JPH06200988A - Reduction gear - Google Patents

Abstract

PURPOSE:To restrain generation of rotation sound of a carrier for supporting a planet gear, and improve durability of a planetary gear mechanism, in a reduction gear. CONSTITUTION:A pinion 17 combined with the output shaft 16 of a motor is engaged with a first spur gear 18. A first reduction gear 19 in one body with the first spur gear 18 is engaged with a second spur gear 22. A second reduction gear 28 in one body with the second spur gear 22 is engaged with a planet gear 29 supported with a carrier 30. The motor is combined with first, second, third cases 13, 14, 15, and an internal gear 32 provided in the third case 15 is engaged with the planet gear 29. An output gear 36 is integratedly provided on the carrier 30, and the carrier 30 is rotatably supported by a bearing hole openingly provided on the third case 15, a guide shaft 41 similarly provided on the third case 15, and a supporting body 37 projected from the side of the carrier 30 and having its extreme end in slidable contact with the back face 47 of the second case 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reduction gear having an output gear for transmitting rotational power to the outside.

[0002]

2. Description of the Related Art Conventionally, in order to reduce the size of a speed reducer, FIG.
A planetary gear speed reduction mechanism as shown in FIG. In the figure, the drive gear 3 is attached to the motor shaft 2 at the center of the small motor 1.
Is installed. A lower case 9 is arranged around the motor shaft 2, and the lower case 9 is fixed to the shoulder portion of the motor 1 with a screw (not shown). An upper case 9A is fixed to the upper end of the lower case 9.

A plurality of stages of carriers 4 are rotatably loaded in a lower case 9. Two or four support shafts 5 are provided on the lower side surface of each carrier 4 on a concentric circle at equal intervals. A planetary gear 6 is supported on each of the support shafts 5. The planetary gear 6 meshes with an internal gear 7 provided inside the lower case 9. An output shaft gear portion 8 is provided at the center of the rear side of the carrier 4, and the output shaft gear portion 8 meshes with the planetary gear 6 of the next stage.

According to the planetary gear reduction mechanism described above, the gear at the center serves as a driving force, and one set is set until the carrier 4 is rotated through the planetary gear 6, and when a large reduction ratio is required, this is set. It has a mechanism to stack sets in multiple stages. At the final stage of stacking this set, the output shaft 4A is arranged at the center of the carrier 4, and the output gear 10 is mounted on the output shaft 4A.

The planetary gear reduction mechanism described above is composed of a plurality of stages of carriers that hold a plurality of planetary gears rotated by drive gears, thereby reducing the load applied to the teeth.

[0006]

Also in the planetary gear speed reduction mechanism described above, the rotation speed of the gears stacked in multiple stages is faster on the input side, that is, closer to the first stage, and the higher the rotation speed of the gears, the greater the noise. There is a problem of becoming. In particular, there is a problem that the rotational sliding noise due to the high speed rotation of the carrier that supports the planetary gears becomes loud, which causes an increase in noise as a speed reducer. In addition, the output shaft located at the final stage of the reduction gear mechanism is unstable because it is supported by only one bearing, and if an external load is applied during use, the gear meshes with wear and the carrier slides and rotates. There was a problem such as causing abrasion of the part.

An object of the present invention is to provide a speed reducer that solves the above drawbacks.

[0008]

A speed reducer according to the present invention includes a first gear that is axially supported so as to mesh with an input gear that is connected to an input shaft, and a speed reducer that is provided coaxially with the first gear. A non-planetary gear reduction mechanism that includes a gear and a second gear that meshes with the reduction gear; a reduction gear that is coaxial with the second gear; a planetary gear that meshes with the reduction gear; A planetary gear speed reduction mechanism, which is rotatably supported coaxially with two gears, supports the planetary gears, and is constituted by a carrier having an output gear.

The non-planetary gear reduction mechanism and the planetary gear reduction mechanism are housed in a case coupled to a motor, and the shaft portion of the carrier is provided with a bearing hole provided in the case and the carrier shaft portion. It may be supported by a guide shaft inserted into the shaft hole.

The non-planetary gear reduction mechanism and the planetary gear reduction mechanism may be housed in a case coupled to a motor, the output gear may be provided in the case, and may be supported by a guide shaft inserted into a shaft hole of the output gear. .

[0011]

According to the above construction, the rotation output of the input shaft is transmitted to the output gear through the non-planetary gear reduction mechanism and the planetary gear reduction mechanism. In this configuration, since the non-planetary gear is arranged in the first stage of the reduction gear mechanism, the influence of the rotation sound of the carrier in the planetary gear mechanism is small. Further, since the carrier arranged in the subsequent stage of the speed reduction mechanism is supported by the plurality of bearings, it can be stably rotated and slid even if an external load is applied during use. Since the force applied to the gear teeth is not large at the first stage of the reduction gear mechanism, it is not necessary to use this first stage as a planetary gear mechanism to distribute the load with multiple planet gears. However, the load bearing capacity of the reduction mechanism does not decrease.

