Checking the input joint I (spherical towing coupling preloaded by a helical compression spring) — example

Design data

Loading data

F_X = 1500 N, F_Y = 300 N, F_Z = 700 N; the resultant (radial) force is F_r = 1682.3 N.

Operating constraints: temperature T = (−30…40) °C; outdoor working environment with high humidity.

Design constraints: interchangeability with the coupling systems in use in the EU.

Materials and heat treatments

The elements in contact, 3 and 2, are made of C45 steel, quenched and tempered to HB = 280…300.

The spherical pair (ball joint) is lubricated with the general-purpose grease U90Ca3, with allowable pressure p_a = 10 MPa and dropping point T_max = 80 °C.

Check

Maximum actual pressure p_max = 1.3 MPa;

p_max ≤ p_a; 1.3 < 10 MPa (satisfied).