The State Of Shaftless p.26

By: JIM ROSENBERG PRESS MAKERS' work with what would become shaftless design dates back to independently driven reelstands and subsequent experimentation in the 1970s and '80s.
Success awaited advancements on the electrical side, particularly improvements in AC motors and development of the powerful and affordable digital processing that is the brains behind the electronic synchronization required by a press lacking a central drive system.
At the 1990 DRUPA exposition, MAN Roland demonstrated a shaftless drive system on a commercial press. The next year, Koenig & Bauer-Albert introduced motor-per-unit DC drives (using digital voltage converters and synchronizing shafts) on its Journal press.
Three years later, Wifag offered individual AC "gearless transmission drive" for rotating elements on its OF 370 newspaper press (E&P, July 1, 1995, p. 18). The next year, again at DRUPA, MAN unveiled a shaftless Geoman press and offered a shaftless version of its Colorman.
All three companies soon had buyers for shaftless presses in Europe, where they later were joined by U.S. press maker Goss Graphic Systems. Today, presses of various sizes with shaftless drive systems of one type or another also are or soon will be installed in North and South America, Asia and Africa (see story, p. 34).

DISTRIBUTING DRIVES
Presses differ in number of motors used and the ways they transfer motion to press elements. Press makers disagree over which had the first shaftless design, which design is truly shaftless, the practicality of independently driving each print couple and the manner by which one or more elements may be indirectly driven (e.g., belts, shafts, gears).
MAN newspaper sales vice president Vince Lapinski equates "true shaftless" with one motor directly driving each print couple by means of the former's rotor flanged to the latter's blanket cylinder. According to MAN, impression cylinder vibration is minimized by directly driving the blanket cylinder.
In any event, by employing a centralized control system relying on separate motors to rotate separate elements, all designs dispense with the need for a centralized drive system relying on a main shaft.
While Lapinski argues that the greatest benefits of shaftless reside in the control, flexibility, efficiency and economy afforded by a design that powers each rotating element with its own motor, to varying extents, MAN and other press makers offer versions of shaftless presses with fewer motors.
Indeed, a MAN Roland engineer remarked last fall that while eliminating the main shaft makes sense, it may also prove sensible to retain vertical shafts as backup in the event of motor failure in a tower.
As it happens, MAN's first U.S. order for a shaftless press calls for one motor for each four-couple H-type printing unit (see story, p. 17).
KBA does not build presses with motor-per-couple drive systems, arguing that few newspapers have a need for the number of page changes (and the corresponding press crew size) that would justify such a design (see E&P, Oct. 5, 1996, p. 29).
Goss makes much the same point, saying that those who ordinarily rely on simpler press configurations will save little time and money by running a motor-per-couple shaftless press. At last year's Nexpo it questioned the wisdom of running a couple without the backup supplied by a vertical shaft. Today, however, Goss offers per-couple shaftless, saying in its literature that the latest drive technology is reliable enough that it "should preclude the risk of a single couple fault interrupting print production."
Further, in its "distributed shaftless drive," the pair of print couples at each level of a tower has its own motor, and all motors in each tower are connected by a vertical shaft, which can employ a clutch to run two webs through the tower. Separated towers are electronically synchronized. While this still obviates the inching motor, it requires conventional circumferential register adjustment.
Just for a mid-size press, said MAN engineer and manager of newspaper press activities Hans E. Mamberer, "we have to synchronize up to 100 drives," and about double that number for a large press. "You cannot develop different drive systems for different configurations," said Mamberer.
Beyond the additional motors are the controls and diagnostics essential to keeping the electrically more-complex systems operating properly, for which reason most press makers have partnered with motor suppliers to develop entire systems ? for example, Goss traditionally (but not exclusively) with Rockwell Automation Drives Systems, MAN Roland with Germany's Baum?ller N?rnburg and Swiss manufacturer Wifag with Swiss-Swedish Asea Brown Boveri.

