Traverse head for rotary drill rig

Abstract

A traverse head for a rotary drill rig includes a motor and gearcase supported by and drivably connected to a rotatable shaft disposed on a frame. The shaft includes a pair of spaced apart pinions drivably engaged with a pair of parallel gear racks mounted on an elongated mast whereby the traverse head may be driven along the mast to perform pulldown and hoisting movements on a drill stem. The traverse head includes a motor and gear housing mounted on the frame and connected to the drill stem. The mast of the drill rig includes a pair of spaced apart elongated flanged beams which support the gear racks and provide a track for guiding the traverse head.

Parent Case Text

This is a continuation of application Ser. No. 447,694, filed Mar. 4, 1974 now abandoned.

Description

BACKGROUND OF THE INVENTION

Various arrangements are known in the art of rotary earth drilling rigs for supporting the upper end of the drill stem for reversible traversing movements along the rig mast. U.S. Pat. Nos. 2,972,388 and 3,198,263 disclose arrangements of traverse heads for rotary drill rigs in which a system of cables driven by motor means mounted on the main deck of the rig or the base of the mast are used to operate the head for pulldown and hoisting movements on the drill stem.

U.S. Pat. No. 3,446,295 suggests a more compact and unitized arrangement in which the traverse head has the drill stem rotation motor and the traverse or feed motor mounted on the head itself. The feed motor is drivably connected to a flexible chain mounted in a looped arrangement on the mast. It has been determined that in the art of drilling rigs it is desirable to eliminate elongated feed chains or cables and their attendant supporting sprockets or sheaves together with other ancillary components therefor such as load equalizers and tensioning devices. Such arrangements require considerable maintenance and are more susceptible to early failure due to vibration and heavy shock loads which are often encountered in the use of large rotary drilling rigs for well and blasthole drilling.

SUMMARY OF THE INVENTION

The present invention provides an improved traverse head for a rotary drill rig in which the traverse or feed motor and drive means is mounted on the head itself and which drive means is engaged directly with cooperating means rigidly supported on the rig mast. In this way positive and more reliable operation of the traverse head for performing pulldown and hoisting movements on the drill stem may be attained.

The traverse head of the present invention also provides an arrangement wherein the traverse motor and drive means is substantially supported by the final drive shaft thereby greatly alleviating any possible condition of misalignment and early failure of the traverse drive mechanism. Moreover, the rack and pinion traverse mechanism in combination with the traverse head of the present invention provides an improved drive means for performing pulldown and hoisting movements on a rotary drill stem. Additionally, the mast structure, including a pair of parallel flanged beams having gear racks mounted on the outwardly facing sides thereof, cooperates with the improved traverse head of the present invention for guiding the traverse head in a positive and trouble-free manner.

Furthermore, the traverse head of the present invention is also adapted to support the rotary motor and drive mechanism for rotating the drill stem and to provide for more efficient drilling in a vertical position of the rig mast as well as positions which will provide for so-called angle drilling.

The present invention further provides a more reliable and easily serviceable traverse head for rotary drilling rigs than was heretofore known.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal side elevation of a mobile rotary drill rig including the traverse head of the present invention;

FIG. 2 is a side elevation on a larger scale of the traverse head of the drill rig of FIG. 1;

FIG. 3 is a view taken from the line 3--3 of FIG. 1;

FIG. 4 is a sectional view taken along line 4--4 of FIG. 2; and,

FIG. 5 is a sectional view taken along line 5--5 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 the traverse head of the present invention is shown in combination with a mobile rotary drill rig generally designated by the numeral 10. The drill rig 10 includes a wheeled undercarriage 12 and an elongated tower or mast 14 mounted on support means 16 to be pivotally moved from a vertical working position shown to a substantially horizontal or transport position. Pressure fluid erection cylinders 18, one shown, are connected to the mast 14 and the undercarriage 12 in a conventional manner for moving the mast between transport and working positions. The mast 14 may be adapted to be supported for drilling in intermediate or "angle" drilling positions also. The drill rig 10 further includes a housing 20 in which is disposed a prime mover such as an internal combustion engine connected to suitable power generating means for operating the drilling rig. An operator's cab 22 is disposed on the rig 10 adjacent to the mast 14 from which the rig may be controlled for drilling blastholes and the like as well as for propelling the rig from one drilling site to another.

Referring to FIGS. 3 and 4 also, the mast 14 is of the built-up configuration and includes support means comprising a pair of spaced apart and parallel beams 24 having T shaped cross sections and extending substantially the entire length of the front of the mast. A plurality of intermediate support members 26 and 28 interconnect the beams 24 to a second pair of longitudinal beam members 30, one shown in FIG. 1. The beams 24 have elongated gear racks 34 fixed in parallel arrangement on the outwardly facing sides of the flanges 32. The support members 26 and 28 are fixed to the outwardly facing sides of legs 36 of the beams 24 to provide for tracks to be formed by the inside portion 38 of the flanges 32.

