JPH0837768A - Brushless motor - Google Patents

Abstract

PURPOSE:To provide a brushless motor in which various rotating characteristics can be obtained by one stator and whose costs are low. CONSTITUTION:In a stator 7, a plurality of hole parts 17 which are used to fix a stationary member are made. The hole parts 17 are made respectively on the basis of a plurality of different prescribed reference positions at the same pitch in the circumferential direction.on the stator 7. Three of the hole parts 17 may be made respectively apart 120 deg. while 0 deg., 31 deg., 62 deg. and 93 deg. are used as the prescribed reference positions. Since the rotating characteristic of a motor is decided by an axial-flow timing to the stator 7 by the positional relationship between the stator 7 and a Hall element, four groups of the hole parts 17 can be formed in one stator 7 in this case. As a result, four kinds of fixed position patterns of the stator 7 can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a small DC brushless motor having an output of 100 watts or less.

[0002]

2. Description of the Related Art A conventional brushless motor is provided with a stator having a coil wound around a core and a rotor magnet which is driven to rotate relative to the stator, and a rotary position of a Hall element or the like provided near the stator. The commutation timing was obtained by the detector. Generally, a stator is provided with a plurality of holes for fixing to a stationary member at equal intervals in the circumferential direction, and any two or more of the holes are used to fix the stator by screwing or the like. Was there.

[0003]

The rotation characteristics of the motor are
It is determined by the timing of commutation to the stator due to the positional relationship between the Hall element of the motor and the stator. For example,
A motor having a characteristic of high-speed rotation has a positional relationship between a hall element and a stator that best suits the characteristic, and a motor having a characteristic of driving force has another positional relationship.
In the conventional structure as described above, since the holes on the stator are provided at equal intervals, whichever hole is used, the positional relationship between the Hall element and the stator is Remained the same, so that only one characteristic could be produced in one stator.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a brushless motor which can obtain various rotational characteristics with one stator and which does not cost much. To provide.

[0005]

In order to achieve the above object, a brushless motor according to a first aspect of the present invention includes a stator having a coil wound around a core, and a rotor magnet which is rotatably supported coaxially with the stator. , And the stator is provided with a plurality of holes for fixing to a stationary member, and the holes have substantially the same pitch in the circumferential direction based on a predetermined reference position on the stator. And the holes are provided on the basis of a plurality of different predetermined reference positions, respectively.

Further, in order to achieve the above object, in the brushless motor of the second invention, the hole portion is 0 in the circumferential direction.
.Degree., 31.degree., 62.degree., And 93.degree. Are predetermined reference positions, and three are provided at 120.degree. Pitch based on the predetermined reference positions.

[0007]

In the brushless motor of the present invention described above, in the stator having the coil wound around the core, the hole for fixing the stator to the stationary member is substantially circumferentially formed based on the predetermined reference position. The holes are provided at the same pitch, and the holes are provided on the basis of a plurality of different predetermined reference positions. The rotation characteristics of the motor are determined by the commutation timing due to the positional relationship between the Hall element of the motor and the stator, but since this motor has multiple combinations of holes with different formation positions on the stator, A plurality of fixed position patterns for the stationary member can be formed in one stator, and motors with various rotation characteristics can be obtained.

The holes 3 formed at 120 ° pitch
When fixing the stator core with one set as a set,
Based on the set of holes, 0 °, 31 °, 62 in the circumferential direction
A total of twelve holes are formed at positions shifted by 90 ° and 93 ° at the same 120 ° pitch. Therefore, in one stator, four fixed position patterns for the stationary member are formed, and it is possible to select from four patterns according to the required characteristics of the motor.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

FIG. 1 is a sectional view showing an embodiment of a brushless motor according to the present invention, and FIG. 2 is a plan view of a stator in the second embodiment.

In FIG. 1, a member 1 is a fixed frame which is attached to an apparatus (not shown), and a thin steel plate is used. Cut-and-raised parts 2 formed in a tongue shape by plastic working are provided at four corners of the fixed frame 1,
The cut-and-raised portion 2 is fixed to the device through a hole portion 3 formed in the cut-and-raised portion 2. The cut-and-raised portion 2 substantially increases the wall thickness for mounting the fixed frame 1.

A cylindrical portion 4 is fixed to the fixed frame 1. The cylindrical portion 4 is made of aluminum, brass, or the like. A flange portion 5 projecting outward is integrally provided on the outer peripheral portion of the cylindrical portion 4. The fixed frame 1 is externally fitted to the side surface of the collar portion 5 and is swaged to be integrally fixed. Three screw holes 6 are provided in the collar portion 5, and a stator 7 described later is fixed by screwing. A printed circuit board 8 is mounted on the fixed frame 1, and is fixed by a mounting screw 10 at a bent portion 9 provided at one end of the fixed frame 1.

A stator 7 is fitted on the outer peripheral portion 11 of the cylindrical portion 4. The stator 7 includes a core formed by laminating thin electromagnetic steel plates, and an armature coil in which a required winding is wound around the core. The inner peripheral portion 12 bored in the central portion of the stator 7 is fitted into the outer peripheral portion 11 of the cylindrical portion 4, and the mounting screw 13 allows the screw hole 6 of the collar portion 5 to be inserted.
The stator 7 is fixed by being screwed in. Specifically, the stator 7 is fixed to the fixed frame 1 (the collar portion 5 of the cylindrical portion 4) via the coupling member 14 and the printed circuit board 8.
It is fixed to.

