power transmission device

Abstract

To provide a power transmission device capable of easily adjusting power necessary for rotating a rotation shaft according to a change in load torque and transmitting the power to the rotation shaft to rotate the rotation shaft.SOLUTION: A power transmission device 10 is used for transmitting drive force to a handle shaft 3 on which load torque acts and rotating it. The power transmission device 10 includes a rotary gear 20 having an outer peripheral part 24 in which a plurality of teeth 25 are formed along a circumferential direction, a gear holder 30 having a gear storage part 33 for rotatably storing the rotary gear 20, and a movable arm 40 configured so as to move with respect to the gear holder 30. The movable arm 40 includes a drive force input part 46 for receiving drive force and a gear part 47 in which teeth meshing with the teeth 25 of the rotary gear 20 are formed and aligned. The power transmission device 10 further includes a coil spring 50 for energizing the movable arm 40 in a direction to reduce a distance from a center G of the handle shaft 3 to the drive force input part 46 of the movable arm 40.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a power transmission device, and more particularly to a power transmission device for transmitting a driving force to a rotating shaft on which a load torque acts. [Background technology]

[0002] For example, a fishing reel has a handle arm attached to a handle shaft that rotates a spool that winds in the fishing line. When the user rotates the handle arm, the spool rotates and the fishing line is wound in. When a fish is caught on the fishing line rig, the tension acting on the fishing line changes depending on the fish's movement. For example, when the fish pulls strongly, the tension in the fishing line increases, and the torque required to rotate the handle arm also increases. A mechanism has been proposed that reduces the force required to rotate the handle arm when the required torque increases by loosening the nut connecting the handle arm to the handle shaft, lengthening the handle arm, and then tightening the nut again (see, for example, Patent Document 1).

[0003] However, with the mechanism disclosed in Patent Document 1, the user must manually adjust the length of the handle arm while fishing in response to the strength of the fish's pull. This operation can distract the user from fishing, and the user may be unable to respond to the fish's movements, which could result in the fish escaping. For this reason, there is a demand for a reel structure that allows the user to adjust the force required to rotate the handle arm without requiring any special operation. Furthermore, in a wide variety of devices other than fishing reels, there is a need for a power transmission mechanism that can easily adjust the force required to rotate the rotating shaft in response to changes in load torque and transmit it to the rotating shaft. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-135624 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the problems of the prior art, and aims to provide a power transmission device that can easily adjust the force required to rotate a rotating shaft in accordance with changes in load torque and transmit the force to the rotating shaft. [Means for solving the problem]

[0006] According to a first aspect of the present invention, there is provided a power transmission device that can easily adjust the force required to rotate a rotating shaft in response to changes in load torque and transmit the force to the rotating shaft. The power transmission device is used to transmit a driving force to a rotating shaft on which a load torque acts, thereby rotating the rotating shaft. The power transmission device comprises a rotating gear having a central portion attached to the rotating shaft so as to rotate together with the rotating shaft and an outer peripheral portion on which a plurality of teeth are formed along the circumferential direction, and a gear receiving portion that rotatably receives the rotating gear. a cylindrical insertion portion; and a hook portion formed on the opposite side of the insertion portion. and a movable arm configured to be movable relative to the gear holder. The movable arm has a driving force input section that receives the driving force, and a gear section that has an array of teeth that mesh with the plurality of teeth of the rotary gear. a shaft portion that is inserted into the insertion portion of the gear holder; and a rail portion that engages with the hook portion of the gear holder to guide the movement of the hook portion. The power transmission device further includes a biasing member that biases the movable arm in a direction that shortens the distance from the center of the rotation shaft to the driving force input portion of the movable arm.

[0007] According to a second aspect of the present invention, there is provided a fishing reel that can easily adjust the force required to rotate the handle shaft in response to changes in load torque and transmit it to the handle shaft to rotate the spool. This fishing reel includes a reel body having a handle shaft for rotating the spool, and a handle mechanism attached to the handle shaft of the reel body. The handle mechanism includes the power transmission device attached to the handle shaft of the reel body as the rotation shaft, and a knob attached to the drive force input section of the power transmission device.

