초록 ▼

A dual hydraulic motor system where motor wobblers are mechanically linked and the motor outputs are torque summed, is controlled by a three position dual valve assembly. Each valve assembly is controlled by pilot pistons that are mechanically linked to provide three functions, one being normal oper

A dual hydraulic motor system where motor wobblers are mechanically linked and the motor outputs are torque summed, is controlled by a three position dual valve assembly. Each valve assembly is controlled by pilot pistons that are mechanically linked to provide three functions, one being normal operation, a second where one motor must be shut-off and its load on the system is minimized and the third where both motors are shut-off and significant drag is then provided. These functions are implemented by a separate spool in each valve which has three independent stable positions.

대표청구항 ▼

A shut off valve system connected to a pair of hydraulic motors geared together to drive a single output shaft by either or both of said motors comprising; means for connecting supply hydraulic fluid to and return hydraulic fluid from each motor including first and second valves in first and second

A shut off valve system connected to a pair of hydraulic motors geared together to drive a single output shaft by either or both of said motors comprising; means for connecting supply hydraulic fluid to and return hydraulic fluid from each motor including first and second valves in first and second cylindrical housings with a spool and a pilot piston in axial alignment and arranged for independent axial movement within each housing; first means for supplying hydraulic pressure to the pilot piston in said first cylindrical housing; second means for supplying hydraulic pressure to the pilot piston in said second cylindrical housing; means for removing hydraulic pressure from the pilot piston in the valve associated with one of said motors for disconnecting the supply hydraulic fluid to said motor while connecting return hydraulic fluid to an inlet of said motor through a path including the spool of said valve to permit recirculation of fluid at a first rate sufficient to avoid excessive drag on the other hydraulic motor; and means for removing hydraulic operating pressure to the pilot pistons in both of said valves for disconnecting the supply hydraulic fluid to each of said motors while connecting return hydraulic fluid from each motor to its inlet through a path including the respective spool for each of said valves to permit recirculation of fluid at a second rate which is lower than said first rate to provide damping of both motors.