Cantilevered rotary roller-arranged circular wheel

Abstract

To provide a cantilevered rotary roller-arranged circular wheel that can be manufactured using fewer parts through simpler assembly steps, and can be configured compactly to be about the same size as a caster.SOLUTION: A cantilevered rotary roller-type circular wheel comprises: a wheel portion; rotors each including a rotary shaft arranged in a plane perpendicular to an axle, and a roller portion supported on the rotary shaft via bearings, and further including a core metal that forms a ring-shaped contact portion centered on the axle; and an arm portion extending radially outward from an outer edge of the wheel portion and cantilever-supporting the rotor on the wheel portion. Therein: the rotary shaft is inclined so that an axial proximal end thereof on a side supported by the arm portion is positioned on an inner diameter side with respect to an axial distal end thereof; the roller portion has an inner peripheral surface with an axial proximal end thereof being larger in diameter than the axial distal end of the rotary shaft; and the arm portion includes an insertion portion that is bent at a middle portion thereof and thereby inserted into the roller portion from the axial proximal end of the roller portion.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a cantilevered rotating roller arrangement type circular wheel. [Background technology]

[0002] Conventionally, a highly maneuverable omnidirectional traveling unit has been proposed that can move in both the rotation direction of the wheel around the axle and the rotation direction of the roller section by applying a cantilevered rotating roller-arranged circular wheel having an annular wheel section that rotates around the axle as an axis and a roller section that is arranged in a ring shape along the outer periphery of the wheel section.

[0003] Patent document 1 describes a wheel with rotating bodies in which multiple rotating bodies that rotate in a direction perpendicular to the straight-ahead direction of the wheel are arranged around the wheel for turning, and each rotating body has a smaller diameter at its tip end than at its base end, so that its circumferential surface forms an arc of the wheel's outer circumference.

[0004] Patent Document 2 describes an omnidirectional wheel whose outer surface is formed by a plurality of rollers and which rotates around an axle rotation axis, and which includes a rotating part that rotates around the axle rotation axis, and a plurality of support parts that are arranged circumferentially around the rotating part and are each attached to the rotating part, and support the plurality of rollers on the rotating part, wherein the plurality of rollers include a plurality of first rollers and a plurality of second rollers that have an outer diameter different from that of the first rollers, and the first rollers and second rollers are arranged alternately in the circumferential direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3682248 [Patent Document 2] Patent Publication No. 2021-75147 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, the tip end of each rotating body is partially inserted into a recess formed in the base end of the adjacent rotating body so that the tip end of each rotating body can be close to the base end of the adjacent rotating body, thereby reducing the gap between adjacent rotating bodies and suppressing wheel rattle.However, there is a problem in that it is not possible to ensure sufficient space for installing bearing arms that support the rotating bodies, and each rotating body cannot be held with sufficient strength, making the entire wheel prone to distortion. In Patent Document 2, each support section has a first arm member that supports one axial end of the first roller and a second arm member that supports the other axial end of the first roller section, and of two circumferentially adjacent support sections, one first arm member and the other second arm member support the corresponding second roller. This makes it possible to support both axial ends of each roller and improve load resistance, but there are issues with the large number of parts and multiple types of rollers, which increase manufacturing costs and make it difficult to reduce the size and diameter.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a cantilevered rotating roller-arranged circular wheel that can be easily manufactured with fewer parts and is capable of rolling smoothly, is compact so as to be about the same size as a caster, and is strong and resistant to distortion. [Means for solving the problem]

[0008] The above object of the present invention can be achieved by the following configuration. [1] A wheel part that rotates around an axle; a rotating body having a rotating shaft disposed in a plane perpendicular to the axle and a roller portion journaled on the rotating shaft via a bearing; an arm portion extending radially outward from an outer edge of the wheel portion and supporting the rotating body on the wheel portion as a cantilever, A cantilevered rotating roller arrangement type circular wheel in which a plurality of the rotating bodies are arranged along the outer edge of the wheel portion to form an annular ground contact portion centered on the axle, the roller portion has a truncated cone-shaped core and a cover portion made of a rubber material or an elastomer and provided on the outer circumferential surface of the core, the rotation shaft is inclined so that an axial base end portion supported by the arm portion is located radially inward relative to an axial tip end portion, the roller portion has an inner circumferential surface whose diameter is larger at a base end in the axial direction than at a tip end in the axial direction of the rotating shaft, The arm portion has a bent intermediate portion, and has an insertion portion that is inserted from the axial base end of the roller portion into the inside of the roller portion. Cantilevered rotating roller-arranged circular wheel. [Effects of the Invention]

