How to Choose the Right Motor: Why a Coconut Can't Grow in the North

Choosing the wrong motor is like transplanting a tropical coconut tree into freezing northern soil—no matter how much effort you put in, it simply won’t bear fruit. Likewise, selecting an unsuitable motor can lead to inefficiencies, breakdowns, and wasted investment, all due to a mismatch between application and motor performance. It's time to stop using a "cow knife to kill a chicken" and start using real motor selection calculation.

• Application Scenarios Corresponding to Different Types of Motors

• How Key Motor Data Such as Power, Speed, etc. are Calculated?

• Recommendations for Motors Given the Data

• Types of Motors Suitable for Gearboxes and Application Scenarios

• Gearbox Diagrams, Representative Data Introduction

• Influencing Factors of Motor Forward and Reverse Rotation

• What matters most:

• How to Reduce the Cost Under the Premise of Ensuring Efficiency

Using the wrong motor damages more than just efficiency — it can delay product launches, increase costs, and even cause equipment failure. The solution? Smart electric motor matching from the start.

Motor data is not just superficial math. Power, torque, and speed calculations must align with actual working conditions, load characteristics, and design goals. Only then can your electric motor drive the project, not drag it down.

Stay with us, and we’ll decode how to choose motor specs that truly fit your product — not just on paper, but in reality.

Application Scenarios Corresponding to Different Types of Motors

Not every motor fits every job. Each application demands specific motor characteristics. Here are some typical scenarios and matching motor types:

• AGV Trolleys/Logistics Robots:These need high torque and low-speed stability. Brushless DC planetary geared motors are ideal due to their compact size, strong torque, and low maintenance.

• Medical Centrifuges/Diagnostic Devices: Require precision and quiet operation. High-speed brushless DC motors are best, providing accurate speed control and low noise.

• Robot Arms/Automation Equipment: These systems need responsive, precision control. Use brushless servo motors with encoders, often integrated with planetary gearboxes.

• Vacuum Cleaners/Cleaning Equipment:Need fast rotational speed. Go for universal AC motors or high-speed vacuum motors

• Lifting Devices/Electric Doors: Require high torque and holding force. Worm gear DC motors or brushed DC geared motors work well.

Choosing the wrong motor type risks reduced efficiency, overheat, or even operational failure. Match the motor to the load — not just based on budget, but on actual mechanical demand.

How Key Motor Data Such as Power, Speed, etc. are Calculated?

Motor selection calculation is rooted in fundamental equations that connect speed, torque, and power.

Basic Formula:

• Power (kW) = Torque (Nm) × Speed (rpm) ÷ 9550

• Torque (Nm) = Power (kW) × 9550 ÷ Speed (rpm)

Other key considerations:

• Efficiency (η):Ratio of output mechanical power to input electrical power. Higher efficiency = less energy loss.

• Load Type: Steady, variable, or impact loads require different motor responses.

• Duty Cycle:S1 (continuous), S2 (short-time), or S3 (intermittent) determines whether the motor can handle heat buildup.

Example: If your machine requires 2 Nm torque at 1500 rpm, you’ll need:

Power = (2 × 1500) ÷ 9550 = 0.314 kW

This number is your starting point. But if you have a gearbox, you'll need to account for mechanical losses and torque multiplication.

Recommendations for Motors Given the Data

Once you know the mechanical needs, here's how to choose motor:

• High Power, Low Speed:Use DC brushless planetary gear motors

• High Speed, Low Torque: Choose high-speed brushless motors or universal motors

• Precision Control: Go for servo brushless motors with encoder feedback

• Small Size, High Torque:Select worm gear DC motors

Don’t forget: match voltage, shaft type, insulation grade, and mounting style to your design. Also consider environmental protection (IP rating)and noise levels, especially for indoor or medical equipment.

BG Motor provides customized solutions — we tailor shaft length, mounting holes, and IP rating to your specific application.

Types of Motors Suitable for Gearboxes and Application Scenarios

Not all motors pair well with gearboxes. Here’s what works best:

- Planetary Gearboxes + Brushless DC Motors: Compact, high-efficiency torque conversion. Best for AGVs, robots.

- Worm Gearboxes + DC Brushed Motors: High reduction ratio, self-locking feature. Ideal for lifting, door openers.

- Helical Gearboxes + AC Motors:Smooth transmission, used in conveyors or continuous-duty machinery.

When torque and space are a concern, gearboxes are essential. Choose motor + gearbox combos that complement each other in both performance and lifespan.

Gearbox Diagrams, Representative Data Introduction

Influencing Factors of Motor Forward and Reverse Rotation

The motor’s ability to rotate forward or backward depends on:

- DC Motors: Change polarity of voltage = change rotation direction.

- AC Single Phase Motors: Requires a reversible capacitor circuit

- Servo/Brushless Motors: Direction controlled by driver signal or encoder feedback.

What matters most:

• Torque symmetry: Some motors have weaker reverse torque.

• Control logic: Reversal must not cause mechanical strain or damage.

• Timing coordination: Especially in synchronized equipment.

If your application needs bi-directional operation (e.g., conveyor, curtain systems), always confirm motor design supports clean, efficient reversing.

How to Reduce the Cost Under the Premise of Ensuring Efficiency

Cutting costs doesn’t mean cutting corners. Here’s how to optimize:

• Right-sizing the motor: Oversized motors waste energy and money.

• Use gearboxes:Instead of high-torque motors, combine standard motors with reduction gears.

• Choose brushless over brushed for long-term use: Higher upfront, but lower lifecycle cost.

• Buy from manufacturers that offer integrated solutions: BG Motor offers motor + gearbox + brake + encoder as one package — less vendor friction, better performance match.

Always balance initial price with energy savings, maintenance cycles, and application fit.

By focusing on real-world performance and precision matching, you’ll no longer be planting coconuts in the cold North. With proper electric motor selection, your project will thrive from root to fruit.