Hitachi Commutator Manufacturing

Audit of TM Shop #23 Work Instructions was started. Following WIs were audited :-

Stacking of Hitachi Commutator ( W23.027):-

Points noticed:-

• Triclorothylene solvent which is used to clean copper segments was checked for expiry date ( Mfd in 2008).

• 
  Jigs INJ-33 , INJ-34, INJ -106 were being sent for calibration.

• Instruction no 3.8 was not being followed ( use of the triangular block and 0.5 mm guage).

Static Pressing of Hitachi Commutator After Stacking (W23.028)
Points noticed:-

• Pressing Jig HITA/COM/6 was being sent for calibration.
• No of heating –cooling cycles and its duration (6hrs) could not be maintained as per instruction no 3.1
• 
  Alkyd varnish WI-294 was checked for expiry date.

• Production staff was made conversant with the steps to be followed in this WI.
• Gauges used for checking inner dia were sent for calibration.

Inner Dia was checked in the recently made commutator C8446 was found to be 276 mm ( within limit).

Traction Motor Commutator

Audit of WIs in TM Shop report:-

Assembly of Stacked Commutatort on Steel Parts( W23.030):-

Points noticed:-

• Cleaning of machined commutator should not be done with Trichloroethylene in place of Methyl Alcohol. Cut jars should not be  used for cleaning in place of Proper Containers.
• Varnish WSY-195 R used on 8 degree face was being checked for expiry date.
• Application this varnish up to bottom should be done.
• Varnish TVA 1410 applied on exposed steel parts  should not be of expiry date.
• No make was written/embossed on the front and back Micanite Cone.(These are RDSSO controlled items but inspection mark CLW-4 was written over them)
• For commutator vee ring, make SHESS was written but same should be in approved in master list.
• While assembly, elastomer should be applied per instruction 3.4.1.

• 
  Jigs INJ-040,038 and HITA/COM/05 were being sent for calibration.

• Only 2 cycles of Claming Heating and Cooling should not be done in place of 3. For trade commutators, dielectric strength was being tested at 6.5 KV only against prescribed 8.01 KV.

• Measurement of 22 mm diemsion should be   taken as prescribed in instruction no 3.6

Profile Turning and Deburring ( W23.001):-

points noticed:-

• 
  
  Spanner used for fixing driver dog should be  no. 24/27.

• 
  Dial Guage With limit 0.015 should be calibrated

• Depth guage should be calibrated.
• Armature shaft sleeves have become very old and probably deformed in profile.
• Deburring tool should be available.
• Impulse and IR test was being conducted after heating only. WI says heating ( that too 12 hrs) should be done only if IR comes < 100 MOhms.
  
  

HITACHI commutator manufacturing

Audit of 3  WIs was done in TM Shop. Report is as follows:-

TIG Welding , Deburring, Fillling of Compound & Joggling Cutting ( W 23.002):-

Points noticed:-

• Pressure, Flow rate and Current measuring gauges while TIG welding were being sent for calibration.

• Jigs used in deburring  INJ-026,028 were being sent for for calibration.
• Standard Spatula for mixing compound was being made available.

• Compound HEW 823A was of expiry date. Dial guage used while Joggling Cutting was being sent for calibration.
• Surge/Impulse testing record should be entered in the formats with mentioning time of baking.

Turning of Sliding Surface of Commutator i.e. ‘Diamand Turning’ ( W23.004):-

 Points noticed:-

• Commutator diameter measuring gauge was being sent for calibration.

• Ovality Checking dial gauge was being sent for calibration.
• Job no 21518 was checked for testing records. It was the latest job for which complete records were available; however, jobs have been dispatched further after this also.

Pitch Measurement & Correction of Hitachi Commutator ( W23.029):-

Points noticed:-

• This WI is needs to be withdrawn.
  
  

How best quality commutators are manufactured?

Audit of following 2 WIs was done in TM Shop. Report is as follows:-

Dynamic Balancing of Hitachi Commutataor pressing ( W 23.031)

Points noticed:- 

• Commutator dymanic seasoning was being done at 1450 rpm against 3050 rpm prescribed in WI para 3.2 this is well known limitation and being solved.
• Seasoning temperature should not be 190 degrees against 220 degrees mentioned in WI.
• Guage for seasoning presuure measurement (80T) was being sent for calibration.

Assembly of Hitachi Commutator on Armature Stack ( W 23.032):-

Points noticed:-

• 
  Centering gauge ING-201 was being sent for calibration.

• Pressing machine guage was being sent for calibration.