WO2006077825A1 - Swinging inscribed engagement type planetary gear device - Google Patents

Abstract

A swinging inscribed engagement type planetary gear device, wherein a plurality of external gears are swingably rotated by a plurality of eccentric bodies mounted on an eccentric body shaft. The outer diameters of at least two eccentric bodies among the plurality of eccentric bodies are different from each other, and a sliding promoting body with an independent inner ring is installed between the outer periphery of the eccentric body with a small outer diameter among the two eccentric bodies and the external gears. Also, a sliding promoting body without an inner ring is installed between the outer periphery of the eccentric body with a large outer diameter among the two eccentric bodies and the external gears.

Description

 Specification

 Oscillating internal meshing planetary gear unit

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a swinging intermeshing planetary gear device.

 Background art

 [0002] It has an internal gear and a plurality of external gears that are internally meshed with the internal gear, and the external gears are respectively oscillated and rotated by a plurality of eccentric bodies formed on an eccentric body shaft. The oscillating internal meshing planetary gear device constructed as described above is widely used.

 [0003] For example, JP-A 2000-65162 discloses a planetary gear device as shown in FIG. The planetary gear device 10 includes an input shaft 12, first and second eccentric bodies 14, 16, first and second external gears 18 and 20, an internal gear 22, a relative rotation take-out mechanism K, and an output element serving as a first output gear. 1. Provided with second support flanges 24 and 26. The reason why the first and second external gears 18 and 20 are arranged in two rows along the axial direction is to increase the transmission capacity.

 The input shaft 12 is a hollow shaft (hollow shaft), and is arranged at the center in the radial direction of the planetary gear device 10. The input shaft 12 also serves as an eccentric body shaft, and the first and second eccentric bodies 14 and 16 are integrally formed on the outer periphery of the input shaft 12. The first and second eccentric bodies 14 and 16 have the same outer peripheral radius (outer diameter) with their forces that are 180 degrees out of phase with each other.

 [0005] The first and second external gears 18 and 20 are mounted on the outer circumferences of the first and second eccentric bodies 14 and 16 via first and second rollers (sliding promotion bodies) 34 and 36, respectively. I'm going.

[0006] The relative rotation take-out mechanism Κ includes first and second inner pin holes 40, 42 that pass through the first and second external gears 18, 20, and an inner portion that is loosely fitted to the inner pin holes 40, 42. This is achieved with pin 44.

When the input shaft 12 is rotated by a motor (not shown), the first and second eccentric bodies 14 and 16 are eccentrically rotated integrally with the input shaft 12 (in reverse phase). Therefore, when the input shaft 12 rotates once, the external gears 18 and 20 mounted on the outer circumferences of the eccentric bodies 14 and 16 swing once. As a result, the first and second external gears 18 and 20 are connected to the internal gear 22 in the stopped state. Relative rotation by the amount corresponding to the difference in the number of teeth from 22 respectively. This relative rotation is extracted as a deceleration output from one of the first and second support flanges 24 and 26 via the first and second inner pin holes 40 and 42 and the inner pin 44 (relative rotation extraction mechanism K). It is.

 [0008] However, in the conventional planetary gear device as described above, the two eccentric body forces (although the phases are different) formed integrally in the center of the input shaft (eccentric body shaft). The outer diameter was the same. Therefore, when the first and second rollers are assembled between the external gears, the first roller must be assembled from one axial direction and the second roller from the other axial direction. There was a problem of poor attachment.

 [0009] Further, in order to smoothly perform the assembly on the other side after the assembly of the roller on one side, the roller on the side on which the assembly has been completed is maintained so as not to be removed by any means at that stage. There was also a problem that it was necessary to keep. For this reason, if the position control means in the axial direction of each column is not provided independently, the assemblability will be further deteriorated, which increases the number of parts and man-hours for assembly. Was the cause of the increase.

 Disclosure of the invention

 The present invention has been made to solve such a conventional problem, and incorporates a sliding promotion body interposed between the eccentric body and the external gear from only one side. The challenge is to make it possible.

