JP5290608B2 - Axial gap motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial gap motor that ensures an installation space for a sensor element without fail and contributes to better performance. <P>SOLUTION: In the rotor 11 of the axial gap motor, the following is implemented: the main flux portion 20a of a magnet 20 is bonded on one side 19x of a disk-like back yoke 19 provided so that it can be rotated integrally with a rotating shaft 15; a sensor magnet portion 20b that causes a magnetic field to act on the other side 19y side of the back yoke 19 is formed integrally with the main flux portion 20a; and a Hall IC 31 for detecting the position of the rotor 11 is placed in a position opposed to this sensor magnet portion 20b in the axial direction. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an axial gap motor in which a rotor magnet and a stator coil are axially opposed to each other.

2. Description of the Related Art Conventionally, an axial gap motor is known in which a rotor magnet and a stator coil are arranged opposite to each other in the axial direction and the direction of the generated magnetic flux is in the axial direction. In the axial gap motor, a sensor element such as a Hall IC is installed to detect the rotational position of the rotor, and the drive power generated based on the detection of the rotor position by the sensor element is supplied to the coil to rotate the coil. A magnetic field is generated, and the rotor is rotated by the action of the magnet. For example, in the motor shown in Patent Document 1, the sensor element is provided side by side on the same plane as the coil in order to detect a magnetic field change due to the main magnetic flux of the magnet.
JP 2008-11611 A

  However, in order to provide the sensor element on the same plane as the coil, it is difficult to secure the installation space, and as in Patent Document 1, the interval between the predetermined coils is widened and the sensor element is installed there. .

  Therefore, the number of coils decreases to secure the arrangement space of the sensor element, so in order to obtain the desired output characteristics, it is necessary to increase the number of turns of the coil or increase the thickness of the conductive wire, It wasn't a good idea.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an axial gap motor that can reliably secure a space for arranging sensor elements and contribute to performance improvement. is there.

In order to solve the above-mentioned problem, a stator having a plurality of coils provided in the circumferential direction, a rotor having a magnet facing the magnetic pole of the coil in the axial direction, and a sensor element for detecting the position of the rotor, An axial gap motor that generates a rotating magnetic field in the coil by supplying driving power generated based on position detection of the rotor by a sensor element to rotate the rotor by the action of the magnet, The rotor includes a sensor magnet portion that has a main magnetic flux portion fixed to one side surface of a disc-shaped back yoke provided so as to be rotatable integrally with a rotation shaft, and a magnetic field acts on the other side surface of the back yoke. It is formed integrally with the main magnetic flux part and detects the position of the rotor at a position facing the sensor magnet part in the axial direction. The sensor elements are arranged to perform, the sensor magnet portion is provided on the periphery of the back yoke, the outer peripheral edge portion of the back yoke configured as an engagement portion engaged with the sensor magnet portion in the axial direction The gist of the present invention is that the outer peripheral edge of the back yoke is formed in a tapered shape that widens toward the stator .

  According to the present invention, the rotor includes a sensor magnet portion in which a main magnetic flux portion of a magnet is fixed to one side surface of a disk-like back yoke provided so as to be rotatable integrally with a rotating shaft and a magnetic field is applied to the other side surface side of the back yoke Is formed integrally with the main magnetic flux part, and a sensor element for detecting the position of the rotor is arranged at a position facing the sensor magnet part in the axial direction. That is, in the past, the sensor element was provided so as to be opposed to the stator side of the magnet and the rotor position was detected. However, in the present invention, the sensor element can be provided on the side opposite to the stator side in the axial direction. Since the position of the rotor is detected by the element, the arrangement space for the sensor element can be secured without the sensor element interfering with the coil. In addition, this makes it possible to improve the degree of freedom of the coil size and the number of turns and contribute to the improvement of the performance as a motor.

  In the present invention, the sensor magnet portion is provided at the peripheral edge portion of the disk-shaped back yoke. In other words, the smaller the angle error is on the outer side in the radial direction, the smaller the angle error is. Therefore, the position of the rotor can be detected with high accuracy by providing the sensor magnet unit at the peripheral edge on the outer side in the radial direction.

The gist of the invention according to claim 2 is that, in the axial gap motor according to claim 1, the sensor magnet portion is provided so as to further protrude in the axial direction from the other side surface of the back yoke.

