JP3946923B2 - Rotation drive device and method of manufacturing the rotation drive device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary drive device having a drive unit that generates rotational power and first and second reduction mechanism units that transmit this rotational power, and in particular, the second reduction mechanism unit has an intermeshing planetary gear structure. About something. Furthermore, the present invention relates to a method for manufacturing such a rotary drive device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a small and high-power rotary drive device, one that employs an intermeshing planetary gear reduction structure as a reduction mechanism unit as disclosed in Japanese Patent No. 2771395 is widely known. The speed reduction mechanism has an internal gear and an external gear that meshes internally with the internal gear, and the center of the internal gear is set inside the periphery of the external gear (International Classification F16H1). It is possible to achieve a high gear ratio of about 1/6 to 1/119 in one stage. Therefore, this rotary drive device is used in a wide variety of applications, for example, when driving a robot arm or driving a lift device that carries a heavy load.
[0003]
However, with the diversification of user needs accompanying the recent development of industry, there is a need for a rotary drive device that is compact and can exhibit a higher reduction ratio (for example, a reduction ratio of 1/200 or more). 6 shows a two-stage reduction type rotary drive device proposed in response to such needs.
[0004]
This rotary drive device 1 has a reduction gear ratio of about 1/1000 by further interposing a reduction gear mechanism portion between the reduction gear mechanism portion and the drive portion of the rotary drive device described in Japanese Patent No. 2771395. Specifically, a drive unit (motor) 2 that generates rotational power, a first reduction mechanism unit 4 that is connected to the drive unit and transmits rotational power, and the first deceleration And a second reduction mechanism portion 6 of an intermeshing planetary gear structure that is connected to the mechanism portion and transmits rotational power.
[0005]
The second reduction mechanism unit 6 of the rotary drive device 1 includes a first shaft 11 coupled to the first reduction mechanism unit 4, and a second shaft 12 that is arranged coaxially with the first shaft 11 and serves as an output shaft. It has. On the outer periphery of the first shaft 11, two eccentric bodies 13 a and 13 b are fitted adjacent to each other in the axial direction with a predetermined phase difference (180 ° in this example), and these rotate together with the first shaft 11. To do. The centers of the eccentric bodies 13a and 13b are eccentric by a predetermined eccentric amount with respect to the axis of the first shaft 11, and the outer circumferences of the eccentric bodies 13a and 13b are external teeth via bearings 14a and 14b, respectively. Gears 15a and 15b are fitted.
[0006]
The plurality of external gears 15a and 15b fitted to the eccentric bodies 13a and 13b are provided with a plurality of inner pin holes 16a and 16b, respectively, and the inner pin 17 is idled in the inner pin holes 16a and 16b. It is fitted.
[0007]
The reason for using two external gears (double row) is mainly to increase the transmission capacity, maintain the strength, and maintain the rotational balance. In particular, when this structure is adopted on the lower stage side in the two-stage reduction type as in this example, it is preferable to use a double row because the transmission capacity (transmission torque) on the lower stage side increases.
[0008]
The outer teeth of the external gears 15 a and 15 b are provided with external teeth having a trochoidal tooth shape or an arc tooth shape, and the external teeth are in mesh with an internal gear 20 provided concentrically with the first shaft 11. The internal gear 20 is integrally formed on the inner periphery of the casing 51, and each internal tooth is constituted by the outer pin 21.
[0009]
After all, the second reduction gear mechanism 6 has an internal gear 20 and external gears 15a and 15b that are in mesh with the internal gear 20, and the center of the internal gear 20 is the external gears 15a and 15b. It has the characteristic (characteristic prescribed | regulated to international classification F16H1 / 32) that it exists inside the outer periphery of.
[0010]
Specifically, the casing 51 includes a central casing 52, a joint casing 53 on the drive unit 2 side, and a front casing 54 disposed on the opposite side of the joint casing 53. Accordingly, the second reduction mechanism 6 is accommodated in the casing 51.
[0011]
A pair of carriers 23 and 24 are arranged on both sides of the two external gears 15a and 15b. The carriers 23 and 24 are rotatably supported by two bearings 31 and 32 fitted to the inner periphery of the casing 51, and a plurality of carrier pins (connection pins) 25 penetrating the external gears 15a and 15b. And the spacer 26 are integrally connected.
