JP3523247B2 - Inner revolution type differential gear reducer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear reducer that decelerates the rotation of an input shaft based on a difference in the number of teeth and transmits it to an output shaft. Two gears having different numbers of teeth and the two internal gears are provided. The present invention relates to an internal revolution type differential gear reducer composed of one external gear that meshes with the internal gear at the same time.

[0002]

2. Description of the Related Art For example, a speed reducer used for driving a control axis of a machine tool that receives a cutting load or a joint of an industrial robot has high speed, high load, large reduction ratio, high positioning accuracy, etc. The backlash is required to be small in order to improve the positioning accuracy.

As a conventional gear reducer for decelerating the rotation of the input shaft based on the difference in the number of teeth and transmitting it to the output shaft,
There is Jitsuhei 2-9151. This fact fair 2-91
A gear reducer such as No. 51 can obtain a reduction gear mechanism with a large reduction ratio with a small space and a small number of parts. It has two internal gears arranged opposite to each other and different in the number of teeth, and two internal gears. One external gear that meshes with the internal gear at the same time and a driving force from the driving means are input, and an input shaft having the center of the internal gear as a rotation shaft is provided, and the reduction ratio is obtained by the difference in the number of teeth. Further, the axial directions of the two internal gears and the external gear are made the same. Such a gear reducer is called an internal revolution type differential gear reducer or an eccentric differential reducer.

Further, JP-A-61-84438 and JP-A-6-109102 describe a method of eliminating backlash between an internal gear and an external gear. JP-A-61-8
No. 4438 discloses a method of eliminating backlash by shifting the center of the input shaft.
No. 2 has a tapered ring on the outer circumference of the internal gear, which is tightened with bolts to eliminate backlash with the mating gear.

[0005]

By the way, an internal revolution type differential gear reduction gear having one external gear that simultaneously meshes with two internal gears arranged opposite to each other, as in Japanese Utility Model Publication No. 2-9151. In a machine, adjusting the axial distance between these three is ideal for precisely adjusting the backlash. That is, the positional relationship between two internal gears having different numbers of teeth is the adjustment of the axial distance between each of the two internal gears and the external gear. In particular, regarding the axial distance between each of the latter two internal gears and the external gear, it is necessary to prevent deviation of the other axial distance when one axial distance is adjusted. In addition, if a gear reducer applied to precision equipment such as a servomotor is given an initial deformation in advance, even if a further force is applied, the amount of deformation due to that force is kept small in order to suppress it ( Preloading is usually performed. Considering only the effect of suppressing this initial deformation, the higher the preload, the higher the accuracy will be obtained, but on the other hand, if the preload is large,
Since it causes a decrease in efficiency and life, and causes heat generation, seizure, and abnormal wear.From these points, it is better that the preload is as small as possible. Set this to the gear reducer with the appropriate preload. That is, the quality of the preload setting affects the performance of the machine.

However, the above Japanese Utility Model Publication No. 2-9151 does not have a backlash adjusting mechanism for adjusting the axial distance between two internal gears. The main purpose of Japanese Utility Model Publication No. 2-9151 is a slip mechanism, and there is no mention of the need for a backlash adjusting mechanism. In addition, the first of the drawings of the conventional publications
As shown in the figure, since the drive shaft is supported on one side, the fixed gear shifts and cannot be used as an accurate positioning mechanism.

Japanese Unexamined Patent Publication No. 61-84438 discloses a method of eliminating backlash by shifting the center of the input shaft. In this method, however, the external gear must be made slightly larger in order to eliminate backlash. If the center of the internal gear and the center of the input shaft do not match, and if they do not match, backlash can be taken at only one rotational position, and backlash will increase on the opposite side. If the center of the input shaft is shifted (fixed by shifting the gear), it may shift during fixing or may shift due to some impact after fixing. In order to prevent of these is the rotation shaft (rotation center) of the rotary shaft and two internal gears of the input shaft is there must coaxially, the center of the input shaft of JP 61-84438 Therefore, the above problem occurs. In addition, the use of the elastically deformable thin-walled hull also has problems in torsional rigidity, strength, and durability of the thin-walled hull.

In Japanese Patent Laid-Open No. 6-109102, a tapered ring is arranged on the outer peripheral portion of an internal gear, and the ring is tightened with a bolt to eliminate backlash with a mating gear. It does not adjust the distance, nor does it describe the application of pressure.

