JPS6224482A - Magnetic memory device - Google Patents

Abstract

PURPOSE:To eliminate the adverse influences of a bimetal effect and to prevent the change of a head position due to the warp of a shake arm by coupling a pair of shake arm members different in thermal expansion coefficient with a coupling shaft, which is parallel with a shaft of the shake center, between them. CONSTITUTION:Shake arms 30 and 60 are supported in halfway positions by a shaft 90, and a magnetic head 10 is arranged in one end side through a head gimbals 20, and the magnetic head 10 is moved along the surface of a magnetic disc 130 in accordance with the shake of shake arms 30 and 60. The following-up member 30 out of shake arms 30 and 60 consists of an aluminium alloy, and the active member 60 consists of a carbon steel and is shrinkage-fitted to the shaft 90, and the following-up member 30 is clearance-fitted to the shaft 90 and is fixed by a set screw 33. Though the following-up member 30 and the active member 60 are contracted and expanded around the axis of the shaft 90 in accordance with the variance of temperature, stress in the axial direction is not caused at all or is hardly caused. Thus, the shake arms 30 and 60 are not warped upward and downward.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic storage device that uses a swinging arm to move a magnetic head.

[Background of the invention]

As this type of swinging arm, for example, JP-A-53-
(As described in Japanese Patent No. 39107, it is often formed integrally from one material.) However, the magnetic head placed at one end of the swinging arm can be accurately positioned on the corresponding magnetic desk! It's difficult to attach. This is because the corresponding position on the magnetic disk changes due to thermal expansion, and the position of the magnetic head at the end of the swinging arm also changes.

It is. It is also possible to absorb such changes due to temperature with two swing arms. Figure 4, which is the premise of the present invention,
FIG. 5 shows this type of device. However, this is not good because a bimetal effect occurs in the swinging arm, causing the swinging arm to warp as the temperature changes.

[Purpose of the invention]

The present invention provides a two-part swinging arm that does not produce bimetallic effects.

[Summary of the invention]

The present invention connects a pair of swinging arm members with different coefficients of thermal expansion via a joint axis parallel to a shaft serving as the center of swing,
This eliminates the negative influence of the bimetallic effect.

[Embodiments of the Invention] First, the magnetic storage device shown in FIGS. 4 and 5 will be described. Although this is the premise of the present invention, it will be discussed here because it is useful for understanding the embodiments of the present invention.

100 base, and a top lid 104 is attached via a gasket 102 to form a sealed container. Inside the airtight container are mainly magnetic heads 1. Swing frames 30, 50. Air filter 120. A magnetic desk 150 and the like can be stored therein. A circuit board 110 is arranged on the lower surface side of the base 100 with a frame 106 interposed therebetween.

The circuit board 110 is equipped with necessary control electrical components.

has been done. A cover 108 is fixed to the frame 106 and covers the entire end surface. Reference numeral 85 denotes an arm drive motor, which is arranged on the lower surface side of the base 100. This is a kind of stepper motor with swing arm 30.6
oscillate 0. In this example, there are three magnetic destars 130, which are stacked one on top of the other with a spacer or the like interposed therebetween, and are fixed to the output shaft side of the spindle motor 140.

The swing arm 30.60 or its related configuration will be explained in more detail. Oscillating arm, m 50.60
The middle part of the shirt is supported by a shirt (90) so that the whole thing can swing. Reference numeral 95 denotes a bearing for the shaft 9o, and the magnetic head 1o is disposed on one end side of the swing arm 30.60, which is fixed to the base 100 via another component 97 via the herad gimbal 2o. magnetic head 104i
As the swing arm 30.60 swings, it is moved along the surface of the magnetic desk (13(1)) in its approximately radial direction.
．． (through steel bell) 70) swinging arm 30. t
50 is transmitted to the other end side. Capstan 80. The steel belt 70 and the like constitute a kind of power transmission means.

A steel bell) 70 is wound around a capstan 8o, and tension is applied to the entire belt by a spring 75 at its free end. There are a plurality of magnetic heads 1°,
A part 4o similar to 3o is fixed to 30. These parts 4o also hold the magnetic head 1o via a head gimbal.

The swing arm 30.60 is composed of two members 30 and 60 having different coefficients of thermal expansion. Here, the member 30 on the side of the magnetic head 10 is used as a driven member, and the power transmission means (70, 80)
The side member 60 is an active member. The length ratio of the driven member 30 and the active member 60 varies depending on their respective coefficients of thermal expansion and ambient temperature. Therefore, it is possible to correct errors depending on the temperature of the magnetic head 10 with respect to one magnetic disk 130.

The relationship between the driven member 60 and the active member 60 is shown in FIG.

They are commonly connected via 3i and 32i. For this reason, the driven member 60. Active member 6
The difference in thermal expansion coefficient between 0 and 0 is a problem, and a bimetallic effect occurs during this period. As a result, the side of the magnetic head 10 is warped vertically, which adversely affects reading and writing from the magnetic disk 150 by the magnetic head 10 both above and below.

Therefore, the present invention is constructed as shown in the embodiments shown in FIGS. 1 and 2, for example. In this embodiment, the active member 60
is shrink-fitted onto the shaft 90.

