JP2010048274A - Deceleration mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deceleration mechanism, small and inexpensively manufacturable, while being the deceleration mechanism having the high reduction gear ratio. <P>SOLUTION: This purpose is attained by the deceleration mechanism having a fixed wheel having a cylindrical inner peripheral surface, a rotary wheel having a cylindrical outer peripheral surface having an outer diameter smaller than an inner diameter of the inner peripheral surface of the fixed wheel and differentially rotating without sliding by engaging the outer peripheral surface with the inner peripheral surface of the fixed wheel with an eccentric position as the center in response to an eccentric quantity by a difference between these inner diameter and outer diameter, an input shaft having an eccentric shaft for differentially rotating by maintaining engagement of the outer peripheral surface of the rotary wheel with the inner peripheral surface of the fixed wheel by eccentrically fitting by the eccentric quantity in a central hole of the rotary wheel with the rotational center as the center of the inner peripheral surface of the fixed wheel, and an eccentric shaft coupling having one end fixed to the rotary wheel, having the other end connected to an output shaft arranged in the center of the inner peripheral surface of the fixed wheel and transmitting only differential rotation of the rotary wheel without transmitting eccentric motion of the rotary wheel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a speed reduction mechanism, and more particularly to a speed reduction mechanism capable of obtaining a high speed reduction ratio.

  As a speed reduction mechanism capable of obtaining a high speed reduction ratio, a planetary gear mechanism, a harmonic drive mechanism, and the like are known. However, since these mechanisms have a complicated structure, they must inevitably be large and expensive, and it is very difficult to make a small and inexpensive reduction mechanism with a high reduction ratio. Have difficulty.

  As such a reduction mechanism that can be configured in a small size with a high reduction ratio, a differential gear mechanism that is inscribed and meshed as shown in Patent Documents 1 to 4 can be considered. However, as disclosed in these patent documents, the indirect meshing differential gear mechanism of the prior art has a complicated transmission mechanism up to the output shaft after being decelerated by the differential gear. However, the speed reduction mechanism is not small enough to be satisfactory and inexpensive.

JP-A-5-231482 FIG. 1 to FIG. Japanese Patent Laid-Open No. 6-33995 FIGS. 4 to 6 JP, 2003-49909, A FIG. 1, FIG. JP-A-2005-42827 FIG. 1 to FIG.

  An object of the present invention is to solve the above-described problems of the prior art and to provide a reduction mechanism that is small in size and can be manufactured at a low cost while being a reduction mechanism having a high reduction ratio. .

  In order to solve the above problems, the present invention has a fixed ring having a cylindrical inner peripheral surface, and a cylindrical outer peripheral surface having an outer diameter smaller than the inner diameter of the inner peripheral surface of the fixed ring. A rotating wheel that rotates differentially without engaging the outer peripheral surface with the inner peripheral surface of the fixed ring and slips around the position eccentric according to the amount of eccentricity due to the difference from the outer diameter, and the center of rotation is fixed. The center of the inner peripheral surface of the ring is inserted into the center hole of the rotating wheel eccentrically by the amount of eccentricity, and the outer peripheral surface of the rotating wheel is engaged with the inner peripheral surface of the fixed ring to maintain the differential. Transmits the eccentric motion of the rotating wheel, which has an eccentric shaft to be rotated, and one end fixed to the rotating wheel and the other end connected to an output shaft arranged at the center of the inner peripheral surface of the fixed wheel And an eccentric shaft coupling that transmits only the differential rotation of the rotating wheel without any rotation. It is intended to provide.

  Here, the mechanism that differentially rotates without sliding the outer peripheral surface of the rotating wheel engaged with the inner peripheral surface of the fixed wheel is a gear mechanism, the fixed wheel is an internal gear, and the rotating wheel Is preferably an external gear having fewer teeth than the internal gear. The internal gear and the external gear are preferably shift gears, or the internal gear and the external gear are preferably gears having tooth shapes formed in an arc shape.

  Further, the gear having the tooth profile formed in an arc shape has a tooth profile formed such that a substantially semicircular arc is convex inward, and the tooth profile is formed on the inner peripheral surface of the fixed ring and the gear It is desirable to form directly on the outer peripheral surface of the rotating wheel. Alternatively, the gear having the tooth profile formed in an arc shape meshes with the tooth profile formed by a cylindrical pin planted on the inner peripheral surface of the fixed ring or the outer peripheral surface of the rotating ring. It is desirable that the gear is formed with a substantially semicircular arc-shaped tooth shape, or a gear having the tooth shape formed in an arc shape is a cylindrical roller at the position of the inner peripheral surface of the fixed ring or the outer peripheral surface of the rotating wheel. It is desirable to have a tooth profile formed by disposing a chain having the shape and a substantially semicircular arc-shaped tooth profile meshing with the cylindrical roller.

