Brushless vs. Brushed geared motors: A total cost of ownership (TCO) analysis

The choice of the drive system often generates friction between two key departments: Engineering, which prioritizes performance and durability, and Shopping, which seeks to optimize the cost of the bill of materials (BOM).

However, in the design of industrial machinery, looking only at the purchase price is a miscalculation. In applications of continuous use, an inadequate technological choice can trigger the Total Cost of Ownership (TCO) due to unplanned shutdowns and maintenance.

Today we technically analyze the two major options: DC gearmotors with brushes In the face of technology Brushless (BLDC). When does taking the leap really pay off?

The Achilles' heel of mechanical commutation

Conventional DC motors rely on physical commutation: graphite brushes that rub against the collector to change the polarity. This design is robust and inexpensive, but it has a inevitable physical obsolescence.

Constant friction creates three enemies for reliability:

1. Conductive powder: Residue from wear that may affect other components.
2. Mechanical wear: Requires periodic replacement of brushes.
3. Electrical Noise (EMI): Voltaic arcs that can interfere with sensitive sensors

In difficult to access or demanding environments, the operating cost (OPEX) of changing a motor far exceeds the initial savings of choosing the version with brushes.

The operational advantage of Brushless (BLDC)

By eliminating physical contact and transferring the switching to an electronic controller, the gearmotors Brushless unlock critical advantages for modern design:

• Extended lifespan: The life of the motor no longer depends on the brushes, but only on the fatigue of the bearings and the gearbox.
• Higher power density: By having the winding in the stator (connected to the housing), heat dissipation is much more efficient. This allows for more torque in a more compact size.
• Speed Stability: The electronics allow for precise closed loop control, keeping the RPM constant even if the load varies

The Verdict: It All Depends on the Work Cycle

Does this mean that the brushed motor is dead? Not at all. Engineering is based on efficiency, not on unnecessary extra cost. The key is in the work cycle:

• Is your application intermittent? (E.g. adjustment actuators, vending machines, door openers). A well-sized brushed motor is the logical and cost-effective option. The product will reach the end of its useful life before the brushes fail.
• Is your application continuous? (E.g. pumps, conveyor belts, internal logistics). Here, Brushless is imperative. The initial investment pays for itself quickly by eliminating maintenance and reducing electricity consumption.

Are you hesitant with the calculation?

In CLR we don't push you to the most expensive technology, but to the most sensible one. Our engineering team analyzes the load histogram of your project to recommend the exact drive.

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