Large diameter drills for the wind turbine industry
- June 2, 2019
Iscar is expanding the CombiCham drill family by adding three drill diameters.
The new diameters are 33.2, 36.2 and 39.2 mm (1.30, 1.42 and 1.54 in.) in drilling depths of 7 and 8 L/D ratio.
The new drills address the most widely employed hole diameters in wind turbine parts such as tower flanges, blade bearings, yaw rings and planetary ring gears. The CombiCham is designed for high feed drilling, providing high drilling rates, high accuracy and premium surface finish.
The vast majority of commercial wind turbines use tubular steel towers. Tower heights depend on rotor diameter and on-site wind speed conditions. Heights range from 50 meters (164 ft.) for a 1 MW turbine to as high as 125 meters (410 ft.) and more for very large turbines.
The flange comprises a large scale of rolled steel which connects the tower’s conical links. The blade bearings, made of bearing steel, adjust the angle of the blades by rotating a bearing at the root of each blade, enabling control of the power and slowing of the rotor.
The wind turbine yaw system is the component responsible for the orientation of the wind turbine rotor towards the wind. The mechanism rotates the nacelle to face the changing wind direction and it is made of alloy or bearing steel. Planetary ring gears embrace the gearbox’s planetary gears, allowing them to transform low incoming speed to high outgoing speed.
The new CombiCham drilling line features a pilot SumoCham drilling head and standard SOGT square precision ground inserts with a wiper in various sizes, made from IC808 SUMO TEC PVD coated grade. The HCP central drilling head provides a self-centring ability for enhanced hole accuracy and no pre-hole is needed. The peripheral SOMT/X wiper inserts feature four cutting edges and ensure surface quality.