46 E&MJ • APRIL 2011 www.e-mj.com

Drive TimeNew stationary and mobile drive systems introduced at CONEXPO 2011 offer higherperformance with improved economy of operation

MATERIALS HANDLING

Held every three years in Las Vegas,Nevada, USA, the CONEXPO-CON/AGGexposition is one of the largest tradeshows in the world—this year attractingan estimated 120,000 visitors and2,000 exhibitors. Traditionally, it’s anevent that industry suppliers view as amilestone at which to introduce theirnewest products and services for theconstruction and aggregate industries.However, the product overlap betweenthe equipment commonly used in theseindustries and in various sectors of large-scale mining makes CONEXPO a must-see event for anyone interested in newmechanical technologies. This holds trueparticularly for new developments inmaterials handling components andequipment such as the drive systemsthat transfer power to conveyors, feed-ers, screens, stackers/reclaimers andother bulk-materials equipment.

The V-Class of 2011At this year’s CONEXPO, RexnordIndustries launched its Falk V-Classline of gear drives.

“The development of the Falk V-Class has been the largest effortRexnord has undertaken in the compa-ny’s history,” said Tim Carpenter,Rexnord’s vice president and generalmanager–gear and product servicesdivisions. In designing the new driveline, Rexnord concluded that manufac-turers, end users and OEMs wanted agear drive with more torque, more relia-bility, and more functionality that deliv-ers optimal thermal performance andcan withstand tough environments.Consequently, various new design ele-ments combine to improve the line’storque capacity, including:• 25° pressure-angle gear teeth;• Case-hardened, ground gears;• Optimized bevel and helical tooth

forms that ensure full contact under load;

• Proprietary peened gear teeth;• Gear sets up to AGMA Class 12; and• A heavy-duty ductile iron housing that

withstands shock loads.

Rexnord pointedout one of the mostdistinguishable fea-tures of the Falk V-Class: the housingitself. Its shape andfeatures were de-signed through theuse of Computa-tional Fluid Dy-namics (CFD), toenhance the drive’sthermal dissipationqualities. Coolingfins on the housinghelp reduce oil tem-perature, and pro-prietary oil feed passages in the housingimprove lubrication and provide addi-tional cooling capability. An oil sam-pling port is built into the housing toallow quick checking of oil condition.

Features that improve installation,serviceability and replacement charac-teristics include removable, adjustablefeet that allow drop-in replacement forcurrent product lines, and can adapt forreplacement of competitor drives anddifferent shaft centerline heights. Base-mounted units can be repaired in place,and the horizontally split housingallows easy disassembly/assembly formaintenance of bearings and gearing,while global compatibility permits easeof service regardless of location andpre-cast locations for condition moni-toring access allow convenient tie-in tomachine-health monitoring systems.

The drive incorporates Magnum no-leak seals with oil drain backs andpurgeable grease chamber to eliminateoil leaks. An optional, DuraPlate cool-ing system requires no water or elec-tricity to operate and achieves optimalcooling to fully utilize the unit’s unpar-alleled torque density.

The Falk V-Class drive line offers atorque range extending up to 3 millionin-lb (341,000 Nm), horsepower rangeof 15 to 10,000 hp (11 to 7,500 kW),and both parallel and right-angle shaftconfigurations, with reduction ratios

ranging from 1.25–5 to 28–160 de-pending on model configuration.

Inching Toward Reliabilityand PerformanceOhio, USA-based Force Control Indus-tries displayed its Two-Speed Drivepackage, comprising a brake motor witha low-speed drive built in. According tothe company, unlike variable speedmotors that lose torque or develop heatproblems at very low speed, its air,hydraulic and electrically activatedunits remain cool while maintaining fulltorque continuously at low inchingspeeds. Benefits include the simplicityof a mechanical drive that can be main-tained by local mechanical mainte-nance staff, as well as freedom fromproblems resulting from electrical linespikes, lightning or other electricalissues. They are suitable for standardNEMA motor mounting and are avail-able for a wide range of gear ratios.Each Force Control Two Speed drive istotally enclosed, protected against dirt,dust and harsh environments.

The Force Control drives are avail-able in two versions: the Posidyne air orhydraulically actuated configuration,and the MagnaShear electrically acti-vated version.

The Posidyne Two Speed Drive con-sists of a high-speed motor connectedthrough a spring-set friction stack oper-

Cutaway view of Rexnord’s new Falk V-Class gear drive.

