JP2020067093A - Gear mechanism and inscribed planetary gear speed reduction mechanism - Google Patents

Abstract

To provide a gear mechanism having a new tooth shape formed to have compactness and to satisfy an isokinetic property.SOLUTION: In a gear mechanism including a fixed gear, and a moving gear engaged with the fixed gear and revolving on a revolution center while auto-rotating, a tooth of one of the fixed gear and the moving gear has a first addendum portion, and a pair of first tooth side portions positioned at both sides of the first addendum portion and kept into contact with a tooth of the other of the fixed gear and the moving gear. Each of the pair of first tooth side portions has a circular arc shape, and center positions of the circular arc shapes are different from each other. The other tooth has a second addendum portion, and a pair of second tooth side portions positioned at both sides of the second addendum portion and kept into contact with the tooth of one side. The shapes of the pair of second tooth side portions are formed so that a moving locus of an intersection q of a common normal line N at a contact portion of the first tooth side portion with the second tooth side portion and a straight line L connecting a center of revolution and a center of auto-rotation O2, becomes a circular locus on the center of revolution, from start of the contact of the first tooth side portion with the second tooth side portion to termination of the contact.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a gear mechanism and an inscribed planetary gear reducer.

  A gear mechanism that includes a fixed gear that is fixed and a moving gear that meshes with the fixed gear and that revolves around a center of revolution while revolving about a center of revolution is well known. Such a gear mechanism is widely used and, for example, is employed in an inscribed planetary gear reducer (for example, Patent Document 1).

JP 2016-133179 JP

  Conventionally, as such a gear mechanism, one in which the tooth profile of the gear is configured by an involute curve has been known. Although the gear mechanism related to such an involute curve satisfies the constant velocity property which is one of the properties of the gear, it has a drawback that a high reduction ratio cannot be obtained due to interference in meshing of gears, A gear mechanism having a tooth shape has been demanded.

  Further, a gear having a semicircular tooth shape is known, but such a gear has a drawback that the pitch becomes large (each tooth becomes large) and it cannot be made compact.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a gear mechanism having a new tooth shape that is compact and that is formed to satisfy constant velocity. .

The main invention for achieving the above object is:
A fixed gear, a gear mechanism comprising: a moving gear that meshes with the fixed gear and revolves around a revolution center while rotating about a rotation center.
One of the teeth of the fixed gear and the movable gear is located on both sides of the first tooth tip and the first tooth tip, and a pair of first teeth that are in contact with the other teeth of the fixed gear and the movable gear. And a tooth side portion,
Each of the pair of first tooth side portions has an arc shape, the center position of each arc shape is different from each other,
The other tooth has a second tooth tip portion and a pair of second tooth side portions that are located on both sides of the second tooth tip portion and are in contact with the one tooth,
The shape of the pair of second tooth side portions,
A common normal line in a contact portion of the first tooth side portion to the second tooth side portion, and a movement locus of an intersection of a straight line connecting the revolution center and the rotation center,
From the start of contact of the first tooth side portion with the second tooth side portion until the end of contact, so as to form a circular locus around the center of revolution,
It is a gear mechanism characterized by being formed.

  Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

It is explanatory drawing for demonstrating the inscribed planetary gear reducer 10 which concerns on this Embodiment. It is an AA sectional view of FIG. It is an explanatory view for explaining the external teeth 42 and the internal teeth 52. It is an explanatory view for explaining the conditions which satisfy constant velocity property. FIG. 6 is a diagram showing a state of the planetary external gear 40 and the fixed internal gear 50 from when the outer teeth 42 start to mesh with the inner teeth 52 to when the outer teeth 42 finish meshing. It is explanatory drawing for demonstrating the predominance of the shape of the external tooth | gear 42 which concerns on this Embodiment. It is explanatory drawing for demonstrating the inscribed planetary gear reducer 10 which concerns on a modification. FIG. 8 is a sectional view taken along line AA of FIG. 7. FIG. 8 is a sectional view taken along line BB of FIG. 7.

