In a wind turbine, a proportion of the kinetic energy generated by the wind is transformed into electric energy and fed into the closed power network.

The wind’s usable kinetic energy increases with the wind speed.  Wind turbines, therefore, use kinetic energy to generate torque and then rotational movement. The rotor, consisting of three rotor blades, creates the kinetic energy and passes it on to the generator, which in turn produces an electric current.

Most wind turbines use adjustable gearboxes which match the wind-dependent speed of the rotor to the constant speed of the generator within a housing called a nacelle. While the rotor only turns slowly at very a high torque, the torque of the quickly rotating generator is low.

The necessary transmission ratio between both torques determines the overall size of the gearbox. The efficiency of the gearbox in a wind turbine is very high. Because the transferred power output is extremely high, there are also great energy losses.

This mostly concerns loss through heat, which is why the gearbox must be cooled. A sophisticated lubrication technology in the gearbox achieves this. Oil pressure and temperature measurements are necessary for this process.

The oil pressure is constantly monitored by sensors. Keller was able to provide these pressure transmitters from the 21Y series to a client who supplies gearboxes for wind turbines.

Keller’s 21Y piezoresistive pressure sensor is welded, fully insulated and encapsulated with no internal seals.  Its robust stainless steel housing and compact design is perfect for space-critical industrial applications, heat pumps, AIRCON technology and in the food industry. The 21Y’s direct analogue signal path with high bandwidth guarantees high, long-term stability.

Keller 21Y Specifications:

Accuracy: + 0,5%FS

Total error band :1,5%FS @ -10…80°C

Pressure range: 0…2,5 to 0…1000 bar



Tel. +27 10 595 1831

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