초록 ▼

A fluid motor control system (11) assures that automatic changes of motor displacement, which are initiated by occurrence of a predetermined operational condition in the system (11), result in a change of motor speed of the desired magnitude. Flow adjustment elements (76) respond to a displacement i

A fluid motor control system (11) assures that automatic changes of motor displacement, which are initiated by occurrence of a predetermined operational condition in the system (11), result in a change of motor speed of the desired magnitude. Flow adjustment elements (76) respond to a displacement increase by reducing the flow of working fluid available to the motor or motors (12, 13) and respond to a motor displacement reduction by increasing the available flow. In one specific form, the system (11) controls a pair of right and left side vehicle drive motors (12, 13) and automatically increases motor displacements while reducing the fluid flow supplied to the motors (12, 13) to reduce travel speed during a turn of travel direction.

대표청구항 ▼

A control system (11) for at least one fluid motor (12) which is driven by pressurized working fluid and which has displacement adjustment means (17) for changing the displacement of said motor (12) to provide for speed changes, the control system having control means (66) for automatically actuatin

A control system (11) for at least one fluid motor (12) which is driven by pressurized working fluid and which has displacement adjustment means (17) for changing the displacement of said motor (12) to provide for speed changes, the control system having control means (66) for automatically actuating said displacement adjustment means (17) upon occurrence of a predetermined condition, a manually operable motor speed control valve means (54) for selectively varying the rate of flow of said working fluid to said motor (12) and including at least one additional manually actuatable control means (58) for selectively initiating said predetermined condition, wherein the improvement comprises: flow adjusting means (76) for reducing the flow of working fluid which is available to said motor (12) when the displacement thereof is increased and for increasing the flow of working fluid available to said motor (12) when the displacement thereof is decreased, said flow adjusting means (76) also being actuated by said control means (66) upon occurrence of said predetermined condition, and wherein said control means (66) senses actuation of said additional control means (58) and responds thereto by causing said displacement adjustment means (17) to increase the displacement of said motor (12) and by causing said flow adjusting means (76) to reduce the flow of working fluid available to said motor (12).