Rotating shaft structure with multiple speed reducers and manufacturing method thereof

Abstract

The rotating shaft structure includes: a first connecting rod; a second connecting rod connected to the first connecting rod; and a plurality of reducers arranged between the first connecting rod and the second connecting rod, and either the reducer side mounting hole and the first connecting rod side mounting hole for connecting the reducer to the first connecting rod is larger than the other or is a long hole.

Description

Technical Field

[0001] The present invention relates to a rotating shaft structure and a manufacturing method thereof, and in particular to a rotating shaft structure including a plurality of speed reducers and a manufacturing method thereof. Background Art

[0002] In the rotating shafts of machines such as robots, construction machinery, vehicles, and aircraft, if a load of more than 1 ton is applied, the load applied to the reducer arranged between the connecting rods also increases. Therefore, a large (large-capacity) reducer is generally used. The large-capacity reducer has a large outer shape, so the rotating shaft structure of the machine is also large-scale. As a method for miniaturizing the rotating shaft structure, the following structure is proposed: two small (small-capacity) reducers are arranged in a form of clamping from both sides for one connecting rod, and each reducer is connected to another connecting rod (see, for example, patent documents 1 and 2). By setting it as such a structure, the rotating shaft structure can be miniaturized without using a large-capacity reducer.

[0003] Patent document 3 states the following: In a wrist mechanism of an industrial robot, a first reducer and a second reducer are arranged on both sides of an arm, pulleys are fixed to input shafts of the first reducer and the second reducer, respectively, and are driven by two drive motors respectively by means of synchronous belts wound around the pulleys.

[0004] Patent document 4 describes the following: In a reduction drive device, a ring having a flange portion is fixed to a motor housing by bolts, a bearing for holding a rotating hub is provided on the ring, a supporting member is mounted on the flange portion by bolts, a gasket is clamped between the supporting member and the flange portion, and the mounting clearance of the bearing is adjusted by adjusting the gasket.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2007 / 072546

[0008] Patent Document 2: Korean Patent No. 10-1881350

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 06-312394

[0010] Patent Document 4: Japanese Utility Model Publication No. 61-010238 Summary of the Invention

[0011] Problems to be solved by the invention

[0012] When assembling a rotating shaft structure with multiple speed reducers, it is necessary to pre-adjust the positional relationship between the multiple speed reducer-side mounting holes and the connecting rod-side mounting holes. However, if a common drive shaft is inserted into multiple speed reducers while being rotated, the input shaft of the speed reducer will rotate, causing the positional relationship between the speed reducer-side mounting holes and the connecting rod-side mounting holes to deviate. As a result, the rotating shaft structure cannot be easily assembled. In addition, even when inserting a single drive shaft into multiple speed reducers, rotating the drive shaft while being inserted will cause the input shaft of the speed reducer to rotate, causing the positional relationship between the speed reducer-side mounting holes and the connecting rod-side mounting holes to deviate.

[0013] Therefore, a technology for improving the manufacturing efficiency of a rotating shaft structure including a plurality of speed reducers is desired.

[0014] Solutions for solving problems

[0015] A technical solution disclosed in the present invention provides a rotating shaft structure comprising: a first connecting rod; a second connecting rod connected to the first connecting rod; and a plurality of reducers arranged between the first connecting rod and the second connecting rod, wherein either one of the reducer side mounting hole and the first connecting rod side mounting hole for combining the reducer with the first connecting rod is larger than the other or is a long hole.

[0016] Another technical solution disclosed herein provides a method for manufacturing a rotating shaft structure, which comprises: a first connecting rod; a second connecting rod connected to the first connecting rod; and a plurality of reducers arranged between the first connecting rod and the second connecting rod, wherein the method for manufacturing the rotating shaft structure comprises the following steps: forming either a reducer-side mounting hole for connecting the reducer to the first connecting rod and a first connecting rod-side mounting hole to be larger than the other or forming it into a long hole; installing the plurality of reducers on the second connecting rod and pre-adjusting the positional relationship between the reducer-side mounting hole and the first connecting rod-side mounting hole; installing one of the plurality of reducers installed on the second connecting rod on the first connecting rod; inserting a drive shaft for driving the reducer into the reducer while rotating; and installing the remaining reducers of the plurality of reducers on the first connecting rod in a state where the position of the reducer-side mounting hole is displaced due to the insertion of the drive shaft.

