Shaft structure

Abstract

To be able to control rotational speed of a rotating shaft with a compact and simple configuration.SOLUTION: There are provided: a speed adjustment member that is provided at a rotating shaft and rotates with the rotating shaft; and a contact member that is provided on the outside in the diameter direction of the rotating shaft when viewed along the longitudinal direction of the rotating shaft. A distance between the periphery of the speed adjustment member and the rotation center of the rotating shaft differs depending on the position in the periphery. As the speed adjustment member rotates, the rotation state is switched between a first state in which the speed adjustment member and the contact member rotate without contact with each other and a second state in which the speed adjustment member and the contact member rotate with contact with each other.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a shaft structure. [Background technology]

[0002] Patent Document 1 discloses a lid opening / closing device that includes a lid body rotatably attached to a case by a support shaft, an interlocking gear that rotates together with the lid body around the support shaft, and a damper member that has a damper gear that rotates meshing with the interlocking gear and brakes the rotation of the interlocking gear. In this lid opening / closing device, the interlocking gear is supported by the support shaft at a position eccentric from the center of the pitch circle of its teeth, and is configured so that when the fall cover is in the middle of closing, the distance from the support shaft to the teeth is short, and when the fall cover has finished closing, the distance from the support shaft to the teeth gradually increases. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-209479 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the configuration described in Patent Document 1 has a complicated structure using gears, and it is difficult to make it compact.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a shaft structure that is compact and has a simple configuration and is capable of controlling the rotation speed of a rotating shaft. [Means for solving the problem]

[0006] The shaft structure of the present invention is characterized in that it comprises, for example, a speed adjustment member that is provided on a rotating shaft and rotates together with the rotating shaft, and a contact member that is provided radially outward of the rotating shaft, wherein the distance between the periphery of the speed adjustment member and the rotation center of the rotating shaft varies depending on the position on the periphery, and as the speed adjustment member rotates, the state switches between a first state in which the speed adjustment member and the abutment member rotate without coming into contact with each other, and a second state in which the speed adjustment member and the abutment member rotate while coming into contact with each other.

[0007] According to this configuration, the speed adjusting member and the abutment member come into contact with each other or not as the speed adjusting member rotates. The abutment between the speed adjusting member and the abutment member slows down the rotation speed of the rotating shaft, and therefore the rotation speed of the rotating shaft, i.e., the supporting member, can be controlled. Furthermore, since the shaft structure does not have gears or the like, it can be made compact and can be used in relatively small structures. Therefore, according to the present invention, the rotation speed of the rotating shaft can be controlled with a compact and simple configuration.

[0008] At least one of the speed adjusting member and the contact member may be made of an elastic material, whereby the speed adjusting member and the rotating shaft can continue to rotate while decelerating.

[0009] The abutment member may be a plate-like member having a fixed first end and an elastic member that is curved so as to be convex toward the center line of the rotating shaft, thereby making it possible to easily adjust the amount of deformation of the abutment member when the speed adjusting member and the abutment member abut against each other, i.e., the degree of deceleration of the rotating shaft.

[0010] The abutting member may have a wide width at the first end and gradually narrower width toward a second end opposite the first end. This allows for complex rotation speed control with a simple configuration, since the frictional force generated between the speed adjusting member and the abutting member increases as the abutting position between the speed adjusting member and the abutting member approaches the first end.

[0011] The rotating shaft may have a rotating shaft part, the speed adjusting member may be provided adjacent to the rotating shaft part, and the abutting member may be formed by curving a plate-like member and have an arc shape that substantially follows the outer circumferential surface of the rotating shaft part when viewed along the longitudinal direction of the rotating shaft. It is easy to adjust the shape of the abutting member so that the length of the arc shape is a desired length, and this makes it easy to adjust the time for adjusting the rotation speed of the rotating shaft.

