JPH0480462B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotational drive device for rotationally driving a magnetic disk having a rigid center hub at its center.

(Prior Art) A magnetic disk for magnetically recording and reproducing information includes a magnetic disk 4 for magnetic recording and a center hub 3 for rotating the magnetic disk 4, as shown in FIG. The center hub 3 has a main shaft insertion hole 3b and a substantially square positioning hole 3a.

A conventional magnetic disk rotation drive device that rotationally drives such a magnetic disk uses a main shaft insertion hole 3 of a center hub 3 provided at the center of the magnetic disk 4.
The spindle 5 includes a main shaft 5 inserted into the main shaft 5, a spindle hub 8 fixed to the main shaft 5, and a drive pin 6 elastically supported by a leaf spring 7. Drive pin 6
As shown in the plan view of Fig. 1a, the leaf spring 7 supporting the . It's something you get.

Then, when the magnetic disk is inserted into the rotation drive device and the center hub 3 is crimped onto the spindle hub 8, the drive pin 6 is inserted into the positioning hole 3a of the center hub 3, as shown in FIGS. 2a and 2d. In the state where the drive pin 6 is not in contact with the back surface of the center hub 3, it pushes down the leaf spring 7,
Relative rotation between the center hub 3 and the spindle hub 8 is allowed.

Next, when the main shaft 5 begins to rotate, the spindle hub 8 of the main shaft 5 rotates relative to the center hub 3 due to the load applied to the magnetic disk 4.
As shown in FIGS. 2b and 2e, when the drive pin 6 and the positioning hole 3a are aligned, the drive pin 6 is pushed upward by the restoring force of the leaf spring 7.
When the drive pin 6 is inserted into the positioning hole 3a and continues to rotate, the drive pin 6 moves along the inner peripheral surface of the positioning hole 3a, as shown in FIG. After being engaged in position, the center hub 3 rotates at the same speed as the main shaft 5.

At this time, the drive pin 6 is pressed radially outward by the leaf spring 7 and centered so that the centers of the main shaft 5 and the magnetic disk 4 are always coaxial.

In such a conventional device, the drive pin 6 is supported by a single leaf spring 7, and elasticity is applied to the drive pin 6 in the outward radial direction and the axial direction.

(Problem to be Solved by the Invention) When the drive pin 6 is supported by the leaf spring 7,
Due to the influence of the accuracy of the mounting position of the drive pin 6 with respect to the leaf spring 7, the variation in the elasticity of the leaf spring 7, the precision of the mounting position of the leaf spring 7 with respect to the spindle hub 8, etc., when the magnetic disk 4 is mounted, the drive pin There was a problem in that the amount of displacement of the shaft 6, that is, the force of pushing and expanding the shaft 5, was not constant and varied. In addition, since the support member of the drive pin 6 also serves as a spring, there is little freedom in the shape of the spring, and in order to obtain appropriate spring elasticity, a certain size is required, making it difficult to downsize. It was difficult.

Furthermore, the axis of the drive pin 6 must always be parallel to the axis of the main shaft 5, but due to fluctuations in the load torque of the magnetic disk 4 or deterioration of elasticity due to aging of the spring, the magnetic disk 4 may When mounted and rotated, the axis of the roller 6 may be tilted, and the position of the magnetic disk 4 in the circumferential direction may fluctuate during rotation.

The timing of writing and reading on the magnetic disk 4 is based on the drive pin 6, so if the drive pin 6 is tilted and its position in the circumferential direction changes, the timing will shift and recording/reproduction will become impossible. It was hot.

(Means for Solving the Problems) Therefore, the present invention was devised to solve such problems, and includes a spindle insertion hole 3b formed in the center, and a radius from this spindle insertion hole 3b. In order to rotationally drive a magnetic disk 4 having a center hub 3 with positioning holes 3a formed at positions spaced apart from each other, a spindle insertion hole 3b is provided.
A rotary drive device including a main shaft 5 that is inserted into the main shaft 5 and a drive pin 6 that engages with the positioning hole 3a has a rotation fulcrum 9 at a position eccentric from the main shaft 5 in the radial direction, and from this rotation fulcrum 9. A lever 1 supporting a drive pin 6 is provided at a spaced apart position, and when the drive pin 6 engages with the positioning hole 3a and receives a reaction force by rotating the magnetic disk 4, the drive pin 6
The center hub 3 is configured to be engaged with the deepest position in the direction connecting the drive pin 6 and the pivot point 9 to restrict the position of the center hub 3 with respect to the main shaft 5.

(Function) As a support for the drive pin 6, the lever 1 having rigidity and rotatable around the rotation fulcrum 9 is used to prevent the drive pin 6 from tilting, and the drive pin 6 engages with the positioning hole 3a. When the magnetic disk 4 is rotated and receives a reaction force, the drive pin 6 engages at the deepest position in the direction connecting the drive pin 6 and the rotation fulcrum 9, and is pushed outward in the radial direction. Furthermore, by providing a spring 2 separate from the lever 1 that simultaneously applies a restoring force in the axial direction to the drive pin 6 and a force for centering the magnetic disk, both the lever 1 and the spring 2 are made independent. The size and spring elasticity of the lever 1 can be set freely, and it is possible to easily respond to miniaturization of the device.

(Example) As shown in FIG. 3, a spindle hub 8 fixed to a main shaft 5 and a main shaft 5 of this spindle hub 8
A pin 9 provided at a position eccentric in the radial direction from
and a lever 1 that rotates about this pin 9 as a rotation fulcrum and is difficult to extend or contract, and a drive pin 6 is supported on this lever 1 at a position spaced apart from the rotation fulcrum.

