JP2008133861A - Rocking gear device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rocking gear device having high transmission efficiency, by making both compatible in securing a degree of freedom of processing accuracy and securing a degree of freedom of positioning accuracy, without impairing an original characteristic such as small type high output. <P>SOLUTION: In this rocking gear device having four bevel gears, first and fourth gears are constituted as a projecting tooth being an equal height tooth out of a cross-sectional semicircular recessed groove extending in the radial direction from the gear center at an equal interval on a pitch cone and a columnar roller rollingly arranged in the recessed groove. Second and third gears respectively meshing with the first and fourth gears are a recessed tooth formed as a generated tooth shape or an approximately generated tooth shape of generating and transferring a tooth shape of the projecting tooth. The projecting tooth is formed longer in the tooth trace length than the tooth trace length of a recessed tooth, and the recessed groove of constituting the projecting tooth is formed in the same circular arc cross section of a uniform cross section so as to non-tiltably support a roller in close contact in the whole tooth trace direction area. The roller is respectively positioned and held by an annular retainer on both ends in the tooth trace direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

In the present invention, a first gear with n ₁ teeth fixed to the housing and a fourth gear with n ₄ teeth attached to the output shaft are arranged with their axis centers aligned with the input shaft, A rotating body integrally provided with a second gear having n ₂ teeth and a third gear having n ₃ teeth is arranged on the input shaft so that the second gear meshes with the first gear and the third gear meshes with the fourth gear. The center point of the common sphere passing through the pitch circles of the first and second gears coincides with the center point of the common sphere passing through the pitch circles of the third and fourth gears. The axis of the input shaft is arranged on the X axis of the XY coordinates with the point as the origin, and the meshing points of the first and second gears and the meshing points of the fourth and third gears are the same in the XY coordinates. The present invention relates to an oscillating gear device placed in a quadrant or a different quadrant.

  Conventionally, the principle of a reduction gear device using a so-called oscillating gear device for oscillating motion has been known. This oscillating gear device can obtain a large reduction ratio with only four gears, and has various advantages. However, the oscillating gear device needs to have a spherical involute tooth profile that is difficult to produce with high accuracy and low cost, and has not been put into practical use. Instead of this spherical involute tooth profile, the present inventor changed the tooth profile of one gear to a so-called contour tooth having the same tooth width and tooth width in the direction of the teeth, and created and transferred the tooth profile of the contour tooth to the other tooth profile. Furthermore, the swing-type gear device can be put to practical use by using the contoured teeth and roller-shaped rollers as convex teeth. The details of the oscillating gear device are disclosed in Japanese Patent Publication No. 7-56324 (Patent Document 1).

FIG. 13 shows a cross section of the main part of the oscillating gear device by the present inventor. In the oscillating gear device, the input shaft 1 and the output shaft 2 are connected by _first to fourth gears A _{1 to} A ₄ , and the speed is reduced by these gears. The first to fourth gears A _{1 to} A ₄ are bevel gears. The first gear A ₁ is integrally fixed to the housing 6. The second gear A ₂ and the third gear A ₃ are provided on one rotating body 3, and the rotating body 3 is rotatably supported by the inclined portion 1 a of the input shaft 1. When the rotating body 3 is supported in an inclined manner as described above, a swinging motion can be generated in the rotating body 3 as the input shaft 1 rotates. A roller is interposed in the meshing portion of each gear, and meshing friction is absorbed by the rolling of the roller.

As shown in FIG. 14, the roller 4a is supported by a concave groove 4b formed in the first gear A ₁ (fourth gear A ₄ ) so as to be able to roll. And the semicylindrical convex tooth | gear 4 is formed with the roller 4a which protrudes from the ditch | groove 4b. Further, the second gear A ₂ (third gear A ₃ ) is also formed with a semicircular arc-shaped groove and formed as a concave tooth 5. When the rotating body 3 swings in the direction indicated by the arrow B, the second gear A ₂ (third gear A ₃ ) moves in the direction indicated by the arrow C, and the concave teeth 5 and the convex teeth 4 are moved. And bite. At this time, the sliding generated between the concave teeth and the convex teeth is absorbed by the rolling of the rollers 4a. Therefore, even if the backlash setting is eliminated and the preload is intentionally applied to the teeth, it is possible to avoid heat generation due to the meshing of the teeth.
Japanese Examined Patent Publication No. 7-56324

  In the above-mentioned oscillating gear device, the convex teeth are composed of concave grooves and rollers, that is, by interposing the rollers in the meshing portion, the frictional resistance of the meshing portion is reduced in principle. It becomes possible to increase the transmission efficiency. However, securing the meshing accuracy becomes a major issue due to the increase in the components of the meshing portion. If it is meshing of integral convex teeth and concave teeth, it is sufficient to ensure the accuracy of each of the two parts and the positioning accuracy between the two, but by increasing the roller as the meshing component, the individual precision of the three parts is increased. In addition, ensuring the positioning accuracy among the three parties becomes extremely complicated.

In other words, in the oscillating gear device, the meshing of the first gear A ₁ and the second gear A ₂ is performed while the second gear A ₂ performs a face-to-face movement with respect to the first gear, so that the meshing begins. During meshing and disengagement, the buses of the gears intersect each other, and meshing interference portions are generated. Therefore, both convex teeth and concave teeth cannot be made simple, and if one is made to be any simple shape, the other is a complicated shape with the interference part removed so as to properly mesh with it. It is necessary to.

  Therefore, it is possible to obtain an appropriate tooth profile by creating and transferring the other tooth profile to one tooth profile, but it is necessary to use a complex creation processing machine, and there is a problem in processing. If the tooth trace length is short, it is possible to make an approximate tooth profile that approximates the tooth generated by simple straight line combination processing. However, if the tooth trace length is long, the tooth traces are constant even if the angle between the busbars is constant. Since the amount of displacement at the end in the direction increases and the width of the interference removal portion increases, the machining process becomes extremely complicated with a simple straight line combination.

