Rotary electric machine

Abstract

To obtain a rotary electric machine capable of further suppressing ingress of liquid such as water into the inside of a bearing device from the outside.SOLUTION: A rotary electric machine is provided with a bearing device 24, a cover 401, and a protrusion 223. The protrusion 223 is located on a side opposite to a rotor core relative to the bearing device 24, protruded from an outer circumferential surface 221f of a shaft 221 in the radial direction of a rotational central axis Ax, located in the cover 401, separated from the cover 401, and is annular around the rotational central axis Ax.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine. [Background technology]

[0002] A rotating electric machine is known that includes a housing, a shaft located inside and outside the housing, a bearing device supported by the housing and rotatably supporting the shaft, and a cover provided on the opposite side of the bearing device from the rotor core. In a rotating electric machine configured in this way, the cover can prevent liquid such as water from flowing into the bearing device from the outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-201516 A Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of rotating electric machine, it would be beneficial if it were possible to further prevent liquid such as water from entering the inside of the bearing device from the outside of the rotating electric machine.

[0005] One example of a problem to be solved by the present invention is to provide a rotating electric machine that can further prevent liquids such as water from entering the inside of a bearing device from the outside. [Means for solving the problem]

[0006] A rotating electric machine according to an embodiment of the present invention comprises a housing, a rotor having a stator accommodated in the housing and fixed to the housing, a shaft arranged across the inside and outside of the housing with a portion located inside the stator, and a rotor core fixed to the shaft and located inside the stator, a bearing device having a fixed portion fixed to the housing and supporting the shaft rotatably around a rotation axis, a cover having a cylindrical portion extending from the fixed portion on the side opposite the rotor core to the bearing device and formed into a cylindrical shape around the rotation axis, and an extension portion on the cylindrical portion extending from a position spaced axially from the fixed portion toward the outer circumferential surface of the shaft and spaced apart from the outer circumferential surface and having a ring shape around the rotation axis, and a protrusion located on the side opposite the rotor core to the bearing device, protruding from the outer circumferential surface in the radial direction of the rotation axis, located within the cover, spaced apart from the cover, and having a ring shape around the rotation axis. Effect of the Invention

[0007] According to the rotating electric machine of the embodiment of the present invention, it is possible to obtain a rotating electric machine that can further prevent liquid such as water from entering the inside of the bearing device from the outside. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a rotating electric machine according to a first embodiment. [Diagram 2] FIG. 2 is a front view of the rotating electric machine according to the first embodiment. [Diagram 3] FIG. 3 is a schematic cross-sectional view of the rotating electric machine according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view of a portion including a bearing device in the rotating electric machine according to the first embodiment. [Diagram 5] FIG. 5 is a cross-sectional view of a portion including a cover in the rotating electric machine according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a portion including a cover in a rotating electric machine according to the second embodiment. [Figure 7]FIG. 7 is a cross-sectional view of a portion including a cover in a rotating electric machine according to the third embodiment. [Figure 8] FIG. 8 is a cross-sectional view of a portion including a cover in a rotating electric machine according to the fourth embodiment. [Figure 9] FIG. 9 is a cross-sectional view of a portion including a cover in a rotating electric machine according to the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, exemplary embodiments of the present invention will be disclosed. The configurations (technical features) of the embodiments described below, as well as the actions and results (effects) brought about by the configurations, are merely examples.

[0010] In addition, the drawings are schematic, and the dimensional relationships and ratios of each element may differ from reality. Furthermore, the drawings may include parts whose dimensional relationships and ratios differ from one another. In this specification, ordinal numbers are used only to distinguish between parts, members, sites, positions, directions, etc., and do not indicate order or priority.

[0011] <First embodiment> Fig. 1 is a side view of a rotating electric machine 1 according to the first embodiment. Fig. 2 is a front view of the rotating electric machine 1 according to the first embodiment. The rotating electric machine 1 is, for example, a motor or a generator. However, the rotating electric machine 1 is not limited to this example. As shown in Fig. 2, the rotating electric machine 1 includes a main body 2, a cooling device 3, a bearing cooling device 4, and a control device 5.

[0012] The rotating electric machine 1 is, for example, a totally enclosed rotating electric machine. Therefore, inside the rotating electric machine 1, a closed space filled with a cooling gas such as air is provided between the main body 2 and the cooling device 3.

[0013] Fig. 3 is a schematic cross-sectional view of the rotating electric machine 1 of the first embodiment. Fig. 4 is a cross-sectional view of a portion including the bearing device 24 in the rotating electric machine 1 of the first embodiment. As shown in Fig. 3, the main body 2 has a housing 21, a rotor 22, a stator 23, two bearing devices 24, and two covers 401.