[0009] According to the present invention, the gap between adjacent rotating bodies can be reduced, suppressing rattle during operation and enabling the cantilevered rotating roller arrangement circular wheel to be more compact. This reduces manufacturing costs. Furthermore, because the roller portion has a core metal and a cover body, the strength of the cantilevered rotating roller arrangement circular wheel is improved, making it less susceptible to distortion, and it can provide an appropriate frictional force to the roller portion and absorb unevenness in the ground. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an example of a traveling unit equipped with a cantilevered rotating roller-arranged circular wheel according to one embodiment of the present invention. [Figure 2] FIG. 2 is a side view showing a cantilevered rotating roller arrangement type circular wheel. [Figure 3] FIG. 3 is a front view showing a cantilevered rotating roller arrangement type circular wheel. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing the rotor. [Figure 6] FIG. 6 is an exploded perspective view showing the wheel unit of the second embodiment. [Figure 7] FIG. 7 is a perspective view showing a wheel portion of the third embodiment. [Figure 8] FIG. 8 is an exploded perspective view showing the wheel unit of the fourth embodiment. [Figure 9] FIG. 9 is an exploded perspective view showing the wheel unit of the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The configuration of a traveling unit using a cantilevered roller-arranged circular wheel of the present invention will be described below with reference to the accompanying drawings. Each drawing is created for the purpose of explaining the present invention, and the embodiment of the present invention is not limited to the content shown in the drawings.

[0012] 1 is a schematic diagram showing an example of a traveling unit equipped with cantilevered roller-type circular wheels according to one embodiment of the present invention. The traveling unit 1, which may be a traveling cart, wheelchair, or autonomous traveling robot, includes a body 2, cantilevered roller-type circular wheels 10 used as a pair of front and / or rear wheels supporting the body 2, a drive motor 3 that drives the cantilevered roller-type circular wheels 10 to rotate, and an axle 4 driven by the drive motor 3.

[0013] In the traveling unit 1, the cantilevered rotating roller-arranged circular wheels 10 are driven to rotate around the axles 4 by the drive motor 3. This causes the traveling unit 1 to move in the forward and backward directions. The cantilevered rotating roller-arranged circular wheels 10 can also move the traveling unit 1 in a direction perpendicular to the direction of movement caused by the rotation of the axles 4. This allows the traveling unit 1 to move in all directions in a plan view. The propulsion unit 1 may be configured with a pair of cantilevered roller-arranged circular wheels 10, or with only one wheel. The propulsion unit 1 may also be configured without a power source equivalent to the drive motor 3.

[0014] Next, the configuration of the cantilevered rotating roller-arranged circular wheel 10 according to this embodiment will be described with reference to Figures 2 to 5. Figure 2 is a side view of the cantilevered rotating roller-arranged circular wheel. Figure 3 is a front view of the cantilevered rotating roller-arranged circular wheel. Figure 4 is a cross-sectional view taken along line AA in Figure 3. Figure 5 is a cross-sectional view of the rotating body.

[0015] The cantilevered rotating roller-arranged circular wheel 10 has a wheel section 20 through which an axle 4, such as the drive shaft of the traveling unit 1, is inserted, multiple rotating bodies 40 arranged in a line along the outer edge of the wheel section 20, and an arm section 30 that cantilevers the rotating bodies 40 on the wheel section 20. The rotating bodies 40 are supported by a rotating shaft 43 that extends in a plane perpendicular to the axle 4. As a result, the cantilevered roller arrangement type circular wheel 10 forms a wheel outer circumference circle 10A, which is the contact surface centered on the axle 4, along the annular contact area formed by the outer circumferential surfaces of the multiple rotating bodies 40. This configuration can be seen in Figure 2. The wheel outer circumference circle 10A is approximately circular at the center in the width direction where the outer diameter of the cantilevered roller arrangement type circular wheel 10 is greatest.

[0016] The wheel unit 20 has a disk-shaped wheel frame 21, an axle hole 22 formed in the center of the wheel frame 21 and through which the axle 4 is inserted, and a support portion 23 formed on the outer edge of the wheel frame 21. The wheel unit 20 as a whole is formed into a gear shape by the wheel frame 21 and the support portion 23. This configuration can be seen in Figure 2.

[0017] The support portions 23 are protruding pieces formed radially outward from the outer circumferential surface of the wheel frame 21, and are arranged at equal intervals along the circumferential direction. Each support portion 23 has a plane perpendicular to the rotation direction of the wheel portion 20, and a fixing hole 23a formed along the tangential direction of the wheel portion 20. The arm portion 30 is detachably attached and fixed to the support portion 23 using a bolt 35 inserted into the fixing hole 23a and a nut 36. In this embodiment, the support portions 23 are provided at ten locations along the outer circumferential surface of the wheel frame 21.

[0018] The arm portion 30 is a frame-like member that extends in a direction perpendicular to the axle 4 and is bent in a V-shape from the outer edge of the wheel frame 21 radially outward, and supports the rotating body 40 in a cantilevered manner so that it can rotate about its axis. From the base end to the tip end, the arm portion 30 has a base end portion 31, an extension portion 32, an insertion portion 33, and an attachment portion 34. This configuration can be seen in Figures 4 and 5.