[0012] A plurality of the abutment members may be provided, and in the first state, the speed adjusting member may abut against at least one of the plurality of the abutment members. This allows the speed adjusting member and the abutment member to abut against each other multiple times while the speed adjusting member makes one revolution, enabling more complicated rotation speed control. Effect of the Invention

[0013] According to the present invention, the rotation speed of a rotating shaft can be controlled with a compact and simple configuration. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing an outline of a shaft structure 1. [Diagram 2] 1A and 1B are longitudinal cross-sectional views showing an outline of the shaft structure 1, in which (a) is a diagram showing a first state in which the speed adjusting member 13 is not in contact with the abutment member 14, and (b) is a diagram showing a second state in which the speed adjusting member 13 is in contact with the abutment member 14. [Diagram 3] 1A is a diagram showing an outline of the shaft structure 1A, where (a) is a longitudinal cross-sectional view showing a first state in which the speed adjusting member 13A is not in contact with the abutment member 14, and (b) is a longitudinal cross-sectional view showing a second state in which the speed adjusting member 13A is in contact with the abutment member 14. [Figure 4] 13 is a diagram showing an outline of shaft structure 1B, and is a vertical cross-sectional view showing a second state in which speed adjusting member 13B abuts against abutment member 14. FIG. [Diagram 5] 13 is a diagram showing an outline of shaft structure 1C, and is a vertical cross-sectional view showing a second state in which speed adjusting member 13B abuts against abutment member 14. FIG. [Figure 6]1A and 1B are diagrams showing an outline of shaft structure 1D, where (a) is a vertical cross-sectional view showing a first state in which speed adjustment member 13A is not in contact with contact member 14A, and (b) is a vertical cross-sectional view showing a second state in which speed adjustment member 13A is in contact with contact member 14A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of a shaft structure according to the present invention will be described with reference to the drawings.

[0016] <First embodiment> Fig. 1 is a diagram showing an outline of a shaft structure 1 according to a first embodiment. Fig. 1 shows a perspective view of the main parts. The shaft structure 1 is configured to rotatably connect and support two members. The shaft structure 1 connects, for example, an actuator (not shown) and an appropriate opening / closing lid (not shown).

[0017] The shaft structure 1 mainly comprises a speed adjusting member 13 and a contact member 14. The speed adjusting member 13 is provided on the rotating shaft 10 provided inside the bearing sleeve 12. The contact member 14 is provided on the bearing sleeve 12. However, the bearing sleeve 12 is not essential.

[0018] 2 is a longitudinal cross-sectional view showing an outline of the shaft structure 1, where (a) is a diagram showing a first state in which the speed adjusting member 13 is not in contact with the contact member 14, and (b) is a diagram showing a second state in which the speed adjusting member 13 is in contact with the contact member 14. Hereinafter, the axial direction of the rotating shaft 10 is defined as the y direction, and the direction from the front to the back of the paper in FIG. 1 is defined as the +y direction. Moreover, the direction from left to right as viewed from the -y direction is defined as the +x direction, and the direction perpendicular to the x and y directions is defined as the z direction.

[0019] Moreover, the arrows in the figures indicate examples of the rotation direction, but this is merely an example, and the rotation may be in the opposite direction.

[0020] The rotating shaft 10 is, for example, a rod-shaped member, and transmits a rotational force from an actuator (not shown) to an opening / closing door (not shown). The rotating shaft 10 may rotate within a predetermined angle range (for example, 180 degrees) or may rotate 360 ​​degrees.

[0021] The rotation of the rotating shaft 10 is not limited to that by an actuator, and may be rotated by an elastic member such as a spring, or may be rotated manually. The rotating shaft 10 may also be rotated by the weight of a member supported by the shaft structure 1. This configuration is assumed, for example, when the rotating shaft 10 is disposed substantially horizontally and a plate-shaped opening and closing lid is provided on the rotating shaft 10, and the opening and closing lid closes from a substantially horizontal open state to a substantially vertical closed state, but is not limited thereto.

[0022] The rotating shaft 10 has, for example, a pair of rotating shaft parts 11. A speed adjusting member 13 is provided between the rotating shaft parts 11. The speed adjusting member 13 rotates together with the rotating shaft parts 11, i.e., the rotating shaft 10. The rotating shaft 10 and the speed adjusting member 13 are provided inside a cylindrical bearing sleeve 12.

[0023] The diameters of the pair of rotating shaft parts 11 do not have to be the same, and the pair of rotating shaft parts 11 may be spaced apart. The speed adjusting member 13 only needs to be provided adjacent to one of the rotating shaft parts 11.

[0024] The speed adjusting member 13 is columnar. The speed adjusting member 13 is elliptical (rectangular with rounded corners) when viewed along the longitudinal direction of the rotating shaft 10 (along the y direction).

