A Method of Calculating the Friction Moment in Cageless Bearings

2019 ◽  
Vol 40 (5) ◽  
pp. 425-430
Author(s):  
E. P. Zhilnikov ◽  
V. B. Balyakin ◽  
A. V. Lavrin
Keyword(s):  
Friction Moment

Methods and Means of Reducing Friction Moment in Face Seals

1980 ◽  
Vol 41 (5) ◽  
pp. 604-611
Author(s):  
V. B Balyakin ◽  
◽  
S. V Falaleev ◽  
Keyword(s):  
Friction Moment ◽  
Face Seals

Modeling of nonlinear torsional vibration of the automotive powertrain

2016 ◽  
Vol 24 (9) ◽  
pp. 1774-1786 ◽  
Author(s):  
Sérgio J Idehara ◽  
Fernando L Flach ◽  
Douglas Lemes
Keyword(s):  
Natural Frequency ◽  
Torsional Vibration ◽  
Degrees Of Freedom ◽  
Front Wheel ◽  
Torsional Stiffness ◽  
Bench Test ◽  
Passenger Car ◽  
Engine Torque ◽  
Friction Moment ◽  
Wheel Drive

A vibration model of the powertrain can be used to predict its dynamic behavior when excited by fluctuations in the engine torque and speed. The torsional vibration resulting from torque and speed fluctuations increases the rattle noise in the gearbox and it should be controlled or minimized in order to gain acceptance by clients and manufactures. The fact that the proprieties of the torsional damper integrated into the clutch disc alter the dynamic characteristic of the system is important in the automotive industry for design purposes. In this study, bench test results for the characteristics of a torsional damper for a clutch system (torsional stiffness and friction moment) and powertrain torsional vibration measurements taken in a passenger car were used to verify and calibrate the model. The adjusted model estimates the driveline natural frequency and the time response vibration. The analysis uses order tracking signal processing to isolate the response from the engine excitation (second-order). It is shown that a decrease in the stiffness of the clutch disc torsional damper lowers the natural frequency and an increase in the friction moment reduces the peak amplitude of the gearbox torsional vibration. The formulation and model adjustment showed that a nonlinear model with three degrees of freedom can represent satisfactorily the powertrain dynamics of a front-wheel drive passenger car.

Road Adhesion Coefficient Estimation Based on the Steering Wheel Rebound After Steering

2018 ◽  
Author(s):  
Liangyao Yu ◽  
Sheng Zheng ◽  
Xiaohui Liu ◽  
Jinghu Chang ◽  
Fei Li
Keyword(s):  
Stability Control ◽  
Front Wheel ◽  
Intelligent Vehicles ◽  
Steering Wheel ◽  
Adhesion Coefficient ◽  
The Road ◽  
Whole Process ◽  
Friction Moment ◽  
Stability Control System ◽  
The Coefficient Of Friction

Accurately estimating road adhesion coefficient is very important for vehicle stability control system. In this paper, an innovation method to estimate the road adhesion coefficient is proposed. This method can be used in vehicles without additional sensors. And this method is especially suitable to be used in the intelligent vehicle equipped with steer-by-wire (SBW) system. When vehicle steers, releasing the steering wheel suddenly will result in rebound to a certain angle. When the steer wheel turns the same angle on different road whose adhesion coefficients are different, the front wheel rebound angles are different. The friction moment between the road and tire is the main factor to prevent the tire from turning back, and the coefficient of friction is equal to road adhesion coefficient when the vehicle is stationary. In this paper, the detailed dynamical models describing the whole process of the front wheel and tire rebound are established. Furthermore, the Luenberger reduced-order disturbance observer is established to estimate the friction moment, and then the adhesion coefficient is estimated. The SBW system which is usually equipped in intelligent vehicles can control the steer moment and steer angle accurately. When the steer wheel turns to certain angle, the SBW system is able to stop outputting torque quickly and timely, which is important for improving the experiment accuracy. In this paper, the SBW system is used to conduct an experiment on different roads. The experiment results demonstrate the validity of this method.

