JP2006017234A - Torque fluctuation absorbing damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque fluctuation absorbing damper capable of providing excellent durability by preventing eccentric loads from being applied to bearings 3 and 6 and the accuracy of swing of a pulley 4 from being deteriorated. <P>SOLUTION: This torque fluctuation absorbing damper comprises a dynamic vibration absorbing part 2 of such a structure that an annular mass body 22 is torsionally displaceably connected to the outer periphery of a hub 1 through a first elastic body 23 formed of a rubber-like elastic material, the pulley 4 supported on the outer periphery of the annular mass body 22 through the bearings 3 and 6, and coupling parts 5 and 5 disposed on both axial sides of the dynamic vibration absorbing part 2 and elastically connecting the hub 1 to the pulley 4 displaceably relative to each other in the circumferential direction. A space 7 between the dynamic vibration absorbing part 2 and the coupling part 5 is allowed to communicate with the outside through ventilation holes 8 and 9 formed in the inner and outer peripheries of the coupling part 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a torque fluctuation absorbing damper that is used in automobiles, agricultural machines, industrial machines, small ships, etc., and transmits torque from a drive shaft to other rotating equipment and absorbs fluctuations in the torque.

  A part of the driving force from the engine of an automobile is given to an auxiliary device such as an alternator or a water pump through an endless belt from a pulley provided at the tip of the crankshaft. Since the pulley is rotated with fluctuation, the pulley is provided with a torque fluctuation absorbing damper for absorbing torque fluctuation and smoothing transmission torque.

As a torque fluctuation absorbing damper according to the prior art, for example, as described in Patent Document 1 below, a coupling portion in which a pulley is connected to the outer periphery of a hub via a coupling bush so as to be able to be torsionally displaced, It is arranged on one side of the coupling part in the axial direction, and has a dynamic vibration absorption part (torsional damper part) having a structure in which an annular mass body is connected to the outer periphery of the hub via a damper bush so as to be able to be torsionally displaced. A structure having a structure supported on the outer periphery of an annular mass body via a bearing is known. This torque fluctuation absorbing damper transmits the torque input from the crankshaft to the hub to the pulley while smoothing it by the torsional direction shear deformation action of the elastic body in the coupling bush, and the dynamic vibration absorber is in a predetermined frequency range. In this case, a vibration damping function for reducing the torsional vibration is exhibited by resonating at a phase opposite to the torsional vibration of the crankshaft.
Japanese Patent Laid-Open No. 08-028626 (FIG. 1)

  In this type of torque fluctuation absorbing damper, for example, in order to increase the torque transmission force, the thickness of the coupling bush is increased in the axial direction. In this case, the conventional torque fluctuation absorbing damper disclosed in Patent Document 1 According to this, since the support portion of the pulley by the bearing is in a cantilever state arranged on one side in the axial direction of the coupling portion, there is a concern about the uneven load on the bearing and the deterioration of the swing accuracy of the pulley. In addition, according to the conventional torque fluctuation absorbing damper described in Patent Document 1, it is necessary to provide a seal lip in order to prevent external dust from intervening in the sliding portion of the bearing.

  The present invention has been made in view of the above points, and its technical problem is to prevent uneven load on bearings and deterioration of pulley runout accuracy, and to absorb torque fluctuation with excellent durability. To provide a damper.

  As a means for effectively solving the technical problem described above, the torque fluctuation absorbing damper according to the invention of claim 1 twists the annular mass body through the first elastic body made of rubber-like elastic material on the outer periphery of the hub. A dynamic vibration absorber having a structure connected to be displaceable, a pulley supported on the outer periphery of the annular mass body via a bearing, and the hub and the pulley arranged on both sides in the axial direction of the dynamic vibration absorber. And a coupling portion elastically connected so as to be capable of relative displacement in the circumferential direction.

  A torque fluctuation absorbing damper according to a second aspect of the present invention is the configuration described in the first aspect, wherein the space between the dynamic vibration absorbing portion and the coupling portion is on the inner periphery and / or outer periphery of the coupling portion. It communicates with the outside through the formed air holes.

  According to the torque fluctuation absorbing damper of the first aspect of the present invention, since the coupling portions are arranged on both sides in the axial direction of the dynamic vibration absorbing portion, the support balance with respect to the pulley is good, and therefore the annular mass body of the dynamic vibration absorbing portion and Uneven wear due to unbalanced load is unlikely to occur in the bearings interposed between the pulleys, and the runout accuracy of the pulley is improved. Further, since the coupling portions are arranged on both sides in the axial direction of the bearing, it is possible to effectively prevent foreign matter from intervening in the sliding portion of the bearing, thus improving the durability.

