"ROTARY DRIVE FOR APPLYING ROTARY TORQUE TO A SPiAFT TO BE AXIALLY

VIBRATED"

The present invention relates to a rotary drive for applying rotary torque to a shaft that has axial vibration applied such as, but not restricted to vibrational drilling. Vibrational drilling involves vibrations being passed down into a drill string to a bit or its equivalent whilst the drill string and the bit is rotated about its rotational axis. Preferably such vibrations are primarily axial.

Various forms of vibrational apparatus have been proposed as vibrational heads adapted to impart such axial vibrations down a drill string. These range from rotated eccentrics to shuttle including arrangements (fluid powered shuttles under rotary valve control, mechanically rotated shuttles that shuttle as a consequence of magnetic interactions and/or shuttle including vibrational heads where vibrational output into a drill string does not require connection to the shuttle) as disclosed in our (PCT/NZ2004/000128) WO2004/113668 published 29 December 2004, PCT/NZ2005/000047 (WO2005/087393 published 23 September 2005), PCT/NZ/2005/000329 and PCT/NZ2006/000244.

The full content of the aforementioned specifications is hereby here included by way of reference but subject to the following rider:

The present invention has as an object die desirability of providing a rotational input into die spindle of, or for, a drill string but at least to some extent to isolate die mechanism providing such an input from at least die axial vibrations to be passed via die spindle into die drill string. Such an arrangement is to reduce destructive wear and/or vibrational damage.

It is a furdier or alternative object of die present invention to provide a gear drive suitable for imparting a rotary motion into a drill string, or the spindle for a drill string, yet which is isolated from at least some of die at least axial vibration to be imparted into die drill string via the spindle from a vibrational head.

It is a furdier and alternative object of die present invention to provide a motored (eg; hydraulic motored) gear drive into a driven gear carried by a carriage that is axially movable within limits on guides disposed about die spindle of, or for, a drill string, such action of die carriage on die guides (as an array about die spindle fixed in relation thereto) being able to impart rotary motion from die driven gear into die spindle and dience, in use, die drill string.

It is a furdier an alternative object of die present invention to provide an assembly adapted for suspension from a vibrational apparatus (eg; vibrational head) itself suspended preferably so as to support die weight not only of die drill string but at least part of die drive train to rotate the drill string.

It is still a farther alternative of the present invention to provide a vibrational drilling assembly where die weight of die drill string and its bit, at least some of die drive tiarn to impait iotational drive to die drill string and the vibrational head is supported from a structure with respect to which diere can be movement as a result of movement upwards against at least one gas bag and downwaids against at least one gas bag.

In one aspect die invention is a rotary drive assembly of or for a drill string or other shaft, die assembly comprising or including a sprndle direcdy or indirecdy connected 01 connectable to die drill string or odier shaft to be rotated, vibrational apparatus, or an adaptation to connect to vibrational apparatus, so as, in use, to impart vibration to the spindle, an array of guides, pins or die like ("pins") about die spindle in a fixed relationship with die spindle, a slideable guide follower, sleeve or die like ("sleeve") on each of said pins, each widi a sliding axis on its pin parallel to die rotational axis of die spindle, a gear mounted direcdy or indirecdy on said sleeve and adapted to slide dierewidi, and a geared drive for die sleeve earned gear, die arrangement being such diat die geared drive can rotate the spindle by die action of die driven gear acting through the sleeves on die pins yet such that die geared diive, die driven gear and die sleeves are less sub _j ect to axial vibration dian is die spindle.

Preferably die adaptation to connect to vibrational apparatus is for a shutde including vibiattonal head to which such an adaptation is to be connected or is connected, die output vibrationally not being direcdy from die shutde, but from some structure relative to winch die shutde shutdes. Preferably the shutde axis is rectilinear and is aligned with die axial direction, i.e.; die rotational axis of die spindle and/or die rotational axis of die drill string or odier shaft.

Preferably said spindle is to be aligned axially with die drill string or odier shaft.

Preferably the vibrational head is a vibrational head of any of die kinds described in our abovementioned patent specifications. Preferably said shutde is driven to shutde as a result of both (i) an input of a rotational drive on die shutde and (ii) magnetic interactions capable of causing a shuttling.

