Screw nut custom processing method

  • Release time:2016-08-02
  • abst:Thread a rectangular, trapezoidal and sawtooth, trapezoidal screw jacks are commonly used. Trapezoidal thread form an isosceles trapezoid-shaped tooth angle α = 30o, internal and external thread trapezoidal thread with tapered snapping easy to loose; its basic tooth shape according to GB / T5796.1-2005 requirements. The self-locking jack line can better, so with a single thread. Therefore, the choice of screw threads are tooth-shaped angle α = 30o singlet trapezoidal thread.

     Original design data is: Q = 60KN Maximum weight and maximum lifting height H = 230mm.

    1. Design and calculation of the screw
    1.1 screw thread type selection
    1.2 Select screw material
    1.3 determine the diameter of the screw
    Thread a rectangular, trapezoidal and sawtooth, trapezoidal screw jacks are commonly used.
    Trapezoidal thread form an isosceles trapezoid-shaped tooth angle α = 30o, internal and external thread trapezoidal thread with tapered snapping easy to loose; its basic tooth shape according to GB / T5796.1-2005 requirements. The self-locking jack line can better, so with a single thread.
    Therefore, the choice of screw threads are tooth-shaped angle α = 30o singlet trapezoidal thread.
    Screw materials commonly Q235, Q275,40,45,55 like.
    In this choice is Q275
    Press abrasion conditions determine the screw diameter d2. After obtaining d2, select the appropriate standard nominal diameter d, t pitch and other dimensions.
    Spiral slide abrasion resistance calculations, the main thread is to limit the working surface pressure p, to less than the allowable pressure [p].
    For isosceles trapezoid thread ,, there, and generally 1.2 to 3.5, so here take 1.5
    Allowable pressure [p] is taken to 20MPa.
    Screw thread diameter, determined according to this pitch diameter, look-up table GB / T5796.3-2005 take:
    Nominal diameter, pitch, screw trails, screw diameter.
    Tooth-shaped angle α = 30o singlet trapezoidal thread
    Screw Material: Q275 = 1.5 [p] = 10MPa
    Screw Size: P = 7mm