JP4426434B2 - Crawler device and assembly method thereof - Google Patents

Description

  The present invention relates to a crawler device used for a suspension part of a lightweight robot or the like and a method for assembling the crawler device.

Rubber crawler belts used for small and light robots have been developed. However, this crawler belt has a drawback that it elongates due to long-term use, causes slack, and is detached from the wheel. Moreover, since the strength is low, it may tear. In order to overcome this drawback, as described in Patent Documents 1 to 3, a technique has been developed in which an endless tensile member made of a metal ribbon or the like is embedded in a rubber belt body of a crawler belt for reinforcement. Yes.
JP-A-6-156333 JP-A-6-199253 JP-A-6-329057

  In the crawler device disclosed in the patent document, since the crawler belt includes a tensile member, the crawler belt expands and contracts only by a minute amount. Therefore, it is necessary to accurately position the wheel to eliminate the slack of the crawler belt. Although not described in the above-mentioned patent document, since the wheel cannot be accurately positioned normally, the tensioner mechanism disposed between the front and rear wheels is urged to widen the distance between the wheels, and the crawler belt is tensioned. . However, this tensioner mechanism has a drawback of increasing the weight of the crawler device.

The present invention has been made to solve the above problems,
(A) a connecting member extending back and forth;
(B) front and rear wheels rotatably supported by front and rear ends of the connecting member;
(C) a crawler belt spanned between the front and rear wheels, including an endless belt body made of an elastic material and an endless tensile member;
In the crawler device provided with
A support portion is provided at the front and rear end portions of the connecting member, and an annular receiving portion fitted and fixed to the support portion is provided on the inner peripheral side of the front and rear wheels, and the support portion and the annular receiving portion are provided. At least one includes a bearing, and the support portion has a fitting portion that fits into the annular receiving portion and a guide portion adjacent to the fitting portion, and an outer peripheral surface of the guide portion has a tapered taper. It is characterized by being.

  According to the above configuration, the guiding portion of the supporting portion can guide the fitting portion of the supporting portion into the wheel-side annular receiving portion, and the wheel can be accurately positioned and attached to the connecting member. Can do. Therefore, the slack of the crawler belt can be eliminated, and the weight can be reduced because the tensioner mechanism is unnecessary.

In the method of assembling the crawler device, a first subassembly having the support portion provided at the front and rear end portions of the connecting member is prepared, and the crawler belt is stretched between the front and rear wheels provided with the annular receiving portion. A second subassembly is prepared, the guide portions of the support portion are inserted into the annular receiving portion by bringing the first and second subassemblies closer, and the guide portions are guided by bringing both assemblies closer to each other. Accordingly, the fitting portion of the support portion is fitted into the annular receiving portion, and thereafter, the supporting portion and the annular receiving portion are fixed.
According to this method, the wheel can be accurately positioned and the assembly workability can be improved.

Preferably, the annular receiving portion is formed integrally with the inner periphery of the wheel, and the support portion rotates to the shaft member via the shaft member fixed to the connecting member, the bearing, and the bearing. A rotating member supported in a possible manner, and the rotating member has the fitting portion and the guide portion, and the annular receiving portion is fitted in the annular receiving portion. It is fixed to.
According to this, since the annular receiving portion is integrated with the wheel, the configuration is simplified.

In the method of assembling the crawler device, a first subassembly having the support portions provided at the front and rear ends of the connecting member is prepared, and a second subassembly having the crawler belt spanned between the front and rear wheels is prepared. Then, by bringing the first and second subassemblies closer, the guide part of the rotating member of the support part is inserted into the annular receiving part of the wheel, and by further bringing both assemblies closer, the guide part is guided. Accordingly, the fitting portion of the rotating member is fitted into the annular receiving portion, and thereafter, the rotating member and the annular receiving portion are fixed.
According to this method, the wheel can be accurately positioned and the assembly workability can be improved.

  Preferably, the connecting member includes a side plate, and in the first subassembly, one end of the shaft member is fixed to the side plate. After the first and second subassemblies are combined, another side plate is provided. Is fixed to the other end of the shaft member. Thereby, a wheel can be stably supported with a pair of side plate.