  In the present invention, the sensor magnet portion is provided so as to further protrude in the axial direction from the other side surface of the back yoke. Thereby, since the axial direction length of the sensor magnet part becomes longer than the axial length of the back yoke, the leakage magnetic flux to the back yoke side is prevented, and the magnetic flux is suitably induced to the sensor magnet part side. For this reason, the position of the rotor can be suitably detected by the sensor element.

According to a third aspect of the present invention, in the axial gap motor according to the first or second aspect , the rotor is configured such that the magnet is integrally formed with the back yoke.

In the present invention, since the rotor is configured by integrally forming a magnet with respect to the back yoke, the number of parts can be suppressed.
According to a fourth aspect of the invention, the axial gap motor according to claim 3, wherein the engaging portion includes a gist of the engagement match Turkey at least in the axial direction bite into the radial direction to the sensor magnet unit To do.

In the present invention, the engaging portion, that match engages at least in the axial direction bite into the sensor magnet portion in a radial direction. Thereby, fixation with a magnet and a back yoke can be strengthened, and drop-off of the magnet from a back yoke can be prevented.

According to a fifth aspect of the present invention, in the axial gap motor according to the second aspect of the present invention, the sensor element includes the sensor element in a recess formed by the other side surface of the back yoke and the axially protruding portion of the sensor magnet unit. The gist is that at least a part of the control circuit component that generates the driving power based on the position detection of the rotor is accommodated.

  In the present invention, at least a part of the control circuit component that generates drive power based on the detection of the position of the rotor by the sensor element is in the recess formed by the other side surface of the back yoke and the axially protruding portion of the sensor magnet unit. Contained and configured. Thereby, a control circuit component can be arrange | positioned effectively using a recessed part, and the physique increase to an axial direction can be suppressed.

  Therefore, according to the above-described invention, it is possible to provide an axial gap motor that can secure an arrangement space for sensor elements and contribute to performance improvement.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of the axial gap motor of the present embodiment. As shown in FIG. 1, the case 2 of the axial gap motor 1 is formed in a substantially bottomed cylindrical shape, and a support cylinder portion extending in a substantially cylindrical shape from the inner surface of the bottom portion 3 to the inside of the case 2 along the axial direction. 4 is provided. The support cylinder part 4 is comprised from the 1st support cylinder part 4a which continues from the bottom part 3, and the 2nd support cylinder part 4b whose diameter is smaller than this 1st support cylinder part 4a. The opening of the case 2 is closed by a substantially disk-shaped end plate 5. A stator 10 and a rotor 11 are provided in an internal space surrounded by the case 2 and the end plate 5.

  A stator core 12 constituting the stator 10 is formed in a substantially disk shape and is fixed to the bottom 3 of the case 2. The stator core 12 is provided with a plurality of teeth 13 protruding in the axial direction at equal intervals in the circumferential direction. Each tooth 13 is provided with a coil 14 formed by winding a conductive wire.

  The rotary shaft 15 constituting the rotor 11 includes a radial bearing 16 fixed to the inner peripheral surface of the second support cylinder portion 4b of the case 2, and a cap fixed to the inner peripheral surface of the first support cylinder portion 4a of the case 2. A thrust bearing 18 fixed to 17 is rotatably supported. A substantially disk-shaped back yoke 19 is fixed to the rotary shaft 15 so as to be integrally rotatable.

  The back yoke 19 is provided with a boss portion 19a having a thickness that is thicker in the axial direction (end plate 5 side) in the axial direction in order to reinforce the mounting strength with the rotary shaft 15, and as a peripheral portion of the back yoke 19. The outer peripheral edge portion 19b is formed in a tapered shape that widens (has a large diameter) toward one side in the axial direction (the stator 10 side in this embodiment). In addition, you may form the outer peripheral edge part 19b so that it may spread toward the opposite side to the stator 10. FIG.