[0019] The base end portion 31 is detachably attached to the support portion 23 of the wheel portion 20 using a bolt 35 and a nut 36 . The extension portion 32 extends radially outward from the base end portion 31 in a direction perpendicular to the axle 4, and the axial base end side is inclined inward from the tangent to the wheel outer circumferential circle 10A. The insertion portion 33 is formed by bending the tip of the extension portion 32 , and extends in a direction along the rotation axis 43 , and is inserted into the interior of the rotor 40 . The attachment portion 34 is a portion provided at the tip of the insertion portion 33, and has a plane perpendicular to the extending direction of the rotation shaft 43. The attachment portion 34 is formed with an attachment hole 34a through which the rotation shaft 43 is inserted.

[0020] The rotating body 40 is a roller with built-in bearings that allows the cantilevered rotating roller arrangement circular wheel 10 to move in a direction perpendicular to the driving direction as the axle 4 is driven, and includes a roller portion 41, a bearing 42, and a rotating shaft 43. The outer peripheral surface of the cone-shaped roller portion 41 forms at least a part of the ground contact portion. The bearing 42 is inserted inside the hollow roller portion 41, and the rotating shaft 43 is journaled via the bearing 42. This configuration can be seen in Figure 5.

[0021] The roller portion 41 has a bearing housing 41A that serves as a core metal, and a cover body 41B that covers the entire outer circumferential surface of the bearing housing 41A and forms the outer circumferential surface of the roller portion 41. The bearing housing 41A is a core metal that forms the outer shape of the roller portion 41, which is formed into a cone shape, and is therefore firmly molded using metal, resin, or the like. The core metal is arranged from the tip to the base end of the roller portion 41. This allows the circular shape of the cantilevered rotating roller arrangement circular wheel 10 to be maintained without distortion even if an external load is applied when the cantilevered rotating roller arrangement circular wheel 10 moves forward or backward or turns. The core metal may be integrated with the bearing outer ring. Since the cover body 41B forms the outer peripheral surface of the roller portion 41, a rubber material or elastomer is selected as a material that provides appropriate friction with the ground, road surface, or floor surface that the cantilevered rotating roller arrangement circular wheel 10 comes into contact with. This allows rolling friction to be appropriately transmitted to the rotating body 40 when the cantilevered rotating roller arrangement circular wheel 10 moves straight or turns. The material used for the cover body 41B is not limited to the above, and any wheel material commonly used for industrial casters may be used. In addition, annular grooves 41B1 are provided at predetermined intervals on the outer circumferential surface of the cover body 41B along the rotation direction, which allows the cantilevered roller arrangement type circular wheel 10 to move smoothly in the direction along the axle 4.

[0022] The outer peripheral surface of the roller portion 41 has a uniform circumferential shape so as to approximately coincide with the outer peripheral circle of the cantilevered rotating roller-arranged circular wheel 10. Therefore, the roller portions 41 of the rotating bodies 40 arranged in a row along the outer peripheral surface of the wheel portion 20 form an annular contact portion that coincides with the wheel outer peripheral circle 10A. Specifically, the outer peripheral surface of the roller portion 41 is formed in a truncated cone or cone shape with a radius that increases as the axial base end approaches the wheel portion 20. In other words, the axial base end is formed to have a larger diameter than the axial tip end of the rotating shaft. The roller portion 41 may also have a shape that combines a truncated cone and a barrel shape.

[0023] Similarly to the outer circumferential surface, the inner circumferential surface of the roller unit 41 is formed so that the axial base end has a larger diameter than the axial tip end of the rotating shaft. Specifically, the inner circumferential surface of the roller unit is also formed in a truncated cone or cone shape with a larger radius as the axial base end side approaches the wheel unit 20. As a result, the roller portion 41 is formed in a cone shape with a diameter that decreases toward the tip. An axial fixing hole 40a for fixing the rotating shaft 43 is formed at the tip of the roller portion 41. An opening 40b is formed at the base end of the roller portion 41, through which the arm portion 30 and a part of the tip of the adjacent rotating body 40 are inserted. This configuration can be seen in Figures 4 and 5.

[0024] The rotating shaft 43 extends in a plane perpendicular to the axle 4 and is inclined so that its axial base end is radially inward of the tangent to the wheel outer circumferential circle 10A. Therefore, the axial base end of the rotating shaft 43 is closer to the wheel unit 20, and the axial tip end is closer to the wheel outer circumferential circle 10A. The rotation axis 43 does not coincide with the tangent to the outer circumference of the cantilevered roller arrangement type circular wheel 10, and this tangent changes depending on the relationship between the number of rollers and the roller size. In Figure 4, the inclination is 13°.

