JP2003254388A - Torque variation absorbing damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the durability of damper rubber 22 and coupling rubber 32, and lighten a torque variation absorbing damper as a whole. <P>SOLUTION: This torque variation absorbing damper is comprised of an annular mass body 21 formed by press work from a plate having an inner cylinder part 21a arranged in the outer circumference of a hub 1 and an outer cylinder part 21c; a pulley 31 formed by press work from plate having a to-be-supported cylinder part 31c in which a dynamic vibration absorbing part 2 comprising damper rubber 22 connecting the hub 1 and the inner cylinder part 21a is extended to the inner circumferential part of the outer cylinder part 21c; coupling rubber 32 connecting the inner cylinder part 21a and the to-be-supported cylinder part 31c; and a resin bearing 33 interposed between the outer cylinder part 21a and the to-be-supported cylinder part 31c and arranged on the inner circumferential side of the coupling part 3, and the damper rubber 22 and the coupling rubber 32 are exposed to a front side. By the engagement of a projection part 21e of the annular mass body 21 with an engaging hole 31e of the pulley 31, relative displacement amount in the circumferential direction of the hub 1 and the pulley 31 is regulated. A turning up part 21f for preventing the coming off of the pulley 31 is formed in the projection part 21e. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque fluctuation absorbing damper for transmitting torque from a drive shaft of an engine or the like to other rotating equipment and absorbing fluctuation of the torque.

[0002]

2. Description of the Related Art A part of the driving force from an automobile engine is given to an auxiliary device such as an alternator or a water pump from an endless belt from a pulley provided at the tip of a crankshaft. Since it is rotated with torque fluctuation due to each stroke of
The pulley is provided with a torque fluctuation absorbing damper for absorbing torque fluctuation and smoothing transmission torque.

FIG. 5 is a sectional view showing a typical conventional example of this type of torque fluctuation absorbing damper, taken along a plane passing through the axis. The illustrated torque fluctuation absorbing damper is attached to a shaft end of a crankshaft and rotates integrally.
And the dynamic vibration absorbing part 110 attached to the hub 100.
And a coupling unit 120.

The hub 100 is cast from an iron-based material and has a boss portion 100a fixed to the crankshaft.
And a disc portion 100b extending to the outer peripheral side thereof, and an inner cylindrical portion 100c and a rim portion 100d which are concentrically formed on the front side (left side in FIG. 5) of the disc portion 100b. The dynamic vibration absorbing portion 110 is the rim portion 100d of the hub 100.
It has a structure in which an annular mass body 112 is attached to the outer periphery of the via a damper rubber 111. Also, the coupling unit 1
Reference numeral 20 denotes a coupling rubber 121 attached to the outer circumference of the inner cylindrical portion 100c of the hub 100, and a double cylindrical shape having a U-shaped cross section so as to cover the inner circumference of the rim portion 100d and the outer circumference of the annular mass body 112 from the front side. The inner peripheral tubular portion 122a is connected to the outer peripheral portion of the coupling rubber 121, and the inner peripheral portion of the rim portion 100d includes a pulley 122 rotatably held via a bearing 123.

That is, this torque fluctuation absorbing damper is
While the torque input from the crankshaft to the hub 100 is absorbed by the coupling portion 120 by the torsional shearing deformation action of the coupling rubber 121,
The dynamic vibration absorbing part 110 transmitted to the pulley 122 and composed of the damper rubber 111 and the annular mass body 112 resonates in a phase opposite to the torsional vibration of the crankshaft in a predetermined frequency range in which the torsional amplitude of the crankshaft increases. By doing so, a vibration damping function for reducing torsional vibration is exhibited. In addition, the pulley 122 for the hub 100
Increase in twist angle of the coupling rubber 121
The amount of torsional deformation of the pin 1 driven into the annular mass body 112
13 and an engaging hole 122a formed in the pulley 122 are loosely fitted to each other, and the stopper mechanism is used to restrict the movement (for example, see Patent Document 1 below).