[0014] In the following drawings, three mutually orthogonal directions are defined for convenience. The X direction is a direction along the longitudinal direction of the housing 21 and the axial direction of the rotation center axis Ax of the rotor 22, and may also be referred to as the front-rear direction. The Y direction is a direction along a direction perpendicular to the lateral direction of the housing 21 and the axial direction of the rotation center axis Ax, and may also be referred to as the left-right direction. The Z direction is a direction along the vertical direction of the housing 21, and may also be referred to as the up-down direction. Note that the expressions indicating directions such as front-rear, left-right, up-down, and down in this embodiment are names for convenience, and do not limit the position, attitude, and usage mode of the rotating electric machine 1.

[0015] 1 to 3, housing 21 is formed in a box shape. Housing 21 accommodates a part of rotor 22 and stator 23. Housing 21 has a bottom wall 21a, a top wall 21b, two end walls 21c, 21d, and two side walls 21e, 21f.

[0016] The bottom wall 21a and the top wall 21b both extend along a direction perpendicular to the Z direction (XY plane) and are provided approximately parallel to each other with a gap in the Z direction. The bottom wall 21a forms the lower end of the housing 21, and the top wall 21b forms the upper end of the housing 21.

[0017] End wall 21c and end wall 21d both extend in a direction perpendicular to the X direction (YZ plane) and are provided parallel to each other with a gap in the X direction. End wall 21c is provided between the ends of bottom wall 21a and top wall 21b in the opposite direction to the X direction. End wall 21d is provided between the ends of bottom wall 21a and top wall 21b in the X direction.

[0018] Both side wall 21e and side wall 21f extend in a direction perpendicular to the Y direction (XZ plane) and are provided parallel to each other with a gap in the Y direction. Side wall 21e is provided between the respective ends of bottom wall 21a and top wall 21b in the Y direction. Side wall 21f is provided between the respective ends of bottom wall 21a and top wall 21b in the opposite direction to the Y direction.

[0019] 2, a cooling device 3 is attached to the top wall 21b. Furthermore, a bearing cooling device 4 is attached to the side wall 21e. Furthermore, a control device 5 is attached to the side wall 21f. That is, the bearing cooling device 4 and the control device 5 are disposed on opposite sides of the housing 21. In other words, the housing 21 is disposed between the bearing cooling device 4 and the control device 5.

[0020] 3, the rotor 22 has a shaft 221 and a rotor core 222. The shaft 221 is supported by the housing 21 via two bearing devices 24 so as to be rotatable about a rotation center axis Ax. In other words, the two bearing devices 24 support the shaft 221 so as to be rotatable with respect to the housing 21. The rotation center axis Ax is, for example, the central axis (center line) of the shaft 221. Note that the rotation center axis Ax may be different from the central axis of the shaft 221.

[0021] In the following description, for convenience, the axial direction, radial direction, and circumferential direction of the rotation central axis Ax are defined. The axial direction is a direction along the rotation central axis Ax. The radial direction is a direction perpendicular to the rotation central axis Ax. The circumferential direction is a direction around the rotation central axis Ax.

[0022] The axial direction, radial direction, and circumferential direction of the central axis of rotation Ax are the same as the axial direction, radial direction, and circumferential direction of the shaft 221. In the following description, unless otherwise specified, the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction of the central axis of rotation Ax, that is, the axial direction, radial direction, and circumferential direction of the shaft 221.

[0023] The shaft 221 extends in the X direction so as to penetrate the end walls 21c and 21d. A portion of the shaft 221 between the axial ends 221a, 221b is housed in the housing 21. On the other hand, the axial ends 221a, 221b of the shaft 221 protrude from the housing 21 to the outside.

[0024] One end 221a is coupled to, for example, a coupling target (not shown). An external fan (not shown) is fixed to the other end 221b. The external fan is covered by, for example, an external fan cover, and rotates together with the shaft 221.

[0025] Rotor core 222 is fixed to a portion of shaft 221 between axial ends 221a, 221b. For this reason, rotor core 222 is housed in housing 21. Rotor core 222 rotates integrally with shaft 221.

[0026] An internal fan 28 is fixed between each of the two bearing devices 24 on the shaft 221 and the rotor core 222. The internal fan 28 rotates integrally with the shaft 221, and circulates a cooling gas in the closed space.

