Page 139 - Tribology in Machine Design

Friction, lubrication and wear in lower kinematic pairs 125

intensity p per unit area, so that

Load on an elementary ring of radius r = 2nrp dr, moment of friction due to
2
the elementary nng = 2nfpr dr,

and eliminating p,

For the solid pivot (case (a), Fig. 4.29), r 2 is zero, hence

For the thrust block bearing of the type shown in Fig. 4.29, case (d), the
thrust is taken on a number of collars, say n, and the pressure intensity p is
then given by

Figure 4.29
as for the single flat collar bearing.

(B). Flat pivot or collar - uniform wear

In this case, the intensity of the bearing pressure at radius r is determined by
the condition

so that