[0012]
Further, both ends of the inner pin 17 loosely fitted in the inner pin holes 16a and 16b of the external gears 15a and 15b are supported by the pair of carriers 23 and 24 so as to be able to slide and rotate. Only the rotation components 15a and 15b are transmitted to the carriers 23 and 24.
[0013]
The carrier 23 on the drive unit 2 side has a ring shape having a central hole 23a. One end of the first shaft is supported in the central hole 23a via a bearing, and the other end is inside the carrier 24 on the opposite side. It is supported via a fitted bearing. That is, the first shaft 11 is rotatably accommodated in the pair of carriers 23 and 24.
[0014]
In the second speed reduction mechanism section, when the first shaft 11 rotates once, the eccentric bodies 13a and 13b rotate together, and accordingly, the external gears 15a and 15b try to swing and rotate around the first shaft 11. To do. However, since the free rotation is restrained by the internal gear 20, the external gears 15 a and 15 b almost swing only while being internally meshed with the internal gear 20.
[0015]
For example, when the number of teeth of the external gears 15a and 15b is N and the number of teeth of the internal gear 20 is N + 1, the difference in the number of teeth is 1, and the external gear 15a, 15b is shifted (rotated) by one tooth with respect to the internal gear 20. As a result, one rotation of the first shaft 11 is decelerated to -1 / N rotation of the external gears 15a and 15b.
[0016]
In the rotation of the external gears 15a and 15b, the swing component is absorbed by the gap between the inner pin holes 16a and 16b and the inner pin 17, and only the rotation component is transmitted to the carriers 23 and 24. It is transmitted to the shaft 12.
[0017]
As a result, in the second reduction mechanism unit 6, reduction of a reduction ratio of −1 / N (− indicates reverse rotation) is achieved.
[0018]
Next, the first reduction mechanism unit will be described.
[0019]
In the rotary drive device 1, the swinging intermeshing planetary gear structure is also adopted in the first reduction mechanism unit 4, and the configuration is substantially the same as that of the second reduction mechanism unit 6. Therefore, in order to avoid duplicate description, the same parts or members are given the same reference numerals for the last two digits, and detailed description of the configuration and operation is omitted.
[0020]
The difference between the first reduction mechanism unit 4 and the second reduction mechanism unit 6 is that the external gear 115 is mainly one (single row). This is because the transmission capacity (transmission torque) is smaller on the front stage side than on the rear stage side, and it is considered that even one sheet can sufficiently cope with the strength and the like.
[0021]
The output-side carrier 324 in the first speed reduction mechanism unit 4 is connected to the first shaft 11 of the second speed reduction mechanism unit 6 by a spline structure. Further, the first shaft 311 in the first reduction mechanism unit 4 is connected to the drive shaft 61 of the drive unit 2.
[0022]
The casing 351 that accommodates the first speed reduction mechanism unit 4 includes a central casing 352, a joint casing 353 on the drive unit 2 side, and a joint casing 53 on the second speed reduction mechanism unit 6 side. It can be said that the first reduction mechanism unit 4 and the second reduction mechanism unit 6 are integrally coupled, and further, a part of both the casings 51 and 151 is also used.
[0023]
The rotary drive device 1 configured as described above reduces the rotational power of the drive unit 2 in two stages by the first and second reduction mechanism units 4 and 6 having a swing inner meshing planetary gear structure. Output from the second axis 12.
[0024]
[Problems to be solved by the invention]
According to the rotary drive device 1 configured as described above, an extremely high reduction ratio can be achieved by the first reduction mechanism unit 4 and the second reduction mechanism unit 6 which are both swinging intermeshing planetary gear structures. Yes, in this respect, it fully meets the broad needs of the market. That is, the feature of this rotary drive device 1 is that the rotational power of the drive unit 2 is transmitted to the second shaft 12 of the second reduction mechanism unit 6 while maintaining its coaxiality, and an extremely high output can be obtained. is there.
[0025]
However, the rotary drive device 1 has a structure in which the central casing 352 and the joint casing 353 are newly interposed between the second reduction mechanism 6 and the drive unit 2 and the first reduction mechanism 4 is accommodated therein. The entire apparatus was greatly lengthened in the axial direction, and the manufacturing cost was considerably high.
