Connection structure between wooden winding drum and rotating shaft

Abstract

To provide a connection structure between a wooden drum and a rotating shaft that can easily attach the wooden drum to the rotating shaft and easily connect the two.SOLUTION: There is provided a connecting structure of a wooden drum 8 and a rotary shaft 7, which are rotationally driven by a rotary shaft 7, wherein a circular hole 8a through which the rotary shaft 7 is inserted is formed at the center of a pair of side plates 8B of the wooden drum 8, and a pair of metal connecting members 9 are each spline-fitted to the rotary shaft 7 so as to be slidable in the axial direction, and each connecting member 9 is a truncated conical member that is reduced in diameter toward the wooden drum 8, and a plurality of teeth (protrusions) 9a along the axial direction are provided on its outer peripheral surface in the circumferential direction, and the pair of connecting members 9 are moved along the rotary shaft 7 in a direction close to each other, and, teeth 9a protruding from the outer periphery of each connecting member 9 are bitten into the circular hole 8a of the wooden drum 8 to connect the wooden drum 8 and the rotary shaft 7 by the connecting member 9.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a connection structure between a wooden winding drum (hereinafter also referred to as a wooden drum) on which a wire is wound and a metal rotating shaft. [Background technology]

[0002] For example, when constructing a tunnel using the shield tunneling method, the inside of the tunnel excavated by the shield machine is ventilated. This ventilation is achieved by supplying outside air blown out from a fan installed on the ground into the tunnel through a duct and an air pipe connected to it.

[0003] Here, the air pipes are expandable, bellows-shaped pipes that are successively added to and installed along the tunnel ceiling as the tunnel excavation progresses. The multiple air pipes arranged along the tunnel ceiling are supported by a wire that is pulled out from a wire take-up drum and installed on the ceiling with an appropriate tension, and are suspended horizontally along the tunnel ceiling. Here, the take-up drum, which has the function of applying appropriate tension to the wire pulled out from the take-up drum, is also called a wire tensioner.

[0004] Incidentally, when a commercially available wooden drum is used as a winding drum equipped with a wire tensioner function at a site such as the above-mentioned tunnel construction, the wooden winding drum needs to be firmly connected to a metal rotating shaft. Various proposals have been made regarding wire winding drums (see, for example, Patent Documents 1 to 3), but no proposals have been found that incorporate any particular innovations in the connection structure or form between the wooden winding drum and the rotating shaft that supports it for free rotation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 57-082157 [Patent Document 2] Japanese Utility Model Application Publication No. 63-128427 [Patent Document 3] Japanese Patent Application Publication No. 8-081186 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, commercially available wooden drums with wound wire are used as the winding drums for the wire used to suspend and support wind pipes along the ceiling of tunnels at construction sites such as tunnel construction. The connection between this wooden drum and the metal rotating shaft that supports it for rotation is not simply a matter of connecting them; in order to apply appropriate tension to the wire pulled out from the wooden drum, the wooden drum and the metal rotating shaft must be securely and firmly connected. However, connecting a wooden winding drum to a metal rotating shaft is not easy, and there is a problem in that it requires a complex structure and many parts.

[0007] The present invention was made in consideration of the above problems, and its purpose is to provide a connecting structure between a wooden drum and a rotating shaft that allows the wooden drum to be easily attached to the rotating shaft and the two to be easily connected. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a connection structure between a wooden drum that is rotatably supported by a rotating shaft and the rotating shaft, wherein a circular hole through which the rotating shaft is inserted is formed in the center of each of a pair of side plates of the wooden drum, and a pair of metal connecting members are spline-fitted to the rotating shaft so that they can slide axially, and each connecting member is a truncated cone-shaped member whose diameter narrows toward the rotating drum, and whose outer surface has multiple protrusions extending circumferentially along the axial direction, and the pair of connecting members are moved toward each other along the rotating shaft, and the protrusions protruding from the outer periphery of each connecting member are inserted into the circular hole in the wooden drum, connecting the wooden drum and the rotating shaft with the connecting members. [Effects of the Invention]

[0009] According to the present invention, the wooden drum and the rotating shaft can be easily connected by a simple operation of moving a pair of metal connecting members toward each other along the rotating shaft and fitting the protrusions on the outer periphery of each connecting member into the circular holes in the wooden drum. [Brief explanation of the drawings]