The mast 14 is adapted to support a traverse head, generally designated by the numeral 40, for longitudinal traversal of the mast for exerting pulldown or feed forces on an elongated drill stem 42 and for hoisting the drill stem out of a drill hole. The drill stem 42 may be made up of one or more hollow tubular drill pipe sections in a conventional manner and includes a rotary drill bit 44 attached to the lower end thereof. As shown in FIG. 1 the drill stem 42 passes through a guide bushing 46 located on a platform 48 secured to the lower end of the mast 24.

Referring particularly to FIGS. 2, 3 and 4 the traverse head 40 comprises a frame including a pair of spaced apart panel members 50, each panel member being made up of a pair of square cross section bars 52, interconnecting plates 53, and ribs 54 and 56 as shown in FIG. 2. The panel members 50 are interconnected at one end by transverse members 58, one shown in FIG. 3, and by a housing 60 disposed between the panel members at the adjacent opposite ends thereof. The housing 60 is removably fastened to each panel member 50 by a plurality of fasteners 62. A motor 64 for rotating the drill stem 42 is mounted on the housing 60 and is drivably connected to a hollow spindle 66 by a gear train. Referring to FIG. 3, a side wall of housing 60 is broken away to show the aforementioned gear train which comprises a pinion 68 mounted on the drive shaft of motor 64, an intermediate shaft having gears 70 and 72 fixed thereto, and a bull gear 74 mounted on the spindle 66. Gear 70 meshes with pinion 68 and gears 72 and 74 are meshed. The spindle 66 is suitably supported on the housing 60 in bearings disposed in bearing housings 76 and 78. The spindle 66 is also adapted to receive drill hole cleansing fluid through a conduit 80 disposed on the housing 60. The lower end of the spindle 66 is drivably connected to the drill stem 42 by a coupling 82.

As shown in FIGS. 3 and 5 the underside of the housing 60 includes a pair of spaced apart brackets 84 which support stub shafts 86, which project laterally outward for rotatably supporting a pair of flanged rollers 88. Each roller 88 is characterized by spaced apart flanges 90 which straddle the gear rack 34 in closely spaced relationship thereto. The bracket 84 also respectively support guide roller units 92, each of which includes two rollers 93 engageable with the inside portions 38 of the beam flanges. Each roller unit 92 is pivotally supported on a stub shaft 94 which in turn is mounted in suitable support means 96 removably fastened to the brackets 84 by fasteners 98.

As may be appreciated by the foregoing description, the housing together with the motor 64 and spindle 66 may be removed from traverse head 40 for servicing or replacement without disassembling or removing the entire traverse head from the mast 14.

The traverse head 40 includes improved drive means for causing the traverse head to exert feed or pulldown forces on the drill stem 42 as well as moving the traverse head in the opposite direction for hoisting the drill stem out of a drill hole. Referring to FIGS. 3 and 4 the traverse head includes a transverse shaft 100 rotatably mounted in bearings 102 which are supported in spaced apart bearing cages 104 fixed on the respective panel members 50. The bearings 102 are desirably the self-aligning antifriction roller type. Each end of the shaft 100 includes a flanged pinion 106 removably secured on the shaft by a retainer cap 108. The pinions 106 are also secured for rotation with the shaft by interfitting splines 110. As shown in FIGS. 2 and 4 each pinion is provided with two spaced apart circular flanges 112 which straddle the gear racks 34 and are disposed for rolling engagement with the flanges 32 of the beams 24. The circular flanges 112 are of the proper diameter to provide for suitable engagement of the pinion teeth with the gear teeth of the racks 34.

The shaft 100 also substantially supports drive means for rotating the shaft, said drive means including a motor and transmission unit 114 adapted to be mounted on a gearcase 116. The gearcase 116 is mounted on the shaft 100 on a suitable self-aligning bearing assembly 118. A support member 120 including a bearing cage 122 and a self-aligning bearing 124 disposed therein is also mounted on the shaft 100 and partially supports the motor and transmission unit 114. The motor and transmission unit comprises a radial piston hydraulic motor driving through a variable speed gear transmission with internal braking means and having an output shaft 126 to which is secured a pinion 128 disposed in the gearcase 116. The pinion 128 is in driving engagement with a gear 130 secured to the shaft 100 by interfitting splines 132. A suitable motor and transmission unit 114 may comprise, by way of example, a model MS 500 radial piston hydraulic motor connected to a model RT 16 two-speed planetary gear drive which is further coupled to a model RT10 planetary gear drive, all model numbers referring to units manufactured by S.A.I. Hydraulics, Inc. Buffalo, New York. The motor and transmission unit 114 of the specific type referred to herein is operable to drive the gear 130 and shaft 100 for causing traversing of the head 40 along the mast 14 through cooperative engagement of the pinions 106 with the gear racks 34. The motor and transmission unit 114 is further adapted to be controlled from the cab 22 by a suitable fluid control circuit to drive the head 40 at variable speed and to brake the head through internal braking means disposed in the transmission unit. The gearcase 116 and support member 120 are respectively secured to the housing 60 by detachable link members 136 to prevent rotation of the gearcase and the unit 114 about the shaft 100.

