In this paper, analytical equations for the central film thickness in slender elliptic contacts are investigated. A comparison of state-of-the-art formulas with simulation results of a multilevel elastohydrodynamic lubrication solver is conducted and shows considerable deviation. Therefore, a new film thickness formula for slender elliptic contacts with variable ellipticity is derived. It incorporates asymptotic solutions, which results in validity over a large parameter domain. It captures the behaviour of increasing film thickness with increasing load for specific very slender contacts. The new formula proves to be significantly more accurate than current equations. Experimental studies and discussions on minimum film thickness will be presented in a subsequent publication.

For axially loaded cylindrical and tapered roller bearings, the dynamic behaviour of individual rollers, wear and friction losses are strongly influenced by roller-flange contact forces. For a realistic modelling of normal and friction forces of the roller-flange contact, it is essential to determine location and theoretical penetration of this contact. The rapid contact detection is particularly significant for rolling element bearing dynamic modelling in multibody systems. In this paper a semi-analytical algorithm for contact detection is introduced and compared to state of the art methods. The new approach adopts piecewise functions of spheres, cones and tori for modelling of roller end and flange geometry. The location of the contact and its theoretical penetration is calculated using analytical and combined analytical-numerical schemes. The semi-analytical approach proves to be significantly faster and numerically more stable than current contact detection algorithms without compromising precision.

This paper examines the roller slip behavior of full-complement cylindrical roller bearings under different radial eccentric load, radial load direction, axial load, speed and temperature. For this purpose, 2240 roller slip measurements are carried out with a coil attached coaxially to the roller set and a roller body equipped with a diametrical magnet. The evaluation is carried out using an improved evaluation system, which includes both the frequency and amplitude proportionality of the induced voltage. Overall, the roller slip decreases with radial loading in the direction of gravity and with increasing axial load, speed and oil temperature. To explain the physical relationships, which are responsible for these changes, a comparison with results of multibody simulation of the bearing with an advanced modeling of contacts, lubrication and friction is carried out.

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In the first paper of this series, a new formula for central film thickness of slender contacts has been proposed. In this paper, interferometry measurement of the film thickness in slender elliptic contacts is performed for comparison with film thickness distribution of EHL simulation. The new film thickness formula presented in part I of this paper series is successfully validated by comparison with the experimental data. State-of-the-art minimum film thickness formulas are compared with the experimental results and results obtained through a multilevel EHL solver. Significant deviation of the analytical minimum film thickness formulas regarding both numerical and experimental results is given. Therefore, an alternative approach for calculation of minimum film thickness via the film thickness ratio with central film thickness is proposed, which yields promising results for moderately slender elliptic EHL contacts.