Power transmission device and gear mechanism meshing adjustment device

Abstract

To provide a power transmission device which can easily adjust an engagement state of gears to an optimum state when necessary, and to provide an engagement adjustment device of a gear mechanism.SOLUTION: A power transmission device includes a first gear, a base member 15, a second gear, a support block 25, a positioning part 30, and a fixing part. The base member 15 rotatably supports the first gear. The second gear engages with the first gear in a manner that enables power transmission therebetween. The support block 25 rotatably supports the second gear. The positioning part 30 may adjust a relative position between the support block 25 and the base member 15 in a direction in which a depth of the engagement between the second gear and the first gear changes. The fixing part may fix the relative position between the support block 25 and the base member 15.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a power transmission device that transmits rotational power to a moving object, and a meshing adjustment device for a gear mechanism. [Background technology]

[0002] 2. Description of the Related Art In many mechanical devices such as turntables and industrial robots, the power of a drive source is transmitted to an object to be operated via a power transmission device including a gear mechanism (see, for example, Patent Document 1).

[0003] In mechanical devices that require high operating accuracy, the meshing accuracy of the gear mechanism used in the power transmission device is important. For this reason, in the manufacturing stage of the power transmission device used in such mechanical devices, each gear of the gear mechanism is assembled to the gear support part with high accuracy using positioning pins or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-158143 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a power transmission device, the meshing state between gears can change due to wear of various parts caused by the usage environment after shipment or long-term use.

[0006] In conventional power transmission devices, although each gear is assembled to the gear support with high precision during manufacturing, no special measures are taken to prevent changes in the meshing state of the gears after shipment. Therefore, if the meshing state of the gears changes significantly after shipment, the power transmission device must be disassembled and parts must be replaced or reassembled.

[0007] The present invention provides a power transmission device that can easily adjust the meshing state of gears to an optimum state when necessary, and a meshing adjustment device for a gear mechanism. [Means for solving the problem]

[0008] A power transmission device according to one aspect of the present invention includes a first gear, a base member rotatably supporting the first gear, a second gear meshing with the first gear so as to transmit power, a support block rotatably supporting the second gear, a position adjustment unit capable of adjusting a relative position between the support block and the base member in a direction in which a meshing depth between the second gear and the first gear changes, and a fixing unit capable of fixing the relative position between the support block and the base member. The position adjustment unit is configured by a screw mechanism in which a screw shaft extends in a direction that changes the meshing depth between the second gear and the first gear, one axial end side of the screw shaft is rotatably held by either the support block or the base member with axial displacement restricted, and the other axial end side of the screw shaft is screwed into the other of the support block or the base member.

[0010] The support block may include a reduction gear housing case that transmits reduced power to the second gear, and an adapter block that is fitted into the outer peripheral surface of the housing case, and the screw mechanism may be configured such that one axial end side of the screw shaft is rotatably held on the base member, and the other axial end side of the screw shaft is screwed into the adapter block.

[0011] The fixing portion may include a fastening member that can be tightened in a transverse direction that intersects with the direction in which the meshing depth of the second gear and the first gear changes, and that fixes the support block to the base member, and an axial hole that is provided in the support block along the transverse direction and through which the shaft of the fastening member passes, and the axial hole may be formed with an inner shape or size that allows displacement of the support block in the direction in which the meshing depth of the second gear and the first gear changes.

[0012] The shaft portion of the fastening member may be formed with an outer diameter such that a gap is formed between the shaft hole and the shaft portion to allow the displacement.

[0013] A meshing adjustment device for a gear mechanism according to one aspect of the present invention includes a base member that rotatably supports a first gear, a support block that rotatably supports a second gear that meshes with the first gear so as to be capable of transmitting power, a position adjustment unit that can adjust a relative position between the support block and the base member in a direction in which a meshing depth between the second gear and the first gear changes, and a fixing unit that can fix the relative position between the support block and the base member; The position adjustment unit is configured by a screw mechanism in which a screw shaft extends in a direction that changes the meshing depth between the second gear and the first gear, one axial end side of the screw shaft is rotatably held by either the support block or the base member with axial displacement restricted, and the other axial end side of the screw shaft is screwed into the other of the support block or the base member. Effect of the Invention

[0014] The above-mentioned power transmission device and the meshing adjustment mechanism of the gear mechanism both include a position adjustment unit capable of adjusting the relative position of the support block supporting the second gear and the base member supporting the first gear, and a fixing unit capable of fixing the relative position of the support block and the base member. Therefore, the relative position of the support block and the base member can be adjusted by the position adjustment unit so that the meshing state between the gears is optimal, and the relative position of the support block and the base member can be fixed in that state by the fixing unit. Therefore, when the above-mentioned configuration is adopted, the meshing state of the second gear and the first gear can be easily adjusted to an optimal state when necessary. [Brief description of the drawings]

[0015] [Figure 1] FIG. 4 is a side view of a rotating jig using the power transmission device of the embodiment. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 3 is an enlarged cross-sectional view of part IV in FIG. 2 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Next, an embodiment of the present invention will be described with reference to the drawings.

