Claims
- 1. A fuel pump to be positioned in a fuel tank of an internal combustion engine the fuel pump having a pump housing and an upright drive shaft, comprising:
- (1) a first stage pump section including
- (a) a first pump passage formed in said pump housing and communicated at one end with an inlet port of said pump housing;
- (b) a first impeller operatively connected to said shaft and operatively arranged in said first pump passage for separating, during rotation thereof, fuel vapor from liquid fuel, introduced from said inlet port, within said first pump passage and pressurizing said liquid fuel; and
- (2) a second stage pump section including
- (c) a second pump passage formed in said pump housing and communicated at one end to the other end of said first pump passage and at the other end to an outlet port of said pump;
- (d) a second impeller operatively arranged in said second pump passage and operatively connected to said first impeller for further pressurizing the liquid fuel supplied from said first pump passage, said second impeller having a larger diameter than said first impeller, said second impeller being arranged at a vertically upper side of said first impeller;
- (e) a vapor discharge port formed in said second impeller at a radially inward portion facing said first impeller and communicated at a vertically lower side thereof with the radial inward portion of said first pump passage for causing the fuel vapor separated on said first impeller to flow vertically and upwardly therethrough; and
- (f) a vapor discharge passage formed upwardly and radially in said pump housing for communicating a vertically upper side of said vapor discharge port with the outside of said pump within the fuel tank, whereby the fuel vapor flowing out of said vapor discharge port is returned to a portion within the fuel tank vertically higher than said inlet port wherein said first impeller is of a centrifugal type, and said second impeller is of a regenerative type.
- 2. A fuel pump apparatus as set forth in claim 1, wherein
- said first impeller is of a regenerative type having open vanes.
- 3. A fuel pump apparatus as set forth in claim 1, wherein
- said first impeller is attached to a vertically lower surface of said second impeller.
- 4. A fuel pump apparatus as set forth in claim 3, wherein
- said vapor discharge port has a configuration substantially corresponding to a space defined between adjacent vanes of said first impeller.
- 5. A fuel pump apparatus for an internal combustion engine having a fuel tank comprising:
- a pump housing having a fuel inlet and a fuel outlet to be positioned within a fuel tank so that said fuel inlet is positioned lower than said fuel outlet;
- an electric motor having a vertical rotatable shaft extending into said pump housing;
- a first pump passage formed in said pump housing in communication with said fuel inlet;
- a first impeller connected to said rotatable shaft and arranged in said first pump passage for separating, when driven by said electric motor, fuel vapor from liquid fuel introduced from said inlet port thereinto and pressurizing said liquid fuel;
- a second pump passage formed in said pump housing in communication with said first pump passage and said fuel outlet and having a larger diameter than said first pump passage, said second pump passage being positioned upwardly and downwardly of said first pump passage and said fuel output, respectively;
- a fuel passage formed in said pump housing and communicating radially outer peripheral portions of said first pump passage and said second pump passage with each other;
- a second impeller connected to said rotatable shaft and arranged in said second pump passage for further pressurizing, when driven by said electric motor, the liquid fuel introduced from said first pump passage to said second fuel passage through said fuel passage so that the further pressurized liquid fuel is supplied through said fuel outlet;
- a vapor discharge port formed in said second impeller at a radially inward portion thereof facing said first impeller to communicate with said first fuel passage so that the separated fuel vapor flows upwardly from said first pump passage therethrough;
- a third fuel passage formed in said pump housing in communication with said vapor discharge port to receive the separated fuel vapor from said vapor discharge port, said third fuel passage being positioned upwardly of said second fuel passage and said vapor discharge port; and
- a vapor discharge passage formed in said pump housing in communication with said third fuel passage and the exterior of said pump housing within the fuel tank, said vapor discharge port extending gradually outwardly and upwardly from a peripheral portion of said third fuel passage so that the separate fuel vapor in said third fuel passage is discharged therethrough to the exterior of said pump housing within the fuel tank wherein said first impeller is of a centrifugal type, and said second impeller is of a regenerative type.
- 6. A fuel pump according to claim 1 wherein said second stage impeller has vanes at a peripheral portion thereof.
- 7. A fuel pump according to claim 5 wherein said second stage impeller has vanes at a peripheral portion thereof.
- 8. A fuel pump according to claim 1 wherein said first and second pump passages are communicated by a connecting passage extending tangentially and upwardly from said first pump passage.
- 9. A fuel pump according to claim 5 wherein said first and second pump passages are communicated by a connecting passage extending tangentially and upwardly from said first pump passage.
Priority Claims (2)
Number |
Date |
Country |
Kind |
58-220524 |
Nov 1983 |
JPX |
|
59-77275 |
Apr 1984 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 671,309, filed Nov. 14, 1984 which was abandoned upon the filing hereof.
US Referenced Citations (14)
Foreign Referenced Citations (3)
Number |
Date |
Country |
447177 |
Mar 1948 |
CAX |
512835 |
May 1955 |
CAX |
932386 |
Jul 1963 |
GBX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
671309 |
Nov 1984 |
|