Increased efficiency of eccentric cycloidal engagement

Gears with eccentric cycloidal engagement have large gear ratios, small overall dimensions, low noise and vibration levels. A relatively low efficiency factor limits their use in transmissions mechanisms, where involute gearing with gear ratios up to 10 and high efficiency (over 0.98) are in demand. The power losses of the eccentric cycloidal engagement are caused by friction in the jointly working kinematic pairs, which are formed by the gear with at least half of the pins, and the latter form the pairs with axles or sockets in the housing. It is possible to reduce the power loss by reducing the number of jointly working kinematic gear-pin pairs, which is done by modifying the theoretical profile of the gear. The modified profile is obtained from the theoretical one by removing the tops of the protrusions so that the remaining parts of the profile provide a smooth transfer of the load to a given number of pins. The study introduces a method for calculating power losses and the efficiency of eccentric cycloidal gearing for theoretical and modified gear profiles. Findings of research show that the modification of the cycloidal gear makes it possible to reduce the power loss in the engagement by more than 60% and to increase the efficiency by 0.03 ... 0.04 without a significant decrease in the strength of the working surfaces. The obtained result confirmed the possibility of increasing the efficiency of eccentric cycloidal gearing for it to be used in transmissions of transport vehicles.

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