Ring gear
A ring gear is an internally, externally or laterally toothed ring gear which , unlike a gear wheel, does not sit directly on an axle or shaft , but is mounted on the circumference of a cylindrical component.
To make assembly easier , gear rims are often split and screwed together .
Large ring gears are used to control the rotary movement of cranes and excavators and are often combined here with the rotary bearing ( ball bearing ) to form a single component.
The sprockets on the rear wheel of bicycles are also called sprockets because they are usually mounted on the hub or freewheel (instead of directly on the axle). Derailleurs need several sprockets, leading to a sprocket assembly (also cassette or sprocket set be put together called).
The drum of small concrete mixers for private use is often driven by gear rims, which are often designed as a toothed ring with side teeth and screwed or pressed with the drum.
Industrial use
Gear rims are used on large cylindrical mills and rotary kilns in the cement and mineral industries.
Gear rims with very large dimensions (sometimes over 10 meters in diameter) are usually not enclosed by a housing , but run open. Special “ cleaning devices” in circulation before the meshing with the pinion clean the teeth and lubricate them with grease . An elastic suspension allows the ring gear to avoid dirt particles .
Few companies in the world manufacture sprockets over ten meters in diameter. The starting material is a cast or rolled steel ring . Sprockets made from rolled material are cheaper, but the welded connection of the seam is a weak point. The cost of a large sprocket can be over 500,000 euros (as of 2005).
literature
- Michael Gressmann, Franz Beck, Rüdiger Bellersheim: specialist knowledge of bicycle technology. 1st edition, Verlag Europa-Lehrmittel, Haan-Gruiten, 2006, ISBN 3-8085-2291-7
- Hans Jörg Leyhausen: The master craftsman's examination in the automotive trade. Part 1: General principles, combustion engines, mixture formation, power transmission, chassis. 12th revised edition. Vogel Buchverlag, Würzburg 1991, ISBN 3-8023-0857-3 .