[0017] Effects of the Invention

[0018] According to one aspect of the present disclosure, the reducer can be mounted on the first connecting rod even when the reducer mounting hole is displaced due to the insertion of the drive shaft. This improves the manufacturing efficiency of a rotating shaft structure equipped with multiple reducers. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a side view showing an example of a machine including a rotating shaft structure.

[0020] Figure 2A This is a plan view showing an example of a speed reducer.

[0021] Figure 2B This is a cross-sectional view taken along the line IIB-IIB showing an example of a speed reducer.

[0022] Figure 3 It is a partial cross-sectional view showing a rotating shaft structure according to one embodiment.

[0023] Figure 4 It is a side view taken along line IV-IV showing the rotating shaft structure of one embodiment.

[0024] Figure 5 It is a partial cross-sectional view showing a modified example of the rotating shaft structure.

[0025] Figure 6 VI-VI is a side view showing a modified example of the rotating shaft structure.

[0026] Figure 7 It is a partial cross-sectional view showing another modified example of the rotating shaft structure.

[0027] Figure 8 FIG. 8 is a side view taken along line VIII-VIII showing another modified example of the rotating shaft structure.

[0028] Figure 9 This is a partial cross-sectional view showing still another modified example of the rotating shaft structure.

[0029] Figure 10 It is a side view taken along line XX showing still another modified example of the rotating shaft structure.

[0030] Figure 11 It is a partial cross-sectional view showing still another modified example of the rotating shaft structure.

[0031] Figure 12 This is a partial cross-sectional view showing an example of a rotation axis structure applied to other joint axes. DETAILED DESCRIPTION

[0032] The following describes the embodiments of the present disclosure in detail with reference to the accompanying drawings. In each of the drawings, the same or similar structural elements are marked with the same or similar reference numerals. In addition, the embodiments described below are not intended to limit the technical scope of the invention described in the claims and the meaning of the terms.

[0033] Figure 1An example of a machine 2 having a rotating shaft structure 1 is shown. The rotating shaft structure 1 is, for example, a joint structure of a robot, but may also be a rotating shaft structure in other machines 2 such as construction machinery, vehicles, and aircraft. The rotating shaft structure 1 includes: a first link 10; a second link 20 connected to the first link 10; and a plurality of speed reducers 30 arranged between the first link 10 and the second link 20. The rotating shaft structure 1 is, for example, a rotating shaft structure of a robot that rotates around a rotation axis J2, the first link 10 is, for example, a rotating base that rotates around a vertical axis, and the second link 20 is, for example, a first arm that rotates around a horizontal axis. Alternatively, the first link 10 and the second link 20 may be opposite components. In this case, it should be noted that the first link 10 may also be, for example, a first arm, and the second link 20 may also be, for example, a rotating base.

[0034] Figure 2A and Figure 2B An example of a speed reducer 30 is shown. The speed reducer 30 includes an input shaft 31 and an output shaft 32. An input shaft side wheel 33 is mounted on the input shaft 31, and power is input via the input shaft side wheel 33. The input shaft side wheel 33 is preferably a gear that meshes with the drive shaft side wheel described later, but may also be a pulley wound with a belt, cable, etc. The output shaft 32 includes an inner output shaft 34 and an outer output shaft 35. The inner output shaft 34 is preferably, for example, a shaft that rotates on the inside, and the outer output shaft 35 is preferably, for example, a shell that rotates on the outside. When the inner output shaft 34 is fixed so as not to rotate, the power of the input shaft 31 is transmitted to the outer output shaft 35, causing the outer output shaft 35 to rotate, thereby outputting the power. When the outer output shaft 35 is fixed so as not to rotate, the power of the input shaft 31 is transmitted to the inner output shaft 34, causing the inner output shaft 34 to rotate, thereby outputting the power. In order to attach the inner output shaft 34 or the outer output shaft 35 to the first connecting rod 10 or the second connecting rod 20, the inner output shaft 34 or the outer output shaft 35 respectively has one or more reducer-side mounting holes 36, 37 that can be fastened with screws such as bolts. The reducer-side mounting holes 36, 37 are preferably arranged at predetermined intervals in the circumferential direction of the reducer 30.

