Busak+Shamban Germany has signed a 4-year agreement with leadinginternational tractor manufacturer Fendt to supply special highpressure rotary seals for the innovative Vario range oftractors.
A major brand of the AGCO Corporation, one of the largest tractormanufacturers in the world, Fendt is located in Marktoberdorf inthe Allgäu region of Germany and has been receiving praise for itsnew Vario tractors, which range from 95HP (70kw) up to 310HP(221kw).
Designed for agricultural, forestry and public works, the Variotractor contains a hydraulic gearbox with stepless drive unit.Within this hydraulic assembly, a high-performance pump drives twoadjustable hydromotors, on a single shaft. In one set of gearsthere are between 6 and 9 seals of two different diameters, with arotary seal consisting of 3 individual components; a PTFEantifriction ring, two thrust rings and a pre-tensioningelement.
Fendt began product development of this innovative gearbox designback in 1990. In the early planning stage, several sealmanufacturers were involved, each trying to offer a rotary sealingconfiguration that would work at elevated temperatures, low idlingspeeds and high pressure. After a number of development stages,Busak+Shamban was chosen to take their sealing design to productionstage.
Picture shows: AGCO Fendt Vario tractor
Working in close partnership with the Europa Research andDevelopment Centre in Stuttgart, the use of specially formulatedhigh-performance plastics solved the problem of failures due tohigh temperature and the configuration met requirements for sealperformance. This helped Fendt launch a world-beating product. Thepartnership working, at all levels - applications engineering,customer service and sales support was seen by Fendt andBusak+Shamban as a major contribution to success from productconcept in 1990, to market launch in 2005.
Dr Weixler, Purchasing Manager from AGCO GmbH stated,“Busak+Shamban is a very cooperative and customer orientatedcompany to work with. We are building a successful future throughinnovative product development.”
Now, with the Vario tractor range in full production, on the worldmarket, Busak+Shamban is supplying batch sizes that match Fendt’sdemanding lineside deadlines.
Background to seal development for the AGCO-Fendt Variotractor project:
At the heart of the drive chain is the variable control gearbox.Called the Vario CVT, the transmission control system offersinfinite speeds within two ranges, helping to deliver optimum driveperformance. The engineering development challenge involvingsealing systems developer, Busak+Shamban, was to provide advancedrotary sealing for the Vario CVT gearbox arrangement. Sealperformance requirements included a capability of optimumperformance at pressures up to 500 bar with temperatures to +130ºCwithin a sealed for life unit. Situated within swivelling rotaryunits, the back-up ring version was required for installationwithin closed grooves, for volume production line assembly.Busak+Shamban developed a special high-performance plastic to meetthese demanding performance requirements.