Gearing

Abstract

To provide a gear unit capable of suppressing deterioration in durability of a gear even with an easy-to-insert positioning pin.SOLUTION: A gear unit 10 has: a gear group in which a large gear 12 and a small gear 16 mesh; a first member to be attached 20 and a second member to be attached 22 arranged to face each other, in which both end parts of a gear shaft 14 to which the large gear 12 is fixed and a gear shaft 18 to which the small gear 16 is fixed are rotatably supported; a bolt 46 that is screwed into a screw hole 48 formed in a joint portion where the first member to be attached 20 and the second member to be attached 22 overlap, to fix the first member to be attached 20 and the second member to be attached 22; and a positioning pin that has a smaller diameter than a positioning hole 52 formed in the first member to be attached 20 and a positioning hole 54 formed in the second member to be attached 22, and is in contact with the hole walls of the positioning hole 52 and the positioning hole 54 by being expanded with a bolt 58 screwed into a screw hole 60 of a shaft part.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a gear device. [Background technology]

[0002] There is a gear device that has gears inside a housing (see, for example, Patent Documents 1 to 4). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-200384 A [Patent Document 2] JP 2006-307899 A [Patent Document 3] JP 2007-255681 A [Patent Document 4] JP 2007-267595 A [Patent Document 5] Japanese Patent Application Publication No. 8-241730 [Patent Document 6] JP 2017-28798 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a gear device in which one gear meshes with another gear whose gear shafts are parallel to each other inside a housing. A possible configuration is to split the housing of such a gear device into two parts, one side of a gear shaft to which a gear is attached and the other side, and to rotatably support one end of the gear shaft on one side of the divided housing and rotatably support the other end of the shaft on the other side of the divided housing.

[0005] Patent Document 5 discloses an example of a configuration in which the housing is divided into two parts. In the structure disclosed in Patent Document 5, a right case and a left case separated into two parts are fixed together using a tapping screw.

[0006] In a gear device, for example, the positional relationship between meshing gears is important, and any error in the positional relationship can cause large stress to act on the tooth surfaces or noise to be generated from the gears.

[0007] Therefore, when applying the case structure disclosed in Patent Document 5 to the housing of a gear device, it is possible to use a positioning pin to position one of the split cases relative to the other so that the positional relationship of the gears is appropriate.

[0008] Patent Document 6 discloses a gear device that uses knock pins as positioning pins, but the use of knock pins requires a press-fitting process using a press-fitting device during assembly, and furthermore, the pressed-in knock pins are not easy to remove, making disassembly and maintenance difficult. To avoid this, positioning between the cases is performed using easily insertable positioning pins instead of knock pins, but when such positioning pins are used, a gap of, for example, about 10 μm is generated between the positioning pins and the positioning holes, and this gap can cause misalignment between the meshing gears, raising concerns that the durability of the gears may decrease.

[0009] In consideration of the above, an object of the present invention is to provide a gear device that can suppress a decrease in durability of gears even when an easily insertable positioning pin is used. [Means for solving the problem]

[0010] First aspectThe gear device described in the above comprises a group of gears whose gears mesh with each other, a gear shaft to which the gears are fixed, both ends of which are supported for free rotation and are arranged opposite each other to be attached to a first member and a second member to be attached to a gear shaft, a bolt that is screwed into a screw hole formed in a joint where the first member to be attached and the second member to be attached to a bolt to fix the first member to the second member to be attached to a bolt, and a positioning pin that has a smaller diameter than a positioning hole formed in the joint and is expanded when an expanding member is pressed into a hole formed in the shaft portion and abuts against a hole wall of the positioning hole.

[0011] First aspect When assembling the gear device described in the above, the first and second workpieces are assembled while meshing the gears of the gear group, and then the positioning pins are inserted into the positioning holes. The positioning pins have a smaller diameter than the positioning holes, so that the positioning pins can be easily inserted into the positioning holes.

[0012] The shaft is then expanded by pushing an expandable member into a hole formed in the shaft of the positioning pin, so that the shaft abuts against the wall of the positioning hole and the positioning pin is fixed without play inside the positioning hole. This allows the first and second mounted members to be positioned, and eliminates the need to improve the machining precision or increase the rigidity of the entire gear device in order to prevent misalignment of the gears.

[0013] After positioning, the first and second mounted members are fixed together using bolts, thereby making it possible to maintain the appropriate positional relationship between the meshing gears.