Further, in the above-mentioned prior art publication, the shaft of the external gear is an eccentric shaft which is displaced from the center position of the input shaft, but as shown in FIG. It merely draws a trajectory that rotates at a position X2 which is eccentrically decentered from the axis X1 of the internal gears 4 and 5, and does not adjust the backlash by the eccentric shaft, nor does it serve as a pressurizing means. That is, in the above-mentioned conventional publication, the two internal gears 4 and 5 and the external gear 6 must be manufactured in advance in a highly accurate meshing state. For example, the size of the external gear 6 is extremely small. When manufactured, the axial distance between the external gear 6 and the two internal gears 4 and 5 cannot be adjusted in the first place.

Therefore, an object of the present invention is to adjust the two internal gears facing each other and having different numbers of teeth and one external gear in a direction to eliminate backlash, and to have meshing teeth between these gears. The object of the present invention is to provide an internal revolution type differential gear reducer which can apply a preload to its surface and therefore has extremely high positioning accuracy between two internal gears and an external gear.

[0011]

An internal revolution type differential gear reducer according to claim 1 of the present invention has two internal gears, an input internal gear and an output internal gear, which are opposed to each other and have different numbers of teeth. Internal gear of
The two internal gears are provided with one external gear that meshes with the two internal gears on the input side and the output side at the same time, and a shaft of the external gear attached to the input shaft to which the driving force from the drive means is input. In the internal revolution type differential gear reducer in which the axes of the two internal gears are on the same axis and the axial directions of the external gears are the same, one internal gear of the two internal gears has an outer diameter side. axially compressing means is structured to compress the internal gear from the outer periphery by fit fits into the fitting portion formed on the shaft of the outer gear, it is shifted to a position from the axial center c of the shaft It has an eccentric shaft whose center is b, and is rotatably attached to the input shaft, so that the shaft center a of the input shaft and the shaft b of the external gear are
It is characterized in that it has a structure in which the distance between axes can be adjusted .

According to the present invention, the position of one of the two internal gears is set as a reference position, and the other internal gear is axially attached to the fitting portion formed on the outer diameter side by the compression means. By fitting in the direction, the internal gear can be compressed from the outer periphery and adjusted in the direction to eliminate backlash. Moreover, the eccentric shaft axis of the external gear that is attached rotatably relative to the input shaft
Since it has, it is possible these by adjusting the axial distance between the two internal gear and the external gear. Therefore, the backlash adjustment of the two internal gears and the external gear is performed by the compression means, and the eccentric shaft, which is the shaft of the external gear, can be used as the pressurizing means for applying the external gear to the two internal gears. And vice versa. In the backlash adjustment, the clearance between the meshing portions of the two internal gears and the external gear is adjusted by the compression means, and then the clearance between the remaining meshing portions is adjusted by the eccentric structure of the shaft of the external gear. On the contrary, the gap between the meshing portions of the two internal gears and the external gear is adjusted by the eccentric structure of the shaft of the external gear, and then the gap between the remaining meshing portions is adjusted by the compression means. You can also

According to a second aspect of the present invention, there is provided a reduction gear transmission in which the internal gears on the input side and the internal gears on the output side are arranged to face each other and have different numbers of teeth.
Two internal gears of the vehicle, one external gear that meshes with these two internal gears on the input side and the output side at the same time, and an external gear shaft attached to the input shaft to which the driving force from the drive means is input. And the two internal gears and the external gear have the same axial direction,
In the internal revolution type differential gear reducer in which the shafts of the two internal gears are on the same axis, the two internal gears have axially compressing means in the fitting portions formed on their outer diameter sides. is structured to compress each of the internal gear from the outer periphery by fit fits, the axis of the outer gear has an eccentric shaft which displaced position from the axial center c of the shaft is the shaft center b, the input By being rotatably attached to the shaft, the shaft center of the input shaft
It is characterized in that it has a structure in which the distance between the shaft a and the shaft b of the external gear can be adjusted .

