JP2014070706A - Eccentric rocking type reducing gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eccentric rocking type reducing gear which performs assembling to a mating member of the reducing gear more conveniently while securing a higher sealing property, in the eccentric rocking type reducing gear having no main bearing.SOLUTION: An eccentric rocking type reducing gear G1 has an internal teeth gear 30 and an external teeth gear 32 which is inscribed and meshes with the internal teeth gear 30, and takes out a relative rotation of the internal teeth gear 30 and the external teeth gear 32 as a relative rotation of a casing 20 and an output block 34 (carrier) to the mating machine side. Therein, the main bearing is not arranged between the casing 20 and the output block 34, a regulation plate 46 (a regulation member) which regulates a movement in the axial direction of at least one side of the internal teeth gear 30 (an external pin 44 of which) and the external teeth gear 32 is provided and a seal rubber 70 (a sealing member) which can seal a part between the regulation plate 46 and the casing 20, and a part between the regulation plate 46 and a first arm 61 (a mating member) is fixed to the regulation plate 46.

Description

  The present invention relates to an eccentric rocking type reduction gear.

  Patent Document 1 discloses an eccentric oscillating speed reduction device suitable for use in, for example, joint driving of an industrial robot. This reduction gear is configured so that the external gear supported by the carrier meshes with the internal gear while swinging, and takes out the relative rotation of both gears generated during the meshing.

  The relative rotation between the internal gear and the external gear is taken out as the relative rotation between the casing integrated with the internal gear main body and the carrier. For this reason, the casing and the carrier can be rotated relative to each other via a bearing having a large diameter called a “main bearing”.

JP 2010-156430 A (FIG. 1)

  Depending on the counterpart machine (master machine) in which the speed reducer is incorporated, or depending on the application of the counterpart machine, the moment of reverse input from the counterpart machine side to the main bearing of the speed reducer sometimes becomes very large. . For this reason, a configuration has been proposed in which such a moment is received by a bearing mechanism provided on the “other machine side”. According to this configuration, as a result, the main bearing can be omitted on the reduction gear side.

  However, on the one side, in the case of a speed reducer that does not have such a main bearing, there is a problem that when the speed reducer is assembled to a counterpart machine, it may be difficult to easily assemble it while ensuring sealing performance. there were.

  The present invention has been made in order to alleviate the problems that occur when assembling an eccentric oscillating speed reduction device that does not have such a main bearing on the counterpart member side. The task is to perform the assembly in a simpler manner while ensuring higher sealing performance.

  The present invention has an internal gear and an external gear that meshes internally with the internal gear, and the relative rotation between the internal gear and the external gear is defined as relative rotation between the casing and the carrier. In the eccentric oscillating type speed reducer to be taken out, a main bearing is not disposed between the casing and the carrier, and a restriction member for restricting axial movement of at least one of the internal gear and the external gear is provided. And, by adopting a configuration in which a sealing member capable of sealing between the regulating member and the casing and between the regulating member and a specific mating member of the mating machine is fixed to the regulating member, It solves the above problems.

  In this type of eccentric oscillating speed reduction device, a regulating member that abuts on the internal gear or the external gear and regulates the axial movement of one or both of the internal gear and the external gear. May be provided.

  The present invention focuses on this regulating member. That is, in the present invention, a sealing member capable of sealing between the regulating member and the casing and between the regulating member and the mating member is fixed to the regulating member.

  Therefore, it is possible to automatically maintain a high sealing performance between the regulating member and the casing and between the regulating member and the counterpart member by simply connecting the speed reducer incorporating the sealing member to the counterpart machine. Can be sealed.

  In addition, since the sealing member is “fixed” to the regulating member, there is no risk of the sealing member being accidentally dropped during assembly. Therefore, the speed reducer can be easily assembled to the counterpart machine.

  Further, since the sealing member is configured to be fixed to the “regulating member”, even when the sealing member is deteriorated, the entire regulating member can be replaced, the cost is low, and the maintainability is high.

  According to the present invention, in an eccentric oscillating type speed reducer that does not have a main bearing, the speed reducer can be easily assembled to a mating member while ensuring higher sealing performance.