[0017] FIG. 1 is a side view of a rotating jig 1 using a power transmission device 10 of the present embodiment, and FIG. The rotating jig 1 is used, for example, when welding equipment. The rotating jig 1 includes a ring gear 11 (first gear) which is a rotation output part, a motor 12 which is a drive source, and a reducer 13 which reduces the rotation of the motor 12 and transmits it to the ring gear 11. A pinion gear 20 is attached to an output part 13a of the reducer 13. Teeth 20a (see FIG. 3) of the pinion gear 20 mesh with external teeth 11a (see FIG. 3) of the ring gear 11, and transmits the rotation of the pinion gear 20 to the ring gear 11. In this embodiment, a power transmission path portion of the rotating jig 1 from the reducer 13 to the ring gear 11 forms a power transmission device 10.

[0018] An adapter ring 14 is fixed to one axial end face of the ring gear 11. To the adapter ring 14, an instrument fixing plate (not shown) or the like that supports a rotating object (for example, an object to be welded) is attached.

[0019] The ring gear 11 is rotatably supported by a base member 15 via a bearing 16. The base member 15 includes a large-diameter first annular portion 15A to which an inner race 16i of the bearing 16 is fixed on one end surface in the axial direction, and a small-diameter second annular portion 15B to which the reducer 13 is fixed. In the present embodiment, the small-diameter second annular portion 15B is integrally formed on the outer periphery of the large-diameter first annular portion 15A. Both the first annular portion 15A and the second annular portion 15B are formed in a cylindrical shape with a short axis. However, the first annular portion 15A and the second annular portion 15B may be formed of separate parts and fixed to each other by a fixing means such as bolt fastening.

[0020] 1 and 2, the reference symbol ax1 denotes the central axis of the first annular portion 15A, and the reference symbol ax2 denotes the central axis of the second annular portion 15B. The inner race 16i of the bearing 16 and the ring gear 11 supported on the outer periphery of the inner race 16i via rolling elements 16r (e.g., balls) are arranged to form a concentric circle centered on the central axis ax1. The ring gear 11 is rotatable around the central axis ax1. The first annular portion 15A of the base member 15 is attached to a support device (not shown) that supports the rotating jig 1. The outside of the ring gear 11 and the pinion gear 20 are covered by a transmission part cover 50 made of a metal plate. The transmission part cover 50 is fixed to the base member 15.

[0021] Fig. 3 is a partially sectional perspective view of the rotating jig 1 cut at the same portion as in Fig. 2. However, in Fig. 3, the transmission part cover 50 covering the outside of the ring gear 11 and the pinion gear 20 has been removed. Fig. 4 is an enlarged sectional view of part IV in Fig. 2. The reduction gear 13 includes a reduction mechanism housed inside a substantially cylindrical housing case 25A. An output portion 13a is provided at one axial end of the reduction gear 13, and a pinion gear 20 is attached to the output portion 13a. A motor 12, which is a driving source, is attached to the other axial end of the reduction gear 13. A fixing flange 25Af is integrally formed on the outer periphery of the other axial end of the housing case 25A, protruding radially outward in an annular shape. A plurality of shaft holes 42a are formed in the fixing flange 25Af, which penetrate the fixing flange 25Af in the axial direction. The shaft holes 42a are formed in the fixing flange 25Af at equal intervals in the circumferential direction. A fastening bolt 40 (fastening member) for fixing the reduction gear 13 to the second annular portion 15B of the base member 15 is inserted into each shaft hole 42a.

[0022] A cylindrical adapter block 25B is fitted to the outer peripheral surface of the housing case 25A of the reducer 13 at a portion adjacent to the fixed flange 25Af. The adapter block 25B is formed to have approximately the same outer diameter as the fixed flange 25Af of the housing case 25A. In other words, the radial thickness of the adapter block 25B is approximately the same as the radial projection width of the fixed flange 25Af. The adapter block 25B is formed with a plurality of shaft holes 42b penetrating in the axial direction. The shaft holes 42b are formed in the adapter block 25B at equal intervals in the circumferential direction so as to correspond one-to-one with each shaft hole 42a of the fixed flange 25Af. A fastening bolt 40 (fastening member) for fastening the reducer 13 to the second annular portion 15B of the base member 15 is inserted into each shaft hole 42b.

