Browse Prior Art Database

Hydraulic Servo System

IP.com Disclosure Number: IPCOM000096967D
Original Publication Date: 1962-Mar-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 3 page(s) / 57K

Publishing Venue

IBM

Related People

Haughton, KE: AUTHOR

Abstract

To position a load connected to shaft 11 at any one of a plurality of discrete positions, hydraulic control valve 12 is utilized. Valve 12 is provided with load piston 13 connected to shaft 11 and control piston 14 connected to a control shaft 15. Fluid is supplied to the inlet at the top of the valve and flows on either side of piston 14 through two parallel conduits 16a, 16b to opposite faces of piston 13 and then through parallel output conduits to a sump. When piston 14 is centered under the inlet conduit, the fluid flow divides evenly on each side of piston 14 and in conduits 16a, 16b. This produces equal pressures on opposite faces of piston 13, thus maintaining 13 in a position of equilibrium.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 3

Hydraulic Servo System

To position a load connected to shaft 11 at any one of a plurality of discrete positions, hydraulic control valve 12 is utilized. Valve 12 is provided with load piston 13 connected to shaft 11 and control piston 14 connected to a control shaft 15. Fluid is supplied to the inlet at the top of the valve and flows on either side of piston 14 through two parallel conduits 16a, 16b to opposite faces of piston 13 and then through parallel output conduits to a sump. When piston 14 is centered under the inlet conduit, the fluid flow divides evenly on each side of piston 14 and in conduits 16a, 16b. This produces equal pressures on opposite faces of piston 13, thus maintaining 13 in a position of equilibrium.

When piston 14 is moved off center by movement of shaft 15, the fluid flow is unevenly divided on opposite sides of the piston 14 face to produce an imbalance of pressure in conduits 16a, 16b and across the opposite faces of piston 13. This pressure imbalance causes piston 13 and shaft 11 to move in a direction tending to equalize the pressures. This movement continues until the piston 13 reaches a stop or until piston 14 is again centered in the fluid flow.

To control the coarse positioning operation, binary coded wheel 20 is connected to shaft 11 by belt 21 so that wheel 20 rotates with movement of shaft
11. Wheel 20 has a plurality of coded openings 20a, each radial line of openings corresponding to the address of a different discrete position of shaft 11. Openings 20a are sensed by light projected from a plurality of light sources 22 through the openings onto a plurality of photocells 23. The outputs from photocells 23 are supplied to address compare register 26 which also receives inputs corresponding to the desired address. As wheel...