Torsional damper
Patent Information
- Application Number
- CN202410855200.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-07-03
- Filing Date
- 2024-06-28
- Publication Date
- 2025-01-03
Smart Images
Figure CN119244692A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a torsional damper. Background Art
[0002] The torsional damper provided on the crankshaft has a pulley for rotating the belt on its outer peripheral surface, and also serves to drive auxiliary equipment. Therefore, the torsional damper is arranged on the outside of the engine case (outside of the front cover). In recent years, in order to improve fuel efficiency, the hybridization of engines is being promoted, and the belt for driving auxiliary equipment is gradually no longer needed. With this, the development of arranging the torsional damper in the engine case is being promoted with the goal of miniaturizing the engine, suppressing the radiated sound from the torsional damper, and abolishing the oil seal.
[0003] However, when the torsion damper is disposed in the engine housing, the use environment conditions are greatly changed, such as being exposed to the scattered oil and the temperature in the engine housing becoming high. Therefore, various new issues arise, such as improving oil resistance, improving heat resistance, suppressing the high temperature of the annular elastic body provided between the hub and the vibration ring constituting the torsion damper, and preventing the vibration ring from falling to the engine side even if the annular elastic body is damaged.
[0004] Prior art literature
[0005] Patent Literature
[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-177469 Summary of the invention
[0007] Technical problem to be solved by the invention
[0008] An object of the present invention is to provide a torsional damper capable of suppressing a vibration ring from falling to an engine side.
[0009] Solutions for solving technical problems
[0010] The present invention adopts the following means to solve the above-mentioned problems.
[0011] That is, the torsional damper of the present invention comprises:
[0012] A hub having an inner cylinder portion, an outward flange portion integrally provided on the inner cylinder portion, and an outer cylinder portion integrally provided on the radially outer side of the outward flange portion, wherein the inner cylinder portion is fixed to the crankshaft;
[0013] a vibration ring, disposed concentrically with the hub; and
[0014] an annular elastic body, provided between the outer cylinder and the vibration ring,
[0015] The torsional damper is arranged in the engine housing, and the torsional damper is characterized in that:
[0016] The relationship between the dimensional shape of the outer peripheral surface of the outer cylinder and the dimensional shape of the inner peripheral surface of the vibration ring provides a stopper structure that prevents the vibration ring from coming out of the outer cylinder toward the region where the engine is disposed.
[0017] According to the present invention, even if the annular elastic body is damaged and the vibration ring attempts to move toward the engine, it is possible to suppress the vibration ring from falling toward the engine.
[0018] The outer cylindrical portion may include an annular protrusion protruding radially outward at the center of the outer peripheral surface in the width direction.
[0019] The maximum outer diameter of the annular protrusion is larger than the minimum inner diameter of the inner peripheral surface of the vibration ring on the side opposite to the region where the engine is arranged relative to the annular protrusion.
[0020] It should be noted that the “center in the width direction” does not necessarily mean the vicinity of the center in the width direction, but means excluding the ends in the width direction.
[0021] Thus, even if the vibration ring attempts to move toward the engine, the inner peripheral surface of the vibration ring is caught by the annular protrusion provided on the outer cylindrical portion of the hub, and thus the vibration ring does not fall to the engine.
[0022] The maximum outer diameter of the annular protrusion is smaller than the minimum inner diameter of the inner peripheral surface of the vibration ring on the side of the annular protrusion closer to the region where the engine is arranged.
[0023] This allows the vibration ring to be embedded in the hub, so there is no trouble during manufacturing.
[0024] In addition, it is also preferred that the vibration ring has an annular protrusion protruding radially inward at the center of the inner peripheral surface in the width direction.
[0025] The minimum inner diameter of the annular protrusion is smaller than the maximum outer diameter of the outer peripheral surface of the outer cylinder portion on the side of the annular protrusion closer to the region where the engine is arranged.