[0008] According to a third aspect of the present invention, there is provided a bicycle that can easily adjust the force required to rotate the crankshaft in response to changes in load torque and transmit it to the crankshaft to rotate the crankwheel. The bicycle includes a wheel, a crankwheel having a crankshaft, a connecting member that connects the wheel and the crankwheel so as to transmit the rotation of the crankwheel to the wheel, and a crank mechanism attached to the crankshaft of the crankwheel. The crank mechanism includes the power transmission device attached to the crankshaft as the rotating shaft, and pedals attached to the driving force input section of the power transmission device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example in which a power transmission device according to an embodiment of the present invention is applied to a fishing reel. [Figure 2] FIG. 2 is a front view showing the handle mechanism of the fishing reel shown in FIG. [Figure 3] FIG. 3 is an exploded perspective view of the handle mechanism shown in FIG. [Figure 4] 4 is a front view of a rotary gear in the handle mechanism shown in FIG. 2. FIG. [Figure 5A] 5A is a front view of a gear holder in the handle mechanism shown in FIG. 2. FIG. [Figure 5B] FIG. 5B is a plan view of the gear holder of FIG. 5A. [Figure 6A] 6A is a front view of an arm body of a movable arm in the handle mechanism shown in FIG. 2. FIG. [Figure 6B] FIG. 6B is a bottom view of the arm body of FIG. 6A. [Figure 7] 7 is a vertical cross-sectional view of the power transmission device of the handle mechanism shown in FIG. [Figure 8] 8 is a cross-sectional view of the gear holder and the movable arm in the handle mechanism shown in FIG. 2 taken along line AA. [Figure 9] FIG. 9 is a schematic cross-sectional view for explaining the operation of the power transmission device shown in FIG. [Figure 10] FIG. 10 is a schematic cross-sectional view for explaining the operation of the power transmission device shown in FIG. [Figure 11] FIG. 11 is a schematic diagram showing an example in which a power transmission device according to an embodiment of the present invention is applied to a bicycle. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of a power transmission device according to the present invention will be described in detail with reference to FIGS. 1 to 11. In FIGS. 1 to 11, identical or corresponding components are designated by the same reference numerals, and redundant description will be omitted. In addition, in FIGS. 1 to 11, the scale and dimensions of each component may be exaggerated, and some components may be omitted. In the following description, unless otherwise specified, terms such as "first" and "second" are used only to distinguish components from one another, and do not represent a specific order or sequence.

[0011] Figure 1 is a perspective view showing an example in which a power transmission device 10 according to one embodiment of the present invention is applied to a fishing reel 1. The fishing reel 1 shown in Figure 1 has a reel body 2 including a spool for winding fishing line, and a handle mechanism 4 attached to a handle shaft 3 provided on the reel body 2. The handle mechanism 4 includes the power transmission device 10 according to the present invention and a knob 5 rotatably attached to the power transmission device 10.

[0012] Figure 2 is a front view of the handle mechanism 4, and Figure 3 is an exploded perspective view. As shown in Figures 2 and 3, the power transmission device 10 that makes up the handle mechanism 4 has a rotating gear 20 attached to the handle shaft 3 of the reel body 2, a gear holder 30 that houses the rotating gear 20, a movable arm 40 that is configured to be movable relative to the gear holder 30, and a coil spring 50 that serves as a biasing member that biases the movable arm 40.

[0013] FIG. 4 is a front view of the rotary gear 20. As shown in FIG. 4, the rotary gear 20 has a central portion 22 in which an axial hole 21 having substantially the same shape as the outer shape of the handle shaft 3 (see FIG. 1) of the reel body 2 is formed, a cylindrical portion 23 extending in the Z direction around the central portion 22, and an outer peripheral portion 24 extending radially outward from the cylindrical portion 23. A plurality of teeth 25 are formed on the outer peripheral portion 24 along the circumferential direction. The handle shaft 3 of the reel body 2 is inserted into the axial hole 21 in the central portion 22 of the rotary gear 20, and a nut 26 (see FIGS. 1 to 4) is fastened to the handle shaft 3, thereby attaching the rotary gear 20 to the handle shaft 3. This allows the rotary gear 20 to rotate together with the handle shaft 3 of the reel body 2.