FIG. 2 is an enlarged cross-sectional view of an essential part corresponding to part I of FIG. 2 of an eccentric oscillation type reduction gear according to an example of an embodiment of the present invention. Overall sectional view of the reduction gear Sectional view along the line III-III of FIG. The principal part expanded sectional view which shows the example of other embodiment of this invention

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

  First, an overall configuration of an eccentric oscillating speed reduction device according to an example of an embodiment of the present invention will be described. 2 is an overall cross-sectional view of the speed reducer, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG.

  The reduction gear G1 is used by being incorporated in an industrial robot R1 (mating machine: the whole is not shown). The reduction gear G <b> 1 is called an eccentric oscillating type, and has an internal gear 30 in the casing 20 and an external gear 32 that is in mesh with the internal gear 30. The relative rotation of the external gear 32 is extracted as the relative rotation between the casing 20 and the output block 34 (carrier). In this embodiment, the casing 20 includes a casing body 22 and a cover body 24 that covers the side opposite to the axial output block of the reduction gear G1.

  Hereinafter, a specific overall configuration of the reduction gear G1 will be described.

  The reduction gear G1 includes an input shaft 36 that is coupled to a motor (not shown) via a key (only the key groove 36A is shown) at the center in the radial direction. Three eccentric bodies 38 are integrally formed on the input shaft 36. The eccentric phase of each eccentric body 38 is 120 degrees. An external gear 32 is incorporated on the outer periphery of the eccentric body 38 via rollers 40. In this example, the three external gears 32 are provided because the transmission capacity is intended to increase. Each external gear 32 is in mesh with the internal gear 30.

  In this embodiment, the internal gear 30 is rotatably incorporated in an internal gear main body 42 integrated with the casing 20 (the casing main body 22 thereof) and a groove 42A formed in the internal gear main body 42. It is comprised with the outer pin 44 which comprises the internal tooth of the internal gear 30. FIG. The number of internal teeth of the internal gear 30 (the number of external pins 44) is slightly larger (only 1 in this example) than the number of external teeth of the external gear 32.

  Both axial ends 44 </ b> A and 44 </ b> B of the outer pin 44 of the internal gear 30 are sandwiched between the cover body 24 and the restriction plate 46 (restriction member). Further, the three external gears 32 are in axial contact with each other via the spacers 33 and 35, and both axial ends 32A and 32B of the three external gears 32 are also regulated with the cover body 24. It is sandwiched between plates 46. That is, the restriction plate 46 restricts the axial movement of the external pin 44 and the external gear 32 that constitute a part of the internal gear 30. A specific configuration of the restriction plate 46 will be described in detail later.

  Each external gear 32 is formed with a through hole 32C, and an inner pin 48 is loosely fitted therein. An inner roller 50 is placed on the outer periphery of the inner pin 48 as a sliding acceleration member. The inner pin 48 is press-fitted into the output block 34. The input shaft 36 is supported at both ends by the output block 34 and the cover body 24 via a pair of bearings 52 and 54.

  The casing body 22 of the casing 20 is connected to a first arm 61 (a specific counterpart member of the counterpart machine) of the industrial robot R1 that is the counterpart machine via a bolt (only the bolt hole 61A is shown). The output block 34 is connected to the second arm 62 of the industrial robot R1 via a bolt (only the bolt hole 62A is shown). When the output block 34 of the reduction gear G1 rotates relative to the casing 20, the first arm 61 and the second arm 62 of the industrial robot R1 can be rotated relatively. In FIG. 2, the reduction gear G1 and the first arm 61 are fastened together. However, this fastening is not essential, and the number, position, and size of the bolts are the same as those of the casing main body 22 and the cover of the reduction gear G1. The connecting portion between the body 24 and the connecting portion between the casing 20 of the reduction gear G1 and the first arm 61 may be different.

  Since the output block 34 is an output member that rotates relative to the casing 20, in a general speed reduction device, the output block is connected to the casing via a so-called “main bearing”. It is configured to be rotatably supported. However, in this embodiment, as is apparent from FIG. 2, the main bearing is not disposed between the casing 20 and the output block 34. That is, in this embodiment, a large bearing (not shown) that exists between the first arm 61 and the second arm 62 of the industrial robot R1 is usually disposed between the casing 20 and the output block 34. It also has the function of a bearing.

  Here, referring to FIG. 2 together with FIG. 1, the configuration of the restriction plate 46 and its surroundings will be described in more detail.

