EXPERIMENTAL IDENTIFICATION OF THE DYNAMIC LOAD OF CONICAL PICKS DURING THE CUTTING PROCESS OF TRANSVERSE CUTTING HEADS OF BOOM–ROADHEADER

Author(s):  
Piotr Cheluszka
2017 ◽  
Vol 62 (1) ◽  
pp. 83-104 ◽  
Author(s):  
Marian Dolipski ◽  
Piotr Cheluszka ◽  
Piotr Sobota ◽  
Eryk Remiorz

Abstract The key working process carried out by roadheaders is rock mining. For this reason, the mathematical modelling of the mining process is underlying the prediction of a dynamic load on the main components of a roadheader, the prediction of power demand for rock cutting with given properties or the prediction of energy consumption of this process. The theoretical and experimental investigations conducted point out – especially in relation to the technical parameters of roadheaders used these days in underground mining and their operating conditions – that the mathematical models of the process employed to date have many limitations, and in many cases the results obtained using such models deviate largely from the reality. This is due to the fact that certain factors strongly influencing cutting process progress have not been considered at the modelling stage, or have been approached in an oversimplified fashion. The article presents a new model of a rock cutting process using conical picks of cutting heads of boom-type roadheaders. An important novelty with respect to the models applied to date is, firstly, that the actual shape of cuts has been modelled with such shape resulting from the geometry of the currently used conical picks, and, secondly, variations in the depth of cuts in the cutting path of individual picks have been considered with such variations resulting from the picks’ kinematics during the advancement of transverse cutting heads parallel to the floor surface. The work presents examples of simulation results for mining with a roadheader’s transverse head equipped with 80 conical picks and compares them with the outcomes obtained using the existing model.


Machines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 43 ◽  
Author(s):  
Enrico Ciulli ◽  
Paola Forte

In the experimental identification of dynamic bearing coefficients, usually small perturbations around the static equilibrium position are assumed and linear coefficients are considered. In the literature, studies on non-linear effects in plain journal bearings, especially from a numerical point of view, are reported. Few similar studies can be found on tilting pad journal bearings (TPJB). The present work reports some peculiar aspects observed during the experimental identification procedure of TPJB linear dynamic coefficients. The tests are performed on a test bench designed for large size journal bearings operating at high peripheral speeds and static loads. A quasi-static procedure is developed to quickly check the results obtained from the usually adopted dynamic excitation. It consists of applying a slowly rotating force to the floating stator and measuring the relative displacement of the stator from the rotating shaft. Different levels of static and dynamic load are applied to two different TPJBs with four and five pads. Deformed orbits have been observed increasing the ratio between dynamic load and static load, suggesting the presence of non-linearity. Similar results are obtained with simple analytical models assuming suitably tuned non-linear stiffness terms.


2011 ◽  
Vol 308-310 ◽  
pp. 1893-1899 ◽  
Author(s):  
Chun Guo Zhou ◽  
Hui Wu Wang ◽  
Chao Feng Ma ◽  
Yan Guo

According to derive the efficiency formula of 2K-H differential gear train, the direction of meshing power has been determined. The test bench of fear train combination and structure analysis has been used to experimentation. The test results of various rotational speeds and torques have been collected by the dynamic load simulation loading. Through analyzing the test data, the efficiency formula of differential gear and its relationship with the dynamic load have been demonstrated. The results of experiment have been provided to experimental identification for the theories research


2014 ◽  
Vol 77 (9-12) ◽  
pp. 1571-1579 ◽  
Author(s):  
Daolong Yang ◽  
Jianping Li ◽  
Liping Wang ◽  
Kuidong Gao ◽  
Youhong Tang ◽  
...  

2013 ◽  
Vol 58 (1) ◽  
pp. 3-21 ◽  
Author(s):  
Marian Dolipski ◽  
Piotr Cheluszka ◽  
Piotr Sobota

The article presents the outcomes of extensive computer investigations the purpose of which was to identify the impact of cutting heads’ rotational speed on the load applied on the cutting heads drive as well as on the efficiency and energy consumption of the cutting process. The investigations were performed based on a simulation of the rock cutting process within a wide range of rocks’ compressive strength with a roadheader transverse head equipped with 80 conical picks. Variations were taken into consideration in the rotational speed of the cutting heads and variations in the factors connected with the properties of the drives driving the cutting heads on the load condition of the cutting system and on the energy consumption of the cutting process. The computer simulations carried out indicate that a reduction is possible in the energy consumption of cutting the rocks with low workability by decreasing the cutting heads’ rotational speed thus preventing also the excessive load on the cutting heads drive. Possibilities are presented along with a concept of the heads‘ automatic speed adjustment according to the power utilised in the cutting process.


2002 ◽  
Vol 12 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Y. Zamachtchikov ◽  
F. Breaban ◽  
P. Vantomme ◽  
A. Deffontaine

2009 ◽  
Author(s):  
William S. Marras ◽  
Steven A. Lavender ◽  
A. Sue ◽  
Ferguson Riley E. Splittstoesser ◽  
Gang Yang

2013 ◽  
Vol 133 (4) ◽  
pp. 891-898
Author(s):  
Takeo Sakairi ◽  
Masashi Watanabe ◽  
Katsuyuki Kamei ◽  
Takashi Tamada ◽  
Yukio Goto ◽  
...  

2017 ◽  
Vol 137 (3) ◽  
pp. 521-531
Author(s):  
Yoko Hirashima ◽  
Kenta Yamasaki ◽  
Tomohiro Morimura ◽  
Norihisa Komoda

2011 ◽  
Vol 131 (7) ◽  
pp. 557-566 ◽  
Author(s):  
Hisao Taoka ◽  
Junya Matsuki ◽  
Michiya Tomoda ◽  
Yasuhiro Hayashi ◽  
Yoshio Yamagishi ◽  
...  

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