JP2009222168A - Rocking gear device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear device for which a commercial bearing can be used and whose inertia moment can be reduced without causing a tooth skipping phenomenon. <P>SOLUTION: The rocking gear device 10 includes a rigid internal gear 20, a flexible external gear 30, and a rocking generator 40. The rocking generator 40 has two circular contour eccentric rollers 41 each consisting of an eccentric cam 42 to be rotated in a predetermined eccentric state, a bearing 43 and a wheel 44, and the centers of the circular contours of the eccentric rollers 41 are overlapped with each other to be located a predetermined distance from a rotational axis XX in the mutually opposite directions. The outer peripheral face of each eccentric roller 41 has contact with the inner peripheral face of the flexible external gear 30 to deflect the flexible external gear 30 so that the flexible external gear 30 partially engages with the rigid internal gear 20. At this time, a curvature radius R at the engaging position of the flexible external gear 30 satisfies an expression 1: 2×(ε+R)=m×Zc and an expression 2: 2×π×R+4×ε=π×m×Zf, where R is the curvature radius at the engaging position of the flexible external gear, ε is the eccentricity of the eccentric roller, m is a module, Zc is the number of internal teeth, and Zf is the number of external teeth. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an oscillating gear device, and more particularly, a high accuracy, high reduction ratio used in a robot, a machine tool, a liquid crystal / semiconductor manufacturing apparatus, etc. that require high positioning accuracy, smooth rotation and quietness. The present invention relates to a rocking gear device having

  Conventionally, a wave gear device is known as a gear device that is lightweight, compact, and capable of obtaining high accuracy and a high reduction ratio without using a complicated mechanism or structure. The wave gear device partially meshes an elastic flexure meshing-type flexible external gear with an annular rigid internal gear, and uses the elastic flexibility to change the meshing position. A structure having a wave generator that moves in the circumferential direction by a difference in the number of teeth of both gears is representative. (See Patent Document 1).

  A typical wave gear device includes, as a specific configuration, an annular rigid internal gear, a cup-shaped flexible external gear disposed on the inside, and an elliptical wave fitted on the inside. And a generator. The flexible external gear is bent into an elliptical shape by a wave generator, and the external teeth at both ends of the major axis of the elliptical shape mesh with the internal teeth formed on the inner peripheral surface of the internal gear. Yes. When the wave generator is rotated by a motor rotating shaft or the like, the meshing position of both gears moves in the circumferential direction. Generally, since the internal gear side is fixed, rotation that is greatly decelerated according to the difference in the number of teeth of both gears is output from the cup-shaped flexible external gear side.

The wave generator includes a cam portion and a bearing formed in an elliptical shape. The cam portion serves to partially mesh the internal teeth of the rigid internal gear by bending the external teeth of the flexible external gear in the radial direction. The bearing has a ball, an inner ring, and an outer ring. The inner ring is fixed to the outer periphery of the cam portion, and the outer ring is fitted to the back side of the outer teeth of the flexible external gear, and is elastically deformed in accordance with the flexible external gear by the rotation of the cam portion.
JP-A-10-110790

  The conventional typical wave gear device has a problem that a commercially available bearing cannot be used because the wave generator uses a special bearing whose inner ring is elliptical and whose outer ring is elastically deformable. In addition, since the outer ring of the bearing is thin, when the overload is applied, the rigid inner gear and the flexible external gear are caused by the bending of the outer ring that occurs between the balls of the bearing. There is a possibility that a ratcheting phenomenon occurs in which the meshing momentarily shifts. Further, since the length of the long axis of the cam portion of the wave generator on the high speed rotation side has a large ratio to the inner diameter of the rigid internal gear, the moment of inertia tends to increase.

  An object of the present invention is to provide a gear device that can use a commercially available bearing, does not cause a ratcheting phenomenon even when an overload is applied, and can reduce the moment of inertia on the high-speed rotation side.

