 గియింపూనడి, న Kanye B.iffe నందావాదంర miraculous engineering department, ని తడ్మా ని In this video I am explaining, Digital wom's Demensity of warm gas At the end of this session students will be able to have a good understanding of the terminology of warm gas and will be able to specify the warm gas ʷ ʷ ʸा ʰ᷆ᵃʰᵋʰᵐᵏ ʸᵃʰᵏʰᵇʰ Ḁʻᵃʳᵇʰ and ʰᵃʰᵃʳᵏʰ ᵐʰᵃʰᵃʳʳᵍ ᵐʰᵃʳᵃʳ ᵐʰᵃʳᵃʳ iʸ. సంరంమరిానికదంకంట్చారే. సారువినాడినింద్ర నివసికాకొియకాసార్ంద్రడ్ ప్లిష్టియుసందానందుప్ద్. . . . . and that is we are knowing that the distance covered by a point measured along the axis during one complete rotation of the worm is defined as the lead. And that is why we find that lead L is shown over as axial distance. The lead angle will be calculated by developing a thread as a gamma over here and naturally నిమనిలవ్ని లిలు ఇపత్వనిందిందథెంద్సొనీలి. కిందింతెయ్వతో కిస్నంద్సుతాపెలిసందింది. ఇరనిందిందిధూడికిందాడినే. షిదా దింది చూచర్యుటో ఇచౌంది ఆప్ప్ర్మే ంఎప్క్ర నాయ్టండింది. ప్రందింది ఇచౌతిసివలూడికకోని. these are certain preferred values of z1, z2, qm for wormgears the wormgears are many times available as a standard set or standard gearbox as a construction depending upon the center distance between the shafts so depending upon transmission ratios like 20 onwards is given over here depending upon center distance we can refer directly some preferred values for z1, z2, q and m for application so now we have just seen that lead of the worm L can be calculated by axial pitch multiplied by number of start so px into z1 axial pitch of the worm is equal to circular pitch of the worm wheel that we have just seen so px is equal to pi m and therefore the value of lead is pi m z1 if we want to calculate tan of gamma that is a lead angle then it is L upon pi d1 where L is substituted as a pi m z1 whereas d1 is q into m because you have seen that q diameter coefficient is d1 by m so naturally d1 is equal to qm to m and that is why substituting that also finally we get tan of gamma that is a lead angle is z1 by q if you are knowing z1, z2, qm and the specification we can know the gamma angle that is a lead angle now for worm gas the requirement is that linear velocity of the worm must be equal to the pitch line velocity of the worm wheel as we know that worm is transmitting linear motion as a rotary motion to the worm wheel so linear velocity of the worm should be equal to the pitch line velocity of the worm wheel linear velocity of the worm is lead into speed of the worm that is rpm of the worm and pitch line velocity is a circumference of the worm wheel pi d2 into speed of the worm wheel so substituting the values we get here velocity ratio as n1 by n2 because pi m, pi m gets cancelled and n1 by n2 which is a velocity ratio is equal to z2 by z1 that is the speed of worm divided by the speed of the worm wheel called as velocity ratio is equal to the number of teeth on the worm wheel divided by the number of start on the worm so this is the way we can define the velocity ratio for worm gear drives as far as the helix angle side to be calculated the worm gears are used for transmitting power between two non intersecting perpendicular shafts so angle between the shaft is 90 degree and that is why psi plus gamma that is helix angle plus lead angle must be equal to the angle between the shaft that is 90 degree so helix angle is 90 minus lead angle so students now your expectors pause the video for a while and find out what way the speed ratio for other types of gears that you have calculated so far now you go for the proportions of the worm and worm wheel so here it is a worm in which we get different geometrical dimensions or proportions of the thread as far as the involved helix angle to form its concern so it has got addendum that is the radial distance between the pitch circle and the outer most circle and that is called as addendum whereas the radial distance between the root circle and the pitch circle is called as addendum so addendum is 1m and addendum is 2.2 cos of gamma minus 1 times the module and the clearance is 0.2m cos gamma so this is the way we have got different proportions for the worm outer most diameter of the worm is pitch circle diameter plus 2 times addendum so 2m plus 2m that way we can calculate the root circle diameter pitch circle diameter and addendum diameter so all geometrical relationship we can calculate for worm and similarly for worm wheel so here are some equations which we are using to calculate different geometrical dimensions for the worm and worm wheel as the proportions now as per the phase width of the gear to this concern this is f is the phase width of the worm wheel tooth which is been calculated by considering the geometry for example it is OAC triangle we can consider in which AC is phase width by 2 so AC square is phase width by 2 square so likewise we consider the geometry of triangle OAC and we can calculate this relationship from which we calculate phase width is equal to 2m plus root of q plus 1 so this is the way phase width of the worm gear is required to be calculated by knowing its dimensions module and q similarly we can calculate another requirement is a length of root of contact that this is xyz distance that is arc xyz is called the length of root of the contact worm wheel with the thread of the worm and that is been calculated once again by considering the geometry as shown over here and considering this angle delta we can calculate the arc and from that we can calculate the lr length of the root of contact now let us consider one example based upon all these proportions and previous simple equations for calculation so a pair of worm gear is designated as 130-108 for which we have to calculate center distance, speed reduction and dimensions of the worm and worm wheel so as far as the solution is concerned the given thing is specification of the worm gear set for which z1 is 1, z2 is 30, q is 10 and m is 8 with the help of this term so we can calculate center distance a is equal to one half of d1 plus d2 that is pcd of worm, pcd of worm wheel we can calculate for which it is one half mq plus z2 so it is 160 degree, 160 mm for step 2 we can calculate speed reduction for which we know that velocity ratio is z2 by z1 so simply we substitute z2 as 30 and z1 is 1 so it is 30, velocity ratio is 30 the third calculation required is dimensions of the worm so we are using all the previous equations that is pcd is qm, random diameter is there tan of gamma is z1 by q so substituting z1, z2, qm appropriately in particular equations we can calculate all the dimensions of the worm and dimensions of the worm wheel so by using all terminology we can calculate all the geometrical dimensions of the worm and worm wheel as shown over here this is my reference design of machine elements thank you