Drive roller

Abstract

This makes it easier to connect the power source to the outer casing and reduces the load on the outer casing. [Solution] A drive roller comprising: an output shaft that rotates by receiving driving force from a drive source housed in an outer cylinder; an outer joint that abuts against the inner circumference of the outer cylinder and has a housing space in its center; and an inner joint connected to the output shaft and housed in the housing space. The outer joint comprises a plurality of inner circumferential recesses with a large inner diameter and a plurality of inner circumferential protrusions with a small inner diameter arranged between the plurality of inner circumferential recesses; the inner joint comprises a plurality of outer circumferential recesses having an outer diameter smaller than the inner diameter of the inner circumferential protrusions and having an outer diameter smaller than the inner diameter of the inner circumferential protrusions and arranged between the plurality of outer circumferential recesses and having an outer diameter larger than the inner diameter of the inner circumferential protrusions; and a shaft hole into which the output shaft is inserted. When the outer circumferential protrusions and the inner circumferential protrusions are aligned, the outer joint is pressed outward by the inner joint, and the outer joint is pressed against the inner circumference of the outer cylinder and fixed in place.

Description

Technical Field

[0001] The present disclosure relates to a drive roller used for roller conveyance.

Background Art

[0002] In a drive roller with a built-in power source, since power is transmitted from a power source that does not rotate itself to the outer cylinder, a joint that connects the output shaft and the outer cylinder is used. As prior art using such a joint member, for example, the techniques described in Patent Document 1 and Patent Document 2 below can be cited.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, in a drive roller having a drive source provided inside the outer cylinder, a joint member that connects the output shaft and the outer cylinder has been press-fitted into the outer cylinder by applying a force in the longitudinal direction. However, in this case, when press-fitting, it is often necessary to move a relatively long distance while applying an inner pressure to the outer cylinder by the joint member. Therefore, not only does it take time to attach the joint, but it also places a burden on the joint member and the outer cylinder. When a burden is placed on the joint member or the outer cylinder, the durable torque may decrease due to deformation and wear. In addition, in order to eliminate such a possibility, for example, when measures such as caulking are used in combination, there is a problem that the manufacturing becomes time-consuming.

[0005] This disclosure aims to facilitate the installation of an output joint in a drive roller and reduce the load on the output joint and the outer cylinder. [Means for solving the problem]

[0006] Aspects of the present disclosure are a drive roller comprising: an outer cylinder; a drive source housed in the outer cylinder and rotating the outer cylinder about an axis; an output shaft that rotates by receiving a driving force from the drive source; a substantially cylindrical outer joint that abuts against the inner circumference of the outer cylinder and has a housing space in its center; and a substantially cylindrical inner joint connected to the output shaft and housed in the housing space, wherein the outer joint comprises a plurality of inner circumferential recesses having a relatively large inner diameter and arranged at intervals along the inner circumference in the housing space, and a plurality of inner circumferential protrusions having a relatively small inner diameter and arranged between the plurality of inner circumferential recesses in the housing space, and the inner joint comprises the inner circumferential protrusions The inner joint has an outer diameter smaller than the inner diameter and is arranged at intervals along the outer circumference, and has a plurality of outer circumferential recesses having an outer diameter smaller than the inner diameter of the inner circumferential recesses and larger than the inner diameter of the inner circumferential protrusions, and is arranged between the plurality of outer circumferential recesses, each of which can be accommodated in each of the inner circumferential recesses, and has an axial hole into which the output shaft is inserted. Starting from a state in which each of the outer circumferential protrusions is accommodated in each of the inner circumferential recesses, the inner joint is rotated relative to the outer joint about its axis so that the outer circumferential protrusions and the inner circumferential protrusions are aligned, and the outer joint is pressed outward by the inner joint, thereby pressing the outer joint against the inner circumference of the outer cylinder and fixing it in place.

