JP3715427B2 - Inner meshing planetary gear structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intermeshing planetary gear structure suitable for application to a small reduction gear or a speed increaser.
[0002]
[Prior art]
Conventionally, as shown in FIG. 6, for example, a technique related to an intermeshing planetary gear structure is known. This will be described below.
[0003]
FIG. 6 is a cross-sectional view showing an example of the intermeshing planetary gear speed reducer. FIG. 7 is a sectional view taken along line VII-VII in FIG.
[0004]
In FIG. 6, what is indicated by reference numeral 120 is a cylindrical casing. The casing 120 has a plurality of bolt insertion holes 122 that penetrate the cylindrical wall in the axial direction in order to fix the casing 120 to a fixing member (not shown). At the center of the casing 120, the tip of the input rotary shaft 102 that is rotationally driven by a motor (not shown) is inserted from the right side in the figure.
[0005]
In the casing 120, a thick disc-shaped first support block (left side in the figure) 124 and a second support block (right side in the figure) 126 are arranged to face each other with an interval in the axial direction. (Both correspond to the second axis). The outer end surface (left end surface) of the first support block 124 serves as a mating member mounting surface 124 a and slightly protrudes outward from the left end surface of the casing 120. The first and second support blocks 124 and 126 are rotatably supported on the inner periphery of the casing 120 via bearings 128a and 128b, respectively.
[0006]
Both support blocks 124 and 126 are integrally connected and fixed by three carrier pins 140 arranged in parallel with the input shaft 102. The carrier pins 140 are arranged at positions near the outer circumferences of the support blocks 124 and 126, and are arranged on the circumference concentric with the input shaft 102 at equal intervals in the circumferential direction (FIG. 7).
[0007]
The front end surface of the carrier pin 140 is exposed flush with the mating member mounting surface 124 a of the first support block 124. A screw hole 134 for screwing the mating member fixing bolt 132 is formed at the center of the exposed front end surface. The bolt 132 passed through the bolt insertion hole of the mating member P is screwed into the screw hole 134. By connecting the mating member P and the carrier pin 140, the first support block 124 and the second support block 126 are simultaneously connected and fixed at a predetermined interval.
[0008]
In the casing 120, three eccentric body shafts (first shafts) 136 are arranged in parallel with the input rotation shaft 102.
[0009]
A transmission gear 138 is attached to each eccentric body shaft 136 on the first support block 124 side.
[0010]
A pinion 142 that meshes with a transmission gear 138 fixed to each of the eccentric body shafts 136 is formed at the tip of the input rotation shaft 102, whereby three rotations of the input rotation shaft 102 are made via the pinion 142 and the transmission gear 138. The eccentric body shaft 136 is equally distributed (see FIG. 7).
[0011]
On the other hand, between the first and second support blocks 124 and 126, two disk-shaped external gears 110 and 111 having an outer diameter slightly smaller than the inner diameter of the casing 120 are arranged side by side in the axial direction. .
[0012]
Hereinafter, the description will focus on the external gear 110 of one of the two external gears 110 and 111.
[0013]
The internal teeth of the internal gear 106 are constituted by columnar external pins 130 engaged with the external pin holes 130 a, and the number thereof is set to two more than the number of external teeth 112. Note that the outer pin 130 is painted black for easy understanding.
[0014]
Since the eccentric portion (eccentric body) 136a of the eccentric body shaft 136 is oscillated and rotated by the rotation of the input rotation shaft 102, the external gear 110 also oscillates and rotates. By the way, when the eccentric body shaft 136 makes one rotation, the meshing position of the external gear 110 and the internal gear 106 shifts sequentially and makes one rotation. At this time, only the difference N in the number of teeth between the external teeth 112 and the external pins 130 occurs. The phases of the gears 110 and 106 are shifted, and the shift is rotated by the external gear 110 and is transmitted to the first and second support blocks 124 and 126 via the carrier pin 140.
