Oil-cooled compressor

Abstract

To secure appropriate cooling relative to a motor and compressed gas while suppressing increase in stirring loss in a bearing and deterioration of the bearing in an oil cooling type compressor.SOLUTION: An oil cooling type compressor 1 includes a compressor body 10, an oil reservoir part 21, a motor 26 and bearings 41A, 42A. The compressor body 10 includes a casing 13 forming a rotor chamber 14 in which a screw rotor 12 is accommodated. Oil is stored in the oil reservoir part 21. The motor 26 includes a motor jacket 30 having a cooling flow passage 31 in which oil flows. The bearings 41A, 42A support the screw rotor 12. The oil cooling type compressor 1 further includes a first oil flow passage 50 and a second oil flow passage 60. In the first oil flow passage 50, oil is supplied from the oil reservoir part 21 through the cooling flow passage 31 to the rotor chamber 14. The second oil flow passage 60 is branched from the first oil flow passage 50 between the oil reservoir part 21 and the motor jacket 30 to supply oil to the bearings 41A, 42A.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an oil-cooled compressor. [Background technology]

[0002] Patent Document 1 discloses a positive displacement compressor in which lubricating oil is supplied to bearings of the compressor via a cooling passage in a motor casing.

[0003] In the positive displacement compressor described in Patent Document 1, the same amount of lubricating oil is supplied to the cooling passage and the bearing. Therefore, in the positive displacement compressor described in Patent Document 1, if an appropriate amount of lubricating oil is supplied to the bearing so as not to increase the churning loss in the bearing, the amount of lubricating oil supplied to the cooling passage may be too small, which may result in insufficient cooling of the motor. Also, if an appropriate amount of lubricating oil is supplied to the cooling passage so as not to insufficient cooling of the motor, the amount of lubricating oil supplied to the bearing may be too large, which may result in increased churning loss in the bearing.

[0004] Furthermore, in the positive displacement compressor described in Patent Document 1, dust and the like generated in the cooling passages may enter the bearings, causing damage to the bearings. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-200058 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to ensure appropriate cooling of the motor and compressed gas in an oil-cooled compressor while suppressing an increase in churning loss in the bearings and deterioration of the bearings. [Means for solving the problem]

[0007] The present invention provides an oil-cooled compressor comprising: a compressor body having a casing that forms a rotor chamber in which a screw rotor is housed; an oil reservoir in which oil is stored; a motor that drives the screw rotor and includes a motor jacket having a cooling passage through which the oil flows; a bearing that supports the screw rotor; a first oil passage that supplies the oil from the oil reservoir to the rotor chamber via the cooling passage; and a second oil passage that branches off from the first oil passage between the oil reservoir and the motor jacket and supplies the oil to the bearing.

[0008] According to the oil-cooled compressor of the present invention, the oil supplied from the oil reservoir flows through a first oil flow path that flows from the oil reservoir to the rotor chamber via a cooling flow path, and a second oil flow path that branches off from the first oil flow path and flows to the bearing. Here, since the second oil flow path branches off on the upstream side of the motor jacket, the oil supplied to the bearing flows from the oil reservoir to the bearing without passing through the cooling flow path. Therefore, the amount of oil supplied to the motor jacket and the rotor chamber and the amount of oil supplied to the bearing can be set separately. That is, a large amount of oil can be supplied to the motor jacket and the rotor chamber while a small amount of oil can be supplied to the bearing. Therefore, it is possible to suppress an increase in the stirring loss occurring in the bearing while ensuring appropriate cooling of the motor and the compressed gas. Furthermore, since the oil supplied to the bearing does not pass through the cooling flow path, dust and the like generated in the cooling flow path cannot enter the bearing. Therefore, damage to the bearing caused by dust and the like entering the bearing can be avoided, and deterioration of the bearing can be suppressed.

[0009] The oil-cooled compressor may further include an oil cooler provided upstream of a point at which the first oil flow path branches off from the second oil flow path.

[0010] The motor jacket may include an inner tube extending in the axial direction of the motor and having a groove portion open to the outside, and an outer tube covering the inner tube from the outside, and the cooling flow path may be defined by closing the groove portion with the outer tube.

