JP2002276744A - Speed reducer and geared motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed reducer and geared motor having an output shaft with a high supporting rigidity and embodied in a compact and simple structure. SOLUTION: At the end 12A of an input shaft 12 on the side with output shaft 14, a hollow hole 18 open coaxially to the output shaft 14 is formed, and part of the output shaft 14 is inserted to the hole 18 and a first output shaft bearing 20 to bear the output shaft 14 is installed in the hole 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reduction gear and a geared motor used for industrial machines, transportation machines and the like.

[0002]

2. Description of the Related Art Conventionally, an input shaft 102, such as a speed reducer 100 shown in FIGS.
There is known a speed reducer including an output shaft 104 arranged coaxially with the motor, and a speed reduction mechanism 106 for reducing the rotation of the input shaft 102 at a predetermined reduction ratio and transmitting the rotation to the output shaft 104.

The speed reduction mechanism 106 is an eccentric oscillating type internally meshing planetary gear mechanism that is compact and can realize a large reduction ratio.

[0004]

Such a conventional speed reducer has a structure in which the load fluctuation and the output shaft 104 generated in the speed reduction mechanism 106 are reduced.
3 is supported by the pair of bearings 108A and 108B that support the output shaft 104. Therefore, in order to increase the stability of support, the X section in FIG. Was needed.

For this reason, there is a problem that the axial length of the speed reducer 100 becomes long as a result of the reduction mechanism 106 being compact.

On the other hand, Japanese Patent Publication No. 2761130 discloses
2. Description of the Related Art There is known a speed reducer having a structure shown in Japanese Patent Application Laid-Open (Kokai) No. H10-26095. In this reduction gear, the reduction in the axial direction is achieved by disposing a reduction mechanism between two bearings that support the output shaft. It was necessary to install a support ring between them, and it was a complicated structure.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a reduction gear having a high rigidity for supporting an output shaft, a compact and simple structure, and a geared motor provided with the reduction gear. Make it an issue.

[0008]

According to the present invention, there is provided an input shaft, an output shaft disposed coaxially with the input shaft, and transmission of the rotation of the input shaft to the output shaft while being reduced at a predetermined reduction ratio. A speed reduction mechanism comprising: a hollow hole that opens coaxially to the output shaft side at an end of the input shaft on the output shaft side; The above-mentioned problem is solved by inserting a part and arranging a bearing for supporting the output shaft in the hollow hole.

That is, a part of the output shaft is inserted into a hollow hole formed in the input shaft so as to be compact in the axial direction, and the output shaft is stably supported via the bearing and the input shaft installed in the hollow hole. It was done.

In a conventional speed reducer, the torque of the input shaft is amplified and transmitted to the output shaft. Therefore, the output shaft is generally thicker than the input shaft.

Therefore, paying attention to the difference in thickness between the two axes,
A structure in which a hollow hole is formed at the end of the output shaft on the input shaft side, the input shaft is inserted into the hollow hole, and a bearing that supports the input shaft is disposed in the hollow hole of the output shaft can also be considered.

However, in this structure, the connecting portion between the input shaft and the speed reduction mechanism is provided outside the hollow hole, that is, at a position axially separated from the output shaft, so that the speed reducer protrudes in the axial direction. The reduction gear cannot be made sufficiently compact.

According to the present invention, the idea is reversed, the input shaft formed thinner than the conventional output shaft is made thicker than the output shaft, and a hollow hole is formed in the input shaft, and the output shaft is formed in the hollow hole. Inserting the shaft solved this problem.

According to the present invention, the combination of the two shafts becomes compact in the axial direction, and the input shaft and the reduction mechanism can be connected radially outside the hollow hole, thereby realizing a compact reduction gear. can do.

In particular, if the tip of the output shaft in the hollow hole passes through the center of the speed reduction mechanism, the input shaft and the speed reduction mechanism can be connected radially outside the overlapping portion of the two shafts. , The output shaft and the speed reduction mechanism can be combined compactly in the axial direction.

