Though one might not think of gears to be flexible, gear couplings are very much regarded as a versatile coupling. A gear coupling can be a mechanical device designed to transmit torque between two shafts that aren’t collinear. The coupling typically contains two flexible joints, one fixed to each shaft. These joints are often linked by a third shaft known as the spindle.
Each joint generally contains a 1:1 gear ratio internal/external equipment set. The tooth flanks and outer diameter of the exterior equipment are crowned to allow for angular displacement between the two gears. Mechanically, the gears are equivalent to rotating splines with modified profiles. They are called gears because of the relatively huge size of one’s teeth. Gear couplings are usually limited by angular misalignments of 4 to 5°.
Gear couplings ordinarily can be found in two variations, flanged sleeve and continuous sleeve. Flanged equipment couplings consist of short sleeves surrounded by a perpendicular flange. One sleeve is placed on each shaft so the two flanges fall into line face to encounter. A number of screws or bolts in the flanges hold them together. Continuous sleeve gear couplings feature shaft ends coupled collectively and abutted against each other, which are then enveloped by a sleeve. Generally, these sleeves are made from metal, but they may also be made of Nylon.
Single joint gear couplings are used to connect two nominally coaxial shafts. In this application the device is named a gear-type flexible, or 
versatile coupling. The one joint allows for minor misalignments such as for example installation errors and changes in shaft alignment because of operating conditions. These types of gear couplings are usually limited to angular misalignments of 1/4 to 1/2°.
Gear couplings are torsionally rigid and are supplied to two styles – completely flexible and flexible/rigid. A totally flexible coupling comprises two hubs with an exterior gear and two outer sleeves with an internal gear. It’s a general coupling for all sorts of applications and accommodates all possible misalignments (angular, offset and mixed) and also large axial moments. Machines, bearings, seals, and shafts are therefore not put through the excess forces, sometimes of considerable magnitude, which occur from unavoidable misalignment usually associated with rigid shaft couplings.
A flexible/rigid coupling comprises one flexible geared half and one rigid fifty percent. It does not support parallel displacement of shafts but will support angular misalignment. This kind of couplings are primarily utilized for “floating shaft” applications.
Sizes 010 – 070 all have crowned tooth with a 20° pressure contact. This enables to accommodate up to at least one 1,5° static angular misalignment per gear mesh. However, reducing the operational misalignment will maximize the life span of the coupling along with the life of various other machinery components such as for example bearings etc.
SERIES H Features & Benefits
Higher Misalignment Capability
Sizes 1-7 compensate for up to ±1 1/2° static angular misalignment per gear mesh.
Minimizing working misalignment will maximize the life span of the coupling. Make reference to the Set up and Alignment Guidelines for alignment recommendations.
Larger Bore Capabilities permit the most economical size selection for shafts up to 10 5/8″.
Higher Torque Ratings because of bigger tooth pitch diameters than additional couplings.
Versatility in that Series H’s are interchangeable by fifty percent coupling with competitive coupling designs.
1 1/2° Curved-Face Teeth are a primary feature of the Series H coupling, sizes 1-7. The crowned hub teeth are a 20° full-depth involute tooth type with flank, tip, and root curvature. When
used in combination with the straight confronted sleeve teeth, these 1 1/2° curved encounter hubs offer improved shaft misalignment capability
CENTER FLANGE BOLTING
All couplings feature precision-drilled flange bolt holes, and tight tolerance Grade 5 flange bolts to make sure a long-long lasting flange to flange and fastener fit. Exposed bolt flanges are
standard. Shrouded bolt flanges could be supplied through size 5. Size #5 1/2 and larger couplings are only available with exposed bolt flanges.
LUBRICATION
Each sleeve flange comes with two pipe plugs 180° aside. This permits assembly of a full flex coupling with four lube plugs positioned every 90°, facilitating lubrication. The lube seal is a Buna-N O-ring to help retain grease and exclude contaminants. KHP or KSG coupling greases are suggested in order to obtain maximum working life.
Ever-power COUPLING Features & Benefits
The Ever-power gear coupling comes in two basic product lines:
Ever-powercoupling for medium to heavy-duty applications
Sizes 1 1/2 through 7 with essential end ring.
Sizes 8 through 30 with bolt-on end ring.