  The mechanism that differentially rotates without engaging and sliding the outer peripheral surface of the rotating wheel with the inner peripheral surface of the fixed wheel is a magnetic gear mechanism, and the inner peripheral surface of the fixed wheel and the outer periphery of the rotating wheel. It is desirable that the opposing positions of the surfaces are magnetized to form a magnetic gear, or there is a mechanism that differentially rotates without slipping by engaging the outer peripheral surface of the rotating wheel with the inner peripheral surface of the fixed ring. In the friction conduction mechanism, it is desirable that contact surfaces that do not cause slippage due to friction are formed on the inner peripheral surface of the fixed wheel and the outer peripheral surface of the rotating wheel.

  Furthermore, the eccentric shaft coupling that transmits only the differential rotation of the rotating wheel without transmitting the eccentric motion of the rotating wheel has grooves perpendicular to each other on both sides, and is slidable along the groove. It is desirable to be an eccentric shaft joint having a structure in which members are engaged, and it is desirable that the sliding member is at least two pins. The pin is more preferably a pin having a structure having a rotating body supported by a rolling bearing, or the slide member is preferably a slide member fitted into the groove. Furthermore, it is desirable that the eccentric shaft joint that transmits only the differential rotation of the rotating wheel without transmitting the eccentric motion of the rotating wheel is an eccentric shaft joint having a structure in which two universal joints are combined.

  It is desirable that there are a plurality of sets of the fixed wheel and the rotating wheel, and that the multi-stage structure is formed by connecting the eccentric shaft of the input shaft directly to the output shaft.

  Since the present invention is configured as described above, it is possible to provide a reduction mechanism that is small in size and can be manufactured at a low cost while having a reduction mechanism having a high reduction ratio.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. 1 is a cross-sectional view showing an embodiment of the speed reduction mechanism of the present invention, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, FIG. 3 is a cross-sectional view taken along the line BB in FIG. FIG. 5 is an exploded perspective view of the eccentric shaft joint, FIG. 5 is a perspective view showing the input shaft, FIG. 6 is an explanatory view showing an example of a shift gear, and FIG. FIG. 8 is an explanatory view showing an example of a tooth profile formed by a cylindrical pin planted at the position of the inner peripheral surface of the fixed ring or the outer peripheral surface of the rotating ring, and FIG. 9 is the inner peripheral surface of the fixed ring. Or explanatory drawing which shows an example of the tooth profile formed with the chain which has the cylindrical roller arrange | positioned in the position of the outer peripheral surface of a rotating wheel, FIG. 10 is explanatory drawing which shows a magnetic gearwheel, FIG. 11 is eccentric shaft coupling shown in FIG. FIG. 12 is an exploded perspective view showing an embodiment in which the pin of the eccentric shaft joint is used as a slide member. 13 is a cross-sectional view showing another embodiment of the eccentric shaft joint, FIG. 14 is a cross-sectional view of an embodiment in which the speed reduction mechanism of the present invention is multistage, and FIG. 15 is a direct input to the output shaft in the multistage speed reduction mechanism of FIG. It is a perspective view which shows an example of the structure which connects the eccentric shaft of a shaft.

  The basic configuration of the speed reduction mechanism of the present invention employs a differential gear mechanism that can reduce the speed with a high reduction ratio, and as a conduction mechanism to reach the output shaft after being reduced by the differential gear mechanism, An eccentric shaft coupling that transmits only the differential rotation of the rotating wheel without transmitting the eccentric motion of the rotating wheel is adopted.

  As shown in FIGS. 1 and 2, the differential gear mechanism of the present invention has a fixed ring (inscribed in this embodiment) having a cylindrical inner peripheral surface (pitch circle 10a of the inscribed gear 10 in this embodiment). A rotating wheel (in this embodiment, the external gear 11) having a gear 10) and a cylindrical outer peripheral surface (in this embodiment, the pitch circle 11a of the external gear 11) smaller than the internal diameter of the inner peripheral surface of the fixed ring. The outer peripheral surface of the rotating wheel is engaged with the inner peripheral surface of the fixed ring, with the position being eccentric according to the amount of eccentricity e due to the difference between the inner diameter of the fixed wheel and the outer diameter of the rotating wheel. Differential rotation without slipping.

  The eccentricity e due to the difference between the inner diameter of the fixed ring and the outer diameter of the rotating ring is fixed so that the outer peripheral surface of the rotating ring engages with the inner peripheral surface of the fixed ring and rotates differentially without slipping. This is half the difference between the inner diameter of the ring and the outer diameter of the rotating wheel.