[0027] 4, the shaft 221 has an axle portion 221c and a mounted portion 221d. The axle portion 221c and the mounted portion 221d are each a part of the shaft 221. For example, an internal fan 28 is attached to the axle portion 221c. The mounted portion 221d is supported by a bearing device 24.

[0028] The mounted portion 221d is, for example, a portion of the shaft portion 221c that is reduced in the radial direction. That is, the diameter of the mounted portion 221d is shorter than the diameter of the shaft portion 221c. The diameter of the mounted portion 221d may be longer than the diameter of the shaft portion 221c.

[0029] 3, the stator 23 is housed in the housing 21. The stator 23 has a stator core 231 and a stator winding 232. The stator core 231 is fixed to the housing 21. The stator core 231 is located outside the rotor core 222 in the radial direction, and is formed in a cylindrical shape surrounding the rotor core 222. The stator winding 232 passes through a plurality of slots (not shown) formed in an inner periphery 231a of the stator core 231 so as to extend in the axial direction, and is fixed to the stator core 231.

[0030] The bearing device 24 is, for example, a sliding bearing, and is lubricated by lubricating oil. The two bearing bodies 24a are provided on the two end walls 21c and 21d. That is, in the shaft 221, the rotor core 222 is located between the two bearing devices 24 in the axial direction.

[0031] 4, each bearing device 24 includes an oil tank 25, a bearing body 24a, an oil tank body 301, two first rotating members 26, and a second rotating member 27. The bearing device 24 is also called a bearing unit. The oil tank 25 is also called a case.

[0032] The oil vat 25 is fixed to the housing 21. The oil vat 25 accommodates the bearing body 24a, the oil vat body 301, two first rotating members 26, and a second rotating member 27. The oil vat 25 is an example of a fixed portion.

[0033] The oil vat 25 has an oil vat body 301, a cover 302, and an attachment part 303. The oil vat body 301, the cover 302, and the attachment part 303 are joined together and integrated. The oil vat body 301 and the cover 302 cover the shaft 221. The cover 302 is located on the upper side of the oil vat body 301. The bearing body 24a, the oil vat body 301, the two first rotating members 26, and the second rotating member 27 are located between the oil vat body 301 and the cover 302. The attachment part 303 is located on the opposite side of the rotor core 222 with respect to the oil vat body 301 and the cover 302, and is located outside the housing 21.

[0034] Fig. 5 is a cross-sectional view of a portion including the cover 401 in the rotating electric machine 1 of the first embodiment. As shown in Fig. 5, the mounting portion 303 is formed in a cylindrical shape around the central axis of rotation Ax. The mounting portion 303 has a base portion 303a and an extending portion 303b.

[0035] The base portion 303a is provided on the opposite side of the oil vat body 301 and the cover 302 from the rotor core 222. The base portion 303a is formed in a cylindrical shape about the central axis of rotation Ax. The base portion 303a is fixed to the oil vat body 301 and the cover 302 by fasteners 501 such as bolts. In addition, a seal member 281 is attached to the base portion 303a.

[0036] The extension portion 303b extends from the base portion 303a toward the outer circumferential surface 221f of the shaft 221. The extension portion 303b is annular about the central axis of rotation Ax. The extension portion 303b is spaced apart from the outer circumferential surface 221f of the shaft 221. That is, a gap B1 is provided between a tip end 303c (inner circumferential surface) of the extension portion 303b and the outer circumferential surface 221f of the shaft 221.

[0037] The bearing body 24a supports the shaft 221 rotatably around the central axis of rotation Ax. The bearing body 24a has a first bearing metal 241 and a second bearing metal 242. In this embodiment, the first bearing metal 241 and the second bearing metal 242 are different components and are separable. Note that the bearing body 24a is not limited to this example.

[0038] The first bearing metal 241 is located above the second bearing metal 242. Furthermore, at least a portion of the first bearing metal 241 is located above the mounted portion 221d of the shaft 221. The first bearing metal 241 has an inner circumferential surface 241a.

[0039] An inner peripheral surface 241a of the first bearing metal 241 faces the outer peripheral surface of the mounted portion 221d. The diameter of the inner peripheral surface 241a is, for example, slightly larger than the diameter of the mounted portion 221d. The inner peripheral surface 241a is capable of supporting the mounted portion 221d.

[0040] A groove 241b is provided in the first bearing metal 241. The groove 241b is recessed from an inner circumferential surface 241a of the first bearing metal 241 toward the outside in the radial direction of the shaft 221, and extends in the circumferential direction of the shaft 221.