[0011] According to the above-mentioned configuration, the inside of the cooling passage is exposed simply by removing the outer cylinder from the inner cylinder. Therefore, the inside of the cooling passage can be easily cleaned. Therefore, damage to the screw rotor caused by dirt generated in the cooling passage entering the rotor chamber can be avoided, and deterioration of the screw rotor can be suppressed.

[0012] The motor jacket and the casing are integrally connected via a connection part. The first oil flow passage may include a motor jacket side oil flow passage provided in the motor jacket so as to open at a first connection surface of the connection part, and a casing side oil flow passage provided in the casing so as to open at a second connection surface of the connection part. The motor jacket side oil flow passage and the casing side oil flow passage communicate with each other via the opening of the first connection surface and the opening of the second connection surface.

[0013] According to the above-mentioned configuration, the oil flow passage that connects the motor jacket and the casing can be provided integrally with the motor jacket and the casing. In other words, it is not necessary to provide the oil flow passage that connects the motor jacket and the casing as a separate pipe. This can reduce costs. In addition, since the oil flow passage can be configured using the shortest route, pressure loss in the oil flow passage can be reduced.

[0014] The connection portion may include a first flange portion formed at an end of the motor jacket on the casing side and protruding toward the circumferential outside of the motor, and a second flange portion formed at an end of the casing on the motor jacket side, protruding toward the circumferential outside and abutting the first flange portion.

[0015] The oil-cooled compressor may further include a strainer disposed in the motor jacket side oil flow passage or the casing side oil flow passage.

[0016] According to the above-mentioned configuration, the strainer collects dirt and other particles generated in the cooling passage, preventing the dirt and other particles from entering the rotor chamber. Therefore, damage to the screw rotor caused by dirt and other particles entering the rotor chamber can be avoided, and deterioration of the screw rotor can be suppressed.

[0017] The oil-cooled compressor may further include a strainer arranged in the motor jacket side oil flow passage or the casing side oil flow passage, and the strainer may be detachably provided inside the motor jacket side oil flow passage or the casing side oil flow passage by separating the connection portion.

[0018] The first oil passage may include a spray nozzle that opens into the rotor chamber.

[0019] According to the above-described configuration, the oil can be supplied to the rotor chamber in the form of an atomized oil, so that the compressed gas can be cooled more effectively. Effect of the Invention

[0020] According to the oil-cooled compressor of the present invention, it is possible to ensure appropriate cooling of the motor and compressed gas while suppressing an increase in churning loss in the bearings and deterioration of the bearings. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic diagram of an overall configuration of an oil-cooled compressor according to the present invention. [Diagram 2] 2 is a cross-sectional view of a compressor body and a motor in the oil-cooled compressor shown in FIG. [Diagram 3] An enlarged view of part III of FIG. [Figure 4] An enlarged view of part IV of FIG. [Diagram 5] 5 is a cross-sectional view taken along line VV in FIG. 4 . [Figure 6] FIG. 13 is a diagram showing a modified example of the oil-cooled compressor according to the present invention. [Figure 7] FIG. 13 is a diagram showing another modified example of the oil-cooled compressor according to the present invention. [Figure 8] An enlarged view of part VIII of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] 1 shows a schematic diagram of an oil-cooled compressor 1 according to the present invention. The oil-cooled compressor 1 includes a compressor body 10, an oil separator 20 having an oil reservoir 21, an oil cooler 22, and a motor 26.

[0023] 2, the compressor body 10 has a screw rotor pair 12 and a casing 13. The casing 13 forms a rotor chamber 14 in which the screw rotor pair 12 is housed. A suction port 15 is formed on one side of the rotor chamber 14, and a discharge port 18 communicating with the discharge flow passage 11a is formed on the other side.

[0024] The screw rotor pair 12 is composed of a male and female pair. The rotor shaft 12c of the male screw rotor 12a is connected to an output shaft 29 protruding from a rotor 27 of a motor 26 so as to be rotatable together with the output shaft 29. When the motor 26 drives the male screw rotor 12a, the female screw rotor 12b meshing with it is driven.

