compressor

Abstract

To provide a compressor capable of reducing vibration of an oil return pipe.SOLUTION: A compressor 1 includes: a housing 11 which stores a rotating shaft 15, a scroll compression mechanism 13, and an upper bearing 31, and has an oil reservoir O1 in a lower side; and an oil return pipe 67 which is provided in the housing 11 and has one end fixed to the upper bearing 31 and the other end extending toward the oil reservoir O1 so as to return oil retained in the upper bearing 31 to the oil reservoir O1. The oil return pipes 67 are arranged in parallel in such a manner that their longitudinal axes are parallel with each other, and the oil return pipes 67 are bundled.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a compressor, and more specifically to a compressor provided with an oil return pipe for returning oil to an oil sump in a housing.

Background Art

[0002] The refrigerant discharged from a compressor that compresses a refrigerant inevitably contains oil used for lubrication. Since the discharged oil discharged together with the refrigerant causes a decrease in the performance of the heat exchanger, it is desirable to reduce the amount of discharged oil. Patent Document 1 provides an oil drain pipe in the housing for returning the oil supplied to the sliding portion of the compression mechanism portion to the oil sump at the lower part of the housing. And, in order to reduce the vibration of the oil drain pipe, the outer diameter of the central portion of the oil drain pipe is made larger than other portions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, although the oil drain pipe of Patent Document 1 described above reduces vibration by making the outer diameter of the center larger than other portions, it is not preferable in terms of cost because the oil drain pipe has a special shape.

[0005] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a compressor capable of reducing the vibration of an oil return pipe for returning oil to an oil sump in a housing with a simpler configuration.

Means for Solving the Problems

[0006] A compressor according to one aspect of the present disclosure comprises a rotating shaft that is driven to rotate; a compression mechanism connected to one end of the rotating shaft for compressing a refrigerant; a bearing for supporting the rotating shaft; a housing that houses the rotating shaft, the compression mechanism, and the bearing and has an oil reservoir at its bottom; and an oil return pipe provided within the housing, with one end fixed to the bearing and the other end extending toward the oil reservoir, for returning the oil held in the bearing to the oil reservoir, wherein a plurality of oil return pipes are provided in parallel so that their respective longitudinal axes are parallel, and each of the oil return pipes is bundled together. [Effects of the Invention]

[0007] This simple configuration, which involves bundling multiple oil return pipes together, can reduce vibrations in the oil return pipes. [Brief explanation of the drawing]

[0008] [Figure 1] This is a longitudinal cross-sectional view showing a compressor according to one embodiment of the present disclosure. [Figure 2] Figure 1 is a longitudinal cross-sectional view showing the main components of the compressor. [Figure 3] This is a cross-sectional view along the cutting line III-III in Figure 2. [Figure 4] This is a cross-sectional view along the cutting line IV-IV in Figure 2. [Figure 5] This is an enlarged view of section A in Figure 2. [Figure 6] Figure 5 is a front view of the lower end of the oil return pipe, seen from inside the housing. [Figure 7] Figure 5 is a cross-sectional view of the lower end of the oil return pipe. [Figure 8] This is a vertical cross-sectional view showing the compressor enlarged at the height of the lower end of the oil return pipe. [Figure 9] This is a cross-sectional view of the stabilizing plate, seen from below. [Figure 10] This is a cross-sectional view of the stabilizing plate, seen from above. [Figure 11] This is a modified example, a longitudinal cross-sectional view showing the main parts of the compressor. [Figure 12] It is an enlarged view of part B in FIG. 11. [Figure 13] It is a front view of the lower end of the oil return pipe shown in FIG. 12 as seen from the inside of the housing. [Figure 14] It is a cross-sectional view of the lower end of the oil return pipe shown in FIG. 12.

