JP2023148139A - power transmission device - Google Patents

Abstract

To provide a power transmission device capable of suppressing speed unevenness of rotary motion output from one of a first motion member and a second motion member.SOLUTION: A power transmission device includes a first motion member having N pieces of first contact surfaces 42, and a second motion member having a plurality of second contact surfaces 46 contacting with the first contact surfaces 42. When one of high-speed rotary motion and low-speed rotary motion around different rotation centers is input, the first motion member and the second motion member can output by changing to the other motion due to contact with the first contact surface 42 and the second contact surfaces 46. The first contact surface 42 has as the whole a circular arc shape projecting to a radial outside relative to a line connecting adjacent apexes of an N square, and the second contact surface 46 has as the whole a linear shape. When a contact position with the center of the first contact surface 42 is the center of the second contact surface 46, at least one of the first contact surface 42 and the second contact surface 46 includes a protrusion 80 disposed in a position shifted from its own center.SELECTED DRAWING: Figure 7

Description

The present disclosure relates to a power transmission device.

Patent Document 1 discloses a power transmission device including a first motion member having a triangular shape and a second motion member that contacts the first motion member. The first moving member and the second moving member convert rotational motion input into the first moving member into reciprocating motion, and then output the rotational motion from the second moving member.

Japanese Patent Application Publication No. 07-112082

The first motion member and the second motion member can be used to perform high-speed rotational motion and low-speed rotational motion around different rotation centers, and when one of the rotational motions is input, There are cases where the rotational motion of the other one is converted and output. The inventor of the present application has discovered that in such a case, depending on the shapes of the first moving member and the second moving member, even when a rotational motion of a constant rotational speed is input, there may be large speed unevenness in the rotational speed of the outputted rotational motion. We have newly discovered that this occurs.

One of the objects of the present disclosure is to provide a power transmission device that can suppress speed unevenness of rotational motion output from either the first motion member or the second motion member.

The power transmission device of the present disclosure includes a first moving member having N first contact surfaces having an N-gonal shape in an outer peripheral shape, and a plurality of a second moving member having a second contact surface, wherein the first moving member and the second moving member have one of high-speed rotational motion and low-speed rotational motion about different rotation centers. When input, it can be converted into the other one and output by contact between the first contact surface and the second contact surface, and the first contact surface connects adjacent vertices of the N-gon. The second contact surface has an arc shape that is convex outward in the radial direction as a whole with respect to the line, and the second contact surface has a straight line shape as a whole, and the contact position with the center of the first contact surface is set by the second contact surface. When set at the center, at least one of the first contact surface and the second contact surface includes a convex portion provided at a position offset from the center thereof.

Another power transmission device of the present disclosure includes a first moving member having N first contact surfaces having an N-gonal shape in an outer peripheral shape, and contacting the first contact surface, where N is a natural number of 3 or more. a second moving member having a plurality of second contact portions, wherein the first moving member and the second moving member perform high-speed rotational movement and low-speed rotational movement around different rotation centers. When one is input, it can be converted into the other and output by contact between the first contact surface and the second contact surface, and the first contact surface connects adjacent vertices of the N-gon. The second contact portion has a circular arc shape that is convex outward in the radial direction as a whole with respect to the connected line, and the second contact portion includes a plurality of roller surfaces that roll into contact with the first contact surface, and the first contact surface is A plurality of recesses are provided with which the roller surface rolls into contact.

According to the present disclosure, it is possible to provide a power transmission device that can suppress speed unevenness in rotational motion output from either the first motion member or the second motion member.

FIG. 1 is a schematic side sectional view of the power transmission device of the first embodiment. FIG. 2 is a schematic cross-sectional view of the first movement member and the second movement member of the first embodiment, viewed from the axial direction. FIG. 3 is a diagram of the first motion member and the second motion member having a standard shape as viewed from the axial direction. FIG. 6 is an operation diagram showing operation trajectories of the first movement member and the second movement member. FIG. 6 is an explanatory diagram regarding a locus drawn by a second rotation center. It is a figure which shows the state in the middle of an operation|movement of the 1st movement member and the 2nd movement member of a standard shape. It is a figure which shows the convex part of the 2nd movement member of 1st Embodiment. FIG. 6 is an explanatory diagram regarding the convex portion of the second movement member of the first embodiment. It is a figure which shows the convex part of the 1st movement member of 2nd Embodiment. FIG. 7 is another diagram showing the convex portion of the first movement member of the second embodiment. FIG. 7 is an explanatory diagram regarding a convex portion of a first movement member according to a second embodiment. It is a figure which shows typically the convex part of the 1st movement member of 3rd Embodiment. It is a typical sectional view of the 1st movement member and the 2nd movement member of a 4th embodiment seen from the axial direction. FIG. 14 is an enlarged view of the first motion member of FIG. 13; FIG. 7 is an operation diagram showing the entire operation locus of the first motion member of the fourth embodiment. FIG. 7 is an operation diagram showing a partial operation locus of the first motion member of the fourth embodiment.

Embodiments will be described below. Identical components are given the same reference numerals and redundant explanations will be omitted. In each drawing, constituent elements are omitted, enlarged, or reduced as appropriate for convenience of explanation. The drawings should be viewed according to the direction of the symbols. Unless otherwise specified, "input" and "output" in this specification include not only the case where the two parties directly satisfy the mentioned condition, but also the case where the condition is indirectly satisfied through other elements. .

(First Embodiment) Refer to FIG. 1. The power transmission device 10 includes a high-speed shaft 12 and a low-speed shaft 14, and a first motion member 16 and a second motion member 18 that change the speed of rotational motion input from one of the high-speed shaft 12 and the low-speed shaft 14 and then output it to the other. and a casing 20 that accommodates the first moving member 16 and the second moving member 18. In addition, the power transmission device 10 includes a movement unit 22 having a first movement member 16, a carrier 24 disposed on the axial side of the movement unit 22, and a pin member inserted through the movement unit 22 and the carrier 24. 26. In this specification, the direction along the rotation center C12 (first rotation center Ca described later) of the high-speed shaft 12 is referred to as the axial direction X.

The high speed shaft 12 serves as an input member into which rotational power is input from a drive source (not shown), and the low speed shaft 14 serves as an output member that outputs power to a driven device. The driving source is, for example, a motor, a gear motor, an engine, or the like. The high-speed shaft 12 is rotatably supported by the casing 20 by a first high-speed shaft bearing 28A, and rotatably supported by the low-speed shaft 14 by a second high-speed shaft bearing 28B. The low speed shaft 14 is rotatably supported by the casing 20 by a low speed shaft bearing 30. The high-speed shaft 12 of this embodiment is rotatably provided integrally with the eccentric body 32. The center C32 of the eccentric body 32 is eccentric from the rotation center C12 of the high-speed shaft 12 by an amount of eccentricity e1. The eccentric body 32 has a circular shape with the center C32 as the center of the circle. An eccentric bearing 34 is disposed between the first moving member 16 and the eccentric body 32 to allow relative rotation thereof. As a result, the center C32 of the eccentric body 32 rotates together with the high-speed shaft 12, so that the first motion member 16 (motion unit 22) can perform a rocking motion together with the eccentric body 32.

The movement unit 22 includes a flange member 36 provided on the axial side of the first movement member 16 and integrated with the first movement member 16 . The flange member 36 is provided so as to protrude radially outward from the first motion member 16 when viewed from the axial direction X.

The carrier 24 in this embodiment is integrated with the low speed shaft 14. The carrier 24 is rotatably supported by the casing 20 via a carrier bearing 38.