[0035] Figure 3 and Figure 4 : represents the rotating shaft structure 1 in this embodiment. Figure 3As shown, the rotating shaft structure 1 includes: a first link 10; a second link 20 connected to the first link 10; and a plurality of speed reducers 30 arranged between the first link 10 and the second link 20. The first link 10 preferably includes, for example, a U-shaped portion, and the second link 20 preferably includes, for example, an I-shaped portion. The first link 10 includes a first link-side mounting hole 11 for coupling the speed reducer 30 to the first link 10. The second link 20 includes a second link-side mounting hole 21 for coupling the speed reducer 30 to the second link 20. The plurality of speed reducers 30 are arranged on both sides of the second link 20, but may also be arranged on one side of the second link 20. In the case where the plurality of speed reducers 30 are arranged on one side of the second link 20, the first link 10 may also include an L-shaped portion instead of a U-shaped portion. In addition, two or more speed reducers 30 may be disposed on both sides of the second link 20 , or three or more speed reducers 30 may be disposed on one side of the second link 20 .

[0036] The rotating shaft structure 1 is a serial drive type, and also includes a drive shaft 40 that is common to multiple reducers 30, but it can also be a method in which a separate drive shaft drives multiple reducers 30 separately. The drive shaft 40 includes a drive shaft side wheel (not shown) that is linked to the input shaft side wheel 33 of the reducer 30. The drive shaft side wheel is preferably a gear that meshes with the input shaft side wheel 33, but it can also be a pulley wound with a belt, cable, etc. The drive shaft 40 is inserted into the multiple reducers 30 to transmit a common driving force to the multiple reducers 30. In the rotating shaft structure 1, the inner output shafts 34 of the multiple reducers 30 are fixed to the first connecting rod 10, the outer output shafts 35 of the multiple reducers 30 rotate, and the second connecting rod 20 rotates relative to the first connecting rod 10. If the drive shaft 40 is moved from, for example Figure 3 If the left side of the reducer 30 is rotated and inserted while being rotated, the input shaft 31 of the right reducer 30 will rotate and the positional relationship between the reducer side mounting hole 36 and the first connecting rod side mounting hole 11 will deviate. Figure 4 As shown, it is better to make the holes larger than the reducer side mounting hole 36 or to make them elongated, or it is better to make the reducer side mounting hole 36 larger or elongated than the first connecting rod side mounting hole 11, so that even if the positional relationship between the reducer side mounting hole 36 and the first connecting rod side mounting hole 11 is deviated, the reducer 30 can be mounted on the first connecting rod 10. The places where these holes are formed larger or formed into elongated holes can also be only the places where the reducer 30 is fastened last (at the end). Figure 3 In the example, it is between the right speed reducer 30 and the first connecting rod 10). In addition, the long hole such as Figure 4 As shown, it is preferable that the reducer 30 extends in a curved manner in the circumferential direction.

[0037] Figure 3The manufacturing procedure of the rotating shaft structure 1 shown is as follows. Figure 3 It is a figure which shows the following (process 5).

[0038] (Step 1) One of the speed reducer-side mounting hole 36 and the first link-side mounting hole 11 for coupling the speed reducer 30 to the first link 10 is formed larger than the other or is formed into an elongated hole.

[0039] (Step 2) The two speed reducers 30 are mounted on the second link 20 and the positional relationship between the speed reducer-side mounting hole 36 and the first link-side mounting hole 11 is adjusted in advance.

