JP2012193829A - Power transmission unit and method for mounting power transmission mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission unit, in which deterioration of a power transmission shaft is suppressed.SOLUTION: The power transmission unit 100, which is fitted to a power transmission shaft 15 rotatable in a predetermined direction and moderates non-constant velocity of the power transmission shaft 15, includes: an input side rotator (clutch 50) provided with an input side locking part (input side clutch pawl 53) at a cylindrical part 51 fitted to the power transmission shaft 15 and rotating together with the power transmission shaft 15; an output side rotator (sprocket 60) fitted with the cylindrical part 51 so that the cylindrical member 51 of the input side rotator as a rotation shaft can be freely rotated and provided with an output side locking part (output side clutch pawl 63) capable of meshing with the input side locking part; and a biasing member (torsional coil spring 70) for biasing the output side rotator in the rotation direction. The input side rotator and the output side rotator are capable of relatively rotating within a predetermined angle range.

Description

  The present invention relates to a power transmission unit, for example, a power transmission unit that is provided on a power transmission shaft in a rotary working machine such as a plowing machine or a tiller, and that relaxes inconstant speed rotation of the power transmission shaft.

  Conventionally, rotary farming machines such as a scraper and a rotary tiller that transmit power from the PTO shaft provided at the rear of the tractor to the input shaft of the farming machine via a universal joint (for example, a wide-angle joint) are known. ing. In such a rotary farming machine, the universal joint may cause an inconstant motion (rotation) due to the angle relationship between the PTO shaft provided in the tractor and the input shaft provided in the rotary farming machine. In this case, for example, the gear of the mission case of the rotary farm work machine collides by repeating the contacted state and the separated state. For this reason, there is a possibility that gear wear or the like is accelerated and deterioration is accelerated.

  Therefore, for example, in Patent Document 1, a rotation unevenness absorbing mechanism that absorbs rotation unevenness due to unequal speed rotation of a universal joint, which is provided between a drive side and a driven side of a transmission system that transmits power via a universal joint. A sprocket with a driven clutch pawl that is rotatably inserted into the transmission shaft, a drive side pawl clutch that is inserted into the transmission shaft via a spline, and a sprocket that is inserted into the transmission shaft via the spline. There is disclosed a power transmission device including a plate with a locking hole, and a torsion coil spring having one end side locked to a driving claw clutch and the other side locked to a locking hole of the plate.

  According to such a power transmission device, the rotation unevenness due to the non-uniform rotation of the universal joint can surely be alleviated, so that it is considered that the collision of the gears in the transmission case of the rotary agricultural machine is suppressed. It is done.

JP 2004-245272 A

However, since the power transmission device described in Patent Document 1 has a configuration in which a sprocket is rotatably inserted into the transmission shaft, the transmission shaft may deteriorate due to wear or the like accompanying use. In such a case, not only the power transmission device but also the power transmission shaft may need to be replaced as maintenance, which may complicate the work.
Moreover, when exchanging a power transmission device in this way, it is desirable that the power transmission device be configured compactly.
Further, since the power transmission device is configured by fixing the plate to the transmission shaft, almost all work is performed at the site where the rotary work machine is placed when the power transmission device is attached or replaced. There was a need.

  The present invention has been made in view of the above-described circumstances. An example of the problem is to solve at least one of the above-described problems, and a power transmission unit and a power transmission mechanism for suppressing deterioration of a transmission shaft. An object is to provide an attachment method.

In order to solve such a problem, a power transmission unit according to the present invention is a power transmission unit that is fitted to a power transmission shaft that can rotate in a predetermined direction, and that alleviates the inconstant speed rotation of the power transmission shaft, An input-side rotating body that is fitted to the power transmission shaft and rotates together with the power transmission shaft, and an input-side locking portion is provided, and the cylindrical portion of the input-side rotating body is rotated about the rotation axis. An output-side rotating body provided with an output-side locking portion that can be engaged with the input-side locking portion, and the output-side rotating body is urged in the rotation direction. And an urging member for rotating the input-side rotator and the output-side rotator in a predetermined angle range.
In addition, the input-side rotating body is provided with the input-side locking portion at an end of the cylindrical portion on the power transmission shaft side, and the power transmission unit is connected to the cylindrical portion of the input-side rotating body. The output-side rotator and the urging member are arranged in the order of the output-side rotator and the urging member from the power transmission shaft side.
The urging member includes a torsion coil spring, and the torsion coil spring includes an engagement hole provided in the output-side rotator and an engagement hole provided in the engagement member fixed to the cylindrical portion. Both ends are locked.
The power transmission mechanism mounting method according to the present invention includes an input-side rotating body provided with an input-side locking portion on one end side of a substantially cylindrical portion, and a cylindrical portion of the input-side rotating body. An output-side rotating body provided with an output-side locking portion that is supported by the cylindrical portion so as to be a rotating shaft and can be meshed with the input-side locking portion, and biases the output-side rotating body in the rotation direction A torsion coil spring that attaches a power transmission mechanism to a power transmission shaft that can rotate in a predetermined direction, wherein the output-side rotating body and the output-side rotating body and the cylindrical portion of the input-side rotating body A power transmission mechanism is unitized in advance by supporting a torsion coil spring, and the cylindrical portion of the unitized power transmission mechanism is attached to the power transmission shaft.

