Daedong CK22 - Power Steering Control Motor

9-8
DS35-W00 May. 2007
CLUTCHCLUTCH CLUTCHCLUTCH
CLUTCH
TRANSMISSIONTRANSMISSION TRANSMISSIONTRANSMISSION
TRANSMISSION
ENGINEENGINE ENGINEENGINE
ENGINE
HSTHST HSTHST
HST
FRONT AXLEFRONT AXLE FRONT AXLEFRONT AXLE
FRONT AXLE
STEERINGSTEERING STEERINGSTEERING
STEERING
BARKEBARKE BARKEBARKE
BARKE
ELECTRICELECTRIC ELECTRICELECTRIC
ELECTRIC
INDEXINDEX INDEXINDEX
INDEX
HYDRAULICHYDRAULIC HYDRAULICHYDRAULIC
HYDRAULIC
GENERALGENERAL GENERALGENERAL
GENERAL
REAR AXLEREAR AXLE REAR AXLEREAR AXLE
REAR AXLE
CK22/CK22H
2.4.1 POWER STEERING CONTROL
MOTOR
A. SPOOL AND SLEEVE
1. The spool (22) and sleeve (23) are the rotary valve
to select the fluid passage as well as the direction
of the fluid flow.
There are three fluid passages; Neutral, Right turn,
and Left turn.
2. The spool is fitted to be rotatable in the sleeve, which
is fitted into the bore of the valve body.
The spool and the sleeve are mechanically
interconnected.
3. The springs (10), (11) are installed through the
spool (22) and sleeve (23) to maintain the con-
nected state of the spool and the sleeve.
This position corresponds to the neutral state, and
is kept as long as the steering wheel is not turned.
4. The pin is fitted to the drive shaft (15) and the sleeve
(23), there being some clearance between the pin
and the holes on the spool.
Therefore, when the shaft and sleeve rotate, the
spool rotates with approx. 10° of clearance. At this
moment, a fluid passage is formed between the
spool and the sleeve to operate the steering system.
When the shaft and sleeve stop rotating, the spool
and sleeve return to their original positions by
means of the spring. Then, the fluid passage is
closed and the return passage is open.
B. DRIVE SHAFT
The pump drive shaft (15) is slightly tilted off the spool
axis, and is splined to the pump gear of the GEROTOR
pump assembly by its bottom end.
In the event of loss of fluid pressure, turning the steer-
ing wheel drives the GEROTOR through this shaft to
operate the steering manually.
C. GEROTOR PUMP
The gerotor pump provides the steering system with a
back-up device for steering, and operates as previously
described.
D. CHECK VALVE
The check valve normally remains closed, which pre-
vents the fluid from flowing from its inlet side to its
outlet side directly. When the steering system is manu-
ally operated, this valve forms the fluid passage so
that the fluid returned from the steering cylinder flows
to the GEROTOR pump for recirculation.
E. RELIEF VALVE
The relief valve (9a) prevents excessive hydraulic pres-
sure from building up in steering pump and circuit. In
other words, it protects the circuit when the steering
cylinder stroke is completed or the steering is not pos-
sible due to outer force.
STEERING SYSTEM - OPERATING PRINCIPLE