About Shaft Couplings
A shaft coupling is a mechanical part that connects the travel shaft and driven shaft of a electric motor, etc., to be able to transmit power. Shaft couplings bring in mechanical flexibility, featuring tolerance for shaft misalignment. Therefore, this coupling versatility can reduce uneven wear on the bearing, gear vibration, and different mechanical troubles because of 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 electric power machinery.
In NBK, the former is named a coupling and the latter is called a shaft coupling. Below, we will discuss the shaft coupling.
Why Do WE ARE IN NEED OF Shaft Couplings?
Even if the electric motor and workpiece are directly connected and properly fixed, slight misalignment may appear over time because of improvements in temperature and changes over a long period of time, creating vibration and damage.
Shaft couplings serve seeing that an important link to minimize impression and vibration, allowing even rotation to always be 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 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 simply by removing the coupling bolt, enabling easy maintenance.
Permits lateral/angular misalignment, and reduces sound. Prevents the thrust load from simply being transmitted.
2 types are available, a cast iron FCL type and a carbon steel?FCLS type Flexible Shaft Couplings
Shaft Coupling Considerations
In choosing couplings a designer initial must consider motion control varieties or power transmission types. Most motion control applications transmit comparatively low torques. Power transmission couplings, in contrast, are made to carry modest to excessive torques. This decision will narrow coupling choice somewhat. Torque transmitting along with maximum permissible parallel and angular misalignment ideals are the dominant considerations. The majority of couplings will publish these ideals and with them to refine the search should produce picking a coupling style simpler. Maximum RPM is another crucial attribute. Maximum axial misalignment could be a consideration aswell. Zero backlash is normally a significant consideration where feedback is employed as in a motion control system.
Some power transmission couplings are designed to operate without lubricant, which can be an advantage where maintenance is a concern or difficult to execute. Lubricated couplings generally require covers to keep the grease in. A large number of couplings, including chain, gear, Oldham, etc., are available either since lubricated metal-on-metal types and as metal and plastic material hybrids where usually the coupling element is constructed of nylon or another plastic material to remove the lubrication requirements. You will find a reduction in torque capacity in these unlubricated varieties compared to the more conventional designs.
A lot of the common styles have already been described above.
Most couplings have a limit on their maximum rotational speed. Couplings for high-rate turbines, compressors, boiler feed pumps, etc. usually require balanced patterns and/or balanced bolts/nuts to permit disassembly and reassembly without raising vibration during procedure. High-speed couplings may also exhibit windage results in their guards, which can result in cooling concerns.
Max Transmitted Horsepower or perhaps Torque
Couplings tend to be rated by their optimum torque capacity, a measurable quantity. Power can be a function of torque circumstances rpm, therefore when these ideals are stated it is usually at a specific rpm (5HP @ 100 rpm, for example). Torque values are the additionally cited of both.
Max Angular Misalignment
One of the shaft misalignment types, angular misalignment ability is usually stated in degrees and represents the maximum 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, offered generally in inches or millimeters, and will be caused by thermal effects.