[0026] It should be noted that the “center in the width direction” does not necessarily mean the vicinity of the center in the width direction, but means excluding the ends in the width direction.
[0027] Thus, even if the vibration ring attempts to move toward the engine, the annular protrusion of the vibration ring is caught on the outer peripheral surface of the outer peripheral ring, so that the vibration ring does not fall to the engine.
[0028] The minimum inner diameter of the annular protrusion may be larger than the maximum outer diameter of the outer peripheral surface of the outer cylinder portion on the side opposite to the region where the engine is arranged relative to the annular protrusion.
[0029] This allows the vibration ring to be embedded in the hub, so there is no trouble during manufacturing.
[0030] The end surface of the annular elastic body may be located inside an end surface of the outer cylinder portion and an end surface of the vibration ring.
[0031] This can suppress the annular elastic body from being greatly deformed.
[0032] It should be noted that the above structures can be used in combination as much as possible.
[0033] Effects of the Invention
[0034] As described above, according to the present invention, it is possible to suppress the vibration ring from falling toward the engine side. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 It is a front view of the torsional damper according to the first embodiment of the present invention.
[0036] Figure 2 It is a schematic cross-sectional view of a torsional damper according to the first embodiment of the present invention.
[0037] Figure 3 It is an enlarged cross-sectional view of the torsional damper of the first embodiment.
[0038] Figure 4 is a graph showing the vibration characteristics of the torsional damper.
[0039] Figure 5 It is a schematic cross-sectional view of a torsional damper according to a second embodiment of the present invention.
[0040] Description of Reference Numerals
[0041] 10. 10X: Torsional Damper
[0042] 20: Crankshaft
[0043] 30: Bolt
[0044] 100, 100X: Wheels
[0045] 110: Inner cylinder part
[0046] 120: Outward flange
[0047] 130, 130X: outer cylinder part
[0048] 131: Annular protrusion
[0049] 132: End face
[0050] 200, 200X: Vibration ring
[0051] 210: End face
[0052] 220: Annular protrusion
[0053] 300, 300X: Ring elastomer
[0054] 310: End face DETAILED DESCRIPTION
[0055] Hereinafter, referring to the accompanying drawings, the method for implementing the invention is described in detail based on the embodiments. However, the size, material, shape and relative arrangement of the structural components described in the embodiments are not intended to limit the scope of the invention to these unless otherwise specified.
[0056] (Example 1)
[0057] Reference Figure 1 to Figure 4 , the torsional damper of embodiment 1 of the invention is described. Figure 1 It is a front view of the torsional damper according to the first embodiment of the present invention. Figure 2 is a schematic cross-sectional view of a torsional damper according to a first embodiment of the present invention, Figure 1 AA section view in. Figure 3 It is a partially enlarged cross-sectional view of the torsional damper of this embodiment. Figure 4 is a graph showing the vibration characteristics of a torsional damper, Figure 4 (a) is an illustration of the effect of the natural vibration frequency of the torsional damper. Figure 4 (b) is an explanatory diagram of the influence of the inertia moment of the vibration ring.
[0058] <Torsional Damper>
[0059] The overall structure of the torsional damper 10 of the present embodiment is described as follows: The torsional damper 10 of the present embodiment includes a hub 100 , a vibration ring 200 disposed concentrically with the hub 100 , and an annular elastic body 300 .
[0060] The wheel hub 100 is a metal annular member. The wheel hub 100 comprises: an inner cylinder portion 110; an outward flange portion 120 integrally provided on the inner cylinder portion 110; and an outer cylinder portion 130 integrally provided on the radially outer side of the outward flange portion 120. In addition, the inner cylinder portion 110 is fixed to the crankshaft 20 of the engine. It should be noted that Figure 2 In FIG. 1 , the crankshaft 20 and the positions of the bolts 30 for fixing the torsional damper 10 to the crankshaft 20 are shown by dotted lines.
