Tatarinskaya N."Estimation the inertial characteristics of the heading machines"

KONDRATUEVA NATALA ARKADYEVNA
(TATARINSKAYA)

Ōheme: "USING THE METHOD OF 3M MODELLING FOR ESTIMATION THE INERTIAL CHARACTERISTICS OF HEADING MACHINES"
Science supervision:ph. V.P. Kondrahin

For modeling the working processes and decision the problems of statics and dynamics heading machines, the great value has knowledge of inertial characteristics to which it is possible to relate weight, coordinates of the center of weights, the moments of inertia, direction of the main axes of inertia.

Modern packages of three-dimensional designing allow to define inertial characteristics of constructed model with any degree of accuracy. In the present work were researched the inertial characteristics of the heading machine with an arrow-type rock breaker, for that was developed the three-dimensional model of a combine (see pic.1). At creation of model were taken up the following simplifications:

Shaft and an axis haven't facets, key slots, flutes for a grinding wheel's exit;
There are no fastening elements , elements of hydraulics: branch pipes and hoses;
Cutting tools (CT) are showed without cutters and tool heads;
Cogwheels are submitted as disks which basic sizes are: width of a ring gear, dividing diameter and diameter of a shaft;
The case, caterpillar mechanisms of movement and hydrojacks are conditionally submitted as the homogeneous bodies, which density are:

p = M / V,

where

With the help of the constructed model were determined the basic inertial characteristics of a combine, such as coordinates of the center of weights, the moments of inertia concerning axes, the centrifugal moments of inertia, the main central moments of inertia (table 1, 2 and 3) depending on position of the cutting tool in excavation's space (here a - a corner of cutting tool inclination in a vertical plane, and b - in horizontal).

Table 1 - the basic inertial characteristics of the heading machine 4PP-2Ė depending on change the position of the cutting tool in vertical plane ( b = 0)

a ,degrees	Coordinates of the center of weights, mm			Radiuses of inertia, mm			The moments of inertia concerning axes, kg *²
a ,degrees	X_c	Y_c	Z_c	r_x	r_y	r_z	I_x	I_y	I_z
1	2	3	4	5	6	7	8	9	10
0	-1000	2760	-882	1902	887	1953	116600	25400	122900
10	-1000	2758	-845	1911	916	1948	117700	27000	112270
20	-1000	2750	-810	1911	956	1940	117700	29300	121270
30	-1000	2734	-776	1914	1004	1918	118000	32500	118500
38.5	-1000	2726	-747	1923	1050	1889	119100	35500	115000

Continuation of the table 1

a ,degrees	The centrifugal moments of inertia, kg*m²			The main central moments of inertia, kg*m²
	I_xy	I_zx	I_zy	I_xx	I_yy	I_zz
	11	12	13	14	15	16
0	88900	-28400	-78400	270500	57280	277660
10	88860	-27200	-75100	268100	55200	277300
20	88600	-26100	-71800	264800	53360	275900
30	88100	-25000	-68400	260200	51600	275900
38.5	87800	-24100	-65600	257400	50200	271600

Table 2- the basic inertial characteristics of the heading machine 4PP-2Ė depending on change the position of the cutting tool in horizontal plane (a = 0)

b ,degrees	Coordinates of the center of weights, mm			Radiuses of inertia, mm			The moments of inertia concerning axes, kg*m< sup>2
b ,degrees	X_c	Y_c	Z_c	r_x	r_y	r_z	I_x	I_y	I_z
1	2	3	4	5	6	7	8	9	10
0	1000	2760	-882	1902	887	1953	166600	25300	122900
10	948	2738	-882	1871	899	1928	112800	26000	119700
20	900	2708	-882	1826	930	1898	107400	27900	116100
30	859	2670	-882	1690	1029	1822	92000	34100	107000
38.5	812	2615	-882	1690	1029	1822	92000	34100	107000

Continuation of the table 2

b ,degrees	The centrifugal moments of inertia, kg *m²			The main central moments of inertia, kg *m²
	I_xy	I_zx	I_zy	I_xx	I_yy	I_zz
	11	12	13	14	15	16
0	88930	-28400	-78400	270500	57300	277700
10	83630	-26900	-77800	266600	54000	270500
20	78500	-25600	-77000	261300	51200	262400
30	73900	-24400	-75900	254800	48800	253500
38.5	69000	-23300	-74300	245400	46700	244300

