DESIGN OF POLYMER GEARS FOR AUXILIARY POWER TRANSMISSION SYSTEMS OF AUTOMOTIVE VEHICLES

The polymer gears owing to their advantages are used in auxiliary power transmission systems of automotive vehicles. For example, the gears occur in transmissions of drives of car wipers or drives of car windows. The polymer gears are mainly used owing to lower production cost than in steel gears. The better silent-running and corrosion resistance are their other advantages in comparison with steel gears. Unfortunately, the polymer gears are not devoid of disadvantages. The main disadvantages are the lower efficiency and the lower capacity and what follows – the bigger dimensions. The conservative attitude of design of polymer gears is still noticeable. As a rule, such gears resemble steel gears, but the polymer gears are designed with bigger module. The most probably owing costs and lack of proper design recommendations, for design of polymer gears is used geometry of classic steel gears, because the procedure of analytical strength calculations for classic gears is well-know. The gears made from polymers are built in the mould matrices. In constructions of many mechanisms, the gears can be replaced in case of consumption or damage, so the construction of such gears that can be produced in the machine shop equipped with gear generating machine for standard gears, was justified. Nowadays, the constructions of mechanisms used in automotive vehicles are often not even dismountable, but the whole mechanism is changed. It is worth changing the attitude to design of such transmissions. The method of gears production gives many opportunities. The production of gears with complicated geometry, also such geometry that is impossible to obtain using traditional methods of machining, is possible in the mould matrices.