[0061] The vibration ring 200 is a metal annular member. In addition, the annular elastic body 300 is made of a rubber material and is provided between the outer cylinder portion 130 of the hub 100 and the vibration ring 200. The annular elastic body 300 can be obtained by vulcanization molding, for example, and is vulcanized and bonded to the outer cylinder portion 130 and the vibration ring 200.
[0062] The torsional damper 10 constructed as described above is arranged in the engine housing. Figure 2 In FIG. 1 , the position of the inner wall surface of a part of the engine housing (a part of the front cover) is shown by a dotted line C. Figure 2 In FIG. 1 , the right side of the torsion damper 10 is the region (E) where the engine is arranged.
[0063] In the torsional damper 10, when vibration of a frequency at which the crankshaft 20 resonates is transmitted, the vibration ring 200 vibrates, thereby suppressing the resonance of the crankshaft 20. That is, the vibration ring 200 is designed to suppress the resonance of the crankshaft 20 with respect to vibration in the rotational direction (torsion direction) of the crankshaft 20.
[0064] <Detailed structure of each member of the torsional damper>
[0065] The detailed structure of each component of the torsional damper 10 is described. In the outer cylinder portion 130 of the wheel hub 100 of the present embodiment, an annular protrusion 131 protruding radially outward is provided at the center of the width direction of the outer circumference (the width direction in the direction in which the central axis of the torsional damper 10 extends). That is, the outer circumference of the outer cylinder portion 130 is configured such that the outer diameter of the portion where the annular protrusion 131 is provided is large, and the outer diameters of both sides of the outer circumference of the outer cylinder portion 130 are smaller than the outer diameter of the annular protrusion 131. Furthermore, the inner circumference of the vibration ring 200 is formed in a shape that is annularly concave at the center of the width direction of the inner circumference of the vibration ring 200 in a manner that follows the shape of the outer circumference of the outer cylinder portion 130. That is, the inner diameter of the inner circumference of the vibration ring 200 is large at the center in the width direction, and the inner diameters of both sides of the inner circumference of the vibration ring 200 are smaller than the inner diameter at the center.
[0066] Furthermore, the maximum outer diameter R10 of the annular protrusion 131 is set to be larger than the minimum inner diameter R21 on the side opposite to the region (E) where the engine is disposed from the annular protrusion 131 in the inner circumferential surface of the vibration ring 200. Furthermore, the maximum outer diameter R10 of the annular protrusion 131 is set to be smaller than the minimum inner diameter R22 on the side of the region (E) where the engine is disposed from the annular protrusion 131 in the inner circumferential surface of the vibration ring 200.
[0067] It should be noted that, in the torsional damper 10 of the present embodiment, the positional deviation of the vibration ring 200 to the side opposite to the region (E) where the engine is arranged after heat aging (after 533 hours in an environment of 130° C.) is set to be 1 mm or less. This prevents the vibration ring 200 from contacting the inner wall surface of a part of the engine case (a part of the front cover).
[0068] <Advantages of the torsional damper of this embodiment>
[0069] According to the torsional damper 10 of the present embodiment, a stopper structure is formed to prevent the vibration ring 200 from slipping out of the outer cylinder 130 toward the area where the engine is arranged, based on the relationship between the size and shape of the outer circumferential surface of the outer cylinder 130 and the size and shape of the inner circumferential surface of the vibration ring 200. More specifically, an annular protrusion 131 is provided on the outer circumferential surface of the outer cylinder 130, and as described above, the hub 100 and the vibration ring 200 are configured in such a manner that R10>R21. Therefore, even if the annular elastic body 300 is damaged and the vibration ring 200 is to move toward the engine side, the inner circumferential surface of the vibration ring 200 will be caught by the annular protrusion 131 provided on the outer cylinder 130 of the hub 100. Therefore, the vibration ring 200 will not fall to the engine side.