[0026]
In addition, since both the first reduction mechanism unit 4 and the second reduction mechanism unit 6 are reduction structures including gears (external gears, internal gears), there is a problem that noise increases greatly when these are connected. It was. This is a structure in which the casings 51 and 151 having internal spaces independent from each other are simply connected (communication), so that the noise in each casing is amplified by resonance in both internal spaces or mutually. It is presumed that a complicated resonance phenomenon is caused by connecting the drive unit 2 and the two speed reduction mechanism units 4 and 6 having different peak frequencies of one or two or more.
[0027]
By the way, in order to achieve a high reduction ratio with the two-stage reduction type, in addition to the rotary drive device 1 described above, the first reduction mechanism unit has a parallel shaft gear structure in which spur gears are combined. It is also possible.
[0028]
However, in order to obtain a large reduction ratio with this parallel shaft gear structure, it is necessary to increase the distance between the centers of the input side gear (pinion) and the output side gear and to set a large difference in the number of teeth between the meshing gears. In addition, the distance between the centers is expected to increase the size of the entire rotary drive device in the radial direction (in addition to the axial direction). Also, in order to make the drive unit (motor) and the output shaft coaxial, it is necessary to restore the shift of the axial center by using only two stages (three stages as a whole), and an increase in the axial direction is inevitable. .
[0029]
The present invention has been made in view of the above problems, and in a state in which the increase in size and cost is suppressed as much as possible, a higher reduction ratio than that of the prior art can be achieved, and the noise has been greatly reduced. An object is to obtain a rotary drive device.
[0030]
Another object is to facilitate the assembly of the rotary drive device and reduce the labor of the operator.
[0031]
[Means for Solving the Problems]
The present invention relates to a drive unit that generates rotational power, a first reduction mechanism unit that is connected to the drive unit and transmits rotational power, a first shaft that is connected to the first reduction mechanism unit, and the first shaft. An external gear that rotates eccentrically with respect to the internal gear, an internal gear that is fixed to the casing and internally meshed with the external gear, and is rotatably supported on the casing via bearings at both axially outer positions of the external gear, A second reduction mechanism of a swinging intermeshing planetary gear structure comprising a pair of carriers that extract only the rotation component of the external gear and a second shaft that is arranged coaxially with the first shaft and transmits the rotation of the carrier. And a rotating roller comprising: a sun roller coupled to the drive shaft of the driving unit, a planetary roller that is in rolling contact with the outer periphery of the sun roller, a ring roller that is inscribed by the planetary roller, and Revolving component of planetary roller A friction transmission type simple planetary roller structure including a planetary carrier that is taken out and transmitted to the first shaft of the second speed reduction mechanism unit, and the outer diameter of the ring roller is set to be equal to that of the pair of carriers of the second speed reduction mechanism unit. Set this ring roller within the outer diameter of the bearing that supports the drive side of this bearing. In the same casing as the casing containing the bearing, and the bearing The above object is achieved by arranging in the space closer to the drive unit.
[0032]
Since the simple planetary roller mechanism transmits rotational power by frictional force, it can be operated extremely quietly compared to gear transmission structures, and it is compact while maintaining a high reduction ratio compared to parallel gears, etc. Can be configured.
[0033]
The inventor pays attention to the characteristics of the simple planetary roller mechanism, and the first reduction mechanism portion on the upper speed reduction side in the rotary drive device has a friction transmission type simple planetary roller structure, and the first reduction mechanism portion It has been found that if the outer diameter of the ring roller is set within the outer diameter of the bearing of the second reduction mechanism, the first reduction mechanism and the second reduction mechanism can be connected very compactly. .
[0034]
In other words, when this configuration is adopted, the space on the drive unit side of the bearing in the casing can be expanded to an extent that can accommodate the simple planetary roller mechanism by a very simple design change (simply extending the casing slightly). Moreover, the expansion space hardly affects the size of the entire rotary drive device.
[0035]
Further, if the outer diameter of the ring roller is set within the outer diameter of the bearing, the ring roller is provided from the opposite side of the driving unit (with the bearing removed), that is, from the side of the second reduction mechanism unit to be incorporated in the future. Can be incorporated into the casing. As a result, the internal structure of the casing is greatly simplified, and the manufacture and assembly of the apparatus become very easy (the manufacturing method and the like will be described later).
