Hydraulic system for controlling a jaw crusher

Patent metadata

Field	Value
Publication number	US-9914127-B2
Application number	US-201314399425-A
Country	US
Kind code	B2
Filing date	Apr 26, 2013
Priority date	May 10, 2012
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A hydraulic system for controlling the position of a movable jaw of a jaw crusher includes a hydraulic cylinder having a piston with a piston rod for positioning the movable jaw. The hydraulic cylinder has a bore side space for containing a hydraulic fluid taking up crushing forces exerted by the movable jaw on the piston rod, and an annular side space containing a hydraulic fluid pressing the piston against hydraulic fluid of the bore side space. The hydraulic system further includes an annular side space accumulator having a fluid compartment, which is in fluid contact with the annular side space, and a gas compartment containing a pressurized gas applying a pressure on the hydraulic fluid in the annular side space.

First claim

The invention claimed is:

1. A jaw crusher hydraulic system for controlling the position of a movable jaw of a jaw crusher, the hydraulic system comprising:
at least one hydraulic cylinder having a piston including a piston rod arranged on a first side of the piston for positioning the movable jaw, the hydraulic cylinder including a bore side space arranged on a second side of the piston, which is opposite to the first side of the piston, arranged to contain a hydraulic fluid taking up crushing forces exerted by the movable jaw on the piston rod during a crushing cycle of the jaw crusher, and an annular side space arranged on the first side of the piston for containing a hydraulic fluid pressing the piston against hydraulic fluid of the bore side space;
an annular side space accumulator having a fluid compartment in fluid contact with the annular side space;
a transfer pipe fluidly connecting the bore side space to the annular side space;
a gas compartment arranged for containing a pressurized gas to apply a pressure on the hydraulic fluid in the annular side space; and
a maximum load pressure relief valve arranged in the transfer pipe to open a connection from the bore side space to the annular side space when a first predetermined pressure of the hydraulic fluid in the bore side space is exceeded; wherein the accumulator is fluidly connected between the annular side space and the maximum load pressure relief valve.

2. A hydraulic system according to claim 1 , wherein a drain pipe fluidly connects the annular side space to a hydraulic fluid tank.

3. A hydraulic system according to claim 2 , wherein an annular side pressure relief valve is arranged in the drain pipe to open a connection from the annular side space to the hydraulic fluid tank when a second predetermined pressure of the hydraulic fluid in the annular side space is exceeded.

4. A hydraulic system according to claim 3 , wherein a pressure relief setting of the maximum load pressure relief valve is at least a factor 5 higher than a pressure relief setting of the annular side pressure relief valve.

5. A hydraulic system according to claim 3 , wherein the pressure relief setting of the annular side pressure relief valve is in the range of 3 to 50 bar(a).

6. A hydraulic system according to claim 3 , wherein the pressure relief setting of the annular side pressure relief valve is in the range of 5 to 40 bar(a).

7. A hydraulic system according to claim 1 , wherein the fluid compartment of the annular side space accumulator has a volume, at a fluid pressure in the annular side space accumulator which is two times the pre-compression pressure of the gas compartment of the annular side space accumulator, of 1 to 20% of the maximum hydraulic fluid volume of the bore side space.

8. A method of controlling the position of a movable jaw of a jaw crusher including at least one hydraulic cylinder having a piston including a piston rod arranged on a first side of the piston for positioning the movable jaw, comprising the steps of:
supplying hydraulic fluid to a bore side space arranged on a second side of the piston, which is opposite to the first side of the piston, to take up crushing forces exerted by the movable jaw on the piston rod during a crushing cycle of the jaw crusher;
supplying hydraulic fluid to an annular side space arranged on the first side of the piston to press the piston against the hydraulic fluid of the bore side space;
applying a pressure to the hydraulic fluid of the annular side space by an annular side space accumulator having a gas compartment containing a pressurized gas and a fluid compartment in fluid contact with the annular side space; and
transferring hydraulic fluid from the bore side space through a maximum load pressure relief valve to the annular side space when the pressure of the hydraulic fluid in the bore side space exceeds a first predetermined pressure; wherein the accumulator is fluidly connected between the annular side space and the maximum load pressure relief valve.

9. A method according to claim 8 , further comprising transferring hydraulic fluid from the bore side space to the annular side space when an uncrushable object has been fed to the jaw crusher.

10. A method according to claim 8 , further comprising transferring hydraulic fluid from the annular side space to a hydraulic fluid tank when the pressure in the annular side space exceeds a second predetermined pressure.

11. A method according to claim 10 , wherein the second predetermined pressure at which hydraulic fluid is transferred from the annular side space to the hydraulic fluid tank is in the range of 3 to 50 bar(a).

12. A method according to claim 10 , wherein hydraulic fluid is supplied to the annular side space until the pressure in the annular side space is equal to the second predetermined pressure, prior to starting operation of the jaw crusher.

13. A method according to claim 10 , wherein a pre-compression pressure of the gas compartment of the annular side space accumulator is lower than the second predetermined pressure, the pre-compression pressure of the gas compartment being 25-75% of the second predetermined pressure.

14. A method according to claim 10 , wherein the second predetermined pressure at which hydraulic fluid is transferred from the annular side space to the hydraulic fluid tank is in the range of 5 to 40 bar(a).

15. A method according to claim 8 , wherein the first predetermined pressure at which hydraulic fluid starts to be transferred from the bore side space to the annular side space is a factor of at least 5 higher than the second predetermined pressure at which hydraulic fluid starts to be transferred from the annular side space to the hydraulic fluid tank.

16. A method according to claim 8 , wherein 40-80% of an amount of hydraulic fluid leaving the bore side space is received in the annular side space.

Assignees

• Sandvik Intellectual Property

Inventors

• Burhoff Kristian
• Sjoberg Patrik
• Wood Andreas

Classifications

• B02C1/005

  hydraulically or pneumatically operated · CPC title

• F15B1/021

  used for damping · CPC title

• F15B2211/3058

  having additional valves for interconnecting the fluid chambers of a double-acting actuator, e.g. for regeneration mode or for floating mode · CPC title

• B02C1/025 Primary

  Jaw clearance or overload control · CPC title

• F15B2211/50518

  using pressure relief valves · CPC title