JP2013044400A - Eccentrically oscillating speed reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain service life longer as a whole speed reducer by preventing only partial external gear series from being deteriorated fast by unbalance of a load that the speed reducer receives from the outside.SOLUTION: An eccentrically oscillating speed reducer 40 includes first and second external gears 42 and 44, and first and second internal gears 46 and 48 engaged with the first and second external gears 42 and 44, respectively. Pitch circle diameters d3, d4 of first and second rollers 114 and 124 (elements constituting first and second tooth profiles) of the first and second internal gears 46 and 48 are different, and outer diameters d5, d6 are different.

Description

  The present invention relates to an eccentric oscillating type speed reduction device.

  For example, Patent Document 1 discloses an eccentric oscillating speed reduction device as shown in FIGS. 4 and 5.

  The eccentric oscillating speed reduction device 10 is configured such that a plurality of external gears 18A and 18B mesh with each other while oscillating inside a (single) internal gear 22 in the radial direction. The reason why the two external gears 18A and 18B are provided in parallel is to increase the transmission capacity and distribute the load, and to maintain the entire life of the speed reduction device 10 longer.

  When the eccentric body shaft 14 corresponding to the input shaft rotates, the eccentric bodies 16A and 16B rotate integrally. Due to the rotation of the eccentric bodies 16A and 16B, the external gears 18A and 18B also rotate and rotate around the eccentric bodies 16A and 16B and mesh with the internal gear 22 internally.

  For example, when the number of external teeth of the external gears 18A and 18B is N and the number of internal teeth (external pin 34) of the internal gear 22 is N + 1, the difference in the number of teeth is “1”. Therefore, each time the eccentric body shaft 14 rotates once, the external gears 18 </ b> A and 18 </ b> B are displaced (rotated) by one tooth with respect to the internal gear 22 fixed to the casing 20. This means that one rotation of the eccentric body shaft 14 is decelerated to -1 / N rotation of the external gears 18A and 18B. Note that the sign of-indicates that the rotation direction is reversed.

  The swinging rotation of the external gears 18A, 18B is absorbed by the clearance between the inner pin 26 and the inner pin holes 36A, 36B, and only the rotation component is transferred via the inner pin 26 to the carrier body 24A and the flange body. 24B and further to the output shaft integrated with the flange body 24B. The eccentric body shaft 14 is supported by bearings 34 </ b> A and 34 </ b> B at the axial position of the internal gear 22 (in the radial center of the reduction gear 10).

JP 2008-304020 A

  Such an eccentric oscillating speed reduction device is widely applied in the fields of industrial robots and production machines. For this reason, depending on the application mode, the load applied to the meshing portions of the plurality of external gears and the internal gear is not necessarily uniform, and some of the meshing portions are more resistant to the meshing portions of the other series. In terms of “load”, it may be placed in a more severe condition.

  Therefore, in the conventional eccentric oscillating type reduction gear, there is a problem that only the meshing portion of the series having severe load conditions may deteriorate quickly.

  The present invention has been made to solve such problems, and by optimizing the load-bearing characteristics of each series, and preventing only a part of the meshing parts from rapidly deteriorating, results are obtained. The problem is to maintain the life of the entire reduction gear as longer as possible.

  The present invention relates to an eccentric oscillating type reduction gear having a plurality of external gears and a plurality of internal gears meshed with the external gears, and the tooth profile of at least two of the internal gears. The above-described problems are solved by using different configurations.

  In the present invention, it is recognized that it is inevitable that the load actually applied to each external gear series depends on the mode of application of the reduction gear, and the tooth profile of the internal gear (and the external gear corresponding thereto) It was decided to cope with this load imbalance by changing the tooth profile).

  In the present invention, the concept of “the tooth shape of the internal gear is different” includes the case where “the shape of the cross section perpendicular to the axis of the internal gear is different” and the case where “the pitch circle diameter of the internal gear is different”. Both shall be included. Further, in the present invention, since each external gear is "meshing with an internal gear", it is assumed that the external gear is appropriately changed corresponding to the change of the tooth profile of the meshing internal gear. .

