Hyster A1.00XL, Руководство по обслуживанию и ремонту

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FIGURE 18. SATISFACTORY COMMUTATOR SURFACES
A light brown surface of the commutator where it
rotates on the brushes is a normal condition. The
surface of the commutator must be smooth. Variations between light brown and dark brown
colors are also normal. The surface of the
commutator must be smooth.
A condition called “slot bar marking” is also
normal if the commutator surface is smooth. The
variable color occurs in a pattern according to the
number of conductors per slot. A very dark surface is also a normal and an
acceptable condition if the commutator surface
is smooth. 6939
STREAKING AND THREADING SURFACE
Streaking on the commutator surface signals the
beginning of serious metal transfer to the carbon brush
which causes threading Threading is a condition where
grooves are completely around the commutator.
In light threading the grooves may just barely be
apparent where the surface film or color is disturbed. In
heavy threading, a rippled surface can be felt along the
surface of a bar. The brush faces wear to fit these
grooves. When the commutator shifts due to armature
end–play, the brushes are lifted out of the grooves. Then
contact between the brush and the commutator is
distrubed. This causes arcing and commutation is
disrupted.