A shaft passer is a device that allows a spoked wheel to rotate despite having a shaft (such as the axle of another wheel) passing between its spokes. The device is usually mentioned as a joke between nerds, in the manner of a fool's errand, however, examples do exist. In ~100 C.E. Heron describes a horse statue with the neck connected to its body with a shaft passer. A sword (acting as the "shaft") could slice through the neck but the head would not detach. In 2023 Blonder created a two and three dimensional shaft passer that allows a wire mesh cube to penetrate a mesh screen under its own weight.
One of the earliest modern references to these devices was made by Richard Feynman, who was told by a colleague at Frankford Arsenal in Philadelphia that the cable-passing version of the device had been used during both world wars on German naval mine mooring cables, to prevent the mines from being caught by British cables swept along the sea bottom. [1]
The device was supposed to work using a spoked, rimless wheel that allows cables to pass through as it rotates. The ends of the spokes are widened, and the cable is held together by a short curved sleeve through which these spoke ends slide. [2]
A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does the work.
A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. The primary purpose of couplings is to join two pieces of rotating equipment while permitting some degree of misalignment or end movement or both. In a more general context, a coupling can also be a mechanical device that serves to connect the ends of adjacent parts or objects. Couplings do not normally allow disconnection of shafts during operation, however there are torque-limiting couplings which can slip or disconnect when some torque limit is exceeded. Selection, installation and maintenance of couplings can lead to reduced maintenance time and maintenance cost.
A differential is a gear train with three drive shafts that has the property that the rotational speed of one shaft is the average of the speeds of the others. A common use of differentials is in motor vehicles, to allow the wheels at each end of a drive axle to rotate at different speeds while cornering. Other uses include clocks and analogue computers. Differentials can also provide a gear ratio between the input and output shafts. For example, many differentials in motor vehicles provide a gearing reduction by having fewer teeth on the pinion than the ring gear.
In the philosophy of thermal and statistical physics, the Brownian ratchet or Feynman–Smoluchowski ratchet is an apparent perpetual motion machine of the second kind, first analysed in 1912 as a thought experiment by Polish physicist Marian Smoluchowski. It was popularised by American Nobel laureate physicist Richard Feynman in a physics lecture at the California Institute of Technology on May 11, 1962, during his Messenger Lectures series The Character of Physical Law in Cornell University in 1964 and in his text The Feynman Lectures on Physics as an illustration of the laws of thermodynamics. The simple machine, consisting of a tiny paddle wheel and a ratchet, appears to be an example of a Maxwell's demon, able to extract mechanical work from random fluctuations (heat) in a system at thermal equilibrium, in violation of the second law of thermodynamics. Detailed analysis by Feynman and others showed why it cannot actually do this.
A wheellock, wheel-lock, or wheel lock is a friction-wheel mechanism which creates a spark that causes a firearm to fire. It was the next major development in firearms technology after the matchlock and the first self-igniting firearm. Its name is from its rotating steel wheel to provide ignition. Developed in Europe around 1500, it was used alongside the matchlock, the snaplock, the snaphance, and the flintlock.
A speedometer or speed meter is a gauge that measures and displays the instantaneous speed of a vehicle. Now universally fitted to motor vehicles, they started to be available as options in the early 20th century, and as standard equipment from about 1910 onwards. Other vehicles may use devices analogous to the speedometer with different means of sensing speed, eg. boats use a pit log, while aircraft use an airspeed indicator.
A manual transmission (MT), also known as manual gearbox, standard transmission, or stick shift, is a multi-speed motor vehicle transmission system, where gear changes require the driver to manually select the gears by operating a gear stick and clutch.
A drive shaft, driveshaft, driving shaft, tailshaft, propeller shaft, or Cardan shaft is a component for transmitting mechanical power, torque, and rotation, usually used to connect other components of a drivetrain that cannot be connected directly because of distance or the need to allow for relative movement between them.
A lift hill, or chain hill, is an upward-sloping section of track on a roller coaster on which the roller coaster train is mechanically lifted to an elevated point or peak in the track. Upon reaching the peak, the train is then propelled from the peak by gravity and is usually allowed to coast throughout the rest of the roller coaster ride's circuit on its own momentum, including most or all of the remaining uphill sections. The initial upward-sloping section of a roller coaster track is usually a lift hill, as the train typically begins a ride with little speed, though some coasters have raised stations that permit an initial drop without a lift hill. Although uncommon, some tracks also contain multiple lift hills.
A horse mill is a mill, sometimes used in conjunction with a watermill or windmill, that uses a horse engine as the power source. Any milling process can be powered in this way, but the most frequent use of animal power in horse mills was for grinding grain and pumping water. Other animal engines for powering mills are powered by dogs, donkeys, oxen or camels. Treadwheels are engines powered by humans.
Rotary wheel blow molding systems are used for the high-output production of a wide variety of plastic extrusion blow molded articles. Containers may be produced from small, single serve bottles to large containers up to 20-30 liters in volume - but wheel machines are often sized for the volume and dimensional demands of a specific container, and are typically dedicated to a narrow range of bottle sizes once built. Multiple parison machines, with high numbers of molds are capable of producing over one million bottles per day in some configurations.
A Feynman sprinkler, also referred to as a Feynman inverse sprinkler or reverse sprinkler, is a sprinkler-like device which is submerged in a tank and made to suck in the surrounding fluid. The question of how such a device would turn was the subject of an intense and remarkably long-lived debate. The device generally remains steady with no rotation, though with sufficiently low friction and high rate of inflow, it has been seen to turn weakly in the opposite direction of a conventional sprinkler.
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links. Chains can be classified by their design, which can be dictated by their use:
A horse harness is a device that connects a horse to a horse-drawn vehicle or another type of load to pull. There are two main designs of horse harness: (1) the breast collar or breaststrap, and (2) the full collar or collar-and-hames.
In horology, a wheel train is the gear train of a mechanical watch or clock. Although the term is used for other types of gear trains, the long history of mechanical timepieces has created a traditional terminology for their gear trains which is not used in other applications of gears.
Bradford Industrial Museum, established 1974 in Moorside Mills, Eccleshill, Bradford, United Kingdom, specializes in relics of local industry, especially printing and textile machinery, kept in working condition for regular demonstrations to the public. There is a Horse Emporium in the old canteen block plus a shop in the mill, and entry is free of charge.
A Bendix drive is a type of engagement mechanism used in starter motors of internal combustion engines. The device allows the pinion gear of the starter motor to engage or disengage the ring gear automatically when the starter is powered or when the engine fires, respectively. It is named after its inventor, Vincent Hugo Bendix.
A thermal wheel, also known as a rotary heat exchanger, or rotary air-to-air enthalpy wheel, energy recovery wheel, or heat recovery wheel, is a type of energy recovery heat exchanger positioned within the supply and exhaust air streams of air-handling units or rooftop units or in the exhaust gases of an industrial process, in order to recover the heat energy. Other variants include enthalpy wheels and desiccant wheels. A cooling-specific thermal wheel is sometimes referred to as a Kyoto wheel.
A motorcycle transmission is a transmission created specifically for motorcycle applications. They may also be found in use on other light vehicles such as motor tricycles and quadbikes, go-karts, offroad buggies, auto rickshaws, mowers, and other utility vehicles, microcars, and even some superlight racing cars.