Preferably such a shutde imparts vibration to the structure from which vibration is earned to said adaptation via a fluid (most preferably a liquid).

Preferably die liquid in die vibrational apparatus can be subject to some bleeding from a chamber or chambers under impact but nevertheless leads to die avoidance of solid to solid

contact at the limits of shuttling. Such bleeding also selves the purpose of allowing remote cooling of such liquid oil.

Preferably the adaptation is a structure lelative to which the spindle and its pins can rotate, such rotation being about the spindle axis winch prefeiably is aligned widi die axial pathway for vibiational feed into die spindle from said adaptation.

Pieferably die driven gear is mounted on a sleeve encompassing structuie, said sleeve encompassing structure carrying die mounted gear such gearing mounting (prefeiably with preloaded axially loaded bearing assemblies) being adapted to rotate coaxially about the spindle axis as part of a carriage diat includes said sleeves. Pieferably the vibrational apparatus, or adaptation to connect to die vibrational apparatus

(e g non iotational axially movable member), is thrust beaiing mounted relative to the spindle.

In another aspect the invention consists in a rotary drive assembly of or for a drill string or odier shaft, die assembly comprising or including a spindle direcdy or indirecdy connected or connectable to the dull string or other shaft to be rotated, vibiational apparatus, or adaptation to connect to vibrational apparatus, so as, in use, to impart vibration to the spindle, a geared carriage slideably carried on parallel slides mat are fixed relative to and rotate with said spindle, and a geared drive to rotate said geared carnage about the rotational axis of die spindle and dius, via die slides, to impart rotation to such spindle.

Preferably the carriage is movable, on die slides thereby pioviding relative axial movement of said carriage and die geared drive relative to said slides and dius bodi (i) die vibrational apparatus or adaptation and (n) die spindle. In yet a further aspect the present invention consists in a drilling assembly comprising or including a support, a vibrational head earned by such support via gas bags which allow movement between die vibrational head and die support but constrains such movement between limits, apparatus carried by die vibrational head direcdy or indirecdy winch is connectable into die drill string, and die drill string, wherein die apparatus carried direcdy or indirecdy by die vibrational head has a geared drive of a sliding carriage adapted to slide relative to die axis of die drill string and/or a spindle therefor yet still to impart rotational drive thereto.

- A -

Preferably such an arrangement includes a rotary dttve assembly of any aspect in accordance with the present invention.

In a fuither aspect the present invention consists in the vise of a sliding mount or sliding mounts ("mount(s)") for a gearbox or gear train carriage, the gearbox or gear train being about a spindle axis able to rotate the spindle under tangential forces applied to the mount(s), die spindle being foi connection into a vibrational drill string.

In a fuither aspect the present invention consists in a gear box or gear train having a drive substantially as herein descnbed, particularly with respect to at least partial isolation from, vibration, of apparatus substantially as herein described with reference to any one or more of the accompanying drawings.

In another aspect die invention is a drive assembly suitable for a spindle connection to a drill string or other shaft, die assembly comprising or including a drive shaft, a shutde rotatable under die action of die drive shaft but being slidable relative diereto, die shutde carrying magnets, a containment assembly to constrain die shutde to a shutde axis, die containment assembly carrying magnets to co-act with those of the shutde as die shutde is rotated by the drive shaft thereby to cause die shuttling of the shutde, a spindle not forming pait of die shutde arrangement to receive vibration from said containment assembly and/or said shutde (e.g.; through a cushion of liquid), a carnage assembly on pait of the spindle slidable on an axis coincident widi and/oi parallel to die spindle's rotational axis, and a drive earned by the cairiage assembly to rotate die spindle or to rotate both the spindle and part of die carriage assembly. In still another aspect the invention is spindled apparatus for supporting, vibrating and driving a drill string or other shaft, die apparatus comprising or including a support, a shutde able to be driven, a containment assembly to constrain die shutde to a shutde axis, the containment assembly being direcdy or indirecdy suspended from die support by gas bags that allow movement up and down, a spindle not forming part of die shutde arrangement to receive vibration from said containment assembly and/or said shutde (e.g.; through a cushion of liquid), a carnage assembly on part of die spindle slidable on an axis coincident with and/or parallel to die spindle's rotational axis, and

a drive carried by the carriage assembly to rotate the spindle or to rotate both the spindle and part of the carriage assembly.

