Transmission mechanism

Abstract

The present invention provides a transmission mechanism that enables a reduction in motion transmission error between an input-shaft side and an output-shaft side. A transmission mechanism (101) is provided with a cam (102), a plurality of pins (105) arranged along a side surface (103) of the cam, guide plates (107a, 107b) in which a plurality of guide holes (109a, 109b) are provided, and gears (106a, 106b) capable of engaging the pins. In conjunction with rotation of the cam, each pin is guided by the corresponding guide hole (109a, 109b) and moves along the cam and the gears, thereby causing the guide plates or gears to rotate relative to the cam. The plurality of pins (105) are divided into a plurality of groups (110a-110f), and the pins (105) in each group (110a-110f) are coupled in series, but are not coupled to the pins (105) in the other groups (110a-110f).

Description

[Technical field]

[0001] The present invention relates to a transmission mechanism capable of reducing a motion transmission error between an input shaft side and an output shaft side. [Background technology]

[0002] Patent Document 1 discloses a speed reduction mechanism including an elliptical cam, a roller link that contacts the outer periphery of the elliptical cam via a roller, a guide plate coaxial with the elliptical cam, and an internally toothed plate. In this speed reduction mechanism, the elliptical cam serves as an input shaft, the guide plate or the internally toothed plate serves as an output shaft, the guide plate has guide holes arranged in a circle corresponding to each pin for the roller of the roller link, the internally toothed plate has internal teeth arranged in a circle with a number of teeth greater than the number of pins of the roller link, the roller link is configured as a roller link chain in which link plates that connect the pins are arranged, and each pin of the roller link is guided via both the guide holes and the internal teeth as the elliptical cam rotates, and advances and retreats in the tooth grooves of the internal teeth to rotate the guide plate or the internally toothed plate relatively.

[0003] Patent document 2 discloses a reduction gear device including a first cam with an annular groove formed on its surface, a number of stepped pins arranged within the annular groove and rolling freely within the annular groove, a second cam with an array of circular holes that individually regulate the movement of each stepped pin, and a third cam with teeth that mesh with the stepped pins and converts the rotational motion of the first cam into rotational motion with a predetermined reduction ratio. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-251374 A [Patent Document 2] JP 2009-281422 A Summary of the Invention [Problem to be solved by the invention]

[0005] The reduction mechanism of Patent Document 1 has a structure in which the roller links contact the outer periphery of the elliptical cam via rollers, and all of the pins for the rollers are connected by link plates, and the polygonal movement of the link plates from the short diameter part to the long diameter part of the elliptical cam creates a speed difference in each pin, and this speed difference interferes with each other, causing a motion transmission error between the input shaft side and the output shaft side. The reduction gear of Patent Document 2 has a structure in which the stepped pins are arranged so as to be surrounded by annular grooves, and there is a problem in that the stepped pins are easily worn due to contact with the annular groove, and a long life cannot be expected.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a transmission mechanism capable of solving the above problems and reducing the motion transmission error between the input shaft side and the output shaft side. [Means for solving the problem]

[0007] According to one aspect of the present invention, a transmission mechanism includes a first shaft rotatable about a first rotation axis, the first shaft including a cam fixed to the first shaft concentrically with the first shaft, the side of the cam having a positive curvature as viewed from the first rotation axis, a plurality of pins arranged along the side of the cam, a second shaft rotatable about a second rotation axis, a guide plate concentric with the second shaft, the guide plate having a plurality of guide holes formed along the rotation direction of the second shaft, each pin being housed in a corresponding guide hole, and a gear concentric with the second shaft, the gear being capable of engaging with each pin, wherein as one of the first shaft and the second shaft rotates, each pin is guided by the corresponding guide hole and moves along the cam and the gear, thereby rotating the other of the first shaft and the second shaft relative to the other, the plurality of pins are divided into a plurality of groups, and the pins in one group are connected in series but are not connected to the pins in another group.

