Abstract: A tandem electrohydrostatic actuator (70) broadly includes a first piston (22) operatively arranged in a first cylinder (23), and a second piston (24) operatively arranged in a second cylinder (25). The pistons are coupled to move together. The first piston has a small extend area (35) and a large retract area (36). The second piston has a large extend area (38) and a small retract area (39). The large areas (36, 38) of the pistons are equal to one another and the small areas (35, 39) of the pistons are equal to one another. A reversible fixed-displacement first pump (45) has equal inlet and outlet flows supplied to the small areas of the first and second pistons, respectively. A reversible fixed-displacement second pump (40) has equal inlet and outlet flows supplied to the large areas of the first and second pistons, respectively. The total volume of the fluid in the actuator remains constant at all positions of the pistons.

Abstract: A tandem electrohydrostatic actuator (70) broadly includes a first piston (22) operatively arranged in a first cylinder (23), and a second piston (24) operatively arranged in a second cylinder (25). The pistons are coupled to move together. The first piston has a small extend area (35) and a large retract area (36). The second piston has a large extend area (38) and a small retract area (39). The large areas (36, 38) of the pistons are equal to one another and the small areas (35, 39) of the pistons are equal to one another. A reversible fixed-displacement first pump (45) has equal inlet and outlet flows supplied to the small areas of the first and second pistons, respectively. A reversible fixed-displacement second pump (40) has equal inlet and outlet flows supplied to the large areas of the first and second pistons, respectively. The total volume of the fluid in the actuator remains constant at all positions of the pistons.