NORD Drive Systems – designed by German precision engineers Getriebebau NORD and assembled locally by industrial solutions provider BMG – encompass modular drive configurations that ensure optimum performance of mechanical speed control for specific applications, in almost every industry. Typical applications are in water, wastewater, waste and raw materials management.

“NORD drive solutions, which meet stringent local and international quality standards, are known for reliability, energy efficiency, low noise levels, extended service life and reduced maintenance,” says BMG Electromechanical Drives division NORD Drive Systems national product specialist Johan Stoltz.

“These modular drive systems incorporate advanced drive technology and special design features to meet the precise requirements of every operation.” He notes that mixing and agitating systems are required to meet exacting demands for environmental technologies, to distribute safe drinking water, convey wastewater and circulate activated sludge.

“BMG’s NORD agitator drive systems – which easily move large masses in agitating and mixing applications – comprise an electric motor, frequency inverter, MAXXDRIVE gear unit and accessories.” The Nord MAXXDRIVE series is the only complete industrial gear unit system on the market with a one-piece Unicase lightweight housing for mixing and agitating processes, he adds.

“NORD’s helical and helical bevel gear units – available from BMG in various sizes and speed ratios – offer high operational reliability and protection against leaks through optimum sealing. The robust and rigid design enables the system to cope with excessive loads, while the short total axis spacing results in low bending torques and extended operation times for the entire drive system.”

Stoltz comments that BMG also offers a range of attachment options for integration into mixing and agitation industry applications. “We also supply numerous NORD drive components as explosion-protected ATEX versions, for safe operation in hazardous areas, including Zone 1, 2, 21 or 22.”

Meanwhile, NORD MAXXDRIVE units offer high output torques, from 15 kNm to 282 kNm and ensure reliable operation even under extreme conditions. These compact industrial gear units are designed for vertical and horizontal installation positions, requiring minimal space.

An important feature is the International Electrotechnical Commission- (IEC-) and US National Electrical Manufacturers Association- (NEMA-) approved sealless adapter for mixers and agitators (SAFOMI), which prevents vibrations during operation.

This adapter includes an oil compensation volume, so attachments and wearing parts, such as an oil tank and drive shaft sealing ring, are not necessary. This results in greater operational reliability and reduced maintenance. Existing MAXXDRIVE helical gear units with standard IEC/NEMA adapters can be easily converted for SAFOMI adapters.

NORD drive systems for agitators, pumps and mixers used in process plants are engineered with reinforced bearings and increased bearing spacing. Meanwhile, reinforced and larger output shaft bearings allow the gear unit to absorb high radial and axial bearing loads that occur during the agitating process. Advantages of oversized output bearings include quick assembly, large bore capacities, high radial load capacity and longer service life.

To enhance efficiency, BMG offers an agitator version (VL2 bearing) with increased bearing spacing and reinforced bearings, as well was a drywell version (VL3) with an additional oil drip plate and leakage or oil sensors. The bearing spacing of VL2 and VL3 versions is increased with attachments, while the gear unit size remains unchanged.

Further, coaxial drives are recommended for agitators and mixers that require a double agitator, owing to the large size of the tank. Double agitators often comprise agitator blades which rotate in one direction in the middle of the tank and a scraper blade that rotates in the opposite direction. This system is designed to efficiently remove material that is stuck to the wall of the tank and return it to the agitation process.

Stoltz notes that NORD offers the option of operating two shafts inside each other for coaxial agitators. The inner agitator is driven by the upper gear unit and the outer agitator by the bottom gear unit. The direction of rotation and the speed of the agitators are independent of each other.

He adds that NORD IE5+ synchronous motors – with the highest defined efficiency class – enhance performance in pump and conveyor applications. Notable features include a compact and hygienic design, with high corrosion resistance and easy cleaning.

For even greater system efficiency in agitating and mixing processes, BMG specialists recommend DuoDrive geared motors, which feature an IE5+ motor integrated into a single-stage helical gear unit.

With a system efficiency of up to 92%, the wash-down-capable geared motor has one of the highest efficiencies on the market in this power class, says Stoltz, adding that is also achieves high efficiency in partial load operation. Together with simple plug-and-play commissioning, this system offers a significant reduction in the total cost of ownership, compared with other drive systems.

Further, NORD’s decentralised frequency inverters are suitable for controlling pump applications. “These units save space in control cabinets, reduce costs for wiring and cables and simplify maintenance, thus increasing efficiency of the entire drive system.”

Stoltz explains that actuating the pump drives through frequency inverters facilitates the selection of different pump characteristics by simple parameter changes. Various parameter sets are directly stored in the inverter and pumps can be adapted to different media, flow rates or process requirements.

“BMG offers fully matched NORD drive systems that are tailored to the exact requirements of every customer’s application. Modular systems are easy to expand or upgrade, using a minimum of different types and sizes of components. Local assembly enables prompt delivery of drive systems and the ready availability of spare parts,” Stoltz concludes.