JP2008271761A - Outer rotor type motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an outer rotor type motor wherein the number of components is decreased to attain size reduction, assembling is easy, and the manufacturing cost is reduced. <P>SOLUTION: An annular portion 16, which is projectively provided at one side of a shaft hole direction of an insulator 12, is fitted into a through hole 14a of a motor board 14. A board fixing portion 17 is provided at an outer wall of the annular portion, wherein the board fixing portion is fitted to a board fitting jaw 21, formed in an inner peripheral portion of the through hole 14a, for attaching. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an outer rotor type motor in which a stator including an insulator that covers and insulates a stator core and a rotor including a rotor shaft are assembled together with a motor board to a mounting portion.

  For example, in OA equipment such as a laser beam printer and a copying machine, an outer rotor type DC brushless motor is preferably used as a driving source for paper feeding, photosensitive drum driving, fixing roller driving, and the like.

  An example of the configuration of the DC brushless motor will be described. A motor board provided with a motor drive circuit is fixed to the bracket (or mounting plate), and a stator is assembled to the outer periphery of the bracket. In the shaft hole of the bracket, a rotor shaft is rotatably supported via a bearing portion, and the rotor is assembled.

The stator is screwed and fixed to the bracket (or mounting plate) through a through hole provided in the stator core. The motor board is fixed with screws to the bracket (or mounting plate).
Japanese Unexamined Patent Publication No. 7-59324 JP 2006-94675 A

  However, fixing the stator and bracket (or mounting plate), and the motor board and bracket (or mounting plate) by screwing increases the number of parts and increases the number of assembly steps, thus reducing the motor size and manufacturing costs. It is difficult to plan.

  The present invention has been made to solve these problems, and an object of the present invention is to provide an outer rotor type motor that can be reduced in size by reducing the number of parts, can be easily assembled, and can reduce manufacturing costs. There is.

In order to achieve the above object, the present invention comprises the following arrangement.
An outer rotor type motor in which a stator having an insulator that covers and insulates the stator core and a rotor having a rotor shaft are assembled to a mounting portion together with a motor board, and protrudes on one side in the axial hole direction of the insulator The annular part thus fitted is fitted into the through hole of the motor board, and the board fixing part for engaging and assembling the board engaging claw formed on the inner peripheral part of the through hole is provided on the outer wall of the annular part It is characterized by.
In addition, a protrusion is provided on the end surface of the annular portion of the insulator, and the protrusion is fitted into a fitting hole provided in the attachment portion, and the stator is positioned and assembled.
The protruding portion of the insulator is characterized in that the leading end side of the protruding portion is welded through the fitting hole of the mounting portion.
Further, a stepped portion is formed on the outer wall of the annular portion of the insulator, and a stopper facing the stepped portion is formed on one end side in the circumferential direction of the stepped portion so as to cut the peripheral portion of the through hole of the motor board. The substrate engagement claw formed in a lacking manner is overlapped with the stepped portion in the axial direction so that the annular portion is fitted, and the substrate engagement claw is moved relative to one end in the circumferential direction until it hits the wall surface of the annular portion. The board engaging claw is sandwiched between the stopper and the stepped portion, and the motor board is positioned and fixed to the insulator.

If the brushless motor described above is used, the annular portion projecting on one side in the axial hole direction of the insulator is fitted into the through hole of the motor board, and the board engaging claw formed on the inner peripheral part of the through hole is engaged. Since the board fixing part to be assembled together is provided on the outer wall of the annular part, the annular part of the insulator is inserted into the through hole of the motor board and the board fixing claw is engaged with the board fixing part, and the circumferential direction and The axial position is fixed. Therefore, the motor assembly screw can be omitted and the motor board can be assembled to the stator, so that the motor can be reduced in size and cost.
Also, a protrusion is provided on the end surface of the annular portion of the insulator, and the protrusion is fitted and fitted in a fitting hole provided in the attachment portion. Therefore, the stator is positioned and assembled with respect to the attachment portion. It is possible to assemble. In addition, if the protrusion of the insulator penetrates the fitting hole of the mounting part and the tip of the protrusion is welded, the stator can be positioned reliably during assembly and the axial strength of the insulator can be increased. It can be improved.
In particular, the annular portion is fitted by overlapping the substrate engaging claw formed by cutting out the peripheral portion of the through hole of the motor substrate in the axial direction on the stepped portion, and the substrate engaging claw is relatively positioned at one end in the circumferential direction. The board engaging claw is sandwiched between the stopper and the stepped portion and the motor board is positioned and fixed to the insulator, so that the number of assembling steps can be reduced and the manufacturing cost can be reduced.

