JP2003097653A - Planetary gear unit and method for manufacturing the same, and method for setting teeth profile of planetary gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibrations and noise of a planetary gear unit while suppressing increase of manufacturing cost and change of gear ratio, strength and the like. SOLUTION: The planetary gear unit 7 has a plurality of planet gears 11, 13, 15, 17 arranged around a sun gear 9 at a central portion thereof, and an internal gear 19 arranged outside the planet gears 11, 13, 15, 17. Any of the number of teeth of the sun gear 9 and the internal gear 19 is a multiple of the number of the planet gears 11, 13, 15, 17, that is, four in this case. The planet gear 11 among these four planet gears 11, 13, 15, 17 has a different tooth flank shape from those of other planet gears 13, 15, 17. Concretely speaking, three planet gears 13, 15, 17 are helical gears having the helical angle from 10 deg. to 30 deg., while the planet gear 11 is modified so as to have a helical angle larger than that of the planet gears 13, 15, 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a plurality of planetary gears arranged around a sun gear arranged at the center and an internal gear arranged outside the planetary gears. The present invention relates to a planetary gear device in which the number of teeth of each gear is divisible by the number of planetary gears, a manufacturing method thereof, and a planetary gear tooth surface shape setting method.

[0002]

2. Description of the Related Art The number of teeth of a sun gear and the number of teeth of an internal gear are
In any planetary gear device that is divisible by the number of planetary gears, the timings at which the planetary gears mesh with the sun gear or the internal gear are the same in each planetary gear. For this reason, the impact generated at the time of meshing is increased by the number of planetary gears, and there is a problem that vibration and noise increase as a planetary gear device.

FIG. 14 shows the outline of the planetary gear device described above. Four planetary gears 3a, 3b, 3c, 3d are arranged around the sun gear 1 arranged at the center, and further outside thereof. The internal gear 5 is arranged. Figure 1
5 (a), (b), (c) and (d) are planetary gears 3
The meshing vibration displacements of a, 3b, 3c and 3d are shown respectively.

According to FIG. 15, each planetary gear 3a, 3b,
The meshing vibration displacements of 3c and 3d are almost the same, and the peaks thereof occur at the same time. By combining these four meshing vibration displacements, as shown in FIG. The maximum value of the amplitude of meshing vibration displacement (transmission error) becomes large.

In order to solve this, Japanese Unexamined Patent Publication No. 9-53690
The publication describes that the axial positions, tooth widths, tooth lengths, chamfering amounts, etc. of a plurality of planetary gears are sequentially changed. Further, in JP-A-6-10994, by adjusting the meshing phases of a plurality of planetary gears, the meshing phases of the respective planetary gears are shifted by meshing period / number of planetary gears (N), and the meshing ratio ε≈ 1+ (N-1) / N
What is said is described.

[0006]

However, in the former case, when the axial position is changed, the assembly work for axial positioning becomes complicated and the manufacturing cost increases, while the tooth width, tooth height, When the chamfering amount is changed in sequence, a large number of planetary gears with different tooth widths and other shapes coexist, resulting in an increase in specifications for rough material shapes, complicated part management, and changes in jig setup in the manufacturing process. Increases costs.

In the latter case, since the meshing points of the gears are limited, the gear specifications (the number of teeth, the helix angle) must be satisfied in order to satisfy the condition of the above formula by shifting the arrangement positions of the plurality of planetary gears. , The pressure angle, etc.) must be changed, and the gear ratio, strength, etc. change, so that there is a problem that a planetary gear device having the required specifications cannot be obtained.

Therefore, an object of the present invention is to reduce vibration and noise as a planetary gear device while suppressing an increase in manufacturing cost and suppressing changes in the gear ratio, strength and the like.

[0009]

In order to achieve the above-mentioned object, the invention of claim 1 is such that a plurality of planetary gears meshing with the sun gear are arranged around the sun gear arranged at the center, An internal gear that meshes with each planetary gear is arranged outside the plurality of planetary gears, and the number of teeth of the sun gear and the number of teeth of the internal gear are both divisible by the number of the planetary gears. At least one planetary gear of the plurality of planetary gears and another planetary gear have different tooth surface shapes so that meshing timings are different.

According to a second aspect of the present invention, in the configuration of the first aspect of the invention, at least one planetary gear has a tooth surface shape having a twist angle different from those of the other planetary gears.

According to a third aspect of the present invention, in the structure of the first aspect, at least one planetary gear includes a raised portion that is raised in the tooth thickness direction on one end side in the tooth width direction of one tooth surface, and the other one of the planetary gears is provided. The toothed surface is provided with a raised portion that is raised in the tooth width direction on the other end side, and the other planetary gear is provided with a raised portion that is raised in the tooth thickness direction on the other end side of the tooth width direction of the one tooth surface, and the other It is configured such that a raised portion that rises in the tooth thickness direction is provided on one end side of the tooth surface in the tooth width direction.

According to a fourth aspect of the present invention, in the configuration of the first aspect of the invention, at least one planetary gear has different tooth thicknesses on one end side and the other end side in the tooth width direction.

