JPH0548366B2 - - Google Patents

Description

[Detailed Description of the Invention] Object of the Invention [Industrial Application Field] The present invention relates to a differential planetary gear device, and more specifically, a differential planetary gear device that uses a planetary gear mechanism to change the speed of the rotation of an input shaft and transmit it to the output shaft. It is related to the device.

[Prior Art] Various planetary gear mechanisms have been widely used as differential mechanisms. As a transmission using such a planetary gear mechanism, for example, a sun gear is connected to an input shaft, one end of a support member that rotatably supports the planetary gear is connected to an output shaft, and an internal gear is driven by an auxiliary drive device. A device is known that rotates the motor and performs a predetermined speed change.

[Problems to be Solved by the Invention] However, such conventional differential planetary gear devices have the following problems. In other words, in a configuration in which the sun gear is used as an input shaft and the support member is used as an output shaft, the rotation speed of the input shaft is once reduced and transmitted to the output shaft, and the rotation speed is changed around the reduced rotation speed. It is easy to obtain from the output shaft. However, in order to obtain from the output shaft a rotation speed that is varied around the rotation speed of the input shaft, the internal gear must be rotated at high speed, which is not practical.

SUMMARY OF THE INVENTION Therefore, the present invention has been made to solve the above-mentioned problems, and to provide a differential planetary gear device that can obtain a rotational speed that is changed before or after the input rotational speed.

Structure of the Invention [Means for Solving the Problems] In order to achieve the above object, the present invention has the following structure as a means for solving the problems. That is, the first planetary gear mechanism includes a fixed first internal gear, a first planetary gear, and a first sun gear, and a second internal gear, a second planetary gear, and a second planetary gear that are rotatably supported. a second planetary gear mechanism including a sun gear, each gear of both planetary gear mechanisms is formed to have the same number of teeth, the first sun gear and the second sun gear are arranged coaxially, and One of the first sun gear and the second sun gear is an input shaft, and the other is an output shaft, and each planetary gear of the first planetary gear mechanism and the second planetary gear mechanism is separately rotatably supported. The support member is rotatably supported, and the second internal gear is rotated by a drive mechanism that rotates the second internal gear of the second planetary gear mechanism, thereby increasing or decelerating the output shaft. This is the configuration of a differential planetary gear system.

Here, the drive mechanism may be any mechanism as long as it can rotate the internal gear; for example, a worm wheel gear may be used to rotate the internal gear; An external gear may be formed on the outer periphery of the motor, and a pinion may be engaged with the external gear to rotate the motor. Further, the power source of the drive mechanism may be, for example, an AC motor, a DC motor, or a pulse motor.

[Function] The differential planetary gear device of the present invention having the above configuration includes two sets of planetary gear mechanisms, rotatably supports a support member that separately rotatably supports each planetary gear, and further includes: By fixing the first internal gear, rotatably supporting the second internal gear, and rotating the second internal gear by a drive mechanism, the number of rotations of the output shaft and the number of rotations of the input shaft can be adjusted. It works by focusing on the center and increasing or decelerating it.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a cross-sectional view of a differential planetary gear device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A-A. This differential planetary gear device includes an input shaft 1 rotated by an external main drive source, a first planetary gear device 2 that engages with the input shaft 1, and a second planetary gear device provided coaxially with the first planetary gear device 2. An output shaft 6 that engages with the second planetary gear device 4 and the second planetary gear device 4, passes through the input shaft 1, and transmits rotation to the outside is provided.

Here, the first planetary gear device 2 includes a first sun gear 8 keyed to the input shaft 1, three first planetary gears 10 that mesh with the first sun gear 8 and are rotatably supported; A first internal gear 12 and the like that mesh with and are fixed to the first planetary gear 10 are provided.

The second planetary gear device 4 also includes a second sun gear 14 integrally formed at one end of the output shaft 6, and three second planetary gears 16 that mesh with the second sun gear 14 and are rotatably supported. , a second internal gear 18 meshed with the second planetary gear 16, and the like are provided. In this embodiment, the first sun gear 8 and the second sun gear 14 have the same number of teeth, 36, and the first planetary gear 10 and the second planetary gear 16 have the same number of teeth, 18. gear gear 12
and the second internal gear 18 have the same number of teeth, 72 teeth.

Further, the first planetary gear 10 and the second planetary gear 16 are rotatably supported by three pins 22 and 24, respectively, on an arm 20 that serves as a support member.

