There is great emphasis in the automotive industry to develop innovative designs using advanced materials and techniques. Not only must these designs be creative and cost effective, they must also meet the ever increasing demands of present and future applications. One area where designers look for savings in both weight and production cost is the camshaft. Innovative design, the excellent use of a wide variety of materials and the power of computer aided engineering are all being combined to produce a lighter, more cost effective camshaft.
This paper will discuss the key aspects of material, design and analysis that led to the development of the composite camshaft. It will list both the economical and physical advantages of sintered, machined, and formed components, stabilized by an engineering plastic. All of this information will show that the right combination of design, material and analysis has produced a breakthrough in the camshaft industry, opening the door for future design in other areas.
SEVERAL COMPANIES are developing new types of camshafts that will be lighter, generate less noise and cost less. There are developments that involve new methods of manufacturing, using separate components that are combined to form a composite camshaft.
One of these methods uses metal lobes and journals that are precisely located on a hollow metal shaft which is then expanded, either mechanically or hydraulically, locking the lobes and journals in place. Another method uses a diffusion bonding technique to weld the lobes and journals into place. A third, and very unique method utilizes an engineering plastic to bind the lobes and journals to the center shaft. The design and development of this unique method of using plastic to create what is truly a composite camshaft will be discussed.