[0015]
For example, when the number of external teeth 112 of the external gear 110 is m (m = 78 in FIG. 7) and the number of external pins (internal teeth) 130 of the internal gear 106 is m + 2 (FIG. 7). Then, 80), the tooth number difference N is 2. The rotation input by the input rotation shaft 102 is once decelerated by the transmission gear 138 and transmitted to each eccentric body shaft 136. Each time each eccentric body shaft 136 makes one rotation, it shifts (rotates) by two teeth corresponding to the difference in the number of teeth with respect to the internal gear 106 fixed to the casing 120. Accordingly, one rotation of each eccentric body shaft 136 is decelerated and converted into 2 / m rotation of the first and second support blocks 124 and 126.
[0016]
[Problems to be solved by the invention]
However, as described above, in the internal mesh planetary gear structure of the type in which the internal teeth of the internal gear 106 are constituted by the external pins 130, in order to improve the transmission efficiency and reduce the noise, Although the pin 130 and the outer pin hole 130a into which the outer pin 130 is engaged must be processed with high precision, the position of each outer pin 130 with respect to the external gear 110 is not necessarily uniform, and thus the processing is not performed. There is a problem that the frictional resistance may increase near the specific outer pin 130 due to an assembly error.
[0017]
Further, the number of the outer pins 130 is several tens or more per one speed reducer, and a great amount of labor and time are required for processing and assembling, so that there is a problem that cost reduction cannot be realized.
[0018]
The present invention has been made in view of such a conventional problem, and solves the above-described problem by a method of reducing the number of built-in external pins 130 and, as will be described later, thereby a new problem. In particular, the friction between the outer pin and the external teeth is reduced, efficient power transmission is achieved, and the reduction of the number of processing steps and parts and the reduction of noise are all achieved at the same time. It is an issue.
[0019]
[Means for Solving the Problems]
The present invention includes a first shaft, an external gear attached in an eccentrically rotatable manner to the first shaft via an eccentric body provided on the first shaft, and an internal gear meshing with the external gear. An internal gear having teeth and a plurality of external pin holes and a cylindrical outer pin group engaged with the external pin holes; and only the rotation component of the external gear is included in the external gear. An internal meshing planetary gear comprising: a second shaft coupled via a means for transmitting the gear; and the number of the outer pin holes being set to a number larger by two than the number of teeth of the external gear In the structure, when the outer pin hole engaged with a specific outer pin among the outer pin groups constituting the inner teeth of the internal gear is used as a reference, the outer pin hole is an even-numbered outer pin hole. The number of outer pins corresponding to the corresponding outer pin group and the outer pin group corresponding to the odd-numbered outer pin hole is almost the same. By omitting the outer pin embedded in match so, it is possible to solve the above problems.
[0020]
The present invention also includes a first shaft, an external gear attached in an eccentrically rotatable manner to the first shaft via an eccentric body provided on the first shaft, and meshing with the external gear. An internal gear formed by a plurality of outer pin holes and a cylindrical outer pin group engaged with the outer pin holes, and the rotation of the external gear to the external gear. A second shaft connected through a means for transmitting only the component, and the number of the outer pin holes is larger by n (n is an integer of 2 or more) than the number of teeth of the external gear. In the intermeshing planetary gear structure set to the above, when an outer pin hole engaged with a specific outer pin among the outer pin groups constituting the inner teeth of the internal gear is used as the reference, An outer pin group corresponding to an outer pin hole corresponding to the multiple of n from the outer pin hole, and an outer pin hole corresponding to the (multiple of n-1) th Outer pin group that, (a multiple of n -2) th falls outside pin group corresponding to the outer pin hole, the outer pin group corresponding to the outer pin hole corresponding to th (multiple -3 n), · · ·, a (n By omitting the incorporation of the outer pins so that the number of outer pins of the outer pin group corresponding to the outer pin hole corresponding to the multiple-n + 1) th outer pin hole substantially coincides, the above problem can be solved similarly.
[0021]
In such an intermeshing planetary gear speed reducer, as a method for reducing the frictional resistance between the outer pin 130 and the outer teeth 112 as much as possible in order to improve transmission efficiency and reduce noise or cost, the outer pin 130 and It is conceivable to make the contact (slip) between the external teeth 112 as smooth as possible.
