The thrashed mass kinematic parameters establishment in the roller thrashing unit clearance

. Planetary mechanisms are used to create the working movement of operating bodies of metallurgical and mining machines. Rolling working bodies, for the drive of which the planetary mechanisms are used are increasingly used in the designs of harvesters. The processes taking place in the differential threshing devices of harvesters are poorly studied due to the lack of information about the properties of the material in the case of rapidly changing stresses in them. The present work is a result of the analysis of theoretical and experimental researches in threshing. We described the technological scheme of the shock-vibration threshing device and the principle of its operation. There were studied the possible options of the placement of rollers and a concave. The relationship between the angular velocities of a roll, rollers and a concave was found out. The installation of three-sided rollers on the threshing device according to the scheme proposed by us makes it possible to shake the whole threshed rice mass from 75 to 110 times per second.

The principal scheme of the roller trashing unit with differential drive is presented in Figure  1. The rice mass that is held by the serving rolls 5 is received at transporter 4 constant speed (Vn) in the working clearance between polyhedral rolls 2 and 3, drum and Concave rolling towards each other at equal relative angular speeds 3 2 . On the drum rolling at a frequency 1 there are nine polyhedral rolls and six are in the concave. Arrangement angle of the drum rolls is twice as large as that of the concave.
In transition through the roller thrashing unit, the rice mass fulfills a complex motion. On the one hand, the rice mass is moved by the feeding rolls at transporting speed that is equal to serving speed, and on the other hand, it is subjected to consequent concave and drum rolls ribs strokes, that force it to fulfill relative oscillation movements in vertical plane [1].
It is experimentally established, that in the working clearance the rice mass is in tense condition due to the fact that the rice mass serving speed is less than absolute circular drum and concave rollers speed 10÷15 times. To study the conformity of the rice mass movement we shall consider kinetics of the first pare of rollers at the moment when the drum and concave rollers axles are on the drum vertical radius (figure 2). The relative position of the first rollers pare is that under which the concave roller rib is perpendicular to drum radius and the concave roller rib is upward directed, the rib of the corresponding drum roller being directed towards the upper side of the concave roller.
Polyhedral rollers influence on the rice mass transportation character in the working zone of thrashing-separating unit is determined by the rollers geometry, by the way of their primary arrangement and by the correlation of rollers and drum rotation frequencies [2].
The study of the rice mass transportation regularity between the thrashing separating unit working zone rollers can be divided into two problems: 1. The establishment of regularity of the thrashed mass transportation under the influence of concave rollers. 2. The establishment of regularity of the thrashed mass transportation under the influence of concave rollers fulfilling complex movement. We study the first problem that includes the threshed mass and concave rollers rotating on their own fixed axles interaction regularities examination.
Here two aspects could be outlined: a) The establishment of the transportation regularity of the total thrashed mass layer when concave rollers ribs interact consequently and the rice mass is accepted as a deformed stem «pivot». b) The regularity establishment of the fixed point movement on the thrashed mass during its transportation through the working thrasher unit clearance. The study of the first aspect allows determination of the kinematic parameters the thrashed mass different points i D in the moment of their contact with the concave roller rib.
The solution of the second problem allows determination of the trajectory and kinematic parameters of the point 0 ' D fixed on a thrashed mass being in the thrasher unit working zone [3].
We shall consider the movement of the thrashed mass point i D when moving from the feeding rollers through first thrashing rollers pair working zone. The stem «pivot» fulfills the plane-parallel motion in the vertical plane at the portable progressive speed that is equal to the mass p V feeding speed and with the relative rotation movement around point O.
In thrashed mass random point kinematic parameters determination and taking into account its the following assumptions are necessary and possible [4].
1. The thrashed mass uniformly fills the total capacity of the thrashing unit working zone DFBE .
2. The first co-stroke of the concave roller rib and the thrashed mass takes place when the side 0 0 D C is parallel to stem «pivot».
3. Under the roller rib co-stroke with the thrashed mass is deformed Where -the falling rollers relation speed s -1 ; 1 R -the falling rollers radius, m.
The circular speed of the concave roller is determined Where 2 -concave roller relation speed, s -1 ; r -circumcircle radius, m.
It is known that due to the friction force between the drum and concave rollers and thrashed mass, the latter is stretched towards the mass movement transmissible speed. This allows, with a negligible error, accept the moving rice mass that is between the falling .
We express the stem «pivot» turning angle around point 0 trough current meaning of concave roller turning anglecos cos where r -roller circumcircle radius; i -roller sides number; L -distance between feeding rollers rotation axles and the concave first roller.
The stem «pivot» turning angle has the maximum meaning when i ; (by any roller sides number). The more is the angle meaning, the less is the roller sides number. In our researches the number of the roller sides changed within 3 6, and that means that the maximum angle meaning and, consequently, the maximum deviation angle of the rice mass will be under i=3. It should be noted that the maximum rice mass deviation angle coincides with the upper most roller rib position [8].
In analyzing expression (7) we found that the maximum deviation angle meaning corresponds to the following meaning of angle In a real thrasher 1  We find the carding speed meaning in speeds plan (fig 2).
As the meaning of is small we suppose that cos 1 and substituting stem «pivot» turning angle meaning out of (9) into (14) after some transformations we get ' 2 cos sin cos The carding concave rollers speed was determined out of expression (15) under the following primary conditions:

Table1
Sides number Angle change range where -the angle between the speeds p V and ' d V vectors.
The angle meaning between the speeds p V and ' d V vectors equals.

Conclusions
The equations (15, 16) defining kinematic parameters of moving rice mass random point i D in costriking with concave roller rib were oblaired, in the interval between the falling rollers and the concave first working pair of rollers in accordance with constructive, kinematic and technology parameters of thrashing-separativy unit operation: -the thrashed mass random point relative speed meaning relative to concave roller rib point D , equal to concave rollers carding speed (15).
-the thrashed mass random point absolute speed meaning (16).