  Even if an appropriate tooth profile can be machined by creation, the tooth profile is complicated, so it is necessary to position both of them in the radial direction, that is, in the tooth trace direction as well as the rotational direction. It is a big issue in sex. That is, the fact that the rollers as the convex teeth increase as the number of parts requires extremely accurate positioning accuracy between the rollers and the concave teeth, and between the rollers and the concave grooves.

  Furthermore, even if the machining accuracy and positioning accuracy during assembly are improved, it is necessary to always maintain the position accuracy between the three during operation under load. As a result, a considerably high load is applied, and in order to maintain an appropriate position, a high support rigidity in the groove is required. In order to secure the support rigidity of the roller, the support length in the longitudinal direction of the roller, that is, the direction of the tooth trace, is required, but simply increasing the length will not only reduce the transmission efficiency but also increase the size of the gear device. Invite new challenges remain.

In particular, when the second gear A ₂ side has convex teeth and is configured to support the roller, it is necessary to increase the length of the roller and the concave groove that supports the roller in order to secure the support length. The thickness of the rotating body forming the second gear A ₂ is increased, the mass as the rotating body is increased, and the balancer structure associated with the eccentric rotational motion (oscillating motion) is complicated. The feature of the small and high output characteristic of the gear device is impaired.

  The present invention has been made in view of the above points, and it is possible to achieve both a high degree of freedom in machining accuracy and a high degree of freedom in positioning accuracy without impairing the original characteristic of a small and high output as a oscillating gear device. An object of the present invention is to provide an oscillating gear device that can transmit and has high transmission efficiency.

Means according to claim 1 of the present invention to solve the above problems, a first gear tooth number n ₁ which is fixed to the housing, and a fourth gear teeth number n ₄ attached to the output shaft, A rotating body in which each shaft core with the input shaft is arranged to be coincident and a second gear having n ₂ teeth and a third gear having n ₃ teeth are integrally provided, and the second gear meshes with the first gear; The third gear is pivotally supported by the inclined portion of the input shaft so as to mesh with the fourth gear, the center point of the common spherical surface passing through the reference pitch circle of the first and second gears, and the third and fourth gears. The axis of the input shaft is arranged on the X axis of the XY coordinates with the origin coincident with the central point of the common spherical surface passing through each pitch circle, and the meshing points of the first and second gears and the fourth An oscillating gear device in which the meshing point of the third gear is placed in the same or different quadrant of the XY coordinates,
The first to fourth gears are configured as bevel gears,
The first gear and the fourth gear of the first to fourth gears meshing with each other and facing each other have a semicircular groove having a semicircular cross section extending radially from the gear center at equal intervals on the pitch cone, and the groove The second and third gears, which are configured as convex teeth as contour teeth with a cylindrical roller that is arranged so as to freely roll inside, are meshed with the first gear and the fourth gear, respectively. It is configured as a concave tooth formed as a created tooth profile or an approximate created tooth profile created by transferring the tooth profile of
The convex teeth are set such that the tooth length is longer than the tooth length of the concave teeth,
The concave grooves constituting the convex teeth are formed in the same circular arc cross section with a uniform cross section in the whole area in the streak direction so as to closely support the roller in a non-tiltable manner in the whole area in the tooth streak direction,
Further, the roller is positioned and held on the first and fourth gears by annular retainers at both ends in the tooth trace direction.

  As described above, the first gear, which is composed of a cylindrical roller having a uniform cross-section in the tooth trace direction and a concave groove and has a sufficient length, has a relatively high degree of freedom in arrangement, and fourth By arranging and fixing on the gear side, the tooth shape of the second and third gears as the other counter gear, that is, the length of the concave tooth in the streak direction can be shortened. The interference width with the roller is reduced, the degree of freedom in processing is increased, and the required meshing accuracy can be ensured even if the dimensional accuracy of the tooth profile is somewhat low. Moreover, even if there is a slight deviation in the assembly accuracy in the tooth trace direction, one tooth profile as the meshing gear is a cylindrical roller having a uniform cross section in the tooth trace direction, and that roller has a uniform cross section in the tooth trace direction. In addition, the entire region is supported by a groove having a sufficient tooth trace length, the support rigidity is enhanced, and the roller and the groove are substantially integrated. The positioning accuracy is determined by the positioning accuracy between the integrated convex teeth and concave teeth, and the degree of freedom is expanded. Therefore, it is possible to ensure the degree of freedom of machining accuracy and positioning accuracy, so that it is possible to simultaneously improve productivity and transmission efficiency as the swinging gear device.

  According to a second aspect of the present invention, in the first aspect of the present invention, the concave teeth are formed in a drum shape in which the openings expand outward in the tooth trace direction and inward in the tooth trace direction across the reference pitch circle diameter. It is characterized by that. According to this configuration, the interference width in the circumferential direction at the opening of the concave tooth can be minimized, leading to an increase in freedom of processing accuracy and freedom of selection of a processing form, improving meshing accuracy and reducing production cost. Greatly contributes to reduction. Moreover, the reduction in the radial interference width means that the contact angle with the convex teeth at the meshing start (meshing end) position is reduced, the axial component force is reduced, and the transmission efficiency is improved. .

  According to a third aspect of the present invention, in the first aspect, the reference pitch circle diameter is set in a range of 30% of the length of the streak in and out of the center of the streak direction. . If the reference pitch circle diameter is shifted inward or outward by 30% or more, the interference removal width increases on one side, which leads to deterioration in transmission efficiency, which is not preferable.

  According to a fourth aspect of the present invention, in the first aspect, the reference pitch circle diameter is set outward from the center of the tooth trace direction so that the width of the interference removal portion of the concave tooth is substantially equal at both ends of the tooth trace direction. It is characterized by. According to this configuration, it is possible to minimize the interference removal width, not only improve transmission efficiency, but also allow processing with a conventional linear processing machine without using a special creation processing machine. The property is greatly improved.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the concave groove constituting the convex teeth is a single arc corresponding to the outer peripheral surface of the roller so that the outer peripheral surface of the roller contacts the entire surface. It is formed by. According to this configuration, coupled with the long support length, the support rigidity of the roller is further improved.