According to a fifth aspect of the present invention, in the structure of the first aspect of the invention, the tooth thickness is different between the one end side and the other end side in the tooth width direction, and the center line between both tooth surfaces is different. A plurality of planetary gears each having a tooth surface shape formed in line symmetry with respect to each other are alternately arranged along the circumference of the sun gear with both ends in the axial direction being opposite to each other, so that the tooth surface shapes are different. .

According to a sixth aspect of the present invention, in the configuration of the first aspect of the invention, at least one planetary gear is provided with a bulge portion that bulges in the tooth thickness direction on one end side in the tooth width direction on both tooth surfaces. .

According to a seventh aspect of the invention, in the structure of the third or sixth aspect of the invention, the raised portion is formed by changing the pressure angle along the tooth width direction.

According to an eighth aspect of the present invention, in the structure of the sixth or seventh aspect, a plurality of tooth surface-shaped planetary gears formed in line symmetry with respect to a center line between the both tooth surfaces are provided. Both ends in the direction are reversed to be alternately arranged along the circumference of the sun gear.

The invention of claim 9 relates to claims 1 to 4,
In the configuration of any one of the inventions 6 and 7, a plurality of N planetary gears are provided, N / 2 when N = even, (N-1) / 2 when N = odd, and others. For the planet gears of
The tooth surfaces have different shapes.

According to a tenth aspect of the invention, in the structure of the ninth aspect, the planetary gears having different tooth surface shapes are alternately arranged along the circumference of the sun gear.

The invention of claim 11 relates to claims 3, 6, 7 and
In the configuration of any one of 8th aspect of the invention, the planetary gears are helical gears.

According to a twelfth aspect of the present invention, a plurality of planetary gears that mesh with the sun gears are arranged around the sun gear that is arranged at the center, and the planetary gears mesh with the outer sides of the plurality of planetary gears. In a method for manufacturing a planetary gear device in which an internal gear is arranged, and the number of teeth of the sun gear and the number of teeth of the internal gear are both divisible by the number of the planetary gears, a plurality of N planetary gears are provided, and N = When the number is even, N / 2 is used, and when N = odd, (N-1) / 2 is used. Is a method for manufacturing a planetary gear device in which different planetary gears are alternately arranged along the circumference of the sun gear.

According to a thirteenth aspect of the present invention, in the structure of the twelfth aspect, the plurality of planetary gears are provided with tooth flank shapes which are formed in line symmetry with respect to a center line between both tooth flanks. A method of manufacturing a planetary gear device in which a plurality of planetary gears are alternately arranged along the circumference of a sun gear with both ends in the axial direction being opposite to each other, and the tooth surface shapes are different between the alternately arranged planetary gears. There is.

According to a fourteenth aspect of the present invention, a plurality of planetary gears meshing with the sun gear are arranged around the sun gear arranged at the center, and the planetary gears mesh with the outer sides of the plurality of planetary gears. An internal gear is arranged, and the number of teeth of the sun gear and the number of teeth of the internal gear are both divisible by the number of the planet gears. Along with calculating the meshing vibrational displacement with and calculating the meshing vibrational displacement between the planetary gear and the internal gear, adding each of these vibrational displacements to each other and comparing this added value with a predetermined target value, When the added value is larger than the target value, at least one planetary gear of the plurality of planetary gears is set to have a different meshing timing with respect to the other planetary gears. There as a planetary gear tooth surface shape setting process of the planetary gear device to vary the surface shape.

[0023]

According to the first aspect of the present invention, at least one planetary gear among the plurality of planetary gears has different tooth surface shapes so that the meshing timings thereof are different from those of the other planetary gears. The meshing state of the gear and the sun gear and the meshing state of the planetary gear and the internal gear will be different between the planetary gears with different tooth surface shapes, which will increase the manufacturing cost and change the tooth ratio, strength, etc. While suppressing the above, the meshing fluctuations of the planetary gears are canceled by each other and the vibration and noise can be reduced in the entire planetary gear device.

According to the second aspect of the present invention, at least one planetary gear among the plurality of planetary gears has a twist angle different from those of the other planetary gears, so that the meshing state between the planetary gear and the sun gear and The meshing state of the planetary gear and the internal gear will be different between the planetary gears having different tooth surface shapes, which will increase the manufacturing cost and suppress changes in the gear ratio, strength, etc. The meshing fluctuations of the planetary gears cancel each other out, and vibration and noise can be reduced.

According to the invention of claim 3, at least one planetary gear is provided with a raised portion that is raised in the tooth thickness direction on one end side in the tooth width direction of one tooth surface, and in the tooth width direction of the other tooth surface. The end portion is provided with a raised portion that is raised in the tooth thickness direction, and the other planetary gear is provided with a raised portion that is raised in the tooth thickness direction on the other end side in the tooth width direction of one tooth surface,
Since the one tooth width direction one side of the other tooth surface is provided with a raised portion that bulges in the tooth thickness direction, the meshing state of the planetary gear and the sun gear and the meshing state of the planetary gear and the internal gear are Different planetary gears will differ from each other, suppressing increase in manufacturing cost and changes in tooth ratio, strength, etc., while the planetary gear system as a whole cancels out meshing fluctuations of each planetary gear, thereby reducing vibration and noise. Can be lowered.

