Many electric vehicle designs today integrate the electric motor, power electronics and drivetrain components within a single housing unit. This new kind of a combined electric axle drive, sometimes known as ‘eAxle’, reduces weight and axial installation space – ideal to accommodate the battery stacks of battery electric vehicles (BEVs) or the second engine and transmission in for hybrid electric vehicles (HEVs). But this design brings new challenges in the quality assurance process for such housings.
As well as shaft and bearing quality, the thermal management of the system becomes an important issue to be verified. eDrive housings require an advanced cooling concept to manage the heat generated within the coils and hairpins of the electric motor, as well as by the power electronics. The integrated transmission and differential are key components for torque adaption and torque vectoring, and require high quality bearing arrangements in the housing.
Such integrate system designs are leading to smaller and more complex housings being developed for electric vehicles, characterised by particular size, form and position specifications as well as lower wall thickness. As a result, dimensional tolerances for the housings are becoming tighter and certain features are harder to access during quality assurance processes. Housing inspections require standard geometries and profile feature measurement, with key features including sealing surfaces, flanges, boreholes, cooling holes or coolant channels, wall thickness, bearing of the shaft and bearing arrangements that also provide support for an integrated drive including gears. Surface inspection and roughness measurement may also be required in some instances.
Because of the number and range of features found on a typical eDrive housing, a comprehensive yet flexible measurement solution is required to achieve the necessary accuracy without compromising on cycle times. Hexagon’s high and ultra-high accuracy coordinate measuring machines (CMMs) with multisensor capabilities offer such flexibility. By integrating a fixed tactile probe head, an indexing wrist and a roughness sensor on a single CMM, all of the important features of the eDrive housing can be captured quickly within a single program.
Explore Hexagon solutions for dimensional inspection of electric vehicle axle drive housings
The Leitz Reference HP CMM with SENMATION offers precise multisensor measurement ideal for the different features of housings.
With the SENMATION automated sensor exchange system, every housing feature is inspected by the optimum sensor within the measuring cycle.
The GLOBAL S Chrome CMM configuration enables manufacturers to maximise throughput without compromising accuracy.