Steam Turbine Turning Gear Swinging Pinion Bronze Bushing

1. Installation Position and Structural Characteristics

• The swinging pinion rotates around the active gear shaft, with its journal mated to the bronze bushing.
• The bronze bushing typically has a cylindrical structure, with a precision-machined inner wall that boasts high surface finish. It is sleeved onto the swinging pinion’s shaft end and fixed to the turning gear device’s housing or rocker arm support structure.
• It provides stable support for two types of motion of the swinging pinion: revolution (rotating around the small active gear shaft) and self-rotation (rotating on its own axis when transmitting torque).

2. Core Functions

• Friction Reduction and Lubrication: Bronze bushings feature good wear resistance and self-lubricating properties (some variants contain solid lubricants like graphite). They reduce friction resistance on the swinging pinion journal during rotation and minimize wear. Particularly during initial startup or low-speed operation of the turning gear (e.g., 1.5 r/min for this unit), they prevent seizing or damage caused by direct metal-to-metal contact.
• Positioning and Guiding: The fit clearance between the bronze bushing and the journal is precisely designed. This ensures accurate axial positioning of the swinging pinion during revolution and self-rotation, guaranteeing that tooth flank clearance meets requirements when engaging with the turning gear. It also prevents tooth surface impact or poor engagement due to swaying.
• Cushioning and Shock Absorption: At the moment the swinging pinion engages or disengages with the turning gear (e.g., during automatic engagement/disengagement), the bronze bushing can absorb part of the impact force through slight deformation. This reduces vibration in the transmission mechanism and protects gears and shaft system components.

3. Relevance to Turning Gear Operation

• When the turning gear engages automatically, the swinging pinion is driven by the pneumatic actuator to revolve clockwise. The bronze bushing ensures a stable movement trajectory, allowing the gear to smoothly enter the engagement position.
• When the steam turbine accelerates to speed, the swinging pinion is driven by the turning gear to revolve counter-clockwise and disengage. The low-friction property of the bronze bushing ensures a smooth process, preventing seizing that could lead to disengagement failure.
• Worn bronze bushings or excessive fit clearance may cause the swinging pinion to sway. This leads to abnormal noise during gear engagement, increased tooth surface wear, and even disrupts the turning gear device’s automatic interlock function.

4. Maintenance Key Points

• Regularly inspect the bronze bushing’s wear condition and lubrication status. Ensure no scratches, flaking, or overheating signs appear on its inner wall.
• Keep the bronze bushing and journal clean to prevent impurities from entering the mating surface, which would cause abrasive wear.
• When replacing the bronze bushing, strictly control the fit clearance to comply with equipment technical specifications and maintain the swinging pinion’s normal operating accuracy.

Custom Fabrication per Drawings

We provide precision manufacturing of steam turbine turning gear swinging pinion bronze bushings strictly according to your technical drawings. Our production complies with your specified material requirements, inner wall surface finish, fit clearance, and structural dimensions.

2. Core Functions

• Friction Reduction and Lubrication: Bronze bushings feature good wear resistance and self-lubricating properties (some variants contain solid lubricants like graphite). They reduce friction resistance on the swinging pinion journal during rotation and minimize wear. Particularly during initial startup or low-speed operation of the turning gear (e.g., 1.5 r/min for this unit), they prevent seizing or damage caused by direct metal-to-metal contact.
• Positioning and Guiding: The fit clearance between the bronze bushing and the journal is precisely designed. This ensures accurate axial positioning of the swinging pinion during revolution and self-rotation, guaranteeing that tooth flank clearance meets requirements when engaging with the turning gear. It also prevents tooth surface impact or poor engagement due to swaying.
• Cushioning and Shock Absorption: At the moment the swinging pinion engages or disengages with the turning gear (e.g., during automatic engagement/disengagement), the bronze bushing can absorb part of the impact force through slight deformation. This reduces vibration in the transmission mechanism and protects gears and shaft system components.

3. Relevance to Turning Gear Operation

• When the turning gear engages automatically, the swinging pinion is driven by the pneumatic actuator to revolve clockwise. The bronze bushing ensures a stable movement trajectory, allowing the gear to smoothly enter the engagement position.
• When the steam turbine accelerates to speed, the swinging pinion is driven by the turning gear to revolve counter-clockwise and disengage. The low-friction property of the bronze bushing ensures a smooth process, preventing seizing that could lead to disengagement failure.
• Worn bronze bushings or excessive fit clearance may cause the swinging pinion to sway. This leads to abnormal noise during gear engagement, increased tooth surface wear, and even disrupts the turning gear device’s automatic interlock function.

4. Maintenance Key Points

• Regularly inspect the bronze bushing’s wear condition and lubrication status. Ensure no scratches, flaking, or overheating signs appear on its inner wall.
• Keep the bronze bushing and journal clean to prevent impurities from entering the mating surface, which would cause abrasive wear.
• When replacing the bronze bushing, strictly control the fit clearance to comply with equipment technical specifications and maintain the swinging pinion’s normal operating accuracy.

Custom Fabrication per Drawings

We provide precision manufacturing of steam turbine turning gear swinging pinion bronze bushings strictly according to your technical drawings. Our production complies with your specified material requirements (e.g., tin bronze, aluminum bronze, or graphite-impregnated self-lubricating bronze), inner wall surface finish, fit clearance (with the swinging pinion journal), and structural dimensions. We also conduct wear resistance and dimensional accuracy tests to ensure each bushing matches your turning gear shaft system perfectly, whether for maintenance replacement or new unit assembly.