Cup-shaped harmonic gear with common tangent double-arc tooth profile and its tooth profile design method

Abstract

The invention provides a cup-shaped harmonic gear with a common tangent type double-circular arc tooth profile. The cup-shaped harmonic gear is composed of a wave generator, a flexible gear and a rigid gear; the tooth profiles of the flexible gear and the rigid gear of the harmonic gear transmission are common tangent type double-circular arc plane tooth profile. The invention also provides a tooth profile design method of the cup-shaped harmonic gear with the common tangent type double-circular arc tooth profile; the tooth profile design method comprises taking the coning deformation of the cup-shaped flexible gear in the axial direction into account, and in order to avoid interference, performing enveloping and fitting calculation on the circular arc part of the tooth root of the rigid gear by use of the movement locus of the gear teeth of the front section of the flexible gear according to the maximum radial deformations on the front, middle and rear sections of the flexible gear and the movement locus difference of the gear teeth of the flexible gear relative to the tooth groove of the rigid gear, and performing enveloping and fitting calculation on the circular arc part of the tooth crest of the rigid gear by use of the movement locus of the gear teeth of the rear section of the flexible gear so that the flexible gear and the rigid gear are in continuous conjugate transmission in the entire engagement interval. The cup-shaped harmonic gear with the common tangent type double-circular arc tooth profile has the advantages of increased number of engaged teeth, increased engagement contact surface, high bearing capacity, long fatigue life and the like.

Description

technical field [0001] The invention belongs to the technical field of gear transmission, and in particular designs a cup-shaped harmonic gear with a common tangent double-arc tooth profile and a tooth profile design method thereof. Background technique [0002] Harmonic gear transmission is proposed by American scholar C.W.Musser in 1955, and is a transmission technology developed on the basis of the theory of elastic deformation of thin shells. Harmonic gears are widely used in many fields such as robots, instruments and meters, and transportation by virtue of their advantages such as large transmission ratio, small size, light weight, high carrying capacity, and high transmission precision. The number of applications in the field of robotics exceeds 70% of the total. Harmonic gears are usually composed of flexsplines, rigid splines and wave generators. As the key components in harmonic gear transmission - flexsplines are always in a state of fluctuating deformation durin...

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Problems solved by technology

[0004] In the harmonic gear tooth profile design scheme proposed in the above literature, the envelope of the involute tooth profile is mostly distributed in the small interval of the long axis of the wave generator; the arc or double arc tooth profile is not considered The cup-shaped flexspline has a tapered deformation feature along the axial direction, so it cannot be used in the tooth profile design of the cup-type flexspline; the combined double-arc tooth profile has fewer tooth pairs that can participate in meshing on the front section, and the transmission The main action surface of the load is designed on the rear section, but since the deformation of the rear section of the ring gear after the deformation of the cup-shaped flexspline is small, the relative tooth height of the gear teeth participating in the meshing on the rear section is relatively small, so the phenomenon of tooth skipping is prone to occur , causing transmission failure

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