KR20150087452A - Improved teeth's gearing structure with strain wave gearing apparauters - Google Patents

Abstract

The present invention relates to a distortional wave gear apparatus having a cam plate provided on a wave generator generating a wave by receiving a rotational force from a drive motor as a drive source, wherein a second curved portion having the radius of curvature larger than that of a first curved portion and smaller than that of a third curved portion between the first curved portion related to a long shaft and the third curved portion related to a short shaft in the cam plate. According to the present invention, the curved portion having a middle size of the radius of curvature is formed between the first curved portion having small radius of curvature and the third curved portion having the largest radius of curvature for a cam curved line therein to protrude compared with the past. Therefore, the second curved portion is related to an extended line of the first curved portion which is coupling portion to substantially extend the coupling portion.

Description

TECHNICAL FIELD [0001] The present invention relates to improved Teeth's gearing structure with strain wave gearing apparauters,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deformed wave gear device used for operating joints of medical robots or industrial robots in various industrial fields such as medical devices, semiconductor manufacturing devices, automobile production lines, printing machines, and the like.

More specifically, the curved structure of the cam plate that elastically deforms the flexure of the deformed wave gear device to an elliptical shape is improved to widen the engagement section of the flexure and the circular spline, thereby facilitating transmission of a large torque, To a modified wave gear device having an improved coupling structure in which a ratching phenomenon due to twisting of a flex fly is prevented.

As is well known, a deformable wave gear device is used in a medical or industrial robot mainly used in a medical or semiconductor manufacturing apparatus, an automobile production line, a printing apparatus, or the like to operate joints such as an arm.

The deformation wave gear device is a technique that dynamically utilizes the elastic force of metal to decelerate the rotational force of a driving motor. It is also called a strain wave gear. In 1959, the first inventor, C, W Musser, Since the grant of the patent,

Such a deformed wave gear device can easily obtain a desired ratio of reduction ratio by controlling the rotational force of the driving motor as compared with other reduction gears, has a relatively small size and has a small back lash, It is widely used in areas where precise operation is required like the arm of a robot.

Fig. 1 is a front view of a conventional deformation wave gear device, and Fig. 2 is a half sectional view showing a side view.

As shown in the figure, a conventional deformation wave gear device includes a wave generator 10 for receiving a rotational force from a drive motor as a driving source to generate a wave, Shaped elastic body that accommodates the wave generator and is elastically deformed into an elliptical shape by the wave of the wave generator 10 while the external teeth 21 on the opening side are flexibly joined to the internal teeth of a circular spline ); A hollow rigid body for receiving the flex fly, the circular rigid body having an internal teeth (31) partially mating with the external teeth (21) on its inner surface; .

The wave generator 10 includes a camshaft 11 that is directly connected to an output shaft of a drive motor (not shown) driven by the drive source to serve as an input shaft of the deformed wave gear device, and an elliptical eccentric body A cam plate 12 having a long axis L and a minor axis S at positions mutually orthogonal to each other and a thin inner and outer ring 13a which surrounds the ball 13c as a ball bearing which is pressed into the periphery of the cam plate 12 And a wave bearing 13 in contact with the cam plate 12 and the flex plate 20, respectively.

The cup-shaped flex plate 20 has a wave bearing 13 inserted into the opening of the body 22, a tooth-like external tooth 21 formed on the outer surface thereof, and a body 22 The boss portion 24 connected through the diaphragm 23 is formed thick.

The diaphragm 23 integrally connects the rear end of the body 22 and the boss portion 24 and the boss portion 24 is mounted on the output side as a hollow shape positioned coaxially with the camshaft 11 .

The circular spline 30 is a hollow rigid body having a tooth-like internal teeth 31 integrally formed on the inner surface thereof and elastically partially engaged with the external teeth 21 of the flex fly 20.

A cross roller bearing, which also serves as an output shaft, may be provided between the flex plate 20 and the circular spline 30 while supporting the flex plate 20 as a rotating body. The description thereof will be omitted here because it is an option according to the specification of the product.

Further, the circular spline 30 may serve as a housing, or a separate casing may be provided to accommodate all of the above components. Since the circular spline 30 is an option according to the specification of the hooking device, the description is omitted here.

