Torsional damper, manufacturing method thereof, engine and vehicle

Abstract

The invention relates to a torsional damper, a manufacturing method thereof, an engine and a vehicle, and belongs to the technical field of engines. The torsion damper comprises a hub and a fastener, the hub is provided with a center groove and a plurality of grooves, the center groove is formed in the first side of the hub, a first mounting hole is formed in the center of the groove bottom of the center groove, the first mounting hole penetrates through the groove bottom, the first mounting hole and the hub are coaxial, and the fastener is arranged in the groove bottom of the center groove. A first mounting hole is formed in the first side of the hub, a plurality of grooves are formed in the groove bottom and distributed around the first mounting hole at intervals, the fastener penetrates to the first side of the hub from the second side of the hub through the first mounting hole and is used for fastening the hub and a crankshaft in the axial direction of the hub, and the groove bottom abuts against the crankshaft. According to the torsion damper, large friction transmission torque can be achieved between the crankshaft and the torsion damper.

Description

Technical Field

[0001] The present disclosure relates to the technical field of engines, and particularly to a torsional damper and a manufacturing method thereof, an engine, and a vehicle. Background Art

[0002] When the engine is running, torsional vibration will occur in the crankshaft system. When the crankshaft has low stiffness, the change frequency of the engine torque is close to the torsional frequency of the crankshaft, resonance will occur, which easily leads to wear of the friction pair and even the problem of crankshaft fracture. In order to reduce the crankshaft vibration, a torsional damper is generally installed at the front end of the crankshaft to reduce the torsional vibration of the crankshaft.

[0003] The torsional damper and the crankshaft are generally fastened by a large crankshaft bolt. When the engine torque increases and the safety factor of the frictional torque transmission between the crankshaft and the installation surface of the torsional damper is insufficient, relative slip will occur between the two, resulting in the torsional damper falling off and the engine being damaged. Summary of the Invention

[0004] In view of this, embodiments of the present disclosure provide a torsional damper and a manufacturing method thereof, an engine, and a vehicle, such that a large frictional transmission torque can be achieved between the crankshaft and the torsional damper. The technical solutions are as follows:

[0005] In a first aspect, a torsional damper is provided. The torsional damper includes a hub and a fastener. The hub has a central groove and a plurality of grooves;

[0006] The central groove is formed on a first side of the hub. The center of the bottom of the central groove has a first mounting hole, and the first mounting hole penetrates the bottom of the groove. The first mounting hole is coaxial with the hub;

[0007] The plurality of grooves are formed on the bottom of the groove and are spaced apart around the first mounting hole;

[0008] The fastener passes from a second side of the hub through the first mounting hole to the first side of the hub, for axially fastening the hub and the crankshaft along the axis of the hub, wherein the bottom of the groove abuts against the crankshaft.

[0009] In the torsional damper of this embodiment, the plurality of grooves spaced apart around the first mounting hole on the bottom of the central groove can make the bottom of the groove have an appropriate surface roughness. Thus, when the crankshaft abuts against the bottom of the groove along the axis of the hub through the fastener, a large friction coefficient can be achieved between the crankshaft and the bottom of the groove. Therefore, when the engine is running and the crankshaft is rotating, a large frictional transmission torque can be achieved between the crankshaft and the torsional damper, which is conducive to avoiding relative slip between the crankshaft and the torsional damper, resulting in the torsional damper falling off and the engine being damaged.

[0010] In some possible embodiments, the plurality of grooves are radially distributed around the axis of the hub.

[0011] Each groove of the torsional damper is in the shape of a strip extending along the radial direction of the hub. This not only facilitates processing but also helps to improve the effect of the groove in increasing the circumferential friction coefficient between the crankshaft and the bottom of the groove.

[0012] In some possible embodiments, the bottom of the groove has an abutting area, which is an annular shape surrounding the first mounting hole. The bottom of the groove abuts against the crankshaft through the abutting area.

