Power transmission in the context of "Roller chain"

A portable engine is an engine, either a steam engine or an internal combustion engine, that sits in one place while operating (providing power to machinery), but (unlike a stationary engine) is portable and thus can be easily moved from one work site to another. Mounted on wheels or skids, it is either towed to the work site or moves there via self-propulsion.

Portable engines were in common use in industrialised countries from the early 19th through early 20th centuries, during an era when mechanical power transmission was widespread. Before that, most power generation and transmission were by animal, water, wind, or human; after that, a combination of electrification (including rural electrification) and modern vehicles and equipment (such as tractors, trucks, cars, engine-generators, and machines with their engines built in) displaced most use of portable engines. In developing countries today, portable engines still have some use (typically in the form of modern small engines mounted on boards), although the technologies mentioned above increasingly limit their demand there as well. In industrialised countries they are no longer used for commercial purposes, but preserved examples can often be seen at steam fairs driving appropriate equipment for demonstration purposes.

A line shaft is a power-driven rotating shaft for power transmission that was used extensively from the Industrial Revolution until the early 20th century. Prior to the widespread use of electric motors small enough to be connected directly to each piece of machinery, line shafting was used to distribute power from a large central power source to machinery throughout a workshop or an industrial complex. The central power source could be a water wheel, turbine, windmill, animal power or a steam engine. Power was distributed from the shaft to the machinery by a system of belts, pulleys and gears known as millwork.

A polyphase system (the term coined by Silvanus Thompson) is a means of distributing alternating-current (AC) electrical power that utilizes more than one AC phase, which refers to the phase offset value (in degrees) between AC in multiple conducting wires; phases may also refer to the corresponding terminals and conductors, as in color codes. Polyphase systems have two or more energized electrical conductors carrying alternating currents with a defined phase between the voltage waves in each conductor. Early systems used 4 wire two-phase with a 90° phase angle, but modern systems almost universally use three-phase voltage, with a phase angle of 120° (or 2π/3 radians).

Polyphase systems are particularly useful for transmitting power to electric motors which rely on alternating current to rotate. Three-phase power is used for industrial applications and for power transmission. Compared to a single-phase, two-wire system, a three-phase three-wire system transmits three times as much power for the same conductor size and voltage, using only 1.5 times as many conductors, making it twice as efficient in conductor utilization.

Copper has been used in electrical wiring since the invention of the electromagnet and the telegraph in the 1820s. The invention of the telephone in 1876 created further demand for copper wire as an electrical conductor.

Copper is the electrical conductor in many categories of electrical wiring. Copper wire is used in power generation, power transmission, power distribution, telecommunications, electronics circuitry, and countless types of electrical equipment. Copper and its alloys are also used to make electrical contacts. Electrical wiring in buildings is the most important market for the copper industry. Roughly half of all copper mined is used to manufacture electrical wire and cable conductors.

A line shaft or millworks is a power-driven rotating shaft for power transmission within factories and industrial complexes. They were used extensively from the Industrial Revolution until the early 20th century. Prior to the widespread use of electric motors small enough to be connected directly to each piece of machinery, line shafting was used to distribute power from a large central power source to machinery transmitted through branching belts or gear drives. The central power source could be a water wheel, turbine, windmill, animal power, or a steam engine. Power was distributed from the shaft to the machinery by a system of belts, pulleys and gears known as millworks.