The pin member 26 includes a carrier pin portion 26a that is rotatably supported by the carrier 24 via a bearing 40A, and a unit pin portion 26b that is rotatably provided to the flange member 36 of the exercise unit 22 via a bearing 40B. Equipped with The unit pin portion 26b is eccentric with respect to the carrier pin portion 26a in the same eccentric direction and eccentricity amount e2 as the eccentric body 32 that swings the motion unit 22 through which it is inserted. Thereby, the pin member 26 follows the swinging motion of the exercise unit 22 and rotates about the axis C26a of the carrier pin portion 26a, thereby allowing the swinging motion of the exercise unit 22. This pin member 26 connects the first moving member 16 and the carrier 24 so as to be synchronized with the rotational component of the first moving member 16 while allowing the swinging movement of the first moving member 16 . Here, "synchronizing with the rotational component" means maintaining the rotational component of interest at the same size within a numerical range that includes zero.

See FIG. 2. The description will now move on to the first movement member 16 and the second movement member 18. Hereinafter, when describing these, the relationship seen from the axial direction X will be described unless otherwise specified. In addition, hatching will be omitted in subsequent figures.

The first motion member 16 includes N first contact surfaces 42 having an N-gonal shape on the outer periphery, where N is a natural number of 3 or more. Unless otherwise specified, the term "shape" as used herein includes not only a shape that geometrically strictly matches the mentioned shape, but also a shape similar to the mentioned shape. In this embodiment, N is 3. The N (three) first contact surfaces 42 as a whole form a Reuleaux N-gon shape (here, a Reuleaux triangle shape) in the outer peripheral shape.

The N polygon formed by the N first contact surfaces 42 includes N vertices 44 . The N vertices 44 are provided at equal distances from the center C16 of the first movement member 16, and at positions shifted by a central angle of 360°/N (here, 120°). The center C16 of the first moving member 16 here is concentric with a second rotation center Cb, which will be described later.

Each of the N first contact surfaces 42 as a whole has an arc shape that is convex outward in the radial direction of the first movement member 16 with respect to a line La connecting adjacent vertices 44 of the N-gon. In order to satisfy this condition, the outer peripheral shape of the first contact surface 42 may be a combination of a plurality of curves having different curvatures, or a combination of a curve and a straight line, in addition to a single curve. Here, "as a whole" means when the object being referred to (here, the first contact surface 42) is viewed as a whole. That is, when viewed as a whole, the first contact surface 42 has a circular arc shape that is convex outward in the radial direction with respect to the line La. Even when the first contact surface 42 is provided with a convex portion 80, which will be described later, the first contact surface 42 as a whole has an arc shape that is convex radially outward with respect to the line La.

The second movement member 18 is integrated with the casing 20. The second movement member 18 includes a plurality of second contact surfaces 46 that contact the first contact surfaces 42 of the first movement member 16 . The plurality of second contact surfaces 46 include at least one pair of second contact surfaces 46 facing each other across a first rotation center Ca, which will be described later. The centers C46 (described later) of the pair of second contact surfaces 46 are provided so that a straight line Lb connecting them passes through the first center of rotation Ca. In this embodiment, the number of the plurality of second contact surfaces 46 is the same as the number of corners of the N+1 polygon, that is, four. The plurality of second contact surfaces 46 include two pairs of second contact surfaces 46 .

The second contact surface 46 has a generally straight shape. The second contact surface 46 has a straight line shape that is perpendicular to the straight line Lb passing through the center C46 of the second contact surfaces 46 of the pair. The plurality of second contact surfaces 46, the number of which is the same as the number of corners of the N+1 polygon, form a straight line along each side of the regular polygon with N+1 angles. This N+1 polygon has N+1 vertices 48 in addition to N+1 sides. The N+1 vertices 48 are located at equal distances from the center 50 of the N+1 polygon, and at positions shifted from the center angle by 360°/(N+1) (here, 90°). The center 50 of the N+1 square here is concentric with a first rotation center Ca, which will be described later.

In this embodiment, the first movement member 16 functions as an external gear, and the second movement member 18 functions as an internal gear that meshes with the first movement member 16 (external gear). The N first contact surfaces 42 of the first moving member 16 function as individual external teeth, and the N+1 second contact surfaces 46 of the second moving member 18 function as individual internal teeth.

See FIG. 3. In this specification, the center C42 of the first contact surface 42 and the center C46 of the second contact surface 46 are defined as follows. The center C42 of the first contact surface 42 is located between the apex 44 that constitutes the farthest diagonal with respect to the sides of the N-gon formed by the first contact surface 42 and the member center (second rotation center Cb) of the first motion member 16. Assuming a straight line Lc passing through , this is the intersection of the straight line Lc and the first contact surface 42 . In this embodiment, the center C42 of the first contact surface 42 is also the midpoint of the first contact surface 42. Moreover, when the center C42 of the first contact surface 42 is arranged on the same straight line Lc as the first rotation center Ca and the second rotation center Cb, which will be described later, the center C46 of the second contact surface 46 is the first contact surface. This refers to the position where the straight line Lc passes on the second contact surface 46 facing the contact surface 42. In this embodiment, when this positional relationship exists, the center C46 of the second contact surface 46 becomes the contact position of the center C42 of the first contact surface 42.

Further, in this specification, a reference shape is assumed as a reference for each of the first contact surface 42 of the first movement member 16 and the second contact surface 46 of the second movement member 18. The reference shape of each first contact surface 42 is a Reuleaux N-gon shape Sa (hereinafter referred to as Reuleaux shape Sa) having the same number of angles as the N-gon formed by the first moving member 16 . The Reuleaux shape Sa serving as the reference shape is a geometrically strict Reuleaux N-gon shape. Each side of the Reuleaux shape Sa serving as the reference shape is an arc having a constant distance L1 from the farthest diagonal. As a result, the Reuleaux shape becomes a constant-width figure whose width L1 is always constant. The width L1 here refers to the distance between a pair of parallel lines when a pair of parallel lines circumscribes the mentioned shape (herein, the Reuleaux shape) when viewed from the axial direction X. When the width L1 is always constant, it means that the interval between the pair of parallel lines is constant, regardless of the circumscribed position of one of the parallel lines. It can also be said that the width L1 is the height in the vertical direction when the mentioned shape is rolled on a horizontal surface. The fact that the width L1 is always constant can also be said to mean that the height in the vertical direction is always constant when the mentioned shape is rolled on a horizontal surface. In the Reuleaux shape Sa serving as this reference shape, the center C42 of each of the N first contact surfaces 42 of the first motion member 16 matches the center (midpoint) of each side of itself.

A line segment Ld having both ends Lda at the center C46 of the opposing pair of second contact surfaces 46 and having the same length as the width L1 is assumed. The reference shape of each second contact surface 46 is a linear shape Sb extending perpendicularly to the line segment Ld from both ends Lda of the line segment Ld. The linear shape Sb serving as the reference shape is a geometrically strict linear shape. When there are N+1 second contact surfaces 46 as in this embodiment, the linear shape Sb formed by the standard shape of the N+1 second contact surfaces 46 is a regular polygon with a side length L1 and an angle number of N+1. It forms a shape (here, a square shape). Hereinafter, the direction along the line segment Ld connecting the centers C46 of the opposing second contact surfaces 46 will be referred to as the opposing direction Da of the second contact surfaces 46.

See FIG. 4. In the following, only the contact surfaces 42, 46 of each moving member 16, 18 are schematically shown. Here, the motion trajectories of the motion members 16 and 18 in the standard shape are illustrated, and the motion of the motion members 16 and 18 of the embodiment will be described.

