JP4971013B2 - Oscillating gear unit - Google Patents

Description

  According to the present invention, a first gear having n1 teeth fixed to a housing and a fourth gear having n4 teeth attached to an output shaft are arranged with their respective axis centers aligned with the input shaft, and the number of teeth A rotating body integrally provided with a second gear with n2 and a third gear with n3 teeth is provided 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. The present invention relates to a rocking gear device placed on top.

  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 of the gears to a so-called contour tooth having the same tooth width and tooth depth in the direction of the tooth trace, 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. 10 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 4a is interposed in the meshing portion of each gear, and meshing friction is absorbed by the rolling of the roller.

As shown in FIG. 11, the roller 4a is supported by a concave groove 4b formed in the first gear A ₁ (fourth gear A ₄ ) so as to roll freely. 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 as a concave tooth 5 by forming a semicircular concave groove. 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.
Japanese Examined Patent Publication No. 7-56324

  In the above-mentioned oscillating gear device, the convex teeth are composed of a concave groove and a roller, that is, a roller is interposed in the meshing portion, and a constant pressure is applied to the meshing portion to reduce backlash to zero. In principle, the frictional resistance of the meshing portion is reduced, and the transmission efficiency and positioning accuracy can be increased.

  By the way, in this type of oscillating gear device, the gear pair of the first and second gears and the gear pair of the third and fourth gears have a phase difference of 180 degrees at each end face in the axial direction of the rotating body. Since this is a partial meshing, the axial force generated at the meshing part of the rotating body causes the rotating body to be distorted radially outward at each end face. If this occurs, there is a possibility that the meshing may be lost and the phase may be shifted or the teeth may be damaged.

  In order to prevent this, if the thickness of the rotating body is increased and the rigidity is increased, the strain can be reduced. However, if the thickness of the entire rotating body is simply increased, it is formed at both axial ends. As a result, the lengths of the first and fourth gears meshing with the second and third gears need to be increased, resulting in a large radial size as a whole. Will lead to a change. In particular, when the first and fourth gears are convex teeth using rollers, and the second and third gears formed on the rotating body are concave teeth, the tendency becomes remarkable.

  The present invention has been made in view of this point, and an object of the present invention is to provide a rocking gear device that can improve the meshing accuracy of the meshing gear without increasing the size of the gear device.

According to a first aspect of the present invention for solving the above-mentioned problems, a first gear having n1 teeth fixed to the housing and a fourth gear having n4 teeth attached to the output shaft are connected to the input shaft. And the second gear meshes with the first gear, and the third gear rotates with the rotating gear integrally provided with the second gear having the number of teeth n2 and the third gear having the number of teeth n3. A center point of a common spherical surface that passes through a reference pitch circle of the first and second gears and is supported by the inclined portion of the input shaft so as to mesh with the fourth gear, and each pitch circle of 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 center point of the common spherical surface that passes through, and the meshing point of the first and second gears and the fourth and third gears And the meshing point of the oscillating gear device in the same or different quadrants of the XY coordinates,
The first to fourth gears are configured as bevel gears,
The rotating body is provided with a thick portion formed therebetween and a thin portion formed in the axial end portions, the second gear and third gear respectively formed on said thin portion,
Each thin portion is formed in a tapered shape whose outer shape increases from the axial end face of the rotating body toward the thick portion,
The bearing means is configured as a rolling bearing means in which a rolling element is interposed between the inner ring and the outer ring,
The rotating body is configured as an inner ring or an outer ring of the bearing means .

By being configured in this way, the rigidity of the rotating body is enhanced by the thick wall portion, and the distortion of the rotating body due to the axial force generated in the meshing portion can be minimized, and the meshing of each gear Can be held properly. Further, by forming the second and third gears in the thin portion, it is possible to minimize the length of the streak of the concave teeth without being affected by the increase in the thickness of the rotating body.

Further, the rotating body, and more and this is configured as an inner ring or outer ring of the bearing means, it is possible to reduce the number of components of the tooth wheel device.

  The present invention can provide an oscillating gear device that can improve the meshing accuracy of the meshing gear without increasing the size of the gear device.

  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.

