Ball Motion and Sliding Friction in an Arched Ball Bearing

2007 ◽  
Author(s):  
Alexandre Leblanc ◽  
Daniel Nelias ◽  
Daniel Plona
Keyword(s):  
Ball Bearing ◽  
Sliding Friction ◽  
Friction Model ◽  
Operating Conditions ◽  
Published Data ◽  
Contact Points ◽  
Coulomb Friction Model ◽  
Gyroscopic Effects ◽  
Non Linear System ◽  
Control Criterion

An analysis of double arched ball bearing which considers centrifugal forces and gyroscopic effects is performed. Based on operating conditions of a 5 DOF inner ring and Coulomb friction model, the conventional bearing theory is extended from 2 to 3 or 4 contact points. The commonly control criterion of ball bearing by the inner or outer raceway is debatable and is known to fit with difficulty with experimental data. In addition when more than two contact points are involved it becomes obsolete. The paper presents a mathematical model to describe the complex ball bearing internal kinematics under the effect of the external working conditions. Lubricant thickness is taken into account in geometrical equations and the non-linear system of this quasi-static model is solved by a Newton-Raphson method. The 3D model is first validated through comparisons with published data for conventional or single arched ball bearings. Results are also compared to those provided by the commercial software RBL4. The analysis of a double arched ball bearing is finally performed and the complex motion of the ball highlighted.

Ball Motion and Sliding Friction in a Four-Contact-Point Ball Bearing

2007 ◽  
Vol 129 (4) ◽  
pp. 801-808 ◽  
Author(s):  
Alexandre Leblanc ◽  
Daniel Nelias
Keyword(s):  
Ball Bearing ◽  
Sliding Friction ◽  
Contact Point ◽  
Friction Model ◽  
Operating Conditions ◽  
Published Data ◽  
Contact Points ◽  
Coulomb Friction Model ◽  
Gyroscopic Effects ◽  
Control Criterion

An analysis of double arched ball bearing, which considers centrifugal forces and gyroscopic effects, is performed. Based on operating conditions of a five DOF inner ring and Coulomb friction model, the conventional bearing theory is extended from two to three or four-contact points. The commonly used control criterion of ball bearing by the inner or outer raceway is debatable and is known to fit with difficulty with experimental data. In addition, when more than two-contact points are involved, it becomes obsolete. The paper presents a mathematical model to describe the complex ball bearing internal kinematics under the effect of the external working conditions. Lubricant thickness is taken into account in geometrical equations and the nonlinear system of this quasistatic model is solved by a Newton-Raphson method. The model is first validated through comparisons with published data for conventional or single arched ball bearings. Results are also compared to those provided by the commercial software RBL4. The analysis of a double arched ball bearing is finally performed and the complex motion of the ball highlighted.

scholarly journals Effect of Geometry and Operating Conditions on Spur Gear System Power Loss

1981 ◽  
Vol 103 (1) ◽  
pp. 151-159 ◽  
Author(s):  
N. E. Anderson ◽  
S. H. Loewenthal
Keyword(s):  
Power Loss ◽  
Ball Bearing ◽  
Large Diameter ◽  
Spur Gear ◽  
Operating Conditions ◽  
Published Data ◽  
Wide Range ◽  
Low Torque ◽  
System Power ◽  
Good Agreement

The results of an analysis of the effects of spur gear size, pitch, width and ratio on total mesh power loss for a wide range of speeds, torques and oil viscosities are presented. The analysis uses simple algebraic expressions to determine gear sliding, rolling and windage losses and also incorporates an approximate ball bearing power loss expression. The analysis shows good agreement with published data. Large diameter and fine-pitched gears had higher peak efficiencies but lower part-load efficiency. Gear efficiencies were generally greater than 98 percent except at very low torque levels. Tare (no-load) losses are generally a significant percentage of the full-load loss except at low speeds.

scholarly journals Analysis of sliding behavior of a biped robot in centroid acceleration space

