Hydraulic system for a work machine
AssigneeCaterpillar Inc.
InventorKazunori Yoshino
Life of this patent
Estimating the term…
Abstract
In one aspect of the invention, the hydraulic system provided with the hydraulic pressure source and at least one meter-in spool valve. Each Spool valve has an inlet and an outlet. A hydraulic actuator is fluidly coupled with the spool valve outlet. A load hold check valve fluidly interconnects the pressure source with at least one spool valve inlet. The load hold check valve has a pressure control chamber. A three way valve has a first port in fluid communication with the pressure control chamber, a second port in fluid communication with at least one spool valve inlet, and a third port in fluid communication with the pressure source. Proved pressure and flow control to an actuator are provided, and make-up and line relief are provided without the use of an additional spool valve.
Claims25
A hydraulic system, comprising:
- a hydraulic pressure source;
- at least one meter-in spool valve, each said spool valve having an inlet and an outlet;
- a hydraulic actuator fluidly coupled with said spool valve outlet;
- a load hold check valve fluidly interconnecting said pressure source with at least one said spool valve inlet, said load hold check valve having a pressure control chamber;
- and
- a three-way valve having a first port in fluid communication with said pressure control chamber, a second port in fluid communication with at least one said spool valve inlet, and a third port in fluid communication with said pressure source.
A work machine, comprising:
- a frame;
- and
- a hydraulic system including:
- a hydraulic pressure source;
- at least one meter-in spool valve, each said spool valve having an inlet and an outlet;
- a hydraulic actuator fluidly coupled with said spool valve outlet;
- a load hold check valve fluidly interconnecting said pressure source with each said spool valve inlet, said load hold check valve having a pressure chamber;
- and
- a three-way valve having a first port in fluid communication with said pressure control chamber, a second fluid port in fluid communication with at least one said spool valve inlet, and a third port in fluid communication with said pressure source.
A hydraulic system, comprising:
- a hydraulic pump;
- at least one meter-in spool valve, each said spool valve having an inlet and an outlet;
- at least one hydraulic actuator, each said hydraulic actuator fluidly coupled with a corresponding said spool valve outlet;
- a load hold check valve fluidly interconnecting said pump with each said spool valve inlet;
- a tank;
- and
- at least one poppet valve assembly, each said poppet valve assembly fluidly connected with a corresponding said spool valve outlet and said actuator, each said poppet valve assembly selectively interconnecting said corresponding actuator with one of said tank and an ambient.
A work machine, comprising:
- a frame;
- and
- a hydraulic system including:
- a hydraulic pump;
- at least one meter-in spool valve, each said spool valve having an inlet and an outlet;
- at least one hydraulic actuator, each said hydraulic actuator fluidly coupled with a corresponding said spool valve outlet;
- a load hold check valve fluidly interconnecting said pump with each said spool valve inlet;
- a tank;
- and
- at least one poppet valve assembly, each said poppet valve assembly fluidly connected with a corresponding said spool valve outlet and said actuator, each said poppet valve assembly selectively interconnecting said corresponding actuator with one of said tank and an ambient.
Dependencies are inferred from the claim text.