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.
In a motor vehicle, the clutch acts as a mechanical linkage between the engine and transmission. By disengaging the clutch, the engine speed (RPM) is no longer determined by the speed of the driven wheels.
The Thor washing machine was the first electric clothes washer sold commercially in the United States. Produced by the Chicago-based Hurley Electric Laundry Equipment Company, the 1907 Thor is believed to be the first electrically powered washer ever manufactured, crediting Hurley as the inventor of the first automatic washing machine. Designed by Hurley engineer Alva J. Fisher, a patent for the new electric Thor was issued on August 9, 1910, three years after its initial invention.
The idea of an automatic washing machine had been around for many years. However, these were crude mechanical efforts that typically involved a manually operated crank or similar design. In many ways, the patent of the new Thor washer sounds modern, even today. The patent states that a "perforated cylinder is rotatably mounted within the tub containing the wash water". A series of blades lifted the clothes as the cylinder rotated. After 8 rotations in one direction, the machine would reverse rotation to "prevent the cloths from wadding up into a compact mass". Drive belts attached to a Westinghouse motor connected to three wheels of different sizes, which moved the drum during operation. The design also included a clutch, which allowed the machine to switch direction, and an emergency stop rod. The new Thor washer was mass marketed throughout the United States beginning in 1908.
In engineering, a mechanism is a device that transforms input forces and movement into a desired set of output forces and movement. Mechanisms generally consist of moving components which may include gears and gear trains; Belts and chain drives; cams and followers; Linkages; Friction devices, such as brakes or clutches; Structural components such as a frame, fasteners, bearings, springs, or lubricants; Various machine elements, such as splines, pins, or keys.
German scientist Franz Reuleaux defines machine as "a combination of resistant bodies so arranged that by their means the mechanical forces of nature can be compelled to do work accompanied by certain determinate motion". In this context, his use of machine is generally interpreted to mean mechanism.
A centrifugal clutch is an automatic clutch that uses centrifugal force to operate. The output shaft is disengaged at lower rotational speed and engages as the output increases to a certain speed. It is often used in mopeds, underbones, lawn mowers, go-karts, chainsaws, mini bikes, and some paramotors and boats to keep the engine from stalling when the output shaft is slowed or stopped abruptly, and to remove load when starting and idling. It has been superseded for automobile applications by the fluid coupling, torque converter and automated manual transmissions.
Machine element or hardware refers to an elementary component of a machine. These elements consist of three basic types:
While generally not considered to be a machine element, the shape, texture and color of covers are an important part of a machine that provide a styling and operational interface between the mechanical components of a machine and its users.
A dog clutch (also known as a dog ring, clutch dog, dog gear, or positive clutch) is a type of clutch that couples two rotating shafts or other rotating components by engagement of interlocking teeth or dogs rather than by friction. The two parts of the clutch are designed such that one will push the other, causing both to rotate at the same speed and will never slip. In engineering, a "dog" is a tool or device used to lock two components in relation to each other.
Dog clutches are used inside constant-mesh manual transmissions to lock different gears to the rotating input and output shafts. A synchromesh arrangement ensures smooth engagement by matching the shaft speeds before the dog clutch is allowed to engage. Racecar, motorcycle, and large truck transmissions, having higher performance demands and less need for smooth engagement than passenger cars, commonly employ dog clutches unsynchronized to engage gears due to their high strength and durability and low complexity and weight. These unsynchronized gearboxes are nicknamed dog boxes and allow clutchless shifting.
A manual transmission (MT), also known as manual gearbox, standard transmission (in Canada, the United Kingdom and the United States), or stick shift (in the United States), 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 (which is usually a foot pedal for cars or a hand lever for motorcycles).
Early automobiles used sliding-mesh manual transmissions with up to three forward gear ratios. Since the 1950s, constant-mesh manual transmissions have become increasingly commonplace, and the number of forward ratios has increased to 5-speed and 6-speed manual transmissions for current vehicles.
A turbine–electric transmission, or turbine–electric powertrain, system includes a turboshaft gas turbine connected to an electrical generator, creating electricity that powers electric traction motors. No clutch is required.
Turbine–electric transmissions are used to drive both gas turbine locomotives (rarely) and warships.
Integrated electric propulsion (IEP), full electric propulsion (FEP) or integrated full electric propulsion (IFEP) is an arrangement of marine propulsion systems such that gas turbines or diesel generators, or both, generate three-phase electricity that is then used to power electric motors that turn either propellers or waterjet impellors. It is a modification of the combined diesel-electric and gas propulsion system for ships which eliminates the need for clutches and reduces or eliminates the need for gearboxes by using electrical transmission rather than mechanical transmission of energy; so, it is a series hybrid electric propulsion, instead of parallel.
Some newer nuclear-powered warships also use a form of IEP. A nuclear power plant produces the steam to operate turbine generators; these in turn power electric propulsion motors.