JPH10306854A - Gear reducer - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the size and manufacturing cost.
Sufficiently secure the strength as a member that transmits torque. SOLUTION: The eccentric body 2 has an eccentric body 2, a plurality of detent shafts 3 arranged side by side on the same circumference, and a plurality of guide holes 4a through which the respective detent shafts 3 pass. The external gear 4 performs a circular motion as a whole while displacing each guide hole 4a around each detent shaft 3 by
A ring-shaped rotary output body 5 which is arranged concentrically with the circumference on which the rotation preventing shafts 3 are arranged, meshes with the external teeth 4b of the external gear 4 and has internal teeth 5a having a different number of teeth. And each detent shaft 3 rotatably supports the rotation output body 5 from the inside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a gear reducer. More specifically, the present invention relates to a gear reducer using a planetary gear mechanism, and more particularly to a gear reducer suitable for being incorporated into a small product such as a CD player or a cassette tape player.

[0002]

2. Description of the Related Art In small home appliances such as CD players,
The rotation of the motor is reduced by a gear reducer using a planetary gear mechanism and used as a driving force. Conventionally, in this type of gear reducer, the rotation of the input shaft is largely reduced by a planetary gear mechanism and then transmitted to the output shaft. This output shaft protruded from a planetary gear mechanism as a reduction mechanism, and was supported by a bearing, which was a separate component.

[0003]

However, in the gear reducer described above, the output shaft protrudes from the speed reduction mechanism, and the output shaft needs to be supported by a bearing.
Since the axial length of the gear reducer cannot be reduced, it is difficult to reduce the size of the gear reducer. In addition, in order to take out the rotation of the output shaft, it is necessary to attach a gear, which is a separate component, to the output shaft, which makes it more difficult to reduce the size of the gear reducer and increases the number of parts, thereby increasing costs. I was Furthermore, it is difficult to use a rolling bearing as a bearing for the output shaft for downsizing and cost reduction. Therefore, a sliding bearing is used, but in consideration of the rotational resistance in this case, the output shaft is made thicker. In particular, it was difficult to secure a sufficiently large strength for a plastic output shaft.

[0004] It is an object of the present invention to provide a gear reducer which can be miniaturized, can be manufactured at low cost, and can sufficiently secure the strength as a member for transmitting rotational force.

[0005]

In order to achieve the above object, a gear reducer according to the present invention comprises an eccentric moving body, a plurality of detent shafts arranged side by side on the same circumference, An external gear having a plurality of guide holes through which the stop shafts respectively penetrate and performing a circular motion as a whole while biasing the respective guide holes around the respective detent shafts by the movement of the eccentric moving body; Are arranged concentrically with the circumference on which the gears are arranged, mesh with the external teeth of the external gear, and have a ring-shaped rotary output body formed with internal teeth having a different number of teeth. Is rotatably supported from the inside.

Therefore, when the eccentric moving body eccentrically moves, the external gear, which is prevented from rotating by the penetration of the plurality of detent shafts, eccentrically moves as a whole while biasing each guide hole around each detent shaft. Performs a circular motion around the center of motion of the body. The rotary output body is arranged concentrically with the circumference on which each rotation preventing shaft is arranged.Also, since the external teeth of the external gear mesh with the internal teeth of the rotary output body, the external gear is circular. When the exercise is performed, the engagement positions of the external teeth and the internal teeth move one after another. Since the number of teeth of the external teeth and the number of teeth of the internal teeth are different, the rotation output member rotates by the movement of the meshing position. That is, the rotation input to the gear reducer is output after being reduced in speed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail based on the best mode shown in the drawings.

FIGS. 1 and 2 show an embodiment of a gear reducer to which the present invention is applied. This gear reducer is incorporated in a small household electric appliance such as a CD player, and is directly attached to the small motor 6.

The gear reducer is an eccentric body 2 which is an eccentric moving body.
And a plurality of detent shafts 3 arranged side by side on the same circumference
Each of the detent shafts 3 has a plurality of guide holes 4a penetrating therethrough, and the eccentric body 2 rotates the eccentric body 2, that is, eccentrically moves the respective guide holes 4a around the respective detent shafts 3 to form a circular motion as a whole. And the outer gear 4 for performing the rotation, and the circumference around which the rotation preventing shafts 3 are arranged, are arranged concentrically,
The external gear 4 is provided with a ring-shaped rotary output body 5 having internal teeth 5a meshing with the external teeth 4b and having a different number of teeth. Here, the eccentric body 2, each rotation preventing shaft 3, the external gear 4, and the rotation output body 5 are formed of, for example, plastic.

The eccentric body 2 has a large diameter portion 2b and the large diameter portion 2b.
A small diameter portion 2c formed coaxially with b and a counterweight 2a formed on the opposite side of the eccentric direction of the large diameter portion 2b are formed integrally. This eccentric 2
Is fitted into the rotary input shaft 1 while the large diameter portion 2b is arranged on the small motor 6 side, and rotates integrally with the rotary input shaft 1 while being eccentric with respect to the rotary input shaft 1. In the case of the present embodiment, the axis serving as the rotation center of the eccentric body 2 is used as the rotation input means. However, the present invention is not particularly limited thereto. You may do it.

