Timing Drive Systems
Chains (Inverted Tooth, Roller, Bush)
Automotive Chains are used for driving the camshafts in engines, counterbalance shafts, or oil pumps. Camshaft drives transmit the crankshaft rotation to the camshaft of the engine at a ratio of 2:1 and maintain synchronicity between the shafts. The counterbalance shafts and oil pumps can also be driven by chains.
A tensioner, pushing either directly on a chain or on a pivoting guide, takes up slack in the chain circuit and controls chain movement, which is important to control noise, chain tension, and vibration resonances. The tensioner plunger also extends to make up for chain wear and thermal expansion. Tensioners can be mechanically and hydraulically tuned to meet application requirements.
Guides and Levers
The role of fixed guides is to provide a low friction, wear resistance platform to guide the chain span between sprockets. Various shapes and materials are used, depending upon the application.
The lever design and function are similar to those of the guide, except its design allows it to pivot. A lever is used in conjunction with a tensioner to take up chain span slack and control chain motion.
Sprockets are the rotating elements which both drive and are driven by the Chain. Sprocket design is tightly controlled by Tsubaki to ensure proper mesh, strength, and durability. Various materials, fabrication methods, and heat treat options can be selected, depending on Chain type, load, speed, and NVH requirements.