[0036]
Therefore, the first speed reduction mechanism portion of the simple planetary roller mechanism can be disposed in the space closer to the driving portion than the bearing in the same casing as the second speed reduction mechanism portion, and the first speed reduction mechanism portion and the second speed reduction mechanism portion. As a result, the axial dimension can be greatly shortened and the manufacturing cost can be reduced as compared with the prior art while achieving a high reduction ratio that can sufficiently meet market needs. Of course, the rotary drive device configured as described above can output the rotational power of the drive unit while maintaining the coaxiality, and does not increase in size in the radial direction.
[0037]
Further, since the first speed reduction mechanism portion is a friction transmission type, it can be operated silently, and in addition, the first speed reduction mechanism portion and the second speed reduction mechanism portion can be accommodated in one casing. Thus, resonance due to the internal space of the two casings can be suppressed, and vibration transmission between the drive unit (motor) and the second reduction mechanism unit is blocked by the presence of the friction transmission type first reduction mechanism unit. Therefore, the resonance of each part is reduced and the noise during operation is greatly reduced. As a result, the high reduction ratio, compactness, and quietness that have been considered difficult in the past can be reasonably solved.
[0038]
Further, if the rotary drive device is configured as described above, the manufacturing process can be greatly simplified. As a specific manufacturing method, the drive unit is assembled to the casing, and the first reduction mechanism unit is incorporated into the casing in a state where the drive unit is assembled from the side opposite to the drive unit. What is necessary is just to make it incorporate a 2nd speed-reduction mechanism part in the casing of the state.
[0039]
According to this manufacturing method, the first reduction mechanism unit and the second reduction mechanism unit (having coaxiality) can be sequentially incorporated with reference to the drive shaft of the drive unit fixed to the casing first. The labor of the person is greatly reduced.
[0040]
In particular, both the simple planetary roller structure employed in the first reduction mechanism and the swinging intermeshing planetary gear structure employed in the second reduction mechanism have strong unit elements (module elements). , Each of them can be assembled together in a casing in a state where they are assembled to some extent in different stages. In addition, since both have a structure for transmitting the rotational power coaxially, positioning is easy and quick assembly is possible.
[0041]
In terms of facilitating assembly, the connecting structure of the drive shaft of the drive unit and the sun roller of the first reduction mechanism unit, the planetary carrier of the first reduction mechanism unit, and the first of the second reduction mechanism unit. The connecting structure with the shaft is preferably a spline coupling structure that allows play in the axial radial direction. In this way, there is almost no need for fine adjustment at each stage of incorporation of the first speed reduction mechanism and the second speed reduction mechanism, and it is possible to assemble more easily and quickly.
[0042]
Further, in consideration of the above idea, the second reduction mechanism portion in the rotary drive device is rotated via a bearing on the reduction gear connected to the first reduction mechanism portion and the casing on both axial sides of the reduction gear. A carrier transmission structure that includes a pair of carriers that are freely supported and that extract the rotational power of the speed reducer may be used, and the above-described invention can be similarly applied.
[0043]
For example, in addition to the already described intermeshing planetary gear structure, the speed reducer in the second reduction mechanism unit is connected to the first reduction mechanism unit, a planetary member arranged around the solar member, The planetary member includes a ring member with which the planetary member is inscribed, and a pair of carriers are rotatably disposed in the casing via bearings at both axially outer positions of the planetary member to surround the solar member around the planetary member. A configuration may be adopted in which only the revolution component is transmitted to the output shaft.
[0044]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0045]
1 is a cross-sectional view of a rotary drive device (geared motor) shown as an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a first reduction mechanism portion therein, and FIG. 3 is a view taken in the direction of arrows III-III in FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. In the following description, the same or similar parts as those in the configuration of the conventional example shown in FIG.
[0046]
The rotational drive device 101 includes a drive unit 102 that generates rotational power, a first reduction mechanism unit 104 that is connected to the drive unit 102 and transmits rotational power, and a first reduction mechanism unit 104 that is connected to the first reduction mechanism unit 104. 2 deceleration mechanism unit 106.
[0047]
The second reduction mechanism 106 is a first shaft (Input shaft) 111, external gears 115a and 115b that rotate eccentrically with respect to the first shaft 111, an internal gear 120 that is fixed to the casing 151 and internally meshes with the external gears 115a and 115b, and an external gear 115a 115b, a pair of carriers 123 and 124 that are rotatably supported by the casing 151 via bearings 131 and 132 at both outer side positions in the axial direction (L), and extract only the rotation components of the external gears 115a and 115b, and The swinging intermeshing planetary gear structure includes a second shaft 112 (output shaft) that is disposed coaxially with the one shaft 111 and to which the rotation of the carriers 123 and 124 is transmitted.
