JPH01229139A - Speed change gear - Google Patents

Abstract

PURPOSE:To prevent occurrence of inclination of an external gear, and to prevent the partial wear of external teeth and internal teeth by interposing balls, which are arranged between opposing surfaces of the external gear and a thrust plate so as to be fitted along the circular hole provided on both surfaces, and by supporting the external gear from both sides in the axial direction. CONSTITUTION:An external gear 4 having been rotatably fitted on the eccentric part 2 of an input shaft 1 is engaged with a fixed internal gear 6. Thrust plates 11, 12 which are rotatable and coaxial with the input shaft 1 are arranged on both sides of the external gear 4 so as to be opposite to each other. On respective opposite surfaces of the external gear 4 and the thrust plates 11, 12, circular holes are provided so as to interpose thrust balls 15, and the external gear 4 is supported from both sides. Thus, occurrence of inclination of the external gear can be prevented, and also the partial wear of external teeth and internal teeth can be prevented, thereby the achievement of a long life can be enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transmission, and more particularly, to a transmission in which speed change rotation is extracted through balls.

(Prior art) As a conventional transmission that is relatively small and has a high reduction ratio of 1M, a gear type transmission is used in which a fixed internal gear is meshed with external teeth that have a smaller number of teeth than the internal teeth of the internal gear. The transmission is JP-A-61-
No. 74935, etc., and Japanese Patent Laid-Open No. 62-2064 proposes a transmission in which decelerated rotation is taken out via a transfer ball.

[Problem to be solved by the invention]

By the way, the former gear-type transmission has a meshing structure in which an eccentrically moving external gear is inserted into a fixed internal gear, so the external gear cannot be adequately supported in the axial direction. ,
There is a problem in that the external gear tilts when an output load is applied, causing uneven wear on the external and internal teeth, resulting in poor durability.

In addition, transmissions using the latter transfer ball use guide grooves with an evicycloid curve and a hypocycloid curve to extract decelerated rotation, so the structure and processing are complicated and manufacturing costs are high, and the ball There is a problem that there is a large number of transfers and the wear and tear is easy.

[Purpose of the invention]

This invention was made to solve the above-mentioned problems, and it is possible to securely support the external gear in the axial direction during eccentric movement, and prevent the occurrence of tilting of the external gear by 3L in the output IB load. In addition to eliminating the
The object of the present invention is to provide a transmission capable of extending the service life by reducing the amount of movement of the poles.

[Means for Solving the Problems] 1. In order to achieve the above objects, the present invention provides an external gear that is rotatably attached to an eccentric portion of an input shaft. The fixed inner gear, which has internal teeth with a larger number of teeth than the external teeth of the gear, is meshed with the J gear, and on both sides of the outer 1i gear, coaxial with the input shaft and freely rotatable, facing the plates 1 to 1. a circular hole is provided in each of the opposing surfaces of the external gear tooth iI and the thrust plate; It has a structure in which the instep is interposed, and the external tooth mountain is supported from both sides.

[Function] External gear crest' that fits 11 degrees into fixed internal gear ridge 111! 1 is supported in the axial direction by a pole interposed between the thrust handler and the external gear, and the rotation of the input shaft causes the external gear to perform eccentric movement, and the rotation is limited by the difference in the number of external and internal teeth. However, each time this rotation is extracted as thrust and deceleration rotation through the pole.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In the first example shown in FIGS. 1 and 2, an external gear 4 is rotatably attached to an eccentric portion 2 provided halfway through an input shaft 1 via a bearing 3, and is fixed to a casing 5. The input shaft 1 and the external gear 4 are inserted into the fixed internal gear 6.

The external teeth 7 of the external gear 4 have two or four fewer teeth than the inner K18 of the internal gear 6, and the external teeth 7 are located in the eccentric direction of the eccentric portion 2 with respect to the internal teeth 8. The parts that fit together.