The first moving member 16 and the second moving member 18 are connected to the first contact surface 42 and the second contact surface when one of a high speed rotational motion and a low speed rotational motion around different rotation centers Ca and Cb is input to either of them. 46, it can be converted to the other and output from either. The high speed rotational motion is motion around the first rotation center Ca, and the low speed rotation motion is motion around the second rotation center Cb. The high-speed rotational motion is either a rocking motion or a rotational motion. The rocking motion is a motion in which the second rotation center Cb is relatively rocked (revolution) around the first rotation center Ca. In the following embodiments, the swing motion is performed by swinging (revolving) the second rotation center Cb around the first rotation center Ca while the first rotation center Ca remains stationary. In addition to this, the swinging movement may be performed by swinging (revolving) the first rotation center Ca around the second rotation center Cb while the second rotation center Cb remains stationary. The rotational movement as a high-speed rotational movement refers to a movement in which a moving member that performs a high-speed rotational movement is rotated around a first rotation center Ca that is concentric with the center of the member. The low-speed rotational movement refers to a movement in which a moving member that performs a low-speed rotational movement is rotated around a second rotation center Cb that is concentric with the center of the member. When the high-speed rotational motion becomes an autorotation motion, the rotation direction (rotation direction) of the high-speed rotational motion and the low-speed rotational motion is the same direction.

In this embodiment, a rocking motion (high-speed rotational motion) is input to the first motion member 16, and after converting the rocking motion into a rotational motion (low-speed rotational motion) of the first motion member 16, the first motion member An example of outputting from 16 will be explained. The power transmission device 10 that performs such an operation functions as an eccentric rocking gear device of an external tooth rocking type in which the first movement member 16 functioning as an external gear performs a rocking motion. In this way, it is sufficient that at least one of the first movement member 16 and the second movement member 18 is moving, and it is not essential that the other one is moving.

In order to perform the swing motion by the first motion member 16, the rotation of the high-speed shaft 12 causes the center C32 of the eccentric body 32, which is concentric with the second rotation center Cb, to rotate around the rotation center C12 of the high-speed shaft 12. What is necessary is just to make the 1st movement member 16 perform a rocking motion together with the eccentric body 32. In order to input the rocking motion to the first motion member 16, the high speed shaft 12 is rotated, so that the rocking motion is input from the high speed shaft 12 to the first motion member 16 via the eccentric body 32.

When the first motion member 16 that performs a rocking motion performs a rotational motion, the rotation of the second motion member 18 is restrained by fixing the casing 20 integrated with the second motion member 18 to an external support member. . At the same time, the carrier 24 integrated with the low-speed shaft 14 and the first moving member 16 (movement unit 22) are connected by a pin member 26 that can synchronize with the rotational component while allowing the swinging motion of the first moving member 16. Just connect them. Thereby, the low-speed shaft 14 can be rotated at the same rotational speed as the rotational component of the first motion member 16 that performs rotational motion. This means that the low-speed shaft 14 can be rotated at the same rotational speed as the rotational motion output from the first moving member 16.

The first motion member 16 and the second motion member 18 change the speed of one rotary motion input at a predetermined speed ratio into the other rotary motion and output the same. The predetermined gear ratio is determined based on the movement mode of each movement member 16, 18 and the magnitude of N. This gear ratio is determined based on the moving member that performs the rotational motion (low-speed rotational motion) and the magnitude of N when the high-speed rotational motion becomes a rocking motion. As this speed ratio, a reduction ratio n for high-speed rotational motion relative to low-speed rotational motion is assumed. At this time, when the first moving member 16 performs a rotational movement, the reduction ratio n is N (here, 3), and when the second movement member 18 performs a rotational movement, the reduction ratio is N+1. In addition to this, when the high-speed rotational motion becomes rotational motion, the reduction ratio n becomes (N+1)/N.

The first movement member 16 and the second movement member 18 are caused by the force acting on the contact point 60 formed at the contact position between the first contact surface 42 and the second contact surface 46 in the process of performing one of the input rotational movements. One rotational movement can be converted into another rotational movement. This contact point 60 moves in the second contact range R46 of the first contact surface 42 with respect to the second contact surface 46 in accordance with the progress of the rotational motion of each moving member 16, 18 in the direction of movement Db. This second contact range R46 ranges from an end position R46a on the side opposite to the traveling direction where the contact starts in the process of the first contact surface 42 coming into contact with the second contact surface 46, to an end position on the traveling direction side where the contact ends. The range is up to R46b. The "counter-progressing direction" here refers to a direction opposite to the proceeding direction Db. The contact point 60 advances in the traveling direction Db while the first contact surface 42 and the second contact surface 46 are in continuous or intermittently contact with each other in the second contact range R46. The traveling direction Db of this contact point 60 differs depending on the movement mode of each movement member 16, 18. When the high-speed rotational motion is a rocking motion as in this embodiment, the advancing direction Db is the same as the rotation direction Dc of the rocking motion around the first rotation center Ca. In addition, when the high-speed rotational motion is an autorotation motion, the traveling direction Db is opposite to the rotational direction Dc of the autorotation motion.

When the contact points 60 of the contact surfaces 42, 46 that are in contact with each other advance in the traveling direction Db, they become adjacent to those contact surfaces 42, 46 in the traveling direction Db while maintaining their contact state. A contact initiation operation is performed in which each of the other contact surfaces 42, 46 initiates contact. Further, when the contact point 60 of each of the contact surfaces 42, 46 that are in contact with each other advances to the end position R46b on the advancing direction side of the second contact range R46, the contact state of each of the contact surfaces 42, 46 that are in contact with each other subsequently A contact release operation is performed to release the contact between the contact surfaces 42 and 46 that have been in contact with each other while maintaining the contact state. While repeating such a contact initiation operation between the subsequent contact surfaces 42 and 46 and a contact release operation between the preceding contact surfaces 42 and 46, the first motion member 16 and the second motion member 18 perform high-speed rotational motion and low-speed rotation. The movement progresses.

Here, problems when using the above-described first movement member 16 and second movement member 18 will be explained. FIG. 5 shows a first trajectory 70A and a second trajectory 70B drawn by the second rotation center Cb when high-speed rotational motion (swinging motion) and low-speed rotational motion (rotation motion) are performed at constant rotational speeds w1 and w2. shows. The first locus 70A moves the first contact surface within the second contact range R46 of each second contact surface 46 without constraining the relative positions of the first rotation center Ca and the second rotation center Cb of the first movement member 16. 42 is depicted when the first moving member 16 is rotated such that it is always in contact with the second contact surface 46. The second locus 70B is drawn when the relative positions of the first rotation center Ca and the second rotation center Cb of the first motion member 16 are constrained. It is assumed that the moving members 16 and 18, both of which have a standard shape, are used. Further, the rotational speed w2 is the rotational speed w1×(1/reduction ratio n). A part of the first trajectory 70A and the second trajectory 70B are also shown in FIG. 4 for reference.

As the high-speed rotational motion for one round progresses, a circular first locus 70A and a second locus 70B are drawn such that the second rotation center Cb rotates relatively around the first rotation center Ca. When the second rotation center Cb rotates relative to the first rotation center Ca according to this first trajectory 70A, continuous contact of the contact points 60 within the second contact range R46 of each second contact surface 46 is maintained. However, this means that high-speed rotational movement and low-speed rotational movement can be performed at constant rotational speeds w1 and w2. The first locus 70A that satisfies this condition draws a circular shape different from a perfect circle centered on the first rotation center Ca.