According to the invention of claim 4, the at least one planetary gear has a tooth thickness different between one end side and the other end side in the tooth width direction, so that the planetary gear and the sun gear mesh with each other. And, the meshing state of the planetary gear and the internal gear is
It will be different between planetary gears with different tooth surface shapes,
While suppressing an increase in manufacturing cost and changes in the gear ratio, the strength, and the like, the meshing fluctuations of the planetary gears are canceled by each other in the entire planetary gear device, and vibration and noise can be reduced.

According to the fifth aspect of the present invention, the tooth thickness is different between the one end side and the other end side in the tooth width direction, and the tooth is formed line-symmetrically with respect to the center line between the tooth surfaces. Since a plurality of surface-shaped planetary gears are arranged alternately with both ends in the axial direction reversed, even if they are planetary gears with different tooth surface shapes in the assembled state, the processing can be the same shape, processing cost While suppressing the, the meshing state of the planetary gear and the sun gear, and the meshing state of the planetary gear and the internal gear will be different between each planetary gear, increase in manufacturing cost and the tooth number ratio,
While suppressing changes in strength, etc.,
The meshing fluctuations of the planetary gears cancel each other out, and vibration and noise can be further reduced.

According to the sixth aspect of the present invention, at least one planetary gear of the plurality of planetary gears is provided with a bulge portion that is bulged in the tooth thickness direction on one end side in the tooth width direction on both tooth surfaces. And the engagement state of the sun gear and the engagement state of the planetary gear and the internal gear will be different between each planetary gear, resulting in an increase in manufacturing cost and
While suppressing changes in the gear ratio, strength, etc., the planetary gear device as a whole cancels out the meshing fluctuations of the planetary gears,
Vibration and noise can be reduced.

According to the invention of claim 7, the raised portion can be easily formed by changing the pressure angle along the tooth width direction.

According to the eighth aspect of the invention, a plurality of planetary gears having tooth flanks which are formed line-symmetrically with respect to the center line between the tooth flanks are arranged so that both ends in the axial direction are opposite to each other, and the sun gears are opposite to each other. Since they are alternately arranged along the circumference of the planetary gear, even if the planetary gears have different shapes in the assembled state, the machining can be done in the same shape, and while reducing the machining cost, the meshing state of the planetary gears and the sun gear and The meshing state of the planetary gears and the internal gears will be different between the planetary gears, suppressing the increase in manufacturing cost and changes in the tooth ratio, strength, etc. The meshing fluctuations of the gears cancel each other out, and vibration and noise can be further reduced.

According to the invention of claim 9, since the number of planetary gears having different tooth surface shapes is substantially the same, it is possible to further reduce the vibration and noise of the entire planetary gear device.

According to the tenth aspect of the present invention, the planetary gear device is configured by alternately arranging the planetary gears having different tooth surface shapes along the circumference of the sun gear. Therefore, the planetary gear device is configured. Vibration and noise as a whole can be reduced more reliably.

According to the invention of claim 11, the planetary gear is
By configuring with helical gears, the tooth surface shape changes along the meshing direction, resulting in good tooth contact in the meshing direction, and planetary gears, sun gears, internal gears, etc. Thus, even if the positional relationship is changed, the change in tooth contact is reduced, the meshing fluctuations of the planetary gears are canceled by each other, and vibration and noise can be reduced.

According to the twelfth aspect of the invention, the two types of planetary gears having different tooth surface shapes are made to have substantially the same number by changing the meshing timing, and the two types of planetary gears having different tooth surface shapes are connected to the sun. By alternately arranging along the circumference of the gear, it is possible to further reduce the vibration and noise of the entire planetary gear device.

According to the thirteenth aspect of the present invention, since the plurality of planetary gears may be arranged around the sun gear by alternately changing the axial direction, it is possible to mount the planetary gears without sacrificing productivity. Even if the planetary gears have different shapes in the state, the machining is the same shape, and while reducing the processing cost, the meshing state of the planetary gear and the sun gear and the meshing state of the planetary gear and the internal gear are This is different from the planetary gears, and while suppressing increase in manufacturing cost and changes in the gear ratio, strength, etc., the meshing fluctuations of each planetary gear are canceled by the planetary gear device as a whole, and vibration and noise are reduced. It can be further lowered.

According to the fourteenth aspect of the present invention, in setting the tooth surface shape of the planetary gear, it is not necessary to carry out trial and error in a trial experiment, and the planetary gear device is reduced while reducing the cost and time for setting. Overall vibration and noise can be reduced.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. As shown in FIG. 1A, the planetary gear unit 7 has
Similar to the conventional example, four planetary gears 11, 13, 1 are arranged at equal intervals in the circumferential direction around the sun gear 9 arranged at the center.
5 and 17 are respectively arranged and mesh with the sun gear 9,
Further, an internal gear 19 is disposed around the planetary gear 1
It meshes with 1, 13, 15, and 17. Planetary gear 1
1, 13, 15, 17 are connected to each other by a carrier (not shown) and are rotatable with respect to this carrier.

It should be noted that the planetary gear unit 7 here uses a helical gear formed by an involute curve, and the number of teeth of the sun gear 9 and the number of teeth of the internal gear 19 are both the planetary gear 11 described above. , 13, 15, 17 (4 in this case).