  ADVANTAGE OF THE INVENTION According to this invention, the power transmission device which suppresses deterioration of a power transmission shaft can be provided.

It is a top view which shows the external appearance of the scraping work machine (working body expansion position) which concerns on one Embodiment of this invention. It is a side view which shows the external appearance of the scraping work machine (working body storage position) which concerns on one Embodiment of this invention. It is a fragmentary sectional view which shows the power transmission system of the scraping work machine which concerns on one Embodiment of this invention. It is an enlarged view which shows the power transmission system of the scraping work machine which concerns on one Embodiment of this invention. (A) It is a left view which shows the clutch in a power transmission unit. (B) It is bb sectional drawing in (a). (A) It is a right view which shows the sprocket in a power transmission unit. (B) It is the left view. (C) It is cc sectional drawing in (a). (A) It is a front view which shows the torsion coil spring in a power transmission unit. (B) It is the same top view. (C) It is the left view. (A) It is a front view which shows the plate in a power transmission unit. (B) It is the same right view. (C) It is the left view. (A) It is a disassembled perspective view which shows a power transmission unit. (B) It is a perspective view which shows a power transmission unit. (C) It is a perspective view which shows a power transmission unit. (A) It is a left view for demonstrating the attachment state of a power transmission unit. (B) It is a left view for demonstrating the operation state of a power transmission unit.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. For convenience, the same or corresponding elements may be denoted by the same reference numerals and description thereof may be omitted. Note that the present invention is widely applicable to a power transmission unit that is provided on a power transmission shaft that can rotate in a predetermined direction and that relieves the inconstant speed rotation of the power transmission shaft. An example of a case where a power transmission unit provided on a power transmission shaft that is input to a chain case is applied to a scraper work machine will be described.

  FIG. 1 is a plan view showing the appearance of the cutting work machine 1, and FIG. 2 is a side view showing the appearance of the cutting work machine 1. The scraping work machine 1 is connected to the rear portion of the traveling machine body T by a three-point link coupling mechanism (not shown), and proceeds with the forward traveling of the traveling machine body T to perform the scraping work. And a left work body 20L and a right work body 20R that are pivotably attached to the left and right ends of the work machine main body 10 and the left work body 20R and the right work body 20R. A rotary working unit is provided.

  Shaft portions 14 and 14 extending in the front-rear direction are provided at the left and right end portions of the work machine main body 10, and the left work body 20L and the right work body 20R are rotatable up and down about the shaft portions 14 and 14. Is provided. A hydraulic cylinder (not shown) is provided between the upper part of the work machine body 10 and the left work body 20L and between the upper part of the work machine body 10 and the right work body 20R. The left working body 20L and the right working body 20R shown in FIG. 1 are folded up above the working machine body 10, and the left working body 20L and the right working body 20R shown in FIG. Move between the unfolded positions.

  As shown in FIG. 3, the work implement body 10 includes a main frame 11 extending in the left-right direction, and a gear box 13 is provided at the center of the main frame 11 in the left-right direction. The gear box 13 is provided with an input shaft 17 protruding forward, and the power from the PTO shaft of the traveling machine body T is transmitted to the gear box 13 via a power transmission means such as a universal joint. It is to be transmitted. The rear end of the input shaft 17 and the right end portion of the power transmission shaft 15 provided in the main frame 11 are engaged with each other by bevel gears 17a and 15a in the gear box 13, whereby the power of the input shaft 17 is transmitted. It is transmitted to the power transmission shaft 15.