In yet another aspect die invention is spindled apparatus for supporting, vibrating and driving a drill string or other shaft, the apparatus comprising or including a support, a drive shaft, a shuttle rotatable under the action of the drive shaft but being slidable relative thereto, the shuttle carrying magnets, a containment assembly to constrain the shuttle to a shuttle axis, the containment assembly carrying magnets to co-act with those, of the shuttle as the shuttle is rotated by the drive shaft thereby to cause the shuttling of the shuttle, and the containment assembly direcdy or indirectly being suspended from die support via gas bags (or the equivalent compliant means), a spindle not forming part of the shutde arrangement to receive vibration from said containment assembly and/or said shutde (e.g.; through a cushion of liquid), a carriage assembly on part of die spindle slidable on an axis coincident with and/or parallel to die spindle's rotational axis, and a drive carried by die carriage assembly to rotate die spindle or to rotate both die spindle and part of the carriage assembly.

In yet a further aspect die present invention consists in apparatus substantially as hereinafter described with reference to any one or more of die accompanying drawings.

The present krvention also relates to an axial drive for vibrational drilling.

Reference herein to "other shaft" however need not be that of a drilling system e.g. could be for part of a materials reduction system.

In our aforementioned patent specifications there is disclosure of a vibrational head used in conjunction widi a transmission down into a drill string.

It is desirable, from time to time, to ensure that die overall girtii or bulk of die vibrational head when viewed transversely of die spindle axis (diat axis that is to be connected into die top of die drill string) is sufficientiy small to be manoeuvred down through gaps and/or into holes.

In our aforementioned patent specifications, we disclose a type of vibrational head dependent upon a mechanical input to a rotatable shutde able to shutde, as a result of magnetic interactions, in a direction along or parallel to its rotational axis, that axis also being preferably aligned with die spindle axis, thereby to provide vibration in its surrounds tiiat transmits to die drill string.

The present invention envisages and has as an alternative or object a non belt drive or an arrangement (optionally including a gear box) where there is no need for any tangential driving of

the rotation of the shuttle which would have the affect of increasing girth or bulk. An object is an axial rotational drive i.e in line.

It is a furthei or alternative object to provide assemblies whereby both vibration and torque can be transmitted into a shaft 01 drill string In another aspect the invention is, or associated with other aspects of die invention diere is, vibtational apparatus connectable to, connected to or suitable for connection (diiectly or indirectly) to a drill string, the apparatus compiising or including a structure to provide fiom at least part diereof a vibrational output (e.g. to such a dull string), a shuttle at least in part confined by said structure between shuffling limits, the shuttle and structure coacting in such that when die shutde is rotated about a rotational axis relative to said structure, die shutde will shutde back and forth along such axis relative to said structure, and a drive shaft adapted to rotate die shutde about said rotational axis yet not provide any substantial fetter to die shuttle's sliding relative thereto as die shutde shuttles relative to said structure.

Please note tihat the inteiaction between die shutde and die drive shaft is pieferably a spline or dogged slide interrelationship.

Preferably said stiuctuie to provide die vibrational output from at least part of die vibrational apparatus is at least a paitial housing or extension from a housing of die shutde. The output can ultimately be that of a spindle not moving axially widi die shutde.

Preferably die structure to provide a vibrational output is associated or associable widi apparatus as previously defined (ie; a rotary dnve assembly, a drilling assembly, sliding mounts for a gear box carnage, etc. as previously). It is die vibrational output as an input to diat apparatus that is isolated from die carπaged sleeves or die like (associated widi the gear drive) that acts dirough die guides or slides of the spindle.

In a furdier aspect die present invention consists in (T) an axial df ive of the rotation of a shuttle in apparatus of any aspect of die present invention, die axial drive allowing relative axial movement between an input member and die shutde and/or (II) a hydraulic motored geared drive of a axially moveable carriage on a spindle assembly to rotate die spindle as it axially vibrates independendy of die carnage.

