JPH05256340A - Structure of inscribed planetary gear - Google Patents

Abstract

PURPOSE:To facilitate fitting to a partner member, and also to achieve miniaturization, while strongly maintaining the rigidity of a carrier. CONSTITUTION:The structure of an inscribed planetary gear comprises a support block 104 in which a carrier body 150 has been integrally formed, and a stop block 105. At the root part of the carrier body 150, or on the inside of the support block 104, a cutout part in which a transmission gear 113 can be fitted from the outside in the radial direction is provided. In the inside of this cutout part 151 (not shown), the transmission gear 113 is provided. As a result, when a partner machinery P is fitted, the transmission gear 113 does not interfere, and also a driving source such as a motor can be arranged on the stop block side without interfering with the partner machinery P, and further the shaft thereof (input shaft 103) can be inserted up to the neighborhood of the support block 104. Thus, when a general-purpose motor (having a given shaft length) is used, the length in the axial direction after assembling can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed reducer or speed increaser, and more particularly to an internal mesh planetary gear structure suitable for application to a speed reducer or speed reducer or a speed reducer which is required to be small in size.

[0002]

2. Description of the Related Art Conventionally, a main rotating shaft, a pinion provided on the main rotating shaft, a plurality of transmission gears that mesh with the pinion, a plurality of eccentric body shafts that rotate together with the transmission gears, and an eccentric body. An eccentric body provided on the shaft, an external gear supported by the eccentric body via an eccentric body bearing and swingably rotating with respect to the main rotation shaft, an internal gear meshing with the external gear, and Both ends of the eccentric body shaft are rotatably supported, and a support block and a stop block for rotating the self-rotating component of the external gear itself are provided, and a carrier body integrally projecting from the support block side is interposed. A reduction gear adopting an internally meshing planetary gear structure in which a support block and a stop block are connected to form a carrier is disclosed in US Pat. No. 3,129,611.
It is known by the issue.

However, in a speed reducer adopting this kind of known intermeshing planetary gear structure, there is play or play in the gears meshing with each other and in the means for attaching to the shaft, so that the forward rotation changes to the reverse rotation. Sometimes there is a phenomenon (reverse rotation on the driving side that does not immediately appear as reverse rotation on the starting side) (angle backlash).
For example, when it is used as a speed reducer for a control device such as a joint device of an industrial robot, there is a problem in that control accuracy is deteriorated due to the angle backlash.

Therefore, in a known internally meshing planetary gear reducer, the tooth profile of the internal gear is a circular arc tooth profile consisting of pins, the tooth profile of the external gear is a trochoidal waveform or circular arc tooth profile, and the number of teeth of the external gear is Japanese Patent Application Laid-Open No. 60-260737 proposes a speed reducer configured to further reduce the angular backlash in a combination in which the number of teeth of the internal gear is one less.

FIGS. 5 and 6 show a conventional example of an internally meshing planetary gear structure of this type.

In these drawings, reference numeral 1 denotes a cylindrical casing having an outer flange 2. At the center of the casing 1, the tip of an input shaft (main rotation shaft) 3 driven by a motor (not shown) is inserted.

A support block 4 and a stop block 5 are arranged in the casing 1 so as to face each other at an axial interval. The support block and the stop blocks 4 and 5 are rotatably supported on the inner circumference of the casing 1 via bearings 6a and 6b, respectively.

In FIG. 5, the support block 4 on the right side has a carrier body 7 (see FIG. 6) of a complicated shape protruding toward the stop block 5 on the left side.
Through the carrier body 7, bolts 29 and pins 30 are connected and fixed to each other to form a carrier as a whole.

Further, in the casing 1, three eccentric body shafts 8 are arranged in parallel with the input shaft 3. The eccentric body shafts 8 are arranged on the circumference of a circle concentric with the input shaft 3 at equal intervals in the circumferential direction, and both end portions of the eccentric body shaft bearings 9a, 9a, 9b are provided.
The eccentric body shaft bearing holes 10a and 10b of the support block 4 and the stop block 5 are rotatably supported via b.

The end portion of each eccentric body shaft 8 on the side of the stop block 5 projects further outward than the portion supported by the eccentric body shaft bearing 9a, and the transmission gear 13 via the spline 12 extends to the projecting portion. Is installed. Here, two transmission gears 13 are mounted in a stacked manner to prevent backlash.

