Viscous fluid-sealed damper

• US 20070259141A1
• Filed: 04/26/2007
• Published: 11/08/2007
• Est. Priority Date: 05/02/2006
• Status: Abandoned Application

• Current Assignee: Polymatech Company Limited
• Original Assignee: Polymatech Company Limited
• Inventors: Ohki, Junji
• Application Number:
  US11/790,531
• Publication Number:
  US 20070259141A1
• Time in Patent Office: Days
• US Class Current: 428/35.200
• CPC Class Codes: F16F 13/08 the plastics spring forming at least a part of the wall of the fluid chamber of the damper F16F13/20 - F16F13/24 take precedence
• CPC Class Codes: F16F 15/022 using dampers and springs in combination
• CPC Class Codes: F16F 9/30 with solid or semi-solid material, e.g. pasty masses, as damping medium in devices where rotary elements are damped by viscous shear effect only, any throttling effect being immaterial F16F9/12; where members moving with a rotating system are being damped F16F15/16
• CPC Class Codes: G11B 33/08 Insulation or absorption of undesired vibrations or sounds
• CPC Class Codes: Y10T 428/1334 Nonself-supporting tubular film or bag [e.g., pouch, envelope, packet, etc.]
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]

Abstract

Disclosed is a viscous fluid-sealed damper including a sealing container with a flexible membrane portion, and a viscous fluid sealed in the sealing container, and adapted to attenuate vibration transmitted between a supporting member and a supported member, the damper involving no deterioration in vibration preventing performance even if placed in an unfavorable position during transportation or storage after assembly to a disk device. A flexible membrane portion is formed of a rubber-like elastic composition containing a styrene-isobutylene-based block copolymer, and, more preferably, a mixture composition including a styrene-isobutylene-based block copolymer containing a styrene-based block and an isobutylene-based block, and a styrene-non-isobutylene-based block copolymer containing a styrene-based block and a non-isobutylene-based block.

Claims

1. A viscous fluid-sealed damper comprising a sealing container with a flexible membrane portion, and a viscous fluid sealed in the sealing container, and adapted to attenuate vibration transmitted between a supporting member and a supported member,

wherein the flexible membrane portion is formed of a rubber-like elastic composition containing a styrene-isobutylene-based block copolymer.

2. A viscous fluid-sealed damper according to claim 1, wherein the flexible membrane portion is formed of a mixture composition including a styrene-isobutylene-based block copolymer containing a styrene-based block and an isobutylene-based block, and a styrene-non-isobutylene-based block copolymer containing a styrene-based block and a non-isobutylene-based block.

3. A viscous fluid-sealed damper according to claim 2, wherein the mixing proportion of the styrene-isobutylene-based block copolymer and the styrene-non-isobutylene-based block copolymer in the composition ranges from 10 wt %:

90 wt % to 70 wt %;

30 wt %.

4. A viscous fluid-sealed damper according to claim 2, wherein the mixing proportion of the styrene-isobutylene-based block copolymer and the styrene-non-isobutylene-based block copolymer in the composition ranges from 10 wt %:

90 wt % to 40 wt %;

60 wt %.

5. A viscous fluid-sealed damper according to claim 1, wherein the styrene-isobutylene-based block copolymer is a styrene-isobutylene-styrene block copolymer (SIBS).

6. A viscous fluid-sealed damper according to claim 1, wherein the reduction ratio in specific gravity as measured from a time of production is 10 wt % or less.

7. A viscous fluid-sealed damper according to claim 1, wherein the sealing container is provided with a peripheral wall portion formed of a hard resin and fixed to the flexible membrane portion, and wherein the peripheral wall portion is formed of at least one of resins selected from the group consisting of:

a polystyrene resin, a polypropylene resin, an acrylonitrile-styrene-acrylate resin, an acrylonitrile-butadiene-styrene resin, a polyamide resin, a polyphenylene oxide resin, a polyphenylene ether resin, and a denatured polyphenylene ether resin.

8. A viscous fluid-sealed damper according to claim 1, wherein the sealing container is provided with an agitation cylinder portion protruding into the sealing container, wherein a cylinder covering portion is provided on an outer surface of the agitation cylinder portion, and wherein a remaining portion of the agitation cylinder portion except for the cylinder covering portion is formed of a rubber-like elastic material integral with the flexible membrane portion.

9. A viscous fluid-sealed damper according to claim 1, wherein the sealing container is provided with a connecting top portion having an insertion recess into which a mounting shaft provided on the supporting member or the supported member is to be inserted, and wherein a bottom surface of the connecting top portion is situated so as not to protrude down to a trough portion of the flexible membrane portion.