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Hydraulic Control System

IP.com Disclosure Number: IPCOM000096008D
Original Publication Date: 1964-Nov-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Tsao, S: AUTHOR

Abstract

In this hydraulic system, two pistons A and B are separated by a column of hydraulic fluid and normally biased by spring 1 to a left limit position while pump P is off. When P is turned on, pressure fluid is supplied to the left-hand face of A, causing both pistons and the intervening hydraulic column to move rightward and compress spring 1. Since the acceleration of the pistons and column ceases before A hits its right limit position, spring 1 is further compressed as A decelerates. The resistance offered by spring 1 prevents developments of a pressure differential in the reverse direction across A. Meanwhile, pressure fluid is displaced through choke 2 in or around B, helping to damp out any oscillations.

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Hydraulic Control System

In this hydraulic system, two pistons A and B are separated by a column of hydraulic fluid and normally biased by spring 1 to a left limit position while pump P is off. When P is turned on, pressure fluid is supplied to the left-hand face of A, causing both pistons and the intervening hydraulic column to move rightward and compress spring 1. Since the acceleration of the pistons and column ceases before A hits its right limit position, spring 1 is further compressed as A decelerates. The resistance offered by spring 1 prevents developments of a pressure differential in the reverse direction across A. Meanwhile, pressure fluid is displaced through choke 2 in or around B, helping to damp out any oscillations.

When A attains its right limit position, it remains there until a fluid pressure differential is developed across A by devices, not shown, effective for a long enough time to return A to its left limit position. Spring 1 drives B leftward as fluid is displaced through 2 to fill the hydraulic column and restore the normal spacing between A and B.

Spring 1 preferably has an increasing value of spring constant to provide fast deceleration of the masses. Also, spring 1 is designed so that A and, hence, piston rod 3, come to a smooth stop at the right limit position. Note that either A or B or both need not necessarily be pistons; they can, e. g., be spool valves.

With this system, impact momentum is desirably minimized by the effective bra...