CN105508553A - Gear - Google Patents

Abstract

The invention discloses a gear which comprises a first inner-tooth gear, a second inner-tooth gear, a harmonic generator and an outer-tooth gear, wherein first inner teeth are arranged on the first inner-tooth gear; second inner teeth are arranged on the second inner-tooth gear; a cylinder is arranged on the outer-tooth gear; the first outer teeth and the second outer teeth are arranged on the peripheral surface of the cylinder; the first outer teeth are engaged with the first inner teeth; the second outer teeth are engaged with the second inner teeth; tooth number of the first outer teeth is different from that of the second outer teeth; the harmonic generator is embedded into the inner peripheral surface of the cylinder of the outer-tooth gear; the outer-tooth gear is bent into a shape of an oval; the first inner teeth and the first outer teeth are engaged at the two end parts of the long shaft of the outer-tooth gear; and the second inner teeth and the second outer teeth are also engaged on the two end parts of the long shaft of the outer-tooth gear. The gear is simple in structure, is convenient to mount and is high in freedom of setting a speed ratio, so that the scope of application of the gear is increased a low speed ratio can be easily realized, and therefore, the gear is suitable for the occasion with low speed ratio requirements

Description

A kind of gear

Technical field

The present invention relates to a kind of gearing.

Background technique

Gear generally can be used for slowing down and also can be used for accelerating, and wherein common speed reducer is exactly harmonic drive speed reducer, because can produce larger reduction speed ratio, structure is simple, and number of components is few, easy for installation, is thus widely used.But the external tooth gear of general harmonic gear directly engages with Stationary side internal-gear and driving side internal-gear, again due to the mechanical property of gear transmission itself, the degrees of freedom of general harmonic gear setting speed ratio is not high, thus generally speaking, the speed ratio of common harmonic gear needs to be set in more than 50, extremely difficulty is applicable to the speed ratio of less than 35, and so common harmonic gear just can not be applicable to the situation of low speed ratio.

Therefore those skilled in the art to be devoted to research and development setting speed ratio degrees of freedom high and can realize low speed ratio gear easily.

Summary of the invention

Because the above-mentioned defect of prior art, it is high and can realize low speed ratio gear easily that technical problem to be solved by this invention is to provide a kind of setting speed ratio degrees of freedom.

For achieving the above object, the invention provides a kind of gear, comprise the first internal-gear, the second internal-gear, harmonic generator and external tooth gear, first internal-gear is provided with the first internal tooth, second internal-gear is provided with the second internal tooth, described external tooth gear is provided with cylindrical body, the outer circumferential face of described cylindrical body is provided with the first external tooth and the second external tooth, described first external tooth is meshed with described first internal tooth, described second external tooth and the second internal tooth are meshed, and described first external tooth is different with the number of teeth of the second external tooth.Described harmonic generator is the inner peripheral surface of the cylindrical body embedding external tooth gear, external tooth gear is bent into ellipse, described first internal tooth engages with the two-end part of the first external tooth at the major axis of external tooth gear, and described second internal tooth also engages at the two-end part of the major axis of external tooth gear with the second external tooth.

In order to harmonic generator better coordinates rotation with external tooth gear, described harmonic generator comprises the rigidity connector of cartouche, the waveform bearing in the elliptical periphery face of the rigidity connector of described cartouche, described waveform bearing have can bend towards radial direction in the ball bearing of foreign steamer.

The invention has the beneficial effects as follows: structure of the present invention is simple, easy for installation, setting speed ratio degrees of freedom is high, thus greatly increases the Applicable scope of gear, can realize low speed ratio easily, thus be applicable to low speed than the situation required.

Accompanying drawing explanation

Fig. 1 is the structural representation of the embodiment of the invention.

Fig. 2 is the plan structure schematic diagram of Fig. 1.

Fig. 3 is the partial enlargement structural representation at the I place of Fig. 1.

Embodiment

Below in conjunction with drawings and Examples, the invention will be further described:

As shown in Figures 1 to 3, a kind of gear, comprise the first internal-gear 1, second internal-gear 2, harmonic generator 5 and external tooth gear 3, first internal-gear 1 is provided with the first internal tooth 1a, its number of teeth is Z1, second internal-gear 2 is provided with the second internal tooth 2a, its number of teeth is Z2, external tooth gear 3 is provided with cylindrical body 4, the outer circumferential face of cylindrical body 4 is provided with the first external tooth 3a and the second external tooth 3b, first external tooth 3a is different with the number of teeth of the second external tooth 3b, first external tooth 3a is in the circular circumference face of cylindrical body 4, be formed at the side of axis L, its number of teeth is Z3, second external tooth 3b is then at the opposite side of axis L, its number of teeth is Z4, first external tooth 3a is meshed with the first internal tooth 1a, second external tooth 3b and the second internal tooth 2a is meshed.Harmonic generator 5 is the inner peripheral surfaces of the cylindrical body 4 embedding external tooth gear 3, external tooth gear 3 is bent into ellipse, first internal tooth 1a engages at the two-end part of the major axis of external tooth gear 3 with the first external tooth 3a, second internal tooth 2a also engages at the two-end part of the major axis of external tooth gear 3 with the second external tooth 3b, ensure that harmonic generator is better fixed on gear with this, so that the input rotated.

