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SERVICE MANUAL FOR SGR19 & SGR17
3.2. FIXED TYPE MOTOR
Nine pistons are housed in the cylinder block. A valve plate with two arched ports, Ps and Pd, is in
contact with one end of the cylinder block. The ports are connected to the delivery pipe or the suction
pipe respectively.
When pressurized fluid is led into the cylinder block port Ps, the fluid pushes the piston, which causes
the cylinder block to turn. This further causes the shaft to turn in the direction of “a” through the spline-
meshed part between the cylinder block and shaft. Thus a motor mechanism is formed.
Sland board
Piston
Cyinder block
Valve plate
Shaft
OUTPUT
a
Pd
Ps
Fig. 5-5
3.3. VALVES
LOW PRESSURE RELIEF VALVE AND
SUCTION CHECK VALVE
The low pressure relief valve works to maintain
the specified charge pressure from the gear
pump. Charge pressure replenishes the lowered
flow rate of the charge fluid due to leaks by let-
ting fluid into the case through the check valve.
Excessive fluid is drained to the case through
the low pressure relief valve.
When the tractor is parked on a slope with the
engine shut off, some reverse torque which is
applied to the output shaft through the rear axle
causes the high pressure side to leak. In this state,
if no fluid were replenished to the closed cir-
cuit, air would become trapped inside the cir-
cuit, spoiling the braking effect of the circuit and
allowing the tractor to start rolling down the
slope. The suction check valve however prevents
materialization of this no braking effect by re-
plenishing the closed circuit.
Relief
valve
Suction valve
The suction valve maintains the specified pressure in the
closed circuit, while there is no charging pressure, by let-
ting in oil, thus compensating the oil lost due to leaking .
Fig. 5-6
Summary of Contents for SCM49
Page 1: ...S E R V I C E M A N U A L I S E K I L A W N M O W E R S LAWN MOWERS MOWER DECKS SCM48 SCM54 ...
Page 7: ...7 CHAPTER 1 INTRODUCTION 3 EXTERIOR VIEW AND DIMENSIONS 1935 mm 1965 mm 1100 mm 1265 mm ...
Page 36: ...36 SERVICE MANUAL FOR SGR19 SGR17 Fig 3 55 III 3 CYLINDER BLOCK 1 EXPLODED VIEWS ...
