Cummins Engine part Valve Spring 3092508 for Cummins QST30 Engine

Engine valve spring introduction

The valve spring is located between the cylinder head and the spring seat at the end of the valve stem. The function of the valve spring is to ensure that the valve can closely fit with the valve seat or valve seat ring when the valve is closed, and overcome the inertial force generated by the valve mechanism when the valve is opened, so that the transmission parts are always controlled by the cam and not separated from each other.

Valve springs are mostly made of high-quality alloy steel wires and heat-treated to improve their fatigue strength. In order to avoid spring corrosion, the surface of the spring should be galvanized and phosphated. Both ends of the spring must be ground flat and perpendicular to the axis of the spring to prevent the spring from skewing during operation.

Most of the valve springs are cylindrical coil springs. When the operating frequency of the valve spring is equal to or an integer multiple of its natural frequency, the valve spring will resonate and the probability of breaking will increase. In order to prevent the occurrence of resonance, variable pitch springs can be used, and most engines currently use concentrically mounted double springs. The rotation directions of the inner and outer springs are opposite, and the stiffness of the outer spring is greater than that of the inner spring. The double spring can not only prevent resonance, but also shorten the length of the spring. And when one of the springs is broken, the other spring can continue to work, so that the valve does not fall into the cylinder.