WO2013118161A1

WO2013118161A1 - Electric motor

Info

Publication number: WO2013118161A1
Application number: PCT/JP2012/000781
Authority: WO
Inventors: 弘文土井
Original assignee: 三菱電機株式会社
Priority date: 2012-02-06
Filing date: 2012-02-06
Publication date: 2013-08-15
Also published as: JPWO2013118161A1; JP5627804B2

Abstract

A holding member (15) has elastic holding sections (21-23) in three directions except where a target-facing surface (16a) of a sensor (16) is present. The outer surfaces of the sensor (16) are pressed by the elastic holding sections (21-23) so that the sensor is held by means of an elastic force.

Description

Electric motor

The present invention relates to a sensor holding member used in an electric motor including a sensor for controlling the rotational speed.

A general three-phase synchronous AC motor creates a magnetic pole in the rotor by a permanent magnet of the stator, and creates a magnetic pole in the stator teeth by a coil disposed between the stator teeth of the stator. The energization direction of the three-phase coils arranged between the stator teeth is switched by a power distribution plate (bus bar), and is switched between the S pole and the N pole. By sequentially switching the energizing directions of the three-phase coils, the polarity of each stator tooth is rotated and the rotor is rotated by a magnetic action.

This motor has a structure that controls the rotational speed by reading the rotational position of the target that rotates integrally with the shaft by means of a sensor installed on the outer periphery of the shaft, and Hall sensors that detect the position by magnetic force change are widely used. . As a sensor holding member, there is, for example, Patent Document 1. In this Patent Document 1, a concave portion is formed in the sensor, and a flexible support piece that can be elastically bent is formed on a support ring fixed to the outer periphery of the shaft, and between the support ring and the flexible support piece. The sensor is pushed in, and the convex portion of the flexible support piece is engaged with the concave portion of the sensor in a snap-fit manner.

On the other hand, in a motor that rotates at high speed, the target must be firmly fixed, and it is difficult to use a magnet as the target. Therefore, by using a large sensor in which a bias magnet is integrated with the Hall sensor, a magnetic material such as iron can be used for the target. Since the bias magnet-integrated sensor is increased in size, strength is required for the fixing method. For example, as shown in the plan view of FIG. 9A and the cross-sectional view of FIG. The sensor 102 was fixed by pouring the filler 101 into the member 100. The holding member 100 is attached to a substrate 104 on the outer periphery of a shaft (not shown), and one target 103 is attached to a shaft (not shown).

JP 2000-221204 A

In the case of the holding structure of the above-mentioned Patent Document 1, there is a problem that versatility is poor because it is necessary to form a recess in the sensor. In addition, since the sensor is held at one place of the concave and convex portions, there is a concern that the strength of the large sensor is insufficient.

On the other hand, when the filler 101 is used, it takes a long time to cure, and depending on the type of the filler 101, there are some cases where heating is required, and there is a problem that the assembly time is long and the efficiency is low. Further, the holding member 100 must be formed in a box shape so that the filler 101 does not leak out, the holding member 100 is interposed between the target 103 and the sensor 102, and the distance between the target 103 and the sensor 102. There was also a problem that L was far away.

This invention has been made to solve the above-described problems, and aims to hold a sensor without using a filler.

The electric motor of the present invention has a target that rotates integrally with the shaft, a sensor that is held at a position facing the target, detects the rotational position of the target, and a plurality of elastically deformable elastic holding portions, and the elastic holding portion And a holding member that presses the outer surface of the sensor from a plurality of directions and holds the sensor by elastic force.

According to the present invention, the filler can be eliminated by holding the sensor by the elastic force of the holding member, and the efficiency of assembly can be improved. In addition, since it is not necessary to form the holding member in a box shape so that the filler does not leak out, the target-facing surface of the sensor can be opened, and the distance between the sensor and the target can be shortened.

