Case Studies & ArticlesLow Maintenance, heavy-duty linear guide provides repeatability and precision for an autonomous EV fleet car charging station

Low Maintenance, heavy-duty linear guide provides repeatability and precision for an autonomous EV fleet car charging station

Industry: Automotive and EV

Product: HDS2 – Heavy Duty Linear Guide System

As the Electric Vehicle (EV) industry continues to rise in popularity, thousands of businesses are choosing to adopt electric fleet vehicles. However, finding the right charging solution for EV fleets can be challenging due to the high installation cost of requiring multiple charging ports to charge multiple vehicles simultaneously.

Responding to market demand, Spanish-based LEMIL, who specialise in industrial electrical equipment and installations, has developed an automated car charging station that optimizes the charging process for fleets of electric vehicles. The system can run eight charging stations with just one 100kW charger, allowing a full charge for eight cars in 8 hours. A traditional charging station would require eight high-power chargers, making the installation cost significantly higher. LEMIL’s system is much more cost-effective for small and medium companies with a fleet of electric cars.

With this system, one charger is moved along 2 x 10 metre parallel linear guides to charge each car in sequence as programmed by a KUKA robot to optimise the recharging infrastructure. Completely autonomous, the robot plugs the cable into an electric vehicle’s charging port, removes it, and plugs it into the next car for charging. Central to the system are HepcoMotion’s heavy-duty HDS2 linear guides, which smoothly move the robot and charging station along the tracks with high repeatability and precision. Specified to move at 2m/s, HDS2 positions the charging station with high repeatability and precision to charge each car. With a payload capacity of up to 68kN, HDS2 can easily manage the 670Kg payload required in this application to move the KUKA robot, electric case, and control case.

Low maintenance

With a 50-year heritage, linear motion expert HepcoMotion has gained a reputation for its high-end, low-maintenance products thanks to its V guide technology. V guide technology guarantees a long service life for bearings as they can easily be readjusted when a small amount of wear occurs, allowing the system to carry on running. Moreover, when the V bearings reach the end of their calculated life, they can be replaced individually, and not as an entire set, saving both time and money. This system has a specified system life of 10 years which HDS2 can confidently handle.

The charging station must operate 24/7 to allow company vehicles to charge constantly. Therefore, continuous operation, without the need to be stopped regularly for routine maintenance, such as re-lubrication of the linear guide, is key. Hepco specified low-maintenance cap wipers for the HDS2 guides, providing lubrication to the contact surfaces in a simple and hassle-free way with long lubrication intervals.

Ease of installation

HDS2 is highly tolerant to misalignment when setting up 2 x rail systems in parallel. This was a key consideration for LEMIL as the guides must perform on un-machined surfaces and tolerate a degree of misalignment. Hepco’s V bearing design allows the bearing to perform on uneven surfaces and cope with variances in the mounting surfaces. Parallelism of +/- 0.05mm enables minimal setup time to assemble the system accurately.

Cost effective solution

In today’s changing times, energy consumption is a key consideration for many, and this application is no exception. The drive motor energy consumption needs to be low as some potential customers will only have 220V power available at their premises. Of course, a low-drive energy consumption solution is also cost-effective to run, further meeting LEMIL’s core requirements. HDS2 is a low friction guide that does not require a powerful motor, providing a cost-effective, low energy consumption solution.

Modular needs

With plans for serial production, it was important to have a modular, scalable charging facility that could adapt to the needs of each customer’s fleet. Hepco’s HDS2 guides are suited thanks to their availability in modular lengths. The HDS2 guides are accurately machined and ended to make up butted sets, allowing LEMIL to provide for different-sized fleets. This also means that customers can easily extend the charging station if their fleet of cars increases in the future, providing flexibility and future-proofing systems.