Motor

Abstract

To provide a motor by which a rotation shaft and a rotor can be efficiently cooled on a downstream side of a fluid distribution route.SOLUTION: A motor includes: a rotation shaft 20 formed into a hollow shape; a rotor 30 fixed to the rotation shaft 20; a pipe 50 that is disposed in an interior space of the rotation shaft 20 and supplies a fluid into the interior space of the rotation shaft 20; a bearing 60 that is disposed in the interior space of the rotation shaft 20 so as to section the interior space into a front space to which the fluid can flow from the pipe 50 and a rear space from which the fluid can flow to the outside of the rotation shaft 20, and supports the pipe 50; a first distribution part 70 that is formed inside the rotor 30 and distributes the fluid from the front space to the rear space; and a second distribution part 80 that is formed inside the rotation shaft 20 and distributes the fluid from the front space to the rear space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the technology of fluid-coolable motors. [Background technology]

[0002] Conventionally, technology for motors that can be cooled by fluid has been publicly known, as described in Patent Document 1, for example.

[0003] The motor described in Patent Document 1 includes a rotating shaft, a cooling pipe, a rotor, and the like. The rotating shaft has a first refrigerant flow path formed on one side in the axial direction and a second refrigerant flow path formed on the other side in the axial direction. One end of the cooling pipe is connected to the first refrigerant flow path. The other end of the cooling pipe is connected to the second refrigerant flow path. A middle portion of the cooling pipe is inserted into an insertion hole formed in the rotor. The inner peripheral surface of the insertion hole contacts the outer peripheral surface of the cooling pipe.

[0004] A refrigerant is supplied to the first refrigerant flow path in Patent Document 1. The refrigerant passes through the cooling pipe and the second refrigerant flow path and is discharged to the outside of the rotating shaft. In this way, the motor in Patent Document 1 is able to cool the rotating shaft and rotor. However, because the refrigerant (the refrigerant that has absorbed heat from the rotor, etc.) that has passed through the first refrigerant flow path and the cooling pipe is supplied to the second refrigerant flow path in Patent Document 1, there is a risk that the rotating shaft and rotor may not be efficiently cooled around the second refrigerant flow path (downstream of the refrigerant flow path). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-39297 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and the problem it aims to solve is to provide a motor that can efficiently cool the rotating shaft and rotor downstream of the fluid flow path. [Means for solving the problem]

[0007] The problem to be solved by the present invention is as described above, and the means for solving this problem will now be described.

[0008] That is, in claim 1, the device comprises a rotating shaft formed in a hollow shape, a rotor fixed to the rotating shaft, a supply member arranged in the internal space of the rotating shaft and supplying fluid to the internal space of the rotating shaft, a support member arranged in the internal space of the rotating shaft to divide the internal space into a first space into which fluid from the supply member can flow and a second space into which the fluid can flow to the outside of the rotating shaft and supporting the supply member, a first circulation portion formed inside the rotor and circulating the fluid from the first space to the second space, and a second circulation portion formed inside the rotating shaft and circulating the fluid from the first space to the second space.

[0009] In claim 2, the amount of fluid flowing through the first flow portion is greater than the amount of fluid flowing through the second flow portion.

[0010] In claim 3, the support member is a plain bearing that supports the supply member so as to be rotatable relative to the rotary shaft.

[0011] In claim 4, the second flow portion includes a clearance between the outer circumferential surface of the supply member and the inner circumferential surface of the support member.

[0012] In claim 5, the second circulation portion includes a groove portion provided in the opposing portion between the outer peripheral surface of the supply member and the inner peripheral surface of the support member, which guides the fluid from the first space toward the second space.

[0013] In claim 6, the groove is formed so as to send out the fluid in accordance with the rotation of the rotary shaft.

[0014] In claim 7, the second space includes a through hole that penetrates the inner and outer surfaces of the rotating shaft and communicates with the downstream end of the first flow section in the fluid flow direction, and the second flow section is formed to connect to the through hole. [Effects of the Invention]

[0015] The present invention has the following effects.

[0016] In claim 1, the second flow section can efficiently cool the rotating shaft downstream of the fluid flow path.

[0017] In claim 2, the amount of fluid flowing through the first flow portion can be ensured, so that the rotor can be cooled efficiently.

[0018] According to claim 3, it is possible to suppress vibration of the supply member when the rotary shaft rotates.

