JP2010203570A - Speed reducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speed reducer capable of outputting the rotation of an input shaft with a high reduction ratio without rotation of a driving gear a round its own axis. <P>SOLUTION: The speed reducer 1 is equipped with a first gear 11 provided with internal cogs and able to rotate round a first shaft 11p, a second gear 21 provided with external cogs to inscribe and mesh with the first gear in which the number of external cogs is smaller than that of internal cogs, a plurality of eccentric pieces 27 supported by a plurality of bearings 26 set on the second gear to be rotatable in eccentricity along with the rotation of the input shaft part 28 in eccentricity by the same amount in the same direction from their respective center shafts 27p, and a synchronously rotating mechanism 30 to rotate a plurality of input shaft parts synchronously, wherein the amount of eccentricity is equal to one half of the difference in the meshing pitch circle diameter between the first gear and the second gear. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a speed reducer that reduces the rotational speed of an input shaft with a gear and outputs the reduced speed.

  Conventionally, a hypocycloid reducer has been used as a reducer capable of obtaining a high reduction ratio (see, for example, Patent Documents 1 and 2). As shown in FIG. 10 (FIG. 2 of Patent Document 1), this is mainly due to the internal gear 101 and the external gear 102 having a different number of teeth and rotating eccentrically with respect to the input shaft 110. As the input shaft 110 rotates, the external gear 102 revolves while meshing with the internal gear 101 and rotates in a direction opposite to the revolving direction by a difference in the number of teeth from the internal gear 101. Therefore, by extracting and outputting the rotation of the external gear 102, the output shaft is decelerated and rotated at a high reduction ratio of (N1-N2) / N2 (N1 is the number of teeth of the internal gear and N2 is the number of teeth of the external gear). Power of high torque can be transmitted.

  Here, as a mechanism for taking out the rotation motion of the external gear 102, in the reduction gear of Patent Document 1, a plurality of pin holes 104 provided on the circumference concentric with the eccentric shaft in the external gear 102 and the output shaft are integrated. In the rotating disk 105, a plurality of pins 103 are used that are provided on a circumference concentric with the output shaft. By loosely fitting the pin 103 into the pin hole 104, the pin 103 rolls while inscribed in the pin hole 104 as the external gear 102 revolves and rotates, and the revolving motion is absorbed by the gap in the pin hole 104. At the same time, the rotation of the external gear 102 is transmitted to the output shaft by the contact between the pin 103 and the inner peripheral surface of the pin hole 104. On the other hand, in the reduction gear of Patent Document 2, a plurality of pins protrude from the external gear, and a plurality of pin holes are provided in an output panel that rotates integrally with the output shaft. The rotation of the external gear is transmitted to the output shaft by contact with the peripheral surface.

  As described above, in the conventional speed reducer, a plurality of pins and a plurality of pin holes are used to extract only the rotation motion from the external gear that rotates while revolving, and the configuration is complicated. Moreover, in order to make the position of the pin and the pin hole and the diameter of the pin hole appropriate, high processing accuracy is required. The present inventor considered that the conventional speed reducer causes the above-mentioned problem because the external gear which is a drive gear rotates.

  In view of the above circumstances, an object of the present invention is to provide a reduction gear that can output rotation of an input shaft at a high reduction ratio without rotating a drive gear.

  In order to solve the above-described problems, the speed reducer according to the present invention includes: a first gear that has an inner tooth and is rotatable about a first axis, and an outer tooth that is inscribed and meshed with the first gear. A second gear provided with a smaller number of teeth than the inner teeth and a plurality of bearings provided on the second gear, respectively, and an input shaft portion that is eccentric from the center axis in the same direction by the same amount of eccentricity. A plurality of eccentric bodies that rotate eccentrically with each other and a synchronous rotation mechanism that rotates the plurality of input shaft portions synchronously, and the amount of eccentricity is the meshing of each of the first gear and the second gear. It is equal to one half of the pitch circle diameter difference.