Table 3 - the basic inertial characteristics of the heading machine 4PP-2Ė in extreme positions of the cutting tool in excavation's space

b degrees,	a ,degrees	Coordinates of the center of weights, mm			Radiuses of inertia, mm			The moments of inertia concerning axes, kg *m²
b degrees,	a ,degrees	X_c	Y_c	Z_c	r_x	r_y	r_z	I_x	I_y	I_z
1	2	3	4	5	6	7	8	9	10	11
Extreme bottom positions of the cutting tool
42	-21.2	-1225	-2676	-993	1760	1030	1890	10000	34200	116100
42	-21.2	-775	-2659	-957	1740	1050	1890	97100	35300	114800
Extreme upper positions of the cutting tool
42	38,5	-1208	-2657	-817	1780	1090	1850	102100	38700	110300
42	3805	-787	-2647	-765	1806	1172	1846	104400	44100	110300

Continuation of the table 3

b ,degrees	a ,degrees	The centrifugal moments of inertia, kg *m²			The main central moments of inertia, kg *m²
		I_xy	I_zx	I_zy	I_xx	I_yy	I_zz
		12	13	14	15	16	17
Extreme bottom positions of the cutting tool
42	-21.2	105600	85600	39200	262500	80100	279000
42	-21.2	103400	69900	31800	249000	68500	274500
Extreme upper positions of the cutting tool
42	38,5	66600	82000	23900	257300	49000	247300
42	38.5	67100	65200	16400	444600	38800	245700

   On the dates, which resulted in tables 1 and 2 it is possible to make the following conclusions.

    Coordinates of the center of weights change at change the position of the cutting tool in excavation's space . Change relatively the X coordinate, at the increase in a corner of an inclination of the cutting tool in the vertical plane from 0 up to 38,5deg., is slightly (0,2 mm), and at change of a corner of turn of the cutting tool in a horizontal plane from 0 up to 42 degr. reach 181 mm. These changes don't exert influence on the transverse stability of the combine, because the caterpillars-width of a combine is 2400 mm.

   Displacements about Y coordinate are:

At increasing the corner of an inclination of cutting tool l in vertical plane - 34 mm;
At change the corner of turn the cutting tool in a horizontal plane - 145 mm.

It is also doesn't exert influence on a stability of the machine, because e longitudinal sizes of a combine's basic base are considerable. Besides longitudinal stability of the combine increases at the expense of the leaning on the end of a feeder's basic table .

At the change of the cutting tool position there is an essential change of the moments of inertia.
We shall analyze, for an example, change of the main central moments of inertia:

At the change of the cutting tool position in vertical plane I_xx changes from 270500 kg*m² up to 257400kg*m² (on 5%) , I_yy from 57280 kg*m ² up to 50200 kg*m ² (12%), I_zz from 277660 kg*m ² up to 271600 kg*m² (2%).
At the change of the cutting tool position in a horizontal plane of excavation's space, the main central moments of inertia changes about X axis from 270500 kg*m² up to 245400 kg*m ² ( 9%), I_yy from 57300 kg*m ² up to 46700 kg*m ² (18%), I _zz from 277700 kg*m ² up to 244300 kg*m ² (12%).

It is necessary for taking into account at the modelling the working processes of the heading machine.

In such a way , using a method of 3Ė modelling were received input dates for modelling the working processes of the heading machine, with the purpose of optimization a parameters of powersubsystems, systems of their automatic control and operating modes.

Picture 1 - Changing the position of the cutting tool in horizontal plane

Picture 1 - Changing the position of the cutting tool in horizontal plane

Picture 2 -Changing the position of the cutting tool in vertical plane

Literature:

1. Kondrahin V.P., Efremov M.A. Estimation the inertial characteristics of mountain machines//Students scient.-techn.magazin š4.-Donezk:DonNTU,2003.-p.120-122.

2. Solod V.I.,Gettopanov V.N., Rachek V.M. Desining of mountain machines.-Ė.,Nedra, 1982, 350 p.

KONDRATUEVA NATALA ARKADYEVNA
(TATARINSKAYA)

Science supervision:ph. V.P. Kondrahin

UP

KONDRATUEVA NATALA ARKADYEVNA (TATARINSKAYA)

Science supervision:ph. V.P. Kondrahin

UP

KONDRATUEVA NATALA ARKADYEVNA
(TATARINSKAYA)