Lightweight electric robotic actuator
First Claim
1. In combination,(a) an electric robotic actuator and a modular resolver affixed to said actuator for indicating the position of a movable portion of said actuator relative to a stationary portion of said actuator;
- (b) said actuator comprising a stationary first housing, a second housing rotatably supported by said first housing, rotating means for causing said second housing to controllably rotate relative to said first housing, said rotating means comprising a motor within said housings including a stator affixed to said first housing and a rotor, said rotor coupled to said second housing through a speed reducing deep cup harmonic drive mechanism, and said second housing having a covering back plate which is provided with a centrally disposed aperture;
(c) said modular resolver comprising a first resolver portion and a second resolver portion, said modular resolver projecting at least partially into said housings through said centrally disposed aperture in said covering back plate of said second housing, removable resolver connecting means for affixing said first resolver portion to said covering back plate of said second housing, mounting means for rotatably mounting said second resolver portion relative to said first resolver portion and for maintaining said modular resolver portions in assembled relationship, slip-fit mating means which when mated rigidly connects said second resolver portion to said stationary first housing actuator portion, said modular resolver including a resolver stator affixed to said second resolver portion and a resolver rotor affixed to said first resolver portion and operable to provide an electrical signal which is an accurate indication of the rotation of said first resolver portion relative to said second resolver portion; and
said modular resolver being readily removable and replaceable on said actuator by removing said removable resolver connecting means to free said first resolver portion from said covering back plate of said second actuator housing and then moving said modular resolver out of said aperture in said covering back plate to disengage said slip-fit mating means;
whereby said resolver can readily be replaced without disassembling said actuator.
2 Assignments
0 Petitions
Accused Products
Abstract
An improved electric actuator is provided, having in association therewith a resolver. The actuator includes a stationary and a rotatable housing, and an electric motor within it. The electric motor drives the rotary housing through a speed reducing harmonic drive mechanism. The actuator has an opening in the rotary housing, and a cavity inwardly of the opening having a mating anchoring element connected with the stationary housing. A modular resolver is provided, of a shape and size to have a major portion of it occupy the cavity provided in the actuator, and having a mating part for engaging the mating part of the stationary housing, upon assemblage of the resolver to the actuator. A rotatable part of the resolver is secured to the rotary housing. A heat dissipation system is provided, including a fan mounted on a rotary member of the actuator and a closed circuit for the passage of air between the fan and a heat conductive plate forming a part of the stationary housing. Stability for the rotary housing is provided by widely spaced ball bearings supporting a rotary shaft extending from the rotary housing, the ball bearings being located at the maximum axial spacing within the stationary housing. In addition, an electromagnetic brake of lightweight construction is provided to prevent rotation of the rotary housing, and the resolver includes a coupling of the bellows type for elastic isolation from distortion of the parts, due to stresses between the fixed and rotary parts of the resolver.
53 Citations
14 Claims
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1. In combination,
(a) an electric robotic actuator and a modular resolver affixed to said actuator for indicating the position of a movable portion of said actuator relative to a stationary portion of said actuator; -
(b) said actuator comprising a stationary first housing, a second housing rotatably supported by said first housing, rotating means for causing said second housing to controllably rotate relative to said first housing, said rotating means comprising a motor within said housings including a stator affixed to said first housing and a rotor, said rotor coupled to said second housing through a speed reducing deep cup harmonic drive mechanism, and said second housing having a covering back plate which is provided with a centrally disposed aperture; (c) said modular resolver comprising a first resolver portion and a second resolver portion, said modular resolver projecting at least partially into said housings through said centrally disposed aperture in said covering back plate of said second housing, removable resolver connecting means for affixing said first resolver portion to said covering back plate of said second housing, mounting means for rotatably mounting said second resolver portion relative to said first resolver portion and for maintaining said modular resolver portions in assembled relationship, slip-fit mating means which when mated rigidly connects said second resolver portion to said stationary first housing actuator portion, said modular resolver including a resolver stator affixed to said second resolver portion and a resolver rotor affixed to said first resolver portion and operable to provide an electrical signal which is an accurate indication of the rotation of said first resolver portion relative to said second resolver portion; and
said modular resolver being readily removable and replaceable on said actuator by removing said removable resolver connecting means to free said first resolver portion from said covering back plate of said second actuator housing and then moving said modular resolver out of said aperture in said covering back plate to disengage said slip-fit mating means;
whereby said resolver can readily be replaced without disassembling said actuator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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- 13. An electric robotic actuator comprising a stationary first housing, a second housing rotatably supported about said first housing in coaxial relationship therewith, rotating means for rotating said second housing relative to said first housing, said rotating means comprising a stator on said first housing and a rotor on a rotating member within said housings, speed reducing harmonic drive means for drivably connecting said rotor to said second housing, and heat transferring means for transferring heat from within said actuator to the exterior thereof, said heat transferring means comprising a heat conductive back plate of said first actuator housing and gas circulating means for circulating gas within said housings from a source of heat energy to said heat conducting back plate, said gas circulating means comprising a fan blade affixed to said rotating member within said housings, and passage means providing an air-circulation path from said fan blade to said heat conducting back plate and return from said heat conducting back plate to said fan blade.
Specification