[0007] With the above configuration, it is easy to move the outer joint to the desired connection position. Furthermore, by first aligning the outer circumferential protrusion of the inner joint with the inner circumferential recess of the outer joint, it is easy to position the inner joint at the location of the outer joint. Moreover, by rotating the inner joint relative to the outer joint at that position, the outer circumferential protrusion aligns with the inner circumferential protrusion of the outer joint and presses it outward, thereby fixing the outer joint to the inner circumference of the outer cylinder. Note that the inner circumferential protrusions and recesses are arranged alternately in multiple locations, preferably three or more. Similarly, the outer circumferential protrusions and recesses are also arranged alternately in multiple locations, preferably three or more.

[0008] In the above-described drive roller, it is desirable that a notch be formed at one location on the outer circumference of the outer joint. This configuration facilitates outward deformation of the outer joint due to pressure from the inner joint.

[0009] In the above-described drive roller, it is desirable that there are multiple reduced-diameter portions on the outer circumference of the outer joint, where the outer diameter is reduced. Furthermore, it is desirable that these reduced-diameter portions are formed at locations corresponding to the inner circumference protrusions. This configuration facilitates outward deformation of the outer joint due to pressure from the inner joint.

[0010] In the above-described drive roller, the inner diameter of the inner circumferential protrusion may be gradually reduced along one side in the circumferential direction. This configuration allows for appropriate adjustment of the outward pressing force by rotating the inner joint relative to the outer joint.

[0011] In the above-described drive roller, it is desirable to have a structure that prevents relative rotation between the outer joint and the inner joint. Furthermore, it is desirable that this structure includes a locking projection formed on the outer joint and a locking step formed on the inner joint with which the locking projection engages. This configuration makes it possible to maintain the pressing state of the inner joint against the outer joint.

[0012] In the above-described drive roller, when the inner joint is housed in the outer joint, it is desirable that the locking projection and the locking step are located at different positions along the axial direction from the housing space. With this configuration, the outward pressing action by the outer peripheral projection onto the inner peripheral projection and the engagement action between the locking projection and the locking step occur at different positions, and these actions do not interfere with each other. [Effects of the Invention]

[0013] As the embodiments of this disclosure are configured as described above, it is possible to facilitate the installation of the output joint, which consists of an outer joint and an inner joint, and to reduce the load on the output joint and the outer cylinder. [Brief explanation of the drawing]

[0014] [Figure 1] This is a front perspective view showing the appearance of the drive roller of the embodiment. [Figure 2] Figure 1 is a front perspective view of the drive roller, with the outer cylinder shown as transparent. [Figure 3] This is a front perspective view of the outer joint and inner joint used in the drive roller of the embodiment. [Figure 4] This is a rear view of the outer joint. [Figure 5] This is a rear view of the outer joint. [Figure 6] This is a front view of the outer joint. [Figure 7] This is a rear view of the inner joint. [Figure 8] It is a rear view of the inner joint. [Figure 9] It is a front view of the inner joint. [Figure 10] It is a front perspective view of the outer cylinder. [Figure 11] It is a front perspective view showing the state where the outer joint is inserted into the outer cylinder. [Figure 12] It is a front perspective view showing the state where the inner joint is further inserted from the state of FIG. 9. [Figure 13] It is a front view showing the state before fastening between the inner joint and the outer joint. [Figure 14] It is a rear view showing the state before fastening between the inner joint and the outer joint. [Figure 15] It is a rear perspective view showing the state before fastening between the inner joint and the outer joint. [Figure 16] It is a rear perspective view showing the state during fastening between the inner joint and the outer joint. [Figure 17] It is a front view showing the state after fastening between the inner joint and the outer joint. [Figure 18] It is a rear view showing the state after fastening between the inner joint and the outer joint. [Figure 19] It is a rear perspective view showing the state after fastening between the inner joint and the outer joint. [Figure 20] It is a front perspective view showing the member inserted into the state of FIG. 12. [Figure 21] It is a rear view of the outer joint of the first modification. [Figure 22] It is a schematic view showing the second modification in a rear view. [Figure 23] It is a schematic view showing the third modification in a rear view.

Embodiments for Carrying Out the Invention

[0015] Embodiments of this disclosure will be described below with reference to the drawings. The drawings referred to below are schematic representations for illustrative purposes and do not necessarily accurately represent the dimensions and proportions of the actual product. Furthermore, reference numerals commonly used in each drawing indicate common components, parts, or configurations, even if not specifically mentioned in the description of each drawing.

