Stepping Motor Guide Slot Segmentation Reduces Friction

Solution Overview

Problem

Stepping motors face challenges in precise control due to external impacts and high friction loads caused by guide configurations, which affect the movement of the moving part coupled with the lead screw.

Innovation Solution

The design incorporates guide protrusions on the moving part with different heights and corresponding guide surfaces on the bracket, minimizing the friction area by ensuring contact only on specific sides, such as top or bottom surfaces, to guide the moving part along the side surfaces of the bracket.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a guide slot is configured to come in contact with both top and bottom portions of a guide protrusion to prevent the moving part from moving, then the moving part is constrained effectively, but the friction area between the guide slot and guide protrusion increases greatly

Engineering Contradiction:

Improveconstraint stabilityVSAvoidfriction load

Core Design Contradiction:

Stability of the object's compositionVSForce

Solution Approach 1:

The guide slot is divided into multiple contact regions: a first contact region at the top, a second contact region at the bottom, and a third contact region at the side. The guide protrusion is segmented into corresponding first, second, and third contact portions. This segmentation allows different portions to contact at different positions, reducing the overall friction area while maintaining constraint stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the guide slot have different contact characteristics. The first contact region contacts the first contact portion, the second contact region contacts the second contact portion, and the third contact region contacts the third contact portion. This local differentiation optimizes the friction characteristics at each contact point while maintaining overall constraint effectiveness.

Inventive Principle:

Principle #3Local quality

2Device complexity

If the moving part is coupled only by the lead screw, then the structure is simple, but the moving part may be easily moved by external impact and difficult to be precisely controlled

Engineering Contradiction:

Improvestructure simplicityVSAvoidcontrol precision

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The guide protrusion and guide slot structure acts as an intermediary between the moving part and the bracket. This intermediary component provides additional constraint and guidance, preventing the moving part from being easily displaced by external impacts while maintaining precise control through the lead screw mechanism.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stability of the object's composition

If a guide configuration with great friction area is used to prevent moving part movement, then constraint is effective, but the friction load becomes very high

Engineering Contradiction:

Improveconstraint effectivenessVSAvoidfriction energy loss

Core Design Contradiction:

Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The guide slot is divided into multiple contact regions: a first contact region at the top, a second contact region at the bottom, and a third contact region at the side. The guide protrusion is segmented into corresponding first, second, and third contact portions. This segmentation allows different portions to contact at different positions, reducing the overall friction area while maintaining constraint stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the guide slot have different contact characteristics. The first contact region contacts the first contact portion, the second contact region contacts the second contact portion, and the third contact region contacts the third contact portion. This local differentiation optimizes the friction characteristics at each contact point while maintaining overall constraint effectiveness.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3145062B1Stepping motor

Publication Date: 2019.01.02 LG INNOTEK CO LTD

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AI summary

Provided is a stepping motor which includes a bracket, a stator and a rotor disposed at the bracket, a lead screw of which both ends are fixed to the bracket, and rotating while coupled to the rotor, and a moving part coupled to the lead screw and guided along a side surface of the bracket to move, wherein guide protrusions are formed at both side surfaces of the moving part, the bracket includes guide slots formed at side surfaces and into which the guide protrusions are inserted, and the guide slots are formed to have heights higher than those of the guide protrusions, thereby providing an advantageous effect of minimizing friction contact.