[0040] (Step 3) Install one of the two speed reducers 30 (in the second link 20) Figure 3 In the example, the left speed reducer 30 is installed on the first connecting rod 10.

[0041] (Step 4) The drive shaft 40 for driving the speed reducer 30 is inserted into the speed reducer 30 while rotating. The drive shaft 40 is a common drive shaft for the plurality of speed reducers 30, but may be a separate drive shaft.

[0042] (Step 5) In a state where the position of the speed reducer side mounting hole 36 is displaced due to the insertion of the drive shaft 40, the remaining speed reducer 30 (in the Figure 3 In the example shown, the right speed reducer 30 is mounted on the first connecting rod 10. In this case, either the first connecting rod mounting hole 11 or the speed reducer mounting hole 36 is larger than the other or is an elongated hole. Therefore, even if the positional relationship between the speed reducer mounting hole 36 and the first connecting rod mounting hole 11 is misaligned, the speed reducer 30 and the first connecting rod 10 can be mounted.

[0043] In addition, the axial dimension of the reducer 30 fluctuates due to individual differences. Therefore, sometimes the gap between the first connecting rod 10, the second connecting rod 20 and the reducer 30 is slightly insufficient, and the reducer 30 interferes with the first connecting rod 10. Therefore, the dimension between the first connecting rod 10 and the second connecting rod 20 is generally slightly increased. However, if the reducer 30 is forcibly installed on the first connecting rod 10 in a state where a gap is generated, an excessive pulling force will be applied to the axial direction of the reducer 30, resulting in premature damage to the reducer 30. Therefore, it is preferable that the rotating shaft structure 1 also has a gasket 50 for adjusting the gap between the first connecting rod 10, the second connecting rod 20 and the reducer 30. The gasket 50 is a circular plate type or an annular type, and has a through hole 51 for a screw such as a bolt to pass through. The through hole 51, for example, has a diameter that can allow a screw such as a bolt to pass through, but it can also have a larger diameter or be a long hole like the first connecting rod side mounting hole 11 or the reducer side mounting hole 36.

[0044] The gasket 50 is arranged at the place where the reducer 30 is fastened last (at Figure 3 In the example, the spacer 50 is between the right-side reducer 30 and the first connecting rod 10), but the spacer 50 can also be arranged between the reducer 30 and the second connecting rod 20, or, when there are multiple reducers 30 on one side or both sides of the second connecting rod 20, the spacer 50 can also be arranged between the multiple reducers 30. In the former case, spacers 50 of various thicknesses are prepared in advance, and the spacers 50 of the required thickness are appropriately selected and arranged before the remaining reducers 30 are installed on the first connecting rod 10 (process 5). In the latter case, the required thickness of the spacer 50 is studied in advance before the manufacture of the rotating shaft structure 1 and the predetermined spacers 50 are prepared in advance, and the predetermined spacers 50 are arranged before the two reducers 30 are installed on the second connecting rod 20 (process 2).

[0045] Figure 5 and Figure 6 The following shows a modified example of the rotating shaft structure 1. In this rotating shaft structure 1, the second connecting rod 20 is installed after the speed reducer 30 is installed on the first connecting rod 10, which is different from the aforementioned rotating shaft structure. In addition, in this rotating shaft structure 1, the first connecting rod 10 is formed in a manner that can be separated into two parts so that the input shaft side wheel 33 of the speed reducer 30 does not interfere with the second connecting rod 20 when the second connecting rod 20 is installed. This point is also different from the aforementioned rotating shaft structure. Figure 5 In the example, the two parts are the L-shaped part and the I-shaped part, but it can also be two L-shaped parts. Moreover, in the rotating shaft structure 1, the place where the speed reducer 30 is finally fastened becomes the second connecting rod 20 and the speed reducer 30 (at Figure 5 In the example, the right side reducer 30) is located between the second connecting rod side mounting hole 21. Figure 6 As shown, it is preferably larger than the speed reducer side mounting hole 37 or a long hole, or it is preferably larger than the second connecting rod side mounting hole 21 or a long hole.