[0019] In claim 4, the clearance can be used to allow the fluid to flow from the first space to the second space.

[0020] In claim 5, the amount of fluid flowing through the second flow portion can be increased, so that the rotating shaft can be efficiently cooled on the downstream side of the fluid flow path.

[0021] In claim 6, the amount of fluid flowing through the second flow section can be increased by utilizing the rotation of the rotation shaft.

[0022] In claim 7, since the fluid can be guided from the first space to the through hole via the second flow portion, the periphery of the through hole can be efficiently cooled. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view showing a motor according to an embodiment of the present invention; [Figure 2] FIG. 4 is a cross-sectional view showing the rear blocking portion, the rotary shaft, and the rotor. [Figure 3] FIG. 3 is an enlarged cross-sectional view of a portion P shown in FIG. 2. [Figure 4] AA cross section. [Figure 5] FIG. 4 is a cross-sectional view showing a flow path of a fluid when the fluid flows through a first flow portion. [Figure 6] FIG. 4 is a cross-sectional view showing a flow path of a fluid when the fluid flows through a second flow section. [Figure 7] FIG. 10 is a development view of a bearing in which a groove for pumping fluid is formed. DETAILED DESCRIPTION OF THE INVENTION

[0024] In the following description, the directions indicated by arrows U, D, F, B, L, and R in the figures are defined as upward, downward, forward, backward, leftward, and rightward, respectively.

[0025] A motor 1 according to one embodiment of the present invention will be described below. The motor 1 shown in FIG. 1 is used, for example, in a drive device for an automobile. However, the use of the motor 1 is not particularly limited. The motor 1 includes a housing 10, a rotating shaft 20, a rotor 30, a stator 40, a pipe 50, a bearing 60, a first circulating portion 70, and a second circulating portion 80 (see FIG. 3).

[0026] The housing 10 accommodates other components (rotor 30, stator 40, etc.) that make up the motor 1. The housing 10 is formed to be hollow. More specifically, the housing 10 is closed at the front by a front blocking portion 11 and at the rear by a rear blocking portion 12, and is formed to be hollow and approximately cylindrical (not shown) with its axis facing the front-to-rear direction. The front blocking portion 11 is formed in the shape of a plate through which the rotating shaft 20, which will be described later, can be inserted. The rear blocking portion 12 has a first portion 12a, a second portion 12b, and a third portion 12c.

[0027] The first portion 12a is a portion that is disposed so as to face the stator 40 and the like. The first portion 12a is formed, for example, in a substantially circular plate shape. The second portion 12b is a portion that is disposed adjacent to the rear side of the first portion 12a. The second portion 12b is formed, for example, in a substantially circular plate shape having an outer diameter that is smaller than that of the first portion 12a. The second portion 12b is disposed concentrically with the first portion 12a. The first portion 12a and the second portion 12b are formed so that the rotating shaft 20 and the pipe 50 can be inserted therethrough.

[0028] The third portion 12c is a portion that serves as an inlet and outlet for a fluid (e.g., cooling water). The third portion 12c is disposed adjacent to the rear side of the second portion 12b. The third portion 12c is formed, for example, in a substantially circular plate shape having substantially the same outer diameter as the second portion 12b. The third portion 12c is disposed concentrically with the second portion 12b. The third portion 12c includes a first through-hole 12d, a recess 12e, and a second through-hole 12f.

[0029] The first through-hole 12d is a hole that penetrates the center of the third portion 12c in the front-rear direction. The first through-hole 12d is connected to a fluid supply source (such as a pump) (not shown). The recess 12e is a portion that is recessed rearward from the front side surface of the third portion 12c. The recess 12e is formed around the first through-hole 12d. The recess 12e is formed, for example, in a generally annular shape when viewed from the front. The second through-hole 12f is a hole for discharging the fluid supplied to the motor 1 via the first through-hole 12d to the outside of the motor 1. The second through-hole 12f is formed so as to communicate between the outer peripheral surface of the third portion 12c and the recess 12e. The second through-hole 12f is connected to a destination of the fluid (not shown). For example, the second through-hole 12f is connected to a reservoir that stores the fluid. The supply source supplies the fluid in the reservoir to the first through-hole 12d, allowing the fluid to circulate between the pump and the motor 1. Furthermore, the fluid is appropriately cooled before being supplied to the motor 1, thereby removing heat from the motor 1.