  According to the present invention, the wheel can be accurately positioned and slack of the crawler belt can be prevented. In addition, since the tensioner mechanism is unnecessary, the weight of the crawler device can be reduced.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an undercarriage A that is the lower half of the light work robot. The undercarriage portion A is configured by attaching a pair of crawler devices 2 </ b> L and 2 </ b> R to the left and right portions of the base 1. The upper body of the robot is attached to the base 1. This upper body has a different structure depending on the role of the robot. For example, in the case of a robot used for searching for a person trapped in debris when a disaster such as an earthquake occurs, the robot is provided with a camera, a detection sensor, and a lighting device, and is provided with a lightweight object gripping mechanism as necessary.

  As shown in FIGS. 1 to 3, each of the crawler devices 2 </ b> L and 2 </ b> R includes a front side wheel 10, a rear side wheel 10, an endless crawler belt 20 spanned between the wheels 10, and a pair of side plates 30. And. A central portion of the side plate 30 inside the pair of crawler devices 2L and 2R is attached to the base 1.

  The left and right crawler devices 2L and 2R have substantially the same structure. However, in the left crawler device 2L, the rear wheel 10 is connected to the actuator 40 and functions as a driving wheel, and the front wheel 10 functions as a driven wheel. In the crawler device 2R on the right side, the front wheel 10 is connected to the actuator 40 and functions as a driving wheel, and the rear wheel 10 functions as a driven wheel.

  Hereinafter, the left crawler device 2L will be described. As shown in FIGS. 4, 6, and 7, each wheel 10 is made of resin or the like, and has a number of holes 13 for lightening for weight reduction. The outer peripheral surface of the wheel 10 is a cylindrical surface, and metal engaging pins 12 are embedded at equal intervals in the circumferential direction at the center in the width direction of the outer peripheral surface. The head portion of the engagement pin 12 has a hemispherical shape and protrudes from the outer peripheral surface of the wheel 10 and is provided as an engagement protrusion 12a. In the present embodiment, the diameter of the engaging protrusion 12a is about 3 mm with respect to the width of 30 mm of the wheel 10.

  As shown in FIGS. 1 to 3, the pair of side plates 30 are arranged on the left and right of the pair of wheels 10. Each side plate 30 includes an oblong metal plate 31 elongated in the front-rear direction and a pair of upper and lower seal members 32. The front and rear end portions of the pair of metal plates 31 cover both side surfaces of the pair of wheels 10.

  The metal plates 31 of the side plates 30 have semicircular front and rear end portions 31 a that respectively extend along the peripheral edges of the front and rear wheels 10. These front and rear edge portions 31a are thinned by cutting the inner side as shown in FIGS.

  The seal member 32 is detachably attached to the upper and lower linear edges that are continuous with the edge 31a of the metal plate 31. More specifically, the seal member 32 is made of a rubber material having a smaller elastic coefficient than the belt main body 22 of the crawler belt 20 described later, and as shown in FIG. The bracket 33 is fixed to the upper and lower edges of the side plate 30 by screws 34 so as to be detachable. The seal member 32 has a standing wall 32a that is thin.

  As shown in FIG. 9, the crawler belt 20 includes a steel belt 21 (metal ribbon, tensile band, tensile member) made of endless stainless steel, and vulcanized and bonded to the entire outer periphery of the steel belt 21. And an endless belt body 22 made of rubber (elastic material) such as SBR and urethane rubber.

  The steel belt 21 is configured by welding both ends of a thin ribbon having a plate thickness of 0.05 to 1.0 mm (0.15 mm in this embodiment). The steel belt 21 has a width substantially equal to that of the wheel 10, and a circular engagement hole 21a is formed at the center in the width direction at an equal pitch in the circumferential direction (a pitch equal to the engagement protrusion 12a of the wheel 10). Is formed. The diameter of the engagement hole 21a is equal to or slightly larger than the diameter of the engagement protrusion 12a.

  In the present embodiment, the steel belt 21 is extremely thin compared to a base portion 23 (thickness 3 mm) described later. In FIG. 9, the thickness of the steel belt 21 is exaggerated and the steel belt 21 is not shown in other drawings.

  As shown in FIGS. 1 and 9, the belt body 22 includes an endless base portion 23 that is wider than the steel belt 21, shielding rods 24 formed on both sides of the base portion 23 in the width direction, a base Two kinds of grounding lugs 25 and 26 formed at intervals on the outer periphery of the portion 23 are integrally provided. A substantially hemispherical relief recess 23 a communicating with the engagement hole 21 a is formed at a position corresponding to the engagement hole 21 a of the steel belt 21 at the center in the width direction of the base portion 23.