  The restriction plate 46 is a ring-shaped member having an axial width L1 and an outer diameter d1. As described above, the restricting plate 46 has the axial side of the internal gear 30 (the external pin 44 constituting a part thereof) and the external gear 32 in the axial direction by the side surface 46A on the axially inner side (on the first arm side). Restricted movement.

  A plate fitting recess 22A having an axial width substantially the same as the axial width L1 of the regulating plate 46 and a radial depth D1 is formed on the inner peripheral side of the axial end of the casing body 22. The restriction plate 46 is fitted into the plate fitting recess 22A.

  In this embodiment, in order to prevent the leakage of the lubricant in the reduction gear G1 (arrow A1), between the regulation plate 46 and the casing 20 (the casing body 22 thereof), and between the regulation plate 46 and the first arm 61, It is comprised so that sealing may be performed between both.

  Specifically, a seal fixing recess 46B is formed in the restriction plate 46 at a corner portion Pc where the three members (61, 22, 46) of the first arm 61, the casing main body 22, and the restriction plate 46 intersect. Seal rubber 70 (sealing member) is fixed to the fixing recess 46B.

  A casing-facing pedestal surface 46 </ b> B <b> 1 that faces the casing body 22 is formed in the seal fixing recess 46 </ b> B of the regulation plate 46 in parallel with the surface 22 </ b> B of the casing body 22. Further, in this seal fixing recess 46B, an arm-facing pedestal surface (a mating member-facing pedestal surface) 46B2 facing the first arm 61 is continuous with the casing-facing pedestal surface 46B1, and a surface 61B of the first arm 61 is provided. Are formed in parallel. As a result, the overall shape of the seal fixing recess 46B is substantially L-shaped in a cross section parallel to the axis (in the cross section of FIG. 1).

  In this embodiment, only one seal rubber 70 is fixed to the seal fixing recess 46B. The seal rubber 70 is fixed across both the casing facing base surface 46B1 and the arm facing base surface 46B2 of the seal fixing recess 46B.

  The anti-pedestal surface side of the seal rubber 70 is shaped so as to be in contact with both the first arm 61 and the casing body 22. FIG. 1 shows the shape of the seal rubber 70 when it is not deformed (a state before the regulation plate 46 is attached to the plate fitting recess 22 </ b> A of the casing body 22) with an imaginary line. As is apparent from the shape of this imaginary line, the seal rubber 70 protrudes toward the first arm 61 in the axial direction by ΔL1 from the side surface 46C on the first arm 61 side in the axial direction of the restriction plate 46 when not deformed. Yes. Further, the seal rubber 70 protrudes radially outward (toward the casing body 22) by ΔL3 from the outer peripheral surface 46D of the regulating plate 46 when not deformed.

  In other words, when the regulating plate 46 is incorporated in the plate fitting recess 22A of the casing body 22 and the casing body 22 of the reduction gear G1 is connected to the first arm 61 side, the seal rubber 70 is attached to the first arm 61. On the other hand, ΔL1 and ΔL3 “deformation allowance” of the casing main body 22 are fixed to the regulating plate 46 in such a shape and size as to generate.

  Next, the operation of the eccentric oscillating speed reduction device according to this embodiment will be described.

  When the input shaft 36 is rotated by operating a motor (not shown), the three eccentric bodies 38 integrated with the input shaft 36 are rotated, and three external gears are provided via rollers. 32 swings with a phase difference of 120 degrees.

  Each external gear 32 is internally meshed with an external pin 44 corresponding to the internal teeth of the internal gear 30. The number of internal teeth of the internal gear 30 (the number of external pins 44) is one more than the number of external teeth of the external gear 32. For this reason, the external gear 32 is swung once every time the input shaft 36 rotates once, and the phase in the circumferential direction is shifted (relatively rotated) by one tooth with respect to the internal gear 30. Become. This relative rotation is transmitted to the output block 84 via the inner roller 50 and the inner pin 48, and as relative rotation between the casing main body 22 and the output block 34 integrated with the internal gear main body 42 of the internal gear 30. It is taken out. The swinging component of the external gear 32 is absorbed by the gap between the inner roller 50 and the through hole 32C of the external gear 32.