  The term “mesh pitch circle diameter” is according to JIS B 0102: 1999.

  With the above configuration, each of the eccentric bodies rotates in the bearing as the input shaft portion rotates. A plurality of eccentric bodies are provided with respect to the second gear, and the plurality of eccentric bodies are rotated synchronously, and all the eccentric bodies rotate eccentrically by the same eccentric amount in the same direction. The second gear does not rotate, but moves so that all points in the second gear draw a circle having the radius of eccentricity. And since the amount of eccentricity is equal to half of the difference between the meshing pitch circle diameter of the first gear and the meshing pitch circle diameter of the second gear, and the number of teeth of the first gear and the second gear is different, With the movement of the second gear as described above, the first gear meshes with the second gear, is fed by an angle corresponding to the difference in the number of teeth, and rotates around the first axis.

  Therefore, according to this invention, without rotating the 2nd gear as a drive gear, the rotational speed of an input shaft part is decreased, a 1st gear is rotated, and power is transmitted to the 1st shaft as an output shaft. be able to. That is, in the present invention, in order to decelerate and output the rotation of the input shaft portion, a configuration such as a pin and a pin hole for taking out the rotation motion of the drive gear as in the conventional hypocycloid reducer is not required, It has an extremely simple configuration and can be easily processed. In addition, it has a very simple configuration compared to the conventional hypocycloid reducer, but it is configured to decelerate by meshing the internal gear and the external gear like the hypocycloid reducer. Can be output. Of course, not only can the output speed of the input shaft portion be reduced, but also the rotation angle of the input shaft portion can be reduced and the rotation can be output as a minute angle.

  The speed reducer according to the present invention includes: “a first gear having inner teeth and outer teeth that are inscribed and meshed with the first gear are arranged with a smaller number of teeth than the inner teeth, and are arranged around a second axis. Each of the rotatable second gear and the plurality of bearings provided on the first gear are respectively supported, and each of them rotates eccentrically with the rotation of the input shaft portion that is eccentric by the same eccentric amount in the same direction from each central axis. A plurality of eccentric bodies and a synchronous rotation mechanism for rotating the plurality of input shaft portions synchronously, and the amount of eccentricity is a half of the difference between the meshing pitch circle diameters of the first gear and the second gear. Equal to one ".

  In the speed reducer described above, the second gear is the drive gear, but in the present invention, the first gear is the drive gear, and the rotation input to the first gear is decelerated and output from the second gear. Then, on the same principle as the speed reducer described above, the first gear as the drive gear does not rotate, and all the points in the first gear move so as to draw a circle whose radius is the amount of eccentricity. While being engaged with the first gear, it is fed by an angle corresponding to the difference in the number of teeth and rotates around the second axis.

  Therefore, according to the present invention having the above-described configuration, the rotation of the input shaft portion is output at a high reduction ratio while being easy to process with a simple configuration by not rotating the drive gear as in the above-described reduction gear. It is possible to realize a speed reducer that can.

  The speed reducer according to the present invention has the above-described configuration, wherein “the synchronous rotation mechanism is integrally rotatable with the plurality of input shaft portions, and has a plurality of spur gears having the same number of teeth, and a plurality of spur gears. And a single drive spur gear meshing at the same time.

  With the above configuration, according to the present invention, a plurality of spur gears and a single drive spur gear meshing with all of these spur gears can be used to rotate a plurality of input shaft portions synchronously. it can.

  The speed reducer according to the present invention has the above-described configuration. “The synchronous rotation mechanism meshes with a plurality of worm wheels that can rotate integrally with the plurality of input shaft portions, respectively, and a plurality of the worm wheels at the same time. , And a single worm having a thread formed in the direction and interval for rotating all of the worm wheels in the same direction and at the same angle.

