Kubota EA330-E4 Series Workshop Manual page 127

EA330-E4, WSM
Commutator and Mica
1. Check the contact face of the commutator for wear, and grind
the commutator with sand paper if it is slightly worn.
2. Measure the commutator O.D. at several points.
3. If the difference of the O.D.'s exceeds the allowable limit, correct
the commutator on a lathe to the factory specification.
4. If the minimum O.D. is less than the allowable limit, replace the
armature.
5. Measure the mica undercut.
6. If the undercut is less than the allowable limit, correct with a saw
blade and chamfer the segment edges.
Factory specification
Commutator O.D.
Allowable limit
Factory specification
Difference of O.D.'s
Allowable limit
Factory specification
Mica undercut
Allowable limit
(1) Segment
(2) Undercut
(3) Mica
Clearance between Shaft and Bushing
1. Measure the bushing I.D. on the drive side and commutator
side.
2. Measure the shaft O.D. on the drive side and commutator side.
3. If the clearance exceeds the allowable limit, replace the
bushing.
Factory
specifica-
Clearance between
tion
shaft and bushing
Allowable
limit
Shaft O.D.
Commutator bushing I.D. Factory specification
Drive bushing I.D.
1-S62
28.0 mm
1.10 in.
27.0 mm
1.06 in.
Less than
0.1 mm
0.004 in.
0.4 mm
0.02 in.
0.5 to 0.8 mm
0.02 to 0.03 in.
0.2 mm
0.008 in.
(a) Correct
(b) Incorrect
9Y1211018ENS0113US0
Commutator 0.030 to 0.10 mm
side 0.0012 to 0.0039 in.
0.050 to 0.10 mm
Drive side
0.0020 to 0.0039 in.
Allowable 0.20 mm
limit 0.0079 in.
12.50 mm
0.4921 in.
12.53 to 12.60 mm
0.4933 to 0.4960 in.
12.55 to 12.60 mm
0.4941 to 0.4960 in.
9Y1211018ENS0114US0
ENGINE
KiSC issued 05, 2015 A