  As shown in FIGS. 2 to 4, the crawler belt 20 is wound around the front and rear wheels 10 over a half circumference. As shown in FIG. 9, the steel belt 21 is in direct contact with the outer peripheral surface of the wheel 10 in the region of the half circumference of the wheel 10, and the engagement protrusion 12 a of the wheel 10 is engaged with the engagement hole 21 a of the steel belt 21. At the same time, the base portion 23 enters the relief recess 23a.

  The shielding rod 24 is formed continuously over the entire circumference of the belt main body 22 and protrudes in an oblique direction from the outer peripheral surface of the base portion 23. The shield rod 24 has a tapered cross-sectional shape and is easily elastically deformed.

  As shown in FIG. 2, the crawler belt 20 has first regions R1 and second regions R2 alternately in the circumferential direction. Two first ground lugs 25 are disposed in the first region R1, and four second ground lugs 26 are disposed in the second region R2.

  The first ground lug 25 extends in the width direction of the crawler belt 20 and has a trapezoidal longitudinal cross-sectional shape. In the present embodiment, the thickness of the bottom of the cross-sectional shape of the first ground lug 25 is 15 mm, the top thickness is 4 mm, and the height is 15 mm. Since the bottom dimension is large, the bending rigidity is sufficiently high. Therefore, even if a force perpendicular to the width direction is applied to the ground lug 25, it does not bend.

  The second ground lug 26 extends in the width direction of the crawler belt 20 and has a trapezoidal longitudinal cross-sectional shape. In the present embodiment, the cross-sectional shape of the second ground lug 26 has a bottom side thickness of 5 mm, a top side thickness of 3 mm, and a height of 15 mm. Since the thickness of the second ground lug 26 is much smaller than the height, the bending rigidity of the second ground lug 26 is much smaller than that of the first ground lug 25. Therefore, a force in a direction perpendicular to the width direction is applied to the ground lug 26. When added, it is easy to bend. The height of the ground lug 26 is preferably 3 times or more and 7 times or less, more preferably 3.5 times or more and 5 times the thickness (average thickness or thickness of the central portion in the height direction). It is as follows. In addition, the planar shape of the ground lug 26 is a shape bent at the center as shown in FIG. This increases the strength against the load in the height direction, that is, the robot's own weight.

  As shown in FIGS. 4, 6, and 7, the front and rear wheels 10 are rotatably supported by a pair of side plates 30 by front and rear support mechanisms 50 (support portions). The support mechanism 50 includes a disk-shaped mounting base 51, a shaft member 52, a bearing 53, and a rotating member 54.

  The mounting base 51 is fixed to one (inner) side plate 30 with screws 51a (shown only in FIGS. 1 and 2). One end of the shaft member 52 is fixed to the mounting base 51 by a screw 52a, and the other end of the shaft member 52 is fixed to the other (outer) side plate 30 by a screw 52b.

  The bearing 53 is housed in a bearing housing 55 and fits on the outer periphery of the shaft member 52, and is supported by a step of the shaft member 52 and a bearing stopper 56 fixed to the shaft member 52.

  The rotating member 54 includes a disk portion 54a, a cylindrical portion 54b connected to the outer peripheral edge of the disk portion 54a, and an annular shape projecting radially and outward from the peripheral edge of the cylindrical portion 54b (periphery opposite to the disk portion 54a). And a flange 54c. A hole for passing the shaft member 52 is formed in the center of the disk portion 54a. The peripheral edge of this hole is fixed to the flange portion of the bearing housing 55 by a screw 58.

  On the other hand, an annular flange 19 (annular receiving portion) projecting in the radial direction and inward is integrally formed on the inner periphery of the central portion in the width direction of the wheel 10. The rotating member 54 is fixed to the flange portion 54c. Thereby, the wheel 10 is rotatably supported by the shaft member 52 via the rotating member 54 and the bearing 53.

  The front and rear support mechanisms 50 have the same structure. However, as shown in FIG. 7, a connection structure with the actuator 40 is further added to the rear support mechanism 50. More specifically, the casing 41 of the actuator 40 (including the electric motor and the speed reduction mechanism) passes through the inner side plate 30 and is fixed to the mounting base 51 with screws, and the output shaft 45 of the actuator 40 passes through the mounting base 51. is doing. A spur gear 46 is fixed to the output shaft 45. On the other hand, a tooth portion 54 d is formed on the inner periphery of the cylindrical portion 54 b of the rotating member 54, and this tooth portion 54 d meshes with the spur gear 46 so that the rear wheel 10 receives the rotational torque of the actuator 40. It has become.

