JPS6293565A - Reduction gear - Google Patents

Abstract

PURPOSE:To take out a rotation of reduction ratio in accordance with a number of rollers, by rotating the roller by one tooth in a reverse direction for internal teeth of an internal gear in one rotation of an input shaft. CONSTITUTION:A locus of the roller center A is calculated by obtaining a distance l from the input shaft center O to the roller center A in a range, forming a rotary angle theta of an output shaft 2 by one pitch amount of an internal gear 3, and when a locus of a roller 14 is traced, the roller 14 generates parallel curves, and a curve in the outside of the parallel curves forms one tooth amount of the internal gear 3. Accordingly, the all rollers come to be brought into contact with the teeth of the internal gear, and a rotation of reduction ratio in accordance with a number of rollers can be taken out.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a speed reduction device that uses an eccentric disc, an internal gear, and a roller interposed between the input shaft to reduce the rotation of the output shaft. The present invention relates to a speed reduction device suitable for use in motion control of industrial robots and the like.

[Conventional technology and problems]

Conventionally, as a reduction gear device used for motion control of industrial robots, etc., there is a
Some devices incorporate an elastically deformable external gear with external teeth that mesh with the internal gear, and use the difference in the number of teeth to obtain a reduction ratio.

By the way, since the above-mentioned speed reduction device uses an external gear that can be elastically deformed, there is a problem that the rigidity is low, and the positioning accuracy is poor because vibrations may occur in the robot drive system.

In addition, since the above-mentioned reduction gear has a reduction ratio of 50 or more due to its structure, it is difficult to keep up with the increase in work speed. At present, there is a desire for a reduction gear that has a high rigidity at a mid-range speed ratio and does not have a hinge.

This invention was made in consideration of the above points, and it is an object of the present invention to provide a reduction gear device that is small in size, has high rigidity, and can obtain a mid-range speed ratio in the range of about 10 to 50. It is a purpose.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention arranges an input shaft, an output shaft, and an internal gear having a plurality of teeth coaxially, and creates a space between an eccentric disk provided on the input shaft and the internal gear. The number of rollers smaller than the number of teeth of the internal gear is rotatably held by the output shaft so as to be in contact with the eccentric disc. Within the range of one pitch, the rotation of the eccentric disk forms a tooth profile in which one tooth corresponds to the curve on the outside of the roller, which is parallel to the locus drawn by the center of the roller. It was brought into contact with

[For production]

Between the eccentric disc provided on the human shaft and the internal teeth of the internal gear, rollers one less than the internal gear are rotatably held on the output shaft, and the eccentric disc on the input shaft is rotated at the center of the input shaft. When the roller rotates in one direction, the roller moves against the internal teeth of the internal gear (ζ), and when the human shaft rotates once, the roller moves against the internal teeth of the internal gear. Rotating in the opposite direction by one tooth (・Konari, output + 1qI + + rotation of the reduction ratio according to the number of two rollers is extracted.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawing numbers.

First, the basic structure of the present invention will be explained based on FIG. 2 and FIGS. 1 to 5.

An input shaft 1, an output IQh 2, and an internal gear 3 are arranged coaxially, and the internal gear 3 is sandwiched between an input shaft housing 4 and an output shaft housing 5, and the three are connected and integrated with a bolt 6. .

The input shaft 1 is rotatably supported by the housing 4 and the ltb bearings 7 and 8 of the output shaft 2, and an eccentric disc 9 is provided between the two bearings 7 and 8, and a bearing is mounted on the outer periphery of the disc 9. 10 is press-fitted.

The output shaft 2 is rotatably supported by a bearing 11 of the housing 5, and a retainer 12 is connected to the end facing the human-powered shaft 1, and the retainer 12 is loosely fitted to the outside of the bearing 10. 1
Nine pockets 13 are provided at positions corresponding to the zero outer circumference, and a torque transmitting roller 14 is rotatably held in each pocket 13.

The internal gear 3 is positioned so as to fit on the outside of the retainer 12, and has 10 teeth 15, one more than the rollers 14, on its inner peripheral surface.
are formed at regular intervals in the circumferential direction, and all of the rollers 14 are in contact with the outer circumference of the outer ring of the bearing 1o, and are also in contact with the teeth 15 of the inner wheel 3.

Next, the deceleration movement of the speed reduction device will be explained. Second
In the figure, when the human power shaft 1 is rotated clockwise, the eccentric disk 9 revolves around the center 0 of the input shaft 1 in the same direction.
The roller 14 will move relative to the teeth 15 of the internal gear 3, and when the input shaft 1 makes 21 rotations clockwise, the roller 14 will move counterclockwise relative to the teeth 15 of the internal gear 3 by one tooth. It will rotate to .

Therefore, the output shaft 2 rotates for one rotation of the input shaft 1.In the reduction gear device of the present invention, in order to obtain a large allowable torque and a high natural frequency, the ff115 of the internal gear 3 is formed with a unique tooth profile of 9. This will be explained based on FIGS. 2 to 4.

Here, R=radius r of bearing 10=radius a of crawler 4=amount of eccentricity n of eccentric disk 9=reduction ratio In FIG. 4, when the input shaft 1 is rotated clockwise by n×θ ζ2N, The roller 14 contacts the outer periphery of the bearing 10 and rotates by θ counterclockwise in the figure.

This: The trace drawn by the center A of the roller 14 is t = a cos (1 + n) θ ten a cos 1, where t is the distance between the center of the human power axis 1 and the center A of the roller 14.
+n 1−a2+R+r 2.