[0016] In this disclosure, the direction in which the output shaft 41 protrudes from the drive source 40 (see Figure 20) is defined as "front," and the opposite direction is defined as "rear." Furthermore, for each component, the end or surface located on the front side is defined as the "front end," and the end or surface located on the rear side is defined as the "rear end." Specifically, the left side in Figures 1-3, 10-12, and 20, the lower side in Figures 4, 7, 15, 16, and 19, the far side in Figures 5, 8, 14, 18, and 21, and the front side in Figures 6, 9, 13, and 17 are defined as "front," and the opposite side is defined as "rear."

[0017] Furthermore, the term "inner diameter" as used in this disclosure refers to the diameter of the inscribed circle around multiple points, and the term "outer diameter" refers to the diameter of the circumscribed circle around multiple points. Therefore, the areas where "inner diameter" or "outer diameter" is mentioned do not necessarily exhibit an arc-shaped curved surface.

[0018] (1) Exterior Figure 1 is a front perspective view showing the external appearance of the drive roller 10 of this embodiment. The drive roller 10 has an external appearance in which a front bracket 14 is attached to the front end of a cylindrical outer cylinder 11 and a rear bracket 15 is attached to the rear end. A front shaft 12 protrudes forward from the axis of the front bracket 14. A rear shaft 13 protrudes rearward from the axis of the rear bracket 15. A connector 16 is provided through the rear shaft 13 to supply power and control information to the drive source 40 (see Figure 2).

[0019] (2) Internal structure Figure 2 is a front perspective view of the drive roller 10 in Figure 1, with the outer cylinder 11 shown transparently. A drive source 40, consisting of a motor, is located slightly forward of the middle portion inside the outer cylinder 11. The drive source 40 may also include a reduction mechanism in addition to the motor. A circuit board holder 42, on which the motor circuit board 43 is mounted, is interposed between the rear end of the drive source 40 and the rear bracket 15. On the other hand, an output shaft 41 protrudes from the front of the drive source 40. The output shaft 41 is inserted into the axis of the inner joint 30. The inner joint 30 is housed in the center of the outer joint 20. In other words, the inner joint 30 and the outer joint 20 are interposed between the output shaft 41 and the outer cylinder 11.

[0020] The outer joint 20 is pressed outward by the inner joint 30 housed inside it, as described later, thereby pressing the outer cylinder 11 from the inside outward and fixing it to the outer cylinder 11. The front bracket 14 and rear bracket 15 are press-fitted to the front and rear ends of the outer cylinder 11, respectively. The front shaft 12 and rear shaft 13 are fixed to bearings (not shown) and do not rotate. The drive source 40 and the substrate holder 42 also do not rotate.

[0021] On the other hand, the front bracket 14 and the rear bracket 15 each have ball bearings (not shown) interposed between them and the front shaft 12 and the rear shaft 13, respectively, allowing them to rotate freely relative to the front shaft 12 and the rear shaft 13. As a result, when the output shaft 41, powered by the drive source 40, rotates, the outer cylinder 11 rotates freely relative to the front shaft 12 and the rear shaft 13 via the inner joint 30 and the outer joint 20.

[0022] (3) Outer joint 20 and inner joint 30 Figure 3 is a front perspective view of the outer joint 20 and inner joint 30 used in the drive roller 10 of this embodiment. The outer joint 20 has a substantially cylindrical shape with a housing space 21 in the center. The inner joint 30 has a substantially cylindrical insertion part 31 that is inserted into the housing space 21, and a disc-shaped flange part 32 behind it. A shaft hole 35 with multiple grooves formed inside passes through the center of the inner joint 30. A part of the outer circumference of the flange part 32 is a notched sliding part 34.

