Linear Driver Guide Structure for Lead Screw Coaxiality

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Solution Overview

Problem

Existing linear drivers for electric furniture suffer from relative tilt between the lead screw and worm wheel, leading to power source suffocation during worm wheel rotation.

Innovation Solution

The linear driver incorporates a guide structure that ensures the coaxiality of the lead screw and worm wheel, using guide holes and/or sleeves to prevent tilting, along with supporting members and lubrication to maintain smooth movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a lead screw and worm wheel are used for linear motion transmission, then the folding and lifting functions are achieved, but relative tilt between the lead screw and worm wheel causes power source suffocation

Engineering Contradiction:
Improvefolding and lifting functionsVSAvoidpower source suffocation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A guide structure is introduced as an intermediary component between the lead screw and worm wheel. This guide structure includes a guide sleeve and guide holes that constrain the relative motion between these components, preventing tilt and ensuring proper alignment during operation, thereby resolving the reliability issue while maintaining the folding and lifting functions

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the worm wheel rotates to drive the lead screw, then linear motion is achieved, but coaxiality cannot be ensured without additional guide structures

Engineering Contradiction:
Improvelinear motion transmissionVSAvoidcoaxiality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The guide structure acts as a mediator that enforces coaxiality between the lead screw and worm wheel during rotation. The guide sleeve and guide holes provide geometric constraints that maintain proper alignment, ensuring manufacturing precision is achieved through the intermediary guide structure rather than relying solely on direct manufacturing tolerances

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If guide structures are added to ensure coaxiality, then stability is improved, but device complexity increases

Engineering Contradiction:
Improvecoaxiality stabilityVSAvoidstructure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The guide structure is designed to perform multiple functions simultaneously: it guides the lead screw, supports the worm wheel, maintains coaxiality, and prevents tilt. By making the guide structure multi-functional, the patent achieves improved stability without proportionally increasing device complexity, as a single component system handles multiple critical tasks

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4213352B1Linear driver for electric furniture, and electric furniture
Publication Date: 2025.12.10 DEWERTOKIN TECHNOLOGY GROUP CO LTD
  • EP4213352B1 patent drawingFigure 1
  • EP4213352B1 patent drawingFigure 2
  • EP4213352B1 patent drawingFigure 3~4

AI summary

Provided are a linear driver for electric furniture and electric furniture. The linear driver for electric furniture includes a housing, a worm (12) with one end extending into the housing, a worm wheel (13) disposed in the housing and meshing with the worm (12), and a lead screw (14). The lead screw (14) penetrates through the worm wheel (13) and is in threaded connection with the worm wheel (14). At least one end of the lead screw (14) extends out of the housing. At least one end of the worm wheel (3) is provided with a guide structure. The guide structure (3) is sleeved around the lead screw (14) and is in clearance fit with the lead screw (14). The guide structure (3) is fixed relative to the worm wheel (13) or the housing.