The present disclosure is generally directed to solid composite shafts or rods and solid core filament winding for forming solid composite shafts.
Filament winding is a fabrication technique used for manufacturing hollow cylinders or shafts or closed end structures, such as pressure vessels or tanks. This process involves winding filaments under tension over a rotating mandrel, which then produces a hollow composite cylinder or shaft due to the presence of the rotating mandrel, and due to the removal of the mandrel from the composite winding. The mandrel rotates around the spindle while a delivery eye (also known as a payout head or payout eye) on a carriage traverses horizontally in line with the axis of the rotating mandrel to lay down strands of fibers in a desired pattern or angle to the rotational axis, typically of the hoop winding type or the helical winding type.
The most common filaments are glass or carbon and are impregnated with resin by passing through a bath as they are wound onto the mandrel. Alternatively, prepeg fibers, also known as pre-impregnated fibers, may be used. Once the mandrel is covered to the desired thickness with layers of the filament fibers laid down onto the rotating mandrel, the resin can be cured. Depending on the particular resin system used, the mandrel can either be autoclaved or heated in an oven or rotated under radiant heaters until the part is cured.
Once the resin has cured, the mandrel can be removed or extracted from the mandrel, leaving the hollow final product. For some products such as gas bottles, the ‘mandrel’ is a permanent part of the finished product forming a liner to prevent gas leakage or as a barrier to protect the composite from the fluid to be stored.
Aspects of the invention include a method for forming a composite rod or shaft. The method can comprise suspending roving strands between two spindles to form suspended roving strands that define a composite core; and winding roving materials through at least two payout eyes and then laying the roving materials around the composite core.
The method can further comprise adjusting a tension on the suspended roving strands prior to the winding step.
The at least two payout eyes can be located on a frame of an eye unit.
The eye unit can comprise a third payout eye located on the frame of the eye unit.
The payout eyes can be generally evenly spaced relative to one another.
The method can comprise winding a plurality of layers of roving materials around the filament core to a desired diameter to form a composite shaft or rod. The composite shaft or rod can be solid and can be formed via filament winding without using a mandrel.
A further aspect of the invention includes a filament winding apparatus or machine comprising two spindles and at least one tensioner. The at least one tensioner is configured to adjust the tension on the suspended roving strands, which form the filament core of the invention without a mandrel.
The filament winding apparatus can further include an eye unit comprising at least two payout eyes. The eye unit can accommodate the filament core therein and the at least two payout eyes can direct at least two different sets of roving materials therethrough to deposit the roving materials onto the filament core, without a mandrel.
The eye unit can further include a plurality of winding arms. Each winding arm can have at least one payout eye.
A still further aspect of the invention is a solid composite shaft or core formed by filament winding without a mandrel.
A further aspect of the invention comprises a preform comprising a solid composite shaft and a composite shell wound around an exterior of the solid composite shaft.
Yet, a still further aspect of the invention comprises a bridge plug frame comprising a solid composite shaft and a composite shell located around an exterior of the solid composite shaft, a first bore at a first end of the bridge plug frame, and a second bore at a second end of the bridge plug frame; and wherein each of the first bore and the second bore comprises a ball seat having a surface formed by both the solid composite shaft and the composite shell.
The bridge plug frame can further comprise at least one machined portion and wherein bridge plug components can be located at the at least one machined portion.
The present invention further includes a method of forming a bridge plug comprising forming a composite solid shaft without a mandrel; and locating the composite solid shaft within a composite bridge plug shell.
The composite shell can be wound directly around the solid shaft or can be formed first and then the solid shaft inserted into a hollow bore of the composite shell.
The method can further comprise placing bridge plug components onto the bridge plug shell.
The bridge plug components can include a slip ring and a slip wedge.
These and other features and advantages of the present devices, systems, and methods will become appreciated as the same becomes better understood with reference to the specification, claims and appended drawings wherein:
The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of solid composite shafts or rods, solid core filament winding for forming solid composite shafts, composite preform, composite bridge plug frame, and composite bridge plug provided in accordance with aspects of the present devices, systems, and methods and is not intended to represent the only forms in which the present devices, systems, and methods may be constructed or utilized. The description sets forth the features and the steps for constructing and using the embodiments of the present devices, systems, and methods in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and structures may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the present disclosure. As denoted elsewhere herein, like element numbers are intended to indicate like or similar elements or features.