According to the present invention, the two internal gears compress the respective internal gears from the outer circumference by the axially fitting the compression means to the fitting portions formed on the respective outer diameter sides. By adjusting the backlash, the backlash between the two internal gears and between the two internal gears and the external gear can be adjusted respectively. The shaft of the external gear is because it has an eccentric shaft that rotatably attached to the input shaft; any of these by adjusting the axial distance between the two internal gear and the external gear. Therefore, the backlash adjustment of the two internal gears and the external gear is performed by the compression means, and the eccentric shaft, which is the shaft of the external gear, can be used as the pressurizing means for applying the external gear to the two internal gears. And vice versa. In the backlash adjustment, the clearance between the meshing portions of the two internal gears and the external gear is adjusted by the compression means, and then the clearance between the remaining meshing portions is adjusted by the eccentric structure of the shaft of the external gear. On the contrary, the gap between the meshing portions of the two internal gears and the external gear is adjusted by the eccentric structure of the shaft of the external gear, and then the gap between the remaining meshing portions is adjusted by the compression means. You can also

According to a third aspect of the present invention, there is provided an internal revolution type differential gear reducer, which is an input side internal gear having opposed teeth and different numbers of teeth.
And two of the internal gear of the internal gear of the output side, out with these input side
One external gear that meshes simultaneously with two internal gears on the force side ,
A shaft of an external gear attached to an input shaft to which the driving force from the drive means is input, and the axial directions of the two internal gears and the external gear are the same, and the shafts of the two internal gears are on the same axis. In an internal revolution type differential gear reducer, the shaft of the external gear is
A position where the axis of b is displaced from the axial center c is the axial center b.
Has a mandrel and is rotatably attached to the input shaft
Therefore, between the shaft center a of the input shaft and the shaft b of the external gear,
It is characterized by having a structure in which the distance can be adjusted .

According to the invention, the shaft of the external gear is
The eccentric shaft whose position deviated from the shaft center c is the shaft center b
Have and are rotatably attached to the input shaft.
Therefore, it is possible to adjust the axial distance between the two internal gears and the external gear.
it can. Backlash adjustment by eccentric shaft of this configuration
However, the eccentric shaft configured as
It can be used as a means for applying pressure to external gears.
It

[0017]

[0018]

[0019]

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

(First Embodiment) In the present embodiment, as shown in FIG. 1, two internal gears 4,
5, an external gear 6 that meshes with two internal gears 4 and 5 at the same time, and an input shaft 2 to which the driving force from the drive means M is input.
And an eccentric shaft 7, which is the shaft of the external gear 6, are provided as main members. A servomotor is used as the driving means M that applies a driving force to the input shaft 2.

The two internal gears 4 and 5 are cylindrical gears,
They are arranged facing each other and have different numbers of teeth. In this embodiment, when the driving force from the servomotor which is the driving means M is input, the input shaft 2 rotates and the left internal gear 5 in FIG. 1 rotates. The internal gear 4 on the right side in FIG. 1 is the fixed side, and the internal gear 5 on the left side in FIG. The output shaft 3 is a gear, and is directly attached to the left internal gear 5 in FIG. The two internal gears 4 and 5 and the external gear 6 have the same axial direction, and the rotation axis of the input shaft 2 and the two rotation centers of the internal gear 4 and the internal gear 5 are on the same axis. That is, the input shaft 2 rotates about the centers of the two internal gears 4 and 5. When the input shaft 2 is rotated by the driving force of the driving means M, the external gear 6 rotates so as to rotate while meshing with the two internal gears 4 and 5 at the same time. In the present embodiment, the difference in the number of teeth between the two internal gears 4 and 5 is 1, the number of gears of the internal gear 4 on the input side is small, and one external gear 6 and two internal gears 4 and 5 mesh with each other. The part (meshing tooth surface) 19 meshes. When the input shaft 2 makes one rotation, the internal gear 5 rotates by one tooth difference, so the reduction ratio is (1 / the number of teeth of the internal gear 5).
It is an internal revolution type differential gear reducer. Further, the diameter of the tooth portion of the external gear 6 is set to be more than half the diameter of the tooth portion of the two internal gears 4 and 5.

The internal gear 5 is supported by the main body (case) 1 via a bearing 13, and the outer ring of the bearing 13 has a bearing retainer 1
5, a bearing seal 15 is attached to the main body 1 and a dust seal 16 is attached to the bearing retainer 15 to cover dust entry and grease leakage. The input shaft 2 is supported by the main body 1 and the internal gear 5 via a ball bearing 8 and a ball bearing 12.