  In this embodiment, a gear mechanism is employed as a mechanism for differentially rotating the inner peripheral surface of the fixed ring and the outer peripheral surface of the rotating ring to engage with each other without slipping, and the fixed ring is an internal gear. 10, the inner peripheral surface is a pitch circle 10 a of the internal gear 10, the rotating wheel is an external gear 11 having a smaller number of teeth than the internal gear 10, and the outer peripheral surface is a pitch circle 11 a of the external gear 11.

  As will be described later, it is not essential to employ a gear mechanism as a mechanism for differential rotation without slipping, but it is definitely one of the optimal mechanisms. Will be described as an example.

  An input shaft 12 (see FIG. 5 for a specific shape) that drives the outer peripheral surface of the rotating wheel (external gear 11) to differentially rotate along the inner peripheral surface of the fixed wheel (internal gear 10). The rotation shaft 12a on the input side rotates about the center O of the inner peripheral surface (pitch circle 10a) of the fixed ring (internal gear 10), and the eccentric shaft 12b eccentric by the amount of eccentricity e is the rotation wheel (external gear 11). ) Is rotatably fitted in the center hole.

  For this reason, when the input shaft 12 rotates, the center O ′ of the eccentric shaft 12b is centered on the center O of the inner peripheral surface (pitch circle 10a) of the fixed ring (internal gear 10), and the rotational radius becomes the eccentric amount. The rotation wheel (external gear 11) is caused to rotate eccentrically, and the outer peripheral surface (pitch circle 11a) of the rotary wheel (external gear 11) is moved to the inner peripheral surface (fixed wheel (internal gear 10)). Since the rotation is performed while maintaining the engagement by the gear with respect to the pitch circle 10a), the rotating wheel (external gear 11) can be differentially rotated with respect to the fixed ring (internal gear 10).

  At this time, as described above, the amount of eccentricity e is equal to the diameter of the inner peripheral surface (pitch circle 10a) of the fixed ring (internal gear 10) and the diameter of the outer peripheral surface (pitch circle 11a) of the rotating ring (external gear 11). By making the difference of ½, the inner peripheral surface of the fixed ring (internal gear 10) and the outer peripheral surface of the rotating wheel (external gear 11) are engaged with each other to perform differential rotation without slipping. Can do. Accordingly, the rotating wheel (external gear 11) is decelerated by rotating without eccentric sliding due to the rotation of the eccentric shaft 12b and the inner peripheral surface of the fixed wheel and the outer peripheral surface of the rotating wheel engaging each other. A combined motion of rotation (differential rotation) is performed.

  Of the movements of the rotating wheels, the rotation (differential rotation) of the reduced rotating wheels (external gear 11) is the difference between the rotating wheels (external gear 11) without transmitting the eccentric motion of the rotating wheels (external gear 11). It is output from the output shaft 14 via an eccentric shaft coupling 13 that transmits only dynamic rotation.

  In this embodiment, as shown in FIGS. 3 and 4, the eccentric shaft joint 13 has an input end fixed to the rotating wheel (external gear 11) and an output end the inner peripheral surface of the fixed ring (internal gear 10). The output shaft 14 is arranged at the center of the shaft, and has a groove 15a, 15b orthogonal to each other on both surfaces between the rotary wheel (external gear 11) as the input end and the output shaft 14 as the output end. The coupling ring 15 is arranged, and sliding members (in this embodiment, two pins 16 provided in each case, provided on the rotating wheel (external gear 11) and the output ring 18 fixed to the output shaft 14) 17) adopts an eccentric shaft coupling having a structure in which the engagement ring 15 is movably fitted along the grooves 15a and 15b.

  In this embodiment, two pins 16 and 17 are provided, but three or more pins may be arranged linearly, or pins having a diameter smaller than the width of the grooves 15a and 15b are staggered. It may be arranged in a shape so as to contact only one side surface of each of the grooves 15a and 15b. And by arrange | positioning in this way, it can prevent that the pins 16 and 17 contact the both sides | surfaces of the groove | channels 15a and 15b, and cannot move the inside of the groove | channels 15a and 15b smoothly.

  In this embodiment, grooves 15 a and 15 b are formed in the engagement ring 15, and two pins 16 are provided on each of the rotating ring (external gear 11) and the output ring 18 fixed to the output shaft 14. However, conversely, even if grooves are formed in the rotating wheel (external gear 11) and the output ring 18 and pins are provided on both surfaces of the engagement ring 15, the same eccentric shaft coupling is obtained. be able to.

  A second side wall 21 is disposed on both side surfaces of the fixed ring (internal gear 10) via a first side wall 19 and an intermediate member 20, and is fixed integrally with bolts 22 so that the entire frame is fixed. Forming. A rotating shaft 12a on the input side of the input shaft 12 is disposed on the first side wall 19 via a ball bearing 23, and the output shaft 14 is disposed on the second side wall 21 via a ball bearing 24. Has been placed.

