Yaw alignment system

An alignment assembly is coupled between a steering assembly and a support foot to maintain an alignment of the support foot with the load transport assembly while the steering mechanism rotates in different steering directions. A biasing device activates in response to non-linear displacements of the load transport assembly relative to the support foot and moves the steering assembly and the support foot back into original alignments with the load transport assembly. The alignment assembly may include a lower main gear assembly that rotates the support foot relative to the steering assembly and an upper main gear assembly that rotates the steering assembly relative to the load transport assembly.

FIELD OF THE INVENTION

This disclosure relates generally to apparatuses for transporting a load, and more particularly to a yaw alignment system.

BACKGROUND

Moving extremely heavy loads has generally been a complicated task because the large forces involved in lifting and transporting the heavy loads. When possible, large loads are often transported by disassembling or breaking up the load into multiple smaller loads. However, this break-down and subsequent reassembly process can be very time consuming, especially when a heavy load is only to be moved a small distance, or needs to be repositioned.

For heavy loads that need periodic movement or adjustment, devices commonly referred to as “walking machines” or “walkers” were developed. These machines typically move the heavy loads over small distances in incremental stages. Walking machines are particularly useful for moving large structures, such as oil rigs, which often times need to be moved in order to properly position them over pre-drilled wells in oil fields, or moved to a new location that is undergoing oil exploration.

Instead of using wheels driven by rotational forces to move heavy loads, walking machines typically use hydraulic lift cylinders to lift the load above a supporting surface, and then move or rotate the load relative to the supporting surface by transporting the load via rollers or tracks in the walking machines. U.S. Pat. No. 5,921,336 to Parker and U.S. Pat. No. 6,581,525 to Smith show two methods of using walking machines to move heavy loads, such as oil rig structures. The '525 patent shows elongated beams under several rollers and lift cylinders, which allows the load from the lift cylinders and rollers to be spread over a large area. However, this disclosed system in the '525 patent does not allow for movement of heavy loads in a direction perpendicular to the long axis of the support beams. That is, movement of the heavy load is restricted in the walking device disclosed in the '525 patent to only particular directions, which can make fine tuning of the position of the heavy load difficult.

SUMMARY

A yaw alignment system aligns a support foot of a walking machine with a load bearing frame when a steering assembly moves a load in different directions.

DETAILED DESCRIPTION

As described above, walkers, or walking machines, are vehicles that transport very heavy loads, such as entire oil well drilling rigs. Such loads may be as great as several thousand tons and may need to be sequentially positioned very precisely over spaced-apart well bores, for example. Embodiments of the present concept are directed to load transporting apparatuses, such as walking machines, for moving heavy loads over small distances with the ability to fine tune the resultant position of the heavy load.

The terms, “walkers,” “walking machines,” “walking devices,” and “walking apparatuses” are used interchangeably below. Load transporting apparatuses or systems may include one or more walking machines. Additionally, a walking machine's subassembly of components that facilitate movement of the walking machine are referred herein as a “walking mechanism.” Walking machines may incorporate one or more walking mechanisms, depending on the specific configuration of a walking machine.

FIG. 1Ashows a walking apparatus100that uses a manual yaw alignment system10A,FIG. 1Bis an end view of the walking apparatus inFIG. 1A, andFIG. 1Cis a top view of the walking apparatus inFIG. 1A. Referring toFIGS. 1A, 1B, and 1C, walking apparatus100includes a lift cylinder104connected to a load bearing frame150. The load bearing frame is alternatively referred to as a load transport assembly and may include any structure used for carrying and/or transporting a load. There may be multiple walking apparatus100located on different corners, ends, or other locations underneath load bearing frame150.

A lift piston106moves vertically up and down inside of lift cylinder104. A steering assembly142is connected between lift piston106and a support foot140. Steering assembly142may include a transport assembly124that moves inside of a roller track123. Transport assembly124may include a roller frame116that retains a set of rollers118. Travel cylinders120and travel cylinder rods121are connected between roller track123and a bracket132connected to lift piston106.

The bottom end of lift piston106may be connected to the top of roller frame116and may lift steering assembly142and support foot140vertically up and down. In the raised position, lift cylinder rod106may lift support foot140off ground surface160. In the lowered position, lift piston106may press support foot140down against ground surface160and lift load bearing frame150up off of ground surface160. With load bearing frame150in the raised position, travel pistons121may retract into travel cylinder120and move transport assembly124, lift piston106, load bearing frame150, and any load on frame150relative to support foot140.

