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Transmission
Phenolic resins with glass fiber reinforcement have been used successfully to manufacture stationary transmission parts with attached revolving rotors in revolutionary one-piece designs. The single-piece design replaces several separate metal components that would otherwise be needed, resulting in a substantial reduction in assembly time and underscoring the outstanding design efficiency attainable when using plastic.
Plastic can also be used to manufacture transmission oil screens and other components requiring exposure to hot transmission oil. As with fuel tanks, plastic helps free designers from the space constraints that arise with the use of sheet metals. The ability to design a transmission with few design limitations allows design engineers to place transmission components in tight-fitting spaces. This is especially important in front-wheel drive vehicles where several components compete for a limited amount of space. The use of plastics in front-wheel drive transmissions also helps lessen the weight in the front of the vehicle, improving vehicle handling. Polyetherimide resins are used extensively in transmissions sensor and valve solenoid applications because of their resistance to high temperatures and creeping.
Plastic has found remarkable acceptance as a substitute for metal in transmission components. Plastics offer engineers a variety of materials featuring an excellent combination of physical properties, including heat and chemical resistance, high strength, impact strength and molding ease. These performance characteristics can be tailored by materials suppliers to meet particular needs. The use of additives, fillers and reinforcements will vary the properties of a plastic to meet specific customer requirements. Polyetherimide, for instance, is used extensively in transmissions for its superior dimensional, heat, and creep performance, while a single piece of nylon can replace several steel washers.
Plastics' light weight, durability, design flexibility, and uniform surface make it them an ideal family of materials to use in a power train. From reducing costs and weight, to dampening noise and vibrations, plastics have been used to make single-piece clutch cylinders, shift control cables, air intake manifolds, engine covers, accelerator and parking brake pedals, fuel system and cooling system components and gear-lever housing.
From housing and covers protecting gears and bearings, to the bearings themselves, specifying plastic adds value by reducing weight, and lowering assembly costs, while providing an economical material capable of durable operation under the most strenuous of conditions.
A key factor behind the strong and steady growth of many of these plastics is recyclability. The use of the large quantities of the same or similar materials greatly improves the economics of recycling. As more plastics are used in automobiles, we are likely to see a trend towards the increasing recycling of these plastics.
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