Stress Analysis Of Low-speed And Heavy-load Sliding Bearing Of Mechanical Press

Sliding bearing is widely used in the rotary transmission mechanism of mechanical equipment because of its excellent mechanical properties, and has a great effect on the stability and accuracy of transmission mechanism.At present, most of the analysis of the sliding bearing is based on the hydrodynamic lubrication theory, but for the low-speed and heavy-load sliding bearing, its impossible to form the full lubricant oil slick due to its low speed and heavy load. Hence, it is not in fluid lubrication state, but in the state of mixed lubrication, therefor its not appropriate to analysis the slow-speed and heavy-load sliding bearing based on the theory of hydrodynamic lubrication. For the slow-speed and heavy-load sliding bearing,because its load is relatively large, the lubrication condition is complex and the coefficient of friction is large, it resulted in the stress distribution of the bearing is inhomogeneous and lead to reduce wear and fatigue crack of part of the bearing, this will seriously affect the accuracy of rotary transmission mechanism. Therefore, stress-strain analysis should be used to the low-speed and heavy-load sliding bearing, and analysis the effects of various factors on it, to improve the capacity of the bearing and make the stress distribution more homogeneous, to reduce the stress concentration phenomenon and the friction coefficient of the bearing, in order to reduce the incidence of wear.In this paper, the low-speed and heavy-load sliding bearing installed on the spindle servo press was studied, the distribution of stress-strain of the bearing was analyzed combined with the finite element theory, and effect of various factors on it were also studied, in order to learn about the stress distribution of the low-speed and heavy-load sliding bearing, and discussed the inhomogeneous stress distribution phenomenon of the bearing. The distribution of contact pressure of the bearing was measured by contacted pressure experiment. The main research contents and results are as follows:1 The finite element model of the low-speed and heavy-load sliding bearing was established, and the stress-strain distribution of the bearing was obtained.The FEM result shows that the working area in the bearing is middle part of the bearing, the stress distribution was inhomogeneous and the stress concentration phenomenon exist.2 By studying the effected of several factors on the bearing’s stress, such as thickness, the gap value and assembly interference etc, the effect of them on the bearing stress distribution is obtained, and proposed the improvement of the homogeneous of the stress distribution of the bearing.3 The steel backing carbon fiber polymer lining layer bearing was analyzed, obtained its stress-strain distribution, and analyzed the effect of the elastic modulus, thickness and other factors of the layer on the stress distribution of the bearing, and analyzed the contact stress of the composite lining alloy layer and steel matrix.4 The contacted pressure experiment was carried out to test the contact pressure between bearing and shaft by using Fuji pressure sensitive paper, through this experiment to learn more about the stress distribution of the low-speed and heavy-load sliding bearing. It was found that the contact pressure experimental results and finite element analysis results are very similar, and verify the accuracy of the finite element analysis results.The stress-strain distribution of the low-speed and heavy-load sliding bearing was obtained by the studying above, indicating that stress distribution of the low-speed and heavy-load sliding bearing was inhomogeneous, and the effect of several factors on the stress distribution of the bearing was obtained; through the contacted pressure experiment to learn more about the stress distribution of the bearing, and verify the accuracy of the finite element analysis model, provide a new method for the analysis of bearing.