GB-PT & GB-COMP Alignment


Thread Starter


Export compressor platform:

We have just aligned the PGT25+G4 -GB (BHS) and also GB to COMP.
So, we need a clear answer about the GB Pinion and Bull gear position during DBFF/Shim measurement.

Step 1
- we took the total float of pinion By rubber hammer( 1.8mm) and I kept in middle 0.8/0.9 mm. measured the DBFF it was 521mm so,
515.9 - 521 = 5.1mm,
Pre-stretch 1.5mm
5.1-1.5mm= 3.6 (shim), each side 1.8mm shims.

Step 2
- we rotate the bull gear by manually at max speed, thinking that double helical gear is self aligned. and we too the DBFF measurement.
measured the DBFF it was 520.2mm
515.9 - 520.2mm = 4.3mm
Pre-stretch 1.5mm
4.3mm-1.5mm= 2.8mm ( Shim) each side 1.4mm

So which method is correct?