  According to a sixth aspect of the present invention, in the first to fourth aspects, the concave groove constituting the convex tooth has a contact point in the vicinity of the opening and forms a predetermined space with the roller at the bottom of the groove. Are formed by a plurality of arcs. According to this configuration, since the roller is supported at two specific contact points, the support rigidity can be stably enhanced. Furthermore, even if the roller is worn, there is no change in the contact angle between the roller and the groove, and no rattling occurs in the groove, so that stable support rigidity can be obtained in the entire region of the tooth trace direction.

  According to a seventh aspect of the present invention, in the first to fourth aspects, a single arc corresponding to the outer peripheral surface of the roller so that the concave groove constituting the convex tooth contacts the outer peripheral surface of the roller over the entire surface thereof. The concave teeth are formed in multiple arcs so as to form a predetermined space between the contact point in the vicinity of the opening and the roller at the groove bottom. According to this configuration, it is possible to simultaneously secure the roller support rigidity and improve the transmission efficiency.

  According to an eighth aspect of the present invention, in the first to fourth aspects, the concave groove and the concave teeth both have a contact point in the vicinity of the opening, and a multiple arc is formed between the bottom of the groove and a roller. It is formed by. According to this configuration, it is possible to achieve stable support rigidity and improve transmission efficiency at the same time.

  According to a ninth aspect of the present invention, in the first to eighth aspects, at least the inner side of the retainer is in contact with the end surface of the roller on the outer peripheral surface thereof, and the roller is elastically held in the tooth trace direction. It is characterized by. According to this configuration, the roller at the meshing portion of each gear is subjected to a frictional force in the direction of the teeth, but the inner end in the axial direction of the roller is elastically held by the retainer. Displacement in the tooth trace direction is possible, and the frictional force between the end surface of the roller and the outer peripheral surface of the retainer is greatly reduced. In this case, if the mesh is released, the roller is returned to the initial position by the elasticity of the retainer.

  The present invention can achieve both a high degree of freedom in machining accuracy and a high degree of freedom in positioning accuracy without compromising the original characteristics of a small and high output as an oscillating gear device, with high meshing accuracy and high transmission efficiency. A high oscillating gear device can be provided.

Embodiments of the present invention will be described below with reference to FIGS. The same or corresponding parts as those in the conventional example are given the same reference numerals, and detailed description thereof is omitted. The oscillating gear device according to the present invention inputs a first gear A ₁ having n ₁ teeth fixed to the housing 6 and a fourth gear A ₄ having n ₄ teeth attached to the output shaft 2. match the respective axis of the shaft 1 is arranged, the rotor 3 having a second gear a ₂ and the third gear a ₃ teeth number n ₃ of the teeth n ₂ together, the second gear a ₂ Is engaged with the first gear A _1, and the third gear A ₃ is supported by the inclined portion 1 a of the input shaft 1 so as to be engaged with the fourth gear A _4, and passes through the pitch circles of the first and second gears. The axis G of the input shaft is arranged on the X axis of the XY coordinates with the origin being a point O where the center point of the common sphere coincides with the center point of the common sphere passing through the pitch circles of the third and fourth gears. and, and, construction by placing the first, second gear a ₂ meshing point and the fourth, identical quadrants or different quadrant on the engagement point of the third gear a ₃ the XY coordinates It is.

More specifically, the oscillating gear device has first to fourth gears A _{1 to} A ₄ as four gears having different numbers of teeth. Each gear is a bevel gear. Among these, the first gear A ₁ is a fixed gear that is integrally fixed to the housing 6 and does not rotate. The second gear A ₂ and the third gear A ₃ are formed on the rotating body 3 supported by the input shaft 1. The fourth gear A ₄ is provided on the output shaft 2 and is rotatably supported by the housing 6. The first gear A ₁ and the second gear A ₂ , and the third gear A ₃ and the fourth gear A ₄ are engaged with each other.

The rotating body 3 is supported by an inclined portion 1 a having an axis H that forms a predetermined angle with respect to the axis G of the input shaft 1. The input shaft 1 itself is also rotatably supported by the housing 6. When the input shaft 1 rotates, the inclined portion 1a performs a motion such as swinging the head, and the rotating body 3 pivotally supported by the inclined portion 1a performs a swinging motion. As the rotating body 3 swings, the second gear A ₂ is engaged with the first gear A ₁ and the third gear A ₃ is engaged with the fourth gear A ₄ . Then, the second gear A ₂ is rotated per oscillating motion of one cycle (one revolution of the input shaft 1), with respect to an amount corresponding first gear A ₁ which corresponds to the difference in the number of teeth between the first gear A ₁ . That is, one-stage deceleration is performed between the first gear A ₁ and the second gear A ₂ .

Here, consider the case where the number of teeth of the first gear A ₁ is 100 and the number of teeth of the second gear A ₂ is 101. When the input shaft 1 rotates forward once, the second gear A ₂ rotates forward by 1/100 with respect to the first gear A ₁ . Movement of the second gear A ₂ is transmitted directly to the third gear A _3, also between the third gear A ₃ and the fourth gear A _4, performs the same engagement. Therefore, one-stage deceleration is performed between the third gear A ₃ and the fourth gear A ₄ . That is, when the rotational movement of the input shaft 1 is transmitted to the output shaft 2, the first and second gears A ₁ and A ₂ and the third and fourth gears A ₃ and A ₄ are decelerated in two stages. The action will be performed.

R = 1− (n ₄ × n ₂ ) / (n ₃ × n ₁ ) where R (the number of rotations of the output shaft 2 when the input shaft 1 makes one rotation) is R ...... (i)
Here, n ₁ : number of teeth of the first gear A ₁ , n ₂ : number of teeth of the second gear A ₂ , n ₃ : number of teeth of the third gear A ₃ , n ₄ : number of teeth of the fourth gear A ₄ Assuming that n ₁ = 1000, n ₂ = 1001, n ₃ = 1000, and n ₄ = 999, the reduction ratio R = 1 / 1,000,000 (forward rotation). Thus, the oscillating gear device can obtain a large reduction ratio with only four gears.