  At least the following matters will be made clear by the description in the present specification and the accompanying drawings.

A fixed gear, a gear mechanism comprising: a moving gear that meshes with the fixed gear and revolves around a revolution center while rotating about a rotation center.
One of the teeth of the fixed gear and the movable gear is located on both sides of the first tooth tip and the first tooth tip, and a pair of first teeth that are in contact with the other teeth of the fixed gear and the movable gear. And a tooth side portion,
Each of the pair of first tooth side portions has an arc shape, the center position of each arc shape is different from each other,
The other tooth has a second tooth tip portion and a pair of second tooth side portions that are located on both sides of the second tooth tip portion and are in contact with the one tooth,
The shape of the pair of second tooth side portions,
A common normal line in a contact portion of the first tooth side portion to the second tooth side portion, and a movement locus of an intersection of a straight line connecting the revolution center and the rotation center,
From the start of contact of the first tooth side portion with the second tooth side portion until the end of contact, so as to form a circular locus around the center of revolution,
A gear mechanism characterized by being formed.

  According to such a gear mechanism, it is possible to provide a gear mechanism having a new tooth shape that is compact and has a constant speed.

Such a gear mechanism,
The fixed gear is an internal gear,
The moving gear may be an external gear.

  According to such a gear mechanism, the gear mechanism can be applied to an inscribed planetary gear reducer or the like.

Such a gear mechanism,
An input shaft, an eccentric shaft integrally provided with the input shaft, and an eccentric bearing for receiving the eccentric shaft,
The moving gear is attached to the eccentric shaft via the eccentric bearing,
The input shaft rotates integrally with the eccentric shaft so that the eccentric shaft revolves eccentrically to revolve the moving gear while rotating.
The center of revolution may be the center of the input shaft.

  According to such a gear mechanism, it is possible to easily realize a gear mechanism having a new tooth shape that is compact and has a constant speed.

  Next, an inscribed planetary gear reducer characterized by including the above gear mechanism.

  According to such an inscribed planetary gear reducer, it is possible to provide an inscribed planetary gear reducer having a new tooth shape which is compact and is formed so as to satisfy constant velocity.

=== Regarding the internal planetary gear reducer 10 according to the present embodiment ===
Next, the gear mechanism 1 according to the present embodiment (specifically, the internal planetary gear reducer 10) will be described with reference to FIGS. 1 and 2. FIG. 1 is an explanatory diagram for explaining an inscribed planetary gear reducer 10 according to the present embodiment. FIG. 2 is a sectional view taken along line AA of FIG.

  The internal planetary gear reducer 10 includes an input shaft 20, a crankshaft 30 (corresponding to an eccentric shaft), a crank bearing 32 (corresponding to an eccentric bearing), a planetary external gear 40 (corresponding to a moving gear), and a fixed shaft. An internal gear 50 (corresponding to a fixed gear), a pin 60, and an output shaft 70 are provided.

  The input shaft 20 is rotatably supported by an input bearing 22 fixed to the housing 12, and is connected to a drive source (motor or the like) not shown. Then, the driving force of the driving source is transmitted to the input shaft 20, so that the input shaft 20 is rotated.

  The crankshaft 30 is provided integrally with the input shaft 20 at the tip of the input shaft 20. The crankshaft 30 is a so-called eccentric shaft, and is configured to rotate eccentrically when the input shaft 20 rotates.

  The crank bearing 32 is a bearing that receives the crankshaft 30. The crank bearing 32 is located outside the crankshaft 30 as shown in FIG.

  The planetary external gear 40 is an external gear attached to the crankshaft 30 via a crank bearing 32. As shown in FIG. 2, the planetary external gear 40 is attached to the crankshaft 30 such that the crankshaft bearing 32 is located outside the crankshaft 30 and the planetary external gear 40 is located outside the crankshaft bearing 32. That is, inside the planetary external gear 40, a hole for accommodating the crank bearing 32 and the crankshaft 30 is provided.

