Mechatronics puts intelligence in the drive

Following on from the MF motor, which was originally developed specifically for speed-controlled operation with frequency inverters, came the Smart Motor. The Lenze Smart Motor essentially allows fixed speeds to be set at will in applications, although in fact it offers a range of other advantages. The company describes the Smart Motor as exemplifying intelligent, mechatronic solutions; in terms of using silicon instead of copper or "intelligence instead of a battle of materials", with electronics being an integral part of the motor. Because it is designed completely differently to other motors, the Lenze Smart Motor offers a range of advantages in terms of both dimensioning and energy efficiency. One of these is that it will not require conversion to meet the IE3 regulations in 2015-2017, while in fact occupying much less space in comparison to conventional, mains-operated IE2 and IE3 motors. In fact, according to Frank Maier, a member of Lenze's executive board, the size and light weight of the Smart Motor mean an energy saving compared to using IE3 motors that are so heavy that, he claims, they can sometimes mean the use of even more energy than the models they replace. Equally, the Smart Motor offers precise dimensioning to the maximum torque, because of which, it is able to optimise its energy efficiency in partial load operation. The Smart Motors' smooth start is another plus. Here, Lenze undertook experiments using the motor and a geared equivalent in a water tank to show the difference in vibrations between the two. Needless to say, the Smart Motor barely caused a ripple in the tank. Now, to complement the Lenze Smart Motor, the company has unveiled a range of three new gearboxes. Designated the g500 range, these offer efficiency rates of between 94% and 96%, much lower weight and a more aerodynamic design. Developed to transform motor speed into torque as intelligently and accurately as possible and due to make their debut at the SPS/IPC/Drives trade fair in Nuremberg, the g500 range again offers a number of key advantages. These include exact dimensioning to the application by an especially fine torque gradation possible, high torque density and elimination of interference contours. The gearboxes' considerable weight reduction is achieved by the use of aluminium and optimisation of the housing by means of Finite Element calculation. This weight reduction is significant – as can be seen from the fact that the model it replaces – the GFL06-2M, while offering the same torque (660Nm), is 7900ccm in volume and 40kg in weight. By contrast, the comparable g500-S660 model has a volume of just 6050ccm and a weight of just 23kg – improvements of 20% and 42% respectively. This improvement is partly a consequence of using aluminium in the gearboxes' construction, but also of a more aerodynamic construction, which both improves torque density by approximately 20% and eliminates interference contours, making integration into the machine much easier. The weight reduction achieved with these units has very real consequences in application, as with four or five gearboxes being used, a 60kg reduction in weight becomes possible. Such a weight reduction saves 10,000 kWh of electrical energy per year, which is equivalent to saving €1,500 per annum. "Intelligence is all about rethinking existing solutions to suit how they are used in actual applications, and bringing them to life in a way that offers maximum benefit to mechanical engineers and plant operators," explains Rune Friis-Knutzen, Head of Strategic Product/Market Development Electromechanical Drives at Lenze. With the g500 gearbox range, Lenze is proving that there is still valuable potential for new developments in the field of electromechanics. The specialist in Motion Centric Automation has succeeded in developing a finely-tiered series of gearboxes with an efficiency of over 94% across the entire transmission range. "We went right back to the drawing board and asked ourselves some serious questions about everything we've achieved so far," notes Rune Friis-Knutzen, before adding: "As the losses are so minimal, the motor has less energy to generate, which improves the bottom-line efficiency of the entire system. What's more, the lower level of generated heat increases the overall service life." These successes have been made possible as a result of working with the latest calculation and simulation methods throughout the development process. The g500 range essentially represents Lenze's next step in pursuing the objectives it had already set out with its Lenze Smart Motor: to maintain the simplicity of an AC motor and use improvements in design to eliminate known imperfections – with the ultimate aim of producing a high-performance, efficient solution. One of the outcomes of taking this broader view of the mechatronic elements is that the speed of the Lenze Smart Motor can be adjusted directly on site simply by using a smartphone app and near field communication (NFC). As a result, just one variant of the equipment is enough to cover motor speeds of between 500 and 2600 revolutions per minute at a constant torque. With this extensive speed range already well established, the new g500 gearboxes are now adding yet another dimension by enabling a huge range of possible speeds and torques to be covered with just one type of gearbox motor. Not only that, but the high levels of efficiency offered by the Lenze Smart Motors and gearboxes also offer clear benefits when it comes to energy efficiency, with the units already conforming to efficiency standards that will apply in the future. Besides the Lenze Smart Motors, the g500 gearboxes can also be combined with the IE2 MH three-phase AC motors, the inverter-optimised MF motors, and the MCA and MCS servo motors from Lenze to create packages that are intelligently tailored to specific applications. The helical, helical-bevel and shaft-mounted helical gearboxes will be coming onto the market in two phases: Lenze is starting with the smaller sizes of 45 to 600 Nm in a newly-constructed aluminium housing, before launching gearboxes with higher ratings of up to 13,000 Nm (produced in cast iron) roughly one year after that.