A lubrication system for a main bearing positioned around a main shaft of a wind turbine includes a seal ring positioned around the shaft adjacent to the bearing, at least one gear adjacent to the seal ring, a mechanical lubricant pump arranged to engage the at least one gear, and at least one lubricant for providing lubrication to the bearing. Thus, as the shaft rotates, the gear(s) drives the lubricant pump such that the pump continuously provides the lubricant to the bearing so long as the shaft is rotating.