The working principle of the cam index and the advantages of the cam index are introduced by Sani engineers in a more popular way based on work experience as follows:
1) Compact structure and large transmission ratio
The cam transmission has only two basic components. Since the number of index rollers is small and the surfaces of multiple lead rollers are involved in meshing, the cam transmission can be compact in the case of a large transmission ratio. Generally, the transmission ratio of one-stage cam transmission is 6-80 when transmitting power, and sometimes the transmission ratio can even reach 1500 when transmitting power, which can replace multi-stage gear transmission.
2) Smooth work and high transmission accuracy
Since the cam surface is generally a spiral surface with a small lift angle, when the cam rotates at a high speed, the normal sub-velocity on the surface is very small, so the cam drive can be regarded as a low-speed translational rack pushing the roller to rotate. Therefore, the cam transmission is relatively stable. Compared with the general involute gear, the transmission stability is significantly improved, and the impact is low and the noise is low, which is suitable for high-speed indexing.
Since the cam surface is a continuous spiral surface, it is easy to obtain high machining accuracy. In addition, the cam transmission has a large overlap, which has a uniform effect on the cam manufacturing error, so higher transmission accuracy can be obtained.
3) Self-locking can be realized as required
When the helix angle of the cam is smaller than the equivalent friction angle between the conjugate surfaces, the reverse stroke of the cam drive is self-locking.
4) The transmission torque is large, and there is a wide dynamic/static ratio range.
5) Standardization and serialization of products.
There are also some shortcomings of its own. The main problem is that the cam is a spatially curved surface, which is difficult to manufacture, and the process characteristics of outer rigidity and inner flexibility must be maintained. The requirements for cam material and machining equipment are high, and the cycle time is high. Moreover, the assembly process of parts and components needs to be completed by experienced technicians to achieve ideal indexing accuracy and dynamic performance.