  The fixed internal gear 50 is an internal gear fixed to the housing 12 with the screw 14. Therefore, the fixed internal gear 50 cannot move (rotate).

  The planetary external gear 40 meshes with the fixed internal gear 50. Specifically, since the crankshaft 30 is an eccentric shaft, the fixed internal gear 50 and the planetary external gear 40 mesh (contact with each other, see reference numeral A1 in FIG. 2) at the top dead center of the crankshaft 30, The fixed internal gear 50 and the planetary external gear 40 do not mesh with each other at the bottom dead center position of the shaft 30 (there is a gap, see reference numeral A2 in FIG. 2).

  When the crankshaft 30 eccentrically rotates, the top dead center position moves along the circumferential direction. By the movement of the top dead center position, the planetary external gear 40 revolves around the revolution center while rotating about the rotation center while changing the contact position with the fixed internal gear 50. The center of revolution of the planetary external gear 40 is the center of the input shaft 20 and is fixed. On the other hand, the rotation center moves because the planetary external gear 40 revolves (performs a circular motion centering on the rotation center).

  The pin 60 is for transmitting the rotation motion of the planetary external gear 40 to the output shaft 70. As shown in FIG. 2, the planetary gear 40 has six pin holes 40a formed at equal intervals along the circumferential direction. Then, the pins 60 are inserted into the respective pin holes 40a in a state along the axial direction of the input shaft 20 (thus, six pins 60 are provided). The pins 60 are fixed to the output shaft 70 at equal intervals along the circumferential direction. Therefore, when the planetary outer gear 40 rotates, the pin 60 is pushed by the pin hole 40a and the output shaft 70 rotates.

  The diameter of the pin hole 40a is larger than the diameter of the pin 60 by twice the amount of eccentricity. That is, there is a gap between the pin hole 40a and the pin 60, and this gap absorbs misalignment due to eccentricity.

  The output shaft 70 is rotatably supported by an output bearing 72 fixed to the housing 12. The central axis of the output shaft 70 is located on the extension line of the central axis of the input shaft 20, and the axial directions of both central axes coincide.

  Next, the operation of the inscribed planetary gear reducer 10 will be described.

  When the driving force of the driving source is transmitted to the input shaft 20 and the input shaft 20 rotates, the crankshaft 30 rotates eccentrically together with the input shaft 20. When the crankshaft 30 is eccentrically rotated, the planetary external gear 40 performs a rotational movement and an orbital movement while changing the contact position with the fixed internal gear 50. That is, when the input shaft 20 rotates integrally with the crankshaft 30, the crankshaft 30 eccentrically rotates, and the planetary external gear 40 revolves while rotating.

  Here, when the input shaft 20 (crank shaft 30) makes one revolution, the planetary external gear 40 revolves once, but during one revolution of the planetary external gear 40, the planetary external gear 40 is fixed to the planetary external gear 40. Rotation of the difference in the number of teeth of the internal gear 50 is performed (where the number of teeth of the planetary external gear 40 is Z1 and the number of teeth of the fixed internal gear 50 is Z2, (Z2-Z1) / Z1 times of rotation).

  In the present embodiment, the planetary external gear 40 has 50 teeth and the fixed internal gear 50 has 51 teeth. Therefore, the planetary external gear 40 rotates (51-50) / 50 = 1/50 during one revolution (in other words, one revolution during 50 revolutions).

