Pitch assembly for a wind turbine having minimized micro-pitching

A method of minimizing micro-pitching of a pitch assembly of a wind turbine, the method comprising:

• securing a pitch bearing having an inner race, an outer race, and a plurality of gear teeth arranged on one of the inner race or the outer race to a hub of the wind turbine;
• securing a pitch drive mechanism having a pitch drive motor and a primary pitch drive pinion to the hub such that the primary pitch drive pinion engages with a first set of the plurality of gear teeth at a first circumferential location of the pitch bearing;
• engaging a secondary pinion with a second set of the plurality of gear teeth at a second circumferential location of the pitch bearing, the first circumferential location being spaced apart from the second circumferential location by a circumferential distance, the secondary pinion constructed of a deformable material;
• and
• rotating one of the inner race or the outer race of the pitch bearing about a pitch axis via the pitch drive mechanism, wherein the deformable material of the secondary pinion eliminates backlash between the secondary pinion and the plurality of gear teeth, thereby minimizing micro-pitching of the pitch assembly,
• monitoring a torque at the secondary pinion;
• holding, via a device, the secondary pinion stationary and allowing the secondary pinion to only rotate when the torque at the secondary pinion exceeds a torque threshold, the torque threshold corresponding to a bearing starting torque.

A pitch drive mechanism for a wind turbine, the pitch drive mechanism comprising:

• a pitch drive motor;
• a primary pitch drive pinion configured to rotate one of an inner race or an outer race of a pitch bearing about a pitch axis by engaging with a first set of a plurality of gear teeth at a first circumferential location of the pitch bearing of one of the inner race or the outer race;
• and
• a secondary pinion configured to engage a second set of the plurality of gear teeth at a second circumferential location of one of the inner race or the outer race, the first circumferential location being spaced apart from the second circumferential location by a circumferential distance, the secondary pinion constructed of a deformable material, wherein the deformable material of the secondary pinion eliminates backlash between the secondary pinion and the plurality of gear teeth, thereby minimizing micro-pitching of the pitch assembly,
• wherein the secondary pinion is held stationary and is only allowed to rotate when a torque at the secondary pinion exceeds a torque threshold, the torque threshold corresponding to a bearing starting torque.