a one piece thrust bearing that uses geometry induced hydrodynamic lubrication to support heavy thrust loads on a lubricant film bearing 74 tolerates high impact loads without performance degradation and reduces friction which permits higher load speed combinations cooler operation and extended operational life bearing 74 is commercially available from kalsi engineering under the model name kalsi bearing as seen in fig2 a 2 b and 9 pressurized drilling fluid or mud is pumped from well surface 76 through drill string 78 and to mud motor 80 in wellbore 81 the fluid or mud travels through the interior of transmission housing 12 to adaptor 16 the fluid or mud may passes through conduits 82 in adaptor 16 and down through the inner bore of drive shaft 14 and to drill bit 84 to actuate drill bit 84 some of the drilling fluid or mud is diverted into channel 86 and flows through bearing section 36 to lubricate and cool stationary and rotating bearing rings 38 40 additionally as rotation commences the drilling fluid is distributed across the faces of bearing ring outwardly extending projections 46 54 resulting in the formation of a hydrodynamic fluid film within bearing section 36 excess drilling fluid may be discharged from bearing assembly 10 through.