Drives and hydraulic aggregates are used in machine construction, raw material production, maritime and many other areas. In hydraulic systems oil transfers power and motion, in drives it’s a vital lubricant. Both as a power transfer medium and lubricant oil is heated by friction losses during operation. Since the viscosity of the oil changes along with the temperature, precise temperature stabilisation using coolers is a vital requirement for systems and drives for consistent power. The temperature further affects the ageing behaviour and the life of oils. Due to the unlimited supply, ambient as air as the coolant for heat dissipation. However, since the air temperature fluctuates throughout the year and oil flow can also fluctuate, the heat exchanger required to stabilise the oil temperature must be carefully configured. The BLK series features efficient cooling matrixes, an easy to maintain design and energy-efficient fan motors.