As described above, when the difference between the number of teeth of the first gear A ₁ and the number of teeth of the second gear A ₂ is 1, the first gear A ₁ and the second gear A are moved when the oscillating motion advances by one cycle. _The teeth that mesh with each other are shifted by one. Further, when the difference in the number of teeth is 2, when the oscillating motion advances by one cycle, the meshing teeth are shifted by two between the first gear A ₁ and the second gear A ₂ . Similarly, when the difference in the number of teeth is n, the meshing teeth are shifted by n. This also applies to the relationship between the _third and fourth gears A ₃ and A ₄ .

Next, a method for obtaining the tooth profile of the oscillating gear device will be described below. Here, FIG. 4 is a development view showing a method for obtaining the tooth profile of each bevel gear of the swinging gear device shown in FIG. 1, and FIG. Each gear A ₁ , A ₂ , A ₃ , A ₄ is schematically shown as a pitch cone.

Here, a common spherical surface Cir1 that passes through each pitch circle (reference pitch circle diameter position) of the first gear A ₁ and the second gear A ₂ and a common that passes through each pitch circle of the third gear A ₃ and the fourth gear A ₄ are used. Consider spherical Cir2. Then, the center points of the respective common spherical surfaces are made to coincide with each other, and the coincidence point is set as a point O. Further, XY coordinates with the point O as the origin are considered. The axis G of the input shaft 1 is arranged on the X axis of the XY coordinates. The meshing point of the first and second gears A ₁ and A ₂ is C ₁ , and the meshing point of the third and fourth gears A ₃ and A ₄ is C ₂ . Then, the meshing points C ₁ and C ₂ are placed in the first quadrant and the third quadrant or the second quadrant and the fourth quadrant.

The angle formed between the axis G of the input shaft 1 and the axis H of the inclined portion 1a is θ, the angle formed between the spine cone of the first gear A ₁ and the center line of the pitch cone is θ ₁ , and the second gear A. _{When the} angle formed by the back cone of ₂ and the center line of the pitch cone is θ ₂ , θ ₁ + θ ₂ = θ. It is also possible to make either one of the angles θ ₁ and θ ₂ zero, and in this case, the gear having the zero angle becomes the crown gear. Similarly, the third angle formed by the fourth gear A _3, the center line of the back cone and the pitch cone of A _4, the third gear A ₃ are theta _3, the fourth gear A ₄ is theta ₄ cutlet theta ₃ + θ ₄ = θ.

Also, the number of teeth of the first to fourth gears is n ₁ , n ₂ , n ₃ , n ₄ , respectively, and the values of n ₁ , n ₂ , n ₃ , n ₄ are different from each other. Here, the vertex _{O 1, O 2, O 3} , O 4 of the pitch cone of the first to fourth gear A ₁ to A _4, vertex D ₁ of the respective back-conical, D _2, D _3, to D ₄ Let us consider cylindrical gears ER ₁ , ER ₂ , ER ₃ , and ER ₄ having a pitch circle radius of distances D ₁ O ₁ , D ₂ O ₂ , D ₃ O ₃ , and D ₄ O ₄ . An involute tooth profile or an arbitrary tooth profile formed on the pitch circle is assumed, and this is used as a corresponding cylindrical gear of the _first to fourth gears A _{1 to} A ₄ . Here, if the equivalent number of teeth of the equivalent cylindrical gear is Z ₁ , Z ₂ , Z ₃ , Z ₄ ,
Z ₁ = n ₁ / Sinθ ₁ (ii)
Z ₂ = n ₂ / Sinθ ₂ (iii)
Z ₃ = n ₃ / Sinθ ₃ (iv)
Z ₄ = n ₄ / Sinθ ₄ (v)
It can be expressed as.

Therefore, the tooth profile according to the present invention is based on the relationship obtained by the above formulas (ii) and (iii). In the equivalent cylindrical gear, the first gear A ₁ is formed with a contour tooth profile, and the second gear to creating transferred tooth shaped to a _2. The third and fourth gears A ₃ and A ₄ are formed in the same manner. That is, the first to fourth gears A _{1 to} A ₄ are formed as two pairs of contour gears, and the oscillating gear device has a higher degree of freedom in machining accuracy than the conventional spherical involute tooth profile. Will be obtained. Further, the tooth profiles of the _first to fourth gears A _{1 to} A ₄ will be described more specifically.

Oscillating gear device according to the present invention shown in FIG. 1, between the first gear A ₁ as an example the second gear A _2, the number of teeth of the second gear A ₂ of the first gear A ₁ tooth set more one than the number, and the third gear a ₃ is set one more than the number of teeth of the fourth gear a ₄ between the third gear a ₃ and the fourth gear a _4, · first gear a The first gear reduction between the second gears A ₂ and the second gear reduction between the third gears A ₃ and A ₄ are set to perform two-stage decelerations. Accordingly, the second gear A ₂ and the third gear A ₃ are set to have a reference pitch circle diameter corresponding to one tooth larger than that of the first gear A ₁ and the fourth gear A ₄ . The reference pitch circle diameter of the first to fourth gears is set at the center of the tooth trace direction.

The first gear A ₁ and the fourth gear A ₄ set in this way have a semicircular cross section that extends radially from the center of the gear at a regular interval on the pitch cone and extends with a predetermined width parallel to the generatrix. The concave groove 4b and a cylindrical roller 4a having a predetermined diameter, which is rotatably disposed in the concave groove 4b, are configured as convex teeth 4 as contour teeth. The second and third gears are formed as a generating tooth profile or an approximate generating tooth profile obtained by generating and transferring the tooth profile of the convex tooth 4. In the present embodiment, the first and fourth gears and the second and third gears have the same tooth profile and basic structure except for the number of teeth. The first gear as the second gear and the second gear as the concave tooth will be described.