In order to solve the above-described problems, an oscillating gear device of the present invention includes an annular rigid internal gear, an annular flexible external gear disposed inside the rigid internal gear, and the flexibility. A swing generator fitted inside the external gear, the flexible external gear is bent, and the two gears are partially connected at two positions facing each other across the center of the rigid internal gear. An oscillating gear for generating relative rotation between the rigid internal gear and the flexible external gear by meshing and moving the meshing position of both gears in the circumferential direction by rotation of the oscillation generator A device,
The swing generator is disposed on an outer periphery of the eccentric cam, a circular contour eccentric cam that rotates eccentrically around a rotation axis of the swing generator, a bearing fitted on the outer periphery of the eccentric cam, and Two eccentric rollers each having a circular contour provided with a wheel, and the two eccentric rollers are overlapped so that the centers of the circular contours of the eccentric rollers are positioned away from the rotation shaft by the predetermined amount in the opposite directions. Arranged,
When the outer peripheral surface of the eccentric roller is in contact with the inner peripheral surface of the flexible external gear, the flexible external gear and the rigid internal gear are partially meshed at the two locations. When the flexible external gear is bent, the curvature radius R of the meshing position of the flexible external gear satisfies the following expressions (1) and (2).
2 × (ε + R) = m × Zc (1)
2 × π × R + 4 × ε = π × m × Zf (2)
However,
R: curvature radius of meshing position of flexible external gear ε: eccentric amount of eccentric roller m: module of rigid internal gear and flexible external gear Zc: number of teeth of rigid internal gear Zf: flexibility Number of teeth of external gear

In order to solve the above-described problem, the oscillating gear device of the present invention includes an annular rigid internal gear, an annular flexible external gear disposed inside the rigid internal gear, and the movable gear. A swing generator fitted inside the flexible external gear, the flexible external gear is bent, and both of the two internal parts are opposed to each other across the center of the rigid internal gear. Engaging the gears and moving the meshing position of both gears in the circumferential direction by the rotation of the oscillation generator, the oscillation causing relative rotation between the rigid internal gear and the flexible external gear. A dynamic gear device,
The swing generator is disposed on an outer periphery of the eccentric cam, a circular contour eccentric cam that rotates eccentrically around a rotation axis of the swing generator, a bearing fitted on the outer periphery of the eccentric cam, and Two eccentric rollers each having a circular contour provided with a wheel, and the two eccentric rollers are overlapped so that the centers of the circular contours of the eccentric rollers are positioned away from the rotation shaft by the predetermined amount in the opposite directions. Arranged,
When the outer peripheral surface of the eccentric roller contacts the inner peripheral surface of the flexible external gear, the central portion of the tooth width of the flexible external gear and the rigid internal gear are partially at the two locations. When the flexible external gear is bent so as to mesh with the internal gear, the radius of curvature R ₀ and the amount of eccentricity ε ₀ of the virtual opening of the flexible external gear without meshing the rigid internal gear. Satisfies the following formulas (3) and (4).
2 × (ε ₀ + R ₀ ) = m × {Zc + (Zc−Zf) × 0.5 × b / S} (3)
2 × π × R ₀ + 4 × ε ₀ = π × m × Zf (4)
However,
R ₀ : radius of curvature of virtual opening of flexible external gear ε ₀ : eccentric amount of virtual opening m: module of rigid internal gear and flexible external gear Zc: number of teeth of rigid internal gear Zf : Number of teeth of flexible external gear b: tooth width of flexible external gear S: length from bottom surface of flexible external gear to center of tooth width

  According to the above configuration, the eccentric cam has a circular contour, and it is not necessary to use a special bearing having an elliptical inner ring and an elastically deformable outer ring. Therefore, a commercially available bearing is used as a bearing that fits on the outer periphery of the eccentric cam. can do. The eccentric roller has a wheel on the outer periphery of the bearing, and the outer peripheral surface of the wheel contacts the inner peripheral surface of the flexible external gear, so that it can be elastically deformed on the back surface of the external tooth of the flexible external gear. It is not necessary to use a bearing having a thin outer ring, and it is possible to suppress the occurrence of a ratcheting phenomenon due to bending of the thin outer ring that can be elastically deformed. Further, the swing generator has two eccentric rollers, and is arranged so that the centers of the circular contours of the eccentric rollers are positioned a predetermined amount away from each other in the opposite directions from the rotation shaft. There is no need to use an elliptical cam and the ratio of the eccentric cam diameter to the inner peripheral diameter of the rigid internal gear can be reduced, so that the moment of inertia on the high speed rotation side can be reduced.