As used herein die term "and/or" means "and" or "or", or both.

As used herein die term "(s)" following a noun includes, as might be appropnate, die singular or plural forms of diat noun.

Tins invention may also be said broadly to consist in the parts, elements and features referred to or indicated in die specification of die application, individually or collectively, and any or all

combinations of any two or more of said parts, elements or features, and wheie specific integers are mentioned herein which have known equivalents in the art to which this invention lelates, such known, equivalents are deemed to be incorporated herein as if individually set foith

A preferred form of the present invention will now be described with iefeience to die accompany drawings in winch

Figuie 1 shows a perspective broken open view of the iotaiy drive appaiatus in accordance with an aspect the present invention, showing a connector or spindle to rotate as it longitudinally vibrates a drill string (die drill string not being shown) and showing (without the housing (being shown for clarity) a diive input gear of a hydraulic motor to a carriaged gear diat transmits torque via its sleeves (eg; bushes) carried on pins, guides, or die like ("pins") fixed to rotate as an array of die plural pins about the rotational (and preferably also) vibrational axis of die spindle and drill string,

Figure 2 shows anotiier view of die apparatus of Figure 1 ,

Figure 3 is a similar view to diat of Figure 2 but showing die carnage with die driven gear moved to one limit of movement on die pins or guides (being realised it could equally be shown at the other kmit, ie; furdier to die left),

Figure 4 shows a preferred embodiment of die present invention as it would be used, air bags dangle supporting die vibrational head (with its preferred axial drive into the shutde), and also showing diat vibrational head supporting die apparatus of Figures 1 to 3, and Figure 5 is a perspective of die apparatus showing die gas bag end to die right and die drill string adaptation to die left, die apparatus being on a mast slidable carriage

A preferred form of die present invention is as shown in Figures 1 diiough 4 In Figure 4 diere is shown air bag 1 and air bag 2 able in die manner described in PCT/NZ2006/000244 of suspending die vibrational head so that it has a general floating disposition, ie; since an air bag 1 or 2 acts on eidier side of a plate structuie interposed between two odier plates, diere is freedom for the structure to move upwardly and downwardly widi respect to the interposed plate structure 3. In die case shown, die underlying plate structure 4 has squeezed die bag 2 but equally, at die odier end of such movement, it could have been die top plate structure 5 squeezing the bag 1 against the structure 3. It is sufficient if diere is vertical support from any appropriate crane, structure, frame or other support member for eidier bodi 4 and 5 or member 3. There is an ability for the overall structure as shown in Figure 4 and any dependent drill string from die spindle 6 to find its own equilibrium with respect to die gas bags.

It can be seen therefore that the gas or air bags have die ability to balance increasing load on the drill string or increasing load of the drill string widiout damping of die vibrational input

wanted in the drill string via the spindle 6 from the contained shuttling. All of this is irrespective of drive force or weight as it is always suspended and can always "wobble" upwardly or downwardly.

Such an arrangement of support is quite different from prior art vibiational damping

Shown in Figure 4 is an input shaft 7 preferably aligned with die drill string spindle 6 as well as die rotational axis of the housed spindle 8.

Shown as part of 8 are an array of fixed magnets 9 and an airay of fixed magnets 10, each to be inteiacted with by coiiesponding or other arrays 11 and 12 respectively of die shutde as the shutde rotates thereby with die alternating polarities causing the shutding.

The shutde rotates under die action of a splined axial dnve from die input shaft 7 which interacts via dogs, splines or odier means shown generally as 13 diereby allowing die shutde to move upwardly and downwardly as a result of die magnetic interactions as diey occur during rotation of die shutde 8 under die input rotational action from 7 via 13.

The movement of die shutde is up and down widi litde in die way of fetter on such movement as a consequence of die drive it receives axially from the input shaft 7. Whilst there may be the prospect of an axial drive exteriorly of die shutde widi a similar ability to have relativity of movement axially, die preferment is the internal receipt of die member 7 by die shutde assembly 8

The opeiaύon of the shutde has been described previously in die aforementioned patent specifications Optionally provision can be made to ensure solid to solid contact avoidance by use of vibiational passage into a liquid. Neverdieless there can be metal choices and/oi syndietic material choices, or sequences diereof, or assemblies thereof, that do not result in damage from contact despite impacts and relativity of rotation.