[0070] Here, in order to suppress the vibration ring from falling to the engine side, it is also considered to provide a flange-shaped stopper at the end of the engine side in the outer cylinder of the wheel hub to limit the movement of the vibration ring to the engine side. However, there is a limit to increasing the width of the outer cylinder as a whole. When such a structure is adopted, it is necessary to reduce the width of the fitting portion between the annular elastomer and the outer cylinder. Therefore, it becomes the main reason for the high temperature of the annular elastomer. In response to this, according to the torsional damper 10 of this embodiment, the width of the fitting portion between the annular elastomer 300 and the outer cylinder 130 can be made wider than the case where a flange-shaped stopper is provided, and the high temperature of the annular elastomer 300 can be suppressed. As a result, the damage of the annular elastomer 300 can be suppressed.
[0071] As described above, according to the torsional damper 10 of the present embodiment, the hub 100 and the vibration ring 200 are configured so that R22>R10. Thus, the vibration ring 200 can be embedded in the hub 100. That is, by making the vibration ring 200 move relative to the hub 100, Figure 2 The relative right movement in the wheel hub 100 and the vibration ring 200 can be made Figure 2 In this state, the torsion damper 10 can be obtained by molding the annular elastic body 300 by vulcanization molding. Therefore, no trouble occurs during manufacturing.
[0072] Here, it is desirable to adopt a structure in which the end surface of the annular elastic body 300 is located inside the end surface of the outer cylinder portion 130 and the end surface of the vibration ring 200. Figure 3 Provide explanation. Figure 3 (a) is an enlarged cross-sectional view of a case where a structure is adopted in which the end surface 310 of the annular elastic body 300 is located inside the end surface 132 of the outer cylinder portion 130 and the end surface 210 of the vibration ring 200 . Figure 3 (b) is an enlarged cross-sectional view of a case where a structure is adopted in which the end surface 310 of the annular elastic body 300 is located outside the end surface 132 of the outer cylinder portion 130 and the end surface 210 of the vibration ring 200 .
[0073] When the vibration ring 200 rotates relative to the hub 100 as the crankshaft 20 rotates, the annular elastic body 300 is deformed. Here, the deeper the position inside the annular elastic body 300, the greater the restraint force on the annular elastic body 300 generated by the hub 100 and the vibration ring 200. Therefore, in the annular elastic body 300, the deeper the position inside (see arrow X1 in the figure), the greater the deformation amount from the initial state, and the closer the position to the end face 310 (surface) (see arrow X2 in the figure), the smaller the deformation amount from the initial state.
[0074] like Figure 3 As shown in (a), in the case of a structure in which the end face 310 of the annular elastic body 300 is located at a position inside the end face 132 of the outer cylinder 130 and the end face 210 of the vibration ring 200, the difference in deformation between the position X1 deep inside and the position X2 close to the end face 310 is relatively small. Figure 3 As shown in (b), in the case of a structure in which the end face 310 of the annular elastic body 300 is located at a position outside the end face 132 of the outer tube portion 130 and the end face 210 of the vibration ring 200, the difference in deformation between the position X1 deep inside and the position X2 close to the end face 310 becomes larger. As a result, cracks are likely to occur in the annular elastic body 300. Once cracks occur, the cracks gradually become larger, and the annular elastic body 300 is likely to break. Therefore, it is desirable to adopt a structure in which the end face 310 of the annular elastic body 300 is located at a position inside the end face 132 of the outer tube portion 130 and the end face 210 of the vibration ring 200. It should be noted that in Figure 3 In FIG. 1 , only the end surface 310 on one side of the annular elastic body 300 is shown, but it is obvious that the same is true for the end surface on the opposite side.
