Rope tensioning system for drilling rig
AssigneeCaterpillar Global Mining Equipment LLC
InventorsCharles T. Hudson, Elangovan Umapathy, Prasana R
Life of this patent
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Abstract
A hydraulic tensioning system is associated with a wire rope feed system of a drilling rig for applying tension to the hoist and pulldown ropes during hoist and pulldown operations. The hydraulic tensioning system includes a hydraulic tensioning circuit with a hoist hydraulic circuit directing hydraulic fluid to a hoist actuator applying tension to the hoist wire rope and a pulldown hydraulic circuit directing hydraulic fluid to a pulldown hydraulic actuator applying tension to a pulldown wire rope. A hydraulic control valve can selectively direct flow to the hoist and pulldown hydraulic circuits.
Claims21
A rotary drilling rig comprising:
- a rig frame supported on a work surface;
- a mast mounted to the rig frame;
- a rotary head movably supported along the mast and operatively coupled to and adapted to rotate a drilling string with respect to the work surface;
- a wire rope feed actuator movable with respect to the mast;
- a wire rope feed system operatively connecting the rotary head and the wire rope feed actuator, the wire rope feed system including:
- a hoist wire rope operatively associated with a hoist tensioning actuator and connected at a hoist rope end to the rotary head;
- and
- a pulldown wire rope operatively associated with a pulldown tensioning actuator and connected at a pulldown rope end to the rotary head;
- and
- a hydraulic tensioning circuit configured to direct hydraulic fluid to the hoist tensioning actuator and to the pulldown tensioning actuator, the hydraulic tensioning circuit including a hydraulic control valve in fluid communication with and configured to selectively direct hydraulic fluid between the hydraulic tensioning circuit and the wire rope feed actuator.
A method of tensioning a wire rope feed system of a drill rig including a drilling system, the method comprising:
- supplying hydraulic fluid under pressure from a hydraulic reservoir to:
- a wire rope feed actuator operatively connected with a rotary head of the drilling system via a hoist wire rope and a pulldown wire rope;
- and
- a hydraulic control valve operatively associated with a hydraulic tensioning circuit including a hoist tensioning actuator and a pulldown tensioning actuator;
- commencing a pulldown operation by directing hydraulic fluid under pressure to an upper chamber of the wire rope feed actuator thereby moving the rotary head toward a work surface via the hoist wire rope and the pulldown wire rope;
- and
- configuring the hydraulic control valve of the hydraulic tensioning circuit to:
- communicate hydraulic fluid under pressure to a rod end chamber of the hoist tensioning actuator to maintain tension and reduce slack on a hoist rope during the pulldown operation;
- and
- communicate hydraulic fluid from a piston end chamber of the hoist tensioning actuator to a lower chamber of the wire rope feed actuator.
A drilling rig comprising:
- a rig frame supported on a work surface;
- a mast mounted to the rig frame;
- a rotary head movably supported along the mast and operatively coupled to and adapted to rotate a drill string with respect to the work surface;
- a wire rope feed actuator movable with respect to the mast;
- a wire rope feed system operatively connecting the rotary head and wire rope feed actuator;
- the wire rope feed system including:
- a hoist wire rope fixed at a first end with respect to the mast, connected at a second end to the rotary head, and operatively associated with a hoist tensioning actuator fixed to the wire rope feed actuator;
- and
- a pulldown wire rope fixed at a first end with respect to the mast, connected at a second end to the rotary head, and operatively associated with a pulldown tensioning actuator fixed to the wire rope feed actuator.
Dependencies are inferred from the claim text.