[0008] According to one embodiment of the present invention, in a transmission mechanism, the curvature of the side surface of the cam obtained by completing one revolution along the rotation direction of the first shaft has two or more maximum values, and the multiple pins are divided into multiple groups based on the number of maximum values.

[0009] According to one embodiment of the present invention, in the transmission mechanism, a plurality of pins are divided into a plurality of groups according to an integer multiple of the number of maximal values ​​that is equal to or greater than two.

[0010] According to one embodiment of the present invention, in the transmission mechanism, the pins are divided into groups by an integer number equal to or greater than two.

[0011] According to one embodiment of the invention, in the transmission mechanism, the pins of one group are connected in series such that two adjacent pins are connected by a chain.

[0012] According to one embodiment of the present invention, in the transmission mechanism, either the guide plate or the gear is fixed to the second shaft.

[0013] According to one embodiment of the present invention, in the transmission mechanism, the gear is an internal gear, and a plurality of pins are arranged on the outside of the cam.

[0014] According to one embodiment of the present invention, in the transmission mechanism, when the gear is an internal gear, the number of teeth of the gear is the sum of the number of the pins and the number of the local maximum values.

[0015] According to one embodiment of the present invention, in the transmission mechanism, the gear is an external gear, and a plurality of pins are arranged inside the cam.

[0016] According to one embodiment of the present invention, in the transmission mechanism, when the gear is an external gear, the number of the pins is the sum of the number of teeth of the gear and the number of the local maximum values. Effect of the Invention

[0017] According to the present invention, by dividing the multiple pins arranged along the side of the cam into multiple groups and connecting the pins in series only in each group, the effect of the speed difference between the pins can be contained within each group alone, and the motion transmission error between the input shaft side and the output shaft side caused by all of the multiple pins can be reduced.

[0018] Other objects, features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0019] [Figure 1A] FIG. 2 is an exploded perspective view of a transmission mechanism according to an embodiment of the present invention. [Figure 1B] FIG. 1B is a top view of the transmission mechanism of FIG. 1A. [Figure 1C] 1B is a cross-sectional view of the transmission mechanism of FIG. 1A taken along line CC of FIG. 1B. [Figure 1D] 1B is a cross-sectional view of the transmission mechanism of FIG. 1A taken along line DD of FIG. 1C. [Figure 1E] 1B is a cross-sectional view of the transmission mechanism of FIG. 1A taken along line EE of FIG. 1C. [Figure 1F] 1B is a perspective view showing a partial cross section of the transmission mechanism of FIG. 1A. [Figure 2A] FIG. 11 is an exploded perspective view of a transmission mechanism according to another embodiment of the present invention. [Figure 2B] FIG. 2B is a top view of the transmission mechanism of FIG. 2A. [Figure 2C] 2B is a cross-sectional view of the transmission mechanism of FIG. 2A taken along line CC of FIG. 2B. [Figure 2D] 2B is a cross-sectional view of the transmission mechanism of FIG. 2A taken along line DD of FIG. 2C. [Figure 2E] 2C is a cross-sectional view of the transmission mechanism of FIG. 2A taken along line EE of FIG. 2C. [Figure 2F] 2B is a perspective view showing a partial cross section of the transmission mechanism of FIG. 2A. [Figure 3A] FIG. 11 is an exploded perspective view of a transmission mechanism according to another embodiment of the present invention. [Figure 3B] FIG. 3B is a top view of the transmission mechanism of FIG. 3A. [Figure 3C] 3B is a cross-sectional view of the transmission mechanism of FIG. 3A taken along line CC of FIG. 3B. [Figure 3D] 3B is a cross-sectional view of the transmission mechanism of FIG. 3A taken along line DD of FIG. 3C. [Figure 3E] 3B is a cross-sectional view of the transmission mechanism of FIG. 3A taken along line EE of FIG. 3C. [Figure 4A] FIG. 11 is an exploded perspective view of a transmission mechanism according to another embodiment of the present invention. [Figure 4B] FIG. 4B is a top view of the transmission mechanism of FIG. 4A. [Figure 4C] 4B is a cross-sectional view of the transmission mechanism of FIG. 4A taken along line CC of FIG. 4B. [Figure 4D] 4B is a cross-sectional view of the transmission mechanism of FIG. 4A taken along line DD of FIG. 4C. [Figure 4E] 4B is a cross-sectional view of the transmission mechanism of FIG. 4A taken along line EE of FIG. 4C. [Figure 5A] FIG. 2 is a perspective view of a pin in a transmission mechanism according to an embodiment of the present invention. [Figure 5B] FIG. 5B is a cross-sectional view of the pin of FIG. 5A. [Figure 5C] FIG. 5B is a top view of the pin of FIG. 5A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