  According to the torque fluctuation absorbing damper according to the invention of claim 2, since the vent hole formed in the inner periphery and / or the outer periphery of the coupling part described in claim 1 is provided, the first of the dynamic vibration absorbing part is provided. The durability of the elastic body can be improved by preventing the elastic body from being deteriorated by the accumulation of heat.

  FIG. 1 is a cross-sectional view showing a preferred embodiment of a torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through its axis. The “front side” used in the following description refers to the left side in FIG. 1, and the “rear side” refers to the side on the right side in FIG. 1 where an unillustrated automobile engine is present. is there.

  In this figure, reference numeral 1 denotes a hub attached to a shaft end of a crankshaft (not shown) of an automobile engine. The hub 1 is cast from a metal material, and includes a boss portion 11 fixed to the crankshaft, a cylindrical portion 12 extending from the outer peripheral portion to the front side, and an axially intermediate portion of the cylindrical portion 12. It consists of a large diameter portion 13 stepped at a position. Reference numeral 11 a is a keyway formed in the shaft hole on the inner periphery of the boss portion 11.

  A dynamic vibration absorber 2 is disposed on the outer periphery of the large-diameter portion 13 in the hub 1. The dynamic vibration absorbing portion 2 vulcanizes a first elastic body 23 between a sleeve 21 press-fitted on the outer peripheral surface of the large-diameter portion 13 and an annular mass body 22 disposed on the outer peripheral side. That is, it has a structure in which an annular mass body 22 is connected to the outer periphery of the hub 1 via a first elastic body 23 so as to be able to be torsionally displaced. The sleeve 21 is manufactured by metal press molding or a metal tube, the annular mass body 22 is manufactured by casting a metal material such as iron, and the first elastic body 23 is heat resistant and cold resistant. It is molded from a rubber-like elastic material that has excellent properties and mechanical strength.

  The torsional direction natural frequency of the dynamic vibration absorber 2 is a predetermined value that maximizes the torsion angle of the crankshaft by the circumferential inertial mass of the annular mass body 22 and the circumferential shear spring constant of the first elastic body 23. It is tuned to match the natural frequency in the torsional direction of the crankshaft, in other words, the crankshaft.

  A pulley 4 is supported on the outer periphery of the annular mass body 22 via a radial bearing 3. The radial bearing 3 corresponds to the bearing described in claim 1 and is formed into a cylindrical shape from a synthetic resin material having a low friction coefficient, such as PTFE, which is excellent in wear resistance. Are slidably in contact with an axially intermediate position on the outer peripheral surface and / or the inner peripheral surface of the pulley 4. The pulley 4 is manufactured by casting or machining a metal material. A poly V groove 41 is formed on the outer peripheral surface of the pulley 4 and an endless belt (not shown) is wound around the pulley 4.

  On both sides in the axial direction of the dynamic vibration absorber 2, a pair of coupling parts 5, 5 are arranged that are elastically connected to the hub 1 and the pulley 4 so as to be capable of relative displacement in the circumferential direction. Specifically, the coupling portions 5 and 5 are respectively connected to the inner sleeve 51 and the pulley 4 that are press-fitted and fitted to positions on both sides in the axial direction of the large-diameter portion 13 on the outer peripheral surface of the cylindrical portion 12 of the hub 1. A guide sleeve 52 press-fitted in the vicinity of both axial ends of the peripheral surface, an outer sleeve 53 press-fitted into the inner periphery of the guide sleeve 52, and the inner sleeve 51 and the outer sleeve 53 were vulcanized and bonded. The second elastic body 54 is provided. The inner sleeve 51, the guide sleeve 52, and the outer sleeve 53 are each made of metal, and the second elastic body 54 is formed of a rubber-like elastic material having excellent heat resistance, cold resistance, and mechanical strength.

  The coupling portions 5 and 5 transmit the driving torque input from the crankshaft to the hub 1 to the pulley 4 while smoothing the driving torque input by the circumferential elastic shearing action of the second elastic body 54. 54, when subjected to the circumferential shear deformation between the hub 1 and the pulley 4, the wall thickness in the connecting direction (axial direction) is such that the shear stress is substantially uniform on the inner peripheral side and the outer peripheral side. It has a shape that decreases toward the side.