[0025] The compressor body 10 includes bearings 41A and 42A that support the male screw rotor 12a. The bearing 42A is disposed on the motor 26 side of the casing 13. The bearing 41A is disposed on the opposite side of the casing 13 to the bearing 42A with respect to the screw rotor 12a.

[0026] The compressor body 10 also includes bearings 41B, 42B that support the female screw rotor 12b. The female bearings 41B, 42B are disposed in the same manner as the male bearings 41A, 42A.

[0027] In this embodiment, the second oil flow passage 60, which will be described later, is connected to the male bearings 41A, 42A as shown in Fig. 1. In this case, oil is supplied to the female bearings 41B, 42B via the male bearings 41A, 42A. The second oil flow passage 60 may be connected to the female bearings 41B, 42B, or may be connected to both the male bearings 41A, 42A and the female bearings 41B, 42B.

[0028] 2, the motor 26 includes a motor jacket 30 having a cooling passage 31 through which oil flows. The motor jacket 30 includes an inner cylinder 33 and an outer cylinder 34. The inner cylinder 33 extends in the axial direction X of the motor 26. An open groove 35 is formed in a spiral shape on the outside of the inner cylinder 33. The outer cylinder 34 covers the inner cylinder 33 from the outside.

[0029] 3, the groove 35 is defined by a pair of groove side surfaces 35a and a groove bottom surface 35b. The cooling flow passage 31 is defined by closing the groove 35 with the outer casing 34. That is, the cooling flow passage 31 is defined by closely contacting the inner surface 34a of the outer casing 34 with the top surface 33b of the groove wall 33a.

[0030] 1 again, an oil separator 20 is provided in a discharge flow passage 11a for compressed gas extending from the compressor body 10. Compressed gas is discharged from the compressor body 10 together with oil, and the compressed gas and oil are separated in the oil separator 20. The compressed gas flows into a discharge flow passage 11b connected to an upper part of the oil separator 20, and the separated oil is stored in an oil reservoir 21 at a lower part of the oil separator 20. That is, the oil is stored in the oil reservoir 21.

[0031] 1, the oil-cooled compressor 1 includes a first oil passage 50 and a second oil passage 60. The oil-cooled compressor 1 further includes an oil cooler 22 provided upstream of a point where the first oil passage 50 branches into a second oil passage 60, which will be described later.

[0032] The first oil passage 50 supplies oil from the oil reservoir 21 to the rotor chamber 14 via the cooling passage 31. The first oil passage 50 includes an oil passage 50a connecting the oil reservoir 21 and the oil cooler 22, an oil passage 50b connecting the oil cooler 22 and the cooling passage 31, the cooling passage 31, and an oil passage 50c connecting the cooling passage 31 and the rotor chamber 14. In addition, an oil filter 23 may be provided in at least one of the first oil passage 50 and the second oil passage 60. It is desirable that the oil filter 23 be provided upstream of a point where the first oil passage 50 branches off from the second oil passage 60 and downstream of the oil cooler 22.

[0033] 2, the oil flow passage 50c includes a motor jacket side oil flow passage 54 and a casing side oil flow passage 55.

[0034] The motor jacket side oil passage 54 is provided in the motor jacket 30 so as to open at a first connection surface 24 of a connection portion 16 described below. At the outlet of the cooling passage 31, the cooling passage 31 and the motor jacket side oil passage 54 are connected.

[0035] The casing side oil passage 55 is provided in the casing 13 so as to open at a second connection surface 25 of a connection portion 16 described below. The casing side oil passage 55 includes a plurality of connection passages 56 that fluidly connect the casing side oil passage 55 and the rotor chamber 14.

[0036] 8, a spray nozzle 57 is provided in the connecting passage 56. That is, the first oil passage 50 is provided with the spray nozzle 57 that opens into the rotor chamber 14. For example, when a desired cooling performance or discharge air volume can be obtained, the spray nozzle 57 does not need to be provided.

[0037] 8, the casing 13 is provided with a plurality of through holes 58 penetrating into the casing-side oil flow passage 55, coaxially with the connecting flow passage 56. The spray nozzles 57 are passed through the through holes 58 and installed in the connecting flow passage 56. After the spray nozzles 57 are installed, the through holes 58 are sealed with plugs 59.

