JP4942706B2 - Bending gear system - Google Patents

Description

  The present invention relates to a flexure meshing gear device.

  The flexure meshing gear device includes an internal gear having rigidity, an external gear having flexibility that can be internally meshed with the internal gear, and the internal gear by bending and deforming the external gear. And a vibration generator that realizes internal meshing between the tooth gear and the external gear.

  Some of the flexible external gears used in this flexure-mesh type gear device have a so-called cup shape having an output shaft in the axial direction (see FIG. 9A). In order to internally mesh such external gear 20 with the internal gear, the vibration generator 4 (see FIG. 9B) for bending and deforming the external gear via the bearing 10 is an external gear. 20 is inserted inside. When inserted, the vicinity of the open end 20B of the external gear 20 is deformed into a shape following the vibration generator 4 via the bearing 10, but the other portion 20A is not deformed. That is, as shown in FIG. 9C, the external gear 20 is bent and deformed in a conical shape. In order to cope with such bending deformation with an angle in the axial direction of the external gear 20, it is desirable that the outer ring 18 can be tilted in the bearing 10 disposed on the outer periphery of the vibrating body 4. From this point of view, in the flexibly meshing gear device using the cup-type external gear 20, a ball bearing in which the rolling elements 16 provided between the inner ring 12 and the outer ring 18 are balls is used. For this reason, since the flexure meshing gear device using the cup-type external gear 20 uses a ball bearing, it has been difficult to extend the life due to the limitation of the load resistance.

  On the other hand, there is also a flexure-type gear device in which the external gear has a cylindrical shape, and two internal gears are internally meshed with the external gear and the output is extracted from one of the internal gears. In such a flexure meshing gear device, the external gear can be prevented from being deformed into a conical shape. For this reason, for example, in the flexure meshing gear device including the cylindrical external gear shown in Patent Document 1, a roller or a bearing using a cylinder is suggested as a rolling element in addition to the ball bearing described above. Yes.

JP 62-200056 A

  However, in the flexibly meshing gear device described in Patent Document 1, since one external gear is vibrated by one vibrator, between the external gear and the vibrator. There is only one bearing and only one rolling element, and there is a problem that it is difficult to extend the life, particularly when the use conditions are severe. A general method for realizing a long service life is to increase the size of the bearing. However, in reality, there has been a problem that the life may not be extended as expected even if the bearing is simply enlarged.

  Accordingly, the present invention has been made to solve the above-mentioned problems, and in a flexure meshing gear device that requires deformation of a cylindrical external gear, a flexure meshing gear that can extend the service life. It is an object to provide an apparatus.

The present invention relates to a vibrating body, a cylindrical external gear that is disposed on the outer periphery of the vibrating body and is flexible and deformed by the rotation of the vibrating body, and the external gear A first internal gear having rigidity for intermeshing engagement; a second internal gear having rigidity for intermeshing engagement with the external gear, which is provided in parallel with the first internal gear; the vibrator, A flexure-meshing gear device comprising a bearing disposed between an external gear and a cylindrical rolling element , an inner ring disposed inside the rolling element, and an outer side of the rolling element. A first rolling element corresponding to a portion of an external tooth of the external gear that meshes with the first internal gear in the axial direction, and the second internal gear. It is divided into the second rolling element corresponding to the portion of the external teeth of the external gear meshing, the outer ring, a first outer ring and the corresponding to the first rolling element Is divided into a second outer ring corresponding to 2 rolling element, further, the inner ring, by which is common to the first rolling member and the second rolling element, is obtained by solving the above problems.

  In the present invention, in order to obtain the action of causing a predetermined identical movement to occur in the entire axial direction of the external gear by the rotation of a single oscillator, the rolling element is the first in the axial direction. The external gear portion of the external gear that meshes with the first internal gear and the external gear portion of the external gear that meshes with the second internal gear are intentionally divided. For this reason, the load by meshing with the first internal gear and the external gear can be received by the first rolling element disposed on the first internal gear side, and the external teeth meshing with the second internal gear. It is possible to prevent the bearing portion (hereinafter referred to as the second vibration body bearing) including the second rolling element corresponding to the external tooth portion of the gear from being affected. At the same time, a load caused by meshing between the second internal gear and the external gear can be received by the second rolling element disposed on the second internal gear side, and the external gear meshing with the first internal gear. It is possible to prevent the bearing portion (hereinafter referred to as the first vibration body bearing) having the first rolling element corresponding to the outer tooth portion from being affected.