A plurality of rotation preventing shafts 3, preferably three or more, are provided. The detent shafts 3 are arranged side by side on the same circumference around the rotation input shaft 1. Each detent shaft 3 is fixed to the motor 6. In the case of the present embodiment, three anti-rotation shafts 3 are formed integrally with the base plate 7, and the base plate 7 is further screwed to the motor 6. The base plate 7 is a disk having substantially the same size as the front surface of the small motor 6, and the three detent shafts 3 are integrally formed at equal intervals on the same circumference. Further, mounting bosses 8 are integrally formed between the detent shafts 3 on the circumference of the base plate 7. The base plate 7 is arranged so that the center of the circumference coincides with the rotation input shaft 1, and is fixed to the front surface of the small motor 6 by screws 9 passing through each mounting boss 8.

The external gear 4 is fitted into the small diameter portion 2c of the eccentric body 2 with a roller 12 interposed. Therefore,
A space is generated between the external gear 4 and the base plate 7 so that the rotary output body 5 can be arranged. The external gear 4 has a guide hole 4a through which each detent shaft 3 passes,
The through holes 4c through which the mounting bosses 8 pass are alternately formed on the same circumference. Each guide hole 4a and each through hole 4c are formed to have substantially the same size. A roller 10 is attached to the detent shaft 3 that penetrates each guide hole 4 a, and the outer shape of the roller 10 is larger than the outer shape of the mounting boss 8. Therefore, the movement of the external gear 4 is limited to the range where each guide hole 4a is formed.
The external gear 4 is retained by a plate 13. The plate 13 is attached to the small motor 6 together with the base plate 7 by screws 9.

The rotary output body 5 is arranged in a space near the outer peripheral edge between the base plate 7 and the external gear 4 generated by fitting the external gear 4 into the small diameter portion 2c of the eccentric body 2. That is, the rotary output body 5 has a concave shape in which the inside is formed thin except for the vicinity of its outer peripheral edge, and the concave portion accommodates the external teeth 4b of the external gear 4 while facing the external teeth 4b. The internal teeth 5a are formed on the inner peripheral surface side. Internal teeth 5a
And the number of teeth of the external teeth 4b is not particularly limited,
In the case of the present embodiment, the number of internal teeth 5a is set slightly larger than the number of external teeth 4b. Since the number of these teeth and the difference in the number of teeth determine the reduction ratio, they are arbitrarily set as necessary. On the outer peripheral surface of the rotation output body 5, means for taking out the rotation of the rotation output body 5, ie, the output of the gear reducer, for example, external teeth 5b are formed. The rotation output body 5 is rotatably supported by three detent shafts 3. That is, the rollers 11 are respectively attached to the rotation preventing shafts 3 and rotatably support the rotation output body 5 from the inside. Each detent shaft 3 is a rotary input shaft 1.
Since they are arranged side by side on the same circumference centered on
The rotation output body 5 is arranged concentrically with the rotation input shaft 1.

In this gear reducer, the rotation of the rotation input shaft 1 is reduced and transmitted to the rotation output body 5 as follows.

When the small motor 6 rotates, that is, when the rotary input shaft 1 rotates, the eccentric body 2 rotates and performs eccentric movement. Since the eccentric body 2 is provided with the counterweight 2a, no large vibration or noise is generated even when the eccentric body 2 rotates at high speed. On the other hand, since the detent shaft 3 penetrates each guide hole 4a of the external gear 4, the external gear 4 can move only within a range where the guide holes 4a are formed. The external teeth 4 b of the external gear 4 mesh with the internal teeth 5 a of the rotary output shaft 5. Therefore, when the eccentric body 2 rotates, the external gear 4 does not rotate (rotate) together with the eccentric body 2, and each of the guide holes 4 a is biased around each of the detent shafts 3 while the rotation input shaft 1 as a whole. Perform a circular motion around. The state of this circular movement is shown in FIG.
To FIG.

When the external gear 4 makes a circular motion without rotating, the position where the external teeth 4b of the external gear 4 mesh with the internal teeth 5a of the internal gear moves. Then, the rotation output member 5 rotates by the movement of the meshing position. The rotary output body 5 is supported at three points, that is, supported by three anti-rotation shafts 3,
In addition, since the rollers 11 are provided between the rotation preventing shafts 3, the rollers 11 rotate smoothly with small rotational resistance.