Embodiments for Carrying out the Invention

[0009] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. As shown in FIG. 1, the compressor 1 is used in an air conditioner and compresses a refrigerant R, which is a gas such as carbon dioxide, in two stages. The compressor 1 is fixed to an installation surface FL via legs 3. The compressor 1 includes a housing 11, a rotary compression mechanism (low-stage compression mechanism) 12 provided inside the housing 11, a scroll compression mechanism (high-stage compression mechanism) 13, an electric motor 14, and a rotating shaft (rotating shaft portion) 15.

[0010] The housing 11 includes a cylindrical main body portion 21, an upper lid portion 22 and a lower lid portion 23 that close the upper and lower openings of the main body portion 21. And the inside of the housing 11 forms a sealed space.

[0011] The rotating shaft 15 is provided so as to extend vertically along the axis X inside the housing 11. The upper end (one end) side of the rotating shaft 15 is rotatably supported by an upper bearing 31. The lower end (the other end) side of the rotating shaft 15 is rotatably supported by a lower bearing 32.

[0012] The electric motor 14 is arranged at the center in the longitudinal direction of the rotating shaft 15 and on the outer peripheral side of the rotating shaft 15, and rotates the rotating shaft 15 around the axis X. The electric motor 14 has a rotor 38 fixed to the outer peripheral surface of the rotating shaft 15, and a stator 39 that faces the rotor 38 in the radial direction with a gap from the outer peripheral surface of the rotor 38 and is fixed to the inner wall of the main body portion 21 of the housing 11 by shrink fitting or the like.

[0013] The rotor 38 is provided with rotor passages 38a provided at predetermined intervals in the circumferential direction. Each rotor passage 38a penetrates the rotor 38 in the vertical direction (axis X direction). Through these rotor passages 38a, the refrigerant discharged from the rotary compression mechanism 12 flows upward. An oil separation plate 38b is fixed to the upper part of the rotor 38. The oil separation plate 38b is in the shape of a disc and is arranged to extend in the horizontal direction. The oil separation plate 38b rotates around the axis X together with the rotor 38.

[0014] On the outer periphery of the stator 39, a plurality of stator passages 39a are formed at predetermined angular intervals in the circumferential direction (specifically, it will be described later using FIG. 3). As shown in FIG. 1, an upper coil end 39b with the winding folded back is located above the stator 39, and a lower coil end 39c with the winding folded back is located below the stator 39. The electric motor 14 is connected to a power source via an inverter (not shown), and rotates the rotating shaft 15 with variable frequency.

[0015] The rotary compression mechanism 12 is provided inside the housing 11 on the lower end (the other end) side of the rotating shaft 15. The rotary compression mechanism 12 has two cylinders in this embodiment, and includes an eccentric shaft portion 41 provided on the rotating shaft 15, a rotor 42 fixed to the eccentric shaft portion 41 and rotating eccentrically with respect to the axis X in the compression chamber C1 as the rotating shaft 15 rotates, and a cylinder 44 in which the compression chamber C1 is formed.

[0016] The refrigerant R is supplied from the suction pipe 33 to the compression chamber C1 formed in the cylinder 44. The refrigerant compressed in the compression chamber C1 is discharged from the rotary discharge pipe 43 through the lower bearing 32 to the region below the electric motor 14 in the housing 11.

[0017] The cylinder 44 is fixed to the lower bearing 32 from below by bolts 48. Below the cylinder 44, there is an oil pump 49, which is also fixed to the cylinder 44 by bolts 48. The oil pump 49 draws oil from the oil reservoir O1 at the bottom of the housing 11, and guides it through the oil supply hole 15a, which penetrates along the axis X of the rotating shaft 15, to the upper bearing 31.

[0018] The scroll compression mechanism 13 is located inside the housing 11, above the electric motor 14. The scroll compression mechanism 13 comprises a fixed scroll 51 fixed to an upper bearing 31, and an orbiting scroll 57 located below the fixed scroll 51 and opposite to the fixed scroll 51.

[0019] The fixed scroll 51 has an end plate 52 fixed to the upper surface of the upper bearing 31 and a fixed wrap 53 protruding downward from the end plate 52. A discharge hole 52a that penetrates vertically is formed in the central part of the end plate 52 (near the axis X).

