Rotor Coil - Kubota WSM J Series Workshop Manual

J SERIES, WSM
(3)

Rotor Coil

Main Field Winding (Rotor Coil)
1. Measure the coil resistance between each end of field coil.
2. If the resistance is not as specified, replace the rotor assembly or
contact service station.
Factory
Resistance
spec.
(1) Rotor Field Coil
Grounding of Rotor Coil
1. Connect leads of a mega ohm meter between each lead and
exciter rotor laminations.
2. Reading should be more than 1 M at 500 V.
3. If continuous, replace the rotor assembly or contact service
station.
(1) Lead
Silicon Diode Stack
1. Disconnect all leads at the connection terminal on diode board.
2. Check the polarity of diode stack leads carefully. It is a good idea

to tag them (+,-, ) during disassembly.
3. A diode in a good condition enables the current to flow in only one
direction from anode to cathode.
4. If the diode is faulty, contact service station or replace with
revolving rectifier assembly.
(1) Silicon Diode Stack
Checking Ball Bearing
1. Measure radial dislocation of the outer ring.
2. If the axial dislocation exceeds the allowable limit, replace the
bearing.
Axial dislocation Allowable limit
3. Measure the I.D. of the bearing housing.
4. If the wear exceeds the allowable limit, replace the end bracket.
I.D. of bearing housing Allowable limit
(1) Ball Bearing
S-53
GENERATOR
Rotor
See page S-18, S-19
field coil
W1109744
(2) Lamination
W1111150
W1111526
0.05 mm
0.002 in.
90.02 mm
3.54 in.
W1111877
KiSC issued 10, 2016 A