ES353984A1 - A Pump-and-Valve Arrangement for Fuel Oil Feeding Apparatus - Google Patents

Abstract

A pump-and-valve unit, or arrangement, Figs. 1 and 2, for feeding a nozzle 2 with fuel-oil that is stored in a tank 4 comprises a rotary positive displacement pump 10 of the internally-meshing n and n + 1 tooth type furnished with a device 18 for removing air entrained with the oil and a combined pressure-regulating and cut-off valve 13. The device 18 is constituted by a flowrestricting passage 43, Fig. 3, in a cover plate 27 adjacent working chambers 33 between pumping gear-wheels 24, 25, said passage being connected to a passage 12 on the high-pressure side of the pump through passages 39, 40, 41 and to the tank through passages 44, 19. The passage 39 is in register with the chambers 33 on the high-pressure side of the gears and the passage 43 allows air in the said chambers to escape while permitting only a small proportion of the oil to do the same. A passage 34 in register with the chambers 33 on the low-pressure side of the gears receives oil from the tank through passages 11, 36, 37 and a chamber 30 containing a filter 31. The valve 13 includes a port 7 controlled by a body 47 fixed to an axiallymovable spring-loaded body 50 having a passage 52 and a flange 53 co-operating with an immovable bush 51 between the passage 12 and a passage 15 comprising two portions 15a, 15b and a chamber 16 for a seal 23 about a driving shaft 22, the portion 15b containing a non-return valve 17 and communicating with the chambers 33 on the lowpressure side of the pump. The bodies 47, 50 are retracted from the port 7 in accordance with the pressure-differential between the passages 12, 15, the passage 52 serving as a by-pass for the oil when said differential becomes excessive.