Electro-hydrostatic actuation system

An electro-hydrostatic actuation system for driving a hydraulic actuator, comprising:

• a container for providing hydraulic liquid;
• a high pressure circuit to direct the hydraulic liquid to a hydraulic actuator;
• a low pressure circuit having multiple branches;
• a main pump for the hydraulic liquid arranged in the high pressure circuit;
• the main pump comprising a housing having a high pressure section and a low pressure section, separated by sealing gaps, wherein the high pressure section comprises a first outlet and a second outlet to provide the hydraulic liquid flow in the high pressure circuit, and wherein the low pressure section comprises a leakage outlet;
• an electric motor driving the main pump;
• a leakage branch connecting the leakage outlet of the low pressure section of the housing of the main pump to the low pressure circuit, wherein an additional pump is arranged;
• and
• a flushing branch connecting a flushing inlet of the low pressure section of the housing of the main pump to the high pressure circuit, and having a hydraulic connection with the leakage branch, wherein a pilot operated check valve is arranged in the flushing branch.

An electro-hydrostatic actuation system for driving a hydraulic actuator, comprising:

• a container for providing hydraulic liquid;
• a high pressure circuit to direct the hydraulic liquid to a hydraulic actuator;
• a low pressure circuit having multiple branches;
• a first valve and a second valve separating the high pressure circuit from the low pressure circuit;
• a main pump for the hydraulic liquid arranged in the high pressure circuit;
• the main pump comprising a housing having a high pressure section and a low pressure section, separated by sealing gaps, wherein the high pressure section comprises a first outlet and a second outlet to provide the hydraulic liquid flow in the high pressure circuit, and wherein the low pressure section comprises a leakage outlet;
• an electric motor driving the main pump;
• a leakage branch connecting the leakage outlet of the low pressure section of the housing of the main pump to the low pressure circuit, wherein an additional pump is arranged;
• a flushing branch connecting a flushing inlet of the low pressure section of the housing of the main pump to the high pressure circuit, and having a hydraulic connection with the leakage branch, wherein the flushing branch comprises a first end connected to the flushing inlet, a second end, and a third valve;
• a first control branch including a third end connected to the second end and a fourth end connected to the high pressure circuit at a first position spaced apart from the first outlet and the second outlet, the first control branch comprising a fourth valve arranged between the third end and the fourth end;
• and
• a second control branch including a fifth end connected to the second end and a sixth end connected to the high pressure circuit at a second position spaced apart from the first outlet and the second outlet, the second control branch comprising a fifth valve arranged between the fifth end and the sixth end.