It is sectional drawing which shows the structure of the electric motor which concerns on Embodiment 1 of this invention. It is a figure explaining rotation operation of the electric motor concerning Embodiment 1. FIG. FIG. 3 is an enlarged external perspective view of the holding member according to the first embodiment. The holding member of Embodiment 1 is shown, Fig.4 (a) is a top view, FIG.4 (b) is sectional drawing cut | disconnected along the AA line. FIG. 5A is a plan view, and FIG. 5B is a cross-sectional view taken along the line BB, showing a state in which the holding member of Embodiment 1 holds the sensor. FIG. 3 is an enlarged view of an elastic holding portion of the holding member according to the first embodiment. FIG. 6 is an external perspective view showing a modification of the holding member according to the first embodiment. 8 shows a holding member for an electric motor according to Embodiment 2 of the present invention, in which FIG. 8 (a) is a plan view and FIG. 8 (b) is a cross-sectional view taken along line CC. 9A and 9B show a conventional sensor holding structure, in which FIG. 9A is a plan view and FIG. 9B is a cross-sectional view taken along the line DD.

Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
An electric motor 1 shown in FIG. 1 constitutes a three-phase AC synchronous motor that rotates at high speed, and mainly includes a cylindrical housing 2, a stator portion 3 fixed inside the housing 2, and a rotor that rotates a shaft 4. Part 5 and bus bar part (distribution part) 6 arranged on one end face side of stator part 3. In FIG. 2, the top view of the stator part 3 and the rotor part 5 seen from the bus-bar part 6 side is shown. However, the housing 2 and the coil 12 are not shown.

The rotor part 5 is configured by laminating electromagnetic steel plates, and has two protrusions protruding outward in the circumferential direction at intervals of 180 degrees, and the protrusions are shifted by 90 degrees in the axial direction of the shaft 4 (

Projections

5a, 5b). The shaft 4 is rotatably supported by

bearings

7 and 8 fixed to the housing 2. The rotor part 5 is fixed to the shaft 4, and the rotational force generated in the rotor part 5 is externally output by rotating the shaft 4 integrally with the rotor part 5. When the electric motor 1 is applied to an automobile turbocharger, an electric compressor, and the like, the shaft 4 is connected to a rotating shaft of a turbine (so-called impeller), and the electric motor 1 rotationally drives the turbine.

The stator unit 3 includes two

stator cores

9 and 10 and a magnet 11 disposed between the

stator cores

9 and 10. Each of the

stator cores

9 and 10 is configured by laminating electromagnetic steel plates in the axial direction of the shaft 4. Each of the

stator cores

9 and 10 is formed with a plurality of

teeth

9a and 10a protruding from the outside toward the central shaft 4 side, and one U-shaped pair of

teeth

9a and 10a overlapping in the axial direction of the shaft 4 is formed. The coil 12 is attached.

One end of each coil 12 attached to each

tooth

9a, 10a penetrates the bus bar portion 6 and protrudes toward the inverter board 13 side, and the copper plate coil 14 (U phase, V phase, W phase) of the bus bar portion 6 It is connected to the. The copper plate coil 14 is a conductive member molded on the bus bar portion 6. The copper plate coil 14 is annularly arranged along the circumferential direction of the shaft 4 and has an end connected to the inverter board 13. The inverter board 13 converts an external power source (not shown) into an alternating current, and sequentially switches the three phases of the copper plate coil 14 such as the U phase, the V phase, and the W phase based on the position signal input from the sensor 16. Current is passed through 14.
The inverter board 13 is attached to the inside of the cover housing 19 and covered with the cover 20.

Here, an outline of the operation of the electric motor 1 will be described.
The magnetic flux generated by the magnet 11 magnetized in the axial direction flows out from the teeth 10a of the stator core 10 arranged on the N-pole side of the magnet 11 to the protrusion 5b of the rotor portion 5, and advances through the rotor portion 5 in the axial direction. It becomes a field magnetic flux which comes out from the protrusion 5a on the pole side and flows into the teeth 9a of the stator core 9 arranged on the S pole side of the rotor part 5. In this way, the magnetic field force of the magnet 11 acts on the rotor part 5, so that the protrusion 5 b of the rotor part 5 facing the N pole side of the magnet 11 is magnetized to the N pole, and the S pole of the magnet 11. The projecting part 5a of the rotor part 5 facing the side is magnetized to the S pole. When a current flows through the U-shaped coil 12 via the copper plate coil 14 of the bus bar portion 6, the