A spherical joint may connect cylinder piston rod106to transport assembly124. The spherical joint may allow piston rod106to rotate in different horizontal and vertical directions relative to transport assembly124. In another example, the coupling joint between piston rod106and transport assembly124may only allow support foot140to rotate horizontally about a vertical axis relative to the cylinder assembly. Example connections between piston rod106and transport assembly124are described in more detail below.

After moving load bearing frame150during a step operation, lift piston106may retract up into lift cylinder104lowering load bearing frame150back onto ground surface160and lifting steering assembly142and support foot140up off of ground surface160. When support foot140is raised above ground surface160, travel cylinder rods121may move support foot140into an extended position relative to transport assembly124and lift piston106. Walking machine100then begins another step operation by lowering support foot140down against ground surface160and raising load bearing frame150up off of the ground surface160. Travel cylinder rods121then retract back into travel cylinder120moving transport assembly124, lift piston106and load bearing frame150relative to support foot140and roller track123.

Examples of the general operation of walking machine100are described in U.S. Pat. Nos. 9,533,723; 9,096,282; 8,573,334, 8,561,733, and 8,490,724, which have been incorporated by reference in their entireties and therefore is not described in further detail.

A rotation device158allows steering assembly142to rotate around a vertical axis relative to support foot140. One example rotation device158is referred to as a king pin and is described in U.S. Pat. No. 8,573,334 which has been incorporated by reference. Rotation device158is just one example, and walking machine100may use other rotation devices described below to rotate steering assembly142relative to support foot140.

Rotation of steering assembly142may cause support foot140to rotate and bump up against the side of load bearing frame150. Or at the least, support foot140may rotate or yaw into a non-aligned longitudinal direction relative to the longitudinal direction of load bearing frame150. Said another way, rotating steering assembly142also may rotate support foot140so a longitudinal axis of support foot140is no longer parallel with a longitudinal axis of load bearing frame150.

A manual yaw alignment system10A moves support foot140back into alignment with load bearing frame150. For example, manual yaw alignment system10A may rotate the longitudinal axis of support foot140back into parallel alignment with the longitudinal axis of load bearing frame150. Manual yaw alignment system10A includes a lower main gear126rotationally connected to support foot140via rotation device158and rigidly fixed to the bottom of roller track123. Yaw alignment system10A also may include a torque platform110rigidly fixed to the top of steering assembly142.

An operator may hold support foot140in a set alignment with load bearing frame150while rotating lower pinion gear130with steering lever154. Lower pinion gear130rotates or yaws steering assembly142and torque platform110about a vertical axis while support foot140is held in a same alignment with load bearing frame150. When steering assembly142is in the desired rotational direction, the operator may use lower locking mechanism128to hold lower main gear126and attached steering assembly142into a locked yaw alignment with support foot140.

Yaw alignment system10may include a yaw control device108attached between load bearing frame150and torque platform110. Yaw control device108may include an upper arm144attached to load bearing frame150and a lower arm146attached via a pin152to torque platform110.

Two plates137extend down from an upper member of load bearing frame150. A rod138extends through holes formed in the lower end of plates137and holes that extend through upper ends of two side members of upper arm144. Upper arm144rotates about rod138. A second rod139extends through concentric holes formed in the bottom of upper arm144and the top of lower arm146.

Upper arm144rotates about rods138and139and lower arm rotates about rod139moving in a scissor fashion to extend downwards as shown by the solid line or retract upwards as shown by the dashed lines. After locking lower main gear126to support foot140with locking mechanism128, the operator may insert pin152into one of holes162that extend around the outside edge of torque platform110.

Yaw control device108then realigns support foot140with load bearing frame150after the step operation. For example, steering assembly142may move the load carried on load bearing frame150in a non-linear direction creating a yaw misalignment or differential angle between load bearing frame150and support foot140. Said another way, steering assembly142may move load bearing frame150in a non-parallel direction relative to the longitudinal axis of support foot140. Yaw control device108elastically deforms, twists, and/or bends into a biased state in response to the non-linear movement of load bearing frame150.

After completion of the step operation, lift cylinder106lowers load bearing frame150onto ground surface160and lifts steering assembly142and support foot140up off of ground surface160. Yaw control device108elastically releases from the biased state back into a previous unbiased state moving steering assembly142and support foot140back into the previous alignment relative to load bearing frame150.

Yaw control device108is just one example device that may correct the yaw movement or differential angle misalignment of support foot140relative to load bearing frame150. Other example yaw control devices are described in more detail below.

