STRAIN WAVE GEARBOX WITH OVER-TORQUE PROTECTION

Number: 20220186787
Published: 2022-06-16
Filed: 2020-12-10
Assignee: DISNEY ENTERPRISES, INC.
Inventors: Thompson; Kyle Robert, LaValley; Scott Christopher
CPC: F16H49/001; F16D11/14; F16D7/024; F16H35/10
Verdict: High Hardware
Source: Google Patents · FreePatentsOnline

The keeper's note

Strain-wave gearbox actuator hardware with over-torque protection (robot/animatronic actuator component).

Abstract

A strain wave gearbox configured to provide over-torque protection. The strain wave gearbox is designed to include a clutch that is at least partially housed within or positioned inside the internal space (herein labeled a chamber or void space interchangeably with internal space) of a flex spline. In some cases, the internal space is utilized to generate the preload for the clutch, and it may be used to provide room for a clutch preload subassembly. The clutch is located outside the flex spline's internal space and is formed to use geometric friction surfaces in the form of mating rings of teeth on mating surfaces or sides of the first and second clutch plates that once preloaded by the clutch preload subassembly require a greater torque than the design torque to rotate to the next tooth.

Background

BACKGROUND 1. Field of the Description

The present invention relates, in general, to design, manufacture, and use of strain wave gearboxes, and, more particularly, to a new design for a strain wave gearbox that is configured to provide over-torque protection. 2. Relevant Background

In robotics and other applications, there is a need to protect the actuator or drive mechanism from damage. Damage to the actuator may occur, in the robot example, from the robot falling or from many other unplanned over-torque conditions. In many mechanical system designs, including but not limited to robots, the actuator or drive mechanism may be at the core of the device and be difficult to replace due to their location in the device. The actuator may also contain very expensive parts such as torque measuring devices making repair and replacement costly and undesirable.

A conventional approach to providing torque protection for actuators is to use industrial clutches. Unfortunately, though, these off-the-shelf clutches are typically very large, and, as a result, these are not useful as such clutches (which operate in the desired torque ranges) are often larger than the entire actuator. For example, robotic devices or robots often are designed to make use of actuators that are quite small and torque dense.

Strain wave gearing, also known as harmonic gearing, is a type of mechanical gear system that can improve certain characteristics compared to traditional gearing sys

Claims

1. A strain wave gearbox with over-torque protection, comprising: a circular spline; a wave generator disposed within the circular spline; a flex spline with a sidewall disposed between the circular spline and the wave generator, wherein the sidewall encloses a chamber; a housing mechanical ground; and a clutch assembly mechanically coupling the flex spline to the housing mechanical ground, wherein the clutch assembly includes a clutch and a preload subassembly for preloading the clutch and wherein the preload subassembly is disposed within the chamber. || 9. A strain wave gearbox with over-torque protection, comprising: a flex spline; mechanical ground; and a clutch coupling the flex spline to the mechanical ground, wherein the clutch comprises a first clutch plate mechanically coupled to an output of the flex spline and a second clutch plate coupled to the mechanical ground, wherein a contact surface of the first clutch plate mates with a contact surface of the second clutch plate, wherein each of the contact surfaces is circular in shape and includes a plurality of teeth, and wherein the teeth in the contact surfaces have matching geometries, whereby the teeth in the contact surfaces are meshed together when the clutch is engaged or seated. || 16. A strain wave gearbox with over-torque protection, comprising: a circular spline; a wave generator disposed within the circular spline; a flex spline at least partially disposed between the circular spline and the wave generator; an output shaft; and a clutch assembly coupling an output of the flex spline to the output shaft, wherein the clutch assembly includes a clutch with mating first and second contact surfaces each comprising a plurality of geometric friction elements, wherein the clutch assembly further includes a preload subassembly applying a preload force the clutch, and wherein the preload subassembly is disposed within a void space within the flex spline.