[0041] At least a portion of the second bearing metal 242 is located below the mounted portion 221d of the shaft 221. The second bearing metal 242 has an inner circumferential surface 242a. The inner circumferential surface 242a faces the outer circumferential surface of the mounted portion 221d.

[0042] The diameter of the inner circumferential surface 242a of the second bearing metal 242 is, for example, slightly larger than the diameter of the mounted portion 221d. For example, the diameter of the inner circumferential surface 242a of the second bearing metal 242 is substantially equal to the diameter of the inner circumferential surface 241a of the first bearing metal 241. Moreover, the inner circumferential surfaces 241a, 242a are arranged concentrically around the central axis of rotation Ax.

[0043] An inner circumferential surface 242a of the second bearing metal 242 is capable of supporting a mounted portion 221d of the shaft 221. The mounted portion 221d is disposed between the inner circumferential surface 241a of the first bearing metal 241 and the inner circumferential surface 242a of the second bearing metal 242.

[0044] The second bearing metal 242 is attached to the first bearing metal 241. As a result, the mounted portion 221d is supported by being sandwiched between the first bearing metal 241 and the second bearing metal 242. In other words, each bearing body 24a supports the shaft 221 between the first bearing metal 241 and the second bearing metal 242.

[0045] The oil tank 25 (oil tank body 301) is attached to the two end walls 21c, 21d around the bearing body 24a. Each oil tank body 301 is provided with a space for storing the lubricating oil F that lubricates each bearing body 24a.

[0046] The oil tank 25 (oil tank main body 301) has, for example, two first storage spaces 251 and a second storage space 252. Lubricating oil F is stored in the first storage space 251 and the second storage space 252. The two first storage spaces 251 and the second storage space 252 are in communication with each other. Therefore, in the oil tank 25 (oil tank main body 301), the lubricating oil F can move between the first storage space 251 and the second storage space 252.

[0047] The first storage space 251 is provided below the shaft portion 221c of the shaft 221. The second storage space 252 is located between the two first storage spaces 251 in the axial direction of the shaft 221. The second storage space 252 is provided below the mounted portion 221d of the shaft 221 and the bearing body 24a.

[0048] The first rotating member 26 has a mounting ring 261 and a plurality of blades 262. It should be noted that the first rotating member 26 is not limited to this example.

[0049] The mounting ring 261 is formed in an annular shape. The mounting ring 261 is attached to the outer circumferential surface of the shaft portion 221c of the shaft 221. In this way, the first rotating members 26 are attached to the shaft portion 221c. The two first rotating members 26 rotate with the rotation of the shaft 221. The first rotating members 26 may be integral with the shaft 221.

[0050] The blades 262 protrude radially outward from the outer circumferential surface of the mounting ring 261. The blades 262 are arranged at intervals in the circumferential direction of the shaft 221. Each blade 262 is formed in a plate shape extending in the axial direction. Note that the shape of each blade 262 is not limited to this example.

[0051] The two first rotating members 26 are positioned at a distance from each other in the axial direction of the shaft 221. In the axial direction of the shaft 221, the position of the first rotating member 26 and the positions of the two first storage spaces 251 approximately coincide with each other. Parts of the two first rotating members 26 are housed in the corresponding first storage spaces 251.

[0052] A part of the plurality of vanes 262 is partially immersed in the lubricating oil F stored in the first storage space 251. The protruding length of each vane 262 may be changed as appropriate as long as each vane 262 is partially immersed in the lubricating oil F stored in the first storage space 251.

[0053] The second rotating member 27 has an oil ring 271. The oil ring 271 is attached to the bearing body 24a. Therefore, the oil ring 271 is located between the two first rotating members 26 in the axial direction of the shaft 221. The oil ring 271 may be a part of the bearing body 24a.

[0054] The oil ring 271 is formed in an annular shape. The oil ring 271 is disposed around the mounted portion 221d of the shaft 221. The oil ring 271 has an inner peripheral surface and an outer peripheral surface. The inner peripheral surface of the oil ring 271 faces the mounted portion 221d of the shaft 221. The diameter of the inner peripheral surface is larger than the outer diameter of the mounted portion 221d. The outer peripheral surface of the oil ring 271 is located on the opposite side of the inner peripheral surface. The outer peripheral surface is provided with a plurality of grooves recessed radially inward from the outer peripheral surface, spaced apart in the circumferential direction. The plurality of grooves are arranged at intervals in the circumferential direction of the shaft 221. The depth of each groove is set so that the lubricating oil F can adhere thereto.

