Abstract: A constant speed hydraulic drive comprising a variable displacement hydraulic pump controlled to maintain a constant flow of hydraulic fluid even though a prime mover therefor is subject to speed variations. The constant flow rate delivered by the hydraulic pump is at a rate sufficient to drive a load hydraulic motor at a predetermined speed when the load hydraulic motor is subject to any given load. A pilot operated relief valve proportionally bleeds hydraulic fluid from ahead of the hydraulic motor in accordance with the speed and load of the hydraulic motor.
Type:
Grant
Filed:
April 29, 1985
Date of Patent:
February 24, 1987
Assignee:
The Oilgear Company
Inventors:
Reginald J. Goss, Jr., Gary S. Jendrzejek