An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy.
A locomotive or engine is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, motor coach, railcar or power car; the use of these self-propelled vehicles is increasingly common for passenger trains, but rare for freight.
A hybrid vehicle is one that uses two or more distinct types of power, such as submarines that use diesel when surfaced and batteries when submerged. Other means to store energy include pressurized fluid in hydraulic hybrids.
A railcar is a self-propelled railway vehicle designed to transport passengers. The term "railcar" is usually used in reference to a train consisting of a single coach, with a driver's cab at one or both ends. Some railway companies, such as the Great Western, termed such vehicles "railmotors".
Regenerative braking is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In this mechanism, the electric traction motor uses the vehicle's momentum to recover energy that would otherwise be lost to the brake discs as heat. This method contrasts with conventional braking systems. In those systems, the excess kinetic energy is converted to unwanted and wasted heat due to friction in the brakes, or with rheostatic brakes, where the energy is recovered by using electric motors as generators but is immediately dissipated as heat in resistors. In addition to improving the overall efficiency of the vehicle, regeneration can significantly extend the life of the braking system as the mechanical parts will not wear out quickly.
A diesel locomotive is a type of railway locomotive in which the prime mover is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conveyed to the driving wheels.
Dynamic braking is the use of an electric traction motor as a generator when slowing a vehicle such as an electric or diesel-electric locomotive. It is termed "rheostatic" if the generated electrical power is dissipated as heat in brake grid resistors, and "regenerative" if the power is returned to the supply line. Dynamic braking reduces wear on friction-based braking components, and regeneration lowers net energy consumption. Dynamic braking may also be used on railcars with multiple units, light rail vehicles, electric trams, trolleybuses, and electric and hybrid electric automobiles.
Propulsion transmission is the mode of transmitting and controlling propulsion power of a machine. The term transmission properly refers to the whole drivetrain, including clutch, gearbox, prop shaft, differential, and final drive shafts. In the United States the term is sometimes used in casual speech to refer more specifically to the gearbox alone, and detailed usage differs. The transmission reduces the higher engine speed to the slower wheel speed, increasing torque in the process. Transmissions are also used on pedal bicycles, fixed machines, and where different rotational speeds and torques are adapted.
A diesel–electric transmission, or diesel–electric powertrain is a transmission system for vehicles powered by diesel engines in road, rail, and marine transport. Diesel–electric transmission is based on petrol–electric transmission, a very similar transmission system used for petrol engines.
A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric or hydrogen vehicles, elevators or electric multiple unit.
A motor–generator is a device for converting electrical power to another form. Motor–generator sets are used to convert frequency, voltage, or phase of power. They may also be used to isolate electrical loads from the electrical power supply line. Large motor–generators were widely used to convert industrial amounts of power while smaller motor–generators were used to convert battery power to higher DC voltages.
A fluid coupling or hydraulic coupling is a hydrodynamic or 'hydrokinetic' device used to transmit rotating mechanical power. It has been used in automobile transmissions as an alternative to a mechanical clutch. It also has widespread application in marine and industrial machine drives, where variable speed operation and controlled start-up without shock loading of the power transmission system is essential.
A retarder is a device used to augment or replace some of the functions of primary friction-based braking systems, usually on heavy vehicles. Retarders serve to slow vehicles, or maintain a steady speed while traveling down a hill, and help prevent the vehicle from "running away" by accelerating down the hill. They are not usually capable of bringing vehicles to a standstill, as their effectiveness diminishes as vehicle speed lowers. They are usually used as an additional "assistance" to slow vehicles, with the final braking done by a conventional friction braking system. As the friction brake will be used less, particularly at higher speeds, their service life is increased, and since in those vehicles the brakes are air-actuated helps to conserve air pressure too.
Hybrid vehicle drivetrains transmit power to the driving wheels for hybrid vehicles. A hybrid vehicle has multiple forms of motive power.
A hybrid train is a locomotive, railcar or train that uses an onboard rechargeable energy storage system (RESS), placed between the power source and the traction transmission system connected to the wheels. Since most diesel locomotives are diesel-electric, they have all the components of a series hybrid transmission except the storage battery, making this a relatively simple prospect.
A drivetrain is the group of components that deliver mechanical power from the prime mover to the driven components. In automotive engineering, the drivetrain is the components of a motor vehicle that deliver power to the drive wheels. This excludes the engine or motor that generates the power. In marine applications, the drive shaft will drive a propeller, thruster, or waterjet rather than a drive axle, while the actual engine might be similar to an automotive engine. Other machinery, equipment and vehicles may also use a drivetrain to deliver power from the engine(s) to the driven components.
A turbine–electric transmission system includes a turboshaft gas turbine connected to an electrical generator, creating electricity that powers electric traction motors. No clutch is required.
Petrol–electric transmission or gasoline–electric transmission or gas–electric transmission is a transmission system for vehicles powered by petrol engines. Petrol–electric transmission was used for a variety of applications in road, rail, and marine transport, in the early 20th century. After World War I, it was largely superseded by diesel-electric transmission, a similar transmission system used for diesel engines; but petrol-electric has become popular again in modern hybrid electric vehicles.
There are numerous versions of vehicle propulsion systems. Many of those came into fruition due to need for cleaner vehicles. Each of them might have many abbreviations and some might be misleading. This article explains shortly what defines them.
An internal combustion locomotive is a type of railway locomotive that produces its pulling power using an internal combustion engine. These locomotives are fuelled by burning fossil fuels, most commonly oil or gasoline, to produce rotational power which is transmitted to the locomotive's driving wheels by various direct or indirect transmission mechanisms. The fuel is carried on the locomotive.