  “Single worm” and “rotate all of the worm wheels in the same direction” are configured in such a manner that a plurality of worm wheels are arranged on the same line and worms are provided on the same side with respect to these worm wheels. A configuration or a configuration in which worms are arranged between adjacent worm wheels, and the directions of the worm threads of the portions in contact with the worm wheels are alternately reversed can be exemplified. In addition, by “corresponding to the number of teeth of the worm wheel and the spacing of the worm threads of the worm wheel that meshes with the worm wheel,“ single worm ”means“ rotate all worm wheels at the same angle ”. Can do.

  When a plurality of spur gears that rotate integrally with the input shaft portion are rotated synchronously using the drive spur gear, the rotation shaft of the drive spur gear is parallel to the input shaft portion. On the other hand, when a plurality of worm wheels that rotate integrally with the input shaft portion are rotated by the worm, the rotation shaft of the worm intersects with the input shaft portion. Thereby, this invention of the said structure is suitable when there is space restriction | limiting in the axial direction of an input shaft part. Moreover, since the rotational speed can be greatly reduced even at the stage of transmitting the rotation of the worm to the input shaft portion, the reduction gear ratio as a whole can be made larger.

  As described above, as an effect of the present invention, it is possible to provide a reduction gear that can output the rotation of the input shaft at a high reduction ratio without rotating the drive gear.

It is a longitudinal cross-sectional view which shows the structure of the reduction gear which is one Embodiment of this invention. It is a figure which simplifies and shows the structure of the reduction gear of FIG. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is a figure explaining the motion of a 2nd gearwheel. It is a figure which expands and demonstrates the motion of a 2nd gearwheel. It is sectional drawing which showed the state which the 1st gearwheel rotated in the cross section corresponded in the BB line cross section in FIG. It is a figure which simplifies and shows the structure of the reduction gear of other embodiment. It is a figure which illustrates other composition of a synchronous rotation mechanism. It is explanatory drawing of a structure of the conventional hypocycloid reducer.

  Hereinafter, a reduction gear according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.

  The speed reducer 1 according to the present embodiment includes a first gear 11 that is provided with inner teeth and is rotatable around a first shaft 11p, and the outer teeth that are inscribed and meshed with the first gear 11 have fewer teeth than the inner teeth. Rotation of the input shaft portion 28 supported by the provided second gear 21 and the plurality of bearings 26 provided on the second gear 21 and eccentric from the central shaft 27p by the same eccentric amount r in the same direction. Accordingly, a plurality of eccentric bodies 27 that rotate eccentrically and a synchronous rotation mechanism 30 that rotates the plurality of input shaft portions 28 in synchronization with each other are provided, and the amount of eccentricity r is the engagement of each of the first gear 11 and the second gear 21. It is equal to one half of the pitch circle diameter difference R. In addition, the synchronous rotation mechanism 30 of the present embodiment meshes with a plurality of spur gears 31 that are rotatable integrally with a plurality of input shaft portions 28 and have the same number of teeth, and all of the plurality of spur gears 31 simultaneously. And a single drive spur gear 33.

  If it demonstrates in detail, the 1st gearwheel 11 will be formed in the aspect by which the tooth profile was hollowed by the 1st plate 10, and 30 internal teeth will be provided. On the other hand, the second gear 21 has 29 outer teeth formed with the same thickness as the first gear 11, and is attached to and integrated with the second plate 20. Further, a plurality of bolt holes (not shown) are formed in the outer peripheral edge of the first gear 11 in the first plate 10, and a disc-shaped holding plate 40 is formed by screwing these bolt holes and bolts (not shown). By being fastened to the first plate 10, the state in which the first gear 11 and the second gear 21 are engaged is maintained.

  The eccentric body 27 has a disk shape with the same thickness as the first gear 11 and the second gear 21, and two are provided in the present embodiment. The second gear 21 is provided with a circular through hole having a diameter slightly larger than that of the eccentric body 27 as a bearing 26 for supporting the eccentric body 27 symmetrically with respect to the central shaft 21 p of the second gear 21. . In addition, one eccentric body 27 is configured to be eccentrically rotated by the rotation of one input shaft portion 28, and the input shaft portion 28 has a columnar shape having a smaller diameter than the eccentric body 27, and is rotatable on the second plate 20. It is inserted. The input shaft portion 28 and the eccentric body 27 are integrated with each other by fitting one end of the input shaft portion 28 into the eccentric body 27. The input shaft portion 28 is notched along the long axis direction at the portion fitted into the eccentric body 27, and the joined state with the eccentric body 27 is good.

