JPH058357Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a dynamic vibration absorber that damps vibrations generated in various rotary drive systems.

[Conventional technology]

Conventionally, as a type of vibration absorber that absorbs vibrations generated in the drive system of an automobile, for example, an annular hub a having an approximately L-shaped cross section has been used, as shown in FIG.
It is known that a vibrating ring b is arranged concentrically and spaced apart on the outer periphery of a cylindrical portion of the hub a, and the hub a and the vibrating ring b are connected by an elastic body c. In addition to a portion c1 that connects the hub a and the vibration ring b, the elastic body c has projecting portions c2 integrally formed on the outer circumferential side of the hub a in an alternating and evenly spaced manner.

The above-mentioned vibration absorber absorbs vibrations in the torsional direction (rotational direction) that are generated in the propeller shaft of an automobile drive system by fitting a hub a to the propeller shaft of the vehicle, etc. Due to the action of force, the vibration ring b becomes largely eccentric with respect to the hub a, that is, the center of rotation, in a certain rotational speed range, resulting in the problem of generating new vibrations and noise. The vibration absorber is equipped with the protruding portion c2 to suppress this eccentricity, but because the parts are inserted into a vulcanization mold, it is not possible to set the gap between the hub a and the vibration ring b small, and the gap between the hub a and the vibration ring b cannot be set small. Since the large protruding portion c2 made of rubber material is provided, there remains a problem that the material cannot function satisfactorily against eccentricity, and a new solution is desired.
Moreover, as mentioned above, in addition to the fact that the radial distance between hub a and vibration ring b cannot be made small, in order to obtain sufficient vibration absorption capacity, the radial width of vibration ring b must be increased. Since it is necessary to set a required inertial mass depending on the size, the overall size is inevitably increased.

[Means for solving the problem]

The present invention was developed in view of the above points, and includes a vibrating ring that is spaced apart from each other on the outer periphery of a hub that is attached to a rotating member of a drive system, and an elastic body is attached to each of the hub and the vibrating ring near both ends in the axial direction. an annular ring formed integrally with the inner periphery of the vibration ring and facing the outer periphery of the hub side with a slight clearance in the axial center portion sandwiched between the two elastic bodies; It has a structure in which a protrusion is provided.

[Effect]

That is, in the dynamic vibration absorber of the present invention, the protrusion functions as a stopper for regulating the eccentricity of the vibrating ring, and the eccentricity of the vibrating ring is suppressed to a slight level by the function of the stopper. Further, since the projection is annular and integrally formed on the inner periphery of the vibration ring, a large inertial mass can be set on the projection itself.

〔Example〕

Next, one embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 to 3, a vibration ring 2 is arranged concentrically and spaced apart from each other on the outer periphery of a hub 1 formed into a substantially T-shaped cross section. and 8 are interconnected through elastic bodies. The elastic bodies 5 and 8 each have a plurality of axially thick portions 5a and 8a, and the portions 5a and 8a are arranged equidistantly (four equidistantly in FIG. 3). 5a, 8a
Thin parts 5b and 8b are integrally molded between them, and the whole is formed into an annular shape. The elastic body numbered 8 whose half-cut side is drawn in Figure 3 is 12, 3, and 6 on the diagram.
The thick part 8a is arranged at the 9 o'clock position and the thin part 8b is set between them, but the other elastic body 5 is displaced about 45 degrees in the circumferential direction and forms the thick part 5a. A thin portion 5b is arranged. The elastic bodies 5 and 8 are generally vulcanized and molded using a rubber material. During this molding, sleeves 3, 4, 6, 7 are concentrically adhered to the inner and outer peripheries of each elastic body 5, 8, and each sleeve 3, 4, 6, 7 is press-fitted onto the hub 1 or the vibration ring 2. By this, the elastic body 5,
8 between the hub 1 and the vibration ring 2. The elastic bodies 5 and 8 are entirely adhered in the form of a thin film to the outer circumferential surfaces of the sleeves 3 and 6 that are fitted onto the outer circumference of the hub 1, and when assembled, the sleeves 3 and 6 and the elastic bodies 5 and 8 Their end surfaces come into contact with each other. The thickness of this thin film portion of the elastic bodies 5 and 8 in the radial direction is set to 0.2 to 0.5 mm in actual size. An annular projection 2a is integrally formed on the inner periphery of the vibration ring 2 so as to face toward the inner periphery. This protrusion 2a faces the thin film portion on the hub 1 side with a slight clearance 9 left, functions as a stopper to suppress the eccentricity of the vibration ring 2 during operation, and has a large inertial mass. Clearance is 0.1-0.2 in actual size
Set to mm. The space 10 between the hub 1 and the vibration ring 2 is defined at both ends in the axial direction by the elastic bodies 5, 8 and the sleeves 3, 4, 6, 7, and is configured airtight. Protrusion 2 in space 10
It is filled with a lubricant that makes sliding between the thin film portions of the elastic bodies 5 and 8 smooth.

