TCM FB-8 Series, Service Manual

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6A. STEERING SYSTEM (ORBITROL type)
Truck model
Item
FB10-8
FB15-8
FB18-8
FB20-8
FB25-8
FB30-8
FB25-8V
FB25-8LB
FB30-8V
FB35-8S
Steering axle
Type
Center-pin supported, Elliot type with box-shaped
cross section of weld construction
King pin spacing 735 mm [28.9 in.] 740 mm [29.1 in.]
King pin angle 0°
Toe-in 0 mm
Camber 1°
Caster 0°
Wheel dimension 16 x 6-8 10PR 18 x 7-8 14PR
Rim size 4.25 x DT
←
Air pressure 850 kPa {8.5 kgf/cm
2
} 900 kPa {9.0 kgf/cm
2
}
Steering angle
Inner wheel 78.4° 75.3°
Outer wheel 53.3° 59.2°
Orbitrol
Type Open-centered, non-load reaction type
Discharge 96 cm
3
[5.86 in.
3
]/rev
Power cylinder
Type Double-acting piston type
Cylinder bore 71 mm [2.8 in.]
Piston rod diameter 40 mm [1.57 in.]
Stroke 132 mm [5.20 in.] 146 mm [5.75 in.]
Flow divider valve
Flow rate 20 liters [5.28 U.S. gal]/min
Pressure setting 8.8 MPa {90 kgf/cm
2
} [1280 psi]
6A.1 GENERAL DESCRIPTION
The steering system consists primarily of a steering wheel, an orbitrol, and a power cylinder.
When the steering wheel is turned, the rotation is transmitted to the orbitrol; the oil passages in the
orbitrol are changed over to direct the hydraulic pressure from the flow divider valve to the power
cylinder, which extends or contracts depending on the hydraulic pressure, thereby steering the
truck.
6A. STEERING SYSTEM (ORBITROL type)