Study On Material And Carrying Capacity Of Slewing Bearing

With the rapid development of domestic large heavy-load machinery, the demand for slewing bearing is growing. Theoretical research of high load slewing bearing also has got certain development, which becomes more and more mature. To combine of theory and practice soon, we need to test on a turntable bearing. Carrying capacity's experimental research of slewing bearing is an important research method. With the complex contact and the large load on rolling ring of slewing bearing, the material of slewing bear is required with a high performance, especially in direct contact surface. The rolling ring surface of usual slewing bearings is hardened through induction quenching to improve its performance. In this paper, the capacity of slewing bearing has been analyzed by its contact capacity and test research. The main works are done as follows:To evaluate whether slewing bearing can meet the requirements, we must know the properties of slewing bearing materials. In this paper, Compression Test at Ambient Temperature is applied to get the yield limit of slewing bearing material. Stress-strain curves of steel 50Mn and 42CrMoa are depicted through the test data.Because the contact stress in contact area between the rolling body and rolling circle is very large, the damage is caused by the contact stress. In this paper, the allowable contact stress test is used to get allowable contact stress of steel 50Mn and 42CrMo. The interaction between rolling circle and rolling body is simulated by allowable contact stress test. The indentation depth and the corresponding load are obtained through the test. According to the test, contact stresses and the corresponding indentation depths under different force loads are gained. Next, The regression analysis is used to study the relation between the ratio of permanent deformation to bowls diameter and contact stress, and the allowable contact stress is calculated by this relationship equation. The results are compared with each other to analyze the bearing capacity.Considering that no comparison is available, the reliability of the test is limited. In order to verify the test results, the finite element model of experimental determination about allowable contact stress on turntable bearing material is established in this paper to replace experimental determination. Contact stresses and the corresponding indentation depths under different loads are gained by analyzing the finite element model. Hereafter, The regression analysis is also used to study the relation between contact stress and the ratio of permanent deformation to steel ball diameter, and another allowable contact stress is calculated by this relationship equation. Then the allowable contact stress of steel 50Mn is obtained by using the finite element method and experimental method in this paper respectively. By comparing the two results obtained above, the reliability of the finite element model is verified. Reliability of test data is also verified by different methods simultaneously.