Fuel system having serially arranged in-tank pumps

Patent metadata

Field	Value
Publication number	US-2016281697-A1
Application number	US-201514669259-A
Country	US
Kind code	A1
Filing date	Mar 26, 2015
Priority date	Mar 26, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

A pump system is disclosed for use with a fuel system of an engine. The pump system may have a first pump with a first end, a second end, a reservoir located at the second end, and at least one pump mechanism configured to receive fluid from the reservoir. The pump system may also have a second pump mounted to the first pump at the second end and having at least one pump mechanism configured to discharge fluid into the reservoir of the first pump. The pump system may further have a mechanical input operatively connected to the at least one pump mechanism of each of the first and second pumps.

First claim

What is claimed is:

1 . A pump system, comprising:
a first pump having a first end, a second end, a reservoir located at the second end, and at least one pump mechanism configured to receive fluid from the reservoir; a second pump mounted to the first pump at the second end and having at least one pump mechanism configured to discharge fluid into the reservoir of the first pump; and a mechanical input operatively connected to the at least one pump mechanism of each of the first and second pumps.

2 . The pump system of claim 1 , wherein the mechanical input is a shaft that extends through the first pump to the second pump.

3 . The pump system of claim 1 , further including an electric motor operatively connected to the mechanical input.

4 . The pump system of claim 1 , wherein the first and second pumps are different types of pumps.

5 . The pump system of claim 4 , wherein:
the first pump is a piston pump; and the second pump is a centrifugal pump having multiple impellers.

6 . The pump system of claim 5 , wherein the first and second pumps are mounted inside a fluid tank.

7 . The pump system of claim 6 , wherein an end of the second pump opposite the first pump is open to the fluid tank.

8 . The pump system of claim 7 , wherein the second pump is located gravitationally lower in the fluid tank than the first pump.

9 . The pump system of claim 8 , further including a high-pressure outlet extending from the second end of the first pump out of the fluid tank.

10 . The pump system of claim 9 , wherein:
the first pump is mounted to the fluid tank at only at the first end; and the second pump is mounted to only the first pump.

11 . The pump system of claim 1 , further including a filter disposed at an inlet of the second pump.

12 . A pump system, comprising:
a fluid tank; a piston pump having a first end mounted to the fluid tank, and a second end hanging inside the fluid tank; and a centrifugal pump mounted to the second end of the piston pump and configured to transfer fluid from the fluid tank to the piston pump.

13 . The pump system of claim 12 , further including a shaft that extends into the fluid tank and operatively drives both of the first and second pumps.

14 . The pump system of claim 13 , further including an external electric motor operatively connected to the shaft.

15 . The pump system of claim 12 , wherein an end of the centrifugal pump opposite the piston pump is open to the fluid tank.

16 . The pump system of claim 12 , further including a high-pressure outlet extending from the second end of the piston pump out of the fluid tank.

17 . The pump system of claim 12 , further including a filter disposed at an inlet of the centrifugal pump.

18 . A fuel system, comprising:
a fuel tank; a piston pump having a first end mounted to the fuel tank, a second end hanging inside the fuel tank, and a plunger configured to pressurize liquid fuel received from a reservoir located at the second end; a centrifugal pump mounted to the second end of the piston pump and configured to transfer liquid fuel from the fuel tank into the reservoir of the piston pump; a filter disposed at an inlet of the centrifugal pump inside the fuel tank; a shaft extending into the fuel tank and configured to operatively drive the piston and centrifugal pumps; an external electric motor operatively connected to the shaft; a vaporizer configured to receive pressurized liquid fuel from the piston pump and to vaporize the pressurized liquid fuel; an accumulator configured to receive vaporized fuel from the vaporizer; and a regulator located downstream of the accumulator.

19 . The fuel system of claim 18 , wherein an end of the centrifugal pump opposite the piston pump is open to the fuel tank.

20 . The fuel system of claim 18 , further including a high-pressure outlet extending from the second end of the piston pump out of the fuel tank.

Assignees

• Caterpillar Inc

Inventors

• Coldren Dana R
• Steffen Joshua W

Classifications

• F04D1/00

  Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps (adapted for pumping specific fluids F04D7/00; priming or boosting F04D9/00) · CPC title

• F04B17/03 Primary

  driven by electric motors · CPC title

• F04D13/06

  the pump being electrically driven · CPC title

• F04B23/14 Primary

  at least one pump being of the non-positive-displacement type · CPC title

• F04D7/02

  of centrifugal type · CPC title