[0030] The rotating shaft 20 is a rotatable hollow member. The rotating shaft 20 is arranged concentrically with the housing 10 with its axis oriented in the front-to-rear direction. The rotating shaft 20 is rotatably supported by the first portion 12a of the rear blocking portion 12 and the front blocking portion 11 via bearings 11a-12g. The front end of the rotating shaft 20 protrudes forward from the front blocking portion 11. The rear end of the rotating shaft 20 is arranged within the rear blocking portion 12. As shown in FIG. 2, a guide passage 21, a first through-hole 22, and a second through-hole 23 are formed in the rotating shaft 20. Note that for ease of explanation, the rear blocking portion 12 is simplified in FIG. 2 (the first portion 12a to the third portion 12c are combined into one, simplifying the shape).

[0031] The guide passage 21 is a portion for guiding fluid in the front-rear direction. The guide passage 21 is formed from the rear end face of the rotary shaft 20 to a midpoint between the front and rear. The cross section of the guide passage 21 is formed to be circular when viewed from the front. The guide passage 21 has a large diameter portion 21a, a medium diameter portion 21b, and a small diameter portion 21c.

[0032] The large diameter portion 21a is the portion with the largest inner diameter in the guide passage 21. The inner diameter of the large diameter portion 21a is larger than the outer diameter of a pipe 50, which will be described later. The large diameter portion 21a extends forward from the rear end surface of the rotating shaft 20. The rear end of the large diameter portion 21a is connected to a recess 12e of the rear blocking portion 12.

[0033] The medium diameter portion 21b shown in FIG. 3 has an inner diameter smaller than that of the large diameter portion 21a. The medium diameter portion 21b is formed in front of the large diameter portion 21a. The front-to-rear width of the medium diameter portion 21b is approximately the same as the front-to-rear width of the bearing 60, which will be described later. The inner diameter of the medium diameter portion 21b is also approximately the same as the outer diameter of the bearing 60. In this way, the medium diameter portion 21b of this embodiment is formed so as to be able to accommodate the bearing 60.

[0034] 2 and 3 is the portion with the smallest inner diameter in the guide passage 21. In this embodiment, the small diameter portion 21c is the portion of the guide passage 21 that is forward of the medium diameter portion 21b.

[0035] 2 is a hole that communicates with a first flow portion 70, which will be described later. The first through hole 22 is formed so as to penetrate the inner circumferential surface and the outer circumferential surface of the rotating shaft 20. More specifically, the first through hole 22 is formed so as to penetrate the front end portion of the inner circumferential surface of the small diameter portion 21c and the outer circumferential surface of the rotating shaft 20 along the radial direction. A plurality of first through holes 22 (eight in this embodiment) are formed along the circumferential direction of the rotating shaft 20.

[0036] 2 and 3 is a hole that is located rearward of the first through hole 22 and communicates with the first flow portion 70. The second through hole 23 is formed to penetrate the inner circumferential surface and the outer circumferential surface of the rotating shaft 20. More specifically, the second through hole 23 is formed to penetrate the front end portion of the inner circumferential surface of the large diameter portion 21a and the outer circumferential surface of the rotating shaft 20 along the radial direction. A plurality of second through holes 23 (the same number as the first through holes 22 in this embodiment) are formed along the circumferential direction of the rotating shaft 20.

[0037] The rotor 30 shown in Figures 2 and 4 is a member that rotates when a magnetic field is generated in the stator 40. The rotor 30 is formed in a substantially cylindrical shape with its axis oriented in the front-to-rear direction. The rotor 30 is fixed to the rotating shaft 20 at a midpoint between the front and rear ends and is housed in the housing 10. The front end surface of the rotor 30 is located forward of the first through-hole 22. The rear end surface of the rotor 30 is located rearward of the second through-hole 23.

[0038] The stator 40 shown in Fig. 1 is a component capable of generating a magnetic field. The stator 40 is formed in a substantially cylindrical shape with its axis oriented in the front-to-rear direction. The stator 40 is fixed inside the housing 10 and disposed radially outward of the rotor 30. A conductive wire is wound around the stator 40 to form a cylindrical coil (not shown).