[0014] FIG. 5A is a front view of the gear holder 30, and FIG. 5B is a plan view. As shown in FIGS. 5A and 5B, the gear holder 30 includes a beam portion 31 extending in the X direction, a cylindrical insertion portion 32 provided at one end of the beam portion 31, a pair of gear accommodating portions 33 extending semicircularly from the other end of the beam portion 31, and a hook portion 34 located on the opposite side of the insertion portion 32. The insertion portion 32 has an insertion hole 32A (see FIG. 3) formed therethrough in the X direction. The inner peripheral portion 33A of the semicircular gear accommodating portion 33 supports the cylindrical portion 23 of the rotary gear 20, and the outer peripheral portion 24 of the rotary gear 20 is positioned between the pair of gear accommodating portions 33. In other words, the rotary gear 20 is accommodated radially inside the gear accommodating portion 33. The rotary gear 20 is rotatably supported (around the handle shaft 3) by the gear accommodating portion 33.

[0015] The hook portion 34 of the gear holder 30 includes a neck portion 35 that extends in the +Y direction from the end of the gear housing portion 33 on the -X side, and a head portion 36 that widens in the Z direction from the end of the neck portion 35 on the +Y side. With this structure, a guide groove 37 that extends in the X direction is formed between the head portion 36 of the hook portion 34 and the end of the gear housing portion 33 on the -X side.

[0016] 3, the movable arm 40 includes an arm body 41 extending in the X direction and an end cap 42 that is detachably attached to the arm body 41. The end cap 42 includes a threaded portion 42A on which a screw thread (not shown) is formed, and a head portion 42B that has a larger diameter than the threaded portion 42A. The outer diameter of the head portion 42B is larger than the outer diameter of the coil spring 50.

[0017] The coil spring 50 is arranged in a compressed state between the head portion 42B of the end cap 42 and the insertion portion 32 of the gear holder 30. Therefore, the movable arm 40 is constantly biased in the +X direction by the coil spring 50. Figure 2 shows the initial state in which no external force is acting on the handle mechanism 4. In this initial state, the biasing force of the coil spring 50 causes the +X direction end (stopper portion 70) of the arm body 41 of the movable arm 40 to abut against the insertion portion 32 of the gear holder 30.

[0018] FIG. 6A is a front view of the arm main body 41, and FIG. 6B is a bottom view. As shown in FIGS. 6A and 6B, the arm main body 41 includes a base 43 extending in the X direction, a substantially cylindrical shaft 44 extending from the base 43 in the +X direction, and a flat operating portion 45 extending from the base 43 in the −X direction. The operating portion 45 is provided with a driving force input portion 46 to which a screw 6 (see FIG. 3) for fixing the knob 5 is attached. The knob 5 is rotatably attached to the operating portion 45 by inserting the screw 6 into a through-hole 46A formed in the driving force input portion 46 and attaching the screw 6 to the knob 5. When a user of the fishing reel 1 grips the knob 5 and rotates the handle mechanism 4 around the handle shaft 3, the force applied to the knob 5 is transmitted to the handle shaft 3 via the power transmission device 10, as described below, and the handle shaft 3 rotates, thereby rotating the spool. As described above, in this embodiment, the driving force input portion 46 of the arm body 41 is configured to receive the force (driving force) applied to the knob 5 by the user of the fishing reel 1.

[0019] 3, a screw hole 44A into which the screw portion 42A of the end cap 42 is inserted is formed at the tip of the shaft portion 44 in the +X direction. The end cap 42 can be fixed to the arm main body 41 by threading the screw portion 42A of the end cap 42 into the screw hole 44A of the shaft portion 44 of the arm main body 41. In this embodiment, the position of the head portion 42B of the end cap 42 in the X direction can be adjusted by adjusting the degree of threading of the screw portion 42A of the end cap 42.

[0020] In this way, in this embodiment, the position of the head portion 42B of the end cap 42 in the X direction can be adjusted, and therefore the degree of compression of the coil spring 50 disposed between the head portion 42B of the end cap 42 and the insertion portion 32 of the gear holder 30 can be adjusted. In other words, by adjusting the position of the head portion 42B of the end cap 42 in the X direction, the force (biasing force) with which the coil spring 50 urges the movable arm 40 can be adjusted.

