Unitized pump system

Claim 2

A unitized pump system comprising a housing having a fluid supply means and an outlet port; a drive means disposed in said housing; a first, second and third pump means disposed in said housing, each of said pump means having a discharge means extending to said outlet port for conveying the output of each pump means thereto, each of said discharge means of said pump means including a check valve, each of said pump means having separate inlet means for receiving fluid from said supply means, the inlet means of said third pump means including a valve means for selectively opening and closing the inlet means of the third pump means to control the output therefrom, the second pump means includes means to feed a small amount of the output fluid from said outlet port to said second pump means so that said second pump means is prevented from overheating when the valve means of the inlet means of the third pump means is in an open position; said second and third pump means being connected to said drive means; and a coupling means including a control means for selectively interconnecting said first pump means to said drive means.

Claim 3

A unitized pump system according to claim 1, wherein said first pump means is a gear pump and said second and third pump means are centrifugal pumps.

Claim 4

A unitized pump system according to claim 1, wherein said fuel supply means includes a fourth pump means connected to said drive means.

Claim 5

A unitized pump system according to claim 1, wherein said drive means includes a drive shaft for each of said pump means, and gear means interconnecting each of said drive shafts so that each of said shafts and their respective pump means are driven by said drive means at a different speed.

Claim 6

A unitized pump system according to claim 1, wherein said third pump means is a high-capacity pump means, and wherein said valve means includes a valve seat formed in the inlet means of said third pump means, a valve member coactable with said valve seat and attached to an actuator means disposed in said housing, said actuator being controlled by a sensor means responsive to flow demands of the fluid passing through said outlet port, so that when a high-capacity output is required from said system the actuator moves the valve member to an open position enabling the high-capacity slide means to begin pumping.

Claim 7

A unitized pump system according to claim 1, wherein said means to feed of the second pump means is a small bleed orifice provided in the check valve of the discharge means for the second pump means.

Claim 8

A unitized pump system according to claim 1, wherein said control means of said coupling means is interconnected to the discharge means of the second pump means so that said control means is actuated by a preselected output pressure of said second pump means to disengage said coupling means.

Claim 9

A unitized pump system according to claim 7, wherein said coupling means is a fluid coupling having fluid input and discharge lines extending to a fluid pressure source, and said control means further includes a spool valve assembly disposed on said housing controlling flow in said input and discharge lines, the valve member of said spool valve assembly being moved to a position closing the inlet lines and opening the drain line by a preselected output pressure of said second pump means.

Claim 10

A unitized pump system according to claim 1, wherein the discharge means of the first pump means includes a pressure control means to divert a portion of the output flow of the first pump means to said fluid supply means.

Claim 11

A unitized pump system according to claim 9, wherein said pressure control means includes a pressure regulator valve means being adjusted to maintain a predetermined discharge pressure of said first pump means, a control bleed means connected to the outlet of said regulator valve means for increasing the discharge pressure of said first pump means, and a bypass valve means connected between the outlet of the regulator valve and the outlet of the control bleed means to selectively bypass the control bleed means.

Claim 12

A unitized pump system according to claim 10, wherein said bypass means includes a temperature responsive unit disposed in the outlet of the control bleed means, said temperature responsive means being connected to a valve member of the bypass valve means so that said bypass valve member is moved to an open position when the temperature in the outlet of the control bleed means reaches a predetermined temperature to prevent overheating of the fluid passing through said outlet of said control bleed means.

Claim 13

A unitized pump system comprising a housing having a fluid inlet means and an outlet port; a booster pump disposed in the inlet means, said booster pump having a discharge passageway in said housing; a cranking stage disposed in said housing, said cranking stage having an inlet in communication with the discharge passageway of said booster pump and having a discharge line communicating with said outlet port; a low-flow stage disposed in said housing and having an inlet means in communication with the discharge passageway of said booster pump and a discharge line communicating with said outlet port; a high-capacity stage disposed in said housing having an inlet means in communication with the discharge passageway of said booster pump, said inlet means of said high-capacity stage including a valve means for selectively opening and closing said inlet means to control flow of fluid to said high-capacity stage, said high-capacity stage having a discharge line communicating with said outlet port, each of said discharge lines having a check valve, vent means between said outlet port and the discharge line of the low-flow stage to deliver fuel for cooling said low-flow stage when fuel is delivered by said high-capacity stage, a drive means disposed in the housing for driving each of said stages and the booster pump, said drive means including a coupling means for selectively interconnecting the drive means with said cranking stage, said coupling means including a control means for selectively engaging and disengaging said coupling so that said cranking stage is selectively driven by said drive means.