[0039] The pipe 50 is a member that supplies fluid to the internal space of the rotating shaft 20. The pipe 50 is formed in a cylindrical shape with its axis oriented in the front-rear direction. The outer diameter of the pipe 50 is smaller than that of the small-diameter portion 21c. The pipe 50 is arranged concentrically with the rotating shaft 20. As shown in FIG. 2, the rear end of the pipe 50 is fixed to the first through-hole 12d of the rear blocking portion 12. This connects the pipe 50 to a pump (a fluid supply source) via the first through-hole 12d. The pipe 50 protrudes forward from the rear blocking portion 12. This protruding portion is arranged in the internal space of the rotating shaft 20. More specifically, the pipe 50 is arranged from its front-rear midpoint to its tip (front end) across the large-diameter portion 21a of the guide passage 21 to the rear end of the small-diameter portion 21c. In this way, the tip of the pipe 50 is in communication with the small-diameter portion 21c. As shown in FIG. 3, the tip end surface (front end surface) of the pipe 50 is disposed within the small diameter portion 21c.

[0040] The bearing 60 shown in Figures 2 and 3 supports the pipe 50. Specifically, the bearing 60 supports the pipe 50 so that it can rotate relative to the rotating shaft 20. The inner diameter of the bearing 60 is slightly larger than the outer diameter of the pipe 50. In this embodiment, the bearing 60 is a plain bearing. The bearing 60 is disposed in the internal space of the rotating shaft 20. More specifically, the bearing 60 is fitted into the medium diameter portion 21b and disposed within the medium diameter portion 21b. In this manner, the bearing 60 is configured to support the tip end of the pipe 50. The internal space of the rotating shaft 20 is divided into a front space S1 located in front of the bearing 60 (medium diameter portion 21b) and a rear space S2 located behind the bearing 60.

[0041] The front space S1 includes the small diameter portion 21c and the first through-hole 22. As described above, the tip of the pipe 50 is in communication with the small diameter portion 21c, so that fluid flows from the pipe 50 into the front space S1.

[0042] 3 includes the large diameter portion 21a (the space between the inner circumferential surface of the large diameter portion 21a and the outer circumferential surface of the pipe 50) and the second through hole 23. As described above, the large diameter portion 21a is in communication with the recess 12e of the rear blocking portion 12. Therefore, the fluid can flow out of the rotating shaft 20 through the rear space S2.

[0043] 2 and 3 is for circulating fluid from the front space S1 to the rear space S2 via the rotor 30. The first circulating portion 70 is formed inside the rotor 30. The first circulating portion 70 includes a first extending portion 71, a second extending portion 72, and a connecting portion 73.

[0044] The first extending portion 71 shown in FIG. 2 is a portion that extends from the inner circumferential surface of the rotor 30 toward the outer circumferential surface. The first extending portion 71 is formed at the front end portion of the rotor 30. The first extending portion 71 is formed so as to extend in the radial direction of the rotor 30. A plurality of first extending portions 71 (the same number as the first through holes 22 in this embodiment) are formed along the circumferential direction of the rotating shaft 20. The radially inner ends of the plurality of first extending portions 71 are respectively connected to the plurality of first through holes 22.

[0045] The second extending portion 72 is a portion that extends from the inner circumferential surface of the rotor 30 toward the outer circumferential surface. The second extending portion 72 is formed at the rear end portion of the rotor 30 (rearward of the first extending portion 71). The second extending portion 72 is formed so as to extend in the radial direction of the rotor 30. A plurality of second extending portions 72 (the same number as the second through holes 23 in this embodiment) are formed along the circumferential direction of the rotating shaft 20. The radially inner ends of the plurality of second extending portions 72 are respectively connected to the plurality of second through holes 23.

[0046] The connecting portion 73 is a portion that connects the first extending portion 71 and the second extending portion 72. The connecting portion 73 is formed to extend in the front-rear direction. As shown in FIG. 4, the cross section of the connecting portion 73 is formed to be circular when viewed from the front. A plurality of connecting portions 73 (the same number as the first through holes 22 in this embodiment) are formed along the circumferential direction of the rotating shaft 20. As shown in FIG. 2, front ends of the plurality of connecting portions 73 are connected to the radially outer ends of the plurality of first extending portions 71, respectively. Rear ends of the plurality of connecting portions 73 are connected to the radially outer ends of the plurality of second extending portions 72, respectively.

