11
BEARINGS, SEALS AND LUBRICATION
Most bearings are double sealed and pre–lubricated.
They do not require lubrication (except traction motor
drive end on E20–100 series). Under normal conditions
the bearings may fail after several years service due to
improper lubrication (contaminants in the grease or
insufficient oil in the grease). When maintenance
repairs are performed after several years of service the
bearings must be automatically replaced as a routine
practice. If excessive bearing failure is experienced
determine the cause. Check the motor temperature,
armature balance, and proper lubrication.
CAUTION
Use Hyster–approved parts. It is important that the
bearing is a class three (loose) fit and has
high–temperature grease. The seal must have the
correct shaft contact and high–temperature
properties. Also, it must be lubricated with
multi–purpose grease containing 2 to 4%
molybdenum disulfide.
BRUSHES AND BRUSH HOLDERS
The brush assembly consists of the brushes, springs,
holders and a mounting device. Electric power from the
battery to the commutator segments travels through the
brushes. The mounting device must be insulated from
the electrical circuit. Before installing brushes always
inspect the brush holders inside and out for burned
spots. Any roughness on the inside of holder should be
removed (fine sandpaper glued to a flat piece of wood
works well). The holder should be parallel to the
commutator.
FIGURE 14. BRUSH ASSEMBLY
1
1
1
2
1. BRUSH HOLDER (4)
2. BRUSH YOKE
3. BRUSH SPRING (4)
4. BRUSH SET (2)
3
3
1
4
4
The brushes are a vital replacement part which are
carefully designed for specific operations. Width and
thickness must be matched to the brush holder and also
to the commutator bar spacing. The length must be
sufficient for adequate service life. The face of the brush
must fit the contour of the commutator. The brush
material must have the correct electrical, chemical and
mechanical properties. Shunt length is important to
allow sufficient brush travel. Shunt connections at the
brush must be able to withstand vibration and must
maintain a positive electrical connection between brush
and cable. The shunts must be specifically sized for load
carrying capacity.
