JPH0650395A - Inscribed meshing type planetary gear structure - Google Patents

Abstract

PURPOSE:To improve rigidity and stability, reduce the whole length, reduce the number of parts items and the manhours of assembly and improve the lubricity of an inner pin, as for an inscribed meshing type planetary gear structure equipped with a carrier pin (carrier body). CONSTITUTION:The flange part 114 of an output shaft 102, carrier pin 116, and a supporting ring 117 are twin-lever-supported by bearings 115a and 115b, and a reduction gear part is arranged between the bearings 115a and 115b. A spacer 125 is fitted onto the carrier pin 116, and the positioning in the axial direction of the flange part 114, carrier pin 116, and the supporting ring 117 is carried out through the spacer 125. Further, at both the edges of an inner pin 107, projection parts 129a and 129b are formed, and since the projection parts 129a and 129b intrude inside the grease holding parts 130a and 130b and revolve relatively for the flange part 114 and the supporting ring 117, lubrication can be secured favourably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internally meshing planetary gear structure suitable for application to a speed reducer or speed increaser, and more particularly to a speed reducer or speed increaser that is small and requires high output. .

[0002]

2. Description of the Related Art Conventionally, a first shaft, an external gear mounted via an eccentric body provided on the first shaft so as to be eccentrically rotatable with respect to the first shaft, and the external gear. There is widely known an internally meshing planetary gear structure including an internally toothed gear that internally meshes with a second shaft that is connected to the externally toothed gear via a means that transmits only the rotation component of the externally toothed gear. Has been.

A conventional example of this structure is shown in FIGS. 9 and 10. In this conventional example, the first shaft is used as an input shaft and the second shaft is used as an output shaft, and the internal gear is fixed, and the above structure is applied to a "speed reducer".

A predetermined phase difference (18 in this example) is applied to the input shaft 1.
The eccentric bodies 3a and 3b are fitted with each other at 0 °. The eccentric bodies 3a and 3b are integrated. Two external gears 5a, 5b are attached to the respective eccentric bodies 3a, 3b via bearings 4a, 4b. This external gear 5
A plurality of inner roller holes 6 are provided in a and 5b, and the inner pin 7
And the inner roller 8 is fitted.

Two external gears (double row) are used.
This is mainly for the purpose of increasing transmission capacity, maintaining strength, and maintaining rotational balance.

External teeth 9 having a trochoidal tooth profile, an arc tooth profile or the like are provided on the outer circumferences of the external gears 5a and 5b. The external teeth 9 are internally meshed with the internal gear 10 fixed to the casing 12. Specifically, the internal teeth of the internal gear 10 have a structure in which the outer pin 11 is loosely fitted in the outer pin hole 13 so that it can be easily rotated.

The inner pin 7 penetrating the external gears 5a, 5b is fixed or fitted into the flange portion 14 of the output shaft 2.

When the input shaft 1 makes one revolution, the eccentric bodies 3a, 3b
Rotates once. By one rotation of the eccentric bodies 3a and 3b,
The external gears 5a, 5b also try to oscillate around the input shaft 1, but their rotation is constrained by the internal gear 10, so the external gears 5a, 5b are Almost only rocking is performed while touching.

Now, for example, when the number of teeth of the external gears 5a and 5b is N and the number of teeth of the internal gear 10 is N + 1, the difference in the number of teeth is 1. Therefore, the external gears 5a and 5b are connected to the internal gear 1 fixed to the casing 12 for each rotation of the input shaft 1.
It is shifted (rotated) by one tooth with respect to 0.
This means that one rotation of the input shaft 1 is reduced to -1 / N rotation of the external gear.

The rotation component of the external gears 5a and 5b is absorbed by the gap between the inner roller hole 6 and the inner pin 7, and only the rotation component is transmitted to the output shaft 2 through the inner pin 7. It

Here, the inner roller holes 6a and 6b and the inner pin 7 (inner roller 8) form a "constant speed internal gear mechanism".

As a result, a reduction ratio of -1 / N is eventually achieved.

