There exist tons of opinions when deciding on which types of motors to use. Technicians, Engineers, Decision makers and industry’s expert have big decisions to make in an attempt to choose motors that is most suitable for their application and machinery. However, major determinant remains speed, torque, cost and more. To clear the air of any doubt and make an informed decision when selecting either of gear motor or brushless motor, come along in this exciting review with dhmotor as we examine both motors, their pros and cons.
What is the Gear Motors?
DC Gear Motors refers to mechanical system comprising of an electric motor and an integrated gearbox. Essentially, the gearbox, which is attached to the motors is aimed at reducing its speed while torque is appreciably increased at a given speed. It is safe to say that gear motors act as torque multipliers and speed reducers, requiring less power to move a given load.
Method of Operation of Gear Motors
Here, the stationary component, known as stator contains non-permanent magnets while the moving part, known as rotor contains electromagnets. Once there is physical contact between the carbon brushes with the commutator in the rotor, electric voltage is transferred to the unit. Thereafter, the voltage creates an electromagnetic field in the rotor. With the spontaneous flipping of polarity of magnetic force through the commutator, spinning motion is achieved.
Furthermore, the rotor rotates 180-degrees when an electric current is applied to the armature. As the rotor rotates, the windings are constantly being energized. The speed of the motor is counted in terms of rotations of the shaft per minute. This is termed RPM (Revolution Per Minute).
Advantages of Gear Motor
- Low Cost. Gear motors are relatively cheaper to produce and affordable to buy in comparison to brushless DC motors.
- Industrial Application. Owing to their high starting torque, gear motors are popular demand and choice in industrial environments.
- High starting torque.: Where an application needs to get up to speed quite immediately, a high torque type of motor is an ideal choice, especially in an industrial environment and heavy duty applications.
Disadvantages of Gear Motors
- Lower speed. Although gear motors are characterized by high starting torque, they are not efficient and are unable to maintain high-level speeds. This is so because subjecting brushed motor to high speed consistently will result in heat.
- High cost of maintenanc. as a result of frictional movement on carbon brushes, there is occurrence of high wear and tear. This means that gear motor will require some level of maintenance like cleaning of the brush and or complete replacement.
A Simple Gear Motor
Applications of Gear Motors
As earlier mentioned above, gear motors are suitable for use in industrial environment which includes but not limited to electric railways, mine hoists, continuous conveyors cranes, rolling mills metallurgical works, mechanical automation and caravan movers. Click here to learn more something about the application of dc motor.
What is the Brushless Motor?
Brushless motor works by alternating the polarity of windings inside the motors. Logically, this is an inside out brushed motor, which eliminates the use of brushes within its mechanism. With brushless DC motors, also known as BLDC, the permanent magnets are fixed onto the rotor, with the electromagnets on the stator. An electronic speed controller (ESC) is then engaged to regulate or commutate the charge to the electromagnets in the stator, thereby allowing the rotor to travel through 360-degrees. Click here to learn more.
Method of Operation of Brushless Motors
Stator windings of BLDC motor are connected to a control circuit which is an integrated switching circuit or inverter circuit. The control circuit energizes proper winding at the proper time, in a pattern which rotates around the stator. Permanent magnets on the rotor tend to align with the energized electromagnets of the stator, and as soon as it aligns, the next electromagnets are activated. The design of gear motors is often described as ‘open circuit’ design. This is so because when the motor isn’t running, the coils are open and don’t generate power.
Advantages of Brushless DC Motors
- Brushless motors are more efficient than gear motors as a result of absence of carbon brushes and mechanical commutator.
- Brushless motors have a considerable low or negligible wear and tear due to absence of brushes, and hence, more durable with longer life span.
- Brushless motor has less energy losses.
- In brushless motor, cost of maintenance is relatively low as there is no brush to maintain or replace.
