Rotating electric machines

Abstract

The present invention provides a rotating electric machine capable of suppressing a local temperature rise. A rotating electric machine according to one embodiment of the present invention comprises a stator, a rotor, a shaft, and a housing. The rotor is arranged inside the stator and can rotate around a rotating shaft. The shaft is fixed to the rotor and extends in the axial direction of the rotating shaft. The housing is provided with a housing chamber for accommodating the stator and the rotor, a vent connected to the housing chamber, and a flow path outside the housing chamber, and supports the shaft.

Description

Technical Field

[0001] An embodiment of the present invention relates to a rotating electric machine. Background Art

[0002] The electric motor as a rotating electrical machine is cooled, for example, by air sent from a fan driven by the motor or another small electric motor. In another example, the electric motor is cooled by water flowing in a water jacket provided outside a frame of the motor.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-268197 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The water cooling method can cool the motor more effectively than the air cooling method. However, depending on the output of the motor, there is a risk that the rotating rotor may not be cooled sufficiently and the temperature of the motor may rise locally.

[0008] An example of the problem to be solved by the present invention is to provide a rotating electrical machine capable of suppressing a local temperature increase.

[0009] Means used to solve problems

[0010] A rotating electric machine according to one embodiment of the present invention comprises a stator, a rotor, a shaft, and a housing. The rotor is arranged inside the stator and is rotatable around a rotating shaft. The shaft is fixed to the rotor and extends in the axial direction of the rotating shaft. The housing is provided with a housing chamber for accommodating the stator and the rotor, a vent communicated with the housing chamber, and a flow path outside the housing chamber, and supports the shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a cross-sectional view schematically showing a motor according to one embodiment.

[0012] Description of Reference Numerals

[0013] 10…motor, 11…stator, 12…rotor, 13…shaft, 14…housing, 16…air cooling device, 17…water cooling device, 20…frame, 25…accommodation chamber, 31…inner frame, 32…outer frame, 35…flow path, 36…inlet, 37…outlet, 45…ventilation port, 46…air supply port, 47…exhaust port, Ax…rotation axis, D1…first direction, D2…second direction, CA…air, CW…cooling water. DETAILED DESCRIPTION

[0014] Below, refer to Figure 1 An embodiment is described. In addition, in this specification, the constituent elements of the embodiment and the description of the element are sometimes described in multiple expressions. The constituent elements and their descriptions are examples and are not limited by the expressions in this specification. The constituent elements may also be specified as names different from the names in this specification. In addition, the constituent elements may also be described by expressions different from the expressions in this specification.

[0015] Figure 1 1 is a cross-sectional view schematically showing the motor 10 of the present embodiment. The motor 10 is an example of a rotating electrical machine. The rotating electrical machine may also be another rotating electrical machine such as a generator. Figure 1 As shown, the motor 10 includes a stator 11, a rotor 12, a shaft 13, a housing 14, a plurality of bearings 15, an air cooling device 16, and a water cooling device 17. The air cooling device 16 is an example of a first cooling device, and the water cooling device is an example of a second cooling device.

[0016] The stator 11, the rotor 12, and a part of the shaft 13 are housed inside the housing 14. The rotor 12 and the shaft 13 are driven by current flowing through the windings of the stator 11 and rotate integrally around the rotation axis Ax. The rotation axis Ax is, for example, the center line of the shaft 13. Figure 1 A cross section of the motor 10 parallel to the rotation axis Ax of the shaft 13 is shown so as to include the rotation axis Ax.

[0017] In the following description, for convenience, the direction along the rotation axis Ax is defined as the axial direction of the rotation axis Ax, the direction orthogonal to the rotation axis Ax is defined as the radial direction of the rotation axis Ax, and the direction rotating around the rotation axis Ax is defined as the circumferential direction of the rotation axis Ax. Furthermore, one direction in the axial direction is defined as a first direction D1, and the other direction in the axial direction is defined as a second direction D2. The second direction D2 is the opposite direction of the first direction D1.

[0018] The stator 11 is formed in a substantially cylindrical shape extending in the axial direction. The stator 11 is fixed to the housing 14. The stator 11 has a stator core made of a magnetic body, for example, and a winding attached to the stator core.

[0019] The rotor 12 is formed in a substantially cylindrical shape extending in the axial direction, and is disposed substantially coaxially with the stator 11. The rotor 12 is disposed inside the stator 11 via a gap G. The rotor 12 includes, for example, a plurality of permanent magnets.

