At home on track
Iron, wood, stone and concrete: the immediate environment alone can be more than a little challenging for wheel sensors. Frauscher has been constantly improving its wheel sensors through the years. Even the most basic model in the range can now withstand the most adverse of conditions.
Wheel sensors are produced for one purpose only – deployment on the track. The conditions that await them there may well strike fear into the hearts of similar products from other industries: heat, frost, flooding, industrial waste, extreme mechanical or electromagnetic influences, to name but a few. Despite all this, these devices need to perform their task dependably whatever the circumstances. From their inner workings and potting compound to their housing and fixing device, all these elements have to be up to the job.
The first wheel sensor Frauscher produced was the RSR180. When Josef Frauscher invented this sensor in 1987 he put in place the foundation stone for all the subsequent models which the company now supplies to operators and system integrators all round the world. Even today the durability of this grandfather to all the later sensors is plain to see: the RSR180 remains in Frauscher’s product range to this day, more than 30 years on. Against a background of new technical possibilities and experience from around the world, it has been optimised time and time again through the years. The changes that have brought it to its latest version, the RSR180 GS05, highlight the positive features than now characterise this sensor:
1. Mechanical enhancement:
The housing design and bolts have been improved in such a way that the sensor can be attached to its mounting with a torque of up to 40 Nm. This increases the stability of the entire system in the face of extreme mechanical influences.
2. Potting compound:
Changing from epoxy to polyurethane further improved the sensor’s durability. As a result, cracks that could allow moisture to penetrate inside the device are even less likely to develop. Furthermore, the potting compound and sensor housing now boast fire resistance to ULV94 V-0, meaning that the sensor is approved for use in tunnels.
3. Cable connection:
Its location in the middle of the sensor makes installation easier. The tensile forces affecting the cable are reduced. This change also makes it easier to lay a larger loop in order to minimise the bend radius of the cable. This has the effect of preventing cable faults and damage to the sensor resulting from stress on the cable connection.
However, the fundamental principle on which the RSR180 is based has remained unchanged throughout the years. To this day this makes it one of the most reliable and accurate wheel sensors ever. The philosophy of Frauscher has always been characterised by a spirit of innovation; a spirit that remains undiminished. This spirit is why Frauscher succeeded in producing such an impressive product that is equal to the differing requirements of railway markets around the world. The RSR180 is now used in over 70 different countries. And those who developed it are still learning new tricks.
A firm grip on the rail
Frauscher also patented a rail claw decades ago, and this too has undergone constant development through the intervening years. It enables sensors to be attached to the track without any drilling. The mounting height is freely adjustable on all models of the Frauscher claw. The SK150 rail claw also has clamps fitted on its sides that make it extremely easy to adjust for different sizes of rail foot. On the SK140, which has until now been supplied along with the RSR180, this was made possible by providing a choice between clamping bolts of differing lengths. Since the RSR180's update, it too is mounted with the SK150, which just adds to its versatility. For other rail profiles Frauscher can also offer, for instance, the SK420 for grooved rails or the SK140-010 for slab tracks with restricted mounting space.
Frauscher is carrying out further market and user-specific development on even the later wheel sensors. The company’s bold approach to implementing user-friendly innovations percolates down and results in a variety of features. One of these is the plug-in connection on the RSR123. The sensor itself combines different inductive processes. It is therefore extremely resistant to electromagnetic interference.
The RSR110 is designed for non-failsafe applications and is now available in two system versions: the single wheel sensor RSR110s has an individual sensor system for direction-independent detection. The double wheel sensor RSR110d is equipped with two sensor systems and enables wheel detection along with directional information. Thanks to their open analogue interface, both wheel sensors can be easily integrated into the electronics of any system. This enables system integrators to adapt the evaluation of the information perfectly in line with individual requirements.