US2104819A - Roller boring drill - Google Patents

Description

1938. R. w. SCHLUMPF -r AL 2,104,819

ROLLER BOR ING DRILL Filed March 9 1935 Haber? Z4). 'cZzl um pf 5 Rag viz P. Sherman INVENTOR ATTORNEY Patented Jam-11, 1938 ROLLER BORING DRILL Robert W. Schlumpf and Ralph P. Sherman,

Houston, Tex., assignors to Hughes Tool Company, Houston, Tex., a corporation of Texas Application March 9,

2 Claims.

Our invention relates to roller boring drills such as are employed in drilling deep wells for oil, gas, sulphur and the like.

The improvement consists in the provision of an effective type of bearing forthe rolling outters.

The invention is particularly applicable to cutters upon the so-called cone cutters employed in hard formation bits.

It is an object of the invention to provide a bearing surface upon thecutter shaft which may have a rotation with the cutter upon the shaft but at a slower rate of rotation than that of the cutter itself, thus allowing a smooth rotation of the cutter and a prolonged life upon the bearing.

We desire to provide a form of anti-friction bearing which will be of strong and sturdy construction and not liable to become broken in use. We wish to avoid the difiiculty commonly experienced with roller bearings where said bearings will be broken and moved out of position during the operation of the cutter.

In the drawing, Fig. 1 is a side view partly in elevation and partly in central vertical section showing one embodiment of the invention.

Fig. 2 is a broken sectional detail showing a cutter upon its shaft with a slightly different form of bearing.

Fig. 3 is a view similar to Fig. 2 but illustrating a still different embodiment of the invention.

Figs. 4 and 5 are perspective views of the bearing members removed from their position upon the shaft.

We have illustrated the invention as applied to the usual type of so-called cone bit. Said bit has a head i with an upwardly tapered and threaded shank 2 for attachment to a drill collar. Said head has two downwardly diverging legs 3, the inner faces of which are inclined upwardly 40 and inwardly and have an integral shaft 4 there- 'on. Said shaft projects downwardly and inwardly at approximately right angles to the plane inner face of the leg upon which it is formed.

The head has a longitudinal passage 5 therethrough to conduct flushing fluid to the cutters in the usual manner.

The shafts 4 are shown as having an upper cylindrical area 6 of strong construction and a forward projection I thereon of smaller diameter.

The general form of the shaft is therefore a tapered one conforming to the general contour of the conical shaped cutter 8 which is mounted thereon.

The cutter 8 is toothed in the-usual manner and has its inner bearing surface shaped to conform to the shape of the shaft 2.

1935, Serial No. 10,257

The bearings between the cutter and the shaft which form the subject matter of our invention include a row of balls 9 fitting within the raceway partly within the shaft and partly within the inner wall of the cutter shell. These balls are 5 introducedinto the raceway when the cutter is mounted upon the shaft through a transverse opening in the head. Said opening is closed thereafter by a plug l0 held in place by a bond of welding material ll. Toward the forward end of the cutter shaft we employ a thin sleeve l2 of bearing metal separating the cutter from the shaft and conforming in shape to the outer surface of the shaft. Its inner end is of enlarged diameter, fitting over the body 4 of the shaft and the forward end is reduced to engage closely but rotatably upon the projection 1. This bearing member forms a sleeve or thimble which is rotatable upon the shaft and also relative to the cutter. The bearing sleeve may be made of any desired metal resistant to wear such as carburized steel and it is intended to increase the life of the cutter and the shaft during the operation of the 'bit.

It is contemplated that when the bit is operated the cutters will roll on the bottom of the hole, thus rotating upon the cutter shaft. The bearings 9 will take up the thrust of the cutter at the outer end thereof. The bearing sleeve i2- will rotate partly with the cutter and there will be relative movement between the cutter and the bearing sleeve and also between the bearing sleeve and the shaft. There will thus be less wear upon the cutter and the sleeve will be of sufficiently strong and sturdy construction that it will not break up in use.

The common difliculty with cutters of this kind, that bearings introduced between the forward end of the cutter and the shaft will crack up and interfere with the operation of the cutter, will be largely eliminated.

In Fig. 2 the structure is approximately the same as in Fig. 1 with the exception of the bearing sleeve. In this particular embodiment we provide two separate rings or sleeves l3 and I4 45 between the interior of the cutter shell and the outer surface of the shaft. The sleeve I3 is set within a recess in the shaft and is supported upon the forward end of the large portion of the shaft. 50 The ring I4 is fitted over the projection 1' upon the shaft and is of materially smaller diameter. The two bearings are both of them rotatable upon the shaft and in use will wear on both their outer and inner surfaces, thus allowing a freer 55 rotation of the cutter but also serving to form a substantial support not liable to break in use.

In Fig. 3 is a still diflerent embodiment. The

shaft 4' has an annular recess l5 adjacent the base of the shaft to receive a row of rollers IE to support the cutter at that point. The retaining row of balls I! is placed forwardly on the shaft from the roller raceway, these ballsbeing inserted through an opening closed by the plug I 0, as previously described. The forward reduced end 1" upon the shaft has an annular recess I 8 to receive a bearing ring i9. Said ring is divided longitudinally, as shown in Fig. 5, so that it may be fitted over the end of the shaft and within the groove la.

The operation of this hearing is similar to those previously described, the rollers and balls serving in the usual manner to provide an antifriction bearing for the shaft along its larger diameter. On the smaller diameter of the projection 'l" the ring l9 operates to provide a reduced friction at that point being rotatable partly with the cutter upon its seat within the recess IS. The ring is thus able to reduce friction at the forward portion of the shaft and still be of such construction that it will not break up under the extreme pressures to which it is subjected in use.

In Fig. 4 we have shown how the bearing sleeve may if desired be formed with perforations 28 to receive lubricating material. It is customary in the mounting of the cutter upon the shaft to thoroughly cover the bearings with a heavy lubricant. The provision of the openings in the bearing sleeves provides still further space into which .even where submitted to heavy pressures.

the lubricant may be received and decrease the friction of operation to some extent. It is to be noted that the cutter is spaced slightly from the shaft except where it rests upon the bearings to thus permit the circulation of water from the hole around, the bearings and keep them cooled during operation. It will be seen that our form of bearing is such that it can not be easily broken The usual difliculty of having the bearings toward the forward end of the shaft broken under the heavy strains encountered will be overcome to a large extent and the life of the bearing materially prolonged.

What we claim as new is: i

1. A drill head, a forwardly inclined cutter shaft thereon, a cutter enclosing the end of said shaft, anti-friction bearings for said shaft acting also to retain said cutter on said shaft, a reduced forward extension on said shaft, an annular raceway recessed in said extension and a longitudinally divided ring of bearing material in said raceway, the end walls of said recess limiting longitudinal movement of said ring.

2. A well drill head, a cutter shaft thereon, a reduced extension on said shaft, a cylindrical recess on said extension, a cutter enclosing the end of said shaft and extension, means to retain said cutter on said shaft, and a bearing ring on said extension fitting behind a shoulder of said recess thereon, and rotatable relative to said shaft and said cutter.

ROBERT W. SCI-ILUMPF.

RALPH P. SHERMAN.

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