When the outer planetary gear 40 rotates, this rotation is transmitted to the output shaft 70 by the pin 60, and the output shaft 70 rotates. Since the output shaft 70 makes one rotation when the planetary external gear 40 makes one rotation, when the input shaft 20 (crank shaft 30) makes one rotation, the output shaft makes (Z2-Z1) / Z1 rotation (in the present embodiment, 1 / 50) will be done. Therefore, the reduction ratio of the internal planetary gear reducer 10 is Z1 / (Z2-Z1) (50 in the present embodiment).
<<< Composition of Teeth of Planetary External Gear 40 and Teeth of Fixed Internal Gear 50 >>>
Next, the configuration of the teeth of the planetary external gear 40 (hereinafter referred to as the external teeth 42) and the teeth of the fixed internal gear 50 (hereinafter referred to as the internal teeth 52) will be described with reference to FIGS. 3 to 5. FIG. 3 is an explanatory diagram for explaining the outer teeth 42 and the inner teeth 52. FIG. 4 is an explanatory diagram for explaining conditions that satisfy constant velocity. FIG. 5 will be described later. In addition, in FIG. 3 and FIG. 4, for the sake of clarity, only one external tooth 42 (internal tooth 52) is shown and the other external tooth 42 (internal tooth 52) is omitted for convenience. There is.

  One of the outer teeth 42 and the inner teeth 52 (in the present embodiment, the outer teeth 42) has a tooth side portion having an arc curve different from an involute curve generally used in gears. That is, the outer teeth 42 are located on both sides of the outer tooth tip portion 43 (corresponding to the first tooth tip portion and not in the shape of an arc) and on the both sides of the outer tooth tip portion 43, and are in contact with the inner tooth 52. And a portion 44 (corresponding to the first tooth side portion), and each of the pair of outer tooth side portions 44 has an arc shape. The center positions C1 and C2 of the respective arc shapes are different from each other.

  On the other hand, the other side of the outer teeth 42 and the inner teeth 52 (in the present embodiment, the inner teeth 52) is determined (designed) in shape of the tooth side portion so as to satisfy constant velocity. Here, the constant velocity means that when the planetary external gear 40 revolves at a constant angular velocity due to the eccentric rotation of the crankshaft 30 by the drive source, the rotational motion of the planetary external gear 40 does not stir and the planetary external gear 40 also rotates at a constant angular velocity. Says the nature that takes place in. Then, the shape of the tooth side portion is designed so that the constant velocity property is satisfied, in other words, the ratio of the revolution angular velocity and the rotation angular velocity is constant.

  That is, the inner teeth 52 are located on both sides of the inner tooth tip 53 (corresponding to the second tooth tip) and contact the outer tooth 42 by a pair of inner tooth side portions 54 (second teeth). (Corresponding to the tooth side portion), and the shape of each of the pair of inner tooth side portions 54 is determined so as to satisfy constant velocity (different from the involute curve and the arc curve). .

  Hereinafter, how the shape of the inner tooth side portion 54 is determined will be described with reference to FIGS. 4 and 5.

が成立し、

となり、公転角速度ω₁と自転角速度ω₂の速度比は以下のように求められる。 When the revolution angular velocity of the planetary external gear 40 is ω ₁ , the rotation angular velocity of the planetary external gear 40 is ω ₂ , and the contact point is p, the common tangent line T and the common normal line N at the contact point p are drawn as shown in FIG. You can As the instantaneous velocity at the contact point p, the velocity associated with the revolution of the planetary outer gear 40 is defined as v _c , and the velocity associated with the rotation of the planetary outer gear 40 is defined as v v. At this time, when the respective velocities are decomposed into the normal direction and the tangential direction, they are expressed as v _c ', v'and v _c '',v'', and the planetary outer gear 40 and the fixed inner gear 50 always keep contact with each other. Must be v _c '= -v'. Therefore, if the angles formed by v _c and v with the common normal line N are α and β, respectively,

Holds,

Therefore, the speed ratio between the revolution angular speed ω ₁ and the rotation angular speed ω ₂ is obtained as follows.

ここで、図４に示すように、点ｑは、共通法線Ｎと、遊星外歯車４０の公転中心Ｏ₁と自転中心Ｏ₂を結んだ直線Ｌと、の交点である。

Here, as shown in FIG. 4, a point q is an intersection of a common normal line N and a straight line L connecting the revolution center O ₁ of the planetary external gear 40 and the rotation center O ₂ .

