Blind Bearing Puller With Ball Bearing Expansion to Cut Friction

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Solution Overview

Problem

Existing blind bearing pullers experience high friction between the drive bolt and collet, leading to increased force requirements for operation and reduced tool lifespan due to wear.

Innovation Solution

A separable blind bearing puller with a ball bearing as the expansion device, allowing for reduced friction and easy replacement of worn parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a tapered face expansion device is used, then the bearing can be extracted, but high friction is created between the drive bolt and collet

Engineering Contradiction:
Improvebearing extraction capabilityVSAvoidfriction force
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the conventional tapered face expansion device with a ball bearing expansion device. The ball bearing's spherical shape allows it to rotate freely between the drive bolt and collet, converting sliding friction into rolling friction. This significantly reduces the friction force generated during bearing extraction while maintaining the ability to expand the collet and grip the bearing inner surface.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The ball bearing expansion device is designed to be freely rotatable, introducing dynamic movement into the system. As the drive bolt advances, the ball bearing rotates, allowing the expansion force to be applied more efficiently. This dynamic rotation prevents the static friction that occurs with fixed tapered faces, reducing the force required to tighten the drive bolt.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a tapered face expansion device is used, then the bearing can be extracted, but the tool lifespan is reduced due to wear

Engineering Contradiction:
Improvebearing extraction capabilityVSAvoidtool lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The ball bearing's spherical geometry enables it to rotate freely, distributing wear uniformly across its surface rather than concentrating it at a single contact point. This rotational movement prevents the localized wear that occurs with tapered faces, significantly extending the tool's service life while maintaining extraction capability.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The ball bearing is designed as a separable, replaceable component. When wear does occur, the ball bearing can be easily replaced without replacing the entire tool assembly. This approach is more economical than using a non-separable tapered face design where wear would compromise the entire tool's functionality.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If a non-separable expansion device is used, then the tool structure is simpler, but the expansion device cannot be easily replaced when worn

Engineering Contradiction:
Improvetool structureVSAvoidexpansion device replaceability
Core Design Contradiction:
Device complexityVSEase of repair

Solution Approach 1:

The expansion device is segmented into separable components: the ball bearing is a distinct element that can be independently removed and replaced from the collet assembly. This segmentation maintains relatively simple tool structure while enabling easy maintenance. The ball bearing can be extracted through the collet without disassembling the entire tool, providing a practical balance between structural simplicity and repairability.

Inventive Principle:
Principle #1Segmentation

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

Reduces operational force requirements and extends tool lifespan by evenly distributing wear through the use of a freely rotating ball bearing expansion device.

Implementation Method 1

a ball bearing can rotate freely so that wear is more evenly distributed as it is free to turn, rather than being locked into one position

Methodology Applied
Scientific EffectRolling friction: Friction

Data Source

PatentEP4650108A1Separable blind bearing puller
Publication Date: 2025.11.19 MOTION PRO INC
  • EP4650108A1 patent drawingFigure 1
  • EP4650108A1 patent drawingFigure 2~3
  • EP4650108A1 patent drawingFigure 4~5

AI summary

A separable blind bearing puller, having a main body assembly having a collet and a drive bolt and an expansion device, which is separable from the main body assembly, where the expansion device is preferably a ball bearing.