  Since the first and second rolling elements are cylindrical, a cylindrical external gear is bent in parallel with the axial direction by a bearing including the first and second rolling elements (hereinafter collectively referred to as a vibration body bearing). Can be deformed. That is, the external teeth are not inclined with respect to the axial direction, and mesh with the internal teeth of the first and second internal gears with a uniform force in the axial direction. And the meshing area of the internal teeth and external teeth that should be meshed with the first internal gear and the second internal gear and the external gear (for example, when the external teeth are not inclined, bent, or worn) It is possible to realize meshing at a meshing area) when meshing with teeth. At the same time, the first and second rolling elements can receive the force from the external gear and the force from the vibration generating body, increasing from “point” to “line”.

  Therefore, combined with the effect of the above-described division of the rolling elements, the load bearing capacity of the vibration body bearing (bearing) can be increased, and the vibration body bearing (bearing) can transmit a larger torque and have a longer life. Can be realized.

  Furthermore, since the rolling element is divided into at least two in the axial direction, the divided first and second rolling elements are shortened in the axial direction. For this reason, it can reduce that the problem of a skew (a bending, distortion, etc.) arises in the 1st and 2nd rolling element. Moreover, since it is not necessary to enlarge the 1st and 2nd rolling element more than necessary for life extension, the expansion to the radial direction of a vibration body bearing (bearing) can also be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the load resistance of a vibration body bearing (bearing) increases, a lifetime can be extended, transmission torque can be enlarged, and the flexible meshing gear apparatus which can maintain the transmission torque long is implement | achieved. It becomes possible.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  1 is a cross-sectional view showing an overall configuration of an example of a flexure meshing gear device according to a first embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a diagram showing a vibration generator, and FIG. 5 is an enlarged view for explaining the shape of the vibration generating body, FIG. 5 is a schematic view combining the vibration generating body and the vibration generating body bearing, FIG. 6 is a conceptual diagram of meshing of the virtual external gear and the internal gear, and FIG. FIG. 3 is a meshing view of an external gear and an internal gear.

  First, the overall configuration of the present embodiment will be schematically described mainly with reference to FIGS. 1 and 2.

  The flexure meshing gear device 100 includes a vibrating body 104 and a cylindrical external gear 120A that is arranged on the outer periphery of the vibrating body 104 and has flexibility to be bent and deformed by the rotation of the vibrating body 104. 120B, a first internal gear 130A having the rigidity with which the external gear 120A meshes internally, and a second internal gear having the rigidity to be internally meshed with the external gear 120B, which is arranged in parallel with the first internal gear 130A. A toothed gear 130B, and a vibration body bearing (bearing) 110 disposed between the vibration body 104 and the external gears 120A and 120B are provided.

  Here, the vibration body bearing (bearing) 110 includes first and second vibration bodies 110A and 110B, and includes cylindrical rolling elements 116A and 116B. The rolling elements 116A and 116B are external teeth that mesh with the first rolling elements 116A and the second internal gear 130B corresponding to the external teeth 124A of the external gear 120A that meshes with the first internal gear 130A in the axial direction O. It is divided into second rolling elements 116B corresponding to the outer teeth 124B of the gear 120B.

  Hereinafter, each component will be described in detail.

  As shown in FIGS. 3 (A) and 3 (B), the vibrator 104 has a columnar shape whose side surface is parallel to the axial direction O, and an input shaft hole 106 into which an input shaft (not shown) is inserted is formed at the center. Has been. A keyway 108 is provided in the input shaft hole 106 so that the vibrator 104 rotates integrally with the input shaft when the input shaft is inserted and rotated.

  Here, as shown in FIG. 3A, when the vibrating body 104 is positioned at the center of the XY coordinates, the outer shape of the vibrating body 104 becomes an axisymmetric shape in both the X axis and the Y axis. Therefore, only the shape of the first quadrant of the vibrator 104 shown in FIG. 4 will be described below.