Descriptions of technical features or aspects of an exemplary configuration of the disclosure should typically be considered as available and applicable to other similar features or aspects in another exemplary configuration of the disclosure. Accordingly, technical features described herein according to one exemplary configuration of the disclosure may be applicable to other exemplary configurations of the disclosure, and thus duplicative descriptions may be omitted herein.
With reference now to
As the axle 106 spins to spin the filament core 110, filament 112 accumulates on the filament core 110, forming layers of such filament 112. A winding angle α of each filament 112 as laid on the filament core 110 is determined by the rotational speed of the axle 106 and the translational speed of the carriage 136. Preferably, the motor 104 and the carriage 136 are electronically controlled by a programmable controller 140 so that the winding angle α, number of layers, etc., can be strictly controlled. As the present invention is directed to solid composite shafts or rods and solid core filament winding for forming solid composite shafts, the winding angle is limited primarily to helical winding type, in the order of about +/−5 degrees to 30 degrees relative to the axis defined by the filament core 110, although there is no prohibition against using larger angles for hoop winding type.
Once sufficient layers of filament of filament are laid onto the filament core 110 to form a solid rod or shaft and cured, it can be removed from the spindles 108 and machined if desired. It is also to be understood that, in some embodiments, the filament that is wound about the mandrel filament core 110 comprises many fibers, such as from the multiple roving spools 118, that can be compressed somewhat into a substantially flat tape that is wound about the filament core 110. Such filament tape 112 preferably is applied to the mandrel filament core 110 so that it is flat in a plane that is substantially parallel to the axis of the filament core 110. The number of roving spools 118 can be selected to simultaneously feed a plurality of payout eyes, as further discussed below. Roving strands that pass through a payout eye in an eye unit comprising a plurality of payout eyes can be referred to as a set of roving strands.
In an exemplary embodiment, roving strands 144 are suspended between two spindles 108 to form a filament core 110 of the present invention. The filament core 110 then provides the foundation for which to lay filament fibers to form layers of fibers of a solid composite shaft or rod. As shown, one or both spindles 108 can be provided with a tensioner 148. Each tensioner 148 can be spring loaded, mechanically adjustable, and/or electronically adjustable based on stress/strain values indicative of the tension of the roving strands suspended by the one or two tensioners 148. The tensioners 148 are configured to maintain appropriate tension on the roving strands 144 for forming the filament core 110 of the present invention via filament winding around the filament core. In an example, the roving strands should be taunt when suspended so that the two rows of roving strands are generally parallel as they are suspended between the two spindles 108. In some examples, there can be more than two rows of roving strands mounted between the two spindles to form the filament core of the present invention. In yet other examples, the roving strands 144 can be taunt and functions as a filament core 110 without the need for any tensioner 148.
In an example, a mounting end 150 can be located on each tensioner 148 for supporting the roving strands 144 in two rows of elongated and parallel fibers. Optionally, more than two rows of fibers may be used to form the filament core of the present invention. The mounting end 150 can embody any number of shapes or structures, such as a hook shape, an eye-bolt, a C-clamp, etc., and is configured to provide physical support for the roving strands, to suspend the roving strands between the two spindles 108. That is, the roving strands can mechanically connect to the two mounting ends 150 to be suspended between the two spindles 108. Two ends of the roving strands can be tied or knotted to remain suspended between the two mounting ends 150.
