Spiral mechanical rotation direction and purpose

 So-calledspiralUsually it refers to thebolt,Screw nutAnd other irregularities on the surface having a spiral or linear stripes cylinder hole, wherein this cylinder called a "screw" hole body called the "nut", and spiral linear stripes called "Thread" . Its analysis of the performance of spiral rotation direction and purpose as follows:

      Analysis helical rotation direction:

      Helical thread, according to the direction of the helix, can be rotated toward the direction of the two kinds. Most spiral thread comply clockwise spiral from either end of the shaft and looked toward, if the coil in a clockwise direction, the right-handed helix will move away from the viewer.

 "Right-handed helix" comply with right-hand rule: the right towards the direction of rotation of the finger grip lever shaft, straight thumb, the thumb will point to the direction of linear movement of the lever shaft. On the contrary, "left-handed helix" comply with the counterclockwise direction from either end of the screw shaft and looked toward, if the screw to rotate in a counterclockwise direction, the left-handed helix will move away from the viewer. Comply with the left hand rule handed screw. The left hand fingers clenched towards the direction of rotation of the lever shaft, straight thumb, the thumb will point to the direction of linear movement of the lever shaft.

      For right-handed, the use of a screwdriver to tighten the right-handed helix than the left-handed screw tightening easy, because this action is used after urging greater spin muscle, rather than having a small biasing pronator. Since most people are right-handed, standard threaded fastener is threaded right-handed thread.

      Left-hand threads commonly used in the following cases:

      a, when the axis of rotation of the lever because fretting induced precession caused by the general right-handed nut becomes loose, not become tight. For example, the fastening left pedal of the bicycle, fastened to the circular saw blade and tighten the wheel on the desktop grinders spiral is left-handed helix.

      b, both ends of the thread has some devices, such as turnbuckle, movable pipe segments, these devices have a right-hand thread and a left-hand thread, the rotary device can be threaded at both ends at the same time tighten or loosen.

      c, activists in order to prevent thieves pilfering theft bulb to use at home, and so on railway stations or underground utilities will use left-handed lamp.

      d, according to tradition, the coffin lid is left-handed screws tightened.

      Based on the performance of spiral, which is the intended use:

      1, self-locking nature of the application helix (will be explained in detail later),Threaded fastenersUse screw to fasten the several objects together. For example, wood screws, sheet metal screws, bolts and nuts, and so on.

      2, self-locking screw key nature is nature in many applications. For example, a screw cap, Vise, C-clamp, screw jack and so on.

      3, the coil can be used in mechanical power transmission linkage group. For example worm gear, the lead screw, ball screw, and so on. Due to the low efficiency of the helical rod group rarely used to transmit high power, more common in low-power, intermittent usage, for example, the position of the actuator.

      4, the coil surface about the rotation axis rotary motion to move the material, for example, Archimedes' screw auger screw conveyor.