Worm gear transmission is a common mechanical transmission method consisting of a worm and a worm wheel, typically used to transmit motion and power between spatially staggered axes. The following is a detailed introduction to worm gear transmission: Working principle • Basic structure: Worm gear transmission consists of a worm gear and a worm wheel, with the worm gear usually being the active component and the worm wheel being the passive component. The helix of a worm can be left or right, and its shape is similar to that of a helical gear Motion transmission: The rotation of the worm gear is driven by the meshing of its helical teeth with the tooth surface of the worm wheel, which drives the worm wheel to rotate. The speed ratio of worm gear transmission is equal to the number of heads of the worm divided by the number of teeth of the worm gear. Features • Advantages: • Large transmission ratio: The single-stage transmission ratio can reach 10-80 or even higher, and the structure is compact Smooth transmission: The worm gear teeth are continuous spiral teeth, and there is no impact, vibration, or noise during meshing Self locking: When the helix angle of the worm is less than a certain value, the worm wheel cannot drive the worm to rotate in the opposite direction, providing safety protection Disadvantages: • Low efficiency: Generally, the transmission efficiency is between 0.7-0.9, and the self-locking transmission efficiency is even lower than 0.5 High heat generation: High relative sliding speed, high friction loss, requiring good lubrication and cooling High cost: Worm gears usually require the use of expensive non-ferrous metals. Classification: According to the different shapes of worm gears, worm gear transmission can be divided into the following types: • Cylindrical worm gear transmission: The indexing surface of the worm gear is cylindrical, and common ones include Archimedes worm gear and circular arc tooth cylindrical worm gear Archimedean worm: The end profile is an Archimedean spiral, which is easy to manufacture but has low precision and low load-bearing capacity Circular arc cylindrical worm: The tooth profile is a concave arc, with low contact stress and high load-bearing capacity and efficiency Torus worm gear transmission: The indexing surface of the worm gear is a torus, which has high transmission efficiency and load-bearing capacity Cone worm gear transmission: The indexing surface of the worm gear is a conical surface, suitable for specific occasions. Worm gear transmission is widely used in the following fields: • Industrial field: such as machine tools, lifting equipment, conveying machinery, etc., used to achieve deceleration or acceleration transmission with large transmission ratios In the automotive field, such as car seat adjustment devices, sunroof opening and closing devices, etc Aerospace field: such as aircraft landing gear, servos and other components. Design and Maintenance • Design Points: When designing worm gear transmission, it is necessary to consider the material, size, strength calculation, and lubrication method of the worm gear. The commonly used lubrication methods are oil lubrication and grease lubrication Maintenance requirements: Due to the high friction loss of worm gear transmission, it is necessary to regularly inspect and replace lubricating oil to reduce wear and extend service life.