 [0011] The present invention includes an internal gear and a plurality of external gears that are internally engaged with the internal gear, and the external gears are respectively swung by a plurality of eccentric bodies provided on an eccentric body shaft. In the planetary gear device of the swing inscribed meshing type to be rotated and rotated, at least two of the eccentric bodies have different outer diameters, and the two eccentric bodies have a smaller outer diameter. A slide promoting body having an independent inner ring is provided between the outer periphery of the eccentric body and the external gear, and of the two eccentric bodies, the outer periphery of the eccentric body having a large outer diameter and the external gear In the meantime, the above-mentioned problem is solved by adopting a structure including a sliding promotion body having no inner ring.

[0012] In the present invention, at least two eccentric bodies have different outer diameters, and each relates to a sliding promotion body interposed between the external gear and one of them. All have an inner ring, and the other one has no inner ring. Therefore, at least for these two rows, even if the outer diameters of the eccentric bodies are different, the substantial outer diameters of the eccentric bodies on the outer circumference of the inner ring can be made equal. Therefore, the sliding promotion body has a smaller outer diameter in the order of a sliding promotion body having an eccentric body with a large outer diameter (without an inner ring) and a sliding promotion body having an eccentric body with a small outer diameter (with an inner ring). They can be incorporated only from the side of the eccentric body, and these can be made common for the sliding promotion body such as a roller or the external gear.

[0013] According to the present invention, the sliding promotion body interposed between the eccentric body and the external gear can be incorporated from only one side, the assemblability can be improved, It is possible to ensure almost the same power transmission characteristics and durability in the row.

 Brief Description of Drawings

 FIG. 1 is a cross-sectional view of a planetary gear device showing an example of an embodiment of the present invention.

 [Figure 2] View along arrow II in Figure 1 II

 [Fig. 3] Sectional view along line III-III in Fig. 1

 FIG. 4 is a cross-sectional view showing an example in which a modification of the above embodiment is applied to a geared motor

 FIG. 5 is a sectional view showing an example of a conventional planetary gear device.

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an example of an embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a longitudinal sectional view corresponding to FIG. 5, showing a planetary gear device according to an example of an embodiment of the present invention.

 [0017] To explain from the outline, this planetary gear device 110 is composed of an input shaft (eccentric body shaft) 112, first, first

 Two eccentric bodies 114 and 116, first and second external gears 118 and 120, an internal gear 122, a relative rotation extraction mechanism Kl, and first and second support flanges 124 and 126 as output elements are provided. The reason why the first and second external gears 118 and 120 are arranged in two rows along the axial direction is to increase the transmission capacity.

 [0018] The input shaft 112 is a hollow shaft (hollow shaft) having a hollow portion 112H.

The input shaft 112 is arranged at the center in the radial direction of the entire apparatus, and is supported first and second by a ball bearing (one eccentric shaft bearing) 130 and a needle bearing (the other eccentric shaft bearing) 132. Supported by flanges 124 and 126.

 [0019] The first and second eccentric bodies 114, 116 are integrally formed on the outer periphery of the input shaft 112 that also functions as an eccentric body axis. The centers Oel and Oe2 of the outer circumferences 114A and 116A of the eccentric bodies 114 and 116 are eccentric by a predetermined amount ΔΕ1 with respect to the axis Oi of the input shaft 112. The first and second eccentric bodies 114 and 116 are 180 degrees out of phase with each other, and the outer radii are Rl and R2, respectively, which are not the same (described later).

 [0020] The first and second external gears 118 and 120 have outer peripheries 114A and 116A of first and second eccentric bodies 114 and 116 via first and second rollers (sliding promoting bodies) 134 and 136, respectively. Are attached to each. An inner ring 134A is attached only to the first roller 134 (described later). Each external gear 118, 120 includes first and second internal pin holes 140, 142 that pass through the external gear 118, 120. An inner pin 144 with an inner roller 143 is loosely fitted in the first and second inner pin holes 140 and 142. The inner pins 144 are fitted into the first and second support flanges 124 and 126, respectively. The relative rotation take-out mechanism K1 is realized by a loose fitting structure of the inner pin holes 140 and 142 and the inner pin 144 (inner roller 143).

 [0021] The first and second external gears 118, 120 are internally engaged with internal teeth (pins) 122A of a single internal gear 122. The internal gear 122 is integrated with the casing 127.

 [0022] The first and second support flanges 124 and 126 are supported by the casing 127 by tapered roller bearings 146 and 148, and are integrated by a carrier bolt 150. In this embodiment, the first support flange 124 functions as an output shaft for a counterpart machine (not shown).