The convex teeth 4 are set so that the tooth length is longer than the tooth length of the concave teeth 5. Its length between the disengaged position meshing from meshing begins position due to the rocking motion of the second gear A _2, interference cancellation width of the second concave tooth opening of the gear A ₂ becomes maximum in the tooth trace direction end Thus, the effective meshing length is set long. Further, since the rollers 4a constituting the convex teeth 4 must be locked in the tooth trace direction end by a retainer 7, 8 as a fixing means to the first base member of the gear A _1, the length of the convex teeth 4 The length is set longer in consideration of the dimension of the locking portion of the roller 4a. That is, the length of the tooth 4a of the roller 4a constituting the convex tooth 4 is a dimension obtained by adding the difference of the effective tooth length and the length of the retainer to the tooth length of the concave tooth 5. Is set as Further, the outer diameter of the roller 4a is the same in the entire region of the tooth trace direction.

  By the way, in the case of the convex tooth 4 constituted by the roller 4a and the concave groove 4b, the diameter of the roller 4a greatly affects the meshing strength and noise. As the diameter increases, the meshing strength increases but the noise increases, and vice versa. Therefore, under the same reduction ratio, when the meshing strength is important, the minimum number of teeth can be set to increase the diameter of the roller 4a. When the reduction of noise is important, the number of teeth is increased. The diameter of the roller 4a may be reduced.

The rollers 4a configured as the convex teeth 4 have the same number of teeth as that of the first and fourth gears, and are positioned and held by the outer retainer 7 and the inner retainer 8 at both ends in the axial direction (tooth direction). Yes. Each retainer 7, 8 are formed in a ring shape, the axially inner end first, annular locking claws 7a that engages the locking groove 9 of the fourth gear A _4, 8a is formed respectively Yes. At the outer end in the axial direction, annular locking claws 7b and 8b for holding the shaft end portion of the roller 4a are formed, respectively. The retainers 7 and 8 are made of polyamide or polyimide resin, and can be deformed by the action of a predetermined external force. A frictional force acts on the roller 4a in the axial direction when the gears are engaged. The roller 4a is elastically allowed to be displaced with respect to this force.

  In this case, although the elastic characteristics of the inner retainer depend on the force acting on the roller 4a, it may be due to elastic deformation of a part of the outer peripheral surface of the inner retainer 8, or the entire retainer may be elastically deformed. In short, what is necessary is just to have the elastic deformation at the time of meshing and the restoring property at the time of non-meshing. Further, the retainer is provided with notches 10 at equal intervals in the circumferential direction, and this notch 10 can also be said to be an effective means for allowing elastic deformation of the inner retainer 8. When the roller 4a is assembled and held with respect to the gear, the notch 10 can be inserted with the tip portion retracted with respect to the inner peripheral surface of the gear. As shown in FIG. 2, the notched portion 10 is formed in an arc shape on the non-opened portion side, and it is possible to prevent stress concentration on a specific portion of the notched portion 10 due to the deformation of the retainer.

  Further, the swinging motion of the rotating body 3, that is, the swinging motion of the second and third gears as described above, is the intersection of the shaft core G of the input shaft and the shaft core H of the tilting portion 1a as the tilting portion 1a rotates. Oscillating motion is performed while moving on an arc centered on O (common spherical surface Cir1), and therefore, at the time of meshing, with respect to the roller 4a constituting the convex teeth 4, the direction of the tooth trace (the axis of the gear). The inner retainer 8 that abuts the inner end of the roller 4a in the axial direction is elastically deformed by this force, and the roller 4a moves in the direction of the tooth trace. The frictional force between the retainer 8 and the outer peripheral surface is greatly reduced, so that the rolling resistance of the roller 4a is greatly reduced. When the state shifts from this state to the non-engagement state, the frictional force acting on the roller 4a in the direction of the tooth streak disappears, so that the roller 4a returns to a predetermined position by the elastic restoring force of the retainer.

  The concave groove 4b that supports the roller 4a as the convex tooth 4 configured as described above is a so-called contoured tooth having a uniform cross-section in the whole tooth line direction on the pitch conical surface, that is, the same width and the same depth. The roller 4a is slidable in the direction of the tooth trace and is intimately supported so as not to tilt in the rotational direction.

As shown in FIG. 6, the cross-sectional shape is formed by multiple arcs as in the cross-sectional shape of the concave teeth 5. Specifically, two arcs having a radius r larger than 1 with respect to the radius of the roller 4a are formed by offsetting the center of the arc with respect to the center of the roller 4a. Therefore, two contact points P ₀ and P ₀ are formed near the openings of the concave groove 4b and the concave teeth 5, and a predetermined (for example, 15 degrees) contact angle smaller than 45 degrees with the roller 4a. α is obtained, and predetermined oil reservoirs 4d and 5b are formed in the vicinity of the groove bottom by gradually separating from the outer periphery of the roller 4a from the contact points P ₀ and P ₀ toward the groove bottom. The contact angle α is an angle at the maximum meshing position where the buses overlap each other in meshing of the convex teeth 4a and the concave teeth 5.

Therefore, the cylindrical roller 4a is reliably supported at the two contact points P ₀ and P ₀ of the concave groove 4b in the entire region of the tooth trace direction, the support rigidity of the roller 4a is increased, and the concave groove of the roller 4a is increased. The tilting in the rotational direction in 4b is reliably prevented, and as a result, the roller 4a and the concave groove 4b are firmly coupled to form a substantially integral convex tooth 4.

Further, the support by the contact points P ₀ and P ₀ in the concave groove 4b is important for increasing the degree of freedom of processing accuracy. In other words, when the contact with the roller 4a comes into contact with the entire surface, the contact with the roller 4a may come into contact with the part depending on the accuracy, but the positioning of the roller 4a may be inaccurate. The degree of freedom in positioning accuracy is high, and the support rigidity of the roller 4a can be ensured relatively stably.

