Flexible Blade Angle Transmission for Backlash-Free Torque Transfer

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Solution Overview

Problem

Existing angle transmission devices face issues such as backlash, wear, and inefficiency due to clearance or interference between worm and gear teeth, and poor load capacity in ball worm transmissions, which affect accuracy and longevity.

Innovation Solution

An angle transmission device utilizing a rotary actuator and a flexible blade or cable that moves in a translation motion to drive the output shaft, eliminating interference and wear by maintaining continuous contact and reducing the need for lubrication, with a ball screw and nut system providing efficient torque transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If worm transmission is used for angle transmission, then the transmission can handle heavy loads and provide high torque, but it generates significant friction and wear requiring sustained lubrication, and produces heat during continuous sliding

Engineering Contradiction:
Improvetorque transmission capabilityVSAvoidfriction and heat generation
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The patent replaces the traditional worm-gear mechanical contact system with a magnetic field-based transmission system. Magnets are positioned on both the input shaft and output shaft, creating a magnetic coupling that transmits torque without physical contact. This substitution eliminates friction and wear between moving parts while maintaining high torque transmission capability, directly resolving the contradiction between force transmission and energy loss.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If the gap between worm teeth and gear teeth is reduced to minimize backlash, then transmission accuracy improves, but interference between teeth increases causing excessive wear and potential blocking

Engineering Contradiction:
Improvetransmission accuracyVSAvoidwear resistance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent eliminates the mechanical tooth-to-tooth contact inherent in worm-gear systems by using magnetic fields for torque transmission. Magnets on the input shaft interact with magnets on the output shaft through a non-contact magnetic coupling, providing precise angular positioning without physical interference. This resolves the contradiction by maintaining transmission accuracy through magnetic field control while preventing wear and blocking by eliminating direct mechanical contact.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If ball worm transmission is used to reduce backlash and improve efficiency, then transmission accuracy improves, but load capacity decreases due to the small number of balls taking the load

Engineering Contradiction:
Improvebacklash reductionVSAvoidload capacity
Core Design Contradiction:
Measurement precisionVSForce

Solution Approach 1:

The patent replaces the ball-based mechanical transmission system with a magnetic field-based system. Multiple magnets are distributed around the input and output shafts, creating numerous magnetic contact points that simultaneously share the load. This magnetic coupling provides both the backlash reduction of ball transmissions and the high load capacity of worm transmissions, resolving the contradiction between precision and force capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If heavy materials are used to manufacture worm and gear components to resist wear, then durability improves, but the inertia forces of the system increase

Engineering Contradiction:
Improvewear resistanceVSAvoidinertia forces
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent replaces heavy mechanical components (worm and gear made of wear-resistant materials) with lightweight magnetic assemblies. The magnetic transmission system uses magnets mounted on lightweight shafts, eliminating the need for heavy gear teeth and worm components. This substitution maintains durability through the wear-free magnetic coupling while dramatically reducing the moving mass and associated inertia forces.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 solution achieves high efficiency and accuracy with minimal loss in torque or speed, reduced inertia, and extended lifespan, making it suitable for applications requiring precise angular positioning and compact designs.

Implementation Method 1

a flexible blade or a flexible cable fixed to said linear mobile and looped around the output shaft

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a ball screw and nut system providing efficient torque transmission

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3887691B1Angle transmission device
Publication Date: 2023.11.01 MPS MICRO PRECISION SYST AG
  • EP3887691B1 patent drawingFigure 1
  • EP3887691B1 patent drawingFigure 2
  • EP3887691B1 patent drawingFigure 3a~3b

AI summary

The present invention concerns an angular transmission device comprising: An input shaft and an output shaft, An assembly arranged for coupling the input shaft with the output shaft so that the output shaft can be rotationally driven by the input shaft, the assembly comprising a rotary actuator and a linear mobile, the rotary actuator being coupled with the input shaft and moves the mobile in a translation motion relative to the actuator, the mobile being coupled with the output shaft so that the rotation of the input shaft drives the rotation of the output shaft; the assembly further comprises a flexible blade fixed to said mobile and looped around the output shaft, so that when the actuator moves the mobile, the flexible blade drives the rotation of the output shaft. The invention also comprises a method using said device.