  A substantially annular magnet 20 is integrally formed and fixed to the back yoke 19 by injection molding or the like. On one side surface 19x of the back yoke 19, that is, the surface facing the teeth 13 around which the coil 14 is wound in the axial direction, a main magnetic flux portion 20a magnetized in the circumferential direction corresponding to the number of the coils 14. The main magnetic flux portion 20 a is formed to have a slightly larger diameter than the back yoke 19. In addition, the magnet 20 is integrally provided with a sensor magnet portion 20b that protrudes in the axial direction toward the other side surface 19y of the back yoke 19 (on the side opposite to the stator 10) so as to be continuous from the outer peripheral edge of the main magnetic flux portion 20a. Is formed. That is, the main magnetic flux portion 20a and the magnetic pole are similarly configured in the sensor magnet portion 20b.

  In addition, the sensor magnet portion 20b is formed with a recess 21 by forming an outer peripheral edge portion 19b as an engaging portion of the back yoke 19 in the radial direction on the base end side thereof. The magnet 20 is prevented from falling off by engaging with the back yoke 19 in the axial direction. Further, since the sensor magnet portion 20b is formed so as to protrude in the axial direction from the other side surface 19y of the back yoke 19, the leakage magnetic flux from the sensor magnet portion 20b to the back yoke 19 side, more specifically, the sensor magnet portion 20b Leakage magnetic flux generated between adjacent magnetic poles on the radially inner side is prevented from passing through the back yoke 19, and the magnetic flux is suitably induced to the sensor magnet unit 20 b side.

  A circuit board 30 fixed to the end plate 5 is provided at a position opposite to the stator 10 of the rotor 11 in the axial direction. The circuit board 30 has a Hall IC 31 as a sensor element for detecting the rotational position of the rotor 11 (sensor magnet unit 20b), and a control circuit component 32 that generates drive power based on the position detection of the rotor 11 by the Hall IC 31. Is provided. Incidentally, a plurality of Hall ICs 31 are provided in the circumferential direction at positions facing the sensor magnet unit 20b in the axial direction (one is shown in the figure), and a part of the control circuit component 32 is connected to the other side surface 19y of the back yoke 19. It is housed in a recess 33 formed by the axially protruding portion of the sensor magnet portion 20b.

  In the axial gap motor 1 configured as described above, electric power is supplied from an external power source (not shown) to each part via the circuit board 30, a rotating magnetic field is generated in the coil 14, and the rotor 11 is rotated by the action of the magnet 20. It has come to be.

Next, characteristic effects of the present embodiment will be described.
(1) In the rotor 11, the main magnetic flux portion 20a of the magnet 20 is fixed to one side surface 19x of a disk-like back yoke 19 provided so as to be rotatable integrally with the rotary shaft 15, and to the other side surface 19y side of the back yoke 19. A sensor magnet portion 20b that applies a magnetic field is formed integrally with the main magnetic flux portion 20a, and a Hall IC 31 that detects the position of the rotor 11 is disposed at a position facing the sensor magnet portion 20b in the axial direction. That is, conventionally, the sensor element is provided so as to be opposed to the stator side of the magnet and the rotor position is detected, but in this embodiment, the Hall IC 31 can be provided on the opposite side of the stator 10 side in the axial direction. Since the position of the rotor 11 is detected by the Hall IC 31, the Hall IC 31 can be secured without interfering with the coil 14. In addition, this makes it possible to improve the degree of freedom of the size and the number of turns of the coil 14 and contribute to the performance improvement as the axial gap motor 1.

  (2) The sensor magnet portion 20b is provided on the outer peripheral edge portion 19b of the disk-shaped back yoke 19. That is, the smaller the angle error is on the radially outer side, the smaller the angle error is. Therefore, the sensor magnet unit 20b is provided on the outer peripheral edge portion 19b on the radially outer side, whereby the position of the rotor 11 can be detected with high accuracy.

  (3) The sensor magnet portion 20 b is provided so as to protrude further in the axial direction from the other side surface 19 y of the back yoke 19. As a result, the axial length of the sensor magnet portion 20b is longer than the axial length of the back yoke 19, so that leakage flux to the back yoke 19 side is prevented, and the magnetic flux is preferably guided to the sensor magnet portion 20b side. Is done. Therefore, the position detection of the rotor 11 can be suitably performed by the Hall IC 31.

(4) Since the rotor 11 is formed by integrally molding the magnet 20 with the back yoke 19 by injection molding, the number of parts can be suppressed.
(5) The back yoke 19 is provided with an engaging portion that digs into the sensor magnet portion 20b in the radial direction and engages at least in the axial direction. Thereby, fixation with the magnet 20 and the back yoke 19 can be strengthened, and the fall-off of the magnet 20 from the back yoke 19 can be prevented.