  Hereinafter, the best embodiment of the outer rotor type motor according to the present invention will be described with reference to the accompanying drawings. In the present embodiment, an outer rotor type DC brushless motor will be described as an example.

A schematic configuration of the DC brushless motor will be described with reference to FIGS. 3, 6, and 7.
In FIG. 6, a cup-shaped rotor yoke 2 is used for the rotor 1. A rotor shaft 4 is integrally fixed to the hub 3 of the rotor yoke 2 by caulking, press fitting or shrink fitting. A ring-shaped magnet 5 is fixed to the inner peripheral surface of the rotor yoke 2. The magnet 5 is magnetized alternately with N and S poles in the circumferential direction. In FIG. 7, the cylindrical part 7 is formed in the attachment plate 6 which is an attachment part. The rotor shaft 4 is rotatably supported on the cylindrical portion 7 via bearings 8 and 9. The output side bearing 9 is preloaded by a wave washer 9a.

  In FIG. 7, the stator 10 is assembled by positioning the stator core 11 in the cylindrical portion 7 and positioning the insulator 12 on the mounting plate 6. 3A and 3B, the stator core 11 is covered with an insulator 12, and a motor coil 13 is wound around a tooth portion. In FIG. 7, the motor board 14 provided with the motor drive circuit is assembled integrally with the insulator 12. The ground pattern of the motor board 14 is electrically connected to the mounting plate 6 by screws 15 and grounded.

  Next, the structure of the insulator 12 and the motor substrate 14 will be described with reference to FIGS. In FIG. 1, an annular portion 16 projects from one side of the insulator 12 in the axial hole direction. Substrate fixing portions 17 for assembling the motor substrate 14 are provided, for example, at three locations on the outer wall side of the annular portion.

Specifically, in FIG. 1, stepped portions 18 are formed at, for example, three locations on the outer wall of the annular portion of the insulator 12. A concave groove 19 and a stopper 20 facing the concave groove 19 are formed on one end side of each stepped portion 18 in the circumferential direction (near the annular wall surface 16b). The concave groove 19 may be omitted.
In FIG. 2A, the peripheral edge of the through hole 14a of the motor board 14 is notched, and the board engaging claws 21 are formed in three places. The annular portion 16 is fitted into the through hole 14a with the substrate engaging claws 21 of the motor substrate 14 overlapped with the stepped portion 18 in the axial direction. Then, the substrate engaging claw 21 is slid in the circumferential direction toward the concave groove 19 and abuts against the annular wall surface 16b, whereby the substrate engaging claw 21 is positioned in the circumferential direction and the stopper 20 and the stepped portion in the axial direction. 18, the motor substrate 14 is positioned and fixed to the substrate fixing portion 17.

  Moreover, in FIG.1 and FIG.2B, the protrusion part 16a is provided in the end surface of the annular part 16 of the insulator 12 at three places. 5A, the attachment plate 6 is provided with three fitting holes 6a. In FIG. 5B, the protrusion 16a of the insulator 12 is fitted into the fitting hole 6a provided in the mounting plate 6, and the stator 10 is positioned and assembled.

Next, an example of the assembly configuration of the motor will be described with reference to FIGS.
3A and 3B, in a state where the stator core 11 is covered with the insulator 12 and insulated, the motor coil 13 is wound around the tooth portion and the stator 10 is assembled.

  Next, in FIGS. 4A and 4B, the motor substrate 14 is assembled to the substrate fixing portion 17 provided in the annular portion 16 of the insulator 12. The substrate engaging claw 21 of the motor substrate 14 is overlapped with the stepped portion 18 (see FIG. 1) in the axial direction, and the annular portion 16 is inserted into the through hole 14a. Then, the board engaging claw 21 is rotated in the circumferential direction until it abuts against the annular wall surface 16 b and is sandwiched between the stopper 20 and the stepped portion 18. As a result, the board engaging claw 21 is positioned in the circumferential direction and the axial direction, and the motor board 14 is positioned and fixed to the board fixing portion 17. Since the recessed portion 19 is formed in the stepped portion 18 at a position facing the stopper 20, when the substrate engaging claw 21 is rotated along the stepped portion 18 until it hits the annular portion wall surface 16b, Since the board engaging claws 21 are escaped, the assemblability is good.

