The present disclosure generally relates to drive systems of the type having a composite tubeshaft and more particularly including a metallic substrate joined to a composite substrate to form a composite tubeshaft.
Conventional driveline systems typically include tubeshaft assemblies for delivering torque from a driving system, such as a motor or engine to a driven system, such as wheels or power equipment. Typically, these shafts have been made from a steel, aluminum or composite material having connection devices such as a constant velocity joint or other joint end mounting attached thereto
Composite drive/shafts offer excellent strength-to-weight and stiffness-to-weight ratios compared to metallic driveshafts. Their coefficients of thermal expansion are generally low, which reduces the load on couplings and hanger bearings caused by thermal excursions. These drive shafts play an increasingly important role in today's air and automotive drivetrain industries, which are constantly seeking ways to increase strength while reducing the gross weight of the vehicle. Composite driveshafts have found many applications in the design of drivetrain systems for the reduction of wear and improved strength.
However, composite driveshafts require metallic adapters for interfacing other shaft components to transmit loads. In general, composite tubeshafts are typically made by weaving composite thread around a shaft mandrel, adding resin and curing. The created tube is then machined to create a desired interlock configuration and a joint end is slid into the end of the shaft and is locked into place by a securing collar or wrapping more composite around the joint end and repeating the curing process. Another common method is to wrap the composite thread around a shaft mandrel with the joint end in place or to insert the joint end onto the end of the finished composite shaft and wrapping additional composite material around the joint end to secure it to the composite shaft. Generally, multiple types of composite-adapter joint end systems are employed for composite driveshafts: notched (cutouts at the end of the shaft with corresponding raised features on a joint end), notched with retaining collar, press-fit (either internal or external), lugged (joint end includes lugs surrounded by composite then cured in place), bonded joints (joint end is placed in tube and additional composite is wrapped around to create a bond after curing) and bonded joints with ribs (joint end is placed in tube prior to curing). These designs are limited by their structural integrity, weight, or manufacturing costs and complexity.
Therefore, what is needed is an integrally fabricated encapsulated connection for a tubeshaft metallic interface end and a method for providing same that is low cost, lightweight and high strength.
Referring now to the drawings, illustrative embodiments are shown in detail. Although the drawings represent some embodiments, the drawings are not necessarily to scale and certain features may be exaggerated, removed, or partially sectioned to better illustrate and explain the present invention. Further, the embodiments set forth herein are exemplary and are not intended to be exhaustive or otherwise limit or restrict the claims to the precise forms and configurations shown in the drawings and disclosed in the following detailed description.
Exemplary illustrations are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual illustration, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints that will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
Referring to the drawings,
The serrated teeth 62 and 64, engage the composite substrate 50. This engagement creates a locking interface between the teeth 62, 64 and the composite substrate 50 by applying simultaneous compressive forces (not shown) to both a first surface 56 and a second surface 58 of the composite substrate 50. These forces (not shown) are the result of the composite substrate 50 being weaved between each tooth 62 and 64 creating tension between the alternating teeth 62, 64. The engagement of the composite substrate 50 and the metallic substrate 60 may be of any known type such as, meshing or weaving, as long as the engagement creates a locking interface between the two substrates 50, 60. While shown as having a generally triangular shape, it is understood that teeth 62 and 64 may be configured with other shapes.
The generally planar composite substrate 50, of
It should be known that the composite substrate 50 and the metallic substrate 60 may be of any suitable dimension capable of being rolled to create the desired length, thickness and diameter of the finished tubeshaft 36 assembly. The composite material may also be of a desirable thickness to provide the required strength of materials properties for each application.
As shown in
The application of the securing agent can be applied before or after the engagement of the metallic substrate 60, but prior to rolling the assembly to create the tubeshaft 36. Further, the serrated teeth 62, 64 can be alternated provided at least one tooth 62, 64 is positioned on top of the composite substrate 50 and at least one tooth 62, 64 is positioned beneath the composite substrate 50.
The preceding description has been presented only to illustrate and describe exemplary embodiments of the methods and systems of the present invention. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. The invention may be practiced otherwise than is specifically explained and illustrated without departing from its spirit or scope. The scope of the invention is limited solely by the following claims.
This application is a continuation of PCT application, US/2011/032663, titled COMPOSITE TUBESHAFT METALLIC INTERFACE, and filed on Apr. 15, 2011.
Number | Date | Country | |
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Parent | PCT/US2011/032663 | Apr 2011 | US |
Child | 14053370 | US |