[0046] Figure 5 The manufacturing procedure of the rotating shaft structure 1 shown is as follows. Figure 5 It is a figure which shows the following (process 3-1).

[0047] (Step 0) The first link 10 is formed so as to be separable into two parts.

[0048] (Step 1) Either the speed reducer-side mounting hole 37 or the second link-side mounting hole 21 for coupling the speed reducer 30 to the second link 20 is formed larger than the other or is formed into an elongated hole.

[0049] (Step 2) The two speed reducers 30 are mounted on the first link 10 and the positional relationship between the speed reducer-side mounting hole 37 and the second link-side mounting hole 21 is adjusted in advance.

[0050] (Step 3) Install one of the two speed reducers 30 (in the first link 10) Figure 5 In the example, the left speed reducer 30 is installed on the second connecting rod 20.

[0051] (Step 3-1) Bringing the Two Portions of the First Link 10 into Contact This step may be performed after the drive shaft 40 is inserted into the speed reducer 30 (Step 4). In this case, the two portions of the first link 10 are brought into contact while the drive shaft 40 is rotated.

[0052] (Step 4) The drive shaft 40 for driving the speed reducer 30 is inserted into the speed reducer 30 while rotating. The drive shaft 40 is a drive shaft commonly used for the plurality of speed reducers 30, but may be a separate drive shaft.

[0053] (Step 5) The remaining speed reducer 30 (in the state where the speed reducer side mounting hole 37 is displaced due to the insertion of the drive shaft 40) is installed. Figure 5 In the example shown, the right speed reducer 30 is mounted on the second connecting rod 20. In this case, either the speed reducer mounting hole 37 or the second connecting rod mounting hole 21 is larger than the other or is an elongated hole. Therefore, even if the positional relationship between the speed reducer mounting hole 37 and the second connecting rod mounting hole 21 is misaligned, the speed reducer 30 and the second connecting rod 20 can be mounted.

[0054] In addition, Figure 5 In the rotating shaft structure 1 shown, the required thickness of the gasket 50 is studied before manufacturing the rotating shaft structure 1 and a predetermined gasket 50 is prepared in advance. The predetermined gasket 50 can be arranged before the two speed reducers 30 are mounted on the first connecting rod 10 (process 2). Alternatively, the gasket 50 can be arranged between the second connecting rod 20 and the speed reducer 30 (in the process 2). Figure 5 In the example of the right reducer 30), a plurality of thicknesses of gaskets 50 are prepared in advance, and the gaskets 50 of the required thickness are appropriately selected and arranged before the remaining reducers 30 are mounted on the second connecting rod 20 (process 5).

[0055] Figure 7 and Figure 8Another variation of the rotating shaft structure 1 is shown. In this rotating shaft structure 1, the outer output shaft 35 of the reducer 30 is fixed to the first connecting rod 10, and the inner output shaft 34 of the reducer 30 rotates, which is different from the aforementioned rotating shaft structure. In addition, in this rotating shaft structure 1, the reducer 30 is first installed on the second connecting rod 20, so that the first connecting rod 10 is formed in a manner that can be separated into two parts so that the input shaft side wheel 33 of the reducer 30 does not interfere with the first connecting rod 10. Moreover, in this rotating shaft structure 1, the place where the reducer 30 is finally fastened becomes the first connecting rod 10 and the reducer 30 (at Figure 7 In the example, the right side reducer 30) is located between the reducer side mounting holes 37. Figure 8 As shown, it is preferably larger than the first connecting rod side mounting hole 11 or a long hole, or the first connecting rod side mounting hole 11 is preferably larger than the speed reducer side mounting hole 37 or a long hole.

[0056] Figure 7 The manufacturing procedure of the rotating shaft structure 1 shown is as follows. Figure 7 It is a figure which shows the following (process 3-1).