[0020] The stator 11 and the rotor 12 are not limited to the above-mentioned configuration as long as they can generate a rotational force by electromagnetic force. For example, the rotor 12 may include a rotor core made of a magnetic body and a conductor attached to the rotor core.

[0021] The shaft 13 is formed into a generally cylindrical shape extending in the axial direction. The shaft 13 has an inner portion 13a and an outer portion 13b. The inner portion 13a is a generally cylindrical portion of the shaft 13 located inside the housing 14. The rotor 12 is fixed to, for example, the outer peripheral surface of the inner portion 13a. The outer portion 13b is a generally cylindrical portion of the shaft 13 extending in the axial direction from the inner portion 13a and located outside the housing 14. The outer portion 13b is, for example, continuous from the inner portion 13a, but the diameter may be different from that of the inner portion 13a. For example, an external device is connected to the outer portion 13b. The external device is driven by the rotation of the shaft 13.

[0022] The housing 14 is made of metal such as aluminum and is formed into a box shape. In addition, the housing 14 may be made of other materials. The housing 14 has a frame 20, a first bracket 21, and a second bracket 22. The frame 20 is an example of a peripheral wall. In addition, a cover 23 is mounted on the housing 14.

[0023] The frame 20 is provided with a receiving chamber 25. The receiving chamber 25 is a substantially cylindrical space extending in the axial direction. Specifically, the receiving chamber 25 is a space surrounded by the frame 20, the first bracket 21, and the second bracket 22. The receiving chamber 25 may also be in other shapes. The stator 11, the rotor 12, and the inner portion 13a of the shaft 13 are received in the receiving chamber 25.

[0024] The frame 20 is formed into a substantially cylindrical shape extending in the axial direction, and is arranged substantially coaxially with the stator 11 and the rotor 12. In addition, the frame 20 may also be in other shapes. The accommodating chamber 25 is provided inside the frame 20 and is surrounded by the frame 20. The frame 20 surrounds the stator 11 and is fixed to the stator 11.

[0025] The frame 20 includes an inner frame 31 and an outer frame 32. The inner frame 31 is an example of an inner wall. The outer frame 32 is an example of an outer wall. In addition, the frame 20 may include other components or may be a single component.

[0026] The inner frame 31 and the outer frame 32 are formed into a substantially cylindrical shape extending in the axial direction, and are arranged substantially coaxially with the stator 11 and the rotor 12. The inner frame 31 surrounds the stator 11. The outer frame 32 surrounds the inner frame 31. For example, the inner frame 31 is pressed into the inner part of the outer frame 32 and fixed to the outer frame 32 by welding. In addition, the inner frame 31 and the outer frame 32 are not limited to this example.

[0027] The inner frame 31 has a first contact surface 31a and a concave surface 31b. The first contact surface 31a is the outer surface of the inner frame 31 and faces radially outward. The concave surface 31b is recessed from the first contact surface 31a. The concave surface 31b forms a groove 31c that opens to the first contact surface 31a. The groove 31c extends spirally around the rotation axis Ax.

[0028] The outer frame 32 has a second contact surface 32a and an outer surface 32b. The second contact surface 32a is the inner surface of the outer frame 32 and faces radially inward. The second contact surface 32a contacts the first contact surface 31a of the inner frame 31. The outer surface 32b is located on the opposite side of the second contact surface 32a and faces radially outward.

[0029] The outer frame 32 covers the groove 31c of the inner frame 31. Thus, the flow path 35 is provided between the inner frame 31 and the outer frame 32. In other words, the flow path 35 is provided inside the frame 20. According to another expression, the flow path 35 is provided between the inner surface 20a of the frame 20 and the outer surface 20b of the frame 20. The flow path 35 is located outside the receiving chamber 25 and is separated from the receiving chamber 25 by the inner frame 31.

[0030] The flow path 35 is formed by the concave surface 31b of the inner frame 31 and the second contact surface 32a of the outer frame 32. The flow path 35 extends in a spiral shape around the rotation axis Ax, similar to the groove 31c.

