Text version of the page

General/Basics

Rotary Measuring Technology - Encoders Particular shaft loading due totoothed-wheels, gear-pulleys andsimilar elements

Measuring wheels, toothed wheels or gearpulleys, which are mounted directly on the encoder shaft, exert radial forces on the latter, dependent on prestressing and angu- lar acceleration. Kübler encoders are designed so that they can absorb these forces to a great extent. The maximum per- missible load capacity of the shaft is shown in the technical data for the encoder. Ifthese load values may be exceeded in aparticular application, then the encoder shaft must be isolated from the radial load by interposing an appropriate shaft with its own bearings that can absorb the forces. Kübler offers suitable bearing blocks and bearing boxes for this purpose (please refer to the 'Accessories' section in the cata- logue).

Rotary Measuring Technology – Incremental Encoders

LED Mask

Incremental encodersAssembly and function:

Kübler encoders operate on an electro-opti-cal scanning principle.A disk with a radial grating of lines andgaps rotates between a light source (mostly an LED) and a receiver which pro-duces a sine wave signal proportional to the light received. Receiver Disk with radial lines and gaps Mechanical advantages of Kübler encoders • Interlocked bearings, large bearing span and extra strong outer bearings ensure stabilitywhen subjected to vibration and tolerance of installation errors. Machine downtime and repairs are eliminated.• Ideal for use outdoors thanks to its solid die-cast housing and radial shaft seal. TheSendix Inkremenal benefits from a high IP 67 protection rating and a wide operating tem- perature range from –40 ºC up to +85 ºC. P Processing of the signals: The sine wave signals are processed fur-ther in an electronic circuitry, usually aKübler specific ASIC. This is necessary because most controllers (like e.g. Kübler counters) require digital signals with a cer-tain voltage level. For that the signals arepre-processed in the encoder. The pre-processed signals are provided by the out-put circuit depending on the application. Selecting an incremental encoder: When selecting a suitable incremental encoder, then in addition to the generalselection criteria shown on Page 13 thefollowing special points must be observed:
1/2008 www.kuebler.com 19