Gear mechanism and speed reducer or speed increaser using the same

Abstract

It provides a gear mechanism with high power transmission efficiency and dynamic balance. [Solution] The gear mechanism 1 of the present invention includes a rotating shaft 10, a first fixed internal gear 20, a second fixed internal gear 30, a rotating internal gear 40, a first planetary first external gear 51 that meshes with the first fixed internal gear, a first planetary second external gear 52 that meshes with the rotating internal gear and is fixed to the first planetary first external gear, a second planetary first external gear 61 that meshes with the second fixed internal gear, and a second planetary second external gear 62 that meshes with the rotating internal gear and is fixed to the second planetary first external gear. The rotating shaft 10 has a first eccentric portion 11 and a second eccentric portion 12, and the phase difference between the first eccentric portion 11 and the second eccentric portion 12 is 180 degrees. The first eccentric portion 11 supports the revolution and rotation of the first planetary first external gear 51 and the first planetary second external gear 52. The second eccentric portion 12 supports the revolution and rotation of the second planetary first external gear 61 and the second planetary second external gear 62.

Description

[Technical Field]

[0001] This invention relates to a gear mechanism and a speed reducer or speed increaser using the same. [Background technology]

[0002] A gear mechanism (hereinafter also called a differential gear mechanism) is known that comprises an outer ring member and a specific power transmission member that revolves inside it, where the power transmission member revolves within the outer ring member, and the difference in circumference (number of teeth) between the inner ring of the outer ring member and the outer ring of the power transmission member during the revolving causes the power transmission member to rotate, and this rotation of the power transmission member is extracted as output. In this differential gear mechanism, the reduction ratio is the ratio of the difference (and therefore the differential) in circumference (number of teeth) to the circumference (number of teeth) of the power transmission member over one revolution. Examples of such differential gear mechanisms include the "eccentric oscillating gear mechanism," which rotates a circular power transmission component eccentrically, and the "harmonic gear mechanism," which uses the elasticity of the mechanism to cause the power transmission component to deform elliptically. For example, in an eccentric oscillating gear mechanism, the planetary gears (power transmission members) are eccentric to the sun gear (outer ring member), and for each revolution of the planetary gears, the sun gear rotates by the difference in the number of teeth between the sun gear and the planetary gears. When the rotation of this planetary gear is taken as output, the reduction ratio R can be calculated using the following formula. R=z p / (z p -z s ) Here z p is the number of teeth of the planetary gear, z s This is the number of teeth on the internal gear of the sun.

[0003] In recent years, as mechanical devices such as robots have become more sophisticated, there has been a demand for both further miniaturization and increased output of the actuators used in them. In particular, in order to make electric motors small and high-output, it is desirable to rotate them at high speeds even if the torque is small. To mechanically convert the motor output of a high-speed, low-torque motor into a low-speed, high-torque motor that is easy to use in robots and the like, a gearbox with a high reduction ratio is necessary, and various differential gear mechanisms are being researched in order to realize a small gearbox with a high reduction ratio.

[0004] In the reference example of the second embodiment of Patent Document 1, a planetary gear device 80 (Figures 15-18), and in Figure 1(d) Type IV of Non-Patent Document 1, a gear mechanism with a two-stage eccentric oscillating gear mechanism (hereinafter also referred to as a differential two-stage planetary gear mechanism) is disclosed, as shown in Figure 13a. More specifically, this differential two-stage planetary gear mechanism 100 includes a rotating shaft 101, a fixed internal gear 102 provided radially outward of the rotating shaft 101 and coaxially with the rotating shaft 101, fixed and not rotating, a rotating internal gear 103 provided radially outward of the rotating shaft 101 and rotating coaxially with the rotating shaft 101, a first planetary external gear 104 that meshes with the fixed internal gear 102 and has a pitch circle diameter larger than the pitch circle radius of the fixed internal gear 102, and a second planetary external gear 105 that meshes with the rotating internal gear 103, has a pitch circle diameter larger than the pitch circle radius of the rotating internal gear 103, and is coaxially with the first planetary external gear 104 and fixed to the first planetary external gear 104. The rotating shaft 101 also comprises a cylindrical main shaft portion 106 provided coaxially with the rotating shaft 101, and a cylindrical eccentric shaft portion 107 provided eccentrically at a distance (a) shifted from the main shaft portion 106 in a first direction perpendicular to the main shaft portion 106, and supporting the revolution and rotation of the planetary first external gear 104 and the planetary second external gear 105. The planetary first external gear 104 and the planetary second external gear 105 are fixed to each other by a pin 108. This differential two-stage planetary gear mechanism is compact and achieves a high reduction ratio because it uses a two-stage differential gear mechanism. Furthermore, according to Patent Document 1 and Non-Patent Document 1, the power transmission efficiency is high because the difference in the number of teeth between the meshing internal gear and planetary external gear is small. On the other hand, in the differential two-stage planetary gear mechanism 100, since the centers of gravity of the planetary first external gear 104 and the planetary second external gear 105 that rotate eccentrically (revolve) do not coincide with the rotation center of the rotating shaft 101, dynamic balance is not achieved. Therefore, in a gear mechanism where higher output can be obtained as the rotational speed increases, there is a serious problem that the vibration increases as the rotational speed increases. As described in

[0005] of Patent Document 1, "Since such a configuration disrupts dynamic balance, it has been conventionally overlooked." Even if it is small-sized, has a high reduction ratio, and has high power transmission efficiency, this problem becomes a bottleneck, and it has not been put into practical use until now.

[0005] In Non-Patent Document 2, as shown in FIG. 13b, two planetary first external gears and two planetary second external gears are prepared, and a differential two-stage double planetary gear mechanism 100A is disclosed in which the phases of the revolutions of the two planetary first external gears 104a and 104b and the respective revolutions of the two planetary second external gears 105a and 105b are shifted by 180 degrees by an eccentric cam. Reference numerals 107a and 107b indicate the respective eccentric shafts. In the gear 100A, the inner planetary first external gear 104a and the planetary second external gear 105a are fixed to each other by a pin 108. On the other hand, the outer planetary first external gear 104b and the planetary second external gear 105b are fixed to each other by a bridge 109. In the case of this differential two-stage double planetary gear mechanism 100A, it is possible to eliminate the breakdown of dynamic balance, which is a problem of the differential two-stage planetary gear mechanism 100 of Patent Document 1 and Non-Patent Document 1.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Non-Patent Documents

[0007]