[0010] [Figure 1] A partial cross-sectional side view showing the construction of a tunnel using the shield tunneling method. [Figure 2] 1 is a partially cutaway front view of a wire tensioner to which a connecting structure according to the present invention is applied; [Figure 3] FIG. 2 is a plan view of the wire tensioner of FIG. 1. [Figure 4] Left side view of the wire tensioner in Figure 1. [Figure 5] Enlarged end view of line AA in Figure 2. [Figure 6] 1A is a side view of a connecting member used in a connecting structure between a wooden drum and a rotating shaft according to the first embodiment of the present invention, and FIG. 1B is a front view taken along an arrow B in FIG. 1A. [Figure 7] 1 is a perspective view of a connecting member used in a connecting structure between a wooden drum and a rotating shaft according to a first embodiment of the present invention. [Figure 8] 8(a) to 8(c) are partial cross-sectional front views showing the steps of a method for connecting a wooden drum and a rotary shaft according to the first embodiment using the connecting member of FIGS. 6 and 7. [Figure 9] FIG. 10 is a side view of a connecting member used in a connecting structure between a wooden drum and a rotating shaft according to a second embodiment of the present invention. [Figure 10] 10(a) to 10(c) are partial cross-sectional front views showing a method for connecting a wooden drum and a rotary shaft according to the second embodiment using the connecting member of FIG. 9 in the order of steps. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0012] [Example of wire winding drum usage] First, as an example of the use of a wire take-up drum, the construction of a tunnel using the shield method will be outlined based on Figure 1. In Figure 1, the direction ahead of the shield machine's direction of travel is referred to as "front," the opposite direction is referred to as "rear," the direction perpendicular to the plane of the page in Figure 1 is referred to as "left and right," and the top and bottom of Figure 1 are referred to as "up and down."

[0013] Fig. 1 is a partial side cross-sectional view showing the construction of a tunnel using the shield tunneling method. In the construction of a tunnel 100, as shown in Fig. 1, the ground is excavated by a shield machine 50 moving in the direction of the arrow in the figure, and a circular hole-shaped tunnel 100 is formed in the ground. Here, multiple (two in the illustrated example) carriages 51, 52 are connected to the rear of the shield machine 50, and the rearmost carriage 52 is equipped with a wooden wire take-up drum 1 (hereinafter, this take-up drum 1 may also be referred to as wire tensioner 1) that has a wire tensioner function described below. The multiple carriages 51, 52 run along temporary rails 101 laid inside the tunnel 100.

[0014] During construction, the tunnel 100 is ventilated by external air discharged from a blower 60 installed on the ground, which is supplied into the tunnel 100 via a duct 61 and multiple air pipes 62 connected to this duct 61. The duct 61 extends from the discharge side of the blower 60, extends vertically downward through the shaft 200, and is then bent at a right angle along the ceiling 100a of the tunnel 100, with multiple (two in the illustrated example) air pipes 62 arranged along the ceiling 100a of the tunnel 100 connected to its end.

[0015] The air pipes 62 are expandable and contractible bellows-shaped pipe members, and within the tunnel 100, these air pipes 62 are successively connected along the ceiling 100a of the tunnel 100 as the excavation of the tunnel 100 progresses. The multiple air pipes 62 arranged along the ceiling 100a of the tunnel 100 are suspended approximately horizontally along the ceiling 100a of the tunnel 100 by wire W that is pulled out from the wire take-up drum 1 and laid across the ceiling 100a. More specifically, the end (free end) of the wire W pulled out from the wire take-up drum 1 is fixed to the ceiling 100a of the tunnel 100 at point a in Figure 1, and each connected air pipe 62 is arranged approximately horizontally along the ceiling 100a of the tunnel 100 by having its flange portion 62a suspended and supported by the wire W at points b and c shown in the figure. The wire W that suspends and supports the plurality of air ducts 62 is folded back at point d shown in FIG. 1 and wound around the wire winding drum 1, and an appropriate tension is applied to the wire W.

[0016] As the construction work of the tunnel 100 progresses, the shield machine 50 moves forward (to the left in FIG. 1), and accordingly, the multiple (two in the illustrated example) carriages 51, 52 connected to the rear of the shield machine 50 also move forward along the temporary rails 101. Then, the wire take-up drum 1 mounted on the rearmost carriage 52 also moves forward together with the carriages 52, and the wire W is pulled out from the wire take-up drum 1.