  Since the speed reduction mechanism in this embodiment is configured as described above, when the rotation shaft 12a on the input side of the input shaft 12 is rotated by being driven by a drive source (not shown), the rotation of the input shaft 12 causes the rotation. The eccentric shaft 12b rotates eccentrically, and the rotating wheel (external gear 11) performs an eccentric motion. By this eccentric motion, the outer peripheral surface (pitch circle 11a) of the rotating wheel (external gear 11) becomes a fixed ring (internal gear 10). ) Along the inner peripheral surface (pitch circle 10a).

The movement of the outer peripheral surface (pitch circle 11a) of the rotating wheel (external gear 11) is along the inner peripheral surface (pitch circle 10a) of the fixed wheel (internal gear 10) in the direction opposite to the rotation direction of the input shaft 12. Because it moves
(Number of teeth of internal gear 10-number of teeth of external gear 11) / (Number of teeth of internal gear 10)
The differential rotation is performed at the reduction ratio.

  As described above, the movement of the rotating wheel (external gear 11) at this time is a combined movement of the eccentric rotation of the eccentric shaft 12b of the input shaft 12 and the differential rotation of the fixed wheel and the rotating wheel. Therefore, in the present invention, the eccentric shaft coupling that transmits only the rotational motion of the rotating wheel without transmitting the eccentric motion of the rotating wheel is configured to output only the differential rotation of the rotating wheel, and the output The shaft 14 is configured to rotate at the same rotational speed as the differential rotation of the rotating wheel (external gear 11).

  The calculation of the reduction ratio in the speed reduction mechanism of the present invention will be described with a specific example. In the embodiment shown in FIGS. 1 and 2, the number of teeth of the internal gear 10 is 60 and the number of teeth of the external gear 11 is 56. Since it is drawn, the reduction ratio is (60−56) / 60 = 1/15 from the number of both teeth, and a reduction mechanism with a reduction ratio of 1/15 can be obtained. At this time, the amount of eccentricity e is the amount of eccentricity e = (number of teeth of the internal gear−number of teeth of the external gear) × gear module / 2, so if the gear module is 1, the amount of eccentricity is 2 mm. The amount of eccentricity e between the rotating shaft 12a on the input side of the input shaft 12 and the eccentric shaft 12b is 2 mm.

  In the present invention, in order to surely reduce the speed with a constant reduction ratio, it is essential that the inner peripheral surface of the fixed wheel and the outer peripheral surface of the rotating wheel are securely engaged and differentially rotated without slipping. In the embodiment shown in FIGS. 1 to 5, in order to differentially rotate without engaging and slipping, the outer peripheral surface of the rotating ring is engaged with the inner peripheral surface of the fixed ring and differentially rotated without slipping. A gear mechanism is employed as a mechanism for the operation.

  Accordingly, in the embodiment shown in FIGS. 1 to 5, the internal gear 10 is adopted as a member constituting the fixed ring, and the external gear having a smaller number of teeth than the internal gear 10 as the member constituting the outer peripheral surface of the rotating wheel. 11 is adopted. The tooth shape of the gear is unevenness for preventing slipping, and the inner peripheral surface of the fixed ring is a pitch circle 10 a of the internal gear 10, and the outer peripheral surface of the rotating ring is a pitch circle 11 a of the external gear 11.

  As in this embodiment, it is known that when the internal gear and the external gear mesh with each other, tooth profile interference occurs. It is also known that if the difference in the number of teeth between the internal gear and the external gear is made small in order to increase the reduction ratio, tooth profile interference is more likely to occur. In order to prevent this, it is desirable that both the fixed ring (internal gear 30) and the rotating ring (external gear 31) be shift gears as shown in FIG. FIG. 6 shows an example of a tooth profile 32 of a shift gear used for a fixed ring (internal gear 30) and a tooth profile 33 of a shift gear used for a rotary wheel (external gear 31).

  Alternatively, as a gear tooth profile, for example, as shown in FIG. 7, the tooth profile of the internal gear 30 of the fixed ring and the external gear 31 of the rotating ring can be formed in an arc shape. Arc-shaped tooth forms 34 and 35 of the internal gear 30 of the fixed ring and the external gear 31 of the rotating ring shown in FIG. 7 are tooth shapes formed so that a substantially semicircular arc is convex inward. The tooth profiles 34 and 35 are directly formed as the internal gear 30 on the inner peripheral surface of the fixed ring and as the external gear 31 on the outer peripheral surface of the rotating wheel, thereby forming the internal gear 30 and the external gear 31. As described above, when the tooth profile 34 of the fixed ring (internal gear 30) and the tooth profile 35 of the rotating wheel (external gear 31) meshing with the tooth profile are formed in a circular arc shape, the difference in the number of teeth is small. Even if the contact gear 30 and the external gear 31 are meshed with each other, the tooth profile does not interfere. Although FIG. 7 is not a cross-sectional view, hatching is applied to the internal gear 30 and the external gear 31 in order to clearly show the tooth profile 34 of the internal gear 30, the tooth profile 35 of the external gear 31, and the meshing state thereof. It has been subjected.

