New Turbocharger Ball Bearing Technology

September 4, 2009 --The Comp Turbo 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. Two angular contact bearings are mounted in tandem on the compressor end of the cylinder in an arrangement that carries rotor thrust in both axial directions. A single angular contact bearing is slid ably mounted under pre- load on the turbine end of the cylinder and is free to move axially with shaft elongation when heat is conducted down the shaft from the hot turbine wheel. The elongated steel cylinder containing the angular contact bearings represents complete bearing system and can be inserted and/or removed as an assembly making the CT3B turbocharger fully upgradeable, serviceable and re-buildable. Racing Applications require a turbocharger that builds boost as rapidly as possible, thus allowing the engine develop high torque at low engine speeds and with boost capability that can produce very high maximum power output .The CT3B turbocharger does exactly that. For example when mounted on one dragster, the CT3B produced 1.7 bar boost in two tenths of a second and developed 650 HP ready for takeoff. Now that’s phenomenal response and very impressive. In street applications, the acceleration rate of a vehicle equipped with a CT3B turbocharger is enhanced and moves the engine out of inefficient operating regimes more rapidly. An improvement in number of gallons of fuel used is the usual result when a vehicle is accelerated faster. Under steady-state operation, the lower HP losses in the CT3B ball bearing system means power is available to the turbocharger compressor which results in higher intake manifold pressure. In most cases, higher boost can make an additional contribution to improving engine fuel consumption. Comp Turbo can supply the CT3B turbocharger with various compressors and turbine wheel trims to tailor its performance so that it matches specific engine application requirements; whether they be racing, street or stationary. In addition, the CT3B will be followed in the near future by other model sized now under development at Comp Turbo. These new models will utilize the proprietary technology that has been designed into the successful CT3B to complete a line of high performance turbochargers utilizing the many advantages of ceramic ball bearings. They will also accelerate like greased lightning to produce the ultimate in engine and vehicle response