[0057] (Step 0) The first connecting rod 10 is formed so as to be separable into two parts. Figure 7 In the example, the two parts are the letter L-shaped part and the letter I-shaped part, but it can also be two letter L-shaped parts.

[0058] (Step 1) Either the speed reducer-side mounting hole 37 or the first link-side mounting hole 11 for coupling the speed reducer 30 to the first link 10 is formed larger than the other or is formed into an elongated hole.

[0059] (Step 2) The two speed reducers 30 are mounted on the second link 20 and the positional relationship between the speed reducer-side mounting hole 37 and the first link-side mounting hole 11 is adjusted in advance.

[0060] (Step 3) Install one of the two speed reducers 30 (in the second link 20) Figure 7 In the example, the left speed reducer 30 is installed on the first connecting rod 10.

[0061] (Step 3-1) Bringing the Two Portions of the First Link 10 into Contact This step may be performed after the drive shaft 40 is inserted into the speed reducer 30 (Step 4). In this case, the two portions of the first link 10 are brought into contact while the drive shaft 40 is rotated.

[0062] (Step 4) The drive shaft 40 for driving the speed reducer 30 is inserted into the speed reducer 30 while rotating. The drive shaft 40 is a drive shaft commonly used for the plurality of speed reducers 30, but may be a separate drive shaft.

[0063] (Step 5) The remaining speed reducer 30 (in the state where the speed reducer side mounting hole 37 is displaced due to the insertion of the drive shaft 40) is installed. Figure 7 In the example shown, the right speed reducer 30 is mounted on the first connecting rod 10. In this case, either the speed reducer mounting hole 37 or the first connecting rod mounting hole 11 is larger than the other or is an elongated hole. Therefore, even if the positional relationship between the speed reducer mounting hole 37 and the first connecting rod mounting hole 11 is misaligned, the speed reducer 30 and the first connecting rod 10 can be mounted.

[0064] In addition, Figure 7 In the rotating shaft structure 1 shown, the required thickness of the gasket 50 is studied before manufacturing the rotating shaft structure 1 and a predetermined gasket 50 is prepared in advance. The predetermined gasket 50 can be arranged before the two speed reducers 30 are mounted on the second connecting rod 20 (process 2). Alternatively, the gasket 50 can be arranged between the first connecting rod 10 and the speed reducer 30 (in the process 2). Figure 7 In the example of the right reducer 30), in the case of the spacers 50, various thicknesses are prepared in advance, and the spacers 50 of the required thickness are appropriately selected and arranged before the remaining reducers 30 are mounted on the first link 10 (step 5).

[0065] Figure 9 and Figure 10 Another variation of the rotating shaft structure 1 is shown. In this rotating shaft structure 1, the outer output shaft 35 of the reducer 30 is fixed to the first connecting rod 10, and the inner output shaft 34 of the reducer 30 rotates. In addition, in this rotating shaft structure 1, the reducer 30 is first installed on the first connecting rod 10 and then the second connecting rod 20 is installed. However, since the input shaft side wheel 33 of the reducer 30 does not interfere with the second connecting rod 20 when the second connecting rod 20 is installed, the first connecting rod 10 is not formed in a manner that can be separated into two parts, which is also different from the aforementioned rotating shaft structure. Moreover, in this rotating shaft structure 1, the place where the reducer 30 is finally fastened becomes the second connecting rod 20 and the reducer 30 (at Figure 9 In the example, the right side reducer 30) is located between the second connecting rod side mounting hole 21. Figure 10 As shown, it is preferably larger than the speed reducer side mounting hole 36 or is an elongated hole, or it is preferably larger than the second connecting rod side mounting hole 21 or is an elongated hole.

[0066] Figure 9 The manufacturing procedure of the rotating shaft structure 1 shown is as follows. Figure 9 It is a figure which shows the following (process 5).

[0067] (Step 1) Either the speed reducer-side mounting hole 36 or the second link-side mounting hole 21 for coupling the speed reducer 30 to the second link 20 is formed larger than the other or is formed into an elongated hole.