  The vibrator 104 has a shape obtained by connecting two arcs. Here, an arc portion of the vibrating body 104 for meshing the external gear 120A and the first internal gear 130A is defined as a first arc portion FA, and its radius of curvature is R1. A portion of the arc connecting the two first arc portions FA is defined as a second arc portion SA, and the radius of curvature is R2. An angle that determines the length of the first arc portion FA is defined as θ.

  At this time, as shown in FIG. 4, if the radius of the long axis direction X of the vibrating body 104 is R, the amount of eccentricity is L, and the radius of curvature R1 of the first arc portion FA is expressed by equation (1). Can do.

    R1 = RL (1)

  Also, as shown in FIG. 4, the tangent line T is common at the connecting portion A between the first arc portion FA and the second arc portion SA. As described above, the outer shape of the vibrator 104 is axisymmetric. For this reason, the curvature radius R2 of the vibrator 104 has a point B in common with the curvature radius R1 from the connecting portion A between the first arc portion FA and the second arc portion SA at the angle θ and further extends from the point B. It is the length to the intersection C with the Y axis (short axis direction of the vibrator 104). That is, the radius of curvature R2 of the second arc portion SA can be expressed by Expression (2).

    R2 = R−L + L / cos θ (2)

  As is clear from the equations (1) and (2), the radius of curvature R1 of the first arc portion FA is smaller than the radius of curvature R2 of the second arc portion SA. Here, the curvature radius of the external gear 120A that is bent and deformed by the arc having the curvature radius R1 (first arc portion FA) is set equal to the curvature radius of the virtual external gear 120C. As shown in FIG. 6, the virtual external gear 120 </ b> C has a perfect circular shape and rigidity, as shown in FIG. 6, so that the external gear 120 </ b> A and the first internal gear 130 </ b> A ideally mesh with each other.

  As described above, assuming the virtual external gear 120C, if the angle θ and the amount of eccentricity L are determined, the radius of curvature of the virtual external gear 120C can be obtained. The curvature radius R1 and the curvature radius R2 that define the outer shape of the vibration body 104 can be uniquely determined in consideration of the radial thickness of the first vibration body bearing 110A described later.

  Among the vibration body bearings 110, the first vibration body bearing 110A includes an inner ring 112, a cage 114A, a first rolling element 116A, and an outer ring 118A, as shown in FIG. The first vibration body bearing 110 </ b> A is disposed inside the external gear 120 </ b> A and on the outer periphery of the vibration body 104 as shown in FIGS. 1 and 5. That is, the first vibration body bearing 110A is disposed between the vibration body 104 and the external gear 120A, which bends and deforms the external gear 120A. For this reason, the inner ring 112 contacts the vibration generator 104 inside the inner ring 112, and the inner ring 112 rotates integrally with the vibration generator 104.

  As shown in FIG. 1, the retainer 114 </ b> A holds the first rolling element 116 </ b> A so as to be rotatable along the outer periphery of the inner ring 112. 116 A of 1st rolling elements are cylindrical shape (a needle pin and a roller are included). For this reason, compared with the case where the 1st rolling element 116A is a ball | bowl, the area | region where the 1st rolling element 116A contacts with the inner ring | wheel 112 and the outer ring | wheel 118A increases. That is, since the force from the external gear 120A and the force from the vibrating body 104 can be received in a “line” state in the axial direction O, the load resistance of the first vibrating body bearing 110A can be increased. Can do. The outer ring 118A is disposed outside the first rolling element 116A. The outer ring 118 </ b> A is bent and deformed by the rotation of the vibration generator 104 together with the external gear 120 </ b> A arranged on the outer side thereof.

