(New Delhi, 8th December 2010)
The ARB Bearings CT3B turbocharger is relatively new on the scene, is dynamite in a small package and has a bearing system that utilizes the latest in ball bearing technology. Racing applications need turbochargers that accelerate at the fastest possible rate and the CT3B bearing system allows it to do just that.
The acceleration rate of a turbocharger is a function of the rotor inertia and the friction losses in the bearing system. Conventional bearing systems have floating sleeve bearings that have an inner and outer oil film fed by lube oil under pressure from the engine lubricating system. They also must employ a stationary thrust bearing that is also fed by lube oil under pressure from the engine. The friction loss attributed to a stationary thrust bearing is proportional to the fourth power of the radius and can amount to several horsepower at the high speed at which turbochargers operate. The oil films in conventional sleeve bearing systems have significant viscosity that produces appreciable friction losses due to oil film shear when the turbocharger rotor accelerated and running at high speed. The friction losses in the sleeve bearings and in the thrust bearing result in mechanical efficiencies in the middle 90% range in conventional turbochargers. There is little or no oil film shear in ball bearings which operate with rolling friction only so that the CT3B accelerates much faster than turbochargers using sleeve bearings systems.
The CT3B bearing system is a proprietary design that is unique in the industry. It utilizes full compliment, angular contact ball bearings with ceramic balls. Compared with steel balls, ceramic balls in ball bearings have a number of advantages. Bearing service life is two to five times longer. They run at lower operating temperatures and allow running speeds to be as much as 50% higher. The surface finish of ceramic balls is almost smooth, producing lower friction losses and lower vibration levels. There is less heat buildup during high speed operation, they exhibit reduced ball skidding and have a longer fatigue life. All these characteristics make ceramic ball bearings ideal for use in turbochargers where they must operate at very high speeds and survive in a high temperature environment. The Full compliment bearings do now use a cage to position the balls and this additional feature, combined with the ceramic material provides a combination that has minimal friction losses. The mechanical efficiency of the CT3B turbo can approach 99%, and this contributes to rotor acceleration rates that have been shown to be faster than competition.
The angular contact bearings are mounted in an elongated steel cylinder that is free to rotate in the bearing housing. The outside diameter of the cylinder is fed with lube oil and this outer oil film provides a cushion against shock and vibration.
Product Model | Inside Diameter | Outside Diameter | Thickness |
NU236R KOYO | 180 | 320 | 52 |
NU236 KOYO | 180 | 320 | 52 |