[0014] On the other hand, when disassembling the gear device, the expanded shaft portion can be returned to its original diameter by removing the expanding member, the positioning pin can be easily pulled out of the positioning hole, and the first mounted member and the second mounted member can be easily separated by removing the bolt.

[0015] In addition, in this gear device, the first and second workpieces are positioned using a positioning pin, and the proper positional relationship of the gears is maintained, thereby minimizing unnecessary stress on the tooth surfaces, improving the durability of the tooth surfaces and reducing noise.

[0016] Second aspect The invention described in First aspect In the gear device described in , the positioning pin has a split groove formed along a surface connecting the axes of the adjacent gear shafts, and has a diameter enlarged in a direction intersecting with the surface.

[0017] Second aspect In the gear device described in the above, the positioning pin inserted into the positioning hole has a split groove formed along the plane connecting the axes of adjacent gear shafts, so that the shaft portion can be easily expanded in diameter in a direction intersecting the plane connecting the axes of adjacent gear shafts. In addition, since the outer peripheral portion of the shaft portion in the direction intersecting with the plane connecting the axes of adjacent gear shafts abuts against the hole wall of the positioning hole, misalignment in the direction intersecting with the plane connecting the axes of adjacent gear shafts is reliably suppressed.

[0018] Therefore, even in a group of gears in which the gear shafts are supported by a first mounting member and a second mounting member, misalignment of the gears in a direction intersecting the plane connecting the axes of adjacent gear shafts is reliably suppressed.

[0019] The deviation in the direction intersecting the plane connecting the axes of adjacent gear shafts corresponds to the direction of the misalignment error in the meshing gears, so Second aspect By adopting this configuration, it is possible to suppress misalignment errors between the gears that mesh with each other.

[0020] Third aspect The invention described in First or second aspect In the gear device described in , the shaft portion is formed with the hole into which the bolt or wedge can be removably attached.

[0021] Third aspectIn the gear device described in the above, a bolt or a wedge serving as a diameter expanding member is removably attached to the hole in the shaft portion.

[0022] Therefore, the diameter of the shank of the positioning pin can be easily expanded by screwing a bolt having a diameter relatively slightly larger than the hole into the hole or by inserting a wedge into the hole.

[0023] In addition, by loosening the bolt and removing it from the hole or pulling out the wedge, the shaft of the positioning pin can be reduced in diameter or the pressing force of the shaft against the positioning hole can be reduced, making it possible to easily pull out the positioning pin inserted into the positioning hole.

[0024] Fourth aspect The invention described in Any one of the first to third aspects In the gear device described in the above, at least one of the positioning pin and the bottom of the positioning hole is provided with a rotation prevention portion that prevents the positioning pin from rotating.

[0025] Fourth aspect In the gear device described in the above, a rotation prevention portion that prevents rotation of the positioning pin is provided on at least one of the positioning pin and the bottom of the positioning hole, so that free rotation of the main body can be suppressed, for example, when a bolt screwed into a hole formed in the shaft portion is screwed in or loosened. Effect of the Invention

[0026] As described above, the gear device of the present invention has the excellent effect of making it possible to suppress a decrease in the durability of the gears even when easy-to-insert positioning pins are used. [Brief description of the drawings]

[0027] [Figure 1] 1 is a cross-sectional view showing a gear device according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is an exploded view showing a gear device according to a first embodiment of the present invention. [Diagram 3]1A is a plan view of the first mounting member as viewed from the inside, and FIG. 1B is a plan view of the second mounting member as viewed from the outside. [Figure 4] 4A is a cross-sectional view (corresponding to the cross-section along line 4-4 in FIG. 3) showing the state before the first mounting member and the second mounting member are fixed, and FIG. 4B is a cross-sectional view showing the state after the first mounting member and the second mounting member are fixed. [Diagram 5] 1A is a cross-sectional view showing the positioning pin, FIG. 1B is a view showing the end face of the main body of the positioning pin, and FIG. 1C is a plan view showing the positioning pin inserted into the pin hole of the housing. [Figure 6] FIG. 1A is an explanatory diagram for explaining the gear misalignment error and parallelism error, FIG. 1B is an explanatory diagram for explaining an imaginary plane connecting the axis line of the large gear and the axis line of the pinion, and FIG. 1C is a graph showing the relationship between the misalignment error and parallelism error and the tooth surface stress. [Figure 7] 10A is a cross-sectional view showing a main portion of a gear device according to a second embodiment, and FIG. 10B is a perspective view showing a portion of the outer surface side of a first mounting member. [Figure 8] FIG. 13(A) is a perspective view showing a main portion of a gear device according to a third embodiment, and (B) is a cross-sectional view showing a portion of a first mounting member. [Figure 9] 13 is a cross-sectional view showing a modified example of the positioning pin. FIG. [Figure 10] FIG. 13 is a perspective view showing a pin body of a positioning pin according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] A gear device 10 according to one embodiment of the present invention will be described with reference to Figs. As shown in Figures 1 and 2, the gear device 10 of this embodiment is composed of a large-diameter gear 12, a gear shaft 14 to which the large gear 12 is fixed, a small-diameter pinion 16 that meshes with the large gear 12, a gear shaft 18 to which the pinion 16 is fixed, a box-shaped housing 24 composed of a first mounting member 20 and a second mounting member 22, a bearing 26, a positioning pin 28 (not shown in Figures 1 and 2) described later, a housing fixing bolt 46 (not shown in Figures 1 and 2) described later, and the like.