[0075] (Various methods for suppressing deterioration of annular elastic body)
[0076] Various methods for suppressing the degradation of the annular elastic body 300 are described. In order to suppress the damage (breakage) of the annular elastic body 300 and to suppress the degradation of the annular elastic body 300, it is necessary to suppress the high temperature of the annular elastic body 300. Then, in order to suppress the high temperature of the annular elastic body 300, it is necessary to reduce the strain of the annular elastic body 300 when the crankshaft 20 rotates at a high speed. In the case of a four-cylinder engine, various vibrations are generated, but a significant large vibration peak is generated in the fourth vibration and the sixth vibration. It should be noted that N times refers to the vibration cycle that occurs in one rotation of the crankshaft. For example, it is one time when the vibration occurs once in one rotation. In addition, for the vibration peak generated by the crankshaft monomer (in the state where the torsion damper is not provided), the vibration peak is reduced by providing a torsion damper. As a result, a vibration peak smaller than the initial vibration peak that can occur at a low frequency side than the frequency generating the original vibration peak is called 1 section, and a vibration peak smaller than the initial vibration peak that can occur at a high frequency side is called 2 sections. In addition, the following insights are also obtained. That is, if the resonant frequency (natural vibration frequency) of the torsional damper is made consistent with the frequency frequency of the vibration peak generated by the crankshaft alone, the vibration peak of section 1 is equal to the vibration peak of section 2. In contrast, if the resonant frequency (natural vibration frequency) of the torsional damper is shifted toward a lower frequency than the frequency of the vibration peak generated by the crankshaft alone, the vibration peak of section 2 is higher than the vibration peak of section 1. Conversely, if the resonant frequency (natural vibration frequency) of the torsional damper is shifted toward a higher frequency than the frequency of the vibration peak generated by the crankshaft alone, the vibration peak of section 1 is higher than the vibration peak of section 2. In addition, the heavier the inertial mass of the vibration ring 200, the lower the vibration peaks of sections 1 and 2, and the greater the difference between the frequency of the vibration peak generated by section 1 and the frequency of the vibration peak generated by section 2.
[0077] exist Figure 4 A graph is shown in which the horizontal axis is the engine speed (rpm) and the vertical axis is the strain (%) of the annular elastic body 300. It should be noted that the horizontal axis corresponds to the frequency, and the vertical axis corresponds to the magnitude of the vibration. In the figure, the solid line L11 and the solid line L31 show a sixth-order graph, in which the vibration peak on the left is 1 knot of the sixth order, and the peak on the right is 2 knots of the sixth order. In addition, in the figure, the solid line L21 and the solid line L41 show a fourth-order graph, in which the vibration peak is 1 knot of the fourth order. These are graphs in the case where the natural vibration frequency of the torsional damper 10 is made consistent with the resonant frequency of the crankshaft 20. As shown Figure 4As shown in (a), it can be seen that when the engine speed is around 5000 rpm, the fourth-order 1-node and the sixth-order 2-node are coupled, and the heat generation of the annular elastic body 300 becomes higher. Therefore, when the natural vibration frequency of the torsional damper 10 is shifted to the high-frequency side, the vibration peak of the high-order sixth-order 2-node can be reduced. The dotted line L12 and the dotted line L22 are graphs showing the sixth and fourth orders, respectively, when the natural vibration frequency of the torsional damper 10 is shifted to the high-frequency side. According to these graphs, although the vibration peak of the sixth-order 2-node can be reduced, the vibration peak of the fourth-order 1-node tends to increase. Therefore, the effect of reducing the temperature of the annular elastic body 300 is insufficient only by adjusting the natural vibration frequency of the torsional damper 10.
[0078] exist Figure 4 In (b), the dotted line L32 and the dotted line L42 are graphs showing the sixth-order vibration and the fourth-order vibration, respectively, when the inertial mass of the vibration ring 200 becomes heavier. According to such graphs, the peak value of the sixth-order 2-node vibration is shifted to the high-frequency side while decreasing, and the peak value of the fourth-order 1-node vibration is shifted to the low-frequency side while decreasing, so the coupling of the two orders is also suppressed.