[0055] The oil ring 271 extends in an annular shape through the gap between the first bearing metal 241 and the second bearing metal 242 of the bearing body 24a in a state in which the shaft 221 is supported by the bearing body 24a. The center of the oil ring 271 is eccentric from the central rotation axis Ax.

[0056] An upper portion of the oil ring 271 is covered by the first bearing metal 241, and is rotatably fitted in a groove of the first bearing metal 241. The oil ring 271 is suspended from the mounted portion 221d and supported near the top of the mounted portion 221d. Therefore, the oil ring 271 rotates in conjunction with the rotation of the shaft 221.

[0057] The oil ring 271 except for its upper portion is exposed to the outside from the groove 241b of the first bearing metal 241. The lower portion of the oil ring 271 is partially immersed in the lubricating oil F stored in the second storage space 252 of each oil tank body 301. Therefore, the lubricating oil F enters the groove 272 provided in the lower portion of the oil ring 271.

[0058] In this embodiment, in each oil tank body 301, the two first rotating members 26 and the second rotating member 27 are attached to the shaft 221. However, for example, the rotating electric machine 1 may have one of the two first rotating members 26 and the second rotating member 27 attached to the shaft 221.

[0059] 1, the cooling device 3 is placed on and fixed to the top wall 21b of the housing 21. The cooling device 3 cools the rotor 22 and the stator 23 by exchanging heat between the cooling gas in the housing 21 and the outside air outside the housing 21. An external fan causes the outside air to flow past the cooling device 3.

[0060] The bearing cooling device 4 has a housing 41, a cooling section, a first piping section 44, a second piping section 45, and a connecting section .

[0061] The housing 41 is formed in a box shape and houses the cooling unit. The housing 41 is detachably fixed to the side wall 21e of the housing 21 of the main body 2 by fasteners such as bolts.

[0062] The cooling section cools the lubricating oil F passing through the cooling section. The cooling section has, for example, a heat exchanger through which the lubricating oil F passes and a fan, and is cooled by heat exchange with the air outside the heat exchanger (outside air). The fan blows air so that the air flows along the surface of the heat exchanger.

[0063] The first piping section 44 has pipes 44a and 44b. The pipe 44a extends from the oil vat body 301. The pipe 44b extends from the cooling section. The pipes 44a and 44b are detachably connected to each other at a connection section 46. The first piping section 44 is provided between each oil vat body 301 and the cooling section. That is, the first piping section 44 connects each oil vat body 301 and the cooling section.

[0064] 4, the inlet 44c of the first piping section 44 is connected to one of the first storage spaces 251 in each of the oil tank bodies 301. That is, the first piping section 44 is connected to the oil tank body 301 at a position in the axial direction of the shaft 221 where the first rotating member 26 is provided.

[0065] The second piping section 45 has pipes 45a and 45d. The pipe 45a extends from the oil vapour body 301. The pipe 45d extends from the cooling section. The pipes 45a and 45d are detachably connected to each other at a connection section 46. The second piping section 45 is provided between each oil vapour body 301 and the cooling section. That is, the second piping section 45 is provided between each oil vapour body 301 and the cooling section, and connects each oil vapour body 301 and the cooling section.

[0066] The lubricating oil F cooled in the cooling section can flow through the second piping section 45 from the cooling section to each oil tank body 301. The outlet 45c of the second piping section 45 communicates with the internal space of the oil tank body 301 above each bearing body 24a. Therefore, in the oil tank body 301, the lubricating oil F is supplied from above the bearing body 24a to the bearing body 24a, the first storage space 251, and the second storage space 252.

[0067] The control device 5 controls the rotational operation of the rotating electric machine 1 and the bearing cooling device 4. For example, the control device 5 has a board and various electronic components such as a microcomputer mounted on the board. The control device 5 is electrically connected to the bearing cooling device 4 and the stator 23.

[0068] When the rotating electric machine 1 is operated, the first rotating member 26 and the second rotating member 27 attached to the shaft 221 rotate in accordance with the rotation of the shaft 221. The plurality of blades 262 of the rotating first rotating member 26 increase the pressure of the lubricating oil F stored in the first storage space 251. In addition, the plurality of grooves 272 of the rotating second rotating member 27 increase the pressure of the lubricating oil F stored in the second storage space 252.

