Dumitru Olaru

TL;DR: In this paper, a new model to estimate all friction losses between the balls and the circular arch grooves races (two contact ball screw) has been developed based on the equilibrium of the forces and moments acting on the ball, the sliding forces between ball and both screw and nut races are determined without integrating the shear stress on contact ellipses.

TL;DR: In this paper, the authors proposed a theoretical model and an experimental methodology for defining the friction torque in a modified thrust ball bearing, operating in mixed and full film lubrication conditions, using a spin-down method.

TL;DR: In this article, the authors developed a new micro tribometer consisting in a driving rotational disc in contact with three microballs which sustain an inertial driven rotational disk, and a camera monitored the angular position of the inertial disc, from the start of the deceleration process to his completely stop (the spin-down method).

TL;DR: A complex analytical model for the starvation mechanism in ball-race contacts, in correlation with thermal effects, has been developed in this paper, where the reduction factor of the film thickness by starvation and thermal effects can be computed in a correlation with the ball race lateral oil meniscus thicknesses.

TL;DR: In this paper, a new methodology to determine experimentally the Young's modulus of the human fingers was developed, which consist in the experimentally variation of the elastic deformation for the finger in contact with a steel cylinder normal loaded from zero to 10 N.