Design method of elliptical-sine-non-circular-non-circular three-pulley synchronous belt drive

Abstract

The invention discloses a design method of elliptical-sine-non-circular-non-circular three-pulley synchronous belt drive. According to the design method, firstly, an elliptical driving synchronous belt pulley and sine-non-circular driven synchronous belt pulley pitch curve equation is built, and the drive ratio of an elliptical driving synchronous belt pulley to a sine-non-circular driven synchronous belt pulley is computed by the adoption of a tangential polar coordinate theory; and then the perimeter of a synchronous belt is computed, and a non-circular tension synchronous belt pulley pitch curve is computed through an iterative algorithm according to the perimeter looseness amount change of the synchronous belt. A tension pulley is a non-circular synchronous belt pulley of the free pitch curve, the synchronous belt looseness variation generated in the drive process can be compensated for in real time, and the problem that the non-uniform-speed drive and the real-time tension cannot be met at the same time by means of traditional two-pulley-type non-circular belt drive is solved; and the parameters of the long axis and the eccentricity of the elliptical driving pulley pitch curve, the amplitude of the sine-non-circular driven pulley pitch curve and the like are the adjustable amount, by adjusting the changes of the parameters, the shape of the driving pulley and driven pulley pitch curve is changed, and the large-center-distance specific non-uniform-speed drive requirement is met.

Description

technical field [0001] The invention relates to a design method of a non-circular synchronous belt drive, in particular to a design method of an ellipse-sine non-circle-non-circle three-wheel synchronous belt drive with variable slack self-compensation. Background technique [0002] The transmission mechanism changes the motion form and speed of the input and output components to meet the requirements of different working environments. Among them, the non-uniform transmission mechanism occupies a very important position, and the common ones are the connecting rod mechanism, the cam mechanism, and the non-circular gear mechanism. Compared with the connecting rod mechanism and the cam mechanism, the non-circular gear mechanism has the advantages of compact structure, stable transmission, large transmission power, and easy dynamic balance. Therefore, it has been successfully used in processing machine tools, automatic machinery, transportation, instrumentation, pumps, etc. , fl...

AI Technical Summary

Problems solved by technology

However, non-circular gear transmission is only suitable for non-uniform speed transmission occasions with small center distance and convenient lubrication, so non-circular flexible member (belt / chain) transmission suitable for large center distance, inconvenient lubrication and low manufacturing cost should be used born

Among them, the polygonal effect of non-circular chain transmission is obvious, so it is limited when there are strict requirements on the change law of non-uniform transmission ratio; at the same time, ordinary friction belt transmission cannot guarantee accurate transmission ratio law due to elastic sliding.

[0003] The current non-circular belt (chain) transmission has only 2 non-circular belt (chain) wheels - the driving wheel and the driven wheel. During the transmission process, because the pitch curve is non-circular, the slack of the belt (chain) is real-time. Therefore, it is impossible to guarantee the non-uniform transmission ratio change law and the real-time tension of the belt (chain) required by the work at the same time.

In practical application, in order to compensate the slack change of the belt (chain) in the transmission, the tension is realized by adding a spring, because the tension force changes in a movement cycle, and the tension force increases with the aggravation of the non-uniform velocity characteristic. The greater the range of change, this will in turn affect the accuracy of non-uniform speed transmission, and the dynamic characteristics will become worse; therefore, in actual engineering, non-circular belt (chain) transmission is rarely used in precise load high-speed transmission occasions

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