Table 1 shows specific gear specifications of the planetary gear unit 7 described above. That is, module: 1.23, tooth right angle pressure angle: 20 °, helix angle 23.3 °, tooth width: 1
6.5 mm, distance between center of sun gear and center of planet gear: 48.2 mm, number of teeth of sun gear: 44, number of teeth of planet gear: 28, number of teeth of internal gear: 100, number of planet gears:
It is 4.

[0041]

[Table 1] 1B shows the tooth surface shape of the planetary gear 11, and FIG.
(C) shows the tooth surface shape of the planetary gears 13, 15, and 17. The arrows in FIGS. 1B and 1C indicate the meshing direction, in which the left side indicates the meshing start and the right side indicates the meshing end. The three planetary gears 13, 15, and 17 shown in FIG. 1C are helical gears having a helix angle of about 10 to 30 ° (in Table 1, 23.3 °). On the other hand, the planetary gear 11 is the planetary gear 1
The twist angle is different for 3, 15, and 17. That is, one planetary gear 11 and the other planetary gears 13, 1
The tooth surface shapes are different so that the meshing timings of the gear teeth 5 and 17 are different.

The tooth flank shape shown by the chain double-dashed line in FIG. 1 (b) is the same as the tooth flank shape in FIG. 1 (c). Planetary gear 11
For the planetary gears 13, 15, 17 is 0.5 μ per unit tooth width (1 mm) for both tooth flanks L, R.
It has been modified to be larger.

Thus, the planetary gear 11 is replaced by the planetary gear 1
By making the tooth surface shape different for 3, 15 and 17,
The planet gears 11 and the planet gears 13, 15 and 17 have different meshing states with respect to the sun gear 9 and the internal gear 19.

As a result, the planetary gear unit 7 as a whole is
The meshing fluctuations between the planetary gear 11 and the planetary gears 13, 15, and 17 cancel each other out, and vibration and noise are reduced. In this case, the tooth surface shape of one planetary gear 11 is simply made different from that of the other three planetary gears 13, 15 and 17, so that the specification of the rough material shape is increased, the parts management becomes complicated, and the machining process becomes difficult. It is possible to suppress an increase in manufacturing cost, such as a change in jig setup, and to suppress changes in the gear ratio, strength, and the like, and it is possible to obtain a planetary gear device having required specifications.

FIG. 2 shows the planetary gears 11, 13, 15, 17
Shows the meshing vibration displacement of. (A) is the planetary gear 1
Nos. 1 and (b), (c), and (d) are planetary gears 13, 15, and 17, respectively. Planetary gears 13, 1
The meshing fluctuations of 5, 5 are the same as each other, but the planetary gear 11 is different from the planetary gears 13, 15, 17. These four planetary gears 11, 13, 15, 17
FIG. 3 is a combination of the meshing vibration displacements of FIG. According to this, it can be seen that the transmission error (the maximum value of the amplitude of meshing vibration displacement) of the planetary gear device 7 as a whole is reduced as compared with the conventional one shown in FIG.

In the above embodiment, one planetary gear 11 has different tooth surface shapes with respect to the other three planetary gears 13, 15 and 17, but for example, two planetary gears 1
The tooth surface shapes of 1 and 13 may be different from those of the other two planetary gears 15 and 17. In this case, the planetary gears 11, 13, 15, 17 having different tooth surface shapes are alternately arranged,
That is, by alternately arranging the planetary gears 11 → 15 → 13 → 17 along the periphery of the sun gear 9, vibration and noise can be further reduced.

FIG. 4 shows the tooth flank shape of the planetary gear according to the second embodiment of the present invention. The second embodiment is applied to a planetary gear device 7 having the same basic configuration as that shown in FIG. FIG. 4A shows the planetary gears 11, 1.
5 shows the tooth flank shape of FIG. 5, and FIG.
2 shows the tooth surface shape. The arrow in the figure indicates the meshing direction. In the figure, the left side is the meshing start and the right side is the meshing end.

The tooth surface shapes of the two planetary gears 11 and 15 shown in FIG. 4A are the same as those shown in FIG. 1B. That is, the planetary gears 11 and 15 are the same as those shown in FIG.
To the tooth surface shape of the planetary gears 13, 15, 17 shown in
The twist angle is corrected so that both tooth flanks L and R are increased by 0.5 μm per unit tooth width (1 mm). On the other hand, the two planetary gears 13 and 17 of FIG. 4B have a helix angle of both tooth surfaces L with respect to the tooth surface shape of the planetary gears 13, 15 and 17 shown in FIG. 1C. , R are unit tooth width (1
(mm) is corrected to be 0.5 μm smaller.
The shape indicated by the two-dot chain line in FIGS. 4 (a) and 4 (b) is
It is the same as the tooth surface shape of FIG.

FIG. 5 shows the planetary gears 11, 13, 15, 17
Shows the meshing vibration displacement of. (A) and (c) are for planetary gears 11 and 15, and (b) and (d) are for planetary gears 13 and 17. The meshing fluctuations of the planetary gears 11 and 15 are the same, the meshing fluctuations of the planetary gears 13 and 17 are the same, and the meshing fluctuations of the planetary gears 11 and 15 and the planetary gears 13 and 17 are different from each other. FIG. 6 is a combination of the meshing vibration displacements of these four planetary gears 11, 13, 15, and 17. According to this, it is understood that the transmission error (the maximum value of the amplitude of meshing vibration displacement) of the planetary gear device 7 as a whole is further reduced as compared with that shown in FIG. 3 according to the first embodiment. .

