Manufacturers of industrial gearboxes and geared motors need to address the market demand for higher operating efficiency and global availability, according to Philip Crowe, Marketing Manager of Bauer Gear Motor GmbH.
The need to convert customers from super price-sensitive buyers to intelligent, specification and purchasing entities remains an ongoing challenge for any quality brand manufacturer of power transmission products. Both OEM manufacturers and MRO distribution channels will demand the lowest purchase price possible, often because the results of using a poorer quality product will only happen after the standard warranty period has run out on a particular machine or replacement, therefore shifting the cost burden to the end user every time.
When cheap electric motors burn out, poor-quality gears wear and cheap bearings seize, it is most often the buyer that says ‘at least they were cheap’, not the engineer, or the production manager and the maintenance department who are secretly delighted there is something for them to do, justifying their existence. Accountants also cannot argue with something that is broken and needs repairing; the money has to be spent.
The good news for quality manufacturers of gears and geared motors is the rising cost of manufacturing. With today’s energy costs, and at the speeds and volumes of production, the high cost of downtime means stoppages cannot be tolerated and the need to reduce energy costs and show corporate efficiency targets are being driven by political and environmental reasons.
It is hard to make a cheap motor and gearbox that is very efficient; to reach 95 per cent efficiency in a mechanical gearbox and an IE4 super premium efficiency rating for an electric motor takes good design, top quality materials and highly advanced manufacturing techniques.
In some applications, where a geared motor is used rarely and is in a non-critical application in an unchallenging environment, then a cheap, inefficient geared motor might suffice. But for every other application, efficiency and reliability are absolutely vital, and this is true for the majority of industrial applications.
Bauer Gear Motors PMSM (permanent magnet synchronous motors) already fulfil the requirements of the future IE4 (Super Premium Efficiency) classification. The PMSM series employs a highly efficient design of rotor that integrates embedded permanent magnets made from rare-earth material rather than the squirrel-cage rotor found in more conventional induction motors.
This design offers a number of key benefits. It reduces heat losses from the rotor by 100 per cent, total losses by approximately 25 per cent, and increases total efficiency by 10 per cent or more compared with the most efficient conventional motors. For the PMSM user, this improved performance translates into lower total cost of ownership, a reduction in CO2 emissions, and ongoing savings that buffer against future increases in energy costs.
Applications in explosion hazardous areas are currently exempt from the EU regulations on minimum energy efficiency because, clearly, explosion protection takes precedence over energy savings. This puts industries such as Oil and Gas and Mining at a disadvantage when trying to improve overall site efficiency. As such, Bauer has developed an Ex rated IE4 PMSM motor, which offers the same levels of energy efficiency as the rest of its range as well as ATEX classification for Zones 1 and 21.
Keen to prove the real-life savings potential of using a PMSM, Bauer was a willing volunteer to take part in a direct product comparison test which was carried out at a live and operational waste water treatment plant in Landsberg am Lech, South West Germany. The disc thickener which was used is in continuous operation for seven hours per day, seven days a week, so provided an excellent real-life test opportunity.
Prior to the PMSM being installed, an inverter drive was retro-fitted to the original system in order to ensure an accurate comparison. The frequency inverter was programmed to monitor the loads on each motor to ensure that they ran at optimum efficiency.
To ensure that any differences in efficiency could be attributed to the motors, each drive used the same Bauer gearbox, which had a reduction ratio of 381, 5:1 at 94 per cent efficiency. It was found that with the frequency inverter installed on the original ASM created 2.62Nm torque at 1350rpm and operated with 61.5 per cent efficiency using 0.26kW/H.
Having completed the measurements on the ASM, the PMSM was installed. The new product from Bauer created 3.5Nm at 1500rpm and operated with 87.7 per cent efficiency using only 0.16kW/H. The energy savings from installing the PMSM yielded a 40 per cent saving in energy use over the ASM with the same inverter drive installed.
Bespoke or standard?
For OEMs and design engineers one of the hardest decisions when specifying parts for a new machine is making the choice between bespoke or standard components. Bespoke options may increase the purchase price, while standard components will often involve some degree of engineering compromise. Bauer believes with flexible, modular manufacturing techniques that a bespoke gearmotor can be created for a cost that outweighs the difficulties of integrating standard products into non-standard applications.
Special Serial Demand products are designed completely from the ground up, meaning that they often look nothing like Bauer’s standard product range. Increasing customer demand for the service shows how bespoke is another theme that is moving the purchasing decision away from piece cost and more towards TCO.
Having an extensive range to support the custom-build service is also proving to be an important factor when it comes to specifying geared motors for large projects. To be a total supplier means that the burden of responsibility for compatibility and system performance can be shouldered by the power transmission supplier, aiding project costs and delivery times.
A large hospital complex, for example, can often resemble a small town in its size and complexity; many separate wards are joined by a narrow corridor system where the smooth transfer of supplies is often interrupted by busy doctors and nursing staff. One of Europe’s largest hospitals has solved the problem with an automated underground mono-rail that supplies medicine, food and linen with minimal effort and at low cost. Bauer geared motors drive the vehicles and operate the track points for the 6.7km of tunnels.
The supply vehicles need to accelerate smoothly to a pre-determined velocity, even when loaded with heavy supplies, and so Bauer’s BG series of helical geared motors were used as they offer torque values of up to 18,500Nm with high output speeds. The motors were easily integrated with an inverter to ensure that the acceleration curve is constant in every journey. The gears are designed with ingress protection of up to IP66 and lubricant changes are only required after 15,000 operating hours, which is a useful feature for an application located underground.
Choice and flexibility
At various stages throughout the rail network the points are driven by Bauer BF shaft-mounted geared motors, BK bevel geared motors and BS worm-geared motors for lower speed applications requiring higher torque values. The choice and flexibility of the Bauer range proving that there is a suitable model for most applications, another advantage which wins over more limited supply partners.
Market growth and long-term survival is not just focussed on the German market, even for a company originating in Germany. In addition to a strong market position in Germany, Bauer already has a well-established sales network in Western and Eastern Europe, Russia, China and more recently the United States, where parent company, Altra Industrial Motion, is headquartered, providing the company with unprecedented access to the key North American market.
Purchase price is, however, always important and no company can afford to lose sight of that. Global supply provides volume, which in turn provides profit and investment capital, the life-blood of any engineering company. The sales proposition to global markets is that Bauer offers the quality and reliability benefits of a German-engineered product, across a wide range of geared motors: helical, bevel, shaft-mounted, worm, overhead monorail and integrated inverter-driven units (including IE4 options) for general applications, plus ATEX-rated units for use in hazardous environments, and the innovative Aseptic Drive and Clean Drive geared motors for food, beverage and pharmaceutical applications.
To learn more about industrial gearboxes and geared motors from Bauer, please visit www.bauergears.com.