In this prior art example, the internal gear of the internal mesh planetary gear structure is fixed and the first shaft is the input shaft and the second shaft is the output shaft, but the second shaft is fixed and the first shaft is the output shaft. The speed reducer can also be configured by using one shaft as the input shaft and the internal gear as the output shaft. Further, it is possible to construct a speed increaser by reversing these inputs and outputs.

By the way, as described above, the inner pin 7 has a function of forming an arc tooth profile which is one of the elements of the constant velocity internal gear mechanism constituted by the inner roller holes 6a and 6b, and the external gear. Rotational force due to rotation of 5a and 5b is output shaft 2
However, in order to secure a good function of the former among them, the presence of the inner roller 8 that can freely rotate on the outer periphery of the inner pin 7 is essential. there were. Since the inner roller 8 is required to be coaxially and accurately machined on both the outer circumference and the inner circumference with a functionally hard material, there is a problem that the cost tends to increase.

Therefore, the function of forming a circular arc tooth profile which is one element of the constant velocity internal gear mechanism of the inner pin 7,
The internal roller 8 is separated from the function as a carrier body that transmits the rotational force due to the rotation of the external gears 5a and 5b to the output shaft 2.
It has been proposed that the same performance can be obtained by using the inner roller 8 even if the inner roller 8 is eliminated.
27951).

This structure is shown in FIGS. 11 and 12.

In this structure, as a means for transmitting the rotation component of the external gear, the internal pin 7 which can constitute a constant velocity internal gear mechanism with respect to the internal pin holes 19a, 19b provided in the external gears 5a, 5b. And an annular support ring 17 that receives rotation of the internal pin 7 corresponding to the rotation component of the external gear, and a carrier body that projects from the flange portion 14 formed on the output shaft 2 and is connected and fixed to the support ring 17. 16 and.

The inner pin 7 is rotatably fitted in the flange portion 14 and the support ring 17 via bushes 18a and 18b, respectively. That is, since the inner pin 7 does not need to be firmly connected to the output shaft 2 due to the existence of the carrier body 16, it can be configured to rotate itself, and as a result, the conventional inner roller 8 can be omitted. There is something. The annular support ring 17 is incorporated in the tip portion of the carrier body 16.

Since the carrier body 16 need only have a function of transmitting the rotational force of the support ring 17 to the output shaft, the carrier pin 16 does not oscillate at the corresponding portions of the external gears 5a and 5b. A large through hole 20a that does not interfere with
20b is provided.

In FIG. 8, reference numerals 15a and 15b are bearings of the output shaft 2, 21 is an inner pin retainer plate for axially positioning the inner pin 7, 22 is a steel plate race ring, and 23 is an inner pin retainer bolt. Is.

[0021]

However, as is apparent from FIGS. 9 and 11, such a conventional speed reducer has a load fluctuation occurring in the speed reduction mechanism portion and an external force from the mating machine which acts on the output shaft 2. Since the radial load is supported by the pair of bearings 15a and 15b that support the output shaft 2, in order to increase the stability of the support, generally, FIG.
It was necessary to lengthen the Y section of FIG. 11 and make the X section as short as possible.

However, since it is difficult to shorten the X section, the Y section must be lengthened inevitably, resulting in a problem that the axial length of the speed reducer becomes long.

In the structure shown in FIGS. 11 and 12, the carrier body 16 is formed integrally with the output shaft 2, so that the manufacturing is extremely difficult and the cost is high, and the inner roller 8 is used.
There is also a problem that the cost reduction effect due to the omission of is omitted.

Furthermore, in supporting the inner pin 7 in a freely rotatable manner, since the inner pin pressing plate 21, the steel plate race ring 22, the inner pin pressing bolt 23, etc. are indispensable, the number of parts and the number of assembling steps are increased. There was also a problem.

Further, since the inner pin 7 is pressed by the inner pin pressing plate 21 and the steel plate race ring 22, the bush 1
The structure was such that it was difficult to supply the lubricating oil to 8a and 18b. In other words, this requires the bushes 18a and 18b made of a material having good self-lubricating property.
In addition to increasing the number of parts and the number of assembly steps, it meant that the materials for the parts themselves were expensive.