[0025] The rotating shaft 43 has a fixing hole 43a formed in the axial direction from the base end. With the rotating shaft 43 inserted into the mounting hole 34a of the mounting portion 34, a fixing bolt 45 is bolted into the fixing hole 43a, whereby the rotating shaft 43 is firmly attached and fixed to the arm portion 30 (mounting portion 34). The base end of the rotating shaft 43 is fixed to the mounting portion 34 of the arm portion 30 with a bolt, so that the rotating shaft 43 is cantilevered along the central axis of the roller portion 41. The rotating shaft 43 is inserted into the inner ring of the bearing 42, thereby supporting the rotating body 40. As a result, the rotating shaft 43 becomes the axis of the rotating body 40. The method of fixing the rotary shaft 43 and the arm portion 30 is not limited to bolting, but may be adhesive or press-fitting. By previously attaching and fixing the rotating body 40 and the arm portion 30 to form a unit, it is possible to eliminate the process of attaching and detaching the rotating body 40 to the wheel portion 20. This configuration can be seen in FIGS. 4 and 5.

[0026] The bearing 42 is a deep groove ball bearing having an inner ring, an outer ring, balls disposed between the inner ring and the outer ring, and a cage (not shown). A rotating shaft 43 is inserted and supported in the inner ring, and the outer ring is fitted and fixed inside the rotating body 40. This allows the roller portion 41 to rotate smoothly around the rotating shaft 43. Furthermore, a pair of bearings 42 are provided inside the roller portion 41, aligned in the axial direction of the rotary shaft 43. This allows the roller portion 41 to be supported on the rotary shaft 43 without rattle. The bearing 42 is not limited to the deep groove ball bearing described above, but may be replaced with a configuration that rotatably supports a rotating body, such as a cam follower or other bearing that is integrated with the shaft (rotating shaft 43), or a sliding bearing.

[0027] Furthermore, the method of fixing roller portion 41 to rotating shaft 43 is not limited to the above. For example, the inner ring side of bearing 42 that supports roller portion 41 may be integrated with arm portion 30, thereby eliminating rotating shaft 43. Furthermore, the method of fixing the member on the inner ring side of bearing 42 to rotating shaft 43 may be a method of fixing with a fixing screw, or a method of caulking a rivet or a shaft. The bearings 42 supporting the roller portion 41 are preferably configured to be arranged in two axial rows to apply preload as in this embodiment, but they may also be configured as double-row ball bearings, as in cross roller bearings with staggered roller arrangements, or as in four-point contact ball bearings where a preload structure is achieved with a single bearing. In addition, by providing an axial groove (not shown) in the rotating shaft 43 on the inner ring side of the bearing 42 or in the roller portion 41 itself, the inner ring of the bearing 42 and the rotating shaft 43 may be integrated, or the outer ring of the bearing 42 may be integrated with the roller portion 41.

[0028] Next, a method for assembling the cantilevered rotating roller arrangement type circular wheel 10 and a specific arrangement configuration of the rotating body 40 in the cantilevered rotating roller arrangement type circular wheel 10 will be described with reference to FIGS. The cantilevered rotating roller arrangement type circular wheel 10 can be assembled by bolting the arm parts 30, to which the rotating bodies 40 are attached, to each of the multiple support parts 23 (ten in the illustrated example) arranged in a row on the outer circumferential surface of the wheel frame 21. In addition to bolts, other fixing methods such as press fitting, caulking, riveting, and welding may also be used.

[0029] Each rotating body 40 has a rotating shaft 43 that supports a roller portion 41 formed in a truncated cone shape, and each rotating shaft 43 is arranged side by side on the outer periphery of the wheel portion 20 with its axial tip end closer to the wheel outer circumferential circle 10A than its axial base end and its axial base end tilted toward the inner diameter side closer to the wheel portion 20 than its axial tip end. Specifically, the rotating shaft 43 is approximately parallel to a tangent to the roller portion 41 at its axial base end. At this time, a part of the radially inner side of the tip end of the rotor 40 is inserted into the opening 40b of the base end of the adjacent rotor 40. As a result, a second radial gap h2 formed between an inner diameter side end of the outer peripheral surface of the roller portion 41 and an adjacent inner diameter side end of the base end of the outer peripheral surface of the roller portion 41 is larger than a first circumferential gap h1 formed between an outer diameter side end of the tip end of the outer peripheral surface of the roller portion 41 and an outer diameter side end of the adjacent base end of the outer peripheral surface of the roller portion 41. This configuration can be seen in FIG.

[0030] This configuration minimizes the first gap h1, which reduces vibrations and rattles caused by the gap (first gap h1) between adjacent rotating bodies 40 when the cantilevered rotating roller arrangement type circular wheel moves forward or backward. In this embodiment, the first gap h1 is formed to be approximately the same as the width of a circumferential groove 41B1 formed in the cover body 41B of the rotor 40, or equal to or smaller than the width of the groove 41B1.

