About Shaft Couplings
A shaft coupling is a mechanical aspect that connects the drive shaft and driven shaft of a electric motor, etc., to be able to transmit electric power. Shaft couplings expose mechanical flexibility, offering tolerance for shaft misalignment. Subsequently, this coupling flexibility can reduce uneven dress in on the bearing, tools vibration, and other mechanical troubles due to misalignment.
Shaft couplings are available in a small type mainly for FA (factory automation) and a sizable casting type used for significant power transmission such as in wind and hydraulic electrical power machinery.
In NBK, the former is named a coupling and the latter is named a shaft coupling. 
Below, we will speak about the shaft coupling.
Why Do WE ARE IN NEED OF Shaft Couplings?
Even if the engine and workpiece are immediately connected and effectively fixed, slight misalignment can occur over time because of alterations in temperature and improvements over an extended period of time, triggering vibration and damage.
Shaft couplings serve seeing that an important link to minimize impression and vibration, allowing easy rotation to become transmitted.
Flexible Flanged Shaft Couplings
Characteristics
These are the most used flexible shaft couplings in Japan that adhere to JIS B 1452-1991 “Flexible flanged shaft couplings”.
A simple structure made of a flange and coupling bolts. Easy to set up.
The bushing between your flange and coupling bolts alleviates the consequences of torque fluctuation and impacts during startup and shutdown.
The bushing can be replaced by just removing the coupling bolt, enabling easy maintenance.
Permits lateral/angular misalignment, and reduces noises. Prevents the thrust load from staying transmitted.
2 types can be found, a cast iron FCL type and a carbon steel?FCLS type Flexible Shaft Couplings
Shaft Coupling Considerations
In choosing couplings a designer initially needs to consider motion control varieties or power transmission types. Most motion control applications transmit comparatively low torques. Power tranny couplings, in contrast, are designed to carry moderate to large torques. This decision will narrow coupling choice relatively. Torque tranny along with optimum permissible parallel and angular misalignment ideals are the dominant considerations. Most couplings will publish these values and with them to refine the search should produce deciding on a coupling style a lot easier. Optimum RPM is another important attribute. Optimum axial misalignment may be a consideration as well. Zero backlash is certainly an essential consideration where feedback is employed as in a motion control system.
Some power transmission couplings are created to operate without lubricant, which may be an advantage where maintenance is a concern or difficult to perform. Lubricated couplings sometimes require addresses to keep carefully the grease in. A large number of couplings, including chain, equipment, Oldham, etc., can be found either because lubricated metal-on-metal kinds and as metal and plastic hybrids where generally the coupling element is made of nylon or another plastic-type to eradicate the lubrication requirements. There is a reduction in torque capacity in these unlubricated forms when compared to more conventional designs.
Important Attributes
Coupling Style
Almost all of the common styles have been described above.
Maximum RPM
Many couplings have a limit on their maximum rotational velocity. Couplings for high-rate turbines, compressors, boiler feed pumps, etc. usually require balanced patterns and/or balanced bolts/nuts allowing disassembly and reassembly without increasing vibration during procedure. High-speed couplings can also exhibit windage results within their guards, which can bring about cooling concerns.
Max Transmitted Horsepower or Torque
Couplings tend to be rated by their optimum torque potential, a measurable quantity. Vitality is a function of torque circumstances rpm, thus when these ideals are stated it is normally at a specified rpm (5HP @ 100 rpm, for example). Torque values will be the more commonly cited of both.
Max Angular Misalignment
Among the shaft misalignment types, angular misalignment capacity is usually stated in degrees and represents the utmost angular offset the coupled shafts exhibit.
Max Parallel Misalignment
Parallel misalignment capacity is usually given in linear devices of inches or millimeters and represents the utmost parallel offset the coupled shafts exhibit.
Max Axial Motion
Sometimes called axial misalignment, this attribute specifies the maximum permissible growth between the coupled shafts, given generally in inches or millimeters, and will be caused by thermal effects.