[0020] The orbiting scroll 57 is positioned between the upper bearing 31 and the fixed scroll 51. The orbiting scroll 57 has an end plate 58 connected to the upper end of the rotating shaft 15 and an orbiting wrap 59 that protrudes upward from the end plate 58.

[0021] The end plate 58 is fixed to an eccentric shaft portion 56 provided at the upper end of the rotating shaft 15 via a bush 55, and rotates eccentrically with respect to the axis X as the rotating shaft 15 rotates.

[0022] The rotating wrap 59 engages with the fixed wrap 53, forming a compression chamber C2 between them that compresses the refrigerant R.

[0023] A balance weight chamber 63 is formed between the central recess of the upper bearing 31 and the lower part of the orbiting scroll 57. Within the balance weight chamber 63, a balance weight 54 rotates together with the rotating shaft 15.

[0024] The refrigerant R, compressed by the rotary compression mechanism 12 and discharged into the housing 11, is drawn into the compression chamber C2 from the outer circumference of the scroll compression mechanism 13 and compressed toward the center. The compressed refrigerant R is discharged to the outside of the housing 11 through the discharge hole 52a of the fixed scroll 51 and the discharge pipe 34.

[0025] Below the upper bearing 31, a cover 45 is provided to cover the upper bearing 31. The cover 45 is formed by sheet metal processing and has a roughly conical shape that widens from bottom to top. An intake opening 45a is provided at the lower end of the cover 45. That is, the intake opening 45a faces downward and is an annular region formed between the cover 45 and the rotating shaft 15. The cover 45 separates the space below the housing 11 from the space on the upper bearing 31 side, so that only the refrigerant drawn in from the intake opening 45a is guided to the scroll compression mechanism 13.

[0026] An oil level tank 60 is provided outside and below the housing 11. The oil level tank 60 is a hollow container and is connected to the inside of the housing 11 via a lower pipe 61 and an upper pressure equalizing pipe 62. The oil level tank 60 measures the oil level of the oil reservoir O1 inside the housing 11 by guiding oil from the reservoir O1 through the lower pipe 61.

[0027] The downstream end of the oil separator return pipe 65 is connected to the lower side of the housing 11. The upstream end of the oil separator return pipe 65 is connected to an oil separator (not shown). The oil separated from the refrigerant discharged from the compressor 1 by the oil separator is returned to the oil reservoir O1 inside the housing 11 via the oil separator return pipe 65. The height at which the downstream end of the oil separator return pipe 65 is connected to the housing 11 is below the lower bearing 32.

[0028] An oil return pipe 67 is provided inside the housing 11, extending vertically while in contact with the inner wall of the housing 11. As shown in Figure 2, the oil return pipe 67 is provided such that its upper end (one end) is fixed to the upper bearing 31 and its lower end (the other end) is located in the oil reservoir O1 at the bottom of the housing 11.

[0029] The oil return pipe 67 is provided to penetrate the space formed between the stator 39 and the housing 11. Specifically, as shown in Figure 3, notches are provided on the outer circumference of the stator 39 at predetermined angular intervals in the circumferential direction, thereby forming a plurality of stator passages 39a in the circumferential direction between the stator 39 and the inner wall of the housing 11. Coolant and oil flow through these stator passages 39a. The oil return pipe 67 is inserted through one or more of these stator passages 39a. In the example shown in Figure 3, the oil return pipe 67 is inserted through one of the stator passages 39a.

[0030] As can be seen in Figure 3, the rotor passages 38a are provided at predetermined intervals in the circumferential direction. The refrigerant discharged from the rotary compression mechanism 12 flows upward through these rotor passages 38a.

[0031] As can be seen from Figure 3, two oil return pipes 67 are installed in parallel. That is, the two oil return pipes 67 are installed in parallel so that their longitudinal axes are parallel. Each oil return pipe 67 is made of, for example, copper pipe and has the same outer and inner diameter along its length. The number of oil return pipes 67 installed in parallel is determined by the amount of oil to be returned, and it is possible to have three or more.

