Abstract A drilling bit for drilling earthen material such as an oil well rotary cone drilling bit, which includes means for preventing foreign particles such as sand, rock cuttings, etc., from reaching the rotational bearings of the bit cones. This end result is principally achieved by means of a centrifugal slinger disc or wall which is positioned in external concentricity with the drill bit cone bearing, and operates to drive granular particles away from the bearings, thereby preventing such particles from reaching these bearing surfaces. The granular particles are driven by the slinger action through a series of apertures forming a channel running out to a peripheral region of the bit cones. A channel continuation is also provided for lubricating fluid, which may comprise ambient water or oil placed in chambers surrounding the bearings, this channel providing access for such lubricating fluid inwardly to the bit cone bearings. A disc-shaped wall member is provided opposite the slinger disc to minimize the escape of oil from the chambers when the bit is stationary. A ring member carrying a plurality of curved vanes, this ring member being externally concentric with the supporting shaft of the cone and located near the outer periphery of the bit cone may also be employed to prevent larger foreign particles, such as cuttings, from entering into the region of said slinger.
In a drill bit employing a roller cone, a central cavity formed in said cone, said cavity having a closed end towards the apex of the cone and an open end at the base of the cone, bearings formed within the walls of said cavity with a peripheral portion of said cavity outside the periphery of said bearings, oil contained in said cavity for lubricating said bearings, a bearing pin mounted on said bit, said bearings rotatably mounted on said bearing pin, a disc-shaped wall member forming a slinger disc having a central aperture formed therein through which the pin passes in internally concentric relationship with said wall member, said wall member being mounted on said cone for rotation therewith near the base of the cone so as to partially close the open end of said cavity, port means including an opening formed in an outer peripheral portion of said wall member for providing fluid communications between said cavity and the outside environment of the cone, and a second disc-shaped wall member mounted on said cone for rotation therewith and positioned opposite the outer peripheral portion of said first mentioned wall member in parallel relationship thereto, a narrow radial annular passage being formed between said wall members, said second wall member operating to trap said oil and minimize its escape from said cavity when the cone is stationary, whereby particulate material entering from outside the bit is forced outwardly by the centrifugal force generated by the disc-shaped member with the rotation of the cone so as to pass through the opening in said wall member and is centrifugally trapped in said outer peripheral portions of said cavity away from said bearings.
Claim 2
Dependent Claim
281 words
In a drill bit employing a roller cone, a central cavity formed in said cone, said cavity having a closed end towards the apex of the cone and an open end at the base of the cone, bearings formed within the walls of said cavity with a peripheral portion of said cavity outside the periphery of said bearings, oil contained in said cavity for lubricating said bearings, a bearing pin mounted on said bit, said bearings rotatably mounted on said bearing pin, a disc-shaped wall member forming a slinger disc having a central aperture formed therein through which the pin passes in internally concentric relationship with said wall member, said wall member being mounted on said cone for rotation therewith near the base of the cone so as to partially close the open end of said cavity, port means including an opening formed in an outer peripheral portion of said wall member for providing fluid communications between said cavity and the outside environment of the cone, and a second disc-shaped wall member mounted on said cone for rotation therewith and positioned opposite the outer peripheral portion of said first mentioned wall member in parallel relationship thereto, a narrow radial annular passage being formed between said wall members, said second wall member operating to trap said oil and minimize its escape from said cavity when the cone is stationary, whereby particulate material entering from outside the bit is forced outwardly by the centrifugal force generated by the disc-shaped member with the rotation of the cone so as to pass through the opening in said wall member and is centrifugally trapped in said outer peripheral portions of said cavity away from said bearings.