Regarding the rotation angle around the first rotation center Ca of high-speed rotational motion, the center C42 of the first contact surface 42 and the center C46 of the second contact surface 46 are located on a straight line passing through the first rotation center Ca and the second rotation center Cb. The rotation angle at which the contact point 60 is located is referred to as the contact rotation angle θa. For example, FIG. 3 shows a state in which the rotation angle of the high-speed rotational motion is the contact rotation angle θa. The first locus 70A of the second rotation center Cb has the narrowest distance from the first rotation center Ca when the rotation angle of the high-speed rotation motion becomes the contact rotation angle θa. A contact rotation angle θa that satisfies such conditions appears at every angle obtained by equally dividing 360° by N+1 (that is, every 90° here). A rotation angle that bisects the rotation angle of adjacent contact rotation angles θa is called an intermediate rotation angle θb. At this time, the first locus 70A draws a circular shape such that the distance from the first rotation center Ca increases as the rotation angle of the high-speed rotation movement approaches the intermediate rotation angle θb from the contact rotation angle θa.

In reality, since the relative positions of the first rotation center Ca and the second rotation center Cb are constrained, the second rotation center Cb draws a second locus 70B that is a perfect circle, and has a circular shape different from a perfect circle. cannot draw the first locus 70A. Due to this, when the first moving member 16 and the second moving member 18 having the standard shape perform high-speed rotational motion and low-speed rotational motion at the same time, continuous contact of the contact point 60 within the second contact range R46 is caused. The contact surface cannot be maintained, and the first contact surface 42 and the second contact surface 46 are separated.

See FIG. 6. When the first contact surface 42 and the second contact surface 46 separate in the process of moving within the second contact range R46, a minute gap 72 momentarily forms between the first contact surface 42 and the second contact surface 46. arise. Due to this gap 72, the first moving member 16 maintains the rotation angle of the input high-speed rotational motion (swinging motion here), and the first contact surface 42 and the second contact surface 46 The contact point 60 performs a low-speed rotation movement (rotation movement in this case) that momentarily changes the rotational speed until contact is made, and then the contact point 60 attempts to advance from the contact position again. In other words, if the first contact surface 42 and the second contact surface 46 separate during the process of moving within the second contact range R46, the speed of the rotational motion (here, rotational motion) output from the first motion member 16 It causes unevenness.

Here, when the center C42 of the first contact surface 42 of the first movement member 16 and the center C46 of the second contact surface 46 of the second movement member 18 contact, as described above, the first locus 70A, the second The second rotation center Cb is arranged at the same position no matter which trajectory 70B is drawn. In this case, the positions of the first and second moving members 18 are taken as the reference rotational positions, and from there, high-speed rotational motion progresses by a rotational angle θ1, and low-speed rotational movement occurs by a rotational angle θ2 (=θ1×(1/reduction ratio n)). Consider when the movement progresses (see Figure 6). At this time, the first contact surface 42 contacts the second contact surface 46 on the straight line Le extending from the farthest diagonal Sa1 of the side of the Reuleaux shape Sa facing the second contact surface 46 in the opposing direction Da of the second contact surface 46. Become the closest. At these rotation angles θ1 and θ2, the interval at the position closest to the reference shape is referred to as the reference interval Ls.

As a countermeasure for the above-mentioned speed unevenness, the inventor of the present invention has proposed that the distance between the closest positions between the first contact surface 42 and the second contact surface 46 at rotation angles θ1 and θ2 be narrower than the reference distance Ls. I have newly discovered that it is effective to do so. The narrower this interval is, even if the contact surfaces 42 and 46 are separated from each other while the contact point 60 is moving within the second contact range R46, the speed of the rotational motion output from either of the moving members 16 and 18 will decrease. The gap 72 that allows variation can be made smaller. The smaller the gap 72 is, the smaller the speed difference can be made even if speed fluctuations occur in the output rotational motion due to the gap 72. Furthermore, when a rotational motion at a constant rotational speed is input to either of the moving members 16, 18, an output from either of the moving members 16, 18 due to the separation between the first contact surface 42 and the second contact surface 46. It is possible to suppress large speed irregularities in rotational motion. Such an effect can be obtained regardless of whether the high-speed rotational motion is a rocking motion or rotational motion, and regardless of the combination of the moving members 16 and 18 that perform high-speed rotational motion and low-speed rotational motion. In realizing this, it is effective to provide the first moving member 16 and the second moving member 18 with a convex portion 80, which will be described later. The details of this convex portion 80 will be explained below.

See FIG. 7. This figure shows a state in which the center C42 of the first contact surface 42 and the center C46 of the second contact surface 46 are in contact with each other at the reference rotation position. Further, in this figure, for explanation, a linear shape Sb serving as a reference shape of the second contact surface 46 is also shown. At least one of the first contact surface 42 and the second contact surface 46 includes a convex portion 80 provided at a position offset from the centers C42 and C46 thereof. In this embodiment, the second contact surface 46 includes a convex portion 80 . In this embodiment, although not shown, all the second contact surfaces 46 of the second movement member 18 are provided with convex portions 80 . The convex portions 80 of this embodiment are individually provided on both sides of the center C46 of the second contact surface 46. The convex portion 80 is provided so as to be convex toward the second contact surface 46 side (the first movement member 16 side) that faces the convex portion 80 rather than the linear shape Sb serving as the reference shape.

Refer to FIGS. 7 and 8. As described above, the positions of the first movement member 16 and the second movement member 18 when the center C42 of the first contact surface 42 and the center C46 of the second contact surface 46 are in contact with each other are defined as reference rotation positions. Similarly to the above, when the high-speed rotational motion advances by the rotational angle θ1 and the low-speed rotational motion advances by the rotational angle θ2 from this reference rotational position, the diagonal Sa1 of the side of the Reuleaux shape Sa facing the second contact surface 46 A straight line Le extending from the second contact surface 46 in the opposing direction Da is assumed. As described above, the first contact surface 42 is closest to the second contact surface 46 on this straight line Le. The first rotation angle θ1 is in a range of less than ±90°. The convex portion 80 is provided so that the distance between the first contact surface 42 and the second contact surface 46 on the straight line Le is narrower than the reference distance Ls when the first contact surface 42 and the second contact surface 46 are in the reference shape. In this embodiment, they are provided so that the interval on this straight line Le is zero. That is, the convex portion 80 is provided so that the contact point 60 between the first contact surface 42 and the second contact surface 46 is located on this straight line Le. In addition to this, there may be a gap between the first contact surface 42 and the second contact surface 46 on the straight line Le. The convex portion 80 that satisfies this condition may be provided in a part of the second contact range R46 continuous from the center C46 of the second contact surface 46. In this embodiment, the convex portion 80 that satisfies this condition is provided over the entire range from the center C46 of the second contact surface 46 to the end positions R46a and R46b of the second contact range R46.

The convex portion 80 includes a convex amount increasing region 82 in which the convex amount gradually increases as the distance from the center C46 of the second contact surface 46 increases. The amount of protrusion here refers to the distance in the opposing direction Da from the linear shape Sb in the above-mentioned standard shape to the surface of the protrusion 80 when the protrusion 80 is provided on the second contact surface 46. In addition, the convex portion 80 includes a decreasing convexity region 84 which is continuous with the opposite end of the increasing convexity region 82 and whose convexity gradually decreases as it moves away from the center C46.

