Offset stator bores for pump sealing

Patent metadata

Field	Value
Publication number	US-11255326-B2
Application number	US-201816480103-A
Country	US
Kind code	B2
Filing date	Jan 11, 2018
Priority date	Jan 24, 2017
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

Abstract

A pump includes a first housing part defining a first portion of a bore extending within the first housing part and shaped to receive a rotor; and a second housing part defining a second portion of the bore extending within the second housing part and shaped to receive the rotor. The first housing part has a first face abutable against an opposing second face of the second housing part to position the first portion of the bore with the second portion of the bore to receive the rotor. The first portion of the bore has a first circular cross-section portion centered along the first face and the second portion of the bore having a second circular cross-section portion centered, within the second housing part, at a distance from the second face.

First claim

The invention claimed is:

1. A pump, comprising:
a first housing part defining a first portion of a bore extending within said first housing part and shaped to receive a rotor; and
a second housing part defining a second portion of said bore extending within said second housing part and shaped to receive said rotor,
said first housing part having a first face abutable against an opposing second face of said second housing part to position said first portion of said bore with said second portion of said bore to receive said rotor,
said first portion of said bore having a first circular cross-section portion centered along said first face and said second portion of said bore having a second circular cross-section portion, wherein a center of the second circular cross-section portion is offset into said second housing part at a distance from a plane that extends across said second portion of the bore and is defined in part by said second face.

2. The pump of claim 1 , wherein a radius of said first circular cross-section portion and said second circular cross-section portion match an external radius of a portion of said rotor receivable therein.

3. The pump of claim 1 , wherein said first portion of said bore defines a first hemi-cylinder portion having a longitudinal axis extending along said first face.

4. The pump of claim 1 , wherein said second portion of said bore defines a second hemi-cylinder portion having a longitudinal axis extending parallel to said second face, within said second housing part at said distance from said plane.

5. The pump of claim 1 , wherein said second portion of said bore has extension portions extending from said second circular cross-section portion to said second face.

6. The pump of claim 5 , wherein said extension portions extend tangentially from either end of said second circular cross-section portion to said second face.

7. The pump of claim 5 , wherein said extension portions have a length which matches said distance from said plane.

8. The pump of claim 1 , wherein said first portion of said bore comprises a pair of intersecting first circular cross-section portions centered along said first face.

9. The pump of claim 1 , wherein said first portion of said bore defines a pair of intersecting first hemi-cylinder portions having a longitudinal axis extending along said first face.

10. The pump of claim 1 , wherein said second portion of said bore defines a pair of intersecting second circular cross-section portions centered, within said second housing part, at said distance from said plane.

11. The pump of claim 1 , wherein said second portion of said bore defines a pair of intersecting second hemi-cylinder portions having a longitudinal axis extending parallel to said second face, within said second housing part at said distance from said plane, wherein said extension portions extend tangentially from either non-intersecting end of said second circular cross-section portions to said second face.

12. The pump of claim 1 , wherein said distance comprises up to a location tolerance of said first face of said first housing part.

13. The pump of claim 1 , wherein said distance comprises up to said location tolerance of said first face of said first housing part together with a displacement tolerance of said rotor.

14. The pump of claim 1 , wherein said first housing part defines a plurality of first portions of bores shaped to receive said rotor and said second housing part defines a plurality of second portions of bores shaped to receive said rotor.

15. The pump of claim 14 , wherein a radius of a first circular cross-section and a second circular cross-section portion of said plurality of first and second portions of bores matches an external radius of a portion of said rotor received therein.

16. The pump of claim 14 , where said plurality of first portions of bores have a first circular cross-section centered along said first face and said plurality of second portions of bores have a second circular cross-section portion centered, within said second housing part, at said distance from said plane.

17. The pump of claim 14 , wherein said plurality of second portions of bores have said second circular cross-section portion centered, within said second housing part, at the same distance from said plane.

18. The pump of claim 14 , wherein said plurality of first portions of bores are centered, within a bore position tolerance, from said first face.

19. The pump of claim 18 , wherein said plurality of first portions of bores are centered, within said bore position tolerance together with a displacement tolerance of said rotor, from said first face.

20. A method for forming a pump, comprising:
defining a first portion of a bore shaped to receive a rotor and extending within a first housing part;
defining a second portion of said bore shaped to receive said rotor and extending within a second housing part,
said first housing part having a first face abutable against an opposing second face of said second housing part to position said first portion of said bore with said second portion of said bore to receive said rotor,
centering said first portion of said bore having a first circular cross-section portion along said first face and
centering said second portion of said bore having a second circular cross-section portion offset into, said second housing part, at a distance from a plane that extends across said second portion of the bore and is defined in part by said second face.

Assignees

• Edwards Ltd

Inventors

• Holbrook Alan Ernest Kinnaird
• Bedwell David

Classifications

• F04C2240/10

  Stators · CPC title

• F04C27/005

  Axial sealings for working fluid · CPC title

• F04C2270/17

  Tolerance; Play; Gap · CPC title

• F04C18/123

  with radially or approximately radially from the rotor body extending tooth-like elements, co-operating with recesses in the other rotor, e.g. one tooth · CPC title

• F04C18/086

  Carter · CPC title