The Difference between Cycloidal Gears And Involute Gears

The difference between cycloidal gears and involute gears

There are differences between cycloidal gears and involute gears in terms of tooth surface formation principles, transmission characteristics, and application fields. The specific analysis is as follows

1. Principle of tooth surface formation: Involute is a special case of cycloid. When the diameter of the outer circle is infinite, the cycloid becomes a straight line, thus forming an involute. The tooth profile of involute gears usually consists of a segment of involute and a segment of tooth root transition curve, while the tooth profile of cycloidal gears consists of an outer cycloid, an inner cycloid, and a segment of tooth root transition curve.

2. Transmission characteristics: The meshing line of involute gears is a straight line, and the direction of force remains unchanged during transmission, so the transmission stability is good. The meshing line of a cycloidal gear is two circular arcs, and the direction of force transmission changes, resulting in less stable transmission than an involute gear.

3. Center distance sensitivity: Cycloidal gears are very sensitive to center distance and do not possess the characteristic of separable center distance in involute gear transmission. This means that the center distance of the cycloidal gear must be precise, otherwise it will affect its normal meshing.

4. Wear resistance: Cycloidal gears come into contact with convex surfaces (outer cycloids) and concave surfaces (inner cycloids) during meshing. Usually, their tooth surface has a larger comprehensive curvature radius. According to Hertz stress theory, the surface contact stress is smaller than the contact stress generated by the meshing method between the convex and convex surfaces of involute gears. Therefore, in harsh working environments without lubrication in open transmission, the tooth surface of cycloidal gears is more wear-resistant than that of involute gears.

5. Manufacturing difficulty: The cutting tools for cycloidal gears are more complex compared to involute gears, and the manufacturing process is more difficult.

6. Application areas: Cycloidal gears are commonly used in precision machinery fields such as clock and planetary transmissions, while involute gears are widely used in the construction machinery manufacturing industry.

In summary, involute gears have been widely used in industrial production due to their advantages such as smooth transmission, good center distance separability, and relatively easy processing. Cycloidal gears, on the other hand, have important applications in specific fields such as precision machinery and harsh environments due to their special tooth shape and wear resistance.