Gearbox Selection: The Most Common Mistakes

Selecting the right gearbox isn’t as straightforward as it seems. Here are the most common pitfalls we see — and how to avoid them.

Mistake #1: Incorrect torque calculation

If the actual load exceeds the rated torque, the gearbox runs overloaded for extended periods. This leads to:

· Pitting, wear, and even tooth breakage or shaft fracture
· Bearing pitting and damage
· Abnormal noise, overheating, shaft migration, and oil seal leakage — all within a short time

Mistake #2: Barrel pressure not matched

The axial thrust generated by barrel pressure must be within the gearbox’s thrust bearing capacity. When the pressure exceeds the limit — especially at high speeds — bearing pitting and failure become almost inevitable.

Mistake #3: Speed mismatch

Even if the torque rating meets the requirement, prolonged high-speed operation demands a more robust design. Speed is just as critical as torque — don’t overlook it.

Mistake #4: Service factor ignored

Shock loads, frequent starts and stops, high ambient temperatures, dusty environments — these factors must be factored in. Ignoring them can cut gearbox service life in half, or worse.

Getting it right from the start

A proper selection considers all these variables together — not just torque and power, but also speed, axial load, and operating environment.

Not sure if your selection is correct?
Send your process parameters to Kunka Tech — we’ll review them and recommend the right model for your application.

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