Wind turbines
Reliably Converting Wind into Motion
Wind turbines operate under changing and often difficult-to-predict conditions. Wind speed and wind direction fluctuate continuously, while the rotor, gearbox, generator and control system must work together reliably. Gusts, load changes and high mass inertia place significant demands on the entire drivetrain.
At the same time, wind turbines are frequently installed in locations that are difficult to access. Onshore installations must withstand dust, moisture and considerable temperature fluctuations.
Offshore turbines are additionally exposed to salt-laden air, high humidity, wave-induced movement and more challenging maintenance conditions.
In this environment, couplings, brakes and shaft connections perform critical functions. They can connect and disconnect drives, transmit torque, hold assemblies in position, limit load peaks and support maintenance and emergency operations. The key requirement is that these components operate reliably and integrate seamlessly into the overall safety and operating concept of the turbine.
When Every Revolution Counts
Mönninghoff components can be used in various areas of wind turbines and related systems, including
- Drives for rotor and generator functions
- Pitch control and adjustment systems
- Yaw and tracking systems
- Rotor and shaft connections
- Braking and holding mechanisms
- Locking systems for maintenance and servicing
- Auxiliary drives and ancillary equipment
- Test and validation systems for wind turbine components
- Installations for both onshore and offshore applications
- Positioning and securing systems for assembly and maintenance
The specific task depends on the turbine design. An adjustment system must respond quickly and precisely. A holding brake must maintain position securely. A clutch may be required where drive branches need to be connected or disconnected under different operating conditions.
What all applications have in common is the need for drive technology capable of handling high forces while responding in a controlled manner. Wind may not always be predictable, but the mechanics should be.
Requirements for Couplings and Brakes
Wind turbines place demanding requirements on drive technology.
- High torque capacity Rotor, gearbox and generator systems generate substantial forces and torques that must be transmitted safely.
- Variable loads Wind speeds, gusts, turbulence and changing operating conditions create fluctuating loads.
- High mass inertia Large rotating masses must be accelerated, decelerated and held in a controlled manner.
- Reliable holding capability Rotors, shafts and adjustment systems must be securely locked during maintenance and specific operating conditions.
- Resistance to vibration Oscillations and varying loads must not impair component functionality.
- Weather resistance Moisture, cold, heat, dust, ice and salt-laden air must all be considered during design.
- High availability Downtime and unplanned maintenance are particularly costly for installations that are difficult to access.
- Long service life Components must withstand many operating hours and a high number of load cycles.
- Low maintenance requirements Maintenance intervals should be predictable, and components should remain as accessible as possible.
- Safe behaviour during power loss Critical braking and holding functions must be considered even when the power supply is interrupted.
- Compact integration Space within the nacelle, hub and auxiliary assemblies is often limited.
- Low additional mass For moving or adjustable assemblies, weight and inertia can significantly influence system design.
- Overload protection The drivetrain and connected components must be protected from excessive load peaks.
- Documented verification The design, testing and maintenance of safety-related components must be fully traceable and documented.
The challenge is to combine high power density, dependable operation and long service life. The right solution must not only handle nominal operating conditions but also withstand changing and exceptional loads.
Connect, Hold and Protect
Mönninghoff develops clutch and brake systems tailored to the torque, speed, load profile, switching frequency, environmental conditions and installation space requirements of each wind power application.
Electromagnetic Tooth Clutches
Electromagnetic tooth clutches provide positive-locking engagement and disengagement. They can be used wherever drive branches, auxiliary drives or adjustment systems must be connected and disconnected with precision.
Potential applications include
- Engaging and disengaging auxiliary and service drives
- Defined switching operations within adjustment systems
- Synchronisation of drive stages
- Switching maintenance and assembly functions
- Positioning and locking applications
- Applications requiring minimal backlash
The positive-locking connection ensures a clearly defined engagement state and precise torque transmission. Design considerations include torque, speed, switching time, mounting orientation and performance during power failure conditions.
Electromagnetic Multi-Disc Clutches
Electromagnetic multi-disc clutches are suitable for frequent switching operations and high torque transmission within a compact design. They are particularly attractive where drive functions must regularly be connected and disconnected under varying operating conditions.
Potential applications include
- Auxiliary drive switching
- Connections between motors, gearboxes and working shafts
- Service and assembly drives
- Applications with changing loads and speeds
- Frequent start-stop operation
- Drives requiring long service life and minimal maintenance
A properly specified multi-disc clutch can combine reliable switching performance with high power density. The key factors are torque, speed, switching frequency and thermal loading.
Electromagnetic Tooth Holding Brakes
Electromagnetic tooth holding brakes can positively lock shafts and axes in a defined position. This is particularly relevant for maintenance, assembly and safety functions where unintended rotation must be prevented.
