Rotating electric machines and drive systems

Abstract

To suppress vibration of a pipe for supplying cooling oil to a conduit in a shaft formed in the shaft.SOLUTION: A rotary electric machine includes a shaft in which a shaft inside conduit having an opening at an end portion in a direction of a rotation axis of a rotor is formed, a pipe inserted into the opening of the shaft inside conduit in a state where the pipe is not in contact with an inner wall of the shaft inside conduit, and a pipe fixing member inserted into the opening of the shaft inside conduit in a state where the pipe is not in contact with the inner wall of the shaft inside conduit and covering at least a part of the pipe.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a rotating electrical machine and a driving device.

Background Art

[0002] When driving a rotating electrical machine such as a motor or a generator, it may be difficult to drive efficiently because the coil generates heat. For this reason, technologies for cooling the coil mounted on the rotating electrical machine have been developed. As such a technology, for example, there is a cooling device for a rotor of a rotating electrical machine disclosed in Patent Document 1. The cooling device for a rotor of a rotating electrical machine according to Patent Document 1 includes a shaft of the rotor and a pipe inserted into the shaft and supplying a coolant inside the shaft.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the pipe according to Patent Document 1 vibrates due to the rotation of the rotor and may contact the inner wall of the shaft of the rotor. As a result, the pipe according to Patent Document 1 may inhibit the rotation of the rotor or may not be able to supply the coolant into the rotor properly.

[0005] Therefore, an object of the present invention is to provide a rotating electrical machine and a driving device capable of suppressing vibration of a pipe that supplies cooling oil to a shaft inner conduit formed in a shaft.

Means for Solving the Problems

[0006] To solve the above-mentioned problems, the rotating electric machine of the present invention comprises a shaft having an internal shaft conduit with an opening at its end in the direction of the rotor's axis of rotation, a pipe inserted into the opening of the internal shaft conduit without contacting the inner wall of the internal shaft conduit, and a pipe fixing member inserted into the opening of the internal shaft conduit without contacting the inner wall of the internal shaft conduit and covering at least a portion of the pipe, A resolver for detecting the rotation angle of the shaft, and a cover attached to the pipe fixing member, covering the surface of the resolver that faces outward from the opening of the shaft conduit, It is equipped with.

[0007] In the rotating electric machine of the present invention, the piping is press-fitted into the piping fixing member.

[0008] In the rotating electric machine of the present invention, the piping is Outer surface from The rotation axis perpendicular to the said axis A first protrusion is formed that protrudes in the direction, and the pipe fixing member is a cylindrical member, and the pipe fixing member Inner surface from The rotating shaft Towards That It protrudes, and a second protrusion is formed which contacts the first protrusion.

[0009] In the rotating electric machine of the present invention, the pipe fixing member covers at least a portion of the pipe within the shaft conduit.

[0011] The drive device of the present invention comprises one of the above-described rotating electric machines and an inverter positioned adjacent to the rotating electric machine in the direction of the rotation axis. [Effects of the Invention]

[0012] According to the present invention, vibrations of the piping that supplies cooling oil to the shaft-internal conduit formed in the shaft can be suppressed. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view of the drive device according to an embodiment. [Figure 2] This is a cross-sectional view of the motor according to the embodiment, taken from a plane passing through the rotation axis and parallel to the ZX plane. [Figure 3] This figure shows the state before the piping according to the embodiment is pressed into the pipe fixing member. [Figure 4] This figure shows the state after the piping according to the embodiment has been pressed into the pipe fixing member. [Figure 5] This diagram shows the piping, pipe fixing member, and cover according to the embodiment as viewed from the -Y direction. [Modes for carrying out the invention]

[0014] The embodiments for carrying out the present invention will be described below with reference to the drawings. In the following description, we will use the X-axis, which is an axis parallel to the rotation axis A of the motor 11 described later, the Y-axis which is perpendicular to the X-axis, and the Z-axis which is perpendicular to both the X-axis and the Y-axis. Furthermore, the X-axis, Y-axis, and Z-axis form a right-handed system.

[0015] (Embodiment) Figure 1 is a perspective view of a drive unit according to an embodiment. The drive unit 1 is mounted on a vehicle, for example, to rotate the wheels of a vehicle such as an electric vehicle. As shown in Figure 1, the drive unit 1 comprises a motor 11, a cooling oil cooler 12, a cooling oil pump 13, and an inverter 14.