teeth

9 a and 10 a of the

stator cores

9 and 10 are magnetized according to the direction of the flowing current to generate a rotating magnetic field, Torque is generated. By sequentially switching the direction of the current flowing through the coil 12, the NS polarities of the

teeth

9a and 10a rotate and move as shown in FIGS. 2 (a) to 2 (c). Rotate.

In this electric motor 1, a sensor 16 and a target 17 are used for rotation control of the rotor unit 5. One end portion of the shaft 4 protrudes from one end face of the stator portion 3 to the inner circumferential space of the bus bar portion 6, and a target 17 is fixed to the protruding tip by a screw 18. The target 17 is a magnetic material such as iron. The other sensor 16 is a Hall sensor with a built-in bias magnet, and is held by a holding member 15 formed at a position facing the target 17 in the inner space of the bus bar portion 6. The magnetic field generated by the bias magnet changes according to the displacement of the target 17 as the shaft 4 rotates, and the Hall sensor detects the change in the magnetic field and outputs a position signal indicating the rotational position of the shaft 4.

Here, details of the holding member 15 will be described.
3 is an enlarged external perspective view of the holding member 15, FIG. 4A is a plan view, and FIG. 4B is a cross-sectional view taken along the line AA. 5A is a plan view showing a state in which the holding member 15 holds the sensor 16, and FIG. 5B is a cross-sectional view taken along the line BB. The rectangular parallelepiped sensor 16 has a target facing surface 16 a facing the target 17 and a terminal 16 b for electrical connection to the inverter board 13.

The holding member 15 is formed of a resin material, and elastic holding portions 21 to 23 that generate an elastic force for holding the sensor 16 and contact portions 24 to 27 that contact the sensor 16 protrude from the bottom surface. ing. In addition, a terminal hole 28 through which the terminal 16b passes is formed on the bottom surface. The upper surface of the holding member 15 is open, and the sensor 16 is inserted from the open end while the elastic holding portions 21 to 23 are elastically deformed and expanded. Note that the elastic holding portions 21 to 23 project in three directions excluding the direction facing the target 17 so as not to cover the target facing surface 16a of the sensor 16.

FIG. 6 shows an enlarged view of the elastic holding portion 21. A claw 21a is formed at the tip of the elastic holding part 21, and a tapered surface 21b is formed at the lower part of the claw 21a. By engaging the claw 21a with the outer surface of the upper end portion of the sensor 16 and applying the tapered surface 21b, the axial component force F1 that presses the sensor 16 toward the bottom surface side and the lateral component force that moves the sensor 16 toward the center side. F2 can be obtained simultaneously. The sensor 16 that has received the lateral component force F <b> 2 from the claw 21 a of the elastic holding portion 21 is pressed against the abutting

portions

26 and 27 that are provided on the opposite side of the elastic holding portion 21, and the elastic holding portion 21. And the abutting

portions

26 and 27. Further, since the axial component force F <b> 1 is received from the tapered surface 21 b, the sensor 16 does not come out to the open top end of the holding member 15.

Similarly, the

elastic holding portions

22 and 23 form claws and a tapered surface to simultaneously generate the axial component force F1 and the lateral component force F2. The sensor 16 is sandwiched between the elastic holding part 22 and the opposing

contact parts

24 and 27, and the sensor 16 is sandwiched between the elastic holding part 23 and the opposing

contact parts

24 and 25.

Thereby, the sensor 16 can be securely held by the elastic force of the elastic holding portions 21 to 23. Further, the sensor 16 is applied to each tapered surface to absorb the dimensional variation of the sensor 16, and the position is held by pressing.