[0079] In addition, as a method of suppressing the temperature rise of the annular elastic body 300, a structure that improves the heat dissipation effect can be adopted. That is, by increasing the thickness of the vibration ring 200 (equivalent to the width in the radial direction) or increasing the fitting width (width in the central axis direction) between the vibration ring 200 and the annular elastic body 300, the heat dissipation from the annular elastic body 300 can be increased. In this way, the temperature rise of the annular elastic body 300 can be suppressed.
[0080] Furthermore, if the thickness of the annular elastic body 300 is thick, the heat dissipation and heat storage amount becomes larger, so the thin thickness can suppress the temperature rise of the annular elastic body 300. It should be noted that by providing the vibration ring 200 with concave and convex to increase the surface area, the heat dissipation effect from the vibration ring 200 can also be improved, and the temperature rise of the annular elastic body 300 can be suppressed. In this embodiment, Figure 2 As shown, a structure is adopted in which projections and depressions are provided on the side of the region (E) of the vibration ring 200 where the engine is arranged.
[0081] According to the above-mentioned countermeasures, it is possible to suppress the high temperature of the annular elastic body 300. It should be noted that when H-NBR (hydrogenated acrylonitrile butadiene rubber) is used as the material of the annular elastic body 300, the common heat resistance limit temperature is 130°C, but by the above-mentioned countermeasures, the maximum temperature of the annular elastic body 300 can be made below 130°C.
[0082] (Example 2)
[0083] exist Figure 5 The second embodiment of the present invention is shown in FIG. Figure 5 is a schematic cross-sectional view of a torsional damper according to a second embodiment of the present invention, and Figure 1 The overall structure of the torsional damper 10X of this embodiment is the same as that of the first embodiment. That is, the torsional damper 10X of this embodiment also includes a hub 100X, a vibration ring 200X arranged concentrically with the hub 100X, and an annular elastic body 300X.
[0084] In addition, similar to the first embodiment, the wheel hub 100X is a metal annular member and has an inner cylinder portion 110, an outward flange portion 120 and an outer cylinder portion 130X. In addition, the inner cylinder portion 110 is fixed to the crankshaft 20 of the engine. Figure 5 In FIG. 1 , the crankshaft 20 and the positions of the bolts 30 for fixing the torsion damper 10X to the crankshaft 20 are also shown by dotted lines.
[0085] Also, the vibration ring 200X is a metal annular member similar to the first embodiment. In addition, the annular elastic body 300X is made of a rubber material and is provided between the outer cylinder portion 130X of the hub 100X and the vibration ring 200X.
[0086] The torsional damper 10X constructed as described above is also disposed in the engine housing. Figure 5 In FIG. 1 , the position of the inner wall surface of a part of the engine housing (a part of the front cover) is shown by a dotted line C. Figure 5 In FIG. 1 , the right side of the torsion damper 10X is the region (E) where the engine is arranged. The vibration suppression function of the torsion damper 10X is as described in the first embodiment, and the description thereof is omitted.
[0087] <Detailed structure of each member of the torsional damper>
[0088] The detailed structure of each component of the torsional damper 10X is described. In the vibration ring 200X of this embodiment, an annular protrusion 220 protruding radially inward is provided at the center of the width direction of the inner circumference (the width direction in the direction in which the central axis of the torsional damper 10X extends). That is, the inner circumference of the vibration ring 200X is configured such that the inner diameter of the portion where the annular protrusion 220 is provided is small and the inner diameters of both sides of the inner circumference of the vibration ring 200X are larger than the inner diameter of the annular protrusion 220. In addition, the outer circumference of the outer cylinder 130X is formed in a shape that is annularly concave at the center of the width direction of the outer circumference of the outer cylinder 130X in a manner that follows the shape of the inner circumference of the vibration ring 200X. That is, the inner diameter of the outer circumference of the outer cylinder 130X is small at the center in the width direction, and the inner diameters of both sides of the outer circumference of the outer cylinder 130X are larger than the inner diameter of the center.