  A chain case 8 is suspended from the left end of the main frame 11, and a side frame 9 is suspended from the right end. Between the lower part of the chain case 8 and the side frame 9, a tilling rotor 30C to which a number of tilling claws are attached is rotatably supported. The power transmission shaft 15 is connected to the power transmission system in the chain case 8 so that the power from the input shaft 17 is transmitted to the tilling rotor 30C of the work machine body 10 via the power transmission system. 30c is configured to rotate in a predetermined direction.

  The left working body 20L and the right working body 20R are respectively provided with side frames 21L and 21R at outer end portions in the unfolded position, and a large number of support parts 23L and 23R provided on the side frames 21L and 21R One end side (outer end) of the tilling rotors 30L and 30R to which the tilling claws are attached is rotatably supported. The other end side (inner end side) of the tilling rotors 30L, 30R is rotatably supported by support frames 25L, 25R provided inside the left working body 20L and the right working body 20R in the left-right direction. The driven clutches 31L and 31R are connected to the portion. The driven clutch 31L of the left working body 20L is exposed to the outside (left side) from the chain case 8, and the driven clutch 31R of the right working body 20R is directed to the outside (right side) from the side frame 9. The drive clutch 19 exposed in this manner is engaged with each other at the deployed position. Accordingly, the tilling rotors 30L, 30C, and 30R (collectively referred to as “cultivation rotor 30”) rotate in conjunction with the same direction.

  Here, the power transmission system in the chain case 8 will be described with reference to FIGS. The left end of the power transmission shaft 15 (the end opposite to the side where the bevel gear 15 a is provided) is inserted into the chain case 8, and the left end is connected to the power transmission shaft 15. A clutch 50 as an input side rotating body that is fixed and rotates together with the power transmission shaft 15, a sprocket 60 as an output side rotating body that can mesh with the clutch 50, and a direction in which the sprocket 60 is rotated (in the embodiment, the tilling rotor 30 is operated) A torsion coil spring 70 is provided as an urging member that urges the sprocket 60 in the rotation direction. A chain 68 is hung on the sprocket 60, and this chain 68 is hung on an output side sprocket 69 provided at the lower part of the chain case 8 (a part of the chain 68 is omitted in the drawing). The output side sprocket 69 is connected to the tilling rotor 30C of the work machine body 10, and to the tilling rotor 30L of the left working body 20L via the drive clutch 18, and to the right working body 20R via the tilling rotor 30C and the driving clutch 19. Thus, the power of the power transmission shaft 15 is transmitted to the tilling rotor 30.

  As shown in FIGS. 4 and 5, the clutch 50 as the input side rotating body provided in the chain case 8 is provided on a cylindrical portion 51 having a substantially cylindrical shape and on one end side of the cylindrical portion 51. Input-side clutch pawl 53 (input-side locking portion). The cylindrical portion 51 has a spline groove 50a (a groove shape is omitted in the illustrated example) as a fitting means on the side where the input side clutch pawl 53 is provided. The spline groove 50 a can be fitted with a spline groove 15 b provided at the end of the power transmission shaft 15. As a result, the clutch 50 is supported (fixed) on the power transmission shaft 15 in a state where the rotation with respect to the power transmission shaft 15 is restricted, and can rotate with the rotation of the power transmission shaft 15.

  The outer peripheral surface of the cylindrical portion 51 of the clutch 50 is formed smoothly, and a single groove portion 55 that makes one round in the circumferential direction is formed on the center side in the left-right direction (axial direction). A plurality of notches 57 provided at equal intervals are provided at the end of the cylindrical portion 51 on the other end side (the side opposite to the side where the input side clutch pawl 53 is provided). In the illustrated example, four notches 57 are provided at intervals of 90 degrees.

  As shown in FIGS. 4 and 6, the sprocket 60 is formed with a plurality of tooth portions 67 around which the chain 68 is wound, and is formed slightly larger than the outer diameter of the cylindrical portion 51 of the clutch 50 at the center. A shaft hole 61 is provided. By inserting the cylindrical portion 51 of the clutch 50 into the shaft hole 61 of such a sprocket 60, the sprocket 60 is rotatably supported around the cylindrical portion 51 of the clutch 50 as a central axis.

  An output-side clutch pawl 63 (output-side locking portion) is formed in the axial direction on one side of the sprocket 60 (in the illustrated example, on the side of the power transmission shaft 15). The sprocket 60 can be locked to the input side clutch pawl 53 while being supported by the cylindrical portion 51 of the clutch 50. As shown in FIG. 10, the input side clutch pawl 53 and the output side clutch pawl 63 are engaged with each other with a gap of a predetermined angle θ1 (about 20 degrees in the illustrated example). It can be rotated.