[0031] Furthermore, since the second gap h2 is large, sufficient space can be secured radially inside the second gap h2 to arrange the arm unit 30. This makes it possible to smoothly attach and detach the arm unit 30 (rotating body 40) to and from the wheel unit 20. Furthermore, by increasing the second gap h2, the arm portion 30 can be made sufficiently thick to increase its strength. The external shape of the cantilevered roller arrangement circular wheel 10 is maintained, which results in more stable driving of the cantilevered roller arrangement circular wheel 10.

[0032] In addition, by making a portion of the radially inner side of the tip end of the rotating body 40 fit into the opening 40b of the base end of the adjacent rotating body 40, the truncated cone-shaped rotating body 40 can be contained within the wheel outer circumference circle 10A, while the outer surface of the roller portion 41 of each rotating body 40 can be made to approximately coincide with the wheel outer circumference circle 10A.

[0033] Furthermore, the rotating body 40 formed in a truncated cone shape is disposed along the outer circumferential surface of the wheel portion 20 and is journaled on a rotating shaft 43 extending in a direction perpendicular to the axle 4, so that the outer circumferential cross section of the rotating body 40 forms the wheel circumference across the width of the cantilevered rotating roller-arranged circular wheel 10 and is disposed so as not to protrude at least in the radial direction. This configuration can be seen in Figure 2.

[0034] In the example described above, ten rotating bodies 40 are arranged along the outer periphery of the wheel unit 20, but the number of rotating bodies 40 is not limited to this. Increasing the number of rotating bodies 40 can reduce the inclination between the rotation axis 43 and the tangent to the outer periphery of the cantilevered rotating roller-arranged circular wheel 10. This allows the second gap h2 to be made wider, ensuring space for arranging an arm unit 30 that is formed thicker in the radial direction.

[0035] (Second embodiment) Next, a second embodiment of a wheel unit constituting a cantilevered roller-arranged circular wheel will be described with reference to Fig. 6. Fig. 6 is an exploded perspective view showing the wheel unit of the second embodiment. Some bolts have been omitted.

[0036] The wheel unit 61 has a wheel frame 62 in the shape of a polygonal disc (a decagon in this embodiment), and a pair of plates 63 formed in the shape of a disk that is slightly larger than the wheel frame 62 and that sandwich the wheel frame 62. A separate arm unit 64 is attached and fixed to the wheel frame 62.

[0037] The wheel frame 62 has an axial hole 62A, a support portion 62B formed on the outer edge of the wheel frame and against which the base end of the arm portion 64 abuts, and a fixing hole 62C for fixing the plate 63 to the side of the wheel frame 62.

[0038] The plate 63 has a flat surface facing the axial direction of the axle 4, and is provided with an axle hole 63A formed in the center, a frame fixing hole 63B for fixing to the wheel frame 62, and an arm fixing hole 63C for fixing the arm portion 64 provided on the support portion 62B. As shown in Fig. 6, the plate 63 is attached to the wheel frame 62 side using fixing bolts 65 inserted through the frame fixing hole 63B and the fixing hole 62C on the wheel frame 62 side.

[0039] The arm portion 64 is a frame-like member that extends from its base end in a direction perpendicular to the axle 4 and bends in a U-shape radially outward from the outer edge of the wheel frame 62. The base end of the arm portion 64 has a first abutment portion 64A that abuts against the support portion 62B of the wheel frame 62, a pair of second abutment portions 64B that are flat surfaces formed upright in the radial direction from the first abutment portion 64A, and a third abutment portion 64C that abuts against the plate 63, and a fixing hole 64C1 for fixing the plate 63 with a bolt is formed in the third abutment portion 64C.

[0040] The first contact portion 64A can receive a load applied in the radial direction of the wheel from the ground by coming into contact with the support portion 62B of the wheel frame 62. The first contact portion 64A has an end face that is approximately perpendicular to the radial load applied to the roller portion 41, so that the load can be received evenly. Therefore, the load applied to the roller portion 41 is transmitted to the first contact portion 64A, and therefore a decrease in the support rigidity of the arm portion 64 when the arm portion 64 and the wheel frame 62 are formed as separate members can be suppressed. The first contact portion 64A is preferably flat in terms of processing and load, but may be arcuate or have other shapes. The positional relationship between the arm portion 64 and the roller portion 41 is such that it is tangent to the range (perpendicular to the load direction) assuming that a radial load is applied to the arc portion of the outermost circle of the roller portion 41. It is desirable that the first contact portion 64A be a plane perpendicular to the wheel portion 61 or the wheel axle. This allows the roller portion 41 to receive the load evenly in the vehicle width direction. This is also convenient for processing and improves the uniformity of the plane, which results in smoother load transmission.