As described above, the planetary gears 11 and 15 having a large helix angle and the planetary gears 13 having a small helix angle,
By alternately arranging 17 and 17 along the circumference of the sun gear 9, it is possible to further reduce vibration and noise as compared with the first embodiment.

FIG. 7 shows the tooth flank shape of the planetary gear according to the third embodiment of the present invention. The third embodiment is applied to a planetary gear device 7 having the same basic configuration as that shown in FIG. FIG. 7A shows the planetary gears 11, 1.
5 shows the tooth flank shape of FIG. 5, and FIG.
2 shows the tooth surface shape. The arrow in the figure indicates the meshing direction. The left side in the figure is the meshing start side that is one side in the width direction, and the right side is the meshing end side that is the other side in the tooth width direction.

The tooth flanks of the two planetary gears 11 and 15 in FIG. 7 (a) form a raised portion A that rises in the tooth thickness direction on one tooth flank L at the meshing start side on the left side in the figure. I am doing it. As for the other tooth surface R, a raised portion B that rises in the tooth thickness direction is formed on the engagement end side on the right side in the drawing.

Another two planetary gears 1 shown in FIG. 7B.
The tooth surface shapes 3 and 17 form a raised portion A that rises in the tooth thickness direction on the right end of the meshing side in the drawing for one tooth surface L. For the other tooth surface R,
A bulging portion B bulging in the tooth thickness direction is formed at the meshing start side on the left side in the drawing.

As described above, between the planetary gears 11 and 15 and the planetary gears 13 and 17, the formation portions of the raised portions A and B are made different from each other to have different tooth surface shapes, and the planetary gear 1
By alternately arranging 1, 15 and the planetary gears 13, 17 along the periphery of the sun gear 9, the same effect as that of the second embodiment can be obtained.

Further, in the above-described third embodiment, the formation of the raised portions A and B causes a change in the tooth surface shape in the meshing direction indicated by the arrow, so that tooth contact is improved and vibration and noise are increased. Will be further reduced.

The heights of the raised portions A and B are gradually reduced as shown by contour lines along the circumference from the highest vertex portion. Such a height change is achieved by modifying the pressure angle. Specifically, the pressure angle correction amount of one tooth surface L in FIG. 7A is 10 μm tooth tip up at the end on the left side of the meshing start side in the figure, and 5 μm tooth tip up at the center in the tooth width direction. In the figure, 0 μm is set at the end portion on the right side where the meshing ends.
The pressure angle correction amount of the other tooth surface R in FIG. 7A is 0 μm at the end on the left meshing start side in the figure, 5 μm at the center in the tooth width direction, and the end of meshing on the right side in the figure. At the side end, the tooth tip is raised by 10 μm.

Further, the pressure angle correction amount of one tooth surface L in FIG. 7B is 0 μm at the end on the left side of the meshing start side in the figure, and 5 μm at the center in the tooth width direction. At the end on the right side of the end of meshing, the tip of the tooth is raised by 10 μm. The pressure angle correction amount of the other tooth surface R in FIG. 7B is 10 μm tooth tip up at the left meshing start side end in the figure, and 5 μm tooth tip up at the center in the tooth width direction,
In the figure, the end portion on the right-hand side where the meshing ends is 0 μm.

FIG. 8 shows the tooth flank shape of the planetary gear according to the fourth embodiment of the present invention. The fourth embodiment is applied to a planetary gear device 7 having the same basic configuration as that shown in FIG. FIG. 8A shows the planetary gears 11, 1.
5 shows the tooth flank shape of FIG. 5, and FIG.
2 shows the tooth surface shape. The arrow in the figure indicates the meshing direction. In the figure, the left side is the meshing start and the right side is the meshing end.

The tooth surface shapes of the two planetary gears 11 and 15 in FIG. 8A and the two planetary gears 13 and 1 in FIG. 8B are shown.
The tooth flank shape of 7 is on the left side which is one end side in the figure,
The tooth thickness is different on the right side which is the other end side.

Specifically, the planetary gears 11 shown in FIG.
15 is the planetary gears 13, 15, shown in FIG.
With respect to the tooth surface shape of 17, the helix angle was corrected to be 0.5 μm larger per unit tooth width (1 mm) for the tooth surface R, and 0.5 μm per unit tooth width (1 mm) for the tooth surface L. It has been modified to be smaller. As a result, in FIG. 8A, the tooth thickness on the left side is small and the tooth thickness on the right side is large. The tooth flank shape is such that both tooth flanks L, R
Are symmetrically formed with respect to the center line S between them.

Further, the planetary gears 13 and 17 shown in FIG.
Is the planetary gears 13, 15, 17 shown in FIG.
With respect to the tooth surface shape of No. 1, the helix angle was corrected so that the tooth surface R was smaller by 0.5 μm per unit tooth width (1 mm), and the tooth surface L was less than 0.
It is corrected to be 5 μm larger. As a result, FIG.
In (b), the tooth thickness on the left side is large, and the tooth thickness on the right side is small. The tooth surface shape is formed line-symmetrically with respect to the center line S between the tooth surfaces L and R.