In the deformed wave gear device configured as described above, both the wave bearing 13 and the flex plate 20 are elastically deformed into an elliptical shape by the elliptical cam plate 12 constituting the wave generator 10, L) and a short axis (S).

Therefore, when the rotational force of the drive motor is inputted through the camshaft 11, the cam plate 12 of the wave generator 10 rotates first to generate a wave, which is transmitted through the wave bearing 13 to the flex plate 20 Thereby causing the external teeth 21 to elastically partially engage and disengage from the internal teeth 31 of the circular spline 30 and to decelerate the input rotational force.

The decelerated rotational force is output to the outside through the output shaft 21 of the flex fly 20, the body 22, the diaphragm 23, the boss portion 24, and the output shaft.

The reduction ratio output to the outside in the above operation is determined by the difference in the number of teeth (number of teeth) of the internal teeth 21 and internal teeth 31 formed in the flexplane 20 and the circular spline 30. [

Generally, the number of teeth (number of teeth) formed on the flex fly 20 for deceleration is 2 to 6 smaller than the number of teeth (number of teeth) formed on the circular spline 30, and is made up of an even number.

The ratio of the external teeth of the flexplane 20 to the internal teeth 21 and 31 of the circular spline 30 at the long axis L of the wave generator 10 is about 30% It is known.

Here, the operation will be described on the assumption that the size of the flexplane 20 is smaller than the dimension of the circular spline 30 by two.

3 (a), when the long axis L of the cam plate 12 is positioned vertically and the short axis S is horizontally positioned, the flex plate 20 is deformed into a long oval shape up and down.

In this state, only the external teeth 21 in the long axis L direction are engaged with the internal teeth 31 of the circular spline 30, and the external teeth 21 in the short axis S direction are separated.

the cam plate 12 and the wave bearing 13 of the wave generator 10 rotate in the same direction to generate a wave when the drive motor rotates 90 degrees clockwise as shown in Fig. S is rotated by 90 degrees.

The flexplane 20 which is an elastic body is rotated by 90 degrees while causing a linear deformation so that the external teeth 21 of one side are inserted into the internal teeth 31 of the circular spline 30, (L), and the short axis (S) portion is spaced apart from each other.

when the wave generator 10 rotates 180 degrees as shown in Fig. 5C, only one tooth of the tooth of the flex plate 20 rotates in the counterclockwise direction.

(number of teeth) of the flexplane 20 is smaller than the dimension (number of teeth) of the circular spline 30 when the wave generator 10 rotates 360 占 (one rotation) Clockwise direction by the difference of the number of teeth (teeth number), and this amount of movement is the reduction ratio of the output shaft.

The rotational force of the drive motor inputted through the camshaft 11 is constant in accordance with the difference in the number (teeth number) of the external teeth and the internal teeth 21 and 31 formed in the flexplane 20 and the circular spline 30 Deceleration rate and output.

Further, in order to output the rotational force inputted in the above-mentioned process after being accurately decelerated at a desired ratio, the gear connection between the flexplane 20 and the circular spline 30 must be precisely performed.

That is to say, if the coupling section (area) of the external teeth 21 and the internal teeth 31 formed in the flexplane 20 and the circular spline 30 is wide and the gear connection between the teeth is properly performed, .

However, in the course of deceleration, the flexure 20 repeats rotation and simultaneous elastic deformation, so that twisting phenomenon occurs in the body 22, and this twisting interferes with smooth gear connection between the two teeth Causing a chattering phenomenon, which impedes precise rate deceleration and large torque transmission due to the ratcheting phenomenon.

This twist phenomenon is basically caused by the elastic deformation of the flexplane and the external teeth 21 and internal teeth 21 of the flexplane 20 and the circular spline 30 are deformed in accordance with the change of the Corning angle according to the elastic deformation 31) have different contact areas.

Corning refers to the deflection in the axial direction when the flexplane is deformed into an elliptical shape, and the amount of deflection from the center line toward the outer side or the inner side is called a corning angle.

Therefore, the corning angle increases as the axial length of the flexure becomes shorter, becomes smaller as the length becomes longer, and becomes larger as it goes toward the opening end rather than the diaphragm 24 side, and becomes the maximum at the opening end.

