JPH0544601Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a dynamic damper that is attached to a rotating shaft to suppress harmful vibrations generated in the rotating shaft. The dynamic damper of the present invention is used, for example, for damping vibrations in automobile drive shafts.

[Prior Art] Dynamic dampers are often used to suppress harmful vibrations such as bending vibrations and torsional vibrations caused by rotational imbalance that occurs with the rotation of the rotating shafts of drive shafts and propeller shafts in automobiles, etc. ing. These dynamic dampers achieve their functions by matching the natural frequency to the dominant frequency of the excited vibration, converting the vibration energy of the rotating shaft through resonance and absorbing it as vibration energy of the dynamic damper. is fulfilled.

An example of a dynamic damper conventionally used in drive shafts of automobiles, etc. is shown in the fourth example.
As shown in the figure. This dynamic damper includes a central support member 101 that is inserted through and held by a rotating shaft, and a cylindrical mass member 1 that is disposed on the outer periphery of the central support member 101.
02, and an elastic member 10 that is sandwiched between the central support member 101 and the mass member 102 and connects them.
It is composed of 3. When this dynamic damper is mounted on a rotating shaft, one insertion opening of the central support member of the dynamic damper is aligned with the shaft end of the rotating shaft, and the damper is press-fitted in this state. At this time, to ensure fixation when installed,
The inner diameter of the insertion hole is set to be somewhat smaller than the outer diameter of the rotating shaft.

[Problem to be solved by the invention] However, the above-mentioned conventional dynamic damper is attached to the rotating shaft by press-fitting, but the inner diameter of the central support member is larger than the outer diameter of the rotating shaft through which it is inserted. Since it is somewhat smaller, the rotating shaft pushes the entire central support member toward the outer circumference when inserted, thereby expanding its inner circumferential surface. Generally, the central support member has a thick ring shape, and a large amount of force is required to fully expand the inner peripheral surface of the central support member. As described above, conventional dynamic dampers have been difficult to install and remove due to press-fitting and the like, and have had problems in terms of workability.

An object of the present invention is to provide a dynamic damper that has low resistance during press-fitting and is easy to install.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the dynamic damper of the present invention has a central support member whose overall shape is a ring, which is divided into arcs and has a shaft hole that is inserted through and held by the rotating shaft. a fixing member that fixes the center support member to the rotating shaft; and a ring-shaped member having an inner circumferential shape larger than the outer circumferential shape of the rotating shaft, disposed coaxially with the rotating shaft, and mainly composed of a mass body. a mass member, and a plurality of elastic elements that coaxially and integrally connect the central support member and the mass member, and that are provided at least one in each divided arcuate portion of the central support member and extend radially as a whole. The structure is characterized by having a member.

[Function] In the dynamic damper of the present invention, the central support member through which the rotating shaft is inserted has a ring shape as a whole, but is divided into a plurality of arc shapes. and,
At least one elastic member is provided in each divided arcuate portion of the central support member, and a plurality of elastic members are sandwiched radially as a whole to integrally connect the ring-shaped mass member coaxially arranged on the outer periphery. has been done. And when it is not attached to the rotating shaft,
Each divided arcuate portion of the central support member is pushed toward the shaft center by an elastic member, and these arcuate portions form a shaft hole for insertion and holding that is slightly smaller than the outer diameter of the rotating shaft. At this time, the dividing surfaces of each arcuate portion are in a substantially close contact state.

When the central support member is pressed into the mass member, the inner diameter of the central support member is slightly smaller than the outer diameter of the rotating shaft to be inserted, so the shaft end of the rotating shaft expands the inner peripheral surface of the central support member outward. At this time, since the central support member is divided, there is no tensile force that tries to return the inner peripheral surface to its original size, and only the reaction force against compression or shear of the elastic member that connects the central support member to the mass member acts as a resistance force. However, this reaction force against compression or shear of the elastic member is considerably smaller than the restoring force against expansion that exists in conventional dynamic dampers. Therefore, the dynamic damper of the present invention can significantly reduce the press-in resistance force during press-in.

[Example] An example according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view of a dynamic damper according to an embodiment, and FIG. 2 is a side view thereof.

The dynamic damper of this embodiment is used for damping vibrations of a drive shaft of an automobile, and includes a central support member 1 that is inserted into and held by a drive shaft S that is a rotating shaft, and a center support member 1 that is connected to a drive shaft S. A pair of fixing members 2, 2 fixed to
, a mass member 3 arranged around the outer periphery of the drive shaft S, and an elastic member 4 that integrally connects the central support member 1 and the mass member 3. The overall shape of the dynamic damper is cylindrical, with a larger outer diameter at the center, smaller outer diameters at both ends, and a step between them.

The central support member 1 as a whole has a ring shape and is made of a natural rubber material, and the size of the inner peripheral surface forming the shaft hole 11 into which the drive shaft S is inserted is equal to the outer diameter of the drive shaft S. It's a little smaller than that. And this central support member 1
is an arcuate portion 1 divided into four equal parts by a plane that includes the axis center line.
It is divided into 2. Almost no gap is formed on the dividing plane between each of the divided arcuate portions 12. Locking grooves 13, 13 for fixing to the drive shaft S by fixing members 2, 2 are formed at both ends in the axial direction of each arcuate portion 12, and the locking grooves 13, 13 are formed outward from the outer peripheral surface excluding both ends. 2 each radially
The elastic members 4 are integrally connected.

