Pratt & Whitney Canada PT6A Turboprop, Instruction Manual

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Support of the main shafts in the PT6A engine is accomplished by a
combination of ball and roller bearings. Ball bearings support axial and
radial loading, while the roller bearings support only radial loads, allowing
for thermal expansion.
Propeller Shaft Power Turbine Compressor
No. 5: Roller No. 3: Roller No. 1: Ball
No. 6: Ball No. 4: Ball No. 2: Roller
No. 7: Roller**
** Smaller reduction gearboxes do not utilize a No. 7 bearing.
beArings
A-52
A-61
A-64
A-66
A-60
A-65
A-67
7 6 5
6 5
4
3 2 1
Support of the main shafts in the PT6A engine is accomplished by a
combination of ball and roller bearings. Ball bearings support axial and
radial loading, while the roller bearings support only radial loads, allowing
for thermal expansion.
Propeller Shaft Power Turbine Compressor
No. 5: Roller No. 3: Roller No. 1: Ball
No. 6: Ball No. 4: Ball No. 2: Roller
No. 7: Roller**
** Smaller reduction gearboxes do not utilize a No. 7 bearing.
beArings
A-52
A-61
A-64
A-66
A-60
A-65
A-67
7 6 5
6 5
4
3 2 1