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ating as a clutch and a brake (primarybrake clutch) to a four-lug shaft mount-ed to a worm gear. A secondary driveconsists of a small low speed motorconnected to one end and a spring-setbrake (low-speed brake) to the otherend. The spring-set brake on the sec-ondary drive is set while in operation,thus holding the worm and worm gearset locked. The primary brake clutch isspring set so the entire drive is locked.To actuate high speed (main motoronly) the primary brake clutch isreleased and the main motor functionsnormally. To stop the high-speed motorthe primary brake clutch is engaged,connecting it to the locked secondarydrive and causing the main motor tostop. To operate the drive in low speed,the low-speed brake is released, theprimary brake clutch is released, andthe low-speed motor drives through thegear ratio driving the main motor at lowspeed.

The MagnaShear drive employs thesame concept, except the brakes areactuated by an electrical coil instead ofan air piston. High-speed and low-speed modes are selected by energizingthe appropriate electrically controlledcoils. The spring-set braking mode isselected when both coils are de-ener-gized, allowing the springs to engageboth disc stacks to stop the drive sys-tem. Low speed is selected by releasingboth brakes and energizing the second-ary low-speed feed motor.

A Drivetrain Designed for ProductivityOver in the mobile drives and transmis-sions sector, Dana Holding Corp.’s Off-Highway Products Group introduced thefirst hydromechanical variable trans-mission (HVT) system resulting from a

cooperative effortbetween Dana andBosch Rexroth AG.The HVT displayedat CONEXPO is partof a loader drivetrainsystem that alsoincludes the SpicerHercules 37R axleand Spicer Model114 axle.

Targeted for use on off-highway vehi-cles—such as wheelloaders, graders,

etc.—requiring 115 to 360 hp (90-270kW), Dana said the HVT improves pro-ductivity by enabling sensitive, precisevehicle positioning and stepless drivewith uninterrupted acceleration. Itoccupies the same space within thedesign envelope as conventional torqueconverter transmissions while allowingfor engine downsizing. The HVT opti-mizes the operating point of the dieselengine by decoupling engine speed fromdrive speed, and maintenance costs arereduced by utilizing hydrostatic brakingand wear-free directional reversals.

According to the company, simula-tion testing of smaller front-end loadersequipped with the new HVT demon-strated fuel savings of more than 20%when compared to thesame vehicle outfittedwith a conventional torqueconverter transmission.

Engineered with arigid, modular load-bear-ing structure including thedifferential carrier, hous-ing arms, high-energy wetbrakesb and planetarywheel ends, the SpicerHercules 37R axle accom-modates multiple vehicleplatform configurations.

Spicer 37R axles areavailable with Posi-Torqand Hydraloc differentialdesigns. Using large multi-plate clutch discs actuat-ed by gear-separatingforces, the Posi-Torqdesign provides a 45%locking capacity, resultingin up to 72% torque trans-fer to the high-tractionwheel. As an operator-con-trolled differential, the

Hydraloc design for 37R series axlesallows for moment-to-moment lock-and-release control, delivering superiorground torque bias in severe tractionconditions. In its unlocked condition,the Hydraloc differential permits freevehicle steering to facilitate maximummaneuverability. Once locked, ahydraulic piston applies force to a largemulti-plate wet clutch, resulting in upto 100% torque transfer to the high-traction wheel.

The Spicer Model 114 drive axleincludes a limited-slip differential lockthat Dana said provides a 45% lockingcapacity, delivering excellent tractiveforce and nimble vehicle steering forfront-end loader applications. The axlecan be configured with a variety ofother hydraulic-locking differentialoptions, including dog clutch andmulti-disc clutch.

Inboard wet disc brakes offer fail-safe stopping performance and energyabsorption, while a fail-safe park brakefeaturing internal negative SAHR isavailable as an option.

The Spicer Model 114 and 37Raxles incorporate 6.00-to-1 ratio out-board planetary wheel ends with 425mm wheel bolt-circle mountings, self-adjusting internal wet brakes, and atrunnion mounting option.

APRIL 2011 • E&MJ 47www.e-mj.com

MATERIALS HANDLING

Force Control’s Two-Speed Drive.

Hydromechanical variable transmission developed jointly by Dana Off-Highway Products and Bosch Rexroth.

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