[0006]

[Patent Document 1] Utility model registration No. 2605662

[0007]

However, according to the conventional torque fluctuation absorbing damper, since the dynamic vibration absorbing portion 110 is arranged on the outer peripheral side of the coupling portion 120, the damper rubber 111 has a large radius and the same displacement. In the case of corners, the larger the diameter of the damper rubber 111, the larger the amount of strain, and there was a problem in durability. Moreover, the outer diameter of the hub 100 made of cast iron or the like is large, and the weight thereof is large. Further, since the pulley 122 has a shape that covers from the inner circumference of the rim portion 100d of the hub 100 to the outer circumference of the annular mass body 112 from the front side, heat from the engine existing on the back side (right side in FIG. 2), Damper rubber 111
The heat generated due to the repeated torsional deformation operation is likely to be accumulated, which also causes the durability of the damper rubber 111 to be deteriorated.

Further, since the pin 113 driven into the annular mass body 112 is provided as a stopper mechanism for limiting the amount of torsional deformation of the coupling rubber 121, the number of parts and the number of assembling steps increase, and moreover, the coupling rubber 121 by any chance. If it is damaged, the pulley 122 may fall off, which is dangerous, and the transmission of the driving torque from the pulley 122 to the engine accessory may be interrupted, causing a serious problem such as the engine stopping. there were.

The present invention has been made in view of the above problems, and its technical problem is to improve the durability of the damper rubber and the coupling rubber and to reduce the weight of the torque fluctuation absorbing damper as a whole. Especially.

Another technical problem is to ensure safety even if the coupling rubber should be damaged.

[0011]

As a means for effectively solving the above-mentioned technical problems, a torque fluctuation absorbing damper according to the present invention has a hub attached to a rotating shaft with a dynamic vibration absorbing portion and a coupling portion. Provided, the dynamic vibration absorbing portion is arranged on the outer periphery of the hub from an annular mass body having an inner cylinder portion and an outer cylinder portion, and a damper rubber that elastically connects the hub and the inner cylinder portion of the annular mass body. The coupling portion elastically connects the pulley having a supported cylinder portion that extends toward the inner peripheral side of the outer cylinder portion of the annular mass body, the inner cylinder portion of the annular mass body, and the supported cylinder portion of the pulley. And a coupling rubber that is connected between the outer peripheral cylindrical portion of the annular mass body and the supported cylindrical portion of the pulley, and the damper rubber and the coupling rubber are exposed to the front side. . That is, since the dynamic vibration absorbing portion is arranged on the inner peripheral side of the coupling portion, the outer diameter of the hub is small.

A torque fluctuation absorbing damper according to a second aspect of the present invention is the structure according to the first aspect, wherein the annular mass body and the pulley are made of pressed sheet metal.

According to a third aspect of the present invention, in the torque fluctuation absorbing damper according to the first or second aspect, the protrusion is provided on either one of the annular mass body and the pulley.
The other side is provided with an engaging hole, and the projection and the engaging hole are loosely fitted to each other in the circumferential direction with a required degree of freedom.

According to a fourth aspect of the present invention, in the torque fluctuation absorbing damper according to the third aspect, the engagement is performed by folding back to the outer peripheral side or the inner peripheral side at the tip of the protruding portion penetrating the engaging hole. A folded-back portion is formed so as to axially face the outer peripheral edge or the inner peripheral edge of the hole, and the radial width of the engagement hole is a size that allows passage of the protrusion and the folded-back portion.

[0015]

1 is a sectional view showing a first preferred embodiment of a torque fluctuation absorbing damper according to the present invention, taken along a plane passing through its axis. It should be noted that the “front side” used in the following description means the left side in FIG. 1, and the “back side” means the right side in FIG. 1 on which an unillustrated automobile engine exists. is there.

As shown in FIG. 1, the torque fluctuation absorbing damper according to the present embodiment has a hub 1 attached to an axial end of a crankshaft of an automobile engine, and a dynamic vibration absorbing portion 2 provided on the outer peripheral side of the hub 1. And a coupling unit 3.

The hub 1 is cast from an iron-based material, and has a boss portion 11 fixed to the crankshaft, a radial portion 12 extending to the outer peripheral side, and a front surface from the outer periphery of the radial portion 12. The rim portion 13 is formed concentrically with the boss portion 11 toward the side.

