Rotary electrical machine

Abstract

A rotary electrical machine (1) has: a cylindrical motor case (3) in which a motor (2) is accommodated; a flange (32) projecting radially outward from the motor case (3) and connecting to an external device; and a protrusion (37) that is different from the flange (32) and projects radially outward with respect to the rotation axis of the motor (2) on the outer periphery of the motor case (3).

Description

Rotating electric machine

[0001] The present disclosure relates to a rotating electric machine including a motor case that accommodates a stator and a rotor.

[0002] In a conventional rotating electric machine, a control device is covered by a cover and a motor case in order to prevent electromagnetic noise generated from electronic components mounted on a control board from being emitted to the outside or intruding into the interior. A flange protruding radially outward relative to the rotation shaft of the motor in the circumferential direction of the motor case and configured to connect to an external device is provided (see, for example, Patent Document 1 below).

[0003] International Publication No. 2023 / 079670

[0004] In a conventional rotating electric machine, when the rotating electric machine is fixed to a test apparatus for performing a performance test or the like, after the motor case is fixed with a pin so as not to rotate around the rotation shaft, the flange is configured to be fixed by a jig of the test apparatus. The flange is provided at a different angle for each model of rotating electric machine depending on the specifications of the external device, and when rotating electric machines of different models are processed on a mass production line, it is necessary to replace the jig of the test apparatus.

[0005] The present disclosure has been made to solve the above problem, and an object of the present disclosure is to obtain a rotating electric machine that eliminates the need to replace a jig fixed to a flange even when rotating electric machines of different models are put into a mass production line, reduces production time and labor costs, and improves the efficiency of the mass production line.

[0006] A rotating electric machine that transmits rotation of a motor to an external device, comprising: a cylindrical motor case in which the motor is accommodated; a flange protruding outward in a radial direction of the motor case and connected to the external device; and a projection different from the flange, the projection protruding outward in a radial direction relative to a rotation shaft of the motor on an outer circumference of the motor case.

[0007] According to the rotating electric machine of the present disclosure, by providing a projection protruding radially outward relative to the rotation shaft of the motor, which is different from the flange, on the outer circumference of the motor case, even when rotating electric machines of different models are processed on a mass production line, there is no need to replace jigs such as those of a test apparatus, and the effect of achieving standardization of the test apparatus can be obtained.

[0008] This is a plan view of the output shaft side of the rotating electric machine of Embodiment 1. This is a cross-sectional view of the rotating electric machine of Embodiment 1. This is a cross-sectional view of the rotating electric machine fixed to the test apparatus in Embodiment 1. This is a top view of the rotating electric machine fixed to the test apparatus in Embodiment 1. This is a side view of the rotating electric machine of Embodiment 1. This is a diagram of the rotating electric machine fixed to the airtightness test apparatus in Embodiment 1. This is a top view of the rotating electric machine fixed to the test apparatus in Embodiment 2. This is a schematic diagram of the rotating electric machine fixed to the test apparatus in Embodiment 3. This is a schematic diagram of the rotating electric machine fixed to the test apparatus in Embodiment 3.

[0009] The embodiments will be described below.

[0010] Embodiment 1. Figure 1 shows a plan view of the output shaft side of the rotating electric machine 1. In the following description, the direction in which the rotating shaft O of the rotating electric machine 1 extends is referred to as the axial direction, the direction intersecting the rotating shaft O is referred to as the radial direction, and the direction around the rotating shaft O is referred to as the circumferential direction. The rotating electric machine 1 is fitted with an external device, a gear (not shown), by attaching a fixing device such as a boss 50 to the output shaft of the rotating electric machine 1. In order to accurately fit the gear with the rotating shaft O, a flange 32 is provided at the bottom of the motor case 3, projecting radially outward from the rotating shaft O. A spigot projection 70 is provided on the gear connection surface of the motor case 3. The flange 32 and the spigot projection 70 accurately position the input shaft of the motor and the output shaft of the gear. A positioning hole 100 is provided at the bottom of the motor case 3 for positioning on a performance testing device.

[0011] Figure 2 shows a cross-sectional view of the II-II cross-section passing through the center of the connector 5 and the rotation axis O in Figure 1. As shown in Figure 2, the rotating electric machine 1 comprises a motor 2 and a control unit that controls the motor 2. The control unit comprises a control board 4 on which a control circuit and a power circuit are mounted, and a connector 5. The connector 5 has multiple power connection terminals 5a that supply power from an external power source to the control board 4, and multiple signal connection terminals 5b that supply various signals from a control device to the control board 4.