  Further, when the cylindrical portion 51 of the clutch 50 is inserted into the shaft hole 61 of the sprocket 60, the annular ring member 56 is fitted into the groove portion 55 of the cylindrical portion 51, so that the input of the clutch 50 is performed. The side clutch pawl 53 and the output side clutch pawl 63 of the sprocket 60 are held at positions where they can be locked. The distance L1 (see FIG. 5) from the left side surface of the input side clutch pawl 53 to the groove portion 55 into which the ring member 56 is fitted is slightly smaller than the distance L2 (see FIG. 6) from the right side surface of the sprocket 60 to the left end portion. It is a large degree, and there is almost no play with respect to the left-right direction of the sprocket 60.

  4 and 7, the torsion coil spring 70 has both end portions 71 and 73 extending in the axial direction, and one end (end portion 73) of the torsion coil spring 70 is opposite to the power transmission shaft 15 side of the sprocket 60. It is locked in a locking hole 62 provided on the side surface. The other end (end portion 71) of the torsion coil spring 70 is a locking hole 82 (locking hole 82a or 82b) of the plate 80 (locking member) provided at the outer end portion of the cylindrical portion 51 of the clutch 50. It is locked to. Here, in the embodiment, an example in which the locking hole 62 is provided at only one position with respect to the sprocket 60 is shown, but the present invention is not limited to this. In addition to the locking hole 62 provided at the center in the rotational direction of one output side clutch pawl 63 shown in the illustrated example, the angle from the center of the other output side clutch pawl 63 in the rotational direction is shifted to a predetermined direction. Can be provided. In this case, the urging force of the torsion coil spring can be changed by changing the locking hole for locking the torsion coil spring 70, and the urging force can be adjusted to a desired value. The cylindrical portion 51 of the clutch 50 is inserted inside the torsion coil spring 70, but a cylindrical outer collar 90 is disposed in the gap between the cylindrical portion 51 and the torsion coil spring 70. Never touches.

  As shown in FIGS. 4 and 8, the plate 80 is provided with a through hole 81 for inserting a fastening member 91 such as a bolt in the center, and the periphery of the through hole 81 is on one side in the axial direction (power transmission). A convex portion 83 protrudes on the side opposite to the shaft 15 (outside). The convex portion 83 has a polygonal shape (rectangular shape in the illustrated example) in plan view, and can be held by a wrench or the like. On the side opposite to the side where the convex portion 83 is provided, fitting pieces 87 corresponding to the four notches 57 provided at the end of the cylindrical portion 51 are formed. 57 can be fitted. The locking hole 82 provided in the plate 80 is provided at a plurality of positions (two positions in the illustrated example) at positions shifted by a predetermined angle with respect to the position of the fitting piece 87, and the torsion coil spring is changed by changing the locking hole 82. The urging force of 70 can be changed. In the illustrated example, locking holes 82a and 82b are provided at positions at different angles (α and β) from the fitting pieces 87a and 87b provided at opposing positions toward the biasing direction of the torsion coil spring 70, respectively. In the locking hole 82a having a larger angle, a larger urging force can be obtained. Moreover, even when it is a case where it latches to the same latching hole 82, since the fixed position in the rotation direction of the plate with respect to the cylindrical part 51 can be changed at 90 degree intervals, this can also change urging | biasing force.

  Then, as shown in FIG. 9, the sprocket 60, the ring member 56, the torsion coil spring 70, and the outer collar 90 are sequentially supported by the cylindrical portion 51 of the clutch 50, and the plate 80 is fitted. The power transmission unit 100 as a power transmission mechanism is configured by fitting the piece 87 and the cutout 57 of the cylindrical portion 51. Here, the fitting between the fitting piece 87 of the plate 80 and the notch 57 of the cylindrical portion 51 is performed by holding the plate 80 against the urging force of the torsion coil spring 70 in a state where the convex portion 83 is sandwiched by a wrench or the like. This is done by rotating. At this time, by providing a transmission portion 89 that is a gap between the convex portion 83 and the fitting piece 87, at least one (two in the embodiment) fitting pieces among the four fitting pieces 87. 87 is visible, and the notch 57 is visible. Accordingly, the plate 80 can be rotated while confirming the positional relationship between the fitting piece 87 of the plate 80 and the cutout 57 of the cylindrical portion 51, and the fitting piece 87 of the plate 80 and the cutout of the cylindrical portion 51 can be rotated. Fitting with 57 can be performed easily. An inner collar 93 having a cylindrical shape is disposed inside the cylindrical portion 51 of the clutch 50 on the plate 80 side. When the power transmission unit 100 is fitted to the power transmission shaft 15, the inner collar 93 is disposed. The strength of the power transmission unit 100 (particularly the clutch 50) is ensured by having one end of 93 contact the plate 80 and the other end abuts the end of the power transmission shaft 15.

