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E-Mobility – STRUNK ensures secure connections in HEV, BEV, FCEV

About 10 years ago we designed the first connection technology for geared motors together with an OEM. From this the E-Traction / Powertrain division developed for geared motors in the “E-Mobility” area, which extends to fully automated production. Furthermore, our applications in the area of HEV, BEV, FCEV include:

  • Power distribution (power distribution) via BUS bar on-board networks and power distributors
  • Connections of connector systems to high-voltage lines
  • Butt welded connections and overlapping welded connections from BUSBARS to cables and braids for module connectors of the individual high-voltage storage units
  • Connections in the high-voltage on-board network from the battery to the inverter or from the inverter to the electric machine through to the phase connection in the assembly.
  • Connections in the ECUs
  • Components
  • Traction distributor
  • Pyrofuses
  • Connection technology in the gear motor (phases and star points) as well as connection to current rings


In general, this area involves welding high-voltage connector systems to high-voltage lines (HV lines) with cross-sections from 25 to 120 mm² for cable connector systems or BUS bars and traction distribution systems for four-wheel-driven e-mobility up to a cross-section of 300 mm².

Absolute reproducibility in the connection is of the utmost importance, since there is a risk of fire in the event of a field failure. For this case, we have developed systems for welding under braze, which enable fully automatic production including monitoring.

The specially designed STRUNK-MES software ensures individual product-related traceability. This provides the required data by networking the systems in individual production steps within the automated production in an SQL database or uploads the customer-specific data to the customer’s own MES system.

In the area of E-Drives from HEV, BEV, FCEV, connections can be made with wound stators or with hairpin stators. The wound stators are firmly connected using hot crimping technology and the hairpin stators using brazing solder.

High-voltage cable set and module connector

Cable and non-ferrous metal connections in electric vehicles must be designed for the conditions of high current loads. The contact resistance at the connections must be close to zero. If this is not guaranteed, the resulting heat build-up (hot spots) which then lead to field failure as the resistance continues to rise. The aim is therefore to ensure transmission is as loss-free as possible. In addition, the mechanical holding forces are extremely important here, so that no high-resistance effect or even a loosening of the connection can occur even under mechanical stress and environmental stress. In these cases, our technologies offer you the opportunity to achieve secure and demonstrably long-term stable connections even under high loads.

In the area of high-voltage technology, Strunk develops and manufactures technologies for you for the following areas of application:

  • E-traction: everything related to the drive train, e.g. B. Welding the phase connections and star points,
  • Connections to stators using winding and hairpin technology
  • Connection technology for rotors,
  • Connection technology in assembly (phase connection to terminal board),
  • Power Distribution / BUS-Bars / Lead Frames: high-voltage electrical systems, BUS-Bar electrical systems,
  • High-voltage storage systems: Development of new technologies for battery cell connectors (HV cable set),
  • HV connection technology from high-voltage cables to HV connectors,
  • AC / DC charging systems,
  • Pyro fuse.

In the area of HV cabling, we can carry out welding under hard solder as an overlapping process or as a butt welding process.

Would you like to find out more about our solutions for e-mobility? Just get in touch with us . We are happy to answer all of your questions.