The types of wool felt gears can be divided into three categories based on the mutual position of the gear transmission axis: parallel axis transmission, intersecting axis transmission, and staggered axis transmission. The gears for axial transmission include spur cylindrical gears, helical cylindrical gears, and herringbone cylindrical gears. The intersecting axis transmission gears include spur bevel gears, helical bevel gears, and helical bevel gears. The staggered axis transmission gears include hyperbolic gears, worm gear transmission gears, and helical cylindrical gears.