When the rotation angle θ of the output shaft 2 corresponds to one pitch of the internal gear 3, that is, in the case of Fig. 4, θ is within the range of 36° (range of n x θ = 324° for the human-powered shaft 1), and the center of the input shaft is set. The distance t from 0 to the roller center A is calculated, and the trajectory of the roller center A is calculated. When the roller 4 traces this 41ILi + + as shown in Fig. 3, the roller 4 moves out by one and becomes a part of the parallel curve. The one on the outside is the -m portion of the internal gear 3.

FIG. 1 (The specific assembly structure of the speed reduction device shown here shows one that balances the load and eliminates backlash.

In FIG. 1, two eccentric disks 9a and 9b having the same diameter and eccentricity are installed between bearings 7 and 8 of input shaft 1 with a phase shift of 180 degrees, and both eccentric disks 9a and 9b are mounted on retainer 12. ,9
Pockets 13 are provided at two-ring pitches in the circumferential direction at positions corresponding to the outer peripheries of the bearings 10, 10 press-fitted into the bearings 10, 10b.

The pockets 13 are arranged in two rows corresponding to the bearings 10 and 10, and the phases of the negative row and the second row are shifted by Y in the circumferential direction.

The eccentric disk 9a located on the left side of FIG. 1 is integrated with the input shaft 1, and the eccentric disk 9b on the right side of the figure is integrated with the input shaft 1.
As shown in FIG. 5, this eccentric disk 9bG has an arc-shaped (k hole 16)
is provided, and by screwing the bolt 17 inserted into the elongated hole 16 to the mating eccentric disc 9a, both eccentric discs 9a and 9)
) are combined = - are united.

Rotate the eccentric disk 9b on the movable side by Jf1 degree α in FIG.
By joining both eccentric discs 9a and 9b together, it is possible to realize a reduction gear without buffing cracks without increasing the machining accuracy of the parts. Alternatively, a structure similar to that of a knock bottle may be adopted.

Next, the example shown in FIGS. 6 and 7 shows a structure for obtaining high deceleration, in which the number of teeth of the internal gear 3 is 25, and the number of teeth of the internal gear 3 is 25.
The number of rollers 4 is set to 12, the reduction ratio is 24, and the number of rollers 4 is set to the end of the reduction ratio. If you want to obtain higher speed reduction, increase the number of rollers 4 to 3' 4 for the speed reduction ratio.
-, since the number of rollers 4 is small,
Machining of pockets on the retainer 12 becomes easier.

FIG. 8 shows another example of the tooth profile in the internal gear 3 shown in FIG. This is realized by making the curve larger, and the fourth part 15b is realized by making it slightly larger than the theoretical curve.

The protrusion 15a and the recess 15b have a small contact angle, and even if the load applied to the roller ζ is large, the component that contributes to the torque is small.

That is, as shown in FIG. 9, in the relationship between the internal gear 3 and the roller 14, at a point below the friction angle, the roller 14 is not pushed out due to frictional force and no force is generated, so an excessive load is applied to the roller 14. , it generates heat and has a negative effect on vibration, and when rotating at low speeds, there is an effect of torque fluctuation, but the protrusion 1
By making the recess 5a and the recess 15b non-contact, there is no excessive load on the roller, and torque fluctuations at low speeds are also eliminated.

〔effect〕

As described above, this invention (mainly because it has the above-described configuration) has the following effects.

(+) If the rotation angle of the output shaft is within the range of one pitch of the internal gear, the teeth of the internal gear are located on the outside of the roller within the curve parallel to the trajectory drawn by the center of the roller. The curve is formed into a tooth profile with one tooth, and all the rollers are brought into contact with the teeth of the internal gear, making it possible to achieve constant velocity specific transmission, which is similar to the tooth profile of the involutes and trochoids currently in use. It has a tooth profile, has a large load capacity, and provides quiet operation with no shock at the beginning of mating.

(n) Since the number of engagements between the roller and the internal gear is large, even if there is a manufacturing error, the influence is evened out, and constant velocity specific conduction can be reliably obtained.

(III) Since the roller is rotatable on the output shaft, there is no relative slippage between the eccentric disc or the internal gear, and no chapping or wear occurs.

(IV) Since the rollers are kept rotatable on the output shaft, the functions of reduction and constant velocity joints can be obtained at the same time, and unlike cyclo reducers, there is no need for a separate constant velocity joint, simplifying and downsizing the structure. is possible ζ 3゜

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view of the reduction gear according to the present invention; Fig. 2 is a longitudinal sectional side view of the same as the above; Figs. 3 and 4 are explanatory diagrams showing the tooth profile of the internal gear in the same; Fig. 5 is removal of the vano crusher. Fig. 6 is a longitudinal side view showing another example of an internal gear with a different tooth profile, Fig. 7 is a front view showing only the same internal gear, and Fig. 8 is a still different example of the same tooth profile. FIG. 9, an enlarged sectional view showing an example, is an explanatory diagram showing the relationship between the friction angle between the roller and the internal gear. 1...Input shaft, 2...Output shaft, 3...Internal gear, 9
... Eccentric disc, 10... Bearing, 12... Cage,
13...pocket, 14...roller, 15...tooth agent sickle 1) Sentence 2Figure 1Figure 3Figure 2Figure 4

Claims (1)

[Claims] An input shaft, an output shaft, and an internal gear having a plurality of teeth are arranged coaxially, and a number of rollers smaller than the number of teeth of the internal gear is provided between an eccentric disk provided on the input shaft and the internal gear, The output shaft is rotatably held and arranged so as to be in contact with the eccentric disk, and the teeth of the internal gear are rotated by the rotation of the eccentric disk within a range where the rotation angle of the output shaft is one pitch of the internal gear. When the output shaft rotates in the opposite direction, the curve parallel to the locus drawn by the center of the rollers, which is on the outside of the rollers, is formed into a tooth profile that corresponds to one tooth, and all rollers are brought into contact with the teeth of the internal gear. reduction gear.