FLUID WORKING SYSTEMS

• US 20160327038A1
• Filed: 05/08/2015
• Published: 11/10/2016
• Est. Priority Date: 05/08/2015
• Status: Active Grant

• Current Assignee: Danfoss Power Solutions GmbH & Co. OHG (Danfoss A/S)
• Original Assignee: Danfoss Power Solutions GmbH & Co. OHG (Danfoss A/S)
• Inventors: Gruber, Elliott, Wadsley, Luke
• Granted Patent: US 11,655,816 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F04B 11/00 Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation
• CPC Class Codes: F04B 11/0091 using a special shape of fluid pass, e.g. throttles, ducts
• CPC Class Codes: F04B 39/12 Casings; Cylinders; Cylinder heads; Fluid connections
• CPC Class Codes: F04B 53/16 Casings; Cylinders; Cylinder liners or heads; Fluid connections
• CPC Class Codes: F04C 15/0049 Equalization of pressure pulses silencing for compressors F04C29/06
• CPC Class Codes: F04C 15/064 with inlet and outlet valves specially adapted for rotary or oscillating piston machines or pumps
• CPC Class Codes: F04C 18/0215 where only one member is moving
• CPC Class Codes: F04C 18/126 with radially from the rotor body extending elements, not necessarily co-operating with corresponding recesses in the other rotor, e.g. lobes, Roots type
• CPC Class Codes: F04C 18/16 with helical teeth, e.g. chevron-shaped, screw type for non-parallel axes of movement F04C18/48
• CPC Class Codes: F04C 18/18 with similar tooth forms F04C18/16 takes precedence
• CPC Class Codes: F04C 18/344 with vanes reciprocating with respect to the inner member
• CPC Class Codes: F04C 2/025 the moving and the stationary member having co-operating elements in spiral form
• CPC Class Codes: F04C 2/126 with radially from the rotor body extending elements, not necessarily co-operating with corresponding recesses in the other rotor, e.g. lobes, Roots type
• CPC Class Codes: F04C 2/16 with helical teeth, e.g. chevron-shaped, screw type for non-parallel axes of movement F04C3/00
• CPC Class Codes: F04C 2/18 with similar tooth forms F04C2/16 takes precedence
• CPC Class Codes: F04C 2/344 with vanes reciprocating with respect to the inner member
• CPC Class Codes: F04C 29/0035 Equalization of pressure pulses silencing F04C29/06
• CPC Class Codes: F04C 29/063 Sound absorbing materials
• CPC Class Codes: F04C 29/124 with inlet and outlet valves specially adapted for rotary or oscillating piston pumps
• CPC Class Codes: F05C 2253/14 Foam

Abstract

A fluid working system such as a pump for displacing a working fluid such as hydraulic fluid or a motor using a working fluid is provided. The system may have a positive displacement machine which includes one or more working chamber with displacement means such as a cylinder with a reciprocating piston. There are also two or more fluid ports to allow the working fluid to flow into and out of the working chamber. The working fluid flows from one fluid port means to another either being forced to do so when pumped or moving the piston when functioning as an engine. The fluid working system has associated therewith a non-dead compliance volume of a material such as syntactic foam. This compliance volume acts to smooth any pressure fluctuations within the working fluid system.

Claims

1. A fluid working system for a working fluid including a positive displacement machine, said positive displacement machine comprising:

at least one working chamber and, at least two, fluid port means allowing working fluid to flow into and out of said working chamber,

displacement means within, or defined by, said working chamber to displace, or be actuated by, working fluid from one fluid port means to another,

wherein the fluid working system has associated therewith a compliance volume smoothing pressure fluctuations of said working fluid within said fluid working system.

2. The fluid working system for a working fluid including a positive displacement machine as claimed in claim 1, wherein said fluid port means comprises valves operable to be individually opened and closed at a selected rate.

3. The fluid working system for a working fluid including a positive displacement machine as claimed in claim 1, wherein the compliance volume is housed within the working chamber.

4. The fluid working system for a working fluid including a positive displacement machine as claimed in claim 3, wherein the compliance volume is housed within the displacement means.

