Search results

This paper aims to confirm that increasing the hardness of thrust collars can improve the load carrying capacity (LCC) and wear resistance of water lubricated thrust bearings (WTBs) made of polymers paired with non-polymeric thrust collars, and to design a WTB with high LCC and durability for a shaftless pump-jet propulsor of an autonomous underwater vehicle. Six kinds of WTBs were manufactured by matching aluminum bronze, stainless steel and silicon nitride with two different polymer bearing materials. Their tribological behaviors were tested and compared.

The tribological behaviors of the WTBs made with different materials were investigated experimentally on a specially designed test rig.

Aluminum bronze is not suitable for crafting thrust collars of heavy load WTBs due to severe abrasive wear. Two body abrasive wear first occurred between the thrust collar and the polymer bearing. Next, aluminum bronze wear particles were produced. The particles acted between the two materials and formed three body abrasive wear. Stainless steel/polymer bearings showed better wear resistance while Si₃N₄/polymer bearings were the best. Improving the hardness of thrust collars is significant to the LCC and service life of WTBs.

The wear mechanism of WTBs under heavy load conditions was revealed. Improving the hardness of the thrust collar was confirmed to be a preferable method to improve the wear resistance and LCC of WTBs. The results of this study may provide an important reference for the selection of water lubricated materials and the design of heavy load WTBs.

The purpose of this study is to investigate the effects of partial texture location and dimple depth on load carrying capacity (LCC), friction coefficient and circumferential flow of journal bearing.

Based on the Navier-Stokes equation, the methodology used computational fluid dynamics (CFD). A phase change boundary condition was applied on fluid domain, and the negative pressure at divergent region of oil film was considered.

It has been found that texture located at lubricant inlet area can improve the performance of the bearing, and the effect of shallow dimples is superior to the deep ones. However, the bearing performance will be reduced due to the texture located at the maximum pressure area. When texture is located at the lubricant outlet area, there will be two different situations: the part of the texture located within the oil film divergent area can improve the LCC, while the part that is beyond the divergent region will make the LCC decrease.

The lower-half oil film model was established only in this study to analyze the hydrodynamic lubrication performance of partial textured journal bearing, and the lower-half oil film was divided into three parts. A new cavitation algorithm was introduced to deal with the negative pressure. The formula for calculating the friction of liquid film is refined, including the consideration of vapor phase. The simulation results show that the location of partial texture have a great influence on the bearing performance.

Drawing on affective events theory (AET), this study aims to investigate how and when leader voice solicitation affects employees’ innovative behavior. Specifically, this study proposes that leader voice solicitation evokes employees’ feelings of pride, which subsequently motivate employees’ innovative behavior. Moreover, collectivism orientation plays a moderating role in this process.

This study collected 251 supervisor–subordinate dyadic data in two phases and employed structural equational modeling (SEM) to test the hypotheses.

The results revealed that employees’ feelings of pride mediate the positive relationship between leader voice solicitation and employees’ innovative behavior. Collectivism orientation intensifies the mediated relationship.

This study extends the potential outcome variables of leader voice solicitation. Moreover, it introduces a novel theoretical perspective to explore the impact of leader voice solicitation on employees. Importantly, this study examines the mediating effect of pride and the moderating effect of collectivism orientation, deepening the understanding of how and when leader voice solicitation affects innovative behavior.