Robotica ◽  
2015 ◽  
Vol 35 (3) ◽  
pp. 636-653 ◽  
Author(s):  
Taku Senoo ◽  
Masatoshi Ishikawa
Keyword(s):  
Coulomb Friction ◽  
State Transition ◽  
Sliding Friction ◽  
Biped Robot ◽  
Friction Model ◽  
Two Dimensional ◽  
Sliding Motion ◽  
Coulomb Friction Model ◽  
Sliding Dynamics ◽  
Concrete Model

SUMMARYIn this article, a two-dimensional analysis of biped robot sliding dynamics is performed. First, the dynamics of a biped robot based on feet-slip are derived using the coulomb friction model. The state transition can be formulated in the centroid acceleration space whose diagram is defined as a “triangle of sliding friction” (TSF). The TSF's characteristics are explained by focusing on comparison with the cone of friction which has a similar state decision diagram. Next, for the behavioral simulation of a concrete model, a 2-DOF biped robot is used to analyze the sliding features in terms of the asymmetry of the dynamics of each leg. Finally, the sliding characteristics are applied to the two tasks of running and somersaulting. The results show the robot takes short rapid repetitive steps for running based on frictional asymmetry and theoretically based on torque asymmetry can make one revolution using the large angular momentum acquired during sliding motion.

Dynamic Analysis of an A-Shaped Piezo-Actuated Walking Microrobot

2010 ◽  
Author(s):  
Ali Kamali Eigoli ◽  
GholamReza Vossoughi
Keyword(s):  
Power Consumption ◽  
Dynamic Analysis ◽  
Natural Frequency ◽  
Dynamic Modeling ◽  
Coulomb Friction ◽  
Translational Motion ◽  
Friction Model ◽  
Contact Points ◽  
Linear Behavior ◽  
Coulomb Friction Model

In this paper, a novel, A-shaped microrobot with nanometric resolution for precision positioning applications is addressed. The locomotion concept of the mechanism is founded on the “friction drive principle”. To achieve the translational motion, a stack piezoelectric actuates the microrobot near its natural frequency. The dynamic modeling of the mechanism is based on the assumptions of linear behavior of piezo stack actuator and Coulomb friction model at contact points. The suitability of three simple, friction-based locomotion modes for implementation on the proposed device is presented. Influences of different friction coefficients on the behavior of the microrobot, with respect to defined criteria, are invoked. Simulations show a velocity of 1 mm/s, a motion resolution of 180 nm, and a power consumption of 1.5 mW. Comparisons made with other microrobots of the same locomotion principle indicate good improvements in all criteria.

A Simplified Analytical Model of Rolling/Sliding Behavior and Friction in Four-Point-Contact Ball Bearings and Screws

2017 ◽  
Author(s):  
Bo Lin ◽  
Molong Duan ◽  
Chinedum E. Okwudire ◽  
Jason S. Wou
Keyword(s):  
Analytical Model ◽  
Contact Point ◽  
Point Contact ◽  
Contact Angles ◽  
Friction Model ◽  
Contact Forces ◽  
Ball Bearings ◽  
Contact Points ◽  
Pure Rolling ◽  
Coulomb Friction Model

Four-point contact between ball and raceways is common in machine elements like ball bearings and ball screws. The ideal four-point-contact machine element is designed with pure rolling (i.e., no sliding at contact points) to minimize friction. However, this ideal may not always be achieved, leading to sliding and higher frictional forces. In this paper, a simplified analytical model for rolling/sliding behavior and friction in four-point contact is developed, based on Coulomb friction model and rigid body assumption. It is found that pure rolling is only possible when the contact-point geometry satisfies a certain relationship. When pure rolling condition fails to hold, the sliding contact point(s) can be determined analytically as a function of contact forces and contact angles. Case studies are presented to demonstrate how the proposed model could elucidate the roles of misalignments, manufacturing errors and loading conditions on rolling/sliding behavior and friction.