[0013] The minimum distance between the groove and the axis of the first mounting hole is less than or equal to the inner diameter of the abutting area, and the maximum distance between the groove and the axis of the first mounting hole is greater than or equal to the outer diameter of the abutting area.

[0014] In the torsional damper, the abutting area of the torsional damper that abuts against the crankshaft coincides with the middle section or the whole of each groove, which is conducive to improving the axial coincidence degree between the crankshaft and the groove, and is conducive to improving the frictional torque transmission between the crankshaft and the bottom of the central groove.

[0015] In some possible embodiments, the depth of the groove is 0.01 mm to 0.05 mm.

[0016] When the depth of the groove of the torsional damper is within this range, on the one hand, it will not be too deep, so the strength of the groove can be improved, which is conducive to avoiding stress concentration, having good fatigue resistance, and not being easily worn. On the other hand, it will not be too shallow, which is conducive to avoiding the reduction of the roughness of the bottom of the groove due to wear, and further avoiding the reduction of the friction coefficient between the bottom of the groove and the crankshaft. At the same time, the groove with this depth is also convenient for processing.

[0017] In some possible embodiments, the roughness Rp of the bottom of the groove is 30 μm to 70 μm.

[0018] When the roughness Rp of the bottom of the groove of the torsional damper is within this range, on the premise of ensuring a large contact area between the bottom of the groove and the crankshaft, the mechanical interlocking between the crankshaft and the bottom of the groove can be enhanced, the friction coefficient between the crankshaft and the bottom of the groove can be increased, and it is conducive to the improvement of the frictional torque transmission.

[0019] In some possible embodiments, the central groove includes a mating section and a transition section.

[0020] The mating section is in clearance fit with the crankshaft.

[0021] The transition section is located on the side of the mating section away from the bottom of the groove, and the diameter of the transition section is greater than the diameter of the mating section.

[0022] The central groove of the torsional damper has a transition section with a diameter larger than that of the crankshaft, enabling the crankshaft to easily extend into the central groove.

[0023] In a second aspect, there is provided a method for manufacturing a torsional damper, which is used to manufacture the torsional damper as described in any one of the first aspects, and includes: obtaining the groove by using laser etching technology.

[0024] The manufacturing method of this embodiment is used to manufacture the torsional damper as described in the first aspect, and is conducive to improving the success rate of forming the groove at the bottom of the central groove and reducing the manufacturing cost of the torsional damper. At the same time, the obtained torsional damper has the beneficial technical effects of all the embodiments in the first aspect of the present disclosure.

[0025] In a third aspect, there is provided an engine, which includes a crankshaft and a torsional damper as described in any one of the first aspects. The crankshaft extends axially into the central groove along the hub and abuts against the bottom of the groove.

[0026] The engine of this embodiment adopts the torsional damper of the first aspect of the present disclosure and has the beneficial effects of all the embodiments in the first aspect of the present disclosure.

[0027] In some possible implementation manners, the crankshaft has a second mounting hole;

[0028] The fastener is rod-shaped, and the first end of the fastener abuts against the second side of the hub. The second end of the fastener passes through the first mounting hole and extends into the second mounting hole of the crankshaft to be connected to the second mounting hole.

[0029] In this way, the crankshaft can be conveniently connected to the fastener through the second mounting hole, and at the same time, the space occupied when the torsional damper and the crankshaft are installed together is avoided from increasing.

[0030] In a fourth aspect, there is provided a vehicle, which includes the engine as described in any one of the third aspects.