  As shown in FIG. 1, the second vibration body bearing 110B is composed of an inner ring 112, a cage 114B, a second rolling element 116B, and an outer ring 118B, like the first vibration body bearing 110A. The The inner ring 112 is common to the first and second vibration body bearings 110A and 110B. Therefore, the first and second vibration body bearings 110 </ b> A and 110 </ b> B bend and deform the external gears 120 </ b> A and 120 </ b> B in the same phase according to the rotation of the vibration body 104. The second rolling element 116B has the same cylindrical shape as the first rolling element 116A and is formed with the same outer diameter. Therefore, the two external gears 120A and 120B are bent and deformed with the same in-phase and the same eccentric amount L. That is, the rotation decelerated by the first internal gear 130A is reliably transmitted to the second internal gear 130B via the external gears 120A and 120B.

  As shown in FIG. 1, the external gear 120A is in mesh with the first internal gear 130A. The external gear 120A includes a base member 122 and external teeth 124A. The base member 122 is a cylindrical member that is disposed outside the first vibrator bearing 110A and has flexibility to support the external teeth 124A. The external teeth 124A are constituted by cylindrical pins. The external teeth 124 </ b> A are rotatably held by the holding ring 126 </ b> A on the outer side so that the external teeth 124 </ b> A are not dropped from the base member 122 when rotated. The holding ring 126A is an annular elastic ring. In the present embodiment, two holding rings are used to hold the external teeth 124A at both ends. Note that the load applied to the outer teeth 124A when meshing with the inner teeth 128A is basically received by the base member 122 (for example, a semicircular groove structure for supporting the cylindrical shape of the outer teeth 124A). ing.

  The external gear 120B is in mesh with the second internal gear 130B as shown in FIG. Similarly to the external gear 120A, the external gear 120B includes a base member 122 and external teeth 124B, and the external teeth 124B are held on the base member 122 by a holding ring 126B. Here, the base member 122 supports the external teeth 124B together with the external teeth 124A. For this reason, the eccentric amount L of the vibrator 104 is transmitted to the external teeth 124A and the external teeth 124B in the same phase. The external teeth 124B are configured by the same number of external teeth 124A and the same cylindrical pins.

  The first internal gear 130A is formed of a rigid member as shown in FIG. The first internal gear 130A has a number of teeth i (i is 2 or more) greater than the number of external teeth 124A of the external gear 120A. A casing (not shown) is fixed to the first internal gear 130A via a bolt hole 132A. Then, the first internal gear 130A meshes with the external gear 120A to reduce the rotation of the vibration generator 104.

  On the other hand, the second internal gear 130B is juxtaposed with the first internal gear 130A, and is formed of a rigid member similarly to the first internal gear 130A. The second internal gear 130B has the same number of teeth as the external teeth 124B of the external gear 120B. Since the number of teeth of the external teeth 124A of the external gear 120A and the number of teeth of the external teeth 124B of the external gear 120B are the same, eventually, the number of teeth of the internal teeth 128A of the first internal gear 130A is the second internal gear. It is i more than the number of teeth of the internal teeth 128B of the tooth gear 130B. Note that an output shaft (not shown) is attached to the second internal gear 130B via the bolt hole 132B, and the same rotation as the rotation of the external gear 120B is output to the outside.

  Here, as shown in FIG. 1, the cages 114A and 114B, the first and second rolling elements 116A and 116B, and the outer rings 118A and 118B are externally meshed with the first internal gear 130A in the axial direction O. The portion is divided into a portion corresponding to the teeth 124A and a portion corresponding to the external teeth 124B meshing with the second internal gear 130B. For this reason, 110 A of 1st vibration body bearings can prevent the influence of the load by mesh | engagement with the external gear 120A and the 1st internal gear 130A from giving to the 2nd vibration body bearing 110B. At the same time, the second vibration body bearing 110B can prevent the first vibration body bearing 110A from being affected by the load caused by the engagement between the external gear 120B and the second internal gear 130B. In addition, since the first rolling element 116A has a cylindrical shape, the load resistance increases in combination with the above-described division effect, and the life of the first vibration body bearing 110A can be extended.