On the other hand, in order to have flexibility in the mounting direction of the reduction gear, that is, in order to prevent the lubricating oil from leaking to the outside or the motor side regardless of the mounting direction, so-called grease lubrication is preferable. However, when the grease lubrication is used, there is a problem that lubrication between the inner pin 7 and the bushes 18a and 18b becomes difficult because the fluidity is not good. More specifically, the inner pin 7 and the bush 1
The amount of grease that can enter the gap between 8a and 18b and fulfill the function of lubrication is extremely small, and this small amount of grease is deteriorated by being subjected to load, heat, and shearing of liquid. In this case, this deteriorated grease is not particularly problematic when it is smoothly replaced with the grease which is outside the bushes 18a and 18b and has not deteriorated. However, in the speed reducer adopting the above structure, However, there is a problem that it is very difficult to replace the grease with the non-deteriorated grease, and therefore maintenance must be frequently performed.

The present invention has been made in view of such a conventional problem, has high rigidity and stability, and reduces the number of parts to reduce the cost and the number of assembling steps. It is an object of the present invention to provide a so-called inscribed mesh planetary gear structure with a carrier, which allows grease lubrication to function well and maintains initial performance over a long period of time.

[0028]

According to the present invention, there is provided a first shaft and an externally toothed gear which is eccentrically rotatable with respect to the first shaft via an eccentric body provided on the first shaft. A second internal gear to which the external gear internally meshes, and a second gear connected to the external gear via means for transmitting only the rotation component of the external gear
And an inner pin that can constitute a constant-velocity internal gear mechanism with respect to an inner pin hole provided in the external gear and an external gear rotation of the internal pin. In an internally meshing planetary gear structure having an annular support ring that receives rotation corresponding to components, and a carrier body that projects from a flange portion formed on the second shaft and is connected and fixed to the support ring, The annular support ring and the flange portion of the second shaft are arranged so as to sandwich the external gear, and both the support ring and the flange portion are both-supported and supported by the casing through a pair of bearings. To
The above problem is solved by providing a protrusion extending in the axial direction from the annular support ring and the flange of the second shaft, and bringing the lubricating oil into contact with the protrusion.

If grease lubrication is adopted as a lubrication method for the intermeshing planetary gear structure, and a grease holding portion is provided around the protruding portion and the grease in the grease holding portion is brought into contact with the protruding portion. , No matter which direction the reducer is installed, the lubricating oil does not leak to the outside or the motor side, and even if the grease has poor fluidity, the deteriorated grease and the new grease in the grease holding part can be replaced well. Can be made.

Further, when the surface of the inner pin is subjected to a porous film treatment, for example, a phosphate film treatment, a capillary phenomenon peculiar to the porosity makes it possible to more smoothly replace deteriorated lubricating oil with new lubricating oil. You will be able to do it.

[0031]

In the present invention, the carrier body is arranged so as to penetrate through the external gear, and the external gear is provided with an annular support ring and a second ring.
The shaft is sandwiched between the flange portions, and both the support ring and the flange portion are supported by the casing on both sides via a pair of bearings. As a result, the rigidity and stability of the deceleration mechanism can be significantly improved.

Further, in the present invention, the inner pin is provided with the annular support ring and the protruding portion extending in the axial direction from the flange portion of the second shaft, and the lubricating oil is brought into contact with this protruding portion.

Specifically, the protrusion can be obtained by making the length of the inner pin longer than the outer end distance between the support ring and the flange portion. Due to the presence of the protrusion, even if a lubricating oil having poor fluidity such as grease is used, it is possible to maintain a very smooth lubricating function for a long time as compared with the conventional one.

Furthermore, due to the presence of this protrusion,
It is possible to prevent the inner pin itself from moving and coming off in the axial direction by a simple means such as pressing the end portion of the protruding portion with a bearing or a housing. Therefore, the conventional inner pin pressing plate, steel plate race ring, etc. are not required, and the number of parts and the number of assembling steps can be reduced, so that the cost can be reduced.