As described above, the revolution center O ₁ of the planetary external gear 40 is fixed, while the rotation center O ₂ moves (performs a circular motion about the revolution center O ₁ ). FIG. 5 shows the planetary external gear 40 and the fixed internal gear 40 from the time when the outer teeth 42 start to mesh with the inner teeth 52 to the time when they finish meshing (from the time when the outer tooth side portions 44 start to contact the inner tooth side portions 54 to the time when they finish contact). It is the figure which showed the mode of 50. The left diagram of FIG. 5 is a diagram at the beginning of meshing, the center diagram is a diagram in the middle, and the right diagram is a diagram at the end of meshing. As shown in FIG. 5, the rotation center O ₂ makes a circular motion centering on the revolution center O ₁ so that the straight line L also moves (rotates about the revolution center O ₁ ) and accordingly the straight line L The point q on L also moves.

Then, according to the above equation, if the length ratio of O ₂ q and O ₁ q does not change even if the point q moves, the ratio of the revolution angular velocity and the rotation angular velocity becomes constant, and the constant velocity property is satisfied. Become. The rotation center O ₂ makes a circular motion centering on the revolution center O ₁ , and the length of O ₁ O ₂ is always constant. Therefore, the condition that the length ratio of O ₂ q and O ₁ q does not change is O ₁ q Can be replaced by the condition that the length of the is not changed (this means that O ₂ q / O ₁ q = (O ₁ q−O ₁ O ₂ ) / O ₁ q = 1−O ₁ O ₂ / O ₁ It is clear from q).

That is, even if the intersection point q on the straight line L moves along with the rotation of the straight line L about the revolution center O ₁ , the constant velocity is satisfied unless the length of O ₁ q changes. In other words, if the movement locus of the intersection point q is a circular locus centering on the revolution center O ₁ , the constant velocity property is satisfied.

In the present embodiment, as shown in FIG. 5, the movement locus of the intersection q of the common normal line N and the straight line L is such that the outer tooth side portion 44 is the inner tooth side portion so as to satisfy this constant velocity property. The shape of the internal tooth tip portion 53 is such that a circular locus with the revolution center O ₁ as the center is formed from the time of starting contact with 54 (the left view of FIG. 5) to the end of contact (right view of FIG. 5). Formed (determined). On the computer, while rotating and revolving the planetary external gear 40, the common normal line N and the straight line L are drawn to obtain the intersection point q, so that O ₁ q is constant (predetermined value). By determining the shape, such shape can be easily designed.

=== Effectiveness of the gear mechanism 1 according to the present embodiment ===
As described above, the gear mechanism 1 according to the present embodiment revolves around a fixed gear (fixed internal gear 50 in the present embodiment) fixed with the fixed internal gear 50 while rotating about a rotation center. A moving gear that revolves around the center (in the present embodiment, the planetary external gear 40) is provided.

Further, one tooth of the fixed internal gear 50 and the planetary external gear 40 (in the present embodiment, the external tooth 42) is located on the outer tooth tip portion 43 and both sides of the outer tooth tip portion 43, and the fixed gear And a pair of outer tooth side portions 44 that come into contact with the other tooth (in the present embodiment, the inner tooth 52) of the moving gear, and each of the pair of outer tooth side portions 44 has an arc shape. The center positions of the respective arcuate shapes are different from each other, and the inner teeth 52 are located on the inner tooth tips 53 and on both sides of the inner tooth tips 53 and contact the outer teeth 42. The pair of inner tooth side portions 54 has a common normal line N at the contact portion of the outer tooth side portion 44 with the inner tooth side portion 54, the revolution center 0 ₁ and the rotation center 0. The movement locus of the intersection q of the straight line L connecting the _two and the outer tooth side portion 44 starts to come into contact with the inner tooth side portion 54 until the contact ends. It was determined that the circular locus was centered on the center 0 ₁ .

  Conventionally, as such a gear mechanism, one in which the tooth profile of the gear is configured by an involute curve has been known. Although the gear mechanism related to such an involute curve satisfies the constant velocity property, it has a drawback that a high reduction ratio cannot be obtained due to interference in meshing of gears, and thus a gear mechanism having a new tooth shape is required. It was requested.