First, the basic structure and basic principle of the oscillating gear device will be described. The oscillating gear device according to the present invention includes a first gear A ₁ having n1 teeth fixed to the housing 6 and an output shaft 2. a fourth gear a ₄ of the attached teeth number n4, by matching each axis of the input shaft 1 is disposed, the third gear a ₃ of the second gear a ₂ and the number of teeth n3 of the number of teeth n2 the rotating body 3 provided integrally, the second gear a ₂ is first gear a ₁ and meshing, the third gear a ₃ pivotally supported by the inclined portion 1a of the input shaft 1 so as to mesh with the fourth gear a ₄ XY coordinates with the origin O as the point where 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 G of the input shaft is disposed on the X axis and the axis is inclined at a predetermined angle from the origin O. The axis H of the inclined portion 1a is disposed, and the meshing points of the _first and second gears A ₁ and A _{2 and} the meshing points of the fourth and third gears A ₃ are on the same quadrant or different quadrants of the XY coordinates. Composed by putting on.

More specifically, the oscillating gear device has first to fourth gears A _{1 to} A ₄ as four bevel gears set to the number of teeth corresponding to the reduction gear ratio. Two gear pairs, that is, a gear pair of two gears and a gear pair of third gear and fourth gear are configured. A predetermined number of teeth difference is provided between the first gear and the second gear, the number of teeth difference between the third gear and the fourth gear is set to zero, and the overall reduction ratio is set to the first gear and the second gear. It is equal to the reduction ratio between the two gears. Among the first gear A ₁ is integrally fixed to the housing 6, a fixed wheel not to rotate. The second gear A ₂ and the third gear A ₃ are formed on the rotating body 3 that is 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. This, along with the swinging motion of the rotating body 3, a second gear _{A 2} to the first gear _{A 1,} also will engage respectively the third gear _{A 3} to the fourth gear A4. Then, the second gear A ₂ rotates relative to the first gear A ₁ by an amount corresponding to the difference in the number of teeth from the first gear A ₁ per one cycle of the swinging motion (one rotation of the input shaft 1). . That is, the first gear _{A 1,} between a second gear _{A 2,} 1 stage speed reduction is performed.

Here, let us consider a 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 . The movement of the second gear A ₂ is directly transmitted to the third gear A 3, and the same meshing is performed between the third gear A 3 and the fourth gear A 4. However, the number of teeth of the third gear A 3 and the fourth gear A 4 is the same. Are set to the same number, no deceleration action occurs during this time. In this case, if a difference in the number of teeth is given between the third gear A3 and the fourth gear A4, a one-stage reduction is performed even between the third gear A3 and the fourth gear A4. That is, when the rotational movement of the input shaft 1 is transmitted to the output shaft 2, the first and second gears A1 and A2 and the third and fourth gears A3 and A4 perform a two-stage deceleration action. It will be.

R = 1− (n4 × n2) / (n3 × n1) (i) where R is the speed reduction ratio of the oscillating gear device (the number of rotations of the output shaft 2 when the input shaft 1 makes one rotation). )
It can be expressed as.
Here, n1: the first number of teeth of the gear _{A 1,} n2: a second number of teeth of the gear _{A 2,} n3: number of teeth of the third gear A3, n4: the number of teeth of the fourth gear A4, n1 = 1000, If n2 = 1001, n3 = 1000, and n4 = 999, the reduction ratio R = 1 / 1,000,000 (forward rotation). In the above description, if the number of teeth of the third gear and the fourth gear is the same, the reduction ratio R = 1/1000. 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 engaged with each other are shifted by one. Also, if the number of teeth difference is 2, the swinging motion progresses one period, between the first gear A ₁ and the second gear A _2, meshing teeth deviates two. 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 A3 and A4.

  Next, a method for obtaining the tooth profile of the oscillating gear device will be described below. Here, FIG. 6 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 A1, A2, A3, A4 is schematically shown as a pitch cone.

