Thermal regulation plays an important role in ensuring the reliability and efficiency of electronic systems. Among possible solutions, cooling fans stand out for their essential function in thermal management. This blog will explore the aspects of cooling fan sizing and specification requirements, guiding you through the nuances of selecting the optimal cooling solution for your electronic components and systems.
What is a Cooling Fan?
Cooling fans are an indispensable component that regulates temperature within system chambers, enclosures, and electronic devices. Heat sinks utilize mechanically designed fins to dissipate heat transfer across the sink’s geometry design via conduction while cooling fans use electronic power to dissipate heat by use of convection heat transfer. These fans focus on maintaining an optimal thermal environment for electronics. By moving air over and around the components, cooling fans remove excess heat generated during operation, preventing overheating, increasing performance efficiency, and extending lifespan. Cooling fans are critical in safeguarding electronic systems against thermal-related failures, highlighting their significance in the tech industry.
Cooling Fan Thermal Sizing and Specification Requirements
1. Air Flow: The cornerstone of cooling fan specification, air flow is the volume of air a fan moves, typically measured in cubic feet per minute (CFM). Determining the correct air flow requires calculating the amount of heat generated by the device, the temperature reduction needed, and the ambient temperature. Higher air flow translates to better cooling efficiency, as it signifies more heat being carried away from the device within a given time.
2. Static Air Pressure: Air flow and air pressure are interconnected; a balance must be struck between the two. Fans operating at higher airflows decrease air pressure values relative to the maximum static pressure specification. Fans with high air pressure might not provide adequate air flow for effective heat exchange, compromising cooling efficiency. An increase of air pressure specification means that thermal control applications will need more cooling to counteract the increased temperature.
3. Fan Speed: Measured in revolutions per minute (RPM), fan speed is a functional correlation of motor specifications, blade design, and other mechanical factors. While higher speeds can indicate greater air movement, they don’t always equate to better cooling performance. It’s essential to consider the fan speed in relation to the device’s heat generation and cooling requirements.
4. Heat Generation Within the Device: A fundamental step in fan selection is assessing the device’s internal heat production. This figure helps in calculating the necessary air flow and, consequently, choosing a fan that can handle the thermal load. One commonly used component to monitor and control the temperature within a device is a thermistor. This small device measures changes in temperature and sends signals back to the fan controller to adjust the fan speed accordingly. It helps maintain an optimal temperature by increasing or decreasing airflow as needed.
Selecting a Fan
Choosing the right cooling fans for your device is a critical decision that hinges on several key factors, ensuring optimal thermal management and device performance. Here’s a structured approach to fan selection:
1. Device Specifications and Conditions: Start by identifying the ideal operating temperature for your device. This involves understanding the thermal limits and the conditions under which the device will operate, including the ambient temperature range.
2. Heat Generation Within the Device: Assess the total heat generated by the device during normal operation. This step is crucial for determining the thermal load that the cooling fan needs to manage.
3. Calculate Required Air Flow: With the device’s heat generation and desired temperature reduction in mind, calculate the necessary air flow. This calculation should factor in the ambient temperature and the heat to be dissipated to maintain the device within its optimal temperature range.
4. Selecting a Fan: Choose a fan based on the calculated air flow requirement. The selection process involves comparing the fan’s air flow capabilities against the static pressure and the thermal resistance of the device. Since calculating the exact pressure loss can be challenging, a practical approach is to select a fan with a maximum air flow of 1.3 to 2 times the required air flow. This buffer ensures the fan can adequately cool the device under various conditions.
When selecting a fan, it is important to not only consider the air flow requirement but also any dimensional constraints. This means taking into account the available physical space and any limitations on fan size due to mounting requirements or other factors. In some cases, this may lead to the need for multi-fan configurations in order to achieve higher thermal specifications.
Multi-fan configurations (parallel vs. series vs. single units)
When optimizing thermal management, the arrangement of multiple fans—parallel, series, or single units—plays a crucial role. Parallel configurations enhance air flow, offering redundancy and improved cooling over larger areas. Series setups, where fans are aligned one after the other, increase air pressure, ideal for systems requiring air to travel through dense components or long ducts. Single units, while simpler, must be carefully selected to balance air flow and pressure needs efficiently. Each configuration has distinct advantages, and the specific cooling requirements and spatial constraints of the application should guide the choice.
Elinco recognizes the importance of fan trays in multi-fan configurations, especially for larger electronic devices that require multiple cooling solutions. We have the ability to design and assemble fan trays, allowing for simpler installation and reducing the risk of malfunctions due to misaligned fans.