The dynamic vibration absorbing portion 2 includes an annular mass body 21 arranged concentrically around the outer periphery of the hub 1, a hub 1 and an annular mass body 21.
It is made of a damper rubber 22 that elastically connects and, and its natural frequency in the torsional direction is made to match a predetermined frequency range in which the torsion angle of the crankshaft is maximum, in other words, the natural frequency in the torsional direction of the crankshaft. It is in tune.

The annular mass body 21 in the dynamic vibration absorbing portion 2 is
An inner cylinder part 21a extending on the outer peripheral side of the rim part 13 of the hub 1, a disk part 21b extending from the rear end to the outer peripheral side, and an outer peripheral end part thereof, which are manufactured by press molding of a sheet metal. From the front side to the front side, the outer cylinder portion 21c is formed concentrically with the inner cylinder portion 21a. Further, the damper rubber 22 is
The rim portion 13 of the hub 1 and the inner cylindrical portion 21a of the annular mass body 21 are integrally vulcanized and vulcanized and bonded by a rubber-like elastic material between the facing surfaces.

The coupling portion 3 includes a pulley 31, a coupling rubber 32 that elastically connects the pulley 31 and the annular mass body 21, and a bearing that holds the pulley 31 concentrically with respect to the annular mass body 21. It consists of 33.

The pulley 31 in the coupling section 3 is
A pulley main body 31a, which is manufactured by press-forming a metal plate such as a steel plate, is on the outer peripheral side of the outer cylindrical portion 21c of the annular mass body 21 and has a poly V groove formed on the outer peripheral surface, and the end portion on the front side thereof. From the inner peripheral side to the inner peripheral side, and a supported cylindrical portion 31c extending from the inner peripheral end portion to the inner peripheral side of the outer cylindrical portion 21c of the annular mass body 21.

The coupling rubber 32 in the coupling portion 3 is integrally formed with the outer peripheral surface of the metal sleeve 34 whose inner peripheral portion is press-fitted to the outer peripheral surface of the inner cylindrical portion 21a of the annular mass body 21 with a required tightening margin. The outer peripheral portion is integrally vulcanized and adhered to the inner peripheral surface of the supported cylindrical portion 31c of the pulley 31. The coupling rubber 32 has a required thickness and a shape that is long in the radial direction in order to secure the strength required to transmit torque, and thus is compared with the damper rubber 22 in the dynamic vibration absorbing portion 2. Then, the torsional spring constant is made sufficiently low. Further, when subjected to torsional deformation, it is formed to have a tapered cross-sectional shape that is relatively thick on the inner peripheral side and relatively thin on the outer peripheral side so that the strain per unit volume becomes uniform. .

Bearing 33 in coupling section 3
Is formed of a synthetic resin material having a low friction coefficient such as PTFE and having a high wear resistance in a cylindrical shape, and the inner peripheral surface of the outer cylinder portion 21c of the annular mass body 21 and the supported cylinder of the pulley 31. It is interposed between the outer peripheral surface of the portion 31c and supports the annular mass body 21 and the pulley 31 concentrically with each other so as to be relatively rotatable.

Projecting portions 31d are formed at the rear end of the supported cylindrical portion 31c of the pulley 31 at equal intervals in the circumferential direction, while the protruding portions 31d are formed on the disk portion 21b of the annular mass body 21. Engagement holes 21d extending in an arc shape centered on the shaft center of the pulley 31 are provided at positions corresponding to, and the protrusions 31d and the engagement holes 21d have an appropriate clearance in the circumferential direction. They are loosely fitted together. That is, the protrusion 31d and the engagement hole 21d interfere with each other when the relative displacement amount in the circumferential direction between the annular mass body 21 and the pulley 31 reaches a predetermined amount, so that the annular mass body 2 is formed.
1 functions as a stopper that restricts the relative displacement between the pulley 1 and the pulley 31 in the circumferential direction and prevents excessive torsional deformation of the coupling rubber 32.

