The water fountains shoot up to 40 meters into the sky, drawing beautiful images, criss-crossing or forming parallel lines that harmonically swivel from side to side. Such water shows with dozens of fountains can be found all over the world: in the US, in Abu Dhabi, in China. Stationary or transportable. What they all have in common are high precision and attention to detail.
An unusual task
maxon is also about to dive into this waterworld. At the production site in Sexau, Germany, the engineers are developing an electrically controlled jet – lighter and more accurate than customary models. This is an unusual task for maxon. After all, as drive specialist, maxon is renowned worldwide for high-precision motors, gearheads, encoders and controllers. Yet in this case, maxon is delivering entire installation units of these water jets to the German customer LKE GmbH. In Sexau, everything comes together: engineering, manufacturing and assembly. “We have all the necessary expertise to offer such a complete solution in-house,” says designer Matthias Mamier. This is of advantage to the customer as it involves only a single contact partner who quickly implements his wishes and suggestions.
Motors completely immersed in oil
The short communication channels are beneficial when it comes to an application with high requirements. This also applies to the water jet. An example: All parts have to be made of stainless steel, so that they do not rust under water. Salty sea water must also not affect the unit. On the first floor at maxon, the mechanics machine the high-quality metal on CNC mills with micromillimeter precision. Here they create the cross manifold block, the heart of the water jet, so to speak. This work is no child’s play, as employee Lothar Scheerer tells us. “The high percentage of chromium in the metal requires a certain amount of experience with machining it.”
The entire motion apparatus of the water jets is also quite sophisticated. It consists of two axles that are each moved by a motor-gearhead unit – completely immersed in oil. This makes it possible to operate the drives in overload, as the fluid has a cooling effect. However, the oil must not leak out. Although it is biodegradable, it would discolor the water.
The drive itself consists of a brushless DC motor and a three-stage GP 42 planetary gearhead. The gearhead only has to travel a short distance. After all, maxon builds gearheads of all types in Sexau, from standard to special custom models.
Electrical controller offers many advantages
For the past two years, maxon Sexau has been working on the development of the water jet. With the third generation of this product, the engineers have eliminated the last teething troubles: A new controller is able to compensate for an uneven position. This is useful when the jet is standing on the bottom of a lake. The seals of the oil-immersed drives have also been improved, plus the entire unit is now easier to assemble. Markus Diringer, who has assembled all prototypes hitherto, is particularly happy about this last benefit. “The water jets weigh 19 kilograms, so any simplification of the assembly procedure is very welcome,” he says, laughing.
Actually, the low weight is one of the big advantages of the electrically controlled water jets. Hydraulic models weigh around 80 to 90 kilograms each. They also need large, loud oil units. Electronic water jets make such units superfluous. And they offer more flexibility.
LKE wants to conquer the water show market with these advantages – and has found the right partner in maxon. A partner that is more than just a drive specialist. 
1.7 million gearheads annually
The maxon production facility in Sexau (Germany) was established in 1989. A large part of the factory has been completely rebuilt in 2014. Around 400 employees work in Sexau – mainly in the engineering and production of gearheads and special drive solutions. The center for ceramics, where different components such as cogwheels, spindles or headphone housings are manufactured, is also located there.
In Sexau, maxon annually produces 1.7 million precision gearheads, with diameters of 4 to 52 millimeters. In addition to the headquarters in Sachseln (Switzerland), there are other production sites, in Hungary, South Korea, France, the Netherlands, Great Britain and the USA.