4 is a diagram schematically showing a change in the Corning angle according to the elastic deformation of the flex plate 20. As shown in Fig.

The upper side of the center line in the drawing shows a cross section in the major axis direction, and the lower side shows a cross section in the minor axis direction. Two flexplanes having different lengths are shown in one figure for convenience of explanation.

As can be seen, the cornering angle? Of the flexplane 20 is found to be shorter in the length of the flexplane 20 and larger toward the end of the opening, and the maximum value is shown at the opening end.

Also, the change in the corning angle? Affects the engagement of the tooth profile.

5 shows the state of engagement of the external teeth 21 and internal teeth 31 of the flexplane 20 and the circular spline 30 when the Corning angle is small. In the case of a large size.

As shown in the drawing, the smaller the cornering angle? Of the flexure 20 is, the larger the contact area (hatched portion) between the external teeth 21 and the internal teeth 31 becomes, and the larger the cornering angle, 31) is smaller than the contact area (hatched portion).

Accordingly, when the cornering angle is small, the contact area between the two teeth becomes relatively large. However, as the cornering angle increases, the contact area between the teeth becomes small, so that the ratcheting phenomenon can easily occur and transmission of a large torque becomes difficult.

(Patent Document 0001) Korean Patent Publication No. 10-2013-31348

(Patent Document 0002) Korean Patent Publication No. 92-7996

(Patent Document 3) Korean Patent Registration No. 10-245287

(Patent Document 0004) Korean Patent Registration No. 10-245288

(Patent Document 0005) Korean Patent Registration No. 10-1312577

In order to solve these problems, various measures have been proposed.

In Korean Patent Laid-Open No. 10-2013-0031348, an involute dual-tooth position with a low pressure angle smaller than 20 DEG is adopted as a basic tooth profile, and a height of a tooth at a right angled section of the reference set near the center of the root of the flex plate (M is a module, n is a positive integer, and is usually n = 1), and a value of a tooth taking coring is taken along the root direction of the external teeth is applied to the root tooth of the external tooth, When the straight portion of the rack tooth profile is viewed along the root direction, it is made to coincide.

By doing so, the external teeth and the internal teeth of the flexplane and the circular spline maintain wide engagement at the main end face, while partial engagement at the other axial right end face is maintained, and ratcheting of the external tooth and internal tooth at high load torque is prevented even at a high reduction ratio .

In Korean Patent Laid-Open No. 10-2013-0031348, the tooth potential is considered to be inclined so as to be a conical gear of a hatch tooth, and the internal tooth gradually decreases in height from the main end surface toward the diaphragm Interference is prevented.

Another technique is disclosed in Korean Patent Publication No. 92-0007996, entitled " wave-form meshing gear unit ".

Korean Patent Publication No. 92-0007996 discloses that the end surfaces of the inner and outer gears are formed in the shape of an imaginary plane obtained by transformation of the upper gear with a 1/2 reduction ratio applied to the outer gear with respect to the motion locus of the inner gear, And the similarity transformation is effected on a reference point that moves from the contact state of the inner and outer gears to the disengaged state.

That is, the amount of the inner and outer gears is formed into a convex shape along a skew curve obtained by the top-shift transformation so as to continuously contact the outer gear in the gear region where the inner gear meshes, The present invention provides a gear device with high torsional rigidity and high efficiency by improving the fatigue strength of the root, especially of the fatigue strength.

As another technique, there is a "three-dimensional undulating flexible type gear device of a non-volatile type " in Korean Patent Registration No. 10-0245287.

치형의 주요부로 하고, 치형의 기준점 근방에 삽입시킨 개구부의 굽힘량에 상당하는 유한의 압력각을 가지는 직선과 이 직선을 상기

치형 주요부에 원활하게 이어주는 이행곡선을 갖춘 복합곡선 및 그 근접곡선을 양기어의 치끝단부 치형으로 하는 것이다.The above-mentioned Japanese Patent No. 10-0245287 discloses a structure in which the teeth of the circular spline and the flex fly are both spur gears without electromagnetism, the opening of the flex fly is set to a sub-deviation state smaller than a normal bending amount, (The movement locus of the tooth) of the movement locus by superimposing the locus of movement on one right-angled cross-section, by finding the locus of movement by rack approximation of the value of the outer tooth relative to the inner tooth, And obtaining a composite curve composed of the envelope and the movement locus by smoothly connecting the movement locus on the diaphragm side apex or the end face of the end portion in the direction perpendicular to the axis at an angled cross section on the envelope, The portion from the apex of the movement locus to the end point corresponding to twice the tooth height in the tooth depth direction, The top curve is obtained by performing top-to-bottom conversion with a reduction ratio of 1/2 with the end point as the origin, and the top curve is defined as the

