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Wheel
A wheel is a rotating component (typically circular in shape) that is intended to turn on an axle Bearing (mechanical), bearing. The wheel is one of the key components of the wheel and axle which is one of the Simple machine, six simple machines. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, or performing labor in machines. Wheels are also used for other purposes, such as a ship's wheel, steering wheel, potter's wheel, and flywheel. Common examples can be found in transport applications. A wheel reduces friction by facilitating motion by rolling together with the use of axles. In order for a wheel to rotate, a Moment (physics), moment must be applied to the wheel about its axis, either by gravity or by the application of another external force or torque. Terminology The English word '':wikt:wheel, wheel'' comes from the Old English word , from Proto-Germanic language, Proto-Germanic , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steering Wheel
A steering wheel (also called a driving wheel, a hand wheel, or simply wheel) is a type of steering control in vehicles. Steering wheels are used in most modern land vehicles, including all mass-production automobiles, buses, light and heavy trucks, as well as tractors and tanks. The steering wheel is the part of the steering system that the driver manipulates; the rest of the steering system responds to such driver inputs. This can be through direct mechanical contact as in recirculating ball or rack and pinion steering gears, without or with the assistance of hydraulic power steering, HPS, or as in some modern production cars with the help of computer-controlled motors, known as Power steering#Electric systems, electric power steering. History Near the start of the 18th century, many sea vessels appeared using the ship's wheel design. However, historians are unclear when that approach to steering was first used. The first automobiles were steered with a Tiller (automobi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chariot
A chariot is a type of vehicle similar to a cart, driven by a charioteer, usually using horses to provide rapid Propulsion, motive power. The oldest known chariots have been found in burials of the Sintashta culture in modern-day Chelyabinsk Oblast, Russia, dated to c. 1950–1880 BC and are depicted on cylinder seals from Central Anatolia Region, Central Anatolia in Kültepe dated to c. 1900 BC. The critical invention that allowed the construction of light, horse-drawn chariots was the spoked wheel. The chariot was a fast, light, open, two-wheeled conveyance drawn by two or more Equidae, equids (usually horses) that were hitched side by side, and was little more than a floor with a waist-high guard at the front and sides. It was initially used for ancient warfare during the Bronze Age, Bronze and Iron Age, Iron Ages, but after its military capabilities had been superseded by Light cavalry, light and Heavy cavalry, heavy cavalries, chariots continued to be used for travel and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spoke
A spoke is one of some number of rods radiating from the center of a wheel (the hub where the axle connects), connecting the hub with the round traction surface. The term originally referred to portions of a log that had been riven (split lengthwise) into four or six sections. The radial members of a wagon wheel were made by carving a spoke (from a log) into their finished shape. A spokeshave is a tool originally developed for this purpose. Eventually, the term spoke was more commonly applied to the finished product of the wheelwright's work than to the materials they used. History The spoked wheel was invented to allow the construction of lighter and swifter vehicles. The earliest physical evidence for spoked wheels was found in the Sintashta culture, dating to 2000 BCE. Soon after this, horse cultures of the Caucasus region used horse-drawn spoked-wheel war chariots for the greater part of three centuries. They moved deep into the Greek peninsula, where they joined w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheel And Axle
The wheel and axle is a simple machine, consisting of a wheel attached to a smaller axle so that these two parts rotate together, in which a force is transferred from one to the other. The wheel and axle can be viewed as a version of the lever, with a drive force applied tangentially to the perimeter of the wheel, and a load force applied to the axle supported in a bearing, which serves as a fulcrum. History The Halaf culture of 6500–5100 BCE has been credited with the earliest depiction of a wheeled vehicle, but this is doubtful as there is no evidence of Halafians using either wheeled vehicles or even pottery wheels. One of the first applications of the wheel to appear was the potter's wheel, used by prehistoric cultures to fabricate clay pots. The earliest type, known as "tournettes" or "slow wheels", were known in the Middle East by the 5th millennium BCE. One of the earliest examples was discovered at Tepe Pardis, Iran, and dated to 5200–4700 BCE. These wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potter's Wheel
In pottery, a potter's wheel is a machine used in the shaping (known as throwing) of clay into round ceramic ware. The wheel may also be used during the process of trimming excess clay from leather-hard dried ware that is stiff but malleable, and for applying incised decoration or rings of colour. Use of the potter's wheel became widespread throughout the Old World but was unknown in the Pre-Columbian New World, where pottery was handmade by methods that included coiling and beating. A potter's wheel may occasionally be referred to as a "potter's lathe". However, that term is better used for another kind of machine that is used for a different shaping process, turning, similar to that used for shaping of metal and wooden articles. The pottery wheel is an important component to create arts and craft products. The techniques of jiggering and jolleying can be seen as extensions of the potter's wheel: in jiggering, a shaped tool is slowly brought down onto the plastic clay bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axle
An axle or axletree is a central shaft for a rotation, rotating wheel and axle, wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearing (mechanical), bearings or Bushing (bearing), bushings are provided at the mounting points where the axle is supported. In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type of axle is referred to as a ''spindle (tool), spindle''. Terminology On cars and trucks, several senses of the word ''axle'' occur in casual usage, referring to the shaft itself, its housing, or simply any transverse pair of wheels. Strictly speaking, a shaft that rotates with the wheel, being either Bolt (fastener), bolted or rotating spline, splined in fixed relation to it, is called an ''axle'' or ''axle shaft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bearing (mechanical)