  At the same time, the cylindrical first rolling element 116A bends and deforms the base member 122, which is a cylindrical member of the external gear 120A, in parallel with the axial direction O. For this reason, the external teeth 124 </ b> A of the external gear 120 </ b> A that have been bent and deformed are not inclined with respect to the axial direction O and mesh with the internal teeth 128 </ b> A with a uniform force in the axial direction O. That is, a state that can occur when the first rolling element 116A is a sphere (the outer teeth 124A are inclined with respect to the axial direction O and mesh with part of the meshing area of the inner teeth 128A and the outer teeth 124A that should be meshed with each other). Can be prevented. That is, the meshing of the internal teeth 128A and the external teeth 124A that should be meshed with each other (for example, the meshing area when meshing with the internal teeth 128A when the external teeth 124A are not inclined, bent, or worn) is performed. As a result, the life of the outer teeth 124A and the inner teeth 128A can be extended, the transmission torque can be increased, and the transmission torque can be maintained. The first rolling element 116 </ b> A is short in the axial direction O because the first rolling element 116 </ b> A is disposed in the portion of the external teeth 124 </ b> A without straddling the external teeth 124 </ b> B in the axial direction O. For this reason, possibility that the problem of a skew will arise can be made low. In addition, since the 2nd rolling element 116B is the same shape as 116 A of 1st rolling elements, there exists the above-mentioned effect similarly with respect to the external tooth 124B and the internal tooth 128B.

  Further, considering that the first internal gear 130A and the second internal gear 130B have different numbers of teeth, different tooth profile configurations, and different load states, the first internal gear 130A and the second internal gear 130B are different from each other. The forces acting on the external gears 120A and 120B have different sizes and directions. However, as shown in FIG. 1, the external teeth 124A and 124B are divided in the axial direction O into a portion where the first internal gear 130A meshes and a portion where the second internal gear 130B meshes. For this reason, the influence of meshing between the external teeth 124A and the internal teeth 128A is not given to the external teeth 124B adjacent in the axial direction O. That is, when the external gear 120A and the first internal gear 130A mesh with each other, the external teeth 124A and the internal teeth 128A in the axial direction O are not affected by the external teeth 124B and should be meshed with each other. Engage with the meshing area of 128A and external teeth 124A. Similarly, the influence of meshing between the external teeth 124B and the internal teeth 128B is not given to the external teeth 124A adjacent in the axial direction O. That is, when the external gear 120B and the second internal gear 130B mesh with each other, the external teeth 124B and the internal teeth 128B in the axial direction O are not affected by the external teeth 124A and should be meshed with each other. Engage with the meshing area of 128B and external teeth 124B. That is, by dividing the external teeth 124A and 124B, it is possible to maintain rotational accuracy and prevent a reduction in transmission torque.

  Here, the virtual external gear 120C is determined in order to determine the tooth profile to be engaged. The number of teeth (102) of the internal teeth 128A of the first internal gear 130A is two more than the number of teeth (100) of the external teeth 124A of the external gear 120A. That is, the tooth number difference i = 2. Accordingly, assume that the virtual external gear 120C is, for example, four teeth fewer (j = 4, j> i) than the number of teeth (102) of the first internal gear 130A.

  Therefore, the virtual external gear 120C having the number of teeth (98) smaller by 4 teeth than the number of teeth (102) of the internal teeth 128A of the first internal gear 130A is determined, and the tooth profile is used as a reference. In this embodiment, since the external gear 120A uses a cylindrical pin as the external tooth 124A, the tooth profile is an arc tooth profile. That is, the reference tooth profile of the virtual external gear 120C is an arc tooth profile formed by the external teeth 124A. Here, the internal tooth 128A has a trochoidal tooth profile in order to realize complete theoretical meshing between the external tooth 124A and the internal tooth 128A. In addition, the external shape of the vibration body 104 is determined at the stage where the virtual external gear 120C is determined. For this reason, the external gears 120 </ b> A and 120 </ b> B are bent and deformed according to the outer shape of the vibrating body 104. In addition, you may apply another tooth profile to the tooth profile of the internal tooth 128B which meshes with the external tooth 124B.

  Next, the operation of the flexure meshing gear device 100 will be described mainly with reference to FIG.

  When the vibration generator 104 is rotated by rotation of an input shaft (not shown), the external gear 120A is bent and deformed via the first vibration generator bearing 110A according to the position by the rotation. At this time, the external gear 120B is also bent and deformed in the same phase as the external gear 120A via the second vibration body bearing 110B.