Here, a common spherical surface Cir1 that passes through the pitch circles of the first gear A1 and the second gear A2 and a common spherical surface Cir2 that passes through the pitch circles of the third gear A3 and the fourth gear A4 are considered. 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. Further, the meshing point of the first and second gears A ₁ and A2 is C1, and the meshing point of the third and fourth gears A3 and A4 is C2. Then, the meshing points C1, C2 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 back cone of the first gear A1 and the center line of the pitch cone is θ1, and the back of the second gear A2. When the angle formed by the cone and the center line of the pitch cone is θ2, θ1 + θ2 = θ. It is also possible to make either one of θ1 and θ2 have an angle of zero, and in this case, the gear having the angle of zero becomes the crown gear. Similarly, the angles formed by the back cones of the third and fourth gears A3 and A4 and the center lines of the pitch cones are θ3 for the third gear A3, θ4 for the fourth gear A4, and θ3 + θ4 = θ.

The number of teeth of the first to fourth gears is n1, n2, n3, and n4, respectively. Here, the distances D1 O1, D2 O2, D3 O3 from the vertices O1, O2, O3, O4 of the pitch cones of the first to fourth gears A1 to A4 to the vertices D1, D2, D3, D4 of the dorsal cones. , D4 O4 is considered as cylindrical gears ER1, ER2, ER3, ER4 with a pitch circle radius. An involute tooth profile formed on the pitch circle or an arbitrary tooth profile is assumed, and this is used as an equivalent cylindrical gear of the first to fourth gears A1 to A4. Here, if the equivalent number of teeth of the equivalent cylindrical gear is Z1, Z2, Z3, Z4,
Z1 = n1 / Sinθ1 (ii)
Z2 = n2 / Sinθ2 (iii)
Z3 = n3 / Sinθ3 (iv)
Z4 = n4 / Sinθ4 (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 tooth profile of the contour tooth is formed on the first gear A1, and further the second gear A2 The tooth profile is created and transferred. The third and fourth gears A3 and A4 are formed in the same manner. That is, the first to fourth gears A _{1 to} A ₄ are formed with two pairs of constant-tooth 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.

  The features of the oscillating gear device of the basic configuration and differential principle as described above will be described in more detail below.

In Figure 1-9, the first gear A ₁ and the fourth gear A ₄ is on the pitch conical, equidistant extends from gear center in the radial direction and the meridional cross section semicircular of parallel extending a predetermined width with respect to The concave groove 4b and a cylindrical roller 4a having a predetermined diameter, which is arranged so as to be able to roll 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.

As shown in FIGS. 3 to 5, the rollers 4 a configured as the convex teeth 4 have the same number of teeth as that of the first and fourth gears, and outer retainers at both ends in the axial direction (line direction). 7. Positioned and held by the inner retainer 8. The retainers 7 and 8 are formed in a ring shape, and annular locking claws 7a and 8a that engage with the locking grooves 9 of the first and fourth gears A ₁ and A ₄ are formed at the inner ends in the axial direction. In addition, positioning portions 7b and 8b are formed at outer ends in the axial direction to hold the rollers at both ends in the tooth trace direction and position the rollers 4a with respect to the grooves 4b. The locking claws 7a, 8a are inclined surfaces 9a formed on the first hub gear A _1, for contact with the 9a to secure the retainer 7,8 inclined surface 7c, 8c are formed. The positioning portions 7b and 8b protrude to the inner periphery or the outer periphery in the radial direction, and projecting portions 7d and 8d for positioning and holding the outer peripheral surface in the direction of the concave groove 4b at the outer end in the toothed direction. The end surfaces 7e, 8e for positioning and holding the roller axial end surface on the inner side in the axial direction from the portion, and abutting against the land portion 4c of the first gear adjacent to the end surface, the protruding portions 7d, 8d and the land portion 4c. It consists of positioning end faces 7f and 8f that regulate the position between them.

  Therefore, by attaching the outer retainer 7 and the inner retainer 8, the roller 4a is sandwiched between the end surfaces 7e, 8e and positioned and held in the direction of the tooth trace, and between the inner end surface of the projecting portions 7d, 8d and the groove 4b. The positioning is held in the direction of the bottom of the groove 1b. In this case, even if there is a slight shift between the locking claws 7a, 8a and the locking grooves 9, 9, there is a slight shift in the engagement position between them, the positioning end faces 7f, 8f and the land of the first gear. Due to the contact with the portion 4c, the relative positions of the projecting portions 7d, 8d and the roller outer peripheral surface are kept constant. The relative position may be in direct contact as long as the rolling of the roller 4a is not restricted, but a slight gap may be provided in consideration of thermal expansion and the like.