  The guide sleeves 52, 52 in the coupling portions 5, 5 are formed with guide flanges 52 a facing the inner peripheral side at their inner ends, and the guide flanges 52 a, 52 a have the annular mass body 22. Annular thrust bearings 6 and 6 provided on the outer peripheral portions of both end faces are in slidable contact. The thrust bearings 6 and 6 are formed of a synthetic resin material having a low friction coefficient that is excellent in wear resistance such as PTFE and is formed into a cylindrical shape, and annular recesses formed on the outer peripheral portions of both end surfaces of the annular mass body 22 It is incorporated by fitting or the like.

  A plurality of grooves 12a are formed at predetermined intervals in the circumferential direction on both sides in the axial direction of the large diameter portion 13 on the outer peripheral surface of the cylindrical portion 12 of the hub 1, and the inner sleeve 51 on the outer periphery thereof is formed by the grooves 12a. Are formed between the dynamic vibration absorbing portion 2 and the coupling portion 5 so as to communicate the inner peripheral portion of the space 7 to the outside. In addition, the outer sleeve 53 in each coupling portion 5 is formed with a plurality of groove-shaped bent portions 53a bent toward the inner circumference side at predetermined intervals in the circumferential direction. A vent hole 9 is formed between the guide sleeve 52 and the outer periphery of the space 7 to communicate with the outside.

  The dynamic vibration absorber 2 is manufactured by setting the sleeve 21 and the annular mass body 22 concentrically in a mold (not shown) and defining the gap between the sleeve 21 and the annular mass body 22 by the mold. This is performed by filling the annular cavity with an unvulcanized rubber material, heating and pressurizing, and vulcanizing and bonding the first elastic body 23 to the sleeve 21 and the annular mass body 22 simultaneously with the vulcanization molding. .

  The coupling portion 5 is manufactured by setting an inner sleeve 51 and a guide sleeve 52 and an outer sleeve 53 that are press-fitted in advance in a mold (not shown) concentrically with each other. An unvulcanized rubber material is filled in an annular cavity defined by the mold between the inner sleeve 51 and the outer sleeve 53 at the same time as the second elastic body 54 is vulcanized. This is done by vulcanizing and adhering.

  In assembling the torque fluctuation absorbing damper, first, the sleeve 21 of the dynamic vibration absorber 2 manufactured as described above is press-fitted onto the outer peripheral surface of the large-diameter portion 13 of the cylindrical portion 12 of the hub 1. Thus, the dynamic vibration absorbing portion 2 is attached, and the pulley 4 is extrapolated to the outer periphery of the annular mass body 22 via the radial bearing 3.

  Next, coupling portions 5 and 5 are attached between the cylindrical portion 12 of the hub 1 and the pulley 4 from both sides in the axial direction. Specifically, the coupling portion 5 on the front side press-fits the inner sleeve 51 to the outer peripheral surface on the front side of the large-diameter portion 13 in the tubular portion 12 of the hub 1, and the guide sleeve 52 is connected to the pulley 4. The inner peripheral surface is attached by press-fitting to a portion of the inner peripheral surface near the front end, and the coupling portion 5 on the rear side is connected to the inner sleeve 51 by the rear side of the large-diameter portion 13 in the tubular portion 12 of the hub 1. The guide sleeve 52 is attached to the inner peripheral surface of the pulley 4 by press-fitting into a portion of the inner peripheral surface of the pulley 4 near the end on the back side. The thrust bearings 6 and 6 are mounted in advance on the outer peripheral portions of both end surfaces of the annular mass body 22 by means such as fitting.

  The torque fluctuation absorbing damper having the above-described configuration is rotated together with the crankshaft by attaching the boss portion 11 of the hub 1 to the shaft end of the crankshaft of the engine (not shown). The torque of the crankshaft is transmitted from the hub 1 to the pulley 4 through the coupling parts 5 and 5, and further through a belt (not shown) wound around the pulley 4 such as a cooling fan or an alternator. Is transmitted to the rotary shaft of the machine.

  According to this embodiment, since a pair of coupling portions 5 are provided in parallel in the axial direction, a large torque transmission force by the second elastic bodies 54 and 54 can be obtained. In particular, since the second elastic bodies 54 and 54 support the vicinity of both ends in the axial direction of the pulley 4, the axial thickness of the elastic body of the coupling portion provided only on one side in the axial direction as in the prior art. In comparison, the sum of the axial thicknesses of the second elastic bodies 54, 54 required to obtain the same torque transmission force can be reduced.

  Here, a radial load due to the tension of the V-belt acts on the pulley 4, but the pulley 4 is attached to the annular mass body 22 of the dynamic vibration absorbing portion 2 through the radial bearing 3 at the intermediate portion in the axial direction. Since it is supported and has a structure in which the coupling portions 5 are arranged on both sides thereof, it is supported in a balanced manner without being in a cantilever state. Therefore, an uneven load is unlikely to act on the radial bearing 3, and the uneven wear is effectively prevented, and the durability is improved.