Further, as described above, the cross section of the concave groove 4b and the concave tooth 5 is formed by multiple arcs, and the contact points P ₀ and P ₀ are set close to the opening, thereby reducing the contact angle α. In particular, the concave tooth 5 greatly contributes to improvement of transmission efficiency and durability of each part of the gear.

That is, when the engagement of the first gear A ₁ and the second gear A ₂ occurs, a load P is applied to the roller 4a at the contact point P ₀ of the concave tooth 5 of FIG. This load P includes a rotational transmission force T, which is a component force in a direction parallel to the pitch cone of the first and second gears A ₁ , A ₂ , and an axial force F, which is also a component force in a direction perpendicular to the pitch cone. The components can be considered separately. Conversely, if this axial force increases, the rotation transmission force decreases. In addition, the axial force acts as a bending force on the rotating body 3 on which the second gear A ₂ is formed, adversely affects the bearing that interferes with the rotating body 3, and impairs the durability of the gear device. Therefore, if the contact angle α is reduced, the axial force is reduced, and both transmission efficiency and durability can be improved.

  In the concave groove 4b constituting the convex teeth, this axial force is received by the housing 6 to which the first gear is fixed, and thus the above-described durability is not affected.

  By the way, if the contact angle is reduced in the concave teeth, the axial force is reduced as described above, and it is possible to reduce the bending force (torsional force) with respect to the rotating body 3 and the bearing to cooperate with. If it passes too much, the concave tooth 5 may be disadvantageous for the durability of the tooth of the concave groove 4b as well. That is, if the contact angle α is reduced, the acting direction of the load P acts in the tooth tip direction from the bottom of the adjacent concave grooves 4b and the concave teeth 5, and the land portions between the concave grooves 4b and between the concave teeth 5 are obtained. 4c and 5a may act as a bending load starting from the root of the tooth, and may cause problems such as damage to the land portions 4c and 5a due to the action of a high load.

  In particular, when the diameter of the roller is increased and the width of the land portions 4c and 5a is reduced, the inner diameter side of the land portions 4c and 5a is particularly thin, so that damage may occur in this portion.

  In this embodiment, as shown in FIG. 9, the contact angle α is set so that the load direction at the time of meshing is directed inward (gear base material side) from the roots of the adjacent concave grooves 4 b and concave teeth 5. In addition, the durability of the land portions 4c and 5a is satisfied at the same time without increasing the axial load unnecessarily. Note that the meshing position in the present embodiment is a reference pitch circle position.

  Further, as described above, oil reservoirs 4d and 5b are formed between the bottoms of the concave grooves 4b and the concave teeth 5 and the rollers 4a, and lubrication between the rollers 4a is performed appropriately. In addition, although the cross-sectional shape of the concave groove 4b is formed by multiple arcs, if it is formed by a single arc as shown in FIG. 8, the contact surface of the roller 4a becomes surface contact. Can be further increased, and the tilting of the roller 4a can be reliably prevented. In this case, the concave teeth 5 that repeatedly engage and disengage are formed in multiple arcs so as to reach two points as in FIG.

Further, the depth L ₁ of the concave groove 4b is preferably as deep as possible with respect to the radius of the roller 4a in order to increase the support rigidity of the roller 4a, but the end surface land portion 4c is the same as the end surface land portion 5a of the concave tooth 5. In order to avoid interference at the time of meshing between the two, it is necessary to form a predetermined gap, and it is not possible to increase the depth unnecessarily. In the embodiment shown in FIG. 6, it is set to be the same as the depth L ₂ of the concave tooth 5 and slightly shorter than the radius of the roller 4a.

With regard to the depth of the concave groove 4b, in another embodiment shown in FIG. 7, the depth L ₁ of the concave groove 4b of the convex tooth 4 and the depth L ₂ of the concave tooth 5 are relatively different from each other. The deep groove 4b is formed shallow. As described above, by deepening the concave teeth 5, it is possible to further reduce the contact angle α while ensuring the strength at the opening. On the other hand, the shallow groove 4b is disadvantageous for the support rigidity of the roller 4a. However, in this embodiment, the cross section is formed by a single arc so that the contact with the roller is around the entire surface. It is configured to compensate for the deterioration. In any of the embodiments shown in FIGS. 6 to 8, a minimum gap for preventing mutual interference is provided between the land portions 4c and 5a.

Next, the tooth profile of the concave tooth 5 formed on the second gear A ₂ will be described in detail. The concave teeth 5 are formed by generating and transferring the convex teeth 4 as the first gear A ₁ as schematically described above. As the generative transfer (processing) method, as disclosed in detail in the previous patent application (Japanese Patent Application Laid-Open No. 10-235519), the present inventor employs a so-called swinging mechanism in which the present invention targets a holding means for holding a workpiece. Interference removal that interferes with the convex teeth 4 by moving the cutter wheel paired with the workpiece in the direction of the tooth trace while moving the workpiece and the holding means in a swinging manner. The part is removed, and the creation transfer can be performed as an appropriate tooth profile.

  The shape of the concave tooth 5 created and transferred by such a method will be described in detail below. FIG. 10 shows that when the first gear and the second gear are engaged, the concave teeth of the second gear have the same depth and the same width as the convex teeth of the first gear. (Virtual shape for explaining the situation) When the second gear swings in the direction of the arrow, the relationship between the roller 4a as the convex contour tooth and the concave tooth 5 as the contour groove is two-dimensional. It is a schematic diagram shown in FIG. In this case, the number of teeth of the second gear is set to be larger than the number of teeth of the first gear, and the reference pitch circle diameter is set to be larger than the difference in the number of teeth and set to the center of the tooth line direction. The center of the first gear is centered on the axis G of the input / output shaft, the second gear has the center on the axis H of the inclined portion, and the center H rotates eccentrically around the center G.