[0031] The vehicle of this embodiment adopts the engine of the third aspect of the present disclosure and has the beneficial technical effects of all the embodiments in the third aspect of the present disclosure. Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1It is a schematic side - view sectional structure diagram of a torsional damper provided by an embodiment of the present disclosure;

[0034] Figure 2 It is a schematic front - view structure diagram of a torsional damper provided by an embodiment of the present disclosure;

[0035] Figure 3 It is a schematic front - view structure diagram of the bottom of a groove provided by an embodiment of the present disclosure;

[0036] Figure 4 It is a schematic side - view sectional structure diagram of the connection between a torsional damper and a crankshaft provided by an embodiment of the present disclosure;

[0037] Figure 5 It is a schematic side - view sectional structure diagram of a torsional damper with fixing parts removed provided by an embodiment of the present disclosure;

[0038] Figure 6 It is a schematic side - view sectional structure diagram of a crankshaft provided by an embodiment of the present disclosure.

[0039] Explanation of reference numerals

[0040] 1. Hub; 11. Central groove; 111. Fitting section; 112. Transition section; 113. Contact area; 114. Bottom of the groove; 12. Groove; 13. First mounting hole; 2. Fastener; 3. Crankshaft; 31. Second mounting hole. Detailed implementation manners

[0041] To make the purpose, technical solutions and advantages of the present disclosure clearer, the following will further describe the embodiments of the present disclosure in detail with reference to the drawings.

[0042] In a first aspect, this embodiment relates to a torsional damper. Refer to Figure 1 the schematic side - view sectional structure diagram of the torsional damper shown. The torsional damper includes a hub 1 and a fastener 2. Among them, refer to Figure 2 the schematic front - view structure diagram of the torsional damper shown and Figure 3 the schematic front - view structure diagram of the bottom 2 of the groove shown. The hub 1 has a central groove 11 and a plurality of grooves 12.

[0043] Continue to refer to Figure 1 shown. The central groove 11 is formed on the first side of the hub 1. In Figure 1 , the central groove 11 can be formed on the right side of the hub 1, but the central groove 11 can also be formed on the left side of the hub 1. In this way, the end of the crankshaft 3 can extend into the central groove 11. In this embodiment, taking Figure 1 where the central groove 11 is formed on the right side of the hub 1 as an example.

[0044] Continue to refer to Figure 2As shown, a first mounting hole 13 is provided at the center of the bottom 114 of the central groove 11. The first mounting hole 13 penetrates the bottom 114, and the first mounting hole 13 is coaxial with the hub 1. In this way, when the crankshaft 3 rotates, it can drive the hub 1 to rotate coaxially.

[0045] Continue to refer to Figure 3 As shown, a plurality of grooves 12 are formed in the bottom 114 and are distributed at intervals around the first mounting hole 13. In this way, through the plurality of grooves 12, the bottom 114 can have an appropriate surface roughness.

[0046] Refer to Figure 4 Refer to the schematic side sectional structure diagram of the torsional damper shown connected to the crankshaft 3. The fastener 2 passes through the first mounting hole 13 from the second side of the hub 1 to the first side of the hub 1, for axially fastening the hub 1 and the crankshaft 3 along the axis of the hub 1. It should be noted that the first side and the second side of the hub 1 refer to the two sides opposite to each other along the axis of the hub 1 centered on the hub 1.

[0047] Among them, continue to refer to Figure 4 As shown, the bottom 114 abuts against the crankshaft 3. In this way, when the crankshaft 3 rotates, a frictional torque can be transmitted between the bottom 114 and the crankshaft 3.

[0048] For example Figure 4 As shown, the fastener 2 can pass through the first mounting hole 13 from the left side of the hub 1 to the right side of the hub 1. And, since the first mounting hole 13 is located at the center of the bottom 114, therefore, the fastener 2 can be connected to the crankshaft 3 extending into the central groove 11, realizing the axial fastening between the hub 1 and the crankshaft 3 along the axis of the hub 1. Thus, the bottom 114 can be tightly abutted against the crankshaft 3.

[0049] As can be seen from the above, the plurality of grooves 12 distributed at intervals around the first mounting hole 13 on the bottom 114 of the central groove 11 can make the bottom 114 have an appropriate surface roughness. Thus, when the crankshaft 3 abuts against the bottom 114 along the axis of the hub 1 through the fastener 2, a large friction coefficient can be between the crankshaft 3 and the bottom 114. Therefore, when the engine is running and the crankshaft 3 rotates, a large frictional torque can be between the crankshaft 3 and the torsional damper, which is beneficial to avoiding relative slip between the crankshaft 3 and the torsional damper and causing the torsional damper to fall off and the engine to be damaged.