  The axial displacement of the pulley 4 is transmitted to the annular mass body 22 through the thrust bearings 6 and 6 from the guide flanges 52a and 52a of the guide sleeves 52 and 52 fitted to the inner peripheral surfaces near both ends thereof. Since it is received by the annular mass body 22 elastically connected to the hub 1 side via the one elastic body 23, the deflection accuracy of the pulley 4 during rotation is improved.

  Further, according to this embodiment, since the radial bearing 3 and the thrust bearings 6 and 6 are located between the hub 1, the pulley 4 and the couplings 5 and 5, it is difficult for dust to enter from outside. Even if no dust seal means is provided, it is possible to prevent the radial bearing 3 and the thrust bearings 6 and 6 from being worn due to the intervention of dust into the sliding portion.

  The engine is driven while repeating the intake, compression, explosion, and exhaust strokes, and the reciprocating motion of the piston is converted into the rotational motion of the crankshaft. Although torque fluctuation occurs, the torque fluctuation is converted into heat energy by the second elastic bodies 54 and 54 in the coupling portions 5 and 5 being shear-deformed in the torsional direction (circumferential direction) by a low spring. Therefore, the transmission torque to the belt is smoothed. Further, the dynamic vibration absorber 2 resonates in the circumferential direction in the frequency range where the torsional angle due to the torsional vibration of the crankshaft becomes maximum, and the torque due to the resonance is opposite in direction to the torque of the input vibration. The peak of the crankshaft torsion angle can be effectively reduced by the dynamic vibration absorbing action.

  The first elastic body 23 of the dynamic vibration absorber 2 generates heat by repetitive shear deformation accompanying the resonance operation. However, since centrifugal force acts on the air present in the space 7 existing between the dynamic vibration absorbing portion 2 and the coupling portion 5 as it rotates, the cylindrical portion of the hub 1 is formed in the space 7. 12 and the inner sleeve 51 of the coupling part 5, and through the vent hole 9 formed between the outer sleeve 53 and the guide sleeve 52 in the coupling part 5, Outside air circulates by the pump action.

  Therefore, the heat generated in the first elastic body 23 is not accumulated between the couplings 5 and 5 and is released to the outside. For this reason, deterioration of the first elastic body 23 due to heat accumulation is prevented. Further, the heat generated in the second elastic bodies 54 and 54 of the couplings 5 and 5 due to the repeated shear deformation is directly released to the outside, but a part thereof is caused by the air flowing through the space 7. Released.

  The vent hole 8 may be provided by forming a groove-like bent portion bent toward the outer peripheral side in the inner sleeve 51, contrary to the illustrated form, and the vent hole 9 is provided on the inner peripheral surface of the guide sleeve 52. You may provide by forming a groove | channel in this. Further, by forming the vent holes 8 and 9 so as to form a predetermined inclination angle with respect to the circumferential direction, forced air flow can be caused by the screw pump action and the air cooling effect can be enhanced. .

It is sectional drawing which cut | disconnects and shows the preferable form of the torque fluctuation | variation absorption damper which concerns on this invention by the plane which passes the axial center.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub 11 Boss part 12 Cylindrical part 13 Large diameter part 2 Dynamic vibration absorption part 21 Sleeve 22 Annular mass 23 First elastic body 3 Radial bearing (bearing)
4 Pulley 5 Coupling portion 51 Inner sleeve 52 Guide sleeve 52a Guide flange 53 Outer sleeve 54 Second elastic body 6 Thrust bearing (bearing)
7 Space 8, 9 Vent

Claims (2)

  A dynamic vibration absorber (2) having a structure in which an annular mass body (22) is connected to the outer periphery of the hub (1) via a first elastic body (23) made of a rubber-like elastic material in a torsionally displaceable manner, and the annular mass A pulley (4) supported on the outer periphery of the body (22) via a bearing (3), and the hub (1) and the pulley (4) disposed on both sides in the axial direction of the dynamic vibration absorber (2). And a coupling portion (5) elastically coupled so as to be capable of relative displacement in the circumferential direction.   The space (7) between the dynamic vibration absorbing part (2) and the coupling part (5) has vent holes (8, 9) formed in the inner periphery and / or outer periphery of the coupling part (5). The torque fluctuation absorbing damper according to claim 1, wherein the torque fluctuation absorbing damper is in communication with the outside through the outside.

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