Patent Grant
9297223
This invention relates to the field of power transmissions for use with for example, top drives and in particular to a slewing power transmission, for conveying energy for example between a top drive and a slewing pipe handler.
In the prior art of which the applicant is aware, conventional top drives employ a slewable pipe handler assembly. Prior art pipe handlers normally include a number of remote controlled mechanised functions, for example, link tilt, make-up and break-out and/or backup wrench gripping, wrench axial positioning, well control valve actuation, elevator open/close actuation and elevator axial cushioning. Power or energy, and control of the pipe handler is typically transmitted to the pipe handler across the slewing interface between the top drive and the pipe handler, where conventionally the slewing interface is hydraulic or pneumatic and such transmissions are via a multi-channel fluid rotary union, as would be known to one skilled in the art.
In applicant's experience, the conventional fluid rotary unions at the slewing interface are prone to failure and in particular prone to failure at the rotary union seals. Failure can be between channels, resulting in loss of functionality, or external resulting in leakage as well as functionality loss. Inter-channel failures usually result in loss of functionality of two functions. A conventional slewing interface will have many seals, and in applicant's experience, normal wear and tear during conventional drilling operations causes one or more seals to fail. Leakage of hydraulic fluid from a hydraulic rotary union will cause hydraulic fluid to drip down onto the rig floor and personnel. Additionally, such rotary union seals typically have poor accessibility for servicing and require specialized technicians to do such servicing.
In the case of conventional fluid rotary unions, although undesirable and impractical, fluid-based sensors may be provided on the pipe handler, although usually the use of conventional fluid rotary unions means that no sensors are employed at all. The use of electronic sensors is desirable, however, to applicant's knowledge in the prior art attempts to employ wireless data communication across a fluid rotary union have required the use of battery power from batteries on the pipe handler system. The obvious drawback of having to use batteries is the batteries' limited battery life before swapping out or recharging of the batteries is required.
In summary, the power transmission for a slewing interface according to one aspect of the present invention may be characterized as including:
Power is thereby delivered continuously from the first drive to at least one of the at least two satellite sprockets at all times during rotation of the rotor about the slewing axis.
The transmission may further include a slewing drive acting between the rotor and the stator, whereby the rotor is selectively slewed relative to the stator about the slewing axis. The rotor may be adapted for mounting an object thereto for rotation with the rotor, and in one form of the invention the object is mounted to the rotor. By way of example, the object may be a pipe handler. In one embodiment, the stator may be mounted to a top drive.
Advantageously the satellite sprockets are mounted substantially equally radially spaced from the slewing axis, and so that a satellite sprocket spacing between adjacent satellite sprockets is substantially equal. In one embodiment the satellite sprocket spacing and the equal radial spacing of the satellite sprockets, the diameter of each of the satellite sprockets, and a spacing of the at least one drive sprocket from the slewing axis and the satellite sprockets is such that the drive belt will not contact the object, when the object is mounted to the rotor, during rotation of the rotor about the slewing axis.
In one embodiment a synchronizer synchronizes rotation of all of the satellite sprockets.
In a further embodiment at least one load is mounted on the rotor and coupled to the at least one satellite sprocket. The load may include an energy conveyor chosen singly or in combination from the following group, which is not intended to be limiting: an energy transfer medium, at least one hydraulic fluid pump, at least one pneumatic pump, at least one fluid pump which is other than hydraulic or pneumatic, at least one generator, at least one alternator, a mechanical drive, a mechanical linkage, an electric drive. The at least one load may also power at least one pipe handler function chosen from the group including: a gripper, a gripper positioner, a link tilt, a valve actuator, an elevator operator. Advantageously the at least one load may power an electrical control system. The at least one load may power a wireless communicator. Further, the load may include energy storage, for example chosen from the group which includes at least one gas accumulator, at least one battery, at least one capacitor, at least one flywheel.
In a preferred embodiment a tensioner cooperates with the drive belt to maintain tension in the drive belt as the rotor rotates. The drive belt may be at least one flexible loop member including a belt, chain, or cable. In embodiments employing a synchronizer, the synchronizer may be at least one flexible loop member, including a belt, chain, or cable, which is mounted around all of the satellite sprockets.
Advantageously the first drive runs continuously to continuously supply power to the at least one load, independently of the rotation of the rotor.
In further embodiments the satellite sprockets may include a minimum number of three satellite sprockets, or may include a minimum number of four satellite sprockets.
