Hyundai Elantra MD/UD: Electric Oil Pump. Description
and Operation
Description
This transaxle has a standard Mechanical Oil Pump (MOP) linked to the
input shaft to generates oil pressure when input shaft rotates.
But, this transaxle equipped with ISG system also has an Electric Oil
Pump (EOP). Because the ISG system features Auto-Stop which starts and stops
the engine as needed. The Auto-Stop feature prevents the Mechanical Oil Pump
(MOP) from operating and building enough pressure for the transaxle to operate.
When the vehicle comes to a stop with the engine off, Mechanical Oil Pump (MOP)
cannot generate sufficient oil pressure during the initial startup or during
low speed driving.
For these reasons, the Electric Oil Pump (EOP) takes on this role as an
additional device that can generate the required oil pressure when the vehicle
comes to a stop or during low speed driving. The Electric Oil Pump (EOP) supplies
oil pressure to the Under Drive Brake (UD/B).
