Clamping Assembly With Roller Bearing for Higher Tightening Force

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Solution Overview

Problem

Existing clamping devices face difficulties in applying significant tightening force due to the nut rubbing against the part being tightened, which limits the clamping force and efficiency.

Innovation Solution

A clamping device with a threaded screw, an actuating element, a sleeve, and a rolling bearing that prevents the actuating element from rubbing against the part, using inclined bearing surfaces and clamping elements to distribute force radially and axially, enhancing the clamping force without rotating the sleeve during tightening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a nut is screwed onto the rod to actuate the clamping device, then the actuating unit can be simple and compact, but the nut rubs against the part to be tightened making it difficult to apply significant tightening force

Engineering Contradiction:
Improveactuating unit structureVSAvoidtightening force
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

A roller bearing is introduced as an intermediary element between the actuating nut and the workpiece. The roller bearing includes rolling elements (needles or small cylinders) that roll between the nut and the workpiece surface, eliminating direct friction contact. This allows the actuating force to be transmitted efficiently without the rubbing friction that would otherwise prevent significant tightening force application.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the actuating element directly contacts the workpiece during tightening, then the structure can be simpler, but the friction prevents application of significant tightening force

Engineering Contradiction:
Improvecontact structureVSAvoidtightening operation
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The roller bearing serves as a mediator between the actuating element and the workpiece contact surfaces. The rolling elements navigate the interface, converting sliding friction into rolling friction which is significantly lower. This enables smooth operation during tightening without the resistance that would make the operation difficult.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The direct mechanical contact and sliding friction between the actuating nut and workpiece is replaced with a rolling contact system. The roller bearing introduces a different mechanical interaction mode (rolling instead of sliding) that fundamentally changes the friction characteristics and enables effective tightening operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the actuating element rotates during tightening, then the screw mechanism can function, but the sleeve rotates unnecessarily adding complexity and reducing precision

Engineering Contradiction:
Improvetightening speedVSAvoidclamping position precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The rotational movement of the sleeve is extracted and eliminated from the tightening process. The roller bearing is designed to allow the actuating nut to rotate independently while the sleeve remains stationary, guided by the bearing's outer race. This separation of rotational and translational movements enables the screw mechanism to function without inducing unwanted sleeve rotation, maintaining positioning precision.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The solution allows for a greater clamping force to be exerted on the edges of the orifice while preventing the actuation unit from rotating the sleeve, ensuring effective clamping without excessive effort, and enabling easy loosening with an elastic ring.

Implementation Method 1

a roller bearing engaged around the screw and having rolling elements interposed between the flange and the actuating element

Methodology Applied
Scientific EffectRolling friction: Roller

Implementation Method 2

the screw head having a first inclined bearing surface and intended to be housed in the second orifice... the cylindrical body comprising a second inclined bearing surface

Methodology Applied
Scientific EffectInclined plane mechanical advantage: Inclined Plane

Data Source

PatentEP4180675B1Tightening device
Publication Date: 2024.05.15 NORELEM
  • EP4180675B1 patent drawingFigure 1
  • EP4180675B1 patent drawingFigure 2
  • EP4180675B1 patent drawingFigure 3~4

AI summary

The invention relates to a clamping device (1) for clamping a first part (2) and a second part (4) against each other, the clamping device (1) comprising: - a threaded screw (6) having a threaded shank (7) and a screw head (8) having a first inclined bearing surface (18), - an actuating element (9) having a tapped hole (10) into which a second end of the threaded shank (7) is screwed, - a sleeve (11) fitted and mounted freely for rotation around the threaded screw (6) between the screw head (8) and the actuating element (9), the sleeve (11) having a collar (13) and a cylindrical body (12) having a second inclined bearing surface (19), - at least one clamping element (15) disposed around the threaded screw (6) between the first inclined bearing surface (18) and the second inclined bearing surface (19). at least one clamping element (15) being configured to move radially,- a bearing (16) engaged around the screw and comprising rolling elements (17) interposed between the flange (13) and the actuating element (9).