JP2009303428A - Stator structure of thin radial motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin radial motor which reduces the cost of a component, magnetically connecting upper and lower yokes and has a stator assembly and a case, in a structure which is less apt to separate axially and to obtain further reduction in the thickness. <P>SOLUTION: The upper yoke 5 is fixed by caulking to a space yoke 20, a coil 9 is inserted, and then the lower yoke 6 and a PCB 4 are engaged with the space yoke 20, to form the stator assembly. A cylindrical bearing housing 35 of a case 30 is inserted into an inside diameter hole of the space yoke 20, and a case hooking nail of the space yoke 20 is hooked, on the base of the bearing housing to fix the space yoke. The stator assembly thus becomes less apt to come off from the case, and in this manner, the stator assembly is formed by the space yoke that is low in cost. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a structure of a thin radial motor, and more particularly to a structure of a coupling portion between a stator and a case.

FIG. 8 shows the structure of a conventional radial motor.
The bearing housing 52 includes a cylindrical portion 52a that is press-fitted into the case 53, and a cylindrical portion 52b that is thicker than the cylindrical portion 52a to which the upper yoke 55 and the lower yoke 56 are attached. An upper yoke 55, a coil 59, and a lower yoke 56 are attached to the cylindrical portion 52b. A printed circuit board (PCB) 54 on which an IC such as a driver is mounted is fitted on the lower yoke 56.
The rotor 60 having a fan installed on the outer periphery has a magnet 61 attached to the inner periphery thereof via a ring yoke 62, and one end of a shaft 57 that is rotatably attached to a bearing 58 is fixed at the center of the rotor 60. ing. The bearing 58 is press-fitted into the cylinder of the bearing housing 52.
The cylindrical portion 52 a of the bearing housing 52 is press-fitted into the press-fitting hole 53 a at the center of the case 53. The end surface 53b of the press-fitting hole 53a is bonded to the upper surface of the PCB 54 with an adhesive.

The bearing housing 52 configured as described above has the following role.
(1) The bearing 58 is held.
(2) The upper yoke 55 and the lower yoke 56 are mechanically and magnetically connected to form a structure and a magnetic circuit that connect the upper and lower yokes 55 and 56 (the upper and lower yokes 55 and 56 are attached to the bearing housing 52 by press fitting).
(3) The stator assembly is fixed to the case (when the stator assembly is fixed to the case 53, the bearing housing 52 is press-fitted into the case 53).
The stator assembly includes a bearing housing 52, upper and lower yokes 55 and 56, a bearing 58, a PCB 54, and a coil 59.

Incidentally, the bearing housing 52 having such a structure has the following drawbacks.
(1) Since it is produced by cutting, the component cost is increased.
(2) Since the case 53 and the bearing housing 52 are fixed by press-fitting and an adhesive, the pull-out strength between the case 53 and the stator assembly changes due to dimensional tolerances of parts. In other words, problems such as floating of the substrate, tilting of the substrate, or disassembly of the stator occur.
(3) In the case of a thin fan, since the length of the bearing housing 52 and the length of the bearing housing press-fitting portion of the case 53 are shortened, it is difficult to ensure the strength in the axial direction.

Further, the following demands have been made for radial motors.
(1) We want to reduce the cost of components (iron core: bearing housing) that magnetically connect the upper and lower yokes.
(2) I want to make the structure that prevents the stator assembly and case from coming off in the axial direction.
(3) I want to make the current radial motor thinner.

  The present invention solves the disadvantages of the conventional thin radial motor and meets the above-mentioned demands. The purpose of the present invention is to reduce the cost of parts that magnetically connect the upper and lower yokes, and to disengage the stator assembly and the case in the axial direction. An object of the present invention is to provide a thin radial motor that has a difficult structure and realizes a further thin shape.