Non-Patent Document 1

[0008] However, while the differential two-stage twin planetary gear mechanism 100A described in Non-Patent Document 2 can eliminate the disruption of dynamic balance, the following problems arise. Firstly, to eliminate dynamic balance, the moments of inertia of two eccentric gear sets with different structures must be perfectly matched, requiring complex design and high-precision machining. In other words, in the differential two-stage twin planetary gear mechanism 100A, the first planetary external gear 104a and the second planetary external gear 105a (the two inner gears) are integrated as a set, and the first planetary external gear 104b and the second planetary external gear 105b (the two outer gears) are connected to sandwich this set to form another set. Then, in order to synchronize the rotation of the two outer gears as a set, the bridge 109 passes through the two inner gears. That is, the two inner gears have weight-reducing holes formed to allow the bridge 109 to pass through, so that the set of two inner gears and the set of two outer gears can rotate independently without interfering with each other. In this structure, the two outer gears 104b and 105b will have their weight increased by the amount of the bridge 109, while the two inner gears 104a and 105a will have their weight decreased by the amount of the weight-reducing holes (first weight difference). Thus, the structure and weight of the corresponding gears are different, and the task of perfectly matching their moments of inertia is complicated. Secondly, the bridge 109, which synchronizes the rotation of the two gears at both ends, is subjected to a large force equivalent to the torque after deceleration, so the strength of the bridge 109 must be ensured. Increasing the durability of this bridge not only increases the first weight difference, but also places constraints on the miniaturization and shape of the gear mechanism. In particular, it becomes difficult to provide a large-diameter hollow section extending axially inside the gear mechanism. Thirdly, the complexity of the bridge 109, weight-reducing holes, and structures for matching the moment of inertia increases the number of parts, leading to higher costs and a greater risk of failure. This invention was researched and developed in consideration of these circumstances, and aims to provide a gear mechanism that is compact, has a high reduction ratio, high power transmission efficiency, is easy to dynamically balance, has a simple structure with few parts, and is low in cost and risk of failure. [Means for solving the problem]

[0009] The gear mechanism of the present invention (differential two-stage double planetary gear mechanism) comprises a rotating shaft, a first fixed internal gear and a second fixed internal gear provided radially outward of the rotating shaft and coaxially with the rotating shaft, fixed and not rotating, a rotating internal gear provided radially outward of the rotating shaft and between the first fixed internal gear and the second fixed internal gear, and rotating coaxially with the rotating shaft, a first planetary first external gear that meshes with the first fixed internal gear and has a diameter larger than the radius of the first fixed internal gear, a first planetary second external gear that meshes with the rotating internal gear and has a diameter larger than the radius of the rotating internal gear, and is fixed to the first planetary first external gear coaxially with the first planetary first external gear, a second planetary first external gear that meshes with the second fixed internal gear and has a diameter larger than the radius of the second fixed internal gear, and a rotating internal gear that meshes with the rotating internal gear and the rotating internal gear The rotating shaft comprises a second planetary external gear having a diameter larger than the radius of the vehicle, and being coaxial with the second planetary first external gear and fixed to the second planetary first external gear, wherein the rotating shaft comprises a first eccentric portion and a second eccentric portion that rotate integrally with the rotating shaft, the first eccentric portion being cylindrical or columnar, with its central axis eccentrically positioned at a predetermined distance offset in a first direction perpendicular to the rotation axis of the rotating shaft, and supporting the orbit and rotation of the first planetary first external gear and the first planetary second external gear, and the second eccentric portion being cylindrical or columnar, with its central axis eccentrically positioned at a predetermined distance offset in a second direction perpendicular to the rotation axis of the rotating shaft and having a phase difference of 180 degrees with respect to the first direction, and supporting the orbit and rotation of the second planetary first external gear and the second planetary second external gear.

[0010] In the gear mechanism of the present invention, it is preferable that the rotating shaft is cylindrical. In this case, it is preferable that the rotating shaft is provided on the radially inward side of the rotating shaft and that a fixed shaft passes through the rotating shaft, and that the fixed shaft supports the rotation of the rotating shaft. Furthermore, it is preferable that this fixed shaft be cylindrical.

[0011] The gear mechanism of the present invention, comprising a fixed shaft, preferably includes a first fixed flange and a second fixed flange fixed to the fixed shaft, and a rotating flange that rotates coaxially with the rotating shaft, wherein the first fixed internal gear is fixed to the first fixed flange, the second fixed internal gear is fixed to the second fixed flange, and the rotating internal gear is fixed to the rotating flange. In the case where a first fixed flange, a second fixed flange, and a rotating flange are provided in this manner, it is preferable that the rotating flange, the first fixed flange, and the second fixed flange each support the radial load from each gear via bearings. In the case where a first fixed flange, a second fixed flange, and a rotating flange are provided in this manner, it is preferable that a slip ring is provided between the fixed shaft, the first fixed flange, or the second fixed flange and the rotating flange.

[0012] The gear mechanism of the present invention preferably includes either or both of the following: a first angle sensor for detecting the rotation angle of the rotating shaft and a second angle sensor for detecting the rotation angle of the rotating internal gear. The gear mechanism of the present invention preferably includes either or both of the following: a first angular velocity sensor for detecting the rotational angular velocity of the rotating shaft and a second angular velocity sensor for detecting the rotational angular velocity of the rotating internal gear. A gear mechanism of the present invention is preferably one that includes a torque sensor for detecting the torque of the rotating internal gear.

[0013] The reduction gear of the present invention comprises the gear mechanism of the present invention and a drive device that inputs rotational force to the rotating shaft, and is characterized by outputting the rotational force of the rotating internal gear. The speed increaser of the present invention comprises the gear mechanism of the present invention and a drive device that inputs rotational force to the rotating internal gear, and is characterized by outputting the rotational force of the rotating shaft. [Effects of the Invention]

