GB948590A - Flutter damper - Google Patents

Abstract

948,590. Hydraulic dampers. LIONELPACIFIC Inc. July 19, 1962, No. 27762/62. Heading F2S. An hydraulic damper comprises a housing having a chamber 24 at least part of which is cylindrical, the chamber being closed at each end by members 46, 60 which are provided with bores coaxial with the chamber and forming a clearance fit for a shaft 20. The shaft 20 and the cylindrical chamber wall are provided with at least one longitudinal vane 80, 82, 84 and rib 26, 28, 30 respectively, which rib(s) extends between closure members 46, 60, there being a small clearance between the adjacent faces of the rib(s) and shaft and of the vane(s) and chamber wall. In the construction shown, six variable chambers (a), (b), (c), (d), (e) and (f) are formed in the housing. The shaft 20 is mounted at each end in bearings 53, 66 which are pre-loaded by members 58, 70 screwed into the housing. A temperature-sensitive metering device is housed in a bore 168 of shaft 20. The device includes a stack of bi-metallic thermostatic elements 182 mounted on a rod 180 which is adjustably positioned in the bore 168 by screw members 174, 176. The thermostatic elements at one end engage a washer 194 of a spring-loaded valve element 190, the position of which varies the metering effect between ports 212, 216 and a groove 200 of an axially tapered depression 198 in the valve element 190. Variable chambers (a), (c) and (e) communicate with groove 200 through ports 206, 208, 210 and ports 202, 203, 204 respectively and chambers (b), (d) and (f) communicate with bore 164 through ports 218, 220, 222 (not shown). Thus in operation fluid may pass from one set of variable chambers to the other set through the tapered depression 198. A reservoir housing 14 is formed integral with the shaft housing, the reservoir being provided with a spring- loaded piston 100 having a bore in which a fluid filling device 118, 122, 124 and a filtering device 116 are positioned. Pressurized fluid is fed into the two sets of variable chambers through commo n passage 130 and then through branch passages 136, 134 (not shown) and ball valves 144, 145 (not shown). Bleed chambers, passages and grooves for escaping fluid and gases which may have been entrained in the damping fluid are formed at each end of the shaft housing, these chambers, passages and grooves being vented through ducts 160, 162 into the fluid reservoir.