[0016] Motor 11 is an example of a rotating electric machine that generates power to rotate the vehicle's wheels. Cooling oil cooler 12 is, for example, a water-cooled cooler that cools the cooling oil whose temperature has risen due to the cooling of various parts of motor 11. Cooling oil pump 13 draws up the cooling oil cooled by the cooling oil cooler 12 and sends it into motor 11. Inverter 14 supplies power to motor 11. The inverter 14 is positioned adjacent to motor 11 in the direction of rotation axis A. Specifically, as shown in Figure 1, the inverter 14 is positioned on the -X side of motor 11.

[0017] FIG. 2 is a cross-sectional view taken along a plane parallel to the ZX plane passing through the rotation axis of the motor according to the embodiment. As shown in FIG. 2, the motor 11 includes a housing 111, a bearing 112, a resolver 113, a stator 114, a shaft 115, a rotor 116, a pipe 117, a pipe fixing member 118, and a cover 119.

[0018] The housing 111 houses the bearing 112, the resolver 113, the stator 114, the shaft 115, the rotor 116, the pipe 117, the pipe fixing member 118, and the cover 119. The outer rings of the two bearings 112 are fitted into the housing 111. The bearing 112 has the shaft 115 fitted into its inner ring and supports the shaft 115 in a manner rotatable about the rotation axis A. The resolver 113 is disposed around the shaft 115 at the end of the shaft 115 on the -X direction side. The resolver 113 is, for example, a variable reluctance (VR) type resolver with single-phase excitation and two-phase output, and detects the rotation angle of the shaft 115.

[0019] The stator 114 includes a stator core 1141 and a coil 1142. The stator core 1141 is a cylindrical member into which the shaft 115 and the rotor 116 are inserted, and a plurality of teeth are formed on the inner side. The coil 1142 is formed by winding a copper wire around the teeth. The coil 1142 generates a magnetic force for rotating the rotor 116 when energized.

[0020] The shaft 115 is fitted into the rotor 116 and is a rod-shaped member that supports the rotor 116 in a manner rotatable about the rotation axis A of the rotor 116. Further, the shaft 115 has a shaft inner conduit 115a having an opening at the end on the -X direction side in the direction of the rotation axis A of the rotor 116. The rotor 116 is circular and is formed by laminating plate-like members made of electromagnetic steel in the direction of the rotation axis A, and the shaft 115 is fitted therein.

[0021] The piping 117 is a cylindrical tube that guides the cooling oil, cooled by the cooling oil cooler 12 and sent out by the cooling oil pump 13, to the shaft conduit 115a. Figure 3 shows the state of the piping according to the embodiment before it is pressed into the pipe fixing member. Figure 4 shows the state after the piping according to the embodiment has been pressed into the pipe fixing member. As shown in Figures 3 and 4, the piping 117 is pressed into the pipe fixing member 118. Figure 5 shows the piping, pipe fixing member, and cover according to the embodiment as viewed from the -Y direction side. By being pressed into the pipe fixing member 118, the piping 117 is attached to the pipe fixing member 118 such that the angle in the YZ plane centered on the pipe fixing member 118 is a predetermined angle, as shown in Figure 5.

[0022] As shown in Figure 2, a portion of the pipe 117 is inserted into the shaft conduit 115a without contacting its inner wall. The central axis of the portion of the pipe 117 inserted into the shaft conduit 115a coincides with the axis of rotation A. Cooling oil flows into the shaft conduit 115a after passing through the pipe 117, as indicated by the white arrows in Figure 2. The pipe 117 also has a first projection 117a that protrudes from the inside outward. The first projection 117a is formed in an annular shape along the intersection of a plane perpendicular to the axis of rotation A and the pipe 117. That is, the first projection 117a is formed in a flange shape that protrudes annularly from the outer surface of the pipe 117 in a direction perpendicular to the axis of rotation A.

