Mechanical systems go high-tech

March 7, 2002
Finnish engineers upgrade performance and efficiency of traditional designs.

Kone's EcoDisc elevator hoisting machine is about half the size of conventional units. It can mount between elevator guide rails and eliminate the need for a machine room above the shaft.

Hydraulic power pack from Hytar provides 3,000-psi sea water for underwater tools and remote-operated vehicles.

The compact CTX wire-rope hoist from KCI Konecranes allows close approaches to walls and roofs, maximizing usable space within a factory.

According to a recent United Nations Development Program study, Finland is the most technologically advanced country in the world, ahead of the second-ranked U.S. The study gaged factors such as the population's technical know-how, Internet availability, and the ability of a country to develop technology and put it to good use.

While the report may be somewhat subjective, Finland's dramatic economic transformation is not. The country has developed a prosperous, high-tech industrial economy when only a decade ago it was mired in recession and plagued by double-digit unemployment.

One reason for the turnaround is the emergence of telecommunications and IT, most notably Nokia, as key economic drivers. But another is that with a population of only 5.2 million, the Finns know their neighbors and competitors.


Companies in this close-knit community tend to foster a spirit of networking and cooperation in order to compete globally — this according to Pekka Pokela, director of business and technology for MET, the Federation of Finnish Metal, Engineering and Electrotechnical Industries. This networked corporate environment, coupled with an educated workforce and a long-term focus on R&D, lets even small and medium-size companies innovate and compete globally. For instance, expertise in controls, ICs, software and the like is readily available and finding its way into oldline products such as diesel engines, elevators, and industrial cranes. The result is world-class designs that feature high performance and efficiency. Here's a look at some recent innovations.

Visible smoke emitted from marine engines has become a major issue for cruise and passenger ships because most harbors are located close to densely populated areas. Helsinki-based W?rtsil? ( is a leading global supplier of ship engines and propulsion systems and decentralized power-generation systems.

The company's EnviroEngines are among the industry's most environmentally friendly and economical, according to Matti Kleimola, vice president for technology. They produce no visible smoke by optimizing combustion across the entire load range, including start up and during transient load changes.

Contrast this with conventional mechanical systems where fuel-injection pressure is a function of engine load. At engine loads below about 25%, low injection pressure leads to large fuel droplets that generate smoke on contact with combustion surfaces.

W?rtsil?'s Common Rail fuel-injection technology keeps injection pressures high and constant over the entire load range. It controls fuel droplet size and prevents contact with combustion chamber surfaces, enabling operation without visible smoke regardless of engine speed. In this system, direct crankshaft-driven, high-efficiency fuel pumps feed a 1,000-bar fuel manifold — called the common rail. The common rail supplies fuel through a volumetric injection-control unit to the fuel-injection valves. One control unit per cylinder regulates injection timing, fuel volume, and shape of the injection pattern. Electronically controlled hydraulic actuators for each cylinder control exhaust-valve timing.

EnviroEngines also use computer-controlled direct water injection to reduce nitrogen-oxide emissions. NOx results when atmospheric nitrogen oxidizes in localized hightemperature regions during combustion. Injecting water directly into the combustion chamber at pressures of 200 to 400 bar typically cuts NOx emissions by 50 to 60%.

Kone Corp. (, headquartered in Espoo, is a leading global elevator manufacturer with more than 500,000 units in service. One recent technology breakthrough is the company's EcoDisc hoisting machine. Loosely based on linear-motor technology, the EcoDisc features a permanent-magnet synchronous ac motor in combination with frequency control and lowfriction gearless construction that produces a high power-to-weight ratio.

According to Risto Kontturi, project manager for R&D, the unique axial design has a size and weight only about half that of conventional ac or dc units. This lets builders mount the EcoDisc between elevator guide rails and shaft walls, eliminating the need for a machine room atop a building.

The permanent-magnet design minimizes slip and magnetizing losses, boasts a 92% efficiency, and a 0.95 power factor that combine to reduce energy consumption. Peak starting current is 30 to 40% lower than equivalent hydraulic and traction units, saving on fusing and power supplies. High efficiency also equates to low thermal losses that can eliminate the need for external cooling.

For instance, Kone's EcoDisc-based Alta elevators run at speeds to 3,400 fpm yet offer up to 35% better energy efficiency than conventional ac or dc gearless machines. Annual savings can amount to tens of thousands of kilowatt hours for a high-speed elevator group.

On the control side, Kone has developed an elevator dispatch system based on the advanced, high-speed Genetic Algorithm controller. It selects the best possible routing for the most effective passenger service while cutting energy consumption.

