Pressure regulating modules with controlled leak paths

Patent metadata

Field	Value
Publication number	US-10865718-B2
Application number	US-201716083334-A
Country	US
Kind code	B2
Filing date	Mar 7, 2017
Priority date	Mar 7, 2016
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A pressure regulating module for regulating the pressure of a first fluid using a reference pressure of a second fluid. A pressure transfer assembly including a piston slidably disposed within a cylinder bore between a control fluid chamber and a reference fluid chamber is dimensioned to provide a predefined radial clearance between at least a portion of the outer side wall and the inner circumferential surface of the housing along a predefined axial length of the main body. The predefined radial clearance and predefined axial length are dimensioned to control the flow rate and amount of fluid along one or more fluid communication passages formed between at least a portion of the piston and the housing inner circumferential surface from one or more high pressure fluid zones to a lower pressure fluid zone which can include a leak and/or weep orifice directing fluid to a drain and/or vent circuit.

First claim

What is claimed is:

1. A pressure regulating module comprising:
a) a housing including a fluid inlet, a control fluid outlet, a reference fluid port, and at least a portion of the housing having an inner circumferential surface defining an axially extending cylinder bore, said cylinder bore being fluidly coupled to the fluid inlet on a first side of the housing and fluidly coupled to the reference fluid port on a second side of the housing;
b) a pressure transfer assembly including a piston linked to a restricting element that controls flow of fluid from the fluid inlet to the control fluid outlet, said piston slidably disposed within the cylinder bore, said piston comprising a main body having a first face in communication with a control fluid chamber, a second face in communication with a reference fluid chamber, and a cylindrical outer side wall; said piston dimensioned to provide a predefined radial clearance between at least a portion of said outer side wall and said inner circumferential surface of the housing along a predefined axial length of said main body; and
c) a fluid leak orifice extending from said inner circumferential surface of said housing to an exterior surface of said housing between said reference fluid chamber and said control fluid chamber;
wherein said predefined radial clearance and predefined axial length are dimensioned to control the flow rate of fluid along a fluid communication passage formed between at least a portion of said piston and said inner circumferential surface from a high pressure fluid zone to a lower pressure fluid zone.

2. The pressure regulating module of claim 1 , wherein said predefined radial clearance and said predefined axial length are dimensioned to limit fluid flow below a predetermined amount between said high pressure fluid zone and said lower pressure fluid zone.

3. The pressure regulating module of claim 1 , wherein said predefined axial length extends substantially from said second face to said fluid leak orifice.

4. The pressure regulating module of claim 1 , wherein said high pressure fluid zone is said control fluid chamber and said lower pressure fluid zone is said fluid leak orifice.

5. The pressure regulating module of claim 1 , wherein said high pressure fluid zone is said reference fluid chamber and said lower pressure fluid zone is said fluid leak orifice.

6. The pressure regulating module of claim 1 , further comprising a radial groove in substantial alignment with said fluid leak orifice to guide fluid flowing along said fluid communication passage from said high pressure fluid zone to said fluid leak orifice.

7. The pressure regulating module of claim 1 , further comprising a leakage preventing seal disposed between said control fluid chamber and said fluid leak orifice to form a seal between the outer side wall of said piston and the inner circumferential surface of the housing.

8. The pressure regulating module of claim 7 , further comprising a weep passage formed in said main body of said piston fluidly connecting said control fluid chamber to said fluid leak orifice.

9. The pressure regulating module of claim 1 , further comprising a weep passage formed in said main body of said piston fluidly connecting said control fluid chamber to a weep orifice; said weep orifice extending from said inner circumferential surface to an exterior surface of said housing.

10. The pressure regulating module of claim 9 , wherein said weep orifice is configured to be fluidly coupled to at least one of a drain circuit, a vent circuit, a fluid supply line for supplying fluid to one or more of a fluid supply reservoir, an after treatment system, an internal combustion engine, and an auxiliary power unit.

11. The pressure regulating module of claim 1 , wherein said piston is dimensioned to provide a second predefined radial clearance between a second portion of said outer side wall and a second portion of said inner circumferential surface of the housing along a second predefined axial length; wherein said second predefined radial clearance and said second predefined axial length are dimensioned to control a flow rate of fluid along a second fluid communication passage formed between said piston and said second portion of said inner circumferential surface from a high pressure fluid zone to a lower pressure fluid zone.

12. The pressure regulating module of claim 1 , wherein the predefined radial clearance is less than 0.05 mm.

13. The pressure regulating module of claim 1 , wherein a pressure bias of 3 bar or greater is provided between a reference fluid chamber and said control fluid chamber.

14. The pressure regulating module of claim 1 , wherein said pressure regulating module is disposed upstream of an internal combustion engine to control fluid pressure of a fuel directed to said internal combustion engine.

15. The pressure regulating module of claim 1 , wherein reference fluid in said reference chamber and control fluid in said control chamber are substantially the same fluid.

16. The pressure regulating module of claim 1 , wherein reference fluid in said reference chamber and control fluid in said control chamber have disparate viscosities.

17. The pressure regulating module of claim 1 , wherein a gaseous fluid is employed as at least one of said control fluid and said reference fluid.

18. The pressure regulating module of claim 6 , wherein said piston further comprises an upper extended portion having an outer side wall and an upper second face; said upper extended portion is in fluid communication with said fluid leak orifice through an upper drain orifice and is dimensioned to provide a second predefined radial clearance between at least a portion of said outer side wall and a second inner circumferential surface of said housing along a second predefined axial length; wherein said second predefined radial clearance and second predefined axial length are dimensioned to control a flow rate of fluid along a second fluid communication passage formed between said outer side wall and said second inner circumferential surface from high pressure fluid zone of said reference fluid chamber to lower pressure fluid zone of said upper drain orifice.

19. The pressure regulating module of claim 14 , wherein a reference fluid in said reference chamber is a second fuel also directed to said internal combustion engine.

20. The pressure regulating module of claim 16 , wherein a liquid is employed as said reference fluid and a gaseous fluid is employed as said control fluid.

Assignees

• Westport Power Inc

Inventors

• Mumford David K

Classifications

• Y02T10/30

  Use of alternative fuels, e.g. biofuels · CPC title

• F02M21/0239

  Pressure or flow regulators therefor · CPC title

• F23K2300/206

  Control devices · CPC title

• F16K31/1225

  with a plurality of pistons · CPC title

• G05D16/187

  using pistons within the main valve · CPC title