Incremental encoder
Hightech-materials for low-cost, sturdy encoders
The vital task in many positioning cycles is capturing rotary movements – and mostly encoders are the appropriate product. Fairly “simplified” incremental encoders can turn into effective positioning systems convenient to operate. By absolute position sensing any reference cycle is superfluous and furthermore the absolute encoder will not lose the positions in case of power loss. The fact that both the incremental and the multiturn principle meanwhile are available at a reasonable price with improved sturdiness is not only due to advanced electronics but also to progress in material and manufacturing technology.
Plastics – man-made materials – have changed the world. They belong to modern civilization and you cannot imagine automation technology without them. Although they are not the material of preference in basic mechanical constructions and plant engineering concepts, plastics provide vital benefits compared to metal. They are lighter, resistant to even very aggressive chemical substances and provide excellent shock-absorbing characteristics.
The vital task in many positioning cycles is capturing rotary movements – and mostly encoders are the appropriate product. Fairly “simplified” incremental encoders can turn into effective positioning systems convenient to operate. By absolute position sensing any reference cycle is superfluous and furthermore the absolute encoder will not lose the positions in case of power loss. The fact that both the incremental and the multiturn principle meanwhile are available at a reasonable price with improved sturdiness is not only due to advanced electronics but also to progress in material and manufacturing technology.
Plastics – man-made materials – have changed the world. They belong to modern civilization and you cannot imagine automation technology without them. Although they are not the material of preference in basic mechanical constructions and plant engineering concepts, plastics provide vital benefits compared to metal. They are lighter, resistant to even very aggressive chemical substances and provide excellent shock-absorbing characteristics.
Plastic better than metal?
Especially carbon-fibre plastics (CFP) have opened up many innovative possibilities in housing technology. It is a compound material where the basic Polymere matrix is reinforced by carbon fibres what means improved product characteristics regarding mechanical resistance, mass and volume. In the past, both production and application used to be quite expensive and thus were restricted to aerospace, medicine or high-end fitness equipment. Thanks to progress in manufacturing technology things have changed and nowadays the sturdy material is affordable in other branches.
Light weight combined with very accurate dimensions regarding thermal expansion make them perfect for use in mechanical engineering and electronics where they provide another benefit against conventional plastics: Thanks to their electric conductivity they serve like metal housings as shield against electromagnetic interference. BaumerIVO as manufacturers disposing of the necessary know-how in plastic processing therefore utilizes CFP plastics for encoders.
Encoders in CFP housing
By the new product series “IncreTivo” Baumer IVO offers both incremental and absolute encoders featuring a carbon-reinforced polyamide housing. The housing is capable of draining electromagnetic interferences and thus the new encoders are in line with EMC- standard DIN 6000-6-2. Only precondition is grounding the CFP housing what is already effected by connector and coupling spring.
CFP is the perfect selection as housing material to reduce encoder dimensions. With a diameter of approx. 58 mm and -depending on the selected mounting option- only 34,5 mm respectively 41,5 mm in length the encoders fit even narrow spaces with easy and convenient mounting. The encoders in CFP housing are intended for quick installation by direct mounting on shafts of max. 14 mm diameter. Through-hollow shaft mount is by clamping ring, end shaft mount (non-through hollow shaft) by screw. Torque support is either by a torque pin assembled by the customer into the recess provided at the rubber buffer or easily by mounting spring. A buffered torque support is available as accessory. The tangential encoder cable output means another dimensional reduction and enables at the same time both an axial and radial cable output. The conventional PG cable gland is replaced by new integrated strain relief.
The housing provides a uniform smooth die-cast surface where dirt, grease and other polluting substances cannot stick to. The encoders are in line with IP 54 to IP 64 with an ambient temperature range of –20 and + 85°C, optional max. +120°C.
Light and improved mechanical ratings
CPF encoders convince by their light weight of only 150 grams with improved mechanical ratings. Last but not least, the “light” encoder can stand shocks up to 200 g and vibrations up to 10 g without any negative impact on operation. The little weight is also a benefit during high-speed load frequencies, for example during motor acceleration. The high-end plastic is lighter than aluminium but offers similar characteristics regarding strength and temperature. Rough industrial conditions are not a problem at all. Maximum relative humidity is 95% (not condensing).
The new encoders in CFP housing are intended for rotation speeds up to 6000 rpm. They are available as incremental encoders with optional commutation signal tracks (commutation U, V, W, three pairs of poles).
Incremental or absolute
Incremental encoders utilize a resolution of max. 2048 steps per revolution and matches the requirements on accuracy in many applications, for example guiding systems in packaging industry, positioning of paper rollers at printing machines, etc. The scanning principle enables “1-error-monitoring”, i.e. any incorrect value is immediately recognized by the master control and a crash due to a void value not corresponding to the real position is avoided.
By combining incremental encoders with an electronic counter you end up with a simple but efficient positioning system that above all provides a low-cost solution with high performance.
Absolute encoders in CFP housing utilize a 12 bit resolution and thus are a perfect choice for almost any application. Even when requiring a high-resolution encoder the customer will find his own individual customised solution within the Baumer IVO program and will not be forced to pay for technical overhead.