[0031] The outer frame 32 is provided with an inlet 36 and an outlet 37. The inlet 36 and the outlet 37 respectively penetrate the outer frame 32 in a substantially radial direction and open to the second contact surface 32a and the outer surface 32b. For example, when the motor 10 is placed on a horizontal surface, the inlet 36 and the outlet 37 open to the outer surface 32b in a manner facing vertically upward.

[0032] The inlet 36 communicates with one end of the flow path 35. The outlet 37 communicates with the other end of the flow path 35. Alternatively, the inlet 36 and the outlet 37 may communicate with the flow path 35 between both ends of the flow path 35.

[0033] The inlet 36 is axially separated from the outlet 37 along the second direction D2. At least a portion of the stator 11 and at least a portion of the rotor 12 are located between the inlet 36 and the outlet 37 in the axial direction.

[0034] The first bracket 21 and the second bracket 22 are mounted on both ends of the frame 20 in the axial direction and close the accommodation chamber 25. The first bracket 21 is fixed to the end of the frame 20 in the first direction D1 by, for example, a plurality of bolts. The second bracket 22 is fixed to the end of the frame 20 in the second direction D2 by, for example, a plurality of bolts. The stator 11 and the rotor 12 are located between the first bracket 21 and the second bracket 22 in the axial direction.

[0035] The first bracket 21 is provided with a first insertion hole 41. The first insertion hole 41 axially penetrates the first bracket 21. The second bracket 22 is provided with a second insertion hole 42. The second insertion hole 42 axially penetrates the second bracket 22.

[0036] The shaft 13 is disposed so as to pass through the first insertion hole 41 and the second insertion hole 42. The first bracket 21 and the second bracket 22 support the shaft 13 via the bearing 15. With such a structure, the shaft 13 is rotatable around the rotation axis Ax.

[0037] The first bracket 21 and the second bracket 22 are provided with a vent 45. In addition, the vent 45 may also be provided in other parts of the housing 14. The vent 45 is connected to the storage chamber 25. The vent 45 has an air supply port 46 and an exhaust port 47. In the present embodiment, the vent 45 provided on one of the first bracket 21 and the second bracket 22 becomes the air supply port 46, and the vent 45 provided on the other of the first bracket 21 and the second bracket 22 becomes the exhaust port 47.

[0038] The air supply port 46 is provided in the first bracket 21. The air supply port 46 penetrates the first bracket 21 substantially in the axial direction. The exhaust port 47 is provided in the second bracket 22. Therefore, the air supply port 46 is separated from the exhaust port 47 in the first direction D1 in the axial direction. The exhaust port 47 penetrates the second bracket 22 in the axial direction. At least a portion of the stator 11 and at least a portion of the rotor 12 are located between the air supply port 46 and the exhaust port 47 in the axial direction. In addition, for example, when the air supply port 46 and the exhaust port 47 are provided in the frame 20, the air supply port 46 and the exhaust port 47 may also be located between the two ends of the stator 11 and the rotor 12 in the axial direction.

[0039] When viewed from the axial direction, the size (opening area) of the air supply port 46 is smaller than the size of the exhaust port 47. For example, when a plurality of air supply ports 46 are provided in the first bracket 21 and a plurality of exhaust ports 47 are provided in the second bracket 22, the sum of the sizes of the plurality of air supply ports 46 is smaller than the sum of the sizes of the plurality of exhaust ports 47. In addition, when one air supply port 46 is provided in the first bracket 21 and one exhaust port 47 is provided in the second bracket 22, the size of the air supply port 46 is smaller than the size of the exhaust port 47.

[0040] The first bracket 21 is further provided with a lead-out hole 48. The lead-out hole 48 is, for example, adjacent to the air supply port 46 in the circumferential direction. The lead wire 11a connected to the winding of the stator 11 passes through the lead-out hole 48 and extends to the outside of the housing 14. The sealing material 49 seals between the lead wire 11a and the edge of the lead-out hole 48. The sealing material 49 is, for example, a synthetic resin.

[0041] The cover 23 is located outside the storage chamber 25 and covers the exhaust port 47 of the second bracket 22. The cover 23 is separated from the second bracket 22. In addition, the housing 14 may omit the cover 23.

[0042] The air cooling device 16 is located outside the housing 14 and has a compressor 51 and a conduit 52. The compressor 51 is connected to the air supply port 46 through the conduit 52. The compressor 51 supplies high-pressure air CA to the air supply port 46. The air CA is an example of a gas. The compressor 51 filters the air CA through a filter. In addition, the compressor 51 can also supply other gases to the air supply port 46.