(A) By providing such a convex portion 80, even if the first contact surface 42 and the second contact surface 46 are separated while the contact point 60 is moving within the second contact range R46, the movement of either A large gap 72 that allows fluctuations in the rotational motion output from the members 16 and 18 is less likely to occur. Furthermore, when rotational motion at a constant rotational speed is input to either of the moving members 16, 18, large speed irregularities in the rotational motion output from any of the moving members 16, 18 can be suppressed.

(B) Furthermore, the convex portions 80 are individually provided on both sides of the center C46 of the second contact surface 46. As a result, compared to the case where the convex portion 80 is provided only on one side with respect to the center C46 of the second contact surface 46, the rotational motion output from either of the moving members 16, 18 in the wider second contact range R46. It is possible to obtain the effect of suppressing large speed irregularities.

Note that an interference avoidance portion 88 for avoiding interference with the second movement member 18 is provided at a corner 86 including the apex 44 of the first movement member 16 . The interference avoidance portion 88 is provided by locating the corner 86 of the actual first motion member 16 inside the corner 86 of the first motion member 16 in the standard shape (the corner of the Reuleaux shape Sa). The interference avoidance section 88 of this embodiment has a curved shape. In this embodiment, the first contact surface 42 of the first movement member 16 has a shape that matches the Reuleaux shape Sa except for the position where the interference avoidance part 88 is located. Further, the second contact surface 46 of the second movement member 18 of this embodiment is provided so as to extend outside the second contact range R46, but may be provided only within the second contact range R46.

(Second Embodiment) Refer to FIGS. 9 and 10. In the subsequent embodiments, the same content as in the first embodiment applies to matters not specifically mentioned. Here, an example in which the aforementioned convex portion 80 is provided on the second contact surface 46 instead of the first contact surface 42 will be described. In this embodiment, all the first contact surfaces 42 of the first movement member 16 are provided with convex portions 80 . In this embodiment, the convex portions 80 of the first contact surface 42 are individually provided on both sides of the center C42 of the first contact surface 42 . The convex portion 80 is provided so as to protrude outward in the radial direction of the first movement member 16 from the side of the Reuleaux shape Sa serving as the reference shape. The convex portion 80 of the first contact surface 42 has a radius of curvature smaller than the radius of curvature of the side in the Reuleaux shape Sa. The convex portion 80 of this embodiment is configured by a plurality of circular arc shapes that satisfy this condition.

Please refer to FIGS. 9 to 11. FIG. 11 is a diagram of the moving members 16 and 18 of the second embodiment viewed from the same viewpoint as section B in FIG. 8 when the rotational movement has progressed from the reference rotational position by the same rotation angles θ1 and θ2 as in FIG. 8. It is. Similar to the first embodiment, when the rotational motion progresses by the rotation angles θ1 and θ2 from the reference rotational position, the distance between the second contact surface 46 and the farthest diagonal Sa1 of the side of the Reuleaux shape Sa facing the second contact surface 46 increases. A straight line Le extending in the opposing direction Da is assumed. At this time, similarly to the first embodiment, the convex portion 80 of the present embodiment also sets the distance between the first contact surface 42 and the second contact surface 46 on this straight line Le to the standard distance when they are in the standard shape. It is provided to be narrower than Ls. In this embodiment, they are provided so that the interval on this straight line Le is zero. That is, the convex portion 80 is provided so that the contact point 60 between the first contact surface 42 and the second contact surface 46 is located on this straight line Le.

The contact range of the second contact surface 46 with respect to the first contact surface 42 is referred to as a first contact range R42. The first contact range R42 ranges from an end position R42a on the side opposite to the traveling direction where the contact starts in the process of the second contact surface 46 making contact with the first contact surface 42, to an end position R42b on the side of the traveling direction where the contact ends. The range is up to. At this time, the convex portion 80 may be provided in a part of the first contact range R42 continuous from the center C42 of the first contact surface 42. In this embodiment, the convex portion 80 that satisfies this condition is provided over the entire range from the center C42 of the first contact surface 42 to the end positions R42a and R42b of the first contact range R42.

The convex portion 80 includes a convex amount increasing region 82 in which the convex amount gradually increases as the distance from the center C42 of the first contact surface 42 increases. When the convex portion 80 is provided on the first contact surface 42, the convex amount here is the distance in the radial direction centered on the farthest diagonal of the side that overlaps with the first contact surface 42 in the Reuleaux shape Sa. This refers to the distance from the Reuleaux shape Sa to the surface of the convex portion 80. In addition, the convex portion 80 includes a decreasing convexity region 84 which is continuous with the opposite end of the increasing convexity region 82 and whose convexity gradually decreases as it moves away from the center position.

Thereby, also in this embodiment, the same effect as the above-mentioned (A) can be obtained. Further, the convex portions 80 are individually provided on both sides of the center C42 of the first contact surface 42. Therefore, as in (B) above, compared to the case where the convex portion 80 is provided only on one side with respect to the center C42 of the first contact surface 42, the effect of suppressing large speed unevenness in the wider first contact range R42 is achieved. Obtainable.

Note that also in this embodiment, an interference avoidance portion 88 is provided at the corner portion 86 of the first movement member 16. In this embodiment, the convex portion 80 of the first movement member 16 is provided at a location other than the interference avoidance portion 88 and the center C42 on the first contact surface 42. Further, in this embodiment, the second contact surface 46 of the second movement member 18 has a shape that matches the linear shape Sb, which is the reference shape.

(Third Embodiment) Refer to FIG. 12. Preferable conditions to be satisfied when providing the convex portion 80 will be explained. When high-speed rotational movement and low-speed rotational movement are performed, the contact point 60 is undergoing rotational movement about the instantaneous center 90. Assume a distance e from the first rotation center Ca to the second rotation center Cb. This distance e is also the amount of eccentricity from the rotation center C12 of the high-speed shaft 12, which is concentric with the first rotation center Ca, to the center C32 of the eccentric body 32, which is concentric with the second rotation center Cb. At this time, if the high-speed rotational motion advances by a first rotational angle θ1 and the low-speed rotational motion advances by a second rotational angle θ2 (=θ1×(1/n)) from the reference rotational position, the instantaneous center of the contact point 60 90 exists on the straight line Lf passing through the first rotation center Ca and the second rotation center Cb from the three-instantaneous center theorem. In addition, in this case, the instantaneous center 90 of the contact point 60 is geometrically located on the opposite side of the second rotation center Cb from the first rotation center Ca on this straight line Lf, and at a distance from the second rotation center Cb. It always exists at the position ex×N (here, the position ex3).

Here, in a certain rotational angle range (0≦|θ1|<90°) in which high-speed rotational movement is performed, the first contact surface 42 and the second contact are made on the straight line Lg extending from the instantaneous center 90 along the opposing direction Da. Consider the case where there is a contact point 60 on surface 46. In this case, within the rotation angle range that satisfies the conditions regarding the contact point 60, the generally known mechanical requirements for gears can be satisfied. Furthermore, in the rotational angle range that satisfies the conditions regarding the contact point 60, the ratio of the angular velocity of the high-speed rotational motion to the angular velocity of the low-speed rotational motion can be made constant.

It is preferable that the convex portion 80 of the first contact surface 42 is provided so that the contact point 60 is on the straight line Lg passing through this instantaneous center 90. The convex portion 80 that satisfies this condition may be provided in at least a portion of the first contact range R42 continuous from the center C42 of the first contact surface 42, as described above. In this embodiment, the convex portion 80 that satisfies this condition is provided in the entire first contact range R42 (excluding the center C42). This condition is satisfied at each of the plurality of first contact surfaces 42. Thereby, in the rotation angle range that satisfies this condition (here, the entire rotation angle range that does not depend on the rotation angle), the ratio of the angular velocity of the high-speed rotational motion to the angular velocity of the low-speed rotational motion can be made constant.

