About Shaft Couplings
A shaft coupling is a mechanical component that connects the drive shaft and driven shaft of a electric motor, etc., so as to transmit electrical power. Shaft couplings bring in mechanical flexibility, providing tolerance for shaft misalignment. As a result, this coupling versatility can reduce uneven put on on the bearing, tools vibration, and additional mechanical troubles due to misalignment.
Shaft couplings are available in a little type mainly for FA (factory automation) and a large casting type used for large power transmission such as for example in wind and hydraulic power machinery.
In NBK, the former is named a coupling and the latter is named a shaft coupling. Right here, we will talk about the shaft coupling.
Why Do WE ARE IN NEED OF Shaft Couplings?
Even if the engine and workpiece are directly connected and properly fixed, slight misalignment may appear over time due to adjustments in temperature and changes over a long period of time, creating vibration and damage.
Shaft couplings serve seeing that an important connect to minimize effects and vibration, allowing even rotation to end up being transmitted.
Flexible Flanged Shaft Couplings
These are the most used 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 staying transmitted.
2 types can be found, a cast iron FCL type and a carbon metal?FCLS type Flexible Shaft Couplings
Shaft Coupling Considerations
In choosing couplings a designer primary needs to consider motion control varieties or power transmission types. Most movement control applications transmit comparatively low torques. Power transmitting couplings, in contrast, are created to carry modest to excessive torques. This decision will narrow coupling choice somewhat. Torque transmission along with optimum permissible parallel and angular misalignment values are the dominant considerations. The majority of couplings will publish these values and with them to refine the search should help to make picking a coupling style a lot easier. Maximum RPM is another important attribute. Maximum axial misalignment could be a consideration aswell. Zero backlash is usually a significant consideration where feedback is employed as in a action control system.
Some power transmission couplings are made to operate without lubricant, which is often a plus where maintenance is a problem or difficult to perform. Lubricated couplings typically require addresses to keep the grease in. Many couplings, including chain, equipment, Oldham, etc., are available either as lubricated metal-on-metal varieties and as metal and plastic-type hybrids where generally the coupling element is constructed of nylon or another plastic-type material to eradicate the lubrication requirements. There exists a reduction in torque ability in these unlubricated varieties compared to the more conventional designs.
Almost all of the common models have already been described above.
Many couplings have a limit on the maximum rotational swiftness. Couplings for high-velocity turbines, compressors, boiler feed pumps, etc. generally require balanced styles and/or balanced bolts/nuts to permit disassembly and reassembly without raising vibration during procedure. High-speed couplings can also exhibit windage results within their guards, which can lead to cooling concerns.
Max Transmitted Horsepower or Torque
Couplings tend to be rated by their optimum torque capability, a measurable quantity. Electric power is normally a function of torque times rpm, thus when these ideals are stated it is generally at a specific rpm (5HP @ 100 rpm, for instance). Torque values will be the more commonly cited of both.
Max Angular Misalignment
Among the shaft misalignment types, angular misalignment potential is usually stated in degrees and represents the utmost angular offset the coupled shafts exhibit.
Max Parallel Misalignment
Parallel misalignment capacity is generally given in linear systems of inches or millimeters and represents the maximum parallel offset the coupled shafts exhibit.
Max Axial Motion
Sometimes called axial misalignment, this attribute specifies the maximum permissible growth between the coupled shafts, presented generally in inches or millimeters, and can be caused by thermal effects.