  Here, the bending deformation of the external gear 120A is performed according to the outer shape of the vibrator 104 (the first arc part FA having the curvature radius R1 and the second arc part SA having the curvature radius R2).

  At that time, the external gear 120A is bent and deformed in the long axis direction X (FIG. 3) of the vibrator 104, so that the external teeth 124A mesh with the internal teeth 128A of the first internal gear 130A. At the same time, the external teeth 124B mesh with the internal teeth 128B of the second internal gear 130B. Here, FIG. 7A shows a state where the first internal gear 130A and the external gear 120A mesh, and FIG. 7B shows a state where the second internal gear 130B and the external gear 120B mesh. Each is shown. When meshing, the external teeth 124A and 124B are rotatable pins, so that loss of transmission torque due to meshing is reduced. Further, the tooth profile of the inner teeth 128A is formed so as to be theoretically meshed with the outer teeth 124A, and therefore meshes with each other with a plurality of teeth. For this reason, the surface pressure concerning a tooth surface can be reduced and a big torque can be transmitted. The external teeth 124A and 124B are held on the base member 122 by the holding rings 126A and 126B. For this reason, the external teeth 124A and 124B do not fall off due to the rotation even in the portion where the external gear 120A and the first internal gear 130A and the external gear 120B and the second internal gear 130B do not mesh.

  Further, when meshing, a force (direction and size) different from that of the external teeth 124B is applied to the external teeth 124A. However, the external teeth 124A and 124B are separated in the axial direction O into a portion that meshes with the first internal gear 130A and a portion that meshes with the second internal gear 130B. For this reason, the influence of the force applied to each external tooth 124A, 124B is mutually excluded. Further, the first and second rolling elements 116A and 116B (first and second vibration body bearings 110A and 110B) disposed inside the external teeth 124A and 124B are also axially O in the first internal gear 130A. Is divided into a portion corresponding to the external teeth 124A meshing with the second internal gear 130B and a portion corresponding to the external teeth 124B meshing with the second internal gear 130B. For this reason, the load by the first internal gear 130A and the second internal gear 130B does not affect the first and second vibration body bearings 110A and 110B whose positions are different in the axial direction O, respectively. At this time, since the first and second rolling elements 116A and 116B have a cylindrical shape, the load resistance is increased and a large torque can be transmitted in combination with the effect related to the above-described division.

  The meshing position of the external gear 120 </ b> A and the first internal gear 130 </ b> A is rotationally moved with the rotational movement of the vibration generator 104 in the long axis direction X. Here, when the vibrating body 104 rotates once, the rotation phase of the external gear 120A is delayed by a difference in the number of teeth from the first internal gear 130A. That is, the reduction ratio by the first internal gear 130A can be obtained by ((number of teeth of the external gear 120A−number of teeth of the first internal gear 130A) / number of teeth of the external gear 120A). The specific reduction ratio is ((100−102) / 100 = −1 / 50). Here, “−” indicates that the input / output is in a reverse rotation relationship.

  Since both the external gear 120B and the second internal gear 130B have the same number of teeth, the external gear 120B and the second internal gear 130B do not move with each other, and the same teeth can move. Will mesh. For this reason, the same rotation as the rotation of the external gear 120B is output from the second internal gear 130B. As a result, an output obtained by reducing the rotation of the vibrating body 104 to (−1/50) can be extracted from the second internal gear 130B.

  In this way, the rolling elements 116A and 116B have the external tooth 124A portion of the external gear 120A that meshes with the first internal gear 130A in the axial direction O and the external tooth portion 124B that meshes with the second internal gear 130B. It is divided corresponding to. For this reason, the load caused by the engagement between the first internal gear 130A and the external gear 120A can be received by the first rolling element 116A disposed on the first internal gear 130A side, and the second internal gear 130B. The second vibration body bearing 110B including the second rolling elements 116B corresponding to the external teeth 124B of the external gear 120B meshing with the external gear 120B can be prevented from being affected. At the same time, the load caused by the engagement between the second internal gear 130B and the external gear 120B can be received by the second rolling element 116B disposed on the second internal gear 130B side, and the first internal gear 130A It is possible to prevent the first vibration body bearing 110A including the first rolling elements 116A corresponding to the external teeth 124A of the meshing external gear 120A from being affected.