[0038] Referring again to FIG. 1, the second oil flow passage 60 branches off from the first oil flow passage 50 between the oil reservoir 21 and the motor jacket 30, more specifically, from the oil flow passage 50b, and supplies oil to the bearings 41A and 42A.

[0039] The second oil flow passage 60 includes an oil flow passage 60a and an oil flow passage 60b. The oil flow passage 60a supplies oil from the oil flow passage 50b to the bearing 41A. The oil flow passage 60b branches off from the oil flow passage 60a and supplies oil to the bearing 42A.

[0040] 2, in this embodiment, a portion of the oil flow passage 60a is drilled in the casing 13 near the bearing 41A and is connected to the bearing 41A. The other portion of the oil flow passage 60a is connected to the oil flow passage 50b, thereby connecting the oil flow passage 50b to the bearing 41A.

[0041] The oil flow passage 60b is drilled in the casing 13 so as to branch off from the portion where the oil flow passage 60a is drilled. Although only a portion of the oil flow passage 60b is shown in Fig. 2, the oil flow passage 60a and the bearing 42A are connected by the oil flow passage 60b.

[0042] The second oil passage 60 may branch off from the first oil passage 50 inside the casing 13. That is, a portion of the first oil passage 50 may be drilled in the casing 13, and the second oil passage 60 may be drilled in the casing 13 so as to branch off from the drilled first oil passage 50.

[0043] 2, the motor jacket 30 and the casing 13 are integrally connected via the connection portion 16. The motor jacket side oil passage 54 and the casing side oil passage 55 communicate with each other via the opening 39 of the first connection surface 24 and the opening 40 of the second connection surface 25.

[0044] The connection portion 16 includes a first flange portion 36 and a second flange portion 17. That is, in this embodiment, the first flange portion 36 and the second flange portion 17 configure the connection portion 16. The first flange portion 36 is formed at an end portion of the motor jacket 30 on the casing 13 side, and protrudes toward the outside in the circumferential direction of the motor 26. The second flange portion 17 is formed at an end portion of the casing 13 on the motor jacket 30 side, and protrudes toward the outside in the circumferential direction of the motor 26 and is in contact with the first flange portion 36.

[0045] 4 and 5, the motor 26 further includes a strainer 37A disposed in the motor jacket side oil flow passage 54. The strainer 37A is inserted from below the motor jacket 30. In the present embodiment, the strainer 37A is a plate-shaped member provided with a stainless steel mesh screen 38, and an example is shown in which the strainer 37A is installed away from the connection portion 16, but when the strainer 37A is installed away from the connection portion 16, the strainer 37A may be a round bar-shaped member provided with a mesh screen that can easily seal gaps with holes.

[0046] 6, as a modified example, the compressor body 10 may further include a strainer 37B arranged in the casing side oil flow passage 55. The strainer 37B is detachably provided in the inside of the casing side oil flow passage 55 by separating the connection portion 16. As another modified example, the compressor body 10 may include a strainer 37A arranged in the casing side oil flow passage 55 instead of the strainer 37B.

[0047] 7, as another modification, the motor 26 may include a strainer 37B disposed in the motor jacket side oil passage 54. The strainer 37B is provided detachably in the motor jacket side oil passage 54 by separating the connection portion 16.

[0048] Hereinafter, the flow of oil in the oil-cooled compressor 1 of the present embodiment will be described with reference to FIGS.

[0049] First, a description will be given of the flow of oil in the first oil flow passage 50. The oil temporarily stored in the oil reservoir 21 flows into the oil flow passage 50a by the discharge pressure of compressed gas or by using an oil pump (not shown), and passes through the oil cooler 22. The oil that has passed through the oil cooler 22 is cooled by the oil cooler 22.

[0050] The oil cooled by the oil cooler 22 passes through the oil passage 50b, and then passes through the spiral cooling passage 31. When passing through the cooling passage 31, heat is exchanged between the oil and the motor 26, and the motor 26 is thereby cooled.

[0051] The oil that has passed through the cooling passage 31 passes through the oil passage 50c, i.e., the motor jacket side oil passage 54, the casing side oil passage 55, and the connecting passage 56, and reaches the rotor chamber 14. At that time, the oil is supplied to the rotor chamber 14 in the form of a mist by the spray nozzle 57 provided in the connecting passage 56.