[0048]
The casing 151 of the second speed reduction mechanism unit 106 includes a central casing 152 that is integral with the internal gear 120, a joint casing 153 on the drive unit 102 side (first speed reduction mechanism unit 104 side), and the central casing 152. And a front casing 154 disposed on the opposite side of the joint casing 153.
[0049]
A bearing 131 that supports the carrier 123 is fitted inside the joint casing 153, and the joint casing 153 is slightly extended in the axial direction L, so that the space closer to the drive unit 102 than the bearing 131 formed thereby. In addition, the first reduction mechanism 104 is accommodated.
[0050]
That is, the first reduction mechanism unit 104 corresponds to a front-stage reduction unit, and the second reduction mechanism unit 106 corresponds to a rear-stage reduction unit.
[0051]
The casing 155 of the drive unit 102 is composed of a cylindrical casing 156 with a built-in stator, the above-described joint casing 153, and a rear cover 157 located on the opposite side of the joint casing 153. The casing 153 serves as both the casing 151 on the speed reduction mechanism side and a part of the casing 155 on the drive unit 102 side.
[0052]
More specifically, two eccentric bodies 113a and 113b are fitted on the outer periphery of the first shaft 111 of the second speed reduction mechanism unit 106 adjacent to each other in the axial direction with a predetermined phase difference (180 ° in this example), These rotate integrally with the first shaft 111. As shown in FIG. 4, the centers O1 of the eccentric bodies 113a and 113b are eccentric by a predetermined eccentricity amount e with respect to the axis O2 of the first shaft 111. External gears 115a and 115b are fitted to the outer circumferences of the eccentric bodies 113a and 113b via bearings 114a and 114b.
[0053]
A plurality of inner pin holes 116a and 116b are respectively formed in the double row (two) external gears 115a and 115b, and the inner pins 117 are loosely fitted into the inner pin holes 116a and 116b. The outer teeth of the external gears 115 a and 115 b are provided with external teeth of trochoidal teeth and arc teeth, and the external teeth are in mesh with an internal gear 120 provided concentrically with the first shaft 111. The internal gear 120 is integrally formed on the inner periphery of the central casing 152, and each internal tooth is constituted by an outer pin 121 held on the inner periphery of the central casing 152.
[0054]
The difference in the number of teeth between the external gears 115a and 115b and the internal gear 120 is “4” (see FIG. 4).
[0055]
Both carriers 123 and 124 arranged outside the two external gears 115a and 115b are rotatably supported by bearings 131 and 132 fitted inside the joint casing 153 and the front casing 154, respectively. A plurality of carrier pins (connection pins) 125 and spacers 126 penetrating the gears 115a and 115b are axially positioned and integrally coupled. Further, both ends of the inner pin 117 loosely fitted in the inner pin holes 116a and 116b of the external gears 115a and 115b are coupled to the carriers 123 and 124 on both sides so as to be able to slide and rotate, thereby the external gears 115a and 115b. Only the rotation component is transmitted to the carriers 123 and 124 on both sides.
[0056]
The carrier 123 on the drive unit 102 side has a ring shape having a central hole 123a, and the tip 111a of the first shaft 111 faces the central hole 123a. The opposite carrier 124 is formed integrally with the base of the second shaft 112, and the other end 111 b of the first shaft 111 is inserted into a recess 124 a formed in the carrier 124. The first shaft 111 is rotatably supported by a bearing 133 fitted in the through hole 123a of the carrier 123 and a bearing 134 fitted in the vicinity of the recess 124a of the other carrier 124. Yes.
[0057]
As shown in an enlarged view in FIG. 2, the first speed reduction mechanism unit 104 includes a sun roller 211 that is coupled to the drive shaft 161 of the drive unit 102, a planet roller 212 that is in rolling contact with the outer periphery of the sun roller 211, and the planet The friction transmission type simple planetary roller structure includes a ring roller 213 in which the roller 212 is inscribed, and a planet carrier 215 that extracts a revolution component of the planetary roller 212 and transmits it to the first shaft 111 of the second speed reduction mechanism unit 106.
