The water jacket of a motor case with a one piece structure has a large amount of change in the design shape (volume) of the internal cavity due to the draft angle needed for production by conventional die casting and therefore uniform cooling performance has been an issue. We are currently developing a technology that eliminates this draft angle.
Until now, the production of e-axle cases with complicated cooling circuits has been done by sand casting or gravity casting, but there are problems such as thick wall, weight, and high manufacturing cost.
For die casting, a two-piece structure assembly method is used, but in this case a seal is required.
Ryobi is currently developing a technology that integrate this two piece structure through welding.