Precision Non-standard Worm and Worm Gear
Precision worm and worm gear is a common transmission mechanism, which consists of a worm wheel and a worm. A worm wheel is a disc-shaped gear with a helical tooth surface called a worm tooth; a worm is a helical rod whose helix and the helix of the worm gear tooth surface mesh with each other. The two shafts of a worm gear drive are intersecting and perpendicular to each other; the worm can be seen as a helix with one tooth (single head) or several teeth (long) along a cylinder. A worm gear is like a helical gear, but its teeth cover the worm gear. When meshing, the worm rotates, driving the worm gear to rotate one tooth or several teeth, so the worm and worm gear transmission speed ratio i=number of worm heads/number of teeth of worm gear.
Features
● A large transmission ratio can be obtained, and it is more compact than a cross-axis helical gear mechanism.
● The meshing tooth surfaces of the two wheels are in line contact, and its carrying capacity is much higher than that of the crossed-axis helical gear mechanism.
● The worm transmission is equivalent to the screw transmission, which is a multi-teeth meshing transmission, so the transmission is stable and the noise is small.
● It is self-locking. When the lead angle of the worm is smaller than the equivalent friction angle between the meshing teeth, the mechanism is self-locking and can realize reverse self-locking, that is, only the worm can drive the worm wheel, but not the worm wheel.
● The transmission efficiency is low and the wear is serious. When the worm gear meshes and drives, the relative sliding speed between the meshing gear teeth is large, so the friction loss is large and the efficiency is low.
● The axial force of the worm is relatively large.
Application of worm and worm gear transmission
● In the field of industrial machinery: In cranes, conveyors, machine tools and other equipment, worm and worm gear transmissions are used to transmit power and torque.
● Automotive field: In automotive transmissions, worm and worm gear drives are used to shift gears. In a transmission, the worm gear is responsible for transmitting power and torque, and the worm is responsible for controlling the rotation of the worm gear.
● Aerospace field: In aircraft landing gear, worm and worm gear transmission is used to transmit power and torque, and control the retraction and retraction of aircraft landing gear.
● Medical equipment field: In the operating bed, worm and worm gear transmission is used to control the lifting and tilting of the operating bed.
● In the field of robotics: In industrial robots, worm and worm gear transmissions are used to control the joint motion of robots.