  When the rollers 4a are pressed into contact with the concave grooves 4b by the retainers 7 and 8 and the rolling of the rollers is restricted, the slippage of the mesh increases and the transmission efficiency is deteriorated, and the lubricity between the rollers 4a and the concave grooves 4b is increased. Will be worsened. Therefore, it is necessary to set the relative position of the outer peripheral surface of the roller and the retainer within a range where no play occurs and a range where the roller rolling is not restricted. The retainers 7 and 8 are made of polyamide or polyimide resin, and are configured to elastically deform in the radial direction so as to allow displacement of the rollers 4a in the direction of the teeth when meshing.

  That is, in this type of oscillating gear device, the rotator 3 is engaged and disengaged while oscillating, and a large force acts on the rollers even in the tooth trace direction during the engagement. . Therefore, the end face of the roller is strongly pressed against the inner periphery or the outer periphery of the retainer by the force in the tooth line direction acting on the roller. At this time, if the retainer has high rigidity, an excessive frictional force is applied to the end face. This frictional force restrains the rolling of the rollers and deteriorates the transmission efficiency. It leads to wear. Therefore, by forming the retainer so as to be elastically deformable as described above, even if a force in the direction of the tooth line acts on the roller, the force is absorbed by the elastic deformation of the retainer, and the above-described problem is solved.

  In this case, the elastic characteristics of the inner retainer may depend on the elastic deformation of a part of the peripheral surface of the retainer 8 or the entire retainer may be elastically deformed, although it depends on the force acting on the roller 4a. In short, it is only necessary to have elastic deformation at the time of meshing and resilience at the time of non-meshing.

  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. 8, the cross-sectional shape is formed by multiple arcs as in the cross-sectional shape of the concave tooth 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 2 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.

Moreover, the contact angle α can be reduced by forming the cross section of the concave groove 4b and the concave tooth 5 with multiple arcs as described above and setting the contact points P ₀ and P ₀ near the opening, In particular, the concave tooth 5 greatly contributes to improvement of transmission efficiency and durability of each part of the gear.

That is, the load P is applied to the roller 4a at the contact point P ₀ of the concave tooth 5 of Figure 8 when the meshing of the first gear A1 and the second gear A2 is generated. This load P includes a rotational transmission force T that is a component force in a direction parallel to the pitch cone of the first and second gears A ₁ and A ₂ , and an axial force F that 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. Moreover axial force will impair the durability of the gear adversely affect the bearing means for hindrance of the rotating body 3 acts as a bending force to the rotating body 3 in which the second gear A ₂ is formed.

  Therefore, if the contact angle α is reduced, the axial force is reduced, and both transmission efficiency and durability can be improved. Note that, 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.

Next, the tooth profile of the concave tooth 5 formed on the second gear A ₂ will be described. The concave tooth 5 is formed by transferring the convex tooth 4 as the first gear A ₁ as schematically described above. It is formed. 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.

  As a specific tooth profile of the concave tooth, as shown in FIG. 9, it is formed in a drum shape from which the interference portion of the opening is removed. This shape changes depending on the set position of the reference pitch circular system. In this embodiment, the shape is set at the center of the tooth trace direction, and the interference width is minimized.

The housing 6 that houses the first to fourth gears configured as described above includes a first housing member 61 and a second housing member 62 that are divided into two in the axial direction. The first housing member 61 includes a cylindrical portion 61a and a screw cap 61b fixed to the end of the cylindrical portion, and a stepped portion 61c that performs axial positioning of the first gear on the inner periphery of the cylindrical portion 61a. is provided, the first gear a ₁ is configured to positioned and fixed between the screw cap 61b. The inner periphery first gear A ₁ hub, and the outer ring of the bearing means 64 is press-fitted, also in the outer periphery of the cylindrical portion 61a is formed a flange portion 61d is, the flange portion 61d and the second housing member Between the flange portion 62d of 62, a shim 63 as an adjusting means for adjusting the axial length of the housing 6 is disposed.

