JPS6363772B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a reduction gear, and particularly to a reduction gear that is capable of obtaining a large reduction ratio while reducing the overall size. [Background Art of the Invention and Problems Therewith] For example, many devices that use a motor as a power source transmit the rotation of the motor to a load via a speed reducer. By the way, various reduction gears have been considered for this kind of use, but the most common one is a planetary gear type, which combines a sun gear S, a ring gear R, and a planetary gear P, as shown in Figure 1. Reducer C is often used. However, such a conventional reduction gear has the following problems. In other words, now the first
Taking the planetary gear type shown in the figure as an example, when the number of teeth of the sun gear S is Z _s and the number of teeth of the ring gear R is Z _r , how to select the relationship between each gear, input/output, and fixation. Therefore, the reduction ratio X shown in the table below is obtained.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to provide a reduction gear that is small, highly efficient, and can provide a large reduction ratio. [Summary of the Invention] According to the present invention, an internal gear having a hypotrochoid parallel curve tooth profile is fixedly provided, and an epitrochoid parallel curve tooth profile having two teeth less than the number of teeth of the internal gear is provided inside the internal gear. An external gear having a curved tooth profile is rotatably provided on the outer periphery of an auxiliary shaft that receives power from an input rotating shaft and rotates eccentrically. One more rolling elements than the number of teeth of the external gear are interposed between the internal gear and the external gear. Supported by a support member. A means for transmitting the rotation of the support member to the output rotation shaft is provided. [Effects of the Invention] The trochoidal internal planetary mechanism is configured as described above, and the automatic rotation of the support member that supports the rolling elements inserted between the internal gear and the external gear is output. Therefore, a large reduction ratio can be set by increasing the number of teeth without increasing the overall size. In addition, the ability to have all the rolling elements simultaneously participate in power transmission and the ability to transmit power by rolling transmission combine to make it possible to efficiently transmit a large amount of power. [Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 2, 1 is a case provided in a stationary state, and inside this case 1, a circular room 2 is formed. In the chamber 2 of the case 1, an internal gear 3 having a hypotrochoid parallel curve tooth profile H on its inner peripheral edge is fixed. This tooth H is, for example, the third
As shown in the figure, 13 are formed. Inside the internal gear 3, an external gear 4 having an epitrochoid parallel curve tooth profile E on its outer periphery is rotatably disposed on the outer periphery of an auxiliary shaft 5 via a bearing 6. Note that the number of teeth E is the number of teeth of the internal gear 3 minus 2, that is, in this example, 1 as shown in FIG.
It is set to 1. The auxiliary shaft 5 passes through the wall of the case 1 coaxially with the axial center line of the internal gear 3, and is eccentrically attached to the end of the input rotation shaft 7 whose one end is located inside the room 2. connected. Note that a bearing 8 is mounted between the wall of the case 1 and the input rotating shaft 7. As shown in FIG. 3, between the internal gear 3 and the external gear 4, rolling elements, that is, rollers 9 are arranged at equal intervals in the circumferential direction, 12 in this example, each roller 9.
It is mounted in such a manner that its two circumferential surfaces are in contact with the internal gear 3 and the external gear 4, respectively. Each roller 9 is rotatably supported on the outer periphery of a shaft 10 that extends parallel to the axial center line of the input rotation shaft 7 .
