JPH03223546A - Speed reducer - Google Patents

Abstract

PURPOSE:To smoothly reduce a speed without generating heat so as to transmit power by letting a planetary gear be formed with both a first meshing section and a second meshing section the number of teeth of which is less by one than that of the first meshing section, and thereby making the number of teeth of an output side revolution member meshed with the second meshing section less by one than that of an input side revolution member. CONSTITUTION:The inner circumferential surface is provided with an input side revolution member 31 which is meshed with a first meshing section 27 of a planetary gear 29, includes a third meshing section 30 having the number of teeth which is the internal multiple of the number of teeth of the third meshing section 27 and is coaxially fixed onto an input shaft 26. In addition, the inner circumferential surface is provided with an output side revolution member 33 which is meshed with a second meshing section 28 of the planetary gear 29 and includes a fourth meshing section 32 whose number of teeth is less by one than that of the third meshing section 30. Furthermore, an output shaft 34 is coaxially fixed onto the output shaft revolution member 33. It is so constituted that the third meshing section 30 of the input side revolution member 31 is meshed with the fourth meshing section 32 of the output side revolution member 33 while the radius of an identical pitch circle is being kept, and the first meshing section 27 and the second meshing section 28 of the planetary gear 29 are meshed with the third meshing section 30 of the input side revolution member 31 and with the fourth meshing section 32 of the output side revolution member 33 while a module pitch is being kept respectively.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a speed reduction device.

Prior Art FIG. 6 is a front view schematically showing a typical prior art. The worm type speed reduction device 1 includes a worm 2 and a worm wheel 3 with which the worm 2 meshes. In such a worm type reduction gear 1, the output of the worm wheel 3 corresponding to one revolution of the worm 2 on the input side is the most efficient number of teeth minus the number of teeth, and the number of teeth of the worm wheel 3 is set to 100. If this is done, a speed ratio of 1000:1 will be established.

However, since the ohm 2 is a screw, there is a structural problem in that the tooth surface of the worm wheel 3 must be constantly rubbed.

FIG. 7 is a front view schematically showing another prior art.

In the planetary gear reduction device 5 , a planetary gear 8 is provided between a first sun gear 6 and a second sun gear 7 . The number of teeth of the first sun gear 6 is greater than the number of teeth of the second sun gear 7, which is the output, and the reduction ratio becomes smaller.

FIG. 8 is a front view schematically showing still another prior art. This journal bearing device 10 is composed of an internal gear 11 having internal teeth formed on its inner circumferential surface and an external gear 12 having external teeth formed on its outer circumferential surface. The problem is that the number of teeth that can be input is limited to the difference in the number of teeth between two teeth.

FIG. 9 is a front view schematically showing still another prior art. Although the guard type reduction gear 15 is composed of a small gear 16 and a large gear 17, it is generally used as a reduction gear with a large number of teeth, and is different from the worm type reduction gear 1 shown in FIG. Similarly, since the small gear 16 and the large gear 17 are always in mesh with each other, the amount of skewer wear is relatively large, and there is a pressure between them that easily causes backlash.

FIG. 10 is a front view of still another prior art. When the number of teeth of the output gear 20 is, for example, 100, the face gear reduction device 19 has a tilt gear 21 and an input gear 22.
The number of teeth is 101, and although this is a speed reduction device that does not cause back crash due to a difference in the number of teeth by one tooth, it has the problem of geometrical unnaturalness of the face curve due to the inclination of the inclined gear 21.

Problems to be Solved by the Invention To summarize the problems of each of the prior art shown in Figs. Considering that it is a speed reduction device, the mutually opposing involute curves are
The ideal module pitch is one that allows power to be transmitted without sliding on the tooth surface through line contact, but due to processing needs, when cutting gears with dislocation, the size of the dislocation is slides on the tooth surface in direct proportion to the

That is, friction and heat generation phenomena occur.

Therefore, an object of the present invention is to provide a speed reduction device that can prevent the ml and heat generation phenomenon by using a regular module pitch with a difference in the number of teeth of one tooth.

Means for Solving the Problems The present invention comprises: an input shaft that is rotationally driven around a rotational axis; a first meshing portion that revolves around the rotational axis as the input shaft rotates and has a predetermined number of teeth N; a plurality of planetary gears having a second meshing part that is fixed coaxially with the first meshing part and has one tooth less than the number of teeth N of the first meshing part; having a third meshing part that meshes with each other and has a number of teeth that is an integral multiple of the number of teeth N of the first meshing part,
the input-side revolving member coaxially fixed to the input shaft, and the second meshing portion of the planetary gear meshing with the inner circumferential surface, and
an output-side revolving member having a fourth meshing part with one tooth less than the third meshing part; and an output shaft coaxially fixed to the output-side revolving member, the third meshing part of the input-side revolving member and the output The fourth meshing part of the side revolving member has the same pitch circle radius, the first meshing part of the planetary gear meshes with the third meshing part of the input side revolving member at a module pitch, and the second meshing part This speed reduction device is characterized in that it meshes with the fourth meshing portion of the output-side revolving member at a module pitch.