[0014] The reduction and acceleration principle of the differential two-stage twin planetary gear mechanism of the present invention is the same as that of the planetary gear device 80 (Figures 15-18) according to the reference example of the second embodiment of Patent Document 1 shown in Figure 13a, and the differential two-stage planetary gear mechanism shown in Figure 1(d) Type IV of Non-Patent Document 1, and is equipped with high power transmission efficiency. The gear mechanism of the present invention achieves perfect dynamic balance because the phases of the eccentric gear set, in which the first planetary first external gear and the first planetary second external gear are arranged next to each other, and the eccentric gear set, in which the second planetary first external gear and the second planetary second external gear are arranged next to each other, are shifted by 180 degrees relative to each other. This is because, in the gear mechanism of the present invention, the structures of the two eccentric gear sets can be made completely identical, eliminating the need for any special ingenuity to match the moments of inertia. In other words, by making the structures of the first planetary first external gear and the second planetary first external gear identical, and the structures of the first planetary second external gear and the second planetary second external gear identical, the moments of inertia of the two eccentric gear sets around the rotation axis of the rotating shaft can be perfectly and easily matched. Furthermore, even if the structures of the two eccentric gear sets are not made completely identical, it is relatively easy to adjust the structure of each eccentric gear set so that the moments of inertia perfectly match, and dynamic balancing is easier to achieve compared to the differential two-stage twin planetary gear mechanism of Non-Patent Document 2 shown in Figure 13b. The gear mechanism of the present invention simply arranges two eccentric gear sets in conjunction with a sun gear that is arranged in the order of a first fixed internal gear, a rotating internal gear, and a second fixed internal gear. In other words, the first fixed internal gear meshes with the first planetary first external gear, the rotating internal gear meshes with the first planetary second external gear and the second planetary second external gear, and the second fixed internal gear meshes with the second planetary first external gear. This simple structure also allows for a reduced number of parts. The meshing between the gears mentioned above involves a large torque comparable to the output torque after deceleration. However, in the gear mechanism of the present invention, all gear diameters can be made close to the maximum value achievable within the mechanical constraints of the gear mechanism. In other words, by creating a gear mechanism without small-diameter gears, a large torque can be transmitted. Similarly, large torques comparable to the output torque after reduction are applied to the connection points between the first planetary gear and the second planetary gear, the connection points between the first planetary gear and the second planetary gear, and the connection points between the first and second eccentric parts. However, by manufacturing all of these connection points mechanically as a single integrated unit (as one component), it is possible to transmit large torques. Furthermore, as described above, the connection between the first planetary first external gear and the first planetary second external gear, the connection between the second planetary first external gear and the second planetary second external gear, and the connection between the first eccentric part and the second eccentric part can all be manufactured mechanically as a single unit (as one part). Therefore, in the gear mechanism of the present invention, special structures for power transmission, such as carriers and carrier pins commonly found in eccentric oscillating gear mechanisms, and bridges and weight-reducing holes in the differential two-stage double planetary gear mechanism 100A of Non-Patent Literature 2, can be eliminated. This means that in the gear mechanism of the present invention, the structure is further simplified, the number of parts is reduced, and the space within the gear mechanism that was occupied by special structures for power transmission is freed up, allowing for the provision of a relatively large diameter hollow section. In the gear mechanism of the present invention, the phases of the eccentric gear set, in which the first planetary first external gear and the first planetary second external gear are arranged next to each other, and the eccentric gear set, in which the second planetary first external gear and the second planetary second external gear are arranged next to each other, are shifted by 180 degrees. However, by intentionally making the phase difference between the first and second eccentric parts slightly different from 180 degrees, the preload when the two eccentric gear sets mesh with the first fixed internal gear, the second fixed internal gear, and the rotating internal gear can be increased, thereby eliminating backlash (play in the gear mechanism). In other words, the principle of so-called no-backlash gears can also be utilized. [Brief explanation of the drawing]

[0015] [Figure 1] This is a conceptual diagram showing the configuration of the first embodiment of the differential two-stage twin planetary gear mechanism of the present invention. [Figure 2] Figures 2a, 2b, and 2c are a front view, a cross-sectional view (line AA), and a side view, respectively, showing a first embodiment of the gear mechanism of the present invention. [Figure 3]Figures 3a to 3d are cross-sectional views along lines BB, CC, DD, and EE, respectively, of Figure 2c. [Figure 4] Figure 2 is an exploded view of the gear mechanism. [Figure 5] Figures 5a to 5c show a front view, an FF line cross-sectional view, and a side view, respectively, of a second embodiment of the gear mechanism of the present invention. [Figure 6] Figures 6a to 6d are cross-sectional views along the GG line, HH line, II line, and JJ line, respectively, of Figure 5c. [Figure 7] Figure 5 is an exploded view of the gear mechanism. [Figure 8] This is a side cross-sectional view showing a third embodiment of the gear mechanism of the present invention. [Figure 9] This is a conceptual diagram showing the configuration of a fourth embodiment of the gear mechanism of the present invention. [Figure 10] Figures 10a and 10b are a front view and a cross-sectional view along line KK, respectively, showing an embodiment of a gear reducer (rotary drive unit with gear reducer) using the gear mechanism of the present invention. [Figure 11] Figure 10 is an exploded view of the gear mechanism. [Figure 12] This is a schematic diagram of a wind power generation device equipped with a speed increaser using the gear mechanism of the present invention. [Figure 13] Figure 13a is a conceptual diagram showing a conventional differential two-stage planetary gear mechanism, and Figure 13b is a conceptual diagram showing a conventional differential two-stage twin planetary gear mechanism. [Modes for carrying out the invention]

[0016] Next, embodiments and examples of the differential two-stage twin planetary gear mechanism of the present invention will be described. However, the present invention is not limited to these embodiments and examples.

[0017] First, in this invention, the term "gear" is not limited to a specific type of gear, but refers to gears in general, including both gears with mechanical teeth and gears without mechanical teeth. For example, examples of tooth profiles for gears with mechanical teeth include involute tooth profiles using an involute curve, cycloid tooth profiles using a cycloid curve, and trochoid tooth profiles using a trochoid curve. On the other hand, examples of gears without mechanical teeth include magnetic gears (magnetic gears) that use magnetism, friction drives that use frictional force, and traction drives that use shear force. A traction drive is a mechanism that transmits rotational force (torque) to a gear without teeth by utilizing the phenomenon of solidification (crystallization) of a special oil under high pressure. Furthermore, in this invention, "radius or diameter of the gear" refers to the pitch circle radius or pitch circle diameter in the case of a gear having mechanical teeth. In the case of a gear without mechanical teeth, it refers to the radius or diameter of the circle that acts as a gear.

