What are the advantages of helical gears over spur gears in CNC laser cutting machines?

Several common linear axis transmission methods for CNC laser cutting machines include ball screws, rack and pinion systems, and linear motors. Ball screw transmission is typically used in CNC machines operating at medium to low speeds with short travel distances. Rack and pinion transmission is widely applied, capable of achieving high speeds and large travel ranges. Linear motors are predominantly used in CNC machines requiring high speeds, high acceleration, or featuring special structural designs. Additionally, currently common rack and pinion systems are categorized into spur gear and helical gear types.

1. Superior meshing performance. When straight-toothed cylindrical gears mesh, their contact line is a straight line parallel to the axis. Consequently, both tooth profiles enter or disengage simultaneously across the tooth width, easily causing impact and noise. This results in poor transmission smoothness, making them unsuitable for high-speed gear drives. In helical gears, the contact line forms an inclined straight line relative to the gear axis. During meshing, the contact line length gradually increases from zero due to height limitations, then gradually decreases beyond a certain point until disengagement. This gradual engagement and disengagement process ensures smooth transmission and low noise. Additionally, this meshing method reduces the impact of manufacturing errors on transmission performance.

2. High overlap ratio. This reduces the load on each pair of teeth, thereby relatively increasing the gear's load-carrying capacity, extending its service life, and ensuring smooth transmission.

3. The minimum number of teeth required to prevent root cutting is lower for standard helical gears than for spur gears. Consequently, helical gear transmission enables more compact mechanisms.