Luvata has been manufacturing custom-made copper hollow conductors for nearly sixty years. When high magnetic fields are required, the magnetic winding is made from internally cooled hollow sections. While the majority are still looking for square hollow conductor with a round or rectangular cooling channel, the demand for different outer dimensions and hole sizes is growing.

Applications

Tailored Hollow Conductor Solutions

Copper Conductors in Different Shapes and Sizes

Our long history in making hollow conductors has given us thousands of tools for creating most sizes of conductors with very short lead times without tooling costs. The sizes start from 3 x 2 mm (< 0.07 kg/m) and continue up to above 100 mm in width (>30 kg/m). We also supply conductors in small quantities for testing and prototype purposes.  

Square Copper Tubing Solutions

Through our square copper tubing solutions, we facilitate the construction of efficient and affordable particle accelerators, plasma research devices, MRI scanners, and ion implantation units for our customers. The rectangular and square tubing shape provides a better fill factor compared to round tubing. An equal amount of copper can be formed into a coil within a smaller space, which is especially advantageous in applications where coil size needs to be optimized.

Rectangular and square copper tubing shapes also provide a larger surface area compared to round conductors, making the coil formation easier. The larger surface area not only helps in the formation of the coil but also increases its stability. The greater contact between windings reduces the risk of movement or shifting compared to round shapes.

Hollow Conductors for Induction Furnaces

Our copper hollow conductors are widely used in induction solutions because of their abilities to facilitate cooling. What makes our hollow conductors special is that almost everything in the conductor can be customized: its shape, size and wall thickness. Read more about the usage of our hollow conductors in induction furnaces:

Stator Direct Cooling

Our hollow conductors provide new possibilities to cool down electric motors. The internal cooling hole on the stator windings enables efficient thermal transfer out from the core – exactly from the source where the heat is generated. Cooling with air improves the performance significantly and liquid cooling even more. As a result increased power and torque are achieved by direct cooling with Luvata’s hollow conductors.

Direct Versus Indirect Cooling

In electric motors, the current flows in the windings, which are made of copper because of its low resistance. Electrical losses are an unavoidable obstacle and increase with the amount of current; for example, doubling the current quadruples the losses, which increases heat in the motor. In addition, magnetic losses heat both the stator and the rotor, further increasing the heat load. This heat can be extracted by direct or indirect cooling. The big benefit of direct cooling is that it treats the heat where it is generated, in the winding itself instead of in the housing. Effective cooling of the stator also ensures a lower rotor temperature, enabling the use of less expensive lower temperature graded permanent magnets.

The Benefits of Direct-Cooled Electrical Motors

Direct cooling offers the highest power density for an electric motor – especially continuous power output – alongside excellent efficiency over a broad range. Partial load is the most realistic use case for an electric motor, and tests conducted have shown that a direct-cooled motor offers approximately twice the power output at peak load and three times the power output at continuous steady-state operation compared to a standard, indirect-cooled motor.

The higher efficiency of direct-cooled motors means that smaller power units can be used in EVs, saving both weight and costs. It also enables the use of electric powertrains in larger vehicles such as trucks. Direct-cooled motors can use standard, cost-effective materials, including magnets, providing higher performance at a lower cost – a key enabler for the wider adoption of EVs.