Insert Bearing Fixing Ring for Accurate Shaft Centering

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for fixing a rotary shaft to an insert bearing unit using set screws or collars are inefficient, requiring significant time and effort for centering, and risk misalignment and instability due to loose fits.

Innovation Solution

A fixing device with an extension ring portion and a ring body that are press-fitted into an interference-fit state, allowing for easy and accurate fixation of the rotary shaft through slits and a fastening member that radially contracts the ring body to ensure stable contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If set screws are used to fix the rotary shaft, then the rotary shaft can be secured to the insert bearing unit, but centering requires time and effort and workability is low

Engineering Contradiction:

Improvefixing reliabilityVSAvoidmounting efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The fixing device is divided into multiple set screws distributed around the circumferential direction, allowing incremental tightening rather than requiring all screws to be fastened equally. This segmentation enables progressive centering while maintaining secure fixation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fixing method transitions from a static requirement (all set screws fastened by the same amount) to a dynamic process (incremental tightening where each screw can be adjusted independently in stages), enabling easier centering and improved mounting efficiency.

Inventive Principle:

Principle #15Dynamics

2Reliability

If a collar is used to fix the rotary shaft, then the rotary shaft can be secured through radial contraction, but the collar may shift due to clearance fit and stable performance cannot be obtained

Engineering Contradiction:

Improvefixing stabilityVSAvoidmounting ease

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The collar is divided into multiple separate pieces (segments) with slits, allowing independent adjustment of each segment. This enables the segments to be pushed against and pulled toward the shaft separately, achieving accurate centering without shift while maintaining ease of operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fixing mechanism transitions from a static clearance fit that allows shifting to a dynamic segmented structure where each piece can move independently during mounting, eliminating shift while maintaining ease of installation.

Inventive Principle:

Principle #15Dynamics

3Strength

If multiple set screws are used, then the rotary shaft can be firmly fixed, but a large number of working steps are required and workability is low

Engineering Contradiction:

Improvefixing strengthVSAvoidnumber of fastening steps

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The fastening process is made dynamic and flexible, allowing set screws to be tightened incrementally in any sequence rather than following a rigid step-by-step procedure. This reduces the perceived complexity while maintaining strong fixation through multiple contact points.

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Facilitates quick and precise mounting of the rotary shaft without misalignment, reducing the need for skilled labor and ensuring stable performance of the insert bearing unit.

Implementation Method 1

The ring body (22) is press-fitted over the extension ring portion (21) of the inner ring (12). Thus, the ring body (22) and the extension ring portion (21) of the inner ring (12) are not brought into a loose-fit state but are brought into an interference-fit state.

Methodology Applied

Scientific EffectInterference fit:

Implementation Method 2

The cut-portion end surfaces are brought relatively closer to each other by fastening a fastening member to be mounted into the ring body so that a radially contracting force for radial contraction is applied to the extension ring portion (21)

Methodology Applied

Scientific EffectRadial contraction:

Implementation Method 3

a radially contracting force for radial contraction is applied to the extension ring portion (21) to bring the extension ring portion into close contact with the rotary shaft (3)

Methodology Applied

Scientific EffectClose contact through radial contraction:

Data Source

PatentUS20250207637A1Fixing device for insert bearing unit and insert bearing unit

Publication Date: 2025.06.26 NTN CORP

AI summary

A ring body configured to be fitted over the extension ring portion is provided. The ring body is a non-endless ring body having a cut portion formed in a part of the ring body. Opposed cut-portion end surfaces of the cut portion are separated from each other by a predetermined distance under a state in which the ring body is press-fitted over the extension ring portion of the inner ring. The cut-portion end surfaces are brought relatively closer to each other to radially contract the ring body by fastening a fastening member to be mounted into the ring body so that a radially contracting force for radial contraction is applied to the extension ring portion to bring the extension ring portion into close contact with the rotary shaft.