The rotation output member 5 has external teeth 5b formed thereon, and the rotation of the external teeth 5b is taken out as an output of the reduction gear device. Therefore, a separate output shaft is not required to take out the output, and the entire gear reducer can be arranged within the range of the length of the output shaft of the small motor 6, as shown in FIG. In addition, this gear reducer eliminates the need for an output shaft and a bearing for supporting the output shaft, and also uses each detent shaft 3 for preventing rotation of the external gear 4 as a bearing for the rotation output body 5. Therefore, the number of components is reduced, and the manufacturing cost can be reduced. In addition, since the output of the gear reducer is taken out from the external teeth 5b of the rotation output body 5, by reducing the rotation speed, it is possible to sufficiently secure the strength as a transmission member that transmits the increased rotation torque. Further, since the external teeth 5b are formed in advance as a means for extracting the output of the gear reducer, it is possible to save the trouble of attaching a separate component such as a gear for extracting the output.

The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, in the above description, as the means for extracting the output of the gear reducer, the external teeth 5b are formed on the rotary output body 5 and gear transmission is used. However, the present invention is not necessarily limited to gear transmission. The transmission may be performed by a winding intermediate node such as a shaft or a chain, or may be transmitted by a hard intermediate node such as an arm or a link.

In the above description, the rollers 10 to 12 are mounted on the eccentric body 2 or the non-rotating shaft 3. However, instead of the rollers 10 to 12, rolling bearings such as ball bearings and needle bearings are used. May be.

In the above description, the non-rotating shaft 3 is
Although only the book is formed, the number of the rotation preventing shafts 3 is not limited to three, and it is needless to say that two or four or more can be formed.

Further, in the above description, the transmission of the rotational force between the external gear 4 and the rotary output body 5 is performed by the external teeth 4b and the internal teeth 5
Although the method is performed by meshing with a, the method is not necessarily limited to this method, and the rotational force may be transmitted by, for example, a frictional force or the like.

In the above description, the eccentric body 2 is eccentrically moved by rotating the rotary input shaft 1 since the gear reducer is directly attached to the small motor 6, but the eccentric body 2 is eccentrically moved. The structure is not limited to this, and the eccentric body 2 may be eccentrically moved by, for example, connecting a moving arm or link to the eccentric body 2.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the gear reducer having the structure shown in FIGS. 1 and 2, the number of internal teeth 5a was 90 and the number of external teeth 4b was 88. In this case, the number of teeth of the outer teeth 4b and the number of teeth of the inner teeth 5a are 88 and 90, respectively, and there is a difference between the two teeth. Therefore, the rotation output member 5 is rotated by the movement of the meshing position. Then, the rotation of the rotation input shaft 1 was reduced to a rotation speed of 1/45 by the planetary gear mechanism and transmitted to the rotation output body 5.

[0024]

As described above, in the gear reducer according to the present invention, the eccentric moving body, the plurality of detent shafts arranged side by side on the same circumference, and the respective detent shafts respectively penetrate. An external gear having a plurality of guide holes and performing a circular motion as a whole while biasing the respective guide holes around the respective detent shafts by the movement of the eccentric moving body, and a circumference on which the respective detent shafts are arranged And a ring-shaped rotary output body which is arranged concentrically with the external teeth of the external gear and is formed with internal teeth having a different number of teeth, and each detent shaft allows the rotary output body to rotate freely from the inside. Since it is configured to support, it is possible to use the components of the planetary gear mechanism that performs deceleration as components that take out rotation (rotation output body),
In addition, a non-rotating shaft that prevents rotation of the external gear can be used as a bearing of the rotation output body. For this reason, it is possible to reduce the size of the gear reducer and reduce the number of components, thereby reducing the manufacturing cost. Also,
Since the rotation output body can be formed large, it is possible to sufficiently secure the strength of the member transmitting the increased rotation torque by deceleration.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of an embodiment of a gear reducer according to the present invention, which is partially sectioned along the line II of FIG.

FIG. 2 is a plan view of the gear reducer of FIG. 1 with a plate removed.

FIG. 3 is a plan view showing a rotational relationship between an external gear and a rotary output body of the gear reducer of FIG. 1;

FIG. 4 is a plan view showing a state in which the eccentric body has rotated 90 degrees from the state of FIG. 3;

FIG. 5 is a plan view showing a state in which the eccentric body is rotated by 90 degrees from the state of FIG. 4;

FIG. 6 is a plan view showing a state in which the eccentric body is rotated 90 degrees from the state of FIG.

[Explanation of symbols]

 2 Eccentric body (eccentric moving body) 3 Non-rotating shaft 4 Drive gear as external gear 4a Guide hole 4b External tooth 5 Rotary output element 5a Internal tooth

Claims (1)

[Claims] An eccentric moving body, a plurality of detent shafts arranged side by side on the same circumference, and a plurality of guide holes through which each of the detent shafts penetrates, and the motion of the eccentric moving body. An external gear that performs a circular motion as a whole while biasing the respective guide holes around the respective detent shafts, and the external gear that is arranged concentrically with the circumference on which the respective detent shafts are arranged. A ring-shaped rotary output member having internal teeth having different numbers of teeth meshed with the external teeth of the gears, wherein each detent shaft rotatably supports the rotary output member from the inside. Decelerator.