  The cylindrical portion 54b of the rotating member 54 has a fitting portion 54x and a guide portion 54y that are adjacent to each other. The fitting portion 54x is located on the flange portion 54c side, the outer peripheral surface forms a cylindrical surface, and this fitting hole is fitted into the fitting hole 19a defined by the inner peripheral surface of the flange portion 19 of the wheel 10. It has the same diameter as 19a. The guide portion 54y is located on the disk portion 54a side (the tip side in the rotation axis direction of the wheel 10), and the outer peripheral surface forms a conical surface, that is, a tapered surface. The base end of the tapered surface is continuous with the same diameter as the fitting portion 54x.

  The fitting portion 54x and the guide portion 54y are useful when assembling the crawler device 2L. Referring to FIG. 5, after assembling the front support mechanism 50 and the rear support mechanism 50 with the actuator 40, the support mechanism 50 is fixed to the side plate 30 (connecting member), and the first assembly 101. Get.

On the other hand, the second assembly 102 is assembled by passing the crawler belt 20 around the front and rear wheels 10.
Next, the rotating members 54 of the support mechanism 50 before and after the first assembly 101 are fitted into the wheels 10 before and after the second assembly 102. At this time, the guide portion 54 y of the rotating member 54 guides the fitting portion 54 x to the fitting hole 19 a of the wheel 10 while widening the distance between the front and rear wheels 10, that is, while applying tension to the crawler belt 20. To fit. Thus, the wheel 10 is accurately positioned and set so as to prevent the crawler belt 20 from loosening. Thereafter, the flange portion 19 of the wheel 10 is fixed to the flange portion 54 c of the rotating member 54 using the screw 59.
Next, the other side plate 30 is fixed to the shaft member 52 of the front and rear support mechanisms 50.

  The right crawler device 2R is also assembled in the same manner as the left crawler device 2L. As described above, the crawler devices 2L and 2R can be accurately assembled with good workability by the action of the guide portion 54y and the fitting portion 54x. In addition, by forming the wheel 10 from resin, the fitting and fixing of the wheel 10 to the rotating member 54 can be performed more smoothly.

  In the robot configured as described above, when the actuators 40 of the left and right crawler devices 2L and 2R are driven, the rear wheel 10 of the left crawler device 2L and the front wheel 10 of the right crawler device 2R receive rotational torque, and the crawler belt 20 rotates. Thereby, the robot travels.

  Although the crawler belt 20 uses a rubber belt body 22, it is reinforced by a steel belt 21, so that the crawler belt 20 does not stretch even if it is continuously used and can be prevented from coming off the wheel 10. In addition, the crawler belt 20 can be significantly reduced in weight. The first reason is that the crawler belt 20 is reinforced with a thin steel belt 21 without increasing the wall thickness, and the second reason is that the steel belt 21 engages with the wheel 10. This is because it is not necessary to form a protrusion for engaging the wheel 10 on the belt body 22.

  Since the projection 12a of the wheel 10 is fitted into the engagement hole 21a of the steel belt 21, it is possible to reliably prevent the crawler belt 20 from coming off in the left-right direction.

  As shown in FIG. 10, the robot according to the present embodiment can get over a step S higher than the diameter D from the center of the wheel 10 to the top ends of the ground lugs 25 and 26 (the height of the step is indicated by a symbol H). . More specifically, when the robot travels and hits the step S, if the tip of the second ground lug 26 hits the step S, the second ground lug 26 starts to bend due to the force in the direction opposite to the arrow direction. It bends greatly in response to the force in the opposite direction. In this state, since the top end portion of the first ground lug 25 is caught on the upper end of the step S, the robot can get over the high step S.

  For comparison with the present embodiment, it is assumed that the second grounding lug 26 does not bend as shown by an imaginary line in FIG. 10 as in the conventional crawler belt. In this case, since the top end of the second ground lug 26 hits the step S, the crawler devices 2L and 2R do not approach the step S, and the first ground lug 25 is not caught on the upper end of the step S. Therefore, the robot cannot get over a step having a height greater than the diameter D.

  Although the interval between the ground lugs 25 and 26 is shown wide in the figure, the above effect can be obtained even if the interval is reduced.