Note that when both the first movement member 16 and the second movement member 18 are in the standard shape, the above-mentioned first contact occurs on the straight line Lg extending from this momentary center 90 along the opposing direction Da of the second contact surface 46. A gap 72 is created between the surface 42 and the second contact surface 46. This straight line Lg passes through a slightly different position from the straight line Le in FIG. 8 described above depending on the magnitude of the first rotation angle θ1. It can be said that the convex portion 80 of this embodiment is provided so that the gap 72 on the straight line Lg passing through a position different from the straight line Le is eliminated.

(Fourth Embodiment) Refer to FIG. 13. The power transmission device 10 of this embodiment is different in the configuration of the first movement member 16 and the second movement member 18. The first movement member 16 and the second movement member 18 of this embodiment are not provided with the above-mentioned convex portion 80. The second movement member 18 of this embodiment includes a main body member 100 that is integrated with the casing 20 and a plurality of contact members 102 that are detachably attached to the main body member 100. Each of the plurality of contact members 102 is provided with a separate second contact surface 46 .

The second contact surface 46 of the second movement member comprises a plurality of roller surfaces 103 that are in rolling contact with the first contact surface 42 of the first movement member 16 . The roller surface 103 is composed of the outer peripheral surface of a roller 104 rotatably supported by the contact member 102. The second contact surface 46 is provided so that the inner circumferential surface 102a of the contact member 102 and the roller surface 103 are arranged alternately. The roller 104 is rotatably supported by being fitted into a groove 102b provided in the contact member 102. In addition to this, the roller 104 may be rotatably supported via a pin provided on the contact member 102. The plurality of rollers 104 are arranged in a row in a direction perpendicular to the straight line Lb connecting the centers C46 of the opposing pairs of second contact surfaces 46. In this embodiment, each of the individual second contact surfaces 46 is provided with ten roller surfaces 103 .

Refer to FIGS. 13 and 14. The first contact surface 42 of the first movement member 16 includes a plurality of recesses 106 with which the roller surface 103 rolls into contact. The plurality of recesses 106 on one first contact surface 42 correspond one-to-one with at least some of the roller surfaces 103 on one second contact surface 46. In this embodiment, six recesses 106 are provided on one first contact surface 42, and six roller surfaces 103 out of ten roller surfaces 103 on one second contact surface 46 are provided with six recesses 106. One-on-one correspondence.

One or both of the moving members 16 and 18 perform a high-speed rotational movement at a constant first rotational speed w1, and a low speed at a constant second rotational speed w2 (=first rotational speed w1 x (1/reduction ratio n)). Consider the case of rotational motion. In this case, the recess 106 is formed so that the corresponding roller surface 103 rolls into contact with the recess 106 . This means that when molding the first moving member 16, the roller surface 103 is placed at a certain position of the roller surface 103 while performing a high speed rotational movement at the first rotational speed w1 and a low speed rotational movement at the second rotational speed w2. This can be achieved by arranging rotary blades that can cut with the same diameter.

In the plurality of convex portions 80 on one first contact surface 42, the concave amounts d1 to d3 become smaller as the distance from the center C42 of the first contact surface 42 increases. The amount of recess here refers to the maximum length from the line segment Lh in the direction perpendicular to the line segment Lh connecting both ends of the recess 106 on the first contact surface 42 to the bottom of the recess 106 . When the recess amounts of each of the three recesses 106 on one side of the center C42 of the first contact surface 42 are defined as d1 to d3 in order from the center C42 side, d1, d2, and d3 become smaller in this order.

The widths w1 to w3 of the plurality of recesses 106 on one first contact surface 42 increase as the distance from the center C42 of the first contact surface 42 increases. The widths w1 to w3 of the recess 106 herein refer to the length of the line segment Lh connecting both ends of the recess 106. When the widths of the three recesses 106 on one side of the first contact surface 42 are defined as w1 to w3 in order from the center C42 side, the widths increase in the order of w1, w2, and w3. .

In order to satisfy such conditions, the radius of curvature of the recess 106 on one first contact surface 42 is the smallest at the center C42 side of the first contact surface 42, and the radius of curvature increases as the distance from there increases. It forms an arc that gradually increases in size. In order to satisfy this condition, each recess 106 has an arc shape that is a combination of a single arc or a plurality of arcs.

See FIG. 15. Similarly to the first embodiment, each of the above-mentioned moving members 16 and 18 is also controlled by the contact between the first contact surface 42 and the second contact surface 46 when one of the high-speed rotational motion and the low-speed rotational motion is input. It is possible to convert one to the other and then output it. Further, similarly to the first embodiment, each of the moving members 16 and 18 changes the speed of one rotational motion to the other rotational motion at a predetermined gear ratio, and then outputs the same. Similar to the first embodiment, the contact point 60 (not shown) of the first contact surface 42 with respect to the second contact surface 46 is the contact point 60 (not shown) of the first contact surface 42 with respect to the second contact surface 46 during the movement of each movement member 16, 18. 42 in the second contact range R46 in the traveling direction Db. Further, as in the first embodiment, the first movement member 16 and the second movement member 18 repeat the contact initiation operation between the subsequent contact surfaces 42 and 46 and the contact release operation between the preceding contact surfaces 42 and 46. High-speed rotational motion and low-speed rotational motion progress. Hereinafter, similarly to the first embodiment, a rocking motion (high-speed rotational motion) is input from the high-speed shaft 12 to the first motion member 16, and after converting the rocking motion into an autorotational motion (low-speed rotational motion), An example of outputting from the moving member 16 to the low-speed shaft 14 will be explained.

See FIG. 16. Here, an example is shown in which the movement members 16 and 18 operate in the order of FIG. 16(A)→FIG. 16(B)→FIG. 16(C)→FIG. 16(D). In each figure, the locus of movement of the contact point 60 between the first contact surface 42 and the second contact surface 46 is also shown. Moreover, here, for convenience of explanation, each roller surface 103 and roller 104 are distinguished by assigning ordinal numbers that gradually increase toward the traveling direction Db. That is, regarding each roller surface 103, it is distinguished in the order of the first roller surface 103, the second roller surface 103, . In the figure, the ordinal numbers from 1 to 10 are shown attached to the rollers 104.

According to the present embodiment, in the process of the contact point 60 advancing through the second contact range R46, the roller surface 103 of the second contact surface 46 that contacts the first contact surface 42 is changed to the traveling direction Db, and the second contact point 60 is Within the range R46, the contact points 60 can be made to advance in the advancing direction Db intermittently. The roller surface 103 that is in contact with the first contact surface 42 within the second contact range R46 is referred to as a contact roller surface. FIG. 16(A) shows an example in which the fifth roller surface 103 to the eighth roller surface 103 are contact roller surfaces. Similarly, in FIG. 16(B), the sixth roller surface 103 to the ninth roller surface 103, in FIG. 16(C), the seventh roller surface 103 to the ninth roller surface 103, and in FIG. 16(D), the ninth roller surface An example is shown in which roller surfaces 103 to 103 are contact roller surfaces.

As the contact point 60 advances, while maintaining the contact between the contact roller surface 103 and the first contact surface 42, the contact roller surface 103 and the roller surface 103 and the first contact surface 42 adjacent to each other in the traveling direction Db A contact initiation action is performed to initiate contact. The contact initiation operation is performed by the eighth roller surface 103 in FIG. 16(A), by the ninth roller surface 103 in FIG. 16(B), and by the tenth roller surface 103 in FIG. 16(D).