Carried by die shutde, but not as a linked mechanical out put, is a member 14 which dips its partitioning member 16 into a member 16 partitioned chamber 15 having some liquid or other fluid content. Preferably the content is a hquid (such as oil). Preferably diat oil is pressunsable independendy of die pressures created by die shutding diereby to enable tuning of die nature of die vibrational transfers. That oil is preferably able to move to some extent from one partition to the other of chamber 14. The oil irrespective acts as a vibration transmitting cushion of die axial downward limit and die axial upward limit of die shutde 8. This avoids solid to solid contact, eg; of die magnet banks 9 and 11 and/or 10 and 12. The act of pressurising the oil allows a flow circuit for cooling purposes. Pressunsation can also allow sacrificial oil flow through seals for lubrication purposes.

Such an arrangement is a variation of that previously disclosed but nonetheless provides vibrational output dependent on shutding but not taken directly by a rigid mechanical link from die

shuttle, ie; the shuttling through the interaction of the members 14 and 16 on the liquid as a cushioning provides a vibrational output of the overall structure of the shuttle and its housing into component 17 (variously referred to previously as an "adaptation' ¹ to receive the vibration from the vibrational head or the "vibrational head" or part thereof). The arrangement from member 17 downwards as well as its connections upwardly thereof is what is depicted in greater clarity in Figures 1 through 3.

It can be seen however there is a drive down into the spindle of the axial vibration carried through the structure.

The spindle 6 itself is rotatable under the action of one or more motors (preferably hydraulic motors 18) which act to rotate input gears 19 which in turn drive a carriage carried gear

20, the carriage (generally shown as 21) is an assembly around sleeves or having bores, chambers or yokes.

It can be seen that the guides or pins 22 allow die carriage 21 to move upwardly and downwardly widiin limits thereby driving the associated spindle 6 under the action of applying tangential force via die pins or guides 22 to die spindle. The arrangement however has die desirable outcome of ensuring die motor, its housing carried by die carriage 21 etc. is or can be largely isolated from die vibrational downput to die spindle 6 yet it nevertheless provides a capability of providing a high torque rotational drive.

That rotational padiway, as well as die role of die thrust bearings 23 and die other bearing structures 24 will now be described in greater detail.

In die preferred form of the present invention die padis of rotary power transfer, die padis of rotary power transfer and vibrational transfer can be described as follows. Also reference will be made to die axial float described in our patent specification numbers aforesaid.

Path of Rotary Power Transfer

The input torque from die hydraulic motors is transferred through die pinion gears (B) to die main gear (C) which is fastened to die two centre carrier halves (D). These carriers retain the bushes (E) (ie; the sleeves) that are oil fed internally to reduce die friction between diemselves and die chrome plated drive pins (F). Please note all of die above parts except for die drive pins are not subject to direct vibration.

The carrier halves (D) are supported in die gearbox housing (not shown) by the two deep groove ball bearings (G). Because diese bearings are subject to a small amount of residual axial vibration, we need to pre load the outer bearing ring in an axial direction. This is achieved by the

multiple compression springs (H) reacting between the outer bearing race (G) and die gearbox housing (not shown).

Path of Vibration Part A centre shaft cannot rotate, but does move axially at the amplitude and frequency supplied via the oil bath from the vibrational head as a consequence of shuttling. This vibration is then transferred through the two spherical roller thrust bearings (I) and then into part Q) + (I ¹ C) + (L) and finally out through die output spindle (TVI).

Axial Float

Because of die thrust supplied via die gas (air) bellows at die back or top end of die machine, we have a +/- limit (e.g. of 35mm) built into die spindle design. This movement takes place between die bushes (E) and die drive pins (F).

Another way of describing this is that die gearbox housing and parts B, C, D, E, G and H are all stationary and the rest of die assembly slides inside it.