scholarly journals Structural Design and Friction Performance Test of a New Conical Groove Friction Disks in Wet Clutch

2021 ◽  
Vol 11 (16) ◽  
pp. 7231
Author(s):  
Yanzhong Wang ◽  
Kai Yang ◽  
Xiangyu Wu
Keyword(s):  
Friction Coefficient ◽  
Performance Test ◽  
Calculation Model ◽  
Friction Torque ◽  
Constant Speed ◽  
Equivalent Radius ◽  
Speed Test ◽  
Friction Disk ◽  
Wet Clutch ◽  
Friction Performance

Wet clutch transmits its power by the friction torque between friction and separate disks. Conical groove friction disk is a new attempt in Wet clutch. Its configurations allow significant enhancement of torque delivery performances, compared with the traditional plane friction disk. In order to study the frictional performances of the conical groove friction configuration, the friction coefficient calculation model of conical groove friction disk was established, and experimental investigation was used to measure the friction coefficient under sliding velocity conditions. The influence of configuration parameters: cone heights and angles on friction coefficients were evaluated in a typical variable speed test. The results indicated that configuration parameters can affect friction performance in a constant speed period. The equivalent radius can directly describe the friction region of a conical groove friction disk. The constant speed test can be a useful method.

The calculation model of the friction torque on a dry clutch

2017 ◽  
Vol 231 (13) ◽  
pp. 1796-1805 ◽  
Author(s):  
Xiaohua Lin ◽  
Junqiang Xi ◽  
Shengqiang Hao
Keyword(s):  
Finite Element ◽  
Friction Coefficient ◽  
Surface Temperature ◽  
Calculation Model ◽  
Friction Torque ◽  
Force Model ◽  
Clamping Force ◽  
Temperature Model ◽  
Load Characteristic ◽  
Dry Clutch

The influencing factors of the friction torque on a dry clutch are analysed, the load characteristic of a diaphragm spring is modified and the clutch clamping force model is established by using the modified load characteristic. Also, the friction coefficient model is analysed and established on the basis of the sliding speed, the pressure and the surface temperature of clutch plates using a designed friction coefficient bench. Then, the temperature model of the friction plates is obtained by the finite element programming method, and the calculation model of the friction torque on a dry clutch is constructed on the basis of the above-mentioned models. By using an automobile powertrain bench, it is verified that the friction torque calculation model helps to determine the accuracy of the friction torque on the clutch.

The Tribological Characteristics of Cu-Based Friction Pairs in a Wet Multidisk Clutch Under Nonuniform Contact

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Er-hui Zhao ◽  
Biao Ma ◽  
He-yan Li
Keyword(s):  
Friction Coefficient ◽  
Test Bench ◽  
Friction Torque ◽  
Thermal Buckling ◽  
Tribological Characteristics ◽  
Total Output ◽  
Contact Ratio ◽  
Output Torque ◽  
Wet Clutch ◽  
Comprehensive Test

This work is devoted to investigate the effects of thermal buckling on the tribological characteristics of a Cu-based wet clutch by artificially modifying friction pairs into different contact ratios. A thermal lubrication model is provided, and corresponding experiments are conducted on the wet clutch comprehensive test bench. The friction results from measurements and simulations for such modified friction pairs are analyzed. The results show that, as the contact ratio reduces, surface temperature rises obviously, and friction coefficient increases dramatically, so that local friction torque and total output torque grow significantly. In addition, the vibration of the output torque becomes more severe as the contact ratio reduces. Therefore, the nonuniform contact after thermal buckling exacerbates the friction characteristics of friction pairs severely and accelerates the failure of wet clutches.

Real-Time Measurement of Friction Coefficient in the Frictional Performance Test of Brake Disk

2008 ◽  
Vol 373-374 ◽  
pp. 484-487
Author(s):  
Xiao Jing Huo ◽  
Rui Qing Zhang ◽  
Hui Wang ◽  
Dong Ping Qian ◽  
Jia Xu Teng
Keyword(s):  
Friction Coefficient ◽  
Data Acquisition ◽  
Real Time ◽  
High Speed ◽  
Performance Test ◽  
Friction Material ◽  
Friction Torque ◽  
Time Data ◽  
Brake Disk ◽  
Frictional Performance

Development and optimizing of friction material formula, oriented to improve the service life and security of brake disk, is largely based on advanced measurement method to accurately provide the friction coefficient. In this study, virtual instrumentation technique was used to design an automation measurement system of friction coefficient. With proper sensors, data of four measured variables such as temperature, rotation speed, pressure and friction torque are acquired by the computer combined with a plug-in data acquisition board. The system work principle, selection of sensors, multi-channel sampling, signal processing and anti-jamming measures have been presented in detail. Those functions of the software such as real-time data acquisition, dynamic wave displaying, high-speed report saving and inquiry, and so on, have been realized by LabWindows/CVI 7.1. The system works safely with high accuracy and friendly user interface in practical operation.