Therefore, when the second gear swings in the direction of the arrow, that is, moves eccentrically, the concave teeth as the contour teeth and the rollers are engaged in a predetermined angle range E. In this case, since the rollers and the concave teeth are formed to have the same width (same diameter) in the direction of the teeth with respect to the buses M ₁ and M ₂ , proper engagement is achieved at the maximum meshing position W ₁ where the buses overlap. However, at the meshing angle positions before and after that, the bus lines intersect with each other, and the concave teeth 5 interfere with the rollers 4a.

The intersection of the buses is maximum at the meshing start position W ₂ and the meshing disengagement position W ₃ , and the intersecting direction has a reverse inclination before and after the maximum meshing position as a base point. ) engages begins to occur in the counter-rotational direction of the concave tooth 5 at reference pitch circle diameter (PCD) outer in an angular range from the position W ₂ to the maximum engagement position W _1, generated in the rotation direction side of the reference pitch diameter inner To do. Further, in the angular range up to the disengaged position W ₃ mesh from the maximum engagement position W _1, the outer and inner reference pitch circle diameter, the interference portion is generated in the opposite direction to the above. Therefore, in the opening portion of the concave teeth 5, a drum-shaped interference portion is created that expands inward and outward from the reference pitch circle diameter in the meshing range from the meshing start position to the meshing disengagement position.

  As the tooth trace length increases, the interference width of the interference portion increases at the end of the tooth trace direction, and is greatly affected by the setting position of the reference pitch circle diameter even if the tooth trace length is constant. For example, if the reference pitch circle diameter is set at the inner and outer ends of the tooth trace direction, the distance from the reference pitch circle diameter to one end increases, so the tooth pitch direction and other points start from the reference pitch circle diameter. An extremely large interference portion is generated spreading in a so-called trumpet toward the end.

  Therefore, the concave teeth can be properly meshed in the predetermined meshing range by removing the interference part by the above-described generating machine, but the tooth profile after the interference part removal is free of transmission efficiency and machining accuracy. Therefore, it is necessary to consider the setting of the streak length of the concave tooth that governs the interference width and the reference pitch circle diameter so that the interference width is minimized. That is, when the interference width increases, the meshing angle range with the roller 4a, particularly the contact angle with the roller at the meshing start position and the meshing disengagement position, and the axial force increases accordingly, leading to a decrease in transmission efficiency. .

  In addition, the increase in the interference width also affects the degree of freedom of the processing form and the degree of freedom of the processing accuracy. In other words, as long as machining is performed using a creation machine as described above, accuracy can be ensured, but a special machining machine needs to be newly prepared. An extremely complicated machining process is required, and it becomes difficult to ensure both accuracy and freedom of productivity. Therefore, in this embodiment, the length of the tooth of the concave tooth is set to be significantly shorter than that of the convex tooth, and the reference pitch circle diameter is set at the center of the tooth, so that the interference portion is minimized. It is possible to ensure both accuracy and productivity.

  FIG. 11 shows the tooth profile of the concave tooth with the interference part clarified in FIG. 10 removed, and shows the removal state of the interference part at the five front and rear meshing positions including the maximum meshing position in the meshing range. .

In the drawing, a triangular area drawn from the root of the tooth to the opening end shows an interference removing portion from which the interference portion generated at each angular position is removed. That is, the first area E ₁ is an area corresponding to the interference removing portion at the meshing start position, and is located on the rotation direction side and the half rotation direction side across the reference pitch circle diameter PCD1. The second area E ₂ indicates an area corresponding to an interference removing unit at an intermediate angular position between the meshing start position W ₂ and the maximum meshing position W ₁ . The third and fourth areas E ₃ and E ₄ indicate the same interference removal area as described above in the mesh disengagement direction from the maximum mesh position W ₃ . Area E ₅ is a non-interference removing portion where no interference occurs, and indicates an area where the roller contacts at the maximum meshing position W ₁ .

  As is apparent from this figure, each of the interference canceling parts expands radially inward and outward (inside and outside of the streak direction) with the reference pitch circle diameter as a base point. Because the streak length is short, the enlargement ratio is kept relatively small. Note that the area indicating the above-described interference removal unit shown in FIG. 11 is a continuous curved surface under continuous rotation, and there is no line that defines the area, but the removal area for each angular position is shown for convenience of explanation. It was.

  As is clear from the above explanation, the enlargement ratio of the interference removal portion at both ends of the tooth trace direction can be made relatively small by shortening the tooth trace length and setting the reference pitch circle diameter to the center of the tooth trace. Accordingly, the contact angle with the roller at the meshing start position and the meshing release position is reduced, and transmission efficiency is improved. In that sense, it is desirable that the reference pitch circle diameter is set within a range of 30% of the length of the tooth streak inward or outward from the center of the streak direction, and further deviates from the center. Since the enlargement ratio of the interference removal portion at one end is too large, it is not preferable. More preferably, it is necessary to set the reference pitch circle diameter so that the interference removal portions at both ends are substantially equal.

In that sense, the position of the reference pitch circle diameter needs to be arranged slightly outward from the center of the tooth trace. In other words, when the reference pitch circle diameter is set at the center of the tooth trace direction, there is a difference in the modul on the inner end and the outer end in the radial direction, and this causes a difference in the interference width between the inner end and the outer end. The outer end tends to be larger than the inner end. FIG. 11 shows the inner and outer edges of the opening when the reference pitch circle diameter is set at the center of the concave teeth (PCD1) and radially outward from the center (reference pitch circle diameter PCD2). FIG. 6 shows the relationship between the opening widths of the ends. As is apparent from this figure, in the case of PCD1, the width H ₁ of the radially outer end is wider than the width H _{2 of the} inner end, and in the case of PCD2, the opening thereof The width is reduced on the outer end side and enlarged on the inner end side to become H ₁ ′ and H ₂ ′. As a result, both have substantially the same opening width. Therefore, the interference width can be made equal by setting the reference pitch circle diameter outward from the center. FIG. 12 is a cross-sectional view at the reference pitch circle diameter (PCD) position, where the dotted line indicates the outer end of the tooth trace, and the one-dot difference line indicates the inner end of the tooth trace.

