Patent GB-447188-A (GB)
Title: Torsional vibration damper
IPC: F16F15/167
Filed: 1934-11-06
Abstract: 447,188. Flywheels; balancing moving parts of engines. THEGE, E. O. P., 59A, Hornsgatan, Stockholm. Nov. 6, 1934, No. 31929. Convention date, Dec. 4, 1933. [Classes 122 (i) and 122 (iii)] [See also Group XXXII] In a torsional vibra tion - damper for a rotating shaft in which the inertia of one or more masses, adapted to move freely or against the action of springs, liquid-friction devices, &c., between abutments carried by the shaft, is adapted to damp vibrations, each abutment comprises a liquid buffer formed by the liquid being enclosed between the vibrating part and each mass or between the vibrating part and a piston controlled by the mass, when the mass or the mass-controlled piston closes a liquid outlet port or ports leading from the liquid-enclosing chamber. In a modification the buffer is formed by an auxiliary regulating piston closing an outlet port or ports in a cylinder formed inside each mass or in the housing of the vibration-damper. As shown in Fig. 4, a housing 3 fixed to the rotating shaft 4 contains cylinders in which masses in the form of pistons 6, 7, 10, 14 reciprocate, the chambers on either side of each piston being connected by a channel 13 to permit the passage of oil &c. until the inlet end of the channel is covered by the piston. Oil is admitted to one channel by means of a stationary grooved bushing surrounding the shaft and a passage 17, a non-return valve preventing flowing-back of the oil. In a modification curved pistons move in an annular, rotatable, two-part housing, in chambers separated by partitions fixed to the housing. In a second modification, Figs. 8, 9, a sleeve 41 fixed to the shaft carries vanes extending into chambers formed by inwardly-projecting portions of a two-part housing 39, 40 freely rotatable on the shaft, corresponding endportions of the chambers communicating through channels 44 ... 47 and 48 ... 51 respectively with passages 56, 57 connected by an exteriorly-adjustable slide 54 past which replenishing liquid may be forced. Fig. 10 shows a construction wherein pistons 63 are rigidly secured to an arm 59 fixed to the shaft 60 and are enclosed by a slidable two-part cylinder 61, 62 having end-grooves 33 communicating through a channel 36 in the pistons. In another construction, Fig. 12, masses 66, 67 are pivoted at 68, 69 to a member 64 fixed to the shaft 65, the ends of the masses bearing on pistons 70, 72, 71, 73 slidable in cylinders intercommunicating through channels 37. In a modification only one mass 75, Fig. 14, is provided, pivoted at 76 to the web 74 of a crankshaft and bearing at its ends on pistons 77, 78 slidable in intercommunicating cylinders. Fig. 21 shows a construction embodying an auxiliary spring-centred regulating piston 110 mounted in a central chamber in the main piston 109 the ends of the chamber communicating through channels 112, 113 with the main cylinder chambers while extensions of the piston project into auxiliary chambers connected by channels 115, 116 with the main cylinder chambers. The conduits 89, 93 are provided for refilling purposes and each is closed by a non-return valve (not shown). Various modifications of this construction are shown. Various constructions in which the auxiliary piston is mounted in the housing are also shown. Figs. 32, 33 and 35 illustrate devices whereby the free stroke of the main piston can be varied by varying the amount of liquid in the damper. As shown in Figs. 32, 33 liquid is continuously supplied through channels 206, 207 and flows away through orifices 204, 205 the outlets being regulated by slides 210 controlled by screws 214. In the construction shown in Fig. 35, the regulation of the stroke is effected automatically by a spring-pressed centrifugal weight 221 which as it moves outwardly uncovers the outlet 224 and diminishes the quantity of liquid in the working chamber, thus increasing the piston stroke. In another construction an opposite effect is obtained, the weight acting on one end of a lever the other end of which governs the slide so that at high speeds the piston-stroke is smaller.