[0017] Furthermore, as described above, as the shield machine 50 and the bogies 51, 52 move forward, the length of the tunnel 100 being excavated gradually increases, so in order to provide sufficient ventilation deep into the tunnel 100, it is necessary to add a new air duct 62 to the existing air duct 62.

[0018] Therefore, the number of air pipes 62 suspended and supported substantially horizontally by the wire W erected along the ceiling 100a of the tunnel 100 increases as the construction of the tunnel 100 by the shield machine 50 progresses. In order to support the additional air pipes 62 suspended substantially horizontally along the ceiling 100a of the tunnel 100, the wire W needs to be pulled with a predetermined tension at all times, including when the wire take-up drum 1 is moving forward together with the cart 52. For this reason, in this embodiment, a braking means is provided on the wire take-up drum 1 and formed into a wire tensioner 1, and this braking means will be described later.

[0019] Here, the detailed configuration of the wire winding drum 1 (wire tensioner 1) will be described below with reference to FIGS.

[0020] [Wire winding drum (wire tensioner)] FIG. 2 is a partially cutaway front view of the wire winding drum 1, FIG. 3 is a plan view of the wire winding drum 1, FIG. 4 is a left side view of the wire winding drum 1, and FIG. 5 is an enlarged cross-sectional view taken along line AA in FIG. 2. In these figures, the arrows indicate the "front-rear," "left-right," and "up-down" directions, respectively.

[0021] The illustrated wire winding drum 1 has a rectangular frame-shaped base 2 at its bottom, and side walls 3A, 4A of L-shaped support frames 3, 4 are erected vertically on the left and right sides of the base 2. Bearing blocks 5, 6 are attached to the side walls 3A, 4A of the support frames 3, 4 at the same height, and a rotating shaft 7 arranged horizontally in the left-right direction is rotatably inserted and supported in these bearing blocks 5, 6. In other words, the rotating shaft 7 is rotatably supported at both left and right ends by the side walls 3A, 4A of the left and right support frames 3, 4 via the bearing blocks 5, 6.

[0022] A wooden winding drum 8 (hereinafter referred to as the wooden drum 8) is disposed in the left-right middle of the rotating shaft 7 and is rotatably supported by the rotating shaft 7. The wooden drum 8 is composed of a cylindrical body 8A and left and right disc-shaped side plates 8B attached to both axial ends of the body 8A. As shown in FIG. 2, a circular hole 8a is formed in the center of each of the left and right side plates 8B, through which the rotating shaft 7 passes. Therefore, the wooden drum 8 is disposed coaxially with the rotating shaft 7 via a connecting member 9 (described later) and rotates integrally with the rotating shaft 7 around the axis O of the rotating shaft 7. The portion of the rotating shaft 7 sandwiched between the left and right bearing blocks 5, 6 (the central portion) is a spline shaft, as shown in its cross section in FIG. 5. Although not shown, a wire W is wound around the outer periphery of the body 8A of the wooden drum 8.

[0023] The wooden drum 8 and the rotary shaft 7 are connected by a pair of left and right connecting members 9 that are spline-fitted to the rotary shaft 7 so as to be slidable along the axial direction, and the details of this connecting structure will be described later.

[0024] The wire winding drum 1 in this embodiment is provided with a disc brake 10 as an example of a braking means for applying a brake to the rotation of the wooden drum 8 in the wire-pulling direction and applying a predetermined tension to the wire W being pulled out from the wooden drum 8.

[0025] As shown in Figures 2 to 4, the disc brake 10 includes a disk-shaped brake disc 11 attached to the left end of the rotating shaft 7, and a brake caliper 12 equipped with a pair of left and right brake pads 12a, 12b for sandwiching the disc brake 11 from both the left and right sides. Here, as shown in Figure 2, the brake caliper 22 is attached to the support frame 3 via a support stay 13 that extends horizontally leftward from the side wall 3A of the left support frame 3, and an adjustment bolt 14 is threadedly engaged with the brake caliper 12 so that it can advance and retreat. The tip of the adjustment bolt 14 abuts against one of the brake pads 12a, and therefore the adjustment bolt 14 forms an adjustment mechanism that adjusts the braking force of the disc brake 10.

