Elastic rotary actuator

摘要

Rotary actuators having a final output member rotatable about an axis of rotation; a motor unit designed to drive the final output member for rotation about the axis of rotation; and an elastic unit arranged between the motor unit and the final output member and having an input member torsionally coupled to the motor unit and an output member rigidly connected for rotation with the final output member are provided.

主权项

1. A rotary actuator comprising:
a final output member rotatable about an axis of rotation; a motor unit designed to drive the final output member for rotation about said axis of rotation; and an elastic unit arranged between the motor unit and the final output member and having an input member torsionally coupled to the motor unit and an output member rigidly connected for rotation with the final output member, wherein the elastic unit comprises an elastic element and a hypocycloid mechanism designed to convert a relative rotation of the input member with respect to the final output member about said axis of rotation into elastic deformation of said elastic element along a direction of deformation, in such a way that the deformation of said elastic element varies in a non-linear manner depending on said relative rotation, wherein said elastic unit comprises a shaft as input member, a ring gear assembly as output member, a gearwheel assembly and an actuating member connected to said elastic element, wherein the shaft extends with its own axis parallel to said axis of rotation at a certain distance therefrom, wherein the ring gear assembly comprises at least one internal-tooth ring gear, the axis of which coincides with said axis of rotation, wherein the gearwheel assembly comprises at least one gearwheel freely rotatably mounted on the shaft and meshing with said at least one internal-tooth ring gear, wherein said at least one gearwheel has a number of teeth which is half the number of teeth of said at least one internal-tooth ring gear, and wherein the actuating member is hinged at a proximal end thereof to the gearwheel assembly about a hinge axis positioned on the pitch circle of said at least one gearwheel, in such a way that as a result of the rotation of the shaft, and hence of the gearwheel assembly, relative to the ring gear assembly, and hence relative to the final output member, the hinge axis about which the actuating member is hinged to the gearwheel assembly moves along said direction of deformation.