  Further, as another shape of the gear whose tooth profile is formed in an arc shape, as shown in FIG. 8, it is located at the position of the inner peripheral surface of the fixed ring (internal gear 30) or the outer peripheral surface of the rotating ring (external gear 31). A tooth shape is formed by the outer periphery of the implanted cylindrical pin 36, and can be meshed with a substantially semicircular arc-shaped tooth shape formed on the other side. In the embodiment shown in FIG. 8, a pin 36 is implanted in a fixed ring (internal gear 30), the outer periphery of the pin 36 is formed into an arcuate tooth profile 34, and the outer peripheral surface of the rotating wheel (external gear 31). In FIG. 2, a semicircular arc-shaped tooth profile 35 is shown, but conversely, a pin is implanted at the position of the inner peripheral surface of the rotating wheel (external gear 31) to fix the fixed ring (internal gear). An arcuate tooth profile 34 may be formed on the inner peripheral surface 30).

  Furthermore, as another shape of the gear whose tooth profile is formed in an arc shape, as shown in FIG. 9, at the position of the inner peripheral surface of the fixed ring (internal gear 30) or the outer peripheral surface of the rotating ring (external gear 31). A chain 38 having a cylindrical roller 37 is disposed, and a tooth profile 35 is formed by the outer periphery of the cylindrical roller 37. The tooth profile 35 formed by the outer periphery of the cylindrical roller 37 is substantially formed on the fixed ring (internal gear 30). A semicircular arcuate tooth profile 34 can also be engaged. In this embodiment, contrary to the embodiment of FIG. 8, the cylindrical roller 37 is fixed to a rotating wheel (external gear 31), and an arcuate tooth profile 35 is formed on the fixed ring (internal gear 30). Has been. However, in this embodiment as well, it is natural that the cylindrical roller 37 can be fixed to the fixed ring (internal gear 30) and an arcuate tooth profile can be formed on the rotating ring (external gear 31).

  The chain 38 is for holding the cylindrical roller 37 in a predetermined position, and is a type called a sprocket or a retainer, and may hold a cylindrical roller or a needle roller. Further, in the embodiment of FIG. 9, the position of the cylindrical roller 37 is positioned by the tooth profile 35 of the rotating wheel (external gear 31). May be a V-shaped groove only positioned. Of course, when the cylindrical roller 37 is positioned in this way, it is sufficient for the chain 38 to hold the cylindrical roller 37 within a predetermined range.

  Alternatively, as shown in FIG. 10, a mechanism that differentially rotates without engaging and sliding the outer peripheral surface of the rotating wheel with the inner peripheral surface of the fixed ring can be a magnetic gear mechanism. That is, N poles and S poles are alternately formed at the same pitch at positions facing the inner peripheral surface 30a of the fixed ring corresponding to the internal gear 30 and the outer peripheral surface 31a of the rotating wheel corresponding to the external gear 31. The magnetic gear is constituted by the inner peripheral surface 30a of the fixed ring (30) and the outer peripheral surface 31a of the rotating ring (31) by mutually adsorbing the N pole and the S pole without engaging and slipping. It can also be configured to perform dynamic rotation.

  In this case, the inner peripheral surface 30a of the fixed ring (30) and the outer peripheral surface 31a of the rotating ring (31) do not need to be processed into teeth, and the inner peripheral surface 30a of the fixed ring (30) and the rotating ring ( It is sufficient that both the outer peripheral surface 31a of 31) are processed into a cylindrical shape and magnetized to N and S poles at a predetermined interval. In the case of the magnetic gear mechanism, it is also possible to provide a clearance between the inner peripheral surface 30a of the fixed ring (30) and the outer peripheral surface 31a of the rotating wheel (31) and perform differential rotation without contact. is there. Further, in this case, since the fixed ring (30) rotates while being supported by the ball bearing 20 inside the rotating ring (31), troubles such as failure due to wear do not occur.

  By configuring the magnetic gear mechanism in this manner, even if the load increases and slip occurs between the inner peripheral surface 30a of the fixed ring (30) and the outer peripheral surface 31a of the rotating ring (31), N and N Or the same polarity of S and S approach each other, and acts so as not to cause slip by repelling more strongly. However, since a slip occurs when a large overload is applied, a function as an overload safety device can be provided.