[0025] The peripheral edge 13c of the speed adjusting member 13 has two linear flat portions 13a and two curved portions 13b provided between the flat portions 13a. The curved portions 13b are curved. The radius of curvature of the curved portions 13b when viewed along the y direction may or may not be constant.

[0026] The speed adjusting member 13 is eccentric with respect to the rotating shaft 10. That is, when viewed along the y direction, a line a2 including the center of gravity of the speed adjusting member 13 does not coincide with the center line a1 of the rotating shaft 10. Also, when viewed along the y direction, the distance L between the center line a1 and the periphery 13c varies depending on a position p on the periphery 13c. Note that the position p is an imaginary point, and is located at an arbitrary position on the periphery 13c.

[0027] The abutment member 14 is provided radially outward of the rotating shaft 10 (rotating shaft part 11) when viewed along the y direction. Note that the radially outward of the rotating shaft 10 includes a case where most of the abutment member 14 is on the outer side of the rotating shaft 10 and a part of the abutment member 14 overlaps with the rotating shaft 10.

[0028] In the present embodiment, the abutment member 14 is fixed to the bearing sleeve 12, but the configuration for fixing the abutment member 14 is not limited to this. The abutment member 14 abuts against the speed adjusting member 13 to control the rotation speed of the speed adjusting member 13 and the rotating shaft 10.

[0029] In this embodiment, the abutment member 14 is a plate-like member with a fixed first end 14a, and is an elastic member (here, a leaf spring) that is curved so as to be convex toward the center line a1. In other words, the abutment member 14 is a cantilevered leaf spring. The amount of curvature of the abutment member 14 can be easily adjusted, and this makes it possible to easily adjust the amount of deformation of the abutment member 14 when the speed adjustment member 13 and the abutment member 14 abut against each other, i.e., the biasing force applied to the rotating shaft 10.

[0030] The speed adjusting member 13 and the contact member 14 may have a surface shape that generates an appropriate frictional force when they are in contact with each other. For example, at least one of the speed adjusting member 13 and the contact member 14 may have a rough surface (not roughened or polished).

[0031] When viewed along the y direction, the distance between the center line a1 and the periphery 13c varies depending on the position p on the periphery 13c, and therefore, as the speed adjustment member 13 rotates, the speed adjustment member 13 switches between a first state (the state shown in FIG. 2(a)) in which the speed adjustment member 13 and the abutment member 14 do not abut, and a second state (the state shown in FIG. 2(b)) in which the speed adjustment member 13 and the abutment member 14 abut.

[0032] In the first state, the rotating shaft 10 can rotate without load. In contrast, in the second state, the curved surface portion 13b of the speed adjusting member 13 comes into contact with the abutting member 14, and the abutting member 14 is pressed against the curved surface portion 13b and elastically deforms. In addition, the elastic deformation of the abutting member 14 causes the speed adjusting member 13 to become unfixed, and the speed adjusting member 13, i.e., the rotating shaft 10, continues to rotate.

[0033] While the speed adjusting member 13 and the abutment member 14 are in contact with each other, the abutment member 14 elastically deforms, and the speed adjusting member 13 receives a biasing force due to this elastic deformation. That is, in the second state, the speed adjusting member 13, i.e., the rotating shaft 10, receives a load from the abutment member 14, and the rotation speeds of the speed adjusting member 13 and the rotating shaft 10 become slower than in the first state.

[0034] In addition, the abutment member 14 is curved so as to be convex toward the center line a1, and the curved portion 13b and the abutment member 14 abut against each other, so that the speed adjustment member 13 and the abutment member 14 abut in a linear area along the width direction of the abutment member 14.

[0035] The abutment member 14 has a wide width at the first end 14a and gradually narrows toward the second end 14b, which is the end opposite the first end 14a. Therefore, as the distance L increases, the abutment position between the curved surface portion 13b and the abutment member 14 approaches the first end 14a. As the abutment position between the curved surface portion 13b and the abutment member 14 approaches the first end 14a, the contact area between the curved surface portion 13b and the abutment member 14, i.e., friction, increases, the load on the speed adjustment member 13 increases, and the rotation speed of the speed adjustment member 13 decreases further.

