A fuel pump drive system is provided. A system for an engine driven by an
engine crankshaft may include a first variable cam device including a
first hydraulic actuator, and a second variable cam device including a
second hydraulic actuator. The system may further include an intermediate
power transfer mechanism coupled between the first variable cam device
and the second variable cam device upstream, in a direction of power flow
from the engine crankshaft, of the first hydraulic actuator and the
second hydraulic actuator. The system may further include an auxiliary
device coupled to and driven by the intermediate power transfer
mechanism. In this way, because the auxiliary device is driven via the
intermediate power transfer mechanism and thus derives its power from
upstream of the hydraulic actuator of the variable cam device, the
actuator can be adjusted without having to overcome resistance torque of
the auxiliary device.