  In the power transmission unit 100, both end portions 71 and 73 of the torsion coil spring 70 are engaged with the engagement holes 62 of the sprocket 60 and the engagement holes 82 of the plate 80. Here, as shown in FIG. 7, the torsion coil spring 70 in the embodiment has one end (end portion 71) and the other end (end portion 73) that coincide with each other in the axial direction in an unloaded state. However, as shown in FIG. 10, in a state where the plate 80 is engaged with the clutch 50, the locking hole 82 of the plate 80 and the locking hole 62 of the sprocket 60 are shifted in position in the axial direction by a predetermined angle θ2. Yes. Therefore, the engagement between the plate 80 and the clutch 50 is performed when the both ends 71 and 73 of the torsion coil spring 70 are inserted into the locking holes 82 and 62 between the plate 80 and the sprocket 60. This can be achieved by holding 83 with a wrench or the like and rotating it in a direction to reduce the spring diameter.

  Thus, since the power transmission unit 100 is configured with the torsion coil spring 70 biased, in the mounted state shown in FIG. 10A, the biasing force causes the input side clutch pawl 53 to rotate. A force is applied so that the rear end side in the direction contacts the front end side in the rotational direction of the output side clutch pawl 63 of the sprocket 60. In the driving state shown in FIG. 10B, the clutch 50 that rotates together with the power transmission shaft 15 causes the input side clutch pawl 53 of the clutch 50 to rotate and the output side clutch pawl 63 of the sprocket 60 to follow the rotational direction. The power of the clutch 50 is transmitted to the sprocket 60 by contacting the end side. In this state, the torsion coil spring 70 is further urged, and the positions of the end portion 71 and the end portion 72 become an angle θ3 larger than the angle θ2 when viewed in the axial direction, and the spring diameter is further reduced. In FIGS. 10A and 10B, the rotation direction is indicated by an arrow.

  Thus, the rear end side in the rotational direction of the input side clutch pawl 53 and the output side clutch are provided by the torsion coil spring 70 while providing a predetermined gap between the input side clutch pawl 53 of the clutch 50 and the output side clutch pawl 63 of the sprocket 60. Even if an unequal speed of the power transmission shaft 15 is generated by urging in the direction in which the front end side of the claw 63 contacts the rotational direction, this is mitigated by the power transmission unit 100, and the output of the sprocket 60. As a result, the inequality is reduced. Thereby, the output of the output side sprocket 69 provided in the lower part of the chain case 8 is easily stabilized. Then, power transmission between the drive clutches 18 and 19 and the driven clutches 31L and 31R is stabilized, and wear and impact sound of the drive clutches 18 and 19 and the driven clutches 31L and 31R are suppressed.

  In addition, according to the embodiment, the sprocket 60 does not rotate in contact with the power transmission shaft 15 but rotates with the cylindrical portion 51 of the clutch 50 as a central axis, so that the power transmission shaft It can suppress that 15 deteriorates by wear etc. Further, when the cylindrical portion 51 is deteriorated due to wear or the like, it is sufficient to replace only the power transmission unit 100, and it is not necessary to replace the power transmission shaft 15.

  The chain case 8 is provided with a cover 98 provided with an oil insertion hole at a portion to which the power transmission unit 100 is attached. The oil insertion hole is provided with a cap 98a, which can be attached and detached as necessary. Further, the cover 98 can be attached to and detached from the chain case 8, and when the power transmission unit 100 is consumed, the cover 98 and the like can be removed to perform replacement and maintenance of the power transmission unit 100.

  When the power transmission unit 100 is exchanged, the sprocket 60 and the ring member 56 are attached to the clutch 50 in this order, and the torsion coil spring 70, the outer collar 90, and the inner collar 93 are attached, and then the plate 80 is attached. It is preferable to configure the power transmission unit 100 by attaching the power transmission unit 100 to the power transmission shaft 15 by the fastening member 91 or the like. For example, the clutch 50, the sprocket 60, and the ring member 56 are attached to the power transmission shaft 15 in this order, and the torsion coil spring 70, the outer collar 90, and the inner collar 93 are attached, and then the plate 80, the washer 95, and the fastening. The attachment of the member 91 also attaches the power transmission unit 100 to the scraping work machine 1, but in this case, almost all work must be performed at the site where the scraping work machine is located. However, as described above, attaching the power transmission unit 100 assembled in advance to the power transmission shaft 15 facilitates replacement work and the like.