[0022]
However, the outer pins 130 and the outer teeth 112 have already been processed (buffing, mirror finishing, etc.) so that the frictional resistance is reduced as much as possible, and further mirroring is very expensive.
[0023]
Therefore, when a large rotational torque is not required as another method, as shown in FIG. 8, for example, every other outer pin 130 may be inserted (omitted from the state of FIG. 7). It is done. In this case, although the allowable transmission capability is reduced as compared with the case where the external pins 130 are installed (assembled) in all the external pin holes 130a (state of FIG. 7), the outer pin 130 is within the range of the allowable transmission capability. Thus, the frictional resistance between the outer pin and the outer teeth 112 (particularly due to assembly errors) can be reduced, and a low noise and low cost internal meshing planetary gear reducer can be achieved.
[0024]
For example, if the number of outer pins is 80, about 10% of the outer pins 130 are pushed closer to the external gear side than the other outer pins (so as to increase the frictional resistance) and assembled. If this is the case, the number will be eight, and the external gear 110 will receive a large frictional resistance each time it engages with the eight outer pins 130, but the number of outer pins 130 will be halved. If the same ratio is used, the reason is that the number is 4 because it is a simple calculation (so as to increase the frictional resistance), and the effect is halved.
[0025]
However, as shown in FIG. 8, for example, if the installation of the outer pins 130 is omitted every other pin, there is a possibility that the following drawbacks may occur.
[0026]
FIG. 9 is an enlarged view of a part IX in FIG.
[0027]
As shown in FIG. 9A, the external teeth 112 are a ', b', ..., i ', ..., and the external pins 130 are A', B ', ..., E', respectively. ... and so on.
[0028]
In such a state, when the external gear 110 rotates once, naturally, the external pins A ′, B ′,... E ′,... Remain stationary because the internal gear 106 is stationary. is there. Further, since the external gear 110 has a difference in the number of teeth of 2, there is a shift of 2 teeth from each external pin. For this reason, an outer pin and an external tooth become like FIG.9 (B).
[0029]
Here, the external gear 110 rotates counterclockwise, but this is determined by the rotation direction of the rotation input shaft 102.
[0030]
That is, in FIGS. 9A and 9B, the external teeth (for example, a ′, c ′, e ′, g ′, i ′,...) Meshed with the outer pins in FIG. However, even after one rotation of the external gear 110 (FIG. 9B), these external teeth mesh with the external pins again. That is, the same result is obtained even if the external gear rotates one more time. As a result, the external teeth that mesh with the external pin 130 are always constant regardless of how many times the external gear 110 rotates (a ′, c ', E', g ', i', ...). In other words, external teeth that do not mesh with the external pin do not mesh at all no matter how many times the external gear 110 rotates.
[0031]
When this happens, naturally only certain external teeth (in this example, a ′, c ′, e ′, g ′, i ′,...) Work. The degree of wear differs from the external teeth (in this example, b ′, d ′, f ′, h ′,...) That do not mesh with the adjacent external pins 130 at all. It will end up. That is, the life of the external gear 110 is shortened.
[0032]
Therefore, in the present invention, the incorporation of the outer pin 130 is omitted according to a predetermined rule, and the external gear 110 can be evenly worn to improve its durability.
[0033]
Claim 1 refers to the case where the difference between the number of internal teeth (the number of external pins before being omitted: the number of external pin holes) and the number of external teeth is “2”. Including claim 1, the relationship between the difference in the number of teeth and the outer pin to be omitted is more generally defined.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
The present invention has the greatest feature in the way of omitting the incorporation of the outer pin, and the basic structure of the speed reducer itself according to this embodiment is the same as that of the conventional one already explained (the difference in the number of teeth is 2). This will not be described repeatedly.
[0035]
In this embodiment, as shown in FIG. 8, the installation of the outer pins 130 is not omitted every other one, but as shown in FIG. 1, two outer pins 130 are provided for every two outer pin holes 130a. We will omit each book as a set.