  As a result, the first arm 61 connected to the casing body 22 and the second arm 62 connected to the output block 34 can be rotated relative to each other. When an impact is applied to the first arm 61 or the second arm 62 during the operation of the industrial robot R1, the impact load connects the first arm 61 and the second arm 62 so as to be relatively rotatable. It is received by a bearing on the industrial robot R1 side (not shown). Therefore, such an impact load is basically not transmitted to the casing body 22 and the output block 34 of the reduction gear G1. Therefore, even if the main bearing is not interposed between the casing body 22 and the output block 34, the output block 34 of the reduction gear G1 can smoothly rotate relative to the casing body 22.

  Here, the restricting plate 46 is positioned in the axial direction by being sandwiched between the receiving surface 22A1 of the plate fitting recess 22A of the casing body 22 and the first arm 61. Further, in this positioned state, the external pin 44 and the external gear 32 constituting the internal teeth of the internal gear 30 are sandwiched between the cover body 24 of the casing 20. Therefore, the restriction plate 46 restricts the axial movement of the internal gear 30 (the external pin 44) and the external gear 32 as its original function.

  On the other hand, a problem that arises when the reduction gear G1 having no main bearing is incorporated into the industrial robot R1 is prevention of leakage of the lubricant in the reduction gear G1. As a conventional representative method, a configuration in which a sealing member such as an O-ring is interposed between the casing body 22 of the reduction gear G1 and the first arm 61 of the industrial robot R1 can be considered. Since there is a risk that the O-ring may be accidentally dropped due to the contact between the surfaces perpendicular to each other, it is not easy to incorporate the reduction gear G1 into the industrial robot R1 while attaching a separate sealing member. It takes. Forming the groove for fitting the O-ring in the casing main body 22 or the first arm 61 may cause a cost increase, and may drop out of the groove and be bitten.

  However, in the present embodiment, a seal rubber 70 that can seal between the regulation plate 46 and the casing body 22 and between the regulation plate 46 and the first arm 61 is fixed to the regulation plate 46. Therefore, the restriction plate 46 to which the seal rubber 70 is fixed is fitted into the plate fitting recess 22A of the casing body 22, and the reduction gear G1 in which the restriction plate 46 is fitted is incorporated into the industrial robot R1. The space between the casing body 22 and the space between the restriction plate 46 and the first arm 61 can be automatically sealed.

  That is, since the reduction gear G1 can be incorporated into the industrial robot R1 without attaching a separate sealing member such as an O-ring, there is no risk of accidentally dropping the O-ring, etc. Can be

  Furthermore, even if the seal rubber 70 deteriorates with time, it is only necessary to replace the regulating plate 46 to which the seal rubber 70 is fixed, so that the cost is low and the maintainability is high.

  In addition, in this embodiment, since the seal fixing recess 46B is further provided in the restriction plate 46 and the seal rubber 70 is fixed to the seal fixing recess 46B, a relatively large seal rubber 70 is disposed. And large deformation allowances (ΔL1, ΔL3) can be secured. Therefore, better sealing performance can be obtained.

  Further, the seal fixing recess 46B of the restriction plate 46 is provided at a corner portion Pc where three members (61, 22, 46) of the first arm 61, the casing body 22 and the restriction plate 46 intersect, and the seal rubber 70 is provided with the first seal rubber 70. The seal fixing recess 46B is fixed so as to be in contact with both the one arm 61 and the casing body 22. Therefore, it is possible to seal between the regulation plate 46 and the casing body 22 and between the regulation plate 46 and the first arm 61 at the same time only by arranging one seal rubber 70. Therefore, the number of parts and the cost can be reduced accordingly.

  In this embodiment, the seal fixing recess 46B is provided with a casing-facing pedestal surface 46B1 facing the casing body 22 and an arm-facing pedestal surface 46B2 facing the first arm 61, and the seal rubber 70 is connected to the casing-facing pedestal. The surface 46B1 and the arm facing base surface 46B2 are fixed to both surfaces. Accordingly, even when a deformation reaction force is applied to the seal rubber 70 from a direction different from the axial direction and the radial direction, the seal rubber 70 can be stably fixed to the seal fixing recess 46B.

  In the present invention, the configuration for fixing the seal rubber (sealing member) to the regulation plate (regulation member) is not limited to the above configuration.

