System for stabilizing pressure fluctuations in a hydraulic line of a hydraulic circuit

Patent metadata

Field	Value
Publication number	US-2016298657-A1
Application number	US-201514684463-A
Country	US
Kind code	A1
Filing date	Apr 13, 2015
Priority date	Apr 13, 2015
Publication date	Oct 13, 2016
Grant date	—

Abstract

A system for stabilizing pressure fluctuations in a hydraulic line of a hydraulic circuit includes a hydraulic vessel coupled to the hydraulic line; a separator element disposed within the vessel to define a first fluid chamber and a second fluid chamber within the vessel; and a relief valve disposed in communication with the second fluid chamber of the vessel. The vessel includes a first fluid receivable in the first fluid chamber from the hydraulic line and a second fluid that is disposed within the second fluid chamber. The separator element is moveable within the vessel in response to a volume change of the first fluid received from the hydraulic line. The relief valve is configured to selectively release the second fluid from the vessel in response to a pressure of the first fluid exceeding a pre-determined amount of pressure within the hydraulic vessel.

First claim

We claim:

1 . A system for stabilizing pressure fluctuations in a hydraulic line of a hydraulic circuit, the system comprising:
a hydraulic vessel coupled to the hydraulic line, the hydraulic vessel having a first end, a second end, and an inner cavity defined therebetween, a movable separator element disposed within the inner cavity of the hydraulic vessel, the separator element defining a first fluid chamber disposed between the separator element and the first end and a second fluid chamber disposed between the separator element and the second end; the hydraulic vessel comprising a first fluid receivable in the first fluid chamber from the hydraulic line that is disposed proximal to the first end and a second fluid disposed within the second fluid chamber proximal to the second end, wherein the separator element is moveable within the inner cavity of the vessel between the first and second ends in response to a volume change of the first fluid received from the hydraulic line; and a relief valve disposed in fluid communication with the second fluid chamber of the hydraulic vessel, the relief valve configured to:
selectively release a pressure of second fluid from the second fluid chamber of the vessel in response to a pressure of the first fluid exceeding a pre-determined amount of pressure within the hydraulic vessel; and
selectively permit a charge of the second fluid to enter the second fluid chamber of the hydraulic vessel in response to a pressure of the first fluid falling below the pre-determined amount of pressure within the hydraulic vessel.

2 . The system of claim 1 further comprising a breather element coupled between the second end of the hydraulic vessel and the relief valve, the breather element configured with a pressure limit value for the second fluid, the pressure limit value corresponding to the pre-determined amount of pressure within the hydraulic vessel.

3 . The system of claim 1 , wherein the separator element is configured to move to a first operating point in the hydraulic vessel in response to the first fluid flowing from the hydraulic line into the hydraulic vessel.

4 . The system of claim 3 , wherein the separator element is configured to move to a second operating point in the hydraulic vessel in response to the first fluid flowing from the hydraulic vessel into the hydraulic line, the second operating point being distinct from the first operating point and located proximal to the first end of the hydraulic vessel.

5 . The system of claim 1 , wherein the hydraulic vessel is disposed upright with respect to a horizontal.

6 . The system of claim 1 , wherein the separator element is configured to travel along a longitudinal axis of the hydraulic vessel.

7 . The system of claim 1 further comprising a seat defined at the first end of the hydraulic vessel, the seat shaped to form a sealable engagement with the separator element.

8 . The system of claim 1 , wherein the separator element includes:
a first float element disposed proximal to the first end of the hydraulic vessel and configured to define the first fluid chamber with the first end of the hydraulic vessel; a second float element disposed proximal to the second end of the hydraulic vessel and in a spaced apart relation to the first float element, the second float element configured to define the second fluid chamber with the second end of the hydraulic vessel; and a connecting element coupling the first float element to the second float element.

9 . The system of claim 8 , wherein the connecting element is a spring.

10 . A hydraulic system for stabilizing pressure fluctuations in a hydraulic line of a machine, the system comprising:
a hydraulic subsystem having a variable pressure to perform a hydraulic function, the hydraulic subsystem including a port; a hydraulic line coupled to the port; a hydraulic vessel coupled to the hydraulic line, the hydraulic vessel having a first end, a second end, and an inner cavity defined therebetween, a movable separator element disposed within the inner cavity of the hydraulic vessel, the separator element defining a first fluid chamber disposed between the separator element and the first end and a second fluid chamber disposed between the separator element and the second end; the hydraulic vessel comprising a first fluid receivable in the first fluid chamber from the hydraulic line that is disposed proximal to the first end and a second fluid disposed within the second fluid chamber proximal to the second end, wherein the separator element is moveable within the inner cavity of the vessel between the first and second ends in response to a volume change of the first fluid received from the hydraulic line; and a relief valve disposed in fluid communication with the second fluid chamber of the hydraulic vessel, the relief valve configured to:
selectively release a pressure of second fluid from the second fluid chamber of the vessel in response to a pressure of the first fluid exceeding a pre-determined amount of pressure within the hydraulic vessel; and
selectively permit a charge of the second fluid to enter the second fluid chamber of the hydraulic vessel in response to a pressure of the first fluid falling below the pre-determined amount of pressure within the hydraulic vessel.

11 . The hydraulic system of claim 10 further comprising a breather element coupled between the second end of the hydraulic vessel and the relief valve, the breather element configured with a pressure limit value for the second fluid, the pressure limit value corresponding to the pre-determined amount of pressure within the hydraulic vessel.

12 . The hydraulic system of claim 10 , wherein the separator element is configured to move to a first operating point in the hydraulic vessel in response to the first fluid flowing from the hydraulic line into the hydraulic vessel.

13 . The hydraulic system of claim 12 , wherein the separator element moves to a second operating point in the hydraulic vessel in response to the first fluid flowing from the hydraulic vessel into the hydraulic line, the second operating point being distinct from the first operating point.

14 . The hydraulic system of claim 10 , wherein the hydraulic vessel is disposed upright with respect to a horizontal.

15 . The hydraulic system of claim 10 further comprising a seat defined at the first end of the hydraulic vessel, the seat shaped to form a sealable engagement with the separator element.

16 . The hydraulic system of claim 10 , wherein the hydraulic subsystem is a cooling circuit associated with a brake station of a wheel hub.

17 . The hydraulic system of claim 16 , wherein the relief valve is configured to supply the second fluid in a low-pressure state to the cooling circuit for cooling the brake station.

18 . A machine comprising:
a hoist cylinder; a hoist control valve system coupled to the hoist cylinder, the hoist control valve system configured to selectively actuate movement of the hoist cylinder; a wheel hub; a brake station positioned at the wheel hub; a brake cooling circuit coupled to the brake station; a hydraulic line coupled between a rod end of the hoist cylinder via the hoist control valve system and the brake cooling circuit when the hoist control valve system is in a raise position; a hydraulic vessel coupled to the hydraulic line, the hydraulic vessel having a first end, a second end, and an inner cavity defined therebetween, a movable separator element disposed within the inner cavity of the hydraulic vessel, the sepa

Assignees

• Caterpillar Inc

Inventors

• Kleitsch Andrew
• Vacca John Cody

Classifications

• F15B2211/625

  Accumulators · CPC title

• F15B2201/20

  Accumulator cushioning means · CPC title

• F15B2201/4155

  having valve means · CPC title

• F15B1/021 Primary

  used for damping · CPC title

• F15B2211/611

  Diverting circuits, e.g. for cooling or filtering · CPC title