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Technology Stocks : Turbodyne Technologies Inc. (TRBDF) -- Ignore unavailable to you. Want to Upgrade?

To: current trend who wrote (1799)	8/21/1998 11:03:00 AM
From: Nathan Hansen	Read Replies (1) \| Respond to of 3458

TWO THUMBS UP!!!, for Turbodyne's response.

To: current trend who wrote (1799)	8/27/1998 11:36:00 AM
From: current trend	Read Replies (2) \| Respond to of 3458

New System Looks At Dealing With Turbo Lag by William E. Woollenweber Looking at addressing the common performance problem of "turbo lag" in diesel engines has led Turbodyne Systems, Inc., Carpenteria Calif., and its chairman, Edward Halimi, to couple an electric motor to the turbocharger rotating assembly in order to raise its operating speed during acceleration when there is a deficiency in exhaust gas energy to drive the turbine. By taking power form the engine's electrical system, the motor, through an overriding clutch, was used to eliminate conventional turbo lag by adding power to the turbocharger rotor; thereby supplying a significant a ount of charge-air pressure to the engine at low idle speed in preparation for an acceleration. In addition, the electric motor, through the use of an appropriate electronic controller, was super-energized during the acceleration period, greatly enhancing the rate of speed increase of the turbocharge rotor. The idea of assisting the turbocharger with an electric motor has subsequently resulted in the development by Turbodyne of the Dynacharger. The components of the high-speed brushless motor have been designed into the interior of the turbocharger, thereby eliminating the need for the external overriding clutch. In the original Dynacharger design, the magnet assembly of the motor was attached to the turbocharger shaft between the standard sleeve bearings that support the rotor. The motor windings were placed in the bearing housing and surrounded by a cooling jacket connected to the engine cooling system. This design retained interchangeability with the standard turbocharger. The wires connecting the motor windings with the electronic controller exit the bearing house through a sealed fitting. Dynamometer testing at a California university has now been completed to explore the potential of the electric motor-assisted turbocharger mounted on a 14 L, four-cycle diesel truck engine. In an acceleration test, where boost pressure versus time is measured with and without the motor being engaged, the boost pressure provided to the engine at low idle with the motor engaged is over 5 in. Hg compared with zero without the assistance of the motor. During the acceleration from low idle speed, the boost pressure with the motor assist is more than double that of the unassisted turbocharger. The extra air provided to the engine during acceleration can be utilized to reduce emissions, increase power or a combination of both. After the turbocharger rotor reaches a speed where it is capable of fully charging the engine, the electric motor is disengaged to shut off the power supplied by the engine electrical system. In an alternate Dynacharger design, the motor magnet assembly has been moved outboard of the bearing system. The motor windings are mounted in an aluminum housing that contains the cooling jacket connected to the engine cooling system. Both components are located in the coolest section of the turbocharger, compared with the previously described design where the motor winding is located in the turbocharger bearing housing. Test results obtained with a Dynacharger that was tested on an 8.6 L, four-cycle diesel engine showed the boost pressure available to the engine is significantly increased during the acceleration period. When the engine was accelerated from low idle to 1000 rpm, with the motor energized, acceleration time lag was elminated and the motor assisted turbocharger supplied the engine with much higher boost during the entire acceleration period. To investigate the potential of the motor-assist technology applied to small turbochargers used on passenger cars, a motor was added to a commercial turbocharger used on a 1.9 L diesel passenger car engine. In this small Dynacharger conversion, the magnet assembly was mounted outboard of the bearing system and a water-cooled aluminum backplate was added to contain more motor windings. Since many small turbochargers used on gasoline-powered passenger car engines currently employ water cooling of the bearing housing, the addition of the water jacketed aluminum backplate is easily accomodated. In an acceleration test on the 1.9 L diesel passenger car engine where the engine speed was held constant, the boost pressure increase evrsus time clearly demonstrated the improvement obtained by energizing the assisting electric motor. There is another very important aspect to the addition of a motor assist to the rotor of a turbocharger. When the rotation of the magnet assembly of the motor reaches high values, the motor begins to feed back current into the electrical circuitry. Thus, the motor becomes a generator at very high speed and this additional characteristic makes the Dynacharger a useful device for matching the needs of a turbocharged engine. From low idle speed up to the torque peak speed, the motor is utilized to assist the turbocharger in charging the engine. Above torque peak speed there is usually an excess of energy in the engine exhaust and it is conventional to limit the maximum speed of the turbocharger often, by using a waste gate to bypass exhaust gas around the turbine over the high speed range. By allowing the motor to become a generator over the high engine speed range, the excess energy in the engine exhuast gas can be converted into useful electrical energy while at the same time exerting a braking effect on the turbocharger rotor. Through the use of suitable electronic controls, the output current from the generator might also be used to charge the battery of a vehicle engine or diverted for some other useful purpose. When considering the application of the Dynacharger to a two-cycle engine, the obvious advantage is the potential of eliminating the mechanically-driven supercharger used to start the engine. The motor in the Dynacharger can be energized from the battery while the engine is being cranked for starting. The motor-assisted turbocharger can then be rotated at high enough speed to provide a positive pressure differential across the engine cylinder that is necessary for starting the engine. In summary, the combination of a high speed electric motor with a turbochargerrepresents an interesting development in matching the requirements of modern vechile-type engines. The additional charge-air that can be made available to the engine by the elctric motor assist when there is a lack of exhuast gas energy can significantly enhance the performance of turbocharged engines. Turbo lag can be eliminated, fuel consumption improved and, at the same time, harmful exhaust emissions can be reduced. The additional potential of the Dynacharger acting as a generator over the high engine speed range is an added advantage. This technology, applied to bothtwo- and four-cycle engines, could become a big contributor to extending their useful life well into the future. reprinted from Diesel Progress (August 1998 edition)