In order to achieve the above object, according to a first aspect of the present invention, a space yoke is attached to the outer periphery of a cylindrical bearing housing portion for press-fitting a case bearing, and an upper yoke, a coil and a lower yoke are attached to the space yoke. A thin radial motor having a yoke mounted thereon and a PCB disposed on the lower yoke, wherein the space yoke is cylindrical and has an upper yoke caulking claw on the upper surface, a lower yoke coupling portion on the lower surface, A PCB fitting groove and a case hooking claw, wherein the upper yoke caulking claw is used to caulk the upper yoke to the space yoke, a coil is accommodated in the upper yoke, the lower yoke coupling portion is coupled to the lower yoke, A stator assembly is formed by fitting the PCB into a PCB fitting groove, and a case hooking claw of the space yoke is engaged with the case. Characterized in that attaching the stator assembly in a cylindrical bearing housing portion of the case.
The invention according to claim 2 is the invention according to claim 1, wherein the upper yoke is formed with a hole having substantially the same size as the cylindrical inner diameter of the space yoke, and a plate having a caulking groove on the inner peripheral surface of the hole; The upper yoke is fixed to the space yoke by bending the upper yoke caulking claw into the caulking groove and caulking the upper yoke caulking claw. Features.
According to a third aspect of the present invention, in the first aspect of the invention, the space yoke has a protrusion having a lower yoke coupling portion and a PCB fitting groove on the lower surface, and the PCB is substantially equal to a cylindrical inner diameter of the space yoke. A hole having the same dimension is formed, and a space yoke fitting groove is formed on the inner peripheral surface of the hole. The lower yoke is formed with a hole having substantially the same size as the cylindrical inner diameter of the space yoke, and a space is formed on the inner peripheral surface of the hole. It is composed of a plate having a yoke coupling groove and a bent portion bent at approximately 90 ° from the plate, the space yoke coupling groove is coupled to the lower yoke coupling portion, and the space yoke is fitted to the PCB fitting groove The PCB and the lower yoke are attached to the space yoke by engaging a groove.
The invention according to claim 4 is the invention according to claim 1, wherein the space yoke has a protrusion having a case hooking claw on a lower surface, and the case is formed on a bearing housing base connected to a cylindrical bearing housing portion. The space yoke is hooked and fixed to the case by having a hooking convex portion and engaging the case hooking claw with the hooking convex portion.

  According to the above configuration, (1) by using a space yoke without using a housing, the processing cost has been reduced and the cost has been reduced. (2) By having a structure for hooking the case and the stator, the shaft (3) By applying the above structure to a thin fan, the stator assembly can be achieved. And the assembly strength (mechanical) of the case can be secured.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a sectional view showing an embodiment of a thin radial motor to which a stator structure according to the present invention is applied.
The thin radial motor according to the present invention is constituted by assembling a rotor assembly, a stator assembly and a case 30.
The stator assembly includes a space yoke 20, an upper yoke 5, a lower yoke 6, a coil 9, a PCB 4, and a bearing 8. The rotor assembly includes a rotor portion 10, a ring yoke 12, a magnet 11 and a shaft 7.
The case 30 is an integral member, and includes a case housing 36, a bearing housing base 34, three support portions 31 (see FIG. 5A) that support the bearing housing base 34 on the case housing, and the bearing housing portion 34. It has each functional part of the cylindrical bearing housing part 35 connected.

The space yoke 20 of the stator assembly is inserted into the cylindrical bearing housing portion 35 of the case 30, and the case hooking claw 25 (see FIG. 2) of the space yoke 20 is hooked on the hooking protrusion 32 (see FIG. 6A) of the bearing housing base 34. Thus, the stator assembly is attached to the case 30.
Further, the rotor portion 10 is attached to the case by press-fitting the bearing 8 of the stator assembly into the cylindrical bearing housing portion 35 of the case 30. The shaft 7 is rotatable with respect to the bearing 8.

FIG. 2 is a perspective view showing details of the space yoke.
The space yoke 20 is made by press curling. The space yoke 20 has a cylindrical portion 21, and three upper yoke caulking claws 22 are provided on the upper surface of the cylindrical portion 21 at intervals of 120 degrees. Three projections 23 are provided on the lower surface of the cylindrical portion 21 at intervals of 120 degrees.
The projection 23 has a lower yoke coupling portion 27 at the base portion, a PCB fitting groove 26 for fitting the PCB 4 in the middle portion, and a case hooking claw 25 for hooking the case at the tip portion thereof. Yes.

