Roller bearing for wind turbines

A bearing assembly for supporting a main shaft of a wind turbine, the wind turbine comprising at least a blade rotor, a main shaft and a gearbox, the assembly comprising:

• an outer ring;
• at least two bearing raceways formed on a radially inner circumferential surface of the outer ring;
• an inner ring;
• at least two bearing raceways formed on a radially outer circumferential surface of the inner ring;
• a first row of rolling elements retained by a first cage;
• a second row of rolling elements retained by a second cage;
• all of the first row of rolling elements having the same length as all of the second row of rolling elements;
• and
• the first row of rolling elements arranged at a different contact angle from the second row of rolling elements.