[0021] Various embodiments of the transmission mechanism 101 will be described with reference to FIGS. 1A to 5C. The transmission mechanism 101 includes a first shaft (not shown) that can rotate around a first rotation axis 104, and a second shaft (not shown) that can rotate around a second rotation axis 108. The first rotation axis 104 and the second rotation axis 108 may be on the same line. The first shaft may be an input shaft, and the second shaft may be an output shaft. The second shaft may be an input shaft, and the first shaft may be an output shaft. The first shaft includes a cam 102 that is fixed to the first shaft and is concentric with the first shaft. The transmission mechanism 101 further includes a plurality of pins 105 arranged along a side surface 103 of the cam 102, a guide plate that is concentric with the second shaft and has a plurality of guide holes provided along the rotation direction of the second shaft, and a gear that is concentric with the second shaft and can engage with each pin 105. Each pin 105 is received in a corresponding one of a plurality of guide holes provided in a guide plate.

[0022] The side surface 103 of the cam 102 has a positive curvature when viewed from the first rotation axis 104. That is, if a normal vector of the side surface 103 of the cam 102 faces the direction of the first rotation axis 104 in a cross section of the side surface 103 of the cam 102 in a plane perpendicular to the first rotation axis 104, the curvature of the side surface 103 of the cam 102 is always positive in the cross section. As shown in FIGS. 1A to 1F and 3A to 3E, when the gear that can engage with each pin 105 is an internal gear, the cam 102 may have a side surface 103 formed by a column having a convex side surface when viewed from the first rotation axis 104. 2A to 2F and 4A to 4E, when the gear that can engage with each pin 105 is an external gear, the cam 102 may have a side surface 103 due to a through hole of a column having a convex side surface when viewed from the first rotation axis 104. For example, the side surface 103 of the cam 102 may have the shape of the side surface of an elliptical cylinder, or a substantially regular polygonal cylinder such as a substantially regular triangular cylinder, a substantially regular square cylinder, a substantially regular pentagonal cylinder, etc., with the first rotation axis 104 as the center.

[0023] Each pin 105 is guided by the corresponding guide hole and moves along the cam 102 and the gear as one of the first shaft and the second shaft rotates, and the other of the first shaft and the second shaft rotates relative to the other. For example, when the first shaft or the second shaft as the input shaft rotates, each pin 105 is guided by the guide hole in which the pin 105 is accommodated and moves along the cam 102 and the gear. The movement of each pin 105 causes the second shaft or the first shaft as the output shaft to rotate relative to the first shaft or the second shaft as the input shaft. Note that each guide hole is formed in a shape that causes each pin 105 to move a predetermined amount in the corresponding guide hole when the first shaft or the second shaft as the input shaft rotates. For example, each guide hole may be formed in a substantially elliptical shape with the major axis facing the direction of the second rotation axis 108.

[0024] The gears may be arranged on one side of the cam 102, or may be a pair of gears including a first gear 106a concentric with the second shaft and having a plurality of teeth along the rotation direction of the second shaft, and a second gear 106b concentric with the second shaft and having a plurality of teeth along the rotation direction of the second shaft, as shown in Figs. 1A to 4E. The first gear 106a and the second gear 106b are arranged to sandwich the cam 102 therebetween. The first gear 106a and the second gear 106b are arranged so that the positions of the teeth of the first gear 106a and the teeth of the second gear 106b roughly match, and the phases of the teeth roughly match, when the transmission mechanism 101 is viewed from above. In the following, the description will be given on the assumption that the gears are a pair of gears consisting of a first gear 106a and a second gear 106b, but the same applies when the gears are arranged on one side of the cam 102.