[0089] Furthermore, the minimum inner diameter R20 of the annular protrusion 220 is set to be smaller than the maximum outer diameter R12 on the side of the outer circumferential surface of the outer cylinder 130X that is closer to the region (E) where the engine is arranged than the annular protrusion 220. In addition, the minimum inner diameter R20 of the annular protrusion 220 is set to be larger than the maximum outer diameter R11 on the side of the outer circumferential surface of the outer cylinder 130X that is opposite to the region (E) where the engine is arranged than the annular protrusion 220.
[0090] It should be noted that, in the torsional damper 10X of the present embodiment, the positional deviation of the vibration ring 200X to the side opposite to the region (E) where the engine is arranged after heat aging (after 533 hours under an environment of 130° C.) is set to be 1 mm or less. This prevents the vibration ring 200X from contacting the inner wall surface of a part of the engine case (a part of the front cover).
[0091] The torsional damper 10X of this embodiment also forms a stopper structure that prevents the vibration ring 200X from slipping out of the outer cylinder 130X toward the area where the engine is arranged, based on the relationship between the size and shape of the outer circumferential surface of the outer cylinder 130X and the size and shape of the inner circumferential surface of the vibration ring 200X. More specifically, an annular protrusion 220 is provided on the inner circumferential surface of the vibration ring 200X, and as described above, the hub 100X and the vibration ring 200X are configured in such a manner that R20 < R12. In addition, as described above, according to the torsional damper 10X of this embodiment, the hub 100 and the vibration ring 200 are configured in such a manner that R11 < R20. With the above structure, the same effect as that of the first embodiment described above is obtained.
[0092] The configuration in which the end surface of the annular elastic body 300X is preferably located inside the end surface of the outer cylinder 130X and the end surface of the vibration ring 200X is the same as described in the first embodiment. The various methods for suppressing the degradation of the annular elastic body are the same as described in the first embodiment.
Claims
1. A torsional damper, comprising: A hub having an inner cylinder portion, an outward flange portion integrally provided on the inner cylinder portion, and an outer cylinder portion integrally provided on the radially outer side of the outward flange portion, wherein the inner cylinder portion is fixed to the crankshaft; a vibration ring, disposed concentrically with the hub; and an annular elastic body, provided between the outer cylinder and the vibration ring, The torsion damper is arranged in the engine housing. The torsion damper is characterized in that The relationship between the dimensional shape of the outer peripheral surface of the outer cylinder and the dimensional shape of the inner peripheral surface of the vibration ring provides a stopper structure that prevents the vibration ring from coming out of the outer cylinder toward the region where the engine is disposed.
2. The torsional damper according to claim 1, characterized in that: The outer cylindrical portion has an annular protrusion protruding radially outward at the center of the outer peripheral surface in the width direction. The maximum outer diameter of the annular protrusion is larger than the minimum inner diameter of the inner peripheral surface of the vibration ring on the side opposite to the region where the engine is arranged relative to the annular protrusion.
3. The torsional damper according to claim 2, characterized in that: The maximum outer diameter of the annular protrusion is smaller than the minimum inner diameter of the inner peripheral surface of the vibration ring on the side of the annular protrusion closer to the region where the engine is arranged.
4. The torsional damper according to claim 1, characterized in that: The vibration ring has an annular protrusion protruding radially inward at the center of the inner circumference in the width direction. The minimum inner diameter of the annular protrusion is smaller than the maximum outer diameter of the outer peripheral surface of the outer cylinder portion on the side of the annular protrusion closer to the region where the engine is arranged.
5. The torsional damper according to claim 4, characterized in that: The minimum inner diameter of the annular protrusion is larger than the maximum outer diameter of the outer peripheral surface of the outer cylinder portion on the side opposite to the region where the engine is arranged relative to the annular protrusion.
6. The torsional damper according to any one of claims 1 to 5, characterized in that: An end surface of the annular elastic body is located inside an end surface of the outer cylinder portion and an end surface of the vibration ring.