[0047] 3 is for allowing fluid to circulate from the front space S1 to the rear space S2 without passing through the rotor 30. The second circulating portion 80 is formed inside the rotating shaft 20. In this embodiment, the second circulating portion 80 is formed by clearances between the rotating shaft 20, the pipe 50, and the bearing 60. The clearances include a first clearance 81 and a second clearance 82.

[0048] The first clearance 81 is a gap between the outer peripheral surface of the pipe 50 and the inner peripheral surface of the rotating shaft 20 (small diameter portion 21c). The second clearance 82 shown in FIGS. 3 and 4 is a gap between the outer peripheral surface of the pipe 50 and the inner peripheral surface of the bearing 60. In this embodiment, the radial width of the second clearance 82 is 50 μm. As shown in FIG. 3, the second clearance 82 is formed so as to connect to the second through hole 23. In this embodiment, the second clearance 82 is formed so as to directly communicate with the radially inner end of the second through hole 23.

[0049] In the motor 1 shown in FIG. 1, when the coil of the stator 40 is energized, a magnetic field is generated in the stator 40. When a magnetic field is generated in the stator 40, the magnetic field generates a rotational force in the rotor 30, causing the rotor 30 and the rotating shaft 20 to rotate. As described above, the pipe 50 is supported by the bearing 60 so as to be rotatable relative to the rotating shaft 20. Therefore, when a rotational force is generated in the rotor 30, the rotating shaft 20 rotates relative to the pipe 50. When the coil is energized, the coil generates heat due to internal resistance. In this embodiment, a fluid is circulated through the rotating shaft 20 and the rotor 30 to cool the rotating shaft 20 and the rotor 30, thereby suppressing the occurrence of problems (such as reduced efficiency).

[0050] Specifically, as shown in Fig. 5, the fluid is supplied from the pump to the rear end of the pipe 50 through the first through-hole 12d of the rear blocking portion 12, and flows forward inside the pipe 50. The fluid flows from the tip of the pipe 50 into the front space S1 (inside the small diameter portion 21c). The fluid that flows into the front space S1 flows through either the first circulating portion 70 or the second circulating portion 80 (see Fig. 3). First, the flow path of the fluid when flowing through the first circulating portion 70 will be described below.

[0051] The fluid that has flowed into the front space S1 flows forward through the small diameter portion 21c. The fluid flows into the first extending portion 71 of the first flow portion 70 via the first through hole 22, and flows through the first flow portion 70 (inside the rotor 30) via the connecting portion 73 and the second extending portion 72 in that order. The fluid then flows into the rear space S2 (see FIG. 3) from the second through hole 23 and flows rearward through the large diameter portion 21a. The fluid then flows out of the motor 1 via the recess 12e and the second through hole 12f. By flowing through the rotating shaft 20 and the rotor 30 in this manner, the rotating shaft 20 and the rotor 30 can be cooled.

[0052] Here, the fluid that has absorbed heat from the rotating shaft 20 (around the front space S1) and the rotor 30 flows into the rear space S2, so that the rotating shaft 20 and the rotor 30 may not be cooled easily downstream in the direction of fluid flow. For this reason, in this embodiment, a second flow section 80 is provided in the rotating shaft 20, and the rotating shaft 20 and the like are efficiently cooled downstream in the direction of fluid flow by the fluid flowing through the second flow section 80.

[0053] In this embodiment, the downstream side in the fluid flow direction is defined based on the first circulating portion 70. Specifically, the rear space S2, the recess 12e, and the like, which are downstream of the first circulating portion 70 (rotor 30), are considered to be on the downstream side in the fluid flow direction.

[0054] Next, the flow path of the fluid when it flows through the second flow section 80 will be described. As shown in FIG. 6, the fluid that has flowed into the front space S1 flows from the first clearance 81 into the second flow section 80 and flows rearward through the second clearance 82. The fluid then flows into the rear space S2 and flows rearward through the large diameter portion 21a. The fluid then flows out of the motor 1 through the recess 12e and the second through-hole 12f (see FIG. 5). In this way, the fluid is supplied to the rear space S2 without flowing through the rotor 30, so that the low-temperature fluid that has not absorbed heat from the rotating shaft 20 and the rotor 30 can efficiently cool the rotating shaft 20 and the rotor 30 downstream in the flow direction of the fluid.

