Types of ic engines
In fact, cam can be used to obtain unusual or irregular motion that would be difficult to obtain from other linkage. In other word, cam mechanism transforms a rotational or oscillating motion to a translating or linear motion. The cam may be defined as a machine element having a curved outline or a curved groove, which, by its oscillation or rotation motion, gives a predetermined specified motion to another element called the follower. Again the cam and follower has a very important function in the operation of many classes of machines, especially those of the automatic type, such as printing presses, shoe machinery, textile machinery, gear-cutting machines, screw machines etc. The finite element approach is used to perform the analysis.Ĭam and follower mechanism is preferred over a wide variety of internal combustion engines because due to the cam and follower it is possible to obtain an unlimited variety of motions. It is observed that the frequency of vibration in the existing and modified cam and follower mechanism remains almost same. As line contact between existing cam and follower mechanism results in high frictional losses which results in low mechanical efficiency. In this work an attempt is made to change the flat face of follower to a curved face follower, so that the required point contact can be achieved. The current cam and follower mechanism in four stroke internal combustion engine employs a flat follower. Keywords: Follower & Cam Point Contact Vibration Analysis Finite Element Approach Society’s College of Engineering, Pune, IndiaĤKIT College of Engineering, Kolhapur, IndiaĮmail: Marevised accepted May 14, 2012 Ltd., Pune, IndiaĢDepartment of Mechanical Engineering, Rajarambapu Institute of Technology, Islampur, IndiaģDepartment of Mechanical Engineering, M. This number is multiplied by the number of cylinders in the engine, to determine the total displacement.1Research and Development, MAN Trucks India Pvt. The stroke length is how far the piston travels in the cylinder, which is determined by the cranks on the crankshaft.Įngine displacement is calculated by multiplying the cross-section area of the cylinder (determined by the bore) by the stroke length. Most automotive engines are a four-stroke design. Four-stroke engine įour-stroke engines complete a power cycle every four strokes, which means a power cycle is completed every two crankshaft revolutions. lawnmowers and chainsaws) and motorcycles. Two-stroke engines are commonly used in (typically large) marine engines, outdoor power tools (e.g. Two-stroke engines complete a power cycle every two strokes, which means a power cycle is completed with every crankshaft revolution. Less common designs include five-stroke engines, six-stroke engines and two-and-four stroke engines.
The most common designs for engines are two-stroke and four-stroke. The thermodynamic cycle used by a piston engine is often described by the number of strokes to complete a cycle. At the end of this phase, the exhaust valve closes and the intake valve opens, which then closes to allow a fresh air/fuel mixture into the cylinder so the process can repeat itself. The gasses exit the cylinder through an exhaust valve at the top of the cylinder.
In this phase, the piston moves upwards, squeezing out the gasses that were created during the combustion stroke.
The exhaust stroke is the final phase in a four stroke engine. The force created by this expansion is what creates an engine's power. The combustion stroke is the third phase, where the ignited air/fuel mixture expands and pushes the piston downwards. Towards the end of this phase, the mixture is ignited - by a spark plug for petrol engines or by self-ignition for diesel engines.Ĭombustion/Power/Expansion stroke This is the result of the piston moving upwards, reducing the volume of the chamber. In this stage, the fuel/air mixture (or air alone, in the case of a direct injection engine) is compressed to the top of the cylinder by the piston.
The compression stroke is the second of four stages in a four-stroke engine.