A porous film treatment is applied to the surface of the inner pin,
For example, if a phosphate film treatment is carried out, the capillary phenomenon peculiar to the porous material makes it easier for the lubricating oil to move through the porous film portion, so that a structure with a higher lubricating function is obtained. You will be able to.

[0036]

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

FIG. 1 is a sectional view of a speed reducer to which an internally meshing planetary gear structure according to the present invention is applied, and FIG.
FIG. 3 is a sectional view taken along line II-II, and FIG. 3 is an enlarged sectional view of an essential part near the end of the inner pin 107.

In the following description, the last two digits have the same reference numerals for the same or similar parts as in the configuration of the conventionally known example shown in FIGS. 9, 10 and 11, 12.

One end of a carrier pin (carrier body) 116, which is a separate member from the flange portion 114, is fitted (press-fitted) into the flange portion 114 of the output shaft 102. A support ring 117 is fitted (press-fitted) into the other end of the carrier pin 116, and the support ring 117 and the carrier pin 116 form a carrier.

The flange portion 114, the carrier pin 116,
The support ring 117 includes a pair of bearings 115a, 115a.
Both ends are supported by the casing 112 by b.

A pipe-shaped spacer 125 is fitted (press-fitted) into the carrier pin 116 at substantially the center thereof.
Therefore, even if there is some variation in the fitting depth of the carrier pin 116 into the support ring 117 or the flange portion 114, the distance between the support ring 117 and the flange portion 114 is always kept constant by the function of the spacer 125. Moreover, the same distance can be easily ensured in all the four carrier pins 116.

Carrier pin holes (through holes) 120 through which the carrier pins 116 pass are formed in the external gears 105a and 105b.
Are formed. The carrier pin hole 120 has a size such that the carrier pin 116 and the external gears 105a and 105b do not contact each other even if the external gears 105a and 105b swing.

Here, the inner pin 107 is the support ring 11
7 and the inner pin holding holes 126a, 126 of the flange 114.
It is loosely fitted in b and can rotate freely. The length Lp of the inner pin 107 is sufficiently longer than the outer end length Lf of the support ring 117 and the flange portion 114, and the inner end length L of the bearings 115a and 115b.
It is shorter than b. Specifically, in this embodiment, Lb-Lp = 2 mm. This allows
The inner pin 107 has projecting portions 129a, 12 whose end portions project from the outer ends of the flange portion 114 and the support ring 117.
9b will be formed.

The inner pin 107 has a length Lp and a bearing 1
It is possible to move in the axial direction by the difference (2 mm in this embodiment) from the outer end length Lb of 15a and 115b. Since the outer end length Lf of the flange portion 114 and the support ring 117 is sufficiently shorter than the inner end length Lb of the bearings 115a and 115b, the grease holding portions 130a and 130b are formed therein. The grease holding portions 130a and 130b are formed as a mere step in this embodiment, but the grease has a fluidity, for example, NLGI No shown in JIS K2220, and a grease harder than No. 1 is the protruding portion 129.
Since the grease is applied around a and 129b, the grease can be sufficiently retained.

A porous phosphate film is formed on the surface of the inner pin 107.

The inner pin protrusions 129a, 129b
The practical length of is from 0.2 times the inner pin diameter to 2
It is best to double it.

Next, the operation of this embodiment will be described.

The external gears 105a and 105b are the input shaft 10
When the external pin 111 corresponding to the internal teeth of the internal gear 110 and the external gears 105a and 105b mesh with each other, the rotation of the input shaft 101 causes the external gear 105a to rotate.
The decelerated rotation (rotation) of 105b is exactly the same as the known example in the related art.

In the rotation of the external gears 105a and 105b, the swing component is absorbed by the gap between the inner pin hole 119 and the inner pin 107, and only the rotation component is passed through the inner pin 107 to the flange of the output shaft 102. Part 114 and support ring 1
17 is transmitted to. The rotational force transmitted to the support ring 117 is transmitted to the output shaft 102 via the carrier pin 116.

