Pump impeller housing with integral flow regulator

Claim 1

In a motor driven centrifugal pump of the type adapted to be driven by a constant speed motor and which requires a minimum fluid flow therethrough in order to prevent the motor from running under dry and unloaded conditions and from overheating beyond the normal design limits of the pump, apparatus including: a motor; a motor housing in which said motor is mounted; a centrifugal pump operatively connected to said motor and including an impeller adapted to be driven by said motor; a pump housing in which said pump is confined, said housing defining an interior chamber sized and shaped so as to operatively accommodate said impeller; inlet conduit means defining a path for fluid entering said interior chamber; outlet conduit means defining a path for fluid exiting said interior chamber to an outlet, said outlet conduit including a well integral therewith adapted to receive said flow restricting means interposed in the path of fluid flow in said outlet conduit for reducing the rate of fluid flow from said outlet means; said flow restricting means comprising a shaft rotatably mounted on said outlet conduit means and a baffle plate mounted on said shaft, said baffle plate being selectively movable between two extreme positions namely, a ''''restricted'''' position wherein said baffle plate is substantially perpendicular to the path of fluid flow and there being a clearance between said baffle plate and said outlet conduit permitting at least a minimum rate of fluid flow necessary to prevent the pump from overheating beyond its normal design limits, and an ''''open'''' position wherein said baffle plate is substantially parallel to the path of the fluid flow permitting maximum flow with minimum restriction, thereby insuring that fluid is present in said pump housing at all times for cooling at least a portion of said motor housing adjacent to said pump housing and thereby preventing damage to the pump as a result of overheating.