Optical Analysis of Ball Bearing Starvation

Abstract

Elastohydrodynam5c o i l film measurements f o r r o l l i n g point cont a c t under s t a r v a t i o n conditions a r e obtained using o p t i c a l i n t e r f e rometry. The experimental measurements present a reasonably c l e a r p i c t u r e of t h e s t a r v a t i o n phenomenon and a r e shown t o agree with t h e o r e t i c a l predictions, Starvation i n h i b i t s t h e generation of pressure and, therefore, reduces f i l m thickness. It a l s o causes t h e o v e r a l l pressure, s t r e s s and e l a s t i c deformation t o become more Hertzian.

In contact observation of model synovial fluid lubricating mechanisms

“…Such models assume articular joints predominantly operate within the EHL regime. It should be noted that within this lubrication regime film thickness is determined by the viscosity of the material in the contact inlet [16].…”

Boundary Conditions for Elastohydrodynamics of Circular Point Contacts

“…The results show that the inlet meniscus is partially formed inside the starvation demarcation boundary, found through experimental work of Wedeven et al [33] and numerical analysis by Hamrock and Dowson [32] (figure 7), based on Swift-Stieber exit boundary conditions. Crucially, the inlet distance feeding the central Hertzian region of the contact falls within this starvation boundary.…”

“…This case has been investigated by Wedeven et al [33]. The balance between the rate at which oil is entrained into the contact zone and that at which it leaks out of the contact edges determines the inlet boundary position according to Pemberton et al [36].…”

“…Numerical analyses often assume fully flooded inlet boundaries and exit constrictions based upon Swift-Stieber film rupture conditions beyond the Hertzian domain. More representative analyses have included inlet boundaries based upon demarcation lines for just fully flooded conditions, determined numerically (Hamrock and Dowson [32]) or experimentally using interferometric studies (Wedeven et al [33]). However, these were not based on any quantitative free surface lubricant flow analysis such as that underlying Prandtl-Hopkins zero reverse flow boundaries.…”

Effect of lubricant molecular rheology on formation and shear of ultra-thin surface films

“…Hydrodynamic entrainment of the lubricant also has its own better known influence upon film rupture and cavitation. The height of lubricant at the meniscus and its distance to the leading edge of contact is critical to its wetting action (Hamrock and Dowson [24], Wedeven et al [25]). These are affected by the sliding speed.…”