[0023] Figures 4, 5, and 6 are rear perspective, rear view, and front view, respectively, of the outer joint 20. The outer joint 20 is made of metal and is formed into the shape shown in each figure by known forming methods such as cutting or sintering. The outer joint 20 has a substantially cylindrical appearance with four D-cuts evenly spaced on its outer circumference. These four D-cuts form a reduced-diameter section 25 where the outer diameter is reduced. The outer diameter of the outer joint 20 other than the reduced-diameter section 25 is approximately the same as the inner diameter of the outer cylinder 11 shown in Figure 10, but is formed to be slightly smaller so that it can be inserted into the outer cylinder 11 without requiring any special pressure. Note that the reduced-diameter section 25 is not limited to the D-cuts shown; for example, a groove along the axial direction may be formed on the outer circumference.

[0024] A roughly "+" shaped through-hole is formed in the center of the outer joint 20. This through-hole is the housing space 21. The housing space 21 has four inner circumferential recesses 22 with relatively large inner diameters and four inner circumferential protrusions 23 with relatively small inner diameters, which are alternately and equally distributed. The reduced diameter portion 25 is formed at a position corresponding to the inner circumferential protrusion 23. In addition, an open portion 24, which is a notch that connects the inside and outside of the housing space 21, is formed in one of the inner circumferential recesses 22. Due to the formation of this open portion 24, the outer joint 20 has a roughly C shape when viewed from the front and rear (see Figures 5 and 6).

[0025] A locking projection 26 is formed on one of the locations where the inner circumferential protrusion 23 is located on the rear side of the outer joint 20. Specifically, in a rear view (see Figure 5), the locking projection 26 is located to the left of the inner circumferential recess 22 facing the opening 24. As shown in Figure 5, the locking projection 26 has a roughly trapezoidal shape with the shorter side being the center and the longer side being the edge. Of the corners on the shorter side, the right-hand corner in a rear view is chamfered, and this portion is the sliding corner 26A.

[0026] Figures 7, 8, and 9 are rear perspective, rear view, and front view, respectively, of the inner joint 30. The inner joint 30 is made of metal and is formed into the shape shown in each figure by known forming methods such as cutting or sintering. The inner joint 30 has a substantially cylindrical insertion portion 31 located on the front side, a disc-shaped flange portion 32 located behind it with a larger outer diameter than the insertion portion 31, and a cylindrical shaft guide 33 that protrudes rearward from its center and has an inner diameter into which the output shaft 41 (see Figure 20) can be inserted. From the tip of the shaft guide 33 to the tip of the insertion portion 31, a shaft hole 35 into which the output shaft 41 is inserted passes through the center. The outer diameter of the flange portion 32 is smaller than the outer diameter of the outer joint 20, but larger than the inner diameter of the inner circumferential protrusion portion 23.

[0027] A sliding portion 34, which is cut inward, is formed on a part of the circumference of the flange portion 32. Both ends of the sliding portion 34 form a step between them and the circumference of the flange portion 32. Of these steps, the one located on the right when viewed from the rear (see Figure 8) is the locking step 34A, and the one located on the left is the guide step 34C. In addition, a small outwardly protruding projection, a check projection 34B, is formed near the locking step 34A (specifically, at a distance from the locking step 34A corresponding to the width of the locking projection 26 shown in Figure 5).

[0028] As shown in Figure 9, the outer circumference of the insertion portion 31 has four outer circumferential protrusions 36 with relatively large outer diameters and four outer circumferential recesses 37 with relatively small outer diameters, arranged alternately and equally. The outer diameter of the outer circumferential recesses 37 is smaller than the inner diameter of the inner circumferential protrusions 23 (see Figure 6). The outer diameter of the outer circumferential protrusions 36 is smaller than the inner diameter of the inner circumferential recesses 22, but larger than the inner diameter of the inner circumferential protrusions 23 (see Figure 6). Furthermore, the circumferential size of the outer circumferential protrusions 36 is smaller than the circumferential size of the inner circumferential recesses 22, and each of the outer circumferential protrusions 36 can be accommodated in each of the inner circumferential recesses. In other words, when attaching the inner joint 30 to the outer joint 20, the insertion portion 31 can be easily inserted into the accommodating space 21 by aligning the outer circumferential protrusions 36 with the inner circumferential recesses 22.

