Patent GB-666238-A (GB)
Title: Improvements in flow divider apparatus for dividing a liquid into a plurality of streams of equal or related flow rates
IPC: B64C25/22
Filed: 1948-11-15
Abstract: 666,238. Fuel systems. SIMMONDS AEROCESSORIES, Inc. Nov. 15, 1948 [May 18; 1948], No. 29640/48. Class 7(iii) [Also in Groups XXIX and XXX.III] A flow divider, which may be used for supplying fuel to aircraft engines, for dividing a stream of liquid under pressure into a plurality of streams having predetermined rates of flow comprises a pair of intermeshing motor gears mounted for rotation in a housing, a plurality of pairs of intermeshing metering gears, a housing for separately enclosing each pair of the metering gears, a driving connection between the pair of motor gears and each pair of metering gears for driving the latter, means for delivering the liquid to be divided to the pair of motor gears to effect their rotation and the rotation of the metering gears, means for conducting liquid passed through the motor gears and for distributing it to the pairs of metering gears, a conduit leading from each pair of the metering gears for delivering a divided portion of the liquid and a control valve for the liquid conducted through each pair of metering gears arranged to control the pressure differential of the liquid between the inlet and outlet of the pair of metering gears. As shown liquid is supplied under pressure through a conduit 26 to a housing 28 associated with a pair of gears 10, 12 and flows through the gears to the opposite side of the housing. The gears are rotated and the gear 10 drives a shaft 14 to which it is keyed. The gear 12 is mounted for rotation on a shaft 16. On the shafts 14, 16 are arranged the number of pairs of gears for which the apparatus is designed. As shown there are two pairs 20, 22, 20a, 22a. The gears 20, 20a are keyed to the shaft 14 and respectively drive the gears 22, 22a. Liquid from the housing 28 flows through a conduit 30 to the inlet sides of housings associated with each pair of gears, valves 34, 34a, being interposed between the conduit and the housings. The delivery from the housings passes to conduits 36, 36a which may. for example, be connected to similar actuating cylinders of a pair of landing flaps ofan aircraft. The valves 34, 34a may be either in the conduits leading to or from the pairs of metering gears. They are similarly arranged and only the valve 34 will be described. It comprises a piston -valve member 48 acted on above and below by springs 60, which may be compression or tension springs. A spring may be applied to one end only of the valve if desired. A space above the valve is connected by a conduit 40 to the delivery side of the gears 20, 22 and a space below the valve'is connected to an inlet conduit 33 of the gears. The valve casing is connected to the conduit 30 by means of a conduit 32 and to the inlet side of the gears by means of the conduit 33. The springs for the control valves are adjustably loadable and may be used to equalize flow from the metering gear units. Initially, there may be unequal flow because of temperature influences or because sets of metering gears or housings were not .machined or cast exactly alike. The piston 48 for one unit, for example, is therefore unbalanced to the necessary extent to produce enough leakage around or pressure difference across the pairs of metering gears to make the flow equal to that for another unit. Unequal flow having a known relationship may be obtained in the same manner if desired. The pairs of motor gears are preferably made with a slightly smaller capacity than that of the aggregate of the driven metering gears. The necessary extra liquid for the pairs of metering gears is made up by providing a byepass duct or line 68 and orifice 70. The parts of the apparatus may be included in a compact block of assembled sections. The liquid delivered through the inlet line may be divided into any convenient number of equal parts for delivery to an equal or lesser number of operating stations for the supply of fuel or liquid to engines of any kind, or for other purposes. In some cases the metering gear units need not be of identical widths but may bear any desired relationship to each other in width or capacity. The metering gears need not be driven at the same rate as the motor gears, and the relative sizes and,/or speeds of the pairs of metering gears may be varied. While all pairs of gears are preferably mounted on a pair of shafts as described the metering gears may be driven by other types of driving means. It is stated specifically that the output of the motor gears could be divided into nine separate streams.