[0032] As shown in Figure 2, the upper end of the oil return pipe 67 is attached so as to communicate with the oil return hole 31a formed in the upper bearing 31. The oil return hole 31a extends horizontally and is formed so that its inner circumferential end opens into the balance weight chamber 63 which houses the balance weight 54.

[0033] Figure 4 is a cross-sectional view along the cutting line IV-IV in Figure 2, showing the fixing point between the oil return pipe 67 and the upper bearing 31. The upper ends of the two oil return pipes 67 are fixed to a common boss 68. The boss 68 is made of metal and is fixed by brazing or the like after inserting the upper ends of each oil return pipe 67. The upper ends of each oil return pipe 67 communicate with a communication hole 68a formed in the boss 68. The communication hole 68a opens toward the upper surface of the boss 68. The boss 68 is fixed to the lower surface of the upper bearing 31 by multiple bolts 69. The communication hole 68a formed in the boss 68 opens into a vertical hole 31b connected to the oil return hole 31a of the upper bearing 31, thereby connecting the oil return pipe 67 and the balance weight chamber 63.

[0034] Figure 5 is an enlarged view of section A in Figure 2, showing the lower end of the oil return pipe 67. The lower end of the oil return pipe 67 is fixed to the inner wall of the housing 11 via a rod-shaped member 70. The rod-shaped member 70 is made of steel and is a solid round bar. The length of the rod-shaped member 70 overlaps with the tip of the oil return pipe 67 for a predetermined length (e.g., several mm to several tens of mm) and protrudes downward from the tip of the oil return pipe 67 for a predetermined length (e.g., several mm to several tens of mm).

[0035] As shown in Figures 6 and 7, the rod-shaped members 70 are fixed to the respective sides of the lower ends of adjacent rod-shaped members 70. The rod-shaped members 70 are fixed to the oil return pipes 67, for example, by brazing. The outer diameter of the rod-shaped members 70 can be arbitrary as long as it can be inserted between the oil return pipes 67 and fixed to each oil return pipe 67, and it is preferable that it is smaller than the outer diameter of the oil return pipes 67. The cross-sectional shape of the rod-shaped members 70 may be circular as shown in Figure 7, or it may be polygonal.

[0036] The rod-shaped member 70 is fixed to the inner wall of the housing 11. Specifically, the lower end (tip) of the rod-shaped member 70 is fixed by welding. For example, the lower end of the rod-shaped member 70 is welded by accessing it from below the main body 21 before the lower cover portion 23 (see Figure 1) of the housing 11 is attached. By fixing the lower end of the rod-shaped member 70 to the inner wall of the housing 11, the oil return pipe 67 is in close proximity to the inner wall of the housing 11 over almost its entire length (for example, more than half of the longitudinal dimension from the lower end of the oil return pipe 67). For example, as shown in Figure 1, the oil return pipe 67 is bent from the fixing position of its upper end to the height position of the upper coil end 39b of the electric motor 14, so that the oil return pipe 67 is in close proximity to the inner wall of the housing 11 over its entire length from the height position of the upper coil end 39b downwards. This restricts the movement of the oil return pipe 67 and suppresses the generation of vibrations in the oil return pipe 67. It is preferable that the oil return pipe 67 be in contact with the inner wall of the housing 11, but a small gap (for example, 0.1 mm to several mm) is acceptable as long as it is sufficient to restrict the movement of the oil return pipe 67 during vibration.

[0037] As shown in Figure 5, the lower end of the rod-shaped member 70 is tapered, cut on a single plane inclined with respect to the longitudinal axis of the oil return pipe 67. The tapered tip 67a of the oil return pipe 67 is located on the inner wall side of the housing 11. This allows the oil return pipe 67 to be inserted along the inner wall of the housing 11 during manufacturing, by advancing the pointed tip 67a along the inner wall, thus avoiding interference with other components inside the housing (such as the stator 39) and enabling smooth insertion.

