Ultracompact water-cooled motors

Paul Boughton

Ultracompact water-cooled motors, which enable engineers to save space by delivering the same power in a frame size one or two times smaller than ordinary water-cooled motors, have been introduced by WEG.

Designed by WEG’s new subsidiary, AKH (Antriebstechnik KATT Hessen) – acquired in late 2014 - the UTTW and USTW series feature an innovative cooling system and offer 1.5 to 2.6 times the power density of conventional water-cooled motors, ensuring reduced heat dissipation and thus a smaller frame size. These characteristics enable them to achieve high torque and maximum speed of up to 12,000rpm in a very small package.

Saving space and reducing energy are top of the agenda in today’s manufacturing world, especially when it comes to applications such as electric vehicles, mobile machinery and test stand equipment as well as machine tools, shipboard equipment and agricultural and forestry machinery. 

With this in mind, AKH water-cooled motors feature a cooling system - with cooling elements integrated into the stator laminations - which allows the dissipated heat to be removed directly at the source. This feature dramatically reduces the size and weight of the motor by eliminating the concentric steel tubes of the water jacket surrounding conventional water-cooled motors. For example, an AKH water-cooled motor with 300 kW rated power in frame size 180 (type UTTWp 180.4-4) is equivalent to a conventional motor with water jacket cooling and the same rated power in frame size 315.

The AKH water-cooled motors are energy efficient, reaching efficiency levels up to IE5, enabling users to optimise their processes and they ensure very smooth running and low noise levels, which is vital for users working in confined spaces. 

The induction motors in the UTTW series cover the power range from 24 to 240kW with a shaft height of 112 to 180mm, while the UTTW(p) series of premium induction motors - equipped with a water-cooled rotor - covers the range up to 300kW with the same shaft heights. The water-cooled synchronous motors in the USTW series feature the same compact design and are available with rated power of up to 440kW.