Further, unlike the case where the protrusion 31d is formed by driving a pin or the like, since it is formed when the pulley 31 is formed, the number of parts, the number of steps, and the manufacturing cost are not increased. .

According to the above construction, since the damper rubber 22 in the dynamic vibration absorbing portion 2 is located on the inner peripheral side of the coupling portion 3, the outer diameter of the rim portion 13 of the hub 1 to which the damper rubber 22 is vulcanized and adhered. That is, the outer diameter of the hub 1 is small, and therefore its weight is small. In addition, since the annular mass body 21 and the pulley 31 are press-molded products of sheet metal, they are lightweight, and thus the torque fluctuation absorbing damper is lightened as a whole. Further, the damper rubber 22 also has a small diameter, and the damper rubber 22 has the same displacement angle.
The smaller the diameter is, the smaller the amount of strain is, so that the durability is improved.

In manufacturing the torque fluctuation absorbing damper of this embodiment, the damper rubber 22 is provided between the hub 1 and the annular mass body 21.
While integrally vulcanizing and molding the sleeve 34 and the pulley 3
1, the coupling rubber 32 is integrally vulcanized and molded,
The bearing 33 is externally inserted into the outer cylinder portion 21c of the pulley 31, and the integrally molded product including the hub 1, the annular mass body 21, and the damper rubber 22, the sleeve 34, and the pulley 31.
And the integrally molded product made of the coupling rubber 32 are fitted to each other. At the time of this fitting, the protrusion 31d and the engagement hole 21d are aligned, the sleeve 34 is press-fitted into the outer periphery of the inner cylindrical portion 21a of the annular mass body 21 from the front side, and the outer cylindrical portion of the annular mass body 21 is pressed. 21c is extrapolated to the bearing 33.

Inner cylinder 2 of sleeve 34 and annular mass 21
Since an appropriate tightening margin is set between the damper rubber 22 and 1a, the damper rubber 22 and the coupling rubber 32 are slightly compressed to the inner peripheral side and the outer peripheral side, respectively, in the process of press-fitting each other. Therefore, the tensile stress generated in the damper rubber 22 and the coupling rubber 32 due to the contraction after molding is effectively eliminated or reduced.

The torque fluctuation absorbing damper according to this embodiment is rotated together with the crankshaft of the engine by mounting the hub 1 on the shaft end of the crankshaft. The torque of the crankshaft is from the hub 1 to the damper rubber 22, the inner cylinder portion 21a of the annular mass body 21, the sleeve 3
4 and the coupling rubber 32 are transmitted to the pulley 31. Further, a V-belt (not shown) for transmitting rotational torque to the rotating shaft of the accessory is wound around the poly V groove formed on the outer peripheral surface of the pulley body 31a of the pulley 31.

At this time, a load in a direction perpendicular to the shaft center acts on the pulley 31 due to the tension of the V belt, but a bearing 33 is interposed between the pulley 31 and the annular mass body 21, and Since the damper rubber 32 has high radial rigidity, eccentricity of the pulley 31 is prevented.

The engine is driven by repeating each process of intake, compression, explosion (expansion) and exhaust, and the reciprocating motion of the piston is converted into the rotary motion of the crankshaft. Although the torque fluctuates periodically with the rotation, this torque fluctuates due to the coupling rubber 3 having a low spring constant in the coupling portion 3.
The torsional deformation of 2 effectively absorbs the heat energy, so that the torque transmitted to the V-belt is smoothed. On the other hand, the dynamic vibration absorbing portion 2 composed of the annular mass body 21 and the damper rubber 22 resonates in the circumferential direction in the frequency range where the torsion angle due to the torsional vibration of the crankshaft becomes maximum, and the torque due to the resonance causes the input vibration. Since the torque and the direction are reversed, the peak of the twist angle of the crankshaft can be effectively reduced.

Although the annular mass body 21 itself is relatively lightweight, its outer peripheral portion (outer cylinder portion 21c) extends to the outer peripheral side of the supported cylindrical portion 31c of the pulley 31, and is integrated with the annular mass body 21. Since the sleeve 34 and the damper rubber 22 that are fitted to each other also function as a mass body, the dynamic vibration absorbing portion 2
It is possible to secure excellent dynamic vibration absorption performance due to resonance by making the substantial inertial mass of the sufficiently large.