  Or although not shown in figure, it can also be set as the cylindrical contact surface which does not produce a slip by friction by press-contacting the inner peripheral surface 30a of a fixed ring | wheel (30), and the outer peripheral surface 31a of a rotating wheel (31) as it is. In this case, while strongly pressing so as not to cause a slip between the inner peripheral surface 30a of the fixed ring (30) and the outer peripheral surface 31a of the rotating ring (31), at least one surface is roughened, or It is desirable to apply a material having a high friction coefficient such as a brake material and having high wear resistance so as not to cause slipping.

  With this configuration, in the case of a gear, since the number of teeth of the fixed ring and the number of teeth of the rotating ring must be integers, the reduction ratio must be an integer ratio. Thus, any reduction ratio can be freely selected.

  The eccentric shaft joint 13 that transmits only the rotational motion of the rotating wheel (external gear 11) without transmitting the eccentric motion of the rotating wheel (external gear 11) shown in FIG. 3 and FIG. The pin 16, 17 has a cylindrical rotating body 42 supported by a rolling bearing 41 fitted in the fixed pin 40, as shown in FIG. 11. The pin 43 can be used.

  With this configuration, the cylindrical rotating body 42 of the pin 43 rotates, so that friction with the side surfaces of the grooves 15a and 15b can be greatly reduced, and differential rotation can be extracted more effectively. it can. It should be noted that the configuration of the pin 43 is not limited to the configuration shown in FIG. 11, and it is obvious that the pin 43 can have any configuration, such as using a commercially available cam follower that employs a needle bearing.

  The pins 43 may be arranged in a staggered manner as pins having a diameter smaller than the width of the grooves 15a and 15b so that each pin 43 contacts only one side surface of the grooves 15a and 15b. . By arranging in this way, it is possible to prevent the pin 43 from simultaneously contacting both side surfaces of the grooves 15a and 15b and being unable to smoothly move inside the grooves 15a and 15b.

  The sliding member that fits into the grooves 15a and 15b of the engagement ring 15 of the eccentric shaft joint 13 is not limited to at least two pins 16, 17 (or pins 43), and as shown in FIG. The slide members 50 and 51 can be fitted into the grooves 15a and 15b. Although the slide members 50 and 51 have a single block body shape as in this embodiment, there is no problem, but the friction between the side surfaces of the grooves 15a and 15b and the slide members 50 and 51 that are the slide members. In order to reduce this, it is desirable to use a linear motion support mechanism by rolling rotation such as a slide mechanism using a roller chain.

  As shown in FIG. 13, an eccentric shaft coupling that transmits only the rotational motion of the rotating wheel (external gear 11) without transmitting the eccentric motion of the rotating wheel (external gear 11) includes two universal joints 60 and 61. It can be set as the eccentric shaft coupling 62 of the combined structure. The eccentric shaft joint 62 has a structure in which a first universal joint 60 fixed to the externally rotating gear 11 that rotates differentially and a second universal joint 61 fixed to the output shaft 14 are connected by a relay shaft 63. It is desirable that the relay shaft 63 is configured to be non-rotatable and extendable in the axial direction with respect to the first universal joint 60 or the second universal joint 61 although it is not essential.

  When the eccentric shaft joint 62 having a structure in which the two universal joints 60 and 61 are combined is employed, as is apparent from the drawing, there is a drawback that the speed reduction mechanism becomes larger in the axial direction. However, as the eccentric shaft joint, a well-known shaft joint is employed as a highly efficient joint, so that stable high performance can be exhibited.

  Since the configuration other than the above in the speed reduction mechanism of FIG. 13 is substantially the same as that of the embodiment shown in FIG. 1, only the reference numerals are entered in the drawing, and the detailed description of the configuration is omitted.

  The speed reduction mechanism of the present invention can be easily a multistage speed reduction mechanism by providing a plurality of sets of fixed wheels and rotating wheels in series. As shown in FIG. 14, this speed reduction mechanism connects the speed reduction mechanism of FIG. 1 in series with almost no change, and is connected to the second side wall 21 and the output shaft 14 in the first stage speed reduction mechanism 70. Instead, the second side wall 71 and the output shaft 72 are used, and instead of the first side wall 19 and the input shaft 12 in the second-stage reduction mechanism 73, the first side wall 74 and the input shaft 75 are used.

  The ball bearing 76 is sandwiched and held by the second side wall 71 and the first side wall 74, and the input shaft 75 is directly connected to the output shaft 72 inside the inner ring of the ball bearing 76. The rotating wheel (external gear 11) of the second stage reduction mechanism 73 is directly rotated by the eccentric shaft 73a of the input shaft 75.

  As a means for directly connecting the input shaft 75 to the output shaft 72 inside the inner ring of the ball bearing 76, in this embodiment, as shown in FIG. A structure is adopted in which these parts are combined inside the inner ring of the ball bearing 76. By constructing in this way, the first-stage reduction mechanism 70 and the second-stage reduction mechanism 73 are assembled, and finally the halved portion between the output shaft 72 and the input shaft 75 inside the inner ring of the ball bearing 76. By combining the two, the two-stage reduction mechanism can be easily assembled.