[0012]

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

As shown in FIG. 1, in the speed reducer according to the present embodiment, the first case 13 is fixed to the shoulder of the motor 11 with the fixing screw 12, and the second case is closed so as to close the opening of the first case 13. 14 is loaded, and the third case 15 is loaded with the opening edge abutting on the back side of the second case 14.
Each of the first, second, and third cases 13, 14 and 15 also serves as a bearing portion of the gear, and a plurality of spur gears or deviated gears (positions of gear shafts) are provided in an internal space closed by each case. A non-planetary gear that does not change) and a reduction gear mechanism including a planetary gear are stored.

In FIG. 1, a pinion 17, which is an input gear, is press-fitted and fixed to an output shaft 16 of a motor 11. A first spur gear 18 meshes with the pinion 17. A first reduction gear 19 is integrally provided on the back surface of the first spur gear 18, and a spindle 20 penetrates through the axes of the first spur gear 18 and the first reduction gear 19. 20 is supported by the first case 13 and the second case 14.
The first gear 18 and the first reduction gear 19 may be integrally formed with a shaft and supported by a shaft hole provided in the case.

Further, by making the inside of the first case 13 project, a supporting shaft portion 21 is provided at a position where the axis line is slightly deviated from the output shaft 16 of the motor 1, and the supporting shaft portion 21 is provided.
A second spur gear 22 is supported on the. The second spur gear 22 meshes with the first reduction gear 19. Then, the pinion 17 housed inside the first case 13 and the second case 14.
The first spur gear 18, the first reduction gear 19, and the second spur gear 22 meshing with each other constitute a non-planetary gear (non-planetary gear whose gear shaft position does not change) reduction mechanism 23.

A first shaft portion 24, a second shaft portion 25, and a third shaft portion 26 are integrally provided from the rear surface of the second spur gear 22 so as to project in a step-like manner so that the diameter becomes smaller toward the tip. The first shaft portion 24 is received in the shaft hole 27 formed in the second case 14. A second reduction gear 28 is integrally provided on the second shaft portion 25, and the second reduction gear 28 meshes with a planetary gear 29. The planetary gear 29 is supported by a support shaft 31 provided integrally with the carrier 30. An internal gear 32 is provided on the inner surface of the third case 15, and the planetary gear 29 also meshes with the internal gear 32.

As shown in FIG. 1, the carrier 30 has a large diameter portion 34 on the lower end side and a small diameter portion 35 on the upper end side via an intermediate shaft portion 33. The support shaft 31 supporting the planetary gear 29 is provided integrally with the lower surface of the large diameter portion 34 so as to project therefrom. An output gear 36 is integrally provided on the small diameter portion 35.

The carrier 30 has a disc shape when viewed from the axial direction, and as shown in FIG. 3, three planetary gears 29 are arranged at substantially equiangular intervals via three support shafts 31. Also,
As shown in FIGS. 1 and 3, a support 37 is provided between the planetary gears 29 and integrally with the carrier 30 to secure a space in the axial direction (regulate a gap). The support 37 contacts the back surface 47 of the second case 14 and rotates while sliding on the back surface 47. In addition, the shaft portion 33 of the carrier 30
The outer periphery of is rotatably supported in a bearing hole 38 formed in the third case 15. The support shaft 31 may be extended if it does not affect the planetary gear 29.
The gear 29 and the shaft may be integrally supported. Further, a shaft hole 39 is opened through the shaft portion 33 of the carrier 30 and the small diameter portion 35 on the upper side thereof, and a guide integrally provided on the inner surface of the tip portion 40 of the third case 15 is provided in the shaft hole 39. Axis 4
1 is inserted.

A guide hole 43 having a predetermined depth is formed in the guide shaft 41 from the tip thereof, and the third shaft portion 26 of the second spur gear 22 is inserted into the guide hole 42 and is rotatably supported. . The second reduction gear 28, the planetary gear 29, and the internal gear 32 housed in the third case 15 constitute a planetary gear reduction mechanism 42. A guide shaft may be provided upright along the shaft on the carrier 30 side, and a shaft hole may be provided on the case 40 side to support the guide shaft.

The first case 13 is integrally provided with an engaging arm 44, and the fixing claw 45 provided at the tip of the engaging arm 44 engages with the engaging step portion 46 of the third case 15. ing.
Therefore, the third case 15 is inserted through the fixing claw 45.
The second case 14 is sandwiched between the first case 13 and the first case 13, and the non-planetary gear reduction mechanism 23 and the planetary gear reduction mechanism 4 are provided inside each case.
While holding the two gears, the cases are fixed by snap fit.

Next, the operation of this embodiment will be described.