[0026] By providing a disc brake 10 that applies a brake to the rotation of the wooden drum 8, the wire take-up drum 1 becomes a wire tensioner 1, and when this wire tensioner 1 is mounted on the rearmost carriage 52 in the tunnel 100 under construction as shown in Figure 1, the disc brake 10 applies a brake to the rotation of the wooden drum 8. Therefore, as the traveling carriage 52 and the wire tensioner 1 (wire take-up drum 1) mounted thereon move forward as construction progresses, a predetermined tension is applied to the wire W that is pulled out from the wire take-up drum 1. In other words, the wire W is pulled out from the wire take-up drum 1 (wire tensioner 1) while being pulled with a predetermined tension.

[0027] Therefore, as described above in Figure 1, as the construction work of the tunnel 100 by the shield machine 50 progresses, additional air pipes 62 are added, and in a state in which multiple air pipes 62 are suspended approximately horizontally by wires W along the ceiling 100a of the tunnel 100, the wires W are always in a taut state with a predetermined tension, as described above, so the multiple air pipes 62 suspended and supported approximately horizontally by the wires W do not sag due to their own weight, and these air pipes 62 are suspended and supported approximately horizontally by the wires W along the ceiling 100a of the tunnel 100.

[0028] The tension applied to the wire W by the disc brake 10 (see FIGS. 2 to 4) can be adjusted as desired by rotating the adjustment bolt 14. Specifically, when the adjustment bolt 14 is turned in the direction of arrow x (clockwise) in FIG. 4, the force with which one brake pad 12a of the brake caliper 12 presses against the brake disc 11 increases, increasing the braking force of the disc brake 10, and therefore increasing the tension applied to the pulled-out wire W. Conversely, when the adjustment bolt 14 is turned in the direction of arrow y (counterclockwise) in FIG. 4, the force with which one brake pad 12a of the brake caliper 12 presses against the brake disc 11 decreases, reducing the braking force of the disc brake 10 and therefore reducing the tension applied to the wire W.

[0029] [Connection between wooden drum and rotating shaft] Next, an embodiment of the connecting structure between the wooden drum 8 and the rotary shaft 7 will be described.

[0030] <First Embodiment> Figure 6(a) is a side view of the connecting member used in embodiment 1 of the present invention, Figure 6(b) is a view in the direction of arrow B in Figure 6(a), Figure 7 is an oblique view of the connecting member in Figure 6, and Figures 8(a) to (c) are partial front cross-sectional views showing the process steps of the method for connecting a wooden drum and a rotating shaft in embodiment 1 of the present invention.

[0031] The connecting member 9 used in the first embodiment is a frusto-conical metal member whose outer diameter tapers toward the wooden drum 8 (toward the right in FIG. 6(a)). A plurality of (eight in the illustrated example) plate-like teeth 9a extending linearly along the axial direction (left-right direction in FIG. 6(a)) are provided on its tapered outer surface at equal angular intervals (45° intervals in the illustrated example) along the circumferential direction (see FIGS. 6(b) and 7). The minimum circumscribed circle diameter φDmin (see FIG. 6) of the teeth 9a provided on the outer periphery of the connecting member 9 is smaller than the inner diameter φd (see FIG. 8) of the circular hole 8a of the wooden drum 8 (φDmin<φd), and the maximum circumscribed circle diameter φDmax (see FIG. 6) of the teeth 9a is larger than the inner diameter φd of the circular hole 8a of the wooden drum 8 (φDmax>φd). The pair of left and right connecting members 9 have the same configuration, and only one (left) connecting member 9 is shown in Figures 6 and 7. As shown in Figures 6 and 7, a spline hole 9A is formed in the center of the connecting member 9, and the spline portion of the rotating shaft 7 is inserted and fitted into the spline hole 9A.

[0032] Next, a method for connecting the wooden drum 8 and the rotary shaft 7 using the pair of left and right connecting members 9 configured as above will be described below with reference to FIGS. 8(a) and 8(b).

[0033] As shown in Figure 8(a), the rotating shaft 7 is inserted into the circular holes 8a opening in the left and right side plates 8B of the wooden drum 8, and a pair of left and right connecting members 9, which are spline-fitted to the rotating shaft 7 so as to be slidable in the axial direction, are spaced apart in the axial direction from the left and right side plates 8B of the wooden drum 8. Then, the left and right connecting members 9 are slid toward each other along the rotating shaft 7. Then, the multiple teeth 9a erected on the outer circumferential surfaces of the left and right connecting members 9 are fitted into grooves formed by the respective teeth 9a in the circular holes 8a opening in the left and right side plates 8B of the wooden drum 8, as shown in Figure 8(b). Then, from this state, if the left and right connecting members 9 are pushed strongly toward each other (in the direction of the arrow in Figure 8(b)), the multiple teeth 9a formed on the left and right metal connecting members 9 will bite into the inner surfaces of the circular holes 8a opening in the left and right side panels 8B of the wooden drum 8, and the wooden drum 8 and the rotating shaft 7 will be connected via these connecting members 9 in the state shown in Figure 8(c), and the two will be able to rotate together.

