Standardized rotary actuator
View Patent ↗A rotary actuator incorporating a shell, an output plate and a cross-roller bearing retaining the output plate within the shell. A prime mover, disposed within the shell, exerts torque on a gear train within the shell. A pair of gears, disposed on either side of the cross-roller bearing, mesh with one or more gears in the geartrain. Depending on the application, the geartrain may be a planetary epicyclic or an eccentric hypocyclic type.
1. A rotary actuator comprising:
an actuator shell;
an eccentric cage, disposed within the actuator shell;
a prime mover having a first prime mover portion rigidly fixed to the actuator shell and a second prime mover portion, rotatable with respect to the first prime mover portion, rigidly fixed to the eccentric cage, and capable of exerting a torque on the first prime mover portion;
a cross-roller bearing having a first bearing portion rigidly fixed to the actuator shell and a second bearing portion, free in rotation with respect to the first bearing portion;
an output attachment plate rigidly fixed to the second bearing portion;
a shell gear rigidly fixed to the actuator shell;
an output gear rigidly fixed to the output attachment plate;
an eccentric, disposed about the eccentric cage, having a first gear portion meshed to the shell gear and a second gear portion, adjacent to the first gear portion, meshed to the output gear;
a first structural link rigidly attached to the actuator shell using by quick-change attachment structure; and
a second structural link rigidly attached to the output attachment plate by quick-change attachment structure.
2. The rotary actuator of claim 1 wherein each of the quick-change attachment structures comprises a first radial groove in the structural link, a second radial groove, adjacent to the first radial groove, in the mating portion of the rotary actuator and a radial clamp, extending about the circumference of the first and second radial grooves.
3. The rotary actuator of claim 1 wherein the first structural link is attached to the actuator shell immediately adjacent to the cross-roller bearing and the second structural link is attached to the output attachment plate immediately adjacent to the cross-roller bearing.
4. The rotary actuator of claim 1 wherein one or more of the first and second gear portions employs gear teeth having a circular profile.
5. The rotary actuator of claim 4 wherein the gear teeth having a circular profile are dimensioned to have a slight interference.
6. The rotary actuator of claim 5 wherein one or more of the gear teeth having a circular profile have a cavity disposed therein in order to reduce the stiffness of the gear teeth.
7. The rotary actuator of claim 1 wherein 10 or more gear teeth within one or more of the first and second gear portions are in contact at any point in time.