[0069] The lubricating oil F pressurized in the first storage space 251 and the second storage space 252 is sent to the cooling section from the inlet 44c of the first piping section 44. In other words, each of the first rotating members 26 and the second rotating members 27 contacts the lubricating oil F in each oil tank body 301 and rotates with the rotation of the shaft 221 to send the lubricating oil F in each oil tank body 301 to the cooling section through the first piping section 44. At this time, the lubricating oil F adhering to the multiple vanes 262 and the groove 272 is wiped off near the top of the shaft 221. The wiped off lubricating oil F enters between the shaft 221 and the bearing body 24a and lubricates this portion.

[0070] The lubricating oil F that has passed through the cooling section is cooled and discharged from the outlet 45c of the second piping section 45. The lubricating oil F discharged from the outlet 45c of the second piping section 45 is supplied to each bearing body 24a to lubricate and cool the bearing body 24a.

[0071] The lubricating oil F supplied to each bearing body 24a flows down and is stored in the first storage space 251 and the second storage space 252 of each oil tank body 301. Thereafter, the lubricating oil F circulates between each oil tank body 301 and the cooling section in a similar manner.

[0072] 4 and 5, the cover 302 is located on the opposite side of the bearing device 24 from the rotor core 222. The cover 302 is located outside the housing 21. The cover 302 is fixed to a mounting portion 303 of the oil tank 25 of the bearing device 24 by a fastener 502 such as a bolt.

[0073] The cover 302 is formed in a cylindrical shape around the central axis of rotation Ax. The cover 302 has a cylindrical portion 401a and an extending portion 401b.

[0074] The cylindrical portion 401a extends from the oil tank 25 on the opposite side of the bearing device 24 from the rotor core 222, and is formed in a cylindrical shape about the central axis of rotation Ax.

[0075] The extension portion 401b extends from a position in the cylindrical portion 401a spaced from the oil vat 25 in the axial direction of the rotation axis Ax toward the outer circumferential surface 221f of the shaft 221. The extension portion 401b is annular about the rotation axis Ax. The extension portion 401b is spaced from the outer circumferential surface 221f. That is, a gap B2 is provided between a tip end 401c (inner circumferential surface) of the extension portion 401B and the outer circumferential surface 221f of the shaft 221.

[0076] 5, the cover 302 is formed by combining a plurality of members. For example, the cover 302 has a spacer 402 including a part of the cylindrical portion 401a, and a baffle 403 including a part of the cylindrical portion 401a and an extension portion 401b. The spacer 402 and the baffle 403 are fixed to the mounting portion 303 of the bearing device 24 by a fastener 502 such as a bolt. The cover 302 may be formed by a single member.

[0077] As shown in FIG. 5, the rotating electric machine 1 has a protrusion 223 provided on the shaft 221. The protrusion 223 is located on the opposite side of the rotor core 222 with respect to the bearing device 24, protrudes from the outer circumferential surface 221f of the shaft 221 in the radial direction of the rotation center axis Ax, and is located inside the cover 401. The protrusion 223 is annular around the rotation center axis Ax. The protrusion 223 is spaced apart from the cover 401. That is, a gap B3 is provided between the tip portion 223b (outer circumferential surface) of the protrusion 223 and the inner circumferential surface 401d of the cylindrical portion 401a of the cover 401. The protrusion 223 is formed integrally with the shaft 221, for example, and is made of the same metal material as the shaft 221. The protrusion 223 may be made of a separate member from the shaft 221 and fixed to the shaft 221. The material of the protrusion 223 may be different from that of the shaft 221.

[0078] The protrusion 223 is constituted by an annular base portion 223a that protrudes radially outward from the outer circumferential surface 221f and is shaped like a ring around the rotation axis Ax. The base portion 223a, i.e., the protrusion 223, has a rectangular cross section perpendicular to the circumferential direction of the rotation axis Ax.

[0079] In the rotating electric machine 1 having the above configuration, when a fluid such as water flows from the outside of the rotating electric machine 1 toward the bearing device 24, the cover 401 prevents the fluid from entering the inside of the bearing device 24. At this time, for example, if the momentum of the fluid flow is relatively large, a part of the fluid may enter the inside of the cover 401 through the gap B2 between the extension part 401b of the cover 401 and the outer circumferential surface 221f of the shaft 221 and proceed toward the bearing device 24. In this case, the fluid collides with the protrusion 223. This reduces the momentum of the fluid flow, and the fluid flows downward without climbing over the protrusion 223. Therefore, the fluid is prevented from entering the inside of the bearing device 24. Examples of a fluid flow with a large momentum include a jet stream and ocean waves.