[0055] Furthermore, since the radial width of the second clearance 82 is relatively small (50 μm in this embodiment), the amount of fluid flowing through the second circulating portion 80 is smaller than the amount of fluid flowing through the first circulating portion 70. This ensures the amount of fluid flowing to the rotor 30, allowing the rotor 30 to be cooled efficiently.

[0056] As described above, the motor 1 according to this embodiment comprises a rotating shaft 20 formed in a hollow shape, a rotor 30 fixed to the rotating shaft 20, a pipe 50 (supply member) arranged in the internal space of the rotating shaft 20 and supplying fluid to the internal space of the rotating shaft 20, a bearing 60 (support member) arranged in the internal space of the rotating shaft 20 to divide the internal space into a front space S1 (first space) into which fluid from the pipe 50 can flow and a rear space S2 (second space) into which the fluid can flow out to the outside of the rotating shaft 20, and supporting the pipe 50, a first circulating section 70 formed inside the rotor 30 and circulating the fluid from the front space S1 to the rear space S2, and a second circulating section 80 formed inside the rotating shaft 20 and circulating the fluid from the front space S1 to the rear space S2.

[0057] With this configuration, the second flow section 80 can efficiently cool the rotating shaft 20 and the rotor 30 on the downstream side of the fluid flow path (for example, around the rear space S2).

[0058] Furthermore, the amount of fluid flowing through the first flow portion 70 is greater than the amount of fluid flowing through the second flow portion 80 .

[0059] With this configuration, the rotor 30 can be cooled efficiently.

[0060] The bearing 60 is a plain bearing that supports the pipe 50 so as to be rotatable relative to the rotary shaft 20 .

[0061] This configuration makes it difficult for the pipe 50 to come into contact with the bearing 60. As a result, it is possible to suppress vibration of the pipe 50 when the rotating shaft 20 rotates, and also to reduce noise generated when the rotating shaft 20 rotates.

[0062] The second flow portion 80 also includes a second clearance 82 (clearance) between the outer peripheral surface of the pipe 50 and the inner peripheral surface of the bearing 60 (see FIG. 3).

[0063] With this configuration, the second clearance 82 can be used to allow fluid to flow from the front space S1 to the rear space S2.

[0064] In addition, the rear space S2 includes a second through hole 23 (through hole) that penetrates the inner and outer surfaces of the rotating shaft 20 and communicates with the downstream end of the first flow section 70 in the fluid flow direction (the radially inner end of the second extension section 72), and the second flow section 80 is formed to connect to the second through hole 23 (see Figure 3).

[0065] With this configuration, the fluid can be guided from the front space S1 to the second through-hole 23 via the second flow portion 80, so that the periphery of the second through-hole 23 can be cooled efficiently.

[0066] The pipe 50 according to this embodiment is one embodiment of a supply member according to the present invention. The front space S1 according to this embodiment is one embodiment of the first space according to the present invention. The rear space S2 according to this embodiment is an embodiment of the second space according to the present invention. The bearing 60 according to this embodiment is one embodiment of a support member according to the present invention. Moreover, the second clearance 82 according to this embodiment is one embodiment of the clearance between the outer peripheral surface of the supply member and the inner peripheral surface of the support member according to the present invention. The second through hole 23 according to this embodiment is one embodiment of a through hole that communicates with the downstream end of the first circulating portion in the fluid circulating direction according to the present invention.

[0067] Although the embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

[0068] For example, although the bearing 60 is a sliding bearing, the type of the bearing 60 is not particularly limited.

[0069] Furthermore, although the tip end of the pipe 50 and the bearing 60 are arranged at the rear end of the small diameter portion 21c and within the medium diameter portion 21b in the above embodiment, the arrangement of the tip end of the pipe 50 is not limited to this embodiment. For example, the tip end of the pipe 50 may be arranged at the midpoint between the front and rear of the small diameter portion 21c. Furthermore, the number of bearings 60 is not particularly limited. For example, multiple bearings 60 may be arranged at the midpoint between the front and rear of the small diameter portion 21c.

[0070] Furthermore, although the number of first through holes 22 and the number of second through holes 23 in the rotating shaft 20 are eight, the number of first through holes 22, etc. is not particularly limited. Furthermore, the number of each part of the first flow section 70 (first extending portions 71, second extending portions 72, and connecting portions 73) is not particularly limited either.