The second housing member 62 includes a fourth gear housing portion 62a and a small-diameter output shaft support portion 62b. The output shaft support portion 62b has two sets of bearing means 65 and 66 positioned on the inner peripheral surface thereof. A stepped portion 62c is provided. The two sets of bearing means 65 and 66 are fixed by lock nuts 67 and 68 in different directions. An output shaft 2 arranged in the second housing member 62, the fourth gear A ₄ is integrally formed, axially in contact with the inner ring of the end face of the fourth bearing means 65 formed in the hub portion of the gear A ₄ And an inner ring receiving portion 2b loosely fitted to the inner rings of the bearing means 65 and 66, and an outer ring of the bearing means 69 for supporting one end of the input shaft is provided on the inner periphery of the hub portion. It is press-fitted.

The input shaft 1 is press-fitted to the first inner ring receiving portion 1b to be fitted loosely to the inner ring of the bearing means 64 press-fitted into the first gear A _1, the hub portion of the fourth gear A ₄ The second inner ring receiving portion 1c is loosely fitted to the inner ring of the bearing means 69, and the inclined portion 1a is located between the first inner ring receiving portion and the second inner ring receiving portion. The inclined portion 1a includes a press-fit portion 1d into which the inner ring 70b of the bearing means 70 is press-fitted and a flange portion 1e for positioning the inner ring of the bearing means in the axial direction. In this case, the bearing means 70 and its outer ring 70a are configured as a part of the rotating body 3, and second and third gears A ₂ and A ₃ are formed on the end faces in the axial direction, respectively. Therefore, the positioning of the bearing means 70 described above positions the rotating body 3 as the outer ring 70a, that is, with respect to the origin O as the intersection of the axis H of the inclined portion 1a and the axis G of the input shaft. Three gears are properly positioned. The inner ring is fixed by a lock nut 70d in a state where one end is pressed against the flange portion 1e.

  Next, assembly of the oscillating gear device configured as described above will be described. As shown in FIG. 2, the components can be assembled as three subunits in advance, and the subunits can be sequentially coupled.

This subunit, first housing member 61, a first sub-unit comprising a first gear A ₁ and the bearing member 64 is positioned and fixed to the first housing member, the second housing member 62, positioned and fixed to the second housing member a second sub-unit consisting of the output shaft 2 and three bearing means 65,66,69 includes a fourth gear _{a 4} is, the input shaft 1, the rotating body 3 is positioned and fixed to the input shaft (second, third And a third subunit composed of bearing means 70 including a gear).

  These three units are placed between the first subunit and the second subunit, the third subunit is positioned, and the first subunit and the second subunit are placed on the axis G and the first of the input shaft 1 The flanges 61d and 62d are brought into contact with each other in a state where the inner ring receiving portion 1b and the second inner ring receiving portion 1c are fitted into the inner rings 70b of the bearing means 64 and 69, and the assembly is completed by fastening with the bolts 71. In this state, the first gear and the fourth gear are positioned at appropriate dimensions necessary for meshing with the second and third gears, and the rotating body held between them has an input shaft connected to the inner ring of each bearing means. On the other hand, by being fitted loosely, it is arbitrarily moved in the axial direction by the self-centering action and positioned at the center position.

  Accordingly, an equal pressure is applied between the two pairs of meshing gears between the first and second gears and the third and fourth gears, and the backlash is zero. Note that when the dimension between the first and fourth gears deviates from a predetermined dimension due to variations in the processing accuracy of the housing and the like, the thickness of the shim 63 located between the flanges of the first housing and the second housing By adjusting the thickness, it can be adjusted to an appropriate size.

The rotating body 3 formed on the outer ring 70a of the bearing member 70 includes small-diameter thin portions 3a and 3a formed at both axial ends, and a large-diameter thick portion 3b formed therebetween. Concave teeth 5 of the second and third gears are formed in the thin portions 3a and 3a, respectively, and the thickness of the end surfaces thereof is made equal to the length of the streaks of the concave teeth 5, from the end surfaces to the thick portion 3b. It is formed in a taper shape so that the outer shape becomes larger toward it. A raceway groove of the rolling element 70c is formed on the inner peripheral surface of the thick portion 3b, and the outer diameter thereof is set to a value substantially equal to the outer diameter of the outer retainer 7 that locks the roller 4a. In the present embodiment, between the thin portion and the thick portion that has step it is provided.

