JPH02177115A - Fluid bearing type rotary magnetic head device - Google Patents

Abstract

PURPOSE:To curtail the number of parts which require high accuracy, and also, to contrive the improvement of assembly accuracy by placing the thrust bearing fitting surface, the rotary cylinder fitting surface and the magnetic head fitting surface on the same plane. CONSTITUTION:A rotary cylinder 5 is fixed to a thrust bearing 4, and attached so as to become the same plane as the thrust bearing fitting surface and the radial bearing 9 fitting surface, and a non-radial bearing 9 is placed in the same plane as the thrust bearing 4 fitting surface and the rotary cylinder 5 fitting surface. That is, the thrust bearing fitting surface, the rotary cylinder fitting surface and the magnetic head fitting surface are placed on the same plane. In such a way, a tolerance in the axial direction of each parts is eliminated, and the working method, as well, step difference working is eliminated, the device can be constituted by flattening which can obtain most easily high accuracy, and the improvement of working accuracy and assembly accuracy can be contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluid bearing type rotary magnetic head device for a magnetic recording/reproducing device such as a video tape recorder.

(Prior Art) Fig. 2 is a front cross-sectional view of a conventional hydrodynamic bearing having a double-rotating magnetic head device. A fixed cylinder 3 is supported by the fixed cylinder 2 and has a central shaft whose upper snout is a thrust bearing, 4 is a thrust bearing attached to a radial bearing 9, and 5 is fixed to the thrust bearing 9 and is a thrust bearing. is a mounting surface and the radial bearing is a mounting surface or a rotating cylinder with a step. 6 is attached to the rotating cylinder 5 and records information on the magnetic tape l or reproduces information already recorded on the magnetic recording tape l. Co-rotating magnetic head (hereinafter simply referred to as head); 7 is a rotary transformer that exchanges information between the head 6 and a stationary signal processing circuit (not shown) without contact; 8 is a rotating cylinder that drives the rotating cylinder 5; 9 is a radial bearing in which the thrust bearing 4 mounting surface and the rotary cylinder 5 mounting surface have a step, and 11 is a bearing that supports a cargo storage, and the bearing is grease.

Next, the operation will be explained. When the radial bearing 9 is rotated once by il#es1 g, the radial bearing is
Pressure is generated in the grease 11, and the thrust bearing 4 slightly floats up, and an appropriate gap is maintained between the radial bearing 9 and the center shaft 3, and the center shaft 3
The rotating cylinder 5 is rotated without direct contact between the thrust bearing 4 and the thrust bearing 4.
Rotate. The head attached to the rotating cylinder 5 also rotates to record and reproduce information on the magnetic tape 1 that is guided along the lead groove 201 and runs on the outer peripheral surfaces of the fixed cylinder 2 and the rotating cylinder 5. During this time, information to be recorded or reproduced is transferred between the head 6 and the signal processing circuit via the rotary transformer 7 without contact.

When the rotation of imi# machine 8 stops, the thrust bearing
As for the radial bearings, the pressure of the grease 11 is removed, and the thrust bearings 4 and radial bearings 9 are brought into direct contact. When the rotation is stopped, the part that is integrated with the rotating cylinder 5 can freely rotate once and move in the axial direction.

(Problem to be solved by the invention) Since the conventional fluid bearing type extraction magnetic head device is constructed as described above, it is possible to obtain the dimensions of the magnetic head from the reference plane, which is important for a rotating magnetic head device. In order to do this, the thrust bearing on the central axis must be from the reference plane with a surface dimension of D1.The dimension between the thrust bearing mounting surface and the rotating cylinder mounting surface is 0. Since precision must be ensured in eight stages, such as dimension B1, each part must be machined with eight times as much precision.

This invention was made to solve the above-mentioned problems.In addition to reducing the number of parts that require high-precision machining, the hydrodynamic bearing can easily improve assembly accuracy by using a rotary magnetic head device. The purpose is to obtain.

