Air gap and shimming, Axial float, Anti-friction bearing assemblies – Rockwell Automation 1325L DC Motors User Manual User Manual
Page 22: Bearing replacement
22
DC Motors
Air Gap And Shimming
(Frame C180ATZ)
Main Pole
Steel or brass shims, when used, are placed between pole and frame. If for
any reason the shims are removed they must be replaced under the same
poles. Main pole bolts are steel SAE Grade 5 (120,000 psi).
Axial Float
Frames C180ATZ have wavy spring washers between B.E. bracket and
bearing. Axial float should be within the limits listed on the chart below.
Axial Float
Anti-friction Bearing Assemblies
The bearings are positioned and secured by various means depending on
size and application requirements. Open type ball bearings are used for
direct coupled and belt drive applications. Below are standard construction
details for the various frames.
DC180ATZ & DC210ATAZ
Drive end bearing fits in a machined cavity in the bracket with inner cap.
Commutator end bearing has single seal on side facing commutator.
C180ATZ
Bearings fit in a machined cavity in the end brackets. Inner caps are used.
Bearing Replacement
Remove bearing by means of bearing puller. Clean bearing housing and
bearing seat prior to assembly of bearing. Place new bearing in a bake oven
for one hour at 121 degrees C (250 degrees F). Place bearing onto shaft and
push home to bearing shoulder. Hold it in place for a minimum of 30
seconds.
After bearing has cooled down for about 1 minute, add 1/2 cu. in. of fresh
grease into back of bearing. When the motor has been assembled, grease per
instructions found on
Frame
Maximum
Minimum
All
1.22 mm (0.048 in.)
0.20 mm (0.08 in.)