JPH0984299A - Spindle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a spindle motor for magneto optical disc or the like in which the size and the thickness can be reduced without sacrificing the characteristics and the cost. SOLUTION: A plurality of pins connected with the end 10 of a stator coil 8 are molded integrally with an insulator 7 of the same insulating material, e.g. resin. A preload spacer 205 has an inside diameter smaller than that of a housing 103 touching the preload spacer 205 and that of a preload spring and a Hall element insertion hole is made through the housing 103 while being stepped in order to ensure the insulation and strength of a Hall element 101. The spindle motor further comprises means provided with a land 402 for inspecting the output from Hall element, for example, on a flexible board 401 led out to the outside of the rotor diameter. This structure realizes a thin, excellent and inexpensive spindle motor which satisfies the need in the industry while keeping the features of a small size, high characteristics and low power consumption.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor for driving a disk of an audio visual device or a computer memory device, which mainly uses a digital disk in the field of OA / AV.

[0002]

2. Description of the Related Art In recent years, miniaturization and high density of audio visual devices and computer memory devices have been rapidly progressing toward the realization of multimedia. Among these technological innovations, a spindle motor for rotating a disk is required to be particularly small, thin, low in power consumption, and low in cost.

As the apparatus itself becomes smaller and thinner, the space for the motor body structure is naturally limited.

A conventional spindle motor will be described below. FIG. 2 shows a structural sectional view of a conventional spindle motor. In FIG. 2, reference numeral 1 is a magneto-optical disk medium (hereinafter referred to as a disk). Reference numeral 2 is a mounting plate made of a ferromagnetic material provided on the disk 1. A spindle hub 3 receives the disk 1.

At the center of the spindle hub 3, there is a rotary shaft 201.
Is mounted and rotates together with the spindle hub 3 and the disk 1 to form the center of rotation. The rotating shaft 201
Are supported by ball bearings 202a and 202b. 203a and 203b are the ball bearings 2
A preload spring for preloading 02a and 202b, 205 a preload spacer for stabilizing the spring pressure of the preload spring, and 204 a ball bearing 202
These are preload screws for restricting the positions of a and 202b.
The stator coil 9 is wound around the stator core 8 with the resin insulator 7 for insulation interposed therebetween, and the terminal 10 is soldered onto the circuit board 102 on which electric wiring is formed. Rotational driving force of the motor is generated by the rotating magnetic field generated by exciting the stator coil 9 with power supply and the multi-pole magnetized drive magnet 5 surrounding the rotating magnetic field. The stator core 8 is fixed to the housing 103. Reference numeral 101 denotes a Hall element that detects a leakage magnetic flux from the end face of the drive magnet 5 and outputs a signal for detecting the rotational position of the rotor, and is provided on the circuit board 102 so as to face upward. Reference numeral 301 denotes a drive circuit unit for controlling the rotation of the motor, which is provided on an extension of the circuit board 102 and is used for output inspection of the Hall element 101 or insulation inspection of the housing 103 and the stator coil 9. Lands (not shown) are provided. Using the land, it is reasonably inspected by an automatic inspection machine in the manufacturing process. The drive magnet 5 is fixed to the inner circumference of the frame 6, and the frame 6 is fixed to the spindle hub 3 to form a rotor, which rotates the disk 1. A clamp magnet 4 is mounted on the frame 6, and the clamp magnet 4 has a role of fixing the disk 1 to the spindle hub 3 by a magnetic attraction force.

[0006]

However, in the above-mentioned conventional structure, when the thickness of the stator core is reduced to make the motor thinner, the diameter and number of turns of the copper wire of the stator coil are maintained in order to maintain the output characteristics of the motor. Have to increase. Therefore, the space occupied by the copper wire in the slot portion of the stator core increases, and the space for soldering the stator coil terminal wire to the circuit board becomes narrower, which deteriorates the workability of the soldering process and hinders automation, resulting in high cost. There is a problem of becoming.