[0036]
An enlarged view of part II in FIG. 1 is shown in FIG.
[0037]
As shown in FIG. 2A, the external teeth 112 are a, b, c,..., I, j,... And the external pins are A, B,.・ Let's say.
[0038]
As described above, since the difference between the number of external teeth and the number of internal teeth in this embodiment is “2”, when the external gear 110 rotates once, each external tooth is as shown in FIG. It shifts by two teeth and engages with the outer pin.
[0039]
That is, the external teeth 112 (for example, a, b, e, f, i, j,...) Meshing with the outer pin 130 in FIG. In (B), it does not mesh with the outer pins 130 (A, B,...). Conversely, the external teeth 112 (for example, c, d, g, h,...) That have not meshed with the external pin 130 in FIG. ) Meshes with the outer pin 130.
[0040]
Next, when the external gear 110 is rotated one more time, the external teeth 112 are further shifted by two teeth, so that the state shown in FIG. 2C is brought into engagement with the outer pin 130 again in FIG. 2A. The external teeth 112 (for example,..., E, f, i, j,...) That have been meshed with the outer pin 130.
[0041]
That is, the external teeth 112 are alternately changed in mesh with the external pins 130 every time the external gear 110 rotates once, and as a result, all the external teeth 112 are uniformly engaged with the external pins 130.
[0042]
When the difference in the number of teeth is two, it is basic that two outer pins 130 are assembled into the outer pin hole 130a in sets of two, as described above. When the surface pressure is sufficient (the mutual strength can be sufficiently secured), the two sets of the outer pins 130 may be further partially omitted as shown in FIG.
[0043]
Moreover, it is not limited to the one in which all the outer pins 130 are regularly incorporated in a set of two, for example, and may be incorporated randomly as shown in FIG. 5, for example. In FIG. 5, the total number of outer pins (group) corresponding to the even numbered outer pin holes from the outer pin P corresponding to the specific outer pin hole is 20, and the total number of odd numbered outer pins (group) is also 20. A total of 40 outer pins 130 are randomly incorporated in 80 outer pin holes 130a. That is, short, regular, irregular manner regardless, of the outer pins that constitute the internal teeth, if a particular external pin P is relative to the outer pin holes engaged, the outer pin hole If the assembly is randomly omitted so that the number of outer pins corresponding to the outer pin holes corresponding to the even-numbered outer pin holes and the number of outer pin groups corresponding to the odd-numbered outer pin holes substantially coincide with each other from FIG. An effect similar to that shown in FIG. Since the ratio of the omitted number and the decrease in the allowable transmission capacity are substantially proportional, the omitted number may be set appropriately according to the request.
[0044]
As described above, when the outer pin hole engaged with a specific outer pin P is used as a reference, the number of outer pin groups corresponding to the outer pin holes corresponding to the even-numbered outer pin holes and the odd-numbered outer pin holes correspond. Since the number of outer pin groups corresponding to the outer pin holes does not cause any trouble even if they do not exactly coincide with each other, it is described as “substantially coincide” in the claims.
[0045]
In the present embodiment, the example in which the difference in the number of teeth is 2 is mainly described as an example, but the present invention is also applied to the case where the difference in the number of teeth is n (n is an integer equal to or greater than 2; Applicable. Hereinafter, this will be described in more detail.
[0046]
Based on the theory described above, when the difference in the number of teeth is n, it is best to omit (or incorporate) n outer pins 130 as a set every n as shown in FIG.
[0047]
Here, as shown in FIG. 4 (B), when based on the external pin holes specific external pins P 'is engaged, the first from the outside pin hole, a second, outer Niataru · · · n-th When the outer pins corresponding to the pin holes are P1, P2,... Pn,... And the outer pins corresponding to the outer pin holes corresponding to the multiples of n are Pn, P2n, P3n,. When returning once, the outer pin P ′ can be expressed as Pkn (k times n). This is because if the number of outer pins (holes) is not a multiple of the difference in the number of teeth, the rotation cannot be continued because of the tooth profile.