[0050] In one example, refer to Figure 3 As shown, the plurality of grooves 12 are radially distributed around the axis of the hub 1. For example Figure 3 As shown, each groove 12 can be a strip-shaped groove extending along the radial direction of the hub 1.

[0051] In this way, each groove 12 is perpendicular to the circumferential direction of the hub 1, which is beneficial to increasing the friction coefficient between the crankshaft 3 and the bottom 114 of the groove along the circumferential direction of the hub 1. At the same time, the strip-shaped groove 12 is also convenient for machining, which is beneficial to the molding of the torsional damper and reduces the manufacturing cost of the torsional damper.

[0052] In one example, referring to Figure 3 As shown, a plurality of grooves 12 can be evenly distributed radially around the axis of the hub 1. In this way, it is beneficial to the uniformity of the surface roughness of the bottom 114 of the groove along the circumferential surface of the hub 1, and increases the friction coefficient between the bottom 114 of the groove and the crankshaft 3 along the circumferential direction of the hub 1. Thus, it is beneficial to increase the frictional transmission torque between the bottom 114 of the groove and the crankshaft 3 when the engine is running and the crankshaft 3 is rotating.

[0053] In one example, referring to Figure 3 As shown, the bottom 114 of the groove has an abutting area 113, and the abutting area 113 is an annular shape around the first mounting hole 13. Among them, referring to Figure 4 As shown, the bottom 114 of the groove abuts against the crankshaft 3 through the abutting area 113.

[0054] Continuing to refer to Figure 3 As shown, the minimum distance between the groove 12 and the axis of the first mounting hole 13 is less than or equal to the inner diameter of the abutting area 113, and the maximum distance between the groove 12 and the axis of the first mounting hole 13 is greater than or equal to the outer diameter of the abutting area 113.

[0055] For example, the minimum distance between the groove 12 and the axis of the first mounting hole 13 can be less than the inner diameter of the abutting area 113, and the maximum distance between the groove 12 and the axis of the first mounting hole 13 can be greater than the outer diameter of the abutting area 113.

[0056] For another example, the minimum distance between the groove 12 and the axis of the first mounting hole 13 can be equal to the inner diameter of the abutting area 113, and the maximum distance between the groove 12 and the axis of the first mounting hole 13 can be greater than the outer diameter of the abutting area 113.

[0057] For still another example, the minimum distance between the groove 12 and the axis of the first mounting hole 13 can be less than the inner diameter of the abutting area 113, and the maximum distance between the groove 12 and the axis of the first mounting hole 13 can be equal to the outer diameter of the abutting area 113.

[0058] Or, the minimum distance between the groove 12 and the axis of the first mounting hole 13 can be equal to the inner diameter of the abutting area 113, and the maximum distance between the groove 12 and the axis of the first mounting hole 13 can be equal to the outer diameter of the abutting area 113.

[0059] In this way, the coincidence range of the crankshaft 3 and the groove 12 along the axial direction of the central groove 11 can be increased, which is beneficial to improving the frictional torque transmission between the crankshaft 3 and the bottom 114 of the central groove 11.

[0060] In one example, the depth of the groove 12 is 0.01 mm to 0.05 mm.

[0061] For example, the depth of the groove 12 can be 0.01 mm. Again, for example, the depth of the groove 12 can be 0.03 mm on average. Still, for example, the depth of the groove 12 can be 0.05 mm. Or, the depth of each groove 12 can be 0.043 mm.

