JPH01253876A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To realize the positioning of high precision by correcting thermal off-track by winding a steel belt around an output shaft by plural number of turns. CONSTITUTION:The length of the steel belt 1 from a fixed part to a pulley 3 to the fixed part to a carriage 4 is selected so that its expansion quantity becomes such that a magnetic head 6 is positioned always at a target position independently of temperature change. Generally, since the linear expansion coefficient of the steel belt 1 is smaller in the Al alloy belt and the steel belt 1 of the same length, nearly twice as long length as the Al alloy belt is required for the steel to obtain the expansion quantity equivalent to the Al alloy belt. Because if the length of the steel belt 1 is doubled simply, the steel belt can not be stored in the limited space of the inner part of the device, it is wound around the outer circumference of the pulley 3 by plural number of turns. Thus, the optimization of the expansion quantity and the security of the space are realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device used as an external storage device for computers, word processors, and the like.

[Prior Art] Conventionally, as shown in FIG. 2, this type of magnetic disk device has a magnetic disk rotating section 10, a magnetic head drive section, a base 8 that supports them, and a problem in which dust enters the inside of the magnetic disk device. It is composed of a cover 9 and the like to prevent this.

A carriage 4 supporting a magnetic head 6 of a magnetic head drive section is moved by a steel belt 1 by a rotary positioning motor 2.
The magnetic head 6 is positioned at a target position on the magnetic disk 11, and writing and reading operations to and from the magnetic disk 11 are performed.

[Problems to be Solved by the Invention] In such a magnetic disk device, the base 8, carriage 4, magnetic disk 11, etc. are made of an aluminum alloy, and the magnetic head supporting spring 7, steel belt 1, etc. are made of a stainless alloy. Since the magnetic head 6 positioned on the magnetic disk 11 may move from its intended position due to changes in temperature conditions such as the operating environment temperature of the device and self-heating of the device (hereinafter referred to as thermal off-track). This makes it impossible to perform stable read/write operations.

In recent magnetic disk drives, high precision positioning in microns is required for positioning the magnetic head as the recording capacity increases. As a means to solve the problem of thermal off-track, it is possible to select materials for each component and use special materials (low expansion alloys, etc.) for some of them. However, such a solution has problems such as an increase in cost due to the use of special materials and an increase in the number of parts for installation. Additionally, there was a problem in that it was difficult to select a special material due to the structural limitations of ε.

[Means for Solving the Problems] The present invention solves the above-mentioned conventional problems in a magnetic disk drive in which a carriage to which a magnetic head is attached is driven by a steel belt wound around an output shaft of a magnetic head positioning motor. , the steel belt is wound around the output shaft multiple times.

[Example] Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the present invention. The steel belt 1 is fixed to a pulley 3 attached to the output shaft of a rotary positioning motor 2. The steel belt 1 is always wound around the outer circumference of the pulley 3 for more than one rotation, and the movable part of the steel belt 1 does not directly contact the outer circumference of the pulley 3.

The carriage 4 is connected to the output shaft of a rotary positioning motor 2 via a steel belt 1 which has tension applied in advance by a leaf spring 5.

The magnetic head 6 on the carriage 4 performs writing and reading operations at a target position by positioning by the rotary positioning motor 2.

The length of the steel belt 1 from the part fixed to the pulley 3 to the part fixed to the carriage 4 is selected so as to provide an expansion amount such that the magnetic head 6 is always located at the target position regardless of temperature changes. - Generally, when aluminum alloy and steel belt 1 are of the same length, steel belt 1
Since the coefficient of linear expansion is smaller for aluminum, it requires nearly twice the length to obtain the same amount of expansion as aluminum. If the length of the steel belt 1 is simply doubled, it will not be possible to store the steel belt in the limited space inside the device. Therefore, by wrapping the belt around the outer circumference of the pulley 3 multiple times, the expansion amount can be optimized and the space can be increased. has been achieved.

In this case, the length of the steel belt 1 is not necessarily simply doubled, but can of course be appropriately selected depending on the purpose of correcting thermal off-track.

As an incidental effect, conventionally, the outer periphery of the pulley 3 had to have a good surface finish in order to make contact movement with the steel belt 1, but in this embodiment, since the steel belts 1 make contact with each other, the conventional The contact movement is performed in a portion with a more dense surface condition than that of the pulley 3. Therefore, it is sufficient that the outer peripheral surface of the pulley 3 has a rougher finish than the conventional one. Also,
Since the contact operation is performed between metals of the same type, the electrolytic corrosion phenomenon that occurs due to the contact operation between different metals can also be reduced.

[Effects of the Invention] As explained above, the present invention provides a magnetic disk drive in which a carriage to which a magnetic head is attached is driven by a steel belt wound around the output shaft of a magnetic head positioning motor. By wrapping it around the output shaft multiple times, thermal off-track can be corrected and highly accurate positioning can be achieved.

Additionally, there is no need to use special materials for each component.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a magnetic head drive unit according to an embodiment of the present invention, and FIG. 2 is a perspective view of a conventional magnetic disk device. 1 Steel belt 2: Rotary positioning motor 3: Boule 4: Carriage 5: Leaf spring 6: Magnetic head 1: Micro head support spring 8: Base 9: Cover 10:
Magnetic disk drive unit 11: magnetic disk

Claims (1)

[Claims] A magnetic disk drive in which a carriage to which a magnetic head is attached is driven by a steel belt wound around an output shaft of a magnetic head positioning motor, characterized in that the steel belt is wound around the output shaft multiple times. magnetic disk device.