Further, if the bearing in the hollow hole can be arranged on the input side of the speed reduction mechanism, and another bearing for supporting the output shaft is provided on the output side of the speed reduction mechanism, the output shaft can be formed. Thus, the speed reduction mechanism is supported at both ends, and the speed reduction mechanism can be stably supported.

In particular, if the bearing in the hollow hole and the bearing for supporting the input shaft from the outside are arranged so that at least a part thereof is located on the same plane perpendicular to the axial direction, the output shaft and the deceleration can be reduced. The support rigidity of the mechanism can be increased.

Since the input shaft is increased in thickness to increase the bending rigidity of the input shaft, the input shaft can be stably supported even if the input shaft is connected to the reduction mechanism in a cantilever state.
It is possible to provide a reduction gear that is more compact in the axial direction than supporting the input shaft on both sides in the axial direction of the reduction mechanism.

Further, the speed reduction mechanism includes a center portion that rotates together with the input shaft, a ring-shaped internal gear that is arranged coaxially with the input shaft and that is fixed and installed, and an internal gear that is mounted on the internal gear. An external gear that meshes with and engages with the center portion and swings by the rotation of the center portion; and engages with the external gear and synchronizes with the rotation component of the external gear. An eccentric oscillating internal meshing planetary gear mechanism including a carrier portion that rotates with the output shaft.

The inscribed planetary gear mechanism can realize a relatively large reduction ratio and is compact.

Further, since the (thick) input shaft rotates together with the center portion arranged closest to the input shaft, the connecting structure between the input shaft and the inscribed planetary gear mechanism has a high rigidity and a compact structure. be able to.

The reduction gear and the motor are combined, the motor shaft of the motor is integrated with the input shaft, and the input shaft side bearing of the motor shaft and the input shaft bearing are also used. A geared motor may be configured such that the shaft is used as the dual-purpose bearing and faces the inside of the reduction gear in a cantilever state.

By doing so, a compact geared motor having high support rigidity can be realized.

That is, the motor shaft generally requires high support rigidity, and is supported by two bearings. By integrating the input shaft with the motor shaft, the input shaft is stably supported with high rigidity.

Further, since the input shaft is thickened and has high bending rigidity as described above, the input shaft can be brought into the reduction gear in a cantilever state. Therefore, by using both the bearing on the input shaft side of the motor shaft and the bearing on the input shaft, a bearing for only the input shaft can be eliminated.

As a result, the motor shaft, the input shaft and the output shaft can be supported by a total of four bearings, two bearings supporting the output shaft and the input shaft, that is, two bearings supporting the motor shaft. Compared to a conventional geared motor requiring five to six or more bearings, a compact and low-cost geared motor can be realized.

[0027]

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

As shown in FIGS. 1 and 2, a speed reducer 10 according to an embodiment of the present invention includes an input shaft 12, an output shaft 14 coaxially arranged on the input shaft 12, and an output shaft 14. A speed reduction mechanism 16 that reduces the rotation of the input shaft 12 at a predetermined reduction ratio and transmits the rotation to the output shaft 14.

End 1 of input shaft 12 on output shaft 14 side
2A has a hollow hole 1 coaxially opened on the output shaft 14 side.
8 are formed. The hollow shaft 18 has an output shaft 14.
Are inserted, and a first output shaft bearing 20 for supporting the output shaft 14 is arranged.

Further, the speed reducer 10 is integrated with a motor 21 to form a geared motor 22. The geared motor 22 integrates the motor shaft 24 of the motor 21 with the input shaft 12 and also
The two-side bearing 26 is also used as the bearing of the input shaft 12, and the end 12 </ b> A of the input shaft 12 faces the reduction gear 10 in a cantilevered state from the first motor shaft bearing 26 that is also used as the dual shaft. The first motor shaft bearing 26 is a ball bearing, and a second motor shaft bearing 28 which is a ball bearing is also arranged at an end 24A of the motor shaft 24 integrated with the input shaft 12 on the opposite side to the end 12A. I have.

The input shaft 12 is rotatably supported at two points by the first motor shaft bearing 26 and the second motor shaft bearing 28, and its movement in the axial direction is restricted.