[0012] The control board 4 is, for example, a multilayer printed circuit board in which multiple insulating layers and multiple conductive layers are laminated. The control board 4 has power connection holes 44a and signal connection holes 44b. The power connection terminal 5a is inserted into the power connection hole 44a and electrically connected to the conductive layer of the control board 4. The signal connection terminal 5b is inserted into the signal connection hole 44b and electrically connected to the conductive layer of the control board 4.

[0013] The control board 4 is equipped with numerous electronic components for implementing the control circuit and power circuit. The control circuit includes a CPU and driver ICs, while the power circuit includes switching elements, shunt resistors, capacitors, choke coils, and the like.

[0014] The motor 2 comprises a rotor 22 and a stator 23, and is housed in a motor case 3. The rotor 22 is mounted on the outer circumference of the rotating shaft 21. Permanent magnets are provided on the outer surface of the rotor 22. The stator 23 is mounted on the outer circumference of the rotor 22. The stator 23 comprises windings 24 and is fixed to the motor case 3 by shrink fitting or press fitting. The windings 24 have windings corresponding to each phase of the motor and are wound on bobbins 24a and 24b. For example, if the motor 2 is a three-phase motor, the windings 24 have windings corresponding to the U phase, windings corresponding to the V phase, and windings corresponding to the W phase.

[0015] The motor case 3 is cylindrical in shape with a bottom. The motor case 3 is made of a heat-dissipating material such as aluminum. A through hole 3a is formed in the center of the bottom of the motor case 3, through which the rotating shaft 21 passes. A second bearing 26b is provided in the through hole 3a.

[0016] A housing 6 is provided on the opening side of the motor case 3. The housing 6 is fixed to the motor case 3 and closes the opening side of the motor case 3. A predetermined gap is set between the housing 6 and the control board 4 to ensure insulation between the heating element and the housing 6. A heat dissipation material 61 is provided in the gap between the control board 4 and the housing 6. Heat generated by the heating element is dissipated to the housing 6 via the heat dissipation material 61. The housing 6 has a through hole 6a through which the rotating shaft 21 is positioned. The through hole 6a is provided with a first bearing 26a that rotatably supports the rotating shaft 21. The rotating shaft 21 is rotatably supported by the first bearing 26a and the second bearing 26b.

[0017] A sensor magnet 25 is attached to the upper end of the rotating shaft 21. The sensor magnet 25 has one or more north poles and one or more south poles. The sensor magnet 25 transmits magnetism to a rotation sensor 25a mounted on the control board 4. The rotation sensor 25a detects the rotation angle of the rotating shaft 21 by detecting the magnetic field generated by the sensor magnet 25.

[0018] The cover 7 covers the control board 4 from above. The cover 7 and the motor case 3 are connected to the same potential as GND by connecting components (not shown), such as snap-fit ​​connectors. By covering the control board 4 with the cover 7 and the motor case 3, the generation of electromagnetic noise can be suppressed, and the requirements for EMC performance can be met.

[0019] The above is a description of a permanent magnet type motor, but a field-wound type motor may also be used, and the field type, winding type, and number of phases may differ. It may be a motor or a motor-generator that has the functions of both a motor and a generator.

[0020] Figure 3 shows a cross-sectional view of the rotating electric machine 1 fixed to the test apparatus. Figure 4 shows a top view of the rotating electric machine 1 fixed to the test apparatus. Figure 3 is a cross-sectional view of the III-III section passing through the center of the projection 37 shown in Figure 1. The rotation axis O of the rotating electric machine 1 is defined as the Z-axis direction, the radial direction of the rotating electric machine as the X-axis direction, and the direction perpendicular to both the X-axis and Z-axis directions as the Y-direction. The X-axis, Y-axis, and Z-axis directions are mutually orthogonal coordinates.

[0021] On the outer circumference of the rotating electric machine 1, a projection 37 is formed at a position different from the flange 32, projecting radially outward with respect to the rotation axis O of the motor. The projection 37 is used as a fixing device for the test apparatus. The upper surface 101 of the projection 37 is formed to conform to the shape of the bottom surface 371 of the jig 10. If the bottom surface 371 of the jig 10 is flat, the upper surface 101 of the projection 37 is flat, and both the upper surface 101 and the bottom surface 371 are made of rough, as-cast surfaces.

[0022] Figure 5 shows a side view of the rotating electric machine 1. The flange 32 and projection 37 are arranged such that the distance L1 from the external device connection surface of the flange 32 to the test fixture contact surface of the projection 37 is greater than the thickness La of the flange 32. The radial length of the projection 37 is arranged to be shorter than the radial length of the flange 32.