FIG. 2Ashows a side view of a walking apparatus with a second example yaw alignment system10B that includes an upper main gear134,FIG. 2Bis an end view of the walking apparatus inFIG. 2A, andFIG. 2Cis a top view of the walking apparatus inFIG. 2A. Referring toFIGS. 2A, 2B, and 2C, torque platform110is coupled to lift piston106. An upper main gear134is rotationally coupled to torque platform110and is rigidly attached to the top of transport assembly124via a cylinder166. A load on load bearing frame150is transferred through lift piston106and interface connector166onto the top of transport assembly124.

An upper pinion gear114is rotationally attached to torque platform110. An operator may use an upper steering lever164to rotate upper pinion gear114causing upper main gear134to rotate about a vertical axis relative to torque platform110. Yaw control device108may keep torque platform108from rotating relative to upper main gear134. Rotation of upper main gear134may rotate steering assembly142, lower main gear126, and support foot140. However, when levers164and154are operated simultaneously, support foot140does not rotate.

To counteract the rotation or yaw of support foot140into a non-aligned position relative to load bearing frame150, the operator may use lower steering lever154to rotate lower pinion gear130. Lower pinion gear130may cause support foot140to rotate in an opposite direction relative to lower main gear126, steering assembly142, and upper main gear134. The rotation of support foot140offsets the rotation of steering assembly142and maintains support foot140in substantially a same yaw alignment relative to load bearing frame150.

After steering assembly142is rotated to the desired steering position, upper main gear134is locked to torque platform110with upper locking mechanism136. After support foot140is rotated to maintain the correct alignment relative to load bearing frame150, support foot140is locked to lower main gear126with lower locking mechanism128. At this point, torque platform110, upper main gear134, steering assembly142, lower main gear126, and support foot140are all rotationally locked together.

Lift piston106may lower support foot140and raise load bearing frame150off of ground surface160. Travel piston121may retract into travel cylinder120moving load bearing frame150, and the load on load bearing frame150, relative to support foot140. Steering assembly142may move a load transported on load bearing frame150in a lateral direction relative to the longitudinal axis of support foot140creating a yaw or differential angle between support foot140and load bearing frame150. Yaw control device108may elastically deform into a biased state from the torque created by the non-linear angular displacement of load bearing frame150relative to support foot140and steering assembly142.

After completion of the step operation, lift piston106may lower load bearing frame150and lift support foot140up off of ground surface160. Biased yaw control device108releases back into a non-biased state moving steering assembly142and support foot140back into their original yaw alignment relative to load bearing frame150. Travel piston121extends back out of travel cylinder120while support foot140is in the raised position moving support foot140and roller track123forward relative to transport assembly124, lift piston106, and load bearing frame150.

FIGS. 3A-3Dshow an example automated yaw alignment systems10C.FIG. 3Ashows a side view of a first automated yaw alignment system,FIG. 3Bis an end view of the yaw alignment system inFIG. 3A,FIG. 3Cis a top view of the yaw alignment system inFIG. 3A, andFIG. 3Dis a perspective view of the yaw alignment system inFIG. 3A.

Referring toFIGS. 3A, 3B, 3C, and 3D, as described above, lift piston106moves vertically up and down inside of lift cylinder104that is coupled via a plate102to the load transport assembly. As also described above, steering assembly142is connected between lift piston106and a support foot140and may include a transport assembly124that moves inside of a roller track123. Transport assembly124may include a set of rollers118. Travel cylinders120are connected between roller track123and a bracket132connected to transport assembly124.

Yaw alignment system10C may include a torque platform110, upper main gear134, and lower main gear126similar to those described above inFIGS. 2A-2C. Yaw alignment system10C also may include an upper pinion gear114, upper locking mechanism136, lower pinion gear130, and lower locking mechanism128similar to those shown inFIG. 2.

Instead of using manual levers, an upper motor170is connected to and rotates upper pinion gear114and a lower motor168is connected to and rotates lower pinion gear130. In another example, motor168may be located on top of lower pinion gear130. A motor controller167may control operation of motors170and169. In one example, motor controller167may include a central processing unit (CPU) and memory storing a set of computer instructions that are executed by the CPU to control the yaw of steering assembly142and support foot140.

Upper locking mechanism136and lower locking mechanism128may be unlocked from upper main gear134and lower main gear126, respectfully. While support foot140is in the raised position, controller167may cause motor170to rotate steering assembly142into a desired position relative to load bearing frame150. For example, upper motor170may rotate upper pinion gear114causing upper main gear134and attached steering assembly142to rotate in either a clockwise or counter-clockwise direction about a vertical axis.

At the same time, controller167may cause lower motor168to rotate lower pinion gear130rotating support foot140in an equal and opposite rotational direction relative to steering assembly142. For example, if upper motor170rotates steering assembly142, controller167may cause lower motor168to rotate lower pinion gear130keeping support foot140in substantially the same yaw alignment relative to load bearing frame150.