[0068] (Step 2) The two speed reducers 30 are mounted on the first link 10 and the positional relationship between the speed reducer-side mounting hole 36 and the second link-side mounting hole 21 is adjusted in advance.

[0069] (Step 3) Install one of the two speed reducers 30 (in the first link 10) Figure 9 In the example, the left speed reducer 30 is installed on the second connecting rod 20.

[0070] (Step 4) The drive shaft 40 for driving the speed reducer 30 is inserted into the speed reducer 30 while rotating. The drive shaft 40 is a drive shaft commonly used for the plurality of speed reducers 30, but may be a separate drive shaft.

[0071] (Step 5) In a state where the position of the speed reducer side mounting hole 36 is displaced due to the insertion of the drive shaft 40, the remaining speed reducer 30 (in the Figure 9 In the example shown, the right speed reducer 30 is mounted on the second connecting rod 20. In this case, either the speed reducer mounting hole 36 or the second connecting rod mounting hole 21 is larger than the other or is an elongated hole. Therefore, even if the positional relationship between the speed reducer mounting hole 36 and the second connecting rod mounting hole 21 is misaligned, the speed reducer 30 and the second connecting rod 20 can be mounted.

[0072] In addition, Figure 9 In the rotating shaft structure 1 shown, the spacers 50 of various thicknesses are prepared in advance, and the spacers 50 of the required thickness can be appropriately selected and arranged before the remaining speed reducer 30 is mounted on the second connecting rod 20 (step 5). Alternatively, the spacers 50 can be arranged between the first connecting rod 10 and the speed reducer 30 (in the step 5). Figure 9 In the example of the right reducer 30), the required thickness of the gasket 50 is studied in advance before manufacturing the rotating shaft structure 1 and the predetermined gasket 50 is prepared in advance. The predetermined gasket 50 can be arranged before installing the two reducers 30 on the first connecting rod 10 (process 2).

[0073] Figure 11Another modified example of the rotating shaft structure 1 is shown. The rotating shaft structure 1 also includes a reduction mechanism 60 for transmitting power to the drive shaft 40 and a drive source 61 for supplying power to the reduction mechanism 60. The reduction mechanism 60 may include, for example, a large wheel 63 and a small wheel 64. The large wheel 63 and the small wheel 64 are preferably gears that mesh with each other, but may also be pulleys wound with belts, cables, etc. The large wheel 63 is mounted on the drive shaft 40, and the small wheel 64 is mounted on the rotating shaft 62 of the drive source 61. The reduction mechanism 60 is preferably arranged inside the first connecting rod 10. By having such a reduction mechanism 60, the drive source 61 can be further miniaturized and energy-saving, and thus the rotating shaft structure 1 can be further miniaturized.

[0074] The rotating shaft 62 of the drive source 61 is arranged parallel to the drive shaft 40, but can also be arranged orthogonally using a bevel gear or the like. Alternatively, multiple drive sources 61 can be arranged on the first connecting rod 10, each of which supplies power to the reduction mechanism 60. This allows the output from the drive source 61 to be further increased or the drive source 61 to be further miniaturized.

[0075] Figure 12 FIG. 1 shows an example of a rotation axis structure 1 applied to other joint structures. The rotation axis structure 1 can also be applied to, for example, a robot rotating around the rotation axis J3 (see FIG. Figure 1 ) rotating axis structure. In this case, the first link 10 is, for example, a first arm that rotates about a horizontal axis, and the second link 20 is, for example, a second arm that rotates about a horizontal axis. Furthermore, as described above, the rotating axis structure 1 is not limited to the joint structure of a robot. It should be noted that it can also be applied to other rotating axis structures such as crankshaft mechanisms, steering mechanisms, door opening and closing mechanisms, wiper mechanisms, and four-link mechanisms in other machines such as construction machinery, vehicles, and aircraft.

[0076] According to the above embodiment, the speed reducer 30 can be mounted on the first link 10 even when the speed reducer mounting holes 36 and 37 are displaced due to the insertion of the drive shaft 40. This improves the manufacturing efficiency of the rotating shaft structure 1 including a plurality of speed reducers 30.

