A planetary gear train harmonic reducer

Abstract

The invention discloses a planetary gear train harmonic wave reducer which comprises an input shaft, a middle frame, an output shaft, a small chain wheel, a chain ring, a rotary frame, an output shaft, a planetary shaft and a rear fixing frame. The two ends of the middle frame are provided with chain wheels and an inner gear ring correspondingly. One end of the input shaft is provided with a gear,the planetary shaft and the rear fixing frame form a rotating pair, and three planetary wheels are engaged with a gear at the shaft end of the input shaft and the inner gear ring of the middle frameto form a planetary gear train. The transmission ratio of the input shaft to the planetary shaft is i1, the planetary shaft, three small gears and the rotary frame 10 form an ordinary gear train, theplanetary shaft drives the rotary frame through the small gears to rotate, the transmission ratio of the planetary shaft to the rotary frame is i2, the rotary frame drives the three small chain wheelsto revolve around the axis of the rotary frame, the three small chain wheels are used as wave generators in the harmonic wave reducer, and the three small chain wheels, the chain ring, the output shaft, the front chain wheel and the rear chain wheel form a harmonic wave reduction device. The transmission ratio of the rotary frame to the output shaft is i3. The transmission ratio i of the input shaft to the output shaft meets the formula: i=i1*i2*i3.

Description

technical field [0001] The invention relates to the field of mechanical reduction transmission, in particular to a planetary gear train harmonic reducer. Background technique [0002] Harmonic gear transmission has the advantages of large transmission ratio, high transmission precision, good stability, simple structure, light weight and small volume. Harmonic gear transmission is based on the mechanical harmonics generated by the radial deformation of the thin-walled cylindrical flexible spline to transmit motion and power, and the fatigue fracture caused by the excessive bending stress of the thin-walled cylindrical flexible spline is the main cause of this transmission. The failure mode, the bending stress in the flexspline is proportional to the radial deformation and wall thickness, the radial deformation of the flexspline is related to the transmission ratio, the smaller the transmission ratio, the greater the radial deformation, the shorter the life of the transmission...

AI Technical Summary

Problems solved by technology

Harmonic gear transmission is based on the mechanical harmonics generated by the radial deformation of thin-walled cylindrical flexible splines to transmit motion and power. Among them, the fatigue cracking of thin-walled cylindrical flexible splines caused by excessive bending stress is the main cause of this transmission. In the form of failure, the bending stress in the flexspline is proportional to the radial deformation and wall thickness, and the radial deformation of the flexspline is related to the transmission ratio. The smaller the transmission ratio, the greater the radial deformation, and the shorter the life of the transmission. As the wall thickness of the wheel increases, the bending stress increases and the service life decreases. On the contrary, the wall thickness decreases, the stiffness of the flex spline decreases, the stress concentration of the gear teeth increases, and even the gear teeth interfere, which aggravates the failure of the transmission device.

[0003] The strength and life of the flexwheel are also related to its material and processing technology. Usually, it is necessary to use high-quality alloy steel, and carry out quenching and tempering, nitriding, carburizing and shot peening, and strictly control the dimensional accuracy, shape accuracy and Surface quality, it can be seen that the manufacturing process of the harmonic gear transmission is quite complicated, the manufacturing cost is high, and it is difficult for ordinary manufacturers to meet its technical requirements

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