Research on the Relationship between Bionic Surface Friction Coefficient and Interface Medium

2013 ◽  
Vol 712-715 ◽  
pp. 387-390
Author(s):  
Bo Xu ◽  
Zhou Yu Fu ◽  
Zhao Yang Sun
Keyword(s):  
Friction Coefficient ◽  
Coal Particle ◽  
Friction And Wear ◽  
Performance Test ◽  
Surface Friction ◽  
Conveyor Belt ◽  
Bionic Surface ◽  
Tree Frogs ◽  
Friction Performance ◽  
The Relationship

The convex structure on tree frogs foot pats provide huge adsorption force, we can extract this facture of tree frogs foot pats, and apply on the surface of belt conveyor drum encapsulation in order to increase friction between drum and conveyor belt. But the environment underground is complex. There is always has coal particle and water on the frictional contact surface. The friction performance test was done by MMW-1A universal friction and wear tester in order to verify the friction coefficient of bionic surface under different conditions. At last, we figure out that water or coal particle has little influence on bionic friction surface, but has huge influence on common surface.

scholarly journals Effects of operating and material parameters on the thermal characteristics of a wet clutch

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110341
Author(s):  
Zhigang Zhang ◽  
Ling Zou ◽  
Hang Liu ◽  
Yonglong Chen ◽  
Benzhu Zhang
Keyword(s):  
Heat Flux ◽  
Applied Pressure ◽  
Thermal Characteristics ◽  
Thermal Models ◽  
Material Parameters ◽  
Heat Transfer Theory ◽  
Friction Disk ◽  
Viscous Shear ◽  
Wet Clutch ◽  
Transient Thermal

Based on the frictional mechanism of a wet clutch, frictional models of wet clutch engagement were established using the modified Reynolds equation and the elastic contact model between frictional pairs. Then, the heat flux models for the viscous shear and asperity friction were built, and the two-dimensional transient thermal models for the separator plate, friction disk, and ATF heat convection model were deduced based on the heat transfer theory and conservation law of energy. Finally, the Runge–Kutta numerical method was used to solve the frictional and thermal models. The average temperature of the separator plate, friction disk, and ATF were calculated. The effects of operating and material parameters, such as applied pressure, initial angular velocity, friction lining permeability, surface combined roughness RMS, equivalent elastic modulus, and ATF flow, on the thermal characteristics of friction pairs and ATF during engagement, were studied. The simulation results show that the temperature characteristics of the separator plate, friction disk, and ATF depend mainly on the viscous shear and asperity friction heat flux, and that the operating and material parameters of the wet clutch also have significant impacts on the overall variation trend of the thermal characteristics of the separator plate, friction disk, and ATF.

scholarly journals Influence of the Temperature of Lubricating Oil on the Friction Torque of Cu-based Wet Clutch

2020 ◽  
Vol 56 (20) ◽  
pp. 155
Author(s):  
YU Liang ◽  
MA Biao ◽  
CHEN Man ◽  
ZHANG Cunzhen ◽  
WU Junfeng
Keyword(s):  
Friction Torque ◽  
Lubricating Oil ◽  
Wet Clutch

Study of MoS2-Ti Composite Coatings Applied in Precision Ball Bearings

2012 ◽  
Vol 538-541 ◽  
pp. 281-285
Author(s):  
Hui Zhou ◽  
Jun Zheng ◽  
Ji Xing Hu ◽  
Rui Peng Sang ◽  
Zhi Hua Wan
Keyword(s):  
Storage Time ◽  
Performance Test ◽  
Composite Coatings ◽  
Test Chamber ◽  
Friction Torque ◽  
Solid Lubrication ◽  
Ball Bearings ◽  
Unbalanced Magnetron Sputtering ◽  
Unbalanced Magnetron ◽  
High Humidity Environment

708C Ball bearings were made of 9Cr18 steel which had precision of class 4, MoS2-Ti composite coatings were deposited on inner and outer races of ball bearings by unbalanced magnetron sputtering system, and bearing cages were made of PTFE-based self-lubricating polymers. Bearing’s tribological torques as a function of storage time in high humidity environment were studied by using LHU-2 thermal & humidity test chamber and Bearing 2000 torque measurement device. Developing bearing vacuum performance test rig to research bearing’s torque as a function of running time, bearings were dismantled after test and using XPS to analyze the surfaces of bearing’s races and balls. The results show that storied in the environment of 30°C, 85% RH, bearing’s running torques increased proportionally as the storage time went on. When run-in the bearings which were storied for 440 days, the start and average running torques of bearings could come back to the level which was the same as the test start, but the fluctuation of bearing’s average running torque increased. Running in one direction at the speed of 650 r/min, in vacuum environment (~10-4Pa) and ambient temperature, tested bearings showed good running performance with low friction torque varied only between 1g·cm~2 g·cm until to the test ended at 1.872×108 revolutions. XPS analysis showed that a stable and sustainable solid lubrication system was established among bearing’s races, balls and cages.