Harmonic generator 5 comprises the rigidity connector 6 of cartouche, the waveform bearing 7 in the elliptical periphery face of the rigidity connector 6 of cartouche, waveform bearing 7 have can bend towards radial direction in the ball bearing of foreign steamer, ensure that harmonic generator better coordinates rotation with external tooth gear with this.

The number of teeth of the first internal tooth 1a is different from the number of teeth of the first external tooth 3a, and the number of teeth of the second internal tooth 2a is different from the number of teeth of the second external tooth 3b, and the number of teeth of the first internal tooth 1a is greater than the number of teeth of the first external tooth 3a, and the number of teeth of the second internal tooth 2a is less than the number of teeth of the second external tooth 3b.First internal-gear 1 is set to fixing non-rotary Stationary side internal-gear, second internal-gear 2 is set to export the driving side internal-gear rotated, there is minimum gap between first internal-gear 1 and the second internal-gear 2, and two gears are configured in the direction of central axis L side by side.

When harmonic generator 5 rotates to gear input, external tooth gear 3 is bent into ellipse, first internal tooth 1a engages at the two-end part of the major axis of external tooth gear 3 with the first external tooth 3a, second internal tooth 2a also engages at the two-end part of the major axis of external tooth gear 3 with the second external tooth 3b, now the ratio of the external tooth gear 3 of the first internal-gear 1 and the first external tooth 3a is R1, the ratio of the external tooth gear of the second internal-gear 2 and the second external tooth 3b is R2, and input rotates and the speed ratio of output swing pinion is R.

That is: R1=1/{ (Z3-Z1)/Z3};

R2＝1/{(Z4-Z2)/Z4}；

R＝(R1.R2-R1)/(-R1+R2)；

Change former input by above-mentioned principle to rotate, second internal-gear 2 that is rotated through after change exports, and just can draw different speed ratios by the adjustment number of teeth, thus the setting range of speed ratio is comparatively wide, wherein also comprises the situation of low speed ratio.Such as, set each number of teeth and be respectively Z1=64; Z2=60; Z3=62; Z4=64, carries it into R1=1/{ (Z3-Z1)/Z3}; R2=1/{ (Z4-Z2)/Z4}; In R=(R1.R2-R1)/(-R1+R2) three formula, can draw R=-15.2, negative sign wherein represents that exporting sense of rotation with input sense of rotation is opposite direction.

More than describe preferred embodiment of the present invention in detail.Should be appreciated that those of ordinary skill in the art just design according to the present invention can make many modifications and variations without the need to creative work.Therefore, all technician in the art, all should by the determined protection domain of claims under this invention's idea on the basis of existing technology by the available technological scheme of logical analysis, reasoning, or a limited experiment.

Claims (2)

1. a gear, comprise the first internal-gear (1), the second internal-gear (2), harmonic generator (5) and external tooth gear (3), first internal-gear (1) is provided with the first internal tooth (1a), second internal-gear (2) is provided with the second internal tooth (2a), it is characterized in that: described external tooth gear (3) is provided with cylindrical body (4); The outer circumferential face of described cylindrical body (4) is provided with the first external tooth (3a) and the second external tooth (3b); Described first external tooth (3a) is meshed with described first internal tooth (1a); Described second external tooth (3b) and the second internal tooth (2a) are meshed; Described first external tooth (3a) is different with the number of teeth of the second external tooth (3b); Described harmonic generator (5) is the inner peripheral surface of the cylindrical body (4) embedding external tooth gear (3), and external tooth gear (3) is bent into ellipse; Described first internal tooth (1a) is engaged with the two-end part of the first external tooth (3a) at the major axis of external tooth gear (3); Described second internal tooth (2a) is also engaged at the two-end part of the major axis of external tooth gear (3) with the second external tooth (3b).

2. gear as claimed in claim 1, is characterized in that: described harmonic generator (5) comprises the rigidity connector (6) of cartouche; The waveform bearing (7) in the elliptical periphery face of the rigidity connector (6) of described cartouche; Described waveform bearing (7) have can bend towards radial direction in the ball bearing of foreign steamer.