  (6) A control circuit component 32 that generates drive power in the recess 33 formed by the other side surface 19y of the back yoke 19 and the axially protruding portion of the sensor magnet portion 20b based on the position detection of the rotor 11 by the Hall IC 31. At least a part of which is accommodated. Thereby, the control circuit component 32 can be arrange | positioned effectively using the recessed part 33, and the physique increase to an axial direction can be suppressed.

In addition, you may change the said embodiment as follows.
In the above embodiment, the back yoke 19 and the magnet 20 are integrally formed, but may be configured separately.

  -In above-mentioned embodiment, although the sensor magnet part 20b was provided in the outer-periphery edge part 19b of the back yoke 19, you may provide not only in this but in the radial inside rather than the outer-periphery edge part 19b. In this case, it is preferable to provide a through hole in the back yoke 19 and connect the sensor magnet portion 20b to the main magnetic flux portion 20a side.

  In the above embodiment, the sensor magnet portion 20b is formed to extend in the axial direction from the other side surface 19y of the back yoke 19, but may be formed to be flush with the other side surface 19y, for example. .

  In the above embodiment, the outer peripheral edge portion 19b of the back yoke 19 is formed in a tapered shape to constitute the engaging portion, but the outer peripheral edge portion 19b may have a shape other than the tapered shape, for example, an uneven portion. Good. Moreover, it is good also as a structure which abbreviate | omits an engaging part.

In the above-described embodiment, the control circuit component 32 is disposed in the recess 33 so that a part of the control circuit component 32 is accommodated.
In the above-described embodiment, the back yoke 19 includes the boss portion 19a that is thicker in the axial direction (end plate 5 side) than the other portions on the radial center side. The yoke 19 may be formed with a constant thickness.

It is sectional drawing of the axial gap motor in this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Axial gap motor, 10 ... Stator, 11 ... Rotor, 14 ... Coil, 15 ... Rotating shaft, 19 ... Back yoke, 19b ... Outer peripheral edge (peripheral part and engaging part), 19x ... One side, 19y ... Others Side surface, 20 ... magnet, 20a ... main magnetic flux part, 20b ... sensor magnet part, 31 ... Hall IC (sensor element), 32 ... control circuit component, 33 ... concave part.

Claims (5)

A stator having a plurality of coils provided in the circumferential direction, a rotor having a magnet facing the magnetic pole of the coil in the axial direction, and a sensor element for detecting the position of the rotor;
An axial gap motor that generates a rotating magnetic field in the coil by supplying driving power generated based on detection of the rotor position by the sensor element to the coil, and rotates the rotor by the action of the magnet. ,
The rotor includes a sensor magnet portion that has a main magnetic flux portion fixed to one side surface of a disc-shaped back yoke provided so as to be rotatable integrally with a rotation shaft, and a magnetic field acts on the other side surface of the back yoke. The sensor element that is integrally formed with the main magnetic flux portion and that detects the position of the rotor is disposed at a position facing the sensor magnet portion in the axial direction ,
The sensor magnet portion is provided on a peripheral portion of the back yoke,
The outer peripheral edge portion of the back yoke is configured as an engaging portion that engages with the sensor magnet portion in the axial direction, and the outer peripheral edge portion of the back yoke is formed in a tapered shape that widens toward the stator side. Axial gap motor characterized by that. The axial gap motor according to claim 1 ,
The axial gap motor according to claim 1, wherein the sensor magnet portion is provided so as to protrude further in the axial direction from the other side surface of the back yoke. The axial gap motor according to claim 1 or 2 ,
2. The axial gap motor according to claim 1, wherein the rotor is formed by integrally forming the magnet with respect to the back yoke. In the axial gap motor according to claim 3 ,
The engagement portion, axial gap motors, wherein the engagement match Turkey at least in the axial direction bite into the radial direction to the sensor magnet unit. The axial gap motor according to claim 2 ,
At least a part of the control circuit component that generates the driving power based on the position detection of the rotor by the sensor element in the recess formed by the other side surface of the back yoke and the axially protruding portion of the sensor magnet unit. Is an axial gap motor characterized by being housed.

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