[0034] As described above, in this embodiment 1, the wooden drum 8 and the rotating shaft 7 can be easily connected by a simple operation of moving a pair of metal connecting members 9 in a direction toward each other along the rotating shaft 7 and fitting the multiple teeth 9a protruding from the outer periphery of each connecting member 9 into the circular holes 8a of the wooden drum 8.

[0035] In the first embodiment, eight teeth 9a are provided on the outer periphery of each connecting member 9, but the number of teeth 9a is not limited to eight and may be any number as long as it is plural. Furthermore, in the above description, the wooden drum 8, which is connected to the rotating shaft 7 by the connecting members 9 fitting into the circular holes 8a of the left and right side plates 8B, is free to move in the thrust direction of the rotating shaft 7, but even if the wooden drum 8 moves on the rotating shaft 7, the left and right side plates 8B come into contact with the inner bearings of the left and right bearing blocks 5, 6 and rotate synchronously, so movement in the thrust direction does not pose a problem.

[0036] <Embodiment 2> Next, a second embodiment of the connecting structure between the wooden drum 8 and the rotary shaft 7 will be described below with reference to FIGS.

[0037] Figure 9 is an oblique view of a connecting member used in embodiment 2 of the present invention, and Figures 10(a) to (c) are front cross-sectional views of the main parts showing the steps of a method for connecting a wooden drum and a rotating shaft in embodiment 2 of the present invention.

[0038] The connecting member 19 used in the second embodiment is a metal member having a truncated cone shape whose outer diameter decreases toward the wooden drum 8 (toward the right in FIG. 9), and a spiral male screw 19a is formed as a protrusion on the tapered outer periphery. A spline hole 19A is formed in the center of the connecting member 19, and the spline portion of the rotating shaft 7 is inserted and fitted into the spline hole 19A.

[0039] Here, the minimum value φDmin (see FIG. 9) of the circumscribing circle diameter of the male thread 19a formed on the outer periphery of the connecting member 19 is set to be smaller than the inner diameter φd (see FIG. 10) of the circular hole 8a of the wooden drum 8 (φDmin<φd), and the maximum value φDmax (see FIG. 9) of the circumscribing circle diameter of the male thread 19a is set to be larger than the inner diameter φd of the circular hole 8a of the wooden drum 8 (φDmax>φd). Note that the left and right connecting members 19 have the same configuration, so only one (left) connecting member 19 is shown in FIG. 9. However, the male threads 19a formed on the outer periphery of each of the left and right connecting members 19 are in a reverse thread relationship.

[0040] Next, a method for connecting the wooden drum 8 and the rotary shaft 7 using the pair of left and right connecting members 19 configured as above will be described below with reference to FIGS. 10(a) to 10(c).

[0041] As shown in Figure 10(a), the rotating shaft 7 is inserted into the circular holes 8a opening in the left and right side plates 8B of the wooden drum 8, and a pair of left and right connecting members 19, which are spline-fitted to the rotating shaft 7 so as to be slidable in the axial direction, are spaced apart in the axial direction from the left and right side plates 8B of the wooden drum 8. Then, the left and right connecting members 19 are slid toward each other along the rotating shaft 7. Then, the male threads 19a formed on the outer peripheral surfaces of the left and right connecting members 19 are fitted into the circular holes 8a opening in the left and right side plates 8B of the wooden drum 8, respectively, as shown in Figure 10(b).

[0042] Then, from the above state, the wooden drum 8 is rotated with the rotation of the rotary shaft 7 prevented (locked) by the disc brake 10 (see Figures 2 to 4). When the wooden drum 8 is rotated in this manner with the rotary shaft 7 fixed, the left and right side plates 8B of the wooden drum 8 have large diameters, so by manually turning these large-diameter side plates 8B, the wooden drum 8 can be rotated with a small torque.