That is, by incorporating the two transmission gear bodies 13a and 13b with their phases offset from each other, a backlash is caused by either of the transmission gear bodies 13a and 13b during forward rotation and reverse rotation. It is designed to be able to transmit power without.

Center holes 14 and 15 are formed in the radial centers of the support block 4 and the stop block 5, respectively, and the input shaft 3 penetrates the center holes 14 and 15. Then, the pinion 16 meshing with the transmission gear 13 fixed to each eccentric body shaft 8 is fixed to the tip of the input shaft 3, whereby the rotation of the input shaft 3 is prevented.
And via the transmission gear 13 are equally distributed to the three eccentric body shafts 8.

In this case, the number of teeth of the transmission gear 13 is larger than the number of teeth of the pinion 16, and each eccentric body shaft 8 is decelerated and rotated by the ratio of the numbers of teeth of the transmission gear 13 and the pinion 16.

Two eccentric bodies 17a and 17b are provided side by side in the axial direction at a substantially central portion of each eccentric body shaft 8 in the axial direction. The eccentric bodies 17a and 17b are out of phase with each other by 180 °.

On the other hand, between the support block 4 and the stop block 5, two external gears 18a and 18b are arranged. Each of the external gears 18a, 18b is provided with three eccentric body bearing holes 19a, 19b through which the eccentric body shaft 8 passes, and the eccentric body bearing holes 19a, 19b are respectively provided with the eccentric bodies 17a, 17b. Are fitted via eccentric body bearings 20a and 20b. Thereby, the external gears 18a, 18b
Is supported in a state in which its center Og is eccentric with respect to the rotation center Of of the input shaft 3 by a distance e, as shown in FIG.
Each time the eccentric body shaft 8 rotates once, the eccentric body shaft 8 swings and rotates about the rotation center Of of the input shaft 3 only once.

The external gears 18a and 18b have arcuate or trochoidal external teeth 24, and an internal gear 25 to which the external gears 18a and 18b mesh is arranged on the outer peripheral side thereof. .. The internal gear 25 is formed integrally with the casing 1 on the inner circumference of the casing 1, and has an outer pin 26.
It has internal teeth consisting of.

As shown in FIG. 6, insertion holes (= fitting insertion holes) 28a and 28b having a complicated curved contour are formed in the central portions of the external gears 18a and 18b. Then, with the carrier body 7 of the support block 4 penetrating these insertion openings 28a, 28b and the end face of the carrier body 7 being in close contact with the inner end face of the stopper block 5, both blocks 4, 5 are The carriers are connected and fixed to each other by bolts 29 and pins 30 to form an integral carrier.

The carrier body 7 mutually transmits the rotational force received by the support block 4 and the stop block 5,
The insertion openings 28a, 28b of the external gears 18a, 18b are formed as openings having sizes and shapes that do not interfere with the carrier body 7 even if the external gears 18a, 18b swing.

Next, the operation will be described.

Here, first, it is assumed that the casing 1 is fixed and the rotation output is taken out from the carrier constituted by the support block 4 and the stop block 5.

When the input shaft 3 rotates, the three eccentric body shafts 8 rotate in the same direction (opposite to the input shaft 3) at the same speed via the pinion 16 and the transmission gear 13. The three eccentric body shafts 8 are provided with two eccentric bodies 17a and 17b, respectively, and the eccentric bodies 17a and 17b are eccentrically rotated in the same direction at the same speed, so that the two external gears 18 are provided.
The a and 18b oscillate and rotate with respect to the input shaft 3.

Since it is assumed here that the casing 1 is fixed, that is, the internal gear 25 is fixed, the external gears 18a and 18b are restrained by the internal gear 25 from free rotation. , And swings while inscribed in the internal gear 25. Now, for example, the external gears 18a and 18b
When the number of teeth of N is N and the number of teeth of the internal gear 25 is N + 1,
The difference in the number of teeth is 1. Therefore, each time the eccentric body shaft 8 rotates once, the external gears 18a and 18b are displaced (rotated) by one tooth with respect to the internal gear 25.

This "deviation", that is, the external gears 18a, 18a
The rotation of b is transmitted to the support block 4 and the stop block 5 via the eccentric body shaft 8. The rotational force transmitted to each of the blocks 4 and 5 is taken out as a resultant force because both blocks 4 and 5 are integrated via the carrier body 7. In addition,
When the eccentric body shaft 8 makes one rotation, both blocks 4 and 5 are -1.
/ N rotation is reduced.

