Tooth friction force and transmission error of spur gears due to sliding friction

2019 ◽  
Vol 33 (3) ◽  
pp. 1311-1319 ◽  
Author(s):  
Chan IL Park
Keyword(s):  
Friction Force ◽  
Sliding Friction ◽  
Transmission Error ◽  
Spur Gears

Effect of Teeth Friction on Transmission Errors and Tooth Load of Spur Gears

2015 ◽  
Author(s):  
Chan Il Park
Keyword(s):  
Friction Force ◽  
Sliding Friction ◽  
Primary Source ◽  
Transmission Error ◽  
Spur Gears ◽  
Mesh Stiffness ◽  
Transmission Errors ◽  
Sliding Mechanism ◽  
The Moment ◽  
The Relationship

Transmission error is typically understood to act as the primary source of gearbox noise and vibration. This paper investigates the effect of sliding friction on the transmission error and tooth load of spur gears. To do so, the kinematic relation for the sliding mechanism of spur gears and mesh stiffness was calculated. The relationship between tooth load, tooth errors and mesh compliance as well as the moment balance equation in consideration of the teeth friction force are derived. Transmission error, tooth load, and the teeth friction force of gears with/without modification were investigated. As the results, friction caused an increase in tooth load and transmission error in gear approach and a decrease in tooth load and transmission error in gear recess.

The Instantaneous Friction Force for Relative Motion

2000 ◽  
Author(s):  
Don W. Perumean
Keyword(s):  
Friction Force ◽  
Relative Motion ◽  
Sliding Friction ◽  
Reference Plane ◽  
Spur Gears ◽  
Free Body Diagram ◽  
Force Equation ◽  
Coefficient Of Sliding Friction ◽  
Free Body ◽  
Two Bodies

Abstract This paper derives the free-body diagram for involute spur gears. The principles of this derivation are applicable to any two bodies moving with relative motion having a sliding contact between them. The derived free-body diagram shows that the equation for the instantaneous sliding friction force includes a term for the instantaneous percent sliding of the contact. This percent sliding term allows the equation for the instantaneous sliding friction force to express the influence of the exact relative motion that is taking place at the point of contact. The instantaneous sliding friction force equation for any two bodies moving with relative motion will include a term for the instantaneous percent sliding of the contact when observed from a third reference plane considered at rest. The derived friction force equation will require the instantaneous coefficient of sliding friction to be redefined for relative motion.

Modeling and Analysis of Sliding Friction in Gear Dynamics

2000 ◽  
Author(s):  
Manish Vaishya ◽  
Donald R. Houser
Keyword(s):  
Sliding Friction ◽  
Transmission Error ◽  
Spur Gear ◽  
Spur Gears ◽  
Parameter System ◽  
Modeling And Analysis ◽  
Gear Teeth ◽  
Lumped Parameter ◽  
Force Transmissibility ◽  
Vibration Coupling

Abstract Sliding resistance on gear teeth can have a dominant effect on housing vibration and noise, due to fluctuating excitation and high force transmissibility in the off-line of action direction. Hence reliable modeling of friction from tribological considerations, supported by experimental data, is of utmost importance. This paper examines some lubrication theories and validates them with 2-disk tests and quasi-static loaded gear tests. From the knowledge of friction characteristics, a lumped parameter system is synthesized for a pair of spur gears. This model includes sliding friction, mounting compliances and lateral-torsional vibration coupling. A different formulation has been applied, which unlike most current models, accounts for energy dissipation in the system due to friction. The influence of various excitations like transmission error, friction and parametric variations, on dynamic response of gears is investigated. Finally, the model is evaluated with dynamic tests carried out on a spur gear set, under varying conditions of torque, speed and lubricant.

Design of High Speed Gears, Low Load Gears for Minimizing Gear Whine Noise

2013 ◽  
Author(s):  
Rodney Glover
Keyword(s):  
High Speed ◽  
Sliding Friction ◽  
Transmission Error ◽  
Spur Gear ◽  
Low Noise ◽  
Spur Gears ◽  
Contact Ratio ◽  
Low Load ◽  
Gear Manufacturing ◽  
The Cost

