US5009575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vapor lock preventing mechanism in motor-driven fuel pump
Assignee: Aisan Industry Co Ltd
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Filing: 1989-10-31
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Granted: 1991-04-23
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Expires: 2009-10-31
Abstract
Abstract A multi-stage motor-driven fuel pump including a motor section provided with an electric motor and a pump section to be driven by the electric motor, the pump section having a plurality of pump chambers partitioned by intermediate plates and communicated with each other by a fuel communication hole formed through each of the intermediate plates. A ratio of a sectional area of the fuel communication hole of any one of the intermediate plates between adjacent ones of the pump chambers to a sectional area of the pump chamber on a lower pressure side is set in a predetermined range such that a gradient of fuel pressure increase in the pump section is increased to early prevent vapor lock.
Inventors
- 👤 Kazumichi Hanai
- 👤 Koichi Mine
- 👤 Hikaru Kikuta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:41
CPC Classifications
F; F04; F04D; F04D9/00; F04D9/001; F04D9/002; F04D5/00; F04D5/002; F04D5/003; F04D5/006
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
283 words
A two-stage fuel pump comprising: (a) a first impeller; (b) a first wall for surrounding said first impeller; (b-1) a first pump chamber being defined between an inner surface of said first wall and an outer circumference of said first impeller; (b-2) said first wall being formed with a fuel inlet communicating with said first pump chamber to suck fuel into said first pump chamber; (b-3) said first wall being formed with a vapor jet communicating with said first pump chamber to discharge a vapor of said fuel from said first pump chamber; (c) a second impeller having a size and a shape identical with those of said first impeller; and (d) a second wall for surrounding said second impeller; (d-1) a second pump chamber being defined between an inner surface of said second wall and an outer circumference of said second impeller; (d-2) said second pump chamber having a sectional shape substantially the same as that of said first pump chamber; (d-3) said second wall being formed with a fuel outlet communicating with said second pump chamber to discharge said fuel; (d-4) a part of said second wall partitioning said first pump chamber from said second pump chamber, said part being formed with a communication hole for communicating said first pump chamber with said second pump chamber; (e) wherein a ratio of (a sectional area of said communication hole)/(a sectional area of said first pump chamber) is less than a ratio of (a sectional area of said fuel outlet)/(a sectional area of said second pump chamber); (f) whereby a boosting rate in said first pump chamber can be made larger than that in said second pump chamber to efficiently discharge said vapor.
Claim 2
Dependent Claim
283 words
A two-stage fuel pump comprising: (a) a first impeller; (b) a first wall for surrounding said first impeller; (b-1) a first pump chamber being defined between an inner surface of said first wall and an outer circumference of said first impeller; (b-2) said first wall being formed with a fuel inlet communicating with said first pump chamber to suck fuel into said first pump chamber; (b-3) said first wall being formed with a vapor jet communicating with said first pump chamber to discharge a vapor of said fuel from said first pump chamber; (c) a second impeller having a size and a shape identical with those of said first impeller; and (d) a second wall for surrounding said second impeller; (d-1) a second pump chamber being defined between an inner surface of said second wall and an outer circumference of said second impeller; (d-2) said second pump chamber having a sectional shape substantially the same as that of said first pump chamber; (d-3) said second wall being formed with a fuel outlet communicating with said second pump chamber to discharge said fuel; (d-4) a part of said second wall partitioning said first pump chamber from said second pump chamber, said part being formed with a communication hole for communicating said first pump chamber with said second pump chamber; (e) wherein a ratio of (a sectional area of said communication hole)/(a sectional area of said first pump chamber) is less than a ratio of (a sectional area of said fuel outlet)/(a sectional area of said second pump chamber); (f) whereby a boosting rate in said first pump chamber can be made larger than that in said second pump chamber to efficiently discharge said vapor.
Claim 3
Dependent Claim
34 words
The two-stage fuel pump as defined in claim 1, wherein the ratio of (the sectional area of said communication hole)/(the sectional area of said first pump chamber) is equal to or less than 1.4.
Claim 4
Dependent Claim
34 words
The two-stage fuel pump as defined in claim 2, wherein the ratio of (the sectional area of said communication hole)/(the sectional area of said first pump chamber) is equal to or greater than 0.5.