In the above description, the operation when the casing 1 is fixed and the output is taken out from the support block 4 and the stop block 5 side has been described. However, the support block 4 and the stop block 5 are described.
Can be fixed and the output can be taken out from the casing 1 side. In that case, the outer flange 2 provided on the casing 1
Will be connected to the mating member. As a result, the decelerated rotation output of 1 / (N + 1) rotation (with respect to the input rotation) is extracted from the casing 1 in the reverse rotation of the support blocks 4 and 5.

As described above, the casing 1 side may be fixed and the decelerated rotation output may be taken out from both the blocks 4 and 5, or both blocks 4 and 5 may be fixed and the decelerated rotation output may be obtained from the casing 1 side. You may take it out. That is, when applied as a speed reducer, the above two usage modes are possible. The former is called the carrier rotating type and the latter is called the case rotating type when distinguishing by the way of taking out the output.

Since the conventional structure shown in FIGS. 5 and 6 is constructed on the assumption that it is used as a case rotating type, a cover 31 is provided at the opening of the casing 1 on the transmission gear 13 side. ing.

The intermeshing planetary gear structure of this type can also be used as a speed-up gear by reversing the input / output relationship in both the case rotation type and the carrier rotation type.

The number of the eccentric body shafts 8 may be two, but in practice, the external gears 18a and 18b are stably held, and the column portion of the support block 4 penetrating the external gears 18a and 18b. Depending on the space, it is often the case that there are not too many and not too many.

The positions of the support block, the stop block, and the transmission gear of the above-described conventional example are skeletonized, as shown in FIG.

Another example of the arrangement known in the art is shown in FIG. 8 or FIG. The configuration shown in FIG. 8 is disclosed in JP-A-57-37137.
According to the invention, a detachable stop block is provided with a notch for accommodating a transmission gear, and the transmission gear is incorporated between the support block and the stop block and on the side of the stop block.

On the other hand, in the configuration shown in FIG. 9, the transmission gear is provided outside the support block.

[0032]

By the way, in the field of the speed increasing / decreasing device for this kind of rotation control device, there has been an increasing demand for compactness and high rigidity in recent years.

In general, in order to realize high rigidity, it is preferable to connect to the counterpart machine on the side of the support block integrally provided with the carrier body. In this respect, the configurations of FIGS. 7 and 8 are unreasonable. In this case, it is inevitable that the motor shaft (input shaft: main rotation shaft) that is the drive source is inserted from the side of the stop block to prevent interference in the arrangement of the motor and the partner machine. Moreover, the structure of the internally meshing planetary gear structure itself can be simplified.

On the other hand, since a commercially available motor is often directly connected to the input shaft (main rotation shaft), the shaft length of the motor generally has a fixed length. Therefore, if the pinion (and transmission gear) is arranged as close as possible to the mating machine mounting surface of the support block in the axial direction, the input shaft can be taken into the reducer by that much, so the axial direction when mounting the motor The length can be made compact.

Considering the above two points, the arrangement shown in FIG. 9 is the most rational among the three arrangements.

However, in this case, since the transmission gear occupies a large area of the mating machine mounting surface of the supporting block, it is necessary to make tap holes for mounting the mating machine sufficiently large and many in the supporting block. There is a problem that space cannot be secured, and so-called knocks are used together with bolts for mounting, which makes handling inconvenient.

Due to such circumstances, FIG. 7 (FIG. 5,
In the conventional example shown in FIG. 6), the output is not taken out from both block sides, but the output is taken out from the casing as a carrier rotation type (connected to the mating machine via the outer flange 2 provided on the casing). is there.

The present invention has been made in view of such a conventional problem, and a pinion and a transmission gear are installed in the back as viewed from the input side and a commercially available motor or the like is used as a drive source. In this case, the already decided shaft length can be taken into the reducer for a large overall size, while the mounting surface of the mating machine can be widely secured on the support block. Because it is
It is an object of the present invention to solve the above problems by providing an internally meshing planetary gear structure that can be assembled only by fastening with bolts.

