The gear transmission can be plane motion or space motion according to the relative motion during transmission, and can be divided into two categories: plane gear transmission and space gear transmission.
1. Gear drive
Planar gear transmission is used for transmission between two parallel shafts.
External meshing spur gear drive Internal meshing spur gear drive Gear and rack drive (straight rack)
External meshing helical gear drive Herringbone gear drive Rack and pinion drive (helical rack)
2. Space gear drive
Space gear transmission is used for transmission between intersecting shafts and staggered shafts.
Straight tooth bevel gear transmission Curved tooth bevel gear transmission Helical gear transmission (cross-shaft helical gear transmission)
Worm drive Hypoid gear drive
Type of gear transmission:
Planar gear motion (transmitting motion between parallel shafts)
Spur gear drive
The gear teeth are parallel to the shaft: external meshing, internal meshing; gear rack; helical cylindrical gear transmission
The gear teeth are not parallel to the shaft: external gearing, internal gearing, rack and pinion; herringbone gear drive
Space gear motion (transmitting motion between non-parallel shafts)
Transmit intersecting axis motion: bevel gear drive, straight tooth
Basic law of tooth profile meshing
The gear transmission is required to be accurate and stable, that is, during the transmission process, the instantaneous transmission ratio remains unchanged to avoid shock, vibration and noise.
Regardless of the contact of the tooth profile at any point, the common normal of the two teeth passing through the contact point must intersect the connecting line at a fixed point. This is the basic law of tooth profile meshing.