[0029] (4) Outer cylinder 11 Figure 10 is a front perspective view of the outer cylinder 11. The outer cylinder 11 is made of, for example, a carbon steel pipe. The front and rear ends of the outer cylinder 11 are provided with a front opening 11A and a rear opening 11B, respectively.

[0030] (5) Assembly The assembly of the drive roller 10 in this embodiment will be explained below with reference to Figures 11 to 20. In these figures, the outer cylinder 11 is shown as transparent.

[0031] First, as shown in Figure 11, the outer joint 20 is positioned at the desired location inside the outer cylinder 11 using a jig (not shown). Since the outer diameter of the outer joint 20 is smaller than the inner diameter of the outer cylinder 11, it is easy to position the outer joint 20 at the desired location. Next, as shown in Figure 12, the inner joint 30 is installed inside the outer joint 20.

[0032] Figures 13, 14, and 15 show the inner joint 30 attached to the outer joint 20 before fastening, in front view, rear view, and rear perspective view, respectively. First, as shown in Figure 13, the inner joint 30 is inserted into the outer joint 20 with the outer peripheral projection 36 aligned with the inner peripheral recess 22 and the outer peripheral recess 37 aligned with the inner peripheral projection 23. At this time, as shown in Figures 14 and 15, the locking projection 26 is aligned with the guide step 34C. In other words, by aligning the locking projection 26 with the guide step 34C, the outer peripheral projection 36 aligns with the inner peripheral recess 22 and the outer peripheral recess 37 aligns with the inner peripheral projection 23, allowing the insertion portion 31 to be smoothly inserted into the housing space 21.

[0033] From the state shown in Figures 13 to 15, a tool whose tip shape matches the shape of the shaft hole 35 is inserted into the shaft hole, and the inner joint 30 is rotated relative to the outer joint 20. The direction of rotation is the direction in which the locking projection 26 moves from the guide step 34C to the locking step 34A in Figure 15, or in other words, the direction in which the inner joint 30 is rotated counterclockwise in Figure 14. Figure 16 is a rear perspective view showing the state in which the locking projection 26 is in contact with the check projection 34B in this direction of rotation. At this time, since a sliding angle portion 26A is formed on the rotation direction side of the locking projection 26, the locking projection 26 can overcome the check projection 34B.

[0034] Figures 17, 18, and 19 show the inner joint 30 attached to the outer joint 20 and fastened, in front view, rear view, and rear perspective view, respectively. If the rotation of the inner joint 30 continues from the state shown in Figure 16, the locking projection 26 will engage with the locking step 34A, as shown in Figures 18 and 19, and the rotation will stop at this position. In this state, the inner circumference side of the locking projection 26 fits between the locking step 34A and the check projection 34B, preventing rotation in both directions. Here, since the locking projection 26 and the locking step 34A are located at different positions along the axial direction from the housing space 21, the outward pressing action by the outer circumference projection 36 against the inner circumference projection 23 and the engagement action between the locking projection 26 and the locking step 34A occur at different positions, and these actions do not interfere with each other.

[0035] In this state, as shown in Figure 17, the outer circumferential protrusion 36 of the inner joint 30 aligns with the inner circumferential protrusion 23 of the outer joint 20. As a result, the inner circumferential protrusion 23 presses the outer circumferential protrusion 36 outward, causing the outer diameter of the outer joint 20 to expand. At this time, the formation of the open portion 24 as a notch, and the formation of the reduced diameter portion 25 in the thicker part where the inner circumferential protrusion 23 is formed, makes the entire outer joint 20 more susceptible to outward deformation. Due to this expansion of the outer diameter of the outer joint 20, at the position shown in Figure 12, the outer joint 20 presses outward against the inside of the outer cylinder 11, thereby fixing the outer joint 20 and the inner joint 30 to the outer cylinder 11.

