Flexible Meshing Gear Torque Sensing via Deformable Tooth Ring

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Solution Overview

Problem

In existing bending meshing type gear devices, the distortion gauge is typically attached to the outer periphery of the fixing frame of the internal gear, resulting in insufficient torque detection accuracy due to the location being less prone to distortion caused by the torque from the internal gear.

Innovation Solution

The bending meshing type gear device incorporates an easily deformable portion within the first internal tooth member, where the distortion gauge is strategically placed to detect the distortion caused by torque, thereby enhancing torque detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the distortion gauge is attached to the outer periphery of the fixing frame of the internal gear, then the device structure is simple, but the torque detection accuracy is insufficient

Engineering Contradiction:
Improvetorque detection accuracyVSAvoiddevice structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating a specific easily deformable portion within the internal tooth member structure. This portion has different mechanical properties (higher deformability) compared to the rest of the structure, allowing distortion to concentrate at this specific location where the gauge can effectively measure it, while maintaining overall structural integrity and simplicity.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If the distortion gauge is attached to the outer periphery of the fixing frame, then the device size is compact, but the detection accuracy is insufficient due to location

Engineering Contradiction:
Improvedistortion detection accuracyVSAvoidgauge positioning effectiveness
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent changes the mechanical parameter of the internal tooth member by introducing an easily deformable portion with specific dimensional characteristics (thickness t1 smaller than other portions). This parameter change creates a localized region that exhibits different deformation behavior under torque, enabling accurate distortion measurement while maintaining compact device dimensions.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If an easily deformable portion is added to the internal tooth member, then torque detection accuracy improves, but the manufacturing complexity increases

Engineering Contradiction:
Improvetorque detection accuracyVSAvoidmanufacturing complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent segments the internal tooth member into distinct portions with different functional characteristics: a main body structure and an easily deformable portion. This segmentation allows the deformable portion to be designed and manufactured as a integrated feature of the tooth member, using standard machining processes to create the varying thickness profile, thereby avoiding excessive manufacturing complexity while achieving improved measurement accuracy.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration allows for satisfactory torque detection by positioning the distortion gauge at a location where distortion is more likely to occur, while minimizing gear meshing errors and enabling device miniaturization.

Implementation Method 1

a distortion gauge (416) which is provided in the easily deformable portion (414)

Methodology Applied
Scientific EffectDistortion detection: Deformation

Data Source

PatentEP4130512B1Flexible meshing type gear device
Publication Date: 2025.05.14 SUMITOMO HEAVY IND LTD
  • EP4130512B1 patent drawingFigure 1
  • EP4130512B1 patent drawingFigure 2
  • EP4130512B1 patent drawingFigure 3~4

AI summary

Provided is a bending meshing type gear device which enables satisfactory torque detection. Therefore, a bending meshing type gear device 1 includes a wave generator 30A, an external gear 33 flexibly deformed by the wave generator, and an internal gear 41 meshing with the external gear. The internal gear includes an internal tooth ring portion 412 having an internal tooth 411 formed on an inner periphery, an external connection portion 413 connected to an external member, an easily deformable portion 414 provided between the internal tooth ring portion and the external connection portion, and configured to be more easily deformable than the internal tooth ring portion, and distortion measurement means 416 provided in the easily deformable portion.