THEORETICAL STUDY OF THE CHANGE OF THE TORQUE ON THE SHAFT OF THE FEEDING ROTOR OF THE SHREDDING MACHINE DURING THE CAPTURE AND COMPRESSION OF THE GRASS MASS

Abstract

The shredding machine is any forage harvester's main and most energy-intensive unit. Its structural design determines the machine's technological scheme and the main units' location. Disc and drum shredders, which are equipped with trailed, haulage, and self-propelled forage harvesters, have become widespread. Biter-knife shredding machines are installed on pick-up trucks and balers.

In general, the energy spent on grinding the grass mass includes components for grinding (compression, cutting, friction), transportation of the leaf-stem mass, as well as costs for the idling of the working bodies. A characteristic feature of the bittern-knife apparatus under the research is the use of active disc knives that cut a portion of the leaf-stem mass. Therefore, for an objective assessment of the specific energy intensity of the process of grinding the grass mass, it is relevant to determine the forces and moment on the shaft of the feeding rotor of the shredding machine at the stage of capturing and compressing the grass mass.

The object of the research is the process of grasping and squeezing with the fingers of the feeding rotor a portion of the grass mass in the forming channel of the biter-knife shredding machine.

The purpose of the research is to establish the analytical dependence of the change in the torque on the shaft of the feeding rotor of the shredding machine on the forces of grasping and compressing the grass mass.

The objectives of the work are to perform an analysis of the design features of biter-knife shredding machines, perform an analysis of research and publications on the creation or change of torque (power, energy intensity) on the shaft of the disk, drum, rotor of the shredding machine of forage harvesters, establish the change in effort and torque on the shaft of feeding rotor of the biter-knife shredding machine when capturing and compressing the leaf-stem mass.

The research methodology is based on the analysis of the interaction of the fingers of the feeding rotor with a portion of the captured grass mass in the forming channel of the shredding machine using the methods of theoretical mechanics.

The scientific work considers the process of capturing, compressing the mass, and feeding it into the annular channel by the fingers of the feeding rotor of the shredding machine. The dependence (4) of the horizontal component of the rotation speed of the rotor finger on the angle of its rotation is established. It is noted that the operation of the feeding rotor is possible in three modes, namely, mass loading, intermee, and mass flow stretching. Based on the reliability of the technological process, the mode of operation of the feeding rotor with stretching of the mass flow is more appropriate.

Analytical dependences on the calculation of forces and torques on the shaft of the feeding rotor of the biter-knife shredding machine in such zones as capture, compression of the material (18, 30), its stretching (22, 31), and acceleration into the cutting zone (28, 32) are given. The above dependencies take into account technological, structural, and kinematic factors, as well as the physical and mechanical properties of stem materials. It was found that under the given conditions, the maximum torque on the shaft of the feeding rotor is 132 N·m at an angle of rotation of the beater from 30° to 40°.