Bearings are key components in rotating machinery,which is widely used in many fields,such as CNC machines,wind turbines and induction machines.The increasingly harsh operation environment can lead to wear and tear on...Bearings are key components in rotating machinery,which is widely used in many fields,such as CNC machines,wind turbines and induction machines.The increasingly harsh operation environment can lead to wear and tear on raceways and reduce the precision and reliability of bearing or even machinery.Lubrication could relieve the wear to some degree,which is benefit to prolong the bearing’s life.Thus,investigation on the vibration responses under the influence of oil film is of great significance.However,for mechanism analysis,how to include the oil film into the bearing dynamic model affects the result and efficiency of solution.To address this problem,this study proposed a fast algorithm through load distribution and interpolation when calculating oil film stiffness and thickness during the solution of bearing vibration model.Analysis of oil film on vibration is carried out and a bearing test rig is designed to verify the proposed model.Numerical simulation result shows that rotational speed and load have vital effect on oil film and vibration.The experimental result is consistent with the simulation,which shows that the proposed model has a better performance on modeling bearing vibration and the method of considering oil film is reasonable.展开更多
The traction behavior of space lubricating oil No. 4116 was measured and analyzed at various oil inlet temperatures below 0 ℃ and various rolling speeds under normal loads by a test rig simulating the operating condi...The traction behavior of space lubricating oil No. 4116 was measured and analyzed at various oil inlet temperatures below 0 ℃ and various rolling speeds under normal loads by a test rig simulating the operating conditions of space bearings. A traction coefficient calculation model was presented. The rheological property and rheological parameters of the lubricant at a low oil inlet temperature were analyzed based on the Tevaarwerk-Johnson model. The results showed that the lubricating oil No. 4116 was sensitive to the rolling speed and had lower sensitivity to the normal load. This lubricating oil is more suitable for applications under high speed when it is used below 0 ℃. It behaves as an elastic-plastic fluid operating below 0 ℃. Both the average limiting shear stress and the average elastic shear modulus have a negative correlation with the rolling speed and oil inlet temperature and have a positive correlation with the normal load.展开更多
Bubbly oil lubrication is a type of lubrication method.However,the lubrication model of the bubbly oil has not been thoroughly considered.This paper aims to investigate the modelling for bubbly oil lubrication conside...Bubbly oil lubrication is a type of lubrication method.However,the lubrication model of the bubbly oil has not been thoroughly considered.This paper aims to investigate the modelling for bubbly oil lubrication considering the interfacial effect and thermal effect,and a theoretical model is established based on the theory of multiphase mixtures.The interfacial and thermal effects on the static characteristics of a thrust bearing are analyzed.A test rig for the thrust bearing is developed to measure the static characteristics of the bearing under bubbly oil lubrication.The results show that the bearing static characteristics,i.e.bearing temperature rise,film thickness,friction torque,and volume flow,increase with consideration of three interfacial effects;the bearing temperature rise increases but the film thickness,friction torque,and volume flow rate decrease with consideration of the three thermal effects;the thermal effect on the bearing static characteristics is greater than the interfacial effect.展开更多
基金supported by Key Program of National Natural Science Foundation of China (52035002)National Natural Science Foundation of China (51805353).
文摘Bearings are key components in rotating machinery,which is widely used in many fields,such as CNC machines,wind turbines and induction machines.The increasingly harsh operation environment can lead to wear and tear on raceways and reduce the precision and reliability of bearing or even machinery.Lubrication could relieve the wear to some degree,which is benefit to prolong the bearing’s life.Thus,investigation on the vibration responses under the influence of oil film is of great significance.However,for mechanism analysis,how to include the oil film into the bearing dynamic model affects the result and efficiency of solution.To address this problem,this study proposed a fast algorithm through load distribution and interpolation when calculating oil film stiffness and thickness during the solution of bearing vibration model.Analysis of oil film on vibration is carried out and a bearing test rig is designed to verify the proposed model.Numerical simulation result shows that rotational speed and load have vital effect on oil film and vibration.The experimental result is consistent with the simulation,which shows that the proposed model has a better performance on modeling bearing vibration and the method of considering oil film is reasonable.
基金supported by the National Science Foundation of China (Nos. 51105131 and 51475143)the Henan Provincial Key Scientific and Technological Project (No. 142102210110)the Tianjin Science and Technology Support Program
文摘The traction behavior of space lubricating oil No. 4116 was measured and analyzed at various oil inlet temperatures below 0 ℃ and various rolling speeds under normal loads by a test rig simulating the operating conditions of space bearings. A traction coefficient calculation model was presented. The rheological property and rheological parameters of the lubricant at a low oil inlet temperature were analyzed based on the Tevaarwerk-Johnson model. The results showed that the lubricating oil No. 4116 was sensitive to the rolling speed and had lower sensitivity to the normal load. This lubricating oil is more suitable for applications under high speed when it is used below 0 ℃. It behaves as an elastic-plastic fluid operating below 0 ℃. Both the average limiting shear stress and the average elastic shear modulus have a negative correlation with the rolling speed and oil inlet temperature and have a positive correlation with the normal load.
基金supported by National Natural Science Foundation of China(Nos.12172088 and 51635004).
文摘Bubbly oil lubrication is a type of lubrication method.However,the lubrication model of the bubbly oil has not been thoroughly considered.This paper aims to investigate the modelling for bubbly oil lubrication considering the interfacial effect and thermal effect,and a theoretical model is established based on the theory of multiphase mixtures.The interfacial and thermal effects on the static characteristics of a thrust bearing are analyzed.A test rig for the thrust bearing is developed to measure the static characteristics of the bearing under bubbly oil lubrication.The results show that the bearing static characteristics,i.e.bearing temperature rise,film thickness,friction torque,and volume flow,increase with consideration of three interfacial effects;the bearing temperature rise increases but the film thickness,friction torque,and volume flow rate decrease with consideration of the three thermal effects;the thermal effect on the bearing static characteristics is greater than the interfacial effect.