  Since the configuration other than the above in the multistage reduction mechanism of FIG. 14 is almost the same as that of the embodiment shown in FIG. 1, only the reference numerals are entered in the drawing, and the detailed description of the configuration is omitted.

  For example, as described above, if the first-stage reduction mechanism 70 and the second-stage reduction mechanism 73 are respectively 1/15 reduction mechanisms, the two-stage reduction mechanism is 1/15. 15 × 1/15 = 1/225, which is a reduction mechanism with a high reduction ratio of 1/225. According to the present invention, it is possible to easily obtain a reduction mechanism having a high reduction ratio while having a small size. In addition, the multistage reduction mechanism is not limited to two stages, and similarly, a reduction mechanism having three or more stages can be obtained. Therefore, a reduction mechanism having a higher reduction ratio can be easily obtained.

  When designing a multi-stage reduction mechanism having a desired reduction ratio, first, the reduction ratio of the first-stage reduction mechanism and the reduction ratio of the second-stage reduction mechanism are set from the required reduction ratio. Of course, the product of the reduction ratio of the first stage and the reduction ratio of the second stage is the reduction ratio of the entire reduction mechanism. When the reduction ratio of the first stage and the reduction ratio of the second stage are determined, the gear module and the number of teeth of the fixed ring (internal gear 10) and the rotating ring (external gear 11) are then determined. The eccentricity e between the input shaft 12 (75) and the eccentric shaft 14a (75a) is automatically determined by the difference between the inner diameter of the fixed ring (internal gear 10) and the outer diameter of the rotating ring (external gear 11). Therefore, by determining the reduction ratio (ratio of the number of teeth of the internal gear 10 and the external gear 11) and the gear module, the eccentricity e of the input shaft is also automatically determined.

  Accordingly, if the one-stage reduction mechanism and the input shaft 12 having a combination of the number of teeth of the internal gear 10 and the number of teeth of the external gear 11 corresponding to the desired reduction ratio are set, the reduction ratio of the first stage is set. And a set corresponding to the second stage reduction ratio, and assembling them, a multistage reduction mechanism can be easily manufactured.

  In the above description, the ball bearing has been described as an example of a member that rotatably supports various rotation members such as the input shaft 12 and the output shaft 14 and a rotating wheel (external gear 11). The bearing for supporting the member is not limited to the ball bearing, and it is a matter of course that an arbitrary bearing device, for example, a rolling bearing such as various sliding bearings or needle bearings may be used.

  In the above description, an example in which a gear is used as a mechanism for differential rotation without slipping between the inner peripheral surface of the fixed wheel and the outer peripheral surface of the rotating wheel has been described, but this mechanism is limited to that using a gear. Instead, as described above, an arbitrary differential rotation mechanism can be adopted.

It is sectional drawing which shows one Example of the deceleration mechanism of this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a disassembled perspective view of the eccentric shaft coupling shown in FIG. It is a perspective view which shows an input shaft. It is explanatory drawing which shows one example of a shift gear. It is explanatory drawing which shows an example of the gearwheel in which the tooth type was formed in circular arc shape. It is explanatory drawing which shows an example of the tooth profile formed by the cylindrical pin planted in the position of the inner peripheral surface of a fixed ring, or the outer peripheral surface of a rotating ring. It is explanatory drawing which shows an example of the tooth profile formed with the chain which has the cylindrical roller arrange | positioned in the position of the internal peripheral surface of a fixed ring, or the outer peripheral surface of a rotating wheel. It is explanatory drawing which shows a magnetic gearwheel. It is sectional drawing which shows the example which is a rotary body with which the pin of the eccentric shaft coupling shown in FIG. 4 was supported by the rolling bearing. It is a disassembled perspective view which shows the Example which used the pin of the eccentric shaft coupling as the slide member. It is sectional drawing which shows the other Example of an eccentric shaft coupling. It is sectional drawing of the Example which made the deceleration mechanism of this invention multistage. It is a perspective view which shows an example of the structure which connects the eccentric shaft of an input shaft directly to an output shaft in the multistage deceleration mechanism of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Internal gear 10a Pitch circle 11 External gear 11a Pitch circle 12 Input shaft 12a Input side rotating shaft 12b Eccentric shaft 13 Eccentric shaft coupling 14 Output shaft 15 Engagement ring 15a, 15b Groove 16, 17 Pin 18 Output ring 19 1st Side wall 20 Intermediate member 21 Second side wall 22 Bolt 23, 24 Ball bearing 30 Internal gear 30a Inner peripheral surface 31 Outer peripheral gear 31a Outer peripheral surface 32, 33 Tooth profile 34, 35 Arc-shaped tooth profile 36 Pin 37 Cylindrical roller 38 Chain 40 Fixed pin 41 Rolling bearing 42 Cylindrical rotating body 43 Pin 50, 51 Slide member 60, 61 Universal joint 62 Eccentric shaft joint 63 Relay shaft 70 First stage reduction mechanism 71 Second side wall 72 Output shaft 73 Second Step reduction mechanism 74 First side wall 75 Input shaft 76 Ball bearing

