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 enables one’s teeth to mesh steadily, starting as point get in touch with and developing into collection contact as engagement progresses. Probably the most noticeable benefits of helical gears over spur gears is usually much less noise, especially at medium- to high-speeds. Also, with helical gears, multiple tooth are usually in mesh, which means much less load on every individual tooth. This outcomes in a smoother transition of helical gear china forces in one tooth to another, so that vibrations, shock loads, and wear are reduced.

However the inclined angle of the teeth also causes sliding contact between the teeth, which generates axial forces and heat, decreasing effectiveness. These axial forces enjoy a significant role in bearing selection for helical gears. Because the bearings have to withstand both radial and axial forces, helical gears need thrust or roller bearings, which are typically larger (and more costly) than the simple bearings used in combination with spur gears. The axial forces vary in proportion to the magnitude of the tangent of the helix angle. Although larger helix angles provide higher speed and smoother movement, the helix position is typically limited by 45 degrees because of the creation of axial forces.