Therefore, when the input shaft 1 is rotated, the external gear 4 performs eccentric interlocking, and the external gear 7 and the internal tooth 8 are rotated in response to the rotation of the input shaft 1.
The input side end of the input shaft 1 is rotatably supported via a bearing 10 by an end plate 9 fixed to the casing 5, so that the rotation of the input shaft 1 is possible. External gear 4
Plates 11 and 12 facing the side surface of the external gear 4 are rotatably arranged via bearings 2L and 22 on both sides of the gear.

Both thrust plates 11 and 12 are arranged coaxially with the input shaft 1, and a plurality of circular holes 13.14 are provided at opposing positions of both sides of the external gear 4 and the thrust plate 11.12, respectively. Interposed between the toothed gear 4 and the thrust plate 11.12 is a thrust ball 15 that fits across each opposing circular hole 13.14.

The circular hole 13.14 and the thrust pole 15 fitted therein connect the external gear 4 and the thrust I plate 11.12 in the rotational direction. The resulting rotation is transmitted to the thrust plates 11 and 12,
This will take out the decelerated rotation.

The thrust plates 11 and 12 on both sides are connected by a bolt 16 that loosely passes through the external gear 4, and both thrust plates 11 and 12 are pulled together to apply preload to the thrust I-balls 15 on both sides, and the thrust balls 15 and 15 are circular. Reduces lost threads and hacklashes on the output side due to gaps between holes 13 and 14, supports the external gear 4 from both sides, and prevents the external gear 4 from tilting when an output load is applied. , increasing rigidity.

An output cylinder shaft 17 is integrally connected to the thrust plate 12 located on the right side in FIG. .12 of the decelerated rotation is taken out to this output cylinder shaft 17.

The thrust plates 11 and 12 rotate around the axis of the input shaft 1, whereas the external gear 4 moves eccentrically, so the circular holes 13 and 14 into which the thrust balls 15 fit are arranged so that the external gear 4 rotates around the axis of the input shaft 1. 4 eccentric movements are allowed.

That is, when the eccentricity of the eccentric portion 2 provided on the input shaft 1 is e, and the diameter of the thrust pole 15 is D, the thrust plate 1
The circular hole 13 provided in 1.12 is D as shown in FIG.
-le shape.

Further, the circular hole 14 provided in the external gear 4G is set in the shape of D+2e as shown in FIG.

The circular holes 13 of the thrust plate 11.12 and the circular holes 14 of the external gear 4 are both arranged at equal intervals on the circumference of the same diameter, and the circular holes 13 of the thrust plate 11.12 are arranged at equal intervals on the circumference of the same diameter. As shown in FIG. 4, it is arranged on a circumference concentric with the rotation center ○ of the input shaft 1.

Further, the circular hole 14 of the external gear 4 is arranged on the circumference centered on the center point 0' of the external gear 4, as shown in FIG.
The above-mentioned middle point O' is eccentric with respect to the rotation center O of the input shaft 1 by an eccentric amount e.

4 and 5 schematically show the center trajectory and positional relationship of the thrust ball 15 when the circular holes 13 and 14 are arranged at four locations, and FIGS. 6 and 7 show specific examples of the center trajectory. It shows.

In each of the above figures, the center locus of the thrust ball 15 is equal to the eccentricity e in the circular hole 13 of the thrust plate 11.12, and the outer if'i tooth! 1 (2 for circular hole 14 of 4)
It becomes the diameter of e.

4 and 5 show the phases of the circular hole 13.14 and the thrust ball 15 when the eccentric direction of the external gear 4 is upward, and the thrust ball 15 is connected to the thrust plate 11.
．． It is located at an upper position with respect to the circular hole 13 of 12, whereas it is located at a lower position with respect to the external gear 4 and the circular hole 14.