[0021] 3 and 6B, a gear portion 47 having a plurality of teeth aligned in the X direction is formed inside the base portion 43. The teeth of this gear portion 47 are adapted to mesh with the teeth 25 of the rotary gear 20 housed in the gear holder 30, and the gear portion 47 and the rotary gear 20 form a rack-and-pinion structure.

[0022] An opening 48A is formed on the −Y direction side of base 43, and extension pieces 49 are formed on the −X direction side of opening 48A, extending in the Z direction from both edges of base 43. An opening 48B is formed between these extension pieces 49 and has a narrower width in the Z direction than opening 48A.

[0023] Fig. 7 is a longitudinal cross-sectional view of the power transmission device 10 of the handle mechanism 4 shown in Fig. 2, and Fig. 8 is a cross-sectional view of the gear holder 30 and the movable arm 40 of the handle mechanism 4 shown in Fig. 2 taken along line AA. As shown in Figs. 7 and 8, a guide groove 60 for accommodating the head portion 36 of the hook portion 34 of the gear holder 30 is formed on the +Y direction side of the extension piece 49 of the arm main body 41. This guide groove 60 extends along the X direction and communicates with the opening 48A. In addition, the guide groove 37 of the hook portion 34 is located between the extension pieces 49 extending from both edges of the base portion 43 of the arm main body 41.

[0024] With this configuration, the hook portion 34 and neck portion 35 of the gear holder 30 engage with the extension piece 49 of the arm body 41, while the head portion 36 of the gear holder 30 moves in the X direction inside the guide groove 60 of the arm body 41. In this way, in this embodiment, the extension piece 49 and guide groove 60 of the arm body 41 engage with the hook portion 34 of the gear holder 30 and function as a rail portion that guides the movement of the hook portion 34 in the X direction. By using such a rail portion to guide the movement of the gear holder 30 relative to the movable arm 40, the structure of the power transmission device 10 can be simplified. When assembling the power transmission device 10, the head portion 36 of the hook portion 34 of the gear holder 30 can be introduced into the guide groove 60 through the opening 48A of the arm body 41.

[0025] As shown in FIG. 9, the coil spring 50 biases the movable arm 40 in a direction (i.e., the +X direction) that shortens the distance D1 from the center G of the handle shaft 3 to the center C of the through-hole 46A of the drive force input portion 46. Meanwhile, when the fishing reel 1 is actually used, a load torque corresponding to the tension of the fishing line acts on the handle shaft 3, and this load torque applies a force in the -X direction to the gear portion 47 of the movable arm 40 via the rotating gear 20. If the force with which the coil spring 50 biases the movable arm 40 is P1 and the force that the load torque applies to the gear portion 47 of the movable arm 40 is Q1, when the load torque is small and Q1 is smaller than P1, the movable arm 40 does not move relative to the gear holder 30 and remains in its initial state. Therefore, the effective radius over which the user of the fishing reel 1 turns the handle mechanism 4 is the distance D1 shown in FIG. 9.

[0026] When the tension on the fishing line increases due to, for example, a stronger pull from a fish, the load torque acting on the handle shaft 3 also increases. However, when the force exerted by the load torque on the gear portion 47 of the movable arm 40 becomes greater than the biasing force P1 of the coil spring 50 described above, the movable arm 40 moves in the -X direction relative to the gear holder 30, as shown in FIG. 10. At this time, the movable arm 40 moves to a position where the force P2 exerted by the coil spring 50 on the movable arm 40 (P2 is greater than P1 in FIG. 9 because the coil spring 50 is further compressed from the state shown in FIG. 9 as the movable arm 40 moves) balances with the force Q2 exerted by the load torque on the gear portion 47 of the movable arm 40. Therefore, the effective radius around which the user of the fishing reel 1 rotates the handle mechanism 4 is the distance D2 from the center G of the handle shaft 3 to the center C of the through-hole 46A of the drive force input portion 46, which is longer than the effective radius D1 in the initial state. Therefore, the user of the fishing reel 1 can rotate the handle mechanism 4 with a relatively small force, even when the load torque increases.