  FIG. 4 shows a modification thereof. In addition, the same code | symbol is attached | subjected to the member same as previous embodiment.

  In FIG. 4A, two seal fixing recesses 80A and 80B having an axial width L5 and a radial depth D5 are formed symmetrically at both ends in the axial direction of the outermost peripheral portion of the regulating plate 80. That is, a seal fixing recess 80A is provided on an arm facing surface (counter member facing surface) 80C facing the first arm 61 of the regulating plate 80, and a casing facing surface 80D in which the regulating plate 80 faces the casing body 22. Is provided with a seal fixing recess 80B.

  A seal rubber 82 is fixed to the seal fixing recess 80A on the outer side in the axial direction, and a seal rubber 84 is fixed to the seal fixing recess 80B on the inner side in the axial direction. The seal rubber 82 fixed to the seal fixing recess 80A contributes to the sealing between the regulation plate 80 and the first arm 61, and the seal rubber 84 fixed to the seal fixing recess 80B is between the regulation plate 46 and the casing body 22. Contributes to sealing between.

  In this configuration, the seal fixing recesses 80A and 80B and the seal rubbers 82 and 84 are provided for each of the space between the restriction plate 80 and the casing body 22 and between the restriction plate 80 and the first arm 61. The shapes of the seal fixing recesses 80A and 80B and the shapes of the seal rubbers 82 and 84 can be simplified. Further, since the deformation direction of the seal rubbers 82 and 84 can be only one direction (axial direction) perpendicular to the direction A1 in which the lubricant leaks, the deformation of the seal rubbers 82 and 84 is also simple. The sealing performance can be further improved.

  In the modification of FIG. 4A, seal fixing recesses 80A and 80B are formed at both axial ends of the outermost peripheral portion of the restriction plate 80. However, when the sealing rubber is disposed between the regulating member and the casing and between the regulating member and the counterpart member in this way, the arrangement position of the sealing member is not necessarily limited to these positions. For example, the sealing between the restricting member and the casing is formed at the position indicated by reference numeral P1 or P3, that is, the outer peripheral surface 80F of the restricting plate 80 or the axially inner casing facing surface 80D (avoid corners). You may make it do. The sealing between the regulating member and the mating member is also formed at the position indicated by the symbol P5, that is, on the arm facing surface 80C on the axially outer side of the regulating plate 80 (avoids corners). May be.

  On the other hand, in the modification of FIG. 4B, the opposing recess 90 </ b> A is formed in the casing (main body) 90 at a position facing the seal fixing recess 92 </ b> A of the regulating plate 92, and the seal rubber 94 is opposed to the casing 90. It is configured to be stored in the recess 90A. The axial dimension of the internal gear 30 (not shown in FIG. 4) of the seal fixing recess 92A provided on the restriction plate 92 is L7, and the axial dimension of the facing recess 90A of the casing 90 is L9. For this reason, the opposing recessed portion 90A has a larger dimension in the axial direction than the seal fixing recessed portion 92A side.

  Even when this configuration is adopted, the seal rubber 94 is fixed to the seal fixing recess 92A formed on the regulation plate 92 side, and is not fixed to the casing body 90 side.

  Even with this configuration, as a result, sealing between both the regulating plate 92 and the casing main body 90 and between the regulating plate 92 and the first arm 61 can be performed with one seal rubber 94 (one seal fixing recess 92A). ).

  Further, since the direction in which the seal rubber 94 is deformed can be only one direction (axial direction) perpendicular to the direction A1 in which the lubricant leaks, the deformation of the seal rubber 94 can be simplified, and the sealing performance itself is maintained high. be able to.

  Further, since the axial dimension L9 of the facing recess 90A of the casing 90 is ensured to be larger than the axial dimension L7 than the seal fixing recess 92A side, the deformation allowance ΔL5 of the seal rubber 94 can be increased. The sealing performance can be further increased.

  In the above embodiment, the regulation plate (regulation member) has a function of regulating the axial movement of both the internal gear (the external pin) and the external gear. However, the regulating member according to the present invention does not necessarily have a function of regulating the axial movement of both. For example, when the movement of the external gear in the axial direction is restricted by a member such as an output block, the restriction member has a function of restricting the movement of the internal gear (the outer pin) in the axial direction. It may be only. Further, for example, in the case where the internal teeth of the internal gear are not formed by the external pins but are directly geared to the internal gear main body, the restricting member is the shaft of the external gear. It may only have a function of restricting the direction movement. Conversely, in addition to the internal gear or the external gear, for example, the axial movement of the inner roller may also be restricted.