  Since the first and second rolling elements 116A, 116B are cylindrical, the cylindrical external gears 120A, 120B are moved in the axial direction O by the vibration body bearing 110 including the first and second rolling elements 116A, 116B. It can be bent and deformed in parallel. That is, the external teeth 124A and 124B are not inclined with respect to the axial direction O, and mesh with the internal teeth 128A and 128B of the first and second internal gears 130A and 130B with a uniform force in the axial direction O. And it becomes possible to implement | achieve the mesh | engagement in the meshing area of the internal teeth and external teeth which should mesh | engage with the 1st internal gear 130A and the 2nd internal gear 130B, and external gear 120A, 120B originally. That is, the service life of the external teeth 124A and 124B and the internal teeth 128A and 128B can be extended, and the transmission torque in the flexure meshing gear device 100 can be increased and maintained.

  At the same time, the first and second rolling elements 116 </ b> A and 116 </ b> B are configured so that the force from the external gears 120 </ b> A and 120 </ b> B and the force from the vibrating body 104 are changed from “point” to “ It becomes possible to receive it by increasing it to a “line”. Here, as described above, since the rolling elements 116A and 116B are divided, the forces applied to the first and second rolling elements 116A and 116B provided in the vibration body bearing 110 do not affect each other. Therefore, the load resistance of the vibration body bearing 110 can be increased. For example, when comparing a ball bearing of the same size with a bearing having a cylindrical rolling element, the dynamic load rating of the bearing having a cylindrical rolling element is about 1.7 times larger, and the life of the bearing is about six times longer. Can be extended much more. Therefore, the vibration body bearing 110 can achieve greater torque transmission and longer life.

  Further, since the rolling elements are divided into at least two (first and second rolling elements 116A, 116B) in the axial direction O, the first and second rolling elements 116A, 116B are shortened in the axial direction O. For this reason, it is possible to reduce the occurrence of a skew problem in the first and second rolling elements 116A and 116B. Further, since it is not necessary to make the first and second rolling elements 116A and 116B unnecessarily large in order to extend the life, it is possible to prevent the vibration generating body bearing 110 from expanding in the radial direction.

  That is, according to the present invention, the flexure-type gear device 100 that can increase the load resistance of the vibration body bearing 110 and extend the life, increase the transmission torque, and maintain the transmission torque for a long time is realized. It becomes possible to do.

  Although the present invention has been described with reference to the present embodiment, the present invention is not limited to the present embodiment. That is, it goes without saying that improvements and design changes can be made without departing from the scope of the present invention.

  For example, in the present embodiment, the first and second rolling elements 116A and 116B correspond to portions corresponding to the external teeth 124A meshing with the first internal gear 130A and external teeth 124B meshing with the second internal gear 130B. However, the present invention is not limited to this. For example, in the second embodiment shown in FIG. 8A, the first and second rolling elements 117AA, 117AB, 117BA, and 117BB are connected to the portion corresponding to the external tooth 124A that meshes with the first internal gear 130A. The portions corresponding to the external teeth 124B meshing with the two internal gears 130B are each divided into two. In the third embodiment shown in FIG. 8B, the first and second rolling elements 119AA, 119AB, 119AC, 119BA, 119BB, and 119BC correspond to the external teeth 124A that mesh with the first internal gear 130A. The portions corresponding to the external teeth 124B meshing with the second internal gear 130B are further divided into three parts. In this way, by further dividing the rolling element at least one of the portion corresponding to the external teeth meshing with the first internal gear and the portion corresponding to the external teeth meshing with the second internal gear in the axial direction O, In addition to reducing the possibility of further skew being generated, it is possible to further reduce “per one-piece” by the rolling elements against external load fluctuations. For low cost, for example, the second rolling element is divided into three parts for the second internal gear, and two first rolling elements are used for the first internal gear. It is also possible to divide into two.