[0039]

The present invention comprises a main rotary shaft,
A pinion provided on the main rotating shaft, a plurality of transmission gears that mesh with the pinion, a plurality of eccentric body shafts that rotate together with the transmission gears, an eccentric body provided on the eccentric body shaft, and the eccentric body. An externally toothed gear supported by an eccentric body bearing to oscillate and rotate with respect to the main rotation shaft, an internally toothed gear meshing with the externally toothed gear, and rotatably supporting both ends of the eccentric body shaft. The carrier itself includes a support block and a stop block that rotate the rotation component of the external gear, and the support block and the stop block are connected to each other via a carrier body that is integrally formed to project from the support block side. In the internally meshing planetary gear structure that is formed, a plurality of notches each having a size that allows the transmission gear to be incorporated into the pinion from the outside in the radial direction is formed in the root portion of the carrier body that is integrally formed with the support block. Success And, by accommodating the said transmission kinematic gears within come the notch is obtained by solving the above problems.

By adopting this structure, it becomes easy to insert the main rotary shaft from the side of the stop block.

Further, it is possible to easily realize a structure in which the support block is connected to the counterpart machine.

[0042]

In the present invention, since the base portion of the carrier body formed integrally with the support block is provided with a notch so that the transmission gear can be assembled from the outside in the radial direction, the strength of the carrier body can be maintained sufficiently. The pinion and the transmission gear (while still thick) can be located between the support block and the stop block and on the support block side. As a result, the input shaft (main rotation shaft) can be sufficiently housed in the reduction gear while maintaining high rigidity, so that the axial length in the state where the motor is attached can be shortened.

Furthermore, since the pinion and the transmission gear are housed inside the support block (on the side of the external gear), it is possible to secure a wide area for mounting the mating machine on the supporting block, and for mounting the mating machine. Many tap holes can be provided. As a result, the structure of the carrier rotation type can be easily achieved, and moreover, the transmission torque can be sufficiently secured only by fastening only with the bolts, so that, for example, a knock or the like is not required (therefore, simultaneous machining with the counterpart machine for that purpose, etc. It will be possible to significantly reduce the assembly man-hours.

In this specification, the block on the integrally formed side of the carrier body is defined as the support block, and the other side is defined as the stop block. This definition is, for example, on the side of the stop block on the carrier body. Does not require that the protrusions are formed at all, and substantially more carrier bodies can be defined as the support block, and the other one can be defined as the stop block.

[0045]

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

In FIG. 1, the casing 101 has a plurality of bolt insertion holes 102. Casing 101
A tip end of an input shaft (main rotation shaft) 103, which is rotationally driven by a not-shown (general-purpose) motor, is inserted from the right side in the drawing into the central portion.

In the casing 101, the carrier body 15
A support block (0 on the left side) integrally formed with 0
4 and a stop block (right side in the figure) 105 are arranged to face each other.

The outer end surface (the left end surface in the figure) of the support block 104 is a mating member mounting surface 104a. The blocks 104 and 105 have bearings 106a and 106b, respectively.
It is rotatably supported on the inner periphery of the casing 101 via.

In both blocks 104 and 105, a connecting bolt 155 is connected from the stopper block 105 side with a connecting bolt hole 157.
It is connected and fixed together by being screwed into. At this time, the protrusion height H of the carrier body 150 toward the stop block 105 side keeps the interval between the blocks 104 and 105 constant.

The carrier body 150 basically has a circular cross section, but only the portion corresponding to the root portion of the support block 104 has the transmission gear 113 in the direction of arrow A as shown in FIG. That is, the notches 151 are formed so that they can be assembled from the outside in the radial direction.

The transmission gear 113 meshes with the pinion 116 mounted on the input shaft 103, so that the rotation of the input shaft 103 is equally distributed to the three eccentric body shafts 108 via the pinion 116 and the transmission gear 113. It is supposed to be done. In this case, since the number of teeth of the transmission gear 113 is larger than the number of teeth of the pinion 116, each eccentric body shaft 108 is decelerated and rotated by the ratio of the numbers of teeth of the transmission gear 113 and the pinion 116.

Other configurations and operations are basically the same as those of the conventional example described above. Therefore, only the same or similar portions in the drawings are given the same reference numerals in the last two digits, and duplicate explanations are omitted. To do.

Since this embodiment employs such a structure, the carrier body 150 can have a thickness sufficient to maintain the rigidity of the carrier, and the carrier body 15 can have a sufficient thickness.
0 is integrally formed on the side of the support block 104, and a mating member is attached to the support block 104,
It has a very advantageous structure in terms of strength.

