Understanding how a turboch-arger works is fundamental to the successful application of a turbo and to matching it to an engine correctly. Perhaps the best way to understand how a turbo works is to break it down into its primary sections. This is done in great detail in Chapter 2. But as a preview, the turbocharger simplified has basically three areas of design: the turbine, the compressor, and the bearing system that ties the compressor and turbine ends together. Each of these areas is interdependent on the other for overall turbocharger effectiveness, but they are each developed as discrete machines. Turbocharger manufacturers commonly separate the design engineering teams into areas of specialization where you will find turbine development specialists, compressor specialists, and mechanical design specialists for bearing and support systems.
Turbo: Real World High Performance Turbocharger Systems (S A Design) Jay K. Miller.zip
The turbocharger bearing system is contained within the bearing housing. The bearing housing supports the turbine housing and compressor cover, while the turbine shaft and bearings support the rotational dynamics of the turbine and compressor wheels. Most turbocharger bearing systems are bronze type journal bearings that have oil passages to feed the hydrodynamic lubrication system, while many late-model high-performance turbos utilize specially designed ball-bearing cartridges.
While there are many types of bearing systems they all must do this job while providing a minimum of drag or frictional loss of energy extracted from the turbine to power the compressor. The bearing housing is also home to many more design features that include oil control, gas seals, heat dams, and, in some designs, water jackets to keep extremely high exhaust temperatures away from the lubricating oil.
Unfortunately, this wealth of options and opinions can be hard to understand and navigate. That's where Turbo: Real World High-Performance Turbocharger Systems comes in. This book is the most complete, detailed, up-to-date resource on anything and everything to do with turbochargers. Whether you're running gas or diesel, 4, 6, 8, or more cylinders, this book will teach you to design, test, install, and maintain your high-performance turbo system. You'll learn how turbochargers work, how to choose the right turbo or turbos for your engine by reading flow maps, and how to tune your engine to run perfectly with your turbo system.
The turbine uses a series of blades to convert kinetic energy from the flow of exhaust gases to mechanical energy of a rotating shaft (which is used to power the compressor section). The turbine housings direct the gas flow through the turbine section, and the turbine itself can spin at speeds of up to 250,000 rpm.[27][28] Some turbocharger designs are available with multiple turbine housing options, allowing a housing to be selected to best suit the engine's characteristics and the performance requirements.
A turbocharger's performance is closely tied to its size,[29] and the relative sizes of the turbine wheel and the compressor wheel. Large turbines typically require higher exhaust gas flow rates, therefore increasing turbo lag and increasing the boost threshold. Small turbines can produce boost quickly and at lower flow rates, but can be a limiting factor in the peak power produced by the engine.[30][31] Various technologies, as described in the following sections, are often aimed at combining the benefits of both small turbines and large turbines. 2ff7e9595c