The external radial load acting on the output shaft 102 is supported by the bearing 115a and the bearing 115a via the carrier pin 116 and the support ring 117, so that the external radial load does not affect the inner pin 107. .

According to this embodiment, since the speed reduction mechanism is supported by the pair of bearings 115a and 115b on both sides, the rigidity is extremely high, and the flange 114, the carrier pin 116 and the support ring 117 are connected. Can be performed very easily and with high precision, and the inner roller of the inner pin 107 can be omitted, so that the cost can be further reduced.

Further, the inner pin 107 has the flange portion 114 of the output shaft 102 and the inner pin holding hole 12 of the support ring 117.
Since they are loosely fitted in 6a and 126b, they can rotate freely, which allows the inner pin holes 119a and 11b to rotate.
It is also possible to satisfactorily absorb the slippage that occurs when the 9b and the inner pin 107 are engaged with each other.

Further, since the inner pin 107 is loosely fitted and supported, it is likely to be elastically deformed when receiving a load due to the engagement with the inner pin holes 119a and 119b, which causes machining, assembly or disassembly. It is possible to favorably absorb the error associated with reassembly. Moreover, even if the inner pin 107 is elastically deformed, the rigidity of the entire reduction gear is
Instead, the flange portion 114, the carrier pin 116, and the support ring 117, which are supported on both sides by the casing 112, are provided.
Since it is ensured by the above, extremely stable operation can be continued.

Further, the protrusions 129a, 12 of the inner pin 107
9b is held in the inner pin holding holes 126a and 126b, protrudes outside the flange 114 and the support ring 117, and enters the grease holding portions 130a and 130b. Therefore, the protruding portions 129a and 129
As b slowly rotates in the grease holders 130a, 130b, the grease collects in the inner pin retaining holes 126a, 1b.
It is supplied smoothly into 26b. Moreover, since the surface of the inner pin 107 is treated with a porous phosphate film, a so-called capillary phenomenon occurs at this portion, so that the grease can be supplied to the inner pin holding holes 126a and 126b more easily. become.

That is, the grease that enters the gaps between the inner pin holding holes 126a and 126b and the inner pin 107 and contributes to lubrication is extremely small and easily deteriorates, but it is still outside the inner pin holding holes and deteriorates. Since it can be easily replaced with grease that has not been carried out by entering the protrusions 129a, 129b into the grease (when using a grease with poor fluidity as its lubricating material in order to have flexibility in the mounting direction) However, the lubrication function can be maintained for a long time.

As a result, it is expected that the performance and life of the entire internally meshing planetary gear structure will be improved.

The presence of the protrusions 129a and 129b also facilitates "axial pressing (allowing a slight movement)" by the bearings 115a and 115b, and allows the inner pin to be loosely fitted as in the prior art. Parts such as the inner pin retainer plate and the steel plate race ring can be omitted for holding, and the structure can be further simplified.

Next, FIGS. 4 and 5 show an embodiment of the type which is premised on frequent disassembly and assembly. In this embodiment, the retaining ring 224 is arranged at one end of the carrier pin 216 and the threaded portion 227 is provided at the other end, and the flange portion 214, the spacer 225, and the support ring 217 are provided.
Is strongly sandwiched by the retaining ring 224 and the nut 228 screwed to the screw portion 227, so that the assembly is performed. Therefore, it is possible to disassemble and assemble any number of times.

Moreover, since the carrier pin 216 is not the so-called stepped bolt but the retaining ring 224 is used, it is possible to prevent stress concentration at the stepped portion. Moreover, the stepped carrier pin cannot be processed by a so-called centerless grinding machine, so high cost and low accuracy cannot be avoided. However, since the retaining ring 224 is used in this embodiment, the centerless pin is used. Since it can be processed with a grinding machine, cost reduction and high accuracy can be realized.

Since the other construction is almost the same as that of the above-mentioned conventional example or the above-mentioned embodiment, as described above, the same or similar portions are given the same reference numerals in the last two digits, and the duplicated explanation is omitted. .