Once the filament core 110 are formed as shown, filament layers can be deposited onto the filament core 110 in a helical winding pattern, without any rotating mandrel, to from a solid shaft or rod in accordance with aspects of the invention. In some embodiments, the roving strands 144 are first twisted to form a twisted filament core 110 before filament layers can be deposited thereon in a helical winding pattern, without a rotating mandrel, as shown in
The two spindles 108 are preferably rotated in unison so as to turn the filament core 110 in a synchronous revolution. In an example, the two spindles 108 are directly mechanically engaged so as to rotate in unison by a single motor. For example, the two spindles can be geared and/or linked by a belt drive system in order to rotate in unison. In alternative embodiments, the two spindles 108 are motorized and are electronically controlled so as to rotate in unison. For example, the controller 140 (
With reference now to
In an example, the eye unit 160 comprises a frame 162 having two or more winding arms 164 attached to the frame, such as via a clamp, fastener, strap, and/or welding 166. The frame can embody any number of shapes, such as square or oval, with round or circle being more preferred. A payout eye or head 134 can be located at an end of each winding arm 164. The two or more payout eyes 134 can define a boundary for surrounding the rotating filament core 112 therein and for laying filament fibers thereon, as further discussed below. While as few as two payout eyes 134 can be incorporated with the eye unit 160, preferably the eye unit as three or more payout eyes 134 equally spaced along the periphery of the frame to form axial symmetry about the filament core 110 to ensure a balance load on the filament core during winding. Hooks or pin rings may be mounted on both ends of the rotating axis to allow the roving strands coming out of the payout eyes 134 to catch and build up the tooling from the fiber itself to create a solid part. In some examples, when fiber is wound onto the core 110 and typically during the beginning or start of the winding process, the eyes or mounting ends 150 (
In an example, each winding arm 164 can include a tensioner and/or re-director 130 for directing a corresponding epoxy-impregnated filament through the payout head or payout eye 134 at the opposite end of the winding arm. For example, a single resin bath can be used to coat the multiple roving strands that pass through the multiple payout eyes 134 on the eye unit 160 and the tensioner and/or re-director 130 can assist with routing the coated roving strands through the respective payout eye 134. In alternative examples, each winding arm 164 has an impregnation unit 170 mounted thereon or coupled therewith, which can include a resin bath contained in a reservoir and a tensioner and/or re-director 130 for directing a corresponding epoxy-impregnated filament through the payout head or payout eye 134. That is, each roving strand of the multiple roving strands to be routed through the eye unit 160 can pass through a dedicated resin bath located on the eye unit.
While the eye unit 160 of
With reference now to
At 184, the process continues by adjusting the tension or by twisting the core 110 of the suspended roving strands. The tension can be adjusted by any number of methods, including by adjusting a movable rod to control a gap or distance of the two ends of the roving strands and therefore the tension of the roving strands. The adjustment can include using a threaded adjustable knob, a threaded shaft, a spring, a lever, etc. The tension on the roving strands should cause the strands to be taunt.
Next, the process continues at 186 with winding at least two roving materials through two payout eyes to simultaneously wind the roving materials around the filament core formed at 184. The two payout eyes should be evenly spaced relative to one another to provide axial symmetry around the filament core. In other examples, the process can involve more than two sets of roving materials for use with more than two payout outs. The process can continue with winding a plurality of filament layers around the filament core to build up the core and produce a composite rod or shaft, without using a mandrel.
With reference now to
The shell 202 can be formed by winding filament fibers around the exterior 204 of the composite shaft 116. For example, after forming the composite shaft 116 and allowing the shaft to cure, the shaft 116 can then be used as a mandrel for winding fibers around the exterior 204 of the composite shaft to form the shell 202. Thus, the shell 202 can have an inner most layer 201 that contacts or is wound directly onto the exterior of the composite shaft 116. The inner most layer 201 forms the inside diameter of the shell 202.
The composite shell 202 is filament wound with slightly shorter as the length of the composite shaft 116. In an example, the composite shell 202 can be wound to approximately the same outer diameter 206 along the length of the shell. In another example, the composite shell 202 can be wound with at least two different outer diameter sections 208, 210. For example, the outer shell can have a first diameter section 208 and a second diameter section 210, which is larger than the first diameter section. The same outer diameter 206 or the largest second diameter section 210 of the shell can be selected based on the bridge plug application. In other examples, the length of the inner shaft 116 and the diameter and length of the shell 202 can be other than described and then machined down to size, as further discussed below.