[0058]
The outer diameter of the ring roller 213 of the first speed reduction mechanism 104 is such that the outer diameter of the bearing 131 that supports the drive part 102 side (that is, the carrier 123) of the pair of carriers 123 and 124 of the second speed reduction mechanism 106. It is set within the dimensions. Further, the ring roller 213 is disposed in a space closer to the drive unit 102 than the bearing 131 in the casing 151 (specifically, the joint casing 153).
[0059]
The first reduction mechanism 104 will be described in more detail with reference to FIGS.
[0060]
The inner diameter D3 of the ring roller 213 is set to be slightly smaller than the sum of the diameter D2 of the planetary roller 212 and the diameter D1 of the sun roller 211. Therefore, in the state where the planetary roller 212 and the sun roller 211 are incorporated inside the ring roller 213, the ring roller 213 is elastically deformed slightly outward in the radial direction, and the friction rollers 211, 212, A predetermined pressing force is applied between contact surfaces with 213 to generate a frictional force.
[0061]
Further, the ring roller 213 is fixed to the joint casing 153 by a through bolt 252 as a fixing element in the simple planetary roller structure. The sun roller 211 is an input element, and the planet carrier 215 that supports the planet roller 212 is an output element. In addition, the outer diameter of the ring roller 213 is set smaller than the inner peripheral diameter of the joint casing 153 so that a radial external pressure is not applied to the ring roller 213.
[0062]
A planet carrier 215 for taking out the revolving motion of the planetary roller 212 includes a hollow cylindrical output shaft portion 216 protruding toward the second speed reduction mechanism portion 106 side, and a retainer integrally formed on the proximal end side of the output shaft portion 216. And an inner spline 218 is formed on the inner periphery of the output shaft portion 216. The inner spline 218 is engaged with an outer spline formed on the shaft end portion of the first shaft 111 of the second reduction mechanism unit 106 (see FIG. 1), and rotates together.
[0063]
The retainer portion 217 has four protrusions 217a to 217d that protrude in the axial direction and are respectively inserted between the four planetary rollers 212. The protrusions 217a to 217d are provided with the planetary roller 212. A concave arc surface 219 having the same curvature as the outer peripheral surface is formed.
[0064]
Accordingly, the retainer portion 217 keeps the concave circular arc surface 219 in contact with the planetary roller 212 and keeps the circumferential positions of the planetary rollers 212 constant at 90 ° intervals. The planet carrier 215 provided with the retainer 217 plays a role of holding the planetary roller 212 in a rotatable manner and a function of taking out the revolution component of the planetary roller 212.
[0065]
Ring-shaped side plates 221 are disposed on both end faces of the ring roller 213, and the contact surface portions between the planetary roller 212 and the ring roller 213 are shielded from the outside by the both side plates 221. . The inner peripheral side of the shielded space is also sealed by the outer peripheral surface of the retainer portion 217, and traction grease that is more expensive than gear grease is sealed in the space. This grease is not for reducing friction but for ensuring frictional force.
[0066]
In addition, a partition plate 222 that partitions the space in which the sun roller 211 is accommodated from the internal space of the output shaft portion 216 is also disposed at the back of the sun roller 211.
[0067]
The simple planetary roller structure of the first speed reduction mechanism portion according to the present invention is not limited to the retainer type as described above, and the planetary carrier 215 includes an axial pin, and the ring-shaped planetary roller. 212 may be a pin type that is rotatably held by this pin.
[0068]
In the first speed reduction mechanism unit 104, the sun roller 211 is driven by the drive unit 102, and accordingly, the planetary roller 212 tries to revolve around the sun roller 211. Since the planetary roller 212 is sandwiched between the ring roller 213 and the sun roller 211, the planetary roller 212 revolves around the sun roller 211 so as to roll on the inner peripheral surface of the ring roller 213. In other words, the planetary roller 212 revolves around the sun roller 212 with its rotation. The revolving motion of the planetary roller 212 is taken out by the planetary carrier 215 through the retainer unit 217 and transmitted to the first shaft of the second reduction mechanism unit 106 at a predetermined reduction ratio. The planet carrier 215 and the first shaft of the second reduction mechanism unit 106 may be integrated.
