JP6411062B2 - Anti-vibration structure of rotating body - Google Patents

Description

  The present invention relates to a technique for reducing noise caused by vibration generated in a rotating body such as a gear.

  In a gear that transmits driving force, noise during operation often becomes a problem. In general, the entire gear resonates and generates noise due to the excitation force when the gear is engaged (engaged). As countermeasures, the gear rigidity is increased or the entire gear is made of a material with high damping. (For example, change from metal to synthetic resin).

  However, it is often structurally difficult to increase the rigidity of the teeth, and the resonance frequency value is simply shifted, and eventually a resonance point that has shifted to another frequency band may be a problem. is there. On the other hand, when the entire gear is changed to a material with high attenuation such as synthetic resin, it is possible to reduce the amplitude peak (noise peak) due to resonance itself, and the effect is high. However, changing the material to synthetic resin, etc. is difficult to apply to gears with high driving torque. In such cases, the countermeasure is to use a coupling structure that floats the teeth with an elastic body, etc., and transmission under high torque load. In order to make this possible, it was necessary to install a mechanical stopper.

  Therefore, as shown in the following prior art documents, a plurality of windows are opened in a rotating body such as a gear, and a mass body is held in each of these windows via an elastic material such as rubber. There has been proposed a system in which noise is reduced by a dynamic damper effect in which a secondary vibration system composed of a body resonates in a predetermined frequency band with a vibration waveform having a phase opposite to that of the input vibration and dynamically absorbs the input vibration.

JP 2001-248687 A JP-A-9-273618

  However, according to the structure described in the prior art document, the secondary vibration system is prevented from falling off by closing the window portion in which the secondary vibration system made of the elastic material and the mass body is accommodated from both sides in the axial direction. Therefore, not only the structure is complicated, but also the side vibration of the side of the gear, which is the most problematic problem, that is, the vibration of the secondary vibration system against the vibration in the thickness direction (axial direction) is suppressed by the covers on both sides. Therefore, it is pointed out that the dynamic damper effect becomes small.

  The present invention has been made in view of the above points, and its technical problem is to provide a vibration isolating structure having a simple structure and a high vibration isolating effect in a rotating body such as a gear. is there.

As means for effectively solving the technical problem described above, the vibration isolating structure for a rotating body according to the invention of claim 1 was established at a plurality of locations in the circumferential direction of the disk portion of the rotating body having a disk portion. A vibration damping cover is held in the window portion through an elastic body made of a rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity), and the vibration damping cover is inserted into the inner periphery of the window portion. The elastic body is appropriately compressed between the inner peripheral surface of the window portion and the main body portion of the damping cover, and one end of the elastic body. It consists of a part which extends from the said disk part and is suitably compressed between the collar part of the said damping cover.

  According to the above configuration, the secondary vibration system composed of the vibration damping cover and the elastic body resonates with a vibration waveform having a phase opposite to that of the input vibration in a predetermined frequency band, and dynamically absorbs the vibration of the disk portion of the rotating body. Plays a dynamic damper effect. In particular, since the vibration damping cover cannot be pressed from both sides in the axial direction, an excellent dynamic damper effect and damping function against surface vibration of the disk portion, that is, vibration in the thickness direction (axial direction) is exhibited.

  A vibration isolating structure for a rotating body according to a second aspect of the invention is the structure according to the first aspect, wherein a pair of vibration damping covers are inserted into the window portion from both sides in the axial direction and coupled to each other.

  According to the above configuration, the vibration damping cover is prevented from falling off from the window portion, and an appropriate portion of the elastic body interposed between the disk portion of the rotating body and the flange portion of the vibration damping cover is also appropriately compressed. Damping function can be given.

  According to a third aspect of the present invention, there is provided a vibration isolating structure for a rotating body according to the first or second aspect, wherein the rotating body is a gear.

  According to the vibration isolating structure of the rotating body according to the present invention, the window portion is not closed from both sides in the axial direction, so that the structure can be simplified, and excellent dynamic damper effect and damping against the surface vibration of the disk portion can be achieved. Since the function is achieved, the vibration isolation effect can be improved and noise can be effectively reduced.

1 is a perspective view showing a first preferred embodiment of a vibration isolating structure for a rotating body according to the present invention. It is a principal part expanded sectional view which shows preferable 1st embodiment of the vibration isolating structure of the rotary body which concerns on this invention. It is a perspective view which shows the gear of the vibration isolating object in the first preferred embodiment of the vibration isolating structure of the rotating body according to the present invention. 1 is a cross-sectional perspective view showing a molded body of a vibration damping cover and an elastic body in a preferred first embodiment of a vibration isolating structure for a rotating body according to the present invention. It is a perspective view which shows other preferable embodiment of the vibration isolating structure of the rotary body which concerns on this invention. It is a principal part expanded sectional view which shows other preferable embodiment of the vibration isolator structure of the rotary body which concerns on this invention. FIG. 6 is a cross-sectional perspective view showing a molded body of a vibration damping cover and an elastic body in another preferred embodiment of a vibration isolating structure for a rotating body according to the present invention.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments in which a rotating body vibration isolation structure according to the present invention is applied to gear vibration isolation will be described below with reference to the drawings.

