Yanmar 4JH2E Service Manual page 200

Chapter 6 Cooling Water System
1. Sea Water Pump
9
12
7 8
10
11
5
1. Sea water pump body
2. Side cover
3_ Impeller {C·type)
4. Wear plate
5. Pump shall
6
4 3
6. Mechanical seal
7. Circllp
8. Bearing
9. Bearing
10.
on
seal
2·2 Specifications of sea water pump
Engine speed (max.) 3600 rpm
Gear ratio (crank gear/pump gear)
28/31
Pump speed
3252 rpm
Suction head
0.5m (1.66
fl)
Total head
9.5m (31.16 ft)
2 13 14 15
/;I
lnlelQ
11. Water seal ting
12. Gear
13.0ring
14. Hexagonal boll
15. Impeller blind cover
Delivery capacity
3250 l/h (198315 ln.'/h)
2-3 Sea water pump disassembly
IJH2-Series
Outlel
' L i'
Direction of rotation
(1)
Remove the rubber hose from the sea water pump
outlet and then the sea water pump assembly from the
gear case.
remove the pump shaft, bearings, and drive gear as a
set.
(2) Remove the sea water pump cover and take out the
O·rlng, 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
Standard
Impeller width
31.6
~
31.8 (1.2440
~
1.2519)
Wear plate thickness
2 (0.0787)
Housing width
33.8
~
33.9 (1.3307
~
1.3346)
Side plate thickness
2 (0.0787)
(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
0
~
0.3
(O
~
0.0118) 0.8 (0.0314)
6-4
31.3 (1.2322)
1.8 (0.0708)
-
1.8 (0.0708)
Prinhld in
Japan
AOA1029-9109SP