A straight line having a finite pressure angle corresponding to the amount of bending of the opening inserted into the vicinity of the reference point of the tooth profile,

A composite curve having a transition curve that smoothly connects to the tooth-like main portion, and a proximity curve thereof are made to be tooth-tipped teeth of both gears.

This invention does not require additional processes such as crowing or relieving at the external teeth, and allows smooth and natural meshing throughout the entire root to the apex of the diaphragm while keeping the root thickness constant .

Another technique is disclosed in Korean Patent No. 10-0245288 entitled " Flexible gear device of two-armed unidirectional comb tooth type ".

원호와, 상기 제 1의

원호와 원활하게 접속함과 동시에 이 제 1의

원호 보다도 곡률반경이 큰 제 2의

원호로 형성되고, 이뿌리를 제외한 치원 부분이 기준점에 관한 치끝단부 치형의 점대칭의 곡선 또는 그의 수정곡선에 의하여 형성되어 있는 치형으로 이루어지는 기준랙에 의하여 형성되며, 1)상기 외치의 치근방향에 있어서의 각 위치에서 축 직각단면에서의 상기 내치에 대한 상기 외치의 랙 근사에 의한 운동궤적을 구하고, 2)상기 운동궤적을 하나의 축 직각평면상에 중첩함으로써 상기 운동궤적의 포락선을 구하고, 3)상기 포락선에 다이아프램 측의 치근단부 근방의 축 직각단면에 있어서의 가요성 외치의 이동궤적을 접속시켜 상기 포락선 및 이동궤적으로 구성된 복합곡선을 구하고, 4)상기 복합곡선에 선정한 맞물림의 한계점에서 축비 1/2로 상사변환해서 얻어지는 상사곡선의 근사곡선을 상기 제 1 및 제 2

원호에 의해 규정된 곡선으로 적용하는 것이 특징이다.In the above-mentioned Patent No. 10-0245288, the teeth of the internal teeth and the teeth of the external teeth are formed such that the tooth tip end portion has a straight line in the vicinity of the pitch point,

An arc, and the first

It is possible to smoothly connect with the circular arc,

A second radius of curvature greater than the arc

Wherein the tooth part is formed by a circular arc and the tooth part except the tooth root is formed by a reference rack formed by a curve of a point symmetry of a tooth tip end tooth relative to a reference point or a tooth formed by a quadrature curve thereof, 2) obtaining an envelope of the motion locus by superimposing the locus of motion on one axial right angle plane, and 3) obtaining an envelope of the motion locus by superimposing the motion locus on one axial right angle plane, ) Connecting a movement locus of a flexible external tooth on a cross section perpendicular to the axis of the diaphragm near the apex of the diaphragm to the envelope to obtain a composite curve composed of the envelope and the movement locus, and 4) An approximate curve of a superior curve obtained by transforming the profile into an axial ratio of 1/2,

It is characterized by applying to a curve defined by an arc.

This invention does not require any additional process such as crowning or relieving, and it is possible to smoothly engage the root throughout the root to the apical portion of the diaphragm while maintaining the thickness of the teeth constant, and to provide a high strength, It is possible to provide a high-precision, small-capacity gear device.

However, all of the above-described inventions are intended to achieve the desired purpose by changing the shape and structure of the external teeth and the internal teeth constituting the flexplane and the circular spline in consideration of the amount of deflection or the amount of deflection of the flexplane.

However, in the modified wave gear device, the coupling state of the flexure 20 and the circular spline 30 is affected by the tooth profile, but basically, the shape and structure of the cam plate 12 cause the greatest influence The inventions listed above overlook this point.

That is, the strength and range of the wave force transmitted through the wave bearings are changed along the cam curve of the cam plate 12 which provides the wave force to the flex plate 20, and thus the flex plate 20 and the circular spline The internal teeth 21 and 31 constituting the external teeth 30 and the internal teeth 21 and 31 are different from each other.

