Commutator Profile Inspection and Analysis After Turning

MEASUREMENTS PERFORMED:

• BAR TO BAR: This is the vertical gap between the two adjacent edges on adjacent bars. All such gaps are calculated and the worst case is displayed; the typical tolerance is 3 µm. Values exceeding the tolerance have a dramatic influence on motor life.

• BAR RISE - DELTA BAR: This is the TIR of each single bar. All the TIR's are calculated and the worst case is displayed; the typical tolerance is 5 µm. The value is related to the lathes tool status and indicates when a new tool is required. 

• TIR: This is calculated considering all the bars. The typical tolerance is 10 µm. This value reveals if the shaft is bent and indicates potential problems with the part assembly process.
• COMMUTATOR DIAMETER: The typical tolerance is 200 µm
• ROUNDNESS: The typical tolerance is 5 µm

OPTIONAL CHECKS ON ARMATURE:

• Angle between corresponding commutator and stack slots (commutation): This is performed if the stack slots are straight or if the section being inspected is referenced to a face of the shaft.
• Stack TIR
• Stack diameter
• Shaft TIR in different sections
• Bearing shoulder TIR

BENCH RETOOLABILITY

The standard bench can check all the armatures in the following range:

• Journal diameter: 3-17 mm (1/8-11/16")
• Commutator diameter: 60 mm (2 3/8") max
• Stack lamination diameter: 120 mm (3 15/16") max
• Distance between Journals: 300 mm (11 13/16") max
• Special range fixtures are available on request
• Part change is user friendly exploiting the self-learning retooling technique

This technique guides the operator in repositioning all the adjustable fixture subassemblies, whose positions are detected by sensors and displayed by virtual scales.