  Next, in FIGS. 5A and 5B, the stator 10 is assembled to the mounting plate 6. Assembling is performed by fixing the stator core 11 to the outer peripheral surface of the cylindrical portion 7 (intermediate fitting or press-fitting state). At this time, the protrusion 16a provided in the annular portion 16 of the insulator 12 is fitted into the fitting hole 6a provided in the mounting plate 6, and the stator 10 is positioned and assembled with respect to the mounting plate 6. . The protrusion 16a of the insulator 12 may pass through the fitting hole 6a of the mounting plate 6 and be welded at the tip end of the protrusion to be prevented from coming off. Accordingly, the stator 10 can be reliably positioned during assembly, and the strength of the insulator 12 in the axial direction can be improved.

  Next, the rotor 1 shown in FIG. 6 is assembled to the stator 10. In FIG. 7, the rotor shaft 4 of the rotor 1 is rotatably supported by a bearing 8 on the counter-output side (rotor yoke 2 side), a thrust washer 9b and a wave washer 9a.

  Finally, in FIG. 7, the assembly is completed by fitting screws 15 into the screw holes provided in the circuit pattern of the motor board 14 and the mounting plate 6 and connecting them to the ground.

  In the above embodiment, the number of the board fixing portions 17 and the protrusions 16a of the insulator 12, the board locking claws 21 of the motor board 14, and the fitting holes 6a of the mounting plate 6 are arbitrary. Moreover, although it demonstrated using the DC brushless motor, it can also be used for other outer rotor type motors, such as a motor with a brush and an AC motor.

It is a perspective view of an insulator. It is a top view of a motor board and an insulator. It is the top view and right view of a stator. It is the top view and right view which assembled | attached the motor board | substrate to the stator of FIG. FIG. 5 is a plan view and a right side view of a state in which a mounting plate is assembled to the stator of FIG. 4. It is sectional drawing of a rotor. It is sectional drawing of a DC brushless motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotor 2 Rotor yoke 3 Hub 4 Rotor shaft 5 Magnet 6 Mounting plate 6a Fitting hole 7 Cylindrical part 8, 9 Bearing 9a Wave washer 9b Thrust washer 10 Stator 11 Stator core 12 Insulator 13 Motor coil 14 Motor board 14a Through hole DESCRIPTION OF SYMBOLS 15 Screw 16 Ring part 16a Projection part 16b Ring part wall surface 17 Board | substrate fixing | fixed part 18 Step part 19 Groove | groove 20 Stopper 21 Board | substrate engagement nail

Claims (4)

A stator having an insulator that covers and insulates the stator core and a rotor having a rotor shaft are outer rotor type motors that are assembled together with a motor board to a mounting portion,
An annular portion projecting on one side in the axial hole direction of the insulator is fitted into a through hole of the motor substrate, and a substrate fixing portion for engaging and assembling a substrate engagement claw formed on the inner peripheral portion of the through hole is provided. An outer rotor type motor provided on the outer wall of the annular portion.   The outer rotor type according to claim 1, wherein a projection is provided on an end surface of the annular portion of the insulator, and the projection is fitted into a fitting hole provided in the attachment portion so that the stator is positioned and assembled. motor.   The outer rotor type motor according to claim 2, wherein the protruding portion of the insulator penetrates the fitting hole of the mounting portion and is welded at the leading end side of the protruding portion.   A stepped portion is formed on the outer wall of the annular portion of the insulator, and a stopper facing the stepped portion is formed on one end in the circumferential direction of the stepped portion, and the peripheral portion of the through hole of the motor board is cut out. The formed substrate engagement claw is overlapped with the stepped portion in the axial direction so that the annular portion is fitted, and the substrate engagement claw is moved relative to one end in the circumferential direction until it abuts against the wall surface of the annular portion. The outer rotor type motor according to claim 1, wherein the engaging claw is sandwiched between the stopper and the stepped portion, and the motor board is positioned and fixed to the insulator.