Friction Power Loss of Mineral and Synthetic Lubricants in a Running Engine

1978 ◽  
Author(s):  
F. L. Badiali ◽  
A. A. Cassiani Ingoni ◽  
G. Pusateri
Keyword(s):  
Power Loss ◽  
Friction Power ◽  
Synthetic Lubricants

Reducing friction power losses of flywheel energy storage systems using PTFE composites: A technical note

2019 ◽  
Vol 233 (10) ◽  
pp. 1616-1621
Author(s):  
Shuyun Jiang ◽  
Yujiang Qiu
Keyword(s):  
Energy Storage ◽  
Power Loss ◽  
Magnetic Bearing ◽  
Technical Note ◽  
Flywheel Energy Storage ◽  
Power Losses ◽  
Spiral Groove ◽  
Friction Power ◽  
Ptfe Composites ◽  
Spiral Groove Bearing

This technical note aims to reduce friction power loss of flywheel energy storage system (FESS) supported by hydrodynamic spiral groove bearing and permanent magnetic bearing (PMB). An approach is proposed to fabricate the spiral groove bearing using polytetrafluoroethylene (PTFE) composite. A test rig is developed to test tribological properties of the spiral groove PTFE bearings. Also, two PTFE composites (C-PTFE: 80 vol.% PTFE filled with 20 vol.% graphite; C-Cu-PTFE 50 vol.% PTFE filled with 20 vol.% graphite and 30 vol.% copper powder) are tested. Results show that the friction power losses of the C-PTFE and C-Cu-PTFE bearings are lower than that of the traditional albronze (CuAl) bearing in the whole speed range. In addition, the spiral groove PTFE bearings show an excellent friction-reducing property under boundary or mixed lubrication condition. Finally, a case study is given to show the spiral groove PTFE bearing is capable of reducing the friction power loss of the FESS.

Design and optimization of textures on the surface of crankpin bearing to improve lubrication efficiency and friction power loss of engine

2020 ◽  
pp. 135065012094200
Author(s):  
Zhenpeng Wu ◽  
Vanliem Nguyen ◽  
Vanquynh Le ◽  
Xuanlong Le ◽  
Vancuong Bui
Keyword(s):  
Power Loss ◽  
Asperity Contact ◽  
Bearing Surface ◽  
Film Pressure ◽  
Oil Film ◽  
Design And Optimization ◽  
Friction Power ◽  
Study Results ◽  
The Impact ◽  
Oil Film Pressure

The study proposes a design and optimization of textures on the surface of crankpin bearing to improve the lubrication efficiency and friction power loss (LE-FPL). A hydrodynamic lubrication model of crankpin bearing considering the impact of the external dynamic load and micro asperity contact is established. Based on the established model, the lubrication textures designed on the bearing surface are then simulated and optimized through the algorithms developed in Matlab environment and multi-objective optimization method. Increasing the oil film pressure and reducing the contact force ( Wac) in the asperity contact region, friction force ( Ff), and friction coefficient ( µ) of crankpin bearing are the objective functions to evaluate the LE-FPL. The study results indicate that the lubrication textures designed on the bearing surface have an obvious effect on improving the LE-FPL. Especially, with the optimized textures, the maximum oil film pressure is greatly increased by 44.8% while the maximum values of Wac and Ff are significantly reduced by 22% and 25%. Consequently, the lubrication textures added on the surface of crankpin bearing can greatly improve the LE-FPL.

Power Loss of Slipper within Axial Piston Pump

2015 ◽  
Vol 779 ◽  
pp. 3-12
Author(s):  
Ze Bo Wang ◽  
Ji Hai Jiang ◽  
Yi Sun
Keyword(s):  
Power Loss ◽  
Friction Pair ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Factors Affecting ◽  
Friction Power ◽  
Swash Plate ◽  
Model Of Friction ◽  
Friction Surfaces ◽  
Axial Piston

The pair between slipper and swash-plate is an important friction pair in the axial piston pump. Due to quick relative velocity, alternating load, numerous slippers, and high contact pressure between the friction surfaces, the wear-out and fatigue failure constantly occurs, which is one of the key factors affecting reliability of the piston pump. It is of fundamental significance to investigate the mechanism of slipper power loss and to find an appropriate method to improve the lubrication of the slipper. Here, the model of friction power loss between slipper and swash-plate is established, and the friction power loss between slipper and swash-plate is solved and comparatively analysed. Finally, the correctness of theoretical analysis and simulation results are verified by experiments.

scholarly journals Study on the Thermal Distribution Characteristics of High-Speed and Light-Load Rolling Bearing Considering Skidding

2018 ◽  
Vol 8 (9) ◽  
pp. 1593 ◽  
Author(s):  
Junning Li ◽  
Jiafan Xue ◽  
Zhitao Ma
Keyword(s):  
Temperature Distribution ◽  
Power Loss ◽  
High Speed ◽  
Roller Bearing ◽  
Transient Temperature ◽  
Rolling Bearings ◽  
Slip Ratio ◽  
Friction Power ◽  
Thermal Distribution ◽  
Light Load

