Nov. '12, 194@r ' I A. M. RocKwELl. - 2,411,000 I LIQUÍD vMPE nannten DAMPER ' f AFiled laren 3o.' 1944 Bwfßám ` ATTORNEY 2,411,000 Albert . LIQ lli. Rockwell, TYPE Glastonbury, RATIQN Conn., D i assigner to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware ‘ Application March 30, 1944, Serial No. 528,707 l ' 2 Claims. l i (Cl. 74-604) É ` 'I'his invention relates to vibration dampers and ‘ particularly to a combined torsional and transla tional or axial vibration damper of >theliquid pendulum type. Each of the containers I2 is provided with the _ mercury pockets or receptacles it and >each may ` ' be curved as shown to fit a portion ci’ the outer periphery ofthe counterweight il against which i the containers I2 may be mounted. Each pocket The invention is shown, in the embodiment or receptacle I3 extends transversely through its` selected for illustration, as applied to the crank container i2 and each pocket is partially iilled shaft of an aircraft engine and is housed within with liquid It such as mercury. To enclose these one or more of the counterbalances therefor, there preferably being a plurality ofÍ containers containers i2, Aa cap member i5y fitting their outer> forming dampers in each counterbalance and 10 periphery, the sides and ends of the containers each container having therein a plurality of small I2 is welded thereto throughout the 'edges of the openings forming pockets partially filled with a cap member I5. As shown in Fig.,2, the edge of heavy liquid such as mercury. _ ' the cap member I'5 Welded to 'the containers t2 An object of the invention is to provide a vibra extends along its inner arcuate surface so that tion damping means for crank-shafts'and the like 15 during rotation centrifugal :torce will not serveto in which the liquid, preferably mercury, is re bring the- liquid intov contact` with the. "weld or tained within a container and being sealed in a other form of joint IB. lThe inner arcuate surn ' manner to prevent the pressure of the liquid, due faces of the containers i2 are provided with a to centrifugal force, from being applied against single opening I6, by means of which liquid may >any of the solderedor welded Joints of the con 20 be admitted to the individual receptacles. After tainers. ' `filling each receptacleto the desired level or with Another object of the invention is to enclose the required amount of liquid, this opening may the mercury or other liquid holding containers be closed by a plug filling the opening l5, the within recesses within Yopposed counterweight outer end of which may beA welded to the conu members secured to the crankshaft on opposite tainer _l2 to retain it in liquid tight relation sides of the crank cheeks. . thereto. Other objects and advantages will Ibe apparent - As shown most clearly in Fig. 2, the containers from the specification and claims, and from the I i2 for the pockets i3 are fitted into recesses milled drawing which illustrates what is now considered or otherwise formed in the cap member l5, there 30 being as shown, th'ree aligned recesses in the cap to be a preferred embodiment of the invention. In the drawing: . . ` Fig. 1 is a side elevation of a crankshaft show ing a preferred form of the invention, parts beingA - shown in section on the plane of line l-l in ' member i5 for these containers. ‘ ' Each of the pockets i3 for the liquid it may be divided into compartments by separating dia= phragms I‘l held spaced apart by being ñtted into Fig. 2”; milled grooves formed in the Walls of the pockets. To permit passage of liquid from one portion to another of the pockets i3, small openings 2l in Fig. 1, and „ ‘ 'through the diaphragms Il may be provided. Fig. 3 is a transverse sectional view taken on Also, to permit iiuid to pass fromV one pocket to the planes of broken line 3--3 of Fig. 1. 40 another, slight openings may be formed as indi Fig. 2 is a transverse sectional view on an en larged scale and taken on the plane of line 2--- , In a preferred form the invention may includev the following principal parts: First, a rotating cated at 22 between the side Walls of the con'l tainers and the cap member. - member; second, one or more containers housing To retain the containers l2 and the cap mem a, plurality of small chambers or spaced recep ber i5 in position, counterweight cheeks or clos tacles for a liquid such as mercury; and third, 45 ing members I9 recessed to receive the containers means retaining the container and its contents in and .cap member may be bolted together on op position on the crank cheek or other portion o posite sides> of the crank cheek l I. These cheeks a rotating member. ' or closing members I9 may .be held in position Referring more in detail to the ñgures of the by through bolts or rivets 2li extending trans drawing, there is shown a counterweight portion ^ versely through the opposed closingA members I9 il of an aircraft engine crankshaft it.. To this and through a portion of the crankshaft counter Y counterweight portion il are secured a group of y ' _ \three similar containers i2 each container having i Weight II. ‘ As shown in Fig. 1, there are three similar con a plurality of cylindrical compartments i3 par tainer members I2 placed end to end and ~en tiallygìlled with a heavy liquid it such as mercury. 55 closed by a single cap member li'» so that in eñ‘ect . 2,411,000 there is a continuous series of liquid containing pockets I3 from one end surface of the crank cheek to the other. The pockets il for the liquid are arranged with their axes parallel to each other and parallel to the axis of rotation of the crankshaft. All of the pockets I3. therefore, form an arcuate series concentric with the axis of rotation of the crankshaft. , „ I claim: 4` , 1. A vibration damper of the liquid pendulum type comprising, a rotatable member, a container mounted thereon having a plurality of pockets, aliquid partially ñlling each of said pockets, means tot restrict `but not prevent liquid flowing from one pocket to another, said container hav ing a filling opening extending from the inner surface of said container, a cap member secured In operation fluctuations in the instantaneous speeds of the crankshaft I0, due to intermittent 10 to and enclosing the outer and side portions of said container for retaining said liquid within said power impulses, will cause the fluid within each pockets and retaining said pockets in an arcuate pocket or receptacle I3 to move forward or back series, said ‘container and cap member being per ward, also axial 'or translatory vibrations of the manently secured together along the periphery crankshaft will cause movement of the mercury in the direction lengthwise of the receptacles or 15 of said cap member, and means to secure said container in fixed position to said rotatable' pockets I3. This action of the mercury serves to member. . vary the inertia of the rotating mass and effects '2. A vibration damper of the liquid pendulum a damping of these torsional and axial vibrations. typecomprising, a rotatable member, a container In operation also the construction provides a mounted thereon having a series of parallelly dis large number of spaced pockets within which the posed pockets, a liquid partially filling each of liquid can ilow to uniformly tlll all pockets to an said pockets, means to restrict but not prevent equal degree, and as the weld between the con liquid ilowing from one pocket to another, said tainers and their cap member is on the inner , container having a ñlling opening therefor ex radius of the cap member, centrifugal force does not force mercury against this joint. The order 25' tending from the inner surface of said~ container, _ a plug sealing said opening, a cap member se of 'the vibrations acting upon the crankshaft de cured to and enclosing the outer and side por termines the dimensions of the pockets and their tions of said container for retaining said liquid distance from the axis of rotation. The greater within said pockets and retaining said pockets in the distance from the axis of rotation, the larger the pockets may be,- and also the greater the 30 an arcuate series, said container and cap member being permanently secured together along the effectiveness of the enclosed liquid willbe because '. periphery of said cap-member, and means to se of this greater radius. ‘ , cure said container in fixed position to said rotat It is to be understood that the invention is not able member. l limited to the specific embodiment herein illus I trated and described, butv may be used in other 35 Ways without departure from the spirit of the invention as deñned. by the following claims. ALBERT M.