[0041] A pair of second contact portions 64B are provided to sandwich the first contact portion 64A in the front-to-rear direction, which is the direction of travel of the wheel. The second contact portions 64B, 64B are configured to come into surface contact with the second contact portions 64B of adjacent arm portions 64 in the direction in which the arm portion 64 swings clockwise / counterclockwise as the wheel is driven, and to bear the load of each other. The second contact portion 64B may be parallel to the radial direction of the wheel frame 62, or may be angled relative to the radial direction of the wheel frame 62. When the second contact portion 64B is angled with respect to the radial direction of the wheel frame 62, the second contact portion 64B can receive part of the load applied to the wheel together with the first contact portion 64A. The pair of second contact portions 64B, 64B may be wedge-shaped relative to each other. It is desirable that the second contact portion 64B be a plane perpendicular to the wheel portion 61 or the wheel axle. This allows the roller portion 41 to receive the load evenly in the vehicle width direction. This is also convenient for processing and improves the uniformity of the plane, which results in smoother load transmission.

[0042] The third contact portion 64C has a flat surface to which the plate 63 can be fixed with a bolt. The first contact portion 64A (and second contact portion 64B) prevents the application of loads in the rotational direction of the wheel or in the radial direction to the fixing bolt 66 in the axle direction, thereby preventing the fixing bolt 66 from breaking. The fixing bolt 66 is fixed by tension and friction on the bolt end face, but other fastening means such as rivets may be used instead of bolt fixing. The third contact portion 64C and the plate 63 may be joined by welding. Also, the arm portion 64 and the wheel frame 62 may be joined by welding.

[0043] The first contact portion 64A and the second contact portion 64B are preferably flat surfaces that come into contact with each other, but may also be formed as slots (not shown) that are fitted into each other.

[0044] In this embodiment, it is desirable to provide an arm portion 64 for each of a plurality of roller portions 41 of the same shape, but this may also be applied to roller portions 41 of a plurality of shapes. For example, two types of roller portions 41 may be supported by one arm portion 64. In this case, the end face shapes and positions of the first contact portion 64A and the second contact portion 64B are appropriately determined taking into consideration the direction of the external force acting on the two roller portions 41.

[0045] (Third embodiment) Next, differences from the above-mentioned examples of a third embodiment of a wheel unit constituting a cantilevered rotating roller arrangement type circular wheel will be described with reference to Fig. 7. Fig. 7 is a perspective view showing the wheel unit of the third embodiment.

[0046] The wheel portion 71 has a disk-shaped wheel frame 71A, a shaft hole 71B, and an arm portion 74 extending radially outward from the outer edge of the wheel frame 71A. The arm portion 74 is molded integrally with the wheel frame 71A.

[0047] The arm portion 74 is a frame-like member that extends in a direction perpendicular to the axle 4 and is bent in a U-shape from the outer edge of the wheel frame 71A outward in the radial direction.

[0048] According to this configuration, the wheel frame 71A and the arm portion 74 are molded integrally, which improves the strength of the arm portion 74. In addition, the assembly work of the arm portion 74 can be simplified, which reduces the manufacturing cost of the cantilevered roller-arranged circular wheel.

[0049] (Fourth embodiment) Next, the differences between a fourth embodiment of a wheel unit constituting a cantilevered roller arrangement type circular wheel and the third embodiment will be described with reference to Fig. 8. Fig. 8 is an exploded perspective view showing the wheel unit of the fourth embodiment.

[0050] The wheel portion 81 of the fourth embodiment has a pair of split wheel portions 82, 82 obtained by splitting the wheel portion 71 of the third embodiment in two on a plane perpendicular to the axle 4, and a cylindrical portion 83 having an axial hole 83A.

[0051] Each split wheel portion 82, 82 has a disk-shaped wheel frame 82A, a mounting hole 82B formed in the center of the wheel frame 82A into which the cylindrical portion 83 is fitted, and an arm portion 84 extending radially outward from the outer edge of the wheel frame 82A. The arm portion 84 is molded integrally with the wheel frame 82A.

[0052] The arm portion 84 is a frame-like member that extends in a direction perpendicular to the axle 4 and is bent in a U-shape from the outer edge of the wheel frame 82A outward in the radial direction.

[0053] According to this configuration, the wheel portion 81 can be assembled by bolting the pair of split wheel portions 82, 82 and the cylindrical portion 83 together in an axially overlapping state with the phase of the arm portion 84 shifted. The method for fastening the components is not limited to bolt fastening, and any method that can firmly fasten the components may be used, such as riveting or welding. As described above, the assembly work of the cantilevered rotating roller arrangement type circular wheel having the wheel portion 81 can be simplified, and therefore the manufacturing cost can be reduced.

[0054] (Fifth embodiment) Next, the differences between a fifth embodiment of a wheel unit constituting a cantilevered roller arrangement type circular wheel and the third embodiment will be described with reference to Fig. 9. Fig. 9 is an exploded perspective view showing the wheel unit of the fifth embodiment.

