Advantage:  
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. The 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. Therefore, 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.





Shortcoming:
1. Lead to bad axial force;
2. Slightly increased manufacturing costs.



Overview of spur gears and helical gears of gear reducers
1. It is difficult and uneconomical to manufacture and assemble a large number of thin spur gears with spur gears. Therefore, they are made into gears with gears in which the teeth are in the direction of the spiral;

2. Helical gear is not like spur gear, it will cause bad axial force. However, 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.