Industry News

17251 Cooling Fan:

The dimensions are 170mm x 170mm x 51mm, with a typical operating voltage of 24V or 48V. It commonly features dual ball bearings and employs a standard control mode of 4-wire PWM + FG. This model can be equipped with accessories such as a metal mesh guard, power cable, switch wire, speed control wire, and others.

9238 Cooling Fan:

The dimensions are 92mm x 92mm x 38mm, with an operating voltage of 24V or 48V. It typically uses dual ball bearings and is known for its high rotational speed. The standard control mode is 4-wire PWM + FG.

Formula 1 can be utilized to characterize the relationship between sound pressure level and fan speed, while Formula 2 can be employed to describe the resultant sound intensity when multiple sound sources are present.

The IP rating is a standard used to evaluate the dust and water resistance of equipment. The details are as follows:

Definition of IP level:

The IP rating is used to measure the protection of electrical components (such as fans) and electronic components in the equipment against foreign objects (including dust and water).
This rating consists of two numbers, the first number indicating the dust rating (0 to 6) and the second number indicating the water rating (0 to 8).
The specific meaning of IP level:
For example, an IP65 rating indicates that the equipment has "level 6 dust" and "Level 5 water" protection.
Level 6 dustproof means that the equipment is completely dustproof, that is, it is completely protected from dust intrusion.
Class 5 waterproof means that the device is protected against low-pressure water jets from any direction.
Common IP levels:
Depending on the use environment, common IP levels include IP55, IP65, IP67, and IP68.
These grades are typically used for devices that require a specific level of protection.
Standard source:

The IP rating is specified by the International Electrotechnical Commission (IEC) in the standard IEC 60529.

The Counter-Rotating Fan is an advanced axial-flow fan that substantially enhances airflow performance and static pressure through the integration of two counter-rotating blade modules within a single fan assembly.

When selecting a cooling fan as a critical component of the equipment, it is essential to consider not only its performance and efficiency but also pay close attention to the characteristics of current variations. Excessive current can lead to fan failure, thereby impacting the normal operation and service life of the equipment. The current variation process of the cooling fan encompasses several stages: the inrush current upon power-on, the starting current during startup, fluctuations in rated current during stable operation, and potential current surges when the fan blades are obstructed. To gain a comprehensive understanding of these current variation characteristics, each stage will be analyzed sequentially to facilitate more informed decisions in cooling fan selection and design.

5. Basic equation of fan blade design

The flow in the impeller is very complex, which also causes great difficulties for related research. In order to simplify the difficulty of research, we introduce the following hypothesis for the flow in the impeller, so that the problem is transformed into a unary problem, and a simple equation is derived to describe the characteristics of the machine.

1) The number of blades of the impeller is infinite, and the blades are infinitely thin. Therefore, the flow in the impeller can be regarded as axially symmetric, and the direction of the relative velocity is tangent to the blade surface;

2) The relative flow is steady;

3) The axial velocity is evenly distributed across the flow section.

3. Fan Operation Principle

The operation principle of the fan blade is based on Bernoulli's principle. By utilizing the angle of attack (elevation) of the fan blade, a local vacuum is created above the blade when the fan starts. Due to the resulting pressure differential, air is drawn from above the blade and directed downwards, generating airflow. This forced airflow achieves the effect of air supply.

3， Fan Structure and Flow Field Analysis:

1，Generation of Fan Airflow

The rotation of the fan blade displaces air particles within its vicinity, causing a decrease in air pressure at the inlet and a corresponding increase in air pressure at the outlet. This results in an axial pressure gradient across the entire fan blade region. Since the external air pressure surrounding the inlet is higher than that inside the inlet, this pressure differential causes external air to be drawn into the system. The incoming air is then transported by the rotating blades towards the high-pressure area, further reducing the air pressure at the inlet. This process continues until the rate of air intake matches the rate of air expulsion from the outlet, establishing a dynamic equilibrium

1. The composition and principle of the cooling fan

Involve a magnetic rubber ring embedded within the fan blade, which is filled with magnetic material to form a permanent magnet external magnetic field. Two sets of coils wound on the silicon steel sheet are energized, generating a magnetic field. The Hall effect sensor synchronizes the detection and control circuit, enabling alternating operation of the two coil sets on the silicon steel sheet. This results in the silicon steel sheet producing alternating magnetic poles that generate repulsive forces with the magnetic rubber ring. When the repulsive force exceeds the static friction force acting on the fan, the fan blades rotate. Due to the synchronization signal provided by the Hall effect sensor, the blades continue to operate continuously.

2] Factors of fan structure design

Size specifications, appearance requirements
Air pressure Requirements for air volume
Noise requirement
Speed range
Fan output power
Environmental requirements. Functional requirements

When defining the required volumetric flow rate, it is essential to consider the flow resistance encountered by the fan within the application context, as well as its capability to provide fresh air or support a cooling process. The volumetric flow rate (measured in m³/hr) and pressure (measured in Pascals, Pa) are two critical parameters that must be addressed in fan operation. It is crucial to select a fan whose performance characteristics align with these requirements, ideally operating near its peak efficiency point. Utilizing the fan’s peak efficiency not only minimizes energy consumption and noise levels but also ensures optimal performance.