Traction sizing starts with the complete vehicle
Motor torque is derived from vehicle mass, gradients, acceleration, wheel diameter and transmission ratio. The resulting duty is then checked across starting, continuous running, braking and low-speed operation, where current is high but self-cooling may be limited.
| Vehicle data | Engineering relevance |
|---|---|
| Mass, gradient and acceleration | Define required tractive effort and peak torque. |
| Wheel diameter and gearing | Convert vehicle speed into motor speed and torque. |
| Route and duty profile | Determine thermal loading and cooling requirements. |
| Supply and controller | Define voltage, current limits and field control. |
| Mechanical envelope | Sets mounting, shaft, bearing and coupling interfaces. |
Support for existing fleets
When an original traction motor is no longer available, drawings and measured interfaces can form the basis of a documented replacement. The assessment should also include previous damage, insulation condition, commutation, gearing and vehicle protection so that the new unit does not merely reproduce an existing weakness.
For a quick assessment: provide motor and vehicle nameplates, drawings, wheel and transmission data, route profile, supply limits, controller information and the required documentation scope.