Fluid pump and motor unit
OwnerColin Alfred Pearsoninventor
Life of this patent
Estimating the term…
Abstract
A pump powered partly by a mechanical drive and partly by a pressurized fluid flow and comprised of one or more piston-in-cylinder assemblies in which one face of each piston provides a pumping action while a pressurized driving fluid flow is applied to the opposite piston face, thus supplementing the drive force applied to each piston via a piston rod. Input and output of the pumped flow is controlled by pump valves of a non-return poppet type operated by the pumped flow. Input and output of the driving fluid is controlled by poppet-type valves controlled by connection to the pump valves. Piston movement relative to both the cylinder and the piston rod is controlled, and a two-part pump valve is provided to simplify connection to the motor valves.
Claims20
A fluid pump and motor unit comprising:
- a pump body having formed therein
- a cylinder,
- a first flow path extending from a pump inlet port through a first portion of said cylinder to a pump outlet port, and
- a second flow path extending from a motor inlet port through a second portion of said cylinder to a motor outlet port;
- a piston rod axially reciprocal in a pumping stroke direction and a return stroke direction and having a distal end portion extending through a passageway in said pump body and into said cylinder, said distal end portion having
- a distal rod stop, and
- a proximal rod stop axially separated from said distal rod stop;
- a piston disposed within said cylinder and separating said first and second flow paths;
- said piston being slideably connected to said distal end portion and being free to move axially relative to said piston rod between said distal rod stop and said proximal rod stop, said piston being engageable by said proximal rod stop and drivable by said piston rod in the pumping stroke direction to pump a first fluid flow through said first flow path, and engageable by said distal rod stop and drivable by said piston rod in the return stroke direction within said cylinder, said piston also being at least partially drivable by a second fluid flow through said second flow path,
- a first pair of associated valves respectively disposed in an upstream part of said first flow path and a downstream part of second flow path, a second pair of associated valves respectively disposed in a downstream part of said first flow path and an upstream part of second flow path, and means normally biasing the valves toward their flow path closing positions;
- and
- piston stop means for limiting piston travel in at least one stroke direction within said cylinder to at least one of the following two positions;
- (1) a piston position proximate the position in which the piston would be if it were in engagement with the proximal rod stop when the piston rod is at the end of its pumping stroke, and
- (2) a piston position proximate the position in which the piston would be if it were in engagement with the distal rod stop when the piston rod is at the end of its return stroke.
In a fluid filtration system including a filtering medium having a high pressure side and a low pressure side, at least one fluid pump and motor system for providing a high pressure flow of fluid to be filtered, and mechanical drive means for powering each fluid pump and motor system, an improved fluid pump and motor system comprising:
- a pump body having formed therein a cylinder, a first flow path which traverses from a pump inlet port through a first portion of said cylinder to a pump outlet port connected to an input port on the high pressure side of the filtering medium, and a second flow path which traverses from a motor inlet port connected to an outlet port on the high pressure side of the filtering medium and through a second portion of said cylinder to a motor outlet port;
- an axially reciprocal piston rod moveable in a pumping stroke direction and a return stroke direction, said piston rod having a distal end portion extending through a passageway in said pump body and into said cylinder, said distal end portion having a first rod stop and a second rod stop axially separated from said first stop;
- a piston disposed within said cylinder and separating said first and second flow paths;
- said piston being slideably connected to said distal end portion and being free to move axially relative to said piston rod between said first rod stop and said second rod stop, said piston being reciprocally drivable within said cylinder by said piston rod to pump a first fluid flow through said first flow path, said piston being at least partially drivable by a second fluid flow through said second flow path,
- a first pair of associated valves respectively disposed in an upstream part of said first flow path and a downstream part of said second flow path, a second pair of associated valves respectively disposed in a downstream part of said first flow path and an upstream part of said second flow path, and means normally biasing the valves toward their flow path closing positions;
- and
- piston stop means for limiting piston travel in at least one stroke direction within said cylinder to at least one of the following two positions;
- (1) a piston position proximate the position in which the piston would be if it were in engagement with the proximal rod stop when the piston rod is at the end of its pumping stroke, and
- (2) a piston position proximate the position in which the piston would be if it were in engagement with the distal rod stop when the piston rod is at the end of its return stroke.
Dependencies are inferred from the claim text.