Effect of substrate surface roughness on the wear of molybdenum disulphate coated rolling contact bearings

2021 ◽  
Vol 63 (9) ◽  
pp. 848-854
Author(s):  
Bahar Gokce ◽  
Necdet Geren ◽  
Mahmut Izciler
Keyword(s):  
High Temperature ◽  
Molybdenum Disulfide ◽  
Substrate Surface ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Wear Testing ◽  
Wear Depth ◽  
Phosphate Coating ◽  
Depth Measurement ◽  
Friction Moment

Abstract The objective of the present experimental work is to investigate the influence of subsurface roughness on the friction and wear performance of high-temperature ball bearing. Bearings, which are used in high-temperature applications, are affected by several operating conditions. Some factors under high-temperature conditions such as short grease life, thin-film thickness at low speed, and insufficient internal clearance can drastically reduce bearing service life due to an increase in surface friction. For this reason, rolling contact bearings are coated with molybdenum disulfide. Before the molybdenum disulfide (MoS2) coating, phosphatization is applied to the bearings. Because the phosphate layer is micro-porous, it assures that molybdenum disulfide is entrapped in the interstitials between the phosphates. Also, phosphate coating provides a much larger surface area for the lubricant to attach to. In this study, several process steps, sandblasting, manganese phosphate coating, molybdenum disulfide coating, friction moment testing, wear testing, wear depth measurement, SEM, and XRD analyses were carried out. Wear tests and friction moment tests were applied to the rings of bearings of varied raceway roughness. This process ultimately provides molybdenum disulfide coated bearings optimum raceway roughness parameters for good wear resistance and optimum boundary lubrication.

Belt-Drive Mechanics: Energy Losses in the Presence of Detachment Waves

2019 ◽  
Author(s):  
Yingdan Wu ◽  
Michael J. Leamy ◽  
Michael Varenberg
Keyword(s):  
Rolling Friction ◽  
Drive System ◽  
Energy Losses ◽  
Belt Drive ◽  
Interface Shear ◽  
Shear Traction ◽  
Friction Moment ◽  
The Difference ◽  
Contact Arc ◽  
Good Agreement

Abstract The dissipative rolling friction moment in a simple belt-drive system is estimated both experimentally and computationally while taking into account the detachment events at the belt-pulley interface. Shear traction is estimated based on measurements of the shear strain along the contact arc. It is shown that the dissipative moment can be approximated by taking the difference between the shear traction and the load carried by the belt. A model is developed for analyzing the contributions of different components to this dissipative moment by considering both the volumetric and surface hysteresis losses. The computed rolling friction moment is found to be in good agreement with that estimated based on the experiments. It is also found that while the shear- and stretching-induced energy losses contribute the most to the dissipation in the belt drive system, the losses associated with the Schallamach waves of detachment make up a considerable portion of the dissipation in the driver case.

scholarly journals Friction moment analysis of space gyroscope bearing with ribbon cage under ultra-low oscillatory motion

2014 ◽  
Vol 27 (5) ◽  
pp. 1301-1311 ◽  
Author(s):  
Shaona Jiang ◽  
Xiaoyang Chen ◽  
Jiaming Gu ◽  
Xuejin Shen
Keyword(s):  
Moment Analysis ◽  
Oscillatory Motion ◽  
Friction Moment

IN VIVO MEASUREMENTS OF THE FRICTION MOMENT IN TOTAL HIP JOINT PROSTHESES DURING WALKING

2012 ◽  
Vol 45 ◽  
pp. S268 ◽  
Author(s):  
Philipp Damm ◽  
Robert Ackermann ◽  
Alwina Bender ◽  
Friedmar Graichen ◽  
Georg Bergmann
Keyword(s):  
Hip Joint ◽  
Total Hip ◽  
In Vivo Measurements ◽  
Friction Moment ◽  
Joint Prostheses

scholarly journals INVESTIGATION OF MAGNETIC FIELD IMPACT UPON FRICTION MOMENT AND SEALING ABILITY OF MAGNETIC LIQUIDS

2018 ◽  
Vol 2018 (7) ◽  
pp. 56-59
Author(s):  
Сергей Шец ◽  
Sergey Shets ◽  
Александр Горленко ◽  
Aleksandr Gorlenko
Keyword(s):  
Magnetic Field ◽  
Structural Changes ◽  
Rotation Frequency ◽  
Time Factor ◽  
Magnetic Liquid ◽  
Shaft Rotation ◽  
Friction Moment ◽  
Sealing Ability ◽  
Magnetic Liquids

A magnetic field impact upon a friction moment of magnetic liquids (ML) in a “shaft-bush” joint depending upon shaft rotation frequency is analyzed. There are de-fined pressure values of magnetic liquid breakdown in a “shaft-pole terminal” gap depending upon shaft rotation frequency and a time factor. For the assessment of ML stability there is offered a factor of stability which can take into account ML structural changes in the course of time.

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