  As is apparent from the above description, the oscillating gear device of the above embodiment is configured such that the first gear having a high degree of design freedom is formed as a convex tooth having a long tooth length, and the second gear having a low degree of design freedom. The oscillating gear device can be miniaturized by configuring the tooth as a concave tooth with a short tooth length, and the convex tooth with a long tooth length can be used as a contoured tooth that is easy to process. By setting the reference pitch circle diameter in the vicinity of the center of the tooth trace direction as a creation tooth obtained by creating and transferring the above-mentioned convex tooth or an approximate creation tooth, and increasing the degree of freedom of processing accuracy, Further, the rollers constituting the convex teeth are supported in a non-tiltable manner in the rotational direction with concave grooves having a uniform cross-section in the entire region of the tooth trace direction to increase the support rigidity of the rollers, and the rollers and concave grooves constituting the convex teeth By making the convex teeth that are firmly connected and substantially integrated, It is adapted to improve the flexibility of fit accuracy. Therefore, in the oscillating gear device of the above-described embodiment, the meshing accuracy can be increased by increasing the degree of freedom of processing accuracy and the degree of freedom of positioning accuracy, and the transmission efficiency is improved without impairing productivity. It becomes possible.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

Sectional drawing of the rocking gear apparatus concerning this invention. Sectional drawing of the principal part of the rocking gear apparatus concerning this invention. The front view of the principal part of the rocking gear apparatus concerning this invention. Explanatory drawing to the equivalent spur gear of the rocking gear apparatus concerning this invention. The enlarged view of the principal part of FIG. The tooth profile section of the 1st embodiment of the rocking gear device concerning the present invention. The same figure of the 2nd embodiment of the rocking gear apparatus concerning this invention. The same figure of the 3rd embodiment of the rocking gear apparatus concerning this invention. The same figure of the 4th embodiment of the rocking gear apparatus concerning this invention. The schematic diagram which shows the relationship between the convex-tooth and concave-tooth of the rocking gear apparatus concerning this invention. The expansion perspective view of the concave tooth of the rocking gear device concerning the present invention. Sectional drawing of FIG. Sectional view of a conventional oscillating gear device Explanatory drawing of the meshing part of the conventional rocking | fluctuation type gear apparatus.

Explanation of symbols

1 Input shaft 1a Inclined part 2 Output shaft 3 Rotating body 3
4 Convex tooth 4a Roller 4b Concave groove 5 Concave tooth 6 Housing 7 Outer retainer 8 Inner retainer

Claims (9)

A first gear with n ₁ teeth fixed to the housing and a fourth gear with n ₄ teeth attached to the output shaft are arranged with their axis centers aligned with the input shaft, and the number of teeth n ₂ The rotating body integrally provided with the second gear and the third gear having the number of teeth n ₃ is arranged at the inclined portion of the input shaft so that the second gear meshes with the first gear and the third gear meshes with the fourth gear. A point where the center point of the common sphere passing through the pitch circles of the first and second gears and the center point of the common sphere passing through the pitch circles of the third and fourth gears coincides with the origin. The axis of the input shaft is arranged on the X axis of the XY coordinates to be used, and the meshing points of the first and second gears and the meshing points of the fourth and third gears are the same quadrant or different quadrants of the XY coordinates. An oscillating gear device placed on top,
The first to fourth gears are configured as bevel gears,
The first gear and the fourth gear of the first to fourth gears meshing with each other and facing each other have a semicircular groove having a semicircular cross section extending radially from the gear center at equal intervals on the pitch cone, and the groove The second and third gears, which are configured as convex teeth as contour teeth with a cylindrical roller that is arranged so as to freely roll inside, are meshed with the first gear and the fourth gear, respectively. It is configured as a concave tooth formed as a created tooth profile or an approximate created tooth profile created by transferring the tooth profile of
The convex teeth are set such that the tooth length is longer than the tooth length of the concave teeth,
The concave grooves constituting the convex teeth are formed in the same circular arc cross section with a uniform cross section in the whole area in the streak direction so as to closely support the roller in a non-tiltable manner in the whole area in the tooth streak direction,
Further, the roller is positioned and held on the first and fourth gears by annular retainers at both ends of the tooth trace direction, respectively.   2. The rocking tooth according to claim 1, wherein the concave teeth are formed in a drum shape whose openings are expanded outward in the tooth line direction and inward in the tooth line direction across the reference pitch circle diameter. Dynamic gear device.   2. The oscillating gear device according to claim 1, wherein the reference pitch circle diameter is set within a range of 30% of the length of the tooth streak in and out of the center of the tooth streak direction.   The reference pitch circle diameter is set outward from the center of the tooth trace direction so that the width of the interference removal portion of the concave tooth is substantially equal at both ends of the tooth trace direction. Oscillating gear device.   The concave grooves constituting the convex teeth are formed by a single arc corresponding to the outer peripheral surface of the roller so as to come into contact with the outer peripheral surface of the roller and the entire surface thereof. The rocking | fluctuation type gear apparatus as described in any one of these.   The concave groove constituting the convex tooth has a contact point in the vicinity of the opening and is formed by multiple arcs so as to constitute a predetermined space between the groove bottom and the roller. The rocking | fluctuation type gear apparatus as described in any one of 1-4.   The concave grooves constituting the convex teeth are formed by a single arc corresponding to the outer peripheral surface of the roller so that the concave grooves make contact with the outer peripheral surface of the roller, and the concave teeth are contact points in the vicinity of the opening. 5. The oscillating gear device according to claim 1, wherein the oscillating gear device is formed with multiple arcs so as to form a predetermined space between the groove bottom and the roller.   5. The concave groove and the concave tooth both have a contact point in the vicinity of the opening and are formed in multiple arcs so as to form a predetermined space between the groove bottom and the roller. The rocking | fluctuation type gear apparatus as described in any one of these.   9. The retainer according to claim 1, wherein at least an inner side of the retainer is in contact with an end surface of the roller at an outer peripheral surface thereof, and elastically holds the roller in a tooth line direction. The oscillating gear device described.

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