Hydraulic machine having two cylinder capacities and a safety valve

Patent metadata

Field	Value
Publication number	US-10697442-B2
Application number	US-201615336352-A
Country	US
Kind code	B2
Filing date	Oct 27, 2016
Priority date	Oct 29, 2015
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

The machine comprises distribution ducts connected to respective ones of first, second, and third enclosures ( 40, 42, 44 ), and a cylinder-capacity selector ( 21 ) suitable for being caused to take up a large cylinder capacity configuration in which the second enclosure ( 42 ) is connected to one of the main ducts ( 2 ), while the first and third enclosures ( 40, 44 ) are connected to the other main duct ( 1 ), and a small cylinder capacity configuration in which the second and third enclosures ( 42, 44 ) are connected to said one of the main ducts ( 2 ), while the first enclosure is connected to the other main duct ( 1 ). The machine further comprises a safety valve ( 150 ) having at least a first port ( 56 ) connected to said one of the main ducts ( 2 ), and a second port ( 58 ) connected to the third enclosure ( 44 ). Said safety valve is suitable, when the cylinder-capacity selector ( 21 ) is caused to go into the large cylinder capacity, for being caused to go into a first configuration that isolates the first and second ports ( 56, 58 ) from each other, and, when the cylinder-capacity selector is caused to go into its small cylinder capacity, for being caused to go into a second configuration that interconnects the first and second ports ( 56, 58 ).

First claim

The invention claimed is:

1. A hydraulic machine comprising at least two active operating cylinder capacities and suitable for being connected to two main ducts, respectively a main feed duct and a main discharge duct, the machine comprising:
two series of distribution ducts, each of which has first and second groups of distribution ducts, the first group of distribution ducts of the first series being connected to a first enclosure, the second groups of distribution ducts of the first and second series being connected to a second enclosure, and the first group of distribution ducts of the second series being connected to a third enclosure;
a cylinder-capacity selector suitable for being caused to take up a large cylinder capacity configuration of the at least two active operating cylinder capacities in which the second enclosure is connected to one of the main ducts, while the first and third enclosures are connected to the other main duct, and a small cylinder capacity configuration of the at least two active operating cylinder capacities in which the second and third enclosures are connected to said at least one of the main ducts, while the first enclosure is connected to said other main duct, said large cylinder capacity configuration and small cylinder capacity configuration of the cylinder-capacity selector being different configurations of said cylinder-capacity selector; and
a safety valve having at least a first port fluidly connected to said one of the main ducts, and a second port fluidly connected to the third enclosure, said safety valve being suitable, when the cylinder-capacity selector is caused to go into the large cylinder capacity configuration, for being caused to go into a first configuration in which the first and second ports are isolated from each other, and, when the cylinder-capacity selector is caused to go into the small cylinder capacity configuration, for being caused to go into a second configuration in which the first and second ports are interconnected, the first port of the safety valve being fluidly connected to said one of the main ducts in said first and second configurations of the safety valve.

2. The machine as claimed in claim 1 , wherein the safety valve also has a third port fluidly connected to said other main duct, and the second and third ports are interconnected when said safety valve is in the first configuration.

3. The machine as claimed in claim 1 , wherein said one of the main ducts to which the first port of the safety valve is fluidly connected is the main duct that serves as the discharge duct when the machine is operating in a preferred operating direction thereof.

4. The machine as claimed in claim 1 , wherein, when the safety valve is in the second configuration, the first and second ports are fluidly connected to said one of the main ducts via a check valve allowing fluid to flow only in the direction going from the second port to the first port.

5. The machine as claimed in claim 1 , wherein, in both the large cylinder capacity configuration and the small cylinder capacity configuration of the cylinder-capacity selector, and in both the first and second configuration of the safety valve, the first group of distribution ducts of the first series are connected to the first enclosure, the second groups of distribution ducts of the first and second series are connected to the second enclosure, and the first group of distribution ducts of the second series are connected to the third enclosure.

6. The machine as claimed in claim 1 , wherein the cylinder-capacity selector is controlled hydraulically and comprises a selection control chamber connected to a cylinder capacity control duct for urging said cylinder-capacity selector to go from one of the large cylinder capacity configuration and the small cylinder capacity configuration, to the other of said large cylinder capacity configuration and said small cylinder capacity configuration, and an inverse cylinder capacity control suitable for urging said cylinder-capacity selector to go from said other of said large cylinder capacity configuration and said small cylinder capacity configuration, to said one of said large cylinder capacity configuration and said small cylinder capacity configuration.

7. The machine as claimed in claim 6 , wherein the safety valve is controlled hydraulically, and comprises a safety control chamber connected to a safety control duct for urging said safety valve to go from one of the first and second configurations to the other of the first and second configurations, and an inverse safety control for urging said safety valve to go from said other of the first and second configurations to said one of the first and second configurations, the cylinder capacity control duct and the safety control duct are interconnected.

8. The machine as claimed in claim 1 , wherein the safety valve is controlled hydraulically, and comprises a safety control chamber connected to a safety control duct for urging said safety valve to go from one of the first and second configurations to the other of the first and second configurations, and an inverse safety control for urging said safety valve to go from said other of the first and second configurations to said one of the first and second configurations.

9. The machine as claimed in claim 8 , wherein the safety valve also has a third port fluidly connected to said other main duct, and the second and third ports are interconnected when said safety valve is in the first configuration.

10. The machine as claimed in claim 1 , wherein further comprising an internal fluid distributor comprising the two series of distribution ducts.

11. The machine as claimed in claim 10 , wherein the safety valve is disposed in a casing portion of the internal distributor.

12. The machine as claimed in claim 10 , the cylinder-capacity selector is disposed in the internal fluid distributor.

13. The machine as claimed in claim 12 , wherein the cylinder-capacity selector comprises a slide mounted to move in a bore of the internal fluid distributor, and the first, second, and third enclosures comprise respective ones of first, second, and third grooves in said bore.

Assignees

• Poclain Hydraulics Ind

Inventors

• Bonnard Loic
• Costaz Dominique
• Viard Julien

Classifications

• F04B1/0456 Primary

  Cylindrical · CPC title

• F04B1/107 Primary

  with actuating or actuated elements at the outer ends of the cylinders · CPC title

• F03C1/047

  the pistons co-operating with an actuated element at the outer ends of the cylinders · CPC title

• F03C1/0438

  to cylindrical distribution members · CPC title

• F03C1/0447

  Controlling · CPC title