First, in the first embodiment shown in FIGS. 1 to 4, reference numeral 1 in FIG. 1 is a vibration damping target gear, which corresponds to a rotating body, a disc having a shaft hole 14 at the center A tooth portion 12 is formed on the outer periphery of the portion 11, and as shown in FIG. 3, the disc portion 11 is provided with circular window portions 13 at a plurality of locations in the circumferential direction (seven locations in the illustrated example). Yes.

  Reference numeral 2 is a metal damping cover, and reference numeral 3 is an elastic body made of a rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity), and they are integrated with each other, that is, the elastic body 3. Is vulcanized and molded integrally with the vibration damping cover 2, and the integral molded product is formed in each window portion 13 opened in the disk portion 11 of the gear 1 from both sides in the axial direction as shown in FIG. One pair is press-fitted. That is, the vibration control covers 2 are held on the window portions 13 via the elastic bodies 3 respectively.

  As shown in FIG. 4, the vibration damping cover 2 is formed in a dish shape, that is, composed of a disk-shaped bottom portion 21 a and a cylindrical portion 21 b having an outer diameter, and is inserted into the window portion 13 of the gear 1. It consists of a main body 21 and a flange 22 that extends from the open end (the end opposite to the bottom 21a) of the cylindrical portion 21b to the outer diameter side. In the mounted state shown in FIG. 2, the vibration damping covers 2 on both sides in the axial direction overlap with each other at the bottom 21a of the main body 21 and are integrally coupled to each other by appropriate coupling means such as welding or caulking.

  The elastic body 3 is formed by vulcanization molding integrally with the vibration damping cover 2, and has a cylindrical elastic layer 31 bonded to the outer peripheral surface of the cylindrical portion 21 b in the main body portion 21 of the vibration damping cover 2, and this cylinder. It consists of a hook-shaped elastic layer 32 that extends from one end of the ring-shaped elastic layer 31 to the outer diameter side and is bonded to the flange portion 22 of the vibration damping cover 2.

Cylindrical elastic layer 31 of the elastic body 3 is equivalent to the "optionally compressed in part between the body portion of the damping covering the inner peripheral surface of the window portion", i.e. in the mounting state shown in FIG. 2, An appropriate margin in the radial direction between the inner peripheral surface of the window portion 13 of the gear 1 and the cylindrical portion 21b of the main body portion 21 of the damping cover 2 (5% or more, preferably about 20% with respect to the wall thickness). Has been granted. Further, a flange-like elastic layer 32 of the elastic body 3 is equivalent to a "portion interposed between the side surface and the flange portion of the damping cover of the disk portion", in the fitted state shown in FIG. 2, the gear 1 The collar-like elastic layer 32 is sandwiched between the side surface of the disk part 11 and the collar part 22 of the vibration damping cover 2 with an appropriate tightening margin (5% or more, preferably about 20% relative to the thickness) in the axial direction. Thus, the axial direction length of the cylindrical part 21b of the damping cover 2 is set.

  The damping cover 2 and the elastic body 3 constitute a secondary vibration system including a mass body and a spring. That is, the secondary vibration system has a resonance frequency determined by the inertia mass of the damping cover 2 and the spring constant of the elastic body 3. In particular, the resonance frequency in the axial direction is in a frequency band where the gear 1 resonates due to, for example, an excitation force when the tooth portion 12 is engaged (engaged) and generates surface vibration, that is, vibration in the thickness direction (axial direction). Is set.

  According to the first embodiment having the above-described configuration, the disk portion 11 of the gear 1 resonates due to the excitation force when the tooth portion 12 beats, and generates surface vibration, that is, vibration in the thickness direction (axial direction). Even so, this surface vibration cancels the vibration of the disk portion 11 by the secondary vibration system constituted by the damping cover 2 and the elastic body 3 resonating in the axial direction with a vibration waveform having a phase opposite to that of the input vibration. And the dynamic damper effect that is absorbed dynamically, the cylindrical elastic layer 31 of the elastic body 3 is repeatedly subjected to shear deformation in the axial direction, and the hooked elastic layer 32 of the elastic body 3 is repeated in the axial direction. Attenuating effect due to receiving compression deformation. Further, at this time, the vibration-damping covers 2 on both sides in the axial direction are integrally connected to each other so as to be prevented from coming off by the flange portion 22, so that they will not fall off due to repeated displacement in the axial direction.