[0029] In addition, the large gear 12 and the small gear 16 in this embodiment are helical gears, but may be spur gears.

[0030] As shown in Figures 2 and 3(A), the first mounting member 20 is configured to include a rectangular bottom plate portion 20A, a pair of opposing side walls 20B arranged along the longitudinal direction of the bottom plate portion 20A, and a pair of opposing side walls 20C arranged along the short direction of the bottom plate portion 20A.

[0031] A first boss 32 and a second boss 34 are integrally formed on the inner surface of the bottom plate portion 20A. The first boss 32 and the second boss 34 are each provided with a bearing 26.

[0032] As shown in Figures 2 and 3(B), the second mounting member 22 is configured to include a rectangular bottom plate portion 22A, a pair of opposing side walls 22B arranged along the longitudinal direction of the bottom plate portion 22A, and a pair of opposing side walls 22C arranged along the short direction of the bottom plate portion 22A.

[0033] A third boss 36 is formed on the inner surface of the bottom plate portion 22A at a position facing the first boss 32 of the first mounting member 20, and a fourth boss 38 is formed at a position facing the second boss 34 of the first mounting member 20. The third boss 36 and the fourth boss 38 are each provided with a bearing 26.

[0034] 1, one end of the gear shaft 14 to which the large gear 12 is fixed is supported by a bearing 26 of a first boss 32 formed on the first mounting member 20, and a portion of the gear shaft 14 penetrates the bottom plate portion 20A of the first mounting member 20 and protrudes to the outside. On the other hand, the other end of the gear shaft 14 is supported by a bearing 26 of a third boss 36 formed on the second mounting member 22. One end of the gear shaft 14 is connected to, for example, a power-using device 40 that requires power from a motor 44 (described later).

[0035] One end of the gear shaft 18 to which the pinion 16 is fixed is supported by a bearing 26 of a second boss 34 formed on the first mounting member 20. The other end of the gear shaft 18 is supported by a bearing 26 of a fourth boss 38 formed on the second mounting member 22, and penetrates the bottom plate portion 22A of the second mounting member 22, with a portion of the gear shaft 18 protruding to the outside. The other end of the gear shaft 18 is connected to a rotating shaft 44A of a motor 44 via a coupling 42, for example.

[0036] 3 and 4, the first mounting member 20 has screw holes 48 formed in two diagonal corners, into which the housing fixing bolts 46 are screwed. Moreover, the second mounting member 22 has holes 50 formed coaxially with the screw holes 48 in a position opposite to the screw holes 48 in the first mounting member 20, into which the housing fixing bolts 46 are inserted.

[0037] Furthermore, the first mounting member 20 has pin holes 52, into which the positioning pins 28 are inserted, formed in two diagonal corners different from the corners in which the screw holes 48 are formed.

[0038] In the second mounting member 22, at a position facing the pin hole 52 of the first mounting member 20, a pin hole 54 is formed coaxially, through which the positioning pin 28 passes.

[0039] (Positioning pin configuration) Next, the positioning pin 28 of this embodiment will be described with reference to FIGS. The positioning pin 28 is composed of a pin body 56 serving as a shaft portion, and a bolt 58 serving as a diameter expanding member.

[0040] The pin body 56 is made of a material with a constant diameter, and a screw hole 60 is formed in the axial center from one end to the other end. Examples of materials constituting the pin body 56 include metal materials such as steel and stainless steel. Note that the other end side of the pin body 56 refers to the tip side when inserted into the pin holes 52 and 54.

