The distribution of transmission ratio is one of the important issues in the design of gear transmission chain.Whether the distribution of the transmission ratio is reasonable will affect the structural layout and working performance of the entire transmission chain. Therefore, in the design, the distribution of the transmission ratio must be reasonably carried out according to the requirements of use.
The total transmission ratio of the gear transmission chain is often given in advance according to specific requirements.After the total transmission ratio is given, the number of transmission stages is determined and the transmission ratio of each stage is allocated accordingly.
Generally speaking, it is better that the gear transmission chain has fewer transmission stages.Because the more transmission stages, the more complex the structure of the transmission chain.The small number of transmission stages can not only simplify the structure, but also help to improve the transmission efficiency, reduce the transmission error and improve the working accuracy.
But in the case of a certain total transmission ratio, due to the reduction of transmission stages, it will inevitably lead to an increase in the value of the transmission ratio at all levels.If the value of the transmission ratio of each level (single-stage transmission ratio) is too large, the structure of the transmission chain will not be compact.At the same time, when the single-stage transmission ratio is too large, the diameter of the driven wheel will be large, resulting in an increase in the moment of inertia of the gear, which is not desirable for a gear transmission chain requiring a small moment of inertia.Therefore, the number of transmission stages should be reasonably determined according to the specific working requirements of the gear transmission chain.
When designing, you can refer to the following principles for the allocation of transmission ratios.
1.Allocate the transmission ratio according to the principle of first small and then large
2.Allocate the transmission ratio according to the principle of small volume
3.Allocate the transmission ratio according to the principle of small moment of inertia