The external gear 6 is a cylindrical gear that meshes simultaneously with the two internal gears 4 and 5, and the two internal gears 4 and 5 and the external gear 6 have the same axial direction. The external gear 6 is a roller bearing 9
Is supported by the shaft 7 of the external gear via the shaft 7, and the shaft 7 of the external gear 6 is rotatably attached to the input shaft 2. The rotation of the shaft 7 of the external gear 6 can be stopped by a rotation stop screw 14. The teeth of the internal gears 4 and 5 and the external gear 6 use an involute tooth profile.
The dislocation coefficients of the respective gears (gears) are set so that the center distance between and is the same as the center distance between the internal gear 5 and the external gear 6 on the output side. For example, the dislocation coefficient of the internal gear 5 having a large number of 40 teeth is 0, the dislocation coefficient of the external gear 6 is 28 and the dislocation coefficient is 0, and the dislocation coefficient of the other internal gear 4 having a small number of teeth is 39.
Assuming that the dislocation coefficient is 0.6344 for one sheet, when the module is 1.5, the axial distance between both sets is 9 mm,
The condition of the internal revolution type differential gear reducer is met.

An eccentric shaft 7 is attached to the input shaft 2. As shown in FIG. 2, the eccentric shaft 7 has a cylindrical shape, and includes first eccentric shafts 7a and 7c connected to the input shaft 2,
The first eccentric shaft 7a and the second eccentric shaft 7b whose center b is a position displaced from the axial center c of the first eccentric shaft 7a.
Shaft center c of the shaft center (a) of the input shaft 2 and the first eccentric shaft 7a are different, by the axial center c of the shaft center c and 7c of 7a is the same position, is that the taking-called both, of these It is at a position deviated from the axis center c and the axis center b of the second eccentric shaft 7b. The first eccentric shaft 7a, 7c is to but rotatably mounted to the input shaft 2, (to a locked state) in which unstoppable Ru at a rotational position of a predetermined position in the detent screw 14 like Has become. The input shaft 2 has connection holes J1 and J2 in which the left and right sides of the eccentric shaft 7 and 7a and 7c are rotatably fitted.
Is formed in .

[0025]

A compression means 10A is arranged on the outer diameter side of the internal gear 4. The compression means 10A is a ring having a tapered portion, and by axially fitting with a tapered portion 10c formed on the outer diameter side of the input side internal gear 4, backlash of the two internal gears 4 and 5 is achieved. Adjust. A set screw 11 is used for axial fitting. Note that reference numeral 1
7 is a spacer. Here, the backlash of the input-side internal gear 4 having the tapered portion 10c on the outer diameter side of the input-side internal gear 4 is made slightly larger than the backlash of the output-side internal gear 5, and by the push screw 11. Compression means 1
OA is fitted to the tapered portion 10c in the axial direction. The compression means 10A is similarly arranged on the outer diameter side of the other inner gear 5, and the position of one inner gear 4 is used as a fixed reference position, and the fitting portion 10c formed on the outer diameter side of the inner gear 4 is fixed. The internal gear 5 may be compression-adjusted from the outer periphery by fitting in the axial direction.

When the present embodiment is actually used, first, one internal gear 4 having a backlash slightly larger than that of the other internal gear 5 is a tapered ring with a push screw 11. By pushing the compression means 10A in the axial direction, the compression is performed from the outer circumference, and the clearance of the meshing portion 19 is adjusted so that the backlash is approximately the same as the output side internal gear 5. This way, one side (input side)
In order to adjust the clearance of the meshing portion 19 by compressing the inner gear 4 of the above from the outer circumference and aligning the position of the other (output side) inner gear 5 with the fixed reference position, the gear ( Since there is no work of shifting and fixing the gears), there is no deviation during fixing or deviation due to some impact after fixing, and stable accuracy can be obtained.

Further, according to the present embodiment, the ring 10A having the tapered portion can have a structure in which both the inner diameter portion and the outer diameter portion are in close contact with the mating component, so the rigidity of the internal gears 4 and 5 is high. Since it is efficient and has high rigidity, it has the feature that the backlash caused by the elastic deformation being retained and not returning due to internal frictional force is small. Since the eccentric shaft 7 is connected to the input shaft 2 on both sides 7a and 7c, the eccentric shaft 7 has high rigidity and can rotate stably.

