Hydraulic control system for gyratory crusher provided with safety system for overload conditions

• US 5,725,163 A
• Filed: 07/09/1996
• Issued: 03/10/1998
• Est. Priority Date: 01/17/1994
• Status: Expired due to Term

• Current Assignee: Metso Minerals Tampere Oy (Metso Corporation)
• Original Assignee: Nordberg-Lokomo Oy (Metso Corporation)
• Inventors: Eloranta, Jarmo, Rikkonen, Kari
• Primary Examiner(s): Howell, Daniel W.
• Assistant Examiner(s): KROLIKOWSKI, JULIE
• Application Number:
  US08/669,460
• Time in Patent Office: 609 Days
• Field of Search: 241/209, 241/207, 241/213, 241/37, 241/33
• US Class Current: 241/33
• CPC Class Codes: B02C 2/06 and with top bearing B02C2/042 takes precedence

Abstract

A hydraulic control system for a gyratory crusher has a hydraulically supported main shaft. An inlet line to the cylinder is provided with a pressure relief valve. When the pressure in the cylinder, e.g. because of a disturbance, exceeds the opening pressure of the relief valve, fluid flows from the cylinder through the pressure relief valve to the lubricating circuit of the crusher and further to the return line. The safety system of the crusher is simple, reliable, and quick.

Claims

1. A hydraulic control system for a gyratory crusher in which a main shaft of the crusher is supported hydraulically by a piston movable in a cylinder and the crusher is lubricated by a lubricating circuit, the system comprising:

a tank for hydraulic fluid,

a pump unit and inlet lines which lead hydraulic fluid from the tank into the cylinder and into the lubricating circuit,

a return line which leads hydraulic fluid from the cylinder and from the lubricating circuit into the tank, and

a pressure relief valve connected to the inlet line and having associated therewith an opening pressure at which the relief valve opens, and a by-pass line connected between the relief valve and lubricating circuit, such that when the pressure in the cylinder exceeds the opening pressure of the relief valve, fluid flows from the cylinder through the relief valve to the lubricating circuit and further to the return line.

2. A system in accordance with claim 1, wherein the by-pass line is integrated the crusher.

3. A system in accordance with claim 2, further comprising

a transducer which monitors a height position of the main shaft in the crusher, and

a control unit connected to the transducer and to the pump unit such that when the pressure in the cylinder is below the opening pressure of the relief valve, the control unit operates the pump unit to automatically position the main shaft at a predetermined position.

4. A system in accordance with claim 2, wherein the by-pass line is placed in the frame of the crusher.

5. A system in accordance with claim 4, further comprising

a transducer which monitors a height position of the main shaft in the crusher, and

a control unit connected to the transducer and to the pump unit such that when the pressure in the cylinder is below the opening pressure of the relief valve, the control unit operates the pump unit to automatically position the main shaft at a predetermined position.

6. A system in accordance with claim 1, further comprising

a transducer which monitors a height position of the main shaft in the crusher, and

a control unit connected to the transducer and to the pump unit such that when the pressure in the cylinder is below the opening pressure of the relief valve, the control unit operates the pump unit to automatically position the main shaft at a predetermined position.

7. A system in accordance with claim 1, wherein the pressure relief valve is integrated into the crusher.