[0027] Thus, according to this embodiment, when the load torque acting on the handle shaft 3 increases, the movable arm 40 moves relative to the gear holder 30 to a position where the force that the load torque imparts to the gear portion 47 of the movable arm 40 is balanced with the force that the coil spring 50 applies to the movable arm 40, and the distance from the center G of the handle shaft 3 to the center C of the through hole 46A of the movable arm 40 increases. Therefore, even if the load torque increases, the driving force required to rotate the handle shaft 3 can be continuously and automatically adjusted to a smaller value in a stepless manner, and there is no need to interrupt fishing to adjust the driving force.

[0028] Furthermore, in this embodiment, by adjusting the degree of engagement of the threaded portion 42A of the end cap 42 of the movable arm 40, it is possible to adjust the degree of compression of the coil spring 50 disposed between the head portion 42B of the end cap 42 and the insertion portion 32 of the gear holder 30. In this way, by adjusting the force (biasing force) with which the coil spring 50 urges the movable arm 40, it is possible to adjust the timing at which the movable arm 40 starts to move relative to the gear holder 30.

[0029] Furthermore, since the end cap 42 of the movable arm 40 is detachably attached to the shaft portion 44 of the arm body 41, the end cap 42 can be removed from the shaft portion 44 of the arm body 41 and the coil spring 50 can be easily replaced with a new one or a different type.

[0030] In this embodiment, an example has been described in which the coil spring 50 is used as the biasing member that biases the movable arm 40, but the biasing member that biases the movable arm 40 is not limited to such a coil spring, and may be other types of springs such as leaf springs, or biasing members such as rubber. Also, in this embodiment, the movable arm 40 is biased by compressing the coil spring 50 that serves as the biasing member, but those skilled in the art will understand that it is also possible to configure the movable arm 40 to be biased by holding the coil spring 50 in a tensioned state.

[0031] Furthermore, in this embodiment, the gear portion 47 of the movable arm 40 is formed linearly along the X direction, but the gear portion 47 of the movable arm 40 does not necessarily have to be formed linearly, and may be curved, for example, along a curve or an arc. By curving the gear portion 47 along a curve or an arc in this way, the length of the movable arm 40 in the X direction can be shortened.

[0032] In the above embodiment, an example was described in which the power transmission device 10 according to one embodiment of the present invention is applied to a fishing reel 1, but the above-described power transmission device 10 can be applied to any tool, machine, appliance, device, vehicle, etc., as long as it has a rotating shaft on which a load torque acts. As an example, Figure 11 is a schematic diagram showing an example in which the above-described power transmission device 10 is applied to a bicycle 101.

[0033] The bicycle 101 shown in FIG. 11 has a rear wheel 102 (wheel), a crank wheel 104 having a crankshaft 103, a chain 105 as a connecting member that connects the rear wheel 102 and the crank wheel 104 so as to transmit the rotation of the crank wheel 104 to the rear wheel 102, and a crank mechanism 106 attached to the crankshaft 103. The crank mechanism 106 includes the power transmission device 10 described above and pedals 107 attached to the power transmission device 10. The rotary gear 20 of the power transmission device 10 is attached to the crankshaft 103, and the pedals 107 are rotatably attached to the driving force input portion 46 of the arm main body 41. The connecting member that connects the rear wheel 102 and the crank wheel 104 may be a belt.

[0034] Even with this configuration, when the load torque acting on the crankshaft 103 increases, such as when riding the bicycle 101 uphill, the movable arm 40 moves to a position where the force that the load torque imparts to the gear portion 47 of the movable arm 40 is balanced with the force with which the coil spring 50 biases the movable arm 40, and the distance from the center of the crankshaft 103 to the center C of the driving force input portion 46 of the movable arm 40 increases. Therefore, even if the load torque increases, the driving force required to rotate the crankshaft 103 can be continuously and automatically adjusted to a smaller value in a stepless manner, making it easier to ride uphill.

[0035] As described above, according to the first aspect of the present invention, there is provided a power transmission device that can easily adjust the force required to rotate a rotating shaft in accordance with changes in load torque and transmit the force to the rotating shaft to rotate it. Specifically, the power transmission device according to the present invention can employ the following configuration.

