JP2015136246A - Support structure of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support structure of a motor which can suppress electrolytic corrosion of components in the vicinity of a shaft, while reducing vibration noise.SOLUTION: A support structure of a motor constituted to include a stator core 2 surrounding a rotor core 3 in the circumferential direction, a rotor shaft 4 penetrating the central part of the rotor core 3 and secured thereto, and bearings 5, 6 for supporting the rotor shaft 4 on the motor case 7, is further provided with a stator case 10 having high conductivity, and abutting against the motor case 7 while covering the outer periphery of the stator core 2, a first bolt for fixing the stator case 10 to the stator core 2, and a second bolt 12 for fixing the stator case 10 to the motor case 7. The first bolt and second bolt 12 are arranged so that the phase is shifted in the circumferential direction around the rotor shaft 4.

Description

  The present invention relates to a support structure for an electric motor.

  2. Description of the Related Art Conventionally, there is known a vehicle drive device that includes an internal combustion engine, a first electric motor, a second electric motor, a power split mechanism, a transaxle, and the like. This vehicle drive device has a motor support structure in which a stator of a first motor is fixed to a motor case of a first motor with a bolt (see, for example, Patent Document 1).

JP 2010-149749 A

  However, the conventional motor support structure described above is concerned that when the motor is driven at a high output and high speed, the value of current flowing from the stator to the rotor shaft increases, and electric corrosion occurs on the bearings supporting the rotor shaft. Is done. Further, in the conventional motor support structure described above, there is a concern that vibration noise may be generated due to the stator swinging with respect to the motor case when the motor has a high output and high speed.

  Therefore, the present invention has been made to solve the above-described problems. Even when the electric motor has a high output and a high rotation speed, it is possible to suppress the electrolytic corrosion of components located near the rotor shaft and to reduce vibration noise. An object of the present invention is to provide a motor support structure that can be reduced.

  In order to achieve the above object, the electric motor support structure according to the present invention includes: (1) a stator core that surrounds the rotor core in the circumferential direction; a rotor shaft that passes through a central portion of the rotor core and is fixed to the rotor core; A bearing structure for supporting the rotor shaft on the electric motor case, the electric motor supporting structure, having a high conductivity, and covering the outer periphery of the stator core and contacting the electric motor case; A first fixing member that fixes the stator case to the stator core; and a second fixing member that fixes the stator case to the electric motor case, wherein the first fixing member and the second fixing member are: In this configuration, the phase is shifted in the circumferential direction around the rotor shaft.

  With this configuration, in the motor support structure according to the present invention, current flows from the stator core to the motor case through the highly conductive stator case, and almost no current flows through the rotor core, the rotor shaft, and the bearing. For this reason, the support structure of the electric motor according to the present invention can suppress the electrolytic corrosion of components located near the rotor shaft such as a bearing even when the electric motor has a high output and a high rotation speed.

  With the above configuration, the electric motor support structure according to the present invention includes a first fixing member that fixes the stator case to the stator core and a second fixing member that fixes the stator case to the electric motor case, with the rotor shaft as the center. Therefore, the stator core is prevented from swinging with respect to the motor case by the spring effect of the stator case. For this reason, the motor support structure according to the present invention can reduce vibration noise even when the motor has high output and high rotation speed.

  ADVANTAGE OF THE INVENTION According to this invention, even if an electric motor carries out high output and high rotation, while supporting the electrolytic corrosion of the component located in the rotor shaft vicinity, the support structure of the electric motor which can reduce a vibration noise can be provided.

It is a schematic sectional drawing of the alternating current motor to which the support structure of the electric motor which concerns on embodiment of this invention is applied. FIG. 2 is a perspective view of a stator core, a stator case, a first bolt, and a second bolt in FIG. 1. 1 is a schematic electric circuit diagram of an AC motor to which a motor support structure according to an embodiment of the present invention is applied.

  Hereinafter, a support structure for an electric motor according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, an AC motor M to which the motor support structure according to the present embodiment is applied includes a stator coil 1, a stator core 2, a rotor core 3, a rotor shaft 4, bearings 5 and 6, a motor case 7, and the like. It is configured to include.

  The stator core 2 has a plurality of magnetized portions extending radially in the outer periphery of the rotor core 3, and each stator coil 1 wound around each magnetized portion is supplied with an alternating current from an inverter (not shown). The end portions of the respective magnetized portions facing the rotor core 3 are magnetized by alternating the N pole and the S pole.

  The rotor core 3 is a permanent magnet body that is formed by laminating an annular thin plate of ferromagnetic material, and the outer peripheral surface portion is magnetized by alternating N and S poles in the circumferential direction.

  The rotor shaft 4 passes through the central portion of the rotor core 3 and is fixed to the rotor core 3, thereby supporting the rotor core 3 and supported by the motor case 7 via bearings 5 and 6.

  As shown in FIG. 2, the stator core 2 has bolt receiving portions 2 a that protrude radially outward at three locations in the circumferential direction and extend in the axial direction, and bolt fastening holes 2 b are formed in the bolt receiving portions 2 a. Is forming.