[0036] 2(b), if the rotation continues clockwise or the rotating shaft 10 is rotated in the reverse direction (counterclockwise), the speed adjusting member 13 moves away from the abutment member 14. As a result, the shaft structure 1 transitions to the first state and no longer receives a load from the abutment member 14, so that the rotation speed of the rotating shaft 10 increases (returns to original state).

[0037] According to this embodiment, since the speed adjusting member 13 is provided on the rotating shaft 10, it is possible to control the rotation speed of the rotating shaft 10 with a compact and simple configuration. In addition, since the shaft structure 1 can be made compact, it can be used in a relatively small structure.

[0038] For example, if the shaft structure 1 is used in the portion connecting the lid and the device or container, etc., and the rotation speed is slowed down at an angle before and after the door is fully closed, it is possible to prevent the user from getting their fingers caught in the door. Also, if the shaft structure 1 is used in the opening and closing door of a vending machine, etc., and the rotation speed is slowed down as the door starts to close from its most open position, the user has more time to take out the product, etc., which is convenient to use.

[0039] Furthermore, according to this embodiment, by using a cantilever leaf spring as the abutment member 14, it is possible to control the rotation speed of the rotating shaft 10 with a small and simple configuration. Furthermore, the amount of curvature of the abutment member 14, i.e., the elastic force of the abutment member 14, can be easily adjusted, and this makes it possible to easily adjust the biasing force applied to the rotating shaft 10, i.e., the degree of deceleration of the rotation speed of the rotating shaft 10.

[0040] Furthermore, according to this embodiment, by using the abutment member 14 having a wide first end 14a and a gradually narrower width toward the second end 14b, which is the end opposite the first end 14a, it is possible to control the rotation speed according to the distance L, i.e., the rotation angle of the rotating shaft 10.

[0041] In this embodiment, the speed adjusting member 13 is columnar, but the shape of the speed adjusting member 13 is not limited to this. For example, the speed adjusting member 13 may be thin and plate-like. In this case, the two rotating shaft parts 11 may be connected by a thin rod-like member, and the plate-like speed adjusting member may be provided on this rod-like member. Even in this case, the speed adjusting member is still adjacent to the rotating shaft part 11.

[0042] In addition, in the present embodiment, the abutment member 14 is a leaf spring, but the form of the abutment member 14 is not limited to this. For example, the abutment member may be configured to be biased by a coil spring, or the entire abutment member may be configured from a material that generates elastic force, such as rubber or a sponge-like material.

[0043] In the present embodiment, the abutment member 14 has a wide width at the first end 14a and a gradually narrower width toward the second end 14b, which is the end opposite to the first end 14a, but the shape of the abutment member 14 is not limited to this. For example, the width of the abutment member 14 may be constant. In this case, the rotation speed can be controlled according to the rotation angle of the rotating shaft 10 due to the difference in elastic force of the abutment member 14 at the contact position between the speed adjustment member 13 and the abutment member 14.

[0044] In addition, in this embodiment, the contact member 14 is an elastic member, but it is sufficient that at least one of the speed adjusting member 13 and the contact member 14 is an elastic member. In addition, the surface of at least one of the speed adjusting member 13 and the contact member 14 may have irregularities that generate a predetermined frictional force, or the surface shape may be configured to vary in the circumferential direction so that the magnitude of the frictional force changes according to the rotation angle.

[0045] <Second embodiment> Another embodiment of the shaft structure according to the present invention will be described, focusing on the differences from the previously described embodiment. The second embodiment has a different shape of the speed adjusting member. Note that the same components as those in the previously described embodiment are given the same reference numerals and will not be described.

[0046] FIG. 3 is a diagram showing an outline of a shaft structure 1A according to a second embodiment, in which (a) is a vertical cross-sectional view showing a first state in which the speed adjusting member 13A is not in contact with the abutment member 14, and (b) is a vertical cross-sectional view showing a second state in which the speed adjusting member 13A is in contact with the abutment member 14.

[0047] The shaft structure 1A mainly includes a speed adjustment member 13A and an abutment member 14. The speed adjustment member 13A is provided on the rotating shaft 10. The speed adjustment member 13A is columnar and has an elliptical shape when viewed along the y direction. When the rotating shaft 10, i.e., the speed adjustment member 13A, rotates, a first state in which the speed adjustment member 13A does not abut against the abutment member 14 and a second state in which the speed adjustment member 13A and the abutment member 14 abut against each other are switched. Therefore, the rotation speed of the rotating shaft 10 in the second state can be made slower than the rotation speed of the rotating shaft 10 in the first state.

