초록 ▼

Example fluid circuits (e.g., within aircrafts) include first and second pump assemblies. The first pump assembly has an electric motor and a first fluid pump. The first fluid pump is coupled to the electric motor and has a case drain port that is in fluid communication with a case drain region of t

Example fluid circuits (e.g., within aircrafts) include first and second pump assemblies. The first pump assembly has an electric motor and a first fluid pump. The first fluid pump is coupled to the electric motor and has a case drain port that is in fluid communication with a case drain region of the first fluid pump. The second pump assembly is powered by hydraulic pressure from the first fluid outlet of the first fluid pump and functions to augment flow through the case drain region of the first fluid pump.

대표청구항 ▼

1. A fluid circuit comprising: a first pump assembly including: an electric motor; anda first fluid pump configured to be driven by the electric motor, the first fluid pump having a first fluid inlet, a first fluid outlet and a case drain port that is in fluid communication with a case drain region

1. A fluid circuit comprising: a first pump assembly including: an electric motor; anda first fluid pump configured to be driven by the electric motor, the first fluid pump having a first fluid inlet, a first fluid outlet and a case drain port that is in fluid communication with a case drain region of the first fluid pump; anda second pump assembly in fluid communication with the first pump assembly, the second pump assembly being powered by hydraulic pressure from the first fluid outlet of the first fluid pump when the first fluid pump is driven by the electric motor, the second fluid pump assembly including: a second fluid pump configured to augment flow through the case drain region of the first fluid pump when the second fluid pump assembly is powered by the hydraulic pressure from the first fluid outlet of the first fluid pump. 2. The fluid circuit of claim 1, wherein the second fluid pump comprises: a fluid motor having a fluid inlet and a fluid outlet, the fluid inlet being in fluid communication with the first fluid outlet of the first fluid pump; anda second fluid pump unit coupled to the fluid motor, the second fluid pump unit having a second fluid inlet and a second fluid outlet, the second fluid inlet being in fluid communication with the case drain port of the first fluid pump so that the second fluid pump unit pumps fluid from the case drain region of the first fluid pump. 3. The fluid circuit of claim 1, wherein the second fluid pump assembly comprises: a pilot stage valve assembly having a fluid inlet passage in fluid communication with the first fluid outlet of the first fluid pump; anda main stage valve assembly in fluid communication with the pilot stage valve assembly, the main stage valve assembly having a fluid inlet passage in fluid communication with the case drain port of the first fluid pump so that the second fluid pump assembly pumps fluid from the case drain region of the first fluid pump. 4. The fluid circuit of claim 3, wherein the pilot stage valve assembly includes a first valve housing defining a first spool bore having a first axial end and a second axial end, a first control passage, and a second control passage, the pilot stage valve assembly also including a pilot stage valve disposed in the first spool bore of the valve housing. 5. The fluid circuit of claim 4, wherein the main stage valve assembly includes a second valve housing defining a second spool bore having a first axial end and a second axial end, and a main stage valve disposed in the second spool bore, wherein the first and second control passages of the pilot stage valve assembly are in fluid communication with the second and first axial ends of the second spool bore, respectively, to actuate the main stage valve between a first position and a second position. 6. The fluid circuit of claim 1, wherein the second fluid pump comprises a vane pump. 7. The fluid circuit of claim 6, wherein the vane pump includes a drive port in fluid communication with the first fluid outlet, an intake port in fluid communication with the case drain port, and an output port in fluid communication with the heat exchanger. 8. The fluid circuit of claim 7, wherein the vane pump includes a rotor that rotates within a cam structure, wherein the vane pump includes vanes slidably mounted within radial slots defined by the rotor, wherein the radial slots have inner ends, and wherein a torque for rotating the rotor is provided by pressure from the first fluid outlet that is alternatingly placed in and out of fluid communication with the inner ends of the radial slots as the rotor rotates within the cam structure. 9. The fluid circuit of claim 1, wherein the second fluid pump comprises a spool valve arrangement including: a valve body defining an intake port in fluid communication with the case drain port, a drive port in fluid communication with the first fluid outlet of the first fluid pump, and an outlet port in fluid communication with a cooling line;a piston head reciprocally movable within a piston cylinder, the piston cylinder including first and second piston cylinder ports on opposite sides of the piston cylinder;a first spool valve including a first spool;a second spool valve including a second spool incorporating the piston head such that movement of the second spool moves the piston head within the piston cylinder;a third spool valve including a third spool;the first spool valve being configured to control movement of the second spool, the first spool of the first spool valve being movable between a first position where the first piston cylinder port is connected to the intake port and the second piston cylinder port is connected to the outlet port and a second position where the first piston cylinder port is connected to the outlet port and the second piston cylinder port is connected to the intake port;the second spool valve being configured to control movement of third spool; andthe third spool valve being configured to control movement of the first spool between the first and second positions. 10. The fluid circuit of claim 9, wherein the first, second and third spools each includes a major pilot surface and an opposite minor pilot surface, and wherein the minor pilot surfaces are always in fluid communication with the drive port, and wherein the major pilot surfaces are alternated between being in fluid communication with the drive port and being in fluid communication with a return port connected to a reservoir of the fluid circuit. 