  Further, in the embodiment, the power transmission unit 100 is configured by supporting the cylindrical portion 51 of the clutch 50 in the order of the sprocket 60, the ring member 56, and the torsion coil spring 70. The output side clutch pawl 63 is disposed on the inner side (power transmission shaft side) in the axial direction from the portion 67, and the overhang toward the outer side in the axial direction is reduced by the output side clutch pawl 63. In this way, the power transmission unit 100 is configured to be compact, so that the handling becomes easy at the time of replacement or the like.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. For example, although the example in which the cylindrical portion and the power transmission shaft are fitted by the spline grooves formed in each is shown, the present invention is not limited to this. The cylindrical part and the power transmission shaft need only be fixed with respect to the rotational direction. For example, the inner side of the cylindrical part and the end of the power transmission shaft are both prismatic and may be configured to fit with each other. .

  Further, in order to make the fixing position in the circumferential direction of the plate relative to the cylindrical portion relatively variable, a fitting piece provided on the plate is fitted into a notch provided at an end of the cylindrical portion. An example is shown, but the present invention is not limited to this. For example, spline grooves corresponding to the cylindrical portion and the plate may be formed, and these may be fitted.

  Moreover, although the example which the number of the locking holes formed in a plate is two places was shown, it is not limited to this, Three or more places may be sufficient. The number of the locking holes may be one, but in that case, it is preferable that the fixing positions in the circumferential direction between the plate and the cylindrical portion can be relatively changed.

  Moreover, although the example whose shape is a clutch nail | claw was shown as an input side latching | locking part and an output side latching | locking part, it is not limited to this. The shape of the input side latching portion and the output side latching portion is not particularly limited as long as the input side latching portion and the output side latching portion are rotatable relative to the rotation direction and can be latched in the rotation direction.

1st scratching machine (rotary machine)
8 Chain case (Transmission case)
15 Power transmission shaft 50 Clutch (input side rotating body)
51 Cylindrical part 53 Input side clutch pawl (input side latching part)
60 Sprocket (Output side rotating body)
63 Output side clutch pawl (Output side latching part)
70 Torsion coil spring (biasing member)
80 plate (locking member)
100 Power transmission unit

Claims (4)

A power transmission unit that is fitted to a power transmission shaft that can rotate in a predetermined direction, and that alleviates unequal speed rotation of the power transmission shaft,
An input-side rotating body provided with an input-side locking portion in a cylindrical portion that is fitted to the power transmission shaft and rotates together with the power transmission shaft;
Output side rotation in which the cylindrical portion of the input side rotating body is fitted so as to be rotatable about the rotation axis, and an output side locking portion capable of meshing with the input side locking portion is provided. Body,
An urging member that urges the output-side rotator in the rotation direction,
The power transmission unit, wherein the input-side rotator and the output-side rotator are relatively rotatable within a predetermined angle range. The input-side rotating body is provided with the input-side locking portion at an end of the cylindrical portion on the power transmission shaft side,
In the power transmission unit, the output-side rotating body and the biasing member are arranged in this order from the power transmission shaft side to the output-side rotating body and the biasing member with respect to the cylindrical portion of the input-side rotating body. The power transmission unit according to claim 1, wherein: The biasing member comprises a torsion coil spring,
Both ends of the torsion coil spring are locked to a locking hole provided in the output side rotating body and a locking hole provided in a locking member fixed to the cylindrical portion. The power transmission unit according to claim 1 or 2. An input side rotating body provided with an input side locking portion on one end side of a cylindrical portion having a substantially cylindrical shape;
An output-side rotating body provided with an output-side locking portion that is supported by the cylindrical portion so that the cylindrical portion of the input-side rotating body serves as a rotation axis, and that can mesh with the input-side locking portion;
An attachment method for attaching a power transmission mechanism comprising a torsion coil spring that urges the output side rotating body in a rotational direction to a power transmission shaft that is rotatable in a predetermined direction,
A power transmission mechanism is unitized in advance by supporting the output-side rotator and the torsion coil spring with respect to the cylindrical part of the input-side rotator, and the cylindrical part in the unitized power transmission mechanism is converted into the power. A power transmission mechanism mounting method, wherein the power transmission mechanism is mounted on a transmission shaft.

Images