I. Concept
Gear mechanism is composed of gear pair to transmit motion and power.
2、 Type of gear drive
There are many kinds of gears, which can be classified according to different methods.
(1) According to the relative position of the shaft, it can be divided into two categories, i.e. plane gear drive (two shafts are parallel) and space gear drive (two shafts are not parallel)
(2) According to the different peripheral speed, it can be divided into three types: low speed, medium speed and high speed;
(3) According to different working conditions, there are three types: closed gear drive (enclosed in the box and guaranteed to be well lubricated), semi open gear drive (gear immersed in the oil pool, with shield, but not closed) and open gear drive (gear exposed, not guaranteed to be well lubricated);
(4) According to the skew form of tooth and shaft in the direction of tooth width, it can be divided into straight tooth, oblique tooth and curved tooth;
(5) According to the different profiles of gears, they are divided into involute gear, cycloid gear and circular arc gear;
(6) According to the meshing mode of gears, it can be divided into external meshing gear drive, internal meshing gear drive and rack drive.
3、 Application of gear transmission
Gear ratio
N1 and N2 represent the rotating speed of the driving and driven wheels
Z1 and Z2 represent the number of teeth of the driving and driven wheels
Application features:
Advantages:
It can ensure constant instantaneous transmission ratio, high reliability and accurate transmission movement.
The range of transfer power and peripheral speed is wide, the transfer power can reach 50000kw, and the peripheral speed is 300m / s
Compact structure and large transmission ratio
High transmission efficiency, long service life and easy maintenance
Disadvantages:
Vibration, shock and noise in operation
High gear installation requirements
Unable to realize CVT
Not suitable for the occasion with large center distance