[0041] The outer diameter of the pin body 56 (the outer diameter of the material) is formed slightly smaller than the inner diameters of the pin holes 52 and 54 so that the pin body 56 can be easily inserted into the pin holes 52 and 54 by gripping it with a hand. As an example, when the outer diameter of the pin body 56 is 5 to 6 mm, the outer diameter of the pin body 56 is formed to be smaller than the inner diameters of the pin holes 52 and 54 by about 10 μm.

[0042] The pin body 56 has two split grooves 62 formed along the axis from one end to the other end, and the pin body 56 is capable of changing its diameter by elastically deforming the portion divided by the split grooves 62. The pin body 56 of this embodiment has two split grooves 62 formed at positions facing each other, and is divided into two when viewed from one end.

[0043] Here, in the pin body 56 of this embodiment, the root diameter of the screw hole 60 is formed relatively smaller than the crest diameter of the male thread 58A of the bolt 58. When the male thread 58A of the bolt 58 is screwed into this screw hole 60, a force is applied to the part where the screw hole 60 is formed, pushing it radially outward. As a result, the pin body 56 expands in diameter in a direction (radial direction of the pin body 56, direction of arrow A) perpendicular to the longitudinal direction of the split groove 62 (axial direction of the pin body 56, direction of arrow B).

[0044] (Action, effect) Next, a procedure for assembling the gear device 10 of this embodiment will be described. The gear shaft 14 and the gear shaft 18 are supported by the bearings 26 of either the first mounting member 20 or the second mounting member 22, and the first mounting member 20 and the second mounting member 22 are faced toward each other, and then the first mounting member 20 and the second mounting member 22 are temporarily secured together with two housing fixing bolts 46.

[0045] The term "temporarily fixed" as used herein means, for example, that the end face of the first mounting member 20 and the end face of the second mounting member 22 are lightly in contact with each other, and the first mounting member 20 and the second mounting member 22 are in a state where they can be easily displaced in a direction along the end faces. The amount of "displacement" is equivalent to the dimension of the gap between the hole 50 and the male bolt 46A of the housing fixing bolt 46 (for example, 10 μm).

[0046] With the first mounting member 20 and the second mounting member 22 temporarily fastened in this manner, the pin body 56 of the positioning pin 28 is inserted into the pin hole 54 of the second mounting member 22 and the pin hole 52 of the first mounting member 20, and the male threads 58A of the bolt 58 are screwed into the screw hole 60 of the pin body 56.

[0047] At this time, as shown in Figure 5 (C), the direction in which the pin body 56 expands (the direction of arrow A) is determined to coincide with the direction along the plane (hereinafter, appropriately referred to as the virtual plane) VS connecting the gear shafts 14 and 18 (the direction of arrow V in Figures 1 and 3) perpendicular to the direction (the direction of arrow H in Figures 1 and 3), in other words, the direction of the split groove 62 is determined so that the longitudinal direction of the split groove 62 is along the virtual plane VS.

[0048] The pin body 56 elastically deforms and expands in diameter as the bolt 58 is screwed in, and the outer peripheral portion of the pin body 56 on the direction of arrow A is pressed firmly against the hole wall (inner surface) on the direction of arrow A of the pin hole 52 and the hole wall (inner surface) of the pin hole 54, thereby fixing the positioning pin 28 in the pin holes 52 and 54.

[0049] Thereafter, the housing fixing bolt 46 is further screwed in to fix the first mounting member 20 and the second mounting member 22 together, thereby completing the assembly of the gear device 10.

[0050] Incidentally, when assembling gears, there are misalignment errors and parallelism errors. In this embodiment, the misalignment error and parallelism error are, as shown in Figures 6(A) and 6(B), an error in the in-plane direction along an imaginary plane VS connecting the axis 12CL of the large gear 12 (= axis of the gear shaft 14) and the axis 16CL of the pinion 16 (= axis of the gear shaft 18), which is a parallelism error, and an error in the direction intersecting the imaginary plane VS, which is a misalignment error.

[0051] As shown in Fig. 6(C), when the parallelism error increases, the tooth surface stress generated on the tooth surface increases relatively slightly, but when the misalignment error increases, the tooth surface stress generated on the tooth surface increases significantly compared to when the parallelism error increases. One way to reduce the misalignment error is to improve the machining accuracy or assembly accuracy, but this leads to increased costs.

[0052] In the gear device 10 of this embodiment, the assembly accuracy can be improved while maintaining the same processing accuracy.

[0053] In other words, in the gear device 10 of this embodiment, the first mounting member 20 and the second mounting member 22 can be positioned at two diagonal points using the positioning pins 28, thereby reducing the misalignment error and parallelism error between the large gear 12 and the small gear 16 due to assembly.