Friction Force and Stresses Analysis for Contact of Assembled Details

2006 ◽  
Vol 113 ◽  
pp. 334-338
Author(s):  
Z. Dreija ◽  
O. Liniņš ◽  
Fr. Sudnieks ◽  
N. Mozga
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Plastic Deformation ◽  
Friction Force ◽  
Sliding Friction ◽  
Friction Model ◽  
Contact Interface ◽  
Finite Element Program ◽  
Elastic Plastic ◽  
Element Program

The present work deals with the computation of surface stresses and deformation in the presence of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range from fully elastic through elastic-plastic to fully plastic contact interface. Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact load and areas that have strong effect on the friction force. The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is found out and its connection with plasticity index. A finite element program for determination contact analysis of the assembled details and due to details of deformation that arose a normal and tangencial stress is used.

Analysis, Design, and Modeling of a Rotary Vane Engine (RVE)

2004 ◽  
Vol 126 (4) ◽  
pp. 711-720 ◽  
Author(s):  
B. V. Librovich ◽  
A. F. Nowakowski
Keyword(s):  
Coulomb Friction ◽  
Simple Structure ◽  
Dynamical Behavior ◽  
Friction Model ◽  
Reciprocating Engine ◽  
Torque Transmission ◽  
Analysis Design ◽  
Work Units ◽  
Coulomb Friction Model ◽  
Moving Parts

This paper introduces a mathematical model to analyze the dynamic behavior of a novel rotary vane engine (RVE). The RVE can be considered to have a number of advantages when compared to a majority of other reciprocating engine types. The advantages are found in the simple structure and the small number of moving parts. In this paper the geometrical structure and dynamical behavior of engines with a different number of work units is considered in detail. This has been examined through a study of torque transmission with a particular reference to how this is affected by the noncircular geometry of gear pitch curves. Using the Coulomb friction model, consideration has been given to the mechanical power loss due to friction in different parts of the engine, which must be taken into account. The study also proposes a possible method for balancing of asymmetric cogwheels. The analysis concludes that by using an appropriate design and arrangement of cogwheels and all moving parts, vibration can be attenuated due to impulsive gas torque.

Position Control of Hydraulic Actuators Using Fuzzy Pulse Width Modulation (PWM)

2015 ◽  
Vol 735 ◽  
pp. 294-298 ◽  
Author(s):  
Wei Ying Lai ◽  
Nurfarahin Onn ◽  
Collin Howe Hing Tang ◽  
Mohamed Hussein
Keyword(s):  
Fuzzy Logic ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Solenoid Valve ◽  
Operating Conditions ◽  
Hydraulic Actuators ◽  
Non Linear ◽  
Fuzzy Logic Approach ◽  
Logic Approach ◽  
Non Linear System

Hydraulic actuators are widely employed for industrial automation for its high power over weight ratio, functionality in tough operating conditions and low cost. However, the dynamics of hydraulic systems are non-linear and the system subjected to non-smooth and discontinuous non-linearities due to directional change of valve opening, friction, valve overlap and changes of hydraulic pressure acted on valve spool. Taking into account the effect of nonlinear parameter variations such as bulk modulus, compressibility of oil or viscosity of oil, fuzzy logic approach is chosen. Fuzzy control can adapt the inconstant working condition and non-linear system alongside of its robustness. For PWM controlled hydraulic component such as solenoid valve, effective approximation of the flow properties in a solenoid valve is essential. In this paper, the effect of fuzzy logic approach incorporated on pulse width modulation (PWM) controlled hydraulic system is to be investigated and experimentally verified.

Coupled thermo-mechanical sticking-sliding friction model along tool-chip interface in diamond cutting of copper

2021 ◽  
Vol 70 ◽  
pp. 578-592
Author(s):  
Shiquan Liu ◽  
Haijun Zhang ◽  
Liang Zhao ◽  
Guo Li ◽  
Chunyu Zhang ◽  
...  
Keyword(s):  
Sliding Friction ◽  
Friction Model ◽  
Diamond Cutting
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