[0025] The guide plate may be disposed on one side of the cam 102, or may be a pair of guide plates including a first guide plate 107a concentric with the second axis and a second guide plate 107b concentric with the second axis, as shown in FIGS. 1A to 4E. The first guide plate 107a and the second guide plate 107b are disposed so as to sandwich the cam 102. The first guide plate 107a and the second guide plate 107b may be disposed so as to sandwich the first gear 106a and the second gear 106b, or the first gear 106a and the second gear 106b may be disposed so as to sandwich the first guide plate 107a and the second guide plate 107b. A plurality of first guide holes 109a are provided in the first guide plate 107a along the rotation direction of the second shaft, and a plurality of second guide holes 109b are provided in the second guide plate 107b along the rotation direction of the second shaft. Each pin 105 is accommodated in the corresponding first guide hole 109a of the first guide plate 107a and the corresponding second guide hole 109b of the second guide plate 107b, and is guided by the corresponding first guide hole 109a and second guide hole 109b to move along the cam 102, the first gear 106a, and the second gear 106b. Note that the following description is based on the assumption that the guide plate is a pair of guide plates composed of the first guide plate 107a and the second guide plate 107b, but the same applies when the guide plate is disposed on one side of the cam 102.

[0026] The pins 105 are divided into a plurality of groups. For example, as shown in Fig. 1D, Fig. 2D, Fig. 3D, and Fig. 4D, the pins 105 may be divided into a first group 110a to a sixth group 110f. The pins 105 in each of the first group 110a to the sixth group 110f are connected in series to the pins 105 in the group to which the pin 105 belongs (for example, the first group 110a), but are not connected to the pins 105 in the group to which the pin 105 does not belong (for example, the second group 110b to the sixth group 110f). In this way, by dividing the multiple pins 105 arranged along the side 103 of the cam 102 into first group 110a to sixth group 110f and connecting only the pins 105 in each of the first group 110a to sixth group 110f in series, the effect of the speed difference between the pins 105 can be contained only in each of the first group 110a to sixth group 110f to which the pin 105 belongs, thereby reducing the motion transmission error between the first axis and the second axis due to the entire multiple pins 105.

[0027] The curvature of the side surface 103 of the cam 102 obtained by going around the first axis in the rotation direction from 0 to 360° may have two or more maximum values. In addition, the two or more maximum values ​​of the curvature may be obtained at equal intervals from 0 to 360°. For example, as shown in Figs. 1A to 2F, when the cam 102 has a shape having a side surface 103 of an elliptical cylinder, the cam 102 has a maximum value of curvature at each of two apexes of the long axis of the ellipse at intervals of 180° in a cross section on a plane perpendicular to the first rotation axis 104 of the cam 102, and as shown in Figs. 3A to 4E, when the cam 102 has a shape having a side surface 103 of a substantially equilateral triangle cylinder, the cam 102 has a maximum value of curvature at each of three apexes of a substantially equilateral triangle at intervals of 120° in a cross section on a plane perpendicular to the first rotation axis 104 of the cam 102. The multiple pins 105 may be divided into multiple groups based on the number of maximum values. When one of the first and second shafts rotates, the teeth of the first and second gears 106a and 106b with which each pin 105 engages are changed according to the relationship between the side surface 103 of the cam 102 having such a maximum value and the first and second gears 106a and 106b, so that the rotation of one is transmitted to the other so as to rotate the other. By dividing the multiple pins 105 into multiple groups based on the number of maximum values, even if a speed difference occurs between a certain pin 105 between the side surface of the maximum value and the side surface of the minimum value among the side surfaces 103 of the cam 102, the mutual interference between the pins 105 due to this speed difference can be completed only in each of the first group 110a to the sixth group 110f to which the pin 105 belongs, and thus the motion transmission error between the first and second shafts due to the entire multiple pins 105 can be reduced.

