Linear Motion Guide Rail Meshing Using Circular Hole Racks

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Solution Overview

Problem

Existing linear motion guide apparatuses require complex involute gears, making it time-consuming and difficult to provide guide rails with a meshing portion that engages with a gear.

Innovation Solution

The meshing portion is formed as a plurality of circular holes on the guide rails, allowing for easy installation and simplification of the gear engagement mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If involute gears are used for the meshing portion, then the strength and reliability of the gear engagement is improved, but the manufacturing complexity and time required to provide guide rails with the meshing portion increases significantly

Engineering Contradiction:

Improvegear engagement reliabilityVSAvoidease of providing meshing portion to guide rail

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The meshing portion is segmented into multiple circular holes arranged in a specific pattern on the guide rail, rather than using a continuous involute gear structure. This segmentation allows each hole to be independently formed through simple drilling or punching operations, significantly reducing manufacturing complexity while maintaining engagement functionality through the collective arrangement of multiple holes

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention replaces the expensive and time-consuming involute gear structure with simple circular holes that can be formed using basic machining operations. The circular holes serve as a simplified, cost-effective alternative that achieves the necessary engagement function without requiring complex gear manufacturing processes

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Strength

If involute gears are used for the meshing portion, then the strength of the racks and pinion is secured, but the time and effort required to manufacture and assemble the guide rails increases greatly

Engineering Contradiction:

Improvestrength of racks and pinionVSAvoidtime to provide guide rails with meshing portion

Core Design Contradiction:

StrengthVSLoss of time

Solution Approach 1:

The circular holes are pre-formed on the guide rail in a specific arrangement that enables proper engagement with the gear. This preliminary action of creating the hole pattern allows for rapid assembly of the gear mechanism without requiring time-consuming on-site gear manufacturing or complex fitting operations

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

By dividing the meshing portion into multiple discrete circular holes, the manufacturing process can be completed quickly using standard drilling or punching equipment, eliminating the need for prolonged gear shaping operations while maintaining sufficient structural strength through the distributed hole arrangement

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP4286702B1Linear motion guiding device

Publication Date: 2026.01.07 THK CO LTD

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AI summary

A linear motion guide apparatus in which a guide rail can be readily provided with a meshing portion that meshes with a gear is provided. The linear motion guide apparatus includes: two guide rails (2 and 3) that are movable relative to each other in a longitudinal direction thereof via at least one rolling element; and a cage configured to hold the rolling element and rotatably hold a gear (13) engaging with a meshing portion (2b, 3b) provided to at least one of the two guide rails (2 and 3). The meshing portion (2b, 3b) includes a plurality of circular holes (18) arranged in the longitudinal direction on the guide rail (2, 3). Each of the circular holes (18) has a wall surface (18a) formed in a cylindrical shape.