[0018] "Gear mechanism 1" (first embodiment) As shown in Figures 1 to 4, the gear mechanism 1 comprises a rotating shaft 10, a first fixed internal gear 20, a second fixed internal gear 30, a rotating internal gear 40, a first planetary first external gear 51, a first planetary second external gear 52, a second planetary first external gear 61, and a second planetary second external gear 62. The rotating shaft 10 includes a first eccentric portion 11 that supports the revolution and rotation of the first planetary first external gear 51 and the first planetary second external gear 52, and a second eccentric portion 12 that supports the revolution and rotation of the second planetary first external gear 61 and the second planetary second external gear 62. The first eccentric portion 11 and the second eccentric portion 12 rotate integrally with the rotating shaft 10. A cylindrical fixed shaft 80 is also provided to rotate and support the cylindrical rotating shaft 10. Note that the reference numeral B1 in Figure 1 indicates a bearing. This reference numeral B1 is not provided in Figures 2 to 4. In this gear mechanism 1, as shown in Fig. 3a, with the first fixed internal gear 20 as the sun gear, the first planetary first external gear 51 revolves and rotates; as shown in Fig. 3c, with the second fixed internal gear 30 as the sun gear, the second planetary first external gear 61 revolves and rotates; and as shown in Figs. 3b and 3d, with the rotating internal gear 40 as the sun gear, the first planetary second external gear 52 and the second planetary second external gear 62 revolve and rotate. This gear mechanism 1 functions as a speed reducer by inputting a rotational force to the rotating shaft 10 and outputting the rotation of the rotating internal gear 40, and functions as a speed increaser by inputting a rotational force to the rotating internal gear 40 and outputting the rotation of the rotating shaft 10.

[0019] "Rotating shaft 10" As shown in Figs. 1, 2, and 4, the rotating shaft 10 integrally includes a first eccentric portion 11 that supports the revolution and rotation of the first planetary first external gear 51 and the first planetary second external gear 52, and a second eccentric portion 12 that supports the revolution and rotation of the second planetary first external gear 61 and the second planetary second external gear 62. The rotating shaft 10 also includes a main shaft portion 13 for inputting and outputting a rotational force to the rotating shaft 10. In the rotating shaft 10, the main shaft portion 13, the first eccentric portion 11, and the second eccentric portion 12 are arranged in that order from the left side of Fig. 1. The rotating shaft 10 is a cylindrical body, and its inner surface is cylindrical. A bearing 15 is provided on the inner surface of the rotating shaft 10. The rotating shaft 10 is the rotating shaft 10 axis Rotates around. In particular, it rotates freely around the fixed shaft 80 described later.

[0020] As shown in Fig. 1, the first eccentric portion 11 is eccentrically provided at a position shifted by a predetermined distance x1 in a first direction orthogonal to the rotation axis 10 of the rotating shaft 10. The outer shape of the first eccentric portion 11 is a cylindrical body (or a cylindrical tube). That is, the first eccentric portion 11 rotates (revolves) around the rotation axis 10 integrally with the rotating shaft 10. axis whose central axis 11 axis is orthogonal to the rotation axis 10 of the rotating shaft 10. axis around. The first eccentric portion 11 is rotatably inserted into the first planetary first external gear 51 and the first planetary second external gear 52 (see Figures 1, 2b, 3a, 3b, and 4).

[0021] The second eccentric portion 12 is, as shown in Figure 1, the central axis 12 axis The rotation axis 10 of the rotating shaft 10 axis They are positioned eccentrically in a second direction that is perpendicular to the first direction and has a phase difference of 180 degrees with respect to the first direction, shifted by a predetermined distance x1. In other words, the first eccentric part 11 and the second eccentric part 12 are positioned at the same distance in opposite directions from the rotation axis 10 axis It is eccentrically offset axially, at a position away from the center. The outer shape of the second eccentric part 12 is cylindrical (or cylindrical). The second eccentric portion 12 is rotatably inserted into the second planetary first external gear 61 and the second planetary second external gear 62 (see Figures 1, 2b, 3c, 3d, and 4).

[0022] The main shaft portion 13 is the part that serves as the input or output for rotation. An external gear that meshes with the input or output is formed on the outer circumferential surface of the main shaft portion 13. When inputting rotation to the main shaft 13, for example, as shown in the gear mechanism 5 of Figure 10, the drive device (motor) M can be fixed to the first fixed flange 81 which is fixed to the fixed flange 80, and the drive shaft of the drive device M can be meshed with the main shaft 13, or the main shaft 13 can be used as a driven shaft, and a belt that transmits driving force can be placed between it and the drive shaft of an externally provided drive device. When outputting rotation from the main shaft 13, the rotation of the main shaft 13 can be extracted as output using a universal joint or an L-shaped flange, or the main shaft 13 can be used as a drive shaft, and a belt that transmits driving force between it and an externally provided output shaft can be used to output its rotation.

[0023] "First fixed internal gear 20" As shown in Figures 1, 2b, 3a, and 4, the first fixed internal gear 20 is a ring-shaped annulus that is mounted radially outward from the rotating shaft 10, is coaxial with the rotating shaft, and is fixed and does not rotate. The first fixed internal gear 20 is also fixed to the fixed shaft 80, as will be described later. The internal teeth of the first fixed internal gear 20 have an arc tooth profile, and in particular, an arc tooth profile using rollers 20a. The number of teeth (number of rollers) can be appropriately selected according to the reduction ratio of the first reduction mechanism, which is composed of the first fixed internal gear 20 and the first planetary first external gear 51.

[0024] "Second fixed internal gear 30" As shown in Figures 1, 2b, 3c, and 4, the second fixed internal gear 30 is a ring body that is mounted radially outward from the rotating shaft 10, is coaxial with the rotating shaft, and is fixed and does not rotate. The second fixed internal gear 30 is located on the rotating shaft 10 relative to the first fixed internal gear 20. axis They are fixed at intervals in the direction. The second fixed internal gear 30 is also fixed to the fixed shaft 80, as will be described later. Furthermore, as shown in Figure 3c, the second fixed internal gear 30 has the same structure as the first fixed internal gear 20, and, like the first fixed internal gear 20, it has an arc tooth profile using rollers 30a, and its diameter and number of teeth (number of rollers) are also the same as the first fixed internal gear 20. By making the second fixed internal gear 30 the same structure as the first fixed internal gear 20, the dynamic balance of the gear mechanism 1 can be easily adjusted.

