KEY TRANSMISSION :-Though apparently seems simple but preparing keyway is one of the difficult machining operations- increase in cost due to various operation in involved – setting & down time + machining time + others such as : -Lateral shifting of Keyways: in process it is extremely difficult to set
the centre line of the keyway exactly symmetrical and parallel with
respect to the radial plane; -Heavy torsional stresses are concentrated at the corner of the
keyway so shaft is weakened. -Deviation in keyway width. -Not parallel to the axis. -Inaccuracy in Key.
The cumulative effect of the all above (operational) errors, is really calls for an alternative system-keyless Transmission.
NMTA Keyless Transmission Elements
Entirely eliminates the disadvantages of key transmission and conventional shrink connections and also involved calculations, extremely close machining tolerances - creating problems while fitting & removing parts and during repair work -adjustment, exchanging,etc. It efficiently replaces, key & polygon connections, splined shafts,etc.
NMT GROUP manufactures
KEYLESS TRANSMISSION ELEMENTS which have varied and versatile applications on almost all engineering fields.The elements have great absorbing capacity of kinetic energy by elastic radial deformation of tapered rings. The method is also very simple. By expansion of the outer & shrinkage of inner rings, frictional shaft & hub connections are established, which transmits highest torques free from backlash.
Elements -Shrink Disc (is to be fitted on Hub) forming locking connection by tightening standard hex head screws provided, with standard tools. The same transmissible torque value, almost can be achieved even when varying the nominal dimesnions slightly when using the same clearances. After loosing the locking screws element is released and Hub can be moved along the shaft.
Characteristics: Elements are most suitable for securing all types of bosses and hubs on shafts and axles. -No Keyway,No extra machining No notch effect. -Perfect true running -absolutely no play. -Easy adjustability / Easy exchangeability : Need no stops. -Easy mounting :. elements are tightened using standard screws and standard tools. Extra machining or fitting work is not required. -Easy removal : release screws,saving much time, and the elements can be removed. the step angle of the double tapers prevent self-locking and ensures the the element can be released without difficulty. -Freedom from wear -Having no moving parts. -Overload protec tion effect -When the permissible load is exceeded, elements will slip. In this way, they can safeguard valuable machine components against damage.However the slip causes fretting of the contact surfaces, so elements should not be used as slip clutch. -Maintance Friendly.
Unlimited Applications The elements are used for the connection of gearwheels, chain sprockets, levers, cams, cam plates, belt pulleys, brake drums, flywheels, couplings and clutches, shaft-mounted gearing, flanges, track wheels, impellers, etc.. and are giving every satisfaction in these and countless other applications.