Claims (15)

A fixed ring having a cylindrical inner peripheral surface;
It has a cylindrical outer peripheral surface with an outer diameter smaller than the inner diameter of the inner peripheral surface of the fixed ring, and the inner periphery of the fixed ring is centered on a position eccentric according to the amount of eccentricity due to the difference between the inner diameter and the outer diameter. A rotating wheel that differentially rotates without engaging and sliding with the outer peripheral surface;
The center of rotation is the center of the inner peripheral surface of the fixed wheel, and is inserted into the center hole of the rotating wheel eccentrically by the amount of eccentricity, and the outer peripheral surface of the rotating wheel is engaged with the inner peripheral surface of the fixed wheel. An input shaft having an eccentric shaft that maintains and differentially rotates;
One end is fixed to the rotating wheel, and the other end is connected to an output shaft disposed at the center of the inner peripheral surface of the fixed wheel. Differential rotation of the rotating wheel without transmitting eccentric motion of the rotating wheel And an eccentric shaft coupling for transmitting only the speed reduction mechanism.   The mechanism that differentially rotates without engaging and sliding the outer peripheral surface of the rotating wheel with the inner peripheral surface of the fixed ring is a gear mechanism, the fixed wheel is an internal gear, and the rotating wheel is the inner ring. The speed reduction mechanism according to claim 1, wherein the speed reduction mechanism is an external gear having a smaller number of teeth than the external gear.   The speed reduction mechanism according to claim 2, wherein the internal gear and the external gear are shift gears.   The speed reduction mechanism according to claim 2, wherein the internal gear and the external gear are gears having tooth shapes formed in an arc shape.   The gear having the tooth shape formed in an arc shape has a tooth shape formed so that a substantially semicircular arc is convex inward, and this tooth shape is an inner peripheral surface of the fixed ring and the rotating wheel. The speed reduction mechanism according to claim 4, wherein the speed reduction mechanism is formed directly on the outer peripheral surface of the motor.   The gear whose tooth profile is formed in an arc shape is substantially meshed with a tooth profile formed by a cylindrical pin planted at the position of the inner peripheral surface of the fixed ring or the outer peripheral surface of the rotating wheel. The speed reduction mechanism according to claim 4, comprising a semicircular arc-shaped tooth profile.   The gear having the tooth profile formed in an arcuate shape meshes with the tooth profile formed by arranging a chain having a cylindrical roller at the position of the inner peripheral surface of the fixed ring or the outer peripheral surface of the rotating wheel. The speed reduction mechanism according to claim 4, comprising a substantially semicircular arc-shaped tooth profile.   A mechanism that differentially rotates without slipping because the outer peripheral surface of the rotating wheel engages with the inner peripheral surface of the fixed wheel is a magnetic gear mechanism, and the inner peripheral surface of the fixed wheel and the outer peripheral surface of the rotating wheel are The speed reduction mechanism according to claim 1, wherein the opposing positions are magnetized to form a magnetic gear.   A mechanism that differentially rotates without slipping by engaging the outer peripheral surface of the rotating wheel with the inner peripheral surface of the fixed wheel is a frictional conduction mechanism, and is provided on the inner peripheral surface of the fixed wheel and the outer peripheral surface of the rotating wheel. 2. The speed reduction mechanism according to claim 1, wherein a contact surface that does not cause slippage due to friction is formed.   An eccentric shaft joint that transmits only the differential rotation of the rotating wheel without transmitting the eccentric motion of the rotating wheel has grooves orthogonal to each other on both surfaces, and a sliding member that is movable along the groove. The speed reduction mechanism according to claim 1, wherein the speed reduction mechanism is an eccentric shaft joint having an engaged structure.   The speed reducing mechanism according to claim 10, wherein the sliding member is at least two pins.   The speed reduction mechanism according to claim 11, wherein the pin is a pin having a structure including a rotating body supported by a rolling bearing.   The speed reducing mechanism according to claim 10, wherein the sliding member is a sliding member fitted into the groove.   2. The eccentric shaft joint that transmits only the differential rotation of the rotating wheel without transmitting the eccentric motion of the rotating wheel is an eccentric shaft joint having a structure in which two universal joints are combined. The reduction mechanism described in 1.   15. A plurality of sets of the fixed wheel and the rotating wheel, and the multi-stage structure is configured by connecting an eccentric shaft of an input shaft directly to an output shaft. Speed reduction mechanism.

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