[0038] As shown in Figure 8, a stabilizing plate (oil surface plate) 75 is fixed to the lower surface of the lower bearing 32. The stabilizing plate 75 is fixed to the lower bearing 32 (specifically, the radially protruding leg portion of the lower bearing 32) by bolts 76. The stabilizing plate 75 is a disc with an opening in the center, as shown in Figures 9 and 10. The stabilizing plate 75 is designed to cover the area above the oil surface of the oil reservoir O1 (see Figures 1 and 2). However, the height of the stabilizing plate 75 only needs to be below the refrigerant discharge position of the rotary compression mechanism 12. Also, the fixing position of the stabilizing plate 75 is not limited to the lower bearing 32, but may be fixed to other positions (for example, the housing 11). The stabilizing plate 75 stabilizes the oil surface of the oil reservoir O1 and prevents oil from separating from the oil reservoir O1 as much as possible due to the refrigerant flow discharged from the rotary compression mechanism 12. Note that in Figure 9, oil return pipes 67 are provided in pairs at three locations in the circumferential direction, but this is an example, and there may be only one location as in Figures 10 and 3.

[0039] As shown in Figure 8, the lower end of the oil return pipe 67 is located below the stabilizing plate 75. By separating the opening at the lower end of the oil return pipe 67 from the discharge side of the rotary compression mechanism 12 in this way, even if the oil returned from the oil return pipe 67 splashes on the oil surface of the oil reservoir O1, it is possible to suppress it from being stirred up along with the discharge refrigerant flow of the rotary compression mechanism 12.

[0040] The lower end of the oil return pipe 67 is positioned below the position where the downstream end of the oil separator return pipe 65 opens into the housing 11. By positioning the oil separator return pipe 65 to open below the stabilizing plate 75 in this way, the oil returned from the oil separator return pipe 65 flows in as shown by the black arrow (see Figure 8), and even if it splashes and disturbs the oil surface in the oil reservoir O1, it is possible to suppress the oil from being stirred up in conjunction with the discharge refrigerant flow of the rotary compression mechanism 12.

[0041] The compressor 1 with the above configuration operates as follows: The refrigerant evaporated in an evaporator (not shown) is drawn into the compressor 1 through the suction pipe 33 and compressed by the rotary compression mechanism 12. The refrigerant compressed by the rotary compression mechanism 12 is discharged into the housing 11 through the rotary discharge pipe 43. The refrigerant discharged into the housing 11 is drawn in through the intake opening 45a of the cover 45, passes through the flow path inside the cover 45, and is guided to the scroll compression mechanism 13 where it is compressed. The refrigerant compressed in the scroll compression mechanism 13 is discharged through the discharge hole 52a of the fixed scroll 51 and out of the discharge pipe 34 to an external gas cooler or condenser.

[0042] Oil is separated from the refrigerant discharged from the discharge pipe 34 by an oil separator (not shown). The separated oil is returned to the housing 11 through the oil separator return pipe 65 and stored in the oil reservoir O1.

[0043] The oil stored in the oil reservoir O1 is drawn up by the oil pump 49 and guided through the oil supply hole 15a formed in the rotating shaft 15 to the scroll compression mechanism 13. The oil guided to the scroll compression mechanism 13 lubricates the bearing portion of the upper bearing 31 and sliding parts such as the bush 55, and is then returned to the oil reservoir O1 below. Of the lubricated oil, the oil guided to the balance weight chamber 63 is guided through the oil return hole 31a and vertical hole 31b (see Figure 2) formed in the upper bearing 31 to the oil return pipe 67.

[0044] The oil, guided to the oil return pipe 67, passes through its internal flow path and is discharged from its lower end, returning to the oil reservoir O1.

