Linear Guide Block Assembly to Prevent Ball Race Steps

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Solution Overview

Problem

Miniaturization of linear motion devices leads to increased assembling difficulty due to poor precision alignment of components, resulting in improper formation of stepped structures and reduced device yield.

Innovation Solution

A linear motion device design featuring a guiding member, slide block assembly, ball race members, circulation members, and end covers with specific geometric features such as guiding bevels and stopping planes, allowing for precise positioning and assembly of components, reducing the need for precise alignment and minimizing stepped structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the linear motion device is miniaturized, then the device size is reduced, but the assembling difficulty greatly increases due to poor precision alignment of components

Engineering Contradiction:
Improvedevice sizeVSAvoidassembling difficulty
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by providing a stopping plane on the circulation member that abuts against a positioning plane on the end cover during assembly. This pre-positioning feature ensures that the end cover is accurately located relative to the circulation member before final tightening, thereby maintaining assembly precision even in miniaturized devices where tolerance accumulation is critical.

Inventive Principle:
Principle #10Preliminary action

2Volume of moving object

If the linear motion device is miniaturized, then the device size is reduced, but the manufacturing precision of component alignment deteriorates

Engineering Contradiction:
Improvedevice sizeVSAvoidcomponent alignment precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent applies self-service through the self-aligning mechanism where the stopping plane automatically guides the end cover to the correct position during assembly. The geometry of the stopping plane and positioning plane creates a self-correcting alignment system that does not require external alignment tools or complex fixture systems, thereby maintaining high manufacturing precision in miniaturized devices.

Inventive Principle:
Principle #25Self-service

3Device complexity

If conventional assembly methods are used without positioning features, then the device structure is simpler, but stepped structures form between components due to poor alignment

Engineering Contradiction:
Improveassembly structure complexityVSAvoidcomponent alignment precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent introduces a stopping plane as an intermediary positioning feature between the circulation member and the end cover. This intermediate element mediates the alignment relationship, ensuring that the end cover is precisely located relative to the circulation member without requiring complex direct mating features, thus preventing stepped structures while adding minimal complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If the end cover is assembled without a positioning mechanism, then the assembly process is faster, but the end cover and slide block cannot be aligned properly

Engineering Contradiction:
Improveassembly speedVSAvoidalignment precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The stopping plane performs preliminary positioning action during the assembly process, establishing the correct alignment between the end cover and circulation member before final fastening. This preliminary action ensures that even rapid assembly operations result in properly aligned components, thereby maintaining both high productivity and manufacturing precision.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4023898B1Linear motion device
Publication Date: 2024.07.03 LEE SZU YING
  • EP4023898B1 patent drawingFigure 1
  • EP4023898B1 patent drawingFigure 2
  • EP4023898B1 patent drawingFigure 3

AI summary

A linear motion device includes a guiding member (A) extending along a first direction and a slide block assembly (B) slidably disposed on the guiding member (A). The slide block assembly (B) includes a slide block (2), two ball race members (1) at two sides of the slide block (2), two circulation members (3) at two sides of the slide block (2) along the first direction, and two end covers (4) assembled on the circulation members (3). One or more of the circulation members (3) has two revolve channel members (32). The revolve channel member (32) has an upper protrusion member (321) and a lower protrusion member (322) protruding out of the upper protrusion member (321) in the top view of the linear motion device. Since the protruding portion of the lower protrusion member (322) can be served as the bottom surface of the revolve curve, stepped structures caused by assembling or component tolerances are not formed between the bottom surface and nearby portions, and the balls (5) can roll stably in the linear motion device.