Ming Qiu

Effects of woven liners treated by LaCl3 or CeO2 solution on film formation mechanisms of self-lubricating radial spherical plain bearings

Purpose n n n n nThe fabric self-lubricating liners are the key factors impacting the performances of self-lubricating spherical plain bearings. The purpose of this paper is to improve the friction and wear properties of self-lubricating radial spherical plain bearings by modification of the liners. n n n n nDesign/methodology/approach n n n n nThe liners of hybrid woven PTFE/Kevlar fabrics were treated respectively by the LaCl3 and CeO2 solutions. The tribological properties of self-lubricating spherical plain bearings with treated or untreated liners under continuous swaying conditions were investigated with the bearing tester at the swaying frequency of 2.5 Hz and the swaying angle of ±10°. The film formation and wear mechanisms were analyzed based on the observation of worn surfaces with a scanning electron microscope (SEM) and an energy dispersive spectrometer (EDS). n n n n nFindings n n n n nResults show that the tribological properties of the bearings treated by the LaCl3 or CeO2 solution were improved compared with those of the untreated bearings. In particular, the wear resistance of bearings treated by the CeO2 solution was remarkably improved under higher swaying cycles, but the anti-friction properties and cooling effects of bearings treated by the LaCl3 solution were better under lower swaying cycles. Through SEM analysis, the reasons were analyzed. The bearings with treated liners only produced slight adhesive and abrasive wear, but the bearings with untreated liners produced more serious adhesive and abrasive wear under higher swaying cycles. n n n n nOriginality/value n n n n nThe paper proposed a new pretreatment process for the self-lubricating liners. The investigation on the friction and wear behaviors of the bearings is beneficial for prolonging the service lives of the radial spherical plain bearings.

Effect of Clearance on Thermodynamic Characteristics of Woven Liner Spherical Plain Bearing

The mechanical property of woven liner spherical plain bearing in different clearance has been analyzed using the finite element software. It indicated that when the positive clearance of woven liner spherical plain bearing is 100um, the maximum stress of its inner ring is the lowest. The position of the maximum stress is in the middle of the inner ring. That makes the bearing has a bigger carry capacity. Based on above analysis, the thermal properties between the friction pair of woven liner spherical plain bearing which clearance is 100um is also analyzed. The node temperature variation trend of inner ring and liner along with the analysis process is obtained.

Effect of Acrylamide Modified Liner on Properties of Self-Lubricating Spherical Plain Bearings

The effects of acrylamide modified liner on bonding properties and tribological properties of self-lubricating spherical plain bearings were explored by used of Instron5944 electronic universal testing machine and homemade spherical plain bearings friction and wear tester. The results showed that the bonding properties of bearings modified by acrylamide modified liner were much more improved than those of the unmodified bearings; Self-lubricating spherical plain bearing friction and wear properties and oscillating frequency obvious correlational dependence. With the increase of the oscillation frequency, the friction coefficient and the wear loss increased, while the friction temperature rose. The friction coefficient, wear loss and friction temperature of bearings modified were much more improved than those of the unmodified bearings. It showed that the liners after modification treatment can improve the tribological properties of self-lubricating spherical plain bearings.

Applied Tribology in the Bearing

With the development of industry, more and more mechanical parts have been developed toward the direction of high precision, high speed, and high quality.

Bearing Surface Contact

Tribology is the science and engineering of interacting surfaces in relative motion. Solid surfaces (more specifically, interface of solid/gas or solid/liquid) have complex structures and features.

Materials for Bearing Frictional Pairs

The materials of friction pairs affect the bearing operation performance and proper selection of materials for friction pairs plays an important role in the function and application requirements of the machine and also for the working performance and fatigue life of bearings. In this chapter, selecting principles of the friction pair materials and common materials and performance for sliding bearings and rolling bearings will be introduced.

Sliding Bearing Lubrication Theory

Sliding friction exists in the working process of sliding bearing. The advantages of sliding bearing include the stability, reliability, and noiseless. Requirement of the formation of lubrication film is to ensure the sufficient lubricant for the sliding bearing. Under the condition of liquid lubrication, the surfaces of the sliding bearing are separated by lubricating oil and there is direct contact, so the friction loss and the wear of the surface can be reduced greatly. Besides, the lubricating film also has a certain vibration absorbed performance. In this chapter, the basic theory of sliding bearing lubrication will be introduced, on bases of which the reasons of sliding bearing lubrication failure can be analyzed further, and finally, establish the foundation for seeking the effective way to solve the problem.

Mechanism of Bearing Friction and Wear

Research on mechanism of bearing friction and wear is mainly involved with physics, chemical, metallurgical, and mechanical functions between the surfaces with relative motion and interaction in bearings.

Bearing Lubrication Application

Lubrication has an important influence on the bearing fatigue life, friction, wear, temperature, and vibration. Bearings cannot work without normal lubrication. It can be found that about 40 % of the bearing damage is related to poor lubrication by analyzing the causes to the damage of the bearing.

Rolling Bearing Lubrication Theory

If the lubrication between the rolling element and raceway for the rolling bearing is insufficient, scratches, pitting, and scuffing to different extend will be caused on the rolling elements and raceway, meanwhile, whether the proper lubricant film can be formed or not is important for the fatigue lifetime of the contact area between the rolling elements and the raceway.