The second internal gear 18 is bolted to a ring 26 that has a wheel gear formed on its outer periphery and is rotatably supported. This ring 26 is a worm gear 2 rotated by an external auxiliary drive source (not shown).
It is meshed with 8. Therefore, the second internal gear 18
can be rotated at any rotational speed by an auxiliary drive source.

In the differential planetary gear device of this embodiment, when the input shaft 1 is rotated by an external main drive source, the first sun gear 8
The first planetary gear 10 is rotated via. Here, since the first internal gear 12 is fixed, the first planetary gear 10 revolves around the first sun gear 8,
This causes the arm 20 to also rotate. Therefore, when the arm 20 rotates, the second planetary gear 16 rotatably supported by the arm 20 revolves around the second sun gear 14 while rotating. The rotation speed of the second internal gear is
Orpm, that is, when the second internal gear is not rotated by the auxiliary drive source, the number of teeth of the first sun gear 8 and the second sun gear 14 and the first planet gear 10 and the second planet gear 16 are the same, so the second
The rotation speed and rotation direction of the sun gear 14 are the same as those of the first sun gear 8. Therefore, input shaft 1 and output shaft 6
The rotation speed and rotation direction are the same.

Further, the second internal gear 18 is rotated by the auxiliary drive source via the worm wheel gears 26 and 28, for example, when the rotational speed of the input shaft is 1000 rpm, the second internal gear 18 is
When the rotation speed of the internal gear is rotated at 1 rpm in the same direction as the input shaft 1, the rotation speed of the output shaft 6 is increased.
The rotation speed becomes 1002 rpm, and the difference in rotation speed between the input shaft 1 and the output shaft 6 is 2 rpm. Here, when the second internal gear 18 is rotated at 1 rpm in the opposite direction to the input shaft, the rotation speed of the output shaft is reduced to 998 rpm, and the difference in rotation speed is 2 rpm.

As described above, according to the differential planetary gear device of this embodiment, when the second internal gear 18 is not rotated,
The output shaft 6 can be rotated at the same rotation speed as the input shaft 1, and on the other hand, by rotating the second internal gear 18 at a predetermined rotation speed in a predetermined direction, the output shaft 6 can be rotated around the rotation speed of the input shaft 1. It is possible to give the output shaft 6 any rotational speed that is decelerated or accelerated. Further, according to this embodiment, since the input shaft 1 and the output shaft 6 are arranged coaxially, it can be easily installed as a differential device in existing equipment.

As an application example of this embodiment, the output shaft 6 is made hollow and the input shaft 1 passes through it.
can be used as a lathe spindle, and can also be used to drive other devices such as tool moving devices with the output shaft 6 attached to the tip of the spindle.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments in any way, and it goes without saying that the present invention can be implemented in various forms without departing from the gist of the present invention.

Effects of the Invention As detailed above, according to the differential planetary gear device of the present invention, the drive mechanism rotates the second internal gear in any direction at any rotation speed, so that the rotation speed of the input shaft is centered around the rotation speed of the input shaft. Thus, the rotational speed of the output shaft can be reduced or increased, and when the second internal gear is not rotated, the input shaft and the output shaft can be rotated at the same rotational speed.

Furthermore, since planetary gears are used, it can be made smaller, and furthermore, since the sun gears are coaxially arranged, it can be easily installed in existing equipment.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a differential planetary gear device as an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG. 1... Input shaft, 2... First planetary gear device, 4...
...Second planetary gear device, 6...Output shaft, 20...
Arm, 26...ring, 28...worm gear.

Claims (1)

[Scope of Claims] 1. A first planetary gear mechanism including a fixed first internal gear, a first planetary gear, and a first sun gear, a second internal gear rotatably supported, and a second a second planetary gear mechanism including a planetary gear and a second sun gear, each gear of both planetary gear mechanisms is formed to have the same number of teeth, and the first sun gear and the second sun gear are coaxially arranged. At the same time, one of the first sun gear and the second sun gear is used as an input shaft and the other as an output shaft, and each planetary gear of the first planetary gear mechanism and the second planetary gear mechanism is rotated separately. The second internal gear is rotated by a drive mechanism that rotatably supports a support member that supports the movably, and rotates the second internal gear of the second planetary gear mechanism, thereby increasing or decelerating the output shaft. A differential planetary gear device characterized by: