RU2482920C1 - Solid material grinder - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention may be used fro grinding solid materials. Proposed device comprises housing with inlet and discharge openings that accommodates vertical millstones. Said millstones feature different-grit surfaces and are fitted on common shaft. Medium millstone is coupled with rotary drive. Side millstones have communicated channels provided with gates and are arranged on shaft sections that feature opposite coiling direction. Said side millstones are locked by flexible elements coupled with retainers. Rotary drive is equipped with control unit and composed of flat double-ended linear induction motor with number of pole pairs equal to or smaller than two. Motor stators can effect circular motion relative to rotor. The latter is composed of a disc made from conducting material rigidly secured at medium millstone.

EFFECT: smooth adjustment of grinding speed.

2 dwg

Description

The invention relates to grinding equipment, in particular to devices intended for grinding and grinding materials.

A device for grinding solid materials, comprising a housing with a loading window, unloading windows, lids, a vertical stationary millstone equipped with a loading communicating vertical channel, grooves, and a rotating millstone with grooves mounted on shafts [1].

The disadvantage of this device is that this technical solution does not allow the simultaneous grinding of soft, strong and durum wheat, to grind different crops, use all surfaces in a grind mode, grind without grinding the germ and smoothly control the grinding speed.

Closest to the technical nature of the present invention is a device for grinding solid materials, comprising a housing with loading and unloading windows and vertical millstones placed inside it, which have surfaces with different grain sizes and are mounted on a common axis, the middle millstone being connected with a rotation drive, and side millstones are made with communicating channels having gates and are mounted on axle sections made with the opposite direction of thread winding and fixed using flexible elements connected to fixing devices having an elastic element [2].

The disadvantage of the technical solution is that it does not allow you to smoothly adjust the grinding speed, which limits the possibility of its application.

The purpose of the invention is the provision of smooth regulation of the grinding speed.

This goal is achieved in that the rotation drive is made in the form of a planar double-sided linear asynchronous motor equipped with a control unit with the number of pole pairs equal to or less than two, the stators of which are installed with the possibility of moving along the radius relative to the rotor, the latter is made in the form of a disk of electrically conductive material, rigidly fixed on an average millstone.

The authors know the use of flat double-sided linear asynchronous motors in the drive for the rotational movement, but the authors do not know the use of such motors with the number of pole pairs equal to or less than two, and movably mounted relative to the axis of rotation of the working body, which makes it possible to achieve the purpose of the invention: to ensure smooth adjustable rotation of the working body with its simultaneous vibration, which meets the criterion of "significant difference".

In FIG. 1 shows a general view of the device; in FIG. 2 is a section AA taken in FIG. one.

A device for grinding solid materials contains a housing 1 with loading and unloading windows (not shown in FIGS. 1 and 2). Inside the housing 1, on the axis 2, on the bearing support 3, an average rotating millstone 4 is installed, on the flat surfaces of which there are grooves 5 of various configurations. Millstone 4 is connected with a rotation drive. The rotation drive is made in the form of a flat double-sided linear asynchronous motor (LAD) having stators 6 and 7. Stators 6 and 7 are installed on both sides of the rotor 8. The rotor 8 of the LAD is made in the form of a disk of electrically conductive material, such as copper, and is rigidly fixed to the middle millstone 4. Stators 6 and 7 are fixedly mounted on the frame 9, which is fixed rigidly on the screw 10, and the screw 10 is inserted into the hole on the housing 1 and secured by nuts 11 and 12. To prevent rotation relative to the housing 1, the frame 9 has protrusions movably inserted into building 1 This solution (as an option) provides the ability to move stators 6 and 7 LAD relative to the rotor along its radius. If necessary, move the stators 6 and 7, the nuts 11 and 12 are unscrewed in one direction or another, depending on the direction of the necessary movement of the stators. On the threaded sections of the axis 2 there are two lateral stationary millstones 13, 14, in such a way that the stationary millstone 13 is installed in the area with the right thread and the stationary millstone 14 in the area with the left thread. The lateral stationary millstones 13, 14, having grooves 15 of various configurations on flat surfaces, are fixed by flexible elements 16, 17, in which the elastic element 18 is laid. Flexible elements 16, 17 enclose the stationary millstones 16, 17, drums 19, 20 and connect them to fixing devices 21, 22, for example with worm gears. Channels 23, 24 for supplying material to the working area are made in stationary stationary millstones 13, 14 in the form of communicating channels 25, 26 and 27, 28, directed in opposite directions, and equipped with shutters 29 and 30.