  Here, the amount of eccentricity r in which the center shaft 28p of the input shaft portion 28 is eccentric with respect to the center shaft 27p of the eccentric body 27 is determined by the meshing pitch circle diameter of the first gear 11 and the second gear as shown in FIG. It is set equal to one half of the difference R from the 21 mesh pitch diameter. Accordingly, the central axis (first axis) 11p of the first gear 11 and the central axis 21p of the second gear 21 are also offset by an eccentricity r in a state where the external teeth of the second gear 21 are engaged with the internal teeth of the first gear 11. It's off.

  An end of the input shaft 28 opposite to the end fitted into the eccentric body 27 is fitted and integrated with a spur gear 31, and the spur gear 31 rotates on the central shaft 28 p of the input shaft 28. As a center, it rotates integrally with the input shaft portion 28. Further, the two spur gears 31 respectively provided for the two input shaft portions 28 have the same diameter and the same number of teeth. 1, a drive spur gear 33 that rotates about the central axis 35p of the drive shaft portion 35 is provided between the two spur gears 31 as shown in FIG. It is provided so as to mesh with both gears 31.

  Here, the two spur gears 31 have their centers, that is, the centers of the input shaft portions 28 eccentric with respect to the centers of the eccentric bodies 27, as shown in FIG. The spur gear 33 is meshed with the drive spur gear 33 so that the two directions are the same. A disk-shaped handle 39 is attached to the drive shaft portion 35 so as to form a T-shaped longitudinal section with the drive shaft portion 35, and the drive plane 35 is driven via the drive shaft portion 35 as the handle 39 rotates. The gear 33 rotates.

  In the present embodiment, the drive shaft portion 35 is cylindrical, and a fixed shaft portion 41 that does not rotate with the rotation of the handle 39 is inserted into the drive shaft portion 35. The fixed shaft portion 41 is extended and inserted into through holes formed in the first plate 10, the second gear 21, and the holding plate 40, and then fastened to the holding plate 40 by nuts 44. In this embodiment, the center axis 41p of the fixed shaft portion 41 is configured to coincide with the first axis 11p, which is the center axis of the first gear 11. The diameter of the through-hole 25 provided in the second gear 21 for inserting the fixed shaft portion 41 is such that the fixed shaft portion 41 is moved to the second gear 21 during the movement of the second gear 21 accompanying the eccentric rotation of the eccentric body 27. The size is set so as not to interfere with 21 (see FIG. 5).

  Next, the operation of the speed reducer 1 configured as described above will be described. First, the handle 39 is rotated clockwise or counterclockwise. Hereinafter, a case where the handle 39 is rotated clockwise will be described as an example. However, when the handle 39 is rotated counterclockwise, the operation is reversed. When the drive spur gear 33 rotates clockwise with the rotation of the handle 39, the two spur gears 31 rotate in a counterclockwise direction in synchronization. As a result, the two input shaft portions 28 rotate in the counterclockwise direction, and the two eccentric bodies 27 rotate together with the respective input shaft portions 28 within the bearing 26 provided in the second gear 21. To do.

  Therefore, the second gear 21 moves with the eccentric rotation of the eccentric body 27. However, since a plurality of the eccentric bodies 27 are provided, the second gear 21 does not rotate as shown in FIG. Here, FIGS. 5A to 5D illustrate the movement of the second gear 21 when the input shaft portion 28 makes one rotation. In each figure, the input shaft portion 28 is 90 degrees. The state before rotation is indicated by a one-dot chain line, and the subsequent state is indicated by a solid line. Such movement of the second gear 21 is such that all the points in the second gear 21 move so as to draw a circle M having a radius of the eccentricity r, as shown in an enlarged view in FIG. 5 and 6, the first gear 11 is not shown in order to clearly show the movement of the second gear 21.