In yet a further embodiment at least two drive sprockets are provided, having a corresponding at least two drive belts, one drive belt for each drive sprocket. Each drive belt disengages from at least one satellite sprocket across a corresponding drive gap as the rotor rotates. Advantageously the at least two drive sprockets are spaced apart by a drive sprocket angular spacing which is greater than the angular magnitude of any of the drive gaps.
The rotor may be substantially a plate. The stator may also be substantially a plate. The first drive may be mounted to the stator.
A system according to a further aspect of the present invention includes the transmission first described above and a top drive mounted on top of, and to, the stator, and may further include a pipe handler mounted under, and to, the rotor. The stator may include a first central opening. The rotor may include a second central opening aligned along the slewing axis with the first central opening for receiving a quill extending from the top drive and through the first and second central openings.
As seen in the accompanying Figures wherein like reference numerals denote corresponding parts in each view, the assembled top drive shown in
Motors 12 and plate 14 are sized relative to each other to provide open spaces between the motors into which are mounted electrical junction boxes 16. Also, the spaces or gaps between motors 12, which may in one embodiment be in the order of 12 inch wide gaps, provide for air ducting 18 which directs air from blowers 20, themselves driven by electric motors 22, so as to provide cooling air for motors 12. In a preferred embodiment, two blowers 20 are provided, each providing cooling air flow into the motor housings into a corresponding pair of motors 12 via corresponding ducting 18. A hoisting collar 24 is provided, which straddles the central drilling mud conduit 26. Drilling mud is provided to conduit 26 via drilling mud supply pipes 28. Drilling mud is pumped through pipes 28 and down through central conduit 26 so as to exit downwardly from the internal bore of quill 30 along drive axis A.
Motors 12 drive their corresponding motor drive shafts 12a. Each motor shaft 12a drives its own corresponding belted transmission as better seen in
In one embodiment, although this is not intended to be limiting, the stack of tooth belts 36 includes a closely adjacent vertically stacked stack of five such belts 36. The reason that number of belts are stacked one on top of the other is merely that such belts are conventionally supplied with the teeth to the inside of the belt, and so with the relatively stiff, for example carbon fibres impregnated, belts used to convey the considerable power generated by each motor 12 so as to impart that power to bull sprocket 46, it can be difficult to invert each belt 36 so as to dispose that belt's teeth outwardly. The narrower the belt, the easier it is to invert the belt so as to outwardly expose the teeth. It may be that a single monolithic belt may be employed, for example if manufactured with the teeth outwardly disposed. Thus in the example illustrated, each belt may be described as having 14 mm pitch, with dimensions of 37 mm by 1610 mm.
Identical belted transmissions 32 are mounted under each corner 14b of drive plate 14. Extension tool 50 is an example of a tool which is used to pivot idler 38b about pivot 42 so as to tension belt 36. Preferably extension tool 50 is hydraulic although a mechanical screw or other suitable extension mechanism would work. Once the tension is set and the eccentric anchored to drive plate 44, tool 50 is removed, and the process repeated at each corner 14b for each belted transmission 32 which have had belts changed or during setup or periodically to take up slack due to belt wear or stretching. Belts 36 are held in place on idlers 38a and 38b by means of bottom plates 52 nested against flanged end cap 54 mounted over motor sprockets 34. A bottom plate 56 is mounted substantially in the plane containing bottom plates 52, and is mounted rigidly to drive-plate 14 by means of rigid spacing columns 58. Cover plates 60 are mounted up under corners 14b of plate 14 so as to enclose belts 36.
What follows is a description of a slewing power transmission which is mounted to a top drive. One such top drive is described above. However, and without intending to be limiting, other types of top drives would also work. For example, the top drive may include a gear drive or be a direct drive, that is, having no gear reduction, with motors concentric with the top drive axis (axis A), and wherein the motors may be electric or hydraulic for example, and wherein belts may also be used instead of or in conjunction with gears, or not at all.
By reference to a slewing power transmission, what is intended is to refer to a system which includes a rotary or slewing union, which is not a fluid rotary union, and which supplies energy or power, for example for actuators and for the generation of electricity, to a slewable pipe handling device which slews about axis A (its slewing axis) such as conventionally includes a wrench frame 72 supporting a pipe handling wrench 74, and again however, importantly, without the use of a fluid rotary union as is conventionally employed. Thus it is one object to provide an improved slewing power transmission, for example, for use under a top drive, which provides improved reliability, serviceability, and improved instrumentation feedback capabilities, power for an electric control system on the pipe handler, wherein the electric control system may include wireless communication provisions.