[0023] With the adapter block 25B fitted into the housing case 25A, the reducer 13 is fixed to the second annular portion 15B together with the adapter block 25B by a plurality of fastening bolts 40. The second annular portion 15B is formed with threaded holes 35 into which the tips of the shafts 40a of the plurality of fastening bolts 40 are screwed. The threaded holes 35 are formed at equal intervals in the circumferential direction of the second annular portion 15B.

[0024] Each fastening bolt 40 has an outer diameter of the shaft 40a smaller than the inner diameters of the shaft holes 42a, 42b of the housing case 25A (fixing flange 25Af) and the adapter block 25B. Specifically, the outer diameter of the shaft 40a of the fastening bolt 40 is set so that a gap d that allows radial displacement of the housing case 25A and the adapter block 25B is formed between the shaft holes 42a, 42b. Therefore, when the housing case 25A and the adapter block 25B are provisionally fastened to the second annular portion 15B by the fastening bolt 40 (when not completely fastened), the radial position adjustment is possible. In reality, the adjustable displacement of the accommodating case 25A and the adapter block 25B at this time is limited to only the linear direction connecting the central axis ax2 of the pinion gear 20 and the central axis ax1 of the ring gear 11 (hereinafter referred to as the "inter-gear direction Di"), due to the restriction by the position adjustment unit 30 described later.

[0025] When the housing case 25A and the adapter block 25B are fixed to the second annular portion 15B by the fastening bolt 40, an annular washer 45 is placed on the end face of the fixing flange 25Af (the end face opposite to the adapter block 25B). The washer 45 has a plurality of insertion holes 45a through which the shafts 40a of the fastening bolts 40 are inserted, and the heads of the fastening bolts 40 abut against the periphery of the insertion holes 45a. The inner diameter of the insertion holes 45a is set smaller than the inner diameters of the shaft holes 42a, 42b of the housing case 25A and the adapter block 25B. Therefore, even if a fastening bolt 40 having a small diameter is used for the shaft holes 42a, 42b of the housing case 25A and the adapter block 25B, the fastening load acting on the heads of the fastening bolts 40 can be reliably received by the washer 45 and the fastening load can be transmitted to the housing case 25A and the adapter block 25B. In this embodiment, the accommodating case 25A and the adapter block 25B form a support block 25 that rotatably supports the pinion gear 20 (second gear).

[0026] Here, a rectangular plate-shaped holding block 32 is attached to the outer circumferential surface of the second annular portion 15B of the base member 15. A part of the holding block 32 protrudes from the second annular portion 15B to the other end side in the axial direction of the second annular portion 15B. The holding block 32 is fixed to a chamfered portion of the outer circumferential surface of the second annular portion 15B by, for example, bolt fastening.

[0027] The portion of the holding block 32 protruding from the second annular portion 15B (hereinafter referred to as the "protruding portion") is cut out in a stepped shape on the radially outer side of the second annular portion 15B. Hereinafter, this cut-out portion is referred to as the "cut-out portion 32b." An insertion hole 32a through which the screw shaft 31a of the adjustment screw 31 is inserted is formed in the protruding portion (the portion facing the cut-out portion 32b).

[0028] The insertion hole 32a extends along the inter-gear direction Di. One axial end of the screw shaft 31 of the adjusting screw 31 is rotatably held by the holding block 32 in the insertion hole 32a. Therefore, the screw shaft 31 of the adjusting screw 31 rotatably held in the insertion hole 32a extends along the inter-gear direction Di.

[0029] Further, a rectangular plate-like displacement restriction block 33 smaller than the retaining block 32 is attached to the outer surface of the retaining block 32 (the surface opposite to the side that abuts against the outer circumferential surface of the second annular portion 15B). The displacement restriction block 33 is fixed to the outer surface of the retaining block 32 by, for example, bolting.

[0030] The displacement restricting block 33 extends to a position facing the notched portion 32b of the holding block 32, and faces the outer surface of the protruding portion of the holding block 32 across the notched portion 32b. The head 31b of the adjusting screw 31 held in the insertion hole 32a is positioned in the gap created by the notched portion 32b between the holding block 32 and the displacement restricting block 33. The head 31b abuts against the holding block 32 and the displacement restricting block 33 in the gap, thereby restricting the axial displacement of the adjusting screw 31.