Further, the present invention is characterized in that the planetary gear is biased radially outward by a spring.

According to the present invention, the first meshing portion of the planetary gear meshes with the third meshing portion of the input-side revolving member, and the second meshing portion of the planetary gear meshes with the fourth meshing portion of the output-side revolving member. The number of teeth in the third meshing part of the input side revolution member is an integral multiple of the number of teeth in the first meshing part of the planetary gear, so when the planetary gear makes one revolution around the rotation axis of the input shaft, is rotating by the number of times corresponding to the integer multiple. The number of teeth in the fourth meshing part of the output side revolving member is one less than the third meshing part of the input side revolving member, and is therefore one less than the number of teeth in the first meshing part. When the second meshing part of the number of teeth revolves, the planetary gear makes one revolution when it rotates by the number of revolutions corresponding to the above-mentioned integral multiple, and at that time, the output side revolution member has a difference in the number of teeth of l with respect to the input side revolution member. is only slowed down. With this configuration, it is possible to realize a reduction gear with a difference in the number of teeth by one tooth in the module pitch, which prevents heat generation and achieves smooth rotation without generating large frictional force on the tooth surfaces that mesh with each other. be able to.

Embodiment FIG. 1 is a sectional view showing a reduction gear device 25 according to an embodiment of the present invention, and FIG. 2 is an exploded sectional view showing essential parts of the reduction gear device 25. The reduction gear [25 includes an input shaft 26 that is rotationally driven around a rotational axis, and a first meshing portion that revolves around the axis 11 due to the rotation of the input shaft 26 and has teeth with a predetermined number N of teeth. 27 and a plurality of planetary gears 29 having a second meshing part 28 in which teeth with the number of teeth N-1, which is one less than the number of teeth N of the first meshing part 27, are formed, and the planetary gear 29 on the inner peripheral surface. The third engaging portion 27 of
An input side revolution member 31 having a meshing part 30, an output side revolution member 33 having a fourth mesh part 32 with which the second mesh part 28 of the planetary gear 29 meshes on the inner peripheral surface, and an output side revolution member 3.
3 and an output shaft 34 coaxially fixed to the output shaft 3.

The input shaft 26 and the output shaft 34 have the rotation axis 11 on a common straight line, and the input side revolving member 31 is pivotally supported on the input shaft 26 via a bearing 36. This input side revolving member 31
has a lid 37 extending in a plane direction perpendicular to the axis 11, and a right cylindrical cylindrical portion 38 that integrally projects from one surface of the lid 37 on the output shaft 34 side. 38, the third engaging portion 30 is formed. The input side revolving member 31 is connected to the casing 40 by the bolt 39.
Fixed.

An outward flange 41 is integrally formed on the input shaft 26 . This outward flange 41 has a pair of shaft holes 42a42b formed on a diameter line passing through the axis 11, and one end 43a of the shaft rod 43 of the planetary gear 29 is fitted into these shaft holes 42a, 42b. be done. The other end 4 of the shaft rod 43
3b is an outward flange 45 of the support member 44 formed opposite to the outward flange 41 within the casing 40;
It fits into and is supported by shaft holes 46a and 46b formed in the shaft holes 46a and 46b. In this way, the pair of outward flanges 41.
The planetary gear 29 is pivotally supported by the shaft 43 supported by the shaft 45 via a bearing 47 .

The outward flanges 4145 that pivotally support the planetary gear 29 are fixed at a distance L (see FIG. 1) from each other using bolts 48 and nuts 49 shown in FIG. This nut 49 has a threaded portion 50 with an external thread cut into its outer peripheral surface, and this threaded portion 50 is threaded onto the outward flange 41 . The other outward flange 45 is held between the nut 49 and the flange 51 of the bolt 48. A shaft 52 is integrally formed on the outward flange 45 , and this shaft 52 is supported in a recess 54 of the output shaft 34 via a bearing 53 .

A rod spring 5 is attached to the shaft rod 43 on which the planetary gear 29 is supported.
An insertion hole 56 is formed through which the bar spring 55 is inserted.
The other end is inserted into a locking hole 57 formed in the outward input side revolving member 31 and locked therein. Further, the other rod spring 55 is inserted into a locking hole 57a formed in the output side revolving member 33 and locked.