[0043] The air cooling device 16 is not limited to the above-mentioned example. For example, the air cooling device 16 may include a fan instead of the compressor 51 and the duct 52. The fan is driven by, for example, the outer portion 13b of the shaft 13 or another small motor to supply air CA to the air supply port 46. In addition, the air cooling device 16 may include a blower instead of the compressor 51.

[0044] The accommodation chamber 25 has an upstream space 25a and a downstream space 25b. The upstream space 25a is a part of the accommodation chamber 25 and is located between the stator 11 and the rotor 12 and the first bracket 21. The downstream space 25b is a part of the accommodation chamber 25 and is located between the stator 11 and the rotor 12 and the second bracket 22. The upstream space 25a and the downstream space 25b are connected to each other through the gap G between the stator 11 and the rotor 12.

[0045] The conduit 52 is airtightly connected to the air supply port 46. The outlet hole 48 is airtightly sealed by the sealing material 49. Thus, the upstream space 25a is airtightly isolated from the outside of the housing 14. On the other hand, the downstream space 25b is open to the outside of the housing 14 through the exhaust port 47 of the second bracket 22.

[0046] The water cooling device 17 has a pump 61, a pipe 62, and a heat exchanger 63. The pump 61 is connected to the inlet 36 and the outlet 37 through the pipe 62. The pump 61 supplies cooling water CW to the inlet 36 and draws cooling water CW from the outlet 37. Thus, the pump 61 causes the cooling water CW to flow through the flow path 35. The cooling water CW is an example of a liquid. In addition, the liquid may also be other liquids. The heat exchanger 63 cools the cooling water CW discharged from the outlet 37.

[0047] By pressing the inner frame 31 into the outer frame 32, the cooling water CW flowing in the flow path 35 can be prevented from leaking into the gap between the inner frame 31 and the outer frame 32. The outer frame 32 may be provided with a drain pipe for draining the leaked cooling water CW.

[0048] The motor 10 of this embodiment rotates the rotor 12 and the shaft 13 at high speed. For example, the rotor 12 and the shaft 13 rotate at a rotation number (rotation speed) per unit time of 3000 rpm or more. The rotation speed of the rotor 12 and the shaft 13 is not limited to this example.

[0049] When the motor 10 is driven, heat is generated in the motor 10. When the rotor 12 rotates at a high speed, the heat density of the rotor 12 increases due to wind loss and mechanical loss caused by air resistance of the rotor 12, for example.

[0050] While the motor 10 is driven, the water cooling device 17 allows the cooling water CW to flow through the flow path 35. The cooling water CW flows from the inlet 36 to the outlet 37 while cooling the housing 14. Therefore, the cooling water CW cools more of the portion of the housing 14 closer to the second bracket 22 than the first bracket 21.

[0051] The cooling water CW discharged from the outlet 37 is cooled by the heat exchanger 63 and then supplied to the inlet 36 again by the pump 61. Thus, the cooling water CW circulates through the pump 61 and the flow path 35 while being cooled outside the casing 14.

[0052] While the motor 10 is driven, the air cooling device 16 supplies air CA to the air supply port 46. Therefore, the pressure of the upstream space 25a rises. On the other hand, the downstream space 25b is opened to the outside of the housing 14 through the exhaust port 47. Therefore, the pressure of the downstream space 25b is lower than the pressure of the upstream space 25a.

[0053] The air CA supplied to the upstream space 25a is stirred by the rotating rotor 12. Thus, the pressure distribution in the circumferential direction in the upstream space 25a becomes substantially uniform. In addition, a member for diffusing the air CA supplied to the air supply port 46 may be provided in the upstream space 25a.

[0054] The air CA flows from the high-pressure upstream space 25a to the downstream space 25b through the gap G by using the pressure difference. The air CA flows in the gap G while cooling the stator 11 and the rotor 12. Therefore, the air CA cools more of the stator 11 and the rotor 12 that are closer to the first bracket 21 than the second bracket 22. The air CA in the downstream space 25b is discharged from the exhaust port 47 to the outside of the housing 14.

[0055] The air CA passes through the space between the second bracket 22 and the cover 23 and is released to the outside of the housing 14. The size of the space between the second bracket 22 and the cover 23 is set to sufficiently reduce ventilation resistance. The cover 23 prevents water and dust from entering the exhaust port 47, for example.

