The basic structure of the non-standard motors is shown in the following sectional diagrams.

Sectional diagram of 1LA8

Sectional diagram of 1PQ8

Sectional diagram of 1LL8

In conventional fin-cooled motors, the one-sided external ventilation naturally results in an uneven temperature distribution – this is however not the case with SIMOTICS N-compact motors with their additional internal air-flow channels. This cools, in particular, the stator winding heads, the rotor winding and the drive-end bearings. The resulting reduction in thermal loading increases the operating reliability and lengthens the service life.
The internal air-flow channels increase the efficiency of the ventilation which means that the external air-flow can be reduced. The lower volumetric flow and air-flow optimization of all guide channels results in a low level of fan noise.