[0054] In addition, in this embodiment, the pin body 56 is inserted into the pin holes 54 and 52 to expand its diameter so that the direction in which the pin body 56 expands (the direction of the arrow A) coincides with the direction in which the misalignment error occurs (the direction of the arrow H), and the outer peripheral surface of the pin body 56 is pressed against the hole walls (inner peripheral surfaces) of the pin holes 54 and 52 on the arrow H direction side, thereby reliably suppressing relative movement between the first mounting member 20 and the second mounting member 22 in the direction in which the misalignment error occurs. This makes it possible to minimize the misalignment error, which has a particularly large effect on the tooth surface stress, and is highly effective in improving the durability of the gear tooth surfaces and reducing noise.

[0055] (Disassembly of gear mechanism) Next, a procedure for disassembling the gear device 10 of this embodiment will be described below.

[0056] (1) The housing fixing bolts 46 that fixed the first mounting member 20 and the second mounting member 22 are removed by turning them with a wrench or the like.

[0057] (2) Next, the bolt 58 of the positioning pin 28 is turned with a wrench or the like to loosen it, so that, for example, part of the tip of the bolt 58 is caught in the screw hole 60 of the pin body 56. As a result, the pin body 56, which was pressed by the bolt 58 to expand in diameter, is elastically deformed and returns to its original diameter, or even if it does not return to its original diameter completely, the pressing force with which the outer periphery of the pin body 56 is pressing the inner periphery of the pin hole 52 and the pin hole 54 is reduced. Therefore, the bolt 58, whose tip is caught in the pin body 56, can be easily pulled out by gripping it with one's hand.

[0058] This allows the first mounting member 20 and the second mounting member 22 to be separated, making it possible to inspect, repair, etc. the inside of the gear device 10. When disassembling the gear device 10, the order of steps (1) and (2) may be reversed.

[0059] As described above, in the gear device 10 of this embodiment, the pin body 56 of the positioning pin 28 can be easily expanded and contracted by the simple task of rotating the bolt 58, and the positioning pin 28 can be easily fixed and removed.

[0060] Furthermore, in the gear device 10 of this embodiment, the positioning pin 28 can be used to minimize parallelism errors and misalignment errors between the large gear 12 and the small gear 16, thereby minimizing tooth surface stress, improving durability of the tooth surfaces, and reducing noise.

[0061] {Second embodiment} A gear device 10 according to the second embodiment will be described with reference to Fig. 7. The same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0062] As shown in FIG. 7, in the positioning pin 28 of this embodiment, a key groove 64 is formed at the tip of the pin body 56, extending linearly along the diameter direction.

[0063] In the first mounting member 20 of this embodiment, a pin hole 52 penetrates the first mounting member 20. A key groove 66 that crosses the pin hole 52 in the diameter direction is formed on the outer surface of the bottom plate portion 20A of the first mounting member 20.

[0064] A key 68 formed in a rectangular plate shape is inserted into the key groove 66 of the bottom plate portion 20A. A key pressing plate 70 is disposed on the outer surface side of the bottom plate portion 20A. A key groove 72 into which the key 68 is inserted is formed in the key pressing plate 70, and the key pressing plate 70 is fixed to the first mounting member 20 with a screw 74 in a state in which the key 68 is inserted into the key groove 72 of the key pressing plate 70 and the key groove 66 of the first mounting member 20. As a result, the key 68 is fixed to the first mounting member 20 with a part of the key 68 protruding into the pin hole 52.

[0065] In this way, by inserting the pin body 56 of the positioning pin 28, which has a key groove 64 formed at its tip, into the pin hole 52 with a portion of the key 68 protruding inward, and fitting the key 68 into the key groove 64 of the pin body 56, the orientation of the split groove 62 of the pin body 56 can be oriented in the same direction as in the first embodiment.

[0066] However, if the key groove 64 at the tip of the pin body 56 and the key groove 66 in the first mounting member 20 are not provided, when attempting to loosen the bolt 58 to pull the pin body 56 out of the pin holes 52 and 54, the bolt 58 and the pin body 56 will rotate together (the pin body 56 will spin freely in the pin holes 52 and 54), making it impossible to rotate the bolt 58 relative to the pin body 56 and making it impossible to reduce the diameter of the pin body 56.