[0062] In this way, the depth of each groove 12 of the torsional damper is between 0.01 mm and 0.05 mm. On the one hand, it will not be too deep, so the strength of the groove 12 can be improved, which is beneficial to avoiding stress concentration, having good fatigue resistance, and not being easily worn. On the other hand, it will not be too shallow, which is beneficial to avoiding the reduction of the roughness of the bottom 114 of the groove 12 due to wear, and further avoiding the reduction of the friction coefficient between the bottom 114 and the crankshaft 3. At the same time, the groove 12 with a depth between 0.01 mm and 0.05 mm is also convenient for processing, which is beneficial to improving the yield rate of the torsional damper and reducing the manufacturing cost.

[0063] In one example, the depths of the multiple grooves 12 can all be between 0.01 mm and 0.05 mm, and the depth of each groove 12 can be slightly different.

[0064] For example, the depth of some grooves 12 can be 0.01 mm, and the depth of some other grooves 12 can be 0.011 mm, 0.012 mm, or 0.013 mm, etc.

[0065] Again, for example, the depth of some grooves 12 can be 0.02 mm, and the depth of some other grooves 12 can be 0.021 mm, 0.019 mm, or 0.022 mm, etc.

[0066] Still, for example, the depth of some grooves 12 can be 0.035 mm, and the depth of some other grooves 12 can be 0.034 mm, 0.036 mm, or 0.033 mm, etc.

[0067] Or, the depth of some grooves 12 can be 0.05 mm, and the depth of some other grooves 12 can be 0.048 mm, 0.049 mm, or 0.047 mm, etc.

[0068] In this way, the manufacturing difficulty of the torsional damper can be reduced on the premise of ensuring the depth uniformity among the multiple grooves 12.

[0069] In one example, the roughness Rp of the bottom of the groove 114 is 30 μm to 70 μm. For example, the roughness Rp of the bottom of the groove 114 can be 30 μm. For another example, the roughness Rp of the bottom of the groove 114 can be 45 μm. For still another example, the roughness Rp of the bottom of the groove 114 can be 50 μm. Or, the roughness Rp of the bottom of the groove 114 can be 70 μm.

[0070] In this way, when the roughness Rp of the bottom of the groove 114 is between 30 μm and 70 μm, on the one hand, it will not reduce the contact area between the bottom of the groove 114 and the crankshaft 3 due to being too large, resulting in poor mechanical biting performance between the bottom of the groove 114 and the crankshaft 3; on the other hand, it will not result in a small friction coefficient between the bottom of the groove 114 and the crankshaft 3 due to too low roughness Rp. Therefore, it is beneficial to improve the torque transmission by friction between the bottom of the groove 114 and the crankshaft 3.

[0071] In one example, referring to Figure 5 the schematic side view sectional structure diagram of the torsional damper removing the fixing member 2 shown, the central groove 11 includes a mating section 111 and a transition section 112.

[0072] Among them, referring to Figure 4 the figure shown, the mating section 111 is in clearance fit with the crankshaft 3. For example, it can be that the mating section 111 is in clearance fit with the end of the crankshaft 3. In this way, when the crankshaft 3 rotates and drives the hub 1 to rotate through the end of the crankshaft 3, it is beneficial to improve the stability between the crankshaft 3 and the hub 1 in the radial direction of the hub 1.

[0073] Continuing to refer to Figure 5 the figure shown, the transition section 112 is located on the side of the mating section 111 away from the bottom of the groove 114. In this way, when the end of the crankshaft 3 extends into the central groove 11, it can first pass through the transition section 112 and then enter the mating section 111.

[0074] Continuing to refer to Figure 5 the figure shown, the diameter of the transition section 112 is larger than the diameter of the mating section 111. Since the mating section 111 is in clearance fit with the end of the crankshaft 3, therefore, the diameter of the transition section 112 is also larger than the diameter of the end of the crankshaft 3.

[0075] As described above, when the crankshaft 3 extends into the central groove 11, since the end of the crankshaft 3 needs to first pass through the transition section 112 and the diameter of the transition section 112 is larger than the diameter of the crankshaft 3, therefore, the end of the crankshaft 3 can enter the central groove 11 more easily.

