Wrist driving structure for industrial robot

Abstract

A wrist driving structure for an industrial robot having: a first wrist element supported in cantilever fashion rotatably about a first axis; a second wrist element pivotally supported in cantilever fashion at a distal end side of the first wrist element with a proximal end as a supporting point about a second axis intersecting the first axis; a third wrist element supported in cantilever fashion at a distal end side of the second wrist element rotatably about a third axis intersecting the second axis; two driving motors provided in the first wrist element for driving the second wrist element and the third wrist element, respectively; and two gear sets for reducing a rotational speed of the two driving motors in predetermined reduction ratios. Each of the gear sets has a driving gear driven by one of the two driving motors and a driven ring gear which meshes with the driving gear. Two driven ring gears of the two gear sets are disposed coaxially with the second axis. Two driving gears of the two gear sets are positioned parallel to each other at both sides of the second axis.

Description

technical field [0001] The present invention relates to an industrial robot wrist drive structure provided with a wrist unit which is independently rotatable around mutually intersecting rotation axes and has three degrees of freedom of rotation. Background technique [0002] In general, industrial robots are handled in such a way that many wrist units that move freely with an allowable degree of freedom and pipelines such as electric wires connected to the wrist unit are prevented from interfering with adjacent robots and external devices. In order to improve the production efficiency of the production line in the factory, it is an effective method to arrange more robots in a limited space. For this reason, it is required to provide a robot with a small wrist unit and the pipeline does not extend to the outside of the wrist unit. Industrial robots for out-of-ground processing. [0003] Japanese Patent Application Laid-Open No. 2005-96073 discloses an example of a pipeline ...

AI Technical Summary

Problems solved by technology

In addition, since the moment of inertia of the wrist unit increases when the wrist unit is heavy, there is a problem that it is difficult to improve the responsiveness of the control beyond a certain level.

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