[0071] Furthermore, although the cross section of the connection portion 73 of the first circulating portion 70 is formed to be circular when viewed from the front, the cross-sectional shape of the connection portion 73 is not particularly limited and may be polygonal when viewed from the front, etc. The cross-sectional shapes of the first extending portion 71 and the second extending portion 72 are also not particularly limited. For example, the cross-sectional shapes of the first extending portion 71 and the second extending portion 72 may be circular when viewed in the radial direction, polygonal when viewed in the radial direction, etc.

[0072] Furthermore, the second circulating portion 80 is configured by the clearances (such as the first clearance 81 shown in FIG. 3 ) between the rotating shaft 20, the pipe 50, and the bearing 60, but the configuration of the second circulating portion 80 is not limited to this embodiment as long as the fluid can flow from the front space S1 to the rear space S2 without passing through the rotor 30. For example, the second circulating portion 80 may further include other portions in addition to the first clearance 81 of this embodiment.

[0073] For example, the second circulating portion 80 may further include a groove portion that guides the fluid from the front space S1 to the rear space S2. The groove portion may include, for example, a first groove portion that is formed in at least one of the step surface between the medium diameter portion 21b and the small diameter portion 21c or the front end surface of the pipe 50 and guides the fluid radially outward (second clearance 82). The groove portion may also include, for example, a second groove portion that is formed in a portion where the outer circumferential surface of the pipe 50 and the inner circumferential surface of the bearing 60 face each other and guides the fluid rearward. In this embodiment, because the bearing 60 supports the tip end of the pipe 50, the second groove portion is formed in at least one of the outer circumferential surface of the tip end of the pipe 50 or the inner circumferential surface of the bearing 60. The second circulating portion 80 can increase the amount of fluid circulating therethrough by the first groove portion and the second groove portion.

[0074] As described above, the second flow section 80 includes a second groove section (groove section) that is provided at the opposing portion between the outer peripheral surface of the pipe 50 and the inner peripheral surface of the bearing 60 and guides the fluid from the front space S1 toward the rear space S2.

[0075] With this configuration, the amount of fluid flowing through the second flow portion 80 can be increased, and the rotating shaft 20 can be efficiently cooled on the downstream side of the fluid flow path.

[0076] Furthermore, the second groove portion may be formed to actively guide (send) the fluid rearward or forward as the rotating shaft 20 rotates. For example, the second groove portion may be formed to actively guide the fluid rearward (from the front space S1 toward the rear space S2). The second groove portion may be formed, for example, in a spiral shape oriented in accordance with the rotation direction of the rotating shaft 20 (for example, the rotation direction when the motor 1 rotates forward). FIG. 7 illustrates an example of the second groove portion. FIG. 7 is a developed view showing the inner circumferential surface of the bearing 60, and the bearing 60 in FIG. 7 illustrates a spiral groove 61 as an example of the second groove portion. A plurality of spiral grooves 61 (two in FIG. 7) are formed along the circumferential direction of the bearing 60. The spiral groove 61 is formed from the front end to the rear end of the bearing 60. The spiral groove 61 allows the fluid to be sent from the front space S1 to the rear space S2 as the rotating shaft 20 rotates. The number of spiral grooves 61 is not limited to that shown in FIG. 7 (two).

[0077] As described above, the spiral groove 61 (groove portion) is formed so as to send out the fluid as the rotary shaft 20 rotates.

[0078] With this configuration, the amount of fluid flowing through the second flow section 80 can be increased by utilizing the rotation of the rotary shaft 20.

[0079] The second groove portion and the spiral groove 61 in FIG. 7 are one embodiment of the groove portion according to the present invention.

[0080] Furthermore, for example, the second flow section 80 may include a third groove portion that sends fluid from the front space S1 to the rear space S2 as the rotating shaft 20 rotates when the motor 1 rotates in the reverse direction (for example, when the vehicle backs up). The third groove portion may be configured, for example, by a groove portion that faces in the opposite direction to the spiral groove 61 in Fig. 7. The third groove portion can guide fluid from the front space S1 to the rear space S2 when the motor 1 rotates in the reverse direction.