The hollow hole 18 is provided in the first motor shaft bearing 2.
6 is slightly extended to a position on the motor 21 side.

Output shaft 14 inserted in hollow hole 18
Is penetrated through the center of the speed reduction mechanism 16.

The first output shaft bearing 20 is a needle bearing and is disposed near the tip 14A.

The first output shaft bearing 20 and the first
Are disposed on the same plane perpendicular to the axial direction.

The output shaft 14 is a first output shaft bearing 2
Two points are supported by the 0 and second output shaft bearings 30, and the movement in the axial direction is restricted.

The second output shaft bearing 30 supports a central portion 14B of the output shaft 14 in the axial direction by a ball bearing.

An end 14C of the output shaft 14 on the side away from the input shaft 12 protrudes from the second output shaft bearing 30, and is freely connectable to an external device via a key 14D.

The speed reduction mechanism 16 includes a center portion 32 that rotates together with the input shaft 12, a ring-shaped internal gear 34 that is arranged coaxially with the input shaft 12 and that is fixed and installed, and an internal gear 34. An external gear 36 that meshes with the internal gear and engages with the center portion 32 and swings by the rotation of the center portion 32.
An eccentric oscillating type internally meshing planetary gear mechanism, comprising: a carrier portion 38 that engages with the external gear 36 and rotates together with the output shaft 14 in synchronization with the rotation component of the external gear 36. It has been.

The center portion 32 is a disk-shaped eccentric body, and is connected to the outer peripheral surface of the end portion 12A of the input shaft 12 via an eccentric center hole via a key 32A.

The internal gear 34 has a structure in which an outer pin 34B is fitted into a plurality of arc grooves formed on the inner peripheral surface of a ring-shaped member 34A, and these outer pins 34B form internal teeth.

The ring-shaped member 34A is the output side case member 4.
0 and the input side case member 42 are sandwiched from both sides in the axial direction and integrally fastened by bolts 44.

The output side case member 40 supports the second output shaft bearing 30, and the input side case member 42 supports the first motor shaft bearing 26.

The outer pins 34B are also supported by both case members from both sides in the axial direction and from the inside in the radial direction.

The external gear 36 has an external pin 34 at the external teeth.
B with the needle bearing 4 in the center hole.
6 and rotatably fitted to the center portion 32.

Thus, when the center portion 32 rotates, the external gear 36 is oscillated while meshing with the internal gear 34.

The external gear 36 is formed with a plurality of axial inner roller holes 36A at equal circumferential intervals.

An inner pin 48 covered with an axial inner roller 48A is inserted into each of the inner roller holes 36A. The inner diameter of the inner roller hole 36A is larger than the outer diameter of the inner roller 48A by twice the amount of eccentricity of the center portion 32.

As a result, of the oscillating rotation components of the external gear 36, the revolution component is not transmitted to the inner pin 48, and only the rotation component is transmitted to the inner pin 48.

The carrier 38 has a flange-like shape, is fitted to the inner pin 48 near the outer periphery, and is fitted to the output shaft 14 at the center hole. Thus, the carrier portion 38 and the output shaft 14 rotate in synchronization with the rotation component of the external gear 36. Also, the carrier part 38 and the output shaft 14
Is located between the first output shaft bearing 20 and the second output shaft bearing 30.

The motor 21 includes a rotor 21A supported by a motor shaft 24, a stator 21B disposed with a small gap outside the rotor 21A, and a
Cylindrical side cover 21 for supporting B on the inner peripheral surface
C and an end face cover 21D. The side cover 21C is fitted at one end in the axial direction with the input side case member 42, and the end face cover 21D is fitted at the opposite side to the input side case member 42 with the side cover 21C to close the side cover 21C.

The input side case member 42, the side cover 21C and the end cover 21D are integrally fastened by bolts 50.

The end cover 21D supports a second motor shaft bearing 28.

Reference numerals 52A and 52B in the drawing denote oil seals.
And 52B is filled with lubricating oil.

Next, the operation of the geared motor 22 will be described.

When the motor 21 is energized, the input shaft 12 integral with the motor shaft 24 rotates, and the center portion 32 of the reduction mechanism 16 rotates eccentrically with the input shaft 12.