  The eccentric amount r is set to one half of the difference R between the meshing pitch circle diameters of the first gear 11 and the second gear 21, so that the second gear 21 moves as described above. The one gear 11 is fed while meshing with the second gear 21 and rotates clockwise around the first shaft 11p. In this embodiment, since the difference in the number of teeth between the first gear 11 and the second gear 21 is 1, when the input shaft makes one rotation, the first gear 11 is in relation to the second gear 21 as shown in FIG. Rotates one tooth. FIG. 7 shows a cross section corresponding to the cross section taken along line BB in FIG.

  Therefore, according to the speed reducer 1 of the present embodiment, by rotating the eccentric body 27 in synchronization, the second gear 21 that is the drive gear is not rotated and the first gear 11 is rotated with respect to the second gear 21. Can be rotated, and as a result, the first plate 10 and the second plate 20 can be relatively rotated around the first axis 11p which is the output shaft. That is, unlike the conventional hypocycloid reducer that revolves while rotating the external gear that meshes with the internal gear, it is a simple configuration that does not require a complicated configuration of a pin and a pin hole for taking out the rotational motion of the drive gear. The rotation of the first gear 11 by meshing with the second gear 21 that does not rotate can be output efficiently as the relative rotation of the first plate 10 with respect to the second plate 20 as it is. In this embodiment, since the difference in the number of teeth between the first gear 11 and the second gear 21 is 1, the speed of rotation input to the input shaft portion 28 can be reduced and output at the maximum reduction ratio. it can.

  In the above, the case where the second gear 21 formed with the external teeth is the drive gear and the decelerated rotation is output from the first gear 11 formed with the internal teeth is illustrated, but as shown in FIG. The first gear 11 may be a drive gear, and the speed reducer 2 that is decelerated from the rotation input to the first gear 11 and output from the second gear 21 may be used. That is, the speed reducer 2 is provided around the second shaft 21p, and the first gear 11 having the inner teeth provided therein and the outer teeth that are inscribed and meshed with the first gear 11 have a smaller number of teeth than the inner teeth. Each of the possible second gears 21 and a plurality of bearings provided on the first gear 11 are respectively supported, and are respectively eccentric with the rotation of the input shaft portion 28 that is eccentric by the same eccentric amount r in the same direction from the respective central axes. A plurality of rotating eccentric bodies 27 and a synchronous rotation mechanism for rotating a plurality of input shaft portions 28 synchronously are provided, and the amount of eccentricity r is the meshing pitch circle diameter of each of the first gear 11 and the second gear 21. It is equal to one half of the difference R.

  Further, in the above description, the synchronous rotation mechanism is exemplified by a configuration including a plurality of spur gears 31 that rotate integrally with the plurality of input shaft portions 28 and a drive spur gear 33 that meshes with all the spur gears 31 at the same time. However, the present invention is not limited to this. For example, as shown in FIGS. 9A to 9C, a plurality of worm wheels that can rotate integrally with a plurality of input shaft portions and a plurality of worm wheels that mesh with each other simultaneously, Synchronous rotation mechanisms 50a, 50b, and 50c including a single worm having threads formed in directions and intervals that rotate all at the same angle in the same direction can be used. When the worm is used as described above, the input shaft portion can be rotationally driven from the direction intersecting the input shaft portion, and therefore, it is suitable when the space in the axial direction of the input shaft portion is limited.

