J series from Loher have a modular cooling design featuring double-flow inner cooling for a high power density and a homogeneous temperature distribution.
2 versions are available:

Mounted air-water heat exchanger

(type JHWP–... for roller bearings / JHXP-... for sleeve bearings)
Heat exchangers specifically coordinated for this series guarantee optimum cooling. The motor power loss is dissipated through the cooling water and is therefore de-coupled from the ambient temperature. The heat exchangers are available in a wide variety of versions with single and double pipe types. The high quality materials used for the cooler are adapted to the particular requirements.

Mounted air-air heat exchanger

(type JHRP–... for roller bearings / JHQP-... for sleeve bearings)
The motors are equipped with air-air heat exchangers. The cooling pipes are manufactured out of galvanized steel; stainless steel versions are available for especially aggressive atmospheres. In conjunction with the Ex p system harmonized for the application, these motors can be used in Zone 1 even up to the highest power range.