In order to make the motor thinner, when a Hall element having a low height is used as a rotational position detector of the rotor, this type of Hall element has low sensitivity and a small output signal from the Hall element. You have to use a good drive magnet. Furthermore, the cost of each used component increases.

Further, the preload structure which has conventionally been constituted by the two preload springs and the preload spacers is a factor that hinders the thinning of the motor.

Further, in the conventional integrated structure of the motor and the drive circuit, the electric connection between the motor section and the circuit section can be easily performed on the same circuit board, and the spindle motor can be handled as an independent functional block, which facilitates maintenance. However, in order to reduce the thickness of the disk drive device, it is necessary to increase the packaging density by separating and concentrating the circuit unit and the mechanism unit in the entire device. Therefore, it is necessary to separate the motor unit and the drive circuit unit, and to perform high-density mounting not only on the circuit board unit of the motor body but also on a separate drive circuit unit substrate. For this reason, the above-mentioned circuit boards are all filled with the component mounting portion and the pattern wiring portion, and the inspection lands used for the function inspection of the rotor position detecting Hall element or the insulation inspection between the housing and the stator coil are provided on the circuit board. There is a problem in that it is very difficult to provide it on the upper part, and as a result, automatic inspection cannot be performed, resulting in a high-cost motor.

The present invention provides means for solving the above problems while maintaining characteristics such as small size, thinness, low power consumption and low cost, and realizes the various industrial demands mentioned at the beginning.

[0011]

According to the present invention, a rotary shaft, a ball bearing that supports the rotary shaft, a housing that fixes the ball bearing, a stator core that forms a magnetic circuit, and a magnetic field are generated. A stator coil, an insulator of an insulator for insulating the stator core and the stator coil, and a plurality of pins connected to the stator coil. The insulator and the pin are made of the same material. It is characterized by being made of an insulating material such as molded resin, and applies a preload to the rotating shaft, a ball bearing that supports the rotating shaft, a housing that fixes the ball bearing, and the ball bearing outer ring. And a preload spacer for holding the preload spring in the housing. The spacer inner diameter is smaller than the housing inner diameter and the preload spring inner diameter with which the preload spacer is in contact, and a rotating shaft, a ball bearing that supports the rotating shaft, and a housing that fixes the ball bearing, The rotor fixed to the rotating shaft, a hall element for detecting the rotational position of the rotor, and a printed board having an electrical wiring pattern, and a mounting hole for mounting the hall element downward is provided on the printed board. The housing portion is provided with a stepped hole at substantially the same position as the hole element mounting hole of the printed circuit board, which maintains electrical insulation from the hole element and does not reduce the housing strength. And a ball bearing for supporting the rotating shaft, and fixed to the rotating shaft. A rotor,
The rotor rotation position detecting hall element, a flexible board having an electric wiring pattern and drawn out to the outside of the rotor diameter, and a motor drive circuit section separately provided which is connected to the flexible board, are provided outside the rotor diameter. The spindle motor is characterized in that an inspection land such as the Hall element is provided on the flexible substrate that is pulled out.

[0012]

The present invention realizes a thin and low-cost spindle motor while maintaining characteristics such as small size, high characteristics, and low power consumption by the above structure.

[0013]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a sectional view of the spindle motor of the present invention. FIG. 1 (b) is a top view of an embodiment of one embodiment of the present invention.

1 (a) and 1 (b), portions not directly related to the present invention have the same structure as the conventional one. In FIG. 1A, 1 is a medium of a magneto-optical disk (hereinafter referred to as a disk), 2 is a mounting plate made of a ferromagnetic material provided in the disk 1, and 3 is a spindle hub for receiving the disk 1. is there. A rotary shaft 201 is attached to the center of the spindle hub 3 and rotates together with the spindle hub 3 and the disk 1 to form the center of rotation. In FIG. 1A, the rotational driving force of the motor is generated by the rotating magnetic field generated by the stator core 8 which is wound around the stator coil 9 and is excited by power feeding from the drive circuit section, and the multi-pole magnetized drive magnet 5 surrounding the rotating magnetic field. appear.