  Further, a gear having a semicircular tooth shape is known, but such a gear has a drawback that the pitch becomes large (each tooth becomes large) and it cannot be made compact.

  On the other hand, in the gear mechanism 1 according to the present embodiment, first, the tooth shape of the outer teeth 42 is a semicircular shape (in other words, the outer tooth tip portion and the outer tooth side portion are arcuate shapes, and each is common. A shape having a center position of each of the outer tooth side portions 44 has an arc shape, and the center positions of the respective arc shapes are different from each other (see FIG. 6). (See the image of the tooth shape in the figure on the right). That is, the tooth shape of the outer tooth 42 is configured such that the pair of outer tooth side portions 44 (arc shape) left by removing the one-dot chain line portion shown in the left diagram of FIG. 6 are connected by the short outer tooth tip portion 43. did. Therefore, the outer teeth 42 can be made compact and the gear pitch can be made small. 6. Note that FIG. 6 is an explanatory diagram for explaining the superiority of the tooth shape of the external teeth 42 according to the present embodiment.

Further, in the present embodiment, since the portion of the planetary external gear 40 that contacts the fixed internal gear 50 has an arc shape as described above, the movement locus of the intersection point q is indicated by the external tooth side portion 44 and the internal tooth side portion. From the start of contact with 54 to the end of contact, a circular locus centered on the revolution center 0 ₁ is set. This makes it possible to satisfy the constant velocity.

  That is, according to the present embodiment, it is possible to provide the gear mechanism 1 having a new tooth shape that is compact and has a constant speed.

=== Other Embodiments ===
Although the gear mechanism according to the present invention has been described based on the above-described embodiment, the above-described embodiment of the present invention is for facilitating the understanding of the present invention and does not limit the present invention. . The present invention can be modified and improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof.

  In the above embodiment, the outer teeth 42 are arcuate and the inner teeth 52 are non-arcuate, but they may be reversed.

  Further, in the above embodiment, the fixed gear is the internal gear and the moving gear is the external gear, but the present invention is not limited to this. For example, the present invention can be applied to a gear mechanism in which both the fixed gear and the moving gear are external gears.

  However, when the fixed gear is the internal gear and the moving gear is the external gear, it is desirable that the gear mechanism can be applied to an internal planetary gear reducer or the like.

  Further, in the above embodiment, the input shaft 20, the eccentric shaft (crank shaft 30) integrally provided with the input shaft 20, and the eccentric bearing (crank bearing 32) that receives the eccentric shaft (crank shaft 30). , And the planetary external gear 40 is attached to the eccentric shaft (crank shaft 30) via an eccentric bearing (crank bearing 32), and the input shaft 20 rotates integrally with the eccentric shaft (crank shaft 30). As a result, the eccentric shaft (crankshaft 30) eccentrically rotates and the planetary external gear 40 revolves around its own axis. However, the configuration is not limited to this. For example, the orbital motion of the planetary external gear 40 does not necessarily have to be created by the eccentric shaft (crankshaft 30).

  However, in such a case, the center of revolution is the center of the input shaft 20, so that the center of revolution is easy to understand when designing so that the locus of movement of the intersection q is a circular locus centered on the center of revolution. Become. Therefore, it is possible to easily realize a gear mechanism having a new tooth shape which is compact and is formed so as to satisfy constant velocity. In this respect, the above embodiment is more preferable.

