The developments in the wind power sector certainly do not stand still and technologies from the industry are being incorporated into wind power plants. This also presents the brake systems with new challenges. mayr® power transmission responds to these demands with strong pitch and yaw brakes, which meets the high requirements of wind power plants – and started its production in India.
Wind power plants around the globe are equipped with electromagnetic brakes by mayr® power transmission. As the leading international manufacturer for wind power brakes, the renowned family-run company from the Allgäu region provides the ROBA-stop® M brakes as safety brakes especially developed and tested for yaw and pitch drives. “All brake components are reliably dimensioned and produced only from high-quality, tested and proven materials”, explains Andreas Merz, Product Manager at mayr® power transmission. “Our brakes have been dimensioned to reliably achieve the specified braking torque under all operating conditions which might occur, regardless of e.g. the air humidity or the ambient temperature, depending on the region.” In general, the company always pays attention to careful quality control. This includes quality assurance measures during the design process as well as a comprehensive final inspection. An electronic database in which the measurement values are archived together with the corresponding serial numbers of a product guarantee 100 percent traceability.
Perfect variety – The right solution for every application
mayr® power transmission offers a wide range of braking solutions for servomotors in the pitch area. In addition to the new ROBA-stop® M pitch brake, mayr® power transmission has further brake solutions in its range with the ROBA® servostop® series, which can be installed in the motor on the A or B side and are designed for temperatures of up to 120°C. They have an impressive low mass inertia. For A-side flanged housing designs, the company offers solutions such as the ROBA® alphastop® brakes. Please observe that the motor then has to have an extended shaft, or the brake system has to be designed with an integrated shaft. One important characteristic of these solutions is: If the motor is dismantled, for example for servicing purposes, then there is also no safety brake anymore. Then safety measures are necessary to avoid any unwanted movements of the rotor blades or nacelle. The solution: Safety brakes, such as the ROBA® topstop®, which remain on the plant even when the motor is dismantled, and which hold the drive safely whilst it is de-energised. Modular systems are available with custom-fit mounting flanges, and can thus be integrated flexibly into existing drives.
Safety for yaw drives
The issue of deficient braking power in case of emergency stops is far more acute in yaw drives. There, far larger friction work values are necessary to bring the nacelle to a standstill. It is true that servo drives are used substantially less in this field than conventional AC motors. Nevertheless, servomotors can also already be found in yaw drives. At the latest at this point, the standard industrial solutions with permanent magnet bakes are unable to cope. Users can therefore also here rely on mayr® ROBA-stop® M safety brakes specially developed and tested for yaw drives.
Intelligent safety
Also the monitoring of safety brakes is becoming increasingly important in the wind power sector. “The monitoring of our safety brakes takes place without the use of sensors with the retrofittable ROBA® brake-checker® module,” Andreas Merz explains. “The module is not only interesting for extended data exchange, but also as a classic monitoring solution.” It detects the movement of the armature disk through extended analysis of current and voltage, and knows what condition the brake is in. In addition to monitoring the switching condition and critical coil temperature, the ROBA® brake-checker® also performs preventative function monitoring for wear, functional reserve and malfunctions. “On reaching the tensile force reserve, the ROBA® brake-checker® emits a warning signal early enough so that a certain operating time for the brake is still possible”, Andreas Merz says, describing the advantages. “During this time, the wind power plant operator or manufacturer can undertake maintenance in a targeted manner, aligned to their working process.” Especially when it comes to offshore applications, this is a decisive advantage, as maintenance work can be efficiently bundled and carried out at exactly the right time – e.g. not too early and thus possibly too frequently.
Condition monitoring without a switch
As the ROBA® brake-checker® works without sensors, i.e. no microswitch or proximity switch has to be attached to the outside of the brake for switching condition monitoring, safety brakes in a basic design can be used. Furthermore, the extra wiring and any sealing of switches and sensors which may be required - dependent on the level of protection - are no longer necessary. In contrast to the solution with switches and sensors, which are exposed to impacts and vibrations due to their installation situation on the brake, monitoring with the ROBA® brake-checker® is carried out from the control cabinet, i.e. in a protected environment. Failures due to icing and error signals because of dirt are thus excluded. Through the electrical switching of the ROBA® brake-checker®, the system availability can even be increased, as there is no longer any critical formation of sparks on the contactor, which can lead to micro-welding of the contacts with common wiring.
Mayr Power Transmissions India Private Limited at the Windergy 2025 in: hall H4, booth D402.
