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How to Select a K Series Helical-Bevel Gear Unit

A reliable R Series selection starts with the operating requirement, not with a familiar model number. The same size can support many valid combinations of power, ratio and output speed.

1. Define the input

Record motor power, actual motor speed, frequency, pole count and whether the gearbox will connect directly to an IEC motor or another input arrangement.

2. Determine the required ratio

For a fixed-speed input, the approximate ratio is:

i = input speed / required output speed

Use the nearest selectable ratio that satisfies the process-speed tolerance.

3. Calculate required output torque

A practical reference equation is:

T (Nm) = 9550 × P (kW) × η / n₂ (rpm)

The theoretical value is only the starting point. The selected gearbox must also satisfy the duty/service factor and external-load requirements.

4. Apply service conditions

Consider daily operating hours, starts per hour, shock loading, driven-machine behavior, ambient conditions and process criticality. A gearbox that meets nominal torque but has insufficient service factor is not a robust selection.

5. Choose the mechanical configuration

For the R Series, the defining layout is inline / near-inline. Select the appropriate solid shaft, hollow shaft, flange, foot, shrink-disc or other variant supported by the series.

6. Confirm the motor interface

Check motor frame, mounting form and the specific input adapter/flange. Motor power alone does not uniquely define the motor frame.

7. Final engineering checks

Before order release, confirm rotation direction, radial and axial loads where relevant, mounting position, lubrication requirement, shaft and key details, and any installation-space constraints.

Replacement projects

If the R Series is replacing an existing gearbox, do not treat matching model numbers as proof of interchangeability. Mechanical direct fit requires the mounting arrangement, output interface, centerline references and mounting-hole pattern to match the existing installation.

Next steps

• View R Series specifications
• Review mounting and installation
• Calculate gearbox output torque
• Gear ratio and output speed guide