  According to the oscillating gear device of the present invention, it is possible to use a commercially available bearing, and to provide a gear device capable of reducing the moment of inertia on the high-speed rotation side without causing ratcheting phenomenon even when an overload is applied. be able to.

  Hereinafter, an oscillating gear device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view of a rocking gear device according to an embodiment of the present invention. As shown in FIG. 1, the oscillating gear device 10 includes an annular rigid internal gear 20, an annular flexible external gear 30 that can be elastically deformed, and an oscillation generator 40.

  The rigid internal gear 20 includes an internal tooth portion 21 formed on an inner peripheral surface, and a fixing bolt hole 22 for fixing the rigid internal gear 20 to a fixing member (not shown). The flexible external gear 30 has a cup shape, and an output rotating shaft mounting bolt for connection to an external tooth portion 31 formed on the outer peripheral surface of the cup on the opening side and an output rotating shaft (not shown). And a hole 33. The external teeth 31 are formed with external teeth having a tooth width WW. The swing generator 40 includes two eccentric rollers 41 and an input rotating shaft mounting portion 45.

  FIG. 2 is a cross-sectional view of the oscillating gear device according to the embodiment of the present invention, and includes a rotation shaft of the oscillation generator and a long axis of the flexible external gear bent by the oscillation generator. It is sectional drawing in a plane. FIG. 3 is a cross-sectional view taken along line AA in FIG. As shown in FIGS. 2 and 3, the oscillating gear device 10 has a flexible external gear 30 disposed inside a rigid internal gear 20, and a oscillating generator inside the flexible external gear 30. 40 is inserted to bend the flexible external gear 30, thereby forming the internal teeth formed on the internal tooth portion 21 of the rigid internal gear 20 and the external tooth portion 31 of the flexible external gear 30. These external teeth are configured to mesh with each other at two positions facing each other across the center of the rigid internal gear 20, that is, meshing positions P and Q.

  The rigid internal gear 20 is formed of a rigid body. The flexible external gear 30 may be entirely formed of a flexible material, but is formed of a flexible material except at least the output rotation shaft mounting portion 32 provided annularly on the cup-shaped bottom surface. And is formed thin so as to be elastically deformable. The output rotating shaft mounting portion 32 is formed thicker than other portions, and is provided with an output rotating shaft mounting bolt hole 33. In addition, the external tooth part 31 is also comprised so that elastic deformation is possible.

  The swing generator 40 has two eccentric rollers 41 having a circular contour. The eccentric roller 41 is arranged on a circular contour eccentric cam 42 that rotates eccentrically around the rotation axis XX of the swing generator, a bearing 43 fitted on the outer periphery of the eccentric cam 42, and an outer periphery of the bearing 43. And a wheel 44. The eccentric cam 42 is fixed to the input rotating shaft mounting portion 45.

  FIG. 4 is an explanatory view schematically showing an arrangement state of two eccentric rollers. As shown in FIG. 4, the two eccentric rollers 41 are arranged such that the center 41 a of the circular contour of each eccentric roller is located a predetermined amount (ε) away from the rotation axis XX of the swing generator 40 in the opposite directions. , Are arranged in layers. Since the swing generator 40 has such a shape, when the swing generator 40 is fitted inside the flexible external gear 30, the outer peripheral surface of the eccentric roller 41 becomes the flexible external gear. 30, the flexible external gear 30 bends in contact with the inner peripheral surface of the external tooth portion 31, and the external teeth of the flexible external gear 30 are the internal teeth of the rigid internal gear 20 and the rigid internal gear 20. Are engaged at two opposite locations (see FIG. 3).

  As described above, the oscillating gear device 10 of the present embodiment is different from the wave generator having the elliptical cam and the bearing having the elastically deformable outer ring of the conventional wave gear device, having two circular outlines. A rocker having an eccentric roller 41 and arranged so that the center 41a of the circular contour of each eccentric roller 41 is located at a predetermined distance away from the rotation axis XX of the rocking generator 40 in the opposite direction. A motion generator 40 is provided. Therefore, in the oscillating gear device 10 of this embodiment, the eccentric cam 42 used for the eccentric roller 41 has a circular contour, and it is not necessary to use a special bearing having an elliptical inner ring and an elastically deformable outer ring. Therefore, a commercially available bearing can be used for the bearing 43 fitted to the outer periphery of the eccentric cam 42. Further, since it is not necessary to use a bearing having a thin outer ring that can be elastically deformed on the back surface of the external teeth of the flexible external gear 30, by providing a wheel 44 outside the bearing 43, a thin wall that can be elastically deformed is provided. Occurrence of the ratcheting phenomenon due to the bending of the outer ring can be suppressed. Furthermore, since the ratio of the diameter of the eccentric cam 42 to the diameter of the rigid internal gear 20 is small, the moment of inertia on the high-speed rotation side can be reduced.

