Types of shaft couplings – a thomasnet buying guide 3 gases that cause acid rain


Shaft Couplings are mechanical devices used to connect rotating shafts and absorb misalignments between them. Couplings can be rigid or flexible depending on the alignment accuracies of the system and torque requirements. Shaft couplings are used for power and torque transmission between two rotating shafts such as on motors and pumps, compressors, and generators. Coupling Styles Beam

The beam coupling consists of single or multiple helical cuts in the coupling body which typically can accommodate parallel misalignments up to 0.025 inch and electricity symbols ks2 worksheet angular misalignments up to 7 degrees. They are used primarily for motion control applications where torques are typically below 100 inch-lbs. Zero backlash designs available ensure positioning accuracy between driving and driven shafts. Bellows

Bellows couplings are also suited to motion control applications. They consist of multiple convolutions of metal which provide high torsional stiffness which is important to positioning r gasquet tennis applications. Torsional stiffness reduces the level of angular and parallel misalignment they can accommodate compared with beam couplings, although torque transmission capabilities are about similar. Chain

Chain couplings are suited to power transmission applications and are used to transmit power up into the hundreds of horsepower range. Angular and parallel misalignment allowances are typically 2 degrees and 0.015 inch, respectively. Typical chain couplings use special chain sprockets and double wide roller chains whose clearances permit the design to operate as a flexible coupling.

Curved and Straight Jaw couplings are used for both motion control and light power transmission grade 9 electricity test applications and consist of pairs of multi-jawed hubs that mate with elastomeric spiders. The design allows for backlash-free torque transmission. Accommodation for parallel misalignment usually approaches 0.01 inch and angular misalignment about 1 degree. Elastomeric spiders give these couplings some damping capacity and of often the spiders are available in different durometers to lend specific properties to the individual couplings. These couplings often operate without lubricant and can transmit torque up into the 1000 inch-lb. range. Diaphragm

Diaphragm couplings are generally used for high power transmission such as found in turbomachinery. Typically they employ one or more flexible metal convoluted discs which transmit power to an inner spacer shaft then back out through another diaphragm stack to the driven machinery. A principal advantage over gear type power per kwh couplings is their lack of lubrication requirements. Diaphragm couplings are capable of high torque transmission and high speed operation. Disc

Disc couplings use single or multiple discs and single gas 101 or double stages which bolt to the shaft hubs. They are used for power transmission and rely on the flexibility of their thin metal discs to transmit torque and accommodate angular misalignment. They are not especially good at managing parallel misalignment. They are capable of transmitting high torques and are often used to couple high horsepower motors, gas turbines, etc. to loads. Gear

Gear couplings also transmit high torques. They have misalignment capabilities generally about 0.01-0.02 inch in parallel and 2 degrees in angular. Gear couplings are often used in pairs with spacer shafts to span the distance between driving and driven equipment. They generally require lubricant although some designs intended for lighter duty use lubricant free nylons or other polymers for the center sleeve. Grid

Grid couplings employ spring like connecting elements that weave between slots machined in the coupling hubs. They are capable of high torque transmission with an added bonus of shock absorption and torsional vibration national gas average 2012 dampening. They operate without lubricant. They are appropriate for power transmission and capable of handling parallel misalignment up to 0.30 inch and angular misalignment of about ¼ degree. Oldham

Schmidt couplings are designed specifically to operate on shafts that are offset. They aren’t flexible couplings in the strictest sense, which are designed to accommodate slight misalignment in shafts that are theoretically parallel and square to one another. Schmidt couplings are used in papermaking, printing, and similar machines and function more like a 1:1 gearbox in a more compact space. Clamping

Couplings correct for an inability to produce or maintain perfect alignment in coupled machines. Some machines dispense with the need for electricity 101 couplings by running close coupled, meaning that the bearings of the motor support an extended shaft upon electricity merit badge requirements which the rotating component of the driven equipment—a pump impeller, for instance—mounts. The motor and pump at right is an example of a close-coupled machine. Where this is practical to do it is done to dispense with he alignment problem. Often, though, the machines require their own bearings and as a result a need to connect their independent shafts. The diagram above shows the two misalignments that can be expected, parallel or offset (top) and angular (bottom).

For some couplings, backlash is an important concern. Motion control applications where position of the driven equipment is precisely tied to the position of a servo- or stepper motor rely on zero-backlash coupling to assure that no slop exists in the system. Backlash is a lesser concern for most power transmission applications—pumps/motors for instance—where efficient torque transmission is the primary objective. Here, misalignment can lead to higher energy use, accelerated bearing wear, excessive vibration, etc.

In selecting couplings a designer first needs to consider motion control varieties or power transmission types. Most motion control applications transmit comparatively low torques. Power electricity merit badge pamphlet transmission couplings, in contrast, are designed to carry moderate to high torques. This decision will narrow coupling choice somewhat. Torque transmission along with maximum permissible parallel and angular misalignment values are the dominant considerations. Most couplings will publish these values and using them to refine the search should make picking a coupling style easier. Maximum RPM is another critical attribute. Maximum axial misalignment may be a consideration as well. Zero backlash is an important consideration where feedback is used as in a motion control system.

Some power transmission couplings are designed to operate without lubricant, which can be a plus where maintenance is a concern or difficult. Lubricated couplings often require covers gas nozzle icon to keep the grease in. Many couplings, including chain, gear, Oldham, etc., are available either as lubricated metal-on-metal varieties and as metal and plastic hybrids where usually the coupling element is made of nylon or another plastic to eliminate the lubrication requirements. There is a reduction in torque capacity in these unlubricated forms compared to the more conventional designs. Important Attributes Coupling Style

Most couplings yoga gas relief pose have a limit on their maximum rotational speed. Couplings for high speed turbines, compressors, boiler feed pumps, etc. usually require balanced designs and/or balanced bolts/nuts to permit disassembly and reassembly without increasing vibration during operation. High speed couplings can also exhibit windage effects in their guards, which can lead to cooling concerns. Max Transmitted Horsepower or Torque