Tokai Rubber Industries, Ltd.

Nissan Motor Company Limited

Masaaki Mishima

Masaaki Hamada

Takahiro Aoi

Tetsuya Kohgo

Nobuhiro Hirasawa

A double-mass type dynamic damper mounted on a rod-shaped oscillating member, which includes a first damper system and a second damper system that are tuned to two different frequency ranges. Each of the damper systems includes a cylindrical mass member disposed radially outwardly of the oscillating member, and an elastic support member for elastically supporting the mass member with respect to the oscillating member. The elastic support members of the two damper systems are disposed in series and connected to each other in the axial direction. The dynamic damper further includes an elastic connector formed by adjacent parts of the two elastic support members, for elastically connecting axially opposed faces of the two mass members. The two elastic support members have respective spring constants as measured in the radial directions, which spring constants are both larger than a shearing spring constant of the elastic connector that is subjected to shearing stresses upon relative displacement of the mass members in the radial directions.

Double-mass type dynamic damper having two damper systems

A fluid-filled cylindrical elastic mount is disclosed which includes an inner and an outer sleeve connected by an elastic body, and a pair of fluid chambers formed in the elastic body. A non-compressible fluid contained in the mount flows between the fluid chambers, through one of two differently tuned orifice passages defined by an orifice structure. One of the orifice passages having the higher ratio of its cross sectional area to its length is formed at least partially as a tunnel extending through a tunnel-defining portion of the orifice structure. A valve assembly including a rotary valve and a valve housing is attached to the orifice structure such that the rotary valve is located in the tunnel of the orifice passage and such that the valve housing is fixed to a radially outer surface of the tunnel-defining portion which is exposed to an outside of the mount. The rotary valve rotatably received in the valve housing is selectively placed in a position for permitting flow of the fluid through the orifice passage, and in a position for inhibiting the flow of the fluid therethrough.

Fluid-filled cylindrical elastic mount having two orifices and valve

A dynamic damper of this invention comprises: a pair of ring-shaped fixing members disposed at a predetermined interval, inserted onto and supported by a rotary shaft; a cylinder-shaped mass member having inner surface larger than the outer surface of the rotary shaft, the cylinder-shaped mass member inserted onto the rotary shaft and disposed between the pair of ring-shaped fixing members; and elastic members integrally connecting the ends of the fixing members with the ends of the cylinder-shaped mass member. The dynamic damper has enabled to down-size the configuration thereof while maintaining the performance thereof and to make the installation thereof easier.

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Kasugai, Japan

Masaaki Mishima