Turning gear is a critical step in the installation and maintenance of mechanical equipment, especially during overhaul or before startup of large rotating equipment (such as turbines and compressors). Its operation quality directly impacts equipment safety and operational efficiency. Mastering effective turning gear techniques is crucial for extending equipment life and preventing mechanical failures.
Preparatory work before operation is fundamental. Ensure that the turning gear is intact, the lubrication system oil pressure is normal, and inspect the equipment's rotor for signs of binding or foreign matter. For equipment that has been out of service for an extended period, manually turn the coupling first to ensure smooth rotor rotation. Furthermore, strictly follow operating procedures and wear protective gear to avoid accidental contact and personal injury.
Techniques used during turning gear directly impact the performance. During startup, apply torque slowly and evenly. Observe the rotor's running sound and vibration using a sounding rod or vibration monitor. If any unusual grinding noise or sudden change in resistance is detected, stop the machine immediately and investigate the cause. Common faults include bearing damage and friction between moving and stationary components. During continuous cranking, the speed must be kept stable. Low speeds (e.g., 3-5 rpm) are typically maintained manually or electrically to ensure even distribution of lubricant and dissipate heat.
Post-operation inspections are also essential. After shutdown, check bearing temperature, seal condition, and bolt tightness. Record cranking data (such as resistance and vibration amplitude) as part of the equipment health record. For equipment that is frequently started and stopped, regular preventative cranking is recommended to prevent rotor bending and deformation due to gravity.
In short, cranking is more than just a simple mechanical operation; it involves a thorough diagnosis of the equipment's condition. Operators must combine theoretical experience with careful observation and apply standardized techniques to ensure long-term, stable operation of the equipment.