One’s teeth of a helical gear are set at an angle (relative to axis of the gear) and take the shape of a helix. This enables one’s teeth to mesh gradually, starting as point contact and developing into series contact as engagement progresses. Probably the most noticeable benefits of helical gears over spur gears is usually much less noise, especially at moderate- to high-speeds. Also, with helical gears, multiple the teeth are always in mesh, which means less load on every individual tooth. This results in a smoother transition of forces in one tooth to the next, so that vibrations, shock loads, and wear are reduced.

However the inclined angle of one’s teeth also causes sliding get in touch with between your teeth, which creates axial forces and heat, decreasing performance. These axial forces perform a significant part in bearing selection for helical gears. As the bearings have to withstand both radial and axial forces, helical gears require thrust or roller bearings, which are typically larger (and more costly) compared to the simple bearings used in combination with spur gears. The axial forces vary compared to the magnitude of the tangent of the helix angle. Although larger helix angles provide higher velocity and smoother movement, the helix position is typically helical gear china limited by 45 degrees due to the creation of axial forces.