As a conventional technology related to the cam plate, there is a "bending gear type gear device" of the Korean Patent Registration No. 10-1312577.

[0004] In summary, the Korean Registered Patent No. 10-1312577 discloses an internal gear having a rigid internal gear (flexure spline), an external gear (flexible fly) having flexibility capable of meshing with the internal gear, (Cam plate) for realizing internal-engagement of the internal gear and the external gear by bending deformation of the external gear,

Wherein the shape of the outer periphery of the vibrator is a first curved portion in an arcuate shape with the internal gear and the external gear engaged with each other and a second curved portion having a curvature radius smaller than that of the first curved portion, And a third curved portion having a radius of curvature larger than that of the first curved portion and making the internal gear and the external gear in non-engaged state,

Wherein a tangent of the first curved portion and the second curved portion is common in a connecting portion of the first curved portion, the second curved portion and the third curved portion, and the tangents of the second curved portion and the third curved portion are common In addition,

The second curve portion having a radius of curvature smaller than that of the first curved portion can avoid the interference of the tooth profile between the internal gear and the external gear.

Further, a vibrator bearing (wave bearing) having a plurality of rolling elements is disposed between the vibrator and the external gear.

Another feature is that when the difference in dimension between the internal gear and the external gear is i (i = 2, 4, ...), the difference in dimension between the internal gear and the internal gear is j, Assuming a virtual shout gear having a stiffness for engaging,

And the tooth profile of the external gear that is flexibly deformed by the first curved portion is set to be the same as the tooth profile of the virtual external gear.

That is, the Korean Patent No. 1312577 is characterized in that, in a vibrator having a combination of a first curved line and a third curved line, the radius of curvature is between the first curved line and the third curved line A small second curved portion is formed so that the internal gear in the outside of the instrument body and the external gear in the external gear are rapidly separated from each other so that the tooth-shaped interference is excluded.

However, in such a device, a first curved portion and a third curved portion, which are arc curves, are formed at the periphery of the cam plate, and a second curved portion having the smallest radius of curvature is formed between the first curved portion and the third curved portion, So that vibration and noise are generated due to rapid separation of the internal teeth and the shouting gears engaged in the coupling section of the long axis and the second curved section having the smallest radius of curvature as a result, Resulting in an increase in bending stress and a difficulty in transmitting a large torque.

As described above, the conventional deformation wave gear device increases the contact area between the teeth by changing the shape and / or the configuration of the external teeth and the internal teeth of the flexplane and the circumferential spline in consideration of the Corning angle or the deviation amount of the flexplane To increase the torque, to prevent the phenomenon of ratcheting, and the like.

However, these devices have disregarded the structure of the cam plate which is the fundamental wave.

Korean Patent Registration No. 10-0245288 on the cam plate is used to form a second curved portion having the smallest radius of curvature between the first curved portion and the third curved portion as the arc curves, So that the inner teeth and the outer teeth that are out of the engagement section are separated rapidly, and thus, it is difficult to apply them realistically due to vibration and noise.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and an object of the present invention is to provide a cam plate having a first curved portion corresponding to a long axis of the cam plate and a third curved portion corresponding to a short axis, The second curve portion is integrally formed and the flexure and the circular spline are naturally engaged and spaced apart from each other. As a result, the second curve portion can consequently obtain the effect of expanding the engagement portion, and the transmission of the large torque can be stably performed And to provide a deformed wave gear device having such a deformed wave gear device.

In addition, through the extended engagement section, prevention of backlash and ratcheting phenomenon due to clearance between teeth is prevented, and excessive wear of the teeth is prevented.

In order to accomplish the above object, the present invention provides a wave generator comprising: a wave generator for receiving a rotational force from a drive motor to provide a wave in the device; A flexplane elastically deforming into an elliptical shape by the wave generator and mating with an inner tooth of the circular spline while the outer teeth on the opening side are elastically deformed; A circular spline which receives the flexplane and has an internal teeth on an inner surface thereof; Lt; / RTI >

Wherein the wave generator includes a cam plate formed by a combination of a first curved portion having a circular arc curve and a third curved portion having a larger radius of curvature than the first curved portion at each of the long and short axes at positions orthogonal to each other as an elliptical eccentric body, Wherein the inner and outer rings surrounding the ball each include a wave bearing in contact with the cam plate and the flex fly,

A second curved portion having a curvature radius larger than the first curved portion and smaller than the third curved portion may be integrally formed between the first curved portion corresponding to the long axis of the cam plate and the third curved portion corresponding to the short axis.