[0048] <Third embodiment> Another embodiment of the shaft structure according to the present invention will be described, focusing on the differences from the previously described embodiments. The third embodiment differs from the first and second embodiments in the shape of the speed adjusting member. Note that the same reference numerals are used for the same configurations as the previously described embodiments, and the description will be omitted.

[0049] FIG. 4 is a schematic diagram of a shaft structure 1B according to the third embodiment, and is a vertical sectional view showing a second state in which a speed adjusting member 13B abuts against abutment member 14. As shown in FIG.

[0050] The shaft structure 1B mainly includes a speed adjustment member 13B and a contact member 14. The speed adjustment member 13B is provided on the rotating shaft 10. The speed adjustment member 13B is columnar and triangular when viewed along the y direction. When the rotating shaft 10, i.e., the speed adjustment member 13B, rotates, a first state in which the speed adjustment member 13B does not contact the contact member 14 and a second state in which the speed adjustment member 13A and the contact member 14 contact each other are switched. Therefore, the rotation speed of the rotating shaft 10 in the second state can be made slower than the rotation speed of the rotating shaft 10 in the first state.

[0051] In this embodiment, since the speed adjusting member 13B has a triangular shape when viewed in the y direction, the speed adjusting member 13B and the contact member 14 come into contact with each other three times during one revolution. Therefore, more complicated rotation speed control is possible compared to the first and second embodiments.

[0052] In this embodiment, the speed adjustment member 13B has a triangular shape when viewed in the y direction, but the shape of the speed adjustment member 13B is not limited to this. For example, the speed adjustment member may have a polygonal shape when viewed in the y direction.

[0053] <Fourth embodiment> Another embodiment of the shaft structure according to the present invention will be described below, focusing on the differences from the previously described embodiment. The fourth embodiment has a plurality of abutment members. Note that the same reference numerals are used for the same configurations as the previously described embodiment, and the description thereof will be omitted.

[0054] FIG. 5 is a schematic diagram of a shaft structure 1C according to a fourth embodiment, and is a vertical cross-sectional view showing a second state in which a speed adjusting member 13B abuts against abutment member 14. As shown in FIG.

[0055] The shaft structure 1C mainly includes a speed adjusting member 13B and two abutment members 14. A first end 14a of the abutment member 14 is fixed to the bearing sleeve 12. The two abutment members 14 have different circumferential positions when viewed along the y direction. Therefore, the speed adjusting member 13B abuts against at least one of the two abutment members 14.

[0056] According to this embodiment, as the rotating shaft 10, i.e., the speed adjusting member 13B, rotates, the first state in which the speed adjusting member 13A rotates without contacting the contact member 14, and the second state in which the speed adjusting member 13A rotates while contacting the contact member 14, can be switched more quickly. Therefore, more complicated rotation speed control is possible compared to the first to third embodiments.

[0057] In the present embodiment, the shaft structure 1C has two abutment members 14, but the shaft structure 1C may have two or more abutment members 14.

[0058] <Fifth embodiment> Another embodiment of the shaft structure according to the present invention will be described, focusing on the differences from the previously described embodiment. The fifth embodiment is an embodiment in which the shape of the abutment member is different. Note that the same components as those in the previously described embodiment are given the same reference numerals and will not be described.

[0059] 6A and 6B are diagrams showing an outline of a shaft structure 1D according to a fifth embodiment, in which (a) is a vertical cross-sectional view showing a first state in which the speed adjusting member 13A is not in contact with the abutment member 14A, and (b) is a vertical cross-sectional view showing a second state in which the speed adjusting member 13A is in contact with the abutment member 14A.

[0060] The shaft structure 1D mainly comprises a speed adjusting member 13A and a contact member 14A.

[0061] The abutment member 14A is provided on the radially outer side of the rotating shaft 10. In the present embodiment, the abutment member 14 is fixed to the bearing sleeve 12, but the configuration for fixing the abutment member 14 is not limited thereto. The abutment member 14A controls the rotation speed of the speed adjustment member 13A and the rotating shaft 10 by abutting against the speed adjustment member 13A.