Further, as the contact point 60 advances, it makes first contact with the contact roller surface 103 in the counter-progressing direction while maintaining contact with the contact roller surface 103 in the traveling direction Db among the plurality of contact roller surfaces 103. By separating the surface 42, a contact release operation is performed to release the contact between the two. The contact release operation is performed on the fourth roller surface 103 in FIG. 16(A), the fifth roller surface 103 in FIG. 16(B), the sixth roller surface 103 in FIG. 16(C), and the seventh roller in FIG. 16(D). An example of surface 103 is shown. While repeating such a contact start operation and a contact release operation between the roller surface 103 and the first contact surface 42, the contact points 60 on the second contact surface 46 advance in the traveling direction Db intermittently.

When the contact point 60 is on the roller surface 103 that corresponds one-to-one with the recess 106, the roller surface 103 rolls into contact with the inner surface of the recess 106. FIG. 16(A) shows an example in which the fifth roller surface 103 to the seventh roller surface 103 are in rolling contact with the inner surface of the corresponding recess 106 in a one-to-one manner. The presence of the recess 106 allows the contact point 60 to advance while avoiding interference between the recess 106 and the roller surface 103 that corresponds one-to-one.

As described above, the power transmission device 10 of this embodiment includes the roller surface 103 provided on the second contact surface 46 of the second movement member 18 and the recess 106 provided on the first contact surface 42 of the first movement member 16. There is. As a result, when the roller surface 103 and the first contact surface 42 are in contact with each other, the rolling contact of the roller surface 103 prevents the roller surface 103 and the first contact surface 42 from being separated, and the second contact surface 46 A contact point 60 between the first contact surface 42 and the first contact surface 42 can be advanced. Furthermore, the contact points 60 can be advanced intermittently while maintaining contact between any roller surface 103 of the second contact surface 46 and the first contact surface 42 . Consequently, in the process of advancing the contact point 60 within the second contact range R46, separation between the second contact surface 46 and the first contact surface 42 becomes less likely to occur. As a result, it is possible to suppress large speed irregularities in the rotational motion output from either of the moving members 16 and 18, which is caused by the separation between the first contact surface 42 and the second contact surface 46.

Next, modifications of each of the constituent elements described so far will be described.

The combination of the first moving member 16 and the second moving member 18 that perform high-speed rotational motion and low-speed rotational motion is not particularly limited. Examples of this combination include the following (1) to (3).
(1) The first motion member 16 performs a high-speed rotational motion (swinging motion), and the second motion member 18 performs a low-speed rotational motion (rotation motion).
(2) The second motion member 18 performs a high-speed rotational motion (swinging motion), and the first motion member 16 performs a low-speed rotational motion (rotation motion).
(3) The first moving member 16 performs a high-speed rotational motion (rotation motion), and the second motion member 18 performs a low-speed rotational motion (rotation motion).

The power transmission device 10 of (1) is assumed to function as an eccentric rocking gear device of an external tooth rocking type in which the first moving member 16 functioning as an external gear performs rocking motion, for example. . In this case, in order to perform the oscillating motion by the first moving member 16, it is sufficient to cause the first moving member 16 to perform the oscillating motion together with the eccentric body 32 by rotating the high-speed shaft 12, as described above. Furthermore, in order for the second moving member 18 to perform rotational movement, the carrier 24 is fixed to an external support member to restrain the rotation of the first moving member 16, while the casing 20 is integrated with the low-speed shaft 14. good. Thereby, the low-speed shaft 14 can be rotated at the same rotational speed as the rotational component of the second motion member 18 that performs rotational motion. In this case, the number of second contact surfaces 46 (number of teeth) of the second moving member 18 may be N+1.

The power transmission device 10 of (2) is assumed to function as an eccentric oscillating gear device of an internal oscillating type in which the second moving member 18 functioning as an internal gear performs oscillating motion, for example. . In this case, in order to perform the swinging motion by the second moving member 18, it is sufficient to cause the second moving member 18 to perform the swinging motion together with the eccentric body 32 by the rotation of the high-speed shaft 12. In this case, an eccentric bearing 34 is disposed between the second moving member 18 that performs a rocking motion and the eccentric body 32 to allow relative rotation thereof. Further, in this case, in order to perform rotational motion by the first motion member 16, the first motion member 16 may be provided so as to be rotatable integrally with the low-speed shaft 14. Thereby, the low-speed shaft 14 can be rotated at the same rotational speed as the rotational component of the first motion member 16 that performs rotational motion. In this case, the first rotation center Ca swings (revolutions) around the second rotation center Cb while the second rotation center Cb, which is the rotation center of the rotational movement, remains stationary, thereby performing the swing motion. In this case, the number of second contact surfaces 46 (number of teeth) of the second moving member 18 may be N+1.

In the case of (3), the first motion member 16 that performs high-speed rotational motion may be provided so as to be rotatable integrally with the high-speed shaft 12, and the second motion member 18 that performs low-speed rotational motion may be provided such that it is rotatable integrally with the low-speed shaft 14. . In this case as well, each of the moving members 16 and 18 can convert one of the high-speed rotational motion and low-speed rotational motion into the other and then output the other rotational motion when either the high-speed rotational motion or the low-speed rotational motion is input. In this case, the reduction ratio n is (N+1)/N, as described above. In this case, the number of second contact surfaces 46 (number of teeth) of the second moving member 18 may be N+1.

Up to this point, when high-speed rotational motion is input from the high-speed shaft 12 to either the first motion member 16 or the second motion member 18, it is converted into a low-speed rotational motion, and then the first motion member 16 or the second motion member 18 An example in which the output is output from one of the two motion members 18 to the low-speed shaft 14 has been described. In addition, when low-speed rotational motion is input from the low-speed shaft 14 to either the first motion member 16 or the second motion member 18, it is converted into high-speed rotational motion, and then the first motion member 16 and the second moving member 18 may be output to the high-speed shaft 12. In other words, the first moving member 16 and the second moving member 18 may decelerate the rotational motion input from the high-speed shaft 12 and output it to the low-speed shaft 14, or increase the rotational motion input from the low-speed shaft 14. It may also be output to the high speed shaft 12.

In addition, the first motion member 16 and the second motion member 18 convert one of high-speed rotational motion and low-speed rotational motion into the other, and then convert it into another motion without outputting it as is. You can also output it with For example, when a rocking motion (high-speed rotational motion) is input from the high-speed shaft 12 to the first motion member 16 via the eccentric body 32, the input is converted into the rotational motion (low-speed rotational motion) of the first motion member 16. While converting the motion, the second motion member 18 may also be converted into a linear motion and then output to the low-speed shaft 14 via the casing 20. This assumes that the distance from the first rotation center Ca to the second rotation center Cb of the first motion member 16 (the eccentricity of the eccentric body 32) is increased and the first motion member 16 is used as a cam. There is. In this case, the second movement member 18 may only have a pair of second contact surfaces 46 .

The numbers of the first movement member 16 and the second movement member 18 are not particularly limited. For example, the plurality of first motion members 16 may be coupled together so that they can rotate together, or the plurality of first motion members 16 may be coupled via a pin member so that their rotational components can be synchronized. In this case, the plurality of first motion members 16 are arranged at axially offset positions. In this case, the phases around the center of the plurality of first motion members 16 connected to each other may be shifted from each other. In this case, separate second movement members 18 corresponding to each of the plurality of first movement members 16 may be used.

