JP2000184678A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor that can adjust the balance of a rotor as desired, and can simply and easily mount a weight for the balance. SOLUTION: A motor is equipped with a housing 2, a rotor 18 that is rotatably supported by the housing 2, a rotor magnet 38 that is fitted to the rotor 18, a stator 42 that is provided opposite to the rotor magnet 38, and a weight 62 for balance that is mounted to the rotor 18 to achieve rotary balance. A plurality of through holes 60 are provided in a circumferential direction essentially at even intervals, the weight 62 for the balance has a head part 66 and a leg part 68 and is composed so that the leg part 68 is subjected to elastic deformation in the radial direction, and the weight 62 for the balance is retained at a specific accommodation recessed part by the elastic deformation of the leg part 68.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor for adjusting the rotational balance of a rotor using a balance weight.

[0002]

2. Description of the Related Art For example, a motor disclosed in Japanese Patent Application Laid-Open No. 7-170705 is known as a motor which uses a balancing member to adjust the rotational balance of the motor. This known spindle motor includes a hub on which a magnetic disk is mounted, a rotor frame mounted on the hub, a bracket rotatably supporting the hub via a pair of bearings, and a rotor magnet mounted on the rotor frame. And a stator mounted on a bracket facing the rotor magnet. A groove is formed in the rotor frame, for example, radially or concentrically, and a balancing weight made of an adhesive mixed with metal powder is attached to the groove.

[0003]

However, in such a spindle motor, since the balance weight is made of an adhesive, the weight of the balance weight varies depending on the amount of the adhesive. It is difficult to set the weight to a desired weight, and the workability of attaching the balance weight is not easy. In particular, when mass-producing a motor, it is not easy to measure and mount a required amount, the workability is poor, and the weight may be peeled off from the rotor.

[0004] Such a problem of rotor balance adjustment exists not only in the spindle motor described above, but also in various motors such as a cooling fan motor and a DC motor.

An object of the present invention is to provide a motor which can adjust the balance of a rotor as required and can easily and easily attach a balance weight.

[0006]

According to the present invention, a housing, a rotor rotatably supported by the housing,
A motor comprising: a rotor magnet mounted on the rotor; a stator disposed to face the rotor magnet; and a balance weight attached to the rotor to balance rotation. A recess is provided, and the balance weight is elastically attached to the housing recess by elastic deformation of itself.

As such a motor, it can be widely applied to various motors such as a cooling fan motor, a spindle motor, an LBP motor, and a DC main motor.

According to the present invention, since the balance weight itself is elastically deformed, it can be easily mounted by inserting it into the accommodation recess. In addition, in the state that was attached,
Because it is held elastically by its own elastic deformation,
There is no separation from the rotor. In addition, the balance weight can be easily detached by being elastically deformed using, for example, a tool or the like, and when a mounting error or the like occurs, the attached balance weight can be removed. The material of the balance weight is preferably a single material such as resin or rubber, or a composite material obtained by resin-molding a metal.

In the present invention, the balance weight may be:
It has a head and a leg extending from the head, and the leg is elastically deformed in a radial direction, and the balance weight is held in the housing recess by the elastic deformation of the leg. It is characterized by the following.

According to the present invention, the balance weight has a head and legs extending from the head, and the legs are configured to be elastic in the radial direction. Therefore, the balance weight can be easily attached to the rotor by pushing it into the accommodation recess, and the legs are kept elastically deformed in the attached state, so that the balance weight can be securely attached. . Further, since the balance weight has a head and a leg, the weight of the balance weight can be set to an appropriate weight.

In the present invention, the rotor is cup-shaped, and has a peripheral side wall on which an inner peripheral surface is provided with a rotor magnet, and an end wall provided at one end of the peripheral side wall. A plurality of the accommodating recesses are provided at an outer peripheral portion of the end wall portion at intervals in a circumferential direction, and the balance weight is elastically attached to a predetermined accommodating recess in an axial direction from the outside. And

According to the present invention, a plurality of housing recesses are provided on the outer peripheral surface of the end wall of the cup-shaped rotor.
The balance weight is inserted into the receiving recess to be mounted in the axial direction from the outside. Therefore, the balance weight can be easily mounted in the specific accommodation recess once the position where the balance weight is to be mounted is determined. For example, the balance weight can be easily mounted even when the motor is automatically assembled. Generally, the balance display of the balance measuring device is displayed when viewed from the outer surface side of the end wall of the rotor, and therefore, by mounting the balance weight from the same direction, the mounting operation can be performed. It becomes easier and its workability is improved. Further, since the mounting direction of the balance weight and the direction of the centrifugal force acting on the weight are orthogonal to each other, the detachment of the mounted balance weight can be prevented more reliably.

Further, according to the present invention, the balance weight is
A first balance weight having a heavy weight and a second balance weight having a light weight; the first balance weight or the second balance weight for balancing the rotation of the rotor; A weight is mounted in the predetermined receiving recess.