Value-Add customizations from E-JPC
E-JPC offers value-add customizations that elevate the performance and adaptability of cooling solutions. These customizations include variable speed controls for energy efficiency, IP-rated environmental sealing for protection against dust and moisture, and specialized connectors for seamless plug-and-play integration. Tailoring fans to specific operational requirements ensures optimized thermal management and enhances the longevity of electronic devices.
Existing Applications for E-JPC Fans
E-JPC’s cooling fans are integral to the operation of advanced medical imaging systems, offering unparalleled precision and durability under extreme conditions. Specialized for high G-load environments, these fans incorporate brushless DC and AC technologies, ensuring low noise and high precision through innovative motor and bearing designs. A testament to their reliability and performance, over 50% of global CT scan machines are equipped with E-JPC fans, solidifying our presence in the industry and marking us as a trusted partner to three of the top four CT scan machine manufacturers.
Another example of a specialized application for E-JPC fans is in telecom data servers. These servers require high-performance cooling solutions to maintain optimal operating temperatures and prevent overheating, which can lead to system failures and downtime.
In addition to medical imaging systems and telecom data servers, E-JPC’s cooling fans are also used in hydrogen energy fuel cells. Fuel cells produce electricity through a chemical reaction involving hydrogen, oxygen, and an electrolyte. This process generates heat that needs to be managed to ensure the fuel cell operates efficiently and safely.
Conclusion
In summary, selecting the right cooling fans involves understanding specific requirements like air flow, pressure, and device heat generation. E-JPC enhances these selections with customizations for optimal performance. Trusted by leading medical imaging manufacturers, our fans ensure reliability and efficiency. Contact Us or submit an RFQ today for cooling solutions tailored to your needs.
DC electric motors convert direct current electricity into mechanical power by generating magnetic fields that spin rotor positioning attached to a motor’s output shaft. There are several common types of electric motors, including servo, stepper, and brushless DC motors. We’ll compare mechanical and electrical differences of each, then explain the key factors to consider when selecting the appropriate motor solution for your customer purposes.
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Servo Motors
A servo motor has a similar mechanical build and flat-torque curve of a brushless DC motor with the characteristics and ability to control position, speed, and acceleration at fine-angular points. The servo’s ability to operate requires a position feedback sensor which interfaces with a servo driver module, commanded by a programmable logic controller (PLC). When installed, servo motors are “application specific” as they require manual tuning relative to the application’s inertial load, gain evaluation of the system’s command output vs. input, and homing corresponding to the motion profile’s “start” position.
Stepper Motors
A stepper motor (also commonly recognized as a step or stepping motor) has a set mechanical tooth design on both the stator and rotor components to move the front shaft’s rotational position to specific angles relative to an identified home position. Current excites the stator’s phases by a separate driver that sends revolution-specific voltage pulses using an open-loop system, demarcated by equal step divisions around the shaft. While a stepper can reliably position the rotor in equal step distance between mechanical teeth angles, closed-loop feedback remains an available option for applications that require precise angular positioning measurements. Stepper motors can also operate in continuous duty when the appropriate voltage, current, inertial load and torque are below the motor’s pullout curve. The advantages of utilizing a stepper over other motor types are high response acceleration between angular positions, continuous high torque at low speeds, the ability to add a low-cost encoder for closed-loop feedback, and the elimination of servo tuning/gain output analysis.
Brushless DC Motors
Conventional DC motors require electrical contact points, or carbon brushes, between a stationary electrical feed and the rotary shaft. The current is sent to a commutator designed to maintain the motor’s rotational energy. The disadvantage of a brushed motor is significantly lower duty cycles (less operation time between profile cycles in a single day), and brushes that wear with continued use. A brushless DC motor (BLDC) transmits direct current to the rotor electronically by intricately timed electromagnetic pulses in place of brushes. BLDC motor technology allows for continuous duty below the rated torque across a specified speed range.
Servo vs. Stepper vs. Brushless DC Motors
Deciding between a BLDC vs servo vs stepper motor is simple when you consider the simultaneous need for accurate motor positioning, design simplicity, and component longevity. The latter point is crucial when comparing a stepper to a servo motor because a functioning servo requires additional parameters than simply sending pulse signals. Servo motors cannot function independently of a complex encoder to calibrate the motor’s feedback sensor and controller. If a component fails or an inertial load is changed, the motor can risk equipment damage and costly delays.
