Posted to News on 15th May 2008, 14:58
SEW-Eurodrive launches next-generation modular AC motors
SEW-Eurodrive is launching the DR AC motor series that combine energy-efficient and standard motors in one design. In addition, the company says that, for the first time, the BE brakes allow for up to three different sized brakes to be mounted on one motor size, and encoders are mounted behind the fan rather than on the B end, resulting in a shorter overall length for the motors.
All motor configurations are available for all efficiency classes. In addition, they comply with all worldwide standards and already fulfil the forthcoming IEC standard. DR series motors are also fully interchangeable with the existing DT/DV series motors.
The Standard Efficiency (IE1) four-pole AC motors are designated the DRS models and feature a die-cast aluminium or copper rotor cage. These motors are available in size 71 and larger, with power ratings from 0.37-200kW.
High Efficiency (IE2) four-pole AC motors are designated the DRE models and feature a die-cast aluminium or copper rotor cage. These motors are available in size 80 and larger, with power ratings from 0.75-200kW.
Premium Efficiency (IE3) four-pole AC motors are designated the DRP models and feature a die-cast aluminium or copper rotor cage. These motors are available in size 90 and larger, with power ratings from 0.75-160kW.
Starting with the standard motor (IE1 or EFF2), the energy-efficient motor of the same power (IE2, High Efficiency or EFF1) is one stage larger than the standard motor. An IE3 or Premium Efficiency motor with the same power is two stages larger.
Brake options
Inverter-operated and high-efficiency motors require smaller holding and braking torques, respectively. Conventional motor brakes are often too large for these applications. However, depending on the application requirements, DR motors can be combined with different sizes of BE brake. On motors size 90 and larger, the brake itself is mounted on a friction plate, which only has to be attached to the end shield; without opening the motor, the brake can be demounted and replaced by one of the same or different size.
Another innovation is that the automatic disengaging or lockable manual brake release can be mounted in any of four alternative positions. This is in contrast to traditional designs that enable the brake release to be in one position only.
Built-in encoder
DR series motors and brake motors can be supplied with - or retrofitted with - three types of encoder, which are mounted between the end shield and the fan. This gives a compact motor design in which the encoder option adds nothing to the overall motor length, plus the encoder is protected from physical damage.
Gearmotors
Of course, SEW-Eurodrive can also deliver the motors ready-assembled with a gearbox. Six single-stage and fourteen two- and three-stage sizes are available, covering a torque range from 50-18,000Nm. Helical gear units offer an optimum ratio between performance and space requirements, and the company claims that the fine graduation and variety of torque ratings and gear ratios is unmatched. They can also satisfy demands for high output speeds or low weight due to the many available sizes. If space is restricted, parallel shaft helical gear units can be supplied, with a choice of mounting options.
Alternatively, compact helical-bevel gear units suit applications that require space-saving installation. At the same time, they offer a powerful torque range from 200-50,000Nm, with a remarkably high degree of efficiency of more than 96 per cent in both directions of rotation and for any input speed. The gearing is designed for high endurance and therefore makes for a high-torque, wear-free drive.
Helical-worm gear units are tailored to suit the application's torque and speed requirements, saving installation space and costs when implemented in simple applications. In addition to the large gear ratio in the worm gear stage, the helical-worm gear units also offer a significantly higher level of efficiency than pure worm gear units. Power is transmitted linearly to the drive shaft and the torque shocks are reduced - resulting in low noise levels. Their torque range runs from 92-4000Nm.
Spiroplan right-angle gearmotors are available in power ratings from 0.09-2.2kW and output torques up to 180Nm. Wear-free gearing ensures very quiet operation. In combination with the compact design and the lightweight aluminium housing, the noise level is exceptionally low. The oil fill is independent of the mounting position, which means the Spiroplan gearmotors can be used in any orientation while requiring almost no maintenance. The gear ratio range offers a very high degree of variability with respect to output speed and optimised mechanical efficiency.
To complement the standalone motors and geared motors, SEW-Eurodrive also offers Movidrive, Movitrac and Movimot frequency inverters and inverter drives.
For more information about the DR motors, visit www.sew-eurodrive.com/support/documentation_result.php?gruppen_id=A28.