- It is characterized by noise and vibration free operation, reduced electromagnetic interference (EMI). This feature makes them great for applications where noise levels need to be kept to bearest minimum. An example is patient hoist lift.
- Brushless motors have less electromagnetic interference.
- Brushless motors have high dynamic response.
- Brushless motors offer better performance in terms of torque, consistent speed, speed control, power output etc.
- Elimination of ionizing sparks from the commutator.
Disadvantages of Brushless DC Motors
- In order to ensure reliable operation, they require efficient and expensive cooling system.
- The initial cost of brushless motors is quite expensive than that of gear motors.
- Brushless motors are more sensitive to overheating.
- Spare parts are expensive i.e electronic controllers being used for commutation of the motor.
A simple Brushless Motor
Applications of Brushless Motors
In view of the foregoing, there is no gainsaying that brushless motors gains some superiority over the former largely due to its high efficiency ratio. Thus it has high acceptability into numerous applications.
Moreover, modern devices keying into BLDC motors, making them a preferred choice against gear motors.
For instance, they are largely used in industrial positioning applications that require a great deal of accuracy and precision. Such as construction of a PC hard drive and other electronic hardware like DVD ROM players (drives), CPU fans and DVD ROM (R/RW drives).
I have another article is about: The Significance of Brushless Gear Motors in a Wide Variety of Fields.
More applications of Brushless Motors
- Heating, Ventilation, and Air Conditioning (HVAC)
- Automobiles (Electrical vehicles)
- Medical instruments e.g infusion Pumps, ventilators, medical imaging system etc
- Laboratory equipments
- Fuel controls
- Blowers
- Dental surgical tools
- Respirators
- Drones
- Robots
- Robotic equipment
Differences between Gear Motor and Brushless DC Motor
In case you still find it difficult to make your choice on which motor is suitable for your application, we feel you would find a simplified table highly beneficial, to facilitate your decision making process. In the table below, we present a summary as well as review of differences between Gear Motor and Brushless Motor based on key parameters.
| Parameters | Gear Motor | Brushless Motor |
| Commutation | It uses brushes to deliver current to the motor windings through mechanical commutation | It uses Electrical commutation to deliver current |
| Speed range | Speed is lower compared to BLCD | Speed is high due to the absence of brushes and commutator |
| Control | Simple | Complex and expensive |
| Electrical noise | Arcs in the brushes generate noise and unsuitable for environment that requires notable silence | Noise is considerably low |
| Rotor inertia | There is higher rotor inertia which limits dynamic characteristics | It is low. because it has permanent magnets on the rotor, it increases dynamic response |
| Maintenance | Periodic maintenance is highly required due to presence of brushes | Maintenance is less required with absence of brushes |
| Speed/Torque | Low- mechanical limitation by brushes | Higher- there is no mechanical limitation |
| Efficiency | Moderate. About 45 percent | High efficiency ratio. About 90 percent |
| Life span | Short life | Longer life span, higher durability |
| Building Cost | Cost of construction is lower compare to BLDC | Cost of construction is higher due to permanent magnets |
| Control Requirement | No controller is required | Controller is always required in order to keep the motor running |
| Construction | Armature winding is on rotor; fixed magnets are placed either side of the rotating electromagnet | Armature winding is on stator and fixed magnets are on rotor |
| Application | They are being used in industrial environment; electric railways, mine hoists, continuous conveyors cranes, rolling mills metallurgical works, mechanical automation and caravan movers. | Heating, Ventilation, and Air Conditioning (HVAC)
Automobiles (Electrical vehicles), Electric bicycles, Medical instruments e.g infusion Pumps, ventilators, medical imaging system etc. Laboratory equipments Fuel controls, Blowers, Dental surgical tools, Respirators, Drones Robots, Robotic equipment |
To conclude, brushless DC motors (BLDC), can be said to be an efficient type of motor that is in wide use compare to gear motor. They have so evolved and found their ways into several modern electronic devices and gadgets.
