Multiple pump fuel system

1. A fuel pump assembly, comprising:

a first fuel pump having an electric motor, a pumping element that is driven by the motor, an inlet through which fuel enters the first fuel pump and an outlet through which fuel is discharged from the first fuel pump;

a second fuel pump having an electric motor, a pumping element that is driven by the motor, an inlet through which fuel enters the second fuel pump and an outlet through which fuel is discharged from the second fuel pump;

a passage communicated with the outlet of the first fuel pump and with the outlet of the second fuel pump;

a fuel outlet in communication with the passage and through which fuel exits the fuel pump assembly;

a first valve having an inlet in communication with the passage between the outlet of the first fuel pump and the outlet of the second fuel pump, the valve also having an outlet through which fuel exits the passage and a valve body that controls fuel flow through the valve; and

a second valve located between the outlet of the first fuel pump and the first valve, wherein the second valve prevents fuel that is discharged from the first fuel pump from reaching the first valve.

2. The assembly of claim 1 wherein the first valve is electrically operated to control movement of the valve body between open and closed positions.

3. The assembly of claim 1 wherein at least one of the first fuel pump motor and the second fuel pump motor is driven by a pulse width modulated signal.

4. The assembly of claim 1 which also includes a pressure regulator having an inlet in communication with the passage between the first valve and the second fuel pump outlet, the pressure regulator also having an outlet from which fuel exits the passage and a valve body between the inlet and the outlet, the valve body being responsive to a pressure of fuel at the pressure regulator inlet that is above a threshold pressure to permit fuel to flow through the pressure regulator outlet.

5. The assembly of claim 1 wherein, during at least some operating conditions, fuel from both the first fuel pump outlet and the second fuel pump outlet is discharged from the assembly through the fuel outlet.

6. A fuel pump assembly, comprising:

a first fuel pump having an electric motor, a pumping element that is driven by the motor, an inlet through which fuel enters the first fuel pump, a first outlet through which fuel is discharged from the first fuel pump and a second outlet through which fuel is discharged from the first fuel pump;

a second fuel pump having an electric motor, a pumping element that is driven by the motor, an inlet through which fuel enters the second fuel pump and an outlet through which fuel is discharged from the second fuel pump;

a passage communicated with the first outlet of the first fuel pump and with the outlet of the second fuel pump;

a fuel outlet in communication with the passage and through which fuel exits the fuel pump assembly; and

a valve having an inlet in communication with the second outlet of the first fuel pump, an outlet through which fuel exits the valve, and a valve body that controls fuel flow through the valve, wherein when the valve body is closed to inhibit or prevent fuel flow through the valve, more fuel exits the first fuel pump through the first outlet.

7. The assembly of claim 6 which also includes a reservoir having an interior and a divider in the interior, and wherein the interior includes a first portion on one side of the divider that is in communication with the first fuel pump inlet and a second portion on the other side of the divider that is in communication with the second fuel pump inlet.

8. The assembly of claim 6 which also includes a passage communicated at one end with the valve to receive fuel that flows through the valve, and a jet or restricted orifice located in the passage downstream of said one end, wherein the jet or restricted orifice has a smaller flow area than the adjacent portions of the passage and the jet or restricted orifice controls the flow rate of fuel in the passage.

9. The assembly of claim 8 which also includes a reservoir having an interior and a divider in the interior, and wherein the interior includes a first portion on one side of the divider that is in communication with the first fuel pump inlet and a second portion on the other side of the divider that is in communication with the second fuel pump inlet, and wherein the passage has a second end through which fuel exits the passage and the second end is communicated with the second portion of the interior.

10. The assembly of claim 6 which also includes a pressure regulator having an inlet in communication with the passage, the pressure regulator also having an outlet from which fuel exits the passage and a valve body between the inlet and the outlet, the valve body being responsive to a pressure of fuel at the pressure regulator inlet that is above a threshold pressure to permit fuel to flow through the pressure regulator outlet, and wherein the pressure regulator outlet is in communication with the second fuel pump inlet.

11. The assembly of claim 6 which also includes a reservoir having an interior and a divider in the interior, and wherein the interior includes a first portion on one side of the divider that is in communication with the first fuel pump inlet and a second portion on the other side of the divider that is in communication with the second fuel pump inlet, and the interior is sealed and capable of containing fluid at above atmospheric pressure, and wherein the assembly also includes a fuel pressure regulator that has an inlet communicating with the second portion of the reservoir interior, an outlet communicating with the first portion of the reservoir interior, and a valve body between the fuel pressure regulator inlet and the fuel pressure regulator outlet that is normally closed to prevent fuel flow through the fuel pressure regulator until the pressure at the fuel pressure regulator inlet is above a threshold pressure wherein the valve body moves to an open position and fuel from the second portion of the reservoir interior flows into the first portion of the reservoir interior.

12. The assembly of claim 11 which also includes a second fuel pressure regulator having an inlet in communication with the passage, an outlet from which fuel exits the passage and a valve body between the second fuel pressure regulator inlet and the second fuel pressure regulator outlet, the valve body being responsive to a pressure of fuel at the second fuel pressure regulator inlet that is above a threshold pressure to permit fuel to flow through the second fuel pressure regulator outlet, and wherein the second fuel pressure regulator outlet is in communication with the second fuel pump inlet.

13. The assembly of claim 6 which includes a passage communicated at one end with the valve to receive fuel that flows through the valve, and a jet or restricted orifice located in the passage downstream of said one end, wherein the jet or restricted orifice has a smaller flow area than the adjacent portions of the passage and the jet or restricted orifice controls the flow rate of fuel in the passage, and wherein the passage includes an inlet arranged so that fluid flow through the jet or restricted orifice draws fluid through the inlet and into the passage.

14. The assembly of claim 7 wherein the outlet of the valve is in communication with the second portion of the interior.

15. The assembly of claim 7 which also includes a pressure regulator having an inlet in communication with the passage between the valve and the second fuel pump outlet, the pressure regulator also having an outlet from which fuel exits the passage and a valve body between the inlet and the outlet, the valve body being responsive to a pressure of fuel at the pressure regulator inlet that is above a threshold pressure to permit fuel to flow through the pressure regulator outlet, and wherein the pressure regulator outlet is in communication with the second portion of the interior.