System Operation
Manual Steering Operation
Steering wheel input rotates the pinion of the gearbox through the universal joint. Due to the rack and pinion mechanism,
the rotation of pinion is converted into a transverse motion at the rack, which steers the front wheels throught the tie-
rods and knuckles the same as an ordinary rack and pinion system.
Assisting Operation
In addition to the manual steering operation, the steering sensor on the pinion shaft transmits a signal to the EPS control
unit when it receives a steering input. The EPS control unit calculates an adequate motor control with addition of speed
signals then transmits a control signal to the power unit. Based on the signal from the EPS control unit, the power unit
drives the motor inside the gearbox. The torque generated by the motor is transmitted to ball screw through gears and
converted into an assisting thrust in the axial direction of rack. The assisting thrust acts in the steering direction and
lessens the steering force required at the steering wheel.
POWER UNIT
RECIRCULATING
BALL SCREW
STEERING SENSOR
STEERING GEARBOX
MOTOR
STEERING WHEEL
RACK
EPS CONTROL UNIT
Manual Steering Operation
Steering wheel input rotates the pinion of the gearbox through the universal joint. Due to the rack and pinion mechanism,
the rotation of pinion is converted into a transverse motion at the rack, which steers the front wheels throught the tie-
rods and knuckles the same as an ordinary rack and pinion system.
Assisting Operation
In addition to the manual steering operation, the steering sensor on the pinion shaft transmits a signal to the EPS control
unit when it receives a steering input. The EPS control unit calculates an adequate motor control with addition of speed
signals then transmits a control signal to the power unit. Based on the signal from the EPS control unit, the power unit
drives the motor inside the gearbox. The torque generated by the motor is transmitted to ball screw through gears and
converted into an assisting thrust in the axial direction of rack. The assisting thrust acts in the steering direction and
lessens the steering force required at the steering wheel.
POWER UNIT
RECIRCULATING
BALL SCREW
STEERING SENSOR
STEERING GEARBOX
MOTOR
STEERING WHEEL
RACK
EPS CONTROL UNIT