Therefore, the planetary gears 11 and 15 shown in FIG. 8A and the planetary gears 13 and 17 shown in FIG.
Means that the left and right are simply reversed and the shapes are the same, and when the planetary gear device is assembled, the assembling directions may be reversed with respect to the axial direction. Therefore, according to the above-described fourth embodiment, the same effect as that of the second embodiment shown in FIG. 4 can be obtained, and it is sufficient to prepare one type of planetary gear, which reduces the processing cost. It can be small.

FIG. 9 shows the tooth surface shape of the planetary gear according to the fifth embodiment of the present invention. The fifth embodiment is applied to a planetary gear device 7 having the same basic configuration as that shown in FIG. FIG. 9A shows the planetary gears 11, 1.
5 shows the tooth flank shape of FIG. 5, and FIG.
2 shows the tooth surface shape. The arrow in the figure indicates the meshing direction. In the figure, the left side is the meshing start and the right side is the meshing end.

The tooth flank shapes of the two planetary gears 11 and 15 in FIG. 9A are such that the tooth flanks L and R are raised in the tooth thickness direction at the meshing start side, which is the one end on the left side in the figure. The parts A and B are formed. On the other hand, the tooth flank shapes of the two planetary gears 13 and 17 in FIG. 9B are the raised portions that bulge in the tooth thickness direction at the meshing end side that is the other end side on the right side in the figure for both tooth flanks L and R. A and B are formed.

The tooth flank shapes of the planetary gears 11 and 15 and the planetary gears 13 and 17 are both line-symmetric with respect to the center line S between the tooth flanks L and R. Therefore, the planetary gears 11 and 15 shown in FIG.
The planetary gears 13 and 17 shown in (b) are the same as those in FIG. 8 except that the left and right sides in the figure are reversed, and the shapes are the same. The attaching directions may be opposite to each other at both ends in the axial direction. Therefore, according to the fifth embodiment described above, the same effect as that of the third embodiment shown in FIG. 7 can be obtained, and it is sufficient to prepare one type of planetary gear, which reduces the processing cost. Complete.

The above-mentioned raised portions A and B are shown in FIG.
Similar to that in, the height is gradually reduced as shown by the contour lines along the circumference from its highest apex, and such a height change is achieved by modifying the pressure angle. To be done.

Specifically, in FIG. 9 (a), the pressure angle correction amount of both tooth flanks L and R is 10 μm tooth tip up at the end on the left side of meshing side in the figure, and at the center in the tooth width direction. 5μ
The number of teeth is increased by m, and 0 μm is set at the end on the right side of the meshing end side in the drawing. Both tooth flanks L, R in FIG. 9 (b)
The amount of pressure angle correction is 0 μm at the end on the left side of meshing in the figure, 5 μm tip up at the center in the tooth width direction, and 10 μm tip up at the end on the right side in the figure. .

FIG. 10 shows the transmission torque (Nm) on the sun gear.
And the transmission error (μm) are compared between the conventional example and the present invention according to the first to fifth embodiments. According to this, it can be seen that the transmission error of the present invention is smaller than that of the conventional one.

According to the data shown in FIG. 10, the transmission error in the second to fifth embodiments is smaller than that in the first embodiment in the range where the transmission torque is in the vicinity of 30 to 40 Nm. (First embodiment) and FIG. 6 (second embodiment) correspond to the transmission error in this range.

In each of the embodiments shown in FIGS. 4, 7, 8 and 9, it is not always necessary to alternately arrange the planetary gears having different tooth surface shapes, and the planetary gears having different tooth surface shapes are required. It is also possible that one is different from the other, instead of two.

FIG. 11 is a manufacturing process diagram of the planetary gear device 7 using the planetary gears 11, 13, 15, and 17 having the tooth surface shape of FIG. 8 or 9. First, as a planetary gear machining step, a rough material is turned, gear cutting is performed, and then shaving is performed. In this shaving process, as shown in FIG.
Finish to form the tooth flank shape. Then heat treated,
The inner diameter and the end surface are ground, and as a result, the planetary gears 11, 1
3,15,17 are completed. The process up to this point is the planetary gear machining process. The following is the planetary gear device assembly process.

Four completed planetary gears 11, 13, 1
Reference numerals 5 and 17 have the left and right reversed in FIG. 8 or 9 and are alternately arranged to prepare for loading into the assembly line. A carrier is put into the assembly line, and for this carrier,
The planetary gears 11, 13, 15, and 17 are assembled clockwise in the order of planetary gears 11 → 15 → 13 → 17. further,
The shaft is inserted into and fixed to the planetary gears 11, 13, 15, and 17, and finally the sun gear 9 and the internal gear 19 are assembled, whereby the planetary gear device 7 is completed.

According to the above-described method for manufacturing the planetary gears, the four planetary gears 11, 13, 15, 17 may be arranged around the sun gear by simply changing their axial directions alternately. Without sacrificing the above, and even if the planetary gears have different shapes in the assembled state, they can be machined in the same shape. Therefore, while suppressing the processing cost, the planetary gear device 7 as a whole can reduce vibration and noise. It can be further lowered.

FIG. 12 is a flow chart showing a method for setting the tooth surface shape of the planetary gear used in the planetary gear device 7 described above, and FIG. 13 is a block diagram of a device for carrying out the setting method. Here, the planetary gears in the embodiment of FIG. 7 will be described.

