초록 ▼

Conditional exchanging of working fluid between plural fluid circuits (13A, 13B) having separate supply pumps (18A, 18B) is provided for without continuously bleeding fluid from the pump control pressure lines (21A, 21B). Each circuit (13A, 13B) has a pump control (19A, 19B) responsive to a control

Conditional exchanging of working fluid between plural fluid circuits (13A, 13B) having separate supply pumps (18A, 18B) is provided for without continuously bleeding fluid from the pump control pressure lines (21A, 21B). Each circuit (13A, 13B) has a pump control (19A, 19B) responsive to a control pressure, a plurality of fluid motors (14A, 15A, 16A, 14B, 15B, 16B), and a group of resolver valves (38A, 38B) which compare motor pressures and intercommunicate the pump control (19A, 19B) with the most highly pressurized motor (14A, 15A, 16A, 14B, 15B, 16B). At times when fluid from one circuit (13A, 13B) is being delivered to a motor (16A, 16B) of another circuit (13A, 13B), the pressure comparing function of the resolver group (38A, 38B) of the one circuit (13A, 13 B) is extended to include the motor (16A, 16B) of the other circuit (13A, 13B). Among other uses, the system (11) may be used on excavator vehicles having plural fluid motors performing a variety of different functions. Absence of a bleed in the pump control lines (21A, 21B) conserves power and enables precise response of the pumps to demand changes.

대표청구항 ▼

In a fluid system (11) having first (14A, 15A, 16A) and second (14B, 15B, 16B) pluralities of fluid operated devices, first (12A) and second (12B) fluid source means for supplying working fluid to said first (14A, 15A, 16A) and second (14B, 15B, 16B) pluralities of fluid operated devices respectivel

In a fluid system (11) having first (14A, 15A, 16A) and second (14B, 15B, 16B) pluralities of fluid operated devices, first (12A) and second (12B) fluid source means for supplying working fluid to said first (14A, 15A, 16A) and second (14B, 15B, 16B) pluralities of fluid operated devices respectively, first (19A) and second (19B) control means for varying the outputs of said first (12A) and second (12B) fluid source means, respectively, in response to control pressures, and crossover means (17) for transmitting fluid from said first source means (12A) to at least one device (16B) of said second plurality of devices (14B, 15B, 16B), the improvement comprising: first pressure comparing means (38A) for establishing a two way control pressure flow path between said first control means (12A) and the one of a first predetermined group (14A, 15A, 16A, 16B) of said devices that is most highly pressurized at a particular time, said first predetermined group (14A, 15A, 16A, 16B) including said first plurality of devices (14A, 15A, 16A) and at least said one (16B) of said second plurality of devices (14B, 15B, 16B).