The first curved portion is located on the long axis of the cam plate and corresponds to the engagement section, is a circular curve having a predetermined curvature radius, and its center point is located on the long axis.

The third curved portion is a circular arc curve having a radius of curvature larger than that of the first curved portion and located on the short axis of the cam plate.

The second curved portion is a circular curve having a curvature radius larger than the first curved portion and smaller than the third curved portion, and the center point thereof is located at a position deviated from the short axis.

The first, second and third curved portions are connected to each other to form a single cam curve, and are symmetrical about a long axis and a short axis.

Therefore, in one cam plate, there are two first and third curved portions and four second curved portions, respectively, at positions symmetrical with each other across the long axis.

Since the second curved portion having a medium radius of curvature is formed between the first curved portion having a small radius of curvature and the third curved portion having the largest radius of curvature, the present invention having the above- .

Therefore, the second curved portion corresponds to the extension of the first curved portion, which is the coupling section, and the coupling section is substantially extended.

According to the present invention, a second curved portion having an intermediate radius of curvature between the first curved portion and the third curved portion is formed between the first curved portion belonging to the coupling section and the third curved portion belonging to the non-embedded section, 2 curved portion is projected outwardly, and as a result, the protruding amount results in an enlarging effect of the engagement section, so that a large torque can be stably transmitted.

In addition, since the second curved portion has a radius of curvature that is not larger than or smaller than the first or third curved portion, the coupling and separating operations of the flexure and the circular spline are naturally performed to prevent vibration and noise, The gap between the teeth engaged with each other in proportion to the expanded amount of the engagement section is prevented, thereby preventing the backlash and the excessive wear of the teeth and the ratcheting phenomenon.

1 is a front view of a general modified wave gear device;
2 is a cross-sectional view showing a side view of a general modified wave gear device
3 (a), 3 (b), 3 (c) and 3 (d) are schematic front views showing the operation of the teeth in a general modified wave gear device
Fig. 4 is a side sectional view for explaining a deformation of a flex plane according to Corning in a conventional modified wave gear apparatus; Fig.
5 and 6 are an enlarged cross-sectional view of a recessed portion showing a coupling state of teeth according to a Corning angle in a conventional modified wave gear device
7 is a schematic view for explaining the cam curve of the cam plate according to the present invention;
8 is a front view of a modified wave gear device to which a cam plate of the present invention is applied

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

7 is a schematic view for explaining the cam curve of the cam plate according to the present invention.

As shown in the drawing, the present invention includes: a wave generator that receives a rotational force from a drive motor and provides a wave in the device; A flexplane elastically deforming into an elliptical shape by the wave generator and mating with an inner tooth of the circular spline while the outer teeth on the opening side are elastically deformed; A circular spline which receives the flexplane and has an internal teeth on an inner surface thereof; Lt; / RTI >

The wave generator includes an elliptic eccentric body having a first curved portion S1 which is a circular curved line and a curved radius r3 which is larger than the first curved portion S1 respectively on long and short axes L and S at mutually orthogonal positions, And a third curved portion S3 having a third curved portion S3 having a radius of curvature and a third curved portion S3 having a radius of curvature In the gear device,

A first curved portion S1 corresponding to the long axis L of the cam plate 12 and a third curved portion S3 corresponding to the minor axis S are formed between the first curved portion S1 and the third curved portion S1, The second curved portion S2 having a radius of curvature r2 smaller than that of the portion S3 may be integrally formed.

The first curved portion S1 is a circular arc curve having a predetermined curvature radius r1 corresponding to the coupling section located on the long axis L of the cam plate 12 and the center point S1-1 of the curved portion S1 has a long axis L).

The third curved portion S3 is a circular arc curve having a radius of curvature r3 that is larger than the first curved portion S1 and corresponds to a non-overlapping portion located on the minor axis S of the cam plate 12, The center point S3-1 is positioned on the short axis S.