Further, the carrier body 150 is the support block 10.
Despite being integrally formed with the transmission gear 113, a notch that allows the transmission gear to be incorporated from the outside in the radial direction is provided in the root portion thereof, so that the transmission gear 113 (stops the transmission gear 113 while avoiding interference with the carrier body 150). It can be provided on the support block 104 side (not on the block 105 side).

That is, since the transmission gear 113 is located on the side of the support block 104 in the axial direction, the input shaft 103 inserted from the side of the stop block is accommodated sufficiently inside the case (on the side of the support book). , The axial length when the motor is attached can be shortened.

Further, the pinion 116 and the transmission gear 113.
Is located inside the support block 104 (on the side with the external gear), it is possible to secure a sufficiently large area for the mating member mounting surface 104a of the support block 104, and to secure a large number of mating member taps. The holes 156 can be formed. Therefore, compared to the conventional example shown in FIGS. 7 and 8, in which the pinion 116 and the transmission gear 113 are located outside one of the blocks, a knock or the like is required when the mating member is assembled. Therefore, it is possible to complete the installation only with the bolts without requiring simultaneous machining with the mating member for the knock or the like, so that the number of assembling steps can be greatly reduced.

[0057]

As described above, according to the present invention, the root portion of the carrier body of the support block, that is, the pinion and the transmission gear, without interfering with the carrier body while maintaining the strength of the carrier body sufficiently, that is, It becomes possible to arrange it inside the support block and adjacent thereto. As a result, it becomes possible to secure a wide mounting surface for the mating machine on the support block, and since many mounting taps can be provided, it is possible to secure a sufficient transmission torque capacity by only fastening with bolts. ..

Therefore, for example, knocking or the like is not required, and simultaneous machining with the counterpart machine for that is not required, and the number of assembling steps can be greatly reduced.

Further, since the mating machine can be mounted on the integrally formed support block side of the carrier body, the strength is better than when the mating machine is mounted on the stop block side.

Further, by adopting such a configuration,
The motor can now be placed on the stop block side (without interfering with the mating machine), and because the pinion and transmission gear are located on the support block side, the input shaft of the motor can be moved far enough back. Since it can be housed (up to the side of the support block), when a commercially available motor or the like is used as a drive source, the already determined shaft length can be taken into the speed reducer, and compactification can be realized when assembled.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a speed reducer adopting an internally meshing planetary gear structure according to the present invention.

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

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a view shown by an arrow 4 in FIG.

5 is a sectional view corresponding to FIG. 1 showing an example of a speed reducer adopting a conventional internally meshing planetary gear structure.

6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is a skeleton diagram of the conventional example shown in FIGS. 5 and 6.

FIG. 8 is a skeleton diagram of another conventional example.

FIG. 9 is a skeleton diagram of still another conventional example.

[Explanation of symbols]

 1, 101 ... Casing, 3, 103 ... Input shaft (main rotation shaft), 4, 104 ... Support block, 5, 105 ... Stop block, 8, 108 ... Eccentric body shaft, 13, 113 ... Transmission gear, 17a, 17b 117a, 117b ... Eccentric body, 18a, 18b, 118a, 118b ... External gear, 20a, 20b, 120a, 120b ... Eccentric body bearing, 24, 124 ... External teeth, 25, 125 ... Internal gear, 150 ... Carrier Body, 155 ... connecting bolt, P ... mating member.

Claims (3)

[Claims] 1. A main rotating shaft, a pinion provided on the main rotating shaft, a plurality of transmission gears that mesh with the pinion, a plurality of eccentric body shafts that rotate together with the transmission gears, and an eccentric body shaft. An eccentric body provided, and an externally toothed gear supported by the eccentric body via an eccentric body bearing and swingably rotating with respect to the main rotation shaft,
The support block includes an internal gear that meshes with the external gear, a support block that rotatably supports both ends of the eccentric body shaft, and that itself rotates and rotates a rotation component of the external gear. In an internally meshing planetary gear structure in which a support block and a stop block are connected to each other through a carrier body integrally formed to project from the side to form a carrier, a carrier body integrally formed with the support block is attached. An intermeshing planetary gear structure, characterized in that a plurality of notches having a size capable of incorporating the conduction gear from the outside in the radial direction with respect to the pinion are formed in the root portion, and the conduction gear is accommodated in the notches. .. 2. The internally meshing planetary gear structure according to claim 1, wherein the main rotation shaft is inserted from the side of the stop block. 3. The internally meshing planetary gear structure according to claim 1 or 2, wherein the supporting block is connected to a counterpart machine.