First, the input device 2 including a keyboard and the like.
The gear specifications and the transmission torque are input from step 1 (step S1), and the tooth surface shapes of the sun gear, the planetary gear, and the internal gear are input as an initial value = 0 μm (twist angle correction amount) (step S3), and A target transmission error is input (step S5). Each of these input values is stored in the auxiliary storage device 23.

Next, the CPU 25 calculates the meshing vibration displacement of the sun gear 9 and the planetary gears 11, 13, 15, 17 before the tooth surface shape is changed (step S7), and at the same time, calculates the tooth surface shape. The CPU 25 calculates the meshing vibration displacement between the planetary gears 11, 13, 15, 17 and the internal gear 19 in the state before being changed (step S9).

The calculation of these vibration displacements is performed by solving the following equation (Mechanical Society Paper 43, No. 371 (Sho 52-7), P2771, Kubo, Umezawa "Study on Load Transfer Characteristics of Cylindrical Gears with Errors") reference).

∫K _b (x, ζ) · P (ζ) d ζ + K _c (x) · P (x) = {Δ−e (x)} cosβ _g W _j = ∫P (ζ) d ζ W = ΣW _j cos β _g where K _b : tooth bending shear compliance K _c : tooth contact compliance P: distributed load on the tooth contact line Δ: meshing vibration displacement e: tooth surface shape β _g : base circle helix angle W : Transmission load x, ζ: Seat on tooth surface The meshing vibration displacements calculated in steps S7 and S9 are superimposed and added by the CPU 25 (step S11). Then, the processes of steps S7 to S11 are repeated for the number of planet gears. As a result, the maximum amplitude value (transmission error) of the meshing vibration displacement of the planetary gear device 7 is obtained (step S13). The CPU 25 compares the obtained transmission error (output result) with the target transmission error stored in the auxiliary storage device 23 (step S15).

Here, when the output result is less than the target transmission error and noise and vibration do not pose a problem for the planetary gear device, the fact is output to the output device 27 such as a display or a printer to inform the operator. , The process ends. On the contrary, when it is determined that the output result exceeds the target transmission error and the noise and vibration are large as the planetary gear device, the fact that the tooth surface shape is changed is output to the above-mentioned output device 27 to notify the operator. .

To change the tooth surface shape, half of the total number of planetary gears (here, since the total number of planetary gears is four, two) is used so that the tooth surface shape shown in FIG.
The shaving process shown in the first process step is performed (step S17). If the number of planet gears is odd,
About half of the planet gears (the number of planet gears-1), the tooth surface shape as shown in FIG. 7A is changed. Next, the remaining planetary gears are subjected to the shaving process shown in the process step of FIG. 11 so as to have the tooth surface shape as shown in FIG. 7B which is the reverse of the above (step S19).

According to the above-described method for setting the tooth flank shape of the planetary gear, when setting the tooth flank shape of the planetary gears 11, 13, 15, 17, it is not necessary to carry out trial and error in a trial experiment, and the setting is made. It is possible to reduce the vibration and noise of the entire planetary gear device 7 while reducing the cost and time.

Although the planetary gear unit 7 uses helical gears, it may be spur gears.

[Brief description of drawings]

FIG. 1 shows a first embodiment of the present invention,
(A) is a front view showing the overall configuration of the planetary gear device, (b)
3A is an explanatory view showing a tooth surface shape of one planetary gear in the planetary gear apparatus of FIG. 3A, and FIG. 3C is an explanatory view showing tooth surface shapes of other three planetary gears in the planetary gear apparatus of FIG. .

FIG. 2 is a meshing vibration displacement characteristic diagram with respect to a meshing cycle of a planetary gear in the planetary gear device of FIG.

FIG. 3 is a mesh vibration displacement characteristic diagram in which the mesh vibration displacements of FIG. 2 are combined.

FIG. 4 shows a second embodiment of the present invention,
(A) is explanatory drawing which shows the tooth surface shape of two planetary gears in a planetary gear device, (b) is explanatory drawing which shows the tooth surface shape of other two planetary gears.

5 is a meshing vibration displacement characteristic diagram with respect to the meshing cycle of the planetary gears in the planetary gear device of FIG.

6 is a mesh vibration displacement characteristic diagram in which the mesh vibration displacements of FIG. 5 are combined.

FIG. 7 shows a third embodiment of the present invention,
(A) is explanatory drawing which shows the tooth surface shape of two planetary gears in a planetary gear device, (b) is explanatory drawing which shows the tooth surface shape of other two planetary gears.

FIG. 8 shows a fourth embodiment of the present invention,
(A) is explanatory drawing which shows the tooth surface shape of two planetary gears in a planetary gear device, (b) is explanatory drawing which shows the tooth surface shape of other two planetary gears.

FIG. 9 shows a fifth embodiment of the present invention,
(A) is explanatory drawing which shows the tooth surface shape of two planetary gears in a planetary gear device, (b) is explanatory drawing which shows the tooth surface shape of other two planetary gears.

FIG. 10 is a transmission error characteristic diagram showing the relationship between the transmission torque on the sun gear and the transmission error in comparison between the conventional example and the present invention according to the first to fifth embodiments.

