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Crosshead
In mechanical engineering, a crosshead is a mechanical joint used as part of the slider-crank linkages of long reciprocating engines (either internal combustion or steam) and reciprocating compressors to eliminate sideways force on the piston. Also, the crosshead enables the connecting rod to freely move outside the cylinder. Because of the very small bore-to-stroke ratio on such engines, the connecting rod would hit the cylinder walls and block the engine from rotating if the piston was attached directly to the connecting rod like on trunk engines. Therefore, the longitudinal dimension of the crosshead must be matched to the stroke of the engine. Overview On smaller engines, the connecting rod links the piston and the crankshaft directly, but this transmits sideways forces to the piston, since the crankpin (and thus the direction the force is applied) moves from side to side with the rotary motion of the crank. These transverse forces are tolerable in a smaller engine. A large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Side-lever
A marine steam engine is a steam engine that is used to power a ship or boat. This article deals mainly with marine steam engines of the reciprocating type, which were in use from the inception of the steamboat in the early 19th century to their last years of large-scale manufacture during World War II. Reciprocating steam engines were progressively replaced in marine applications during the 20th century by steam turbines and marine diesel engines. History The first commercially successful steam engine was developed by Thomas Newcomen in 1712. The steam engine improvements brought forth by James Watt in the later half of the 18th century greatly improved steam engine efficiency and allowed more compact engine arrangements. Successful adaptation of the steam engine to marine applications in England would have to wait until almost a century after Newcomen, when Scottish engineer William Symington built the world's "first practical steamboat", the '' Charlotte Dundas'', in 1802. Ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crosshead Bearing
In mechanical engineering, a crosshead is a mechanical joint used as part of the slider-crank linkages of long reciprocating engines (either internal combustion or steam) and reciprocating compressors to eliminate sideways force on the piston. Also, the crosshead enables the connecting rod to freely move outside the cylinder. Because of the very small bore-to-stroke ratio on such engines, the connecting rod would hit the cylinder walls and block the engine from rotating if the piston was attached directly to the connecting rod like on trunk engines. Therefore, the longitudinal dimension of the crosshead must be matched to the stroke of the engine. Overview On smaller engines, the connecting rod links the piston and the crankshaft directly, but this transmits sideways forces to the piston, since the crankpin (and thus the direction the force is applied) moves from side to side with the rotary motion of the crank. These transverse forces are tolerable in a smaller engine. A large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Steam Engine
A marine steam engine is a steam engine that is used to power a ship or boat. This article deals mainly with marine steam engines of the reciprocating type, which were in use from the inception of the steamboat in the early 19th century to their last years of large-scale manufacture during World War II. Reciprocating steam engines were progressively replaced in marine applications during the 20th century by steam turbines and marine diesel engines. History The first commercially successful steam engine was developed by Thomas Newcomen in 1712. The steam engine improvements brought forth by James Watt in the later half of the 18th century greatly improved steam engine efficiency and allowed more compact engine arrangements. Successful adaptation of the steam engine to marine applications in England would have to wait until almost a century after Newcomen, when Scottish engineer William Symington built the world's "first practical steamboat", the '' Charlotte Dundas'', in 1802. Ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crosshead Guide
In mechanical engineering, a crosshead is a mechanical joint used as part of the slider-crank linkages of long reciprocating engines (either internal combustion or steam) and reciprocating compressors to eliminate sideways force on the piston. Also, the crosshead enables the connecting rod to freely move outside the cylinder. Because of the very small bore-to-stroke ratio on such engines, the connecting rod would hit the cylinder walls and block the engine from rotating if the piston was attached directly to the connecting rod like on trunk engines. Therefore, the longitudinal dimension of the crosshead must be matched to the stroke of the engine. Overview On smaller engines, the connecting rod links the piston and the crankshaft directly, but this transmits sideways forces to the piston, since the crankpin (and thus the direction the force is applied) moves from side to side with the rotary motion of the crank. These transverse forces are tolerable in a smaller engine. A large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piston Rod