In the present invention the slewing interface is not merely a slewing interface employing a fluid rotary union to transmit motivating power to the pipe handler but is a rotary drive and power coupling in the sense that not only is selectively controlled slewing of the pipe handler provided at the interface between the top drive and the pipe handler, but the use of a fluidless power transmission provides energy or power to the pipe handler, for example for actuators and for the generation of electricity, thereby providing power to pipe handler accessories, such as described below, and providing power for an electric control system. Such an electric control system may include provisions for the wireless transmission of data between the top drive or elsewhere and the pipe handler. Data could be transferred between the pipe handler and the rig or a cell tower or satellite. Mechanical energy is transferred across the slewing interface, which may be used on the pipe handler in various ways, e.g. hydraulic, electric, pneumatic or mechanical to do work and/or for control systems. To realize control and instrumentation benefits, some or all of the transferred mechanical energy is converted into electrical energy. Again, the substitution of a fluidless power transmission for a fluid rotary union reduces maintenance, reduces fluid leaks which increases safety on the rig floor, and enables improved data communication between the top drive and pipe handler. Electrically powered accessories on the pipe handler may include for example a video camera, for still or motion photography, monitoring, streaming of a video feed, for remote recording, monitoring, or diagnostics, or for remote operation. Again, the data from the accessories may be provided to the top drive, or to elsewhere on the drilling rig, or may be provided to remote locations by wireless transmission according to known methods.
Thus what is an improvement over the use of conventional fluid rotary unions at the slewing interface between top drives and pipe handlers, and which it is an object of the present invention to provide, is to firstly increase reliability of the slewing interface by the use of a slewing power transmission which does not include rotary union seals, and thereby to then eliminate for example hydraulic fluid/oil leakage due to external rotary union seals failing, and to also thereby reduce the extent and complexity of the hydraulic fluid system lines, again thereby reducing the associated fluid leakage. It is further desirable, and a further object of the present invention to provide, improved serviceability at the slewing interface by providing a slewing power transmission which is, for the most part, externally serviceable, and which it is intended will require significantly less expertise in order to perform such servicing. Further, the slewing power transmission at the slewing interface according to another aspect of the present invention provides energy or power across the slewing interface for example for the generation of electricity. Thus in the present application, which is not intended to be limiting, energy is provided to the pipe handler so as to, for example, enable an electric control and instrumentation system. The electrical system may include, but is not limited to, solenoids, motors, relays, switches, sensors, programmable controllers, memory unites, wireless communication systems, still cameras, and/or video cameras. This provides power to various loads or accessories such as for example wireless transmitters or the like for transmitting data, information, etc from the pipe handler, wherein the accessories may thus for example include sensors and the data is feedback from the sensors, etc. Thus by the providing of power across the slewing interface electronic sensing instrumentation in, and electronic data transmission from the pipe handler are enabled, advantageously by wireless data communication, because continuous electrical power is now provided by the slewing power transmission to the pipe handling assembly without the limitations of being reliant on batteries, and thereby, through the expanded use of instrumentation and sensors the functionality and safety of the pipe handling system is improved. That is, such an electric and instrumentation system is impractical with a fluid rotary union system because electrical power is limited to battery capabilities which have limited life.
Thus as seen in the accompanying drawings commencing in
The frame of reference may for other applications of the slewing power transmission which is the subject of the present invention, be merely the frame-of-reference of a body, such as a frame or foundation or other supporting structure, which does not move or is fixed relative to the slewing motion of the rotor, and as used herein such frame of reference is included within the definition of a stator.
Thus in the present example, which is not intended to be limiting, where the slewing power transmission is employed between the top drive and pipe handler, as stated above, bull sprocket 46 is driven by drive belts 36. Drive belts 36 are mounted on idlers 38a and 38b and driven by motor sprockets 34 mounted to motors 12. The idlers 38a and 38b, and spacing columns 58 are mounted onto stator plate 90. Thus by operation of motors 12, bull sprocket 46 may be rotated to thereby rotate main shaft 48 and quill 30 so as to rotate the drill string when attached thereto.
