JPS6091043A - Inner gearing planetary reduction gear - Google Patents

Abstract

PURPOSE:To obtain a reduction gear which is small in size but can transmit great power while having a large reduction ratio, by using trochoidal tooth form curves for the tooth form of the gears of a fixed internal gear and a planetary external gear, and interposing a rolling body between said internal and external gears. CONSTITUTION:When an input rotation is provided to an input shaft 11, a disk 32, which is freely rotatingly linked to an eccentric shaft 12, revolves around the input shaft at the same speed ratio as the input rotation. A groove 42 having an epitrochoidal tooth form is provided on the disk 32, and is opposed to a groove 41 having a hypotrochoidal tooth form, which is fixed on a case 31. And, the movement of a ball 47 interposed between these grooves permits the disk 32 to carry out a rotating movement which is determined by the number of teeth of these grooves. Thereby, speed reduction can be carried out by taking out this rotation as an output.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a speed reducer.

[Prior art and its problems]

・A conventional speed reducer is shown in Fig. 1.

This is a widely used planetary gear reducer. Letting the number of teeth of the sun gear 1 and ring gear 3 be Zs and Zr, respectively, the reduction ratio i (output rotation speed/input rotation speed) obtained by selecting the fixed gear and input/output gear is as shown in the table.

The largest reduction ratio in the table is obtained when the ring gear 3 is fixed, the sun gear is operated by one person, and the planet gear is operated by two outputs, and the reduction ratio i in this case is Zs+Zr. Therefore, in order to obtain a large reduction ratio, the ring gear must be made large, or it must be combined in multiple L stages. However, when the stage is multi-stage, the splitting ratio becomes worse.

As explained above, with conventional speed reducers, when attempting to obtain a large reduction ratio, problems arise in terms of capacity and efficiency.

[Purpose of the invention]

The present invention improves the problems of volume and efficiency that were drawbacks of conventional reduction gears, and aims to provide a reduction gear that is small in size, has a large reduction ratio, and is highly efficient.

[Summary of the invention]

An internal gear with a hypotrochoid equidistant curve tooth profile (hereinafter referred to as the hypotrochoid tooth profile), a pin gear that meshes with the pin gear, and an external gear with an evitrochoid equidistant curve tooth profile (hereinafter referred to as the evitrochoid tooth profile). , by considering two sets of pin gears that mesh with this, and by making the pin gear common in these two sets, an internal planetary mechanism with a difference in the number of teeth of two teeth is formed. This is shown in FIG. The hypotrochoid gear 5, the epitrochoid gear 7, and the pin gear 6 are uniquely determined. At this time, if the hypotrochoid tooth profile and the ebitrochoid tooth profile are formed as grooves on two discs facing each other, and some rolling elements are interposed as pin gears between the discs, the reducer itself can be Can be significantly downsized.

Although rolling elements can transmit rotation without a cage, they require highly accurate machining. In the present invention, by using a retainer, it is possible to easily transmit smooth rotation.

〔Effect of the invention〕

The present invention is compact and has the advantage that all the rolling elements are involved in power transmission, that rolling transmission results in low friction, and that a decimal tooth difference type internal planetary mechanism provides a large reduction ratio. Large power transmission, large reduction ratio, and high efficiency reduction gears are possible.

[Example of the present invention]

Embodiments of the present invention are shown in FIGS. 3 and 4.

A groove 41 with a high borocoid tooth shape is fixed to the case 31.
is formed. Evitrochoid tooth-shaped grooves 42 are formed on the disc 32 to face each other, and the disc 32 is rotatably coupled to the eccentric shaft 12 eccentrically attached to the input shaft 11 via a bearing 22 . Several balls 47 are interposed between the grooves 41, 42 as pin gears.

These balls are assisted in rolling motion between the opposing grooves by the outer retainer 35t or 36, as shown in FIG. 5(a), Φ), and can smoothly transmit rotation. The cage shown in Fig. 5 (zl) has holes 37 for holding balls.
However, in the case of the cage shown in FIG. 5 υ), the shaft can be made concentric with the input shaft 11 by having an oval hole 38 radially extending from the center by the amount of eccentricity. In addition, in the case of the type shown in Fig. 5), it is necessary to hold the hole in the circumferential direction, so the hole may not be oval but may be rectangular, for example.