Further, by forming the elastic holding portions 21 to 23 on the holding member 15 and holding the sensor 16 by its elasticity, it is not necessary to use a filler as in the prior art described above. Therefore, it is not necessary to form the holding member 15 in a box shape so that the filler does not leak out. Accordingly, the target facing surface 16a of the sensor 16 can be opened by opening the target facing surface of the holding member 15, and the distance between the sensor 16 and the target 17 can be shortened.

In addition, although the

contact parts

24 and 27 are required so that the sensor 16 may not fall out from the target facing surface opening of the holding member 15, the

contact parts

25 and 26 may be omitted.

Further, by forming the holding member 15 with a resin material, it can be formed integrally with the bus bar portion 6 made of the same resin material. Since the sensor 16 can be held without adding the holding member 15, the assemblability is improved.
1 and 3, the holding member 15 has a shape protruding from the inner peripheral surface of the bus bar portion 6, but is not limited thereto. For example, a recess 6a may be formed on the inner peripheral surface of the bus bar portion 6 as shown in FIG. 7, and the holding member 15 may be formed so as to be accommodated in the recess 6a, or a part of the holding member 15 may be accommodated in the recess 6a. You may form so that the remaining part may protrude.

Alternatively, the holding member 15 may be formed alone. In this case, for example, as shown in FIG. 4 and FIG. 5, an adhesive portion 29 having a shape protruding outward from the bottom surface of the holding member 15 is formed, and an adhesive is applied. The holding member 15 is bonded and fixed to ().
In addition, for example, when the distance between the inverter board 13 and the sensor 16 is long as shown in FIG. 1 and the terminal 16b of the sensor 16 becomes long and there is a concern about vibration resistance, a board dedicated to the sensor 16 is added during this period. The holding member 15 may be attached to the substrate. Thereby, the terminal 16b can be shortened and the vibration resistance can be improved.
Further, the holding member 15 is not limited to the bus bar portion 6 and the inverter board 13 (or the board dedicated to the sensor 16), but may be attached to the housing 2 or the like.

As described above, according to the first embodiment, the electric motor 1 includes the target 17 that rotates integrally with the shaft 4, the sensor 16 that is held at a position facing the target 17 and detects the rotational position of the target 17, and elastic deformation. A plurality of possible elastic holding portions 21 to 23, and the elastic holding portions 21 to 23 press the outer surface of the sensor 16 from a plurality of directions, and the holding member 15 holds the sensor 16 by elastic force. Configured. For this reason, it becomes possible to abolish the filler by holding the sensor 16 by the elastic force of the holding member 15, and the assembly efficiency can be improved.
Further, since it is not necessary to form the holding member 15 in a box shape so that the filler does not leak out, the elastic holding portions 21 to 23 are formed on the surface excluding the target facing surface 16a of the sensor 16, and the holding member 15 is thus formed. The target-facing surface can be configured to open. Thereby, the distance between a sensor and a target can be shortened.

Further, according to the first embodiment, each of the elastic holding portions 21 to 23 is configured to have a tapered surface at a portion that presses the outer surface of the sensor 16. For this reason, the sensor 16 can be fixed by causing the component force F1 in the axial direction that presses the sensor 16 to the bottom side and the component force F2 in the lateral direction that moves the sensor 16 toward the center simultaneously.

Further, according to the first embodiment, the holding member 15 is made of a resin material, and this holding member 15 is opposed to the target 17 on the inner peripheral side of the bus bar portion 6 also made of the resin material. It comprised so that it might comprise integrally in a position. For this reason, it is not necessary to install the holding member 15 when assembling the electric motor 1, and the assemblability is improved.
Alternatively, the holding member 15 may be configured to be attached to the inverter board 13 or a board dedicated to the bus bar portion 6, and in this case, the terminal 16 b of the sensor 16 can be shortened, so that vibration resistance can be improved. is there.

Embodiment 2. FIG.
FIG. 8A is a plan view of the holding member 15 extracted from the electric motor 1 according to Embodiment 2, and FIG. 8B is a cross-sectional view cut along the CC line. Although the holding member 15 is formed of a resin material in the first embodiment, a part of the holding member 15 is formed of a metal plate in the second embodiment. 8 that are the same as or equivalent to those in FIGS. 1 to 7 are given the same reference numerals, and descriptions thereof are omitted.