  As shown in FIG. 2, the motor support structure according to the present embodiment includes a stator case 10 formed of a metal having high conductivity such as a copper alloy, a first bolt 11 as a first fixing member, It has the 2nd volt | bolt 12 as a 2nd fixing member.

  The stator case 10 is curved so as to cover each of the portions between the bolt receiving portions 2a adjacent in the circumferential direction in the outer peripheral portion of the stator core 2, and three covering portions 10a whose one end abuts against the motor case 7; And an annular flange portion 10b that integrates the three covering portions 10a continuously with the other end portion of each covering portion 10a, and is formed between the adjacent covering portions 10a in the circumferential direction. The bolt receiving part 2a is fitted with a slit part 10c.

  Further, the stator case 10 has three bolt insertion holes 10d and 10e formed in the flange portion 10b alternately in the circumferential direction. The bolt insertion hole 10d corresponds to the bolt fastening hole 2b of the bolt receiving portion 2a. The bolt insertion hole 10e corresponds to a bolt fastening hole 7a formed in the electric motor case 7 as shown in FIG.

  The first bolt 11 is inserted into the bolt insertion hole 10 d of the flange portion 10 b and screwed into the bolt fastening hole 2 b of the bolt receiving portion 2 a, and the stator case 10 is fixed to the stator core 2.

  The second bolt 12 is inserted into the bolt insertion hole 10 e of the flange portion 10 b and screwed into the bolt fastening hole 7 a of the electric motor case 7, and the stator case 10 is fixed to the electric motor case 7.

  Next, the operation of the motor support structure according to the present embodiment will be described.

  In this AC motor M, when the stator core 2 is excited by supplying current to the stator coil 1 from an inverter (not shown), the rotor core 3 and the rotor shaft 4 rotate integrally.

  When the AC motor M is in an operating state, as shown in FIG. 3, there is a potential difference E between the stator coil 1 and the motor case 7 serving as the ground, but in an ideal state, current flows only through the stator coil 1. Absent. However, actually, a leakage current I0 due to the capacitor effect is generated between the stator coil 1 and the stator core 2. In addition, a leakage current I2 due to the capacitor effect is generated between the stator core 2 and the rotor core 3, and a current flows through an electric path constituted by the rotor shaft 4, the bearings 5 and 6, and the motor case 7.

  Since the stator case 10 having high conductivity is interposed between the stator core 2 and the motor case 7, the motor support structure according to the present embodiment includes the stator core 2, the stator case 10, and the motor case 7. The current I1 flows through the electrical circuit.

  The resistance R1 of the electric circuit constituted by the stator core 2, the highly conductive stator case 10 and the electric motor case 7 is significantly higher than the combined resistance R2 of the electric circuit constituted by the rotor shaft 4, the bearings 5, 6 and the electric motor case 7. small. Moreover, the electric circuit comprised by the rotor core 3 and the rotor shaft 4 has resistance R3.

  Therefore, the electric motor support structure according to the present embodiment increases the current I1 flowing through the electric path constituted by the stator core 2, the stator case 10 and the electric motor case 7 and increases the rotor shaft 4, the bearings 5 and 6 and the electric motor case 7. There is almost no leakage current I2 flowing through the constructed circuit. For this reason, the motor support structure according to the present embodiment can suppress the electrolytic corrosion of components located near the rotor shaft 4 such as the bearings 5 and 6 even when the AC motor M has a high output and a high rotation speed. .

  In addition, the motor support structure according to the present embodiment includes a first bolt 11 that fixes the stator case 10 to the stator core 2 and a second bolt 12 that fixes the stator case 10 to the motor case 7. 4 is arranged so that the phase is shifted in the circumferential direction with the center being 4, the spring effect of the stator case 10 suppresses the swing of the stator core 2 with respect to the motor case 7. For this reason, the support structure of the electric motor according to the present embodiment can reduce vibration noise even when the AC electric motor M has a high output and a high rotation speed.

  The technical scope of the support structure of the electric motor according to the present invention is not limited to the above-described embodiment, and various modifications of the constituent elements described in the claims are made without departing from the scope of the present invention. Is included.

  As described above, the electric motor support structure according to the present invention has the effects that even when the electric motor has high output and high rotation, it can suppress the electrolytic corrosion of components located near the rotor shaft and reduce vibration noise. However, it is useful for various electric motors including an electric motor incorporated in a drive device of a vehicle.

  2 ... Stator core, 3 ... Rotor core, 4 ... Rotor shaft, 5, 6 ... Bearing, 7 ... Motor case, 10 ... Stator case, 11 ... First bolt, 12 ... Second bolt

Claims (1)

A stator core surrounding the rotor core in the circumferential direction;
A rotor shaft that passes through the center of the rotor core and is fixed to the rotor core;
A bearing for supporting the rotor shaft on an electric motor case, and an electric motor supporting structure comprising:
A stator case having high conductivity and covering the outer periphery of the stator core and contacting the motor case;
A first fixing member for fixing the stator case to the stator core;
A second fixing member for fixing the stator case to the motor case;
The motor support structure according to claim 1, wherein the first fixing member and the second fixing member are arranged so that a phase is shifted in a circumferential direction about the rotor shaft.

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