[0028] The pins 105 may be divided into a plurality of groups by an integer multiple of two or more of the number of maximum values ​​of the curvature of the side surface 103 of the cam 102. The pins 105 may also be divided into a plurality of groups by an even number. For example, as shown in Figs. 1A to 2F, when the cam 102 has a shape with the side surface 103 of an elliptical cylinder, the cam 102 has maximum values ​​of curvature at two vertices of the long axis of the ellipse at intervals of 180° in a cross section on a plane perpendicular to the first rotation axis 104 of the cam 102. Therefore, the pins 105 may be divided into six groups, such as the first group 110a to the sixth group 110f, by six, which is three times the number of the maximum values, two, and is also an even number. Furthermore, as shown in Figures 3A to 4E, when cam 102 has a shape having side 103 of an approximately equilateral triangular tube, the cross section of cam 102 in a plane perpendicular to first rotation axis 104 has maximum values ​​of curvature at each of the three vertices of the approximately equilateral triangle at intervals of 120°, so that multiple pins 105 may be divided into six, such as first group 110a to sixth group 110f, by 6, which is twice the number of maximum values, 3, and is also an integer greater than or equal to 2.

[0029] The pins 105 in each of the first group 110a to the sixth group 110f may be connected in series such that two adjacent pins 105 are connected by a chain 110. For example, as shown in Fig. 1D, Fig. 2D, Fig. 3D, and Fig. 4D, in each of the first group 110a to the sixth group 110f, each pin 105 and its adjacent pin 105 are connected by the chain 110 so as to be rotatable relative to each other. Thereby, the pins 105 in each of the first group 110a to the sixth group 110f can move along the cam 102 and the gear in conjunction with each other. On the other hand, since the pins 105 in each of the first group 110a to the sixth group 110f are not connected to the pins 105 of the group to which the pin 105 does not belong, the effect of the speed difference between the pins 105 can be contained only in each of the first group 110a to the sixth group 110f to which the pin 105 belongs, thereby reducing the motion transmission error between the first axis and the second axis due to the entire plurality of pins 105.

[0030] As shown in FIG. 5A to FIG. 5C, each pin 105 may include an inner shaft portion 105a and an outer ring portion 105b that rotates around the inner shaft portion 105a. The outer ring portion 105b may rotate around the inner shaft portion 105a by sliding contact, or may rotate around the inner shaft portion 105a by rolling contact via rollers or the like. Each pin 105 is arranged so that the outer ring portion 105b contacts the side surface 103 of the cam 102 and the outer ring portion 105b of the adjacent pin 105. When the gear is arranged on one side with respect to the cam 102, one end of the inner shaft portion 105a of each pin 105 can engage with the gear. When the gear is a pair of gears composed of a first gear 106a and a second gear 106b, both ends of the inner shaft portion 105a of each pin 105 can engage with the first gear 106a and the second gear 106b, respectively. When the guide plate is disposed on one side of the cam 102, one end of the inner shaft portion 105a of each pin 105 is accommodated in the corresponding guide hole of the guide plate. When the guide plate is a pair of guide plates consisting of a first guide plate 107a and a second guide plate 107b, both ends of the inner shaft portion 105a of each pin 105 are accommodated in the corresponding first guide hole 109a of the first guide plate 107a and the corresponding second guide hole 109b of the second guide plate 107b, respectively. Two adjacent pins 105 may be connected so that the outer ring portion 105b of each pin 105 is sandwiched between two chains 110. In addition, a pin stopper 111 may be disposed on the inner shaft portion 105a of each pin 105 to prevent the chain 110 and the outer ring portion 105b from moving in the axial direction of the inner shaft portion 105a.

[0031] One of the pair of guide plates consisting of the first guide plate 107a and the second guide plate 107b and the pair of gears consisting of the first gear 106a and the second gear 106b is fixed to the second shaft, and the other of them is fixed to a housing (not shown) of the transmission mechanism 101. That is, one of the first guide plate 107a and the second guide plate 107b and the first gear 106a and the second gear 106b rotates together with the second shaft.

