Patent ID: 6299422
Filing Date: 2001-10-09
Classification: F04C

Abstract:
A fluid pump comprising an externally-toothed first pulley wheel; a second pulley wheel spaced from a periphery of the first pulley wheel; an endless internally-toothed drive belt drivingly coupled to and wrapped around the externally-toothed first pulley wheel and the second pulley wheel; a fluid-tight housing containing the drive belt and the first and second pulley wheels; means for coupling the motion of the first and second pulley wheels and the drive belt to that of an external drive; a fluid inlet port in the housing communicating with a space between the first pulley wheel and the second pulley wheel; a fluid outlet port closely adjacent a region where the drive belt engages tangentially with the first pulley wheel with their respective teeth in partial engagement; and a guide block located within the space between the first pulley wheel and the second pulley wheel, the guide block having a first face adjacent a portion of the belt which in use approaches the fluid outlet port, and a second face adjacent the portion of the first pulley wheel which in use, approaches the fluid outlet port, wherein the first and second faces of the guide block meet at a point which is closer to a location where the drive belt comes into mesh with the first pulley wheel than the distance between a location where the belt comes out of mesh with the first pulley wheel and the nearest portion of the second face of the guide block, said second face of the guide block including a first portion which extends from the first face in an arc around the periphery of the first pulley wheel, and a second portion which extends from the first portion away from said periphery, whereby motion of the first pulley wheel causes fluid from the space between the first pulley wheel, the second pulley wheel, and the guide block to be drawn into a nip between the first pully wheel and the drive belt and then to be expelled under pressure to the fluid outlet port.