  As described above, by providing the rotating body with a small-diameter portion as a thin-walled portion and a large-diameter portion as a thick-walled portion, both the downsizing of the gear device as a whole and the proper meshing of each gear can be achieved. Is possible. That is, in the oscillating gear device, the gear pair of the first and second gears and the gear pair of the third and fourth gears partially have a phase difference of 180 degrees at each axial end surface of the rotating body. Since the axial force generated by each meshing acts on the meshing part, the rotating body is distorted outward in the radial direction. There is a possibility that peeling, phase shift or tooth damage may occur.

In order to prevent this, if the thickness of the rotating body is increased and the rigidity is increased, the strain can be reduced. However, if the thickness of the entire rotating body is simply increased, the concave teeth on both ends in the axial direction can be reduced. As a result, it is necessary to increase the lengths of the convex teeth of the first and fourth gears that mesh with the concave teeth, resulting in an increase in size in the radial direction as a whole. Therefore, by forming the second and third gears in the thin-walled portions 3a and 3a as the small-diameter portions and making them thick portions as the large-diameter portions, the rigidity of the rotating body and the miniaturization of each gear can be achieved simultaneously. Can be achieved. The outer diameter of the thick wall portion may be larger than the retainer as long as it does not interfere with the inner peripheral surface of the housing.

  Further, in the above embodiment, as the oscillating gear device, the rotating body supported by the inclined portion is formed on the outer ring side of the bearing means, and the driving force from the input shaft is directed radially inward to outward. Although the example applied to the oscillating gear device of the transmission type has been described, as disclosed in Japanese Patent Application Laid-Open No. 2006-46405, the rotating body is provided on the inner ring side of the bearing means and located radially outward. The present invention can also be applied to an oscillating gear device of a type in which a rotating body is driven radially inward from a hollow input shaft.

  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 | fluctuation type gear apparatus of Embodiment 1 concerning this invention. Explanatory drawing explaining the assembly point of Embodiment 1 concerning this invention. The front view of the 1st gearwheel of Embodiment 1 concerning this invention. The enlarged view (state which removed the roller) of the principal part of Embodiment 1 concerning this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is an enlarged view (state which attached the roller) of the principal part of Embodiment 1 concerning this invention, (A) is sectional drawing cut | disconnected in the center part of a roller, (B) is AA sectional drawing of FIG. (C) is sectional drawing cut | disconnected in the land part between adjacent rollers, (2) shows BB sectional drawing of a figure (c). Explanatory drawing to the equivalent spur gear of the rocking | fluctuation type gear apparatus concerning this invention. The enlarged view of the principal part of FIG. The expanded sectional view in the meshing part of a convex tooth and a concave tooth. The perspective view which shows the tooth profile of a concave tooth. Sectional view of a conventional oscillating gear device Explanatory drawing of the meshing part of the conventional rocking | fluctuation type gear apparatus.

DESCRIPTION OF SYMBOLS 1 Input shaft 1a Inclined part 2 Output shaft 3 Rotating body 3a Thin part 3b Thick part 4 Convex tooth 5 Concave tooth

Claims (1)

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, and disposed to match each axis of the input shaft, the number of teeth n ₂ A rotating body integrally provided with the second gear and the third gear having the number of teeth n ₃ 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,
One gear of the first to fourth gears in meshing engagement with each other is provided with a concave groove extending radially from the center of the gear at equal intervals on the pitch cone, and rotatably disposed in the concave groove. Concave tooth formed as a convex tooth as a contour tooth with a cylindrical roller, and a gear meshing with the convex tooth formed as a created tooth profile or an approximate created tooth profile Configured as
The rotating body is provided with a thick portion formed therebetween and a thin portion formed in the axial end portions, the second gear and third gear respectively formed on said thin portion,
Each thin portion is formed in a tapered shape whose outer shape increases from the axial end face of the rotating body toward the thick portion,
The bearing means is configured as a rolling bearing means in which a rolling element is interposed between the inner ring and the outer ring,
The oscillating gear device , wherein the rotating body is configured as an inner ring or an outer ring of the bearing means .

Images