In worm drive, when the worm rotates, it will be subjected to greater axial force. The direction of axial force is related to the rotation direction of worm and thread. You can also use the "right hand rule" or "left hand rule" to judge the direction of axial force. When judging, the direction of thumb is the direction of axial force on worm. When distinguishing, the thumb direction is the direction of the axial force on the worm. In order to counteract the axial force of the worm and prevent the worm from moving axially, thrust bearings or other axial support structures should be installed.
Extended information A. Worms and gears can only contact each other in the same rotation direction. Right rotation means that the right side is higher than the left side and upward, and left rotation means that the left side is higher than the right side and upward. Force is essentially the extrusion force of the inclined plane. The self-locking condition is that when the inclination angle of the inclined plane is small to a certain extent, the friction force of the pressure is greater than the component force of the inclined plane, and it cannot rotate under this pressure condition.
B, the rotation direction of the worm wheel and worm is determined by the spiral direction of the worm. For the combination of worm gear and worm with the same spiral direction, the relationship between worm gear steering and worm steering is the same. For example, when the worm rotates forward, the worm wheel rotates forward; If the worm wheel is required to rotate forward when the worm rotates forward, the direction of the worm helix must be changed; Therefore, the steering relationship between worm wheel and worm depends on the direction of worm screw.
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