[0036] (Configuration 1) A power transmission device is used to transmit a driving force to a rotating shaft on which a load torque acts to rotate the rotating shaft. The power transmission device includes: a rotating gear having a central portion attached to the rotating shaft to rotate together with the rotating shaft and an outer peripheral portion on which a plurality of teeth are formed along a circumferential direction; a gear holder having a gear accommodating portion that rotatably accommodates the rotating gear; and a movable arm configured to be movable relative to the gear holder. The movable arm has a driving force input portion that receives the driving force and a gear portion formed with an array of teeth that mesh with the plurality of teeth of the rotating gear. The power transmission device further includes a biasing member that biases the movable arm in a direction that shortens the distance from the center of the rotating shaft to the driving force input portion of the movable arm.

[0037] With this configuration, when the load torque acting on the rotating shaft increases, the movable arm moves to a position where the force exerted by the load torque on the gear portion of the movable arm and the force exerted by the biasing member on the movable arm are balanced, and the distance from the center of the rotating shaft to the drive force input portion of the movable arm (the effective radius for rotating the power transmission device) increases. Therefore, even if the load torque increases, the drive force required to rotate the rotating shaft can be continuously and automatically adjusted to a smaller value in a stepless manner. In other words, the power transmission device of the present invention makes it possible to automatically adjust the force required to rotate the rotating shaft in response to changes in load torque and transmit it to the rotating shaft.

[0038] (Configuration 2) In the above configuration 1, the gear holder may further have a cylindrical insertion portion. The movable arm may further have a shaft portion inserted into the insertion portion of the gear holder and an end cap detachably attached to the tip of the shaft portion. The biasing member may be disposed between the end cap of the movable arm and the insertion portion of the gear holder. By adopting such a configuration, the biasing member can be easily replaced by simply removing the end cap.

[0039] (Configuration 3) In the above configuration 2, the end cap of the movable arm may be configured so that the fixed position of the end cap to the shaft can be adjusted. By adjusting the fixed position of the end cap of the movable arm to the shaft in this way, it is possible to adjust the biasing force of the biasing member and thereby adjust the timing at which the movable arm starts to move relative to the gear holder.

[0040] (Configuration 4) In the above configuration 2 or 3, the movable arm may further have a stopper portion that can come into contact with the insertion portion of the gear holder.

[0041] (Configuration 5) In the above configuration 1, the gear holder may further have a cylindrical insertion portion and a hook portion formed on the opposite side of the insertion portion. The movable arm may further have a shaft portion inserted into the insertion portion of the gear holder and a rail portion that engages with the hook portion of the gear holder to guide movement of the hook portion. By guiding the movement of the gear holder relative to the movable arm with such a rail portion, the structure of the power transmission device can be simplified.

[0042] (Configuration 6) In the above configuration 5, the movable arm may further have a stopper portion that can come into contact with the insertion portion of the gear holder.

[0043] (Configuration 7) According to a second aspect of the present invention, there is provided a fishing reel that can easily adjust the force required to rotate the handle shaft in response to changes in load torque and transmit it to the handle shaft to rotate the spool. This fishing reel includes a reel body having a handle shaft for rotating the spool, and a handle mechanism attached to the handle shaft of the reel body. The handle mechanism includes a power transmission device according to any one of aspects 1 to 6 that is attached to the handle shaft of the reel body as the rotation shaft, and a knob attached to the drive force input section of the power transmission device.

[0044] With this configuration, when the load torque acting on the handle shaft increases, the movable arm moves to a position where the force that the load torque imparts to the gear portion of the movable arm and the force with which the biasing member biases the movable arm are balanced, and the distance from the center of the handle shaft to the drive force input portion of the movable arm (the effective radius for rotating the handle mechanism) increases. Therefore, even if the load torque increases, the drive force required to rotate the handle shaft can be continuously and automatically adjusted to a smaller value in a stepless manner, so there is no need to interrupt fishing to adjust the drive force.

[0045] (Configuration 8) According to a third aspect of the present invention, there is provided a bicycle that can easily adjust the force required to rotate the crankshaft in response to changes in load torque and transmit it to the crankshaft to rotate the crank wheel. The bicycle includes a wheel, a crank wheel having a crankshaft, a connecting member that connects the wheel and the crank wheel so as to transmit the rotation of the crank wheel to the wheel, and a crank mechanism attached to the crankshaft of the crank wheel. The crank mechanism includes a power transmission device according to any one of aspects 1 to 6 that is attached to the crankshaft as the rotation shaft, and pedals that are attached to the driving force input section of the power transmission device.

