Page 257 - Tribology in Machine Design
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242  Tribology in machine design


                                influence on the film thickness. The highly viscous fluid passes through the
                                parallel zone until the pressure and the viscosity get back to normal at the
                                exit. This means a decrease in thickness of the film. The inlet and exit
                                regions are effectively independent. They meet at the end of the parallel
                                zone with a discontinuity in the slope of the surface which is associated with
                                a sharp peak in the pressure.


     6.7. Analysis of line       In this section line contact lubrication is presented in a way which can be
     contact lubrication        directly utilized by the designer. The geometry of a typical line contact is
                                shown in Fig. 6.5. The minimum film thickness occurs at the exit of the
                                region and can be predicted by the formula proposed by Dowson and
                                 Higginson for isothermal conditions





                                where G = a£ is the dimensionless material parameter, K=[/i 0
                                 (V, + V 2)~\/2ER is the dimensionless speed parameter, W=w/ERL is the
                                dimensionless load parameter, a is the pressure-viscosity coefficient based









































                      Figure 6.5
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