Research On Wear Characteristics Of Friction Pairs Of Large Size-low Speed-heavy Spherical Bearings

Large size spherical bearings play an important role in the support of large equipment,and can effectively complete the transfer of force and movement.Large spherical bearings in engineering are generally under complex working conditions such as heavy load,low speed,poor lubrication and environmental pollution,such as mushroom head-bearing bush at the bottom hinge of miter gate.The failure forms of this kind of bearings include fatigue spalling,wear,plastic deformation,corrosion,and electric corrosion,among which wear is one of the main reasons for the failure of large spherical bearings.The wear failure is mainly affected by the pairing material of friction pair,lubrication mode,rotational speed and load size.Based on the large end of miter gate pivot friction pair as the research object,on the self-made wear simulation test bench for wear test,based on the research of the spherical bearing wear measurement methods,combined with the 3 d surface morphology and wear product features such as shape,composition and element content analysis,discusses in the spherical bearing wear characteristics under different working conditions.Specific research contents are as follows:(1)A measurement and calculation method for measuring the surface wear of large spherical bearings based on the multi-notch measurement method is proposed.The relationship between the number of scratches and the measurement accuracy of wear was obtained by theoretical calculation,and the relationship was verified by wear tests.The relationship between the number of scratches and the friction pairs with different diameters was given.The results show that when the radius is fixed,the error between the wear quantity obtained by this method and the true value decreases with the increase of the number of marks.When the number of scratches increases to a certain value,the wear amount tends to be stable,and the relationship between the size of spherical radius and the number of scratches is fitted.It provides an accurate and feasible method for the field measurement of wear of large spherical bearings.(2)The variation curve between the wear surface morphology of the sample and the test parameters was obtained,and the characterization parameters such as skewness,arithmetic mean deviation,average height,maximum height,maximum peak height,maximum valley depth and arithmetic square root were calculated.Through the analysis of such parameters and the variation law of rotational speed and load,the arithmetic square root was obtained as the best characterization parameter,and the characterization relationship between the parameter and the test parameters was fitted.(3)Using ferrography technology,the wear products under the condition of grease lubrication of the gate bottom hinge friction pair were analyzed.The wear characteristics under different test conditions were obtained by combining the size,surface morphology and color of the wear particles with the wear quantity.The results show that the main wear types of the gate bottom hinge friction pair are adhesive wear,accompanied by cutting wear.