When the N first contact surfaces 42 of the first movement member 16 have an odd angular shape, N is not limited to 3, but may be an odd number of 5 or more. When the second movement member 18 includes N+1 second contact surfaces 46, it can be said that the N+1 second contact surfaces 46 may have an even-angular shape. Further, the N first contact surfaces 42 of the first movement member 16 may have an even-numbered angular shape, and in that case, N may be an even number of 4 or more.

The convex portion 80 may be provided on both the first contact surface 42 and the second contact surface 46. Also in this case, as described above, when the high-speed rotational movement and the low-speed rotational movement progress by the rotational angles θ1 and θ2 from the reference rotational position, the convex portion 80 makes the interval on the aforementioned straight line Le smaller than the reference interval Ls. It suffices if it is provided so as to narrow it.

When provided on the first contact surface 42, the convex portion 80 may be provided only on one side with respect to the center C42 of the first contact surface 42. When provided on the first movement member 16, the convex portion 80 may be provided on only some of the first contact surfaces 42 instead of being provided on all the first contact surfaces 42.

When provided on the second contact surface 46, the convex portion 80 may be provided only on one side with respect to the center C46 of the second contact surface 46. When provided on the second movement member 18, the convex portion 80 may be provided on only some of the second contact surfaces 46, instead of being provided on all the second contact surfaces 46.

The pin member 26 only needs to be able to connect the first moving member 16 and the carrier 24 in a manner synchronized with the rotational component of the first moving member 16 while allowing the swinging movement of the first moving member 16. is not particularly limited. For example, the pin member 26 is provided integrally with the carrier 24, the insertion hole of the pin member 26 provided in the movement unit 22 is made eccentric with respect to the center of the pin member 26, and the direction and amount of the eccentricity are determined by the movement in which the pin member 26 is inserted. It may be the same as the eccentric body 32 that swings the unit 22. When connecting the first moving member 16 and the carrier 24 using the pin member 26, the two may be connected without using the flange member 36 that is integrated with the first moving member 16.

The above embodiments and modifications are illustrative. These abstracted technical ideas should not be interpreted as being limited to the contents of the embodiments and modified forms. The contents of the embodiments and modified forms may be subject to many design changes such as changes, additions, and deletions of constituent elements. In the embodiments described above, the content that allows such design changes is emphasized by adding the notation "embodiment". However, design changes are allowed even if there is no such notation. The hatching added to the cross section of the drawing does not limit the material of the hatched object. Naturally, the structures/numerical values referred to in the embodiments and modifications include those that can be considered to be the same in consideration of manufacturing errors such as dimensional errors.

Any combination of the above components is also effective. For example, an embodiment may be combined with any description of another embodiment, or a modified form may be combined with any description of the embodiment and other modified forms. In the embodiment, a component made up of a single member may be made up of a plurality of members. Similarly, a component configured with multiple members in an embodiment may be configured with a single member.

DESCRIPTION OF SYMBOLS 10... Power transmission device, 16... First movement member, 18... Second movement member, 42... First contact surface, C42... Center, 44... Vertex, 46... Second contact surface, C46... Center, 48... Vertex, 60... Contact point, 80... Convex portion, 82... Convex amount increasing region, 88... Interference avoidance portion, 104... Roller, 106... Concave portion.

Claims (9)

a first motion member having N first contact surfaces forming an N-gonal shape in the outer circumferential shape, where N is a natural number of 3 or more;
A second motion member having a plurality of second contact surfaces that contact the first contact surface, the power transmission device comprising:
The first moving member and the second moving member are configured to adjust the contact between the first contact surface and the second contact surface when one of high speed rotational motion and low speed rotational motion around different rotation centers is input to either of them. By contact, it is possible to output from one of them by converting it into the other,
The first contact surface as a whole has an arc shape that is convex radially outward with respect to a line connecting adjacent vertices of the N-gon.
The second contact surface has a generally linear shape,
When the contact position with the center of the first contact surface is the center of the second contact surface, at least one of the first contact surface and the second contact surface has a convex provided at a position offset from the center thereof. A power transmission device comprising: A Reuleaux N-gon shape that has the same number of angles as the N-gon and the midpoint of each side coincides with the center of each of the N first contact surfaces, and a Reuleaux N-gon shape with both ends at the center of the opposing pair of second contact surfaces. A linear shape extending perpendicularly from both ends of a line segment having the same length as the width across the N rectangular shape of the Reuleaux is the standard shape, and based on the motion mode of the low-speed rotational motion and the high-speed rotational motion and the N. Assuming a reduction ratio n of the high-speed rotational motion to the low-speed rotational motion that is determined,
From the reference rotational position where the center of the first contact surface and the center of the second contact surface are in contact, the high-speed rotational motion advances by a first rotational angle θ1, and the low-speed rotational motion advances to a second rotational angle θ2 (=θ1 ×(1/n)), the convex portion has a distance in the direction along the line segment at the closest position between the first contact surface and the second contact surface. The power transmission device according to claim 1, wherein the power transmission device is provided so as to be narrower than the spacing in the standard shape. a distance e from the first center of rotation of the high-speed rotational motion to the second center of rotation of the low-speed rotational motion, an opposing direction along a line segment connecting the centers of the opposing pair of second contact surfaces, and the low-speed rotation. When assuming a reduction ratio n of the high-speed rotational motion with respect to the low-speed rotational motion determined based on the motion and the motion mode of the high-speed rotational motion and the N,
From the reference rotational position where the center of the first contact surface and the center of the second contact surface are in contact, the high-speed rotational motion advances by a first rotational angle θ1, and the low-speed rotational motion advances to a second rotational angle θ2 (=θ1 x (1/n)), extends along the opposing direction from a position that is a distance e x N from the second rotation center on a straight line passing through the first rotation center and the second rotation center. The power transmission device according to claim 1 or 2, wherein the convex portion is provided so that a contact point between the first contact surface and the second contact surface is on a straight line. Any one of claims 1 to 3, wherein the convex portions are individually provided on both sides of the center of the first contact surface on the first contact surface, or on both sides of the center of the second contact surface on the second contact surface. The power transmission device described in . When assuming a Reuleaux N-gon shape that has the same number of angles as the N-gon and the midpoint of each side coincides with the center of each of the N first contact surfaces,
5. The power transmission device according to claim 1, wherein the convex portion of the first contact surface has a radius of curvature smaller than a radius of curvature of a side of the N-gon shape of the Reuleaux. The power transmission according to any one of claims 1 to 5, wherein the convex portion includes an increasing convexity region in which the convexity increases gradually as the convexity increases away from the center of either the first contact surface or the second contact surface. Device. a first motion member having N first contact surfaces forming an N-gonal shape in the outer circumferential shape, where N is a natural number of 3 or more;
A second motion member having a plurality of second contact surfaces that contact the first contact surface, the power transmission device comprising:
When one of high-speed rotational motion and low-speed rotational motion around different rotation centers is input to the first motion member and the second motion member, the first motion member and the second motion member contact with each other between the first contact surface and the second contact surface. It is possible to convert and output the other one,
The first contact surface as a whole has an arc shape that is convex radially outward with respect to a line connecting adjacent vertices of the N-gon.
The second contact surface includes a plurality of roller surfaces that roll into contact with the first contact surface,
A power transmission device in which the first contact surface includes a plurality of recesses with which the roller surface rolls and comes into contact. The power transmission device according to claim 7, wherein the plurality of concave portions have a concave amount that decreases as the distance from the center of the first contact surface increases. The power transmission device according to claim 7 or 8, wherein the width of the plurality of recesses decreases as the distance from the center of the first contact surface increases.

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