Moreover, in this embodiment, since it has two types of grounding lugs 25 and 26, it can get over various obstacles.
For example, for the relatively low debris S ′ having a flat surface as shown in FIG. 11, the second ground lug 26 is elastically deformed to increase the contact area with the debris S ′, thereby reducing the debris S ′. Therefore, the gripper can be gripped satisfactorily without slipping, and the idling of the crawler belt 20 can be avoided. In addition, if the space | interval of the adjacent 2nd grounding lug 26 is narrowed, the debris S 'can be gripped still more favorably by the 2nd 2nd grounding lug 26 adjacent as shown in FIG. This function works particularly effectively when the debris S ′ is wet or sand is attached.
On the other hand, the first grounding lug 25 has a small grip ability for the relatively low debris S ′ to which the above-mentioned sand or the like adheres, but the second grounding lug 26 for an obstacle such as a pipe having a curved cross section. The grip function is high compared to, and can be easily overcome.

  Since the grounding lugs 25 and 26 have the same height, traveling of the crawler devices 2L and 2R is stable. The ground lug 26 is easy to bend, but has sufficient strength against the load in the height direction, that is, the weight of the robot, and can ensure smooth running without being greatly deformed. In addition, since the ground lug 26 has a shape in which the planar shape is bent, the strength in the height direction can be increased.

  In the region of the crawler belt 20 that is hung on the front and rear wheels 10, the front edge of the shielding rod 24 is in contact with the front and rear edge portions 31 a of the side plate 30, and in the region between the front and rear wheels 10, The leading edge is in contact with the standing wall 32 a of the seal member 32. As a result, the internal space surrounded by the crawler belt 20 and the pair of side plates 30 is sealed, and intrusion of water, sand, and dust can be avoided.

  Since the crawler belt 20 is bent in a region where the crawler belt 20 is stretched over the circumference of the wheel 10, the shielding rod 24 warps in a direction in which the front end edge is separated from the end edge 31 a of the side plate 30. However, as described above, the tip edge portion of the shielding rod 24 is elastically deformed and is in contact with the end edge portion 31a of the side plate 30, so that it can be reliably in contact with the end edge portion 31a despite the warp. . Further, the shield rod 24 of the crawler belt 20 contacts the seal member 32 at the upper and lower edge portions of the side plate 30. However, since the seal member 32 has a smaller elastic coefficient than the shield rod 24 and is thin, it is greatly deformed compared to the shield rod 24. To do. Therefore, even when the crawler belt 20 is swung at a portion not restrained by the wheel 10, the seal member 32 is deformed following the swing, so that the contact between the seal member 32 and the shielding rod 24 can be ensured. Since the seal member 32 is provided with Teflon (registered trademark) coating or the like, friction with the shielding rod 24 can be reduced.

The present invention is not limited to the above embodiment, and various aspects can be adopted. For example, the annular receiving portion may be constituted by the annular flange portion 19 and the rotating member 54, and the support portion may be constituted by the shaft member 52, the bearing 53, and the bearing housing 55. In this case, a fitting hole is formed in the rotating member 54, and a fitting portion and a guide portion are formed in the bearing housing 55.
Further, the support portion is composed of a shaft member 52, and the annular receiving portion is configured to include a bearing 53, a cylindrical inner support disposed on the inner periphery of the bearing, and a rotating member 54 disposed on the outer periphery of the bearing. May be. In this case, the inner support has a fitting hole, and the shaft member has a fitting portion and a guide portion.
The tensile member may be embedded in the belt body. The tensile member may be a wire.

Both of the pair of crawler devices may be front-wheel drive or rear-wheel drive, or may be both-wheel drive.
An intermediate wheel may be disposed between the front and rear wheels. The driven wheel does not mesh with the crawler belt and may only restrict the movement of the crawler belt in the width direction.

The actuator is not limited to an electric motor, and may be a hydraulic motor or an engine.
The crawler device of the present invention may be used for a lightweight robot for cleaning a hospital other than a lifesaving robot, or a lightweight construction machine other than a robot.

