Gear Device Axial Movement Control via Carrier Design

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Solution Overview

Problem

Conventional gear devices without a built-in main bearing face issues with abnormal wear due to relative shifts of internal gear pins and external gears, and they require additional components like snap rings to regulate movement, leading to increased complexity and potential breakage.

Innovation Solution

A gear device design featuring an outer cylinder with pin grooves longer than the internal gear pins, where the carrier regulates the axial movement of both internal gear pins and oscillating gears, eliminating the need for snap rings and reducing the risk of abnormal wear by ensuring a stable contact area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If snap rings are provided to regulate the movement of internal gear pins in the axial direction, then the movement of internal gear pins is controlled, but the number of components increases

Engineering Contradiction:
Improvemovement control of internal gear pinsVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the snap rings from the gear device structure. Instead of using separate snap ring components to regulate axial movement, the design integrates the movement regulation function directly into the carrier structure through precisely positioned through-holes that guide the internal gear pins, thereby controlling pin movement without increasing component count

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the movement regulation function with the carrier structure. The carrier is designed with through-holes that simultaneously serve as mounting positions for internal gear pins and as guides for their axial movement, combining multiple functions into a single integrated component rather than using separate snap rings

Inventive Principle:
Principle #5Merging (Combining)

2Manufacturing precision

If the relative shift amount of internal gear pins and oscillating gear is large, then dimensional errors are absorbed, but the contact width and contact area decrease causing abnormal wear

Engineering Contradiction:
Improveabsorption of dimensional errorsVSAvoidcontact area stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention changes the geometric parameters of the carrier by designing through-holes with specific dimensions and positions. The through-holes are sized and positioned to allow controlled axial movement of internal gear pins within a predetermined range, enabling dimensional error absorption while maintaining sufficient contact width and area to prevent abnormal wear

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces dynamic adjustment capability through the through-hole design. The internal gear pins can move axially within the through-holes to compensate for dimensional variations, creating a dynamic system that adapts to manufacturing tolerances while maintaining stable contact conditions between gear pins and oscillating gear

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2733383B1Gear device
Publication Date: 2017.08.09 NABTESCO CORP
  • EP2733383B1 patent drawingFigure 1
  • EP2733383B1 patent drawingFigure 2
  • EP2733383B1 patent drawingFigure 3

AI summary

Provided is a gear device capable of resolving inconveniences such as abnormal wear that arises due to the relative misalignment between the internal gear pins and the external gear, and inhibiting an increase in the number of components. This gear device 1 has an outer cylinder 2, internal gear pins 3, and a carrier 4. A plurality of pin grooves 13 extending in the axial direction of the outer cylinder 2 are formed on the inner peripheral face of the outer cylinder 2, and the internal gear pins 3 are fitted in the pin grooves 13. The pin grooves 13 are formed so that the length of the pin grooves 13 becomes longer than the length of the internal gear pins 3. The carrier 4 has a pair of pressing members 7 which includes a pressing surface 7c. The pressing surface 7c is configured to regulate movement of the internal gear pins 3 and an oscillating gear 6 which includes external teeth 6a in the axial direction.