  In addition, not only the rolling elements are divided, but in at least one of a portion corresponding to the external teeth meshing with the first internal gear in the axial direction O and a portion corresponding to the external teeth meshing with the second internal gear. The cage may be divided (multiple cages are used). When a plurality of cages are used, since the rolling elements are not adjacent to each other in the axial direction O, loss due to friction between the rolling elements can be reduced. In addition, it is possible to easily change the characteristics of the vibrator bearing itself and partially replace the rolling elements for maintenance.

  Moreover, in the said embodiment, although the external teeth 124A and 124B were comprised with the cylindrical-shaped pin, this invention is not limited to this. For example, the external teeth 124A and 124B may be formed directly on the base member 122. That is, the external teeth do not have to be arc teeth, and trochoidal teeth may be used, or other teeth may be used. For the internal teeth, a tooth profile corresponding to the external teeth can be used.

  In the above embodiment, the difference i between the number of teeth of the internal teeth 128A of the first internal gear 130A and the number of teeth of the external teeth 124A of the external gear 120A is set to 2, but in the present invention this number of teeth is set. The difference i is not limited to 2. For example, an appropriate number may be used as long as it is an even number 2i of 2 or more. Further, the number of teeth of the virtual external gear 120C may be an appropriate number as long as it is smaller than the actual number of teeth of the external teeth 124A of the external gear 120A, and the virtual external gear 120C is not necessarily assumed.

Sectional drawing which shows the whole structure of an example of the bending meshing type gear apparatus which concerns on 1st Embodiment of this invention. Similarly side view of FIG. The figure which also shows a vibration body Similarly, an enlarged view for explaining the shape of the vibrator Schematic diagram of a combination of a vibrator and a vibrator bearing Similarly, a conceptual diagram of meshing between a virtual external gear and an internal gear Similarly, meshing diagram of external gear and internal gear Schematic of vibration body bearings according to second and third embodiments of the present invention Schematic diagram showing the relationship between the exciter and the external gear of the flexibly meshing gear device according to the prior art

Explanation of symbols

4, 104 ... vibrators 10, 109A, 109B, 110, 110A, 110B, 111A, 111B ... vibrator bodies (bearings, first vibrator bearings, second vibrator bearings)
12, 112 ... Inner ring 16, 116A, 116B, 117AA, 117AB, 117BA, 117BB, 119AA, 119AB, 119AC, 119BA, 119BB, 119BC ... rolling element (first rolling element, second rolling element)
18, 118A, 118B ... outer ring 20, 120A, 120B ... external gear 100 ... flexible meshing gear device 113A, 113B, 114A, 114B, 115A, 115B ... cage 120C ... virtual external gear 122 ... base member 124A, 124B ... external teeth 126A, 126B ... holding rings 128A, 128B ... internal teeth 130A ... first internal gears 130B ... second internal gears 132A, 132B ... bolt holes O ... rotary shaft X ... longitudinal direction Y of the vibrator ... Short axis direction of the vibrator FA ... First arc part SA ... Second arc part R ... Long axis radius of the vibrator R1 ... Curve radius of the first arc part of the vibrator R2 ... Second vibrator part Arc radius of curvature

Claims (2)

A vibrating body, a cylindrical external gear that is arranged on the outer periphery of the vibrating body and is flexibly deformed by the rotation of the vibrating body, and a rigidity with which the external gear meshes inwardly A first internal gear having a first internal gear, a second internal gear arranged in parallel with the first internal gear and having a rigidity for internal meshing with the external gear, the vibrator and the external gear, A flexibly meshing gear device comprising a bearing disposed between
The bearing includes a cylindrical rolling element , an inner ring disposed inside the rolling element, and an outer ring disposed outside the rolling element,
The external teeth of the external gear meshing with the first rolling element and the second internal gear corresponding to the external tooth portion of the external gear meshing with the first internal gear in the axial direction. is split into a second rolling bodies corresponding to the portion,
The outer ring is divided into a first outer ring corresponding to the first rolling element and a second outer ring corresponding to the second rolling element;
The inner ring is common to the first rolling element and the second rolling element . A flexibly meshing gear device, characterized in that: In claim 1,
At least one of the first and second rolling elements is further divided into a plurality of parts in the axial direction.

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