Yanmar 4JH2E Service Manual page 201

Chapter 6 Cooling Water System
l. Sea Water Pump
~..:....~~~~--':..._~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4JH2
Series
9 12 7 B 10 11 5 6
I
4 2
13 14 15
Outlet
Direction of rotation
lnletQ
1.
Sea water pump bOdy 6. Mechanical seal
11. Water seal ring
2. Side
cover
7. Circlip 12. Gear
3. Impeller (C·type)
8. Bearing 13. 0 ring
4. Wear plate 9. Bearing
14. Hexagonal bolt
5. Pump shaft
10. Oil seal 15. Impeller blind cover
2.2 Specifications of sea water pump
Engine speed (max.) 3600 rpm
Gear ratio (crank gear/pump gear) 28131
Pump speed 3252 rpm
Suction head 0.5m (1.66
ft)
Total head 9.5m (31.16
ft)
Delivery capacity 3750 l/h (228825in.'/h)
2·3 Sea water pump disassembly
(1) Remove the rubber hose from the sea water pump
outlet and then the sea water pump assembly from the
gear case.
(2) Remove the sea water pump cover and take out the
0-ring, impeller and wear plate.
(3) Remove the mechanical seal side stop ring.
(4) Insert pliers from the drive gear long hole and remove
the stop ring that holds the bearings.
(5) Lightly tap the pump shaft from the impeller side and
Impeller width
Wear plate thickness
Housing width
Side plate thickness
Printed in Japan
AOA1029-9002
Standard
31.6 ~ 31.8 (1.2440 ~ 1.2519)
2 (0.0787)
33.8
~
33.9 (1.3307
~
1.3346)
2 (0.0787)
remove the pump shaft, bearings, and drive gear as a
set.
(6) Remove the oil seal and mechanical seal if necessary.
2·4 Sea water pump inspection
(1) Inspect the rubber impeller, checking for splitting
around the outside, damage or cracks, and replace if
necessary.
mm{in)
Clearance at assembly
Maximum allowable
Wear limit
clearance
31.3 (1.2322)
0 ~ 0.3 (O ~ 0.0118)
0.8 (0.0314)
1.8 (0.0708)
-
1.8 (0.0708)
6-5