The second curve S2 is a circular curve having a radius of curvature r2 that is larger than the first curve S1 and smaller than the third curve S3 and whose center point S2-1 is a long or short axis L, S).

The first, second, and third curved portions S1, S2, and S3 are formed on a single cam plate 12, and are symmetrical with each other with the center point 12-1 of the cam plate 12 therebetween. .

The first, second, and third curved portions S1, S2, and S3 are connected to each other to form a single cam curve. Up, down, left, and right are symmetrical with respect to the long axis L and the short axis S.

The distance from the center point 12-1 of the cam plate 12 to the center points S1-1, S2-1, S3-1 of the first, second and third curved portions S1, S2, And the four center points S1-1 and S3-1 of the first and third curved portions S1 and S3 except for the second curved portion S2 form a rectangle.

The present invention having the above-described structure is characterized in that the first curved portion S1 having the small radius of curvature r1 and the third curved portion S3 having the largest radius of curvature r3 have the curvature radius r2 of medium size between the first curved portion S1 and the third curved portion S3, 2 curved line S2 is formed, the cam curve of the portion is protruded outward compared with the conventional one (see the dotted line portion in Fig. 7).

Therefore, according to the present invention, as shown in FIG. 8, the coupling section is extended by the second curved section S2 formed between the first and third curved sections S1 and S3, and the coupling section is substantially extended .

In FIG. 7, the dotted line indicates the conventional cam curve, and the solid line indicates the cam curve according to the present invention. It can be seen that the second curve S2 protrudes outwardly from the conventional one.

As a result, the protruded portion is added to the first curved portion S1, which is a conventional coupling portion at the long axis L, to widen the coupling portion.

8 shows a front view of a deformed wave gear device to which the cam plate 12 of the present invention is mounted.

As shown in the drawing, the present invention is characterized in that, between the first and third curved portions S1 and S3 constituting the cam curve of the cam plate 12, a second curved portion S2 (which is larger than the first curved portion and smaller than the third curved portion) ) Can be integrally formed to extend the coupling section in which the external teeth of the flexplane 20 and the circular spline 30 and the internal teeth 21 and 31 are connected to each other so that the teeth of the double teeth are engaged in a wider range (See dotted line)

Therefore, the wave gear device of the present invention can stably transmit a larger torque, and vibration and noise can be prevented, thereby contributing to quality improvement.

In addition, there is no clearance between the gears to prevent ratcheting phenomenon due to excessive wear and separation, height of teeth can be increased by improvement of tooth engagement, smooth connection between teeth is contributed, and durability is improved.

In addition, since the arcuate cam curve of the present invention is a cycloid tooth profile, the tooth gear interference between the teeth is eliminated at the time of connecting the teeth, so that a wave gear device having durability, low noise and low vibration as well as high torque can be realized.

10: Wave generator 11: Cam shaft
12: cam plate 12-1: center point
13: wave bearing 20: flex fly
21: shout 22: body
23: diaphragm 24: boss portion
30: Circular spline 31: Inner tooth
L: Long axis S: Short axis
S1: first curve S1-1: center point
S2: second curve S2-1: center point
S3: third curved portion S3-1: center point
r1, r2, r3: radius of curvature

Claims (1)

A wave generator for receiving a rotational force from the driving motor and providing a wave in the device; A flexplane elastically deforming into an elliptical shape by the wave generator and mating with an inner tooth of the circular spline while the outer teeth on the opening side are elastically deformed; A circular spline which receives the flexplane and has an internal teeth on an inner surface thereof; Lt; / RTI >
The wave generator includes an elliptic eccentric body having a first curved portion S1 which is a circular curved line and a curved radius r3 which is larger than the first curved portion S1 respectively on long and short axes L and S at mutually orthogonal positions, And a third curved portion S3 having a third curved portion S3 having a radius of curvature and a third curved portion S3 having a radius of curvature In the gear device,
A first curved portion S1 corresponding to the long axis L of the cam plate 12 and a third curved portion S3 corresponding to the short axis S are formed between the first curved portion S1 and the third curved portion S1, And a second curved portion (S2) having a radius of curvature (r2) smaller than that of the portion (S3) are integrally formed.

Images