[0031] A tool insertion hole 33a is formed coaxially with the insertion hole 32a in the displacement restriction block 33 at a position facing the insertion hole 32a of the holding block 32. A tool such as a hexagonal wrench can be inserted into the tool insertion hole 33a. When rotating the adjusting screw 31, a tool such as a hexagonal wrench is inserted into the tool insertion hole 33a and the tip of the tool is fitted into the hexagonal hole in the head 31b of the adjusting screw 31. By rotating the tool in this state, the adjusting screw 31 can be rotated.

[0032] Further, a screw hole 25Ba is formed in the outer peripheral wall of the adapter block 25B at a position facing the insertion hole 32a of the holding block 32. The screw hole 25Ba extends along the inter-gear direction Di, and a tip end side of the screw shaft 31a of the adjustment screw 31 is screwed into the screw hole 25Ba. When the adjustment screw 31 is rotated in a state where the adapter block 25B is temporarily fastened to the second annular portion 15B together with the accommodating case 25A (reduction gear 13) by the fastening bolt 40, the adapter block 25B moves forward or backward along the inter-gear direction Di according to the rotation direction and amount of rotation of the adjustment screw 31.

[0033] Specifically, when the adjusting screw 31 is rotated in one direction, the pinion gear 20 approaches the ring gear 11 in accordance with the amount of rotation, thereby deepening the meshing depth of the two gears. When the adjusting screw 31 is rotated in the other direction, the pinion gear 20 moves away from the ring gear 11 in accordance with the amount of rotation, thereby shallowing the meshing depth of the two gears.

[0034] In this embodiment, a screw mechanism consisting of an adjustment screw 31, a retaining block 32, a displacement control block 33, a screw hole 25Ba of the adapter block 25B, etc., constitutes a position adjustment unit 30 that adjusts the relative position of the support block 25 and the base member 15 along the inter-gear direction Di.

[0035] In the power transmission device 10 that employs the rotating jig 1 of this embodiment, the meshing depth between the pinion gear 20 and the ring gear 11 can be adjusted after shipment or the like as follows.

[0036] First, a tool is used to loosen the multiple fastening bolts 40 to temporarily fasten the support block 25 (the housing 25A and the adapter block 25B). In this state, the support block 25 is displaceable along the inter-gear direction Di.

[0037] Next, in this state, a tool is inserted into the tool insertion hole 33a of the displacement restriction block 33, and the adjustment screw 31 of the position adjustment unit 30 is rotated using the tool. As a result, the reducer 13 is displaced along the inter-gear direction Di so that the meshing between the pinion gear 20 and the ring gear 11 is in an optimal state.

[0038] Once the meshing between the pinion gear 20 and the ring gear 11 has been adjusted to the optimal state, a tool is then used to tighten the multiple fastening bolts 40 to finally fix the support block 25 (the storage case 25A and the adapter block 25B) to the second annular portion 15B of the base member 15.

[0039] <Effects of the embodiment> The power transmission device 10 of this embodiment includes a position adjustment unit 30 capable of adjusting the relative position between the support block 25 supporting the pinion gear 20 and the base member 15 supporting the ring gear 11, and a fixing unit (fastening bolt 40, shaft holes 42a, 42b, screw hole 35) capable of fixing the relative position between the support block 25 and the base member 15. Therefore, the relative position between the support block 25 and the base member 15 can be adjusted by the position adjustment unit 30 so that the meshing state between the pinion gear 20 and the ring gear 11 is optimized, and in this state, the relative position between the support block 25 and the base member 15 can be fixed by the fixing unit. Therefore, when the power transmission device 10 of this embodiment is employed, the meshing state between the pinion gear 20 and the ring gear 11 can be easily adjusted to an optimal state when necessary.

[0040] In addition, in the power transmission device 10 of this embodiment, the position adjustment unit 30 that adjusts the relative position of the support block 25 with respect to the base member 15 includes an adjustment screw 31 (screw shaft 31a) extending along the inter-gear direction Di, and one axial end side of the adjustment screw 31 is rotatably held on the base member 15 side, and the other axial end side is screwed into the support block 25 (adapter block 25B). Therefore, the meshing state of the pinion gear 20 and the ring gear 11 can be easily finely adjusted by adjusting the rotation of the adjustment screw 31. In particular, in this configuration, since the other axial end side of the adjustment screw 31 is directly screwed into the support block 25 (adapter block 25B), position adjustment on the side that deepens the depth in the meshing direction of the gears and position adjustment on the side that shallows the depth of meshing between the gears can be realized by a simple structure with a small number of parts.