Experimental study on the friction stability of paper-based clutches concerning groove patterns

2019 ◽  
Vol 72 (4) ◽  
pp. 541-548 ◽  
Author(s):  
Liang Yu ◽  
Biao Ma ◽  
Man Chen ◽  
He Yan Li ◽  
Jikai Liu
Keyword(s):  
Experimental Study ◽  
Surface Temperature ◽  
Design Methodology ◽  
Automatic Transmission ◽  
Applied Pressure ◽  
Friction Torque ◽  
Content Type ◽  
Rotating Speed ◽  
Wet Clutch ◽  
Transmission Fluid

Purpose This paper aims to study and compare the friction stability of wet paper-based clutches with regard to the radial grooves (RG) and waffle grooves (WG). Design/methodology/approach This paper presents an experimental study of a wet clutch concerning the effect of groove patterns on the friction torque and surface temperature. The friction stabilities of RG and WG are investigated with the applied pressure, rotating speed and automatic transmission fluid (ATF) temperature taken into consideration. Findings The friction torque and surface temperature of WG are larger than those of RG under the same operating condition. The friction torque difference between RG and WG grows with the increase of applied pressure and narrows with the increase of ATF temperature. Additionally, their temperature difference expands via increasing the rotating speed and ATF temperature or reducing the applied pressure; in this way, not only the variable coefficient difference between RG and WG can be narrowed, but also the friction stability of the clutch can be improved dramatically. Originality/value This paper explains the thermodynamic differences between RG and WG; moreover, it is verified experimentally that WG has a better friction stability than RG.

Experimental study on friction performance of damaged interface in steel-concrete composite beam connected by high-strength bolt

2020 ◽  
pp. 136943322094720
Author(s):  
Ying Xing ◽  
Ya-ning Xu ◽  
Qi Guo ◽  
Jin-feng Jiao ◽  
Qing-wei Chen
Keyword(s):  
Experimental Study ◽  
Friction Coefficient ◽  
Composite Beam ◽  
Structural Characteristics ◽  
Concrete Strength ◽  
Steel Structures ◽  
High Strength ◽  
Steel Strength ◽  
Bare Steel ◽  
Friction Performance

Although traditional steel-concrete composite beam has excellent structural characteristics, it cannot meet the requirement of quick disassembly and repair in the bridge. This article presents an experimental study on friction performance of damaged steel-concrete interface in recoverable composite beam connected by high-strength frictional bolts. A total of 21 specific split tests were carried out using different concrete strength, steel strength, and surface treatment of steel. The experimental results showed that the demountable high-strength frictional bolt used in composite beam has similar performance as in the bare steel structures. The initial friction coefficient and slip stiffness were measured to be 0.34–0.47 and 52.3–116.1 kN/mm, respectively. Friction performance of damaged interface was obtained, proving that friction coefficient and slip stiffness will not decrease after the first slip damage. It is also confirmed that shot blasted steel and concrete with higher strength were more suitable in the demountable composite beam.

Calculation Model of Punch Force during Tube Extrusion

2011 ◽  
Vol 704-705 ◽  
pp. 273-276
Author(s):  
Zhong Tang Wang ◽  
Guang Xia Qi ◽  
Fang Wang ◽  
Shi Hong Zhang
Keyword(s):  
Experimental Study ◽  
Friction Coefficient ◽  
Calculation Model ◽  
Extrusion Force ◽  
Calculation Formula ◽  
Slab Method ◽  
Punch Force ◽  
Tube Extrusion ◽  
Relative Errors ◽  
Theoretical Results

] Theoretical calculation formula of punch force during tube extrusion has been proposed by means of slab method. On the basis of theoretical and experimental study, it is found that theoretical results of extrusion force given by the calculating formula approached to that of the experiment, and the relative errors are less than 20％. It is also found that the extrusion force is closely related to deformation temperature, lubricant and the ratio of extrusion. The calculating formula of extrusion force is given by considering the factors which are the conical angle of die, and the friction coefficient between the deformation zone and the extrusion container, and the friction coefficient between the undeformed zone and the mandrel. Key Words: Tube, Extrusion, Force, Physical model

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