  Next, operation | movement of the rocking gear apparatus 10 is demonstrated using FIG. FIG. 5 is an explanatory diagram of the operation of the oscillating gear device according to the embodiment of the present invention.

  In the swing generator 10 of the present embodiment, when the input rotation shaft is attached to the input rotation shaft mounting portion 45 of the swing generator 40 and driven by a motor or the like, the swing generator 40 starts rotating.

  As shown in FIG. 5, before the rotation, the internal teeth indicated by the oblique lines of the rigid internal gear 20 and the external teeth indicated by the black of the flexible external gear 30 mesh with each other. When the swing generator 40 rotates 90 degrees, the meshing position moves 90 degrees in the circumferential direction. Since the difference between the number of teeth of the internal gear 20 of the rigid internal gear 20 and the number of teeth of the external gear 30 of the flexible external gear 30 is two in the rocking gear device 10 of the present embodiment, the rocking generator 40 is engaged. In order for the meshing position to return to the internal teeth indicated by the diagonal lines of the rigid internal gear 20, the flexible external gear 30 has two external teeth plus two teeth. You have to rotate for minutes. That is, when the swing generator 40 rotates 360 degrees, the external teeth adjacent to the external teeth shown in black are meshed with the internal teeth shown in diagonal lines. As a result, the flexible external gear 30 rotates relative to the rotation direction of the oscillation generator 40 by the number of teeth of two sheets. In the oscillation generating device 10 of the present embodiment, the rigid internal gear 20 is fixed so as not to rotate relatively, so that the flexible external gear 30 is greatly changed according to the number of teeth between the internal teeth and the external teeth. It is possible to output the decelerated rotation.

Here, the swing generator 40 is fitted inside the flexible external gear 30, and the outer peripheral surface of the eccentric roller 41 comes into contact with the inner peripheral surface of the flexible external gear 30. When the flexible external gear 30 is bent so that the gear 30 and the rigid internal gear 20 are partially meshed at two locations, the curvature radius R of the meshed position of the flexible external gear 30 is as follows. Expressions (1) and (2) are satisfied.
(1) 2 × (ε + R) = m × Zc
(2) 2 × π × R + 4 × ε = π × m × Zf
Where R is the radius of curvature of the meshing position of the flexible external gear 30, ε is the amount of eccentricity of the eccentric roller 41, m is the module of the rigid internal gear 20 and the flexible external gear 30, and Zc is the rigid internal gear. The number of teeth of the gear 20, Zf, is the number of teeth of the flexible external gear 30.

  The above formula (1) will be described with reference to FIG. FIG. 6 is an explanatory diagram showing the relationship between the pitch circle of the rigid internal gear of the oscillating gear device according to the embodiment of the present invention and the outline of the meshing position of the deformed flexible external gear. As shown in FIG. 6, the pitch circle 211 of the rigid internal gear 20 is circular, and the diameter thereof is equal to the number of teeth Zc of the rigid internal gear 20 as shown on the right side of the above formula (1). Multiply by module m.

  On the other hand, the swing generator 40 is fitted inside the flexible external gear 30 so that the external teeth of the flexible external gear 30 and the internal teeth of the rigid internal gear 20 are in meshing position P and meshing position Q. The outline of the meshing position of the flexible external gear 30 in the state of meshing at these two locations is shown in FIG. 6 as the outline 312 of the meshing position of the flexible external gear 30 after deformation. As apparent from FIG. 6, the length of the major axis of the meshing position outline 312 of the flexible external gear 30 after deformation, that is, the distance between the meshing positions P and Q is determined by the pitch circle of the rigid internal gear 20. Equal to the diameter of 211. The distance between the PQs can be obtained as the left side of the above equation (1) using the curvature radius R of the meshing position and the amount of eccentricity ε. Therefore, the curvature radius R of the meshing position of the flexible external gear 30 satisfies the above formula (1).