According to the present invention, at least two types of balance weights are prepared. The first balance weight is heavy and the second balance weight is light. The rotation balance of the rotor can be easily and accurately adjusted by selecting the first and second balance weights as desired and mounting the weights in a predetermined accommodation recess of the rotor. As a configuration for changing the weight of the balance weight, for example, there is a configuration in which the length of the head of the balance weight is changed or the specific gravity of the material of the balance weight is changed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a motor according to the present invention will be described with reference to the accompanying drawings. FIG.
FIG. 2 is a sectional view showing a part of a cooling fan motor as an example of a motor according to the present invention, FIG. 2 is a plan view showing a rotor of the cooling fan motor of FIG. 1 and its vicinity, and FIG. FIG. 3 is a perspective view showing an example of a balance weight mounted on the rotor of FIG. 2. In the following embodiments, the present invention will be described by applying the present invention to a cooling fan motor as an example of a motor, but the present invention is not limited to such a cooling fan motor, and a spindle motor, an LBP motor, a DC motor
It can be applied to various motors such as a main motor.

Referring to FIG. 1, the illustrated cooling fan motor includes a housing 2 having a substantially square outer shape, and the housing 2 has a circular flow path 4 formed in a major part thereof. A main body 6 is provided. Housing body 6
At one end is spaced apart circumferentially (for example, 3
1 to 4 (two shown in FIG. 1), and a circular mounting portion 10 is provided at the distal end of each of the connecting arms 8. The circular mounting portion 10 is provided with a cylindrical support wall portion 12, which extends from the mounting portion 10 toward the other end of the housing body 6.

A rotor 18 is rotatably supported on the support wall 12 of the housing 2 via a pair of bearings 14 and 16. In this embodiment, a support sleeve 20 is fixed to the inner peripheral surface of the support wall 12, and this support sleeve 20
A pair of bearings 14 and 16 are mounted at intervals in the axial direction (vertical direction in FIG. 1). Housing body 6, connection arm 8, circular mounting portion 10, and support wall portion 12
Is formed, for example, by integral molding of a synthetic resin,
The support sleeve 20 is formed from a metal such as iron. The tip of the support sleeve 20 extends beyond the support wall 12 in FIG.
Project upward.

The rotor 18 has a cup-shaped rotor body 22.
And a shaft member 26 is fixed to a center portion of the end wall portion 24 of the rotor main body 22.
16 supported. In addition, at the tip of the shaft member 26,
A locking member 28 for preventing the rotor 18 from coming off is mounted, and a pair of inner rings of the bearing 16 (upper bearing in FIG. 1) is provided between the inner surface of the end wall 24 of the rotor body 22 and the inner ring of the bearing 16 (upper bearing in FIG. 1). A preload coil spring 30 for applying a preload to the bearings 14 and 16 is interposed.

On the outer peripheral portion of the end wall portion 24 of the rotor body 22, a peripheral side wall portion 32 extending toward the connection arm 8 is provided. A plurality of ridges 3 projecting inward in the radial direction are provided on the inner peripheral surface of the peripheral side wall portion 32 at intervals in the circumferential direction.
4 are provided, and these ridges 34 extend in the axial direction. An annular yoke 36 is mounted on the inner peripheral surface of the rotor body 22 via the protrusions 34, and an annular rotor magnet 38 is mounted on the inner peripheral surface of the annular yoke 36. A plurality (five in this embodiment) of blades 40 (see FIG. 2) are provided on the outer peripheral surface of the peripheral side wall 32 of the rotor body 22 at intervals in the circumferential direction. The end wall 24, the peripheral side wall 32, the ridge 34, and the blade 40 of the rotor body 22
Is formed, for example, by integral molding of a synthetic resin.

A stator 42 is provided so as to face the rotor magnet 38. The stator 42 has a stator core 44 formed by laminating a plurality of core plates, and a coil 46 wound around the stator core 44 as required. The support sleeve 20 is mounted on the outer peripheral surface of the distal end portion so as to contact the distal end surface of the support sleeve 20. In this embodiment, the stator core 44 is covered as required by an insulator 48 formed of, for example, an insulating synthetic resin. Support legs 50 are provided on the insulator 48, and a circuit board 52 is attached to the distal ends of the legs 50. Although not shown, a predetermined circuit pattern is formed on the circuit board 52, and a driving IC, a Hall element, and the like are electrically connected to the circuit pattern.

With such a configuration, the coil 46 of the stator 42 is passed through the circuit pattern of the circuit board 50.
When the driving current is supplied to the stator core 44, the stator core 44 is magnetized as required, and the rotor 18 and the blade 40 are driven to rotate in a predetermined direction by the mutual magnetic action between the stator core 44 and the rotor magnet 38. The rotation creates a flow of air through the flow path 4 of the housing 2.