[0052] Next, the flow of oil in the second oil flow passage 60 will be described. The oil that flows into the second oil flow passage 60 passes from the oil reservoir 21 through the oil flow passages 60a and 60b without passing through the cooling flow passage 31. The oil that has passed through reaches the bearings 41A and 42A and is used to lubricate the bearings 41A and 42A. The oil supplied to the bearings 41A and 42A then flows into the rotor chamber 14.

[0053] The oil that has passed through the first oil passage 50 and the second oil passage 60 and reached the rotor chamber 14 merges with the compressed gas and is separated again in the oil separator 20.

[0054] As described above, in the oil-cooled compressor 1 according to this embodiment, oil supplied from the oil reservoir 21 flows through the first oil passage 50, which flows from the oil reservoir 21 to the rotor chamber 14 via the cooling passage 31, and the second oil passage 60, which branches off midway through the first oil passage 50 and flows to the bearings 41A, 42A. Here, since the second oil passage 60 branches off on the upstream side of the motor jacket 30, the oil supplied to the bearings 41A, 42A flows from the oil reservoir 21 to the bearings 41A, 42A without passing through the cooling passage 31.

[0055] Therefore, the amount of oil supplied to the motor jacket 30 and the rotor chamber 14 and the amount of oil supplied to the bearings 41A, 42A can be set separately. That is, a large amount of oil can be supplied to the motor jacket 30 and the rotor chamber 14 while a small amount of oil can be supplied to the bearings 41A, 42A. Therefore, it is possible to suppress an increase in the stirring loss occurring in the bearings 41A, 42A while ensuring appropriate cooling of the motor 26 and the compressed gas.

[0056] Furthermore, since the oil supplied to the bearings 41A, 42A does not pass through the cooling passage 31, dust and other particles generated in the cooling passage 31 cannot enter the bearings 41A, 42A. This makes it possible to avoid damage to the bearings 41A, 42A caused by dust and other particles entering the bearings 41A, 42A, and suppress deterioration of the bearings 41A, 42A.

[0057] In addition, since the motor jacket 30 includes the outer cylinder 34 and the inner cylinder 33, the inside of the cooling passage 31 is exposed simply by removing the outer cylinder 34 from the inner cylinder 33. Therefore, the inside of the cooling passage 31 can be easily cleaned. Therefore, damage to the screw rotor pair 12 caused by dust generated in the cooling passage 31 entering the rotor chamber 14 can be avoided, and deterioration of the screw rotor pair 12 can be suppressed.

[0058] In addition, the oil flow passage (oil flow passage 50c) that communicates between the motor jacket 30 and the casing 13 can be provided integrally with the motor jacket 30 and the casing 13. In other words, it is not necessary to provide the oil flow passage (oil flow passage 50c) that communicates between the motor jacket 30 and the casing 13 as a separate pipe. This can reduce costs. In addition, since the oil flow passage can be configured using the shortest route, pressure loss in the oil flow passage can be reduced.

[0059] Furthermore, by providing the strainer 37A or 37B, dust and the like generated in the cooling passage 31 are collected by the strainers 37A, 37B, and the dust and the like can be prevented from entering the rotor chamber 14. Therefore, damage to the screw rotor pair 12 caused by dust and the like entering the rotor chamber 14 can be avoided, and deterioration of the screw rotor pair 12 can be suppressed.

[0060] Furthermore, by providing the spray nozzle 57, it is possible to supply mist-like oil to the rotor chamber 14, thereby more effectively cooling the compressed gas. The spray nozzle 57 may be a single-fluid spray nozzle.

