Patent Number: 6,192,782

Title: Torque control means for hydraulic motor

Abstract: A fluid pressure control system for limiting the torque output of a positive displacement hydraulic motor (21) for rotating a screw anchor (11, 11') into the ground. A normally closed solenoid operated control valve (76) is mounted in a bypass line (86) between the high pressure supply line (30) and the low pressure exhaust line (36). A plurality of electro-hydraulic switches (72) are arranged for setting at different predetermined fluid pressures and are in fluid communication with a differential pressure sensing chamber (63). Upon turning on of a selected switch (72) having the desired pressure level, the reaching of the desired pressure level activates the selected switch (72) for actuation of solenoid operated control valve (76) to move control valve (76) to an open position as shown in FIG. 3 to bypass fluid from high pressure line (30) to exhaust line (36) to limit the torque output of the motor (21).

Inventors: Rogers; John W. (Memphis, TN)

Assignee:

International Classification: F15B 11/042 (20060101); F15B 11/00 (20060101); F15B 11/028 (20060101); F01C 021/12 ()

Expiration Date: 02/27/2013