MORE CONTROL AND SAVINGS
The Tulsa World, Wifag's first U.S. customer and the first North American newspaper to buy shaftless technology, takes delivery of the first of its two OF 370 Gearless Transmission Drive presses early this fall (E&P, June 22 1996, p.18). World president Kenneth S. Fleming told the NAA Operations SuperConference in January that the design affords easy makeready, quick startup and cleanup, and great flexibility in how the press is used.
Fleming said he looks to shaftless for a "significant reduction of paper waste" in a big plant that is already extremely waste conscious. (A former press mechanic, Fleming and World publisher and chairman Robert E. Lorton also own Oklahoma Offset, which "stole business from other newspapers" that once printed commercial jobs.)
"I never saw a press control a web as well," said Fleming of a shaftless OF 370 that Wifag demonstrated in Europe. The press, he continued, held register through stops, restarts and at various speeds thanks to the drives' computer-controled circumferential adjustment. He further noted that a far shorter vertical distance the web must travel through the Wifag tower reduces its tendency to fan out.
Among further benefits of shaftless design, press makers cite: fewer parts and less mechanical maintenance; little or no maintenance on brushless, water-cooled AC motors; faster controls response, independent work at each print couple (where individually motorized); more efficient use of existing capacity during press runs, including quicker zone changes; vibration (including noise) reduction; energy savings from absence of shaft-and-gear power transmission losses and the selective silencing of non-printing cylinders; fewer startup waste copies; easier press expansion, with add-on units that require no mechanical connection to existing pressline(s).
Generation of less heat can also reduce pressroom operating costs and improve consistency of operating conditions and print results. MAN points out that its shaftless design provides a slightly greater available image area. KBA notes a reduced risk of oil leak, because fewer rotating parts penetrate the oil cavity. Goss adds greater walk-through accessibility and fewer web breaks, owing to superior tension control.
When Wifag announced its first shaftless sales, it promoted the capability of making on-the-fly plate changes on such presses. More recently, it shifted emphasis from its page change unit to its PCU+ page count unit.
Wifag CEO Goetz Stein told the SuperConference that this latest way to exploit his company's shaftless press requires split-arm reelstands to change rolls in mid-run, as well as further automation and controls, including folder resetting.
MAN also now offers on-the-fly plate, pagination and color changes.
Two years ago, Wifag made its Nexpo debut, where, in addition to the shaftless OF 370, it introduced the shaftless OF 570 with "ultra-short inking system." This past winter it announced the OF 470, with couple-driven 10-cylinder satellite units (an impression cylinder for each of two vertical pairs of couples).
Last year, Koenig & Bauer-Albert made shaftless design standard on its two single- and four double-width newspaper presses and on its Compacta commercial press (with conventional vertical and main shafts available as an option), and MAN made shaftless an option for all its newspaper presses except the smallest ? the four-page Coroman and Cromoman.
Goss offers fully shaftless motor-per-couple drive and, with vertical shaft, motor-per-level (blanket-to-blanket pair of couples) drive systems on its Colorliner 80, Newsliner and HT70 presses, as well as its various Universal one- and two-around semicommercial machines.
Early this year, Helgi Schmidt-Liermann remarked, "Clearly, the state of the art is shaftless."
Likening the arrival of distributed drives in press technology to the advent of the jet age in aeronautics, the MAN Roland Inc. CEO said there will be a place for mainshaft-driven presses just as there remains a need for propeller-driven aircrafts.
Prompted by the remarks, session moderator John Rodney, production director at the Press of Atlantic City, said he sees "a certain beauty" in a single shaft and several DC motors, any one of which can drive the press, if necessary.
Goss chairman and CEO Robert Kuhn agreed, saying the answer is to supply main-shaft, distributed-drive ? with vertical shaft ? and fully shaftless presses, just as it sells three types of inkers. With a background in the controls industry, Kuhn said he knows that customers who opt for shaftless presses will be responsible for acquiring a level of controls expertise not now common in the newspaper industry.
Press makers' emphases in recent years on training was reinforced by all panelists' remarks at the SuperConference (see sidebar, p. 32).
At that conference, Schmidt-Liermann pointed out that skills required to maintain shaftless presses are not only of a higher level, but also of a different nature.
?( Cross section of MAN Roland motor-to-cylinder direct drive) [Photo & Caption]
?(MAN Roland Drivesys shaftless press diagnostics within Pecom network) [Photo & Caption]
?(Goss distributed shaftless drive, with motors (left sides) and vertical synchronizing shafts) [Photo & Caption]


?( E&P Web Site: http://www.mediainfo.com)
?(copyaright: Editor & Publisher June 21, 1997)