[0076] After that, the end of the crankshaft 3 can enter the mating section 111. Since the mating section 111 is in clearance fit with the end of the crankshaft 3, therefore, when the crankshaft 3 rotates and drives the hub 1 to rotate through the end of the crankshaft 3, it can improve the stability between the crankshaft 3 and the hub 1 in the radial direction of the hub 1.

[0077] In one example, the torsional damper may further include an inertia ring 5. The inertia ring 5 may be coaxially sleeved outside the wheel hub 1. In this way, the rotational inertia of the system can be increased through the inertia ring 5, and the torsional vibration caused by the engine speed fluctuation can be reduced.

[0078] In one example, a belt groove may be formed on the outer edge of the inertia ring 5. A belt can be sleeved through the belt groove to drive other accessories of the engine to work through the belt.

[0079] In one example, the torsional damper may further include a rubber ring 4. The rubber ring 4 is coaxially sleeved outside the wheel hub 1 and is clamped between the wheel hub 1 and the inertia ring 5. The rubber ring 4 can weaken and absorb the torsional vibration during the operation of the crankshaft 3 through deformation. The wheel hub 1 can play a supporting role, and when the rubber ring 4 deforms, heat is continuously generated by friction between the rubber ring 4 and the wheel hub 1 and the inertia ring 5, and then the heat is taken away by the wheel hub 1 to ensure that the rubber ring 4 does not crack and fail.

[0080] In one example, the rubber ring 4 can be made of materials such as hydrogenated nitrile rubber or ethylene propylene diene monomer rubber, so that it can have a relatively high damping coefficient and weaken and absorb the torsional vibration during the operation of the crankshaft 3 through deformation.

[0081] In one example, the inertia ring 5, the rubber ring 4 and the wheel hub 1 can be fixedly connected together by bonding.

[0082] In the embodiment of the present disclosure, a plurality of grooves 12 spaced around the first mounting hole 13 on the bottom 114 of the central groove 11 can make the bottom 114 have an appropriate surface roughness. Thus, when the crankshaft 3 abuts against the bottom 114 along the axial direction of the wheel hub 1 through the fastener 2, a relatively large friction coefficient can be between the crankshaft 3 and the bottom 114. Therefore, when the engine is running and the crankshaft 3 rotates, a relatively large frictional transmission torque can be between the crankshaft 3 and the torsional damper, which is conducive to avoiding relative slip between the crankshaft 3 and the torsional damper and causing the torsional damper to fall off and the engine to be damaged.

[0083] In a second aspect, the present embodiment further provides a manufacturing method of a torsional damper. The manufacturing method is used to manufacture the torsional damper according to any one of the first aspect, and includes: obtaining the groove 12 by using a laser etching technique. For example, the wheel hub 1 can be cast and formed by using gray cast iron material, the inner wall of the central groove 11 can be subjected to a certain surface treatment, and after the bottom 114 is hardened, the laser etching technique can be used to etch the radial groove 12 around the first mounting hole 13 on the bottom 114.

[0084] In the embodiments of the present disclosure, using laser etching technology to obtain the groove 12 is beneficial to improve the success rate of forming the groove 12 at the bottom 114 of the central groove 11, and reduce the manufacturing cost of the torsional damper. At the same time, in the obtained torsional damper, a plurality of grooves 12 spaced around the first mounting hole 13 at the bottom 114 of the central groove 11 can make the bottom 114 have an appropriate surface roughness. Thus, when the crankshaft 3 abuts against the bottom 114 along the axial direction of the hub 1 through the fastener 2, a relatively large friction coefficient can be achieved between the crankshaft 3 and the bottom 114. Therefore, when the engine is running and the crankshaft 3 is rotating, a relatively large friction transmission torque can be achieved between the crankshaft 3 and the torsional damper, which is beneficial to avoiding relative slip between the crankshaft 3 and the torsional damper, resulting in the detachment of the torsional damper and damage to the engine.