FIG. 6 is a side view showing the external shape of the speed reducer shown in FIGS. 4 and 5, FIG. 7 is a plan view thereof, and FIG. 8 is a front view thereof.

[0062]

As described above, according to the present invention, since the speed reducing mechanism is supported by the pair of bearings at both ends, the total length of the speed reducer can be shortened, and the supporting ring and the carrier body can be shortened. Although the structure is provided, the structure is very simple and highly accurate assembly is possible. Further, since the structure for incorporating the inner pins is also very simple, it is possible to realize higher accuracy and lower cost as a whole. Furthermore, due to the presence of the protruding parts of the inner pins, the inner pins can be satisfactorily lubricated for a long period of time even if a lubricating oil with poor fluidity such as grease is used in order to ensure flexibility in the mounting direction. Will be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a speed reducer to which an internally meshing planetary gear structure according to the present invention is applied.

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

FIG. 3 is an enlarged cross-sectional view of an essential part showing the vicinity of the end of the inner pin in FIG.

FIG. 4 is a sectional view of a speed reducer according to another embodiment of the present invention.

5 is a sectional view taken along the line VV of FIG.

6 is a side view showing the external shape of the speed reducer shown in FIG.

FIG. 7 is a plan view showing the external shape of the speed reducer shown in FIG.

FIG. 8 is a front view showing the external shape of the speed reducer shown in FIG.

FIG. 9 is a sectional view showing a basic speed reducer to which a conventional internally meshing planetary gear structure is applied.

10 is a sectional view taken along line XX of FIG.

FIG. 11 is a cross-sectional view of a speed reducer to which a conventional internally meshing planetary gear structure is applied and which includes a carrier pin in addition to the inner pin.

FIG. 12 is a sectional view taken along line XII-XII in FIG.

[Explanation of symbols]

1, 101 ... Input shaft 2, 102 ... Output shaft 3a, 3b, 103a, 103b, 203a, 203b
... Eccentric bodies 5a, 5b, 105a, 105b, 205a, 205b
Outer gears 6a, 6b Inner roller holes 7, 107, 207 Inner pins 8a, 8b Inner rollers 10, 110, 210 ... Inner gears 11, 111, 211 Outer pins 14, 114, 214 ... Output shaft Flange portions 15a, 15b ... 115a, 115b, 215a, 21
5b ... Bearing 16, 116, 216 ... Carrier pin 17, 117, 217 ... Support ring 119a, 119b, 219a, 219b ... Inner pin hole 124a, 124b, 224a, 224b ... Inner ring 125a, 125b, 225a, 225b ... Outer ring 126a, 126b, 226a, 226b ... Inner pin holding hole 129a, 129b, 229a, 229b ... Projection part 130a, 130b, 230a, 230b ... Grease holding part

Claims (3)

[Claims] 1. A first shaft, an external gear mounted eccentrically with respect to the first shaft via an eccentric body provided on the first shaft, and an internal gear internally contacting the external gear. An internal gear that meshes,
A second shaft connected to the external gear via a means for transmitting only the rotation component of the external gear, and the internal shaft provided on the external gear as means for transmitting the rotation component An inner pin that can form a constant-velocity internal gear mechanism with respect to the pin hole, an annular support ring that receives rotation corresponding to the rotation component of the external gear of the inner pin, and a flange that is formed on the second shaft. In the internally meshing planetary gear structure having the support ring and a carrier body connected / fixed to the support ring, the annular support ring and the flange portion of the second shaft are arranged so as to sandwich the external gear. Both the support ring and the flange portion are supported on both sides by a casing through a pair of bearings, and the inner pin is provided with a protrusion extending in the axial direction from the annular support ring and the flange portion of the second shaft. Provide and moisten the protruding part Internally meshing planetary gear structure, characterized in that contacting the oil. 2. The intermeshing planetary gear structure according to claim 1, wherein a grease holding portion is provided around the protruding portion, and grease in the grease holding portion is brought into contact with the protruding portion. 3. The intermeshing planetary gear structure according to claim 1, wherein the surface of the inner pin is subjected to a porous film treatment.