| 摘要 |
A pump assembly used in a fuel injection system, eg for a diesel engine, includes a non-return valve that assists in engine priming. The pump assembly further includes a transfer pump 23 supplying fluid to a high pressure, pump 12 which feeds a common rail 15. The non-return valve 28 fluidly connected between the high pressure pump 12 and the transfer pump 23 allows fluid to flow from the high pressure pump 12 to the transfer pump 23 and prevents reverse flow. A manual priming, eg hand-operated, pump 24 may be connected between the fuel tank 11 and a bypass circuit 25 around the transfer pump 23. A zero-delivery throttle 22 may be provided between an inlet metering valve 28 and an inlet of the transfer pump 23. The non-return valve comprises two connected members 29, 34 forming a chamber for a ball 33 which seats non-sealingly in one flow direction on a castellated nut 29 providing flow apertures and sealingly in the other flow direction on the mouth of a narrowed bore (39,fig.5) in member 34. Member 34 may comprise a banjo union fitting. |