This fan motor is further configured as follows for adjusting the rotational balance of the rotor 18. With reference to FIG. 1 and FIG. 2, a plurality (24 in this embodiment) of through-holes 60 are formed in the outer peripheral portion of the end wall portion 24 of the rotor 18 at substantially equal intervals in the circumferential direction. I have. Each through-hole 60 has substantially the same shape and extends in the axial direction. The inner portion in the axial direction has a larger inner diameter and the inner portion in the axial direction has a smaller inner diameter. These through holes 60 constitute a housing recess, and the rotor 1
In order to adjust the rotational balance of the balance 8, a balance weight 62 is mounted as needed. As shown in FIG. 1, the inner opening of the through hole 60 is formed with the inner flange 64 of the annular yoke 36.
Is closed by.

Referring also to FIGS. 3 and 4, the balance weight 62 in this embodiment includes a cylindrical head 66 and a substantially cylindrical leg 68 extending from the head 66 in the axial direction. For example, it is formed by integral molding of a synthetic resin. As shown in FIGS. 1 and 2, the outer diameter of the head 66 is formed to be somewhat smaller than the inner diameter of the outer portion of the through hole 60, and the outer diameter of the leg 68 is slightly smaller than the inner diameter of the inner portion of the through hole 60. The leg 68 has a substantially inverted U-shaped slit 70 extending inward in the axial direction from the front end surface of the leg 68. By providing the slit 70 in this manner,
The leg 68 is configured to be elastically deformable inward in the radial direction.

In this fan motor, the balance weight 62
Is mounted, for example, as shown in FIGS. In a state where the rotor 18 is assembled as required, that is, in a state where the yoke 36 and the rotor magnet 38 are mounted on the rotor main body 22, the rotor 18 is rotated and its rotational balance is measured using a balance measuring device. To one or two or more of the through holes 60 (housing recesses) corresponding to the parts having a lighter weight (four continuous in the circumferential direction in this embodiment)
A balance weight 62 is attached to the balance to adjust the rotational balance. To mount, as understood from FIG.
The balance weight 6 is provided in the axial direction from the outside of the end wall 24 of the balance 8.
2 may be pushed into the through hole 60 from its leg 68.
When the balance weight 62 is pushed in, its head 66 comes into contact with the end face of the inside portion (the portion having a small inner diameter) of the through hole 60,
This contact prevents further insertion of the balance weight 62, and thus the balance weight 62 is
Will be installed inside. In such a mounted state, since the outer diameter of the leg 68 of the balance weight 62 is slightly larger than the inner diameter of the inner portion of the through hole 60, the leg 68 is elastically deformed somewhat inward in the radial direction and elastically deformed. In this state, the balance weight 62 is securely mounted. In such a mounted state, the head 66 is accommodated in an outer portion (a portion having a larger inner diameter) of the through hole 60, and its leg 68 is accommodated in an inner portion (a portion having a smaller inner diameter) of the through hole 60. The balance weight 62 does not protrude from the end wall 24 of the rotor body 22. The balance weight 62 can be mounted simply by being pushed into the through hole 60, and can be mounted with extremely simple and easy work. When the rotor 18 is rotationally driven in a predetermined direction in such a mounted state, a centrifugal force acts outward on the balance weight 62 in the radial direction, and the direction in which the centrifugal force acts and the mounting direction of the balance weight 62 are different. Since they are perpendicular to each other, detachment of the balance weight 62 is more reliably prevented.

The balance weight shown in FIGS. 1 to 4, ie, the first balance weight 62, and the form shown in FIG. 5, ie, the second balance weight 62A, are used as necessary. It is preferable to attach them in combination. The first balance weight 22 shown in FIGS. 3 and 4 and the second balance weight 22 shown in FIG.
As can be easily understood by comparing FIGS. 4 and 5 with the balance weight 62A, the heads 66 and 66A have different lengths, and other configurations including the legs 68 and 68A are as follows.
Substantially the same. Head 66 of first balance weight 62
Is longer (the length in the axial direction), while the length of the head 66A of the second balance weight 62A is short, and is approximately half the length of the head 66 of the first balance weight 62. Is formed. Therefore, while the weight of the first balance weight 62 is heavy, the weight of the second balance weight 62A is light, and one or two or more of these two types of balance weights 62, 62A are used. By being mounted in combination with the through hole 60, the rotational balance of the rotor 18 can be adjusted more accurately.

After the balance weight 62 (or 62A) is mounted in the through hole 60 of the rotor body 22 as required as described above, a sheet-like member, for example, a circular member, is attached to the outer surface of the end wall 24 of the rotor body 22. A seal may be attached. By sticking in this manner, the sheet-like member closes the outer openings of the plurality of through-holes 60 of the rotor main body 22 and can suppress generation of noise.
The appearance is also good.