Further, the driven member 30 is a clearance fit on the shaft 90, and the set screw 33 is a headless screw and is orthogonal to the shaft 90 between the driven member 30 and the shaft 90. Although a portion of the driven member 30 and the active member 60 overlap vertically, the finishing accuracy of the mutual joint surfaces 66 is improved,
The height of the driven member 60 is kept constant and it is positioned so that it does not tilt.

The driven member 30 or the active member 60 expands and contracts as the temperature changes. In relation to the shaft 90, this expansion and contraction occurs around its axis, or, depending on this, no or almost no stress is generated in the axial direction.

Therefore, the swing arm 1.60 does not warp in the vertical direction at all.

In this embodiment, the driven member 30, the magnetic desk 150,
The capstan 80 and base 100 are made of aluminum alloy, the helad gimbal and steel belt 70 are made of stainless steel, and the active member 60 is made of carbon steel.
Shirt) 90 is also carbon steel. The reason why the active member No. 60 is vague is that its coefficient of thermal expansion is different from that of the aluminum alloy driven member 60, which makes it difficult for the magnetic head 1 to withstand temperature changes.
This is to correct the position of 0 (position error). Further, the reason why the shaft 90 is made of the same carbon steel as the active member 60 is to shrink fit the two.

The driven member 60 is screwed to the shaft 90. Therefore, during assembly, the orientation of the driven member 30 with respect to the active part ladle 60 can be easily adjusted using the set screw 33. As you can see from Figure 2, set screw 3
The screwing direction of 5 coincides with the magnetic head 10. That is, the extension line 56' of the set screw 65 passes through the magnetic head 10 or overlaps the magnetic head 10 vertically. The reason for this is as follows. The shaft 90 and the driven member 50 are not coupled uniformly. The connection point between them occurs on the extended line length'. As the temperature changes, the driven member 60 expands and contracts around its axis in relation to the shirt.

The base point of this expansion and contraction is the connection point, but since this exists on the extension line that includes the magnetic head 10, the position of the magnetic head 10 hardly moves. In this case, the stepped portion 62 of the active member 60
It becomes possible to screw in the set screw 33 using a tool (not shown) without the step portion 62 (facing the driven member 30) becoming an obstacle.

In the embodiment shown in FIGS. 1 and 2, the shaft 90 is connected to the driven member 3.
0 and the active member 60. Therefore, the length ratio of the driven member 30 and the active member 60 occupying the swing arm 50, 60 cannot be freely changed.

For this reason, selection of the thermal expansion coefficient of the active member 60 is particularly important in order to accurately compensate for the effects of temperature changes.
Coefficients as designed are required.

Therefore, it is also desirable to use a sintered alloy for the active member 60 whose coefficient of thermal expansion can be selected almost continuously.

In the embodiment shown in FIG. 3, the active member 60 and the driven member 50 are coupled through a coupling shaft 99 parallel to the shaft 90.

It is something. This coupling shaft 99 does not also serve as the shaft 90, but is different from it.

Therefore, the driven member 50 occupies the swinging member 30.60.
Since the ratio between the length of the active member 60 and the length of the active member 60 can be almost arbitrarily selected, it becomes easy to correct (adjust) the influence of temperature changes. Coupling shaft 99 in this embodiment is part of active member 60 .

Therefore, during this time? There is no need to recombine them. This coupling shaft 99 may be integral with the driven member 30, or the active member 60. It may be separate from any of the driven members 50.

〔Effect of the invention〕

According to the present invention, it is possible to effectively prevent changes in the position of the magnetic head due to thermal expansion, particularly changes in the head position due to warping of the swing arm.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of a magnetic storage device corresponding to one embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a sectional view of the main parts of the device showing another embodiment. FIG. 4 is a cross-sectional view of the essential parts of the device, which is the premise of the present invention, and FIG. 5 is an exploded perspective view thereof. In the figure, 30 is a driven member of the swing arm, 60 is an active member of the arm, 90 is a shaft, 130 is a magnetic desk, 10
is a magnetic head\85 is a motor for driving the arm, 70 is a power transmission means, 99 (90) is a coupling shaft, and 63 is a set screw.

Claims (1)

[Claims] 1. A swinging arm, a shaft that supports the swinging arm so that the whole swings, a rotating magnetic desk, and a swinging arm disposed at one end of the swinging arm. The magnetic head is moved approximately radially along the plate surface of the magnetic desk by the movable arm, the arm drive motor, the arm drive motor, and the output of the arm drive motor is transmitted to the other end of the swing arm. , in a magnetic storage device equipped with a power transmission means for swinging the entire swinging arm, the swinging arm is composed of a driven member on the side of the magnetic head and an active member on the side of the power transmission means, and the swinging arm is composed of a driven member on the side of the magnetic head and an active member on the side of the power transmission means; A magnetic storage device characterized in that the members have different coefficients of thermal expansion, and the driven member and the active member are coupled via a coupling axis parallel to the shaft. 2. The magnetic storage device according to claim 1, wherein the coupling shaft is a part of the shaft supporting the swing arm. 3. The magnetic storage device according to claim 1, wherein the coupling shaft is integrated with either the driven member or the active member. 4. The magnetic storage device according to claim 1, wherein either one of the driven member and the active member is engaged with the coupling shaft via a set screw. 5. The magnetic storage device according to claim 4, wherein the screwing direction of the set screw is made to coincide with the direction of the magnetic head.