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Bipolar Electric Motor
A bipolar electric motor is an electric motor with only two (hence ''bi-'') poles to its stationary field. They are an example of the simple brushed DC motor, with a commutator. This field may be generated by either a permanent magnet or a field coil. The 'bipolar' term refers to the stationary field of the motor, not the rotor. The rotors often have more than two poles, three for a simple motor and potentially more for a high-power motor. A two-pole rotor has the disadvantage that it is not self-starting in all positions and so requires to be flicked to start. Early motors The first DC electrical motors, from the Gramme motor of the 1870s onwards, used bipolar fields. These early machines used crudely designed field pole pieces with long magnetic circuits, wide pole gaps and narrow pole pieces that gave only a limited flux through the armature. These fields were usually horseshoe-shaped, with either permanent horseshoe magnets or else either one or two field coils at some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locomotive Frame
A locomotive frame is the structure that forms the backbone of the railway locomotive, giving it strength and supporting the superstructure elements such as a cab, boiler or bodywork. The vast majority of locomotives have had a frame structure of some kind. The frame may in turn be supported by axles directly attached to it, or it may be mounted on bogies ( UK) / trucks ( US), or a combination of the two. The bogies in turn will have frames of their own. Types of frame 250px, Preserved GWR 9017 showing outside frames Three main types of frame on steam locomotives may be distinguished:, p 255. Plate frames These used steel plates about thick. They were mainly used in Britain and continental Europe. On most locomotives, the frames would be situated within the driving wheels ("inside frames"), but some classes of an early steam locomotive and diesel shunters were constructed with "outside frames". Some early designs were double framed where the frame consisted of plates both in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induction Motor
An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor can therefore be made without electrical connections to the rotor. An induction motor's rotor can be either wound type or squirrel-cage type. Three-phase squirrel-cage induction motors are widely used as industrial drives because they are self-starting, reliable and economical. Single-phase induction motors are used extensively for smaller loads, such as household appliances like fans. Although traditionally used in fixed-speed service, induction motors are increasingly being used with variable-frequency drives (VFD) in variable-speed service. VFDs offer especially important energy savings opportunities for existing and prospective induction motors in variable-torque centrifugal fan, pump and compressor load applications. Squirrel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Drill
A drill is a tool used for making round holes or driving fasteners. It is fitted with a bit, either a drill or driverchuck. Hand-operated types are dramatically decreasing in popularity and cordless battery-powered ones proliferating due to increased efficiency and ease of use. Drills are commonly used in woodworking, metalworking, construction, machine tool fabrication, construction and utility projects. Specially designed versions are made for miniature applications. History Around 35,000 BC, ''Homo sapiens'' discovered the benefits of the application of rotary tools. This would have rudimentarily consisted of a pointed rock being spun between the hands to bore a hole through another material. This led to the hand drill, a smooth stick, that was sometimes attached to flint point, and was rubbed between the palms. This was used by many ancient civilizations around the world including the Mayans. The earliest perforated artifacts, such as bone, ivory, shells, and antler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Cleaner
A vacuum cleaner, also known simply as a vacuum or a hoover, is a device that causes suction in order to remove dirt from floors, upholstery, draperies, and other surfaces. It is generally electrically driven. The dirt is collected by either a dustbag or a cyclone for later disposal. Vacuum cleaners, which are used in homes as well as in industry, exist in a variety of sizes and models—small battery-powered hand-held devices, wheeled canister models for home use, domestic central vacuum cleaners, huge stationary industrial appliances that can handle several hundred litres of dirt before being emptied, and self-propelled vacuum trucks for recovery of large spills or removal of contaminated soil. Specialized shop vacuums can be used to suck up both solid matter and liquids. Name Although ''vacuum cleaner'' and the short form ''vacuum'' are neutral names, in some countries (UK, Ireland) ''hoover'' is used instead as a genericized trademark, and as a verb. The name comes from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food Mixer
A mixer, depending on the type, also called a hand mixer or stand mixer, is a kitchen device that uses a gear-driven mechanism to rotate a set of "beaters" in a bowl containing the food or liquids to be prepared by mixing them. Mixers help automate the repetitive tasks of stirring, whisking or beating. When the beaters are replaced by a ''dough hook'', a mixer may also be used to knead. A mixer may be a handheld mechanism known as an eggbeater, a handheld motorized beater, or a drill mixer. Stand mixers vary in size from small counter top models for home use to large capacity commercial machines. Stand mixers create the mixing action by either rotating the mixing device vertically (planetary mixers), or by rotating the mixing container (spiral mixers). History The mixer with rotating parts was patented in 1856 by Baltimore, Maryland, tinner Ralph Collier. This was followed by E.P. Griffith's whisk patented in England in 1857. Another hand-turned rotary egg beater was paten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Home Appliance
