Circular-Fourier noncircular-noncircular three-wheel synchronous belt transmission design method

Abstract

The invention discloses a design method for transmission of a round-Fourier non-round-non-round three-wheel synchronous belt. The design method is characterized in that an active wheel is a conventional round synchronous belt wheel; a driven wheel is a Fourier synchronous belt wheel, and the output rule of the driven wheel depends on Fourier curve parameters of the driven wheel; and a tensioning wheel is a non-round synchronous belt wheel and plays a role in compensating synchronous-belt relaxation-amount change brought in the transmission process of the driving wheel and the driven wheel in real time. The design method comprises the following steps of: firstly establishing a pitch curve equation of the driving wheel and the driven wheel of the synchronous belt, and utilizing the cutting-pole coordinate theory to calculate the transmission ratio of the driving wheel and the driven wheel; and then calculating the circumference of the synchronous belt, and calculating all parameters of the pitch curve of the tensioning synchronous wheel by an iterative method according to the relaxation-amount change of the circumference of the synchronous belt. The design method disclosed by the invention has the advantages that a new transmission mechanism and a new design method are provided for realizing non-uniform-speed direct and accurate transmission with large center distance, and simultaneously the requirements for non-uniform-speed transmission and real-time tensioning are met.

Description

technical field [0001] The invention relates to a design method of a noncircular synchronous belt transmission, in particular to a design method of a circular-Fourier noncircular-noncircular three-wheel synchronous belt transmission 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,...

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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