Exhibitors from around the globe were touting innovations that built on a theme of “smart efficiency” at last month’s Hannover Fair in Germany.
Engineers at B&R Industrial Automation, Roswell, Ga., are going beyond right-sizing motors and drives for higher efficiency. They’re looking at secondary components as well. “Many individual measures can save large amounts of energy with relatively little effort,” says Alois Holzleitner, Business Manager for Motion Control at B&R.
For instance, complex machines with lots of motion often dissipate kinetic energy as heat in braking resistors. The B&R ACOPOSmulti servodrives, via a dc bus, can store braking energy in capacitors and reuse it later, saving up to 30% of the energy needed for machine motion. Users profit not only from better efficiency, but also from cooler control cabinets because the resistors generate less heat.
Equipment can also save energy by correcting the total power factor (TPF) to 1.0. Conventional inverters with a small TPF tend to consume more power, which leads to unnecessary losses in supply lines and transformers. The ACOPOSmulti active power supply ensures energy is used more efficiently and saves up to 50% of infrastructure costs by reducing the size of wires, feed components, and fuses.
Control-cabinet cold plates are another option for greater efficiency, but in this case it’s recycling heat generated by the servodrives themselves. Circulating fluid and a heat exchanger capture the waste heat, so it can be reused as plant or process heat. And cold-plates eliminate the need for separate cooling devices in the control cabinet, adding to savings, says Holzleitner.
New CVI cylinder-valve units developed by Bosch Rexroth, Lexington, Ky., are sized to maximize flow, performance, and energy efficiency, and come fully assembled and tested. An online configurator lets engineers quickly size and spec CVI assemblies from a family of components and accessories. ISO cylinders with diameters to 125 mm can be combined with valves from five different series to create user-specific modules.
This ensures compatibility among components. And it improves energy efficiency, with compressed air savings exceeding 50% in some applications, thanks to flow rates sized to an application’s precise needs and short tubing connections with minimal losses. An optional pressure regulator between the main valve and cylinder provides low-pressure return strokes for additional compressed-air savings. Stop valves are also available to prevent unintended cylinder movements.
The configurator also generates technical documents, including CAD data, dimensioned drawings, and individual part numbers for quick ordering and delivery. The CVI is suited for decentralized pneumatic tasks such as process controls and for applications with limited space or harsh environments.
Bucher Hydraulics, Frutigen, Switzerland, is addressing efficiency, environmental, and safety concerns with a line of products termed Ecodraulics. Energy conservation is a key aspect, but sustainable use of resources gets equal consideration.
Ecodraulic products are evaluated to ensure they yield an ecological benefit, such as: low energy consumption; low emissions, including noise or lost heat; or protecting the environment in some fashion. Customized designs that entail compact construction, high performance, and long-term durability are other aspects of Ecodraulics.
One example involves replacing proportional valves with frequency-controlled QXM drives in press brakes. This reduces energy use by up to 60% compared with conventional hydraulic controls. It eliminates hydraulic no-load losses and the drive runs considerably quieter. And it generates less heat, so the amount of oil in the tank can be reduced by 80%. This saves fluid and prolongs the life of hydraulic components.
The same technological approach holds for elevators. Ecodraulic drives are sized to generate just the hydraulic energy required. Further, using accumulators permits regeneration that lowers energy consumption. Higher initial investment costs can be quickly recovered in frequently used elevators, like the ones at railway stations and airports.
igus, East Providence, R.I., has expanded its line of its TwisterBand energy chains. The compact cable carriers for power and data lines, as well as hose and tubing, freely turn through 3,000° of motion with minimal friction and wear.
The chain’s light weight means low centrifugal forces, permitting rotary speeds of up to 720°/sec in both horizontal and vertical installations. IDs range from 50 to 100 mm and ODs from 120 to 300 mm.
The new BEARINX-online Easy Friction program from the Schaeffler Group, Ft. Mill, S.C., can calculate rolling-bearing friction and energy efficiency in real-world applications. It also calculates bearing life according to ISO/TS 16281. This lets engineers investigate potential energy savings or downsizing options early in the design phase.
The software looks at internal load distributions and contact pressures of the rolling elements on raceways and carriers. The program is based on a friction calculation theory that, in turn, is based on algorithms that have been confirmed by comprehensive testing.
Simple menu navigation lets users specify bearings and operating conditions. A database contains geometric data for INA and FAG rolling bearings. Operating data includes shaft loads and speeds, internal clearance class, and axial preload of the rolling bearings, as well as details on lubrication and cleanliness. Results are displayed immediately, and input data and calculation results are documented in PDF files.
In addition to load distribution and rating life, the software calculates frictional torque in rolling bearings and, thus, the power loss of entire shaft assemblies or transmissions. This makes it easier to specify bearings with the best friction characteristics early in product development.
The free, online software launches in mid-2011. Users who preregister at: http://BEARINX-online-easy-friction.schaeffler.com will receive email notification when the program is available.
To reduce friction and save energy in fluid-power actuators, Plymouth, Mich,-based Simrit has combined the advantages of elastomers and PTFE in its new Low-Energy dynamic piston seals. However, this required a new manufacturing process to reliably bond PTFE to a variety of seals. Freudenberg Simrit has reportedly perfected this complex manufacturing process, which securely attaches PTFE foil to an elastomer or elastomer-metal composite.
The result is a general-purpose, PTFE and D-ring piston seal that can be used in most any application. The new seals reportedly lower the benchmark for all previous friction-related limits—including initial and running friction, non-linear behavior, and hysteresis, and they also have high heat resistance.
Mounting is simple and independent of orientation, much like an O-ring. Moreover, seals won’t twist. They also resist gap extrusion and can be made in a broad range of designs and diameters.
Wittenstein, with U.S. headquarters in Bartlett, Ill., debuted its eMobile drives for electric vehicles. The units include a motor, gearhead, and power electronics and come in three sizes for small vehicles, mid-range or racing cars, and commercial vehicles.
The high-efficiency motors have high force and torque outputs for their weight, according to the company. Gearheads are built from light materials that reduce weight and further improve power density. And the compact electronics precisely control and monitor the drive. The result is a high power-to-weight ratio – for instance, 2 kW/kg in the mid-range version.
Another key, say company officials, is that mechanical and electrical components are precisely sized and matched to best work together. This improves power-conversion efficiency to both improve road performance and extend the range of EVs.
A modular building-block approach lets users economically construct drive modules for different vehicle types and performance classes from a range of components, with the help of simple, standard interfaces. Additional drives for other vehicles will be available in the near future.