Side runner dynamo
A side rotor dynamo is a bicycle dynamo that is attached to the front fork (fork blade) or to the frame in such a way that its friction wheel can be driven by the side wall (flanks) of the tire or the rim .
history
Simple side-rotor dynamos are built into inexpensive bicycles in particular. Until the 1990s, when other types of dynamo (such as hub dynamo , spoke dynamo ) were increasingly on the market , they were the usual power generators for bicycles .
The rim dynamo is a special design.
To switch on and off
During operation, the dynamo is swiveled against the tire by a spring. To switch it off, it can be locked in the swiveled-out position.
Drive and adjustment
Like all friction transmissions, this one is also subject to slippage . As a result, the friction roller and in particular the tire sidewall are subject to heavy wear. In addition, slipping in wet or slushy conditions can lead to dropouts and even failure of the voltage generation. As a remedy, there are rubber caps that can be placed over the friction wheel. The larger circumference and the coarser profile reduce the slip.
For the optimal running properties of a side-running dynamo it should be noted that
- its longitudinal axis intersects the wheel axis during operation,
- in the pivoted position, its longitudinal axis is usually at right angles to the wheel axis. In this position, a gap of usually 6 to 10 mm (otherwise according to the manufacturer's instructions) must be maintained between the friction wheel and the tire casing.
Types
Traditionally, side-rotor dynamos are attached to the bicycle in such a way that the free end of their fastening strap points backwards (against the direction of travel), i.e. H. the friction roller is in front of the attachment point. This makes sense because such a dynamo, if it gets caught in the spokes due to incorrect suspension, is less likely to get jammed between the fork and the spokes; thus the risk of a fall is reduced.
Right-hand rotating dynamos are mounted to the right of the tire and pivot to the left against the tire for operation. Accordingly, left- hand rotating dynamos are attached to the left of the tire and pivot to the right against the tire.
Comfort
With simple dynamos in particular, the additional force required for driving when the dynamo is switched on is disruptive. This effect is less pronounced in high-quality models: replacing a simple dynamo with a higher-quality product can mean a considerable gain in convenience.
maintenance
The friction roller can be exchanged on classic models. The side-rotor dynamo can be exchanged with simple bicycle tools; the use of low-corrosion screws (hot-dip galvanized, low-corrosion steels such as V2A) of the usual size M6 is advisable.
Energy conversion
Side-running dynamos generate an alternating voltage by means of a rotating permanent magnet and a fixed induction coil . It does this by converting part of the wheel's kinetic energy into electrical energy. The selected design eliminates the need for slip rings that are otherwise required when the coil is rotating, which improves operational safety. The centrally installed fork or roller dynamos that rub on the running surface are a special form . The permanent magnet also rotates in this design.
In the past, the circuit was usually connected via a wire and the bicycle frame as a ground contact, so that only one wire was visible. Today, wiring via two cables is becoming more and more popular. This is due to the use of electrically non-conductive frame components - for example made of plastics - as well as the current passage in question through the bearings of the steering tube.
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
Web links
Individual evidence
- ↑ www.fahrradzukunft.de/fz-0601/0601-02 ( Memento of the original from June 11, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
