Pneumatic motors are welcomed by many users because of their convenience, durability, fire and explosion protection, etc., but it is not difficult to find when using them, and the larger gas noise is unbearable. Compared with electric motors, gas noise has become an obvious disadvantage of air motors. Only after fully understanding the causes of gas noise, we can specifically prescribe the right medicine and optimize the drawbacks.

Analysis of the causes of air motor noise

The power source of a pneumatic motor comes from compressed air, which converts the energy generated by compression into mechanical energy and outputs it to provide power for the machinery. When the air motor is in and out, the air flow will generate the dynamic noise of the gas; during the operation of the air motor, the reciprocating motion of the transmission shaft, connecting rod and piston will produce mechanical vibration.

1.Flowing gas noise analysis

After the compressed air of the pneumatic motors enters the control valve, it flows in the air pipe and generates gas flow noise when it does work on the piston. Therefore, the air flow noise is mainly generated when the air motor control valve is in and out. When the air motor opens the control valve, the safety valve opens, and then the compressed air passes through the control valve and the safety valve, the pressure changes greatly. High-frequency noise is generated when gas flows at high speed. The exhaust noise is mainly caused by the pressure change when the compressed air does work on the piston, and the compressed gas is discharged from the pneumatic motor under the push of the piston. The valve has a periodic cycle of primary exhaust and secondary exhaust. The periodic change of gas is the main cause of exhaust noise. If you want to reduce the noise of the flowing gas, you can consider connecting the muffler not directly to the air motor, but connecting it to a hose and then connecting the air motor. This effect is much better than connecting the muffler directly to the motor.

2. Mechanical noise analysis

The mechanical noise of a air motor is the noise formed by the vibration generated by mechanical collision and inertial force during work. The internal parts of the air motor will have friction, and each part will collide and generate noise. When a pneumatic motor is working, the friction and collision between hundreds of parts and the transfer of unbalanced force will cause strong resonance and noise at the same frequency. To solve the mechanical noise of the air motor, the main point is to analyze the dynamic balance of the air motor crankshaft first, and converting the unbalanced force into a balanced force can effectively reduce the vibration and noise caused by the unbalance.

Faults & Solutions

Pneumatic motors are widely used in the chemical industry, mixers, emulsifiers, reactors, homogenizers, dispersers, shears, conveyor belts, and elevators. Today I will tell you about the common faults and solutions of air motors:

A. Insufficient lifting weight

Reasons:

1. ■ The air motor piston ring wear gap is too large, and the compressed gas leakage is large;
2. ■ The inlet pressure cannot meet the specified requirements;

3. The air supply pipe diameter is not installed according to the specified requirements, the pipe diameter is too small, and the air supply is insufficient And large pressure loss;

Countermeasures:

1. ■ Replace the piston ring;
2. ■ Increase the intake pressure;
3. ■ Install the air supply pipeline as required.

B.Difficulty starting

Reasons:

1. ■ After repairing, the assembly of the piston connecting rod and the housing is not clean;
2. ■ The clutch is not attached;

Countermeasures:

1. ■ Remove the air motor, clean the assembly again;
2. ■ Pull the clutch handle and hang it up;

C. Abnormal impact sound during the operation of the air motor

Reasons:

1. ■ The wear gap between the small end and the big end of the connecting rod is too large;
2. ■ The wear gap of the rolling bearing of the crankshaft main journal is too large;

Countermeasures:

1. ■ Replace the piston pin and crankshaft copper sleeve and ring;
2. ■ Replace the crankshaft rolling bearing.

D. Brake device fails

■ Reason: The brake belt is loose

■ Countermeasure: Adjust the joint bolt.

Learn more details, please feel free to contact us, or contact Doris: doris@dejunindustry.com