[0036] Figure 20 is a front perspective view showing the components to be inserted into the outer cylinder 11 in the state shown in Figure 12. Specifically, the front shaft 12 is mounted on the front bracket 14. The rear shaft 13, through which the connector 16 is inserted, is mounted on the rear bracket 15, and the drive source 40 is mounted in front of the rear bracket 15 via a circuit board holder 42 on which the motor board 43 is mounted. The drive source 40 is then inserted through the rear end opening 11B shown in Figure 12, the output shaft 41 is inserted into the shaft hole 35, and the rear bracket 15 is then press-fitted into the rear end opening 11B. Finally, the front bracket 14 is press-fitted through the front end opening 11A, and the drive roller 10 shown in Figure 1 is assembled.

[0037] Here, as an example of this embodiment, the inner diameter of the outer cylinder 11 is α (see Figure 10), the outer diameter of the outer joint 20 is β, the inner diameter of the inner circumferential recess 22 is γ, the inner diameter of the inner circumferential protrusion is δ (see Figure 6), the outer diameter of the outer circumferential protrusion 36 of the inner joint 30 is ε, and the outer diameter of the outer circumferential recess 37 of the inner joint 30 is ζ (see Figure 9).

[0038] Furthermore, if the inner diameter α of the outer cylinder is made slightly larger than the outer diameter β of the outer joint 20, it becomes easier to install the outer joint 20 at a desired position inside the outer cylinder 11, as shown in Figure 11. Also, if the outer diameter ε of the outer circumferential protrusion 36 of the inner joint 30 is made sufficiently smaller than the inner diameter γ of the inner circumferential recess 22 of the outer joint 20, and the outer diameter ζ of the outer circumferential recess 37 of the inner joint 30 is made slightly smaller than the inner diameter δ of the inner circumferential protrusion 23 of the outer joint 20, and the circumferential size of the outer circumferential protrusion 36 is made smaller than the circumferential size of the inner circumferential recess 22, it becomes easier to install the inner joint 30 inside the outer joint 20 with the outer circumferential protrusion 36 aligned with the inner circumferential recess 22 of the outer joint 20, as shown in Figure 12.

[0039] Furthermore, if the outer diameter ε of the outer circumferential projection 36 of the inner joint 30 is made slightly larger than the inner diameter δ of the inner circumferential projection 23 of the outer joint 20, when the inner joint 30 is rotated relative to the outer joint 20 so that the outer circumferential projection 36 aligns with the inner circumferential projection 23 (see Figures 17 to 19), the outer joint 20 can be pressed outward and expanded in diameter. This expansion in diameter makes it possible to press the outer joint 20 against the inner circumference of the outer cylinder 11 and fix it in place.

[0040] When the drive roller 10 is mounted on a conveyor system (not shown), the front shaft 12 and rear shaft 13 are inserted into and fixed bearings (not shown). In this state, when the drive source 40 is activated, the output shaft 41 rotates, and this rotational force is transmitted to the outer cylinder 11, which is pressed further out, via the inner joint 30 and the outer joint 20 which is pressed outside of it, causing the outer cylinder 11 to rotate. This rotation of the outer cylinder 11 is not transmitted to the front shaft 12 and rear shaft 13 by ball bearings (not shown) housed in the front bracket 14 and rear bracket 15, nor is it transmitted to the circuit board holder 42 and the drive source 40 connected to the rear shaft 13. In other words, the rotation of the output shaft 41 causes the outer cylinder 11 to rotate freely relative to the drive source 40, the circuit board holder 42, the front shaft 12, and the rear shaft 13.

[0041] According to the configuration of this embodiment described above, as shown in Figures 13 to 15, in the fixing preparation state, which is the state just before rotation and fixing, the outer peripheral protrusion 36 is housed in the inner peripheral recess 22, so the fixing preparation state can be easily achieved.

[0042] Furthermore, according to the configuration of this embodiment described above, the outer joint 20 and the outer cylinder 11 are ultimately fixed together by applying force in the rotational direction, making it easier to predict the torque tolerance of the drive roller 10 (i.e., how much conveying torque can be applied to the drive roller 10), and thus easier to detect defective products. In other words, as in the conventional technology, when the output joint is press-fitted in the axial direction, there is no effective relationship between the press-fitting torque and the torque tolerance. On the other hand, when the outer joint 20 is fixed to the outer cylinder 11 as described above, the torque required for fixing is estimated to be approximately equal to the torque tolerance, so the torque tolerance can be predicted from the torque required for rotation. For this reason, it is possible to check whether the torque tolerance meets the desired specifications from the torque required for assembling the outer joint 20 (rotation to fix it to the outer cylinder 11), and defective products that do not meet the desired specifications can be easily detected during assembly.

