Bearings; Commutator - Taylor-Dunn SS-025-34 Service And Parts Manual

SS and MX Models, DC System

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 specified 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 specified 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 specified 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 specified in Service Limits section. Refer to the Repair
Commutator section for information regarding machining the commutator.
MS-534-13
Drive Motor
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