In the holding member 15 shown in FIG. 8, the elastic holding portions 21 to 23 are made of a metal plate. The elastic holding portions 21 to 23 of the metal plate can hold the sensor 16 with the elastic force generated in the metal plate even when the elastic holding portions 21 to 23 of the resin material exceed the allowable stress of the resin in size.
Note that the elastic holding portions 21 to 23 of the metal plate are integrated with the resin material 30 by insert molding, or integrated with screws or screws for electrical insulation. Alternatively, the metal plate elastic holding portions 21 to 23 may be directly screwed or screwed to the inverter board 13 (or the board dedicated to the sensor 16), or the metal plate elastic holding portions 21 to 23 may be connected to the bus bar portion 6. And may be integrally molded.

Also, resin parts or metal

plate contact portions

24 and 27 are formed so that the sensor 16 does not fall out of the target-facing surface opening of the holding member 15. In addition, the contact portions 25 and 26 (shown in FIG. 3 and the like) may be formed in the same manner as in the first embodiment.

As described above, according to the second embodiment, since the elastic holding portions 21 to 23 are made of metal plates, a large-sized sensor 16 can be held and the versatility of the holding member 15 is improved.

In the first and second embodiments, the holding member 15 has been described by taking the rectangular parallelepiped sensor 16 as an example, but it goes without saying that the sensor 16 having a shape other than the rectangular parallelepiped can be held. For example, even if the upper surface of the sensor 16 is a curved surface, the taper surfaces of the elastic holding portions 21 to 23 can be applied to the outer surface of the sensor 16 and held by elastic force.
Moreover, although the Hall sensor which incorporated the bias magnet was mentioned as an example as the sensor 16, a Hall sensor single-piece | unit may be sufficient.

In addition to the above, within the scope of the invention, the invention of the present application can be freely combined with each embodiment, modified any component of each embodiment, or omitted any component in each embodiment. Is possible.

As described above, the electric motor according to the present invention presses the outer surface of the sensor from a plurality of directions with a plurality of elastic holding portions and holds the sensor by elastic force. Suitable for use.

1 electric motor, 2 housing, 3 stator portion, 4 shaft, 5 rotor portion, 5a, 5b protrusion, 6 bus bar portion, 6a recess, 7, 8 bearing, 9, 10 stator core, 9a, 10a teeth, 11 magnet, 12 coil , 13 inverter board, 14 copper plate coil, 15 holding member, 16 sensor, 17 target, 18 screw, 19 cover housing, 20 cover, 21-23 elastic holding part, 21a claw, 21b tapered surface, 24-27 contact part, 28 Terminal hole, 29 bonding part, 30 resin material, 100 holding member, 101 filler, 102 sensor, 103 target, 104 substrate.

Claims

A target that rotates integrally with the shaft;
A sensor that is held at a position facing the target and detects a rotational position of the target;
An electric motor comprising a plurality of elastic holding portions that can be elastically deformed, a holding member that presses the outer surface of the sensor from a plurality of directions with the elastic holding portions and holds the sensor by elastic force.
2. The electric motor according to claim 1, wherein the elastic holding portion is formed on a surface excluding the target facing surface of the sensor, and the target facing surface of the holding member is opened.
2. The electric motor according to claim 1, wherein the elastic holding portion is formed with a tapered surface at a portion pressing the outer surface of the sensor.
The electric motor according to claim 1, wherein the holding member is made of a resin material.
A conductive member that distributes power to the coil is molded with a resin material, and includes a power distribution unit installed on the outer peripheral side of the target and the shaft,
5. The electric motor according to claim 4, wherein the holding member is configured integrally with the power distribution unit at a position facing an inner peripheral side of the power distribution unit and facing the target.
The electric motor according to claim 1, wherein the holding member is attached to a substrate.
The electric motor according to claim 1, wherein the elastic holding portion is made of a metal plate.