[0067] On the other hand, in the configuration of this embodiment in which the key 68 fits into the key groove 64 at the tip of the pin body 56, the bolt 58 and the pin body 56 rotate together, preventing the pin body 56 from rotating freely in the pin holes 52 and 54. This allows the bolt 58 to be loosened relative to the pin body 56, reducing the diameter of the pin body 56 and allowing the pin body 56 to be easily pulled out of the pin holes 52 and 54.

[0068] According to this embodiment, the pin body 56 can be prevented from spinning freely not only when the bolt 58 is loosened but also when the bolt 58 is tightened, so that the pin body 56 can be reliably expanded in diameter.

[0069] {Third embodiment} A gear device 10 according to a third embodiment will be described with reference to Fig. 8. Note that the same components as those in the above-described embodiment are given the same reference numerals, and the description thereof will be omitted. As shown in FIG. 8, in the gear device 10 of this embodiment, a key fixing hole 76 is formed in the first mounting member 20 in a direction perpendicular to the pin hole 52. The key fixing hole 76 has a circular hole 78 and a key groove 80 formed along the axial direction of the hole 78. The key groove 80 can be formed by electric discharge machining or the like.

[0070] A key 82 is press-fitted into this key groove 80, and a portion of the key 82, which is press-fitted and fixed into the key groove 80, protrudes toward the pin hole 52. A portion of the key 82 is inserted into a key groove 64 formed at the tip of the pin body 56 of the positioning pin 28, and can prevent the pin body 56 from spinning freely. Therefore, similar to the gear device 10 of the second embodiment, the pin body 56 will not spin freely when the bolt 58 is loosened or tightened.

[0071] [Other embodiments] Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms without departing from the spirit and scope of the present invention.

[0072] In the positioning pin 28 of the above embodiment, the diameter of the pin body 56 is expanded by screwing the male thread 58A of the bolt 58 into the screw hole 60 of the pin body 56, but the present invention is not limited to this, and as shown in Fig. 9, it is also possible to use a pin body 56 having a round hole 84 formed in its axis, and to push a wedge 86 with a head 86A into the round hole 84 to expand the diameter of the pin body 56. Note that the wedge 86 can be easily pulled out by gripping the head 86A of the wedge 86.

[0073] In the positioning pin 28 of the above embodiment, the pin body 56 is divided into two in the circumferential direction, but the present invention is not limited to this, and the pin body 56 may be divided into three or more in the circumferential direction.

[0074] In the positioning pin 28 of the second embodiment described above, the key 68 is fitted into the key groove 64 formed at the tip of the pin body 56 to prevent rotation of the pin body 56. However, for example, as shown in FIG. 10, a two-sided portion can be provided at the end of the pin body 56 as a rotation prevention portion, and when the bolt 58 is rotated, a wrench or the like can be applied to the two-sided portion to prevent rotation of the pin body 56. [Explanation of symbols]

[0075] 10 Gearing 12 Gear (gear, gear group) 14 Gear shaft 16 Pinion (gear, gear group) 18 Gear shaft 20 First mounting member 22 Second mounting member 24 Housing 28 Locating pin 46 Housing fixing bolt (bolt) 48 screw holes 52 Positioning hole 54 Positioning hole 56 Main body (positioning pin, shaft) 58 Bolt (expanding member) 60 screw holes (holes) 64 Key groove (rotation prevention part) 66 Key groove (rotation prevention part) 68 Key (rotation prevention part) 80 Key groove (rotation prevention part) 82 Key (rotation prevention part) 84 Round hole (rotation prevention part, hole) 86 Taper pin (expanding member, wedge)

Claims

1. A group of gears that mesh with each other, a first attachment member and a second attachment member disposed opposite each other, the first attachment member and the second attachment member being rotatably supported at both ends of a gear shaft to which the gear is fixed; a bolt that is screwed into a screw hole formed in a joint portion where the first and second mounted members overlap, and fixes the first and second mounted members; a positioning pin having a diameter smaller than that of a positioning hole formed in the joint portion, the positioning pin being expanded when the expanding member is pushed into a hole formed in the shaft portion and abuts against a hole wall of the positioning hole, The positioning pin has a slot formed along a surface connecting the axes of the adjacent gear shafts, and has a diameter enlarged in a direction intersecting the surface. Gear mechanism.

2. The hole is formed in the shaft portion so that a bolt or a wedge serving as a diameter expanding member can be attached and detached.

2. The gear arrangement of claim 1.

3. At least one of the positioning pin and the bottom of the positioning hole is provided with a rotation prevention portion that prevents the positioning pin from rotating. A gear device according to claim 1 or 2.

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