  Further, in the above embodiment, the movement restriction of the internal gear (the outer pin thereof) or the external gear toward the axial anti-restricting member side is realized by the cover body of the casing. In the invention, the movement restriction of the internal gear or the external gear toward the axial anti-restricting member is not particularly limited to this configuration. For example, you may regulate using means, such as a retaining ring with which the casing was mounted | worn.

  Moreover, in this invention, it is not limited to the said example also about the position and shape of the recessed part formed in a control member. If necessary, if the concave surface is recessed from the basic surface of the restricting member (the surfaces 46A, 46C, 46D in the example of the first embodiment) and a sealing member is provided in the recessed portion, the recessed portion This portion can be regarded as “a recess formed in the regulating member” in the present invention. Therefore, for example, the corners of the two surfaces of the sealing member are greatly chamfered at a predetermined angle (for example, 45 degrees), and the greatly chamfered portion is regarded as a “concave portion” and the sealing member is fixed to this portion. You may make it do. In the first place, there may be no recess.

  Further, in the above embodiment, the center crank type eccentric oscillating speed reduction device in which one crankshaft (input shaft) is arranged at the center of the internal gear is shown, but it is offset from the center of the internal gear. The present invention can also be applied to a distributed type eccentric oscillating type speed reducer in which a plurality of crankshafts are arranged at the position.

  The counterpart machine is not limited to an industrial robot, and may be a machine tool, for example.

G1 ... Deceleration device R1 ... Industrial robot (mating machine)
DESCRIPTION OF SYMBOLS 20 ... Casing 22 ... Casing main body 24 ... Cover body 30 ... Internal gear 32 ... External gear 34 ... Output block (carrier)
42 ... Internal gear body 44 ... External pin (internal gear of internal gear)
46 ... Regulating plate (regulating member)
46B ... Seal fixing recess 48 ... Inner pin 61 ... First arm (mating member)
62 ... Second arm

Claims (8)

An eccentric gear that has an internal gear and an external gear that meshes internally with the internal gear, and that extracts relative rotation between the internal gear and external gear to the counterpart machine as relative rotation between the casing and the carrier. In a dynamic reduction gear,
No main bearing is arranged between the casing and the carrier,
A regulating member that regulates axial movement of at least one of the internal gear and the external gear, and the regulating member is provided between the regulating member and the casing, and between the regulating member and the counterpart machine. An eccentric oscillating speed reduction device characterized in that a sealing member capable of sealing with a mating member is fixed. In claim 1,
An eccentric rocking type speed reducer characterized in that the regulating member is provided with a recess, and the sealing member is fixed to the recess. In claim 2,
The recess is provided at a corner where three members of the counterpart member, the casing, and the regulating member intersect,
The eccentric oscillating speed reduction device, wherein the sealing member is fixed to the recess so as to be in contact with both the counterpart member and the casing. In claim 2 or 3,
A mating member facing base surface facing the mating member and a casing facing base surface facing the casing are provided in the recess;
The eccentric oscillating speed reduction device, wherein the sealing member is fixed to both the opposing member-facing pedestal surface and the casing-facing pedestal surface. In any one of Claims 2-4,
The eccentric oscillating type speed reducer, wherein the recess is provided on both an opposing member opposing surface where the regulating member opposes the opposing member and a casing opposing surface opposing the casing. In any one of Claims 1-5,
The eccentric oscillating type speed reducer characterized in that a recess is formed in the casing, and the sealing member is housed in the recess of the casing. In claim 6,
The regulating member has no recess, the sealing member is fixed, only the casing has a recess, and the sealing member is housed in the recess of the casing. apparatus. In claim 6,
A recess is provided in the restriction member, the sealing member is fixed to the recess, and the recess of the casing is provided to face the recess of the restriction member,
The eccentric oscillating speed reduction device, wherein the concave portion provided in the casing has a larger dimension in the axial direction of the internal gear than the concave portion provided in the regulating member.

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