About Shaft Couplings
A shaft coupling is a mechanical element that connects the drive shaft and driven shaft of a motor, etc., as a way to transmit electrical power. Shaft couplings present mechanical flexibility, featuring tolerance for shaft misalignment. Because of this, this coupling flexibility can reduce uneven have on on the bearing, products vibration, and additional mechanical troubles because of misalignment.
Shaft couplings can be purchased in a little type mainly for FA (factory automation) and a big casting type used for large power transmission such as in wind and hydraulic electrical power machinery.
In NBK, the former is called a coupling and the latter is called a shaft coupling. Below, we will talk about the shaft coupling.
Why Do WE ARE IN NEED OF Shaft Couplings?
Even if the electric motor and workpiece are immediately connected and correctly fixed, slight misalignment can occur over time due to changes in temperature and alterations over an extended period of time, creating vibration and damage.
Shaft couplings serve since an important link to minimize impact and vibration, allowing soft rotation to be transmitted.
Flexible Flanged Shaft Couplings
Characteristics
These are the most popular flexible shaft couplings in Japan that comply with JIS B 1452-1991 “Flexible flanged shaft couplings”.
A simple structure manufactured from a flange and coupling bolts. Easy to install.
The bushing between the flange and coupling bolts alleviates the effects of torque fluctuation and impacts during startup and shutdown.
The bushing could be replaced simply by removing the coupling bolt, enabling easy maintenance.
Permits lateral/angular misalignment, and reduces noises. Prevents the thrust load from currently being transmitted.
2 types are available, a cast iron FCL type and a carbon metal?FCLS type Flexible Shaft Couplings
Shaft Coupling Considerations
In picking couplings a designer primary must consider motion control varieties or power transmission types. Most movement control applications transmit comparatively low torques. Power transmitting couplings, in contrast, are made to carry modest to excessive torques. This decision will narrow coupling choice relatively. Torque tranny along with maximum permissible parallel and angular misalignment values will be the dominant considerations. The majority of couplings will publish these ideals and with them to refine the search should produce deciding on a coupling style easier. Optimum RPM is another vital attribute. Maximum axial misalignment may be a consideration aswell. Zero backlash is an essential consideration where responses is utilized as in a action control system.
Some power tranny couplings are created to operate without lubricant, that can be an advantage where maintenance is a problem or difficult to execute. Lubricated couplings sometimes require includes to keep the grease in. Various couplings, including chain, gear, Oldham, etc., are available either because lubricated metal-on-metal types and as steel and plastic-type material hybrids where usually the coupling element is made of nylon or another plastic material to eradicate the lubrication requirements. There exists a reduction in torque capacity in these unlubricated forms when compared 
to more conventional designs.
Important Attributes
Coupling Style
Most of the common models have already been described above.
Maximum RPM
The majority of couplings have a limit on their maximum rotational quickness. Couplings for high-quickness turbines, compressors, boiler feed pumps, etc. generally require balanced designs and/or balanced bolts/nuts allowing disassembly and reassembly without raising vibration during procedure. High-speed couplings can also exhibit windage results within their guards, which can bring about cooling concerns.
Max Transmitted Horsepower or perhaps Torque
Couplings tend to be rated by their optimum torque capability, a measurable quantity. Vitality is definitely a function of torque times rpm, so when these ideals are stated it is usually at a specified rpm (5HP @ 100 rpm, for example). Torque values are the more commonly cited of the two.
Max Angular Misalignment
One of the shaft misalignment types, angular misalignment potential is usually mentioned in degrees and represents the maximum angular offset the coupled shafts exhibit.
Max Parallel Misalignment
Parallel misalignment capacity is generally given in linear products of inches or millimeters and represents the utmost parallel offset the coupled shafts exhibit.
Max Axial Motion
Occasionally called axial misalignment, this attribute specifies the utmost permissible growth between your coupled shafts, presented generally in inches or millimeters, and can be due to thermal effects.