  As described above, since the vibration damping covers 2 on both sides in the axial direction are integrally coupled to each other and are prevented from coming off by the flange portion 22, a member for pressing the vibration damping cover 2 from both sides in the axial direction is unnecessary. . For this reason, resonance of the secondary vibration system with respect to the surface vibration of the disk portion 11 is not suppressed, and an excellent dynamic damper effect and damping effect are exhibited.

  Since the amplitude of resonance of the gear 1 is reduced by the dynamic damper effect and the damping effect described above, the radiated sound from the disk portion 11 is reduced and the gear is connected via the rotating shaft coupled in the shaft hole 14. Since the amplitude transmitted to the box or the like is also reduced, noise due to transmission vibration to the gear box or the like is effectively reduced.

  Further, according to the first embodiment, if the gear 1 has the window portion 13, the structure shown in FIG. 1 can be obtained by providing the vibration control cover 2 and the elastic body 3 on the gear having the existing structure. Thus avoiding significant changes in the gear structure. In addition, it is only necessary to press-fit the integrally formed product of the damping cover 2 and the elastic body 3 from both sides in the axial direction into each window portion 13 so that the damping covers 2 are joined to each other, and a member for pressing the damping cover 2 from both sides in the axial direction. Is unnecessary, and thus a simple structure can be obtained.

  Next, FIGS. 5 to 7 show another embodiment. That is, in this embodiment, the difference from the first embodiment described above is that the integrally formed product of the damping cover 2 and the elastic body 3 is axially formed in each window portion 13 opened in the disk portion 11 of the gear 1. The point is that it is press-fitted one by one from one side.

  The cylindrical portion 21b of the main body portion 21 of the damping cover 2 has an axial length equal to or greater than the sum of the thicknesses of the disc portion 11 of the gear 1 and the bowl-shaped elastic layer 32 of the elastic body 3, The elastic body 3 is formed with a hook-like engagement protrusion 33 which is engaged with an edge portion of the window portion 13 in the disk portion 11 of the gear 1 at an end portion on the opposite side to the bowl-shaped elastic layer 32.

  In the second embodiment having the above-described configuration, the surface vibration generated in the disk portion 11 of the gear 1 is also effective by the dynamic damper effect and the damping effect by the damping cover 2 and the elastic body 3 as in the first embodiment. Can be reduced. Further, since the vibration damping cover 2 is prevented from coming off by the flange portion 22 and the engagement protrusion 33 formed on the elastic body 3, it does not fall off due to repeated displacement in the axial direction, and each window portion 13 Since the integral molded product of the vibration damping cover 2 and the elastic body 3 is press-fitted one by one, further simplification is possible.

  In each of the above-described embodiments, the elastic body 3 is integrally formed with the vibration damping cover 2. However, the elastic body 3 is held between the window portion 13 and the vibration damping cover 2, and the sub-vibration spring is used. The vibration damping cover 2 and the elastic body 3 do not necessarily have to be formed as an integral product as long as the means and the damping means are established. Further, the damping cover 2 has a structure in which the inertial mass is increased by, for example, a shape in which the flanges 22 are continuous in the circumferential direction of the gear 1, that is, in a shape that is concentric with the gear 1. You can also.

  The present invention can also be applied as a vibration isolation structure for a rotating body other than a gear, for example, a rotating body such as a pulley.

1 Gear (Rotating body)
DESCRIPTION OF SYMBOLS 11 Disk part 13 Window part 2 Damping cover 21 Main body part 22 Gutter part 3 Elastic body 31 Cylindrical elastic layer (The part compressed suitably between the internal peripheral surface of a window part, and the main-body part of a damping cover)
32 bowl-shaped elastic layer (part interposed between the side surface of the disk part and the collar part of the vibration damping cover)
33 Engagement protrusion

Claims (3)

Vibration control is performed via a resilient body made of a rubber-like elastic material (rubber material or a synthetic resin material having rubber-like elasticity) on a plurality of windows in the circumferential direction of the disk portion of the rotating body having a disk portion. A cover is held, and the vibration-damping cover comprises a main body portion that is inserted into the inner periphery of the window portion, and a flange portion that extends from the open end of the outer diameter, and the elastic body is an inner peripheral surface of the window portion. rotating, characterized in that comprising the a portion is appropriately compressed between the main body portion of the damping cover, portion to be compressed appropriately between extending from one end of the flange portion of the damping cover and the disc portion and Anti-vibration structure of the body.   2. The vibration isolating structure for a rotating body according to claim 1, wherein each pair of vibration damping covers is inserted into the window portion from both sides in the axial direction and coupled to each other.   The vibration isolating structure for a rotating body according to claim 1 or 2, wherein the rotating body is a gear.

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