The rotation of the pinion 17 connected to the output shaft 16 of the motor 1 is transmitted to the first spur gear 18, the first reduction gear 19, and the second spur gear 22 with reduced speed. Second spur gear 22
Is transmitted to the planetary gear 29 supported by the carrier 30 via the second reduction gear 28. At this time, the planetary gears 29 are the internal gears 32 formed integrally with the third case 15.
A carrier 30 that is meshed with and supports the planetary gear 29 so as to freely revolve is a guide shaft 41, a bearing hole 38, and a support body 3.
It is supported and rotated at three positions of 7, and the decelerated rotation is output to the output gear 36.

According to this embodiment, the first stage of the speed reducer is constituted by the non-planetary gear (fixed shaft gear) speed reducing mechanism 23, and the planetary gear mechanism 42 including the carrier 30 is provided in the latter stage, so that FIG. It is possible to prevent the rotation noise of the carrier from being generated at the first stage in the planetary gear speed reduction mechanism as shown in FIG. Further, the carrier 30 and the output gear 36 are connected to the guide shaft 41.
Since it is rotatably supported at a plurality of points by the bearing hole 38 and the support body 37, it stably rotates against an external load,
It is possible to suppress wear of each rotating part of the planetary gear mechanism 42.

In addition to the embodiment shown in the drawing, the number of spur gears or planetary gears 29, the positions of the support members 37, and other configurations may be modified as necessary. . For example, the first and second spur gears 18 and 22 are shown as an example of non-planetary reduction gears, and helical gears may be incorporated as non-planetary reduction gears instead of the spur gears. Further, in order to reduce the overall height, it is also included in the present invention that the motor 11 is switched upside down and disposed so as to be fitted with the gear 18 from the right side of the drawing. By making the input gear 16 a worm gear, the position of the motor 11 can be designed more freely. Further, it goes without saying that various reduction gears can be obtained by combining a plurality of reduction gear mechanisms.

The following embodiments are still other embodiments.

In the present embodiment, the second-stage side is a so-called planetary type planetary gear mechanism, but the present invention is not limited to this and may be a so-called star type planetary gear mechanism. In this case, a shaft 31 is provided upright on the case 14 side, a gear is rotatably supported on the shaft 31, and the gear is meshed with the second reduction gear 28.

Next, the carrier 30 is expanded in the radial direction,
The shaft 31 extends downward and is provided with an internal gear 32.
To be engaged with a gear supported on the output tooth 3
The rotation is transmitted to 6.

[0028]

As described above, according to the speed reducer of the present invention, the non-planetary gear (fixed gear in which the gear shaft does not move) speed reducing mechanism is provided on the side of the first stage having a large number of rotations, and the rear stage having a small number of rotations. Since the planetary gear mechanism is provided on the side, the number of rotations of the carrier that rotatably supports the planetary gear can be reduced. Therefore, when the planetary gear mechanism is provided in the first stage or when all the reduction stages are planetary gear reducers, it is possible to suppress the generation of rotational noise of the carrier. Moreover, since the force applied to the gear teeth is not large at the first stage of the reduction gear mechanism, even if the non-planetary gear reduction mechanism is arranged at this first stage, the load bearing capacity of the entire reduction gear device does not decrease.

Since the carrier and the output gear, which rotate integrally with the revolution of the planetary gear, are supported at a plurality of points, the carrier and the output gear rotate stably against an external load, and the planetary reduction unit It has the effect of suppressing internal wear and improving durability.

[0030]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a speed reducer according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional explanatory view of a spur gear reduction mechanism in the device of FIG.

3 is a cross-sectional explanatory view of a planetary gear speed reduction mechanism in the device of FIG.

FIG. 4 is a sectional view of a conventional planetary gear speed reducer.

[Explanation of symbols]

11 ... Motor, 13 ... 1st case, 14 ... 2nd case,
15 ... Third case, 16 ... Output shaft, 17 ... Pinion, 1
8 ... 1st spur gear, 19 ... 1st reduction gear, 20 ... Spindle, 2
DESCRIPTION OF SYMBOLS 1 ... Support shaft part, 22 ... 2nd spur gear, 23 ... Non-planetary gear reduction mechanism, 24 ... 1st shaft part, 27 ... Shaft hole, 28 ... 2nd reduction gear, 29 ... Planetary gear, 30 ... Carrier, 31 … Spindle, 3
2 ... Internal gear, 33 ... Shaft part, 36 ... Output gear, 37 ... Support, 38 ... Bearing hole, 39 ... Shaft hole, 41 ... Guide shaft, 4
2 ... Planetary gear reduction mechanism.

Claims (1)

[Claims] 1. A first gear that is axially supported so as to mesh with an input gear that is coupled to an input shaft, a reduction gear that is coaxial with the first gear, and a reduction gear that meshes with the reduction gear. A non-planetary gear reduction mechanism that includes a second fixed shaft gear that is axially supported, a reduction gear that is provided coaxially with the second gear, a planetary gear that meshes with the reduction gear, and the second gear. And a planetary gear speed reduction mechanism that is rotatably supported on a coaxial line and that supports the planetary gears and that includes a carrier having an output gear.