[0032] 1A to 1F and 3A to 3E, the first gear 106a and the second gear 106b constituting a pair of gears may be internal gears. In this case, the cam 102 may have a shape having a side surface 103 of an elliptical cylinder (see FIG. 1A) or a substantially regular polygonal prism such as a substantially regular triangular prism (see FIG. 3A), a substantially regular square prism, a substantially regular pentagonal prism, etc., centered on the first rotation axis 104, and a plurality of pins 105 are arranged outwardly along the side surface 103 of the cam 102. For example, in the case where a pair of guide plates consisting of a first guide plate 107a and a second guide plate 107b are fixed to the housing of the transmission mechanism 101, when the cam 102 rotates with the rotation of the first shaft as the input shaft, each pin 105 is guided by the guide holes 109a and 109b in which the pin 105 is accommodated, and moves along the pair of gears between the cam 102 and the pair of gears so as to rotate the pair of gears in the opposite direction to the rotation direction of the cam 102. In the case where the pair of gears are fixed to the housing of the transmission mechanism 101, when the cam 102 rotates with the rotation of the first shaft as the input shaft, each pin 105 is guided by the guide holes 109a and 109b in which the pin 105 is accommodated, and moves along the pair of guide plates between the cam 102 and the pair of gears so as to rotate the pair of guide plates in the opposite direction to the rotation direction of the cam 102. The same applies when the second shaft as the input shaft rotates.

[0033] When one of the first shaft and the second shaft rotates, the teeth of the first gear 106a and the second gear 106b that each pin 105 engages with change according to the relationship between the side surface 103 of the cam 102 having the maximum value of curvature and the first gear 106a and the second gear 106b that are internal gears, thereby transmitting the rotation of one to the other to rotate the other. The number of teeth of each of the first gear 106a and the second gear 106b is N T Let the number of pins be N P Let the number of maximal values ​​of the curvature be N M Then, N T =N P +N MIn the case where the first shaft is the input shaft, when the pair of guide plates are fixed to the housing of the transmission mechanism 101, the gear ratio is N M / N T When the pair of gears is fixed to the housing of the transmission mechanism 101, the gear ratio is N M / N P In addition, when the second shaft is used as the input shaft, if a pair of guide plates are fixed to the housing of the transmission mechanism 101, the gear ratio is N T / N M When the pair of gears is fixed to the housing of the transmission mechanism 101, the gear ratio is N P / N M It is.

[0034] 2A to 2F and 4A to 4E, the first gear 106a and the second gear 106b constituting a pair of gears may be external gears. In this case, the cam 102 may be provided with a through hole having a side surface 103 of an elliptical cylinder (see FIG. 2A) or a substantially regular polygonal prism such as a substantially regular triangular prism (see FIG. 4A), a substantially regular square prism, a substantially regular pentagonal prism, etc., centered on the first rotation axis 104, and a plurality of pins 105 are arranged inside along the side surface 103 of the cam 102. For example, in the case where a pair of guide plates consisting of a first guide plate 107a and a second guide plate 107b are fixed to the housing of the transmission mechanism 101, when the cam 102 rotates with the rotation of the first shaft as the input shaft, each pin 105 is guided by the guide holes 109a and 109b in which the pin 105 is accommodated, and moves along the pair of gears between the cam 102 and the pair of gears so as to rotate the pair of gears in the opposite direction to the rotation direction of the cam 102. In the case where the pair of gears are fixed to the housing of the transmission mechanism 101, when the cam 102 rotates with the rotation of the first shaft as the input shaft, each pin 105 is guided by the guide holes 109a and 109b in which the pin 105 is accommodated, and moves along the pair of guide plates between the cam 102 and the pair of gears so as to rotate the pair of guide plates in the opposite direction to the rotation direction of the cam 102. The same applies when the second shaft as the input shaft rotates.