By contrast, a stepper motor utilizes the mechanical structure of the internal components’ tooth design to execute open-loop positioning capability. With its integrated step divisions, stepper motors can position the rotary shaft with precision while also offering the ability to attach an encoder for closed-loop feedback. All that’s required is to select a stepper motor with specifications that match the intended application.
If wear is a primary consideration for variable speed applications and your motion profile requires a consistent rated torque across a speed range, a BLDC motor is an optimal choice. Eliminating the need for brushes significantly increases product lifespan, decreases the cost of maintenance, and overall is a more powerful motor capable of continuous-duty operation.
Electric Motors by Elinco International JPC
DC electric motors are present across all automation-related industries that require unmanned motion profiles. The decision to select a suitable product is as important as a motor’s quality for achieving efficiency, reliability, and effectiveness. If you have further questions about the advantages of selecting a stepper motor vs. servo motor, or how to select the right BLDC motor for you,contact us and speak with one of Elinco International’s highly knowledgeable service technicians.
Slotless motors were first designed when manufacturers needed to create an improved brushless motor design built for low-power applications. Today’s slotless stators present unique advantages such as smooth performance and less cogging. Cogging, which occurs when the rotor and stator slots align and make the motor unable to start, is a common problem with motors at less than 500 rpm. It is also one of the most common reasons why people switch from slotted to slotless brushless motors.
Learn more about the different constructions of these two motor types, the advantages and common applications of each type, and the value of choosing Elinco as your supplier.
Construction of Slotted vs. Slotless Brushless Motors
Slotted and slotless brushless motors have several key differences in their construction that impact performance and longevity.
Slotted Motors
Brushless motors have a rotating, magnetic rotor with fixed windings arranged around the exterior of the rotor. In a slotted motor, the central stator core is built of laminated steel with slots and teeth. The copper wire winds between the teeth in the slots. When the teeth are longer – or closer to the central magnet – the motor has increased torque.
Slotless Motors
Slotless motors are also brushless motors with a rotating, magnetic rotor. However, the steel lamination is smooth and doesn’t have teeth (or slots) for copper wire to wind around. Instead, manufacturers wind the copper coils in a unique cylindrical shape. This configuration gives slotless motors their signature smooth performance, with low noise levels and little to no vibration, while providing high levels of power.
Performance Differences and Applications for Slotted vs. Slotless DC Motors
Because of the different winding configurations, slotted and slotless motors each provide different advantages. Slotted motors, for example, outperform slotless varieties when it comes to generating high levels of constant torque and being able to accelerate quickly. Slotless brushless motors, on the other hand, excel at smooth motion with little to no velocity ripple and having good tour constant (Kt) linearity. These motors also have the largest through holes.
These differences in performance mean they each work best for different applications and industries.
Parameter
Slotted
Slotless
Smoothest Motion (Lowest Velocity Ripple)
✔
Highest Torque Constant
✔
Torque Constant (Kt) Linearity
✔
Largest Through Hole
✔
Highest Acceleration Rates
✔
Slotted Motors
Slotted motors work best in applications where compact size isn’t an issue and the machinery needs multiple poles. They can also perform in a variety of adverse conditions and environments, because manufacturers can better protect the windings from future debris or likely damage. This means they’re commonly used in appliances, electric vehicles, and other large electrical machines.
Slotless Motors
Slotless motors work best in small precision tools. Not only do these motors have a compact size, but their smooth torque and movement are much less likely to interfere with performance. Manufacturers often pair slotless motors with medical devices and handheld tools.
Elinco DC Motors
Elinco JPC is a leading designer and manufacturer of slotted and slotless brushless motors. Innovation and long-lasting relationships built on product quality are core tenets of our business. We serve the industrial, office, medical, and military marketing sectors with consistently reliable products that are built to be cost-effective and meet our clients’ quality standards across all fields.
Our in-house engineering team is focused on developing new solutions and designs for both our slotted and slotless brushless DC motors. We provide assemblies capable of generating power levels from 400W to 8,000W and beyond. Our Elinco slotless SBLDC product line motors can be used in everything from high-torque surgical tools to medium-power medical pumps to fully autonomous vehicles based on our clients’ performance requirements and design considerations.
Order Your Slotted or Slotless Motor From Elinco International JPC
Slotted brushless motors are powerful, rugged assemblies for powering large machinery, while slotless brushless motors are capable of powering fine-tuned control for a wide variety of handheld tools. Our team at Elinco designs and builds DC motors of both classifications to power our clients’ systems and devices. Contact us today to learn more about our products or to place your order.
Slotless Motors