[0055] The wheel unit 91 has a disk-shaped wheel frame 92 and a detachable arm unit 95 . The wheel frame 92 has an axial hole 92A and a fixed arm portion 94 extending radially outward from the outer edge of the wheel frame 92. The fixed arm portion 94 is integrally formed with the wheel frame 92.

[0056] The fixed arm portion 94 is a frame-like member that extends in a direction perpendicular to the axle 4 and bends in a U-shape from the outer edge of the wheel frame 92 outward in the radial direction. The number of fixed arm portions 94 formed integrally with the wheel frame 92 is one less than the number of rotating bodies attached to the cantilevered rotating roller arrangement type circular wheel.

[0057] The detachable arm portion 95 is detachably fastened to an attachment portion 93 formed on the outer edge of the wheel frame 92 in a portion where the fixed arm portion 94 is not provided, using a fixing bolt 96 whose base end extends in the axial direction of the axle 4.

[0058] According to this configuration, the wheel unit 91 can be assembled by stacking the wheel frame 92 and the detachable arm unit 95 in the axial direction and fastening them with the fixing bolts 96. The method for fastening the components is not limited to bolt fastening, and any method that can firmly fasten them, such as riveting or welding, can be used. As described above, the assembly of the roller portion 41, which is difficult to assemble in the third embodiment, can be simplified. The configuration of the arm portion 64 of the second embodiment shown in FIG.

[0059] As described above, the present specification discloses the following: (1) A wheel portion that rotates around an axle; a rotating body having a rotating shaft disposed in a plane perpendicular to the axle and a roller portion journaled on the rotating shaft via a bearing; an arm portion extending radially outward from an outer edge of the wheel portion and supporting the rotating body on the wheel portion as a cantilever, A cantilevered rotating roller arrangement type circular wheel in which a plurality of the rotating bodies are arranged along the outer edge of the wheel portion to form an annular ground contact portion centered on the axle, the roller portion has a truncated cone-shaped core and a cover portion made of a rubber material or an elastomer and provided on the outer circumferential surface of the core, the rotation shaft is inclined so that an axial base end portion supported by the arm portion is located radially inward relative to an axial tip end portion, the roller portion has an inner circumferential surface whose diameter is larger at a base end in the axial direction than at a tip end in the axial direction of the rotating shaft, The arm portion has a bent intermediate portion, and has an insertion portion that is inserted from the axial base end of the roller portion into the inside of the roller portion. Cantilevered rotating roller-arranged circular wheel. This configuration reduces the gap between adjacent rotating bodies, suppressing rattle during operation and enabling a more compact cantilevered roller-arranged circular wheel. Furthermore, by using rollers with the same shape around the entire outer edge of the wheel, a ring-shaped ground contact area can be formed along the wheel's outer circumference, reducing the number of different parts and simplifying the assembly process. This reduces manufacturing costs. Furthermore, because the rollers have a core and a cover, the strength of the cantilevered roller-arranged circular wheel is improved, making it less susceptible to distortion, and providing the rollers with an appropriate frictional force to absorb uneven ground surfaces.

[0060] (2) A plurality of the rotating bodies have the same shape. (1) A cantilevered rotating roller arrangement type circular wheel. This configuration reduces the number and variety of parts, making it possible to keep manufacturing costs low and facilitating assembly. It also allows for the roller-arranged circular wheel to be made smaller in size and diameter.

[0061] (3) The arm portion and the wheel portion are configured as separate bodies. A cantilevered rotating roller arrangement type circular wheel according to (1) or (2). This configuration facilitates maintenance work on the rotating body.

[0062] (4) The wheel portion has a polygonal wheel frame whose outer edge abuts against the base end of the arm portion. A cantilevered rotating roller arrangement type circular wheel according to any one of (1) to (3). According to this configuration, the radial load transmitted to the wheel portion via the rotating body can be efficiently received by the wheel frame.

[0063] (5) The wheel portion is formed in a disk shape that is slightly larger than the wheel frame and has at least one plate that abuts against a side surface of the wheel frame, The plate is formed with an axle hole through which the axle is inserted, a frame fixing hole for fixing the plate to the wheel frame, and an arm fixing hole for fixing the arm portion. (4) A cantilevered rotating roller arrangement type circular wheel. According to this configuration, the arm portion can be easily and firmly attached to the wheel frame.

[0064] (6) The base end of the arm portion has a first contact portion that contacts the outer edge of the wheel frame and a second contact portion that contacts the adjacent arm portion at the outer edge of the wheel frame. A cantilevered rotating roller arrangement type circular wheel according to (4) or (5). According to this configuration, the load applied to the wheel can be distributed to the adjacent arm portions while being received, thereby making the wheel drive more stable.

