Utility pump

Claim 1

A self-priming pump assembly comprising: motor means for driving the pump assembly, said motor means including drive shaft means extending outwardly therefrom for drivingly rotating relative to said motor means; pump mounting means fixedly secured to said motor means with said drive shaft means extending therethrough for mounting a pump unit on said motor means; seal means carried by said mounting means for sealingly engaging said drive shaft means extending therethrough and providing a seal therebetween; a substantially planar outer end face formed on said mounting means lying in a plane normal to the axis of said drive shaft means extending therethrough; and a pump unit carried by said mounting means adjacent to said outer end thereof, said pump unit comprising: a pump housing having an inner end face and an outer end portion with the inner end face thereof positioned adjacent to said mounting means, said pump housing having a cavity formed therein intersecting the inner end face thereof and defined by a planar end wall lying in a plane substantially normal to the axis of said drive shaft means and by an inner peripheral surface traced by a straight line moving parallel to the axis of said drive shaft means and interconnecting said end wall and said inner end face; an inlet port formed in said pump housing and communicating between the exterior thereof and said cavity formed therein; an outlet port formed in said pump housing and communicating between the exterior thereof and said cavity formed therein; a pump cam having an outer end face and an inner end face and slidably disposed in said cavity, said pump cam having an outer periphery conforming to and slidably engaging the inner periphery of said pump housing, and having an inner periphery of non-circular cross-section and traced by a straight line moving parallel to the axis of said drive shaft means and intersecting the inner and outer end faces of said pump cam; an inlet port formed in said pump cam and communicating between the inner periphery of said pump cam and the outer periphery thereof and the inlet port of said pump housing; an outlet port formed in said pump cam and communicating between the inner periphery of said pump cam and the outer periphery thereof and the outlet port of said pump housing; an impeller, having an inner end face, an outer end face, a hub portion, and a plurality of flexible vanes extending radially outward from the hub portion in spaced relation, disposed within the inner periphery of said pump cam with the outer end portions of the flexible vanes slidably engaging the inner periphery of said pump cam and with the outer End portion of said drive shaft means extending into the center portion of the hub portion; means for demountably connecting said impeller to said drive shaft means for rotation therewith; and a pair of identical wear plates each having an aperture formed therein for receiving said drive shaft means therethrough and disposed respectively between said outer end face of said mounting means and the inner end face of said impeller, and between the planar end wall of said pump housing and the outer end face of said impeller.