As described above, the compression means 1 is used so that the one internal gear 4 and the other internal gear 5 have the same backlash.
After adjusting by 0A, the preload is applied by the rotation of the shaft 7 of the external gear. That is, when the eccentric shaft 7 that supports the external gear 6 is rotated and fixed by the detent screw 14 to apply a preload, the preloads of the two internal gears 4 and 5 can be equalized. The magnitude of preload depends on the eccentric shaft 7 that supports the external gear 6.
It can be easily set by setting the rotation torque of.

By rotating the shaft 7 of the external gear 6 with respect to the input shaft 2, a preload is applied to the meshing tooth surface 19 of the internal gear 5 by a method of changing the axial distance between the external gear 6 and the internal gear 5. There is. The magnitude of the preload is set by the rotational torque applied to the shaft 7 of the external gear 6, and after setting the preload, the rotation stopper screw 1
At 4, the rotation of the external gear shaft 7 with respect to the input shaft 2 is stopped. In this way, the eccentric shaft 7, the orbital rotating at position X2 eccentric constant from the axis X1 of the second external gear 6 by the eccentric shaft 7b of the two internal gears 4,5 rather drawing (FIG. 9 reference).
Backlash adjustment will be described with reference to FIGS. 3 and 4.
Reference sign a is the center of the internal gears 4 and 5 and the shaft center of the input shaft 2, reference sign b is the center of the second eccentric shaft 7b, and reference sign c is the first eccentric shaft 7a, 7c. it is a center,
Before the rotation of the eccentric shaft 7 having these eccentric shaft portions is 3, more rotation of the eccentric shaft 7, Figure after adjusting the clearance of the meshing portion 19 is 4, the axial center a of the input shaft And the
2 distance from the axis b of the eccentric shaft, that is, the center of the input shaft 2.
The axial distance between the core a and the axial center b of the external gear 6 is adjusted. It can be adjusted in a direction to eliminate the backlash by moving the eccentric position.

According to the present embodiment, the compression means 10A and the eccentric shaft 7 having the second eccentric shaft 7b adjust the axial distance between the two internal gears 4 and 5 and the external gear 6 before the two. The backlash between the two internal gears 4 and 5 and the external gear 6 is adjusted, or the backlash between the two internal gears 4 and 5 and the external gear 6 is adjusted, and then the two internal gears 4 are , 5 and the external gear 6 can be adjusted, and various adjustments can be made. For this reason, if the axial distance between the two internal gears 4, 5 and the external gear 6 is adjusted by the eccentric shaft 7 after the backlash adjustment by the compression means 10A is performed, the external gear 6 becomes the two internal gears. It can be used as a pressurizing means for 4,5. Further, for example, even when the size of the external gear 6 is made as extremely small, while adjusting the center distance of the second two internal gears 4,5 and more eccentric shaft 7b of the external gear 6 Backlash can be adjusted.

Next, the cause of backlash will be considered. If all the displacement of the input shaft is converted into the displacement of the output shaft as it is, backlash does not occur in the reduction gear. However, the backlash causes are (1) due to the gap of the contact part and (2) due to the load. There are two types, one caused by elastic deformation, which gives a deviation to the displacement of the output shaft, which causes backlash.

When a load is applied to the device, the components of the device are elastically deformed, which causes a deviation in the displacement of the output shaft (the other internal gear 5 in this embodiment), and the backlash caused by the elastic deformation due to the load is caused. It becomes a factor. For this elastic deformation,
(2-1) The part that returns to the original when the load is removed, and (2-
2) There is a part where elastic deformation is held by the internal frictional force of the device and is not returned to the original state.

The backlash that returns to the original when the load applied to the output shaft (the other internal gear 5 in the present embodiment) from the driven side disappears in (2-1) above is a consideration of the load condition for the final positioning. The qualitative one is dealt with by the backlash compensation of the NC device or the case-by-case, but it is due to the gap of the contact part in the above (1) and the internal frictional force in the above (2-2). Therefore, the backlash caused by the elastic deformation being held and not returning to the original state is often left as an unstable factor in the positioning accuracy of the reduction gear because it is influenced by unpredictable frictional force. However, according to the present embodiment, the efficiency is high, the rigidity is high, and
The backlash can be adjusted not only by the compression means 10A but also by the eccentric shaft 7, and the backlash due to the elastic deformation not being restored due to the internal frictional force of (2-2) can be reduced. is there.