  Note that, at the meshing position of the flexible external gear 30 and the rigid internal gear 20, the flexible external gear 30 meshes in a deformed state, that is, in a state where the external teeth are inclined with respect to the internal teeth. In the center of the tooth width WW of the flexible external gear 30 shown in FIG. Therefore, the contour 312 of the meshing position of the deformed flexible external gear 30 normally matches the contour of the central portion of the tooth width WW of the deformed flexible external gear 30.

  Next, the above formula (2) will be described with reference to FIG. FIG. 7 is an explanatory diagram showing the outline of the meshing position before and after the deformation of the flexible external gear of the rocking gear device according to the embodiment of the present invention. As shown in FIG. 7, since the flexible external gear 30 is originally cup-shaped, the pitch circle 311 of the flexible external gear 30 before deformation is circular, and the length of this contour (circumference). Can be obtained using the number of teeth Zf of the flexible external gear 30 and the module m of this gear, as shown on the right side of the above equation (2).

  On the other hand, the contour 312 of the meshing position of the flexible external gear 30 after the deformation is as shown in FIG. 7, but the length of the contour of the meshing position of the flexible external gear 30 changes before and after the deformation. Therefore, the left side of the equation (2) in which the length of the contour 312 of the meshing position of the flexible external gear 30 after deformation is expressed using the curvature radius R and the eccentricity ε of the meshing position, and the deformation Naturally, the right side of the expression (2) in which the circumference of the pitch circle 311 of the previous flexible external gear 30 is expressed using the number of teeth Zf and the module m is equal. Therefore, the curvature radius R of the meshing position of the flexible external gear 30 satisfies the above formula (2).

  As described above, in the oscillating gear device 10 of the present invention, the curvature radius R of the meshing position of the flexible external gear 30 satisfies the above formulas (1) and (2).

Further, the swing generator 40 is fitted inside the flexible external gear 30, and the outer peripheral surface of the eccentric roller 41 comes into contact with the inner peripheral surface of the flexible external gear 30. When the flexible external gear 30 is bent so that the central portion of the 30 tooth width WW and the rigid internal gear 20 are partially meshed at two locations, the rigid internal gear is not meshed. The radius of curvature R ₀ and the amount of eccentricity ε ₀ of the virtual opening of the flexible external gear 30 satisfy the following expressions (3) and (4).
(3) 2 × (ε ₀ + R ₀ ) = m × {Zc + (Zc−Zf) × 0.5 × b / S}
(4) 2 × π × R ₀ + 4 × ε ₀ = π × m × Zf
Where R ₀ is the radius of curvature of the virtual opening of the flexible external gear 30, ε ₀ is the amount of eccentricity of the virtual opening, m is the module of the rigid internal gear 20 and the flexible external gear 30, and Zc is The number of teeth of the rigid internal gear 20, Zf is the number of teeth of the flexible external gear 30, b is the length of the tooth width WW of the flexible external gear 30, and S is the bottom surface of the flexible external gear 30. To the center of the tooth width WW.

In other words, the swing generator 40 is fitted inside the flexible external gear 30, and the outer peripheral surface of the eccentric roller 41 comes into contact with the inner peripheral surface of the flexible external gear 30. The flexible external gear 30 is bent so that the gear 30 partially meshes with the rigid internal gear 20, and the curvature radius R of the meshed position of the flexible external gear 30 is expressed by the above formulas (1) and (2 ), The radius of curvature R ₀ of the virtual opening of the flexible external gear 30 and the eccentricity when it is assumed that the rigid external gear 30 is not meshed with the deformed flexible external gear 30. The quantity ε ₀ means that the above expressions (3) and (4) are satisfied.