[0069]
Thereafter, as already shown in the conventional example, the rotation is transmitted at a predetermined reduction ratio by the second reduction mechanism 106 of the swinging intermeshing planetary gear structure and output from the second shaft 112.
[0070]
The inventor pays attention to the fact that the ring roller 213 in the simple planetary roller structure has the same ring structure as that of the bearing 131. It has been found that one speed reduction mechanism 104 can be arranged. Therefore, under this idea, the outer diameter dimension of the ring roller 213 is set to be equal to or smaller than the outer diameter dimension of the bearing 131 that supports the carrier 123 of the second reduction mechanism unit 106. Can be accommodated concentrically on the drive unit 102 side.
[0071]
As a result, the rotary drive device 101 uses the first stage reduction mechanism unit as a simple planetary structure and achieves a high reduction ratio (high output). Compared with a rotary drive device that includes only the speed reduction mechanism 106, the length in the axial direction is limited to only about 5%, and there is a conflicting demand for high reduction ratio and compactness, which was previously considered difficult. Can be reasonably compatible. As a result, the manufacturing cost is greatly reduced as compared with the conventional one.
[0072]
Further, the simple planetary roller structure employed in the first speed reduction mechanism unit 104 is a friction transmission type that transmits rotational power by the frictional force generated between the friction rollers 211, 212, and 213. Can also be configured quietly. Therefore, there is no problem that the noise increases even with the two-stage reduction structure in which the first reduction mechanism 104 and the second reduction mechanism 106 are combined. Rather, the noise is far beyond the prediction range. The inventor has confirmed that the reduction can be achieved (Japanese Patent Application No. 11-180641). In particular, since this rotary drive device accommodates the first and second speed reduction mechanism sections 104 and 106 in the same internal space of the casing 151, new resonances are generated by the mutual interference of the two spaces. Noise, and further increase in noise is prevented.
[0073]
Next, an assembly method (manufacturing method) of the rotary drive device 101 will be described with reference to FIG.
[0074]
First, as shown in FIG. 5A, the drive unit 102 is assembled to the casing 151 (a joint casing 153 which is a part of the casing 151). That is, the unit-like drive unit 102 that has already been assembled in another stage is connected to the casing 151.
[0075]
Next, as shown in FIG. 5 (B), the simple planetary roller structure is formed on the casing 151 (joint casing 153) in a state where the driving unit 102 is assembled from the side opposite to the driving unit 102 (from the opposite side). The first reduction mechanism 104 is incorporated. The first speed reduction mechanism 104 is already assembled in another stage by inserting the retainer 217 of the planet carrier 215 into the sun roller 211, the planetary roller 212, and the ring roller 213, which are assembled in advance by shrink fitting. It is only necessary to insert the units together and fix the ring roller 213 with the through bolts 252.
[0076]
Since the sun roller 211 and the drive shaft 161 have a floating connection structure (spline structure) and have play in the radial direction, the first speed reduction mechanism 104 can be easily inserted.
[0077]
Next, as shown in FIG. 5C, the second reduction mechanism unit 106 having a swinging intermeshing planetary gear structure is incorporated into the casing 151 in which the first reduction mechanism unit 104 is incorporated. The second reduction mechanism 106 can also be assembled in a separate stage in a unit state (module state) (except for the internal gear 120), and this can be simply inserted into the casing 151. The internal gear 120 (including the central casing 152) is preferably fixed to the joint casing 153 in advance.
[0078]
Thereafter, when the front casing 154 is assembled, the rotary drive device 101 is completed.
[0079]
According to this method, on the basis of the casing 151 (joint casing 153), the drive unit 102, the first reduction mechanism unit 104, and the second reduction mechanism unit 106 having high unit elements can be assembled at a stretch. This is because the outer diameter of the first speed reduction mechanism 104 (the outer diameter of the ring roller 213) is set smaller than the outer diameter of the bearing 131 of the second speed reduction mechanism 106 so that they can be accommodated in the same internal space. Because.
[0080]
Furthermore, since the first and second reduction mechanism units 104 and 106 having a coaxial power transmission form may be assembled on the basis of the axis of the drive shaft 161 of the drive unit 102 to be assembled first, Positioning is very easy and assembly accuracy and assembly speed are greatly improved.
[0081]
As a result, the assembly labor of the worker is greatly reduced, leading to a reduction in manufacturing cost.