[0023] In the mass production line, the rotating electric machine 1 is continuously transported to the test apparatus via a belt conveyor or the like, and attached to a jig on the test apparatus.

[0024] In the test apparatus shown in Figure 3, the rotating electric machine 1 is mounted such that the control board 4 is above the Z-axis and the output shaft side of the rotating electric machine 1 is below the Z-axis. When the test starts, a positioning pin is inserted into the positioning hole 100 shown in Figure 1 to prevent the rotating electric machine 1 from rotating in the XY axis direction. Next, the jig 10 of the test apparatus moves along the XY coordinate plane toward the axis center of the rotating electric machine 1. The movement of the jig 10 along the XY coordinate plane stops with a small gap between the rotating electric machine 1 and the projection 37 to prevent friction and physical interference. After that, the jig 10 moves in the Z-axis direction and fixes the rotating electric machine 1 by applying appropriate pressure. The bottom surface 371 of the jig 10 moves toward the projection 37 of the rotating electric machine and comes into contact with the upper surface 101 of the projection 37. The jig 10 clamps the rotating electric machine in the axial direction and presses the upper surface 101 of the projection in the Z-axis direction. Once the test is complete, the jig 10 moves along the XY coordinate plane, releasing the constraints on the rotating electric machine 1.

[0025] The jig 10 may move in either the X-axis direction or the Y-axis direction. Figure 3 shows the movement of the jig 10 in the X-axis direction with arrows, but it may also move in the Y-axis direction.

[0026] In the mass production line, various types of rotating electric machines 1 are used. Even if different types of rotating electric machines 1 are used, they are similarly fixed to the test device, and after positioning with positioning pins, the projection 37 is fixed to the jig 10 of the test device.

[0027] Furthermore, the tests include, for example, airtightness tests, cogging torque tests, and torque ripple tests. Figure 6 shows the airtightness test apparatus. A sealing material (not shown) is inserted between the airtightness test apparatus and the contact surface 700 of the rotating electric machine 1 to ensure airtightness. The sealing material is uniformly compressed by pressing the projection 37 in the Z-axis direction with the jig 10. After that, air is injected into the rotating electric machine 1 from the air inlet 300 at a set pressure for a certain period of time using an air supply device.

[0028] In this invention, by providing a projection 37 on the outer circumference of the motor case 3 that is different from the flange 32 and protrudes radially outward with respect to the rotation axis O of the motor, the projection 37 can be fixed to the jig 10 of the test device even when different models of rotating electric machines 1 are introduced into the mass production line, thereby enabling the standardization of the test device. This reduces the production time and labor costs associated with changing jigs, and improves the efficiency of the mass production line.

[0029] The projection 37 is provided perpendicular to the rotation axis O and protrudes radially outward from the outer circumference of the motor case 3 relative to the rotation axis O of the motor. Since it is configured with a shape that has a plane in the vertical direction, if the bottom surface 371 of the jig 10 is flat, the contact area between the jig 10 and the projection 37 can be increased, resulting in the effect of more reliably preventing vibration in the Z-axis direction and movement of the rotating electric machine 1 in the XY-axis directions. Since the upper surface 101 of the projection 37 and the bottom surface 371 of the jig 10 are cast surfaces, processes such as cutting and polishing of the upper surface 101 and the bottom surface 371 are unnecessary, resulting in the effect of improving efficiency in the mass production line. In addition, because the cast surface is rough, the contact area between the upper surface 101 and the bottom surface 371 is increased. As a result, the coefficient of friction is increased, resulting in the effect of more reliably fixing the rotating electric machine 1.

[0030] The flange 32 and projection 37 are positioned such that the distance L1 from the external device connection surface of the flange 32 to the test fixture contact surface of the projection 37 is greater than the thickness La of the flange 32. This prevents collision between the fixture 10 and the flange 32, allowing the rotating electric machine 1 to be accurately mounted on the test device. Even when the flange 32 and projection 37 are close together and their positions overlap, the upper surface 101 of the projection 37 is still the contact surface with the fixture 10 during testing. This ensures that the rotating electric machine 1 can be accurately assembled to the test device even if the angle of the flange 32 differs for each model of the rotating electric machine 1. The radial length of the projection 37 is shorter than the radial length of the flange 32, allowing the rotating electric machine 1 to be mounted in a vehicle or the like even in a confined space. Furthermore, the reduced weight lowers transportation costs and reduces manufacturing costs due to the reduction in materials used.

[0031] By integrally casting the projection 37, flange 32, and motor case 3, high dimensional accuracy of the parts can be maintained, resulting in increased strength of the joint. Furthermore, this reduces assembly man-hours, the number of parts, and manufacturing costs.

