A series of faults caused by insufficient repair of synchronization gears 1. Case background A customer had a self-repaired Roots blower that experienced abnormal vibration and sound during startup and operation, and was forced to shut down, which affected production. Preliminary inspection of the equipment showed that the vibration value on the drive side seriously exceeded the standard. The customer then sent the equipment to our company for in-depth disassembly and repair. 2. Fault phenomenon and preliminary judgment After the equipment arrived at the factory, our maintenance engineers conducted a preliminary operation test (under the premise of ensuring safety), and found that the vibration at the drive end was indeed large, far exceeding the standard value. Based on experience, our engineers judged that the root cause of the fault was likely to be rotor dynamic balance failure, bearing damage, or rotor meshing problems, and decided to immediately disassemble and inspect it. 3. In-depth disassembly and failure analysis Cause of failure: After disassembly, it was found that the root cause of the equipment failure was that the customer's previous repair process for the synchronization gear was not in place or the repair plan was technically undesirable. Evidence of failure: while dismantling