The teeth of a helical gear are set at an angle (in accordance with axis of the apparatus) and take the shape of a helix. This gear rack allows one’s teeth to mesh steadily, starting as point contact and developing into range get in touch with as engagement progresses. One of the most noticeable advantages of helical gears over spur gears is usually much less noise, especially at medium- to high-speeds. Also, with helical gears, multiple the teeth are usually in mesh, which means less load on every individual tooth. This results in a smoother changeover of forces from one tooth to another, to ensure that vibrations, shock loads, and wear are reduced.

However the inclined angle of one’s teeth also causes sliding contact between your teeth, which creates axial forces and heat, decreasing performance. These axial forces enjoy a significant part in bearing selection for helical gears. Because the bearings have to endure both radial and axial forces, helical gears need thrust or roller bearings, which are typically larger (and more costly) compared to the simple bearings used with spur gears. The axial forces vary compared to the magnitude of the tangent of the helix angle. Although bigger helix angles provide higher rate and smoother motion, the helix angle is typically limited to 45 degrees due to the production of axial forces.