Due to the torque fluctuation absorbing operation of the coupling portion 3, the annular mass body 21 and the pulley 31 move to the bearing 3
While sliding with 3, it is relatively displaced in the circumferential direction. The vibration system including the coupling rubber 32 and the pulley 31 has a torsional resonance region in a low frequency region as compared with the dynamic vibration absorbing unit 2, and thus resonates in a low speed rotation region, but the annular mass accompanying the resonance is generated. Since the increase in the circumferential relative displacement amount of the body 21 and the pulley 31 is limited by the interference between the circumferentially opposed ends of the protrusion 31d and the engaging hole 21d, the coupling rubber 32 is prevented from excessive torsional deformation. Never receive.

As described above, since the vibration system constituted by the coupling rubber 32 and the pulley 31 has the resonance region in the torsion direction in the low frequency region as compared with the dynamic vibration absorbing part 2, the dynamic vibration absorbing part 2 has The torque fluctuation caused by the resonance itself is also absorbed by the flexible deformation of the coupling rubber 32, and the pulley 31
Is not transmitted to.

Heat is generated in the pulley body 31a of the pulley 31 by friction with the V-belt, but the pulley 31 is made of a sheet metal press-molded product, and an appropriate space is formed on the inner peripheral side of the pulley body 31a. Therefore, the heat dissipation is good, and therefore the heat transfer to the coupling rubber 32 can be reduced.

Further, the damper rubber 2 in the dynamic vibration absorbing portion 2
2 heats up due to shearing deformation in the torsional direction associated with resonance operation,
The coupling rubber 32 in the coupling portion 3 also generates heat due to the torsional deformation operation, but since its front side is open, it is easy to radiate heat to the space on the front side. Moreover, since the heat dissipation area of the annular mass body 21 is large, heat is less likely to be accumulated. Therefore, the damper rubber 22 due to heat
Also, deterioration of the coupling rubber 32 can be suppressed and its durability can be improved.

Next, FIG. 2 is a sectional view showing a second preferred embodiment of the torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through the axis thereof, FIG. 3 is a perspective view of an essential part, and FIG. FIG. 4 is an explanatory diagram of an assembly process. In the following description, "front side" means the left side in FIG. 2, and "back side" means the right side in FIG.

In this embodiment, the difference from the first embodiment shown in FIG. 1 is that the stopper mechanism for limiting the relative displacement of the hub 1 and the pulley 31 in the circumferential direction has an outer cylindrical portion of the annular mass body 21. 21c, a protrusion 21e integrally formed at equal intervals in the circumferential direction, and an engaging hole 31e formed in the radial portion 31b of the pulley 31 corresponding to the protrusion 21e. 21f is formed.

More specifically, as shown in FIG. 3, the folded portion 21f has a protrusion 21e penetrating the engagement hole 31e.
It is formed at the tip of, and is folded back to the outer peripheral side and closely faces the outer peripheral edge of the engagement hole 31e in the axial direction. Also,
The engagement hole 31e is formed in an arc shape centered on the axial center of the annular mass body 21, and its radial width is large enough to allow the projection 21e and the folded portion 21f to pass while elastically deforming appropriately. It has become. Then, each protrusion 21
e and the engaging holes 31e are loosely fitted to each other with an appropriate gap in the circumferential direction.

In the assembly of the torque fluctuation absorbing damper of the present embodiment, the protrusion 21e formed on the outer cylindrical portion 21c of the annular mass body 21 and the engagement hole 31e formed on the radial portion 31b of the pulley 31 are mutually connected. While aligning in the circumferential direction, the sleeve 34 is attached to the inner cylindrical portion 21 of the annular mass body 21.
While being pressed into the outer periphery of a from the front side, the annular mass body 21
By externally inserting the outer cylindrical portion 21c in the bearing 33, the hub 1, the annular mass body 21, and the damper rubber 22 are attached.
The integrally molded product made of (1) and the integrally molded product made of the sleeve 34, the pulley 31, and the coupling rubber 32 are fitted to each other.

