Static Modelling and Analysis of Cross-spring Flexure Pivots with Variable Cross-section

doi:10.3901/JME.2018.13.073

Abstract

Abstract: The cross-spring flexure pivot is a type of flexure joint which has been widely used in long stroke compliant mechanisms. Due to the distributed compliance, the flexure pivot can generate a large rotation angle, however, this structure also has some disadvantages, i.e., large center shift and low support stiffness. The concept of variable cross-section flexure pivot is proposed. The performance of the flexure pivot can be changed by applying non-prismatic spring leaves since they will concentrate the deformation of the leaves near the ration center of the flexure pivot. A static deformation model of the variable cross-section flexure pivot which considered the geometric nonlinearity of the spring leaves is proposed based on the Euler-Bernoulli beam theory. The model is verified by finite element simulations, the results obtained from those two methods agree with each other very well. Moreover, the relationship between the section factor of the spring leaves and the static deformation performances of the proposed flexure pivot, i.e., rotation range, rotation stiffness, center shift and anti-interference ability are discussed by using the deformation model. The results show that the flexure pivot with variable cross-section has higher rotational accuracy compared with the conventional one.

Key words: deflection characteristics, flexure pivot, geometric nonlinearity, non-prismatic spring leaf

CLC Number:

TH12

YANG Miao, DU Zhijiang, CHEN Yi, SUN Lining, DONG Wei. Static Modelling and Analysis of Cross-spring Flexure Pivots with Variable Cross-section[J]. Journal of Mechanical Engineering, 2018, 54(13): 73-78.

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