[0085] In a third aspect, the present embodiment further provides an engine, which includes a crankshaft 3 and a torsional damper according to any one of the first aspects. The crankshaft 3 extends axially into the central groove 11 along the hub 1 and abuts against the bottom 114. For example, the end of the crankshaft 3 can extend axially into the central groove 11 along the hub 1 and abut against the bottom 114.

[0086] As described above, a plurality of grooves 12 spaced around the first mounting hole 13 at the bottom 114 of the central groove 11 can make the bottom 114 have an appropriate surface roughness. Thus, when the crankshaft 3 abuts against the bottom 114 along the axial direction of the hub 1 through the fastener 2, a relatively large friction coefficient can be achieved between the crankshaft 3 and the bottom 114. Therefore, when the engine is running and the crankshaft 3 is rotating, a relatively large friction transmission torque can be achieved between the crankshaft 3 and the torsional damper, which is beneficial to avoiding relative slip between the crankshaft 3 and the torsional damper, resulting in the detachment of the torsional damper and damage to the engine.

[0087] In one example, referring to Figure 6 the schematic side sectional structure view of the crankshaft 3 shown, the crankshaft 3 has a second mounting hole 31.

[0088] Continuing to refer to Figure 1 and Figure 4 shown, the fastener 2 is rod-shaped, and the first end of the fastener 2 abuts against the second side of the hub 1. The second end of the fastener 2 passes through the first mounting hole 13 and extends into the second mounting hole 31 of the crankshaft 3 to connect with the second mounting hole 31.

[0089] For example Figure 4 shown, the fastener 2 can be rod-shaped. The first end of the fastener 2 can abut against the left side of the hub 1. The second end of the fastener 2 can pass through the first mounting hole 13 and extend into the second mounting hole 31 of the crankshaft 3 located on the right side of the hub 1, and can be threadedly connected with the second mounting hole 31.

[0090] In this way, the crankshaft 3 can be conveniently connected to the fastener 2 through the second mounting hole 31. At the same time, it is also possible to avoid increasing the space occupied when the torsional damper is mounted together with the crankshaft 3.

[0091] In one example, the fastener 2 can be a bolt. The nut located at the first end of the bolt can abut against the hub 1, and the second end of the bolt can pass through the first mounting hole 13 and then be screwed into the second mounting hole 31. Among them, the second mounting hole 31 is a bolt hole. Thus, the hub 1 and the crankshaft 3 can be fixed along the axial direction of the hub 1.

[0092] In another example, the fastener 2 can be a pin. The pin cap located at the first end of the pin can abut against the hub 1, and the second end of the pin can pass through the first mounting hole 13 and extend into the second mounting hole 31 and be riveted to the bottom of the second mounting hole 31. Thus, the hub 1 and the crankshaft 3 can be fixed along the axial direction of the hub 1.

[0093] In another example, the fastener 2 can be a screw. The screw cap located at the first end of the screw can abut against the hub 1, and the second end of the pin can pass through the first mounting hole 13 and be screwed into the second mounting hole 31. Among them, the second mounting hole 31 is a screw hole. Thus, the hub 1 and the crankshaft 3 can be fixed along the axial direction of the hub 1.

[0094] In the embodiment of the present disclosure, the plurality of grooves 12 that are spaced around the first mounting hole 13 and distributed on the bottom 114 of the central groove 11 can make the bottom 114 have an appropriate surface roughness. Thus, when the crankshaft 3 abuts against the bottom 114 along the axial direction of the hub 1 through the fastener 2, a relatively large friction coefficient can be formed between the crankshaft 3 and the bottom 114. Therefore, when the engine is running and the crankshaft 3 is rotating, a relatively large friction transmission torque can be generated between the crankshaft 3 and the torsional damper, which is conducive to avoiding relative slippage between the crankshaft 3 and the torsional damper, resulting in the torsional damper falling off and engine damage.

