Transmission system used in robot and automobiles (Transmission system ) 2

Flat belt
                    

images?q=tbn:ANd9GcSKL7DawTJeZp9By_kMNd2NyTellfdOg0XkJtyaSLsdA_DNFZMD Transmission system used in robot and automobiles (Transmission system ) 2 flat belts are basically used for light duty  power transmission and larger center  distance between two pulleys.they possesses
high power transmission efficiency, are cost effective, and are easy to use and install.it has narrow rectangular cross-section.in earlier mostly used belts are leather belts but due to superior characteristics of  flat belt they become more popular in industrial engineering.  
The important material properties to be considered for the construction of flat belts are high coefficient of friction between the belt and the rim of the pulleys, flexibility, durability and strength of the belt. 

chemical and electrical Properties of the flat belts  
 oil resistance 
 antistatic
 efficient and power saving than v-belts
As with the flat belt drive, the belt is frictionally engaged on the outer pulley diameter, not on the lateral wedge
surfaces as in the case of the V-belt drive, owing to the system design, the wear on the belt and pulleys is
consequently less. Also, if several V-belts run on one drive, they wear unevenly due to production allowances.
Smooth running
In contrast to flat belts which are characterized by a uniform distribution of tension over the entire belt width,
V-belts have the disadvantage that the tensions in the individual belts are unevenly distributed due to different
effective diameters which are brought about by unequal wear on the belt and pulleys as well as manufacturing
tolerances. Such belt tensions lead to vibrations and fluttering, uneven and noisy running. 
    Material  used for Belts
 belts and ropes must be strong, flexible, and durable. It must have a high
coefficient of friction. The belts, according to the material used, are classified as follows:
1.Leather belts
The most important material for flat belt is leather. The best leather belts are
made from 1.2 metres to 1.5 metres long strips cut from either side of the back bone of the top grade steer hides. The hair side of the leather is smoother and harder than the flesh side, but the flesh side is stronger. The fibres on the hair side are perpendicular to the surface, while those on the flesh side are interwoven and parallel to the surface. Therefore for these reasons the hair side of a belt should be in contact with the pulley surface as shown in Fig. 18.2. This gives a more intimate contact between belt and pulley and places the greatest tensile strength of the belt section on the outside, where the tension is maximum as the belt passes over the pulley.

Cotton or fabric belts
Most of the fabric belts are made by folding convass or cotton duck to three or more layers (depending upon the thickness desired) and stitching together. These belts are woven also into a strip of the desired width and thickness. They are impregnated with some filler like linseed oil in order to make the belt water-proof and to prevent injury to the fibres. The cotton belts are cheaper and suitable in warm climates, in damp atmospheres and in exposed positions. Since the cotton belts require little attention, therefore these belts are mostly used in farm machinery.

„
„
„

Save

Leave a Reply

Your email address will not be published. Required fields are marked *