Annular Spring with Symmetrical Elastic Sections for Torque Detection

Solution Overview

Problem

Conventional annular springs used in robot joint mechanisms require larger size and weight to absorb impacts effectively, making them less compact and efficient for torque detection and transmission.

Innovation Solution

An annular spring design featuring symmetrical first and second elastic sections that generate compressive or tensile stress, allowing for increased displacement without increasing size or weight, and a torque detecting device that incorporates these springs for precise strain measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the length in the axial direction and the radius are increased to achieve sufficient displacement for impact absorption, then the impact absorption capability is improved, but the size and weight of the annular spring increase

Engineering Contradiction:

Improveimpact absorption capabilityVSAvoidweight of annular spring

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent changes the stress type parameter from bending stress/torsional stress to tensile stress/compressive stress. This parameter change allows the elastic sections to achieve greater displacement for impact absorption without requiring increased length or radius, thereby maintaining a compact size and reduced weight while improving impact absorption capability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite structure with multiple elastic sections (first and second elastic sections) arranged symmetrically. This composite configuration enables the annular spring to achieve sufficient displacement for impact absorption through the combined effect of multiple sections undergoing tensile and compressive deformation, without increasing overall size or weight

Inventive Principle:

Principle #40Composite materials

2Reliability

If the length in the axial direction and the radius are increased to achieve sufficient displacement for impact absorption, then the impact absorption capability is improved, but the dimensions of the annular spring increase

Engineering Contradiction:

Improveimpact absorption capabilityVSAvoidaxial length and radius

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The patent changes the stress type parameter from bending stress/torsional stress to tensile stress/compressive stress. This parameter change allows the elastic sections to achieve greater displacement for impact absorption without requiring increased length or radius, thereby maintaining a compact size while improving impact absorption capability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite structure with multiple elastic sections (first and second elastic sections) arranged symmetrically. This composite configuration enables the annular spring to achieve sufficient displacement for impact absorption through the combined effect of multiple sections undergoing tensile and compressive deformation, without increasing overall dimensions

Inventive Principle:

Principle #40Composite materials

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

The new annular spring design enhances impact absorption and reduces size and weight, while the torque detecting device ensures high precision in torque calculation with a compact and lightweight configuration.

Implementation Method 1

the first elastic section and the second elastic section are elastically deformed in such a manner that either one of the first elastic section and the second elastic section is compressed, and the other one is stretched

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS9995357B2Annular spring, and torque detecting device and robot joint mechanism using the annular spring

Publication Date: 2018.06.12 HONDA MOTOR CO LTD

AI summary

An elastic section 13 is configured by a first elastic section 13a that has one end connected to an outer circumferential surface of an inner circumferential section 12, and the other end connected to an inner circumferential surface of an outer circumferential section 11, and a second elastic section 13b that is symmetrical to the first elastic section 13a about a line that passes through a center point P1 of the inner circumferential section 12 and a connection point P2 of the inner circumferential section 12 and the first elastic section 13a. When the outer circumferential section 11 and the inner circumferential section 12 relatively rotate, the first elastic section 13a and the second elastic section 13b are elastically deformed in such a manner that one is compressed and the other is stretched.