Linear-Contact Clamping Bolt Locking for Lower Stress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing clamping devices subject locking elements to high local mechanical stresses due to small contact areas, leading to reduced reliability and durability under high clamping forces.
Innovation Solution
A clamping device design with linear contact points between locking elements and the clamping bolt, piston, and housing part, distributing load over a larger area to reduce mechanical stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If locking elements are designed as locking balls with point-like contact points, then the device complexity is reduced and ease of manufacture is improved, but the local mechanical stresses increase significantly leading to reduced reliability and durability
Solution Approach 1:
The contact point is extended from a zero-dimensional point contact (locking ball) to a one-dimensional linear contact (contact surface extending in circumferential direction). This dimensional change distributes the clamping force over a larger contact area, reducing local mechanical stresses while maintaining the locking function.
Solution Approach 2:
The geometric parameters of the locking elements are changed from spherical shape with point contact to a shape with a linear contact surface. The contact surface extends in the circumferential direction over a distance s that is at least 10% of the locking element's axial length, transforming the contact geometry to reduce stress concentration.
2Ease of manufacture
If locking elements are designed as locking balls, then the device complexity is reduced and manufacturing is easier, but the transmission of high clamping forces causes excessive local loading
Solution Approach 1:
The contact interface is extended from a point (0D) to a line (1D) by creating a linear contact surface on the locking elements that extends in the circumferential direction. This allows the same locking element geometry to withstand higher clamping forces by distributing the load along the linear contact rather than concentrating it at a point.
3Device complexity
If point-like contact points are used between locking elements and clamping bolt, then the structural simplicity is maintained, but the mechanical stresses become excessively high reducing component life
Solution Approach 1:
The contact geometry is changed from point contact to linear contact by extending the contact surface in the circumferential direction. The contact surface extends over a distance s that is at least 10% of the axial length of the locking element, creating a line contact that significantly increases the contact area and reduces wear, thereby improving durability while maintaining structural simplicity.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
To create a clamping device for clamping a clamping bolt arranged on a workpiece or on a workpiece carrier, wherein the clamping device comprises locking elements, a piston for moving the locking elements towards a longitudinal center axis of the clamping device, and a housing part, wherein in a clamping state of the clamping device in which a clamping bolt is locked in the clamping device, each of the locking elements bears against the piston, the housing part, and the clamping bolt at a contact point, which makes it possible to transmit very high clamping forces between the clamping bolt on the one hand and the locking elements of the clamping device on the other hand without subjecting these elements to excessive stress through high local mechanical stresses and thereby reducing their reliability and durability, it is proposed that the respective clamping bolt contact point,with which each locking element rests against the clamping bolt in the clamping state, is linear.