Claim 14

A unitized pump system comprising a housing having a fluid inlet means and an outlet port; a booster pump disposed in the inlet means, said booster pump having a discharge passageway in said housing; a cranking stage disposed in said housing, said cranking stage having an inlet in communication with the discharge passageway of said booster pump and having a discharge line communicating with said outlet port; a low-flow stage disposed in said housing and having an inlet means in communication with the discharge passageway of said booster pump and a discharge line communicating with said outlet port; a high-capacity stage disposed in said housing having an inlet means in communication with the discharge passageway of said booster pump, said inlet means of said high-capacity stage including a valve means for selectively opening and closing said inlet means to control flow of fluid to said high-capacity stage, said high-capacity stage having a discharge line communicating with said outlet port, each of said discharge lines having a check valve, vent means between said outlet port and the discharge line of the low-flow stage to deliver fuel for cooling said low-flow stage when fuel is delivered by said high-capacity stage, a drive means disposed in the housing for driving each of said stages and the booster pump, said drive means including a coupling means for selectively interconnecting the drive means with said cranking stage, said coupling means including a control means for selectively engaging and disengaging said coupling so that said cranking stage is selectively driven by said drive means.

Claim 15

A unitized pump system according to claim 12, wherein said coupling means is a hydraulic coupling having a fluid supply port and a fluid drain port with the movement of fluid through said ports being controlled by said control means.

Claim 16

A fuel pump assembly for aircraft engines comprising a fuel supply pump, a high-speed positive displacement cranking stage pump receiving fuel from said supply pump, a high-flow centrifuGal pump also receiving fuel from said fuel supply pump, a low-flow centrifugal pump also receiving fuel from said fuel supply pump, said high-speed positive displacement cranking stage, low-flow centrifugal pump and high-flow centrifugal pump each having a separate discharge passage communicating with a common outlet, a check valve between each separate discharge passage and said common outlet, a sensor controlling fuel flow to said high-flow centrifugal pump for controlling fuel discharge therefrom, vent means between said common outlet and the discharge passage of the low-flow centrifugal pump to deliver fuel for cooling said low-flow centrifugal pump when fuel is delivered by said high-flow centrifugal pump, means for driving said pumps, a disconnect coupling between said means for driving and said high-speed positive displacement pump, means controlled by pressure of fuel delivered from said low-flow centrifugal pump for disconnecting said coupling at a predetermined fuel pressure, whereby fuel from said fuel supply pump is pumped by said high speed positive displacement pump during engine cranking operations, is pumped by said high-flow centrifugal pump during high-powered engine operation and is pumped by said low-flow centrifugal pump during engine cruising operation.

Claim 17

A fuel pump assembly for aircraft engines comprising a fuel supply pump, a high-speed positive displacement cranking stage pump receiving fuel from said supply pump, a high-flow centrifuGal pump also receiving fuel from said fuel supply pump, a low-flow centrifugal pump also receiving fuel from said fuel supply pump, said high-speed positive displacement cranking stage, low-flow centrifugal pump and high-flow centrifugal pump each having a separate discharge passage communicating with a common outlet, a check valve between each separate discharge passage and said common outlet, a sensor controlling fuel flow to said high-flow centrifugal pump for controlling fuel discharge therefrom, vent means between said common outlet and the discharge passage of the low-flow centrifugal pump to deliver fuel for cooling said low-flow centrifugal pump when fuel is delivered by said high-flow centrifugal pump, means for driving said pumps, a disconnect coupling between said means for driving and said high-speed positive displacement pump, means controlled by pressure of fuel delivered from said low-flow centrifugal pump for disconnecting said coupling at a predetermined fuel pressure, whereby fuel from said fuel supply pump is pumped by said high speed positive displacement pump during engine cranking operations, is pumped by said high-flow centrifugal pump during high-powered engine operation and is pumped by said low-flow centrifugal pump during engine cruising operation.