One end side of each type 10 is commonly fixed to a support member 11. As shown in FIG. 4, the support member 11 is formed, for example, in the shape of a disk, and has, for example, four circular holes 12 at equal opening angles near the center thereof. ing. On the other hand, an output rotating shaft 13 that penetrates the wall of the case 1 coaxially with the input rotating shaft 7 and has one end located inside the room 2 is rotatably provided with a bearing 14 interposed between it and the wall. There is. A disk 15 is coaxially fixed to the end of the output rotating shaft 14 located inside the chamber 2. Four shafts 16 having a length that can fit into the circular hole 12 are protruded from the surface of the disc 15 facing the support member 11. A roller 17 having a smaller diameter by an eccentric amount than the circular hole 12 is rotatably mounted at the position as shown in FIG. Next, the operation of the reduction gear configured as described above will be explained. Now, when the input rotation shaft 7 is rotated in a certain direction,
The auxiliary rotating shaft 5 also rotates eccentrically in that direction. The external gear 4 is attached to the outer circumference of the auxiliary rotating shaft 5 via a bearing 6, and the roller 9 is interposed between the external gear 4 and the internal gear 3, so that the auxiliary rotation shaft 5 can be When the rotation shaft 5 rotates eccentrically, the external gear 4 rotates in a direction opposite to the rotation direction of the input rotation shaft 7. As the external gear 4 rotates, each roller 9 rotates around the shaft 10, and this rotation causes the rollers 9 to revolve. Therefore, the support member 11 also rotates, and this rotation is transmitted to the disc 15 via the circular hole 12, the roller 17 fitted therein, and the shaft 16 supporting this roller 17, and eventually This will be transmitted to the output rotating shaft 13. Therefore,
Now, if the diameter of the circular hole 12 and the diameter of the roller 17 are set to predetermined values and a constant velocity conversion configuration is established, the output rotation shaft 13 will rotate at a rotation speed corresponding to the rotation speed of the input rotation shaft 7. The reduction ratio in this case is as follows.
That is, if the number of teeth of the internal gear 3 is Z _h , the number of teeth of the external gear 4 is Z _e , and the number of rollers 9 is Z _r , the external gear 4 is geometrically connected via each roller 9 as shown in FIG. From the condition that the and the internal gear 3 are in contact with each other, it is inevitably set as follows: Z _e =Z _r -1...(2) Z _h =Z _r +1...(3). Therefore, the external gear 4 and the roller 9
constitutes an internal planetary mechanism with a difference in the number of teeth by one, and the external gear 4 and internal gear 3 constitute an internal planetary mechanism with a difference in the number of teeth by two. Here, for example, when the output is extracted from the external gear 4 in a combination of the external gear 4 and the internal gear 3, the reduction ratio X is: X=Z _e /Z _e -Z _h = -Z _e /2...(4) becomes. However, when the output is taken out from the support member 11 that supports the shaft 10 of the roller 9 in a combination of the external gear 4 and the roller 9 as in the present invention, the reduction ratio X is as follows: X=Z _r /Z _e −Z _r = −Z _r …(5). That is, as in the example, Z _e = 11, Z _r =
12, Z _h =13, the reduction ratio X becomes X=12. In this case, as can be seen from equation (5), the sign is negative, which indicates that the direction of rotation is opposite. In this way, by selecting the number of teeth of the external gear 4 and internal gear 4 and the number of rollers 9, the reduction ratio can be set over a wide range. In this case, all of the rollers 9 are involved in power transmission at the same time, and since the form is rolling transmission, the loss is extremely small. Therefore, it is possible to obtain a highly efficient speed reducer that is small in size, capable of transmitting large amounts of power, and can also be set at a large reduction ratio.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining a typical conventional speed reducer, FIG. 2 is a vertical cross-sectional view of a speed reducer according to an embodiment of the present invention, and FIG. 3 shows the speed reducer shown in FIG.
FIG. 4 is a view of the reducer taken along line B--B in FIG. 2 and viewed in the direction of the arrow. 1... Case, 3... Internal gear, 4... External gear, 5... Auxiliary shaft, 6... Bearing, 7... Input rotating shaft, 9... Roller,
10, 16... shaft, 11... support member, 12... circular hole,
13...Output rotation axis.

Claims (1)

[Claims] 1. an input rotation shaft; an auxiliary shaft connected to the input rotation shaft eccentrically in the axial direction;
An external gear having an epitrochoid parallel curve tooth profile is rotatably mounted on the outer periphery of the auxiliary shaft, and a hypo gear is fixed to the outside of the external gear with its axis aligned with the axis of the input rotating shaft. An internal gear having a trochoidal parallel curve tooth profile, a plurality of rolling elements interposed between the internal gear and the external gear, and a rotatable gear that supports these rolling elements so that they can rotate freely and in common. A speed reducer comprising a support member and means for transmitting rotation of the support member to an output rotating shaft.