An insulator 7 is provided between the stator coil 9 and the stator core 8 for the purpose of insulation, and is made of a non-conductive material such as resin. In order to reduce the thickness of the motor while maintaining the performance of the motor, it is necessary to increase the wire diameter of the stator coil 9 and wrap it in order to compensate for the deterioration of the motor characteristics due to the effect of reducing the thickness of the stator core 8. is there. When the stator coil 9 is wound with a large wire diameter, the space between the poles of the stator core 8 is reduced, so that it becomes difficult to perform the stator coil end treatment between the poles of the stator core 8. In order to facilitate this terminal treatment, a binding pin 7a integrally formed of the same material as the insulator 7 is provided so as to extend from the tip of the insulator 7 to the side of the circuit board 400 on which electrical wiring is made, After the end 10 of the stator coil 9 is entangled with the entanglement pin 7a, the circuit board 400
The upper land can be soldered.

With the above structure, the stator coil 9 can be used even in a narrow space between the poles of the stator core 8.
The terminal 10 can be easily soldered. Further, since it is not necessary to separately manufacture the binding pin and press-fit it, terminal wire treatment is easy and automatic soldering can be performed at low cost.

Further, referring to FIG. 1A, the rotary shaft 201 includes a preload spring 203b and a preload spacer 20 inserted between the preload spring 203b and the housing 103.
Ball bearing 202 preloaded by 5 and
It is supported by a and 202b.

In the preload structure which has conventionally been composed of two preload springs and a preload spacer, one preload spring has been eliminated as the motor becomes thinner. In order to remove one preload spring, it is necessary to set the shape so that the change in spring pressure with respect to the change in the load dimension of the spring is small. For this purpose, it is necessary to make the outer diameter of the preload spring 203b large and the inner diameter small. On the other hand, in order to maintain the parallelism of the spindle hub 3 with high accuracy, the inner diameters of the outer ring holding portions of the ball bearings 202a and 202b of the housing 103 are required to have high accuracy of concentricity. Therefore, the ball bearing 202a of the housing 103,
When cutting the outer ring holding portion of 202b, it is necessary to cut from one direction without changing the grip of the chuck. At this time, the cutting tool is the inner diameter portion 10 of the housing 103.
Since the cutting is performed while passing through 3a, it is desirable that the housing inner diameter portion 103a does not protrude into the housing as much as possible. Therefore, the housing inner diameter portion 103
The preload spacer 20 having an inner diameter smaller than the inner diameter of a.
5 is provided between the ball bearing 203b and the housing inner diameter portion 103a to increase the inner diameter of the housing inner diameter portion 103a.
It is possible to reduce the size of the protrusion 03 inside, and also to reduce the inner diameter of the preload spring 203b within a range larger than the inner diameter of the preload spacer 205. As described above, since one preload spring can be reduced and the bearing span can be shortened, a thin motor can be manufactured at low cost.

The housing 103 has a stator core 8 wound with a stator coil 9 and a stator coil 9
An insulator 7 that maintains insulation between the stator core 8 and the stator core 8 is attached, and a circuit board 400 on which electrical wiring is formed is fixed to the housing 103 with screws or the like under the insulator 7. A plurality of rotor position detecting Hall elements 101 are mounted on the circuit board 400. In order to reduce the overall motor height, the stator core 8 and the circuit board 4 are
The distance between 00 should be set narrow. Therefore, the Hall element 101 is inserted with its head facing down, and the dimension protruding toward the stator core 8 side is reduced. Further, the housing 103 includes the Hall element 101.
Is provided with a hole 103b for accommodating the. The hole 103b has a large lead portion of the Hall element 101, and a tip portion of the head of the Hall element 101 is formed in a small step shape so as to cover the housing 103, and thus the rigidity of the housing 103 is reduced. vibration·
The effect on resonance is reduced. Further, with the above configuration, the conventional low cost Hall element and rotor magnet can be used, so that a thin motor having good characteristics can be provided at low cost.