[0061] As described above, according to the oil-cooled compressor 1 of the present embodiment, it is possible to ensure appropriate cooling of the motor 26 and compressed gas while suppressing an increase in agitation loss in the bearings 41A, 42A and deterioration of the bearings 41A, 42A. [Explanation of symbols]

[0062] 1 Oil-cooled compressor 10 Compressor body 11a, 11b Discharge flow path 12 Screw rotor pair 12a Male screw rotor 12b Female screw rotor 12c Rotor shaft 13 Casing 14 Rotor Room 15 Intake port 16 Connection 17 Second flange part 18 Outlet 20 Oil separator 21 Oil Reservoir 22 Oil cooler 23 Oil filter 24 First connection surface 25 Second connection surface 26 Motor 27 Rotor 29 Output shaft 30 Motor jacket 31 Cooling Channel 33 Inner cylinder 33a Groove wall 33b Top surface 34 Outer cylinder 34a Inside surface 35 Groove 35a groove side 35b Groove bottom surface 36 First flange part 37A,B Strainer 38 Screens 39,40 aperture 41A,B Bearing 42A,B Bearing 50 1st oil flow path 50a~c Oil flow path 54 Motor jacket side oil passage 55 Casing side oil flow passage 56 Connection Channel 57 Spray Nozzle 58 Through hole 59 Stopper 60 2nd oil flow path 60a,b Oil flow path

Claims

1. a compressor body having a casing that defines a rotor chamber in which a screw rotor is housed; an oil reservoir in which oil is stored; a motor that drives the screw rotor and has a motor jacket having a cooling passage through which the oil flows; A bearing for supporting the screw rotor; a first oil flow passage that supplies the oil from the oil reservoir to the rotor chamber via the cooling flow passage; a second oil flow path that branches off from the first oil flow path between the oil reservoir and the motor jacket and supplies the oil to the bearing; Equipped with The motor jacket and the casing are integrally connected via a connection portion, The first oil flow path is a motor jacket side oil flow passage provided in the motor jacket so as to open on a first connection surface of the connection portion; a casing-side oil flow passage provided in the casing so as to open at a second connection surface of the connection portion; Equipped with the first connecting surface and the second connecting surface are flush with each other; the motor jacket side oil flow passage and the casing side oil flow passage are directly connected to each other via the opening of the first connection surface and the opening of the second connection surface.

2. A compressor body having a casing that forms a rotor chamber in which a screw rotor is housed; an oil reservoir in which oil is stored; a motor that drives the screw rotor and has a motor jacket having a cooling passage through which the oil flows; A bearing for supporting the screw rotor; a first oil flow passage that supplies the oil from the oil reservoir to the rotor chamber via the cooling flow passage; a second oil flow path that branches off from the first oil flow path between the oil reservoir and the motor jacket and supplies the oil to the bearing; Equipped with The motor jacket and the casing are integrally connected via a connection portion, The first oil flow path is a motor jacket side oil flow passage provided in the motor jacket so as to open on a first connection surface of the connection portion; a casing-side oil flow passage provided in the casing so as to open at a second connection surface of the connection portion; Equipped with the motor jacket side oil flow passage and the casing side oil flow passage communicate with each other via the opening in the first connection surface and the opening in the second connection surface, A strainer is further provided in the motor jacket side oil flow path or the casing side oil flow path, The strainer is detachably provided inside the motor jacket side oil flow path or the casing side oil flow path by separating the connecting portion.

3. The oil-cooled compressor according to claim 1 , further comprising an oil cooler provided upstream of a point at which the first oil flow path branches off from the second oil flow path.

4. The motor jacket is an inner cylinder extending in an axial direction of the motor and having a groove formed therein that is open to the outside; an outer cylinder that covers the inner cylinder from the outside; Equipped with The oil-cooled compressor according to claim 1 , wherein the cooling passage is defined by closing the groove with the outer cylinder.

5. The connection portion is a first flange portion formed at an end portion of the motor jacket on the casing side and protruding toward an outer side in a circumferential direction of the motor; a second flange portion formed at an end of the casing on the motor jacket side, protruding outward in the circumferential direction, and abutting against the first flange portion; The oil-cooled compressor according to claim 1 .

6. The oil-cooled compressor according to claim 1 , further comprising a strainer disposed in the motor jacket side oil flow path or the casing side oil flow path.

7. A strainer is further provided in the motor jacket side oil flow path or the casing side oil flow path, The oil-cooled compressor according to claim 1 , wherein the strainer is detachably provided in the motor jacket side oil flow passage or the casing side oil flow passage by separating the connecting portion.

8. The oil-cooled compressor according to claim 1 , wherein the first oil flow passage is provided with a spray nozzle that opens into the rotor chamber.

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