Input torque control system for a variable displacement pump
AssigneeGeneral Signal Corporation
InventorsJohn E. G. Young, Donald R. Schneckenburger
Life of this patent
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Abstract
A variable displacement pump has a displacement control cam operably connected to a displacement control cylinder within a pump housing and a pressure and flow sensitive compensating valve is connected to the pump housing for regulating output of the pump. The compensating valve is secured to the pump housing through a spacer block. A lever is disposed partly in the spacer block and partly in a housing of the compensating valve responsive to positioning of the pump cam through a mechanical connection for actuating a sleeve in the compensating valve to incorporate torque-limiting feedback regulation of the pump. An adjustment is operable from an outer surface of the spacer block to limit torsional operation of the lever about a pivot point.
Claims4
An input torque control system for a variable displacement pump including a displacement control cam operably connected to displacement control cylinder means within a pump housing, and pressure and flow sensitive compensating valve means connected to the pump housing for regulating output of the pump, wherein improved compensating valve means comprises:
- (a) valve housing means secured to a surface of the pump housing through spacer means;
- (b) the valve housing means having a valve sleeve operable axially in a bore of the housing and a spool valve operable axially within the sleeve;
- (c) spring biasing means for axially biasing the sleeve and the spool valve in opposite directions;
- (d) lever means for axially operating the sleeve disposed in part in the valve housing means and in part in the spacer means having a central pivot from which
- (1) a first arm extends to engage the sleeve,
- (2) a second arm extends to engage feedback means positioned by said displacement control cam, and
- (3) a third arm extends to at times contact an adjustable stop means for limiting output pressure of the pump;
- and
- (e) means including the spool valve for selectively delivering output of the pump to the control cylinder means or output of the control cylinder means to a tank in accordance with pump output pressure sensed by the spool valve.
Dependencies are inferred from the claim text.