As a result, the external gear 36 swings while meshing with the internal gear 34, and the carrier 38 and the output shaft 14 are connected to the input shaft 12 in synchronization with the rotation component of the external gear 36.
The rotation speed is reduced to a rotation speed lower than the rotation speed.

Although a radial load from an external device can be applied to the output shaft 14, the output shaft 14 is supported at two points by the first output shaft bearing 20 and the second output shaft bearing 30, so that the output shaft 14 is stable. Rotation can be maintained.

Since the output shaft 14 is inserted into the hollow hole 18 formed in the input shaft 12, the two shafts are compactly combined in the axial direction.

Further, the output shaft 1 inserted into the hollow hole 18
4 penetrates the center of the speed reduction mechanism 16, and the input shaft 1 extends radially outside the overlapping portion of the input shaft 12 and the output shaft 14.
2 and the speed reduction mechanism 16 are connected, so that the input shaft 1
2. The combination of the output shaft 14 and the reduction mechanism 16 is also compact in the axial direction. That is, the speed reducer 10 is compact in the axial direction.

The output shaft 14 supports the carrier portion 38 of the speed reduction mechanism 16 between the first output shaft bearing 20 and the second output shaft bearing 30 in a double-supported state. It supports with high rigidity.

Further, since the first output shaft bearing 20 and the first motor shaft bearing 26 in the hollow hole 18 are arranged on the same plane in the axial direction, the output supported by the first output shaft bearing 20 is provided. Shaft 14 and reduction mechanism 16
The supporting rigidity is further increased.

The output shaft 14 receives a rotational reaction force when driving an external device, and the rotational reaction force is transmitted from the output shaft 14 to the input shaft 12 via the speed reduction mechanism 16.

The end portion 12A of the input shaft 12 has a speed reduction mechanism 1
6, the radial load from the center portion 32 acts. Although the end portion 12A protrudes from the first motor shaft bearing 26 in a cantilever state, since the input shaft 12 is thicker than the output shaft 14 and has high bending rigidity, the end portion 12A is formed at the center portion 32. Can be stably supported.

The motor shaft 24 of the motor 21 and the input shaft 1
2 and a first motor shaft bearing 2
6, the input shaft 12 also serves as the bearing of the input shaft 12, and the input shaft 12 faces the reduction gear 10 in a cantilevered state from the first motor shaft bearing 26 which is also used as the input shaft 12. Therefore, the reduction gear 10 and the motor 21 are combined. The geared motor 22 has a simple structure and is compact.

That is, the motor shaft 24 is supported by the first and second two motor shaft bearings 26 and 28 and has high rigidity. By integrating the motor shaft 24 and the input shaft 12, the input shaft is 12 is stably supported with high rigidity.

As described above, the input shaft 12 is connected to the output shaft 14.
The input shaft 12 can be allowed to face the reduction gear 10 in a cantilevered state because the input shaft 12 is cantilevered, and the first motor shaft bearing 26
Also, the bearing for the input shaft 12 alone is not required.

Thus, the output shaft 14 is composed of two output shaft bearings 20 and 30 for supporting the output shaft 14 and the input shaft 12, that is, two motor shaft bearings 26 and 28 for supporting the motor shaft 24. , A geared motor 22 supporting the input shaft 12 and the motor shaft 24, and 5 to support the output shaft and the motor shaft.
Compared to a conventional geared motor requiring six or more bearings, a compact and low-cost geared motor has been realized.

In the example of the present embodiment, the speed reducer 10 is integrally combined with the motor 21 to form the geared motor 22, but the present invention is not limited to this. It may be configured as a speed reducer composed of:

In the example of the present embodiment, the hollow hole 1
8, the front end 14A of the output shaft 14 penetrates the center of the speed reduction mechanism 16, and the first output shaft bearing 20 and the first input shaft bearing 28 in the hollow hole 18 are flush with each other in the same vertical plane. Although arranged above, the present invention is not limited to this, and the tip 14A and the first output shaft bearing 20 and the first input shaft bearing 28 may be arranged to be shifted in the axial direction. .