  As a result, the load bearing characteristics of the external gear series on the side to which more load is applied can be relatively improved, and the load bearing characteristics of each series can be balanced.

  According to the present invention, it is possible to prevent only a part of a series of external gears from rapidly deteriorating due to an imbalance of a load that the reduction gear receives from the outside, and as a result, the life of the reduction gear as a whole can be further improved. Can be maintained for a long time.

Sectional drawing of the principal part which shows an example of embodiment of the eccentric rocking | fluctuation type deceleration device which concerns on this invention Overall cross-sectional view of the speed reducer The schematic diagram of the 1st, 2nd internal tooth pin which shows the modification of the said embodiment Overall cross-sectional view of a conventional eccentric oscillating type speed reduction device Sectional view taken along the arrow line V-V in FIG. 4

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view of an essential part showing an example of an embodiment of an eccentric oscillating speed reduction device according to the present invention, and FIG.

  Referring mainly to FIG. 2, this eccentric oscillating speed reduction device 40 includes first and second external gears 42 and 44 and first and second external gears 42 and 44 meshing with each other. 1, and a second internal gear 46, 48.

  First, an outline of the eccentric oscillating speed reduction device 40 will be described.

  The eccentric body shaft 50 also serving as the input shaft is connected to a motor (not shown). The eccentric body shaft 50 is located at the center in the radial direction of the first and second internal gears 46 and 48 (the positions of the shaft centers O1 and O2). First and second eccentric bodies 52 and 54 are integrally formed on the eccentric body shaft 50. Two first and second external gears 42 and 44 are incorporated on the outer circumferences of the first and second eccentric bodies 52 and 54 via first and second roller bearings 56 and 58, respectively. Since the phases of the first and second eccentric bodies 52 and 54 are shifted by 180 degrees, the first and second external gears 42 and 44 are eccentric in directions away from each other.

  The first and second external gears 42 and 44 are first and second trochoidal teeth corresponding to first and second internal teeth 64 and 66 of first and second internal gears 46 and 48, which will be described in detail later. It has external teeth 60, 62 respectively.

  In this embodiment, since the first internal teeth 64 and the second internal teeth 66 are different, the first external teeth 60 and the second external teeth corresponding to the first internal teeth 64 and the second internal teeth 66, respectively. 62 is also not the same.

  In this embodiment, the number of the first and second external teeth 60 and 62 of the first and second external gears 42 and 44 is N, and the first of the first and second internal gears 46 and 48 is the first. The number of second internal teeth 64 and 66 (both N + 1) is smaller by one.

  The first and second external gears 42 and 44 include a plurality of first and second inner roller holes 68 at positions offset from the axial positions O3 and O4 of the first and second external gears 42 and 44, respectively. 69 are formed at equal intervals in the circumferential direction. A plurality of inner pins 70 pass through the first and second inner roller holes 68 and 69 together with the inner roller 72 for promoting sliding, with a gap therebetween.

  Each inner pin 70 is integral with flange member 74. Each inner pin 70 is connected to a carrier body 78 via a bolt 76, and the flange body 74 and the carrier body 78 are integrated. The integrated flange body 74 and carrier body 78 form a large output block 80 and are supported by the casing 90 via a pair of angular ball bearings 82 and 84. The eccentric body shaft 50 is supported by the flange body 74 and the carrier body 78 via a pair of ball bearings 86 and 88.

  In this embodiment, the casing 90 is connected and fixed to an external fixing body (not shown) by a bolt (not shown) using the attachment hole 92. The flange body 74 is connected to a driven pulley 94 through a bolt 96, and the pulley 94 can be rotated by rotating the flange body 74.

  Here, the configuration of the first and second internal gears 46 and 48 will be described in detail.

