SU1476530A1 - Magnetic head positioner - Google Patents

Abstract

The invention relates to instrument making and can be used in external storage devices of computers as a mechanism for precise positioning of magnetic heads. To increase the speed and dynamic accuracy of positioning the magnetic heads, the carriage is made in the form of two parallel shafts, one of which is kinematically connected to a piezoelectric motor, made in the form of a disk, each of which electrodes located on the ends of the disk is divided into three parts - a central 19, 20 in the form of a circle truncated by parallel chords and two side in the form of symmetric equal-sized segments 21 (22). The projections of the chords on one of the ends of the disk form a square with angles lying on the contour of the disk, which is installed in the cassette that presses the piezoelectric motor through the abutment to the support plane of one of the carriage shafts. The stop is installed at the intersection of the projections of the chords that divide the electrodes, the side parts of which are connected to the output bus of the generator 23, the other output bus of which through the switch 24 is connected to the central parts of the electrodes. 5 il.

Description

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The invention relates to instrument making and can be used in external storage devices of computers as a mechanism for precise positioning of magnetic heads.

The purpose of the invention is to increase the speed and dynamic positioning accuracy of magnetic heads.

Figure 1 shows the device, top view; pas figs. - the same, side view; on fig.Z - section aa in figure 1; FIG. A shows a piezoelectric motor with a wiring diagram; FIG. FIG. 3 is a diagram of the amplitude distribution of the piezoelectric motor.

The device comprises a housing 1 (Fig. 1), a carriage 2 (Fig.2), made in the form of paraplel cylindrical rods 3 and 4, rigidly connected to each other by holders 5 and 6, the rod 3 being mounted in a cylindrical guide 7 of housing 1 ( Fig. 1), the rod 4 has a supporting plane 8 (Fig. 3), made in the form of a flathead, at its end a magnetic head 9 is mounted, the second magnetic head 10 (Fig. 2) is fixed on the housing of the holder 11. The piezoelectric motor 12 is made in the form of a disc made of piezoelectric ceramics (for example, DTS-3, 035-4 mm), mounted in the cassette 13, locked captive in the housing on the axis 14 for rotation, the cassette with the piezoelectric engine is preloaded by the spring 15 through the friction assembly 16 (Fig. 3) to the supporting plane 8 of the rod 4, which has a stop in the rotation support 17.

The friction unit 16 of wear-resistant material is located on the piezoelectric motor 12 at the electrode separation 18 (the place of maximum oscillations). Each electrode is divided (figure 4) by intervals in the form of parallel chords (for example, by chemical etching) into the central part 19 (20 from the opposite end) and two side sections in the form of segments 21 (22 from the opposite end), the projections of the chords of the electrodes of the opposite ends to one from the planes form the described square. All segments 21 and 22 are electrically interconnected and connected to one of the buses of the generator 23 of electrical oscillations, and the central parts 19 and 20 through the switch 24 are connected to the second bus of the generator.

The device works as follows.

When the generator is turned on

O along the circuit: grounded bus of generator 23 — switch 24 — electrode 19 — side segments 21 and 22 — second bus of generator 23 (FIG. 4), a current begins to flow, and in a piezoelectric motor 12 a standing wave of deformation of the contour oscillation mode and orthogonal to it is the radial mode of oscillations.

As a result, the friction node 16,

0 fixed in place 18 of the maximum oscillations (deformations) t moves along an ellipsoidal trajectory, as shown in Fig. 5, where the zone of minimum amplitudes of oscillations is hatched.

5 and maximum mechanical stresses are shaded, and the zone of maximum oscillation amplitudes and minimum mechanical stresses is shown without shading. With this movement, the friction unit 16, mounted on a piezoelectric motor 12 (FIG. 3), is mounted in a cassette 13, fixed in housing 1 on axis 14 (FIG. 1) and with a spring-loaded spring

5 to 15, frictional engagement of the friction assembly 16 with the supporting plane 8 of the rod 4, which has an abutment against the rotational support 17, is provided. Friction assembly 16 moves to the right,

0 carries along the carriage 2, consisting of rods 3 and 4, rigidly connected by holders 5 and 6, while the rod 3 slides in the guide 7 of the housing 1, setting the linearity of movement,

5 of the carriage 2. As a result, the magnetic heads 9 and 10 (the latter is fixed on the holder 11) are moved relative to the information carrier (not shown).

The movement is reversed by the switch 24, which disconnects the electrode 19 and connects the electrode 20 to the generator. This changes the phase relationship between the contour and radial modes of oscillation of the piezoelectric motor 12, which leads to a change in the direction of movement of the friction assembly

16 to the opposite (shown in figure 5 by the dotted line).

The implementation of a piezoelectric motor in the form of a disk with separated electrodes and its direct connection with the carriage allow an increase in the positioning speed of the magnetic heads and dynamic accuracy.

Claims (1)

Invention Formula A device for positioning magnetic heads, comprising a carriage mounted in guides of the housing and having a reference plane to which a piezoelectric motor is pressed through the friction assembly, the electrodes of which are connected to the generator output tires through a switch, characterized in that, in order to increase speed and dynamic accuracy positioning the magnetic heads, the carriage is made in the form of two parallel cylindrical rods rigidly connected between one of which is installed in the guide casing, and the supporting plane is made on the other rod, 5 the piezoelectric engine is made in the form of a disc with electrodes at the ends, each electrode is divided into three parts — central in the form of a circle truncated by parallel chords, 0 and two side in the form of symmetric, -. equal-sized segments, the projections of the chords on one of the ends of the disk form a square with angles lying on the contour of the disk, which is installed in 5 a cassette disposed on the housing with the possibility of pressing the cylindrical surface of the disc through a friction assembly to the support plane of the rod, which is kinematically connected with another 0 guide, made in the form rotation supports, with the friction assembly being installed at the intersection of the projections of the chords that divide the electrodes; the side portions of the electrodes are connected 5 with the output bus of the generator, and the central parts through the switch with another output bus of the generator. 15 T " 1 J  /four 9 ten Phage. 2 5 at Fig.Z turned