The Influence of Geometrical Parameters on the Friction Process in the Needle Bearing

2011 ◽  
Vol 490 ◽  
pp. 288-295
Author(s):  
Jerzy Nachimowicz ◽  
Robert Korbut
Keyword(s):  
Contact Area ◽  
Ball Bearing ◽  
Sliding Friction ◽  
Friction Pair ◽  
Rolling Friction ◽  
Geometrical Parameters ◽  
Friction Process ◽  
Motion Resistance ◽  
Initial Clearance ◽  
Analogical Process

The article analyses the process of friction in the needle bearing as the function of the alterations of geometrical parameters, namely the diameter of the shaft – D, the needle – d and the bearing clearance. The change in the relation between the diameters D and d results in the change of the contact area of the friction pair; in the case of two shafts with parallel axes (the needle of the bearing and the shaft pin) the contact area, if compared with the analogical process in the ball bearing, alters significantly and leads to resistance in motion. There are two types of friction in the needle bearing: the rolling friction and the sliding friction; the analysis of the movement of the bearing elements enabled the estimation of the extent to which the sliding friction matters in the overall balance of motion resistance. The article also defines the type of wear as the function of initial clearance.

Rolling Friction in MEMS Ball Bearings: The Effects of Loading and Solid Film Lubrication

2007 ◽  
Author(s):  
M. McCarthy ◽  
B. Hanrahan ◽  
C. Zorman ◽  
R. Ghodssi
Keyword(s):  
Contact Area ◽  
Ball Bearing ◽  
Sliding Friction ◽  
Rolling Resistance ◽  
Rolling Friction ◽  
Experimental Conditions ◽  
Solid Film ◽  
Frictional Forces ◽  
Film Lubrication

The effects of loading and solid film lubrication on rolling friction in MEMS-fabricated ball bearing structures are investigated in this paper. An in-situ non-contact experimental procedure was used to measure the frictional forces transmitted through a linear ball bearing system. The test devices consist of two silicon plates with deep-etched rectangular trenches acting as the housing for 285μm diameter steel microballs. The dynamic friction is measured with respect to relative velocity for several normal loads and it is observed that the frictional force increases linearly with microball contact area. Additionally, test structures with a 1μm silicon carbide (SiC) film deposited in the trenches have been tested. A 70% reduction in rolling resistance is shown between the nonlubricated and the SiC-lubricated test structures under identical experimental conditions. This is attributed to the reduced sliding friction in the SiC-steel contact area during interfacial slipping. To the best of our knowledge this is the first reported characterization of dynamic rolling friction in a MEMS device using a solid film lubricant. It is assumed that all frictional forces measured in this work are due to the desired rolling motion as well as bulk sliding of the microballs.

scholarly journals Wear resistance of strengthened layers with nanocrystalline structure in friction with boundary lubrication

2020 ◽  
Vol 6 (1) ◽  
pp. 83-90
Author(s):  
Volodymyr Gurey ◽  
Keyword(s):  
Surface Layer ◽  
Cast Iron ◽  
Contact Area ◽  
High Speed ◽  
Sliding Friction ◽  
White Layer ◽  
Friction Pair ◽  
Experimental Studies ◽  
Friction Treatment ◽  
Transverse Grooves

Friction treatment refers to surface strengthening (hardening) methods using highly concentrated energy sources. The source of thermal energy occurs in the contact area of the tool-part due to high-speed friction (60–90 m/s) of the tool on the treated surface. The heating rate of the metal surface layer is 105–106 K/s. After moving the energy source from the contact zone, high-speed cooling of the surface layer of the metal takes place. The cooling rate is 104–5∙105 K/s. Under the action of high-speed heating and cooling of the contact area of the tool-part in the surface layers, a strengthened (hardened) nanocrystalline (white) layer is formed. The formed nanocrystalline surface layer has other physical, mechanical, chemical properties in comparison with the base metal of the part. Studies have shown that in the process of friction treatment of working surfaces of parts made of Steel 40NiCr6 (quench hardening and low-temperature tempering) a strengthened layer with a thickness of 250–320 μm with a hardness of 7.6–9.2 GPa is formed. The grain size of the surface strengthened layer was 20–40 nm near the treated surface. The formation of the strengthened layer is influenced by the shape of the working surface of the tool. Thus, a strengthened layer of greater thickness and hardness is obtained when machining with a tool with transverse grooves on the working part than with a tool with a smooth working part. Experimental studies in friction with maximum lubrication of pair “Steel 40NiCr6 and Grey Cast Iron GG20” showed that the strengthened nanocrystalline layer significantly increases the performance during sliding friction. Only samples made of steel were strengthened, counter-samples made of gray cast iron were not strengthened. The wear intensity of strengthened pair is 2.2–3.1 times less compared to unstrengthened pair. During the friction of the strengthened pair, the coefficient of friction and the temperature in the sliding zone also decrease. The best results were obtained when studying the friction pair in which the samples were strengthened with a tool with transverse grooves on its working part.