The external gear 4 moves by 2e due to the eccentricity e, whereas the center locus of the thrust ball 15 in the circular hole 13 of the thrust plate 11, 12 is limited to be equal to the eccentricity e. 4 circular hole 14 is the thrust ball 1
Since the center locus of 5 is 20, it is possible to allow eccentric movement of the external gear 4 while minimizing the amount of displacement of the thrust ball 15.

The first example of the present invention has the above-mentioned configuration, and when the input shaft 1 is rotated, the external gear 4 performs an eccentric movement, and the external gear 7 and the internal gear shift with each rotation of the input shaft 1. Rotation occurs by a difference in the number of teeth of 8, and the thrust plates 11 and 12, which are connected to the external gear 4 through the thrust balls 15 and circular holes 13 and 14, rotate in tandem with the rotation of the external gear 4, and the thrust Board 1
The decelerated rotation is taken out to the output cylinder shaft 17 of No. 2.

Next, the second example shown in Figure 1O is an external gear. ! The same parts as those in the first example will be given the same reference numerals and will not be described further.

In this second example, two eccentric parts 2 and 23 are arranged on the input shaft 1 so that the eccentric directions are opposite, and an external gear 4 is connected to each of the eccentric parts 2.2a via a bearing 3.3a. At the same time, a plurality of circular holes 14.14 are provided in opposing surfaces of both external gears 4.4a, and thrust balls 15a are fitted across the circular holes 14.14 on both sides. 4
and 4a are coupled in the rotational direction.

The means for applying preload to each thrust ball 15.15a are:
In the case shown, the bolt 1 that connects the thrust plates 11 and 12
6 and the pressing of the bearing 22 by the nut 23 screwed onto the end of the output shaft 1 (1), but the preload may be applied only by the nut 23.

In this case, output rotation is taken out only by the thrust plate 12 coupled to the output cylinder shaft 17.

In this second example, two external gears 4 and 43 that are eccentric in opposite directions move the external gears 7 in the same direction by the rotation of the input shaft 1.
It rotates by the difference in the number of internal teeth 8, and this rotation is output to the output cylinder shaft 17 of the thrust plate 12 as a decelerated rotation.

[Effects] As described above, according to the present invention, the eccentrically moving external gear is axially supported from both sides by thrust balls, thereby preventing the external gear from tilting when an output load is applied. , it is possible to prevent uneven wear of the external teeth and internal teeth and extend the service life.

Further, since the decelerated rotation is taken out using the circular hole and the thrust ball, the structure is simplified and processing is extremely easy.

In addition, if the thrust plates are connected with bolts, the output will be increased due to the gap between the circular hole and the thrust ball! IJ's Lost Motion and Banokura no Shuwo Low N-! This has the effect of increasing rigidity.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing a first example of a transmission according to the present invention, Fig. 2 is a longitudinal sectional side view taken along arrow 11-11 in Fig. 1, and Fig. 3 is the relationship between the thrust ball and the circular hole. FIGS. 4 to 7 are explanatory diagrams showing the thrust plate and the center locus of the thrust ball in the external gear. FIGS. 8 and 9 are enlarged sectional views of the circular hole. FIG. 10 FIG. 2 is a longitudinal sectional front view showing a second example of the transmission. 1...Input shaft, 2...--Eccentric part, 4...
・・External gear, 6・・Internal gear, 7・・External teeth, 8・・・Internal teeth, 11.12・・Thrust plate, 13.14・・Circular hole, 15・Sufst ball・
17...Output cylinder shaft.

Claims (1)

[Claims] (1) An external gear that is rotatably attached to the eccentric part of the input shaft is meshed with a fixed internal gear that has internal teeth that have a larger number of teeth than the external teeth of this external gear. Thrust plates that are rotatable and coaxial with the input shaft are arranged facing each other on both sides of the input shaft, and a circular hole is provided in each of the opposing surfaces of the external gear and the thrust plate. A transmission that supports external gears from both sides by interposing balls that fit across the circular holes between the opposing surfaces of the two.