[0032] In the airtightness test, the jig 10 presses the projection 37 in the Z-axis direction, which compresses the sealing material uniformly and effectively prevents air leakage from the contact surface 700.

[0033] Embodiment 2. The rotating electric machine 1 of Embodiment 2 will be described with reference to Figure 7. Note that the reference numerals in Figure 7 are the same as those in Figure 3. In Embodiment 1, two projections 37 are provided axially symmetrically on the outer circumference of the motor case 3, whereas in Embodiment 2, multiple sets of projections 37 are arranged on the outer circumference of the motor case 3.

[0034] Even with the rotating electric machine 1 shown in Embodiment 2, the jig 10 can be fixed to the test device by performing the same operation as in Embodiment 1.

[0035] By providing multiple sets of projections 37 radially outward from the rotation axis O of the motor case 3, the multiple projections 37 are pressed in the Z-axis direction, allowing the rotating electric machine 1 to be fixed to the test device more securely than in the first embodiment. The stress is distributed to multiple points on the projections 37, improving the durability of the projections 37 and the jig 10, and reducing the frequency of maintenance.

[0036] Furthermore, it is preferable to arrange the multiple protrusions 37 at equal intervals around the outer circumference of the motor case 3. This ensures that the pressing force from the jig 10 is evenly distributed, thereby reducing excessive load on the protrusions 37 and improving their durability.

[0037] Embodiment 3. The rotating electric machine 1 shown in Embodiment 3 will be described with reference to Figures 8 and 9. Note that the reference numerals in Figure 8 are the same as those in Figure 2. In the example in Figure 8, the upper surface 101 of the projection 37 in Embodiment 1 is flat, whereas the shape of the projection 37 in Embodiment 3 is circular.

[0038] The jig 10 is shaped to conform to the circular shape of the projection 37, and the contact surfaces of the jig 10 and the projection 37 are shaped like arcs. By having both ends of the arc of the projection 37 contact the jig 10, it is possible to prevent movement of the rotating electric machine 1 in the XY axis direction more reliably than in Embodiment 1. The shape of the projection 37 can be any structure as long as the pressing surface of the jig 10 fits the shape of the projection 37. As shown in Figure 9, the jig 10 may have a structure in which a recess follows the shape of the projection 37. Since surfaces 372 and 373 contact the jig 10, it is possible to prevent the rotating electric machine 1 from moving in the XY axis direction due to the tolerance between the positioning hole and the positioning pin more reliably. In addition, in torque ripple and cogging torque tests, it is possible to suppress vibration of the rotating electric machine 1 and reduce noise in the measurement data. It is possible to securely fix the motor case 3 and accurately measure the torque of the rotating shaft 21.

[0039] Furthermore, the embodiments described above may be combined as appropriate.

[0040] 1...Rotating electric machine, 2...Motor, 3...Motor case, 4...Control board, 5...Connector, 6...Housing, 7...Cover, 10...Jig, 22...Rotor, 23...Stator, 21...Rotating shaft, 32...Flange, 37...Protrusion

Claims

1. A rotating electric machine for transmitting the rotation of a motor to an external device, characterized by comprising: a cylindrical motor case housing the motor; a flange protruding radially outward from the motor case and connecting to the external device; and a projection, different from the flange, protruding radially outward from the outer circumference of the motor case with respect to the rotation axis of the motor.

2. The rotating electric machine according to claim 1, characterized in that the projection is pressed in the direction of the rotation axis by a jig that fixes the rotating electric machine.

3. The rotating electric machine according to claim 2, characterized in that the projection fits into the shape of the pressing surface of the jig.

4. The rotating electric machine according to claim 2, characterized in that the projection is fixed to the test device for the rotating electric machine.

5. The rotating electric machine according to claim 1, characterized in that the projection has a shape having a plane perpendicular to the axis of rotation.

6. The rotating electric machine according to claim 1, characterized in that, in the projection, when the surface of the flange facing the surface connecting to the external device is defined as the upper surface, the distance from the surface of the flange connecting to the external device to the upper surface is greater than the distance from the surface of the flange connecting to the external device to the surface facing the surface of the flange connecting to the external device.

7. The rotating electric machine according to claim 1, characterized in that the flange is integrally molded with the motor case.

8. The rotating electric machine according to claim 1, characterized in that the plurality of protrusions are arranged in the circumferential direction of the motor case.

9. The rotating electric machine according to claim 8, characterized in that the plurality of protrusions are arranged at equal intervals in the circumferential direction of the motor case.

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