11. The fluid circuit of claim 1, wherein the second fluid pump comprises a spool valve arrangement including: a main valve including a main spool for reciprocating a piston head within a piston cylinder, the piston cylinder including first and second cylinder ports positioned on opposite side of the piston head, the main spool having first and second pilot areas facing in opposite axial directions;a sequencing valve including a spool bore defining first, second and third bore ports, the second bore port being positioned between the first and third bore ports, the second bore port being in fluid communication with a fluid outlet of the second fluid pump, the first and third bore ports being in fluid communication with the case drain port;the sequencing valve including a sequencing spool moveable between first and second positions within the spool bore;wherein when the sequencing valve is in the first position: a) the first cylinder port is in fluid communication with the first bore port; b) the second cylinder port is in fluid communication with the second bore port; and c) the first pilot area is exposed to hydraulic pressure from the first fluid outlet of the first fluid pump; andwherein when the sequencing valve is in the second position: a) the first cylinder port is in fluid communication with the second bore port; b) the second cylinder port is in fluid communication with the third bore port; and c) the second pilot area is exposed to hydraulic pressure from the first fluid outlet of the first fluid pump. 12. The fluid circuit of claim 1, wherein the second fluid outlet of the second fluid pump is in fluid communication with a heat exchanger. 13. The fluid circuit of claim 1, wherein the second fluid outlet of the second fluid pump is in fluid communication with a filter. 14. The fluid circuit of claim 1, wherein the second fluid pump comprises part of a cooling circuit for an aircraft. 15. A method for assembling a cooling circuit of an aircraft, the method comprising: providing a first fluid pump having a first fluid inlet in fluid communication with a fluid reservoir, a first fluid outlet and a case drain port;connecting a fluid inlet of a fluid motor to the first fluid outlet of the first fluid pump, wherein the fluid motor is coupled to a second fluid pump; andconnecting a second fluid inlet of the second fluid pump to the case drain port of the first fluid pump so that actuation of the fluid motor causes fluid in a case drain region of the first fluid pump to be pumped out of the first fluid pump by the second fluid pump. 16. The fluid circuit of claim 1, wherein the second fluid pump has a second fluid inlet and a second fluid outlet, the second fluid inlet being in fluid communication with the case drain port of the first fluid pump so that the second fluid pump draws fluid from the case drain region of the first fluid pump when the second fluid pump assembly is powered by the hydraulic pressure from the first fluid outlet of the first fluid pump. 17. The fluid circuit of claim 16, wherein the second fluid outlet is in fluid communication with a heat exchanger for cooling the fluid pumped from the second fluid pump. 18. The fluid circuit of claim 17, wherein the fluid circuit includes a reservoir in fluid communication with the first fluid pump and the heat exchanger, the reservoir being upstream from the first fluid pump and downstream from the heat exchanger. 19. The fluid circuit of claim 1, wherein the motor is a variable speed electric motor. 20. The fluid circuit of claim 7, wherein the vane pump includes a rotor that rotates within a cam structure having a cam surface, wherein the vane pump includes a chamber defined between the cam surface and the rotor, wherein the cam surface defining the chamber includes a first ascending portion separated from a second ascending portion by a first dwell, wherein the cam surface defining the chamber includes a descending portion separated from the second ascending portion by a second dwell, wherein the chamber includes a motor region coinciding with the first ascending portion, an intake region corresponding to the second ascending portion and an output region corresponding to the descending portion, wherein the motor region is in fluid communication with the first fluid outlet, wherein the intake region is in fluid communication with the case drain port, and wherein the output region is in fluid communication with the heat exchanger. 21. The fluid circuit of claim 7, wherein the vane pump includes a rotor that rotates within a cam structure having a cam surface, wherein the vane pump includes a chamber defined between the cam surface and the rotor, wherein the cam surface defining the chamber includes an ascending portion separated from a descending portion by a dwell, wherein the chamber includes an intake region corresponding to the ascending portion and an output region corresponding to the descending portion, wherein the intake region is in fluid communication with the case drain port, wherein the output region is in fluid communication with the heat exchanger, wherein the rotor defines radial slots in which vanes are slidably mounted, wherein the radial slots have inner ends, wherein the cam structure includes a higher pressure passage structure in fluid communication with the inner ends of the radial slots at a first location corresponding to the intake region, and wherein the cam structure includes a lower pressure passage structure in fluid communication with the inner ends of the radial slots at a second location corresponding to the output region. 22. The fluid circuit of claim 21, wherein the higher pressure passage structure is in fluid communication with the first fluid outlet. 23. The fluid circuit of claim 22, wherein the lower pressure passage structure is in fluid communication with the output region of the chamber. 24. The fluid circuit of claim 7, wherein the vane pump includes a rotor that rotates within a cam structure having a cam surface, wherein the rotor carries a plurality of vanes, wherein the vane pump includes a chamber defined between the cam surface and the rotor, wherein the drive port, the intake port and the output port are all in fluid communication with the chamber, wherein pressurized fluid from the first fluid outlet provides a force for rotating the rotor within the cam structure, wherein fluid from the case drain port is drawn into the chamber and mixes with the pressurized fluid from the first fluid outlet as the rotor rotates, and wherein the mixture of the fluid from the case drain port and the fluid from the first fluid outlet are pumped out of the vane pump through the output port. 25. The fluid circuit of claim 1, further comprising a fluid motor for driving the second fluid pump, the fluid motor having an inlet in fluid communication with the first fluid outlet so as to be powered by the hydraulic pressure from the first fluid outlet of the first fluid pump.