Next, adjustment of pressurization will be described with reference to FIG. Generally, when a force is gradually applied from the contact state, elastic deformation increases, but in the initial minute deformation, the force and the deformation amount are not proportional, and a small force often causes a large deformation. Therefore, if the initial deformation is given in advance with the force applied from the beginning, the amount of deformation due to that force can be suppressed to a small amount even if more force is applied. Is called preload.

In this embodiment, if the shaft (support shaft) 7 of the external gear 6 is further rotated after the backlash is eliminated by the compression means 10A, the two internal gears 4,
5 and the external gear 6 are pressed against each other to mesh with each other, and the tooth surface 1
Although a compressive stress is generated in 9, the internal revolution type differential gear reducer of the present embodiment can apply a preload as follows. Assuming that a preload is applied as shown in FIG. 5, F3
And F4 are also the reaction forces of F1 and F2, so F1 + F2 =
F3 + F4.

Since the torque required to rotate the shaft of the external gear is almost entirely due to the frictional force due to F3 and F4, the radius of the shaft of the external gear at the F3 and F4 portions is set to R3 and R4. If the coefficient of friction is μ and the torque required to rotate the shaft of the external gear is T, then T = μ (F3 ・ R3
+ F4 ・ R4). Further, R3 and R4 are not so much different, and if this value is set as R, T = μR
(F3 + F4). Since F1 + F2 = F3 + F4, this results in T = μR (F1 + F2). Since F1 + F2 can be known from the preload determined in advance, an appropriate μ
Given R and R, T can be determined. That is, by setting the torque T required to rotate the support shaft of the external gear 6, the proper preload can be easily set. A torque wrench or the like is used to set the torque T required to rotate the support shaft of the external gear 6.

(Application Example of First Embodiment) In this application example, the external shape is cylindrical, and the shaft 7 of the external gear 6 is an eccentric shaft 20 having a hollow portion 18a therein. Have. This will be described with reference to FIGS. 6 and 7.
The hollow portion 18a formed on the eccentric shaft 20 is formed to reduce the weight thereof and to absorb the load even when the eccentric shaft 20 is loaded. In the cylindrical outer shape, the left and right sides and the center have different diameters. That is, the right portion 20a in FIG. 7 of the eccentric shaft 20 has the smallest diameter, the central portion 20b has a larger diameter than this, and the left portion 20c in FIG. It is attached so that it can be rotated, but the rotation stop screw 14
It will be stopped in a certain position (locked).

[0039]

(Second Embodiment) In the present embodiment, as shown in FIG.
5 has compression means 10A and 10B, respectively. In the present embodiment, not only the internal gear 4 on the input side but also the internal gear 5 on the output side has a tapered fitting portion 10 provided on the outer diameter side.
It has a compression means 10B that fits in d. Compression means 10
B is axially fitted into the tapered fitting portion 10d to adjust the backlash of the internal gear 5 on the output side.

Therefore, both of these compression means 10A, 1
Since each of them has 0B, it is possible to adjust the positional relationship between the two internal gears 4 and 5 having different numbers of teeth, and the axial distance between the two internal gears 4 and 5 and the external gear 6 respectively. .

[0042]

According to the internal revolution type differential gear reducer of the first and second aspects of the present invention, one or both of the two internal gears facing each other and having different numbers of teeth. The internal gear can be adjusted by the compression means in the direction to eliminate backlash, and the shaft of the external gear has the first eccentric shaft and the second eccentric shaft and is rotatable. Thus, after the backlash is adjusted, it is possible to apply the pressurization by the external gear to the two internal gears by the eccentric shaft.

According to the internal revolution type differential gear reducer of the third aspect of the present invention , the internal gear is adjusted by adjusting the rotational position of the eccentric shaft.
And the distance between the external gear axis, backlash, preload, etc.
You can

[0044]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an inner-revolution type differential gear reducer according to a first embodiment of the present invention together with a motor.

FIG. 2 is a sectional view showing an eccentric shaft according to the first embodiment.

FIG. 3 is a view for explaining the adjustment in the direction in which the backlash is eliminated according to the first embodiment, and is a cross-sectional view of the gear portion at a right angle to the axis.