 Hereinafter, the main configuration of each unit will be described in detail.

 As is apparent from FIG. 1, in this embodiment, the outer circumference 112B of the input shaft 112 corresponding to the ball bearing 130, the outer circumferences 114A and 116A of the first and second eccentric bodies 114 and 116, and further, The outer circumference of the input shaft 112 corresponding to the two-dollar bearing 132 is formed with a large diameter in order toward the side force of the ball bearing 130 and the side of the two-dollar bearing 132.

 More specifically, the input shaft 112 has an outer diameter 112 B corresponding to the ball bearing 130 whose outer diameter 112 B is a perfect circle having a radius Ro centered on the center 0i of the input shaft 112. Yes.

[0026] The outer periphery 114A of the first eccentric body 114 is a perfect circle having a radius R1. Rl = Ro + Δ Ε1 is there. The center of the outer periphery 114A is Oel, and is eccentric from the center O1 of the input shaft 112 by 厶 1. Therefore, the outer periphery 114A has an outer line L1 that is common to the outer periphery 112B of the portion corresponding to the ball bearing 130 in the portion closest to the center Oi and eccentric.

 [0027] The outer periphery 116A of the second eccentric body 116 is a perfect circle having a radius R2. Here, R2> R1, more specifically, R2 = Rl + 2 'Δ Ε1. The center Oe2 of the outer periphery 116A is eccentric from the center Oi of the input shaft 112 by ΔΕ1 in a direction opposite to the center Oel of the first eccentric body 114.

 [0028] The outer periphery 112N of the portion corresponding to the needle bearing 132 of the input shaft 112 is a perfect circle having a radius R3 centered on the center Oi. R3 = (R2 + Δ Ε1). Therefore, this outer periphery 112N has an outer line L2 that is common to the portion farthest from the center Oi of the outer periphery 116A of the second eccentric body 116.

 [0029] The outer periphery 112N of the portion corresponding to the needle bearing 132 of the input shaft 112 has the thickest portion 112E having the largest diameter and the largest thickness. Therefore, a gear 160 for receiving a dynamic force from a motor (drive source) (not shown) is fixed to the thick portion 112E via a bolt 162.

 [0030] The first external gear 118 is incorporated into the outer periphery 114A of the first eccentric body 114 via the first roller (sliding promoting body) 134. The first roller 134 has an independent inner ring 134A (see FIG. 2), but does not have an outer ring. The diameter of the first roller 134 is dl. A thickness D1 of the inner ring 134A in the radial direction is set to a difference 2 · ΔΕ1 between R2 and R1.

 The second external gear 120 has an outer periphery of the second eccentric body 116 via a second roller (sliding promoting body) 136.

 Built into 116A. The second roller 136 has neither an inner ring nor an outer ring, and is disposed so as to be capable of direct rolling between the outer periphery 116A of the second eccentric body 116 and the inner periphery 120A of the second external gear 120 ( (See Figure 3). The diameter d2 of the second roller 136 is equal to the diameter dl of the first roller 134 (dl = d2).

[0032] The ball bearing 130 includes both an inner ring 130A and an outer ring 130B. However, the needle bearing 132 has an outer ring 132A, but does not have an inner ring, and the individual needles 132B are in direct contact with the input shaft 112. 1 is a protrusion for positioning the needle bearing 132 in the axial direction. That is, in this embodiment, in order to facilitate the incorporation of the needle 132B of the needle bearing 132, from the right direction of FIG. The needle bearing 132 is incorporated.

 [0033] Between the second roller 136 and the portion of the input shaft 112 supported by the needle bearing 132, an insertion ring 180 for reducing sliding interference between the end of the second roller 136 and the input shaft 112 is provided. Intervened. Further, between the second roller 136 and the inner ring 134A of the first roller 134, an insertion ring 182 for reducing sliding interference between the two rollers 136 and 134A is interposed. Further, between the inner ring 134A and the inner ring 130A of the Bonore bearing 130, a inserting ring 184 is interposed for reducing sliding interference between the both 134A and 130A.

 Reference numeral 190 denotes a retaining ring that positions the inner ring 130A of the ball bearing 130 in the axial direction. This retaining ring 190 is connected to the first and second outer rings 180 through the second ring 136, the second roller 136, the first ring 182, the inner ring 134A of the first roller 134, the second ring 184, and the inner ring 130A of the ball bearing 130. The axial position of the tooth gears 118 and 120 is also restricted. The axial position of the outer ring 130B of the ball bearing 130 is configured to be regulated by the projection 186 and the retaining ring 188.

