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Linear Motor for Positioning and Servo Control

IP.com Disclosure Number: IPCOM000078879D
Original Publication Date: 1973-Mar-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Lennemann, E: AUTHOR

Abstract

For the radial displacement of carriage 3, bearing magnetic heads 4 on arms 5, the positioning and alignment device utilizes two serially connected hydraulic motors 1, 2 in the track seeking and track following modes. Motors 1, 2 are controlled by valve system operated by voice coil motor 7.

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Linear Motor for Positioning and Servo Control

For the radial displacement of carriage 3, bearing magnetic heads 4 on arms 5, the positioning and alignment device utilizes two serially connected hydraulic motors 1, 2 in the track seeking and track following modes. Motors 1, 2 are controlled by valve system operated by voice coil motor 7.

Cylinder 9, shiftable on rollers 8 and 13 and belonging to motor 1, comprises piston 10 whose piston rod 11 is held in base plate 12. Roller-mounted cylinder 14 of motor 2 is linked with cylinder 9. Piston rod 16 of piston 15, moving in motor 2, is connected to carriage 3 movable on rollers 17.

Motor 1 having a long stroke and a long shift per unit of pressure is used for coarse adjustment to a particular track. Motor 2 having a short stroke and a short shift per unit of pressure, is employed for fine adjustment.

Cylinders 9, 14 are connected to valve system 6 via hosing 18, 19 and 2O, 21, respectively. Valve system 6 consists of cylinder 22 in which wide pistons 24, 25 for coarse adjustment control and narrow pistons 26, 27 for fine adjustment control, are shiftable on piston rod 23 by voice coil motor 7.

When a signal for coarse adjustment is applied to a data track via inputs 28, piston rod 23 performs a relatively long stroke, with the pistons assuming the positions designated as 24'...27'. As a function of the forward or backward movement, piston 24 or 25 releases aperture 29 or 30, so that the fluid is discharged into cylin...