[0077] Although various embodiments have been described in this specification, the present invention is not limited to the aforementioned embodiments, and it should be understood that various modifications can be made within the scope of the claims.

[0078] Description of Reference Numerals

[0079] 1. Rotating shaft structure; 2. Machinery; 10. First connecting rod; 11. First connecting rod side mounting hole; 20. Second connecting rod; 21. Second connecting rod side mounting hole; 30. Reducer; 31. Input shaft; 32. Output shaft; 33. Input shaft side wheel; 34. Inner output shaft; 35. Outer output shaft; 36, 37, Reducer side mounting holes; 40. Drive shaft; 50. Gasket; 51. Through hole; 60. Speed ​​reduction mechanism; 61. Drive source; 62. Rotating shaft; 63. Large wheel; 64. Small wheel; J2, J3, Rotating axis.

Claims

1. A rotary shaft structure comprising: a first link; a second link connected to the first link; and a plurality of speed reducers disposed between the first link and the second link, wherein: Either one of the speed reducer side mounting hole and the first connecting rod side mounting hole for combining the speed reducer with the first connecting rod is larger than the other or is an elongated hole. The rotary shaft structure further includes a common drive shaft that is inserted into the plurality of speed reducers to transmit driving force to the plurality of speed reducers, and the position of the speed reducer-side mounting hole is displaced due to the insertion of the drive shaft.

2. The rotating shaft structure according to claim 1, wherein: The rotary shaft structure further includes a shim for adjusting a gap between the first link, the second link, and the speed reducer. The shim is disposed between the speed reducer and the first link, between the speed reducer and the second link, or between the plurality of speed reducers.

3. The rotating shaft structure according to claim 1, wherein: The rotary shaft structure further includes a speed reduction mechanism for transmitting power to the drive shaft and a drive source for supplying power to the speed reduction mechanism, wherein a rotary shaft of the drive source is arranged parallel to the drive shaft.

4. The rotating shaft structure according to claim 3, wherein: A plurality of the drive sources are provided, and each of the drive sources supplies power to the speed reduction mechanism.

5. The rotating shaft structure according to any one of claims 1 to 4, wherein The first connecting rod can be separated into two parts.

6. A method for manufacturing a rotating shaft structure, the rotating shaft structure comprising: a first link; a second link connected to the first link; and a plurality of speed reducers disposed between the first link and the second link, wherein: The manufacturing method of the rotating shaft structure comprises the following steps: forming one of a speed reducer-side mounting hole and a first link-side mounting hole for coupling the speed reducer to the first link to be larger than the other or forming the hole into an elongated hole; Mounting the plurality of speed reducers on the second connecting rod and pre-adjusting the positional relationship between the speed reducer side mounting holes and the first connecting rod side mounting holes; Mounting any one of the plurality of speed reducers mounted on the second connecting rod on the first connecting rod; Inserting a drive shaft driving the reducer into the reducer while rotating it; as well as The remaining speed reducers among the plurality of speed reducers are mounted to the first link in a state where the speed reducer-side mounting hole is displaced due to the insertion of the drive shaft.

7. The method for manufacturing a rotating shaft structure according to claim 6, wherein: The manufacturing method of the rotating shaft structure further comprises the following steps: preparing a shim for adjusting the gap between the first connecting rod, the second connecting rod, and the speed reducer; and The washer is disposed between the speed reducer and the first connecting rod, between the speed reducer and the second connecting rod, or between the plurality of speed reducers.

8. The method for manufacturing a rotating shaft structure according to claim 6 or 7, wherein: The drive shaft is a drive shaft commonly used for the plurality of speed reducers.

9. The method for manufacturing a rotating shaft structure according to claim 6 or 7, wherein: The manufacturing method of the rotating shaft structure further comprises the following steps: forming the first link in such a manner as to be separable into two parts; and The two parts are brought into contact before or after the drive shaft is inserted.

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