[0082]
In the above-described embodiment, the second reduction mechanism in the rotary drive device has been shown to be limited to an intermeshing planetary gear structure. It is not limited to. That is, the second reduction mechanism unit is rotatably supported by the casing via the bearings on both outer sides in the axial direction of the reduction device coupled to the first reduction mechanism unit, and takes out the rotational power of the reduction device. A carrier transmission structure including a pair of carriers is sufficient, and the above-described invention can be similarly applied.
[0083]
【The invention's effect】
Since the present invention is configured as described above, the reduction ratio can be significantly increased while minimizing the size of the rotary drive device as much as possible. Further, since the rotary drive device can be assembled simply and quickly, the labor of the operator is greatly reduced, and the manufacturing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a rotary drive device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a first speed reduction mechanism portion having a simple planetary roller structure in the rotation driving device.
3 is a view taken in the direction of arrows III-III in FIG.
4 is a cross-sectional view taken along line IV-IV in FIG.
FIG. 5 is a schematic view showing an assembly process of the rotation drive device.
FIG. 6 is a cross-sectional view showing a conventional rotary drive device
[Explanation of symbols]
101 ... Rotary drive device
102 ... Drive unit
104: First reduction mechanism
106: Second reduction mechanism
111 ... 1st axis
112 ... second axis
115a, 115b ... external gears
120 ... Internal gear
123, 124 ... Carrier
131, 132 ... bearings
151 ... casing
153. Joint casing
161: Drive shaft
211 ... Sun Roller
212 ... Planetary roller
213 ... Ring roller
215 ... Planetary carrier

Claims (3)

A drive unit that generates rotational power;
A first reduction mechanism coupled to the drive unit for transmitting the rotational power;
A first shaft coupled to the first speed reduction mechanism, an external gear rotating eccentrically with respect to the first shaft, an internal gear fixed to a casing and internally meshing with the external gear, and the external teeth A pair of carriers that are rotatably supported by the casing via bearings at both outer positions in the axial direction of the gear, take out only the rotation component of the external gear, and are arranged coaxially with the first shaft. A rotation drive device comprising: a second reduction gear mechanism having an intermeshing planetary gear structure provided with a second shaft to which rotation is transmitted;
A sun roller coupled to the drive shaft of the drive unit, a planetary roller that is in rolling contact with the outer periphery of the sun roller, a ring roller that is inscribed by the planetary roller, and a revolution component of the planetary roller are extracted from the first reduction mechanism unit. And a planetary carrier that transmits to the first shaft of the second reduction mechanism, and a friction planetary simple planetary roller structure,
An outer diameter dimension of the ring roller is set within an outer diameter dimension of the bearing that supports the driving part side of the pair of carriers of the second reduction mechanism,
A rotary drive device characterized in that the ring roller is disposed in the same casing as the casing housing the bearing and in a space closer to the drive unit than the bearing . It is a manufacturing method of the rotation drive device according to claim 1,
A first procedure for assembling the drive unit to the casing;
A second step of incorporating the first reduction mechanism from the opposite side of the casing into the casing in a state where the driving unit is assembled;
A third procedure for incorporating the second deceleration mechanism into the casing in which the first deceleration mechanism is incorporated;
A method of manufacturing a rotary drive device, comprising: A drive unit that generates rotational power;
A first reduction mechanism coupled to the drive unit for transmitting the rotational power;
A carrier transmission type comprising a speed reducer coupled to the first speed reduction mechanism, and a pair of carriers that are rotatably supported by a casing via bearings on both outer sides in the axial direction of the speed reducer and take out rotational power of the speed reducer. A second drive mechanism comprising:
A sun roller coupled to the drive shaft of the drive unit, a planetary roller that is in rolling contact with the outer periphery of the sun roller, a ring roller that is inscribed by the planetary roller, and a revolution component of the planetary roller are extracted from the first reduction mechanism unit. And a planetary carrier that transmits to the input shaft of the second speed reduction mechanism, and a friction transmission simple planetary roller structure,
An outer diameter dimension of the ring roller is set within an outer diameter dimension of the bearing that supports a drive part side of the pair of carriers of the second reduction mechanism part;
The ring roller, a said casing and within the same casing that houses the bearing, and the rotary drive device, characterized in that arranged in the space of the bearing Keyori driver side.

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