In a piston engine, a piston rod joins a piston to the crosshead and thus to the connecting rod that drives the crankshaft or (for steam locomotives) the driving wheels. Internal combustion engines, and in particular all current automobile engines, do not generally have piston rods. Instead they use trunk pistons, where the piston and crosshead are combined and so do not need a rod between them. The term ''piston rod'' has been used as a synonym for 'connecting rod' in the context of these engines. Engines with crossheads have piston rods. These include most steam locomotives and some large marine diesel engines. Steam engines The first single-acting beam engines, such as Newcomen's, had a single power stroke acting downwards. Rather than a piston rod, they used an iron chain. This could transmit a tensile force, but not a compression force pushing upwards. The piston was sealed in the cylinder around its rim but the top of the cylinder was open. Later, a rudimentary pist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crosshead Piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder. __TOC__ Piston engines Internal combustion engines An internal combustion engine is acted upon by the pressure of the expanding combustion gases in the combustion chamber space at the top of the cylinder. This force then acts downwards through the connecting rod and onto the crankshaft. The connecting rod is attached ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder. __TOC__ Piston engines Internal combustion engines An internal combustion engine is acted upon by the pressure of the expanding combustion gases in the combustion chamber space at the top of the cylinder. This force then acts downwards through the connecting rod and onto the crankshaft. The connecting rod is att ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steam Locomotive
A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomotive's boiler to the point where it becomes gaseous and its volume increases 1,700 times. Functionally, it is a steam engine on wheels. In most locomotives, the steam is admitted alternately to each end of its cylinders, in which pistons are mechanically connected to the locomotive's main wheels. Fuel and water supplies are usually carried with the locomotive, either on the locomotive itself or in a tender coupled to it. Variations in this general design include electrically-powered boilers, turbines in place of pistons, and using steam generated externally. Steam locomotives were first developed in the United Kingdom during the early 19th century and used for railway transport until the middle of the 20th century. Richard Trevithick ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connecting Rod
A connecting rod, also called a 'con rod', is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the crankshaft. The connecting rod is required to transmit the compressive and tensile forces from the piston. In its most common form, in an internal combustion engine, it allows pivoting on the piston end and rotation on the shaft end. The predecessor to the connecting rod is a mechanic linkage used by water mills to convert rotating motion of the water wheel into reciprocating motion. The most common usage of connecting rods is in internal combustion engines or on steam engines. __TOC__ Origins The predecessor to the connecting length is the mechanical linkage used by Roman-era watermills. The earliest known example of this linkage has been found at the late 3rd century Hierapolis sawmill in Roman Asia (modern Turkey) and the 6th century ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Diesel Engine
Marine propulsion is the mechanism or system used to generate thrust to move a watercraft through water. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting of an electric motor or internal combustion engine driving a propeller, or less frequently, in pump-jets, an impeller. Marine engineering is the discipline concerned with the engineering design process of marine propulsion systems. Human-powered paddles and oars, and later, sails were the first forms of marine propulsion. Rowed galleys, some equipped with sail, played an important early role in early human seafaring and warfares. The first advanced mechanical means of marine propulsion was the marine steam engine, introduced in the early 19th century. During the 20th century it was replaced by two-stroke or four-stroke diesel engines, outboard motors, and gas turbine engines on faster ships. Marine nuclear reactors, which appeared in the 1950s, pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gudgeon Pin
In internal combustion engines, the gudgeon pin (UK, wrist pin or piston pin US) connects the piston to the connecting rod, and provides a bearing for the connecting rod to pivot upon as the piston moves.Nunney, Malcolm James (2007) "The Reciprocating Piston Petrol Engine: Gudgeon pins and their location" ''Light and heavy vehicle technology'' (4th ed.) Butterworth-Heinemann, Oxford, UKp. 28 In very early engine designs, including those driven by steam, and many very large stationary or marine engines, the gudgeon pin is located in a sliding crosshead that connects to the piston via a rod. A gudgeon is a pivot or journal. The origin of the word gudgeon is the Middle English word gojoun, which originated from the Middle French word goujon. Its first known use was in the 15th century.Webster's Seventh New Collegiate Dictionary, G & C Merriam Company, 1963, p. 370 Overview The gudgeon pin is typically a forged short hollow rod made of a steel alloy of high strength and hardness tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slider-crank Linkage
A slider-crank linkage is a four-link mechanism with three revolute joints and one prismatic, or sliding, joint. The rotation of the crank drives the linear movement the slider, or the expansion of gases against a sliding piston in a cylinder can drive the rotation of the crank. There are two types of slider-cranks: in-line and offset. # In-line: An in-line slider-crank has its slider positioned so the line of travel of the hinged joint of the slider passes through the base joint of the crank. This creates a symmetric slider movement back and forth as the crank rotates. # Offset: If the line of travel of the hinged joint of the slider does not pass through the base pivot of the crank, the slider movement is not symmetric. It moves faster in one direction than the other. This is called a ''quick-return mechanism.'' There are also two methods to design each type: graphical and analytical. In-line kinematics The displacement of the end of the connecting rod is approximat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
