Teeth clearance effects upon pressure and film thickness in a trochoidal hydrostatic gear pump

Abstract

This paper describes the teeth clearance influence on the tooth number contact in a hydrostatic pump in which arc circular profiles are used. Both the teeth clearance and the teeth deformation in contact are considered. Because of the teeth clearance, a severe reduction in number point contact and diminution in wide surface contact of the pinion are predicted. A steep-by-steep procedure for determining the normal force contact between teeth is outlined. The pressure contact and the film thickness are then deduced. Comparisons with the result obtained for the pump without clearance are made. Despite the appearance, the benefit of the high geometrical conformity, which normally leads to low pressure and a thick film, is strongly altered.