The head 9 of the pin 9 is thicker than the thickness of the plate-shaped lever 1.
Exists between a and the back surface of the spindle hub 8〓
If the gap is set large, the lever 1 can tilt downward with respect to the spindle hub 8 and can rotate around the pin 9.

A wire spring 2 is provided with one end engaged with the lever 1 and the other end fixed to the spindle hub 8, and while pressing the drive pin 6 supported by the lever 1 against the back surface of the center hub 3, It is configured to provide outward elasticity.

Next, the operation of the embodiment of the present invention will be explained in comparison with the operation of the conventional device shown in FIG.

When the drive pin 6 is not inserted into the positioning hole 3a of the center hub 3, the lever 1 is tilted downward between the pins 9 as shown in FIG. , an upward force is exerted by the wire spring 2.

When the main shaft 5 rotates, the spindle hub 8 rotates relative to the stationary center hub 3, and eventually reaches a position where the drive pin 6 can be inserted into the positioning hole 3a, the elasticity of the wire spring 2 It is pushed upward and inserted into the positioning hole 3a,
As the rotation continues, the drive pin 6 moves along the outside of the inner peripheral surface of the positioning hole 3a, and as shown in FIG. Engages in deep positions,
Thereafter, the magnetic disk 4 attached to the center hub 3 rotates at the same speed as the main shaft 5.

At this time, the drive pin 6 receives a reaction by rotating the center hub 3, and the drive pin 6
generates a force pushing outward in the radial direction, so it engages with the deepest position of the positioning hole 3a in the direction connecting the drive pin 6 and the rotation fulcrum 9, regulating the position of the center hub 3 with respect to the main shaft 5. do. moreover,
Since the elasticity of the wire spring 2 also generates a force that pushes it outward in the radial direction, it is possible to accurately control the position. By changing the structure and dimensions of the wire spring 2, the spring characteristics can be freely set without affecting other members such as the lever 1.

Furthermore, since the lever 1 is constructed of a material that can be easily rotated around the rotational fulcrum 9 and has relatively high rigidity, when engaged in the state shown in FIG. Since the lever 1 does not extend or contract and the drive pin 6 does not tilt, the center hub 3 of the magnetic disk 4 is accurately positioned with the main shaft 5, and even if the load torque changes or the spring changes over time, the magnetic disk 4 There is no error in the setting angle between the main shaft 5 and the main shaft 5, and the reliability of recording and reproducing signals is significantly improved.

When the drive pin 6 is engaged and rotationally driven in the state shown in FIG. 3 to accurately regulate the position relative to the main shaft 5.

Therefore, it is sufficient that the wire spring 2 that biases the lever 1 in the radially outward direction generates enough force to simply bring the drive pin 6 into contact with the outside of the inner peripheral surface of the positioning hole 3a of the center hub 3. Therefore, a large force to position the center hub 3 is not necessarily required.

(Other Embodiments) While pressing the drive pin 6 supported by the lever 1 against the back surface of the center hub 3, a compression spring 2 as shown in FIG. , it becomes easier to manufacture springs with desired characteristics.

Drive pin 6 and center hub 3 positioning hole 3a
If it is desired to reduce the sliding resistance between the drive pin and the drive pin, a rotating roller may be used as the drive pin.

(Effects of the Invention) As explained above, according to the rotary drive device of the present invention, the lever 1 that supports the drive pin 6 and the spring 2 that biases the lever 1 with elasticity are configured separately. Therefore, the accuracy required for each member is relaxed, and the elasticity of the spring can be freely set, so that miniaturization can be easily achieved without reducing the positioning accuracy of the magnetic disk.

Since the lever 1 that supports the drive pin 6 is a rigid body, the drive pin 6 will not tilt even if the load torque changes or the spring changes over time, and the circumferential position of the magnetic disk 4 will not change during rotation. It is possible to obtain stable rotational operation that does not fluctuate and cause a time lag between recording and reproduction.

Furthermore, since no substantial large positioning force is applied until the magnetic disk is positioned at the correct position, the frictional force with the inner peripheral surface of the positioning hole 3a is generated before the drive pin 6 reaches the normal position. It is also possible to avoid a situation where the object stops midway and cannot be accurately positioned.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a conventional rotary drive device, in which a is a plan view, b is a longitudinal sectional view, and FIG.
A diagram for explaining the operation of the conventional device shown in FIG.
- c are longitudinal sectional views, d - f are plan views, and Fig. 3 is a diagram showing an embodiment of the rotary drive device of the present invention, a is a plan view, b is a longitudinal sectional view, and c is a main part. Perspective view, 4th
The figure is a longitudinal sectional view explaining the operating state, and FIG.
FIG. 7 is a vertical cross-sectional view showing another embodiment. The same parts are represented by the same reference numerals throughout the figures. 1...Lever, 2...Spring, 3...Center hub, 3a...Positioning hole, 3b...Spindle insertion hole,
4...Disc, 5...Main shaft, 6...Drive pin,
7...Support spring, 8...Spindle hub, 9...
Rotation fulcrum.

Claims (1)

[Scope of Claims] 1. In order to rotationally drive a magnetic disk having a center hub having a spindle insertion hole drilled in the center and a positioning hole drilled at a position spaced apart from the spindle insertion hole in the radial direction, A rotary drive device comprising a main shaft inserted into a main shaft insertion hole and a drive pin engaged with the positioning hole, the rotary drive device having a rotation fulcrum at a position eccentric in the radial direction from the main shaft, and a rotation fulcrum spaced apart from the rotation fulcrum. A lever supporting the driving pin is provided at a position, and when the driving pin engages with the positioning hole and rotates the magnetic disk and receives a reaction, the driving pin is moved between the driving pin and the rotation. A rotary drive device characterized in that the center hub is engaged at the deepest position in a direction connecting it to a dynamic fulcrum to restrict the position of the center hub with respect to the main shaft.