Taylor-Dunn E-451 - Bearings; Commutator

Drive Motor
Page 61
ME-45X-01
E-451 & E-457
Bearings
Pressing the armature out of the bearings is likely to damage the bearings. Once removed the bearings should be
replaced.
Commutator
1: Measure the outside diameter of the commutator.
• If the commutator is less than the minimum diameter specied in section Service Limits, then the motor must
be replaced.
2: Measure the commutator undercut depth in 5 places around the commutator.
• If any one of the measurements is less than the minimum undercut depth specied in Service Limits at the
end of this section, then the commutator must be undercut. Refer to the Repair Commutator section for
information regarding undercutting the commutator.
3: Inspect the commutator for groves.
• If the commutator is grooved then it must be machined on a lathe. Do not machine the commutator past the
minimum diameter specied in Service Limits section. Refer to the Repair Commutator section for information
regarding machining the commutator.
4: Inspect the commutator for burn marks.
• Burn marks and/or raised commutator segments 90 or 180 degrees apart is evidence of a shorted armature. A
tool called a growler is required to reliably test for a shorted armature.
5: Inspect the commutator for raised segments.
• Raised segments could be a result of a stalled motor or shorted armature. A tool called a growler is required
to reliably test for a shorted armature.
• If the armature is not shorted then the raised segments can be removed by machining the commutator. Do not
machine the commutator past the minimum diameter specied in Service Limits section. Refer to the Repair
Commutator section for information regarding machining the commutator.