Abstract: Taking an HSR15A rolling linear guide as a research object， its elastic deformation under the conditions of pre-loading and thermal deformation is analyzed on the basis of Hertz contact theory. The geometric relationship of the deformation of the rolling linear guide’s joint surfaces is established， and the theoretical model for the influence of thermal deformation of joint surfaces on contact stiffness is derived. The temperature distribution of the rolling linear guide under different vertical loads and the influence of thermal deformation on the guides’s stiffness are analyzed by using the finite element software. The results show that with the increase of vertical load， the stiffness of the upper raceway increases gradually， while the stiffness of the lower raceway decreases and the equivalent stiffness decreases also; the stiffness of the rolling linear guide can be reduced by thermal deformation， and the influence of the thermal deformation on the stiffness becomes more and more significant with the increase of vertical load.

Key words: rolling linear guide, contact stiffness, thermal deformation, theoretical model, vertical load