GEAR PUMP WITH GROOVER SEALING MEANS

摘要

A gear pump for pumping viscous material has a housing with an inlet and an outlet and a gear chamber between the inlet and the outlet. A pair of intermeshing gear wheels which are rotatably supported by bearings in the gear chamber of the housing have end faces in rotative contact with abutting faces of the housing. Spiral grooves in end faces of the gear wheels have a direction to move radially outwardly any material entering between end faces of the gear wheels and abutting faces of the housing to prevent such material from reaching the bearings. An integral drive shaft of one of the gears has a helical groove for preventing material from reaching bearings of the drive shaft. The driven gear has a central circular recess in which a bearing stud projects with bearing needles between the stud and the recess in the gear. In one embodiment, the gear pump is mounted on the discharge end of an extruder and interchangeable sieves are provided between the extruder and the gear pump to filter out any foreign objects.