Development of a working tool with an integrated hydraulic drive of an asphalt pavement cold milling machine

Abstract

Machines for milling asphalt pavement have a wide range and are effectively used for restoration and repair of roads. Based on the analysis of the designs, performance and operational characteristics of these machines, the use of an integrated hydraulic drive is proposed, which ensures a reduction in the number of nodes, increasing the reliability and efficiency of operation of equipment for milling asphalt pavement.

The work shows the possible direction of increasing the uptime of the Wirtgen W200 milling machine, which is equipped with an advanced hydraulic system by replacing a mechanical drive that receives energy from the power take-off shaft with an integrated hydraulic drive. The design of the milling drum is developed, which is characterized by reduced dimensions, metal consumption, increased reliability of operation and advanced functionality. Using the developed design according to the above calculations allows to increase the uptime by 25%.

The choice of the mechanical transmission of the cutter gear mechanism has been substantiated. For theoretical studies, a design scheme has been developed in which a seven-mass mechanical system with seven elastic bonds is reduced to a two-mass one. Based on it, a mathematical model is constructed, which is presented in the form of a system of equations that takes into account the dynamic properties of the hydraulic drive unit and the elastic-inertial characteristics of the cutter working links under the assumptions traditional for the hydraulic drive. The solution to the compiled systems of equations was carried out by the numerical Runge-Kutta method, and an algorithm for solving them was developed that makes it possible to obtain a transient drive process for various system parameters. Theoretical studies have been carried out and dependencies have been obtained that allow us to establish the influence of the values of the design parameters on the duration of the transient in the hydraulic drive.