US 4,787,270 A · Robotic manipulator

Abstract

An improved robotic manipulator of the type having a plurality of serially-connected drive shafts and a mounting surface affixed to one end thereof. The manipulator includes a first shaft rotatable about a first axis coincident with one ordinate of a mutually perpendicualr triordinate system and a first housing rotatable about that first axis, a second shaft rotatably mounted to said first shaft for rotation about a second axis obliquely oriented with respect to said first axis, and a second housing rotatable on the first housing about a second axis. Rotational movement is imparted to the second shaft about the second axis in accordance with rotational movement of a shaft rotatable about the first axis. A mounting surface has a centerline angularly oriented with respect to the second shaft, and a third shaft upon which the mounting surface is attached is rotatable about a third axis angularly oriented with respect to the second axis. An axis bearing cylinder is substantially immovably mounted on the second housing parallel to the second axis, with such axis bearing cylinder extending partially inwardly into the first housing and providing support for a gear cluster arrangement substantially independent support for a gear cluster arrangement produces a stiffer drive train, helps control backlash, and simplifies assembly.

Claims19

Dependent claims

An improved robotic manipulator of the type having a plurality of serially connected drive shafts and a mounting surface affixed to one end thereof, said manipulator including a first shaft rotatable about a first axis coincident with one ordinant of a mutually perpendicular triordinant system and a first housing rotatable about said first axis, a second shaft rotatably mounted to said first shaft for rotation about a second axis obliquely oriented with respect to said first axis and a second housing rotatable on said first housing about said second axis, means for imparting rotational movement to said second shaft about the second axis in accordance to rotational movement of a shaft rotatable about said first axis, the mounting surface having a centerline angularly oriented with respect to said second shaft, and a third shaft upon which said mounting surface is attached, said third shaft being rotatable about a third axis angularly oriented with respect to said second axis, wherein the improvement comprises:

an axis bearing cylinder substantially immovably mounted parallel to said second axis, said axis bearing cylinder having a first end mounted on said second housing and a second end extending partially inwardly into said first housing and said bearing cylinder being cantilever mounted to provide sole support, independent of said first housing means, for a gear cluster arrangement for transferring rotational input to said third shaft.

An improved robotic manipulator of the type having a plurality of serially connected drive shafts and a mounting surface affixed to one end thereof, said manipulator including a first shaft rotatable about a first axis coincident with one ordinant of a mutually perpendicular triordinant system, a second shaft rotatably mounted to said first shaft for rotation about a second axis obliquely oriented with respect to said first axis, means for imparting rotational movement to said second shaft about the second axis in accordance to rotational movement of a shaft rotatable about said first axis, a mounting surface having a centerline angularly oriented with respect to said second shaft, and a third shaft upon which said mounting surface is attached, said third shaft being rotatable about a third axis angularly oriented with respect to said second axis, wherein the improvement comprises:

(a) a stationary housing located adjacent said end of said serially connected drive shafts;
(b) a rotatable housing corresponding to said stationary housing and being rotatably affixed thereto, said rotatable housing being rotatable relative said stationary housing about said second axis, said third shaft being rotatably mounted on said rotatable housing;
and
(c) an axis bearing cylinder substantially immovably cantilever mounted parallel to said second axis, on said rotatable housing, said axis bearing cylinder extending partially inwardly into said stationary housing and said bearing cylinder being cantilever mounted to provide sole support, independent of said stationary housing, for a gear cluster arrangement transferring rotational input to said third shaft.

1 more element

An improved robotic manipulator of the type having a plurality of serially connected drive shafts and a mounting surface affixed to the distal end thereof, said manipulator including a first shaft rotatable about a first axis coincident with one ordinant of a mutually perpendicular triordinant system, a second shaft rotatably mounted to said first shaft for rotation about a second axis obliquely oriented with respect to said first axis, means for imparting rotational movement to said second shaft about the second axis in accordance to rotational movement of a shaft rotatable about said first axis, a mounting surface having a centerline angularly oriented with respect to said second shaft, and a third shaft upon which said mounting surface is attached, said third shaft being rotatable about a third axis angularly oriented with respect to said second axis, wherein the improvement comprises:

(a) a substantially spherical wrist joint located adjacent the distal end of said drive shafts, said wrist joint further comprising a stationary, substantially hemispherical housing and a rotatable, substantially hemispherical housing which is to be rotatably affixed to said stationary housing;
(b) said mounting surface being affixed to said rotatable housing and said third shaft being rotatably mounted on said rotatable housing;
and
(c) an axis bearing cylinder substantially immovably cantilever mounted, concentric with said second axis, on said rotatable housing, said axis bearing cylinder extending partially inwardly into said stationary housing and said bearing cylinder being cantilever mounted to provide sole support, independent of said stationary housing for a gear cluster arrangement transferring rotational input to said third shaft.

1 more element

Dependencies are inferred from the claim text.

Robotic manipulator

Life of this patent

Robotic manipulator

Life of this patent

Abstract

Claims19