[0062] The abutment member 14A is formed by curving a plate-like member, and has an arc shape that is approximately along the outer circumferential surface 11a of the rotating shaft 10, i.e., the rotating shaft part 11, when viewed in the y direction. The speed adjustment member 13A abuts against this arc-shaped inner wall 14d. The abutment member 14A is a leaf spring-like elastic member, and the elastic deformation of the abutment member 14A causes the speed adjustment member 13A to become unfixed, and the speed adjustment member 13A, i.e., the rotating shaft 10, continues to rotate.

[0063] The speed adjusting member 13A and the contact member 14A may have a surface shape that generates an appropriate frictional force when in contact with each other.

[0064] When the rotating shaft 10, i.e., the speed adjusting member 13A, rotates, it switches between a first state (see FIG. 6(a)) in which the speed adjusting member 13A does not contact the inner wall 14d, and a second state (see FIG. 6(b)) in which the speed adjusting member 13A contacts the inner wall 14d. Therefore, the rotation speed of the rotating shaft 10 in the second state can be made slower than the rotation speed of the rotating shaft 10 in the first state.

[0065] In this embodiment, when viewed along the y direction, the inner wall 14d covers about half of the outer circumferential surface 11a, but the length of the inner wall 14d, i.e., the shape of the contact member 14A is not limited to this. By adjusting the shape of the contact member 14A so that the inner wall 14d has a desired length, the time for adjusting (slowing) the rotation speed of the rotating shaft 10 can be easily adjusted.

[0066] In the present embodiment, the contact member 14A is an elastic member, but it is sufficient that at least one of the speed adjusting member 13A and the contact member 14A is an elastic member.

[0067] Furthermore, in this embodiment, the shaft structure 1D has one abutment member 14A, but the shaft structure 1D may have a plurality of abutment members 14A.

[0068] Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within the scope of the gist of the present invention are also included. A person skilled in the art can appropriately change, add, convert, and the like each element of the embodiment.

[0069] In the present invention, "approximately" is a concept that includes not only the case of being strictly identical, but also the case of having errors or deformations that do not lose their identity. In the present invention, "vicinity" means including a certain range (which can be determined arbitrarily) near a reference position. For example, in the case of the vicinity of A, it is a concept that indicates a certain range of area near A, which may or may not include A. In the present invention, "adjacent" is a concept that indicates being next to a reference object or part (B), and including the case where it abuts B and the case where it does not abut B. [Explanation of symbols]

[0070] 1, 1A, 1B, 1C, 1D: Axial structure 10: Rotation axis 11: Rotating shaft parts 11a: Outer surface 12: Bearing tube 13, 13A, 13B: Speed ​​adjusting member 13a: Flat part 13b: Curved part 13c: Periphery 14, 14A: Contact member 14a: 1st end 14b: 2nd end 14d:Inner wall

Claims

1. a speed adjusting member provided on the rotating shaft and rotating together with the rotating shaft; a contact member provided radially outward of the rotary shaft when viewed along the longitudinal direction of the rotary shaft; Equipped with a distance between a periphery of the speed adjusting member and a rotation center of the rotation shaft varies depending on a position on the periphery; As the speed adjusting member rotates, a first state in which the speed adjusting member and the contact member rotate without contacting each other and a second state in which the speed adjusting member and the contact member rotate while contacting each other are switched. A shaft structure characterized by:

2. At least one of the speed adjusting member and the contact member is an elastic member. The shaft structure according to claim 1 .

3. The contact member is a plate-shaped member having a fixed first end and is an elastic member that is curved convexly toward the center line of the rotation shaft. The shaft structure according to claim 1 .

4. The abutting member has a wide first end and a gradually narrower width toward a second end opposite the first end.

4. The shaft structure according to claim 3.

5. The rotating shaft has a rotating shaft part, the speed adjusting member is provided adjacent to the rotating shaft part, The abutment member is formed by curving a plate-like member, and has an arc shape that substantially follows the outer circumferential surface of the rotating shaft part when viewed along the longitudinal direction of the rotating shaft. The shaft structure according to claim 1 .

6. A plurality of the abutment members are provided, In the second state, the speed adjusting member abuts against at least one of the plurality of abutment members. A shaft structure according to any one of claims 1 to 5.

Images