A ball bearing A bearing is a machine element that constrains relative motion to only the desired motion and reduces friction between moving parts. The design of the bearing may, for example, provide for free linear movement of the moving part or for free rotation around a fixed axis; or, it may prevent a motion by controlling the vectors of normal forces that bear on the moving parts. Most bearings facilitate the desired motion by minimizing friction. Bearings are classified broadly according to the type of operation, the motions allowed, or the directions of the loads (forces) applied to the parts. The term "bearing" is derived from the verb " to bear"; a bearing being a machine element that allows one part to bear (i.e., to support) another. The simplest bearings are bearing surfaces, cut or formed into a part, with varying degrees of control over the form, size, roughness, and location of the surface. Other bearings are separate devices installed into a machine or mach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Machine
A simple machine is a machine, mechanical device that changes the Direction (geometry) , direction or Magnitude_(mathematics) , magnitude of a force. In general, they can be defined as the simplest Mechanism (engineering) , mechanisms that use mechanical advantage (also called leverage) to multiply force. Usually the term refers to the six classical simple machines that were defined by Renaissance scientists: * Lever * Wheel and axle * Pulley * Inclined plane * Wedge (mechanical device), Wedge * Screw (simple machine), Screw A simple machine uses a single applied force to do Mechanical work, work against a single load force. Ignoring friction losses, the work done on the load is equal to the work done by the applied force. The machine can increase the amount of the output force, at the cost of a proportional decrease in the distance moved by the load. The ratio of the output to the applied force is called the ''mechanical advantage''. Simple machines can be regarded as the eleme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proto-Indo-European Language
Proto-Indo-European (PIE) is the reconstructed common ancestor of the Indo-European language family. No direct record of Proto-Indo-European exists; its proposed features have been derived by linguistic reconstruction from documented Indo-European languages. Far more work has gone into reconstructing PIE than any other proto-language, and it is the best understood of all proto-languages of its age. The majority of linguistic work during the 19th century was devoted to the reconstruction of PIE and its daughter languages, and many of the modern techniques of linguistic reconstruction (such as the comparative method) were developed as a result. PIE is hypothesized to have been spoken as a single language from approximately 4500 BCE to 2500 BCE during the Late Neolithic to Early Bronze Age, though estimates vary by more than a thousand years. According to the prevailing Kurgan hypothesis, the original homeland of the Proto-Indo-Europeans may have been in the Pon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pottery
Pottery is the process and the products of forming vessels and other objects with clay and other raw materials, which are fired at high temperatures to give them a hard and durable form. The place where such wares are made by a ''potter'' is also called a ''pottery'' (plural ''potteries''). The definition of ''pottery'', used by the ASTM International, is "all fired ceramic wares that contain clay when formed, except technical, structural, and refractory products". End applications include tableware, ceramic art, decorative ware, toilet, sanitary ware, and in technology and industry such as Insulator (electricity), electrical insulators and laboratory ware. In art history and archaeology, especially of ancient and prehistoric periods, pottery often means only vessels, and sculpture, sculpted figurines of the same material are called terracottas. Pottery is one of the Timeline of historic inventions, oldest human inventions, originating before the Neolithic, Neolithic period, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship's Wheel
A ship's wheel or boat's wheel is a device used aboard a ship, boat, submarine, or airship, with which a helmsman steering, steers the vessel and controls its course (navigation), course. Together with the rest of the steering mechanism, it forms part of the helm (the term ''helm'' can mean the wheel alone, or the entire mechanism by which the rudder is controlled). It is connected to a mechanical, electric Servomechanism, servo, or hydraulics, hydraulic system which alters the horizontal angle of the vessel's rudder relative to its Hull (watercraft), hull. In some modern ships the wheel is replaced with a simple toggle that remotely controls an electro-mechanical or electro-hydraulic drive for the rudder, with a rudder position indicator presenting feedback to the helmsman. History Until the invention of the ship's wheel, the helmsman relied on a tiller—a horizontal bar fitted directly to the top of the rudder post—or a whipstaff—a vertical stick acting on the arm of the sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalcolithic
The Chalcolithic ( ) (also called the Copper Age and Eneolithic) was an archaeological period characterized by the increasing use of smelted copper. It followed the Neolithic and preceded the Bronze Age. It occurred at different periods in different areas, but was absent in some parts of the world, such as Russia, where there was no well-defined Copper Age between the Stone and Bronze Ages. Stone tools were still predominantly used during this period. The Chalcolithic covers both the early cold working (hammering) of near pure copper ores, as exhibited by the likes of North American Great Lakes Old Copper complex, from around 6,500 BC, through the later copper smelting cultures. The archaeological site of Belovode, on Rudnik mountain in Serbia, has the world's oldest securely dated evidence of copper smelting at high temperature, from . The transition from Copper Age to Bronze Age in Europe occurred between the late 5th and the late In the Ancient Near East the Copper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
