JP2987185B2 - Spindle motor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a spindle motor for rotating a recording member such as a magnetic disk.

(Conventional technology and its disadvantages)

For example, the spindle motor includes a bracket and a hub member that is rotatable relative to the bracket,
A recording member such as a magnetic disk is mounted on the hub member. A rotor magnet is mounted on the hub member, and a stator is arranged to face the rotor magnet.

However, in the conventional spindle motor,
Except for the provision of the cooling fins on the outer peripheral surface of the hub member, no means is provided for positively maintaining the motor at a predetermined temperature. Therefore, the temperature of the motor changes from a low temperature of about 0 degrees to a high temperature of about 60 degrees, and there is a possibility that such a change in the temperature may cause deterioration of the rotation accuracy, deflection of the hub member, and the like.

[Object of the invention]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a spindle motor capable of substantially eliminating an adverse effect due to a temperature change.

[Summary of the Invention]

According to the present invention, a dish-shaped bracket, a shaft member erected at the center of the bracket, and a hub member supported by the shaft member via a bearing and rotatable relative to the bracket And a rotor magnet mounted on the hub member, and a stator disposed on the bracket facing the rotor magnet, wherein the bracket has a predetermined portion near the shaft member. At least two recesses are formed, one of the recesses is provided with a temperature holding means comprising a heat transfer element for heating or cooling the motor, and the other of the recesses is provided with a temperature detecting means for detecting the temperature of the motor. And a control means for controlling the temperature holding means based on a detection signal from the temperature holding means. That.

[Specific examples of the invention]

Hereinafter, a specific example of the spindle motor according to the present invention will be described with reference to FIG.

In FIG. 1, the illustrated spindle motor includes a bracket 2 and a hub member 4. Bracket 2
Is provided with a substantially circular bracket body 6, an annular wall portion 8 protruding upward is provided on an outer peripheral portion thereof, and a flange portion 10 projecting outward in the radial direction is provided at an upper end of the annular wall portion 8. Have been. In a specific example, although not shown, the flange portion 10 is attached to the lower frame of the driving device.

One end of a shaft member 12 is fixed to a substantially central portion of the bracket body 6. The other end of the shaft member 12 is the bracket body 6
The hub member 4, which can be made of, for example, iron, is rotatably mounted on the other end through a pair of bearing members 14 and 16. The hub member 4 has a disk-shaped hub body 18. Hub body
An annular step 18a is formed on the upper surface of 18, and a recording member such as a magnetic disk is attached to the upper surface of the step 18a by a clamp member (not shown). Hub body
An upper support protrusion 20 and a lower support protrusion 22 extending in the vertical direction (the axial direction of the shaft member) are provided on the inner peripheral portion of the support member 18, and the support protrusions 20 and 22 are formed by a pair of bearing members 14 and 16. It is supported by. A bearing member is provided at the upper end of the upper support projection 20.
A cap member 23 is provided so as to cover 14. An annular hanging portion 24 extending downward is provided on the outer peripheral portion of the hub member 18, and an annular rotor magnet 26 is mounted on the inner peripheral surface of the annular hanging portion 24. A stator 28 is provided so as to face the rotor magnet 26. Stator 28 is a stator core formed by stacking plates
30 and a coil 32 wound around the stator core 30, and the stator core 30 is formed in an annular mounting wall on the bracket body 6.
34 Fixed to the outer peripheral surface. Therefore, when current is supplied to the coil 32 of the stator 28 as required, the hub member 4 is rotated in a predetermined direction by the action of the stator 28 and the rotor magnet 26, whereby the recording member (not shown) is also integrally rotated. Is done.

The spindle motor has the following temperature control device
36 are provided. More specifically, the illustrated temperature control device 36 includes a temperature holding unit that can be constituted by, for example, a thermoelectric element 38 known per se, and a temperature detection unit 40 that detects the temperature of the motor. A pair of recesses 42 and 44 are formed on the lower surface of the predetermined portion of the bracket body 6,
The thermoelectric element 38 is mounted in one of the concave portions 42 and the other concave portion 44
The temperature detection means 40 is attached to. The detection signal from the temperature detection means 40 is sent to a temperature detection circuit 46, and the signal from the temperature detection circuit 46 is sent to a control means 48 which can be formed, for example, from a microprocessor. Control means 48
Controls the operation of the drive circuit 50 based on the signal from the temperature detection circuit 46, and the drive circuit 50 heats or cools the thermoelectric element 38 (the thermoelectric element 38 generates heat when a current in a predetermined direction is supplied). To heat the motor, and when a current in a direction opposite to the predetermined direction is supplied, the motor absorbs heat and cools the motor).

Next, the operation and effect of the spindle motor will be described as follows.

When the temperature of the motor itself is lower (or higher) than a predetermined temperature (for example, 40 degrees), the control unit 48 generates a heating signal (or a cooling signal) based on a signal from the temperature detection circuit 46. The heating signal (or cooling signal) is sent from the control means 48 to the drive circuit 50, and the drive circuit 50 heats (or cools) the thermoelectric element 38 based on the heating signal (or cooling signal), and 38 heats (or cools) the motor.
Accordingly, as will be readily understood, the motor is substantially maintained at the predetermined temperature during operation by the action of the thermoelectric element 38,
Thus, the adverse effects (deterioration of the rotation accuracy of the hub member 4, tilting of the shaft member 12, swaying of the hub member 4, changes in the characteristics of the coil 32, and the like) caused by the temperature change conventionally occurring are substantially eliminated.

As mentioned above, although one specific example of the spindle motor according to the present invention has been described, the present invention is not limited to such specific example, and various modifications and corrections can be made without departing from the scope of the present invention.

For example, in the illustrated specific example, one thermoelectric element 38 is arranged on the bracket main body 6, but two or three or more thermoelectric elements may be arranged.

Further, for example, in the specific example shown in the drawings, the motor is maintained at a predetermined temperature by using a thermoelectric element 38 capable of heating and cooling. However, the present invention is not limited to this. The predetermined temperature may be maintained by using one or both of the cooling means for cooling the motor and the motor.

〔The invention's effect〕

According to the spindle motor of the present invention, the motor can be substantially maintained at a predetermined temperature by the action of the thermoelectric element 38. Thus, the adverse effects caused by the temperature change which has conventionally occurred (the deterioration of the rotation accuracy of the hub member 4, The tilting of the shaft member 12, the deflection of the hub member 4, the change in the characteristics of the coil 32, etc.) can be substantially eliminated.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a specific example of a spindle motor according to the present invention. 2 Bracket 4 Hub members 14 and 16 Bearing member 18 Hub body 26 Rotor magnet 28 Stator 38 Thermoelectric element 40 Temperature detecting means 46 Temperature detecting circuit 48 Control means 50 Drive circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 21/22 H02K 29/00 H02K 11/00

Claims (1)

(57) [Claims] 1. A dish-shaped bracket, a shaft member erected at the center of the bracket, and a hub member supported by the shaft member via a bearing and rotatable relative to the bracket. A rotor magnet mounted on the hub member;
A stator disposed on the bracket opposite to the rotor magnet, wherein the bracket has at least two recesses formed in a predetermined portion near the shaft member, and one of the recesses Is provided with a temperature holding means comprising a heat transfer element for heating or cooling the motor, and the other concave part is provided with a temperature detecting means for detecting the temperature of the motor, and detecting the temperature from the temperature detecting means. A spindle motor comprising control means for controlling said temperature holding means based on a signal.