  Referring to FIG. 1, a first internal gear 46 according to this embodiment is rotatably covered on a first support pin 112 and an outer periphery of the first support pin 112, and the first internal gear 46 is substantially the same as the first internal gear 46. The first roller 114 constituting the first internal teeth 64 and the first internal gear main body 116 for rotatably supporting the first support pin 112 are configured.

  The second internal gear 48 is rotatably covered on the second support pin 122 and the outer periphery of the second support pin 122, and a second roller that constitutes a substantial second internal tooth 66 of the second internal gear 48. 124, and a second internal gear main body 126 that rotatably supports the second support pin 122.

  In this embodiment, the first internal gear main body 116 and the second internal gear main body 126 are integrated, and further integrated with the casing 90. The first external gear 42 and the second external gear 44 have the same number of teeth, and the first internal gear 46 and the second internal gear 48 have the same number of teeth. That is, the reduction ratios of the series of the first external gear 42 and the first internal gear 46 and the series of the second external gear 44 and the second internal gear 48 are the same.

  The first and second support pins 112 and 122 are solid cylindrical pins. The outer diameter d1 of the first support pin 112 is larger than the outer diameter d2 of the second support pin 122 (d1> d2). The first and second support pins 112 and 122 are rotatably supported by first and second support pin grooves 118 and 128 formed in the first and second internal gear main bodies 116 and 126, respectively.

  The inner diameter D1 of the first internal gear main body 116 and the inner diameter D2 of the second internal gear main body 126 are the same (D1 = D2). However, the depth D3 of the first support pin groove 118 of the first internal gear main body 116 is formed deeper than the depth D4 of the second support pin groove 128 of the second internal gear main body 126 (D3>). D4).

  The pitch circle diameter of the first roller 114 (= the pitch circle diameter of the first internal teeth 64 = the pitch circle diameter of the first support pins 112) d3 is the pitch circle diameter of the second roller 124 (= the pitch of the second internal teeth 66). Circle diameter = pitch circle diameter of second support pins 122) is larger than d4 (d3> d4). The outer diameter (= the size of the tooth profile of the first inner teeth 64) d5 of the first roller 114 is also larger than the outer diameter (= the size of the tooth profile of the second inner teeth 66) d6 of the second roller 124 (d5>). d6). The axial length of the first roller 114 (= tooth width of the first internal teeth 64) L3 is the same as the axial length of the second roller 124 (= tooth width of the second internal teeth 66) L4 (L3 = L4). ).

  In this embodiment, the diameter of the circle connecting the innermost diameter of the first roller 114 (the tip diameter of the first inner tooth) d7 is the diameter of the circle connecting the innermost diameter of the second roller 124 (second The diameter of the tip of the inner tooth is slightly larger than d8 (d7> d8).

  The first external teeth 60 of the first external gear 42 and the second external teeth 62 of the second external gear 44 are the pitch circle diameter d3 and the external diameter d5 of the first roller 114 and the pitch circle of the second roller 124, respectively. The trochoidal tooth profile is determined corresponding to the diameter d4 and the outer diameter d6.

  That is, the shapes and dimensions of the first external gear 42 and the second external gear 44 are different. For example, the first external gear 42 has a tip diameter or pitch circle diameter larger than that of the second external gear 44.

  Next, the operation of the eccentric oscillating speed reduction device 40 will be described.

  Returning to FIG. 1, in the eccentric oscillating speed reduction device 40, when a motor (not shown) rotates, the eccentric body shaft 50 corresponding to the input shaft rotates and is integrated with the eccentric body shaft 50. 1, the second eccentric portions 52, 54 to rotate. When the first and second eccentric bodies 52 and 54 rotate, the first and second external gears 42 and 44 are oscillated and rotated through the first and second roller bearings 56 and 58, respectively. each inscribed meshing with the second internal gear 46, 48. The first and second internal gears 46 and 48 have the internal gear main bodies 116 and 126 integrated with the casing 90 and fixed to an external member. Is rotated by one rotation, the first and second external gears 42 and 44 are shifted in phase by “one tooth” corresponding to the difference in the number of teeth with respect to the first and second internal gears 46 and 48, respectively. (Rotate). Since the first and second external gears 42 and 44 and the first and second internal gears 46 and 48 have the same number of teeth, respectively, the first external gear 42 and the second external gear The gears 44 rotate at the same speed, and their phases do not deviate from 180 degrees (the first external gear 42 and the second external gear 44 are always kept eccentric in directions away from each other. Rotate while).

