The main characteristics of worm gear and worm drive are as follows:
Large transmission ratio can be obtained, which is more compact than the staggered helical gear mechanism.
2. The meshing tooth surfaces of two wheels are in line contact capacity, and the load-carrying of the two wheels is much higher than that of the staggered gear mechanism. Helical gear mechanism.
3. Worm transmission is equivalent to spiral transmission, which is multi-tooth meshing transmission, so the transmission is smooth and the noise is very low.<4. Self-locking. When the guide angle of the worm is less than the equivalent friction angle between the meshing gear teeth, the mechanism has self-locking If the self-locking worm mechanism is used in lifting mechanism, its reverse self-locking can play a safe protection role.
5. The transmission efficiency is low and the wear is serious. In worm and worm meshing Transmission, the relative sliding speed between meshing gear teeth is high, so the friction loss is large and the efficiency is low. On the other hand, the relative sliding speed makes the tooth surface worn serious and heated serious. In order to dissipate heat and reduce wear, materials with high friction and wear resistance and good lubric They are often used, which are more expensive, so the cost is higher.
Basic parameters of worm gear and worm: modulus m, pressure angle, worm diameter coefficient q, lead angle, number of worm heads, number of turbine teeth, top height coefficient (1) and top clearance coefficient (0.2). Among the m, modulus and pressure ref angle Er to the modulus and pressure angle of the worm axle, that is, the modulus and pressure angle of the turbine end face, and they are all standard values; the worm diameter coefficient q is the ratio of the worm indexing circle diameter to its modulus M.
Worm drive is composed of the worm and worm wheel, and worm is the main part in general. E threads, worm has right-handed and left-handed worm drive, which are called right-handed worm and left-handed worm respectively. There is only on e helix on the worm called a single-head worm, that is, the worm revolves around, the worm wheel revolves a tooth, if there are two helixes on the worm, it calls a double-head worm, that is, the word M revolves around, the worm wheel revolves two teeth.When the worm is active, efficiency & eta; = Tan & gamma; / Tan (& gamma; + & Phi; v), efficiency & eta; increase with the increase of the lead angle of the worm helix & gamma; but usual & gamma; & lt; 30 & deg reduces the friction & equivalent Phi; V can also improve efficiency and efficiency Eta; in multi-stage transmission composed of gear drive and worm drive, if the speed is not too high, the worm drive is usually placed in the high-speed stage to improve the phase. For the relative sliding velocity Vs, the friction angle is reduced and the efficiency is improved.Practice has proved that steel is worm used to coope. Rate with bronze turbine, the turbine mechanism has excellent friction reduction and friction compatibility, and it is also conducive to improving efficiency-eta; UUUUUUUUUUUUUU< p > Total efficiency of worm drive = transmission efficiency of worm helical & times; bearing efficiency of supporting worm wheel & times; transmission efficiency of worm wheel & times; Transmission efficiency of worm helical pair = TG (lead angle) / TG (lead angle + equivalent friction angle)< P > TG (lead angle) = (number of spiral heads of worm & times; modulus) / diameter of worm indexing circleFrom the above three formulas, it can be seen when the diameter of worm is indexing is uarr,, TG (lead angle) & darr, & darr, & TG (lead angle + equivalent friction angle) & darr, & because of the existence of equivalent friction angle, TG (lead angle) decreases faster than TG (lead angle + equivalent friction angle), then the transmission efficiency of helical pair is darr;darr; < p>darr; < so, the dividing circle D. Iameter of worm is closely related to the total efficiency of worm transmission. The plane double enveloping hourglass worm reducer of worm gear reducer is an advanced heavy-duty transmission device, which has such excellent characteristics as large load-carrying capacity, high transmission rate and long service life. It is the best choice to reply. Ace other worm drive.