[0025] "Rotating internal gear 40" The rotating internal gear 40 is located radially outward of the rotating shaft 10 and on the rotating axis 10, as shown in Figures 1, 2b, 3b, 3d, and 4. axis It is located between the first fixed internal gear 20 and the second fixed internal gear 30 in the direction of rotation, and rotates coaxially with the rotating shaft. Furthermore, as shown in Figures 3b and 3d, the rotating internal gear 40 is a ring-shaped body, and its diameter is larger than that of the first fixed internal gear 20 and the second fixed internal gear 30. The rotating internal gear 40 has an arc-shaped tooth profile using rollers 40a, and its number of teeth (number of rollers) is larger than that of the first fixed internal gear 20 and the second fixed internal gear 30. The number of teeth can be appropriately selected according to the reduction ratio of the second reduction mechanism, which is composed of the rotating internal gear 40 and the first planetary second external gear 52 (and the second planetary second external gear 62 having the same structure). However, if a decrease in transmission efficiency is acceptable, the diameter and number of teeth of the rotating internal gear 40 may be smaller than those of the first fixed internal gear 20. In this embodiment, as shown in Figure 4, the rotating internal gear 40 is part of a cylindrical rotating body 41. The rotating body 41 is a cylindrical body that covers the first fixed internal gear 20 and the second fixed internal gear 30, and the rotating internal gear 40 is provided on its inner surface. Furthermore, as shown in Figures 2b and 4, a rotating flange 83 is formed on the rotating body 41 to close one end of the gear mechanism 1. In this gear mechanism, the first planetary second external gear 52 and the second planetary second external gear 62 mesh with a single rotating internal gear 40. However, as shown in Figure 1, for example, the rotating internal gear 40 may be divided into one for the first planetary second external gear 52 and one for the second planetary second external gear 62.

[0026] "First planetary gear 51" The first planetary external gear 51, as shown in Figures 1, 2b, 3a, and 4, meshes with the first fixed internal gear 20 and is a ring-shaped body with a diameter larger than the radius of the first fixed internal gear 20. The tooth profile of the first planetary gear 51 is a trochoidal tooth profile using a trochoidal curve.

[0027] "First planetary gear, second external gear 52" As shown in Figures 1, 2b, 3b, and 4, the first planetary second external gear 52 meshes with the rotating internal gear 40 and is a ring body having a diameter larger than the radius of the rotating internal gear 40 and larger than the first planetary first external gear 51. The tooth profile of the first planetary gear, the second external gear 52, is a trochoidal tooth profile using a trochoidal curve. Furthermore, as shown in Figures 2b and 4, the first planetary first external gear 51 and the first planetary second external gear 52 are fixed coaxially and together constitute a single first cylindrical body 50 (first eccentric gear set). A bearing 55 is provided on the inner surface of the first cylindrical body 50 to support the rotation of the first eccentric part 11, which will be described later. As shown in Figure 4, the first cylindrical body 50 is rotatably positioned around the first eccentric portion 11 of the rotating shaft 10.

[0028] "Second planetary first external gear 61" The second planetary first external gear 61, as shown in Figures 1, 2b, 3c, and 4, meshes with the second fixed internal gear 30 and is a ring-shaped body with a diameter larger than the radius of the second fixed internal gear 30. The tooth profile of the second planetary first external gear 61 is a trochoidal tooth profile using a trochoidal curve. It is preferable that the second planetary first external gear 61 has the same structure as the first planetary first external gear 51. Furthermore, the second planetary gear 61 is 180 degrees out of phase with the first planetary gear 51. Therefore, the first planetary gear 51 in Figure 3a and the second planetary gear 61 in Figure 3c are opposite each other with their axes in between.

[0029] "Second Planetary Second External Gear 62" As shown in Figures 1, 2b, 3d, and 4, the second planetary second external gear 62 meshes with the rotating internal gear 40 and is a ring-shaped body with a diameter larger than the radius of the rotating internal gear 40 and larger than the second planetary first external gear 61. The tooth profile of the second planetary gear 62 is a trochoidal tooth profile using a trochoidal curve. It is preferable that the second planetary gear 62 has the same structure as the first planetary gear 52. Furthermore, the second planetary gear 62 is 180 degrees out of phase with the first planetary gear 52. Therefore, the first planetary gear 52 in Figure 3b and the second planetary gear 62 in Figure 3d are facing each other with their axes in between. Furthermore, as shown in Figures 2b and 4, the second planetary second external gear 62 and the second planetary first external gear 61 are fixed coaxially and together constitute a single second cylindrical body 60 (second eccentric gear set). A bearing 65 is provided on the inner surface of the second cylindrical body 60 to support the rotation of the second eccentric portion 12, which will be described later. As shown in Figure 4, the second cylindrical body 60 is rotatably positioned around the second eccentric portion 12 of the rotating shaft 10.

[0030] "Fixed shaft 80" The fixed shaft 80 is the rotation axis 10 of the rotating shaft 10, as shown in Figures 1, 2, 3, and 4. axis It is mounted coaxially with the rotating shaft 10 and is cylindrical in shape to support the rotation of the rotating shaft 10. By making the fixed shaft 80 a cylinder, a cylindrical space (hollow) can be formed at the center of the gear mechanism 1. However, the fixed shaft 80 may be solid, or some kind of equipment may be installed inside the fixed shaft. As shown in Figures 2b and 4, the fixed shaft 80 has a first fixed flange 81 extending radially outward, and the first fixed flange 81 and the rotating shaft 10 axis It is provided at intervals in the direction and is fixed to a second fixing flange 82 which also extends radially outward. The first fixed flange 81 has the first fixed internal gear 20 fixed to it. In other words, the first fixed internal gear 20 is supported and fixed to the fixed shaft 80 via the first fixed flange 81. The second fixed flange 82 has the second fixed internal gear 30 fixed to it. In other words, the second fixed internal gear 30 is supported and fixed to the fixed shaft 80 via the second fixed flange 82. As shown in Figures 2b and 4, the fixed shaft 80 rotatably supports the rotating flange 83 (part of the rotating body 41), which rotates coaxially with the rotating shaft 10. Because the fixed shaft 80 is configured in this way, the rotating internal gear 40 and the rotating flange 83 (rotating body 41) of the gear mechanism 1 can rotate indefinitely. In other words, the infinite rotation of the rotating body 41 does not interfere with the members supporting the first fixed internal gear 20 and the second fixed internal gear 30. Furthermore, the gear mechanism 1 can be made smaller. Furthermore, since the gear mechanism 1 functions as a speed reducer or speed increaser by attaching at least the first fixed flange 81 or the second fixed flange 82 to an existing mechanism, its installation is also easy.

[0031] "Operation and reduction ratio of gear mechanism 1" Next, the operation of the gear mechanism 1 will be described as a reduction gear that inputs rotational force to the main shaft portion 13 of the rotating shaft 10 and outputs the rotation of the rotating internal gear 40.