The main purpose of the supercharger timing gears is to keep the rotors from contacting each other. They are often lightly loaded and designed for low noise. As timing gears, they have by definition a ratio of 1.0. Furthermore, the timing gears are presently spur gears due to the cost of assembling helical gears onto the rotor shafts without allowing timing errors between the rotors. The original timing gear designs were spur gears with contact ratios slightly above 2.0. A major NVH issue has been gear whine noise, because most applications are in luxury vehicles and are evaluated with the hood open and the engine at idle. In this operating condition, the background noise is very low and any tonal gear whine noise is audible. The first effort was to push the gear manufacturing quality to the limits of modern grinding capability. In order to further reduce gear whine noise, the designs have evolved to finer pitch gearing with a contact ratio over 3.0 to reduce transmission error. Micro-geometries were optimized for low transmission error (TE) at low load. OSU Gear Lab’s RMC and LDP became primary tools in optimizing the gear designs for minimum TE. An important factor when increasing the contact ratio is to not increase the sliding friction significantly to keep the fixed oil sump temperature from increasing too much and cause wear issues in operation. Typically, the new high contact ratio spur gear designs in production have reduced the gear whine levels by more than 6 dB and have had very few noise complaints.

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.

scholarly journals Calculation and AFM Experimental Research on Slip Friction for Unlubricated Spherical Contact with Roughness Effect

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1428
Author(s):  
Shengguang Zhu ◽  
Liyong Ni
Keyword(s):  
Friction Force ◽  
Sliding Friction ◽  
Static Friction ◽  
Friction Model ◽  
Rigid Sphere ◽  
Roughness Effect ◽  
Force Microscopy ◽  
Comparison Results ◽  
Experimental Values ◽  
Calculation Models

Previous research on friction calculation models has mainly focused on static friction, whereas sliding friction calculation models are rarely reported. In this paper, a novel sliding friction model for realizing a dry spherical flat contact with a roughness effect at the micro/nano scale is proposed. This model yields the sliding friction by the change in the periodic substrate potential, adopts the basic assumptions of the Greenwood–Williamson random contact model about asperities, and assumes that the contact area between a rigid sphere and a nominal rough flat satisfies the condition of interfacial friction. It subsequently employs a statistical method to determine the total sliding friction force, and finally, the feasibility of this model presented is verified by atomic force microscopy friction experiments. The comparison results show that the deviations of the sliding friction force and coefficient between the theoretical calculated values and the experimental values are in a relatively acceptable range for the samples with a small plasticity index (Ψ ≤ 1).

Low excitation spur gears with variable tip diameter

2021 ◽  
Vol 263 (5) ◽  
pp. 1275-1285
Author(s):  
Joshua Götz ◽  
Sebastian Sepp ◽  
Michael Otto ◽  
Karsten Stahl
Keyword(s):  
Transmission Error ◽  
Spur Gear ◽  
Low Noise ◽  
Spur Gears ◽  
Mesh Stiffness ◽  
Helical Gears ◽  
Axial Forces ◽  
Tooth Width ◽  
Drive Trains ◽  
Static Transmission Error

One important source of noise in drive trains are transmissions. In numerous applications, it is necessary to use helical instead of spur gear stages due to increased noise requirements. Besides a superior excitation behaviour, helical gears also show additional disadvantageous effects (e.g. axial forces and tilting moments), which have to be taken into account in the design process. Thus, a low noise spur gear stage could simplify design and meet the requirements of modern mechanical drive trains. The authors explore the possibility of combining the low noise properties of helical gears with the advantageous mechanical properties of spur gears by using spur gears with variable tip diameter along the tooth width. This allows the adjustment of the total length of active lines of action at the beginning and end of contact and acts as a mesh stiffness modification. For this reason, several spur gear designs are experimentally investigated and compared with regard to their excitation behaviour. The experiments are performed on a back-to-back test rig and include quasi-static transmission error measurements under load as well as dynamic torsional vibration measurements. The results show a significant improvement of the excitation behaviour for spur gears with variable tip diameter.

Collision of two coins on a horizontal surface

2021 ◽  
Vol 57 (1) ◽  
pp. 015009
Author(s):  
Rod Cross
Keyword(s):  
Friction Force ◽  
Sliding Friction ◽  
Static Friction ◽  
Video Camera ◽  
Horizontal Surface ◽  
Collision Process ◽  
Oblique Angle ◽  
Billiard Ball ◽  
Air Table

Abstract Oblique angle collisions of two penny coins on a smooth, horizontal surface were filmed with a video camera to investigate the physics of the collision process. If one of the coins is initially at rest, then the two coins emerge approximately at right angles, as commonly observed in billiard ball collisions and in puck collisions on an air table. The coins actually emerged at an angle less than 90 degrees due to friction between the coins, which also resulted in both coins rotating after the collision. At glancing angles, the friction force was due to sliding friction. At other angles of incidence the coins gripped each other and the friction force was then due to static friction.

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