By Dave Bachelier
Brunk has been providing laminations to the electric OEM customers for the past 50 years, markets including automotive, marine, and industrial applications.
We are now seeing the fully electric or hybrid vehicle market demand increase with the adoption of this technology. The use of precision laminations is a common requirement shared among electrified vehicles, no matter whether they’re fully electric, hybrid or employ electrification as a standalone motor, in the drivetrain, in the axle or on the wheels. Ultra-thin lamination sheets are stacked to form the motor’s rotor and stator.
Producing laminations for vehicle electrification requires a precision stamping die and, for an electric or hybrid vehicle application, more-efficient, thinner laminations are favored over those used in other motors of comparable size. The complexity of the stamping dies engineered to produce them is also much higher than a typical tool, as the length of these tools can reach 3.65m. A longer length tool requires greater dimensional accuracy due to tolerance buildup, which can occur over the length of the tool. The additional tooling size and complexity require that the tool not only meets the necessary lamination design requirements, but also matches the capabilities of the stamping press and the ability for toolmakers to maintain and service a stamping die of this size. As a part of our capabilities to service the electric vehicle market place, Brunk has invested in the latest state of art 800 ton Minister Nidec press capable of producing production laminations. Tools can be designed to produce individual loose laminations and/or designed to stack laminations in the tool through mechanical interlocking or gluing.
With such a range of considerations associated with the development of an EV/HEV stamping die, it is essential to find a tooling partner who can collaborate with an OEM’s engineering team to specify critical features needed in the tool, as well as the specialized design and manufacturing capabilities for producing this type of stamping die. This will ensure that the dies are capable of efficiently producing the end-product for the duration of the program.
Brunk has been building precision tools for in-house use for the last 60 years. We have developed the use of tungsten carbide to precision stampings for long term high volume stampings.
Collaboration between the OEM and its tooling partner is critical to determining the right specifications for a long-lasting, high performance die. Providing an internal team and stamping die vendor the necessary time needed to correctly specify the stamping die helps achieve the desired motor performance while also helping meet cost and speed to market.