As the fixing member 2, a fixing band made of stainless steel is used, and is wound and fixed in locking grooves 13 formed at both ends of the central support member 1.

The mass member 3 includes a thick-walled steel pipe 31 that is a ring-shaped mass body, and a thick-walled steel pipe with an outer circumferential surface and an inner circumferential surface.
The coating layer 32 is made of a natural rubber material and is coated with a thickness of about mm, and an elastic member 4 that elastically supports the mass member 3 is provided on the inner circumferential surface of the coating layer 32.
One end of the two is connected as a unit.

The elastic member 4 is made of natural rubber material, and
Two pieces are disposed on the outer circumferential surface of each divided arcuate portion 12, one end of each is integrally connected to the outer circumferential surface of each arcuate portion 12, and the other end extends radially from the center of the axis and is disposed on the outer circumference. It is integrally connected to the coating layer 32 on the inner peripheral surface of the mass member 3 provided therein.

The dynamic damper of this embodiment configured as described above is used as follows. first,
When installing the dynamic damper to the drive shaft S, the shaft hole 11 of the dynamic damper is
Align it with the shaft end of drive shaft S. Shaft hole 11
is slightly smaller than the outer diameter of the drive shaft S, but when press-fitted, the arcuate portions 12 constituting the central support member 1 are separated from each other by the dividing plane, and the adjacent arcuate portions 12 A gap is formed between them. Since there is no restoring force against the tension when the central support member 1 is expanded, the press-fit resistance force is only the restoring force of the elastic member 4. The restoring force at this time is not so strong as to become an obstacle during press-fitting work, so press-fitting can be easily performed with almost no resistance. Then, the dynamic damper is placed at a predetermined position, and the locking grooves 13, 13 formed at both ends of the central support member 1 are connected to the fixing member 2, 13, respectively.
2, each arcuate portion 12 constituting the central support member 1 is securely attached to the drive shaft S.

When the drive shaft S rotates and harmful vibrations are excited, the mass member 3 of the dynamic damper whose natural frequency matches the harmful frequency vibrates, and the vibration energy of the drive shaft S is absorbed by the dynamic damper. By doing so, harmful vibrations occurring in the drive shaft S can be effectively suppressed.

Furthermore, instead of the central support member 1 of this embodiment, a central support member 5 shown in FIG. 3 may be used. This central support member 5 as a whole has a ring shape having a shaft hole 51 for the drive shaft S, and the size of the inner peripheral surface forming the shaft hole 51 is slightly smaller than the outer diameter of the drive shaft S. ing. This central support member 5 has 4 points in a plane including the axial center.
It is divided into equal arc-shaped parts 52, and each arc-shaped part 52 consists of an arc-shaped steel plate 52a extending in the axial direction, and a covering made of a natural rubber material that thinly coats the entire steel plate 52a. It is composed of a film 52b. A locking groove (not shown) for fixing to the drive shaft S by the fixing members 2, 2 is formed at both ends of each arcuate portion 52, and the outer circumferential surface excluding the both ends is covered. Two elastic members 4 are integrally connected radially outward from the membrane 52b. Since the central portion of the central support member 5 is made of a steel plate, it has sufficient rigidity to withstand the strong centrifugal force generated by rotation. Therefore, in the dynamic damper using the central support member shown in FIG. 3, stable operation is ensured and its reliability can be increased.

Note that in the parts where the natural rubber material is used in this embodiment, an elastic material such as another rubber material can be used instead of the natural rubber material. Further, the mass body of the mass member 3 is not limited to a thick-walled steel pipe, but is not particularly limited as long as it is formed of a metal material. The fixing band may be made of a material other than stainless steel as long as it has sufficient rigidity and can firmly fix the central support member. Further, the number of divisions of the central support member 1 may be multiple divisions other than four, and the number of elastic members 4 provided in each divided arcuate portion is not particularly limited to two as long as it is one or more.

[Effects of the invention] As is clear from the above explanation, the dynamic damper of the invention can significantly reduce the resistance force during press-fitting, so it has simplified the press-fitting work, which used to be very difficult. We were able to achieve significant improvements in work efficiency, such as increased efficiency and reduced work time.

[Brief explanation of drawings]

FIG. 1 is a plan view of a dynamic damper according to an embodiment of the present invention, and FIG. 2 is a side view thereof. FIG. 3 is a cross-sectional view taken perpendicular to the axis of the central support member in another embodiment. FIG. 4 is a schematic diagram of a conventional dynamic damper. 1, 5...Central support member, 2...Fixing member, 3
...Mass member, 4...Elastic member.

Claims (1)

[Claims for Utility Model Registration] A central support member whose overall shape is a ring and which is divided into arcs and has a shaft hole that is inserted through and held by a rotating shaft; a fixing member that fixes the central supporting member to the rotating shaft; a ring-shaped mass member having an inner circumferential shape larger than the outer circumferential shape of the rotating shaft, coaxially arranged with the rotating shaft, and mainly composed of a mass body; A dynamic damper comprising: a plurality of elastic members which are integrally coupled, are provided at least one in each divided arcuate portion of the central support member, and extend radially as a whole.