Claims
- 1. A dual pumping element fluid pump system comprising:
- a primary pump element having an intake port that receives fluid from a fluid supply and a discharge port;
- a secondary pump element discreet from said primary pump element and having an intake port that receives fluid from a fluid supply and a discharge port;
- a fluid flow control valve that is in fluid communication with said primary pump element and said secondary pump element and movable between a normally open position and a closed position;
- a recirculation conduit that connects said secondary pump element discharge port with said secondary pump element intake port;
- wherein when said system is operating at low speeds, said fluid control valve is in said normally open position and said system is provided with fluid from said primary pump element discharge port and said secondary pump element discharge port; and
- wherein when said system is operating at high speeds, said fluid flow control valve is moved to said closed position directing said fluid from said secondary pump element discharge port through said recirculation conduit to said secondary pump element intake port, said valve also closing off said flow of fluid from said fluid supply to said secondary pump element intake port.
- 2. The system of claim 1 further comprising:
- a cross-over conduit connecting said primary pump element discharge port to said recirculation circuit to prevent cavitation of said secondary pump element.
- 3. The system of claim 2, wherein said fluid flow control valve is a three function valve assembly which remains in said normally open position until a threshold pressure within the system is reached.
- 4. The system of claim 3, wherein upon incremental pressure increases above said threshold pressure, said fluid control valve simultaneously opens an incremental area of said recirculation passage while closing off corresponding incremental areas of both said secondary pump element intake port and said secondary pump element discharge port.
- 5. The system of claim 4, wherein when the system reaches a second threshold pressure, said fluid control valve has fully opened said recirculation passage and prevents said secondary pump element from receiving fluid from said fluid supply and from discharging fluid to the system.
- 6. The system of claim 5, wherein said primary pump element is mounted on and driven by a driving shaft of an internal combustion piston engine's twin counter-rotating balance shaft system.
- 7. The system of claim 6, wherein said secondary pump element is mounted on and driven by a slave shaft of said internal combustion piston engine's twin counter-rotating balance shaft system.
- 8. The system of claim 5, wherein said recirculation passage and the intake passage of said secondary pump element form a jet pump at their union such that the secondary pump element's discharge flow energy is transferred to its intake flow during transitional valving phases, wherein energy is conserved and creation of backflow in said inlet passage is minimized.
- 9. The system of claim 5, wherein said fluid flow control valve is hydraulically actuated.
- 10. The system of claim 5, wherein said fluid flow control valve is electronically controlled.
- 11. The system of claim 5, wherein at least one of said first pump element and said second pump element are of an internal tip sealing rotor type.
- 12. An engine balancer apparatus within an engine comprising:
- a first rotary balance shaft:
- a second rotary balance shaft;
- means for drivingly connecting the balance shafts to a crankshaft of an engine for rotation in a predetermined speed relationship with the crankshaft;
- a first fluid pump in communication with a driving shaft having a fluid inlet that communicates with a fluid reservoir and an outlet that communicates with a load;
- a second fluid pump driven by said second rotary balance shaft, said second fluid pump having a fluid inlet that communicates with a fluid reservoir and an outlet that communicates with a load;
- a flow control valve interconnecting said first and second pumps;
- whereby when the pressure in the engine is below a predetermined threshold, said flow control valve operates to enable both said first and second pumps to supply the load;
- whereby when the pressure in the engine reaches said predetermined threshold, said flow control valve starts to close said second pump inlet and outlet and starts to open a short circuit conduit so that fluid recirculates within said short circuit conduit and is prevented from supplying the load; and
- whereby when the pressure in the engine is above said predetermined threshold, said valve fully closes said inlet and outlet of said second pump and said short circuit conduit is fully opened.
- 13. The engine balancer apparatus of claim 12 wherein at least one of said first and second fluid pumps are of the internal tip sealing rotor type.
- 14. The engine balancer apparatus of claim 12, wherein a cross-over conduit connects said short circuit conduit with said outlet of said first fluid pump to prevent cavitation of said second pump.
- 15. The engine balancer of claim 12, wherein a jet pump is formed at the union of said inlet of said second pump and said short circuit conduit to minimize backflow of fluid into the inlet passage.
- 16. A method of pumping fluid to an engine having a fluid supply, comprising:
- providing a primary pump element with an intake port and a discharge port;
- providing a secondary pump element with an intake port and a discharge port, said secondary pump element being discreet from said primary pump element;
- providing a flow control valve that is movable between a normally open position and a closed position;
- discharging fluid to the engine through said primary pump element discharge port and said secondary pump element discharge port when the pressure in the engine is below a predetermined threshold;
- moving said flow control valve to a partially closed position when the pressure in the engine reaches said predetermined threshold;
- moving said flow control valve to said closed position when the pressure in the engine exceeds said predetermined threshold;
- and connecting said secondary pump element intake port with said secondary pump element discharge port when said flow control valve is in said closed position, such that the engine is provided with fluid through only said primary pump element discharge port while also closing said flow of fluid to said secondary pump element from the fluid supply.
Parent Case Info
This application claims benefit of Provisional Application No. 60/045,470 filed May 2, 1997.
US Referenced Citations (14)
Foreign Referenced Citations (2)
Number |
Date |
Country |
904757 |
Nov 1945 |
FRX |
179177 |
Aug 1991 |
JPX |