 Note that reference numerals 192 and 194 denote oil seals.

 Next, the operation of the planetary gear device 110 will be described.

 When the input shaft 112 is rotated via the gear 160 by driving a motor (not shown), the first and second eccentric bodies 114 and 116 are eccentrically rotated integrally with the input shaft 112 (in reverse phase). . Therefore, when the input shaft 112 rotates once, the first and second external gears 118 and 120 mounted on the outer circumferences 114A and 116A of the first and second eccentric bodies 114 and 116 swing once. . As a result, the first and second external gears 118 and 120 rotate relative to the internal gear 122 in the stopped state by an amount corresponding to the difference in the number of teeth from the internal gear 122. This relative rotation is extracted to the first and second support flanges 124 and 126 side via the first and second inner pin holes 140 and 142 and the inner pin 144 (relative rotation extraction mechanism K1). As a result, the reduction ratio corresponding to (the number of teeth difference between the internal gear 122 and the first external gear 116 (or the second external gear 118)) / (the number of teeth of the external gear 116 (118)) Deceleration can be realized. The deceleration output is provided to the counterpart machine from the first support flange 124 side.

[0038] Here, the outer periphery 112B of the corresponding part of the ball bearing 130 of the input shaft 112, the outer periphery 114A, 116A of the first and second eccentric bodies 114, 116, the force S, the 佃 J force of the Bonore bearing 130, and the needle bearing 132 No J As shown in FIG. 3, the insertion wheel 180, the second roller 136, the insertion wheel 182, the inner ring 134A, the first roller 134, the insertion wheel 184, and the ball bearing 130 are illustrated in this order. The left side force of 1 can be assembled. Finally, each member only needs to be positioned in the axial direction by the retaining rings 188 and 190, so that the assembling workability is very good.

[0039] It should be noted that in order to perform assembly from only one side, for example, a method of preparing rollers having different diameters for the eccentric bodies in each row while differentiating the outer diameters of the eccentric bodies is conceivable. . In this case, the roller is inserted from the side of the eccentric body having the smaller outer diameter, and the small-diameter roller is assembled into the large-diameter eccentric body, and the large-diameter roller is assembled into the small-diameter eccentric body in this order. However, this method must incorporate rollers with different diameters for each row, and there is a risk that the power transmission characteristics and durability will be different for each row as the number of parts increases. . In this embodiment, in order to ensure such good workability, the inner ring 134A is incorporated only in the first roller 134 on the first eccentric body 114 side. The diameters dl and d2 of the two rollers 134 and 136 can be set equal (can be the same roller), and the uniformity of the power transmission characteristics and durability of each row can be obtained. . Also, one type of roller component can be shared.

[0040] However, in the present invention, this method of varying the roller diameter is not prohibited. For example, when three or more rows of external gears are incorporated, two of the eccentric bodies have an inner ring. It is free to use a method based on presence / absence, and to combine all the rollers from only one side by combining this with a method that varies the roller diameter.

 In the present embodiment, the radial thickness D1 of the inner ring 134A of the first roller 134 and the wall thickness of the input shaft 112 are set so as to have the common outer lines Ll and L2. Therefore, an increase in the thickness of the input shaft 112 can be minimized, and a compactness in the radial direction of the input shaft 112 is particularly achieved.

[0042] Also, since one of the bearings (eccentric shaft bearings) that support the input shaft 112 is a "double dollar bearing without an inner ring", a large radial load can be obtained with an extremely small radial occupied volume. Can receive. For this reason, the secured thick part 112E is fixed to the gear 160. Therefore, it can be rationally used as a screwing space for the bolt 162 for this purpose.

[0043] Furthermore, since one of the bearings supporting the input shaft 112 is S, “ball bearing”, the thrust load of the input shaft 112 can be reliably received by this ball bearing 130 portion. However, it is possible to use a needle bearing that does not have an inner ring in one of the bearings (without receiving a thrust load).

 [0044] As a result of the synergies of the actions as described above, it is possible to achieve equipment externalization (especially radial externalization) while maintaining high uniformity in assembly, power transmission characteristics, and durability. The very large-diameter hollow portion 112H can be secured.