[0080] As described above, the rotating electric machine 1 of this embodiment includes the housing 21, the stator 23, the rotor 22, the bearing device 24, the cover 401, and the protrusions 223. The stator 23 is accommodated in the housing 21 and fixed to the housing 21. The rotor 22 has the shaft 221 and the rotor core 222. The shaft 221 is provided across the inside and outside of the housing 21, and a part of the shaft 221 is located inside the stator 23. The rotor core 222 is fixed to the shaft 221 and located inside the stator 23. The bearing device 24 has an oil tank 25 (fixed portion) fixed to the housing 21, and supports the shaft 221 rotatably around the rotation center axis Ax. The cover 401 has a cylindrical portion 401a and an extending portion 401b. The cylindrical portion 401a extends from the oil vat 25 on the opposite side of the rotor core 222 with respect to the bearing device 24, and is formed in a cylindrical shape around the rotation axis Ax. The extending portion 401b extends from a position in the cylindrical portion 401a spaced from the oil vat 25 in the axial direction of the rotation axis Ax toward the outer circumferential surface 221f of the shaft 221, and is spaced from the outer circumferential surface 221f, and is annular about the rotation axis Ax. The protrusion 223 is located on the opposite side of the rotor core 222 with respect to the bearing device 24, protrudes from the outer circumferential surface 221f of the shaft 221 in the radial direction of the rotation axis Ax, is located within the cover 401, and is spaced from the cover 401, and is annular about the rotation axis Ax.

[0081] According to this configuration, when a fluid such as water flows from the outside of the rotating electric machine 1 toward the bearing device 24, the cover 401 can prevent the fluid from entering the inside of the bearing device 24. Even if the force of the fluid flow is strong and a part of the fluid enters the inside of the cover 401 from between the extension part 401b of the cover 401 and the outer circumferential surface 221f of the shaft 221 and moves toward the bearing device 24, the protrusion 223 can prevent the fluid from entering the inside of the bearing device 24. That is, according to the above configuration, it is possible to further prevent liquid such as water from entering the inside of the bearing device 24 from the outside. According to this configuration, for example, the requirement of IP56 in JEC2110 of the JEC standard can be satisfied.

[0082] Moreover, the protrusion 223 has a rectangular cross section perpendicular to the circumferential direction of the rotation center axis Ax.

[0083] With this configuration, the projections 223 are easy to manufacture.

[0084] <Second embodiment> FIG. 6 is a cross-sectional view of a portion including a cover 401 in the rotating electric machine 1 according to the second embodiment.

[0085] As shown in FIG. 6, this embodiment differs from the first embodiment in that a protrusion 223A is provided instead of the protrusion 223 of the first embodiment.

[0086] The protrusion 223A has a base portion 223a, a protruding portion 223c, and a protruding portion 223d.

[0087] The protruding portion 223c is annular about the rotation axis Ax. The protruding portion 223c protrudes from the base portion 223a to the opposite side to the rotor core 222, and is spaced apart from the outer circumferential surface 221f of the shaft 221. The protruding portion 223c is annular about the rotation axis Ax.

[0088] The protruding portion 223d is annular about the rotation axis Ax. The protruding portion 223d protrudes from the base portion 223a toward the rotor core 222 and is spaced apart from the outer circumferential surface 221f of the shaft 221. The protruding portion 223d is annular about the rotation axis Ax.

[0089] According to this configuration, when a fluid enters the inside of the cover 401, the fluid that collides with the base portion 223a and flows radially outward collides with the overhanging portion 223c, and its momentum is reduced. In this manner, in this embodiment, even if a fluid enters the inside of the cover 401, the base portion 223a and the overhanging portion 223c of the protrusion 223A reduce the momentum of the fluid. Therefore, it is possible to further prevent the fluid from climbing over the protrusion 223A and entering the inside of the bearing device 24. In other words, according to the above configuration, the protrusion 223A can further prevent the fluid from entering the inside of the bearing device 24.

[0090] <Third embodiment> FIG. 7 is a cross-sectional view of a portion including a cover 401 in a rotating electric machine 1 according to the third embodiment.

[0091] 7, this embodiment differs from the first embodiment in that a plurality of (three, for example) protrusions 223 are provided. Note that the number of protrusions 223 is not limited to the above.

[0092] The multiple protrusions 223 are arranged at intervals in the axial direction of the rotation center axis Ax.

