Technical reference
Yaw system
The yaw system turns the whole nacelle in the horizontal plane to keep the rotor facing the wind. It also unwinds the cables running down the tower after a set number of turns.
General reference. Values, limits, intervals and torques vary by turbine type; the OEM documentation always governs.
Main parts
- Yaw bearing — rolling or sliding type
- Ring gear and pinions
- Yaw drives — motor, gearbox and pinion, several working together
- Yaw brake — hydraulic callipers or friction elements, depending on design
- Wind direction sensor — vane or ultrasonic
- Cable twist monitoring
Common faults and where to look first
- Yaw hunting: wind vane mounting and alignment, brake pressure, gear backlash
- Noise during yaw: gear and pinion, brake surfaces, bearing lubrication
- Metal in purged grease: point-by-point samples, lubrication line and distributor
Safety
Gears and pinions are a crushing hazard while yawing; lock the yaw to the OEM instructions before maintenance. Sensor work on the nacelle roof only in suitable weather and with fall-protection equipment.
Full version
Parts tables, maintenance checklist and diagnostic tools are in the Turkish version of this page.