[0056] In the motor 10 of the embodiment described above, the housing chamber 25 that houses the stator 11 and the rotor 12, the vent 45 that communicates with the housing chamber 25, and the flow path 35 outside the housing chamber 25 are provided in the housing 14. The motor 10 can be cooled by water cooling by the cooling water CW flowing in the flow path 35. In addition, the air CA supplied from the vent 45 flows in the housing chamber 25, thereby suppressing the local temperature rise in the rotor 12, and improving the cooling capacity of the motor 10. As a result, the output of the motor 10 of a predetermined size can be increased, or the motor 10 of a predetermined output can be miniaturized.

[0057] At least a portion of the stator 11 and at least a portion of the rotor 12 are axially located between the air supply port 46 and the exhaust port 47. Thus, the air CA flowing from the air supply port 46 to the exhaust port 47 in the accommodation chamber 25 can cool the stator 11 and the rotor 12 more.

[0058] At least a portion of the stator 11 and at least a portion of the rotor 12 are axially located between the inlet 36 and the outlet 37. Thus, the cooling water CW flowing from the inlet 36 to the outlet 37 in the flow path 35 can cool the stator 11 and the rotor 12 more.

[0059] The air supply port 46 is separated from the exhaust port 47 in the axial direction, i.e., the first direction D1, in the axial direction. The inlet 36 is separated from the outlet 37 in the axial direction, in the second direction D2 opposite to the first direction D1. Thus, the axial distribution of the portion cooled by the air CA and the axial distribution of the portion cooled by the cooling water CW are substantially opposite. Therefore, the local temperature rise in the motor 10 can be suppressed, and the cooling capacity of the motor 10 is improved.

[0060] The flow path 35 is provided inside the frame 20. Thus, the cooling water CW flowing in the flow path 35 can directly cool the frame 20, thereby improving the cooling capacity of the motor 10. In addition, the flow path 35 does not need to be provided outside the housing 14 through, for example, a pipe, and the motor 10 can be miniaturized.

[0061] The flow path 35 extends in a spiral shape around the rotation axis Ax. Thus, the cooling water CW flowing through the flow path 35 can cool the electric motor 10 uniformly in the axial direction, thereby improving the cooling capacity of the electric motor 10.

[0062] The flow path 35 is provided between the inner frame 31 and the outer frame 32. Thus, the flow path 35 can be easily provided inside the frame 20 by fitting the inner frame 31 and the outer frame 32.

[0063] The above-mentioned embodiments of the present invention do not limit the scope of the invention, but are merely examples included in the scope of the invention. A certain embodiment of the present invention may also be changed, omitted, or added to at least a part of the specific use, structure, shape, function, and effect relative to the above-mentioned embodiments without departing from the scope of the main purpose of the invention.

Claims

1. A rotating electrical machine comprising: stator; A rotor, arranged inside the stator and capable of rotating around a rotation axis; A shaft, fixed to the rotor and extending along the axial direction of the rotating shaft; The housing is provided with a housing chamber for accommodating the stator and the rotor, an air supply port and an air exhaust port connected to the housing chamber and separated in the axial direction, a peripheral wall surrounding the housing chamber, a flow path provided inside the peripheral wall, and an inlet and an outlet connected to the flow path and separated in the axial direction, and supports the shaft. a first cooling device for supplying gas to the gas supply port; and A second cooling device allows liquid to flow through the flow path, cools the liquid discharged from the outlet, and supplies the liquid to the inlet, The peripheral wall includes an inner wall fixed to the stator and an outer wall surrounding the inner wall while being in contact with the inner wall. The inner wall has a groove as a concave surface, the concave surface is recessed from a contact surface between the inner wall and the outer wall, and the groove is provided as the flow path. At least a portion of the stator and at least a portion of the rotor are located between the air supply port and the air exhaust port and between the inlet and the outlet in the axial direction. The air supply port is separated from the air exhaust port along a first direction in the axial direction. The inlet is separated from the outlet in a second direction opposite to the first direction in the axial direction, The opening area of ​​the air supply port is smaller than the opening area of ​​the air exhaust port, The accommodation chamber is open to the outside of the housing through the exhaust port.

2. The rotating electrical machine according to claim 1, wherein: The flow path extends in a spiral shape around the rotation axis.

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