  Further, the following embodiments are also conceivable as modifications of the above embodiment. FIG. 7: is explanatory drawing for demonstrating the inscribed planetary gear reducer 10 which concerns on a modification. FIG. 8 is a sectional view taken along line AA of FIG. 7. FIG. 9 is a sectional view taken along line BB of FIG. 7. The difference from the above embodiment of the modification is that a plurality (two) of planetary external gears 40 are provided. A plurality of crankshafts 30 (eccentric shafts) and a plurality of crank bearings 32 (eccentric bearings) are provided (two) to revolve and rotate the planetary external gears 40. It should be noted that only one input shaft 20 is provided, and two crankshafts 30 are provided integrally with the input shaft 20. Further, only one fixed internal gear 50 is provided, and the two planet external gears 40 mesh with the fixed internal gear 50. The two crankshafts 30 have the same shape, but are integrated with the input shaft 20 such that the top dead center position of one is the bottom dead center position of the other. Therefore, at the portion where one planetary external gear 40 meshes with the fixed internal gear 50 (the position at 6 o'clock, see reference numeral A1 in FIG. 8), the other planetary external gear 40 does not mesh with the fixed internal gear 50 (at 6 o'clock). Position (see reference numeral A2 in FIG. 9), and the other planetary external gear 40 meshes with the fixed internal gear 50 (at 12 o'clock position, see reference numeral A1 in FIG. 9), one planetary external gear 40 is a fixed internal gear. It does not mesh with 50 (the 12 o'clock position, see reference A2 in FIG. 8).

  If the tooth shapes of the two planetary external gears 40 and the fixed internal gear 50 of the internal planetary gear reducer 10 are set to the above-described shapes, compactness and constant velocity are achieved as in the above embodiment. It is possible to provide a gear mechanism having a new tooth shape that is formed so as to satisfy the characteristics. Further, since both planet external gears 40 are arranged in point-symmetrical positions such that when one planet external gear 40 is located at the top dead center, the other planet external gear 40 is located at the bottom dead center, Vibration can be suppressed by canceling the unbalance of the center of gravity due to the eccentricity of the planetary gear 40, the crankshaft 30 (eccentric shaft), and the crank bearing 32 (eccentric bearing). In addition, since a plurality of (two) planetary external gears 40 are provided, the number of meshing gears also doubles (doubles), so the torque that can be output can also double (double). Becomes

1 Gear Mechanism 10 Internal Planetary Gear Reducer 12 Housing 14 Screw 20 Input Shaft 22 Input Bearing 30 Crank Shaft 32 Crank Bearing 40 Planetary External Gear 40a Pin Hole 42 External Teeth 43 External Teeth Tip 44 External Teeth Side 50 Fixed Inside Gear 52 Internal tooth 53 Internal tooth tip 54 Internal tooth side 60 Pin 70 Output shaft 72 Output bearing

Claims (4)

A fixed gear, a gear mechanism comprising: a moving gear that meshes with the fixed gear and revolves around a revolution center while rotating about a rotation center.
One of the teeth of the fixed gear and the movable gear is located on both sides of the first tooth tip and the first tooth tip, and a pair of first teeth that are in contact with the other teeth of the fixed gear and the movable gear. And a tooth side portion,
Each of the pair of first tooth side portions has an arc shape, the center position of each arc shape is different from each other,
The other tooth has a second tooth tip portion and a pair of second tooth side portions that are located on both sides of the second tooth tip portion and are in contact with the one tooth,
The shape of the pair of second tooth side portions,
A common normal line in a contact portion of the first tooth side portion to the second tooth side portion, and a movement locus of an intersection of a straight line connecting the revolution center and the rotation center,
From the start of contact of the first tooth side portion with the second tooth side portion until the end of contact, so as to form a circular locus around the center of revolution,
A gear mechanism characterized by being formed. The gear mechanism according to claim 1, wherein
The fixed gear is an internal gear,
A gear mechanism, wherein the moving gear is an external gear. The gear mechanism according to claim 2, wherein
An input shaft, an eccentric shaft integrally provided with the input shaft, and an eccentric bearing for receiving the eccentric shaft,
The moving gear is attached to the eccentric shaft via the eccentric bearing,
The input shaft rotates integrally with the eccentric shaft so that the eccentric shaft revolves eccentrically to revolve the moving gear while rotating.
The gear mechanism, wherein the center of revolution is the center of the input shaft.   An inscribed planetary gear reducer comprising the gear mechanism according to claim 2 or 3.

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