Extra touch of luxury: electric windows for yachts

• What was needed: ZLW toothed belt axes, DC direct current motor
• Requirements: Electrical components must not only be compact at sea, but also resistant to aggressive salt water and high temperature fluctuations. They must also be as maintenance-free as possible.
• Industry: Ship and boat building
• Success for the customer: As the toothed belt axes have a very small clearance height, they are the ideal solution for light adjustment and positioning tasks where space is limited. The toothed belt axes are also corrosion-free.

Glaskeil, founded in 1898 by master glazier August Keil in Würzburg, has developed into a specialist for ready-to-install and customised glass and plastic products for yacht building.

Electric windows offer more comfort and luxury than conventional windows, as they can be opened and closed at the touch of a button. While this has long been standard in cars, such windows are still a rarity on yachts. Here, electrical components not only have to be compact, but also resistant to aggressive salt water and extreme temperature fluctuations. They should also be as maintenance-free as possible.

"The search for a supplier of electrical linear guide technology that could meet the high demands of upmarket boatbuilding was correspondingly challenging," recalls Glaskeil developer Mirco Eisenhauer.

The Glaskeil designers were faced with several challenges: The products had to be very space-saving, as the available space on boats is limited. In addition, corrosion, especially from salt water, is a major problem.

As these are boats in the premium segment, the motors installed had to be as maintenance-free and quiet as possible in order to offer customers a satisfactory experience. The control system should also be convenient. Modern programmable logic control systems (PLCs) are often oversized for simple automation tasks such as raising and lowering a window pane.

"With igus® from Cologne, we finally found a system that is space-saving, robust, wear-resistant and virtually maintenance-free. And thanks to the plug-and-play principle, it saves us design work."

The centrepiece of this solution is the drylin® ZLW series of toothed belt axes , which are mounted along the longitudinal struts of the black window frame on the right and left. With a clearance height of just 31 millimetres, these toothed belt axes are the perfect choice for light adjustment and positioning tasks, especially when space is limited.

The windows are driven by a DC motor from igus®. With a flange dimension of 42 millimetres, this is also very space-saving, as it does not require a motor flange, coupling or complex external power electronics. It is also resistant in a wide temperature range between -10 °C and +60 °C. When the yacht passenger presses a switch, the motor starts up. The toothed belts now move on both sides of the window frame, connected to each other by a synchronised shaft. And thus the carriages mounted on the profile guides, to which the window pane is in turn attached.

The carriages slide on the aluminium rail via bushes made of high-performance plastic using the WJ200UM series housing bearings . Thanks to microscopically small solid lubricants, hygienic, low-friction and quiet dry operation is possible without external lubricants. This minimises the need for maintenance.

Glaskeil also uses the dryve D5, an igus® motor control system that enables fast commissioning. Designers only need to connect the voltage source, control signals and the motor to the output stage. A signal, triggered by a connected button, then starts and stops the motor. A second signal is used to change the direction of rotation. The speed of the output stage can be set via eight microswitches on the housing. Settings can also be made via smartphone, tablet or laptop. Glaskeil can then set the travel mode, positions, accelerations, speed and pause times of the linear axis in just a few minutes via an intuitive browser interface. The high rated current of 10 A and 30 A peak current also produces powerful and dynamic movements on request.

Another advantage: thanks to a sophisticated combination of materials and microchips, the power amplifiers operate particularly quietly and with low vibration at all speeds. "We don't have to worry about annoying noises, which can occur with many inferior power amplifiers," emphasises Mirco Eisenhauer. "This is an important point for our customers in the premium segment."