[0032] First, the rotating shaft 10 rotates by applying a rotational force around the central axis (hereinafter also referred to as the rotation axis) of the main shaft 13 by a drive device or the like. In other words, the first eccentric part 11 (and the second eccentric part 12) rotates around the rotation axis 10 axis It revolves around the first planetary gear (first cylindrical body 50), which is rotatably supported on the first eccentric part 11, also revolves (see Figure 3a). On the other hand, the first planetary first external gear 51 and the first fixed internal gear 20 constitute an eccentric oscillating gear mechanism. In other words, each time the first planetary first external gear 51 revolves (the main shaft 13 rotates once), the first planetary first external gear 51 rotates in the opposite direction to the rotation of the main shaft 13 by the difference in the number of teeth between the first fixed internal gear 20 and the first planetary first external gear 51. This constitutes the first stage of reduction in the gear mechanism 1.

[0033] Next, as the first planetary gear 51 rotates planetarily, the second planetary gear 52 also rotates planetarily in the same manner. That is, the revolution and rotation of the second planetary gear 52 are integrated with the revolution and rotation of the first planetary gear 51. Therefore, the second planetary gear 52 rotates the internal gear 40 by the difference in the number of teeth between the internal gear 40 and the second planetary gear 52 for each revolution of the second planetary gear 52, using the rotation of the second planetary gear 52 as a reference (see Figure 3b). This constitutes the second stage of reduction in the gear mechanism 1. The combination of these first and second stages of reduction constitutes the overall reduction of the gear mechanism 1.

[0034] And the reduction ratio R of this gear mechanism 1 (differential two-stage twin planetary gear mechanism) BSD This can be expressed as follows: R BSD = 1 / (1-Z KV ) Here's Z KV This is a constant determined by the number of teeth on each gear, and is calculated by the following formula. Z KV =( z K1 / z V1 ) / (z K2 / z V2 ) Here "z K1 " is the number of teeth of the first fixed internal gear 20 (second fixed internal gear 30), and "z V1 " is the number of teeth of the first planetary gear 51 (second planetary gear 61), and "z K2 " is the number of teeth of the rotating internal gear 40, and "z V2 " represents the number of teeth on the first planetary second external gear 52 (second planetary second external gear 62). From these equations, the reduction ratio R of gear mechanism 1 BSD Regarding the constant "Z KV It can be seen that by bringing "" closer to 1, a large value (large reduction ratio) can be obtained.

[0035] Furthermore, the second cylindrical body 60 (second eccentric gear set) of the second planetary first external gear 61 and the second planetary second external gear 62 operates in the same way as the first cylindrical body 50 (first eccentric gear set) of the first planetary first external gear 51 and the first planetary second external gear 52, except that their phases are shifted by 180 degrees (see Figure 3). In other words, the second planetary first external gear 61 revolves and rotates at the same speed as the first planetary first external gear 51, and the second planetary second external gear 62 revolves and rotates at the same speed as the first planetary second external gear 52. And the phases of the first cylindrical body 50 and the second cylindrical body 60, which have the same structure, are shifted by 180 degrees, that is, the rotation center 10 of the rotating shaft 10 axis Because it is axially symmetric with respect to the axis, dynamic balance is maintained.

[0036] "Effect of Gear Mechanism 1" As described above, the gear mechanism 1 configured in this way can achieve a large reduction ratio while maintaining dynamic balance. In addition, the gear mechanism 1 has the following effects: The gear mechanism 1 integrates the two-stage external gears into a single unit. Specifically, the first planetary first external gear 51 and the first planetary second external gear 52 are integrated into the first cylindrical body 50, and the second planetary first external gear 61 and the second planetary second external gear 62 are integrated into the second cylindrical body 60. Similarly, the first eccentric part 11, the second eccentric part 12, and the main shaft part 13 are integrated into the rotating shaft 10. Because these integrated parts can be manufactured as a single unit, the number of parts can be reduced, the structure becomes simpler, and assembly is easier. Production costs can also be lowered. Mechanical strength is also ensured. The gear mechanism 1 can have a large hollow diameter, close to the maximum value due to mechanical constraints.

[0037] "Gear mechanism 2" (second embodiment) Gear mechanism 2 shown in Figures 5 to 7 is a gear mechanism that uses a traction drive, which is a gear mechanism without mechanical teeth. Otherwise, it is substantially the same as gear mechanism 1 shown in Figure 1. A traction drive is a mechanism that utilizes the solidification (crystallization) phenomenon of a special oil under high pressure to transmit rotational force between toothless gears through the shear force of the solidified oil. Because it has no teeth, it does not break even under overload, and it enables ultra-high-speed rotational inputs (for example, tens of thousands of rpm or more) that would break conventional gears. In the gear mechanism 2, traction drives are used between the first fixed internal gear 20A and the first planetary first external gear 51A, between the second fixed internal gear 30A and the second planetary first external gear 61A, and between the rotating internal gear 40A and the first planetary second external gear 52A and the second planetary second external gear 62A. The other components are substantially the same as those in Figure 1, and the same reference numerals are used for the same components.

[0038] Next, we will explain the reduction ratio of the gear mechanism 2 using a traction drive. The reduction ratio R of this gear mechanism 2 (differential two-stage double planetary gear mechanism) BSDT This can be expressed as follows: R BSDT = 1 / (1-R) KVT ) Here R KVT Unlike gear mechanism 1, this is a constant determined by the radius of each gear and is calculated by the following formula. R KVT =(r K1 / r V1 ) / (r K2 / r V2 ) Here "r K1 " is the radius of the first fixed internal gear 20A and the second fixed internal gear 30A, and "r V1 " is the radius of the first planetary gear 51A and the second planetary gear 61A, and "r K1 " is the radius of the rotating internal gear 40A, and "r V2 " represents the radius of the first planetary second external gear 52A and the second planetary second external gear 62A. From these equations, the reduction ratio R of gear mechanism 2 BSDT Regarding the constant "R KVT It can be seen that by bringing "" closer to 1, a large value (large reduction ratio) can be obtained.

[0039] This gear mechanism 2 satisfies all the effects of gear mechanism 1 in Figure 1, and furthermore, it enables ultra-high-speed rotational input by using a traction drive, and has a structure that is also resistant to shock. For this reason, this gear mechanism 2 is suitable for high output applications. For example, its application to robots, electric vehicles, and electric heavy machinery is particularly desirable. In gear mechanism 2, traction drives are employed between the first fixed internal gear 20A and the first planetary first external gear 51A, between the second fixed internal gear 30A and the second planetary first external gear 61A, and between the rotating internal gear 40A and the first planetary second external gear 52A and the second planetary second external gear 62A. However, a gear other than a traction drive may be used in any of these positions, and a traction drive may be used in combination with other tooth profiles.