5. The fluid working system for a working fluid including a positive displacement machine as claimed in claim 1, wherein said compliance volume comprises a volume of material selected from Syntactic foam, micro-balloon material, micro or macro-sphere material, ceramic matrix material, voided media.

6. The fluid working system for a working fluid including a positive displacement machine as claimed in claim 1, wherein

the volume of material is held in place by means of one or more protrusions from the interior of the working chamber.

7. A positive displacement pump for displacing a working fluid, including at least one cylinder each including a working end defining a working chamber and at least two fluid port means allowing working fluid to flow into and out of said working chamber,

a piston moving within said working chamber to displace working fluid flowing from one fluid port means to another;

wherein the positive displacement pump has associated therewith a compliance volume smoothing pressure fluctuations of said working fluid displaced by said pump.

8. The positive displacement pump for a working fluid as claimed in claim 7, wherein the compliance volume is housed within the cylinder.

9. The positive displacement pump for a working fluid as claimed in claim 7, wherein the compliance volume is housed within the working chamber.

10. The positive displacement pump for a working fluid as claimed in claim 7, wherein said compliance volume comprises a volume of material selected from Syntactic foam, micro-balloon material, micro or macro-sphere material, ceramic matrix material, voided media.

11. The positive displacement pump for a working fluid as claimed in claim 7 wherein,

the volume of material is held in place by means of one or more protrusions from the interior of the cylinder.

12. A digital positive displacement pump for displacing a working fluid, including at least one cylinder each including a working end defining a working chamber and at least two fluid port means allowing working fluid to flow into and out of said working chamber,

a piston displaced by displacing means within said working chamber to displace working fluid flowing from one fluid port means to another,

said fluid port means being operable to be individually opened and closed at a selective rate independently of the displacement of the each piston;

wherein the positive displacement pump has associated therewith a compliance volume smoothing pressure fluctuations of said working fluid displaced by said positive displacement pump.

13. A digital positive displacement motor powered by a working fluid, including at least one cylinder each including a working end defining a working chamber and at least two fluid port means allowing working fluid to flow into and out of said working chamber,

a piston displaced by working fluid flowing from one fluid port means to another providing work to displacing means,

said fluid port means being operable to be individually opened and closed at a selective rate;

wherein the positive displacement motor has associated therewith a compliance volume smoothing pressure fluctuations of said working fluid flowing is said positive displacement motor.

14. The use of syntactic foam in a positive displacement machine to provide a compliance volume retained within the piston assembly thereby reducing pressure ripple.

15. A method of retaining a volume of syntactic foam within a positive displacement machine by means of retaining rings.

16. A fluid working system comprising a positive displacement machine including a compliance volume of syntactic foam to provide pressure ripple reducing means.

17. A positive displacement pump for displacing a working fluid, including at least one cylinder each including a working end defining a working chamber and at least two fluid port means allowing working fluid to flow into and out of said working chamber,

a piston moving within said working chamber to displace working fluid flowing from one fluid port means to another;

wherein said working chamber contains a compliance volume of syntactic foam smoothing pressure fluctuations of said working fluid displaced by said pump.

18. The positive displacement pump for displacing a working fluid as claimed in claim 17, wherein said fluid port means are operable to be individually opened and closed at a selective rate independently of displacement of said displacement means.

19. The positive displacement pump for displacing a working fluid as claimed in claim 17, wherein

said volume of syntactic foam is held in place by means of one or more protrusions from the interior of the working chamber.

20. A fluid working system for a working fluid including a positive displacement machine,

said positive displacement machine comprising:

at least one working chamber and, at least two, fluid port means allowing working fluid to flow into and out of said working chamber,

displacement means within, or defined by, said working chamber to displace, or be displaced by, working fluid from one fluid port means to another,

wherein the fluid working system contains a compliance volume of syntactic foam in fluid communication with one or more of said fluid ports smoothing pressure fluctuations of said working fluid within said fluid working system.

21. A fluid working system including at least one working chamber wherein the working chamber includes working chamber compliance volume retaining means comprising working chamber engagement means and a compliance volume engagement protrusion extending along an axis of said working chamber.