[0048]
Here, the outer pin group (Pn, P2n, P3n,... Pkn) corresponding to the outer pin hole corresponding to the multiple of n from the outer pin hole engaged with the specific outer pin P ′, (multiple of n−1) ) Outer pin group corresponding to the outer pin hole corresponding to the second (in FIG. 4B, Pn-1, P2n-1, P3n-1,... Pkn-1), (multiple of n-2) outer Outer pin group corresponding to the pin hole (in FIG. 4B, Pn-2, P2n-2, P3n-2,... Pkn-2),..., (Multiple of n-n + 1) th outer The number of outer pins belonging to the group of outer pins corresponding to the pin holes (in FIG. 4B, P1, Pn + 1, P2n + 1,... P (k-1) n + 1) is almost equal. The incorporation of the outer pin 130 may be omitted so as to match.
[0049]
As a result, the number of outer pins can be reduced by an arbitrary number while preventing uneven wear of the external teeth 112 of the external gear.
[0050]
【The invention's effect】
As described above, according to the present invention, the number of outer pins can be arbitrarily reduced while the reduction ratio is kept as it is , and uneven wear of external teeth can be prevented. In addition, since the number of outer pins 130 can be reduced, excellent effects such as cost reduction based on reduction in the number of processing steps and the number of parts, and further improvement in transmission efficiency and noise reduction can be obtained.
[Brief description of the drawings]
1 is a cross-sectional view taken along line II of FIG. 6 as a main configuration of an intermeshing planetary gear speed reducer according to the present embodiment. FIG. 2 is an enlarged view of a portion II in FIG. FIG. 4 is a diagram showing an n-type differential tooth profile in the present embodiment. FIG. 5 is another embodiment of the intermeshing planetary gear reducer according to the present embodiment. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6; FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. FIG. 9 is an enlarged view of a part IX in FIG. 8.
102 ... Input rotary shaft 106 ... Internal gears 110, 111 ... External gear 112 ... External teeth 130 ... External pin

Claims (2)

A first shaft, an external gear attached in an eccentrically rotatable manner to the first shaft via an eccentric body provided on the first shaft, and an internal tooth meshing with the external gear; The internal gear is constituted by a plurality of external pin holes and a cylindrical outer pin group engaged with the external pin holes, and means for transmitting only the rotation component of the external gear to the external gear. An intermeshing planetary gear structure in which the number of the outer pin holes is set to a number larger by two than the number of teeth of the external gear. Outer pin corresponding to an even numbered outer pin hole from the outer pin hole when the outer pin hole engaged with a specific outer pin among the outer pin group constituting the inner teeth of the internal gear is used as a reference and the group, the number of each of the outer pins of the external pin group corresponding to the outer pin hole corresponding to the odd-numbered substantially coincide Internally meshing planetary gear structure characterized in that omitting the outer pin built in. A first shaft, an external gear attached in an eccentrically rotatable manner to the first shaft via an eccentric body provided on the first shaft, and an internal tooth meshing with the external gear; The internal gear is constituted by a plurality of external pin holes and a cylindrical outer pin group engaged with the external pin holes, and means for transmitting only the rotation component of the external gear to the external gear. And the number of the outer pin holes is set to a number larger by n (n is an integer of 2 or more) than the number of teeth of the external gear. In the meshing planetary gear structure,
Corresponds to the outer pin hole corresponding to the multiple of n from the outer pin hole when the outer pin hole engaged with a specific outer pin among the outer pin group constituting the inner teeth of the internal gear is used as a reference. An outer pin group corresponding to the outer pin hole corresponding to the (multiple of n-1) th, an outer pin group corresponding to the outer pin hole corresponding to the (multiple of n-2) th, (multiple of n-3) The outer pin group corresponding to the outer pin hole corresponding to the second,... (Multiple of n-n + 1) The external pins are incorporated so that the respective outer pin numbers corresponding to the outer pin hole corresponding to the second outer pin hole substantially coincide with each other. An intermeshing planetary gear structure characterized in that is omitted.

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