Also in this case, in order to increase the support rigidity of the output shaft 14 and the like, the first output shaft bearing 20 and the first input shaft bearing 26 are placed on the same plane, a part of which is perpendicular to the axial direction. It is desirable to arrange them so as to overlap.

Further, in the example of the present embodiment, the eccentric oscillating type internally meshing planetary gear mechanism in which the center portion 32 eccentrically rotates is illustrated as a particularly preferable example of the reduction mechanism 16, but the present invention is not limited to this. For example, a reduction mechanism of a simple planetary gear mechanism may be used, and a reduction mechanism of a simple planetary roller mechanism may be used.

[0073]

As described above, according to the present invention,
An excellent effect is achieved in that a reduction gear and a geared motor having high support rigidity of the output shaft and a compact and simple structure can be realized.

[Brief description of the drawings]

FIG. 1 shows a reduction gear according to an embodiment of the present invention, and
Side sectional view showing the entire structure of a geared motor equipped with this speed reducer

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a side sectional view showing the entire structure of a conventional speed reducer.

FIG. 4 is a sectional view taken along the line IV-IV in FIG.

[Explanation of symbols]

 10, 100 speed reducer 12, 102 input shaft 14, 104 output shaft 14A tip 16, 106 speed reduction mechanism 18 hollow hole 20 first output shaft bearing 21 motor 22 geared motor 24 motor shaft 26 ... First input shaft bearing 32 ... Center part 34 ... Internal gear 36 ... External gear 38 ... Carrier part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 7/116 H02K 7/116 (72) Inventor Kazuyoshi Umeda 6-1, Asahimachi, Obu City, Aichi Prefecture Sumitomo Shigeto Machinery Co., Ltd. Nagoya Works (72) Inventor Masahiro Shimada 6-1, Asahimachi, Obu City, Aichi Prefecture Sumitomo Heavy Industries Machinery Co., Ltd. Nagoya Works F-term (reference) 3J017 AA10 CA01 3J027 FA36 FB01 FC04 GA10 GB03 GD03 GD08 GD12 GE25 3J063 AA01 AB15 AC01 BA03 BA04 BB41 CA01 CB04 CB05 CB06 CB41 CD02 3J101 AA02 AA14 AA24 AA42 AA52 AA62 AA72 AA82 AA83 BA77 FA15 FA53 FA55 GA24 GA31 GA41 5H607 AA00 AA12 BB19 BB33 CC03 DD03

Claims (5)

[Claims] An input shaft, an output shaft arranged coaxially with the input shaft, and a reduction mechanism for reducing the rotation of the input shaft at a predetermined reduction ratio and transmitting the rotation to the output shaft. In the speed reducer, at the end of the input shaft on the output shaft side, a hollow hole that is coaxially opened on the output shaft side is formed, and a part of the output shaft is inserted into the hollow hole, A speed reducer wherein a bearing for supporting the output shaft is arranged in the hole. 2. The reduction gear according to claim 1, wherein a tip of an output shaft in the hollow hole passes through a center of the reduction mechanism. 3. The bearing according to claim 1, wherein the bearing in the hollow hole and the bearing for supporting the input shaft are at least partially arranged on the same plane perpendicular to the axial direction. And reducer. 4. The speed reduction mechanism according to claim 1, wherein the speed reduction mechanism is a center part that rotates together with the input shaft, and a ring-shaped member that is arranged coaxially with the input shaft and fixedly installed. And the internal gear meshes with the internal gear,
And an external gear engaged with the center portion and oscillatingly rotated by the rotation of the input portion; and an external gear engaged with the external gear and synchronized with the rotation component of the external gear together with the output shaft. An eccentric oscillating type internally meshing planetary gear mechanism including a rotating carrier portion. 5. The motor according to claim 1, wherein the reduction gear is combined with a motor, and the motor shaft of the motor is integrated with the input shaft, and the input shaft side of the motor shaft is provided. A geared motor, wherein a bearing and an input shaft bearing are used in common, and the input shaft is also used as a cantilever in the speed reducer.