FIG. 3 is a diagram for explaining the caulking structure of the upper yoke and the upper yoke caulking claw of the upper yoke and the space yoke, and the state of engagement between the PCB fitting groove of the space yoke and the PCB, and FIG. 4 is a diagram for explaining the details of FIG. FIG.
The upper yoke 5 has a hole 5d at the center of a circular plate 5b, and three crimping grooves 5c are formed on the inner peripheral surface of the hole 5d. This circular plate 5b is extended to the left and right, and a bent portion 5a is formed in the extended portion.
The lower yoke 6 has the same structure as the upper yoke 5, but the portion corresponding to the caulking groove of the upper yoke 5 is a space yoke coupling groove 6a (see FIG. 6C).
PCB 4 is a circular printed circuit board larger than the disk-like plate 5b of the upper yoke 5, and has a hole 4c in the center, and three space yoke fitting grooves 4b are formed on the inner peripheral surface of the hole 4c. Yes. A cutout 4a is provided around the periphery for mounting an IC or the like and for guiding the coil.
Both the holes 5d and 4c are substantially the same as the inner diameter of the cylindrical portion 21 of the space yoke 20.

In order to caulk the upper yoke 5 to the space yoke 20, the upper yoke 5 is mounted on the cylindrical upper surface portion 24 (see FIG. 2) of the space yoke 20, and the upper yoke caulking claw 22 portion is fitted into the caulking groove 5c. The upper yoke 5 is fixed to the space yoke 20 by caulking the claws 22.
In order to mount the lower yoke 6 on the space yoke 20, the coil 9 is inserted into the crimped upper yoke 5, and the lower yoke 6 is further inserted (press-fitted) thereon, and the space yoke coupling groove 6a of the lower yoke 6 is moved downward. The yoke coupling portion 27 is coupled. By inserting and rotating the PCB 4 from above, the space yoke fitting groove 4b of the PCB 4 is engaged with the PCB fitting groove 26 of the space yoke 20, and the lower yoke 6 is held down. As a result, the lower yoke 6 has a structure that does not come out of the space yoke 20.

5 is a perspective view showing details of the case as seen from above and below, FIG. 6A is a partially enlarged perspective view showing the engagement state of the case hooking claw 25 of the space yoke and the case, and FIG. 6B is a plan view of the stator / case assembly and its FIG. 6C is a partially enlarged plan view showing the state of the case yoke of the space yoke, the PCB fitting groove and the case, the PCB, the lower yoke, and the upper yoke.
Three support portions 31 are connected to the case housing 36 of the case 30, and the bearing housing base portion 34 is supported by the support portions 31. A cylindrical bearing housing portion 35 is connected to the bearing housing base portion 34. Three grooves 33 are provided around the bearing housing base 34, and a hooking protrusion 32 is formed in the groove 33.
The cylindrical bearing housing portion 35 has a press-fitting hole 37 for press-fitting the bearing 8.

A cylindrical bearing housing portion 35 is inserted into the cylinder of the space yoke 20 of the stator assembly. As a result, the case hooking claw 25 of the space yoke 20 protrudes from the groove 33 of the bearing housing base 34 and hooks on the hooking protrusion 32 of the groove 33 to fix the stator assembly to the case.
As shown in FIG. 6C, the stator assembly is fixed to the case. The upper yoke 5 is caulked by the upper yoke caulking claws 22 of the space yoke 20, and the lower yoke 6 is coupled to the lower yoke coupling portion 27 of the protrusion 23. The PCB 4 is fitted in the fitting groove 26, and the case hooking claw 25 is hooked on the hooking protrusion 32 of the case 30.

FIG. 7 is a diagram for explaining another example of the engagement structure between the space yoke and the PCB.
6C shows an example in which the PCB fitting groove 26 is provided in the protrusion 23, the protrusion 23 is inserted into the space yoke fitting groove 4b, and the PCB 4 is rotated to fit the PCB 4 into the PCB fitting groove 26. In this example, no PCB fitting groove is provided in the protrusion 41 of the space yoke 42. Also, the PCB 40 is not provided with a space yoke fitting groove.
The PCB 40 is press-fitted and attached to the space yoke 42 in the same manner as the lower yoke.