Next, in FIG. 1B, 403 is a motor main body, 404 is a circuit board for driving and controlling the motor, ICs and peripheral parts for setting motor characteristics, and a wiring pattern. Are thin and densely arranged. Reference numeral 401 denotes a flexible board which is drawn out from the motor main body 403 and which delivers a Hall element signal, coil power supply, and the like between the circuit board 404 and the motor main body 403, and a plurality of electric wirings are provided.

Further, by providing an inspection land 402 which could not be provided on the motor main body portion 403 or the circuit board 404 in the middle of the pattern wired on the flexible substrate 401, it is possible to easily perform hole output. Inspection and electrical inspection such as insulation inspection between the housing 103 and the stator core 8 are possible, facilitating automation of the inspection process.

In the present embodiment, the motor with a rotor position detecting element has been described, but it goes without saying that the same effect can be obtained with a motor without a rotor position detecting element.

[0024]

As is apparent from the above description, the present invention is
While maintaining characteristics such as small size, high characteristics, and low power consumption, it is possible to provide a thin and excellent spindle motor that meets the needs of the industry at low cost.

[Brief description of drawings]

FIG. 1A is a structural cross-sectional view of a spindle motor according to the present invention. FIG. 1B is a top view of the spindle motor according to the first embodiment of the present invention.

FIG. 2 is a sectional view of a conventional spindle motor.

[Explanation of symbols]

 1 Disc 2 Mounting Plate 3 Spindle Hub 4 Clamp Magnet 5 Drive Magnet 6 Frame 7 Insulator 7a Entangling Pin 8 Stator Core 9 Stator Coil 10 Terminal 101 Hall Element 102 Circuit Board 103 Housing 103a Housing Inner Diameter 103b Hole 201 Rotating Shaft 202a, 202b Ball Bearings 203a, 203b Preload spring 204 Preload screw 205 Preload spacer 301 Drive circuit unit 401 Flexible board 402 Inspection land 403 Motor main unit 400, 404 Circuit board

Claims (4)

[Claims] 1. A rotary shaft, a ball bearing that supports the rotary shaft, a housing that fixes the ball bearing, a stator core that forms a magnetic circuit, a stator coil wire that generates a magnetic field, the stator core and the stator. An insulator arranged between the coil wire and a plurality of pins connected to the stator coil wire, wherein the insulator and the pin are integrally formed of an insulating material such as resin and made of the same material. Characteristic spindle motor. 2. A rotary shaft, a ball bearing for supporting the rotary shaft, a housing for fixing the ball bearing, a preload spring for applying a preload to an outer ring of the ball bearing, and the preload spring for the housing. A spindle motor comprising: a preload spacer for holding in the thrust direction, wherein the inner diameter of the preload spacer is smaller than the inner diameter of the housing and the inner diameter of the preload spring in contact with the preload spacer. 3. A rotary shaft, a ball bearing for supporting the rotary shaft, a housing for fixing the ball bearing, a rotor fixed to the rotary shaft, a hall element for detecting a rotational position of the rotor, and an electric device. A printed circuit board having a dynamic wiring pattern, the printed circuit board is provided with a mounting hole for mounting the Hall element in an axially downward direction, and the housing section is provided with the Hall element mounting hole of the printed circuit board. A spindle motor characterized in that stepped holes are provided at substantially the same position. 4. A rotary shaft, a ball bearing that supports the rotary shaft, a stator core that forms a magnetic circuit, a stator coil wire that generates a magnetic field, a rotor fixed to the rotary shaft, and a rotation of the rotor. A position detecting hall element, a flexible substrate having an electric wiring pattern and having a portion extended to the outside of the rotor diameter, and a motor drive circuit unit connected to the flexible substrate, and the rotor diameter of the flexible substrate. A spindle motor characterized in that an inspection land for the output of the hall element or the like is provided in a portion drawn out to the outside.