[0041] In this embodiment, one axial end of the adjustment screw 31 of the position adjustment unit 30 is rotatably held on the base member 15 side, and the other axial end is screwed into the support block 25, but conversely, one axial end of the adjustment screw 31 may be rotatably supported on the support block 25, and the other axial end may be screwed into the base member 15 side. However, when one axial end of the adjustment screw 31 is rotatably held on the base member 15 side as in this embodiment, the head 31b of the adjustment screw 31 to be rotated is not displaced along the inter-gear direction Di together with the reducer 13 during rotation adjustment, improving the ease of adjustment work.

[0042] Furthermore, in the power transmission device 10 of this embodiment, the adjustment screw 31 (screw shaft 31a) of the position adjustment unit 30 extends along the inter-gear direction Di. Therefore, when a large meshing reaction force acts from the ring gear 11 side to the pinion gear 20 side (reduction gear 13 side) during actual use of the power transmission device 10 (rotation jig 1), the adjustment screw 31 can also receive the meshing reaction force. This makes it possible to effectively prevent minute positional deviation of the pinion gear 20 due to the input of a large impact load (mesh reaction force), the generation of operating noise, damage to meshing portions, wear, and the like.

[0043] Furthermore, in the power transmission device 10 of this embodiment, the tip of the adjustment screw 31 (screw shaft 31a) is screwed into the adapter block 25B that is fitted into the outer peripheral surface of the housing case 25A of the reducer 13. This eliminates the need to form a screw hole in the housing case 25A of the reducer 13 for screwing in the tip of the adjustment screw 31, which results in easier machining of the housing case 25A and maintains high strength of the housing case 25A.

[0044] Furthermore, when this configuration is adopted, it can be easily applied to a reducer 13 having a different outer diameter by replacing the adapter block 25B with one having a different inner diameter. Note that even when using a reducer 13 with different specifications in other parts such as the shaft length in addition to the outer diameter, it can be accommodated by replacing the adapter block 25B. However, it is also possible to employ a configuration in which the tip of the adjustment screw 31 is directly screwed into the peripheral wall of the accommodating case 25A without using the adapter block 25B.

[0045] Furthermore, in the power transmission device 10 of this embodiment, the fixing portion for fixing the support block 25 to the base member 15 can be tightened in a direction parallel to the axial direction of the pinion gear 20 (a direction intersecting the direction in which the meshing depth changes), and includes a fastening bolt 40 (fastening member) for fixing the support block 25 to the base member 15, and shaft holes 42a, 42b provided in the support block 25 parallel to the axial direction of the pinion gear 20. The shaft holes 42a, 42b are formed with an inner diameter (size) that allows radial displacement of the support block 25. Therefore, the position of the support block 25 can be adjusted in the radial direction by loosening the tightening of the fastening bolt 40 (fastening member).

[0046] In particular, when adjusting the radial position of the support block 25, rather than completely removing the fastening bolt 40, the support block 25 can be temporarily held to the base member 15 via the head of the fastening bolt 40 by slightly loosening it, and in this state the position adjustment work for the support block 25 can be easily performed. However, the fixing portion for fixing the support block 25 to the base member 15 is not limited to the above configuration, and other configurations can be adopted as long as they can fix the support block 25 to the base member 15.

[0047] In this embodiment, the inner diameter of the circular shaft holes 42a, 42b is set to be sufficiently larger than the outer diameter of the shaft 40a of the fastening bolt 40 so that a gap d that allows radial displacement of the support block 25 is secured between the fastening bolt 40 and the shaft holes 42a, 42b. However, instead of forming the shaft holes 42a, 42b through which the fastening bolt 40 is inserted into a perfect circle, the shaft holes 42a, 42b may be formed into an elongated hole shape so that a gap that allows displacement in the inter-gear direction Di is secured.

