A friction drive or friction engine is a type of transmission that, instead of a chain and sprockets or gears, uses 2 wheels in the transmission to transfer power to the driving wheels. This kind of transmission is often used on scooters, mainly go-peds, in place of a chain.
The problem with this type of drive system is that they are not very efficient. Since the output wheel (leather covered wheel) has width, the area of contact is spread across various radii on the primary disc. Consequently, since the angular velocity varies as radius varies, the system must overcome these variances. The compromise is slippage of the leather to metal contact area which creates friction, which in turn converts much of the energy transfer of this system into heat. Heat generation also requires a cooling system to keep the transmission working effectively.
Friction drive has been most successfully used in low-power applications, such as driving phonograph turntables.
Automobiles using this drive system included the Anglo-Dane, the Arista, the Armadale, the Astra, the Allvelo, the Bukh & Gry, the Crown 12HP Model Two (1905-1906), the Davis Totem, the Ner-a Car, the Cartercar and the Turicum.
The Turicum's friction drive consisted of a flat steel disc coupled directly to the engine. This primary disc subsequently drove a smaller leather covered wheel oriented normal to its surface. Assuming a constant rotational velocity on the primary wheel, the angular velocity on the disc's surface will increase proportionally to the distance from the center of rotation. Therefore, positioning the smaller wheel at different points along the larger wheel's surface varies the gear ratio. Furthermore, since there are no limitations beyond the minimum and maximum positions, the gear ratios are infinitely adjustable.
Plymouth Locomotive Works's first three models, the AL, BL and CL were equipped with a friction drive.
References / sources
|This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. (October 2012)|
|This page uses some content from Wikipedia. The original article was at Friction drive. The list of authors can be seen in the page history. As with Tractor & Construction Plant Wiki, the text of Wikipedia is available under the Creative Commons by Attribution License and/or GNU Free Documentation License. Please check page history for when the original article was copied to Wikia|
|This technology-related article is a stub. You can help Tractor & Construction Plant Wiki by expanding it.|