  The rotation of the first and second external gears 42 and 44 relative to the first and second internal gears 46 and 48 is transmitted to the flange body 74 (and the carrier body 78) via the inner pin 70 (and the inner roller 72). Then, the flange body 74 is rotated at a speed reduced to -1 / N (a minus sign means rotation in the direction opposite to the eccentric body shaft 50). The swinging components of the first and second external gears 42 and 44 are absorbed by the gap formed between the inner roller 72 and the first and second inner roller holes 68 and 69.

  The rotation of the flange body 74 is transmitted to a pulley 94 connected to the flange body 74 via a bolt 96, whereby a belt (not shown) wound around the pulley 94 is driven.

  Here, the pulley 94 receives a radial load from the belt side when driving the belt. The load applied to the pulley 94 is input to the eccentric rocking speed reduction device 40 via the flange body 74. As a result, the first external gear 42 and the first meshing portion E1 of the first internal gear 46 closer to the pulley 94 are deformed by the load acting on the pulley 94 due to the arrangement position. Therefore, the second external gear 44 and the second internal gear 48 receive a stronger load than the second meshing portion E2.

  However, in this embodiment, the pitch circle diameter d3 of the first roller 114 is formed larger than the pitch circle diameter d4 of the second roller 124. Further, the tip circle diameter d7 of the first roller (first inner tooth) 114 is larger than the tip circle diameter d8 of the second roller (second inner tooth) 124.

  In general, in the case of an eccentric oscillation type speed reducer including this embodiment, a plurality of external teeth and internal teeth are always meshed at the same time, and the meshing positions of the meshed teeth are not uniform. The position in the radial direction of the portion is approximately near the center of the pitch circle diameter and tip diameter of the inner teeth. When applied to this embodiment, the meshing portion radius R1 from the axis O1 of the first internal gear 46 to the first meshing portion E1 of the first roller 114 and the first external gear 42 is the second internal gear. It is larger than the meshing portion radius R2 from the axis O2 (= O1) of the gear 48 to the second meshing portion E2 of the second roller 124 and the second external gear 44 (R1> R2).

  For this reason, the first meshing portion E1 of the first external gear 42 and the first internal gear 46 is more load resistant than the second meshing portion E2 of the second external gear 44 and the second internal gear 48. As a result, the load resistance characteristics of the series of the first external gear 42 and the first internal gear 46 and the load resistance characteristics of the series of the second external gear 44 and the second internal gear 48 are made more uniform. Only the first meshing portion E1 of the series of the external gear 42 and the first internal gear 46 is prevented from being deteriorated or damaged in advance. Therefore, as a result, the lifetime of the entire reduction gear 40 can be increased.

  In the present embodiment, since the pitch circle diameter d4 and the outer diameter d6 of the second roller 124 are set smaller than the pitch circle diameter d3 and the outer diameter d5 of the first roller 114, the second roller 124 side is temporarily set to the first roller 114 side. The distance (thickness) t1 to the mounting hole 92 of the casing 90 can be sufficiently secured in the vicinity of the second roller 124 as compared with the case where the roller 114 is formed to be as large as the roller 114. That is, it can be considered that the load distribution of the first and second external gears 42 and 44 is rationally balanced with the strength enhancement of each part of the casing 90.

  FIG. 3 schematically shows a typical modification of the above embodiment.

