil discharged from the oil pump is discharged to the outside of the region between the lower end surface of the rotating shaft and the oil pump when the rotating shaft moves upward by a predetermined amount or more. Therefore, when the rotating shaft moves upward, that is, when the rotating shaft floats due to the discharge pressure of the lubricating oil discharged from the oil pump, a part of the lubricating oil is discharged, and the pressure of the lubricating oil applied to the lower end of the rotating shaft is reduced. This automatically reduces the upward force acting on the rotating shaft, and makes it possible to prevent the rotating shaft from floating up too much.

[0050] A third aspect of the present disclosure relates to the compressor of the first or second aspect, wherein the oil supply pump is a rotary positive displacement pump driven by the rotating shaft.

[0051] According to the compressor of this aspect, the oil supply pump is a rotary displacement pump that is driven by the rotating shaft, so there is no need to provide a separate drive source for the oil supply pump.

[0052] A compressor according to a fourth aspect of the present disclosure is the compressor of any one of the first to third aspects, further comprising a compression mechanism driven by the rotating shaft, the compression mechanism being a mechanism for compressing a CO2 refrigerant.

[0053] In the compressor according to this embodiment, the compression mechanism is a mechanism for compressing a CO2 refrigerant. When the refrigerant is a CO2 refrigerant, the normal pressure tends to be higher than other refrigerants, and the thrust load and the load on the thrust bearing become large. Therefore, a large amount of lubricant is required, and the importance of adjusting the pressure loss by throttling increases in order to ensure the reliability of the rotating shaft and reduce the sliding loss.

[0054] A manufacturing method of a compressor according to a fifth aspect of the present disclosure is a manufacturing method of a compressor, the compressor comprising: a rotating shaft that drives a compression mechanism by rotating about a central axis extending in a vertical direction; and an oil feed pump provided below the rotating shaft and discharging lubricating oil toward a lower end of the rotating shaft, the rotating shaft having a lubricating oil flow passage that guides the lubricating oil discharged from the oil feed pump from the lower end upward, the lubricating oil flow passage having at least one throttle that imparts a pressure loss to the circulating lubricating oil, and the magnitude of the upward force acting on the rotating shaft during operation of the compressor is adjusted by adjusting the opening area of ​​the throttle. [Explanation of symbols]

[0055] 1 Compressor 10. Housing 11 Main Housing 12 Lower housing 12a Legs 13 Oil storage section 14 Volts 20 Rotary compression mechanism (compression mechanism) 21 Rotor 22 cylinders 30 Rotational Axis 40 spindle 41 Eccentric part 42 Main shaft flow path (lubricating oil flow path) 43 Fitting hole 44 Pockets 44a Pocket passage (lubricant passage) 45 Oil supply passage 46 Oil supply passage 50 Pump shaft 51 Main body 51a Pump shaft flow path (lubricating oil flow path) 51b Orifice restriction (restriction) 51c Fuel filler 52 Tip 60 Fuel Pump 61 Pump case 61a Depression 61b Inlet 62 Thrust plate 62a Outlet 63 Outer rotor 64 Inner rotor 70 Radial bearing 71 Sliding surface 72 Spiral Groove C1 Compression chamber X center axis

Claims

1. a rotating shaft that rotates about a central axis extending in the vertical direction to drive the compression mechanism; an oil supply pump provided below the rotating shaft and configured to discharge lubricating oil toward a lower end of the rotating shaft; Equipped with the rotating shaft has a lubricating oil flow passage that guides the lubricating oil discharged from the oil supply pump upward from the lower end, The lubricating oil passage is provided with at least one throttle that imparts pressure loss to the flowing lubricating oil. Compressor.

2. a radial bearing provided at a lower portion of the rotating shaft and having a sliding surface facing an outer circumferential surface of the rotating shaft Equipped with The sliding surface is provided with a groove, The groove defines, between the groove and the outer circumferential surface of the rotating shaft, a discharge flow passage for discharging a portion of the lubricating oil discharged from the oil supply pump to the outside of a region between the lower end surface of the rotating shaft and the oil supply pump when the rotating shaft moves upward by a predetermined amount or more. The compressor according to claim 1 .

3. The oil supply pump is a rotary positive displacement pump driven by the rotary shaft. The compressor according to claim 1 or 2.

4. The compression mechanism driven by the rotating shaft Equipped with The compression mechanism is a mechanism for compressing a CO2 refrigerant. The compressor according to claim 1 or 2.

5. A method for manufacturing a compressor, comprising the steps of: The compressor includes: a rotating shaft that rotates about a central axis extending in the vertical direction to drive the compression mechanism; an oil supply pump provided below the rotating shaft and configured to discharge lubricating oil toward a lower end of the rotating shaft; Equipped with the rotating shaft has a lubricating oil flow passage that guides the lubricating oil discharged from the oil supply pump upward from the lower end, The lubricating oil passage is provided with at least one throttle that imparts a pressure loss to the flowing lubricating oil, The opening area of ​​the throttle is adjusted to adjust the magnitude of the upward force acting on the rotary shaft during operation of the compressor. A method for manufacturing a compressor.

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