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The Composition and Structure of Centrifugal Fan

Time : 2023-01-18 Hits : 34

1. Fan composition

The fan adopts single inhalation D drive structure, and the fan and the motor are connected by a coupling. The fan body is mainly composed of housing, air inlet, rotor group (impeller and spindle), bearing box, coupling and other parts.
In addition to the fan body, the unit can also be equipped with a variety of external components according to the needs of the user, the common ones are: motor, adjustment door, overall support, electric actuator, muffler, etc.

2. Introduction of the structure of the fan

The fan can be made into two types: from one end of the motor, if the impeller rotates in the clockwise direction, it is called a clockwise wind machine, with 'clockwise'; it rotates in the counterclockwise direction, with 'counter'.
The outlet position of the fan is expressed by the outlet angle of the casing: 'Shun' and 'Reverse' can be made into 0°, 45°, 90°, 135°, 180°, 225°, a total of six angles. Other special angles can also be made according to the user's requirements.

The causes of failure in the operation of the fan

1. Fan Vibration Violent
(1) Fan shaft and motor shaft are not centered.
(2) The foundation or overall bracket stiffness is not enough.
(3) Loose impeller bolts or rivets and deformation of the impeller.
(4) Loose impeller shaft plate hole and shaft fit.
(5) The casing, bearing seat and bracket, bearing seat and bearing cover and other coupling bolts are loose.
(6) The blade has accumulated dust, dirt, blade wear, impeller deformation shaft bending to make the rotor unbalance.
(7) fan inlet and outlet pipe installation is poor, resulting in resonance.

2. bearing temperature rise is too high
(1) bearing box vibration is intense
(2) poor quality grease or oil, deterioration and contains impurities such as dust, sand, dirt or improper filling amount
(3) The shaft and rolling bearing installation is skewed, the front and rear two bearings are not the same center.
(4) Rolling bearing outer ring rotation. (and bearing box friction).
(5) rolling bearing inner ring relative to the spindle rotation (that is, running inner ring and spindle friction).
(6) Rolling bearing damage or shaft bending.
(7) Cooling water is too little or interrupted (for fans requiring water-cooled bearings).

3. Motor current is too high or temperature rise is too high
(1) When starting, the regulating door or the gate in the air outlet pipe is not closed tightly.
(2) The motor input voltage is low or the power supply is cut off in single phase.
(3) The temperature of the medium conveyed by the fan is too low (i.e., the gas density is too high), causing the motor to be overloaded.
(4) The system performance and fan performance do not match. The system resistance is small, and the amount of affluence left is large, causing the fan to operate in the low pressure and high flow area.

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