A device for grinding solid materials works as follows. When a three-phase voltage system supplies the windings of the stators 6 and 7 of the LAD with the control unit (not shown in Fig.), The stators create traveling magnetic fields. The direction of these fields should be the same. Under the influence of traveling magnetic fields in the rotor 8 there are electromotive forces and, as a consequence, currents. When the currents of the rotor 8 interact with the traveling magnetic fields, an electromagnetic force is created, applied to the rotor and directed towards the traveling field. Under the action of this force, the rotor 8 begins to rotate relative to the stators 6 and 7, transmitting rotation to the middle millstone 4. The material to be crushed is fed through loading windows and channels 23, 24 and 26, 28 into the working area formed by the contacting surfaces II, III and / or IV, V of the middle rotating millstone 4 and the side stationary millstones 13, 14. When the millstone 4 rotates, the solid material (grain), once in the working area, turns into flour, which comes off the periphery of the flat surfaces of the millstones 4, 13, 14 and goes to unloading windows (figure 1, 2 not p cauldrons). During the grinding of grain in excess of the calculated torque from the rotating middle millstone 4, i.e. when any solid foreign object enters the working area, the side stationary millstones 13, 14 are automatically turned away by thread, thereby increasing the gap between the grinding surfaces. This is achieved by the fact that the moment of rotation of the middle millstone 4 is directed towards the direction of the thread for the right and left side millstones 13, 14. As a result, oppositely repulsive forces are created between them, which automatically turn the side stationary millstones 13, 14 away by means of flexible elements 16, 17. When the opposite repulsive forces change in the direction of decreasing the critical value, the side millstones 13, 14 are automatically twisted to the millstone 4 due to the flexible elements 16, 17 into the cat The first one is the elastic element 18, which acts as a damper. This is possible due to the fact that the flexible elements 16, 17 are connected with the fixing devices 21, 22, for example, worm gears, which are designed to fix the initial tension of the flexible elements 16, 17, i.e. Are calculated on a certain effort (depending on the grinding material). The fixing devices allow you to track the load forces due to the flexible elements 15, 16 with the elastic element 18 and the threaded version of the axis 2. In addition, by installing the stationary millstones 13, 14 on the threaded sections of the axis 2, you can quickly change the location of surfaces with different grain sizes and adjust grinding of grain, since the fineness of grinding depends on the thickness of the gap between the surfaces of millstones 4, 13, 14 (II and III, I and III, IV and V, VI and IV). When installing stationary millstones 13, 14 for operation, the position of the valves 29, 30 is changed, thereby regulating the flow direction to one or another flat surface.

To rearrange the stationary millstones 13, 14 or one of them, it is necessary to loosen the flexible elements 16, 17 with the help of fixing devices 21, 22, then remove them. After that, unscrew the side stationary millstone 13 or 14 or both by thread, and then remove them. Assemble in the reverse order. The flat surfaces of millstones 4, 13, 14 are made with different grain sizes, for example, surfaces II, III are coarse-grained, IV, V are fine-grained, I is medium-grained, etc. This allows you to grind any grain (wheat, rye, barley, oats, buckwheat, etc.) of various varieties.

In the proposed technical solution, the length of the stator (L _st ) is determined by the radius of the rotor (R), based on the maximum required rotation speed of the average millstone (n _max ) required for grinding a particular material, and is found from the expression:

where p is the number of pairs of stator poles;

ƒ is the frequency of the power source of the three-phase voltage system.

Smooth adjustment of the rotation speed in the proposed device is possible by changing the location of the stators 6 and 7 LAD relative to the axis of the average millstone 4. By approaching the stators 6 and 7 to the axis of the millstone 4, its rotation speed increases, and vice versa, moving the stators 6 and 7 away from the axis of the millstone 4, its rotation speed decreases.

The control unit must be able to turn on the windings of the stators 6 and 7 to the power source in parallel or sequentially with each other, turn on the windings of only one or the other stator. When only one of the LAD stators is turned on to the power source, the second one provides closure of the magnetic power lines of the working stator. The developed moment of LAD and the speed of rotation of its rotor (hence, the average millstone) are determined by the technical parameters of the stator (length, number of pairs of poles). When the windings of stators 6 and 7 are connected in parallel, the moment developed by LAD doubles. When the windings of the stators 6 and 7 are connected in series, the number of pairs of LAD poles is doubled, therefore, the rotor rotation speed is halved. Thus, it becomes possible to additionally control the moment and rotation speed of the developed LAD.

During LAD operation, edge effects take place, which are expressed in the form of superposition of high-frequency oscillations of the electromagnetic force on the main one. Edge effects are significant at p≤4.

Due to the fact that the number of pole pairs of stators is 2 (with a serial connection of 4), the rotating middle millstone will rotate with simultaneous vibration, which increases the grinding effect and helps to remove flour from the working area without difficulty (flour does not freeze).

The proposed device is multifunctional, universal, reliable in operation, quickly reshuffled and easy to operate.

Flat LAD can be performed according to [3]. The control unit can be made on the basis of electromagnetic starters [4].

Information sources

1. AU USSR 1734827, MKI V02C 7/08. A device for grinding solid materials, 1991.

2. RF patent No. 2098183, B02C 7/06. A device for grinding solid materials. Pavlikov V.A. Published December 10, 1997. BI No. 34.

3. Veselovsky O. N. et al. Linear induction motors / O.N. Veselovsky, A.Yu. Konyaev, F.N. Sarapulov. - M.: Energoatomizdat, 1991 .-- 256 p.

4. Electrical equipment and automation of agricultural units and installations / L.S. Gerasimovich and others. - M .: Kolos, 1980. - 391 p., Ill.

Claims (1)

A device for grinding solid materials, comprising a housing with loading and unloading windows and vertical millstones placed inside it, which have surfaces with different grain sizes and are mounted on a common axis, the middle millstone being connected to the rotation drive, and the side millstones made with communicating channels having shutters are mounted on axle sections made with the opposite direction of thread winding, and are fixed by means of flexible elements connected to fixing devices having another element, characterized in that the rotation drive is made in the form of a planar double-sided linear asynchronous motor equipped with a control unit with the number of pole pairs equal to or less than two, the stators of which are installed with the possibility of moving along the radius relative to the rotor, the latter is made in the form of a disk of electrically conductive material, rigidly fixed on the middle millstone.

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