Piezo-electric fluid pump

A piezo-electric hydraulic fluid pump comprising:

• a main housing including a hydraulic fluid inlet port;
• a hydraulic fluid reservoir located within the main housing;
• a piston head moveably mounted within the main housing;
• a piezo-electric stack located within the main housing, wherein the piezo-electric stack includes an internal void that comprises the hydraulic fluid reservoir, the internal void being in fluid communication with the hydraulic fluid inlet port in the main housing;
• a piston rod coupled to the piston head, wherein the piston rod extends from the piston head through the reservoir;
• a bias mechanism arranged to couple the piston head and piezo-electric stack and maintain the piezo-electric stack in compression;
• an outlet plate statically mounted within the main housing adjacent to the piston head, wherein the adjacent surfaces of the outlet plate and piston head define a pumping chamber;
• an inlet disc valve arranged to permit a one-way flow of hydraulic fluid from the reservoir into the pumping chamber;
• and
• an outlet disc valve arranged to permit a one-way flow of hydraulic fluid out of the pumping chamber,
• wherein all free space within the internal void is in fluid communication with the hydraulic fluid inlet port.

A piezo-electric hydraulic fluid pump comprising:

• a main housing including a hydraulic fluid inlet port;
• a hydraulic fluid reservoir located within the main housing;
• a piston head moveably mounted within the main housing;
• a piezo-electric stack located within the main housing, wherein the piezo-electric stack includes an internal void that comprises the hydraulic fluid reservoir, the internal void being in fluid communication with the hydraulic fluid inlet port in the main housing;
• a piston rod coupled to the piston head, wherein the piston rod extends from the piston head through the reservoir;
• a bias mechanism arranged to couple the piston head and piezo-electric stack and maintain the piezo-electric stack in compression;
• an outlet plate statically mounted within the main housing adjacent to the piston head, wherein the adjacent surfaces of the outlet plate and piston head define a pumping chamber;
• an inlet disc valve arranged to permit a one-way flow of hydraulic fluid from the reservoir into the pumping chamber;
• and
• an outlet disc valve arranged to permit a one-way flow of hydraulic fluid out of the pumping chamber,
• wherein the hydraulic fluid inlet port is arranged and configured to enable passage of working fluid entering the hydraulic fluid inlet port to contact the piezo-electric stack.

A piezo-electric hydraulic fluid pump comprising:

• a main housing including a hydraulic fluid inlet port;
• a hydraulic fluid reservoir located within the main housing;
• a piston head moveably mounted within the main housing;
• a piezo-electric stack located within the main housing, wherein the piezo-electric stack includes an internal void that comprises the hydraulic fluid reservoir, the internal void being in fluid communication with the hydraulic fluid inlet port in the main housing;
• a piston rod coupled to the piston head, wherein the piston rod extends from the piston head through the reservoir;
• a bias mechanism arranged to couple the piston head and piezo-electric stack and maintain the piezo-electric stack in compression;
• an outlet plate statically mounted within the main housing adjacent to the piston head, wherein the adjacent surfaces of the outlet plate and piston head define a pumping chamber;
• an inlet disc valve arranged to permit a one-way flow of hydraulic fluid from the reservoir into the pumping chamber;
• and
• an outlet disc valve arranged to permit a one-way flow of hydraulic fluid out of the pumping chamber,
• wherein the hydraulic fluid inlet port is arranged in fluid communication with an outer surface of the piezo-electric stack.