[0035] When one of the first shaft and the second shaft rotates, the teeth of the first gear 106a and the second gear 106b that each pin 105 engages with change according to the relationship between the side surface 103 of the cam 102 having the maximum value of curvature and the first gear 106a and the second gear 106b that are external gears, thereby transmitting the rotation of one to the other to rotate the other. P The number of teeth of each of the first gear 106a and the second gear 106b is N T Let the number of maximal values ​​of the curvature be N M Then, N P =N T +N M In the case where the first shaft is the input shaft, when the pair of guide plates are fixed to the housing of the transmission mechanism 101, the gear ratio is N M / N T When the pair of gears is fixed to the housing of the transmission mechanism 101, the gear ratio is N M / N P In addition, when the second shaft is used as the input shaft, if a pair of guide plates are fixed to the housing of the transmission mechanism 101, the gear ratio is N T / N M When the pair of gears is fixed to the housing of the transmission mechanism 101, the gear ratio is N P / N M It is.

[0036] Although the above description has been given with respect to a particular embodiment, it will be apparent to those skilled in the art that the present invention is not limited thereto, and that various changes and modifications can be made within the principles of the present invention and the scope of the appended claims. [Explanation of symbols]

[0037] 101 Transmission Mechanism 102 Cam 103 Side 104 First rotation axis 105 pin 105a Inner shaft part 105b Outer ring 106a First Gear 106b Second Gear 107a first guide plate 107b second guide plate 108 Second rotation axis 109a First guide hole 109b Second guide hole 110 Chain 110a First Group 110b Second group 110c Third Group 110d Fourth Group 110e Fifth Group 110f 6th group 111 Pinning

Claims

1. a first shaft rotatable about a first axis of rotation, the first shaft including a cam fixed to the first shaft and concentric with the first shaft, the cam having a side surface with a positive curvature as viewed from the first axis of rotation; A plurality of pins arranged along a side surface of the cam; a second shaft rotatable about a second axis of rotation; a guide plate concentric with the second shaft, the guide plate being provided with a plurality of guide holes along a rotational direction of the second shaft, each pin being received in a corresponding guide hole; a gear concentric with said second shaft, said gear being capable of engaging each pin; A transmission mechanism comprising: With the rotation of one of the first shaft and the second shaft, each pin is guided by a corresponding guide hole and moves along the cam and the gear, thereby causing the other of the first shaft and the second shaft to rotate relative to the one of the first shaft and the second shaft; a transmission mechanism, wherein the plurality of pins are divided into a plurality of groups, each group of the plurality of groups having two or more pins, the pins in each group being connected in series between a first end and a second end by a chain having a first end and a second end, the chain in each group not connecting the pins in each group to pins in other groups such that a speed of the pins in each group does not affect a speed of the pins in another group.

2. 2. The transmission mechanism according to claim 1, wherein a curvature of a side surface of the cam obtained by going around once in the rotation direction of the first shaft has two or more maximum values, and the plurality of pins are divided into the plurality of groups based on the number of the maximum values.

3. The transmission mechanism according to claim 2 , wherein the plurality of pins are divided into the plurality of groups by an integer multiple of two or more of the number of the maximum values.

4. The transmission mechanism according to claim 1 , wherein the plurality of pins are divided into the plurality of groups by an integer number of two or more.

5. A transmission mechanism described in any one of claims 1 to 4, wherein the pins in each group are connected in series so that two adjacent pins are connected by a chain in each group.

6. The transmission mechanism according to any one of claims 1 to 5, wherein one of the guide plate and the gear is fixed to the second shaft.

7. The transmission mechanism according to any one of claims 1 to 6, wherein the gear is an internal gear, and the plurality of pins are arranged on the outside of the cam.

8. 8. The transmission mechanism according to claim 7, wherein the number of teeth of the gear is the sum of the number of the plurality of pins and the number of the maximum values.

9. The transmission mechanism according to any one of claims 1 to 6, wherein the gear is an external gear, and the plurality of pins are arranged on an inner side of the cam.

10. 10. The transmission mechanism according to claim 9, wherein the number of the plurality of pins is the sum of the number of teeth of the gear and the number of the maximum values.

Images