Independently of the rotation of the main shaft, quill and drill string, the pipe handler assembly mounted under the pipe handler rotor 80 slews around center axis A so as to slew the pipe handling assembly including wrench or gripper 74, on wrench frame or gripper leg 72 and the associated link tilt cylinders (not shown) and links 87 on supports 84, by the operation of a slewing position actuator. The slewing position actuator may be for example a worm drive 94 driving gear ring 96 about internal race 98, wherein gear ring 96 is mounted up underneath and to stator plate 90. In the illustrated embodiment wherein worm drive 94 is hydraulically actuated, worm drive 94 is driven by hydraulic motors 94a and housed within a housing 94b. Hydraulic fluid for motors 94a is maintained within a reservoir 94c which is mounted on rotor 80 so as to surround gear ring 96. Thus the selective operation of the slewing position actuator selectively slews the pipe handling assembly. As will be appreciated by one skilled in the art, the slewing position actuator may be other than a hydraulically actuated worm drive, and may be located on the stator or fixed structure instead of on the rotor or slewing structure.
Whether the rotor 80 is actively being slewed or not by the slewing position actuator, loads 76, such as for example pumps for fluid systems, generators for electrical systems including an electrical control system, compressors for pneumatic systems on the pipe handler, mounted under and to rotor 80, each corresponding to driven satellite sprockets 78, are continuously powered by the operation of one or more drive belts 82 driven by motors 62 mounted on mounting plate 64.
The electrical system may include, but is not limited to, solenoids, motors, relays, switches, sensors, programmable controllers, memory units, wireless communication systems, still cameras, and/or video cameras. Although six satellite sprockets 78 are illustrated in
Drive sprockets 62a are always in contact with drive belts 82 so as to transfer power from each electric motor 62 to the drive belts 82. Thus as rotor 80 slews, and in the embodiment of
As rotor 80 continues to rotate, the satellite sprocket 78 will regain contact with drive belt 82. The portion of the rotation of rotor 80 about axis A between the loss of contact of an individual satellite sprocket 78 and drive belt 82 and the regaining of contact with the same drive belt 82 is hereinafter referred to as the drive gap. The angular magnitude of the drive gap is referred to as the drive gap angle. In the example of
In
Drive sprockets 62a′ and 62a″ are spaced apart by a drive sprocket angular spacing {acute over (α)}. The drive sprocket angular spacing {acute over (α)} preferably exceeds the drive gap angle DGA so that at all points of angular rotation of rotor 80, each of the satellite sprocket 78a-78f is in contact with and driven by at least one of the drive belts 82 (82′ or 82″), even in the absence of a synchronization belt 92.
Thus the duplication of the drives 62 in their spaced apart or phase-shifted orientation provides for the fail-safe continuity in the supply of power or energy y across the slewing interface to the pipe handler.
As illustrated in
Satellite sprockets 78 may also power an energy storage device, or an energy conveyor, for example an energy conveyor chosen singly or in combination from, without intending to be limiting: an energy transfer medium cooperating between at least one satellite sprocket 78 and for example the pipe handler grip, at least one hydraulic fluid pump, at least one pneumatic pump, at least one fluid pump which is other than hydraulic or pneumatic, at least one generator, at least one alternator, a mechanical drive, or a mechanical linkage.
The energy storage device may be for example at least one gas accumulator, at least one battery, at least one capacitor or at least one flywheel.
Although in the illustrations, the synchronizer of the satellite sprockets 78 is shown as belt 92, one skilled in the art would appreciate that other forms of synchronization would also work and are intended to fall within the intended meaning of the word synchronizer. For example a synchronizer may also include the use of gears, a flexible shaft, a rigid shaft with right-angle gearboxes, a hydraulic or other fluid system to synchronize the movement of the satellite sprockets.
This is a Continuation-in-Part of U.S. patent application Ser. No. 13/367,305 entitled Power Tong filed Feb. 6, 2012, incorporated herein by reference, which is a Continuation-in-Part of U.S. patent application Ser. No. 12/379,090 entitled Power Tong filed Feb. 12, 2009, now U.S. Pat. No. 8,109,179, which claimed priority from U.S. Provisional Application No. 61/071,170 entitled Power Tong filed Apr. 16, 2008 and U.S. Provisional Application No. 61/064,032 filed Feb. 12, 2008. The present application claims priority from U.S. Provisional Application No. 61/555,950 entitled Top Drive With Slewing Power Transmission filed Nov. 4, 2011.
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| Number | Date | Country | |
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| Parent | 13367305 | Feb 2012 | US |
| Child | 13669419 | US | |
| Parent | 12379090 | Feb 2009 | US |
| Child | 13367305 | US |
