Automobile manufacturers and suppliers are facing new challenges when it comes to components for electric motors. The example of the housing of an electric motor shows how big these challenges are: Compared to a transmission housing, this has to be manufactured within significantly tighter tolerances, since the accuracy has a decisive influence on the efficiency of the motor.
In addition, due to the special structure, such as integrated cooling channels, the electric motor housing is usually significantly thinner than a transmission housing. In addition, bearing bushes made of steel materials are pressed into some of these housings. Special protection shields in the tool ensure that steel chips do not come into contact with the aluminium surfaces during processing and damage them.
Machining requirements and features of different housing types
Description: Highly integrated, complex housing with stator mount, transmission mount and connection for the power electronics. High functional integration saves assembly costs. Compact design. Complex cast housing as a result.
The machining process as well as the tools are designed individually depending on the measurement situation, machine park and clamping setup. In this way, the cutting forces applied to the component are kept as low as possible. The machining of the stator bore is divided into 3 steps: Pre-machining, Semi-finish machining and Finish machining.
The use of an ISO boring tool is particularly suitable for pre-machining. This method allows high cutting speeds and feed rates to remove material quickly and economically. Under specific conditions, for example with precisely pre-cast parts and corresponding machine conditions, the first roughing operation can be omitted.
During semi-finish machining, the complex contour train of the electric motor housing is prepared. This is done in such a way that the complete contour with chamfers and radial transitions are produced in the required quality during finish machining. This step allows the housing to be shaped optimally. Depending on spindle power and stock removal, it may be necessary to split the semi-finish machining into two steps.
