Abstract: A linear actuator includes a housing; a motor module that includes a motor; and a drivetrain module coupled to the motor module. The drivetrain module includes a ball screw coupled to the motor, a ball nut coupled to and configured to linearly ride on the ball screw during rotation of the ball screw, a rod coupled to the ball nut and configured to extend or retract from the housing based on the ball nut linearly riding on the ball screw during rotation of the ball screw, and an anti-rotation bushing coupled to the rod and including at least one slot configured to engage with and linearly ride on a key coupled to an inner surface of the housing based on the ball nut linearly riding on the ball screw during rotation of the ball screw. The anti-rotation bushing is further configured to restrain the rod against rotation during extension and retraction.

Abstract: Embodiments of a series elastic actuator (SEA) disclosed herein include an elastic component coupled in series with a motor, wherein the elastic component comprises a pair of springs arranged concentrically around a central shaft of the housing for transmitting force to a mechanical ground of the SEA, and one or more spring support mechanisms arranged within an inner circumference of the springs. Some embodiments of the SEA may also include a spring deflection sensor, which is coupled within a recess formed within the mechanical ground of the SEA and configured to sense the force transmitted to the mechanical ground of the SEA.

Abstract: Embodiments of a series elastic actuator (SEA) disclosed herein include an elastic component coupled in series with a motor, wherein the elastic component comprises a pair of springs arranged concentrically around a central shaft of the housing for transmitting force to a mechanical ground of the SEA, and one or more spring support mechanisms arranged within an inner circumference of the springs. Some embodiments of the SEA may also include a spring deflection sensor, which is coupled within a recess formed within the mechanical ground of the SEA and configured to sense the force transmitted to the mechanical ground of the SEA.