[0043] As described above, when the wooden drum 8 is rotated with the rotation of the rotary shaft 7 prevented (locked), because the male threads 19a formed on the left and right connecting members 19 are reverse-threaded as described above, these connecting members 19 move along the rotary shaft 7 in the direction of the arrow in Figure 10(c) (towards each other), and the male threads 19a formed on these connecting members 19 bite into the inner peripheral surfaces of the left and right circular holes 8a of the wooden drum 8 while threading them. As a result, the left and right connecting members 19 reliably connect the wooden drum 8 and the rotary shaft 7, allowing them to rotate together.

[0044] As described above, in the second embodiment, a pair of metal connecting members 19 are moved toward each other along the rotating shaft 7 by utilizing the reverse-thread relationship of the male screws 19a provided on their outer circumferential surfaces. That is, when the male screws 19a are fitted into the left and right circular holes 8a of the wooden drum 8, respectively, the rotation of the rotating shaft 7 is prevented (locked), and by simply rotating the wooden drum 8, the male screws 19a formed on each connecting member 19 thread and bite into the inner circumferential surfaces of the left and right circular holes 8a of the wooden drum 8, thereby reliably connecting the wooden drum 8 and the rotating shaft 7. This provides the effect of easily and reliably connecting the wooden drum 8 and the rotating shaft 7.

[0045] Although the above describes an example in which the present invention is applied to a wire winding drum used in tunnel construction work using the shield tunneling method, the present invention can also be applied to wire winding drums used for any other purpose.

[0046] Furthermore, in the above embodiment, an example has been described in which a disc brake is used as the braking means, but any other mechanical brake other than a disc brake, such as a drum brake, can be used as the braking means.

[0047] Furthermore, the present invention is not limited to the application of the above-described embodiments, and it goes without saying that various modifications are possible within the scope of the claims and the technical ideas described in the specification and drawings. [Explanation of symbols]

[0048] 1 Wire take-up drum (wire tensioner) 3,4 Support frame 5,6 Bearing block 7 Rotation Axis 8 Wooden drum (wooden winding drum) 8A Wooden drum body 8B Wooden drum side panel 8a Hole in a wooden drum 9 Connecting members 9a Teeth (protrusions) of connecting members 19 Connecting members 19a Male thread (protrusion) of connecting member W Wire

Claims

1. A connection structure between a wooden winding drum (hereinafter referred to as a wooden drum) whose rotation is supported by a rotating shaft and the rotating shaft, The wooden drum has a pair of side plates each having a circular hole formed at the center thereof through which the rotary shaft is inserted. A pair of metal connecting members are spline-fitted to the rotary shaft so as to be slidable in the axial direction, Each of the connecting members is a truncated cone-shaped member whose diameter decreases toward the rotating drum, and has a plurality of axially extending protrusions formed on its outer circumferential surface, A connecting structure between a wooden drum and a rotating shaft is characterized in that a pair of connecting members are moved in a direction toward each other along the rotating shaft, and the protrusions on the outer periphery of each connecting member are inserted into the circular holes in the wooden drum, thereby connecting the wooden drum and the rotating shaft with the connecting members.

2. The connecting structure between a wooden drum and a rotating shaft as described in claim 1, characterized in that the multiple protrusions protruding from the outer surface of the connecting member are composed of plate-shaped teeth protruding parallel to each other along the axial direction.

3. A connecting structure between a wooden winding drum (hereinafter referred to as a wooden drum) whose rotation is supported by a rotating shaft and the rotating shaft, The wooden drum has a pair of side plates each having a circular hole formed at the center thereof through which the rotary shaft is inserted. A pair of metal connecting members are spline-fitted to the rotary shaft so as to be slidable in the axial direction, Each of the connecting members is a truncated cone-shaped member whose diameter decreases toward the rotary drum, and has a helical male screw protruding from its outer circumferential surface, A connecting structure between a wooden drum and a rotating shaft is characterized in that a pair of connecting members are moved in a direction toward each other along the rotating shaft, and the protrusions on the outer periphery of each connecting member are inserted into the circular holes in the wooden drum, thereby connecting the wooden drum and the rotating shaft with the connecting members.

4. 4. The connecting structure between a wooden drum and a rotating shaft according to claim 3, wherein the male screws protruding from the outer periphery of each of the pair of connecting members are configured as reverse threads.

5. 5. The connecting structure between a wooden drum and a rotary shaft according to claim 3, wherein the male screw is caused to bite into the circular hole by rotating the wooden drum.

6. 6. The connecting structure between the wooden drum and the rotary shaft according to claim 5, wherein the rotary shaft is provided with a brake device for stopping the rotation of the rotary shaft.

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