Experimental investigation on the groove effect in hydrodynamic lubrication

Abstract

In this article, a custom-built test apparatus was used to measure the film thickness in a conformal contact consisting of a stationary fixed-incline block and a moving transparent disc. Two groups of grooved block surfaces were used: one with a step at the inlet, and the other without the inlet step. Under parallel-gap conditions, effective load-carrying lubricant films can be found only when surfaces with an inlet step are used, and a partially grooved surface in the inlet region can generate film thickness larger than the fully grooved one. If the outlet land is larger than the inlet land, a thicker film as well as a higher load-bearing capacity will be obtained. In this study, groove shows a negative impact on the hydrodynamic lift. And not all diverging clearance can form the cavitation, as it depends on the geometry configurations. The classical Reynolds' solutions should be carefully used in the analyses of groove effects. The results can be useful for experiments in the case in which no cavitation occurs.

Balancing wedge action in textured converging bearings

“…2 The concept of the present mechanism was found in previous studies, [33][34][35] which changed the surface profile of the pad but wholly different from those suggested in prior studies on textured surfaces. [3][4][5][6][7][8][10][11][12][13][14][18][19][20][21][22][23][24][25][26][27][28][29] Figure 13 shows the pressure distributions among the three conditions to understand the mechanism of the balancing wedge action when it promotes lubrication performance. The first case is a pivoted flat pad bearing.…”

“…In their experimental results, the friction coefficient increased when cavitation was observed in the microchannels. Yang et al 26 showed that cavitation caused by groove patterning on fixed blocks had a negative effect on the lubrication characteristics.…”

The Analysis on the Tribological Properties of TPU/PVC Blends with Chrome-Plated Steel under Dry Sliding

“…The load is selected properly which make the steering gears' life to increase [4][5] . sometimes steering gears is between the metal rotor and rubber bushing under dry friction condition, the dry friction of rubber wear will directly affect the life capacity of metal rotor [6][7][8][9] . Therefore, TPU/PVC blends -steel with a vice to different load on the friction law under dry friction conditions, which will deepen the understanding of the law for different load, in different conditions to guarantee a reasonable load of belts service life and need to improve production efficiency.…”

On the Magnitude of Load-Carrying Capacity of Textured Surfaces in Hydrodynamic Lubrication

“…Although estimation of load-carrying capacity using the micro-wedge action has had several problems because of the difficulties in cavitation estimation, this mechanism is considered important in textured features for the following reasons: 1) cavitation that arises from the textured features seems to support the hypothesis of the micro wedge action and has been observed in past years [2,3] as well as recently [8][9][10][11][12]; 2) the load-carrying capacity is overestimated when the Reynolds boundary condition is used. The validity of the load-carrying capacity arising from the micro wedge action seems doubtful because the significant low load-carrying capacity has been determined [25,26], taking into account the mass conservation of flow between the cavitation zone and the pressure-developed zone.…”

“…Hamilton et al [2] and Anno et al [3] observed cavitation patterns at artificial asperities of a contact area between a transparent glass disc and a stationary ring. In recent studies [6][7][8][9][10][11][12], many other researchers have observed cavitation in textured features.…”