 In this embodiment, in order to facilitate the incorporation of the needle 132B of the needle bearing 132, the outer periphery 112N of the force corresponding to the force needle bearing 132 is designed to incorporate the needle bearing 132 from the right direction in FIG. Is set equal to or larger than the outer periphery 116A of the second eccentric body 116, the axial position of the projection 165 is moved to the opposite side of the needle bearing 132, and the needle bearing 132 is also illustrated. It is also possible to assemble the left side force.

 Further, in the present invention, the configuration of the eccentric body shaft bearing is not necessarily limited to the above example, and both may be a needle bearing, a ball bearing, or a tapered roller bearing. A combination of these may also be used. Each inner ring may or may not have a design.

 [0047] Further, in the above example, by increasing the wall thickness of the input shaft in order so as to have the common outer lines Ll and L2, the force that is particularly intended to achieve a compactness in the radial direction of the input shaft. S, for example, depending on the thickness of the inner ring of the sliding promotion body to be incorporated, it is acceptable to have an outer diameter difference of more than twice the eccentricity Δ E1 on the outer circumference of the two eccentric bodies.

 FIG. 4 shows an application example in which a servo motor M is connected to the modified example of the above-described embodiment to form a geared motor GM for driving an industrial robot.

Here, instead of the gear 160 described above, a (large-diameter) toothed pulley 260 is attached to the thick portion 212 E of the input shaft 212 via a bolt 262. On the other hand, the motor shaft 296 of the servo motor M is also provided with a (small-diameter) toothed pulley 298, and the both 260 and 298 are connected via a toothed benolet 297. Force applied to input shaft 212 is high and radial load Needle shaft By receiving 232, it can be reliably received.

Note that reference numeral 295 in the figure denotes a wire harness inserted through the hollow portion 212H of the widely secured input shaft 212, and 299 denotes a part of the robot attachment.

[0051] Other configurations are the same as in the previous embodiment, and the same operational effects can be obtained. Therefore, the last two digits in the figure are given the same reference numerals as in the previous embodiment, Omit duplicate explanations.

 Industrial applicability

[0052] As a reduction device having a compact and large-diameter hollow shaft, it can be widely applied to industrial robots, conveyors and the like.

Claims

The scope of the claims  [1] It has an internal gear and a plurality of external gears internally engaged with the internal gear, , A planetary gear device of a swinging internal joint type that is swung and rotated by a plurality of eccentric bodies provided on the eccentric body shaft,  Out of the plurality of eccentric bodies, the outer diameters of at least two eccentric bodies are different, and of the two eccentric bodies, the outer diameter of the eccentric body having a small outer diameter and the external gear are independent. Comprising a sliding accelerator having an inner ring, and  Among the two eccentric bodies, a sliding promotion body having no inner ring is provided between the outer periphery of the eccentric body having a large outer diameter and the external gear.  An oscillating internal meshing planetary gear device characterized by the above. [2] In claim 1,  The eccentric body shaft is supported by a pair of eccentric body shaft bearings sandwiching the eccentric body, and of these, the outer periphery of the eccentric body shaft in the portion supported by one eccentric body shaft bearing, and the respective eccentricity The outer circumference of the body is formed with a large diameter sequentially from the one eccentric body shaft bearing side to the other eccentric body shaft bearing side.  An oscillating internal meshing planetary gear device characterized by the above. [3] In claim 1 or 2,  One of the eccentric body shaft bearings is a ball bearing, and the other is a needle bearing.  An oscillating internal meshing planetary gear device characterized by the above. [4] In claim 3,  The ball bearing is a ball bearing having an inner ring, and the needle bearing is a needle bearing having no inner ring.  An oscillating internal meshing planetary gear device characterized by the above. [5] In any one of claims 2 to 4, The outer periphery of the eccentric body shaft at the portion supported by the one eccentric body shaft bearing, the outer periphery of each eccentric body, and the outer periphery force of the eccentric body shaft at the portion supported by the other eccentric body shaft bearing The one eccentricity The diameter gradually increases from the body shaft bearing side toward the other eccentric body shaft bearing side. Formed, and  A member for transmitting power from the drive source side to the eccentric body shaft is fixed to a thick portion of the eccentric body shaft formed on the other eccentric body shaft bearing side.  An oscillating internal meshing planetary gear device characterized by the above.