Driving the future forward with EV Motor Busbars


The adoption of Electric vehicles (EVs) has surged in recent years, prompting advances in motor technology. This is true for almost every component within an electric motor and one such advancement is the use of stator busbars.

What are Motor Stator Busbars and how are they different to cables?

An EV (electric vehicle) motor busbar is a component of the electric motor used to power the vehicle. Busbars are typically made of solid metal bars, usually copper, and are used to transfer high current and high voltage electrical power from the battery to the motor. They are designed to be compact and flexible, allowing them to fit into the limited space available in the motor while also being able to withstand the high electrical loads. The busbars play a critical role in the efficiency and performance of the electric motor, making them an important component in the design and manufacturing of EVs.

While cables have traditionally been used for this purpose, busbars offer several advantages over cables:

  1. Compact size
  2. Design Flexibility
  3. Better Resistance
  4. Lower Lifetime Cost

However, manufacturing EV motor busbar nests, which are groups of interconnected busbars used in the electric motor, has typically been a complex and time-consuming process. The traditional method involves manufacturing individual busbars seperately and then assembling together to form the busbar nest, which can lead to misalignment of the busbars and decreased motor performance.
Moreover, the process requires multiple tools and mouldings, which can increase the cost and complexity of manufacturing.

How does the Low-Pressure Moulding process work for Motor Busbars?

Overmould has recently been working on a customer project involving the low-pressure moulding of high voltage EV motor busbar nests. Traditionally, these have been potted or high pressure moulded as individual bars and then aligned/assembled afterwards to provide a complete nest. This requires multiple tools and mouldings which increases cost, complexity and the takt time of the end part.

Overmould’s low-pressure moulding process provides several advantages over the traditional method of manufacturing busbars. It allows you to mould the multiple busbars (in this case three) in one single moulding. This creates a “single part” at the end of the process which means that further production stages are simplified. Not only does the moulding keep the parts together in the correct location, but it is also an incredible insulator capable of withstanding thousands of volts. This means that no additional insulation is required between the busbars prior to mould.

Using the low pressure moulding process decreases cost, complexity, and takt time, making it an attractive solution for businesses looking to enhance their production efficiency. The great news is that this same process can be applied to many different variants of busbars, from single parts to multi-part assemblies in varying sizes and shapes, driving the future forward with EV motor busbars.

If you are facing similar challenges in your manufacturing, we encourage you to get in touch with our team to learn more about our expertise and how we can help you drive your technology forward.