Power Characteristics of Mulcher Joints When Removing Tree and Shrub Vegetation

Abstract

In recent years, the enterprises of forestry and the Ministry of Energy of the Republic of Belarus and other countries widely implemented advanced milling tools designed to chop wood, stumps and roots without immersing the cutter in the soil (mulchers) and with immersion (rotovators), which allows you to prepare the ground for planting forest crops. They can be mounted on multi-purpose tractors, loaders and excavators. At the same time, there are no methods that allow carrying out a reasonable choice of technological equipment for a particular basic machine, since a significant number of production, technological and technical factors have an impact on the emerging power and capacity parameters. The proposed method allows taking into account a significant number of variable values (working methods, speeds of various operations, parameters of the working body, its drive and base chassis, soil conditions, etc.) and simulate the interaction of milling tools under various operating conditions. It was found that the greatest loads on the mulcher rotor occur during the felling of tree and shrub vegetation, which is associated with an increase in the area of interaction between the cutters and the wood up to 2 times compared with the chopping of similar lying stands. This value can be reduced by 15–30 % depending on the diameter of the trunks being processed. In the case of a significant amount (cluster) of forest stands with a diameter of more than 10 cm, it is preferable to carry out work at a speed of about 0.2 m/s or advanced felling of these trees. The use of hydraulic travel (speed) reducers or hydrostatic transmission is promising in order to reduce dynamic loads and get better adaptability of the working equipment to natural-production conditions (the ability to work at a speed from 0 to 5 km/h). It should be noted that the installed required engine power for the milling equipment drive should be increased by 10–15 % due to the needs of the drive of various equipment located on the base chassis. Also, in the case of the integrated use of tree and shrub vegetation, it is possible to use mulchers that collect biomass; however, this will require additional energy costs. In this regard, the method can be applied when choosing the parameters of technological equipment for the existing base chassis, to solve the inverse problem, and also to select the operating mode of the milling equipment depending on the natural and production conditions with the possibility of subsequent prediction of the effectiveness of the work performed.

Overview of milling implements for grinding trees and shrubs

“…Such designs have power from 40 to 400 hp. and can be equipped with various options for rotors and cutting knives [6,12,13].…”

“…), Rotating at a low speed, is used. As a rule, a pressure roller with a hydraulic lift is installed on the beam of this technological equipment [4,5,6]. For grinding tree and shrub vegetation, in addition to rotary and disk grinding technologies, they are used.…”

“…Ammak-Bel also implemented a number of projects for the introduction of self-propelled milling tools and the aggregation of attachments on various types of chassis manufactured in the Republic of Belarus. Among the considered designs of mounted and self-propelled mulchers, about 80% are mounted with different working widths [1,3,4,5,6].…”

“…This primarily concerns the need to care for power lines, gas and oil pipelines, and the implementation of a number of forestry activities. In recent years, the usual brush cutters and uprooters have been replaced by milling tools (mulchers and rotators) [1,2,3], which are hung on various base chassis [4,5,6,7,8]. This technological equipment is produced by a number of manufacturers, both in our country and abroad.…”