Skidding, which frequently occurs in high-speed rolling bearings, has a significant effect on the thermal distribution and service reliability of the bearings. An improved theoretical model of friction power loss distribution in high-speed and light-load rolling bearings (HSLLRBs) considering skidding is established, and the effects of various operating parameters on the friction power loss are investigated. The results show that the friction power loss of the inner ring and outer ring as well as the total friction power loss of the bearing increase as the slip ratio increases, but that the friction power loss of the cage guide surface and roller oil churning show a reverse trend. In addition, the increase in inner ring speed and kinematic viscosity leads to an increase in bearing friction power loss. The steady and transient temperature field distribution of HSLLRBs is obtained by the finite element method (FEM), and the results show that the inner ring raceway has the highest temperature, whereas the cage has the lowest. The temperature distribution test rig of a full-size roller bearing is constructed, and the influence mechanism of the slip ratio, rotation speed, load, lubrication, and surface topography on the bearing temperature distribution are obtained. The experimental results are consistent with the theoretical results, which also validates the theoretical method.

The Study of Friction Power Loss of Piston Group of a Twin-Rotor Engine

2014 ◽  
Vol 620 ◽  
pp. 375-381 ◽  
Author(s):  
Jin Zhou Chen ◽  
Cun Yun Pan ◽  
Wen Min Li ◽  
Lei Zhang ◽  
Hu Chen
Keyword(s):  
Power Loss ◽  
Mechanical Efficiency ◽  
Scientific Basis ◽  
Low Friction ◽  
Frictional Loss ◽  
Friction Power ◽  
Rotary Engine ◽  
Piston Group ◽  
Higher Power ◽  
Asperity Contacts

Compared with the conventional piston engines, the new rotary engine has many significant advantages, such as smaller volume and higher power density. Current studies at home and abroad are mainly focusing on aspects of its structural design, kinematics, dynamics analysis, except mechanical efficiency. In conventional piston engines, frictional loss of the piston group accounted for 65% of the total friction power loss[1]. In order to provide the scientific basis for designing low friction piston of the rotary engine, this paper combine the average two-dimensional Reynolds equation, the asperity contacts equation, viscosity-temperature equation and loads balance equation, proposing a method for calculating the friction power loss, and the applying the method to calculate the friction power loss of piston group of a new rotary engine.

A New Computational Method of the Friction Power Loss of Spiral Bevel Gears of a Helicopter Reducer

ICTE 2015 ◽  
2015 ◽  
Author(s):  
Yuan Li ◽  
Jiehong Yuan ◽  
Lijun Song ◽  
Guiming Mei ◽  
Kunlun Zhang ◽  
...  
Keyword(s):  
Power Loss ◽  
Computational Method ◽  
Spiral Bevel Gears ◽  
Friction Power ◽  
Bevel Gears ◽  
Spiral Bevel

Thermal insulation effect on EHL of coated cam/tappet contact during start up

2018 ◽  
Vol 70 (6) ◽  
pp. 917-926 ◽  
Author(s):  
Xianghui Meng ◽  
Changya Yu ◽  
Youbai Xie ◽  
Benfu Mei
Keyword(s):  
Thermal Insulation ◽  
Power Loss ◽  
Elastohydrodynamic Lubrication ◽  
Cold Start ◽  
Content Type ◽  
Friction Power ◽  
Warm Start ◽  
Start Up ◽  
Lubrication Performance ◽  
Insulation Effect

Purpose This paper aims to investigate the lubrication performance of cam/tappet contact during start up. Especially, the thermal insulation effects of coating on the lubrication performance during cold start up process and warm start up process are studied. Design/methodology/approach A numerical model for the analysis of thermal elastohydrodynamic lubrication of coated cam/tappet contact is presented. In this model, the Reynolds equation and the energy equations are discretized by the finite difference method and solved jointly. Findings During start up, the contact force at cam nose-to-tappet contact decreases with increasing time, while the absolute entrainment velocity has the upward trend. The minimum film thickness, maximum average temperature and friction power loss increase with increasing time, while the coefficient of friction decreases during start up. Because of the thermal insulation effect, the coating can significantly increase the degree of temperature rise. Compared with the uncoated case, the coated cam/tappet results in a lower friction power loss. Generally, the friction power loss in the cold start up process is much higher than that in the warm start up process. Originality/value By this study, the lubrication performance and the kinematics and the dynamics of the cam/tappet during start up process are investigated. Meanwhile, the thermal insulation effect of coating is also illustrated. The difference of lubrication performance between cold start up process and warm start up process is analyzed. The results and thermal elastohydrodynamic lubrication method presented in this study can be a guidance in the design of the coated cam/tappet.

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