Investigation of the optimum surface roughness of AISI 5120 steel by using a running-in attractor

2020 ◽  
pp. 1-18
Author(s):  
Ding Cong ◽  
Guodong Sun ◽  
Zhen-yu Zhou ◽  
Zhong-yu Piao
Keyword(s):  
Surface Roughness ◽  
Sliding Friction ◽  
Friction Pair ◽  
Friction Process ◽  
Original Surface ◽  
Working Surface ◽  
Disk Friction ◽  
Chaotic Nature ◽  
The Stability ◽  
Pin On Disk

Abstract To investigate the influence of surface roughnesses on the dynamic characteristics of AISI 5120 steel in sliding friction process, a suite of running-in experiments are performed on a pin-on-disk tribometer. The running-in attractor is used to analyze the high-dimensional features of a friction system under different surface roughnesses. The experimental results show that the roughnesses of different original surfaces evolve to the same value in stable wear stage. The pin-on-disk friction system has a chaotic nature and exists a running-in attractor. The original surface of a disk of Ra=0.953 µm is the most conducive to shorten the running-in duration, reduce the friction coefficient value, and improve the stability of the friction system. This roughness value is termed as the optimum surface roughness. It is an ideal working surface for the friction pair in the running-in design.

Algorithms for Dynamic Hardness Measurements by Scratch Testing in the Submicron and Nanometer Scale

2013 ◽  
Vol 853 ◽  
pp. 619-624
Author(s):  
Natalia Lvova ◽  
K. Kravchuk ◽  
I. Shirokov
Keyword(s):  
Contact Area ◽  
Scanning Probe Microscopy ◽  
Scanning Probe ◽  
Nanometer Scale ◽  
Geometrical Parameters ◽  
Scratch Testing ◽  
Dynamic Hardness ◽  
Probe Microscopy ◽  
Parameters Analysis

The automatic scratch geometrical parameters analysis algorithms based on the images obtained by scanning probe microscopy have been developed. We provide a description of the technique to determine the contact area and the scratch volume with and without account of the pile-ups. The developed algorithms are applied to measure the dynamic hardness by sclerometry on the submicron and nanometer scale.

The Brake Device Design for Children Two-Wheel Dynamic Scooter

2011 ◽  
Vol 421 ◽  
pp. 724-727
Author(s):  
Xue Feng Yi ◽  
Li Jun He
Keyword(s):  
Sliding Friction ◽  
Rolling Friction ◽  
Safety Performance ◽  
Device Design ◽  
Emergency Braking ◽  
Design For Children ◽  
Brake Device

Children scooter safety performance is not good enough in the market, the cause of the majority of injuries to children is difficult to control the speed or emergency braking. According to the phenomenon, this paper focuses on designing dynamic scooter brake device for 8-10 child, we conceive that the brake device is given the force of the rolling friction and the sliding friction, so it can play a dual brake effect. It will enhance the security and stability of children dynamic scooter.

scholarly journals Estimation of real contact area during sliding friction from interface temperature

AIP Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 065227
Author(s):  
Sung Keun Chey ◽  
Pengyi Tian ◽  
Yu Tian
Keyword(s):  
Contact Area ◽  
Sliding Friction ◽  
Real Contact Area ◽  
Interface Temperature ◽  
Real Contact

