WP7390 product is a direct fit replacement for the electric slip ring used in the Siemens 2.3 wind turbine. This design utilizes Moog’s high-reliability, no maintenance, fiber brush technology used in our other proven aftermarket pitch slip rings. The WP7390 will reduce nuisance communication issues and improve turbine performance and increase availability of the turbine power output.

Fiber Brush Technology

Over 30 years ago, Moog developed and patented the fiber brush technology that has become our standard in applications where performance matters. The patented approach has led to hundreds of designs for challenging applications which include satellite solar array drives, helicopter rotor, radar pedestals, medical CT systems, military electro optical systems and now wind turbines – just to name a few. The unique feature of the fiber brush technology is its ability to perform in environmental and operational extremes. In addition, the fiber brush has the capability to handle power while simultaneously transferring data signal. And all this performance while maintenance free for over 100 million rotations.

Direct Slip Ring Replacement

Moog’s WP7390 pitch slip rings for the Siemens 2.3 turbine is a direct replacement product. The design bolts to the existing system and provides cables to connect to the stationary junction box.


  • No maintenance required
  • No lubrication required
  • Direct bolt-in replacement
  • Connecting umbilical harness cables
  • Durable, black anodized housing


  • Maintenance free, reduces the number of climbs
  • Capable of 100+ million rotation life
  • Fiber brush technology used
  • No lubrication required
  • Wide operating temperature
  • Lower life cycle cost
  • High reliability

For more information about how Moog's wind turbine slip rings can fit your specific application, contact our slip ring experts.

WP7390 Specifications
Weight 1.6 kg (3.4 lb)
Brush/Ring Material Silver
Brush/Ring Life >100 million revolutions
Operating Temperature -40 to +80°C (-104 to +176°F)
Housing Black anodize aluminum

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