Three-dimensional harmonic wave gear with involute tooth outline

Abstract

A harmonic drive device having three-dimensional modified involute tooth profile includes a flexible ge

Description

Technical field [0001] The invention relates to a mechanical transmission device, in particular to a harmonic transmission device adopting a flexible wheel and a rigid wheel with an involute tooth profile. Background technique [0002] The harmonic drive reducer is a new type of transmission device invented by CWMusser in the 1950s (see US Patent 2906143). The inner hole of the flexible wheel with external teeth is equipped with a wave generator with a cam and a flexible bearing. The cam profile is an ellipse or other similar ellipse curve. The cam profile curve can be expressed in polar coordinates. The line connecting the two points with the largest radial diameter symmetrical to the cam center is called the long axis of the cam. The wave generator is installed on the open end of the flexspline (that is, the end far from the bottom of the flexspline). The open end is braced into an ellipse or other approximately elliptical curve by the wave generator, so that its outer teeth me...

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Problems solved by technology

[0015] 1. The patent only mentioned that the variation coefficient of the flexspline involute tooth profile should be changed along the length direction of the teeth, but it did not mention that the tooth height of the two gears or one of them should be adjusted along the length direction of the teeth at the same time. change to avoid interference

[0016] 2. This patent only allows the variation coefficient of the flexspline involute tooth profile to change along the length direction of the tooth, and does not mention that the variation coefficient of the rigid spline involute tooth profile can also be appropriately changed along the length direction of the tooth if necessary , in order to reduce the change range of the variation coefficient of the flexspline involute tooth profile, and avoid the excessive change range of the variation coefficient of the flexspline involute tooth profile from affecting the strength of the flexspline. The variation coefficient of the open tooth profile remains unchanged, and only the variation coefficient of the involute tooth profile of the rigid wheel changes along the length direction of the tooth

[0017] 3. A variety of cams with different profiles can be used in the harmonic transmission device, such as elliptical cams, cosine cams, two-force cams, four-force cams, etc. This patent does not analyze the influence of cams with different profiles on the calculation formula

In fact, for cams with different profiles, the formulas for calculating the tooth profiles of flexsplines and rigid splines are different. The formula for calculating the displacement coefficient of flexsplines proposed in this patent cannot be applied to many situations.

[0018] 4. The patent restricts the rigid spline and the flex spline to take the same original tooth profile angle. It does not mention that the original tooth profile angle of the flex spline and rigid spline can also be based on the requirements for meshing clearance. take a different value

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