Learn how to calculate the transmission of turbo-worm gears with our in-depth coverage on 涡轮蜗杆的传动计算. Discover the latest advancements and optimize your gearbox's performance to its fullest potential. Get insights now!
worm gear drive
The worm gear drive is used in the case where two shafts intersect at 90 degrees but are neither parallel nor intersecting each other. Usually in the worm gear drive, the worm is the driving member and the worm gear is the driven member. The worm gear and worm gear drive has the following characteristics: 1) compact structure, and can obtain a large transmission ratio, the general transmission ratio is 7-80. 2) Work smooth and no noise 3) drive power range is large 4) can self-lock 5) drive efficiency is low, worm gears are often made of non-ferrous metals. Worm screw has single head and multi-head. The calculation of the transmission ratio is as follows: the rotation speed of the : I=n1/n2=z/K n1- worm n2- the rotation speed of the worm wheel K- the number of worm heads Z- the number of teeth of the worm wheel
worm gear and worm mechanism
1. Purpose: Worm gears and worm mechanisms are often used to transmit motion and power between two staggered axes. Worm gears and worms are in their midplane equivalent to gears and racks, and worms are similar in shape to screws. II. Basic Parameters modulus m, pressure angle, worm diameter coefficient q, lead angle, worm head number, worm gear teeth, top height coefficient (1) and top clearance coefficient (0.2). wherein, the modulus m and the pressure angle refer to the modulus and pressure angle of the worm shaft surface, namely, the modulus and pressure angle of the worm wheel shaft surface, and are all standard values; the worm diameter coefficient q is the ratio of the worm indexing circle diameter and the modulus m; III. Conditions for correct meshing of worm gear and worm 1 the modulus and pressure angle of worm and worm wheel in the middle plane are equal respectively, namely the end surface modulus of worm wheel is equal to the axial surface modulus of worm and is the standard value; The pressure angle of the end face of the worm wheel shall be equal to the pressure angle of the shaft face of the worm and shall be the standard value, i.e. m 2 When the worm gear and worm's staggered angle is, also need to ensure that the worm gear and the worm helix turning direction must be the same.
4. The calculation of the geometric size is basically the same as that of the cylindrical gear. The following problems need to be noted are:
the worm lead angle () is the included angle between the tangent line of the spiral line on the worm indexing cylinder and the end face of the worm, and the relation between the spiral angle and the screw screw screw angle is the helical angle of the worm wheel, and the transmission efficiency is high. The mechanism is self-locked when the equivalent friction angle between the teeth is small. The worm diameter coefficient q is introduced in order to limit the number of worm wheel hobs, so that when the diameter of the worm indexing circle is standardized m, q is larger, and the rigidity and strength of the worm shaft increase correspondingly. When q is small, the lead angle increases and the transmission efficiency increases accordingly. The recommended value of worm head number is 1, 2, 4, 6. When the value is small, its transmission ratio is large and has self-locking; When a large value is taken, the transmission efficiency is high. Different from cylindrical gear drive, the gear ratio of the worm and worm gear mechanism is not equal to the gear ratio, but the center distance of the worm and worm gear mechanism is not equal to the gear ratio. The determination method of worm gear steering in worm gear transmission can be determined according to the direction and direction of meshing point K (tangent line parallel to the helix line) and the speed vector triangle drawn perpendicular to the axis of the worm gear. Also can be used "right-handed worm left hand grip, left-handed worm right hand grip, four-finger thumb" to determine.
Features of Worm Gear and Worm Mechanism
can obtain a large transmission ratio and is compacter than the staggered shaft helical gear mechanism Line contact between the two gears, its bearing capacity is high, the worm drive of the helical gear mechanism of the staggered shaft is rather the worm drive of the helical gear mechanism, it is multi-tooth mesh drive, so the drive is stable and the noise is low has self-locking. When the lead angle of the worm is smaller than the equivalent friction angle between meshing gear teeth, the mechanism has self-locking property and can realize reverse self-locking, namely, only the worm can drive the worm wheel, but not the worm wheel can drive the worm. If the self-locking worm mechanism used in heavy machinery, its reverse self-locking can play a role of safety protection The transmission efficiency is low and the wear is serious. The relative sliding speed between the meshing gear teeth is large, so the friction loss is large and the efficiency is low. On the other hand, the relative sliding speed makes the tooth surface wear serious, heat serious, in order to heat dissipation and reduce wear, often use the more expensive anti-friction and anti-wear materials and good lubrication devices, so the higher cost worm axial force is larger
What can't worm gear drive reversely?
Because the worm screw angle is generally very small, less than the friction angle, can self-lock, general single-line worm will self-lock, so can not reverse. However, there are also multi-wire worms, which are very large to the helix angle, can not lock, can be reversed, in some occasions is to add anti-revolution devices.
Calculation formula of worm gear and worm:
1, transmission ratio = number of worm gear teeth ÷ number of worm heads
2, center distance = (pitch diameter of worm gear + pitch diameter of worm) ÷ 2
3, worm wheel roar diameter = (number of teeth + 2) × modulus
4, worm wheel pitch diameter = modulus x number of teeth
5, worm pitch diameter = worm outer diameter -2 x modulus
6, worm lead = pi x modulus x number of heads
7, Helix angle (lead angle) tgB = (modulus x number of heads) ÷ worm pitch diameter
What is the condition of worm gear drive self-locking
Turbine worm drive, is generally to worm for the active end, turbine driven end, and achieve a large reduction ratio. There are few applications with turbines as the active end. The self-locking in turbine worm drive generally refers to the phenomenon that the torque applied to the turbine can not make the mechanism rotate (you can also think of the turbine as the driving wheel). The condition of self-locking in turbine worm drive is that the unfolding pitch angle of the worm is smaller than the friction angle of the worm contact. namely, beta is less than phi, beta is the unfolding pitch angle of the worm, and phi is the friction angle; tg Φ = μ, μ is the coefficient of friction. This is the same as if an object on an inclined plane does not slip, that is, G * sinα < G * cosα * μ, where α is the inclined plane, μ is the coefficient of friction, and G is gravity. The result is: tg.alpha. <.mu., that is: α < arctanμ = Φ