Claim 5
Dependent Claim
23 words
The two-stage fuel pump as defined in claim 3, wherein said first and second impellers have a diameter of 25 to 50 mm.
Claim 6
Dependent Claim
53 words
The two-stage fuel pump as defined in claim 1, wherein said vapor jet is formed at a position where a fuel pressure is boosted to a value greater than a half of a set pressure of a pressure regulator for regulating a pressure of said fuel to be discharged from said fuel outlet.
Claim 7
Dependent Claim
314 words
A two-stage fuel pump comprising: (a) a first impeller; (b) a first wall for surrounding said first impeller; (b-1) a first pump chamber being defined between an inner surface of said first wall and an outer circumference of said first impeller; (b-2) said first wall being formed with a fuel inlet communicating with said first pump chamber to suck fuel into said first pump chamber; (b-3) said first wall being formed with a vapor jet communicating with said first pump chamber to discharge a vapor of said fuel from said first pump chamber; (c) a second impeller having a size and a shape identical with those of said first impeller; and (d) a second wall for surrounding said second impeller; (d-1) a second pump chamber being defined between an inner surface of said second wall and an outer circumference of said second impeller; (d-2) said second pump chamber having a sectional shape substantially the same as that of said first pump chamber; (d-3) said second wall being formed with a fuel outlet communicating with said second pump chamber to discharge said fuel; (d-4) a part of said second wall partitioning said first pump chamber from said second pump chamber, said part being formed with a communication hole for communicating said first pump chamber with said second pump chamber; (e) wherein a ratio of (a sectional area of said fuel outlet)/(a sectional area of said second pump chamber) is equal to or less than 1.4, and said vapor jet is formed at a position where a fuel pressure is boosted to a value greater than a half of a set pressure of a pressure regulator for regulating a pressure of said fuel to be discharged from said fuel outlet; (f) whereby a boosting rate in said first pump chamber can be made larger than that in said second pump chamber to efficiently discharge said vapor.
Claim 8
Dependent Claim
314 words
A two-stage fuel pump comprising: (a) a first impeller; (b) a first wall for surrounding said first impeller; (b-1) a first pump chamber being defined between an inner surface of said first wall and an outer circumference of said first impeller; (b-2) said first wall being formed with a fuel inlet communicating with said first pump chamber to suck fuel into said first pump chamber; (b-3) said first wall being formed with a vapor jet communicating with said first pump chamber to discharge a vapor of said fuel from said first pump chamber; (c) a second impeller having a size and a shape identical with those of said first impeller; and (d) a second wall for surrounding said second impeller; (d-1) a second pump chamber being defined between an inner surface of said second wall and an outer circumference of said second impeller; (d-2) said second pump chamber having a sectional shape substantially the same as that of said first pump chamber; (d-3) said second wall being formed with a fuel outlet communicating with said second pump chamber to discharge said fuel; (d-4) a part of said second wall partitioning said first pump chamber from said second pump chamber, said part being formed with a communication hole for communicating said first pump chamber with said second pump chamber; (e) wherein a ratio of (a sectional area of said fuel outlet)/(a sectional area of said second pump chamber) is equal to or less than 1.4, and said vapor jet is formed at a position where a fuel pressure is boosted to a value greater than a half of a set pressure of a pressure regulator for regulating a pressure of said fuel to be discharged from said fuel outlet; (f) whereby a boosting rate in said first pump chamber can be made larger than that in said second pump chamber to efficiently discharge said vapor.
Claim 9
Dependent Claim
34 words
The two-stage fuel pump as defined in claim 6, wherein the ratio of (the sectional area of said fuel outlet)/(the sectional area of said second pump chamber) is equal to or greater than 0.5.
Claim 10
Dependent Claim
23 words
The two-stage fuel pump as defined in claim 7, wherein said first and second impellers have a diameter of 25 to 50 mm.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-04-22 | 1994-10-22 | 1995-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-22 | 1998-10-22 | 1999-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-22 | 2002-10-22 | 2003-04-23 | $7700.00 | Window Closed / Lapsed |