[0023] The pipe fixing member 118 is a cylindrical member inserted into the opening of the shaft conduit 115a without contacting the inner wall of the shaft conduit 115a. The pipe fixing member 118 has a step formed at a predetermined distance from the opening of the shaft conduit 115a where the inner diameter becomes discontinuously smaller. That is, the inner diameter of the pipe fixing member 118 beyond the predetermined distance from the opening of the shaft conduit 115a is smaller than the inner diameter of the part of the pipe fixing member 118 that is less than or equal to the predetermined distance from the opening of the shaft conduit 115a.

[0024] The pipe fixing member 118 has a surface on the -X direction side that is parallel to a plane perpendicular to the axis of rotation A, and this surface covers the end face of the shaft 115 on the -X direction side. Furthermore, the pipe fixing member 118 covers at least a portion of the pipe 117. Specifically, the pipe fixing member 118 covers at least a portion of the pipe 117 within the shaft internal conduit 115a. More specifically, the pipe fixing member 118 covers the portion of the pipe 117 that is inserted into the shaft internal conduit 115a. Note that the pipe fixing member 118 may cover the entire portion of the pipe 117 that is inserted into the shaft internal conduit 115a, or it may cover only a portion of that portion.

[0025] As shown in Figure 2, the pipe fixing member 118 protrudes in a direction from the outside to the inside, and a second protrusion 118a is formed which abuts against the first protrusion 117a. The second protrusion 118a is the step described above, that is, a step where the inner diameter becomes discontinuously smaller at a predetermined distance from the opening of the shaft conduit 115a.

[0026] The cover 119 is a disc-shaped member attached to the part of the pipe fixing member 118 that covers the end face of the shaft 115 on the -X direction side. The cover 119 covers the surface of the resolver 113 that faces outward from the opening of the shaft conduit 115a. The cover 119 is made of a metal such as iron, for example, and suppresses the propagation of electrical noise generated in the inverter 14 to the resolver 113. Furthermore, it is preferable that the cover 119 is made of a material that can effectively suppress noise in accordance with the characteristics of the noise propagating from the inverter 14 to the resolver 113. The cover 119 can take any shape as long as it is a shape that can partition the space between the inverter 14 and the resolver 113 in the direction of the rotation axis A.

[0027] The motor 11 according to the embodiment has been described above. The motor 11 comprises a shaft 115, a pipe 117, and a pipe fixing member 118. The shaft 115 has an internal shaft conduit 115a formed at its end in the direction of the rotation axis A of the rotor 116, with an opening. The pipe 117 is inserted into the opening of the internal shaft conduit 115a without contacting the inner wall of the internal shaft conduit 115a. The pipe fixing member 118 is inserted into the opening of the internal shaft conduit 115a without contacting the inner wall of the internal shaft conduit 115a, and covers at least a part of the pipe 117. As a result, the motor 11 can suppress vibrations of the pipe 117 that supplies cooling oil to the internal shaft conduit 115a, and can prevent the pipe 117 from coming into contact with the inner wall of the internal shaft conduit 115a.

[0028] Furthermore, the pipe 117 is press-fitted into the pipe fixing member 118. This allows the pipe 117 to be attached to the pipe fixing member 118 such that the angle in the YZ plane centered on the pipe fixing member 118 is a predetermined angle, even if the dimensional accuracy of at least one of the pipe 117 and the pipe fixing member 118 is low. Moreover, since the motor 11 does not need to have low dimensional accuracy of at least one of the pipe 117 and the pipe fixing member 118, it can be manufactured at a lower cost.

[0029] Furthermore, the pipe 117 has a first projection 117a that protrudes from the inside outward. In this case, the pipe fixing member 118 is a cylindrical member and has a second projection 118a that protrudes from the outside inward and abuts against the first projection 117a. As a result, even if the dimensional accuracy of at least one of the pipe 117 and the pipe fixing member 118 is low, the position of the pipe 117 relative to the pipe fixing member 118 can be easily fixed to a predetermined position. Moreover, since the motor 11 does not need to have low dimensional accuracy of at least one of the pipe 117 and the pipe fixing member 118, it can be manufactured at a lower cost.

[0030] Furthermore, the pipe fixing member 118 covers at least a portion of the pipe 117 within the shaft conduit 115a. As a result, the motor 11 can suppress vibrations of the pipe 117 more effectively than when the pipe fixing member 118 does not cover the pipe 117 within the shaft conduit 115a, and can prevent the pipe 117 from coming into contact with the inner wall of the shaft conduit 115a.