Since such a balance weight 62 is attached by utilizing its own elastic deformation, it can be removed from the through-hole 60 by elastically deforming its leg 68 inward in the radial direction using a tool or the like. Can be. Accordingly, in the case of a mounting error or the like, the balance can be corrected by removing the mounted balance weight 62. The balance weight 6
For example, as shown in FIG. 6, a pair of recesses 82 are provided at opposite portions of the head 66 of the balance weight 62, and the recesses 82 are gripped by the distal end of the removal tool. You may make it. Further, instead of the pair of recesses 82, a projection to be gripped by the tip of the tool may be provided.

The embodiment of the cooling fan motor as an example of the motor according to the present invention has been described above.
The present invention is not limited to the embodiment, and various changes and modifications can be made without departing from the scope of the present invention.

For example, in the illustrated embodiment, two types of balance weights 62, 62A are used in combination.
Three or more types of balance weights having different weights may be used in combination. In such a case, for example, the heads of the balance weights may be configured to have different lengths.

Further, for example, in the illustrated embodiment, the heads 66, 66A of the balance weights 62, 62A have different lengths to change their weights, but the present invention is not limited to this.
For example, the lengths of the legs 68, 68A may be varied to change their weights, and their weights may be varied (in other words, formed from materials having different specific gravities). The weights may be changed, or these may be combined to change their weights.
In addition, the material of the balance weights 62 and 62A may be a material obtained by resin-molding rubber or metal other than the synthetic resin.

Further, for example, in the illustrated embodiment, the accommodation recess for accommodating the balance weight 62 (62A) is formed by the through hole 60, but instead of the through hole 60, for example, an interval is provided in the circumferential direction. To form a plurality of recesses, and these recesses may form a housing recess. Further, the through-holes 60 or the recesses as accommodation recesses are provided independently of each other as described above. However, the present invention is not limited to such a configuration, and they may be provided continuously.

[0032]

According to the motor of the first aspect of the present invention, since the balance weight itself is elastically deformed, it can be easily mounted by inserting it into the receiving recess to be mounted. Further, in the mounted state, since it is held elastically by its own elastic deformation, it does not detach from the rotor.

Further, according to the motor of the second aspect of the present invention, since the legs of the balance weight are kept elastically deformed in the mounted state, the balance weight can be securely mounted.

According to the motor of the third aspect of the present invention, the balance weight is inserted from the outside into the accommodation recess to be mounted in the axial direction, so that the balance weight can be easily mounted. Further, since the mounting direction of the balance weight and the direction of the centrifugal force acting on the weight are orthogonal to each other, the detachment of the mounted balance weight can be prevented more reliably.

Further, according to the motor of claim 4 of the present invention, at least two types of balance weights having different weights are prepared, and these balance weights are combined and mounted as required. Thus, the rotational balance of the rotor can be easily and accurately adjusted.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a part of a cooling fan motor as an example of a motor according to the present invention.

FIG. 2 is a plan view showing a rotor of the cooling fan motor of FIG. 1 and its vicinity.

FIG. 3 is a perspective view showing an example of a balance weight mounted on the rotor of FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is an end view corresponding to FIG. 4, showing a balance weight of another embodiment.

FIG. 6 is a perspective view showing a modification of the balance weight.

[Explanation of symbols]

 2 Housing 6 Housing body 14, 16 Bearing 18 Rotor 22 Rotor body 24 End wall 26 Shaft member 38 Rotor magnet 42 Stator 60 Through-hole 62, 62A Balance weight 66, 66A Head 68, 68A Leg

Claims (4)

[Claims] 1. A housing, a rotor rotatably supported by the housing, a rotor magnet mounted on the rotor, and a stator disposed opposite to the rotor magnet for balancing rotation. A motor provided with a balance weight attached to the rotor, wherein the rotor is provided with an accommodation recess, and the balance weight is elastically mounted in the accommodation recess by its own elastic deformation. And the motor. 2. The balance weight has a head and a leg extending from the head, and the leg is elastically deformed in a radial direction. The motor according to claim 1, wherein a balance weight is held in the housing recess. 3. The housing recess, wherein the rotor has a cup shape, and has a peripheral side wall portion on which an inner peripheral surface is provided with a rotor magnet, and an end wall portion provided at one end of the peripheral side wall portion. A plurality of the weights are provided on an outer peripheral portion of the end wall portion at intervals in a circumferential direction, and the balance weight is elastically attached to a predetermined accommodating concave portion in an axial direction from the outside. 3. The motor according to 1 or 2. 4. The balance weight includes a first balance weight having a heavy weight and a second balance weight having a light weight, and the first balance weight having a light weight is used to balance the rotation of the rotor.
4. The balance weight or the second balance weight is mounted in the predetermined receiving recess.
The motor according to any one of the above.