[0093] According to this configuration, even if the fluid that has entered the cover 401 passes over the first protrusion 223, the fluid hits the second protrusion 223 and its momentum is reduced. Moreover, even if the fluid passes over the second protrusion 223, the fluid hits the third protrusion 223 and its momentum is further reduced. Thus, in this embodiment, even if the fluid has entered the inside of the cover 401, the multiple protrusions 223 reduce the momentum of the fluid, so that the fluid can be further prevented from passing over the protrusions 223 and entering the inside of the bearing device 24. In other words, according to the above configuration, it is possible to further prevent liquids such as water from entering the inside of the bearing device 24 from the outside.

[0094] <Fourth embodiment> FIG. 8 is a cross-sectional view of a portion including a cover 401 in a rotating electric machine 1 according to the fourth embodiment.

[0095] As shown in FIG. 8, this embodiment differs from the first embodiment in that a protrusion 223B is provided instead of the protrusion 223 of the first embodiment.

[0096] The projection 223B is inclined with respect to the rotation center axis Ax so as to move away from the rotor core 222 with increasing distance from the outer circumferential surface 221f.

[0097] According to this configuration, the fluid that hits the protrusion 223B is guided by the protrusion 223B radially outward and in a direction away from the rotor core 222 and the bearing device 24. This further prevents the fluid from climbing over the protrusion 223B. Therefore, according to the above configuration, the protrusion 223B can further prevent the fluid from entering the inside of the bearing device 24.

[0098] <Fifth embodiment> FIG. 9 is a cross-sectional view of a portion including a cover 401 in a rotating electric machine 1 according to the fifth embodiment.

[0099] As shown in FIG. 9, this embodiment differs from the first embodiment in that a protrusion 223C is provided instead of the protrusion 223 of the first embodiment.

[0100] The protrusion 223C has a base portion 223a and a plurality of (for example, two) overhanging portions 223c. The shape of the overhanging portions 223c is the same as that shown in FIG. 6. The overhanging portions 223c are arranged at intervals in the radial direction of the rotation center axis Ax. The number of overhanging portions 223c is not limited to the above.

[0101] According to this configuration, even if the fluid that has entered the cover 401 flows radially outward around the base portion 223a of the protrusion 223C and goes over the first overhanging portion 223c, the fluid hits the second overhanging portion 223c and its momentum is reduced. In this manner, in this embodiment, even if the fluid has entered the interior of the cover 401, the multiple overhanging portions 223c reduce the momentum of the fluid, so that the fluid can be further prevented from going over the protrusion 223C and entering the interior of the bearing device 24. In other words, according to the above configuration, it is possible to further prevent liquids such as water from entering the interior of the bearing device 24 from the outside.

[0102] Although the embodiment of the present invention has been described above, the above embodiment is merely an example and is not intended to limit the scope of the invention. The above embodiment can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the gist of the invention. Furthermore, the specifications of each configuration, shape, and the like (structure, type, direction, format, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be appropriately changed and implemented. [Explanation of symbols]

[0103] 1... rotating electric machine, 21... housing, 22... rotor, 23... stator, 24... bearing device, 25... oil tank (fixed part), 221... shaft, 221f... outer peripheral surface, 222... rotor core, 223, 223A, 223B, 223C... protrusions, 223a... base part, 223c... protrusion, 401... cover, 401a... cylindrical part, 401b... extension part, Ax... rotation axis.

Claims

1. A housing and a stator housed in the housing and fixed to the housing; a rotor including a shaft provided across the inside and outside of the housing and a portion of which is located inside the stator, and a rotor core fixed to the shaft and located inside the stator; a bearing device having a fixed portion fixed to the housing and supporting the shaft rotatably about a rotation center axis; a cover including: a cylindrical portion extending from the fixed portion on a side opposite to the rotor core with respect to the bearing device, the cylindrical portion being formed into a cylindrical shape around the rotation center axis; and an extension portion extending from a position on the cylindrical portion spaced apart from the fixed portion in the axial direction of the rotation center axis toward an outer circumferential surface of the shaft, the extension portion being spaced apart from the outer circumferential surface, and having an annular shape around the rotation center axis; a protrusion located on the opposite side of the rotor core with respect to the bearing device, protruding from the outer circumferential surface in a radial direction of the rotation central shaft, located within the cover, spaced apart from the cover, and having an annular shape around the rotation central shaft; A rotating electric machine equipped with the above structure.

2. The protrusion has a rectangular cross section perpendicular to the circumferential direction of the rotation center axis. The rotating electric machine according to claim 1 .

3. The protrusion is a base portion protruding from the outer circumferential surface in a radial direction of the rotation central axis; a protruding portion protruding from the base portion toward an opposite side to the rotor core and spaced apart from the outer circumferential surface; With The rotating electric machine according to claim 1 .

Images