On the opposing surfaces of the disks 32 and 33, as shown in FIG. 6, there are several circular grooves 43 and 44 each having a radius corresponding to the amount of eccentricity, and a crank mechanism is formed by interposing a ball 48. They are connected at a rotation ratio of 1.

On the opposing surfaces of the discs 33 and 34, discs 33 are formed with evitrochoidal grooves 45, and 34 are formed with noibtrochoidal grooves 46, between which several balls 49 are formed in the retainer 35 or 36 as a pin gear. The disk 34 is a concentric shaft with respect to the input shaft 11, supports the input shaft with the bearing 24, and transmits rotation to the output shaft 14.

Next, the principle of this embodiment will be explained.

When input rotation is applied to the input shaft 11, the disk 32 rotatably coupled to the eccentric shaft 12 rotates around the input shaft at the same rate as the input rotation. The disc 32 has a groove 42 with an epitrochoid tooth profile, which is opposed to a hypotrochoid tooth profile groove 41 fixed on the case 31, and the ball 47 moves between the grooves to open the disc. 32 performs a rotational movement determined by their number of teeth. Here, if this rotation is taken out as an output, deceleration is being performed.

Further, this rotational movement is achieved by a crank mechanism using a ball, and a disc 3 is rotatably mounted on an eccentric shaft 13 on the opposite side of the input shaft 11 from the eccentric shaft 12 via a bearing 23.
It will be transmitted directly to 3. Further, on the opposing surfaces of the discs 33 and 34, there are structures 45 and 46 of ebitrochoid tooth profile and hypotrochoid tooth profile, and there are balls 4 as pin gears.
9 is interposed, and the final deceleration is performed by these numbers of teeth.

First stage epitrochoid tooth profile, hypotrochoid tooth profile,
The number of teeth of the pin gear is Zl e and Z1p+Z+h, respectively.
, the second row is Z 2 e , Z 2 p , Z
2 h, the number of teeth is Z1P=Z1. Given the relationship e+l=Z+h-1 Z2p=Z2e+1=Z2h-1, the first-stage reduction ratio 11 and the second-stage final reduction ratio i2 can be expressed as follows. Here, the negative sign indicates that the input rotation and output rotation directions are opposite. Further, when Z1p=Z2p, the output rotation cannot be controlled by Vη.

In this embodiment, Zfe=10. Zfp=11. Zjh=
12, Z2e=11. Z2p=12. When Z2h=13, the reduction ratio 1 (=i2) becomes -1/65.

As explained above, the present invention allows a wide range of reduction ratios to be selected by changing the disks according to the increase or decrease in the number of balls, and allows easy combination of multiple stages by overlapping them. By using a retainer, smooth rotation can be easily obtained. In addition, each ball is involved in power transmission, and the rollers transmit power, making it compact and
We can provide a reduction gear with large power transmission, large reduction ratio, and high efficiency.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram explaining a conventional speed reducer, Fig. 2 is a principle diagram of an internal bite trapezoidal planetary mechanism using a trochoid tooth profile, and Figs. 3 and 4 are axial directions of an embodiment of the present invention. A sectional view, FIG. 5 is a schematic diagram of a crank mechanism using balls, and FIG. 6 is a schematic diagram of a ball holder. 1. Sun gear, 2. ...Planet gear, 3.
・Ring gear, 4... Hypotrochoid tooth profile, 5...
・Ball 68... Ebitrochoid tooth profile, 7. ...Hypotrochoidal pitch circle, 8. ... Pin gear pitch circle, 9... Ebitrochoid pitch circle, 11. ...Input shaft, 12.13...Eccentric shaft 14,... Output shaft, 21,
22, 23.24.25... Bearing, 31... Case, 32, 33.34... Disc, 35, 36... Ball retainer, 41.46... Hypotrochoid tooth groove, 42゜45... Ebitrochoid tooth profile R143,44
...harmonious, 47.48.49...ball.

Claims (3)

[Claims] (1) An internally toothed trapezoidal planetary gear characterized by using a trochoidal tooth profile curve for the tooth profile of the fixed internal gear and the tooth profile of the planetary external gear, and having rolling elements interposed between the internal gear and the external gear. Decelerator. (2) The tooth profiles of the internal gear and the external gear are formed as grooves on two opposing discs, and the rolling elements roll in the grooves. Internally interlocking planetary gear reducer. (3) The internal trapezoidal planetary gear reducer according to claim 1, characterized in that the rolling elements include a retainer.