The schemes of mechanisms allowing automatic regulation of pressure of smooth drive wheels on the rail depending on the train resistance value and traction force created by these wheels are considered. The torque acting on the drive wheels ensures the realization of a constant coefficient of traction of the drive wheels with the rail in the mode of elastic sliding under any working loads.
At mining enterprises, in agriculture, in clearing construction sites perform a significant amount of work on loading large pieces of stone, which are rectangular blocks of marble, granite, travertine, etc., boulders, the shape of which is close to a ball, oversize in mining, the shape of which can be arbitrarily.
In various industries, there is a great interest in traction devices (TDs) with adjustable pressure of smooth driving wheels on the rail depending on the amount of traction or braking force they generate. ...
As an initial position of work of the rowing-rotor actuator we shall accept the scheme of its work without lifting of the rotor axis. We consider that the work of the rotor gravity force is fully utilized for the work of introduction of combs into the stack. The trajectory of the comb tooth in this case is a circle. ...
The positive properties of the smooth driving wheel used as a driving device of self-propelled carts are proved by the long-term operation of modern locomotives in various industries. The smooth wheel is very technologically advanced, capable of supporting significant normal, tangential and axial loads. ...
The modes of realization of the coefficient of adhesion of smooth driving wheels with rails have been studied in detail. It is established that at constant locomotive speed and constant pressure of driving wheels on rails there is a strict dependence between wheel slip and the coefficient of clutch.
Calculations of modern locomotives with smooth driving wheels are made separately for the conditions of operation in traction and braking modes at the highest loads, when slipping or skidding is especially likely. At train resistance or braking forces, adjacent to zero values, the gravity of the locomotive causes a very large reserve of traction forces, and in the study of these modes was not necessary. Obviously, therefore, it was assumed that the zone of elastic sliding passes through the origin of coordinates.
Leningrad Mining Institute together with “Kizelugol” Combine created an experimental frameless tractor for moving a train of cars on smooth horizontal and inclined rails. The tractor was manufactured in the central mechanical workshops of Kizelugol Combine and in the fall of 1967 it passed successful factory tests.
The Leningrad Mining Institute and the Telman Fine and Technical Fibers Combine were involved in the realization of the contract of creative work. In fulfillment of the agreement on creative cooperation Telman created suspended monorail tractors with automatic regulation of the drive wheel pressure on the rail depending on the train resistance or the required braking force.
Significant value of the forces arising at impact, exceeding the weight of the striking body in hundreds and thousands of times, opens wide opportunities for simplification of modern mining machines by increasing their speed and accumulation of energy by impact elements. On the other hand, the study of the impact phenomenon can facilitate the study of regularities occurring during the destruction of rocks by high-pressure water jet. All this indicates the relevance of studying the regularities of rock destruction and, in particular, of coal by impact.
In order to study some regularities determining the energy intensity of the process of destruction of a solid body by high-pressure water jet (up to 200 atm), a set of studies was carried out in the laboratory of mine transport of the Leningrad Mining Institute.
Considering individual elements of high-pressure jets as a free-falling body thrown into space with a certain velocity, and having the parameters of the jet trajectory, it is possible to judge the amount of energy transferred by the jet to each of the sections under consideration, as well as the losses to overcome the resistance of the medium. But the determination of the trajectory parameters of the power axis of the jet is complicated by a number of features inherent in high-pressure jets. For example, at a pressure of 200 ati, a jet with a diameter of 3 mm passes the most effective zone with a length of 6 g for 0.03 sec, while in the void it would fall by 4.4 mm. Under these conditions, a method with a high degree of accuracy in determining the position in space of the force axis of the high-pressure jet is needed. Determination of the altitude coordinate by visual observation is completely unacceptable, since the halo of spray surrounding and hiding the main central part, of the jet, has a lower velocity, and hence a greater curvature of the trajectory. The method of “core jet” prints does not provide the accuracy required in these conditions and requires labor-intensive preparation and processing of jet prints.
The principle of tractive force creation by modern locomotives with all its simplicity and perfection has a number of significant drawbacks, which are manifested in the form of slipping of drive wheels during starting, braking and traveling on inclined tracks. This is a consequence of overcoming the variable resistance of the train to movement by friction forces, the ultimate value of which is limited by the constant coupling weight. This contradiction can be eliminated by automatically regulating the pressure of the drive wheels on the rail. Then the drive wheels 1, acting on the rail, located on the levers 2, connected with the locomotive (tractor) body 3 by rods 4 and 5, in the presence of the connecting clamp 6 and rod 7 enveloping the rail head should be pressed to the rail with the force HN, proportional to the resistance of the train to movement .....
Развитие механизации процессов погрузки угля и породы при проведении подготовительных выработок требует дальнейшего усовершенствования погрузочных машин и повышения эффективности их работы. Для этого необходимо рассмотреть обоснованность принципов работы машин, установить целесообразность конструкции исполнительного органа и наметить направление их дальнейшего развития. В качестве критерия при сопоставлении принципов работы исполнительного органа погрузочных машин принимаем траекторию его движения и направление перемещения в момент внедрения в груду взорванного материала. Существующие погрузочные машины поэтому признаку могут быть подразделены на три группы: 1) траектория движения исполнительного органа совпадает с вертикальной плоскостью, внедрение в кучу материала происходит снизу; 2) траектория движения находится в плоскости, близкой к горизонтальной; для момента внедрения и отделения материала от груды характерно боковое (фланговое) движение; 3) траектория движения совпадает с вертикальной плоскостью; внедрение в кучу материала происходит сверху.