   In the above embodiment, the upper yoke is fixed to the space yoke by caulking, but the upper yoke can also be locked to the space yoke by press fitting.

  It is a thin radial motor used in equipment that requires a thin shape.

It is sectional drawing which shows embodiment of the thin radial motor to which the stator structure by this invention is applied. It is a perspective view which shows the detail of a space yoke. It is a figure for demonstrating the crimping structure of the upper yoke crimping nail | claw of an upper yoke and a space yoke, and the engagement state of PCB fitting groove | channel and PCB of a space yoke. It is a figure for demonstrating the detail of FIG. It is a perspective view which shows the detail of the case seen from the upper and lower sides. It is a partial expansion perspective view which shows the engagement state of the case hooking claw of a space yoke and a case. It is the top view of a stator case assembly, and its partial enlarged plan view. It is a partial expanded sectional view which shows the engagement state of the case hooking claw of a space yoke, a PCB fitting groove | channel, and a case, PCB, a lower yoke, and an upper yoke. It is a figure for demonstrating the other example of the engagement structure of a space yoke and PCB. It is sectional drawing which shows the structure of the conventional radial motor.

Explanation of symbols

1 Thin radial motor
4,40 PCB
5 Upper yoke
6 Lower yoke 8 Bearing 9 Coil 10 Rotor part 12 Ring yoke 20 Space yoke 21 Cylindrical part 22 Upper yoke caulking claw 23 Projection 24 Cylindrical upper surface part 25 Case hooking claw 26 PCB fitting groove 30 Case 31 Supporting part 32 Hooking convex part 33 Groove

Claims (4)

A thin type in which a space yoke is attached to the outer periphery of a cylindrical bearing housing portion for press-fitting a case bearing, an upper yoke, a coil and a lower yoke are attached to the space yoke, and a PCB is disposed on the lower yoke. A radial motor,
The space yoke is cylindrical and has an upper yoke caulking claw on the upper surface, a lower yoke coupling portion, a PCB fitting groove and a case hooking claw on the lower surface,
The upper yoke is caulked to the space yoke by the upper yoke caulking claw, the coil is accommodated in the upper yoke, the lower yoke is coupled to the lower yoke coupling portion, and the PCB is fitted into the PCB fitting groove. The stator assembly is formed by
A stator structure for a thin radial motor, wherein the stator assembly is attached to a cylindrical bearing housing portion of the case by engaging a case hooking claw of the space yoke with the case. The upper yoke is formed with a hole having substantially the same size as the cylindrical inner diameter of the space yoke, a plate having caulking grooves on the inner peripheral surface of the hole, and a bent portion bent at approximately 90 ° from the plate,
2. The stator structure for a thin radial motor according to claim 1, wherein the upper yoke is fixed to the space yoke by fitting the upper yoke caulking claw into the caulking groove and caulking the upper yoke caulking claw. The space yoke has a protrusion having a lower yoke coupling portion and a PCB fitting groove on the lower surface,
The PCB has a hole of substantially the same size as the cylindrical inner diameter of the space yoke, and has a space yoke fitting groove on the inner peripheral surface of the hole,
The lower yoke is formed of a plate having a hole having substantially the same size as the cylindrical inner diameter of the space yoke, a space yoke coupling groove on the inner peripheral surface of the hole, and a bent portion bent approximately 90 ° from the plate. And
The PCB and the lower yoke are attached to the space yoke by coupling the space yoke coupling groove to the lower yoke coupling portion and engaging the space yoke fitting groove with the PCB fitting groove. Item 2. A stator structure for a thin radial motor according to Item 1. The space yoke has a protrusion with a case hooking claw on the lower surface,
The case has a hooking projection on the bearing housing base connected to the cylindrical bearing housing,
2. The stator structure of a thin radial motor according to claim 1, wherein the case yoke is engaged with the hook projection and the space yoke is hooked and fixed to the case.

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