The above formulas (3) and (4) will be described with reference to FIGS. 8 (a) and 8 (b). FIG. 8A illustrates the relationship between the meshing position of the flexible external gear and the contour of the opening and the pitch circle of the rigid internal gear after the deformation of the oscillating gear device according to the embodiment of the present invention. It is a figure, (b) is a side view of the flexible external gear after a deformation | transformation. As shown in FIG. 8A, the length of the major axis of the contour 313 of the opening of the flexible external gear 30 after deformation is longer than the diameter of the pitch circle 211 of the rigid internal gear 20. Accordingly, the curvature radius R ₀ of the contour 313 of the opening of the flexible external gear 30 after deformation is smaller than the curvature radius R of the meshing position, and the eccentricity ε ₀ is larger than the eccentricity ε of the meshing position. Therefore, the length of the major axis of the contour 313 of the opening of the flexible external gear 30 after deformation can be obtained from R ₀ and ε ₀ as in the left side of Expression (3). Further, the length of the major axis of the contour 313 of the opening of the flexible external gear 30 after the deformation is from the pitch circle 211 of the rigid internal gear 20 of the opening of the flexible external gear 30 after the deformation. By adding the length of the portion where the contour 313 protrudes to the diameter of the pitch circle 211 of the rigid internal gear 20, it can be obtained as in the right side of Expression (3). This protruding length (one side) is a right triangle whose hypotenuse is b / 2 shown in FIG. 8B (half the width WW of the flexible external gear 30 shown in FIG. 1). Equal to the height of. Accordingly, the radius of curvature R ₀ and the amount of eccentricity ε ₀ of the contour 313 of the opening of the flexible external gear 30 after deformation satisfy Expression (3).

Further, since the length of the contour of the meshing position of the flexible external gear 30 does not change before and after the deformation, the length of the contour 313 of the opening of the flexible external gear 30 after the deformation is set to R. Expression (4) expressing the left side of Expression (4) expressed using ₀ and ε ₀ and the circumference of pitch circle 311 of flexible external gear 30 before deformation using the number of teeth Zf and module m The right side of is naturally equal. Accordingly, the radius of curvature R ₀ and the amount of eccentricity ε ₀ of the contour 313 of the opening of the flexible external gear 30 after deformation satisfy Expression (4).

Note that the opening of the deformed flexible external gear 30 that satisfies the above formulas (3) and (4) has the rigid internal gear 20 in the deformed flexible external gear 30 as described above. Since it is a virtual opening when it is assumed that the mesh is not meshed, and the rigid internal gear 20 is actually meshed, the contour 313 of the opening of the flexible external gear 30 after deformation is the rigid internal gear 20. The portion protruding from the pitch circle 211, that is, the arc portion between the two points shown as the meshing branch point 212 in FIG. 8A is in an interference state, and the entire portion of the opening portion of the flexible external gear 30 is rigid. Since it meshes with the internal gear 20, the flexible external gear 30 is further deformed. Here, a straight line connecting the meshing branch point 212 and the center of the flexible external gear 30 (which coincides with the center of the rigid internal gear 20), and the outline of the opening of the flexible external gear 30 after deformation. An angle θ (see FIG. 8A) formed with a straight line including the major axis 313 can be obtained by the following equation (5).
(5) θ = cos ⁻¹ [{(m × Zc / 2) ² −R ₀ ² + ε ₀ ² } / (m × Zc × ε ₀ )]
Therefore, in the actual meshing position of the internal gear and the external gear of the oscillating gear device 10, the arc portion in the range corresponding to the angle 2θ is rigid in the contour 313 of the opening of the flexible external gear 30 after deformation. It is meshed with the internal gear 20.

  The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made within the scope shown in the claims.

It is a disassembled perspective view of the rocking gear apparatus in one Embodiment of this invention. It is sectional drawing of the rocking gear apparatus in one Embodiment of this invention. It is the sectional view on the AA line of FIG. It is explanatory drawing which shows typically the arrangement | positioning state of two eccentric rollers. It is explanatory drawing of operation | movement of the rocking gear apparatus in one Embodiment of this invention. It is explanatory drawing which shows the relationship between the pitch circle of the rigid internal gear of the rocking | fluctuation gear apparatus in one Embodiment of this invention, and the outline of the meshing of the flexible external gear after a deformation | transformation. It is explanatory drawing which shows the relationship between the pitch circle before a deformation | transformation of the flexible external gear of the rocking gear apparatus in one Embodiment of this invention, and the outline of the meshing after a deformation | transformation. (A) is explanatory drawing which shows the relationship between the meshing position of the flexible external gear after a deformation | transformation of the rocking gear apparatus in one Embodiment of this invention, the outline of an opening part, and the pitch circle of a rigid internal gear. FIG. 4B is a side view of the flexible external gear after deformation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Oscillating gear apparatus 20 Rigid internal gear 21 Internal tooth part 22 Fixing bolt hole 30 Flexible external gear 31 External tooth part 32 Output rotating shaft attaching part 33 Output rotating shaft attaching bolt hole 40 Swing generator 41 Eccentric roller 41a Center of circular contour of eccentric roller 42 Eccentric cam 43 Bearing 44 Wheel 45 Input rotating shaft mounting portion 211 Pitch circle of rigid internal gear 212 Meshing branch point 311 Pitch circle 312 of flexible external gear before deformation 312 Deformation Outline of meshing position of rear flexible external gear 313 Outline of opening of flexible external gear after deformation P, Q Meshing position WW Gear width of flexible external gear XX Rotation of oscillation generator axis

