Fluid-working machine and operating method

Patent metadata

Field	Value
Publication number	US-10094372-B2
Application number	US-201514942567-A
Country	US
Kind code	B2
Filing date	Nov 16, 2015
Priority date	Sep 12, 2002
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

A fluid-working machine has a plurality of working chambers, e.g., cylinders, of cyclically changing volume, a high-pressure fluid manifold and a low-pressure fluid manifold, at least one valve linking each working chamber to each manifold, and electronic sequencing means for operating said valves in timed relationship with the changing volume of each chamber, wherein the electronic sequencing means is arranged to operate the valves of each chamber in one of an idling mode, a partial mode in which only part of the usable volume of the chamber is used, and a full mode in which all of the usable volume of the chamber is used, and the electronic sequencing means is arranged to select the mode of each chamber on successive cycles so as to infinitely vary the time averaged effective flow rate of fluid through the machine.

First claim

What is claimed is:

1. A method of operating a fluid-working machine having a plurality of working chambers of cyclically changing volume, said working chambers comprising cylinders within which pistons are arranged to reciprocate, a high-pressure fluid manifold and a low-pressure fluid manifold, at least one valve linking each working chamber of said working chambers to each manifold, the method comprising:
operating the valves of at least one of said working chambers in a partial motoring mode in which only part of the usable volume of the at least one working chamber is used; and
determining a mode of each working chamber of said working chambers on successive cycles of changing working chamber volume so as to vary the time averaged effective flow rate of fluid through the machine according to a demand level; and operating the valves of each of said working chambers to select the determined mode in accordance with an operation sequence which, in the successive cycles of changing working chamber volume, intersperses modes including at least (i) idling modes, and (ii) said partial motoring modes, wherein the sequence of modes of operation is based upon a function of the error between the measured and demanded pressure.

2. A method of operating a fluid-working machine having a plurality of working chambers of cyclically changing volume, said working chambers comprising cylinders within which pistons are arranged to reciprocate, a high-pressure fluid manifold and a low-pressure fluid manifold, at least one valve linking each working chamber of said working chambers to each manifold, the method comprising:
operating the valves of at least one of said working chambers in a partial motoring mode in which only part of the usable volume of the at least one working chamber is used; and
determining a mode of each working chamber of said working chambers on successive cycles of changing working chamber volume so as to vary the time averaged effective flow rate of fluid through the machine according to a demand level; and operating the valves of each of said working chambers to select the determined mode in accordance with an operation sequence which, in the successive cycles of changing working chamber volume, intersperses modes including at least (i) idling modes, and (ii) said partial motoring modes, wherein the sequence of modes of operation is based upon the time history of past systems responses to past decisions.

3. A fluid-working machine comprising:
a plurality of working chambers of cyclically varying volume, said working chambers comprising cylinders within which pistons are arranged to reciprocate;
a high-pressure fluid manifold;
a low-pressure fluid manifold;
at least one valve linking each working chamber of said working chambers to each manifold; and
a controller having a configuration to operate the valves of at least one of the said working chambers in a partial motoring mode in which only part of the usable volume of the at least one working chamber is used,
wherein the controller is further configured to: vary the time averaged effective flow rate of fluid through the machine according to a demand level, and operate the valves of each of the working chambers to select the determined mode in accordance with an operation sequence which, in the successive cycles of changing working chamber volume, intersperses modes including at least (i) idling modes, (ii) said partial motoring modes, wherein the sequence of modes of operation is based upon a function of the error between the measured and demanded pressure.

4. A fluid-working machine comprising:
a plurality of working chambers of cyclically varying volume, said working chambers comprising cylinders within which pistons are arranged to reciprocate;
a high-pressure fluid manifold;
a low-pressure fluid manifold;
at least one valve linking each working chamber of said working chambers to each manifold; and
a controller having a configuration to operate the valves of at least one of the said working chambers in a partial motoring mode in which only part of the usable volume of the at least one working chamber is used,
wherein the controller is further configured to: vary the time averaged effective flow rate of fluid through the machine according to a demand level, and operate the valves of each of the working chambers to select the determined mode in accordance with an operation sequence which, in the successive cycles of changing working chamber volume, intersperses modes including at least (i) idling modes, (ii) said partial motoring modes, wherein the sequence of modes of operation is based upon the time history of past systems responses to past decisions.

5. A machine comprising: a plurality of working chambers of cyclically changing volume; a high-pressure fluid manifold; a low-pressure fluid manifold; at least one valve linking each working chamber to each manifold; and a controller having a configuration to: determine a mode of each working chamber on successive cycles of changing working chamber volume so as to vary the time averaged effective flow rate of fluid through the machine according to a demand level, and operate the valves of each of the working chambers to select the determined mode in accordance with an operation sequence which, in the successive cycles of changing working chamber volume, intersperses modes including at least (i) idling modes, (ii) partial stroke modes in which only part of the usable volume of the working chamber is used and (iii) full stroke modes in which all of the usable volume of the working chamber is used.

6. The machine of claim 5 , wherein the demand level is varied in use.

7. The machine of claim 5 , wherein the partial stroke modes comprise use of only a small fraction of the usable volume of the working chambers, and wherein the small fraction is one in which valve actuations are delayed to almost the end of the stroke such that a rate of change of working chamber volume will be at an acceptably low level to permit valve actuation.

8. The machine of claim 5 , wherein the partial stroke modes comprise use of only a small fraction of the usable volume of the working chambers, and wherein the small fraction is one that provides sufficient stability of valve operation at the low flow end.

9. The machine of claim 5 , wherein, in the partial modes, valve actuations are delayed to almost an end of a stroke such that a rate of change of working chamber volume will be at an acceptably low level to permit valve actuation.

10. The machine of claim 5 , wherein the partial stroke modes are part stroke motoring modes in which the transition from intake from the high-pressure manifold to intake from the low pressure manifold happens a small fraction after top dead center, wherein the small fraction is one in which valve actuations are such that a rate of change of working chamber volume will be at an acceptably low level to permit valve actuation.

11. The machine of claim 5 , wherein the sequence of modes of operation is tailored for one or more of the smoothest flow result, the most seamless change in audible noise, minimal pressure ripple, and optimum actuator motion.

12. A machine comprising: a plurality of working chambers of cyclically changing volume; a high-pressure fluid manifold; a low-pressure fluid manifold; at least one valve linking each working chamber to each manifold; and a controller having a configuration to: vary the time averaged effective flow rate of fluid through the machine according to a demand level, and operate the valves of each of the working chambers to select the determined mode in accordance with an operation sequence which, in the successive cycles of changi

Assignees

• Artemis Intelligent Power Ltd

Inventors

• Stein Uwe Bernhard Pascal
• Caldwell Niall James
• Rampen William Hugh Salvin
• Almond Jonathan Paul

Classifications

• F01B25/10

  Arrangements or adaptations of working-fluid admission or discharge valves · CPC title

• F04B53/1082

  magnetic · CPC title

• F04B2201/02

  Piston parameters · CPC title

• F04B49/225 Primary

  with throttling valves or valves varying the pump inlet opening or the outlet opening · CPC title

• F04B2201/0807

  Number of working cylinders · CPC title