GB974653A - Improvements in or relating to gear pumps - Google Patents

Abstract

974,653. Gear pumps. THOMPSON RAMO WOOLDRIDGE Inc. Oct. 7, 1963 [June 19, 1963], No. 39476/63. Heading F1F. A gear pump comprising a housing 10, Fig. 1, having a figure-of-eight pumping chamber 11 housing a pair of intermeshing gears 17, 21 and aligned inlet and outlet passages 15, 16 on opposite sides of the gears in the region of intermesh is provided with a wear plate 25, Fig. 2, of laminated construction with a bearing face 26. The wear plate is of figure-of-eight shape loosely fitting the pump housing and abutting an end wall 12 of the pump housing with grooves 29, Fig. 3, extending from a groove 27 communicating with the inlet passage 15 on the face of plate facing the end wall 12 and grooves 30 extending from the outlet passage 16 on the face of the plate facing the gears so that the unbalanced fluid pressure forces acting on the plate urges it against the end wall to prevent movement of the plate. The wear plate may be formed with a bevel 33 extending from the outlet passage on the face of the plate facing the gears to provide extra surface area on which pump discharge pressure acts to urge the plate against the pumping chamber in the region of the pump inlet. Instead of the grooves 29 being formed in the wear plate they may be formed in the end wall 12. A further wear plate may be fitted adjacent the cover (not shown) and the faces of the gears may be coated with a bearing surface of, e.g., silicone or plastics material. The wear plate may be of laminated construction having a bearing facing 26 slidably engaging the gears 17, 21.