Potential applications include
- Holding rotor or generator shafts
- Securing adjustment systems
- Holding assemblies during maintenance and inspection
- Positioning drive and assembly units
- Protection during power failure situations
- Supporting redundant holding and safety concepts
Holding torque, rotational speed, load direction, switching time and integration into the maintenance and safety concept must all be considered during the design process. A holding function is only reliable when its condition is clearly defined and verifiable.
Overload Couplings
Overload couplings can disconnect or limit power transmission whenever a predefined torque threshold is exceeded. Depending on the application, they can help protect drivetrains, gearboxes, shafts and connected assemblies against blockages and unexpected load peaks.
Potential applications include
- Protection of auxiliary and service drives
- Safeguarding adjustment and positioning systems
- Limiting torque during blockage conditions
- Protecting sensitive gearbox and shaft connections
- Avoiding secondary damage following malfunctions
- Providing controlled separation of power transmission during fault conditions
The appropriate design depends on factors such as maximum torque, rotational speed, disengagement characteristics and the required behaviour following an overload event. The protection system must be aligned with the overall turbine concept and recommissioning strategy.
Torsionally Rigid Shaft Couplings
Torsionally rigid shaft couplings provide direct torque transmission with minimal backlash. Depending on the design, they can also compensate for minor shaft misalignment.
Typical applications include
- Connections between motors, gearboxes and generators
- Drives for adjustment and positioning functions
- Auxiliary drives requiring high torsional stiffness
- Test and validation systems for rotors and drivetrains
- Applications with changing rotational directions or load profiles
A precision shaft coupling helps guide forces through the drivetrain in a controlled manner. Vibrations, alignment, rotational speed and the thermal conditions within the installation environment must also be considered during design.
Drive Technology for the Energy of the Future
Whether for adjustment systems, auxiliary drives, rotor and shaft connections, maintenance mechanisms or test rigs, Mönninghoff develops couplings, brakes and overload protection systems for wind power applications with demanding requirements for availability, robustness and safety.
Are you developing a new wind turbine, modernising an existing drive system or searching for a compact solution for engagement, holding and overload protection? Speak with our experts about torque, speed, load cycles, environmental conditions, maintenance requirements and installation space. Together, we will develop a drive solution that performs reliably, whatever the wind conditions.
Availability Begins with System Design
A wind turbine functions as an integrated system. The coupling, brake or shaft connection must work seamlessly with the rotor, gearbox, generator, control system, sensors, bearings and maintenance concept.
The following parameters may be considered during design
- Torque and rotational speed
- Rotor size and mass inertia
- Acceleration and deceleration characteristics
- Load fluctuations caused by gusts and changing wind speeds
- Operating modes and switching cycles
- Onshore or offshore operating environment
- Temperature range and thermal cycling
- Moisture, ice, dust and salt-laden air
- Vibrations and potential resonance effects
- Required holding and positioning accuracy
- Behaviour during power loss and emergency stop events
- Overload protection and fault-response requirements
- Available installation space and connection geometry
- Weight and power consumption
- Accessibility for maintenance and replacement
- Monitoring, diagnostic and documentation requirements
Mönninghoff develops customised solutions tailored to the specific turbine architecture and intended operating strategy. The focus is always on reliable overall system performance, even when the wind changes direction.
Defined States for Maintenance and Fault Conditions
Wind turbines must be capable of achieving and maintaining specific safe operating states. This applies to maintenance procedures, assembly operations, shutdown positions and fault-response strategies.
Depending on the application, the following functions may be relevant
- Mechanical holding of shafts and assemblies
- Safe isolation of drive branches
- Controlled braking of rotating masses
- Limiting power transmission during overload events
- Monitoring clutch, brake and holding states
- Securing maintenance and assembly positions
- Integration into emergency stop and safety circuits
- Defined reset procedures after faults
- Safe recommissioning following inspection and approval
The specific safety function must be assessed and validated together with the overall system, control strategy and risk assessment. Particularly in difficult-to-access installations, it is essential that the technology is not only reliable but also inspectable and maintainable.
From Development to a Validated Solution
For new wind turbine components and customised drive systems, prototypes and functional test units can help assess real-world behaviour at an early stage. This is especially important for applications involving high torque, variable loads and demanding environmental conditions.
Potential test criteria include
- Transmission accuracy and torsional behaviour
- Switching time and switching reliability
- Holding torque and holding accuracy
- Response during overload and blockage conditions
- Behaviour at varying torque and speed levels
- Vibrations and resonance characteristics
- Temperature development during continuous operation
- Performance under moisture, cold and thermal cycling
- Long-term operation and wear
- Functionality during power failures and emergency stops
- Integration with mechanics, controls and sensors
- Maintenance and replacement procedures
- Reset and recommissioning behaviour
This allows potential improvements to be incorporated into the design and system integration process at an early stage, creating a robust foundation for reliable series production and long-term operation.