[0065] (7) The arm portion is integrally molded with the wheel portion. A cantilevered rotating roller arrangement type circular wheel according to (1) or (2). This configuration makes it possible to make the arm stronger, which makes the cantilevered roller-arranged circular wheel less susceptible to distortion and stabilizes its running. Furthermore, the number of components and assembly steps that make up the cantilevered roller-arranged circular wheel can be reduced, thereby keeping manufacturing costs low.

[0066] (8) With respect to the gaps formed between the tip end portions of the adjacent rotors and the base end portions of the rotors adjacent to the tip end portions of the rotors, a second radial gap formed on the radial inner side is larger than a first circumferential gap formed on the radial outer side. A cantilevered rotating roller arrangement type circular wheel according to any one of (1) to (7). According to this configuration, the arm portion inserted into the second gap can be formed thicker, so the cantilevered rotating roller arrangement type circular wheel is less likely to be distorted, resulting in stable running. [Explanation of symbols]

[0067] 1. Traveling unit 2. Body 3 Drive motor 4 axles 10. Cantilevered rotating roller arrangement circular wheel 10A Wheel circumference 20 Wheel section 21 Wheel Frame 22 Shaft hole 23 Support part 23a Fixing hole 30 Arm section 31 Proximal end 32 Extension 33 Insertion part 34 Mounting part 34a Mounting hole 35 volts 36 Nut 40 Rotating Body 40a fixing hole 40b opening 41 Roller section 41A bearing housing 41B Cover body 41B1 Groove 42 Bearings 43 Rotation axis 43a fixing hole 45 Fixing bolt 61 Wheel section 62 Wheel Frame 62A shaft hole 62B Support part 62C fixing hole 63 Plate 63A shaft hole 63B Frame fixing hole 63C Arm fixing hole 64 Arm section 64A 1st contact part 64B 2nd contact part 64C 3rd contact part 64C1 Fixed hole 65 Fixing bolt 66 Fixing bolt 71 Wheel section 71A Wheel Frame 71B Shaft hole 74 Arm section 81 Wheel section 82 Split wheel section 82A Wheel Frame 82B Mounting hole 83 Cylindrical part 83A shaft hole 84 Arm section 91 Wheel section 92 Wheel Frame 92A shaft hole 94 Fixed arm part 95 Detachable arm 96 Fixing bolt h1 First gap h2 Second gap

Claims

1. A wheel part that rotates around an axle; a rotating body having a rotating shaft disposed in a plane perpendicular to the axle and a roller portion journaled on the rotating shaft via a bearing; an arm portion extending radially outward from an outer edge of the wheel portion and supporting the rotating body on the wheel portion as a cantilever, A cantilevered rotating roller arrangement type circular wheel in which a plurality of the rotating bodies are arranged along the outer edge of the wheel portion to form an annular ground contact portion centered on the axle, the roller portion has a truncated cone-shaped core and a cover portion made of a rubber material or an elastomer and provided on the outer circumferential surface of the core, the rotation shaft is inclined so that an axial base end portion supported by the arm portion is located radially inward relative to an axial tip end portion, the roller portion has an inner circumferential surface whose diameter is larger at a base end in the axial direction than at a tip end in the axial direction of the rotating shaft, The arm portion has a bent intermediate portion, and has an insertion portion that is inserted from the axial base end of the roller portion into the inside of the roller portion. Cantilevered rotating roller-arranged circular wheel.

2. A plurality of the rotating bodies have the same shape, 2. The cantilevered rotating roller arrangement type circular wheel according to claim 1.

3. The arm portion and the wheel portion are configured as separate bodies.

2. The cantilevered rotating roller arrangement type circular wheel according to claim 1.

4. The wheel portion has a polygonal wheel frame whose outer edge abuts against the base end of the arm portion.

4. The cantilevered rotating roller arrangement type circular wheel according to claim 3.

5. the wheel portion is formed in a disk shape that is slightly larger than the wheel frame and has at least one plate that abuts against a side surface of the wheel frame; The plate is formed with an axle hole through which the axle is inserted, a frame fixing hole for fixing to the wheel frame, and an arm fixing hole for fixing the arm portion.

5. A cantilevered rotating roller arrangement type circular wheel according to claim 4.

6. The base end of the arm portion has a first abutment portion that abuts against the outer edge of the wheel frame and a second abutment portion that abuts against the adjacent arm portion at the outer edge of the wheel frame.

6. A cantilevered rotating roller arrangement type circular wheel according to claim 5.

7. The arm portion is integrally molded with the wheel portion.

2. The cantilevered rotating roller arrangement type circular wheel according to claim 1.

8. Among the adjacent rotating bodies, a gap formed between a tip end portion of one rotating body and a base end portion of another rotating body adjacent to the tip end portion of the rotating body is such that a second radial gap formed on a radially inner side is larger than a first circumferential gap formed on a radially outer side. A cantilevered rotating roller arrangement type circular wheel according to any one of claims 1 to 7.

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