"Tachogenerators for driving cable cars and surface lifts have to withstand enormous loads, while still being able to measure speed accurately and reliably. That's why manufacturers rely on HeavyDuty solutions from Baumer Hübner".says Baumer Hübner.
Tachogenerators with LongLife technology are based on a silver track integrated into the commutator. LongLife tachogenerators combine signal quality for high control dynamics, robustness and long life.
"For many years now, a ropeway has linked the Tyrolean side of the Alps to the summit of the Zugspitze, transporting hundreds of people to an altitude of 2,964 meters every day. Driven by two 500 kW electric motors, it covers this route in 7.5 minutes, at a speed of 10 meters per second. To control the various cabin travel modes - slow, stationary, forward, reverse, acceleration, high speed and braking - high precision and reliability of the speed control system are essential. Last but not least, passenger comfort and safety are paramount. The ropeway's components are subjected to harsh environmental conditions: the machine has to withstand wind, rain and snow, temperatures often drop below -10° in winter and reach positive values in summer. This is a perfect example of the use of HeavyDuty tachogenerators, in this case the TDP 0.2 LT tachogenerator, which acts as a particularly robust and precise speed transmitter.says Baumer Hübner.
HeavyDuty, a promise of global performance
HeavyDuty means "highly resistant". For Baumer Hübner, this means more than just a thick-walled housing and protection against rust. It's also about a promise of all-round performance, the guarantee that the encoder and tachogenerator will do their job reliably for many years without ever letting the operator down. To deliver on this promise, tachogenerators for ropeway drives must withstand shocks, vibrations and other forces exerted on the rotating shaft over long periods, without loss of capacity.
The HeavyDuty housing is particularly waterproof at the key points - the shaft and the electrical connection. Thanks to specially selected materials and coatings, it is also protected against corrosion caused by salt water and chemicals.
Tachogenerators contain no electronics and are therefore highly resistant to potential damage from electromagnetic fields. They can be used in the vicinity of live, unshielded power lines. Differences in voltage can cause current to flow through the shaft, burning the bearing lubricant and destroying it. The internal electrical insulation of a HeavyDuty tachogenerator protects it from this risk.
According to the manufacturer, the flagship HeavyDuty products also feature "unparalleled precision." Tachogenerators need to continuously provide a reliable signal to precisely control and regulate drives. It is this information that enables the control system to detect variations in drive speed and intervene. HeavyDuty tachogenerators must therefore be as precise in large installations, such as ropeways, as smaller speed transmitters.
In 1987, Baumer Hübner patented LongLife... Using a special process, Baumer Hübner integrates solid silver tracks into the switch surface - one or two, depending on the type of tacho dynamo - which can remain thin thanks to the relatively low tacho current. The TDP 0.2 LT features two silver tracks, ensuring consistently low contact resistance, even under difficult conditions. Even with a voltage constant of 60 mV per rpm, the TDP 0.2 LT can therefore measure a wide speed range, from ≤ 0.08 to 10,000 rpm, with mechanical and electrical speed limitation. This gives the TDP 0.2 LT a dynamic range of 1 : 125,000. Baumer Hübner's specially adapted brushes and LongLife switch thus offer maintenance-free running times that exceed the service life of ball bearings.
LongLife, for ski lifts too
The drive controls on surface lifts are also subject to harsh conditions. To ensure passenger safety, the manufacturers of these lifts also use these proven tachogenerators. They guarantee reliable operation of the equipment, even during periods of severe frost, heavy snowfall and icy winds. For a smooth start-up and variable running speed, surface lifts are also equipped with speed-regulated drives. Manufacturers have been using Baumer Hübner's analog tachogenerators, such as the GMP 1.0, for decades. This is directly connected to a slowly rotating pulley via a boost converter and pinion drive. In this way, the motor drive's no-load motion is isolated from the control circuit, and a sufficient speed setpoint signal is output, even under difficult ambient conditions. The GMP 1.0 also features a double silver track for low continuous contact resistance, ensuring a wide measurable speed range and good transmission of the measured value.