Making of Traction Motor

Machining of three phase TM shaft was inspected today in the shop.

Two items are received in TM shop from steel foundry as small foundry. Both of these are among

70 off loaded to trade.

Machining of commutator spider was inspected. It was seen there were lot of surface defects in the spider hub.

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.