A home appliance, also referred to as a domestic appliance, an electric appliance or a household appliance, is a machine which assists in household functions such as cooking, cleaning and food preservation. Appliances are divided into three types: small appliances, major appliances (also known as white goods) and consumer electronics (brown goods). Definition Given a broad usage, the domestic application attached to home appliance is tied to the definition of appliance as "an instrument or device designed for a particular use or function". More specifically, Collins English Dictionary defines "home appliance" as: "devices or machines, usually electrical, that are in your home and which you use to do jobs such as cleaning or cooking". The broad usage, afforded to the definition allows for nearly any device intended for domestic use to be a home appliance, including consumer electronics as well as stoves, refrigerators, toasters and air conditioners. History While many ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Motor
The universal motor is a type of electric motor that can operate on either AC or DC power and uses an electromagnet as its stator to create its magnetic field. It is a commutated series-wound motor where the stator's field coils are connected in series with the rotor windings through a commutator. It is often referred to as an AC series motor. The universal motor is very similar to a DC series motor in construction, but is modified slightly to allow the motor to operate properly on AC power. This type of electric motor can operate well on AC because the current in both the field coils and the armature (and the resultant magnetic fields) will alternate (reverse polarity) synchronously with the supply. Hence the resulting mechanical force will occur in a consistent direction of rotation, independent of the direction of applied voltage, but determined by the commutator and polarity of the field coils.Herman, Stephen L. ''Delmar's Standard Textbook of Electricity, 3rd Edition.'' Clif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-Motor
T-Motor was the class designation given by the New York Central to its ALCO- GE built T-1a, T-1b, T-2a, T-2b, and T-3a electric locomotives. The T-Motors were the New York Central's second electric locomotive purchase after the original class of S-Motors. The T-motors continued on in service with the New York Central and a few continued on with the Penn Central after the 1968 merger. History ALCO and GE co-built T-Motors from 1913 to 1926 to take over the main line passenger duties from the earlier and somewhat less capable S-Motor classes. Like the rest of the eastern electric fleet T-Motors were only used on the third rail territory from Grand Central Terminal on to the Hudson and Harlem Divisions. Compared to the S-Motors the T's had more power and with no unpowered wheels all of the locomotive's weight could be transferred into tractive effort. The T-Motors were also faster than the S-Motors and hauled everything from commuter trains to the flagship ''20th Century Limited ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-Motor
S-Motor was the class designation given by the New York Central to its ALCO- GE built S-1, S-2, S-2a and S-3 electric locomotives. The S-Motors hold the distinction of being the world's first mass-produced main line electric locomotives with the prototype #6000 being constructed in 1904. The S-Motors would serve alone until the more powerful T-motors began to arrive in 1913, eventually displacing them from main line passenger duties. From that point the class was assigned to shorter commuter trains and deadhead rolling stock between Grand Central Terminal and Mott Haven coach yard. Some examples, including the prototype later renumbered #100, would serve in this capacity through the Penn Central merger in 1968, only being retired in the 1970s as long distance passenger traffic to Grand Central dried up. History After a disastrous 1902 accident in the Park Avenue Tunnel the New York legislature passed a law banning steam locomotives within the city limits effective in 1908. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York Central
The New York Central Railroad was a railroad primarily operating in the Great Lakes and Mid-Atlantic regions of the United States. The railroad primarily connected greater New York and Boston in the east with Chicago and St. Louis in the Midwest, along with the intermediate cities of Albany, Buffalo, Cleveland, Cincinnati, Detroit, Rochester and Syracuse. New York Central was headquartered in New York City's New York Central Building, adjacent to its largest station, Grand Central Terminal. The railroad was established in 1853, consolidating several existing railroad companies. In 1968, the NYC merged with its former rival, the Pennsylvania Railroad, to form Penn Central. Penn Central went bankrupt in 1970 and merged into Conrail in 1976. Conrail was broken-up in 1999, and portions of its system were transferred to CSX and Norfolk Southern Railway, with CSX acquiring most of the old New York Central trackage. Extensive trackage existed in the states of New York, Pennsylv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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