[0040] "Gear mechanism 3" (third embodiment) In the gear mechanism 3 shown in Figure 8, the first fixed internal gear 20B and the second fixed internal gear 30B are externally supported via support legs 91, and the rotational force of the rotating internal gear 40B is connected to an external input or output shaft via an L-shaped flange 92. In this gear mechanism 3, the rotation of the L-shaped flange 92 attached to the rotating internal gear 40B interferes with the support leg 91, so the L-shaped flange 92 cannot be rotated more than 360 degrees. However, for example, by connecting the rotating internal gear 40B to the input shaft or output shaft with a belt without using the L-shaped flange 92, the rotating internal gear 40B can be rotated 360 degrees. Otherwise, substantially the same effect as gear mechanism 1 in Figure 1 can be obtained. In this case, the fixed shaft 80 may be omitted, and the rotating shaft 10 may be directly connected to the output shaft or input shaft.

[0041] "Gear mechanism 4" (fourth embodiment) The gear mechanism 4 in Figure 9 has support gears 93a to 93d placed at the points where the gaps are largest between the first fixed internal gear 20C and the first planetary first external gear 51C, between the second fixed internal gear 30C and the second planetary first external gear 61C, between the rotating internal gear 40C and the first planetary second external gear 52C, and between the rotating internal gear 40C and the second planetary second external gear 62C. Each support gear is fixed to the orbital axis of each planetary external gear, i.e., the rotating shaft. The central axes of the external gears 51C, 52C, 61C, and 62C are offset (eccentric) from the central axes of the internal gears 20C, 30C, and 40C, so a gap is always created on the opposite side of the pitch point (the point where the gears mesh) where each planetary external gear and each internal gear are in contact, and this gap is largest in the region where the phase is shifted by 180 degrees. Support gears 93a to 93d are placed in this region. This provides even more stable support for the rotation of the external gear. [Examples]

[0042] "Rotary drive unit with reduction gear R" (Example 1) Next, as Example 1, a rotary drive unit R with a reduction gear will be described. The rotary drive unit R with a reduction gear shown in Figures 10 and 11 comprises a gear mechanism 5 and a drive device M. The gear mechanism 5 is the gear mechanism 1 shown in Figures 1-4, further equipped with a torque sensor 71, angular contact ball bearings 72a and 72b, a cross roller bearing 73, an input encoder 74, an output encoder 75, and a slip ring 76. A space S is provided on the outer circumference of the fixed shaft 80 between the first fixed flange 81 and the first fixed internal gear 20 of the gear mechanism 1, and a drive unit (frameless motor) M is built into space S. The rotating flange 83 (rotating body 41) is rotatably supported by the second fixed flange 82 via a cross roller bearing 73 and connected to the rotating internal gear 40 via a torque sensor 71. In other words, in this embodiment, the rotating body 41 consists of the rotating flange 83, the torque sensor 71, and the rotating internal gear 40. Note that in Figure 11, the rotating flange 83 is shown separately. The angular contact ball bearings 72a and 72b are positioned opposite each other between the rotating flange 83 (rotating body 41) and the first fixed flange 81 (first fixed internal gear 20), and between the rotating flange (rotating body 41) and the second fixed flange 82 (second fixed internal gear 30). These angular contact ball bearings 72a and 72b support the rotating flange 83 (rotating body 41), the first fixed flange 81, and the second fixed flange 82 from each other, at least in the radial direction. In other words, the first fixed internal gear 20 supports the radial load received by the first planetary first external gear 51, the second fixed internal gear 30 supports the radial load received by the second planetary first external gear 61, and the rotating internal gear 40 supports the radial load received by the first planetary second external gear 52 and the second planetary second external gear 62, respectively, due to the eccentric oscillating rotation of each planetary external gear. The cross roller bearing 73 is located between the rotating body 41 and the second fixed flange 83. The cross roller bearing 73 supports the rotation of the rotating flange 83 (rotating body 41), which is coaxial with the rotating shaft 10. Even if a load is applied to the rotating flange 83 (rotating body 41) from outside the rotary drive unit R with reduction gear, the cross roller bearing 73 alone supports radial loads, axial loads, and moment loads in directions different from the axis of rotation, i.e., loads in all directions other than the axis of rotation, and has the function of protecting the rotary drive unit R with reduction gear from external loads. The input encoder 74 measures the rotation angle or angular velocity of the rotating shaft 10. The output encoder 75 measures the rotation angle or angular velocity of the output rotating body 41. By measuring the respective rotation angles or angular velocities with the input encoder 74 and the output encoder 75, the rotary drive unit R with a reduction gear can be properly controlled. The slip ring 76 is provided between the second fixed flange 82 and the rotating flange 83 (rotating body 41). This enables the transmission of power and signals between the continuously rotating input and output shafts. Note that the mounting position of the slip ring 76 is not limited to this embodiment, and it may be mounted at any location between at least one of the first fixed flange 81, the second fixed flange 82, or the fixed shaft 80 and the rotating body 41. Thus, the rotary drive unit R with a reduction gear is an integrated unit in which a drive device (frameless motor) M is built into the gear mechanism 5. Therefore, it satisfies all the effects of the base gear mechanism 1 and can further miniaturize the entire drive unit, including the drive device. In this example, a gear mechanism 5 is used in which a space S is provided between the first fixed flange 81 and the first fixed internal gear 20 of the gear mechanism 1, but the drive device M may also be built into the space S between the first fixed flange and the first fixed internal gear of the gear mechanisms 2, 3, and 4. The drive unit (frameless motor) M may further incorporate its control device (motor driver, motor controller, etc.) or battery.

[0043] Next, we will determine the reduction ratio of the gear mechanism 5. As shown in Figures 3 and 11, the number of teeth (z) of the first fixed internal gear 20 and the second fixed internal gear 30 of the gear mechanism 5 K1 ) is 20, and the number of teeth of the first planetary gear 51 and the second planetary gear 61 is (z V1 ) is 19, and the number of teeth of the rotating internal gear 40 (z K2 ) is 21, and the number of teeth of the first planetary second external gear 52 and the second planetary second external gear 62 is (z V2 ) is 20. In other words, the reduction ratio R of the gear mechanism 1 (differential two-stage double planetary gear mechanism) described above. BSD Substituting this into the formula gives us the following: Z KV =(20 / 19) / (21 / 20)=400 / 399 R BSD =1 / (1-400 / 399)=-399 In other words, it was confirmed that the angular velocity of the output is reduced to 1 / 399 of the angular velocity of the rotating shaft 10, and the direction of rotation is reversed by the negative sign.