[0045] According to this embodiment, the following effects and advantages are achieved. The oil that lubricates the upper bearing 31 is returned to the oil reservoir O1 at the bottom of the housing 11 by the oil return pipe 67. Since the upper end of the oil return pipe 67 is a fixed end fixed to the upper bearing 31, there is a risk that vibrations from the compressor 1 will be transmitted and repeated stress will occur. In this embodiment, the overall rigidity of the oil return pipe 67 is increased by bundling multiple oil return pipes 67, each of which is provided in parallel so that their respective longitudinal axes are parallel, via a rod-shaped member 70. This makes it possible to suppress vibrations of the oil return pipe 67. In addition, by increasing the second moment of area by using multiple oil return pipes 67, the strength of the upper end of the oil return pipe 67 fixed to the upper bearing 31 can be increased, thereby suppressing fatigue failure at the upper end of the oil return pipe 67.

[0046] The lower end of the oil return pipe 67 is fixed to the inner wall of the housing 11 using a rod-shaped member 70. This fixes the upper and lower ends of the oil return pipe 67 at two points, further suppressing vibrations of the oil return pipe 67.

[0047] The two oil return pipes 67 are bundled together by fixing rod-shaped members 70 to the sides of the lower ends of adjacent oil return pipes 67. The rod-shaped members 70 are then fixed to the inner wall of the housing 11. This allows adjacent oil return pipes 67 to be bundled together and easily fixed to the inner wall of the housing 11.

[0048] In the embodiment described above, a rod-shaped member 70 was used to bundle and fix the lower end of the oil return pipe 67, but this can be modified as follows. As shown in Figures 11 to 14, the lower ends of the oil return pipes 67 are bundled and fixed using fixing brackets 78. The fixing brackets 78 can be formed by bending a flat plate. Specifically, as shown in Figure 14, they are bent so that a space is formed between them and the inner wall of the housing 11. Then, the legs 78a on both sides of the fixing brackets 78 are fixed to the housing 11 by welding or the like. The lower ends of the oil return pipes 67 are inserted into the space formed by the fixing brackets 78. The displacement of each oil return pipe 67 is constrained within the space formed by the fixing brackets 78. This makes it easy to bundle and position the lower ends of the oil return pipes 67.

[0049] The compressors described in each of the embodiments above can be understood, for example, as follows.

[0050] A compressor according to one aspect of the present disclosure comprises a rotationally driven rotating shaft (15), a compression mechanism (13) connected to one end of the rotating shaft for compressing a refrigerant, a bearing (31) supporting the rotating shaft, a housing (11) housing the rotating shaft, the compression mechanism, and the bearing and having an oil reservoir (O1) below it, and an oil return pipe (67) provided within the housing, with one end fixed to the bearing and the other end extending toward the oil reservoir, for returning the oil held in the bearing to the oil reservoir, wherein a plurality of oil return pipes are provided in parallel so that their respective longitudinal axes are parallel, and each of the oil return pipes is bundled together.

[0051] The oil that lubricates the bearing is temporarily held in the bearing and returned to the oil reservoir at the bottom of the housing via an oil return pipe. One end of the oil return pipe is a fixed end fixed to the bearing, so vibrations from the compressor are transmitted, causing repeated stress. By bundling together multiple oil return pipes arranged in parallel so that their respective longitudinal axes are parallel, the overall rigidity of the oil return pipe can be increased. This suppresses vibration of the oil return pipe. Furthermore, by increasing the second moment of area by using multiple oil return pipes, the strength of one end of the oil return pipe fixed to the bearing can be increased, thereby suppressing fatigue failure at that end of the oil return pipe. As a compression mechanism, for example, a scroll compression mechanism is used.

[0052] In a compressor according to one aspect of this disclosure, the other end of the oil return pipe is fixed to the inner wall of the housing.

[0053] The other end of the oil return pipe was fixed to the inner wall of the housing. This fixes both ends of the oil return pipe, further suppressing vibrations of the oil return pipe.