FIG. 11 is a manufacturing process diagram of a planetary gear device using a planetary gear having the tooth surface shape of FIG. 8 or 9;

12 is a flow chart showing a tooth surface shape setting method of a planetary gear used in the planetary gear device in the embodiment of FIG.

FIG. 13 is a block diagram of an apparatus for implementing the setting method of FIG.

FIG. 14 is a front view showing the overall configuration of a planetary gear device according to a conventional example.

15 is a meshing vibration displacement characteristic diagram with respect to the meshing cycle of the planetary gears in the planetary gear device of FIG.

16 is a mesh vibration displacement characteristic diagram in which the mesh vibration displacements of FIG. 15 are combined.

[Explanation of symbols]

7 Planetary gear unit 9 sun gears 11, 13, 15, 17 Planetary gears 19 Internal gear L, R tooth surface A, B heap section

Claims (14)

[Claims] 1. A plurality of planetary gears meshing with the sun gear are arranged around a centrally arranged sun gear, and an inner gear meshing with each planetary gear is arranged outside the plurality of planetary gears. In the planetary gear device in which the number of teeth of the sun gear and the number of teeth of the internal gear are both divisible by the number of the planet gears, at least one planet gear among the plurality of planet gears and another planet gear A planetary gear device having different tooth surface shapes so that meshing timings are different between them. 2. The planetary gear device according to claim 1, wherein at least one planetary gear has a tooth surface shape having a twist angle different from those of the other planetary gears. 3. At least one planetary gear is provided with a raised portion that bulges in the tooth thickness direction on one end side in the tooth width direction of one tooth surface, and in the tooth thickness direction on the other end side in the tooth width direction of the other tooth surface. The other planetary gear is provided with a raised portion that is raised in the tooth width direction on the other end side in the tooth width direction of one tooth surface, and in the tooth thickness direction on the other end side of the other tooth surface in the tooth width direction. The planetary gear device according to claim 1, further comprising a rising portion. 4. The planetary gear device according to claim 1, wherein at least one planetary gear has different tooth thicknesses on one end side and the other end side in the tooth width direction. 5. A plurality of tooth surface shapes formed to be line-symmetrical with respect to a center line between both tooth surfaces while having different tooth thicknesses on one end side and the other end side in the tooth width direction. The planetary gears,
2. The planetary gear device according to claim 1, wherein both ends in the axial direction are opposite to each other and are alternately arranged along the periphery of the sun gear to have different tooth surface shapes. 6. The planetary gear device according to claim 1, wherein at least one planetary gear has a bulge portion that bulges in the tooth thickness direction on one end side in the tooth width direction on both tooth surfaces. 7. The planetary gear device according to claim 3, wherein the raised portion is formed by changing the pressure angle along the tooth width direction. 8. A plurality of tooth-shaped planetary gears formed line-symmetrically with respect to a center line between both tooth surfaces are alternately arranged along the circumference of the sun gear with their axial ends opposite to each other. The planetary gear device according to claim 6, wherein the planetary gear device is arranged. 9. A plurality of N planetary gears are provided, N / 2 when N = even and (N-1) / 2 when N = odd.
The planetary gear device according to any one of claims 1 to 4, 6 and 7, wherein each tooth has a tooth surface shape different from that of the other planetary gears. 10. The planetary gear device according to claim 9, wherein the planetary gears having different tooth surface shapes are alternately arranged along the circumference of the sun gear. 11. The planetary gear device according to claim 3, 6, or 7, wherein the planetary gear is a helical gear. 12. A plurality of planetary gears meshing with the sun gears are arranged around the sun gear arranged at the center, and inner gears meshing with the respective planetary gears are arranged outside the plurality of planetary gears. In a method for manufacturing a planetary gear device in which the number of teeth of the sun gear and the number of teeth of the internal gear are both divisible by the number of planet gears, a plurality of N planet gears are provided, and N is an even number. / 2 pieces
When N is an odd number, (N-1) / 2 pieces are made to have different tooth surface shapes with respect to other planet gears so that the meshing timings are different, and the planet gears having different tooth surface shapes are arranged around the sun gear. A method for manufacturing a planetary gear device, which is characterized in that it is manufactured by alternately arranging the planetary gears. 13. A plurality of planetary gears are provided with tooth flanks formed line-symmetrically with respect to a center line between both tooth flanks, and the plurality of planetary gears have axial ends opposite to each other. The method for manufacturing a planetary gear device according to claim 12, wherein the planetary gears are alternately arranged along the periphery of the sun gear, and the tooth surface shapes are different between the alternately arranged planetary gears. 14. A plurality of planetary gears meshing with the sun gears are arranged around a centrally arranged sun gear, and inner gears meshing with the planetary gears are arranged outside the plurality of planetary gears. The number of teeth of the sun gear and the number of teeth of the internal gear are both divisible by the number of the planet gears, in a planetary gear tooth surface shape setting method of a planetary gear device, a meshing vibration displacement between the sun gear and the planetary gears. Together with calculating the meshing vibrational displacement of the planetary gear and the internal gear, adding each of these vibrational displacements and comparing the added value with a predetermined target value, and the added value is the target value. When it is larger than the value, at least one planet gear among the plurality of planet gears,
A planetary gear tooth surface shape setting method for a planetary gear device, wherein the tooth surface shape is made different from that of another planetary gear so that the meshing timing is different.