Diesel Engines Industry Research Report 2026

Definition

A diesel engine is an internal combustion engine whose working principle was completed by the German engineer Rudolf Diesel in 1892. An internal combustion engine is a heat engine that generates power by burning a fuel and an oxidizer. The working principle of a diesel engine is to compress air with a piston to increase the temperature inside the cylinder, and then inject atomized diesel into the cylinder. When the fuel comes into contact with the high temperature, it ignites, producing energy that pushes the piston downwards, transferring energy to the crankshaft and the power transmission system. This process repeats at high speed, making the diesel engine a powerful technology. Different types of diesel engines have different compression ratios. The compression ratio of a diesel engine affects the power output of the engine. The higher the compression ratio, the greater the power produced. Components and Functions of a Diesel Engine: Cylinder Block: As the foundation of a modern diesel engine, the cylinder block houses all components of the basic internal combustion process. It provides open spaces for each cylinder where combustion occurs. Piston: The piston forms the bottom of the combustion chamber and moves up and down inside the cylinder during engine operation. The movement of the piston compresses the air, leading to combustion. Cylinder Head: The cylinder head closes off the open space at the top of the cylinder block to reach the combustion chamber. The cylinder head can be a single unit covering all cylinders or multiple units covering sections. Valves: Since the cylinder is closed off by the piston at the bottom and the cylinder head at the top, there needs to be a way for fresh air to enter and exhaust gases to exit. This is the role of the valves. Each cylinder typically has two intake valves and two exhaust valves. Fuel Injectors: There needs to be a way to deliver fuel into the cylinder for combustion. These components are the complex part of the process, injecting fuel in a very precise pattern and highly controllable timing. Camshaft: Most engines do not rely on electrical systems to open valves and inject fuel but instead use a mechanical process. The rotation of the camshaft controls the timing of these events through lobes on the shaft that cause the camshaft to move. Connecting Rods: These parts connect to the piston head at the wrist pin and transfer the force of combustion to the crankshaft. Crankshaft: The crankshaft converts the linear motion of combustion (the up-and-down parts of the process) into rotational motion. Diesel engines can be classified in various ways. Typically, they are divided into single-cylinder and multi-cylinder diesel engines based on the number of cylinders. A single-cylinder diesel engine has only one cylinder for compressing air, injecting fuel, and burning to generate power. The single-cylinder structure is simple, cost-effective, and compact, applicable to small tractors, water pumps, lawn mowers, tillers, and small generators. Multi-cylinder diesel engines have two or more cylinders, with numbers ranging from 2, 3, 4, 6, 8, 12, or even more. Multi-cylinder engines have high power, smooth operation, high efficiency, complex structure, and high cost, used in vehicles, large generators, compressors, ships, excavators, bulldozers, and other applications. Other classifications can be made based on the size of output power (small, medium, and large), or the number of strokes required for the engine cycle (two-stroke and four-stroke engines). This report analyzes from the perspectives of single-cylinder and multi-cylinder engines.