Home Page T-8 SECTION 4    DRIVE COMPARATIVE STUDIES The  development  of  the  PowerGrip  GT  belt  has  produced  an  impressive  range  of  enhanced properties and subsequent design opportunities for engineers. Comparative  studies,  shown  in  Figures  7  through  10,  allow  designers  to  make  quantitative assessments and to highlight the most significant improvements and design opportunities.  Particularly significant points from the comparative studies follow: 4.1    Durability The greatly increased durability of the PowerGrip GT design has resulted in power capacities far above those quoted for similar size belts of previous designs.  The resulting small drive packages will increase design flexibility, space utilization and cost effectiveness. 4.2    Tooth Jump Resistance The very significant improvement in tooth jump resistance of PowerGrip GT when compared to similar belts has several important advantages. 1.    Ratcheting resistance during high start-up torques. 2.    Reduced bearing loads, particularly in fixed-center drives.  Lower average tensions can be used without encountering tooth jump at the low tension end of the tolerance ranges. 3.    Reduced  system  losses  result  from  lower  pre-tensioning,  with  less  potential  for  tooth jumping. Fig. 7    Comparison of Performance Ratios for Various Belts Fig. 8    Comparison of Tooth Jump Torques for Various Belts Test Stopped –––3 3 mm HTD Versus 3 mm PowerGrip GT 3 mm HTD 3 mm GT TEST CONDITIONS:  Speed = 6000 rpm Power = 1.00 lb×in/mm width Pulleys: Driver = 20 grooves Driven = 20 grooves Test Stopped –––3 5 mm HTD Versus 5 mm PowerGrip GT 5 mm HTD 5mm GT TEST CONDITIONS:  Speed = 2300 rpm Power = 3.35 lb×in/mm width Pulleys: Driver = 20 grooves Driven = 20 grooves 200 150 100 50 0 200 150 100 50 0 10 8 6 4 2 0 1 2 3 4 5 2 mm GT MXL 2 mm PowerGrip GT Versus MXL 3 mm PowerGrip GT Versus 3 mm HTD 5 mm PowerGrip GT Versus 5 mm HTD 5 mm GT 5 mm HTD 3 mm GT 3 mm HTD 60 50 40 30 20 10 0 450 375 300 225 150 75 0 2 4 6 8 10 15 30 45 60 75 Installed Tension (lb) TEST CONDITIONS: Speed = 1130 rpm Belt Width = 4.8 mm Pulleys: Driver = 20 grooves Driven = 20 grooves Installed Tension (lb) TEST CONDITIONS: Speed = 750 rpm Belt Width = 6 mm Pulleys: Driver = 30 grooves Driven = 30 grooves Installed Tension (lb) TEST CONDITIONS: Speed = 2300 rpm Belt Width = 15 mm Pulleys: Driver = 20 grooves Driven = 20 grooves