[0031] The motor 11 also includes a resolver 113 and a cover 119. The resolver 113 detects the rotation angle of the shaft 115. The cover 119 is attached to the pipe fixing member 118 and covers the surface of the resolver 113 that faces outward from the opening of the shaft conduit 115a. This allows the motor 11 to suppress the propagation of electrical noise generated by the inverter 14 to the resolver 113.

[0032] Furthermore, the drive unit 1 includes an inverter 14 positioned adjacent to the motor 11 in the direction of the rotation axis A. More specifically, in the direction of the rotation axis A in Figure 2, the inverter 14, cover 119, and resolver 113 are arranged in that order from the -X direction to the +X direction. As a result, the drive unit 1 is made low profile, making it less likely to interfere with the space of the vehicle's passenger compartment, etc.

[0033] In the embodiments described above, the example given was that the pipe 117 has an annular first projection 117a formed along the intersection line of the pipe 117 and a plane perpendicular to the rotation axis A, but the invention is not limited to this. The first projection only needs to have a shape that abuts against a second projection formed on the pipe fixing member and allows the position of the pipe relative to the pipe fixing member to be set to a predetermined position. For example, the first projection may be a plurality of protrusions projecting from the outer circumferential surface of the pipe 117 in a direction perpendicular to the rotation axis A.

[0034] Furthermore, in the embodiments described above, the pipe fixing member 118 was described as having a second projection 118a, which is a step where the inner diameter is discontinuously reduced at a predetermined distance from the opening of the shaft conduit 115a, but the invention is not limited to this. The second projection only needs to have a shape that abuts against the first projection formed on the pipe fixing member and allows the position of the pipe relative to the pipe fixing member to be set to a predetermined position. For example, the second projection may be a plurality of protrusions projecting from the inner circumferential surface of the pipe fixing member 118 toward the rotation axis A. Alternatively, the second projection may be an annular member projecting from the inner circumferential surface of the pipe fixing member 118 toward the rotation axis A.

[0035] Furthermore, although the above-described embodiment explained the case in which the pipe 117 is press-fitted into the pipe fixing member 118, the manner in which the pipe is connected to the pipe fixing member is not limited to this. For example, the pipe may be connected to the pipe fixing member by threads formed in the pipe and threads formed in the pipe fixing member.

[0036] Preferred embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above. That is, the present invention includes embodiments that have been modified, substituted, or redesigned in accordance with the spirit of the present invention, and these embodiments are not excluded. [Explanation of symbols]

[0037] 1...Drive unit, 11...Motor, 12...Cooling oil cooler, 13...Cooling oil pump, 14...Inverter, 111...Housing, 112...Bearing, 113...Resolver, 114...Stator, 115...Shaft, 116...Rotor, 117...Piping, 118...Piping fixing member, 119...Cover

Claims

1. A shaft having an internal conduit formed at its end in the direction of the rotor's axis of rotation, A pipe inserted into the opening of the shaft conduit without contacting the inner wall of the shaft conduit, A pipe fixing member is inserted into the opening of the shaft conduit without contacting the inner wall of the shaft conduit and covers at least a portion of the piping, A resolver for detecting the rotation angle of the shaft, A cover attached to the aforementioned pipe fixing member, which covers the surface of the resolver that faces outward from the opening of the shaft conduit, A rotating electric machine equipped with the following features.

2. The aforementioned pipe is press-fitted into the pipe fixing member. The rotating electric machine according to claim 1.

3. The aforementioned pipe has a first projection that protrudes from its outer surface in a direction perpendicular to the rotation axis, The pipe fixing member is a cylindrical member, and a second protrusion is formed that protrudes from the inner circumferential surface of the pipe fixing member toward the rotation axis and abuts against the first protrusion. The rotating electric machine according to claim 1.

4. The aforementioned pipe fixing member covers at least a portion of the pipe within the shaft conduit. The rotating electric machine according to claim 1.

5. A rotating electric machine according to any one of Claims 1 to 4, An inverter is positioned adjacent to the rotating electric machine in the direction of the rotation axis, A drive device equipped with the following features.

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