Such an axis 43 and therefore the axis 1 of the planetary gear 29
2, the axes 13 of each end 43a, 43b are formed to be deviated outward in the radial direction, and as shown in FIG. It presses elastically outward. Due to long-term use, the planetary gear 29 and the third planetary gear 29 that mesh with each other
And the fourth! When the lit joints 30 and 32 are worn out, as shown in FIG. 4(2), they are angularly displaced in the direction of arrow A around the axis 13 by the spring force of the bar spring 55, and the distance is smaller than the distance d1. The distance d2 after the angular displacement becomes smaller. This makes it possible to compensate for the wear and to reliably prevent backlash from occurring.

FIG. 5 is a diagram showing an example for explaining the relationship between the pitch circle and the number of teeth to achieve a modular structure. Note that the unit of numbers shown in FIG. 5 is millimeter [mm]. If the pitch circle diameter of the third meshing part 30 formed on the input side revolving member 31 is 52 mm, the pitch circle diameter of the first meshing part 27 of the two planetary gears is 26 mm, and the number of teeth N is N1=51, The number of teeth N3 of the third meshing part 30 with which the first meshing part 27 meshes is N5=10.
2, the number of teeth N2 is an integral multiple (in this embodiment, twice) of the number of teeth N1, and when the planetary gear 29 rotates once, it rotates twice, so that a module structure can be achieved. That is,
The circumferential pitch φ of the third meshing portion 30 is divisible by a small fraction of N×number of teeth d: diameter of the pitch circle, and the diameter d of such a pitch circle is 52 mm.

On the other hand, when the pitch circle diameter d of the fourth meshing part 32 of the output side revolving member 33 is 51.5 mm, the number of teeth 43 is selected to be N3-1=lOL, and the number of teeth is It is set one less than . In the second meshing part 28 of the planetary gear 29 that meshes with the fourth meshing part 32, the number of teeth N2 is selected to be 50, and it is possible to achieve a module structure with such a pitch diameter and the number of teeth. I can do it. That is, on the input side and the output side, the first meshing part 27 and the third meshing part 30, and the second meshing part 28 and the fourth meshing part 30, which mesh with each other, have a large frictional force applied to each other over the entire circumference in the circumferential direction. In this way, a reduction gear device with a difference in the number of teeth of 1 between the input side and the output side can be realized without any meshing parts.

Generally speaking, the modular structure achieved as described above is as follows: m: 1 that can be represented by a module In the present invention, the module m
is a rational number and not an irrational number.

Effects of the Invention According to the present invention, a first meshing portion and a second meshing portion having one fewer teeth than the first meshing portion are formed in the planetary gear.
Since the number of teeth on the output side revolving member with which the meshing part meshes is made one less than the number of teeth on the input side revolving member, the output is reduced by one tooth difference compared to the input, achieving a module. This makes it possible to smoothly decelerate and transmit power without creating a large frictional force between teeth that mesh with each other, and therefore without generating heat.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a reduction gear device 25 according to an embodiment of the present invention, FIG. 2 is an exploded sectional view showing the main parts of the reduction device 25, and FIG. 3 is a sectional view showing a bolt 48 and a nut 51. FIG. 4 is a diagram for explaining the installation state of the bar spring 55,
Fig. 5 is a diagram showing an example for explaining the relationship between the pitch circle and the number of teeth, Fig. 6 is a front view schematically showing a typical prior art worm type reduction gear f, and Fig. 7 is a diagram showing another example. FIG. 8 is a front view schematically showing a planetary gear reduction device 5 of the prior art, FIG. 8 is a front view schematically showing a jar pull bearing device 10 of another prior art, and FIG. FIG. 10 is a front view schematically showing the speed reduction device 15, and FIG. 10 is a front view schematically showing a face gear speed reduction device 19 of another prior art.

Claims (2)

[Claims] (1) An input shaft that is rotationally driven around the rotational axis, a first meshing part that revolves around the rotational axis as the input shaft rotates, and has a predetermined number of teeth N, and is fixed coaxially with the first meshing part. The second tooth is one tooth less than the number of teeth N of the first meshing part.
a plurality of planetary gears having meshing portions; and a third meshing portion having an inner peripheral surface in which the first meshing portion of the planetary gear meshes and whose number of teeth is an integral multiple of the number N of teeth of the first meshing portion. death,
the input-side revolving member coaxially fixed to the input shaft, and the second meshing portion of the planetary gear meshing with the inner circumferential surface, and
An output-side revolving member having a fourth meshing part with one tooth less than the third meshing part, and an output shaft coaxially fixed to the output-side revolving member, the third meshing part of the input-side revolving member and the output The fourth meshing part of the side revolving member has the same pitch circle radius, the first meshing part of the planetary gear meshes with the third meshing part of the input side revolving member at a module pitch, and the second meshing part is output. A speed reduction device characterized in that the fourth meshing portion of the side revolving member meshes with a module pitch. (2) The planetary gear is biased radially outward by a spring.
Reduction device as described in section.