[0046] With this configuration, when the load torque acting on the crankshaft increases, the movable arm moves to a position where the force exerted by the load torque on the gear portion of the movable arm and the force exerted by the biasing member on the movable arm are balanced, and the distance from the center of the crankshaft to the drive force input portion of the movable arm (the effective radius for rotating the crank mechanism) increases. Therefore, even if the load torque increases, the drive force required to rotate the crankshaft can be continuously and automatically adjusted to a smaller value in a stepless manner. In other words, with the bicycle of the present invention, the force required to rotate the crankshaft can be automatically adjusted in response to changes in the load torque and transmitted to the crankshaft.

[0047] Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments and may be embodied in various different forms within the scope of the technical concept thereof. [Explanation of symbols]

[0048] 1 fishing reel 2 Reel body 3 Handle shaft (rotating shaft) 4. Handle mechanism 5 Knob 6 screws 10 Power transmission device 20 Rotating Gear 22 Central part 23 Cylindrical part 24 Outer periphery 25 teeth 26 Nut 30 Gear holder 31 Beam section 32 Insertion part 33 Gear housing 34 Hook part 35 Neck 36 Head 37 Guide groove 40 Movable Arm 41 Arm body 42 End cap 43 Base 44 Shaft 45 Operating unit 46 Driving force input section 47 Gear section 49 Extension piece 50 Coil spring (biasing member) 60 Guide groove 70 Stopper part 101 Bicycle 102 Rear wheel (wheel) 103 crankshaft 104 crank wheel 105 Chain (connecting member) 106 Crank mechanism 107 Pedals

Claims

1. A power transmission device for transmitting a driving force to a rotating shaft on which a load torque acts, thereby rotating the rotating shaft, a rotary gear having a central portion attached to the rotary shaft so as to rotate together with the rotary shaft, and an outer peripheral portion on which a plurality of teeth are formed along a circumferential direction; a gear holder having a gear accommodating portion that rotatably accommodates the rotary gear, a cylindrical insertion portion, and a hook portion formed on the opposite side of the insertion portion; a movable arm configured to be movable relative to the gear holder, the movable arm including: a driving force input portion that receives the driving force; a gear portion formed with an array of teeth that mesh with the plurality of teeth of the rotary gear; a shaft portion that is inserted into the insertion portion of the gear holder; and a rail portion that engages with the hook portion of the gear holder to guide movement of the hook portion; a biasing member that biases the movable arm in a direction that shortens the distance from the center of the rotation shaft to the driving force input portion of the movable arm; A power transmission device comprising:

2. The movable arm further has an end cap that can be detachably attached to the tip of the shaft portion, the biasing member is disposed between the end cap of the movable arm and the insertion portion of the gear holder. The power transmission device according to claim 1 .

3. The power transmission device according to claim 2 , wherein the end cap of the movable arm is configured so that a fixed position to the shaft portion can be adjusted.

4. 3. The power transmission device according to claim 2, wherein the movable arm further includes a stopper portion that can come into contact with the insertion portion of the gear holder.

5. 2. The power transmission device according to claim 1, wherein the movable arm further includes a stopper portion that can come into contact with the insertion portion of the gear holder.

6. a reel body having a handle shaft for rotating the spool; a handle mechanism attached to the handle shaft of the reel body; Equipped with The handle mechanism includes: The power transmission device according to claim 1 , which is attached to the handle shaft as the rotation shaft; a knob attached to the driving force input portion of the power transmission device; Including, Fishing reel.

7. Wheels and a crank wheel having a crankshaft; a connecting member that connects the wheel and the crank wheel so as to transmit rotation of the crank wheel to the wheel; a crank mechanism attached to the crankshaft of the crank wheel; Equipped with The crank mechanism includes: The power transmission device according to any one of claims 1 to 5, which is attached to the crankshaft as the rotation shaft; a pedal attached to the driving force input portion of the power transmission device; Including, bicycle.

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