With elevator banks linked by a high-speed serial communications network, the system uses artificial intelligence to "learn" traffic patterns and forecast use. Based on this knowledge, a fuzzy-logic module generates detailed models of prevailing traffic patterns. The Genetic Algorithm then compares actual traffic with prevailing patterns, together with running and waiting times. With these results the control system optimizes dispatch decisions and selects the best possible elevator routing.

KCI Konecranes (, based in Hyvinkaa, is a leading supplier of industrial and harbor cranes. Standard lifting equipment ranges to 50-ton capacity, and special cranes can exceed 1,000 tons.

One recent advance is the company's CXT wire-rope hoist ( which, says Chief Operating Officer Matti Ruotsala, reduces weight, number of parts, and assembly time by one-third, compared with previous versions with the same lift capacity. In fact, the platform hoist is said to have the smallest dimensions in the market.

The key is a mechanical design that uses a shorter, but larger-diameter rope drum. The result: a more-compact hoist that gets closer to walls and allows higher lifts with the same available headroom. A larger drum also cuts bending, fatigue, and wear of the wire rope. This improves safety and can extend rope life up to ten times over previous designs.

The unit offers high torque with low current draw and features integrated motor and inverter controls, an industry first in a standard package. Stepless speed control not only enhances operator productivity, it helps keep the load from swinging.

Control electronics and software are embedded in the CTX hoist components. The system features advanced overload and thermal protection for hoist motors, and it monitors loads, operating hours, number of starts, hoisting cycles, average load, and remaining life of the hoisting brake. An interactive digital display on the control pendant makes monitoring these parameters easier.

Water-hydraulic systems are gaining interest because they minimize environmental damage in the event of leaks. In addition, water is readily available, does not burn, and is less expensive than oil. But to match traditional oilbased systems in terms of controllability, reliability, and cost, water-hydraulics requires better components, materials, and intelligent controllers.

The Institute of Hydraulics and Automation (IHA) at the Tampere University of Technology ( is a major research center specializing in water-hydraulic technology. IHA employs 13 professors and more than 50 researchers, and has an expansive test laboratory for both oil and water systems. Successful offshoots of the Institute's work include water-injection systems for marine engines and water-jet cutters for the paper industry.

Current water-hydraulic research centers on three areas, says Prof. Kari Koskinen. A motion-control group focuses on position control using on/off, proportional, and servovalves, as well as systems that provide velocity and force control. A second water-quality group focuses on filtration systems and microbiology research.

A third group is devoted to low-pressure water hydraulics that operate at pressures less than 50 bar. The systems are intended to combine the low cost of pneumatics with the controllability of traditional hydraulics — in essence, forming the basis for a new technology between pneumatics and hydraulics. Applications are envisioned in paper, food, and consumer industries.

One spin-off of IHA's efforts is Hytar (, based in Tampere. The company manufactures a range of water-hydraulic pumps, valves, cylinders, and motors that match the performance of oil-based counterparts. Expertise, according to Olli Pohls, manager for water hydraulics, includes areas such as poppet and ceramicspool technology and noncorroding materials and coatings for water-based systems. The company has supplied systems to steel and power plants, and has developed water-cutting machines and hydraulic test stands.

One development is a sea-water hydraulic power pack that supplies high-pressure sea water to subsea tools, pipe and cable-handling systems, and remote-operated vehicles. No reservoir is necessary, as water enters directly from the surrounding sea. A three-phase suction filter system — prefilter, hydrocylone, and self-cleaning filter unit — delivers 5 m sea water. Flow is to 60 lpm at pressures to 3,000 psi over ambient. It operates at depths to 6,000 m.

Sea-water systems for underwater applications are considerably simpler than conventional oil hydraulics. Water-ingression into the fluid-power system no longer poses a problem. They eliminate the risk of oil leakage, and do not require oil tanks and umbilical hoses to and from the seabed.

MET, the Federation of Finnish Metal, Engineering and Electrotechnical Industries (, serves as a catalyst for expansion among its 1,140 member companies. MET's mission is to improve the competitiveness of member companies, promote their interests, and provide a forum for networking and cooperation.

It also influences economic and industrial policy, tracks production trends and industrial outlook, and works to ensure the availability of a skilled workforce.

Another goal is to influence national research. One such program MET is promoting is "Machinery for the Future," in development with Tekes (, Finland's National Technology Agency. Four main areas of focus will be intelligent machines and systems, advanced structures, life-cycle service, and reliability and sustainable development. Funding for Machinery for the Future will be split equally by Tekes and private industry participants. The goal is to invest about $50 million over the next five years.

About the Author

Kenneth Korane

Ken Korane holds a B.S. Mechanical Engineering from The Ohio State University. In addition to serving as an editor at Machine Design until August 2015, his prior work experience includes product engineer at Parker Hannifin Corp. and mechanical design engineer at Euclid Inc. 

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