VARIABLE DRIVE FOR LIQUIFIED NATURAL GAS PUMP

摘要

A fuel pump assembly (20) including a fuel pump (30) and a variable drive mechanism (32) is provided. The fuel pump has a pump input shaft (38) rotatably coupled to an impeller (36). The variable drive mechanism has a drive input shaft that receives torque from the engine (26) of a vehicle and a drive output shaft that is rotatably coupled to the pump input shaft. The variable drive mechanism further comprises a planetary gearset interconnecting the drive input shaft and the drive output shaft. The planetary gearset has a variable gear ratio that varies rotational speed of the drive output shaft and therefore the pump input shaft relative to the rotational speed of the drive input shaft. Accordingly, the rotational speed of the pump input shaft and thus the volume flowrate of the fuel pump can be adjusted for any given engine speed to minimize pump related losses.