[0054] A compressor according to one aspect of the present disclosure includes a rod-shaped member (70) provided between the other ends of adjacent oil return pipes and fixed to the respective sides of the other ends of the adjacent oil return pipes, wherein the rod-shaped member is fixed to the inner wall of the housing.

[0055] The oil return pipes are bundled together by fixing rod-shaped members to the sides of the other ends of adjacent oil return pipes. The rod-shaped members are then fixed to the inner wall of the housing. This allows adjacent oil return pipes to be bundled together and easily fixed to the inner wall of the housing. The rod-shaped member can be fixed to the oil return pipe, and / or to the inner wall of the housing, for example, by brazing or welding.

[0056] A compressor according to one aspect of the present disclosure is provided with a fixing bracket (78) that is fixed to the inner wall of the housing and forms a space between itself and the inner wall, and the other ends of a plurality of oil return pipes are bundled together while inserted into the space.

[0057] A fixing bracket was secured to the inner wall of the housing, creating a space between the inner wall and the fixing bracket. The other ends of multiple oil return pipes were then inserted into this space, thereby bundling the oil return pipes together. This allows for easy bundling of the other ends of the oil return pipes.

[0058] In a compressor according to one aspect of the present disclosure, the oil return pipe is installed in close proximity to the inner wall of the housing for a length of at least half the length in the longitudinal direction from the other end.

[0059] The oil return pipe was positioned close to the inner wall of the housing for more than half of its longitudinal length from the other end. This restricts the movement of the oil return pipe and suppresses the generation of vibrations in the oil return pipe. Furthermore, "proximity" means that the oil return pipe and the inner wall of the housing may be in contact, or there may be a gap of, for example, 0.1 mm to several mm.

[0060] In a compressor according to one aspect of this disclosure, the oil return pipe has the same diameter along its longitudinal direction.

[0061] Since oil return pipes can be manufactured using piping of the same diameter, costs can be reduced.

[0062] In a compressor according to one aspect of the present disclosure, the other end of the oil return pipe is tapered, cut by a plane inclined with respect to the longitudinal axis of the oil return pipe, and the tip (67a) of the tapered shape is located on the inner wall side of the housing.

[0063] The other end of the oil return pipe is tapered, cut by a single plane inclined with respect to the longitudinal axis, and its tip is located on the inner wall side of the housing. This allows the oil return pipe to be inserted smoothly along the inner wall of the housing, avoiding interference with other components within the housing, by allowing the pointed tip to advance along the inner wall.

[0064] A compressor according to one aspect of the present disclosure, comprising: another compression mechanism (12) connected to the other end of the rotating shaft portion for compressing a refrigerant; and an oil surface upper plate (75) provided below the refrigerant discharge position of the other compression mechanism and above the oil surface formed in the oil reservoir, and covering the oil surface, according to any one of claims 1 to 7.

[0065] An oil surface upper plate covering the oil surface is provided below the refrigerant discharge position of other compression mechanisms connected to the other end of the rotating shaft. Furthermore, the oil surface upper plate is positioned above the oil surface formed in the oil reservoir. This makes it possible to prevent oil from separating from the oil reservoir as much as possible due to the refrigerant flow discharged from other compression mechanisms. Other compression mechanisms include, for example, rotary compression mechanisms.

[0066] In a compressor according to one aspect of the present disclosure, the other end of the oil return pipe opens below the oil level plate.

[0067] Since the other end of the oil return pipe opens below the oil surface plate, even if the oil returned from the oil return pipe splashes on the oil surface, the oil surface plate prevents it from being carried away by the discharge refrigerant flow of other compression mechanisms.

[0068] A compressor according to one aspect of the present disclosure is provided with an oil separator return pipe (65) that returns oil from an oil separator in which oil separated from the refrigerant discharged from the compressor is stored, and the oil separator return pipe opens below the oil level plate.

