Composite Technology in Couplings and Shafting for Power Transmission

Abstract

Abstract Composite technology is growing in the power transmission industry. Composite structures of predominately carbon fibers and epoxy resins form a matrix structure for which one use is to transmit mechanical power. Of significant importance in this paper is the use of composite structures for shafting and coupling flexible elements. Filament wound composite shafting consists of winding a continuous band of the carbon fiber and epoxy resin matrix around a mandrel to obtain optimized end product characteristics. These optimized characteristics include: minimized weight with superior tensile strength when compared to steel, variable modulus of elasticity for critical speed requirements, virtually no thermal expansion of the composite shaft and corrosion resistance. The ability to modify the wind angles during the manufacture of the composite shaft permits the designer to achieve desirable system characteristics through variations in the composite matrix or laminate with negligible change in component cost or delivery. Coupling flexible elements are also manufactured from carbon fiber and epoxy resin laminates. These flexible elements take advantage of the greater tensile strength of the carbon fiber versus carbon or stainless steels to achieve a superior torque capacity within a given coupling outside diameter, or greater power density with equivalent or greater misalignment capacities. The carbon fiber and epoxy resin composite coupling flexible element embodies the desirable coupling characteristics of low deflection stiffnesses resulting in low reaction forces transmitted to the connecting equipment, with minimized possibility of fretting fatigue and significant corrosion resistance. This paper will provide an overview on the composite structure, the materials used, the filament winding process, other manufacturing processes and the application and benefits of this technology in mechanical power transmission.