Question 353Steam Plants - 1st Asst/Chief

The correct answer is C) It permits axial movement between the high speed gear and low speed pinion. The quill shaft allows for axial movement between the high speed gear and low speed pinion, which is necessary to accommodate thermal expansion and other dimensional changes that can occur during turbine operation. This axial movement helps maintain proper gear alignment and engagement, preventing damage to the gear teeth. The other answer choices are incorrect because: A) The quill shaft does not provide torsional rigidity, but rather allows for controlled axial movement. B) The quill shaft does not absorb axial thrust, which is typically handled by other components in the gear train. D) The quill shaft does not compensate for radial misalignment, but rather allows for controlled axial movement.