  In either case, an example is shown in which the internal teeth of the internal gear are constituted by cylindrical first and second internal teeth pins, and the first and second rollers are omitted for convenience. When the first and second rollers are provided, the first and second rollers may be replaced with the first and second internal teeth pins, respectively. The left side of each example in FIG. 3 is the first internal tooth pin (first internal tooth), the right side is the second internal tooth pin (second internal tooth), and the first internal tooth pin is the side on which the load is applied. That is, it corresponds to the side where the load burden should be further reduced.

  In the example of FIG. 3A, the pitch circle diameter d11 of the first internal tooth pin (first internal tooth) 151 is larger than the pitch circle diameter d12 of the second internal tooth pin (second internal tooth) 152 by δa1. (D11> d12) and the outer diameter d13 of the first inner tooth pin 151 is equal to the outer diameter d14 of the second inner tooth pin 152 (d13 = d14).

  In the present invention, when the pitch circle diameters d11 and d12 are different (even when the outer diameters d13 and d14 of the first inner tooth pin 151 and the second inner tooth pin 152 are equal), It is included in the concept that is different ".

  In the example of FIG. 3A, the meshing portion radius Ra1 of the meshing portion Ea1 on the first external gear 42 side is larger than the meshing portion radius Ra2 of the meshing portion Ea2 on the second external gear 44 side (Ra1> Ra2), the first internal tooth pin 151 on the left side of FIG. 3A tends to be superior in terms of load resistance.

  In the example of FIG. 3 (B), the pitch circle diameter d21 of the first internal tooth pin 161 and the pitch circle diameter d22 of the second internal tooth pin 162 are equal (d21 = d22), but the outer diameter of the first internal tooth pin 161. d23 is smaller than the outer diameter d24 of the second inner tooth pin 162 (d23 <d24), and the tip circle diameter d25 of the first inner tooth pin 161 is larger than the tip circle diameter d26 of the second inner tooth pin 162 by δb1. (D25> d26). Therefore, in the case of FIG. 3B, the strength of the tooth profile itself of the first internal tooth pin 161 is stricter than that of the second internal tooth pin 162, but from the viewpoint of “load resistance at the meshing portion”, FIG. Also in the case of (B), the meshing portion radius Rb1 of the meshing portion Eb1 on the first external gear 42 side is larger than the meshing portion radius Rb2 of the meshing portion Eb2 on the second external gear 44 side (Rb1> Rb2). 3), the first internal tooth pin 161 on the left side of FIG. 3B tends to be superior in terms of load resistance.

  In the case of the example of FIG. 3 (B), the casing on the first internal tooth pin 161 side can have a sufficient wall thickness, so that the first internal tooth pin 161 side is more advantageous in terms of “load resistance of the casing”. Tend to be.

  In the example shown in FIG. 3C, the tip circle diameter d31 of the first internal tooth pin 171 is equal to the tip circle diameter d32 of the second internal tooth pin 172 (d31 = d32), and the outside of the first internal tooth pin 171 is outside. An example in which the diameter d33 is larger than the outer diameter d34 of the second internal tooth pin 172 is shown (d33> d34). In this case, the pitch circle diameter d35 of the first internal tooth pin 171 is larger by δc1 than the pitch circle diameter d36 of the second internal tooth pin 172 (d35> d36).

  Therefore, also in the case of FIG. 3C, the meshing portion radius Rc1 of the first meshing portion Ec1 is larger than the meshing portion radius Rc2 of the second meshing portion Ec2 (Rc1> Rc2). The left first internal tooth pin 171 tends to be superior in terms of load resistance.

  3A to 3C, the external gear that meshes with each internal tooth (pin) has a trochoidal tooth profile corresponding to each internal tooth, and as a result, has different shape dimensions.

  In actual application, as shown in the example of the previous embodiment, these elements can be combined or combined.

  In addition, as a method of changing the size (outer diameter) of the internal tooth pin between the first internal gear and the second internal gear, for example, the first support pin only on the first internal gear. A configuration may be adopted in which the second internal gear is covered only with the second support pin (without the second roller). In this case, the first internal gear can reduce the rotation resistance of the first roller (less than the rotation resistance of the second support pin on the side of the second internal gear without the second roller). as, good results can be obtained for the load-bearing.

