US3790312A

US3790312A - Pumps for liquids

Info

Publication number: US3790312A
Application number: US00274295A
Authority: US
Inventors: H Bottoms
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-07-23
Filing date: 1972-07-24
Publication date: 1974-02-05
Anticipated expiration: 1991-02-05
Also published as: JPS4829001A; DE2236082A1; GB1389222A; FR2147632A5

Abstract

A pump for a liquid comprises a housing a first chamber in the housing, an inlet and an outlet for said front chamber a second chamber in the housing sealingly separated from the first chamber, an electric motor in the second chamber, a third chamber between the first and second chambers, an outlet from said third chamber, a main impeller in the first chamber, an anusiliary impeller in the third chamber to urge any fluid leaking from said first and second chamber to the outlet.

Description

Feb. 5, 1974 United States Patent 91 Bottoms 3,495,537 2/1970 Archibald 417/424 3,513,942 5/1970 Sato...... 417/424 3,652,186 3/1972 Carter................................. 4l7/424 PUMPS FOR LIQUIDS [76] Inventor: Harry Simister Bottoms, 4O Kineton Green Rd., Solihull, England July 24, 1972 Appl. No.: 274,295

Primary Examiner-C. J. Husar [22] Filed:

Attorney, Agent, or Firm-John C. Holman et al.

[57] ABSTRACT A pump for a liquid comprises a housing a first cham- [30] Foreign Application Priority Data July 23, 1971 ber in the housing, an inlet and an outlet for said front chamber a second chamber in the housing sealingly separated from the first chamber, an electric motor in Great Britain................... 34,551/71 [52] US. Cl. 417/424 [51] Int. F04b 17/00 the second chamber, a third chamber between the first and second chambers, an outlet from said third chamber, a main impeller in the first chamber, an anusiliary impeller in the third chamber to urge any fluid leaki from said first and second chamber to the outlet.

[58] Field of 417/424 [56] References Cited UNITED STATES PATENTS 2,470,563 5/1949 Jennings 417/424 3 Claims, 1 Drawing Figure i PUMPS FOR LIQUIDS This invention relates to pumps for liquids, and has as an object to'provide such a pump in a convenient form.

According to the invention a pump for a liquid comprises a housing, a first chamber within the housing, an

- inlet and an outlet for said first chamber, a second An example of the invention will now be described with reference to the accompanying drawing which shows a longitudinal section through a pump.

The pump has a housing with an inlet 11 at one end thereof. Brackets 12 extend from the housing adjacent the inlet 11 whereby the pump may be mounted on the bottom 13 of a tank containing a liquid fuel. Sealingly secured within the housing 10 is a block 14 which in part defines a volute chamber 15. Chamber 15 communicates with an outlet 16 in the housing 10.

Sealingly mounted on the block 14 is a plate 17 which defines a chamber 18 within the'housing 10. A further chamber 19 is defined between the plate 17 and block 14, and communicates with an annular passage 20 in the block 14. Passage 20 communicates in turn with a second outlet 21 in the housing 10. Within chamber 18 is an electric motor, shown generally at 22, whose shaft 23 passes through a sealed and prelubricated bearing 24 supported by plate 17. Shaft 23 also passes through a labyrinth seal 25 in plate 17, through chamber 19 and through a shaft sealing arrangement 31 in block 14 to the chamber 15.

Surrounding motor 22 within housing 10 is a space 26. Space 26 communicates via a conduit 27 with atmosphere, supply cables for motor 22 being also led through conduit 27. Secured to shaft 23 within chamber 15 is a centrifugal impeller 28. Also secured to shaft 25 within chamber 19 is a further centrifugal impeller 29. A passage 30 permits space 18 to communicate with the side of bearing 24 remote from motor 22.

In use, the impeller 28 operates in a known manner to draw fuel from inlet 11 and to discharge it via outlet 16. Air leaking from chamber l8 into chamber 19, via passage 30, and labyrinth 25, is urged by impeller 29 to outlet 21, which is connected to a drain. Fuel leaking past sealing arrangement 31 into chamber 19 is also discharged via outlet 21. The substantially constant flow of air through labyrinth 25 into chamber 19 ensures that no fuel or vapour passes to bearing 24 or the chamber 18.

Any fuel vapour which may be present within chamber 18 is thus withdrawn via passage 30 and labyrinth 18 and expelled via outlet 21. Bearing 24 is thus exposed to fuel vapour for a minimum time and this vapour bypasses bearing 24 via passage 30. Lubricant within bearing 24 does not, therefore, deteriorate as a result of exposure to fuel vapour.

I claim:

1. A pump for a liquid comprising a housing, a first chamber within the housing, an inlet and an outlet for said first chamber a second chamber within the housing sealingly separated from said first chamber, an electric motor within said second chamber, a third chamber within the housing between said first and second chambers and sealingly separated therefrom, an outlet from said third chamber, a first impeller in said first chamber drivable by the motor to urge liquid from the inlet to the outlet of said first chamber, and a second impeller in the third chamber drivable by the motor to urge fluid leaking from said first and second chambers to the third chamber outlet.

2. A pump as claimed in claim 1 in which there is provided a labyrinth sea] separating the second chamber from the third chamber, second impeller causing, in use, a substantially constant flow of air from said second chamber to said third chamber through said labyrinth seal so as to prevent any liquid which enters said third chamber passing through said labyrinth seal.

3. A pump as claimed in claim 2 including a sealed bearing supporting the motor shaft adjacent said labyrinth seal, said housing being formed with at least one by-pass passage adjacent said bearing through which air passes towards said labyrinthseal whereby no pressure drop is created across said bearing.

Claims

2. A pump as claimed in claim 1 in which there is provided a labyrinth seal separating the second chamber from the third chamber, second impeller causing, in use, a substantially constant flow of air from said second chamber to said third chamber through said labyrinth seal so as to prevent any liquid which enters said third chamber passing through said labyrinth seal.

3. A pump as claimed in claim 2 including a sealed bearing supporting the motor shaft adjacent said labyrinth seal, said housing being formed with at least one by-pass passage adjacent said bearing through which air passes towards said labyrinth seal whereby no pressure drop is created across said bearing.