Controller167does not have to rotate support foot140the same amount as steering assembly142. For example, controller167may be coupled to a sensor169that monitors the amount of rotation of support foot140. Controller167may cause motor168to rotate support foot140any amount that maintains sufficient spacing between support foot140and load bearing frame150.

Motors168and170may be controlled electrically, hydraulically, or with pressurized air. In one example, motors168and170are hydraulically connected together in series where any rotation by one motor170causes a specific amount of rotation by motor168. Alternatively, controller167may monitor sensors169the identify the amount of rotation or position of steering assembly142and support foot140.

Any type of mechanical, electrical, or optical sensors169may be used for measuring the amount of rotation or rotational position. Controller167uses the sensor readings to rotate steering assembly142a desired amount and to maintain support foot140in a desired alignment with load bearing frame150. Alternatively, an operator may manually control motors168and170via a user interface (not shown) coupled to controller167.

After rotating steering assembly142and support foot140, upper locking mechanism136may lock upper main gear134to torque platform110and lower locking mechanism128may lock support foot140to lower main gear126. In other examples, locking mechanisms136and128are optional. Locking mechanisms128and136may be manually locked and unlocked, or may be automatically or manually controlled via controller167or by any other control system that operates with the walking apparatus.

Yaw control device108may be attached to torque platform110to realign steering assembly142and support foot140with load bearing frame150after the step operation as described above. Yaw alignment system10may allow motors168and170to slip due to the differential angle created between load bearing frame150and support foot140. Feedback sensors169may determine support foot140and steering assembly142are no longer in a previous position relative to load bearing frame150. Steering controller167then may cause motors168and170to rotate support foot140and steering assembly142back to their previous pre-step positions relative to load bearing frame150.

FIGS. 4A-4Dshow another example automated yaw alignment systems10D.FIG. 4Ashows a side view of the automated yaw alignment system,FIG. 4Bis an end view of the automated yaw alignment system inFIG. 4A,FIG. 4Cis a top view of the yaw alignment system inFIG. 4A, andFIG. 4Dis an isolated view of a gear assembly used in the yaw alignment system inFIG. 4A.

Referring toFIGS. 4A, 4B, 4C, and 4D, yaw alignment system10D includes a splined or telescoping assembly172. Instead of using upper and lower motors as shown inFIGS. 3A-3D, yaw alignment system10D uses a single motor174to rotate two splined telescoping shafts180and182. Motor174is coupled to shafts180and182through a gear assembly176. Universal joints178A and178B at the top ends of shafts180and182, respectively, are coupled to gears190and186, respectively, in gear assembly176. Universal joint184A at the bottom end of shaft180is coupled to lower pinion gear130and a universal joint184B at the bottom end of shaft182is coupled to upper pinion gear114.

Shafts180and182each include extending members192A and192B, respectively, that retract upwards when lift piston106raises support foot140off of ground surface160and extend downwards when lift piston106lowers support foot140down onto ground surface160. In other examples, torsion springs may be used instead of shape modifying shafts180(may include flexible, or telescoping) and182or torsion springs may be integrated into shafts180and182.

In one example, gear186in gear assembly176is coupled to motor174and rotationally coupled to gear190through a middle gear188. In another example, a chain may be used instead of middle gear188to rotationally couple gear186to gear190. Motor174rotates gear186rotating shaft182and attached upper pinion gear114. As described above, upper pinion gear114rotates upper main gear134and attached steering assembly142in a first rotational yaw direction relative to torque platform110and load bearing frame150. While shown coupled to gear186, motor174may be coupled anywhere in gear assembly176so shafts180and182can transfer associated torque to turn gears114and130.

Rotation of gear186, rotates middle gear188in an opposite direction that rotates gear190in a same direction as gear186. Gear190rotates shaft180and lower pinion gear130in a same direction as upper pinion gear114. Lower pinion gear130in turn rotates support foot140in an opposite rotational yaw direction than steering assembly142. Support foot140maintains a same alignment with loading bearing frame150as motor174rotates steering assembly142. Shaft180also may extend vertically to accommodate any difference in rotational movement between support foot140and steering assembly142.

FIGS. 5, 6, and 7are isolated side views of different example yaw control devices. Each yaw control device may extend vertically up and down to move in coordination with the vertical raising and lowering of steering assembly142and support foot140.

Referring first toFIG. 5, yaw control device108was described above inFIGS. 1-4and may include upper arm144connected by hinge139to lower arm146. Yaw control device108operates in a scissor manner with upper arm144and lower arm146rotating about hinge139toward each other when lift piston106lifts torque platform110upward toward load bearing frame150. Upper arm144and lower arm146rotate downward about hinge139away from each other as lift piston106moves torque platform110downward.