It is a perspective view of the suspension part of a robot provided with a pair of right and left crawler devices which constitute a 1st embodiment of the present invention. It is a right view of the left crawler device. It is a left view of the left crawler device. FIG. 4 is a cross-sectional view of the crawler device taken along line IV-IV in FIG. 2. It is sectional drawing of the crawler apparatus which decomposes | disassembles and shows sectional drawing of FIG. FIG. 5 is an enlarged cross-sectional view of a front end portion of the crawler device shown in FIG. 4. FIG. 5 is an enlarged cross-sectional view of a rear end portion of the crawler device shown in FIG. 4. It is a longitudinal cross-sectional view of the crawler apparatus which follows the VIII-VIII line in FIG. It is an expanded longitudinal cross-sectional view of a crawler belt which exaggerates and shows the thickness of a steel belt. It is the schematic which shows a state when a crawler apparatus gets over a high level | step difference. It is the schematic which shows the state in which the 2nd grounding lug of a crawler belt grips debris.

Explanation of symbols

2L, 2R crawler device 10 wheel 19 annular collar (annular receiving part)
20 Crawler belt 21 Steel belt (tensile member)
22 Belt body 30 Side plate (connecting member)
50 Support mechanism (support part)
52 Shaft member 53 Bearing 54 Rotating member 101 First subassembly 102 Second subassembly

Claims (5)

(A) a connecting member extending back and forth;
(B) front and rear wheels rotatably supported by front and rear ends of the connecting member;
(C) a crawler belt spanned between the front and rear wheels, including an endless belt body made of an elastic material and an endless tensile member;
In the crawler device provided with
A support portion is provided at a fixed position of the front and rear end portions of the connecting member, and an annular receiving portion that is fitted and fixed to the support portion is provided on the inner peripheral side of the front and rear wheels. At least one of the parts includes a bearing,
The annular receiving portion has a fitting hole whose inner peripheral surface forms a cylindrical surface,
The support portion has a fitting portion whose outer peripheral surface forms a cylindrical surface having the same diameter as the fitting hole, and a guide portion which is adjacent to the fitting portion and whose outer peripheral surface forms a tapered taper ,
When the front and rear wheels are attached to corresponding support portions, the fitting holes of the annular receiving portions are adapted to fit into the fitting portions through the guide portions, and the taper guide action of the guide portions The crawler apparatus is characterized in that tension is applied to the crawler belt by widening the distance between the front and rear wheels . The tensile member comprises a plate-shaped tensile band, and the belt body is provided on the outer periphery of the tensile band. The tensile band is in direct contact with the wheel, and an engagement hole formed in the tensile band. The crawler device according to claim 1, wherein engagement protrusions formed on the outer periphery of the wheel are engaged. The annular receiving portion is integrally formed on the inner periphery of the wheel,
The support portion includes a shaft member fixed to the coupling member, the bearing, and a rotating member rotatably supported by the shaft member via the bearing.
The rotating member has the fitting portion and the guide portion, and is fixed to the annular receiving portion in a state where the fitting portion is fitted to the annular receiving portion. The crawler device according to 1 or 2 . In the method of assembling the crawler device according to any one of claims 1 to 3 ,
Preparing a first sub-assembly comprising the support portions at fixed positions of the front and rear ends of the connecting member;
Prepare a second subassembly that spans the crawler belt between the front and rear wheels ,
By bringing the first and second subassemblies closer, the guide portion of the support portion is inserted into the annular receiving portion, and by further bringing both assemblies closer, the guide portion of the support portion is guided according to the guide of the taper of the guide portion. The fitting portion is fitted into the fitting hole of the annular receiving portion, and in this process, tension is applied to the crawler belt while widening the distance between the front and rear wheels, and thereafter, the supporting portion and the annular receiving portion are fixed. A method for assembling the crawler device. In the method of assembling the crawler device according to claim 3,
By fixing one end of the shaft member of the support portion to the front and rear end portions of the side plate as the connecting member, a first subassembly in which the support portion is provided at a fixed position is prepared,
Prepare a second subassembly that spans the crawler belt between the front and rear wheels,
By bringing the first and second subassemblies closer, the guide portion of the rotating member of the support portion is inserted into the annular receiving portion of the wheel, and by further bringing both assemblies closer , guidance of the taper of the guide portion is achieved. Accordingly, the fitting portion of the rotating member is fitted into the fitting hole of the annular receiving portion, and in this process, tension is applied to the crawler belt while increasing the distance between the front and rear wheels, and then the rotating member and the annular receiving portion are provided. The crawler device assembly method is characterized in that the first and second subassemblies are united by fixing the other and the other side plate is fixed to the other end of the shaft member .

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