The protrusion 15 formed on the connecting member 14 is
It is formed so as to project in one direction along the axis 16 and corresponds to a hole 17 formed in the stator 7. Also, the engaging piece 1
8 is formed so as to project outward in the radial direction and its end portion hangs down (to the other side in the direction of the axis 16), and is provided corresponding to the through hole 19 of the printed circuit board 8. The tip of the engagement piece 18 is formed in a substantially tapered shape, and is engaged and fixed in the through hole 19 by elastic bending of the engagement piece 18 itself. Further, the groove portion 20 forms an insertion portion of the mounting screw 13 used when fixing the stator 7 to the collar portion 5.

The coupling member 14 is made of an insulating resin material, and is interposed between the stator 7 and the printed circuit board 8 to electrically insulate the stator 7 and the printed circuit board 8 from each other and in the circumferential direction. And positioning in the direction of the axis 16. The connecting member 14 is also used for temporarily holding the stator 7 and the printed circuit board 8 when assembling the brushless motor. That is, the coupling member 14 is an assembly assisting member used when fixing the stator 7 and the printed circuit board 8 to the fixed frame 1.

The inner peripheral portion 21 of the cylindrical portion 4 has a pair of bearings 2
2 and 23 are attached. The rotor 24 is rotatably supported via the bearings 22 and 23. The rotor 24 includes a shaft 25, a rotor yoke 26 integrally fixed to the shaft 25, and an annular wall 2 of the rotor yoke 26.
7 and a rotor magnet 28 provided on the inner peripheral portion of the rotor 7. The shaft 25 is fitted and fixed to a base portion 30 provided on the horizontal portion 29 of the rotor yoke 26, and the base portion 30 and the rotor yoke 26 are fixed by a mounting screw 31.

A preload spring 32 is interposed in the bearing 22 in contact with a step portion 33 formed on the inner peripheral portion 21 of the cylindrical portion 4. Further, the bearing 23 is preloaded by the action of the preload spring 32 by the retaining ring 34 fitted in the shaft 25 and the step portion 35 of the cylindrical portion 4.

The printed circuit board 8 is provided with a hall element 36 that faces the rotor magnet 28 in the direction of the rotation axis and detects the rotation speed of the motor.

In FIG. 2, three holes A, A2, A3 having a pitch of 120 ° in the circumferential direction are provided as a group A as predetermined reference positions. Next, holes B1, B2, and B3, which also have a pitch of 120 °, are grouped into the group B at positions 31 ° circumferentially displaced from the predetermined reference positions A1, A2, and A3.
It is provided as. And the hole of 120 ° pitch, C
1, C2, C3 are formed at a position displaced by 62 ° from the group A, and holes D1, D2, D3 are formed at a position displaced by 93 ° from the group A at the same pitch of 120 °. Therefore, four combinations of the hole portions 17 having different formation positions can be formed in the stator 7.

The stator 7 has holes 17 with a pitch of 120 °.
Are used as a set of three and are fixed to the stationary member using the mounting screws 13, so when using this stator 7,
The fixed position can be selected from the four hole groups.

The rotation characteristic of the motor is determined by the commutation timing to the stator due to the positional relationship between the stator and the Hall element. Therefore, in the case of this stator 7, four characteristics can be formed in one stator 7, which is convenient when it is desired to change the characteristics of the motor or when manufacturing motors having various types of rotation characteristics with one stator. Is.

Although the embodiment of the brushless motor according to the present invention has been described above, the present invention is not limited to this embodiment, and various modifications can be made without departing from the scope of the present invention. In particular, the holes 17 provided in the stator 7 may be attached by screwing, rivet tightening, fusion welding, or the like. For that purpose, various through holes, tapping holes, or knurled inside may be used.

[0023]

Since the present invention is configured as described above, it has the following effects. The stator 7 has a hole for fixing the stator 7 to a stationary member,
A plurality of them are provided at different positions based on the predetermined reference position. For example, when three holes 17 formed at a pitch of 120 ° are used as one set and the stator 7 is fixed, a set of three holes 17 at a pitch of 120 ° is used as a base and 31 ° in the circumferential direction. A total of twelve holes 17 are formed at positions shifted by 62 ° and 93 ° at the same pitch of 120 °. This is different from the case where the groups of holes 17 are provided at equal intervals, and they deviate from the predetermined reference position by 1 ° in the B group, 2 ° in the C group, and 3 ° in the D group, and 4 in one stator. One hole 1
7 groups will be created. Therefore, from the four fixed position patterns of the stator, a position that matches the characteristics of the motor can be selected. Therefore, when it is desired to change the characteristics of the motor, the stator 7 in which the hole 17 is newly formed is changed.
It is not necessary to form a brushless motor, and various types of brushless motors can be manufactured from one stator 7.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a brushless motor according to the present invention.

FIG. 2 is a plan view of a stator showing a second embodiment of the brushless motor according to the present invention.

[Explanation of symbols]

 7 Stator 16 Hole 27 Rotor magnet

Claims (2)

[Claims] 1. A stator having a coil wound around a core,
A brushless motor comprising this stator and a rotor magnet that is rotatably supported coaxially, wherein the stator is provided with a plurality of holes for fixing to a stationary member, and the holes are A brushless motor characterized in that the holes are provided at substantially the same pitch in the circumferential direction based on a predetermined reference position on the stator, and the holes are respectively provided based on a plurality of different predetermined reference positions. 2. The holes are 0 °, 31 °, 6 in the circumferential direction.
2. The brushless motor according to claim 1, wherein 2 [deg.] And 93 [deg.] Are set to predetermined reference positions, and three units are provided at 120 [deg.] Pitch based on the predetermined reference positions.