FIG. 6shows a yaw control device196that may include a drawbar198with a first end hinged to torque platform110and a second end that inserts into a slot202formed in a support200that extends down from load bearing frame150. The first end of drawbar198rotates upward about hinge204and the second end of drawbar198rotates downward within slot202when lift piston106raises torque platform110. The first end of drawbar198rotates downward about hinge204and the second end of drawbar198rotates upward within slot202when lift piston106lowers torque platform110. Drawbar198also slides axially within slot202.

Drawbar198also may prevent torque platform110from rotating while main upper gear134and attached steering assembly142are being rotated. Drawbar198also may elastically deform into a biased state in response to the yaw displacement created between load bearing frame150and support foot140when walking machine100moves load bearing frame150in a non-linear direction. A non-linear direction is alternatively referred to as moving the longitudinal axis of the load bearing frame in a non-linear or lateral direction relative to a longitudinal axis of support foot140. When support foot140is raised, drawbar198elastically releases back into an unbiased state rotating steering assembly142and support foot140back into a pre-step alignment with load bearing frame150.

FIG. 7shows a yaw control device220including two concentric tubes222and224that elastically couple load bearing frame150to torque platform110. Tube222extends vertically down from load bearing frame150. A first end of tube224concentrically and slidingly inserts into tube222and a second end is rigidly attached to torque platform110. As lift piston106moves torque platform110downward, tube224extends vertically down and partially out of tube222. As lift piston106moves torque platform110upward, tube224slides partially up into tube222.

Tubes222and224may have non-circular cross-sectional shapes. For example, tubes222and224may have square or triangular cross-sectional shapes. Tube222and/or224may elastically twist and/or bend into a biased state in response to the differential yaw created between load bearing frame150and support foot140during a step operation. When support foot140is raised, tube222and/or224elastically untwist and/or bend back into an unbiased state moving steering assembly142and support foot140back into a pre-step alignment relative to load bearing frame150.

Other types of biasing members also may be used for holding torque platform110, elastically connecting load bearing frame150with torque platform110, and realigning steering assembly142and support foot140with load bearing frame150.

FIGS. 8-11show different types of rotation devices that may rotationally couple steering assembly142and lower main gear126to support foot140. In one example, rotation device150may include a king pin205as shown inFIG. 8and as described in U.S. Pat. No. 8,573,334.

FIG. 9Ais an isolated side view andFIG. 9Bis an isolated top view of another example rotation device206. Rotation device206may include an inwardly inclining set of rollers207that press against a top outer edge of lower main gear126. Rollers207allow main gear126to rotate about a vertical axis while also holding main gear126in a same vertical and horizontal position on support foot140.

FIG. 10Ais an isolated side view andFIG. 10Bis an isolated top view of another example rotation device208. Rotation device208may include a first set of rollers210that extend vertically up around the outer perimeter of lower main gear126. A set of arms212include first ends that extend vertically up from support foot140and second ends that extend transversely from the first ends over the outer circumference of lower main gear126. A second set of rollers214are rotationally attached to the second ends of arms212and extend over the top outside periphery of lower main gear126. Rollers210may hold lower main gear126in a same longitudinal and lateral position on support foot140. Rollers214may hold lower main gear126vertically over support foot140when support foot140is raised off the ground surface.

FIG. 11Ais an isolated side view andFIG. 11Bis an isolated top view of another example rotation device220. Rotation device220may include a set of arms or clips222that include first ends that extend vertically up from support foot140and second ends that extend transversely from the first ends over the outer circumference of lower main gear126. Clips222hold lower main gear126in a same longitudinal and lateral position on support foot140and hold lower main gear126vertically over support foot140when support foot140is raised off the ground surface.

Any of the yaw control and alignment systems described above can be used in combination with any of the rotation devices described above, where lower main gear126rotates about a vertical axis relative to support foot140to change a direction of steering assembly142while at the same time maintaining a same yaw position of support foot140relative to load bearing frame150.

Some embodiments have been described above, and in addition, some specific details are shown for purposes of illustrating the inventive principles. However, numerous other arrangements may be devised in accordance with the inventive principles of this patent disclosure. Further, well known processes have not been described in detail in order not to obscure the invention. Thus, while the invention is described in conjunction with the specific embodiments illustrated in the drawings, it is not limited to these embodiments or drawings. Rather, the invention is intended to cover alternatives, modifications, and equivalents that come within the scope and spirit of the inventive principles set out herein.