Advantages and Disadvantages of Intuitive Spur Gear Reducer and Helical Gear Reducer

The main disadvantage of spur gears in spur gear reducers is that they produce vibrations. Whether due to design, manufacturing, or deformation, some changes in the involute profile may occur along the entire tooth surface at the same time. This will result in a regular, once per tooth excitation, which is often very strong. The resulting vibration not only causes a large load on the gear, but also causes noise. Another disadvantage is that sometimes the additional strength obtained by the engagement of two pairs of teeth during the contact time cannot be used because the stress is limited by the condition of the single tooth engagement during the cycle. The helical gear used in the helical gear reducer can be regarded as a cylindrical gear made of a set of thin gears with suitable teeth. In this way, the contact of each piece is at a different part of the tooth profile, thereby producing compensation for the error of each thin gear This compensation effect is very effective due to the elasticity of the gear teeth. Therefore, the result is that the gear teeth with an error within 10mm can make the error take an average effect, so under load, it can be like a wheel with an error within 1mm The teeth run smoothly. Because at any instant, about half of the time (assuming the coincidence is about 1.5) there will be two teeth meshing, which brings additional benefits in terms of strength. Therefore, the stress can be established on the basis of 1.5 times the tooth width instead of a tooth width.
It is difficult and uneconomical to manufacture and assemble a large number of thin spur gears. Therefore, they are manufactured as a whole gear with the teeth along the spiral direction. Helical gears are not like spur gears in that they cause undesirable axial forces. But the advantages in terms of vibration and strength far outweigh the disadvantages caused by axial thrust and slightly increased manufacturing costs. Therefore, helical gears are used instead of spur gears in the manufacture of reducers. For example, four series: R series coaxial helical gear reducer, K series spiral bevel gear reducer, S series helical gear worm gear reducer, F series parallel shaft Helical gear reducer.