  However, the present invention can also be applied to a case where the internal teeth of the internal gear are not formed as cylindrical pins, but are constituted by “solid type” internal teeth integrated with the internal gear body. An effect can be obtained.

  Further, although not shown, the “load resistance of the external gear” is the same for the eccentric bearings between the eccentric and the external gear (first and second roller bearings 56 and 58 in the previous embodiment). it may be the point of view of design. The larger the pitch circle diameter of the rolling elements of the eccentric body bearing is, and the larger the outer diameter of the rolling elements is, the more margin is provided for the load resistance. Therefore, considering the magnitude of the load burden, the outer diameter of the eccentric bearing or the pitch circle diameter of the one with the greater load burden (one with a larger pitch circle diameter of the internal gear or one with a larger tooth tip circle diameter) If a configuration in which at least one of them is increased is adopted, a more effective configuration can be achieved with respect to the uniformity of load resistance.

  In the above embodiment, the present invention is applied to a so-called center crank type eccentric oscillating type speed reducer in which the eccentric body shaft is disposed at the axial center position of the internal gear. There is no particular limitation on the configuration in which the external gear is swung. For example, a so-called sort-type eccentric swing, in which a plurality of eccentric body shafts are provided at positions offset from the axis of the internal gear, and the external gears are swung and rotated by simultaneously rotating the eccentric body shafts in the same direction. it may be a dynamic-type reduction apparatus.

  In the above embodiment, the reduction gear is employed in which the internal gear (casing) is fixed and the output is taken out by the rotation of the external gear. However, the rotation of the external gear is restricted, and the internal gear. The present invention can also be provided for a frame rotation type reduction gear that rotates.

  Furthermore, the present invention can also be applied to an eccentric oscillating type speed reducer of the internal oscillating type in which the internal gear side oscillates relatively to the external gear.

  In the above-described embodiment, the eccentric oscillating speed reduction device in which the driven pulley is connected to the flange body is shown. However, the application of the present invention is not limited to such an example. However, the present invention can be similarly applied to a situation in which the load applied in the axial direction is different and there is a difference in load load between the series of external gears.

DESCRIPTION OF SYMBOLS 40 ... Eccentric oscillation type reduction gear 42 ... 1st external gear 44 ... 2nd external gear 46 ... 1st internal gear 48 ... 2nd internal gear 50 ... Eccentric body axis | shaft (input shaft)
52 ... 1st eccentric body 54 ... 2nd eccentric body 56 ... 1st roller bearing 58 ... 2nd roller bearing 60 ... 1st external tooth 62 ... 2nd external tooth 90 ... Casing 112 ... 1st support pin 114 ... 1st roller 116: 1st internal gear main body 122 ... 2nd support pin 124 ... 2nd roller 126 ... 2nd internal gear main body

Claims (5)

In an eccentric oscillating type reduction gear having a plurality of external gears and a plurality of internal gears respectively meshed with the external gears,
Of the internal gears, at least two internal gears have different tooth profiles. An eccentric oscillating speed reduction device. In claim 1,
The eccentric gear type speed reducer characterized in that the internal gears having different tooth shapes have different pitch circle diameters. In claim 1 or 2,
The eccentric gear type speed reducer characterized in that the internal gears having different tooth shapes have different tip diameters. In any one of Claims 1-3,
Each of the plurality of external gears is externally fitted to an eccentric body bearing,
An eccentric oscillating speed reduction device characterized in that at least one of the diameter of the rolling element or the pitch circle diameter of the eccentric bearing having the larger pitch circle diameter of the internal gear is larger. In any one of Claims 1-4,
Each of the plurality of external gears is externally fitted to an eccentric body bearing,
An eccentric oscillating speed reduction device characterized in that at least one of the diameter of the rolling element or the pitch circle diameter of the eccentric body bearing having the larger tooth tip circle diameter of the internal gear is larger.

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