[0081] The second circulating portion 80 may have a configuration different from that of the present embodiment, and may communicate between the front space S1 and the rear space S2. The configuration of the second circulating portion 80 can be changed as appropriate, for example, depending on the arrangement of the tip of the pipe 50. For example, if the tip of the pipe 50 does not protrude forward of the bearing 60, the second circulating portion 80 may communicate between the front space S1 and the rear space S2 only through the second clearance 82 of the first clearance 81 and the second clearance 82 of the present embodiment (or may include only the second clearance 82). Furthermore, for example, the second circulating portion 80 may communicate between the front space S1 and the rear space S2 through a fluid guide passage having one end opening at the inner circumferential surface of the small diameter portion 21 c and the other end opening at the inner circumferential surface of the large diameter portion 21 a. The second flow section 80 may also connect the front space S1 and the rear space S2, for example, by a groove formed on at least one of the outer surface (outer peripheral surface, etc.) of the bearing 60 or the inner surface (inner peripheral surface of the medium diameter section 21b, etc.) of the rotating shaft 20.

[0082] Although the radial width of the second clearance 82 is set to 50 μm, the radial width of the second clearance 82 is not particularly limited. For example, the radial width of the second clearance 82 may be smaller than 50 μm. By setting the radial width of the second clearance 82 to be smaller than 50 μm, the amount of fluid flowing through the second circulating portion 80 can be reduced compared to the present embodiment. Furthermore, the radial width of the second clearance 82 may be larger than 50 μm. By setting the radial width of the second clearance 82 to be larger than 50 μm, the amount of fluid flowing through the second circulating portion 80 can be increased compared to the present embodiment. As the amount of fluid flowing through the second circulating portion 80 increases or decreases, the amount of fluid flowing through the first circulating portion 70 also increases or decreases. In this way, by adjusting the radial width of the second clearance 82, the amount of fluid flowing through the first circulating portion 70 and the second circulating portion 80 can be appropriately controlled.

[0083] However, if the radial width of the second clearance 82 is made too large, the amount of fluid flowing through the first circumferential portion 70 will be too small, which may result in insufficient cooling of the rotor 30. Therefore, an obstruction portion that obstructs the flow of fluid from the front space S1 to the rear space S2 may be provided at the opposing portion between the outer circumferential surface of the pipe 50 and the inner circumferential surface of the bearing 60. The obstruction portion may be, for example, a protrusion formed on the inner circumferential surface of the bearing 60. This prevents excessive fluid from flowing from the front space S1 to the rear space S2 via the second circumferential portion 80 (ensuring the amount of fluid flowing through the first circumferential portion 70), thereby preventing insufficient cooling of the rotor 30. [Explanation of symbols]

[0084] 1 motor 20 Rotation axis 30 rotors 40 Stator 50 Pipe 60 bearings 70 1st Distribution Department 80 2nd Distribution Department S1 front space S2 rear space

Claims

1. a hollow rotating shaft; a rotor fixed to the rotary shaft; a supply member disposed in the internal space of the rotating shaft and supplying a fluid to the internal space of the rotating shaft; a support member that is disposed in an internal space of the rotating shaft to divide the internal space into a first space into which the fluid from the supply member can flow and a second space into which the fluid can flow out to the outside of the rotating shaft, and that supports the supply member; a first flow section formed inside the rotor and allowing the fluid to flow from the first space to the second space; a second circulating portion formed inside the rotating shaft and allowing the fluid to circulate from the first space to the second space; Equipped with Motor.

2. The amount of fluid flowing through the first flow portion is the amount of fluid flowing through the second flow section is greater than the amount of fluid flowing through the second flow section; The motor according to claim 1 .

3. The support member is a sliding bearing that supports the supply member so as to be rotatable relative to the rotation shaft; The motor according to claim 1 or 2.

4. The second circulation section includes: a clearance between an outer circumferential surface of the supply member and an inner circumferential surface of the support member; The motor according to claim 1 or 2.

5. The second circulation section includes: a groove portion provided in an opposing portion between an outer circumferential surface of the supply member and an inner circumferential surface of the support member, the groove portion guiding the fluid from the first space toward the second space; The motor according to claim 1 or 2.

6. The groove portion is The fluid is discharged in accordance with the rotation of the rotary shaft. The motor according to claim 5.

7. In the second space, a through-hole penetrating an inner circumferential surface and an outer circumferential surface of the rotary shaft and communicating with a downstream end of the first circulating portion in a fluid circulating direction; The second circulation section is formed to connect to the through hole, The motor according to claim 1 or 2.

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