Accordingly, from the state shown in FIG. 4 (A), each protrusion 21e is inserted into each engagement hole 31e in the direction opposite to the tip of the folded portion 21f, that is, in the axial direction toward the front side. In the process of being inserted into, the folded-back portion 21f first interferes with the outer peripheral edge of the engagement hole 31e, and as a result, as shown in FIG.
With the elastic deformation of 1e, the folded-back portion 21f rides on the inner surface of the engagement hole 31e, and when the folded-back portion 21f passes through the engagement hole 31e toward the front side by further insertion, as shown in FIG. As shown, the protrusion 21e and the folded-back portion 21f are returned by the elasticity so as to be able to flip toward the outer peripheral side. In this returning state, the tip of the folded portion 21f is closely opposed to the outer peripheral wall surface of the engagement hole 31e in the radial portion 31b of the pulley 31 so as to be able to interfere.

That is, when the integrally molded product made up of the hub 1, the annular mass 21 and the damper rubber 22 and the integrally molded product made up of the sleeve 34, the pulley 31 and the coupling rubber 32 are fitted to each other and assembled, a folded-back portion is formed. 21f
Is easily inserted into the engaging hole 31e, and the folded portion 21
f is the pulley 31 after passing through the engaging hole 31e.
It has the function of retaining

In the torque fluctuation absorbing damper according to this embodiment, the basic structure of the dynamic vibration absorbing portion 2 and the coupling portion 3 is the same as that shown in FIG. 1, so that the dynamic vibration absorbing portion 2 is used as in the first embodiment. It has an excellent dynamic vibration absorbing function and an excellent torque transmitting function and torque fluctuation absorbing function by the coupling portion 3.

Then, the pulley 3 for the annular mass body 21
The amount of relative displacement in the circumferential direction of 1 corresponds to the protrusion 21 e and the engagement hole 31.
The coupling rubber 32 has a required durability because it is limited by the interference between the circumferentially opposed ends of e, the heat dissipation of the pulley 31 is good, and the heat is not easily accumulated in the coupling rubber 32. However, even if the coupling rubber 32 is damaged, the pulley 31 does not fall off, and safety is ensured. This is because the pulley 31 is prevented from coming off by the folded-back portion 21f formed on the protrusion 21e.

Moreover, when the coupling rubber 32 is damaged, the protrusion 21e and the engaging hole 31e are engaged with each other in the circumferential direction, and the engaged state is held by the folded portion 21f. Therefore, the drive torque is transmitted from the annular mass body 21 to the pulley 31 by the coupling rubber 32.
Even if the engine is damaged, the operation is continued, and it is possible to avoid a situation in which the engine is stopped due to the torque cutoff to the auxiliary machine.

In the first embodiment shown in FIG. 1, the protrusion 31d of the supported cylindrical portion 31c of the pulley 31 is also used.
The folded-back portion is formed on the disk portion 21 of the annular mass body 21.
Although it can be easily inserted from the front side into the engagement hole 21d formed in b, it can be configured so that it does not easily come out once the folded-back portion has passed through the engagement hole 21d. In addition, the folded portion, contrary to the illustrated example,
It may be folded back to the inner peripheral side, and in this case, the projection is elastically deformed to the outer peripheral side when it is inserted into the engagement hole.

[0047]

As described above, according to the torque fluctuation absorbing damper of the first aspect of the invention, since the dynamic vibration absorbing portion is arranged on the inner peripheral side of the coupling portion, the radius of the damper rubber is small. Therefore, the durability can be improved. Further, since the outer diameter of the hub is also reduced, the weight thereof is reduced, and as a result, the torque fluctuation absorbing damper can be reduced in weight as a whole. Moreover, since heat is less likely to be accumulated in the damper rubber and the coupling rubber, the durability of the damper rubber and the coupling rubber can be improved.

According to the torque fluctuation absorbing damper of the second aspect of the present invention, since the annular mass body and the pulley are made of pressed sheet metal, the weight can be reduced and the heat radiation from the damper rubber and the coupling rubber can be improved. The durability can be improved.