Referring to FIGS. 2, 3, and 4 the traverse head 40 is retained on the mast 14 by plural sets of spaced apart guide roller units 138 similar to the roller units 92. The roller units 138 are disposed for rolling engagement along the trackway formed by the portions 38 of the beam flanges 32. Each roller unit 138 includes a pair of rollers 140 rotatably mounted on a frame which in turn is pivotally supported by a pin 141 on a member 142. The members 142 are also pivotally mounted on a transverse stationary shaft 144. The shaft 144 is mounted in suitable bores formed in spaced apart support members 146 which in turn are detachably fastened to the panel members 50 by fasteners 148. Retainer plates 150 are removably secured to the panel members 50 by fastener means 152. The retainer plates 150 also include suitable bores for journalling the shaft 144. Shims 154 may be placed between the members 146 and the panel members 50 upon assembly of the traverse head on the mast 14 to also prevent imposing any unwanted radial forces on the bearing 102 or the rollers 140 which might be caused upon tightening the support members 146 against the panel members 50.

As may be appreciated by the foregoing disclosure, the traverse head 40 in combination with the mast 14 provides improved means for effecting pulldown and hoisting movements on the drill stem of a rotary drill rig. The parallel gear racks 34 together with the pinions 106 drivenly connected to drive means mounted on the traverse head itself eliminates many of the friction losses encountered by prior art chain or cable feed systems and furthermore provides a traverse head which is reliable in operation and is economically constructed.

Moreover, the arrangement of the transmission and drive motor unit 114 mounted on the driven shaft 100 eliminates many problems of misalignment caused by twisting and flexing of the traverse head frame under the forces encountered during operation of the drill rig. The pulldown drive mechanism of the traverse head 40 may also be used on drill rigs employing so-called rotary table drive means as well as the disclosed embodiment in which the drill stem rotation drive means is mounted on the traverse head.

Claims

What is claimed is:

1. In combination with a drill rig:

an elongated mast including a pair of spaced apart elongated beams and a gear rack mounted on each of said beams; and,

a traverse head for effecting longitudinal pulldown and hoisting movements of a drill stem with respect to said mast and characterized by:

a frame;

rotatable spindle means supported by said frame and connected to said drill stem;

bearing means disposed on said frame;

a shaft rotatably supported in said bearing means;

pinions mounted on opposite ends of said shaft and each engaged respectively with one of said racks;

drive means including a motor drivably connected to said shaft for driving said pinions to effect pulldown and hoisting movement of said traverse head and said drill stem; and,

support means for supporting said drive means on said shaft and substantially independent of said frame.

2. The invention set forth in claim 1 wherein:

said support means include self-aligning bearing means for supporting said support means on said shaft to permit rotation of said shaft with respect to said support means.

3. The invention set forth in claim 1 wherein:

each of said pinions includes a pair of circular flanges disposed spaced apart in straddling relationship to said racks and for rolling engagement on said beams whereby said traverse head is guided for movement along said beams and said pinions are supported in properly spaced relationship with respect to said racks.

4. The invention set forth in claim 2 wherein:

said drive means comprises a gear train including a gear mounted on said shaft for rotation therewith and said gear is disposed in a gearcase supported on said shaft by said self-aligning bearing means.

5. The invention set forth in claim 4 wherein:

said motor and the remainder of said gear train are connected to said gearcase.

6. The invention set forth in claim 3 wherein:

each of said beams includes a flange supporting a respective one of said racks on one side of said flange, and said traverse head includes means engaging the opposite sides of each of said flanges for retaining said pinions in engagement with said racks.

7. The invention set forth in claim 6 wherein:

said means comprises rollers mounted on said frame for rolling engagement with the respective ones of said opposite sides of said flanges.

8. The invention set forth in claim 1 wherein:

said traverse head includes a housing supporting a rotary drive motor and means drivably interconnecting said motor and said spindle,

said housing is removably fastened to said frame by fastening means whereby said housing together with said rotary drive motor and said spindle may be removed from said traverse head as a unit.