[0044] "Wind power generation device with speed increaser W" (Example 2) Furthermore, as an example, a wind power generation device W with a speed increaser will be described. The wind turbine W with a speed booster shown in Figure 12 comprises blades B, a speed booster I using the gear mechanism 1 shown in Figure 1, and a generator G. By increasing the rotation speed of the blades B, which rotate at a relatively low speed due to wind force, using the speed booster I, and converting it into a high-speed rotation suitable for power generation, the generator G can be driven, enabling efficient wind power generation. Generally, such speed increasers are composed of conventional planetary gear mechanisms, but by using the differential two-stage twin planetary gear mechanism of the present invention, which is highly efficient and resistant to overload, as a speed increaser, the risk of failure can be reduced and maintenance costs can be lowered. Furthermore, since the upper limit of the wind speed at which power generation is possible is raised, it is possible to increase the amount of power generated in strong winds, which previously had to be stopped. [Explanation of symbols]

[0045] 1, 2, 3, 4, 5 Gear mechanism 10-rotation shaft 10 axis Rotation axis of a rotating shaft 11 First eccentric part 11 axis Central axis of the first eccentric part 12 Second eccentric part 12 axis The central axis of the second eccentric section 13 Main shaft part 15 bearings 20, 20A, 20B, 20C First fixed internal gear 20a Roller 30, 30A, 30B, 30C Second fixed internal gear 30a Roller 40, 40A, 40B, 40C Rotary internal gears 40a Roller 41. Solids of revolution 50 First cylinder (first eccentric gear set) 51, 51A, 51C First planetary gear, first external gear 52, 52A, 52C First planetary gear, second external gear 55 Bearings 60. Second cylinder (second eccentric gear set) 61, 61A, 61C Second planetary gear, first external gear 62, 62A, 62C Second planetary gear, second external gear 65 bearings 71 Torque recovery 72a, 72b Angular Contact Ball Bearings 73 Cross roller bearing 74 Input side encoder 75 Output encoder 76 Slip Rings 80 Fixed shaft 81 First fixed flange 82 Second fixed flange 83 Rotating flange 91 Support leg 92 L-shaped flange 93a~93d Support gears B Blade B1 bearing I Speed ​​Increaser G Generator M drive unit R Rotary drive unit with reduction gear S space Wind turbine with speed increaser

Claims

1. Rotating shaft and A first fixed internal gear and a second fixed internal gear are provided on the radially outer side of the rotating shaft, coaxial with the rotating shaft, connected to each other, fixed and not rotating. A rotating internal gear is provided on the radially outer side of the rotating shaft and between the first fixed internal gear and the second fixed internal gear, and rotates coaxially with the rotating shaft, A first planetary external gear meshes with the first fixed internal gear and has a diameter larger than the radius of the first fixed internal gear, A first planetary second external gear meshes with the rotating internal gear, has a diameter larger than the radius of the rotating internal gear, is coaxial with the first planetary first external gear, and is fixed to the first planetary first external gear. A second planetary first external gear meshes with the second fixed internal gear and has a diameter larger than the radius of the second fixed internal gear, A second planetary gear meshes with the rotating internal gear, has a diameter larger than the radius of the rotating internal gear, and is fixed to the second planetary gear coaxially with the second planetary gear, Equipped with, The first planetary gear and the second planetary gear are arranged next to each other. The second planetary first external gear and the second planetary second external gear are arranged next to each other. The rotating shaft comprises a first eccentric portion and a second eccentric portion that rotate integrally with the rotating shaft, The first eccentric portion is cylindrical or columnar, and its central axis is eccentrically positioned at a predetermined distance from the rotation axis of the rotating shaft, and supports the revolution and rotation of the first planetary first external gear and the first planetary second external gear. The second eccentric portion is cylindrical or columnar, and its central axis is positioned eccentrically at a predetermined distance in a second direction that is perpendicular to the rotation axis of the rotating shaft and has a phase difference of 180 degrees with respect to the first direction, and supports the revolution and rotation of the second planetary first external gear and the second planetary second external gear. Gear mechanism.

2. The rotating shaft is cylindrical. The gear mechanism according to claim 1.

3. A fixed shaft is provided on the radially inward side of the rotating shaft and passes through the rotating shaft, The fixed shaft supports the rotation of the rotating shaft. The gear mechanism according to claim 2.

4. The aforementioned fixed shaft is cylindrical. The gear mechanism according to claim 3.

5. A first fixing flange and a second fixing flange are fixed to the aforementioned fixing shaft, A rotating flange that rotates coaxially with the aforementioned rotating shaft, Equipped with, The first fixed internal gear is fixed to the first fixed flange, The second fixed internal gear is fixed to the second fixed flange, The aforementioned internal gear is fixed to the rotating flange. The gear mechanism according to claim 3.

6. The rotating flange, the first fixed flange, and the second fixed flange are Each via a bearing, The structure is such that the radial loads from each of the gears are mutually supported. The gear mechanism according to claim 5.

7. The fixed shaft, the first fixed flange, or the second fixed flange, The aforementioned rotating flange, A slip ring is provided between them. The gear mechanism according to claim 5.

8. A first angle sensor for detecting the rotation angle of the rotating shaft, Any of the second angle sensors that detect the rotation angle of the rotating internal gear, or having both, A gear mechanism according to any one of claims 1 to 7.

9. A first angular velocity sensor for detecting the rotational angular velocity of the rotating shaft, Any of the second angular velocity sensors that detect the rotational angular velocity of the rotating internal gear, or having both, A gear mechanism according to any one of claims 1 to 7.

10. The system includes a torque sensor that detects the torque of the rotating internal gear. A gear mechanism according to any one of claims 1 to 7.

11. The gear mechanism is as described in any one of claims 1 to 7, and the drive device is used to input rotational force to the rotating shaft. Outputting the rotational force of the aforementioned internal gear, reducer.

12. The gear mechanism comprises the gear mechanism according to any one of claims 1 to 7, and a drive device that inputs rotational force to the rotating internal gear, Outputting the rotational force of the aforementioned rotating shaft, Speed ​​increaser.

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