According to the torque fluctuation absorbing damper of the third aspect of the present invention, the excessively twisted deformation of the coupling rubber is prevented by the projection and the engagement hole which are loosely fitted to each other with a required degree of freedom in the circumferential direction. And its durability can be increased. Since the protrusion is integrally formed on one of the annular mass body and the pulley,
It can be provided without increasing the number of parts and man-hours.

According to the torque fluctuation absorbing damper of the fourth aspect of the present invention, since the pulley is prevented from coming off by the folded-back portion formed at the tip of the protrusion, even if the coupling rubber is damaged, the protrusion is prevented. The engagement state of the portion and the engagement hole is maintained, and the drive torque can be continuously transmitted to the pulley, and safety can be ensured. Further, the folded-back portion can be easily inserted into the engagement hole in the direction opposite to the tip end thereof, and after passing through the engagement hole once,
Since it has a function to prevent slipping out, it is easy to assemble.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first form of a torque fluctuation absorbing damper according to the present invention, cut along a plane passing through an axis thereof.

FIG. 2 is a cross-sectional view showing a second form of the torque fluctuation absorbing damper according to the present invention, cut along a plane passing through the axis thereof.

FIG. 3 is a perspective view of an essential part of a second form of a torque fluctuation absorbing damper according to the present invention.

FIG. 4 is an explanatory diagram of an assembly process of the torque fluctuation absorbing damper according to the present invention.

FIG. 5 is a sectional view showing a typical conventional example of a torque fluctuation absorbing damper, taken along a plane passing through the axis thereof.

[Explanation of symbols]

1 hub 11 Boss 12 Radial part 13 Rim section 2 Dynamic vibration absorber 21 annular mass 21a Inner tube part 21b Disk part 21c Outer cylinder part 21d, 31e Engagement holes 21e, 31d Projection 21f Folding part 22 Damper rubber 3 Coupling part 31 pulley 31a Pulley body 31b Radial part 31c Supported cylinder 32 coupling rubber 33 bearings 34 Sleeve

Claims (4)

[Claims] 1. A hub (1) attached to a rotating shaft is provided with a dynamic vibration absorbing part (2) and a coupling part (3),
The dynamic vibration absorbing part (2) is arranged on the outer periphery of the hub (1) and has an annular mass body (21) having an inner cylinder part (21a) and an outer cylinder part (21c), the hub (1) and the It is composed of a damper rubber (22) that elastically connects the inner cylinder part (21a) of the annular mass body (21), and the coupling part (3) is
A pulley (31) having a supported tubular portion (31c) extending toward the inner peripheral side of the outer tubular portion (21c) of the annular mass body (21).
A coupling rubber (32) that elastically connects the inner cylinder part (21a) of the annular mass body (21) and the supported cylinder part (31c) of the pulley (31), and the annular mass body (2).
1) A bearing (33) interposed between the outer cylinder part (21c) and the supported cylinder part (31c) of the pulley (31), and the damper rubber (22) and the coupling rubber (32) are on the front side. A torque fluctuation absorbing damper that is exposed to the side. 2. An annular mass (21) and a pulley (31)
The torque fluctuation absorbing damper according to claim 1, wherein the torque fluctuation absorbing damper is a pressed sheet metal product. 3. An annular mass (21) and a pulley (31)
One of them is provided with a protrusion (21e, 31d), and the other is provided with an engagement hole (31e, 21d). The protrusion (21e, 31d) and the engagement hole (31e, 21d) are formed.
3. The torque fluctuation absorbing damper according to claim 1, wherein d) are loosely fitted to each other in a circumferential direction with a required degree of freedom. 4. A protrusion (2) penetrating the engagement hole (31e).
1e) has a folded-back portion (21f) which is folded back to the outer peripheral side or the inner peripheral side and axially faces the outer peripheral edge or the inner peripheral edge of the engaging hole (31e), and the engaging hole (31
The torque fluctuation absorbing damper according to claim 3, wherein a radial width of e) is a size that allows passage of the protruding portion (21e) and the folded portion (21f).