The electromagnetic vibration of the rotor rotation frequency ((1-s)f0P) and the rotating magnetic field synchronization frequency (f0P) may occur simultaneously; the electromagnetic vibration vibrates at the beat of the cycle with a period of 1 (2sf0). Therefore, when the motor load increases greatly, s is increasing, and the vibration tempo is also increasing (the period value is decreased); the motor itself tends to generate electromagnetic noise consistent with the pulsating beat.
When the electromagnetic vibration of the rotor winding abnormality is broken, the rotor circuit of the wound asynchronous motor is unbalanced, and an unbalanced electromagnetic force is generated, which is an unbalanced force image. The dynamic air gap in the section changes as the rotor rotates, and the pulsating waveform of the beat is induced to vibrate. Features: (1) The electromagnetic vibration and the electromagnetic vibration generated by the dynamic eccentricity of the rotor are similar and similar in image shape, and are difficult to distinguish. However, when the cage is broken, there is often a burnt stink that causes the insulating paint to coke due to high temperature. (2) When the load increases, it also increases, and the beat period slows down. When the load exceeds 50%, the law is more significant; (3) the vibration disappears after the power is off; (4) For the spectrum analysis of the stator current waveform and the vibration waveform, the side frequency of 2sf0 appears on both sides of the fundamental frequency.
After the rotational speed of the structural resonant fan is determined, the rotational frequency of the rotating component has become a fixed value. When the natural frequency of the fan itself or nearby objects is the same or close to the fan rotation frequency, resonance or vibration is formed. For example: (1) After the modified fan, the impeller is too heavy, so that the critical speed of the fan shaft system drops to near the working speed of the fan, and the bending resonance occurs when the critical speed is formed. (2) The basic stiffness is insufficient, the weight is not enough, and its natural frequency is close. Rotation frequency; (3) The air cooler on the motor has insufficient support stiffness, or the connection between the motor and the motor is not good, and excessive forced vibration is formed; (4) other objects, pipes, structures around the fan Resonance. (5) Adjust the resonance of the door actuator transmission rod.
Selection and precautions of hydraulic cylinders for excavators
The hydraulic cylinder of an excavator is one of the important components, which converts hydraulic energy into mechanical energy,
Drive mechanical movement. When purchasing hydraulic cylinders for excavators, the following points should be noted:
1. Size and quality: The size and quality of the excavator hydraulic cylinder should match the model and specifications of the excavator to ensure its normal operation.
2. Pressure and flow rate: The pressure and flow rate of the excavator hydraulic cylinder should match the requirements of the hydraulic system,
To fully utilize the capabilities of the hydraulic system.
3. Sealing performance: The hydraulic cylinder of the excavator has good sealing performance to avoid hydraulic oil leakage or entering the mechanical interior.
4. Durability: The hydraulic cylinder of the excavator has good durability and can withstand long-term heavy load work.
5. Brand and Quality: Choose well-known excavator hydraulic cylinders to ensure their quality and after-sales service
For Zaxis Cylinder Seal Kit,Bucket Cyl Kit,Travel Motor Seal Kit,Middle Arm Cylinder Seal Kit
Safe Seal Technology Co., Ltd. , https://www.jolseals.com