[0048] However, in the power transmission device 10 of this embodiment, the support block 25 is formed with circular axial holes 42a, 42b having an inner diameter sufficiently larger than the outer diameter of the shaft 40a of the fastening bolt 40, which makes it easy to machine the axial holes 42a, 42b in the support block 25. Furthermore, when a reducer 13 of the same specifications is used in a power transmission device 10 having a position adjustment unit 30 (mesh adjustment device) and a power transmission device not having a position adjustment unit 30, a fastening bolt 40 with a smaller axial diameter than the fastening bolt 40 used to fix the power transmission device not having the position adjustment unit 30 may be used in the power transmission device 10 having the position adjustment unit 30. For this reason, when this configuration is used, a reducer with the same specifications can be used in the power transmission device 10 having the position adjustment unit 30 and in a power transmission device that does not have a position adjustment unit.

[0049] <Other embodiments> In the above embodiment, the position adjustment unit 30 is configured with an adjustment screw 31, the main component of which is rotatably held on the base member 15 side and has a tip that is fastened to the support block 25 side, but the position adjustment unit 30 is not limited to this. For example, it may be configured with an adjustment screw that can be operated by pressing the outer circumferential surface of the support block 25 toward one side in the intergear direction Di, and a spring member such as a disc spring that applies an elastic reaction force toward the other side in the intergear direction Di at the opposite position on the outer periphery of the support block 25. In this case, it is also possible to use another operating mechanism such as a lever mechanism instead of the adjustment screw.

[0050] The present invention is not limited to the above embodiment, and various design changes are possible without departing from the gist of the present invention. For example, in the above embodiment, the first gear is formed by the pinion gear 20, and the second gear is formed by the ring gear 11, but the first gear and the second gear may have any shape or size as long as they mesh with each other.

[0051] In addition, in the above embodiment, the second gear (pinion gear 20) is rotatably connected to the reducer 13, but the second gear does not necessarily have to be structured to be connected to the reducer 13. The second gear may be structured to be directly connected to a power source such as the motor 12 without passing through the reducer 13, for example.

[0052] Furthermore, the application of the power transmission device 10 is not limited to the rotating jig 1, but can be applied to the movable parts of various other devices, such as the rotating part of a robot arm. [Explanation of symbols]

[0053] 10...power transmission device, 11...ring gear (first gear), 13...reduction gear, 15...base member, 20...pinion gear (second gear), 25...support block, 25A...housing case, 25B...adapter block, 31a...screw shaft, 35...screw hole (fixing part), 40...fastening bolt (fastening member, fixing part), 40a...shaft, 42a, 42b...shaft hole (fixing part).

Claims

1. A first gear; a base member that rotatably supports the first gear; a second gear that is in mesh with the first gear so as to be capable of transmitting power; a support block that rotatably supports the second gear; a position adjustment unit that adjusts a relative position between the support block and the base member in a direction in which a meshing depth between the second gear and the first gear changes; a fixing portion capable of fixing a relative position between the support block and the base member; Equipped with The position adjustment portion is a power transmission device configured by a screw mechanism in which a screw shaft extends in a direction that changes the meshing depth between the second gear and the first gear, one axial end side of the screw shaft is rotatably held by either the support block or the base member with axial displacement restricted, and the other axial end side of the screw shaft is screwed into the other of the support block or the base member.

2. The support block is a reduction gear housing for transmitting reduced power to the second gear; an adapter block fitted to an outer peripheral surface of the housing case, 2. The power transmission device according to claim 1, wherein the screw mechanism has one axial end of the screw shaft rotatably held by the base member and the other axial end of the screw shaft screwed into the adapter block.

3. The fixing portion is a fastening member that can be fastened in a direction intersecting a direction in which a meshing depth between the second gear and the first gear changes, and that fixes the support block to the base member; a shaft hole provided in the support block along the transverse direction and through which a shaft of the fastening member passes, 3. The power transmission device according to claim 1, wherein the shaft hole is formed with an inner shape or size that allows displacement of the support block in a direction in which the meshing depth between the second gear and the first gear changes.

4. 4. The power transmission device according to claim 3, wherein the shaft portion of the fastening member is formed with an outer diameter that forms a gap between the shaft hole and the shaft portion to allow the displacement.

5. a base member that rotatably supports the first gear; a support block that rotatably supports a second gear that is in power transmissible mesh with the first gear; a position adjustment unit that adjusts a relative position between the support block and the base member in a direction in which a meshing depth between the second gear and the first gear changes; a fixing portion capable of fixing a relative position between the support block and the base member; Equipped with The position adjustment unit is a gear mechanism meshing adjustment device configured by a screw mechanism in which a screw shaft extends in a direction that changes the meshing depth between the second gear and the first gear, one axial end side of the screw shaft is rotatably held by either the support block or the base member with axial displacement restricted, and the other axial end side of the screw shaft is screwed into the other of the support block or the base member.

Images