Wheel nut surface treatment on the influence of prestressing force

Wheel connection vice is vehicle applications extremely important components, its role is to the wheels connected to the hub reliably – together, guarantee the safety of the vehicle. Wheel connection of failure will lead to serious consequences, not only can cause the damage to the vehicle parts, can also cause great economic losses and casualties.

Wheel to connect deputy vice failure forms mainly loose, bolt fracture, the direct result is that the wheel fly out of causing accidents. Through the analysis of wheel bolt fracture failure many times, before the fracture bolt looseness of vice cause the loss of prestressing force, cause the relative movement between the wheel and the wheel bolt caused by wheel mounting holes shear force caused fatigue fracture is the main reason, so the stability of the pre-tightening force is an important factor to ensure the normal order of the wheel connection.

China truck wheel fastening enterprise mostly used automatic tightening machine by using the method of fixed torque tighten, according to the analysis of wheel bolt, nut, the wheel of different manufacturers, different surface treatment there is biggish difference fitting coefficient of friction, constant torque method is used to tighten the prestressing force will appear larger differences, thus influence on the performance of the wheel fastening.

Below the standard network to share different surface treatment methods on wheel nut the influence of friction coefficient, improve the reliability of the wheel fastening.

1) through the wheel bolt torque and pre-tightening force analysis and calculation, it is concluded that in the constant torque assembly pre-tightening force depends on the size of the thread surface and contact surface friction coefficient, friction coefficient and friction coefficient of the slight change of pre-tightening force has a great influence.

2) based on the determination of the coefficient of friction, wheel connection deputy contact surface friction coefficient than thread much bigger friction coefficient, surface friction coefficient of friction coefficient.

3) from the test data, white zinc plated with yellow zinc plating on the contact surface friction coefficient and friction coefficient, the influence of the friction coefficient is not big, in the absence of sealants and friction coefficient, thread stable friction coefficient, show the batch consistency nut thread machining, surface treatment is good, but there is a big fluctuations, interface friction coefficient that contact area, especially the coefficient of friction between nut and the locking washers stability is very poor, but because of rust-proof for phosphating nut, interface friction coefficient is very stable.

4) through to the normal supply of the different surface treatment of form wheel nut test, it is concluded that, the phosphating treatment of nut, in the case of without using the friction coefficient of blocking agent can provide very stable friction coefficient, which can provide stable and controllable pre-tightening force, ensure reliable connection vice connection.

Post time: Oct-08-2021