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Hobson's Joint
A Hobson's joint or Hobson's coupling is a type of right-angle constant-velocity joint; rods bent 90° are able to transmit torque around a corner because they are all free to turn in their mounting holes in both legs of the coupling. Hobson's joints are used to make elbow engines, a novelty device, but also for practical purposes in tools and shaft-driven bicycle A shaft-driven bicycle is a bicycle that uses a drive shaft instead of a chain to transmit power from the pedals to the wheel. Shaft drives were introduced in the 1880s, but were mostly supplanted by chain-driven bicycles due to the gear ranges ... gearing. External links * * * References Gears Rotating shaft couplings {{mech-engineering-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constant-velocity Joint
A constant-velocity joint (also called a CV joint and homokinetic joint) is a mechanical coupling which allows the shafts to rotate freely (without an appreciable increase in friction or Backlash (engineering), backlash) and compensates for the angle between the two shafts, within a certain range, to maintain the same velocity. A common use of CV joints is in front-wheel drive vehicles, where they are used to transfer the engine's power to the wheels, even as the angle of the driveshaft varies due to the operation of the steering and Car suspension, suspension. History The predecessor to the constant-velocity joint was the universal joint (also called a ''Cardan joint'') which was invented by Gerolamo Cardano in the 16th century. A short-coming of the universal joint is that the rotational speed of the output shaft fluctuates despite the rotational speed of the input shaft being constant. This fluctuation causes unwanted vibration in the system and increases as the angle betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elbow Engine
An elbow engine is a piston-based steam engine typically fed by steam or compressed air to drive a flywheel and/or mechanical load. It is based on a mechanism known as a Hobson's joint. Although not commonly used today for practical purposes, it is still built by hobbyists for its rarity and unconventionality. Principle of operation Elbow engines have two rotating, circular, cylinder blocks. Each block contains a ring of parallel cylinders and can itself rotate on a central axis, similar to a Cylinder (firearms), revolver cylinder. The two blocks are placed at 90° to each other. Each piston is L-shaped, and circular in cross section with one end fitted into each cylinder block. The two cylinder blocks rotate together, coupled only by the pistons. Engine output is taken from the rotation of one cylinder block. Pressure is supplied to each cylinder by means of a fixed plate forming a plain thrust bearing with the back of the cylinder block. This has two openings in it which suppl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shaft-driven Bicycle
A shaft-driven bicycle is a bicycle that uses a drive shaft instead of a chain to transmit power from the pedals to the wheel. Shaft drives were introduced in the 1880s, but were mostly supplanted by chain-driven bicycles due to the gear ranges possible with sprockets and derailleurs. Around the 2000s, due to advancements in internal gear technology, a small number of modern shaft-driven bicycles have been introduced. Shaft-driven bikes have a large bevel gear where a conventional bike would have its chain ring. This meshes with another bevel gear mounted on the drive shaft. The use of bevel gears allows the axis of the drive torque from the pedals to be turned through 90 degrees. The drive shaft then has another bevel gear near the rear wheel hub which meshes with a bevel gear on the hub where the rear sprocket would be on a conventional bike, and canceling out the first drive torque change of axis. The 90-degree change of the drive plane that occurs at the bottom bracket a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gears
A gear or gearwheel is a rotating machine element, machine part typically used to transmit rotation, rotational motion and/or torque by means of a series of teeth that engage with compatible teeth of another gear or other part. The teeth can be integral saliences or cavities machining, machined on the part, or separate pegs inserted into it. In the latter case, the gear is usually called a cogwheel. A cog may be one of those pegsDefinition of "cog" in the ''Oxford Learner's Dictionary'' online. Accessed on 2024-07-29.Definition of "cog" in the ''Merriam-Webster Dictionary'' online. Accessed on 2024-07-29. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