  Here, in the synchronous rotation mechanism 50a of FIG. 9A, a worm 55 is provided between two worm wheels 51a and 51b, and the worm 55 meshes with a portion that meshes with the worm wheel 51a and the worm wheel 51b. This is an example in which a reverse thread is formed at the portion. 9B is a case where the worm 56 is provided on the same side with respect to the two worm wheels 51a and 51b. Even if there are three or more worm wheels, they are on the same line. If they are arranged side by side, the same configuration can be obtained. On the other hand, even when three or more worm wheels are not on the same line, the worm 57 is passed between the adjacent worm wheels 52 and adjacent to each other in the worm 57 as in the synchronous rotation mechanism 50c of FIG. A plurality of worm wheels 52 can be rotated synchronously with a single worm 57 by making the screw thread of the portion in contact with the worm wheel 52 reverse. In addition, the number of teeth of the plurality of worm wheels may be the same or different as long as the worm screw threads correspond to the teeth of the worm wheel at the portion where each of the plurality of worm wheels meshes. Absent.

  The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements can be made without departing from the scope of the present invention as described below. And design changes are possible.

  For example, in the above, the case where two eccentric bodies are provided is illustrated, but the present invention is not limited to this. If there are a plurality of eccentric bodies that rotate in synchronization, the first gear and the first gear are not rotated without rotating the drive gear. The two gears can be rotated relative to each other. In addition, although the case where the two eccentric bodies 27 are provided symmetrically with respect to the central shaft 21p of the second gear is illustrated in the reduction gear 1 described above, the present invention is not limited to this. However, if there are two eccentric bodies in this way, it is the minimum configuration that does not rotate the second gear and is extremely simple, and a plurality of eccentric bodies are provided symmetrically with respect to the central axis of the second gear. If this is the case, a good balance is achieved when the eccentric body rotates.

  In the above description, the input shaft portion 28 is separate from the eccentric body 27, and one end of the input shaft portion 28 is fitted into the eccentric body 27 and integrated, but the present invention is limited to this. Instead, the input shaft portion and the eccentric body can be integrally formed.

1, 2 Reduction gear 11 First gear 11p First shaft 21 Second gear 21p Second shaft 26 Bearing 27 Eccentric body 28 Input shaft portion 30, 50a, 50b, 50c Synchronous rotation mechanism 31 Spur gear 33 Drive spur gear 51a, 51b , 52 Worm wheel 55, 56, 57 Worm

JP 2001-212124 A JP 2000-120810 A

Claims (4)

A first gear that has inner teeth and is rotatable around a first axis;
A second gear in which external teeth inscribed and meshed with the first gear have a smaller number of teeth than the internal teeth; and
A plurality of eccentric bodies that are respectively supported by a plurality of bearings provided on the second gear and that are eccentrically rotated in accordance with the rotation of the input shaft portion that is eccentric by the same eccentric amount in the same direction from the respective central axes;
A synchronous rotation mechanism that synchronously rotates a plurality of the input shaft portions,
The reduction gear according to claim 1, wherein the amount of eccentricity is equal to one half of a difference in mesh pitch diameter between the first gear and the second gear. A first gear with internal teeth arranged around,
A second gear that is rotated around a second axis, and has external teeth that are inscribed and meshed with the first gear less than the inner teeth.
A plurality of eccentric bodies that are respectively supported by a plurality of bearings provided in the first gear and that are eccentrically rotated in accordance with the rotation of the input shaft portion that is eccentric by the same eccentric amount in the same direction from the respective central axes;
A synchronous rotation mechanism that synchronously rotates a plurality of the input shaft portions,
The reduction gear according to claim 1, wherein the amount of eccentricity is equal to one half of a difference in mesh pitch diameter between the first gear and the second gear. The synchronous rotation mechanism is
A plurality of spur gears that can rotate integrally with the plurality of input shaft portions and have the same number of teeth;
The speed reducer according to claim 1 or 2, further comprising a single drive spur gear that meshes simultaneously with all of the plurality of spur gears. The synchronous rotation mechanism is
A plurality of worm wheels that can rotate integrally with the plurality of input shaft portions, respectively;
And a single worm having a thread formed in a direction and at an interval for simultaneously engaging all of the plurality of worm wheels and rotating all of the worm wheels in the same direction by the same angle. The speed reducer according to claim 1 or 2.

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