[0095] Fourthly, this embodiment also provides a vehicle, which includes an engine as described in any one of the third aspects.

[0096] In the embodiment of the present disclosure, the plurality of grooves 12 that are spaced around the first mounting hole 13 and distributed on the bottom 114 of the central groove 11 can make the bottom 114 have an appropriate surface roughness. Thus, when the crankshaft 3 abuts against the bottom 114 along the axial direction of the hub 1 through the fastener 2, a relatively large friction coefficient can be formed between the crankshaft 3 and the bottom 114. Therefore, when the engine is running and the crankshaft 3 is rotating, a relatively large friction transmission torque can be generated between the crankshaft 3 and the torsional damper, which is conducive to avoiding relative slippage between the crankshaft 3 and the torsional damper, resulting in the torsional damper falling off and engine damage.

[0097] It should be noted that in the description of this application, unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0098] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, "a plurality of" means two or more unless otherwise specifically defined.

[0099] In the description of this specification, the descriptions referring to the terms "certain embodiments", "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of this application.

[0100] The above are only the embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the principles of this application shall be included in the protection scope of this application.

Claims

1. A torsional damper, characterized in that, The torsional damper includes a hub (1) and a fastener (2), and the hub (1) has a central groove (11) and a plurality of grooves (12); The central groove (11) is formed on the first side of the hub (1). The center of the bottom (114) of the central groove (11) has a first mounting hole (13), and the first mounting hole (13) penetrates through the bottom (114), and the first mounting hole (13) is coaxial with the hub (1); The plurality of grooves (12) are formed on the bottom (114) and are spaced around the first mounting hole (13); The fastener (2) passes from the second side of the hub (1) through the first mounting hole (13) to the first side of the hub (1) for axially fastening the hub (1) and the crankshaft (3) along the axis of the hub (1), wherein the bottom (114) abuts against the crankshaft (3).

2. The torsional damper according to claim 1, characterized in that, The plurality of grooves (12) are radially distributed around the axis of the hub (1).

3. The torsional damper according to claim 2, characterized in that, The bottom (114) has an abutting area (113), and the abutting area (113) is an annular shape around the first mounting hole (13). The bottom (114) abuts against the crankshaft (3) through the abutting area (113); The minimum distance between the groove (12) and the axis of the first mounting hole (13) is less than or equal to the inner diameter of the abutting area (113), and the maximum distance between the groove (12) and the axis of the first mounting hole (13) is greater than or equal to the outer diameter of the abutting area (113).

4. The torsional damper according to claim 1, characterized in that, The depth of the groove (12) is 0.01 mm to 0.05 mm.

5. The torsional damper according to claim 1, characterized in that, The roughness Rp of the bottom (114) is 30 μm to 70 μm.

6. The torsional damper according to claim 1, characterized in that, The central groove (11) includes a mating section (111) and a transition section (112); The mating section (111) is in clearance fit with the crankshaft (3); The transition section (112) is located on the side of the mating section (111) away from the bottom (114), and the diameter of the transition section (112) is greater than the diameter of the mating section (111).

7. A manufacturing method of a torsional damper, characterized in that, The manufacturing method is used to manufacture the torsional damper according to any one of claims 1 to 6, and includes: obtaining the groove (12) by using a laser etching technique.

8. An engine, characterized in that, The engine includes a crankshaft (3) and the torsional damper according to any one of claims 1 to 6. The crankshaft (3) axially extends into the central groove (11) along the axis of the hub (1) and abuts against the bottom (114).

9. The engine according to claim 8, characterized in that, The crankshaft (3) has a second mounting hole (31); The fastener (2) is rod-shaped, and the first end of the fastener (2) abuts against the second side of the hub (1). The second end of the fastener (2) passes through the first mounting hole (13) and extends into the second mounting hole (31) of the crankshaft (3) to be connected with the second mounting hole (31).

10. A vehicle, characterized in that, The vehicle includes the engine according to any one of claims 8 or 9.

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