Bendix Commercial Vehicle Systems C-300N HYDRAULIC POWER STEERING1/99 - Manual (Page 3)

3
FIGURE 1 - MECHANICAL OPERATION
FIGURE 2 - SPINDLE ASSEMBLIES
INPUT
SHAFT
PISTON
STEERING
WHEEL
PITMAN
ARM
SPINDLE
ASSEMBLY
PITMAN
ARM
PISTON
OUTPUT
SHAFT
RIGHT HAND
THREAD
LEFT HAND
THREAD
BALL
SCREW
PISTON OVER OUTPUT SHAFT MOUNTING
(LEFT HAND THREAD SPINDLE)
VEHICLE
RIGHT
TURN
STEERING
WHEEL
PISTON UNDER OUTPUT SHAFT MOUNTING
(RIGHT HAND THREAD SPINDLE)
OUTPUT
SHAFT
SPINDLE
ASSEMBLY
INPUT
SHAFT
VEHICLE
LEFT
TURN
INPUT
SHAFT
OPERATION
GENERAL
Both steering gears are composed of mechanical and
hydraulic power assist components.
Actual steering is accomplished mechanically. Effort applied
at the vehicle’s steering wheel results in mechanical
movement within the steering gear which causes the vehicle
to change its direction of travel. The hydraulic power assist
components function solely to reduce the mechanical effort
required to turn the vehicle’s steering wheel. Loss of hydraulic
power will in no way prevent the vehicle from being
maneuvered mechanically, however greater effort will be
required to turn the steering wheel.
MECHANICAL OPERATION
The turning effort exerted by the driver on the steering wheel
is transmitted to the input shaft which is part of the spindle
assembly. The spindle and piston function like a screw and
nut through the action of a chain of recirculating balls that
serve as an interface. Rotation of the spindle causes axial
movement of the piston within the power cylinder. Gear teeth,
cut directly into the piston, mesh with corresponding gear
teeth on the output shaft. As the piston moves, the output
shaft and the attached pitman arm are rotated. Figure 1
Spindle and piston sets are provided with either right or left
hand screw threads. Figure 2 The manner in which the
steering gear is mounted on the vehicle determines of the
thread used. Figures 1, 2 & 3