FIG. 4 is a view for explaining the adjustment in the direction in which the backlash is eliminated according to the first embodiment, and is a cross-sectional view of the gear portion at a right angle to the axis.

FIG. 5 is a cross-sectional view illustrating adjustment of pressurization application according to the first embodiment.

[6] The inner revolving type differential gear reducer in response tail example of the first embodiment the present invention is a cross-sectional view showing the motor.

FIG. 7 is a sectional view showing an eccentric shaft of an application example of the first embodiment.

FIG. 8 is a sectional view of an internal revolution type differential gear reducer according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram illustrating an eccentric state of a conventional external gear shaft.

[Explanation of symbols]

1 main body 2 input shaft 3 output shaft 4 internal gear 5 internal gear 6 external gear 7 , 20 external gear shaft (eccentric shaft) 7a , 7c first eccentric shaft, 7b second eccentric shaft, 8 ball bearing 9 bearing ( Rolling bearing) 10A, 10B Compressing means (tapered ring) 10c, 10d Fitting part (tapered part) 11 Push screw 12 Ball bearing 13 Bearing 14 Anti-rotation screw 16 Dust seal 19 Interlocking tooth surface (two internal gears and 1 20a is a small diameter portion of the eccentric shaft (first eccentric shaft) , 20b is a central portion of the eccentric shaft ( second eccentric shaft), and 20c is a large diameter portion of the eccentric shaft ( first portion). Eccentric shaft), a rotation center of the input shaft ( axial center of the input shaft), b second eccentric shaft (axial center of the second eccentric shaft), c first eccentric shaft (axial center of the external gear shaft) ), F1 Out from the output shaft side internal gear due to preload Force on gear F2 Force from fixed side internal gear to external gear due to preload F3 Reaction force of external gear shaft output shaft side support part by F1 and F2 Fixing external gear shaft by F1 and F2 Reaction force of side support

Claims (3)

(57) [Claims] 1. An input side which is arranged opposite to each other and has a different number of teeth
Two internal gears, a gear and an internal gear on the output side, and these input side
And one external gear that simultaneously meshes with the two internal gears on the output side, and an external gear shaft attached to the input shaft to which the driving force from the drive means is input, and two internal gears and an external gear In the internal revolution type differential gear reducer in which the axes of the two internal gears are on the same axis, one internal gear of the two internal gears is formed on the outer diameter side. compression means in the axial direction into the fitting portion is structured to compress the internal gear from the outer periphery by fit fits, the axis of the outer gear, and shifted from the axis <br/> center c of the shaft position Has an eccentric shaft whose center is b and is rotatably attached to the input shaft .
Adjust the distance between the shaft center a of the input shaft and the shaft b of the external gear.
An internal-revolution type differential gear reducer characterized by a structure that can be adjusted . 2. Among the input sides which are arranged facing each other and have different numbers of teeth
Two internal gears, a gear and an internal gear on the output side, and these input side
And one external gear that simultaneously meshes with the two internal gears on the output side, and an external gear shaft attached to the input shaft to which the driving force from the drive means is input, and two internal gears and an external gear In the internal revolution type differential gear reducer in which the axes of the two internal gears are the same, and the axes of the two internal gears are on the same axis, the two internal gears are fitting portions formed on the respective outer diameter sides. axially compressing means is constructed to compress the outer periphery of each of the internal gear by fit fits to the axis of the outer gear, position shifted from the shaft in <br/> heart c of the shaft axis It has an eccentric shaft that is the center b and is rotatably attached to the input shaft .
Adjust the distance between the shaft center a of the input shaft and the shaft b of the external gear.
An internal-revolution type differential gear reducer characterized by a structure that can be adjusted . 3. Among the input sides which are arranged facing each other and have different numbers of teeth
Two internal gears, a gear and an internal gear on the output side, and these input side
And one external gear that simultaneously meshes with the two internal gears on the output side, and an external gear shaft attached to the input shaft to which the driving force from the drive means is input, and two internal gears and an external gear In the internal revolution type differential gear reducer in which the axes of the two internal gears are on the same axis , the axis of the external gear is
Indicates that the position shifted from the axis center c of this axis is the axis center b.
It has an eccentric shaft that can be rotated with respect to the input shaft.
As a result, the shaft center a of the input shaft and the shaft b of the external gear are
An inner-revolution type differential gear reducer having a structure in which the shaft distance of the is adjustable .