Cylinder liner

An important appHcation of MMCs in the automotive area is in diesel piston crowns (53). This appHcation involves incorporation of short fibers of alumina or alumina—siHca in the crown of the piston. The conventional diesel engine piston has an Al—Si casting alloy with a crown made of a nickel cast iron. The replacement of the nickel cast iron by aluminum matrix composite results in a lighter, more abrasion resistant, and cheaper product. Another appHcation in the automotive sector involves the use of carbon fiber and alumina particles in an aluminum matrix for use as cylinder liners in the Prelude model of Honda Motor Co. 

Eunctional or hard chromium plating (169,175) is a successfljl way of protecting a variety of industrial devices from wear and friction. The most important examples are cylinder liners and piston rings for internal combustion engines. Eunctional chromium deposits must be appHed to hard substrates, such as steel, and are appHed in a wide variety of thicknesses ranging from 2.5 to 500 ]Am. 

Damage will be confined to the bubble-collapse region, usually immediately downstream of the low-pressure zone. Components exposed to high velocity or turbulent flow, such as pump impellers and valves, are subject. The suction side of pumps (Case History 12.3) and the discharge side of regulating valves (Fig. 12.6 and Case History 12.4) are frequently affected. Tube ends, tube sheets, and shell outlets in heat exchanger equipment have been affected, as have cylinder liners in diesel engines (Case History 12.1). 

If the cavitation intensity is low and corrosion is a significant accelerating factor, appropriate inhibitors can be useful. Notable successes have been achieved with diesel engine cylinder liners. 

Specimen Location Diesel engine cylinder liner... 

Figure 12.9 Typical vertical alignment of cavities resulting from cavitation damage in a diesel engine cylinder liner.

Other options, such as replaceable cylinder liners, must be covered. API mandates replaceable liners with some variations allowed when they are not available. It would be beneficial to state the acceptable alternatives. This approach is probably useful in all areas. 

Pistons are precision-ground for a perfect fit in a honed cylinder liner bore. Long-skirt, lightweight piston reduces wear. 

Figure 11-6. Cut-away view showing cylinder liner. (Courtesy of Dresser-Rand Company.)...

A cylinder liner such as that shown in Figure 11-6 may be used to help prolong the life of the cylinder and improve operating flexibility. Any dtunage caused by the action of the piston or heat generated by compression will affect the cylinder liner, which may be removed and replaced. As the surface of the liner wears, it is much easier and quicker to repair it than to repair the cylinder itself. In addition, liners enable the diameter of the piston to be varied without changing the cylinder and thus provide flexibility to respond to different conditions of pressure and flow rate. 

In addition, piston displacement and thus throughput can be changed by changing cylinder liners, installing sleeves, or boring the cylinder. 

Cylinder Liner Piston Rings Piston Piston Pin... 

Collins, H. H., Pitting of Diesel Cylinder Liners, Diesel Engineers and Users Association (1961)... 

This type of damage is dealt with comprehensively in Section 8.8. It can be particularly severe in seawater giving rise to cavitation corrosion or cavitation erosion mechanisms, and hence can be a considerable problem in marine and offshore engineering. Components that may suffer in this way include the suction faces of propellers, the suction areas of pump impellers and casings, diffusers, shaft brackets, rudders and diesel-engine cylinder liners. There is also evidence that cavitation conditions can develop in seawater, drilling mud and produced oil/gas waterlines with turbulent high rates of flow. 

Machined deposits on new equipment, including undercoats for chromium, are usually 125-500 im thick. Applications include cylinder liners (on the water side), cylinders used in the rubber, pulp and paper handling industries, compressor rods and armatures for electric motors. 

Locomotive diesels As larger volumes of coolant are required in railway locomotives than in road vehicles, the cost of inhibition is proportionally greater. An additional factor is the possibility of cavitation attack of cylinder liners. These considerations place a restriction on the choice of inhibitors. In the past, chromates have been used at concentrations of up to 0-4%, but their use presents handling and disposal problems. Chromates cannot be used with ethanediol antifreeze solutions. A IS I borate-metasilicate at a concentration of 1 % has been used in the UK. Nitrate is added to this to improve inhibition of aluminium alloy corrosion. Tannins and soluble oils are also used, but probably to a lesser extent than in the past. The benzoate-nitrite formulation (formerly BS 3151) is effective and has been used by continental railways . ... 

Iron Cylinders, liners, pistons, rings, valves, valve guides, gears, shafts, clutch plates, antifriction bearings, rust... 

No. In/Out Mat l of Const Cylinders Cylinder Liners Pistons Piston Rings Piston Rods Cooling Water ... 

Other typical applications are piston pins, crankshafts, cylinder liners, timing gears, gauges, and ball and roller bearing parts. 

Figure 6.39 Cavitation erosion damage of a cylinder liner of a diesel engine7...

---