[0043] (6) First torture Figure 21 is a rear view of the outer joint 20 of the first modified example. This outer joint 20 does not have the open portion 24 as in the embodiment described above. However, as described above, it can be elastically deformed outward by being pressed by the inner joint 30, and similarly can be fixed to the outer cylinder 11.

[0044] (7) Second variation Figure 22 is a schematic diagram of the outer joint 20 and inner joint 30 of the second modified example. However, the shaft hole 35 of the inner joint 30 is omitted. In this outer joint 20, a locking recess 26B is provided on the inner surface of the inner circumferential protrusion 23, which is a structure that prevents relative rotation between the outer joint 20 and the inner joint 30. As in the above embodiment, when the inner joint 30 housed in the outer joint 20 is rotated, the outer circumferential protrusion 36 fits into the locking recess 26B of the inner circumferential protrusion 23, thereby preventing relative rotation between the outer joint 20 and the inner joint 30.

[0045] (8) Third variation Figure 23 is a schematic diagram of the outer joint 20 and inner joint 30 of the third modified example. However, the shaft hole 35 of the inner joint 30 is omitted. In this outer joint 20, the inner diameter of the inner circumferential projection 23 gradually decreases along the rotational direction for fixing. Accordingly, the outer diameter of the outer circumferential projection 36 also gradually decreases along the same rotational direction. In this modified example, when the inner joint 30 is rotated relative to the outer joint 20 for fixing, the outward pressing force increases as the rotation progresses. This configuration makes it possible to adjust the appropriate torque for fixing.

[0046] (9) Summary As described above, the drive roller 10 described in this embodiment comprises an outer cylinder 11, a drive source 40 housed in the outer cylinder 11 and rotating the outer cylinder 11 around its axis, an output shaft 41 that rotates by receiving a driving force from the drive source 40, a substantially cylindrical outer joint 20 that abuts against the inner circumference of the outer cylinder 11 and has a housing space 21 in its center, and a substantially cylindrical inner joint 30 connected to the output shaft 41 and housed in the housing space 21, wherein the outer joint 20 comprises a plurality of inner circumferential recesses 22 having a relatively large inner diameter and being spaced apart from each other along the inner circumference in the housing space 21, and a plurality of inner circumferential protrusions 23 having a relatively small inner diameter and being located between the plurality of inner circumferential recesses 22 in the housing space 21, and the inner joint 30 is the The inner joint 30 has an outer diameter smaller than the inner diameter of the inner circumferential protrusion 23 and is arranged at intervals from one another along the outer circumference, and has a plurality of outer circumferential protrusions 37 that are smaller than the inner diameter of the inner circumferential recess 22 and larger than the inner diameter of the inner circumferential protrusion 23 and is arranged between the plurality of outer circumferential recesses 37, each of which can be accommodated in each of the inner circumferential recesses 22, and an axial hole 35 into which the output shaft 41 is inserted. Starting from a state in which each of the outer circumferential protrusions 36 is accommodated in each of the inner circumferential recesses 22, the inner joint 30 is rotated relative to the outer joint 20 about its axis so that the outer circumferential protrusions 36 and the inner circumferential protrusions 23 are aligned, and the outer joint 20 is pressed outward by the inner joint 30, thereby pressing the outer joint 20 against the inner circumference of the outer cylinder 11 and fixing it in place.

[0047] In the drive roller 10 described above, it is desirable that a notch is formed at one location on the outer circumference of the outer joint 20.

[0048] In the drive roller 10 described above, it is desirable that reduced-diameter portions 25, which are parts with a reduced outer diameter, be arranged at multiple locations on the outer circumference of the outer joint 20.