Parameter Study of Offset Press Cylinder Based on Sliding Friction

2010 ◽  
Vol 174 ◽  
pp. 299-302 ◽  
Author(s):  
Hai Yan Zhang ◽  
He Ping Hou ◽  
Jun Feng Si ◽  
Xiao Yu Chen
Keyword(s):  
Contact Area ◽  
Sliding Friction ◽  
Accurate Determination ◽  
Rolling Process ◽  
Elastic Cylinder ◽  
Parameter Study ◽  
Cylinder Radius ◽  
Printing Quality ◽  
Dot Gain

In the contact area of offset, a relative slide occurs between the surface of plate cylinder and blanket cylinder, which changes the print image and influences the printing quality. The relative slide in the cylinders’ rolling process is investigated, and the determination rule of cylinders’ geometric parameters of offset press is proposed. The results show that the relative slide is minimization under the condition that the compression of elastic cylinder radius is 0.2 times bigger than that of rigid cylinder radius, and the deformation of print image and dot gain both are minimization. The results provide theoretical direction for accurate determination of cylinder radius of offset press.

An improved model for investigating the vibration characteristics of ball bearing owing to outer race waviness under high speed

2021 ◽  
Vol 69 (2) ◽  
pp. 89-101
Author(s):  
Pingping Hou ◽  
Liqin Wang ◽  
Zhijie Xie ◽  
Qiuyang Peng
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
Vibration Measurement ◽  
Vibration Frequencies ◽  
Outer Race ◽  
Response Characteristics ◽  
Lagrange’S Equation ◽  
Rolling Elements ◽  
Initial Clearance ◽  
Improved Model

In this study, an improved model for a ball bearing is established to investigate the vibration response characteristics owing to outer race waviness under an axial load and high speed. The mathematical ball bearing model involves the motions of the inner ring, outer ring, and rolling elements in the radial XY plane and axial z direction. The 2Nb + 5 nonlinear differential governing equations of the ball bearing are derived from Lagrange's equation. The influence of rotational speed and outer race waviness is considered. The outer race waviness is modeled as a superposition of sinusoidal function and affects both the contact deformation between the outer raceway and rolling elements and initial clearance. The MATLAB stiff solver ODE is utilized to solve the differential equations. The simulated results show that the axial vibration frequency occurred at l fc and the radial vibration frequencies appeared at l fc fc when the outer race waviness of the order (l) was the multiple of the number of rolling elements (k Nb) and that the principal vibration frequencies were observed at l fc fc in the radial x direction when the outer race waviness of the order (l) was one higher or one lower than the multiple of the number of rolling elements (k Nb 1). At last, the validity of the proposed ball bearing model was verified by the high-speed vibration measurement tests of ball bearings.

scholarly journals Analytical substantiation of constructive parameters of rotating field board of plow’s body

2019 ◽  
Vol 126 ◽  
pp. 00038
Author(s):  
Vladimir Konovalov ◽  
Sergey Konovalov ◽  
Victoria Igumnova
Keyword(s):  
Sliding Friction ◽  
Rolling Friction ◽  
High Energy ◽  
Cultivated Plants ◽  
Friction Forces ◽  
Technical Parameters ◽  
Cutting Resistance ◽  
Different Depths ◽  
Analytical Relations ◽  
Rotating Field

The article shows importance of use of dump plowing for formation and maintenance of soil structure and pest control and diseases of cultivated plants. A significant drawback of plowing process is indicated, which is its high energy intensity. To reduce energy consumption, it is proposed to use rotating field boards, which allow replacing sliding friction forces with rolling friction forces. The article presents a description of design of plow’s body with rotating field board and notes that without a preliminary analytical study and justification of initial parameters, their use may not be effective. Analytical relations connecting value of radius of rotating field of board, rate of collapse of soil, allowable value of indentation of field board into soil and specific force of cutting resistance of soil that ability to use it for baseline technical parameters. To analyze obtained dependence, the article presents its graphical solution. The authors obtained an expression for determining the value of arm’s force of reference reaction from soil to balance a plow’s body, in addition, this indicator can be used to adjust a body when working on soils with different physical and mechanical parameters and at different depths.

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