jcb JS 200 Series, Service Manual

Page: 444 / 531

3 - 2
Section F
Transmission
9803/6400
Section F
3 - 2
Issue 1
Motor/Gearbox
When reading the operations section, refer to the schematics, specifications section in conjunction with the accompanying
section illustrations.
Operation
Swash Plate Type Axial Piston Motor
Fig.1 Swash Plate Type Axial Piston Motor
Nine pistons S/A are integrated in the Cylinder block B . The valve plate which has two sets of half-moon ports C and D
(High/low pressure switching valve) is in contact with the face of the Cylinder block.
When high-pressure oil (pressure
P ) is guided to port C , the force presses against the swash plate at the rate of force F = P X
A
, (
A
: cross-sectional area of piston) per piston sub-assembly. The corresponding reaction force works on the pistons on the
high-pressure side generating rotation of the Cylinder block. Through the spline, torque is transmitted to the shaft and the shaft
rotates.
The piston motor's output torque and revolution speed are dependent on the pressure (
P ) and flow-in rate ( Q ), calculated as
follows:
T: Output torque (Nm)
N: Revolution speed (rpm)
P: Effective drive pressure (Pa)
Q: Flow - in rate (l/min)
D: Displacement volume (cm
3
/rev)
η
m: Machine efficiency
η
v: Volume efficiency
T=
Px Dx
η
m
2xšx10
2
N=
Qx 10
3
x
η
v
D
E
S/A
B
Valve Plate
D
C