What Causes Vibration in Corrosion-Resistant, High-Temperature Fan Belt-Driven Motors

What Causes Vibration in Corrosion-Resistant, High-Temperature Fan Belt-Driven Motors

Vibration in corrosion-resistant, high-temperature fans is caused by imbalance in rotating components, mechanical failures, or electromagnetic factors. First, imbalance in the rotating parts of a corrosion-resistant, high-temperature fan is primarily due to imbalance in the rotor, couplings, and speed-changing pulleys (brake pulleys). The solution is to ensure proper balancing from the outset. If the drive pulley, brake pulley, or coupler is large, it must be separated from the rotor to maintain balance. Additionally, mechanical looseness in rotating components can occur. If the core support becomes loose—due to the failure of wedge keys or pins to function properly, or the loosening of rotating fasteners—the balance of the rotating assembly will be compromised. Second, mechanical failures in corrosion-resistant, high-temperature-resistant fans primarily include the following: 1. The shaft system of the corrosion-resistant, high-temperature-resistant fan has not been properly sensed, resulting in misaligned centerlines and incorrect sensing. This failure is primarily caused by improper alignment and installation during the assembly process. Additionally, while the centerlines of some connecting components may align when the unit is cold, they may become misaligned again during operation due to deformation of the rotor support points and the foundation, leading to vibration. 2. Issues with the gears and couplings connecting the motor. This type of failure is primarily caused by poor gear meshing, severe gear tooth wear, inadequate hub lubrication, coupling misalignment or tilting, and incorrect gear tooth profiles or pitch in the gear couplings, resulting in specific vibrations due to excessive speed or severe wear. 3. Structural defects and installation issues in the corrosion-resistant, high-temperature-resistant fan itself. These faults primarily manifest as elliptical shaft journals, shaft bending, excessive or insufficient clearance between the shaft and bearing sleeves, and insufficient rigidity in the bearing housings, base plates, and foundation. Other issues include instability in the overall motor mounting foundation, unstable fixation of the motor to the base plate, loose anchor bolts, and looseness in the bearing plates and base plates. However, if the clearance between the shaft and the bearing sleeve is too large or too small, it will not only cause vibration but also lead to lubrication issues and abnormal temperatures in the bearing sleeve, as well as the transmission of vibrations from the motor-driven load. For example, vibrations from steam turbine generators and vibrations from motor-driven fans and pumps can cause the motor to vibrate. III. Electrical faults in corrosion-resistant, high-temperature-resistant fans are caused by the following electromagnetic factors: incorrect wiring of the AC motor stator; short circuits in the rotor windings of induction motors; short circuits in the field windings of synchronous motors; incorrect connections in the field coils of synchronous motors; broken bars in the rotor of squirrel-cage induction motors; and deformation of the rotor core, resulting in an uneven air gap between the stator and rotor, which causes unbalanced magnetic flux and vibration in the air gap.