Rock breaking machine and method for storing pressure energy

Patent metadata

Field	Value
Publication number	US-12083663-B2
Application number	US-202117796336-A
Country	US
Kind code	B2
Filing date	Jan 29, 2021
Priority date	Jan 31, 2020
Publication date	Sep 10, 2024
Grant date	Sep 10, 2024

Abstract

A pressure accumulator, rock breaking machine and method of storing pressure energy. The accumulator includes a casing and an elastic membrane arranged inside the casing. The membrane divides an inner space of the casing into two separate pressure spaces. A gas space is prefilled with pressurized gas. On the opposite side of the membrane is a hydraulic space for receiving hydraulic fluid. The membrane is a hat-like element having side walls, a mounting flange at its open end and a closed top end. The mounting flange of the membrane is mounted between the casing and a flange element. The accumulator is without a screen. The flange element is provided with a sealing for sealing a piston.

First claim

The invention claimed is:

1. A hydraulic rock breaking machine, comprising:
a percussion device including a frame and a piston arranged inside the frame and configured to perform reciprocating longitudinal movement due to pressure of hydraulic fluid fed to the percussion device;
a tool connectable to the percussion device and configured to receive impact pulses from the percussion device;
a hydraulic system of the percussion device, the hydraulic system including a feed port for feeding hydraulic pressure fluid into the percussion device and a discharge port for discharging the pressure fluid out of the percussion device, and pressure conduits for directing the pressure fluid to and out of working pressure spaces of the piston; and
a pressure accumulator for storing hydraulic pressure energy and being connected to the hydraulic system, wherein the pressure accumulator is located at an extension of the piston so that an upper end of the piston moves inside a hydraulic space of the accumulator during the operation of the percussion device and wherein the accumulator comprises:
a casing defining an inner space;
an elastic membrane arranged inside the inner space and configured to divide the inner space into two separate pressure spaces, wherein a gas space is prefilled with pressurized gas, and on the opposite side of the membrane is a hydraulic space for receiving hydraulic fluid;
a flange element, wherein the membrane has radial side walls, edges at its open first axial end and a closed top end at its opposite second axial end, wherein the edges of the membrane are mounted between the casing and the flange element, the edges of the membrane having a transverse mounting flange, whereby the membrane has a hat-like configuration, the mounting flange, of the membrane is being pressed in an axial direction of the accumulator between the casing and the flange element;
the flange element including at least one pressure channel for feeding hydraulic fluid to the hydraulic space and for discharging hydraulic fluid, whereby the pressure channel allows provision of hydraulic fluid flow from a hydraulic operating system of the rock breaking machine to and out of the hydraulic space ( 18 ) during the operation of the machine;
the flange element including a central sleeve-like support portion protruding axially inside the casing, whereby an outer surface of the support portion is configured to provide axial support for the membrane at least when the hydraulic rock breaking machine is non-pressurized; and
wherein an inner surface of the support portion of the flange element is provided with sealing elements for sealing an end portion of the piston.

2. The breaking machine as claimed in claim 1 , wherein the flange element includes an annular mounting portion transverse to the axial direction of the accumulator, wherein the pressure channels are located at the mounting portion.

3. The breaking machine as claimed in claim 1 , wherein the edges of the membrane are provided with at least one protrusion at least on one side of the membrane to serve as a sealing element, and wherein at least one of the axial mounting surfaces between the casing and the flange element is provided with a groove for receiving the at least one protrusion.

4. The breaking machine as claimed in claim 1 , wherein an axial length of the sleeve-like support portion of the flange element is at least ¼ of an axial length of the accumulator.

5. The breaking machine as claimed in claim 1 , wherein outer side surfaces of the sleeve-like support portion of the flange element are slanted towards a distal end of the support portion so that the support portion tapers towards the distal end.

6. The breaking machine as claimed in claim 1 , wherein the top surface portion facing towards the gas space and the top surface includes an annular edge portion, a central portion and an annular recess portion therebetween.

7. The breaking machine as claimed in claim 1 , wherein the side walls of the membrane are angled relative to the axial central line of the accumulator, whereby the side walls open towards the open end of the membrane.

8. The breaking machine as claimed in claim 1 , wherein the hydraulic space of the accumulator is connected to the hydraulic system of the percussion device and pressure fluid is configured to flow towards the hydraulic space and out of the hydraulic space during operation of the percussion device.

9. The breaking machine as claimed in claim 1 , further comprising at least one valve for adjusting pressure of the hydraulic fluid prevailing in the hydraulic system connected to the pressure accumulator.

10. The breaking machine as claimed in claim 1 , wherein a top end of the percussion piston ( 9 ) facing towards the hydraulic space of the accumulator is rounded.

11. A method of storing hydraulic pressure energy of a rock breaking machine, the method comprising:
providing the rock breaking machine with at least one pressure accumulator in accordance with claim 1 , the pressure accumulator including a gas space and a hydraulic space separated by a membrane, the membrane having a cup-like configuration provided with a closed top end, an open end and side walls between the ends;
prefilling the gas space with pressurized gas;
receiving a top end portion of a reciprocating piston of a percussion device of the rock breaking machine inside the hydraulic space during operation of the percussion device, whereby hydraulic volume inside the hydraulic space changes due to a protruding top end portion of the piston;
compensating the volumetric change in the hydraulic space by allowing the membrane to expand towards the gas space; and
using the membrane;
using the pressure accumulator;
mounting the membrane by pressing a mounting flange, which is located at an open end of the membrane, axially between two axial mounting surfaces.

Assignees

• Sandvik Mining & Construction Oy

Inventors

• Airas Erik

Classifications

• F15B1/04

  Accumulators · CPC title

• B25D2250/365

  Use of seals · CPC title

• B25D2222/72

  Stone, rock or concrete · CPC title

• B25D2209/002

  Pressure accumulators · CPC title

• F15B2201/3156

  characterised by their attachment · CPC title