[0049] In the above-described drive roller 10, the reduced diameter portion 25 may be formed at a location corresponding to the inner circumferential protrusion 23. Also, in the above-described drive roller 10, the inner diameter of the inner circumferential protrusion 23 may gradually decrease along one side in the circumferential direction.

[0050] In the drive roller 10 described above, it is desirable to have a structure that prevents relative rotation between the outer joint 20 and the inner joint 30. Furthermore, it is desirable that the structure includes a locking projection 26 formed on the outer joint 20 and a locking step 34A formed on the inner joint 30 with which the locking projection 26 engages. Moreover, when the inner joint 30 is housed in the outer joint 20, it is desirable that the locking projection 26 and the locking step 34A are located at different positions along the axial direction from the housing space 21. [Explanation of Symbols]

[0051] 10 Drive roller 11 Outer cylinder 11A Tip opening 11B Rear end opening 12 Front shaft 13 Rear shaft 14 Front bracket 15 Rear bracket 16 Connector 20 Outer joint 21 Storage space 22 Inner circumferential recess 23 Inner circumferential protrusion 23A Locking recess 24 Open portion 25 Reduced diameter section 26 Locking projection 26A Sliding angle section 26B Locking recess 30 Inner joint 31 Insertion part 32 Flange part 33 Axis guide 34 Sliding part 34A Locking step 34B Check valve projection 34C Guide step 35 Shaft hole 36 Outer peripheral protrusion 37 Outer peripheral recess 40 Drive source 41 Output shaft 42 Circuit board holder 43 Motor board

Claims

1. Outer cylinder and A drive source housed in the outer cylinder and which rotates the outer cylinder around its axis, An output shaft that rotates by receiving driving force from the aforementioned drive source, A substantially cylindrical outer joint that abuts against the inner circumference of the outer cylinder and has a housing space in its center, A substantially cylindrical inner joint connected to the output shaft and housed in the housing space, A drive roller equipped with, The aforementioned outer joint is In the aforementioned storage space, there are a number of inner circumferential recesses that have a relatively large inner diameter and are spaced apart from each other along the inner circumference, In the aforementioned storage space, the inner diameter is relatively small, and there are multiple inner circumferential protrusions arranged between the multiple inner circumferential recesses, Equipped with, The aforementioned inner joint is The outer diameter is smaller than the inner diameter of the inner circumferential protrusion, and a plurality of outer circumferential recesses are arranged along the outer circumference at intervals from one another, Having an outer diameter smaller than the inner diameter of the inner circumferential recess and larger than the inner diameter of the inner circumferential protrusion, and having a plurality of outer circumferential protrusions arranged between the plurality of outer circumferential recesses, each of which can be accommodated in each of the inner circumferential recesses, The shaft hole into which the output shaft is inserted, Equipped with, A drive roller in which, starting from a state in which each of the outer peripheral protrusions is housed in each of the inner peripheral recesses, the inner joint is rotated relative to the outer joint around its axis so that the outer peripheral protrusions and the inner peripheral protrusions are aligned, and the outer joint is pressed outward by the inner joint, thereby pressing and fixing the outer joint to the inner circumference of the outer cylinder.

2. The drive roller according to claim 1, wherein a notch is formed at one location on the outer circumference of the outer joint.

3. The drive roller according to claim 2, wherein multiple reduced-diameter portions, which are parts with a reduced outer diameter, are arranged at multiple locations on the outer circumference of the outer joint.

4. The drive roller according to claim 3, wherein the reduced diameter portion is formed at a location corresponding to the inner circumferential protrusion.

5. The drive roller according to claim 1, wherein the inner diameter of the inner circumferential protrusion gradually decreases along one side in the circumferential direction.

6. The drive roller according to any one of claims 1 to 5, further comprising a structure for preventing relative rotation between the outer joint and the inner joint.

7. The drive roller according to claim 6, comprising, as the structure, a locking projection formed on the outer joint and a locking step formed on the inner joint with which the locking projection engages.

8. The drive roller according to claim 7, wherein, when the inner joint is housed in the outer joint, the locking projection and the locking step are located at different positions along the axial direction from the housing space.

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