[0069] Since the oil separator return pipe opens below the oil surface plate, even if the oil returned from the oil separator return pipe splashes on the oil surface, the oil surface plate can isolate it from the discharge refrigerant flow of other compression mechanisms. [Explanation of Symbols]

[0070] 1. Compressor 3 legs 11 Housing 12. Rotary Compression Mechanism (Lower Stage Compression Mechanism) 13. Scroll compression mechanism (high-stage compression mechanism) 14 Electric motor 15. Rotating shaft (rotating shaft part) 15a Oil supply hole 21 Main body 22 Upper lid 23 Lower lid 31 Upper bearing (bearing section) 31a Oil return hole 31b Vertical hole 32 Lower bearing 33 Suction pipe 34 Discharge pipe 38 rotors 38a Rotor aisle 38b Oil Separation Plate 39 Status 39a Stator passage 39b Upper coil end 39c Lower coil end 41 Eccentric shaft part 42 rotors 43 Rotary discharge pipe 44 cylinders 45 Cover 45a Suction opening 48 volts 49 Oil pump 51 Fixed Scroll 52 End plate 52a Discharge hole 53 Fixing Wrap 54 Balance weights 55 Bush 56 Eccentric shaft part 57 Rotating Scroll 58 End plate 59 Turning lap 60 Oil level tank 61 Lower piping 62 Pressure equalization pipe 63 Balance Weight Room 65 Oil separator return oil pipe 67 Oil return pipe 67a Tip 68 Boss 68a Communication hole 69 volts 70 Rod-shaped member 75 Stabilizing plate (plate above oil level) 76 volts 78 Fixing brackets 78a Legs C1 Compression Chamber C2 Compression Chamber FL installation surface O1 Oil pool X axis

Claims

1. A rotating shaft that is driven to rotate, A compression mechanism connected to one end of the aforementioned rotating shaft portion for compressing the refrigerant, A bearing portion that supports the aforementioned rotating shaft portion, A housing that accommodates the rotating shaft, the compression mechanism, and the bearing, and has an oil reservoir at the bottom, An oil return pipe is provided within the housing and, to return the oil held in the bearing portion to the oil reservoir, has one end fixed to the bearing portion and the other end extending toward the oil reservoir, Equipped with, The compressor is provided with multiple oil return pipes arranged in parallel so that their respective longitudinal axes are parallel, and each of the oil return pipes is bundled together.

2. The compressor according to claim 1, wherein the other end of the oil return pipe is fixed to the inner wall of the housing.

3. The oil return pipes are provided with rod-shaped members that are placed between the other ends of adjacent oil return pipes and fixed to the sides of each of the adjacent other ends, The compressor according to claim 2, wherein the rod-shaped member is fixed to the inner wall of the housing.

4. The housing is equipped with a fixing bracket that is fixed to the inner wall and forms a space between it and the inner wall, The compressor according to claim 2, wherein the other ends of the plurality of oil return pipes are bundled together while inserted into the space.

5. The compressor according to any one of claims 1 to 4, wherein the oil return pipe is installed in close proximity to the inner wall of the housing for a length of at least half the length in the longitudinal direction from the other end.

6. The compressor according to any one of claims 1 to 5, wherein the oil return pipe has the same diameter along its longitudinal direction.

7. The other end of the oil return pipe is tapered, cut by a plane inclined with respect to the longitudinal axis of the oil return pipe. The compressor according to any one of claims 1 to 6, wherein the tapered tip is located on the inner wall side of the housing.

8. Connected to the other end of the aforementioned rotating shaft is another compression mechanism for compressing the refrigerant, An oil surface upper plate is provided below the refrigerant discharge position of the other compression mechanism and above the oil surface formed in the oil reservoir, and covers the oil surface. A compressor according to any one of claims 1 to 7, comprising:

9. The compressor according to claim 8, wherein the other end of the oil return pipe opens below the oil surface plate.

10. It is equipped with an oil separator return pipe that returns oil from an oil separator, which stores oil separated from the refrigerant discharged from the compressor. The compressor according to claim 8 or 9, wherein the oil separator return pipe opens below the oil level plate.

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