The dynamic vibration absorber having the above structure has the following advantages over the conventional technology.

Eccentricity of the vibrating ring 2 caused by rotational operation can be sufficiently suppressed by the engagement of the projection 2a integrally formed on the vibrating ring 2 with the member on the hub 1 side. On the hub 1 side, thin film portions of the elastic bodies 5 and 8 are constructed as a surface layer that directly contacts the protrusions 2a, and function as a kind of cushioning material. This makes it possible to prevent the occurrence of problematic vibrations and noise. Also, this protrusion 2
The eccentricity prevention stopper using a is simpler in structure and assembly than the case where a dedicated bearing member is used, and costs can be kept low.
Furthermore, since errors due to thermal expansion are less likely to occur compared to the case where a resin sliding bearing is interposed, accuracy in the operation of the stopper can be expected.

Between the hub 1 and the vibration ring 2, a stopper with the protrusion 2a is arranged at the center in the axial direction, and both sides of the stopper are sealed using elastic bodies 5, 8 and sleeves 3, 4, 6, 7. This structure prevents dust and foreign matter from entering the stopper portion, thereby preventing inconveniences such as seizure and malfunction.

The protrusion 2a forms an inertial mass integral with the vibrating ring 2, and since the protrusion 2a is continuous in an annular shape and can have a large inertial mass, the radial thickness of the main body of the vibrating ring 2 can be increased. It is possible to reduce t. Moreover, since the protrusion 2a is annular, the permissible eccentricity of the vibration ring 2 with respect to the hub 1 is constant on any phase, and also forms a smooth bearing surface for the hub 1, so the circumference of the vibration ring 2 is Relative movement in direction is made very smoothly.

[Effect of idea]

As explained above, in the dynamic vibration absorber of the present invention, the protrusion that restricts the eccentric movement of the vibration ring can itself have a large inertial mass, so the vibration absorber can be made smaller by reducing the outer diameter of the vibration ring. Since the protrusion is annular, the permissible eccentricity of the vibrating ring is suppressed to a very small amount at any position in the circumferential direction, and the circumferential movement of the vibrating ring relative to the hub is extremely smooth, and the torsion is prevented. Demonstrates excellent vibration absorption performance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view taken along line A-O-A in FIG. 3 of a dynamic vibration absorber according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the same main part, and FIG. 3 is a half-cut side view of the same. FIG. 4 is a half-cut side view of a conventional dynamic vibration absorber. 1...Hub, 2...Vibration ring, 2a...Protrusion, 3, 4, 6, 7...Sleeve, 5, 8...Elastic body, 5a, 8a...Thick wall portion, 5b, 8b...
Thin part, 9... Clearance, 10... Space.

Claims (1)

[Scope of utility model registration request] A vibration ring 2 is arranged at a distance on the outer periphery of a hub 1 attached to a rotating member of a drive system, and the hub 1 and vibration ring 2 are connected via elastic bodies 5 and 8 near both ends in the axial direction. An annular projection 2a is formed integrally with the inner periphery of the vibration ring 2 at an axially central portion sandwiched between the bodies 5 and 8, and faces the outer periphery of the hub 1 side with a slight clearance 9 therebetween. A dynamic vibration absorber characterized by being provided with.