Dynamic Simulation Analysis of Track Tension and the Influencing Factors of Deep-Sea Tracked Mining Vehicle

The deep-sea mining miner requires good passability to operate in complex and changeable terrain environment of the seabed. Among them, the track tension is an important factor to ensure the normal running of the vehicle. Aiming at the complex track tension problem on track link, the forces on each component of the tracked system were analyzed, and the theoretical formulas of track tension were established. The theoretical estimation and dynamic simulation of track tension in uniform speed were carried out by using the multibody dynamics model of the tracked vehicle, and the rationality of the theoretical estimation formula was verified. The influencing factors of track tension also were analyzed, and the significance of each factor on track was discussed by dynamic simulation. The results provided a theoretical basis for design of tracked vehicles.

MATHEMATICAL AND PHYSICAL BASIS FOR DEVELOPING A SIMULATOR FOR TOWING AND PULLING OF WHEELED AND TRACKED MACHINES

The subject matter of the article is the towing and pulling of wheeled and tracked vehicles with the use of cable ropes and dynamic slings. The goal of the study is to determine the mathematical and physical basis for the development of a simulator for towing and pulling wheeled and tracked vehicles for researching to study the possibility of using aramid fibers of cable-ropes and dynamic slings. The tasks to be solved are: based on the analysis of the main roads and ground characteristics to formalize the list of calculated parameters and physical quantities determine the amount of evacuation work when pulling, towing and transporting wheeled and tracked vehicles; to develop a mathematical model that describes the process of pulling and towing wheeled and tracked vehicles using cable ropes and dynamic slings. General scientific and special methods of scientific knowledge are used. The following results are obtained. By analyzing the main characteristics of roads and ground, a formalized list of design parameters and physical quantities that determine the volume of evacuation work during the towing and pulling of wheeled and tracked vehicles was obtained. Mathematical model, describes the process of pulling and towing wheeled and tracked machines using cable ropes and dynamic slings have been compiled as a system of equations with different order. analyzed existing technology for the production of aramid fibers, their strengths and weaknesses, and formed a research polygon with regard to the peculiarities of the operation of wheeled and tracked vehicles. Existing technology for the production of aramid fibers, their strengths and weaknesses, and formed a research polygon with regard to the peculiarities of the operation of wheeled and tracked vehicles have been analyzed. Conclusions. The main roads and ground characteristics that determine the vehicles. evacuation conditions are the following: the type of road or ground, their possibility depending on the season and precipitation, the presence of ascents and descents, as well as the nature of road (ground) interaction with caterpillars determined by resistance coefficients. movement and traction. The mathematical model of pulling a wheeled and tracked vehicle using cable ropes and dynamic can be presented as a system of equations: the jerk carried out by the machine in time reflected third-order differential equation, assuming that all the energy accumulated by the cable is numerically equal to the work of moving stuck machine, corresponds to the equality of the corresponding integrals; the properties of aramid fibers that affect the strength and performance characteristics of cable ropes can be formally expressed through the elongation of the cable. Analysis of strength and service properties of aramid fibers opens the way to improvement of manufacturing technology of cable ropes and dynamic slings for pulling and towing of wheeled and tracked vehicles.

Methodology for Assessing and Managing the Environmental Performance of Skidding and Feller Buncher Tractors

Systematic assessments on the effects of skidding systems on features of forest blueberry pine soil were conducted as part of this study. Assessing the ecological efficiency of forest skidding machines showed that the most significant impact (by 2.0–2.2 times) on soil compaction was observed at loading sites rather than during transportation. Lightweight loam density and sand density increased by 25% and 2%, respectively, after more than two passages of the skidding system. Pressure in 33L-32 tires of forestry machinery in operation on a solid surface varied from 46.5 kPa to 196 kPa at maximum load. Studying the impact of tires on soil compaction showed that the environmental efficiency of forestry equipment can be enhanced if the optimal tire pressure at average loads does not exceed 70 kPa for tracked vehicles and 150 kPa for wheeled vehicles in summer seasons. When ground grips were fully immersed, the pressure of forwarders on soil was reduced. These study results can be used to establish organizational and technological measures in order to manage the negative impact of skidding systems and to increase the environmental effects of their performance.

Research on a high power density mechanical-electrical-hydraulic regenerative suspension system for high-speed tracked vehicles

High power density energy regeneration is one of the effective solutions to solve the contradiction between improving the damping performance and energy consumption of active suspension. The hydraulic commutator is used to realize hydraulic rectification and hydraulic variable speed/pump/motor with few teeth difference gear pairs is used to match the speed, combined with permanent magnet motor power generation and power supply to put forward kilowatt level high power density mechanical-electrical-hydraulic regenerative suspension system for high-speed tracked vehicles. The mathematical model and fluid-solid-thermo-magnetic multiphysics coupling model are built to analyze the damping performance and regenerative characteristics of the system under passive and semi-active working conditions. The simulation results show that the damping force of the system increases with the increase of the road excitation amplitude and the semi-active control can be realized by adjusting the duty cycle with the PWM control rectifier module. The high power density mechanical-electrical-hydraulic regenerative suspension system can realize kilowatt level energy regeneration, and the regenerative efficiency is more than 50% under low-frequency excitation. The temperature rise of the system is low during operation, which is helpful to improve the reliability and service life.

Mathematical model for assessing lateral stability of articulated tracked vehicles

The article considers the problem of increasing transport productivity, operational reliability and safety during cargo transportation by using articulated tracked vehicles and road trains with active trailers. The influence of the introduction of an electromechanical drive, the modernization of the propulsion unit and the steering control system on the lateral stability of an articulated tracked vehicle is analyzed. A mathematical model is described for calculating the lateral stability of the chassis of articulated tracked vehicles used in the regions of the Far North, Arctic and Antarctic. The model is based on developments carried out for the chassis of an articulated wheeled vehicle. The model allows calculating to determine the key geometric and kinematic parameters of the rotation, taking into account the action of external forces. The use of holonomic constraints in determining the critical speed of movement is determined by the physical picture of the beginning of overturning, which corresponds to the achievement of the critical folding angle of the sections. This approach makes it possible not to use empirical coefficients when assessing the instantaneous position of the center of gravity of the system, the center of rotation, the radius of rotation of the center of mass, and the critical speed of the chassis. The moment of the beginning of the rollover is determined by the disappearance of the normal reaction under the link caterpillar. The onset of lateral sliding is determined by the lateral force exceeding the lateral adhesion limit.