The shell 202 is allowed to cure following formation around the inner shaft 116, preferably in a heated environment, such as in a temperature controllable oven. The curing time and temperature range are epoxy and thickness dependent, which those skilled in the art understand.
With reference now to
Internally at the first end 220, a bore 230, also referred to as a first bore, can be machined with a sidewall 232 and a bore bottom 234. The bore 230 can have an inside diameter that is smaller than a ball plug to be used with the bridge plug frame 203 and larger than 116, as further discussed below. In an example, the sidewall 232 of the bore 230 defines an inside diameter having a dimension of about 6 mils to about 30 mils smaller than the diameter of the ball plug with about 12 mils to 18 mils being preferred. The interference can depend on the hardness of the ball plug used. The hardness can depend on the application environment, such as pressure, temperature, and corrosive chemical present. In an example, the inside diameter of the bore 230 has a dimension that is larger than the outside diameter of the inner shaft 116. Thus, the bore bottom 234 is made up of both the end surface of the inner shaft and part of the shell. The bore bottom 234 defines a ball seat.
In an example, the bore bottom 234 can be machined with a conical or a frusto-conical cross-section, which forms a ball seat at the first end of the bridge plug frame 203. The conical or frusto-conical bottom or flat bottom allows the ball plug to seat against the ball seat and forms a circular line seal where the two contact.
A second bore or upper bore 240 is located at the opposite end of the bridge plug frame 203. In an example, the second bore 240 is shaped like the first bore 230. That is, the second bore 240 can be machined with a sidewall 242 and a bottom wall 244, which can have a conical or a frusto-conical shape or flat. The bottom wall 244 of the bore defines a ball seat. The bore bottom 244 is made up of both the end surface of the inner shaft and part of the shell. In some examples, a small through bore may be machined through the center of the inner shaft 116.
In another exemplary embodiment, the shell 202 may be formed over a traditional mandrel and then separate from the mandrel when cured. The mandrel may be selected to have an outer diameter that is slightly larger than the outer diameter of the composite inner shaft 116. The shell 202 may be wound with a single diameter and then machined to final size or wound with two or more different diameters and then machined to final size. The inner shaft 116 can then be inserted into the hollow core of the formed shell 202, with a small gap between the outer surface of the inner shaft 116 and the inner surface of the formed shell 202. For example, the small gap can be about 0.005″-0.010″ of an inch but can vary depending on the adhesive used. Adhesive can then be used to secure the inner shaft 116 to the interior of the formed shell 202, to prevent the two from separating during machining. The combination inner shaft 116 and shell 202 can then be machined to form the first and second bores 230, 240, as shown in
With reference now to
A first ball plug 264 is located in the first bore 230 and held therein by a pin 266. A second ball plug 270 is located in the second bore 240 and held therein by a pin 272. After the bridge plug 250 is set within the well and the sealing element 256 sealed against the well casing, pressure above and below the bridge plug forces the first ball plug 264 to seal against the seal seat at the first bore 230 and the second ball plug 270 to seal against the seal seat at the second bore 240.
In general, for bridge plug applications, a single continuous wound, such as a single solid rod, to form the composite preform assembly similar to that of
Composite shafts or rods and methods of making and of using the composite shafts or rods and components thereof are within the scope of the present invention. Composite bridge plug frames and methods of making and of using bridge plug frames and components thereof are within the scope of the present invention. Bridge plugs and methods of making and of using bridge plugs and components thereof are within the scope of the present invention.
Although limited embodiments of the winding assemblies and their components for forming composite shafts or rods without a mandrel and bridge plug frames and bridge plugs utilizing the composite shafts have been specifically described and illustrated herein, many modifications and variations will be apparent to those skilled in the art. Accordingly, it is to be understood that the winding assemblies and their components and products formed thereby, including solid composite shafts and composite bridge plug and composite bridge plug frames using the solid composite shafts constructed according to principles of the disclosed devices, systems, and methods may be embodied other than as specifically described herein. The disclosure is also defined in the following claims.