[Means to solve the charge]

In the fluid bearing type rotary magnetic head device according to the present invention, the thrust bearing mounting surface, the rotating cylinder mounting surface, and the magnetic head housing are arranged on the same plane.

[Effect]

The hydrodynamic bearing type rotating magnetic head device in this invention includes:
By arranging the mounting surface, the rotary cylinder mounting surface, and the magnetic head mounting 101 on the same plane, the thrust bearing eliminates tolerances in the axial direction of each component, and also eliminates the machining process, making it easier to obtain the highest accuracy. By using plane processing, it is possible to improve processing accuracy and assembly accuracy.

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

The same parts as those of the above-mentioned conventional one are given the same reference numerals, and the explanation thereof will be omitted.

FIG. 1 is a front sectional view of a hydrodynamic bearing type rotary magnetic head device of the present invention. In the figure, l is a magnetic tape, and 2 is a lead groove 'l!' that guides the running of the magnetic tape. A fixed cylinder 3 having a DI on its outer peripheral surface is supported by the fixed cylinder 2, and a central shaft whose upper part is a thrust bearing surface;
4 is a thrust bearing attached to a radial bearing 9; 5 is a rotating cylinder fixed to the thrust bearing; the thrust bearing is flush with the mounting surface; and the radial bearing is flush with the mounting surface; 6 is fitted into the rotating cylinder 5; A rotary magnetic head (hereinafter simply referred to as a head) that records information on the magnetic tape 11C7ll or reproduces information recorded on the magnetic recording tape L (,:a); 8 is a rotary transformer that exchanges information with the TG circuit (not shown) without contact.
An electric motor rotationally drives the rotating cylinder 5, a radial bearing 9 is flush with the thrust bearing 4 mounting surface and the rotating cylinder 5 mounting surface, and a bearing 11 supports the load, and the bearing is grease.

Next, the operation will be explained.◇When the radial bearing 9 is rotated by the electric motor 8, pressure is generated in the grease 11 of the radial bearing and the thrust bearing. A proper gap is also maintained between the bearing 9 and the central shaft 3, and the rotating cylinder 5 is rotated without direct contact between the central shaft 3 and the thrust bearing 4. The head attached to the rotating cylinder 5 also rotates to record and reproduce f'# information on the magnetic tape l which is guided along the lead iJ4+1 and runs on the outer peripheral surfaces of the fixed cylinder 2 and the rotating cylinder 6. During this time, f# information to be recorded or reproduced is exchanged between the head 6 and the signal processing circuit via the rotary transformer 7 without contact. When the rotation of the electric motor 8 stops, the pressure of the grease 11 disappears in the thrust bearing and the radial bearing.
The thrust bearing 4 and the radial bearing are in direct contact.

When the rotation is stopped, the portion integrated with the rotating cylinder 5 can freely rotate and move in the axial direction.

In the above embodiment, the rotary cylinder and the thrust bearing are separated, and the thrust bearing is integrated with the rotary cylinder, but the same effect as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to improve the assembly accuracy of a hydrodynamic bearing type rotary magnetic head device and to reduce processing costs and assembly costs due to the simple structure.

[Brief explanation of the drawing]

FIG. 1 is a front cross-sectional view of a hydrodynamic bearing-type rotary magnetic head device according to an embodiment of the present invention, and FIG. 2 is a front cross-sectional view of a conventional hydrodynamic bearing-type rotating magnetic head. In the figure, l is a magnetic tape, 2 is a fixed cylinder, 3 is a central axis, 4 is a thrust bearing, 5- is a rotating cylinder, 6 is a magnetic head, 7 is a rotary transformer, 8 is an "It" motive, 9
is a radial bearing.

Claims (1)

[Claims] A fluid bearing type rotary magnetic head device using a fluid bearing in a magnetic recording/reproducing device, characterized in that a thrust bearing surface, a rotary cylinder mounting surface, and a magnetic head mounting surface are configured on the same plane.