Claims (2)

An annular rigid internal gear, an annular flexible external gear disposed inside the rigid internal gear, and a swing generator fitted inside the flexible external gear The flexible external gear is bent so that the two gears are partially meshed at two positions facing each other across the center of the rigid internal gear, and the meshing position of both gears is determined by the rotation of the oscillation generator. An oscillating gear device that causes relative rotation between the rigid internal gear and the flexible external gear by moving in a circumferential direction,
The swing generator is disposed on an outer periphery of the eccentric cam, a circular contour eccentric cam that rotates eccentrically around a rotation axis of the swing generator, a bearing fitted on the outer periphery of the eccentric cam, and Two eccentric rollers each having a circular contour provided with a wheel, and the two eccentric rollers are overlapped so that the centers of the circular contours of the eccentric rollers are positioned away from the rotation shaft by the predetermined amount in the opposite directions. Arranged,
When the outer peripheral surface of the eccentric roller is in contact with the inner peripheral surface of the flexible external gear, the flexible external gear and the rigid internal gear are partially meshed at the two locations. When the flexible external gear is bent, the curvature radius R of the meshing position of the flexible external gear satisfies the following expressions (1) and (2).
2 × (ε + R) = m × Zc (1)
2 × π × R + 4 × ε = π × m × Zf (2)
However,
R: curvature radius of meshing position of flexible external gear ε: eccentric amount of eccentric roller m: module of rigid internal gear and flexible external gear Zc: number of teeth of rigid internal gear Zf: flexibility Number of teeth of external gear An annular rigid internal gear, an annular flexible external gear disposed inside the rigid internal gear, and a swing generator fitted inside the flexible external gear The flexible external gear is bent so that the two gears are partially meshed at two positions facing each other across the center of the rigid internal gear, and the meshing position of both gears is determined by the rotation of the oscillation generator. An oscillating gear device that causes relative rotation between the rigid internal gear and the flexible external gear by moving in a circumferential direction,
The swing generator is disposed on an outer periphery of the eccentric cam, a circular contour eccentric cam that rotates eccentrically around a rotation axis of the swing generator, a bearing fitted on the outer periphery of the eccentric cam, and Two eccentric rollers each having a circular contour provided with a wheel, and the two eccentric rollers are overlapped so that the centers of the circular contours of the eccentric rollers are positioned away from the rotation shaft by the predetermined amount in the opposite directions. Arranged,
When the outer peripheral surface of the eccentric roller contacts the inner peripheral surface of the flexible external gear, the central portion of the tooth width of the flexible external gear and the rigid internal gear are partially at the two locations. When the flexible external gear is bent so as to mesh with the internal gear, the radius of curvature R ₀ and the amount of eccentricity ε ₀ of the virtual opening of the flexible external gear without meshing the rigid internal gear. Satisfies the following expressions (3) and (4).
2 × (ε ₀ + R ₀ ) = m × {Zc + (Zc−Zf) × 0.5 × b / S} (3)
2 × π × R ₀ + 4 × ε ₀ = π × m × Zf (4)
However,
R ₀ : radius of curvature of virtual opening of flexible external gear ε ₀ : eccentric amount of virtual opening m: module of rigid internal gear and flexible external gear Zc: number of teeth of rigid internal gear Zf : Number of teeth of flexible external gear b: tooth width of flexible external gear S: length from bottom surface of flexible external gear to center of tooth width

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