RU2566483C1 - Laboratory grinder - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: grinder contains vertically oriented grinding chamber in form of a sleeve 1 with cone internal surface. In the chamber coaxially working element is installed, in contains driven shaft 2 and grinding bodies in form of the cylindrical springs 4 in contact with internal surface of the chamber. The cylindrical springs 4 are installed on rods 5 located around the shaft 2 parallel to the internal walls of the chamber. The rods 5 by top end are connected with secured on shaft tow bar 6. The rod ends 5 connected with the tow bar 6 are at distance from the shaft exceeding the distance from their opposite ends.

EFFECT: higher intensity of grinding.

4 cl, 3 dwg

Description

FIELD OF THE INVENTION

The invention relates to devices for fine grinding of materials intended for use in laboratory conditions. It can find application in the production of building materials and other industries for dry and wet grinding of various materials.

State of the art

A known laboratory mill containing a cup fixed in the frame by means of a bayonet holder and a working body mounted in a cup with a gap in the form of a disk with grooves on the lower working surface mounted on the electric drive shaft (patent for invention SU 1576202, IPC В02С 19/08, publ. 07.07.90). The disadvantage of such a mill is the low grinding efficiency.

Known grinding device containing a conical shape of the drum mounted for rotation around a vertical axis, and grinding the working body in the form of a roller, pressed against the inner surface of the drum (see patent RU 2484902, IPC В02С 15/06, publ. 06/20/2013). The device is characterized by low grinding intensity and increased sticking of the material to the inner wall of the drum, for cleaning which a scraper is used.

Known mill for fine grinding of small quantities of materials by dry or wet method (see patent for invention SU 1681956, IPC V02C 19/22, publ. 07.10.91), containing a grinding chamber, inside which is placed the working body in the form of a toroid a helical spiral, one end of which is connected to the output shaft of the electric motor, and the other to the axis of the additional support. The use of a spring as a grinding element can significantly increase the grinding intensity of the material falling into the inter-turn space of a curved spiral. To ensure the discharge of the crushed material, it is possible to rotate the chamber relative to its stationary end wall.

Known chopper containing a cylindrical body with a vertical axis of rotation, inside of which there is a working body in the form of a cylindrical spring, the lower end of which is fixed to the flange of the drive shaft, and the upper end is on the flange of the hollow shaft through which the material is loaded (see patent for invention RU 2008973, IPC V02C 19/22, publ. March 15, 1994). To increase the grinding intensity, additional ones are coaxially placed inside the main spring.

As the closest analogue, by the presence of features similar to the essential features of the proposed technical solution, the design of the reactor-mixer is disclosed in the patent SU 1011234, IPC B01J 19/18, publ. 04/15/1983, Similar features of the aforementioned reactor-mixer with the proposed device are as follows: the presence of a housing (grinding chamber in the form of a body of revolution), in which a working body is located, including a shaft located along the axis of the housing, connected to the rotation drive, and mounted on the shaft carrier with rigidly fixed in it, parallel to the inner walls of the housing, rods with grinding media in the form of cylindrical springs loosely worn on the rods and in contact with the inner surface of the housing.

The disadvantage of the mentioned reactor-mixer is the insufficiently high grinding intensity, due to the fact that the springs under the action of centrifugal forces roll along the cylindrical inner surface of the housing, while their elastic properties are practically not used.

Disclosure of invention

The invention is aimed at increasing the intensity of grinding and a more complete use of the elastic properties of grinding springs by creating conditions for periodically constant tension and compression of the springs.

The aforementioned became possible due to the fact that in the proposed laboratory mill, containing a grinding chamber and coaxially placed in the chamber, a working body, including a shaft connected to a rotation drive, and grinding media in the form of cylindrical springs in contact with the inner surface of the chamber, worn on rods placed around shaft parallel to the inner walls of the chamber and rigidly connected to the shaft by means of a carrier mounted on the shaft, according to the claimed invention, the grinding chamber with the working body are oriented vertically In principle, the rods are connected to the upper end fixed on the shaft by the carrier and placed at an angle to the shaft so that their ends connected to the carrier are removed from the shaft by a distance greater than their opposite ends, while the inner surface of the chamber is made in the form of a cone surface.

As in the prototype, during the rotation of the shaft, the springs are pressed against the inner surface of the housing under the action of centrifugal forces, and under the action of the rods pushing them, they perform a complex rotation, as in a planetary gear: rotation around the shaft with simultaneous rotation around their bearing axis (rod) to the side opposite to the pressure of this axis. In other words, the coil of the spring rolls - "run" along the inner surface of the housing. In the closest analogue, all the rods carrying coil springs are placed at an equal distance from the drive shaft and parallel to it, due to which all the coils of the springs perform synchronous movement, and only particles of material falling between the coils can cause the coils to move relative to each other.

In the proposed design, all the rods carrying the springs are placed at an angle to the shaft so that one end of the rod is removed from the shaft by a distance greater than its other end. When the shaft rotates, the ends of each rod will describe circles of different radii, the value of which corresponds to the distance that this end is removed from the shaft.

As a result, for one period of time at different ends of the coil worn on the spring rod its coils having the same radius, because coil springs will run a different distance. According to well-known mathematical dependencies, the distance traveled by the turns at the upper and lower ends of the spring will be determined as follows.

S _in = R _in · φ, a S _n = R _n · φ, where φ is the angle of rotation of the shaft, R _in and R _n are the distances from the shaft to the upper and lower ends, respectively. Moreover, R _in > R _n , and therefore the distance S _in which the upper coil of the spring runs, is greater than the distance S _n that runs in the lower coil of the spring.

As a result of different movements of the turns of the same spring, the spring is twisted. Increasing elastic forces periodically tighten the "lagging" turns, leveling their position. The mentioned effect allows you to intensify the process of grinding material.

Compared with the known analogues, the proposed mill has a simple design, providing high grinding intensity.

Particular features of the proposed solution contribute to the simplicity of the technological implementation of the device and the convenience of its maintenance and operation.

The grinding chamber is preferably made in the form of a removable bowl in the form of an inverted truncated cone, worn from below on the working body and pushed to it by means of a folding stop. Such a "removable" design of the grinding chamber is possible due to the small size of the mill and provides simplicity and convenience of unloading the crushed material, allowing you to exclude special unloading devices from the design.

The working body, the rotation drive and the tilt stop are preferably mounted on the same carrier frame.

In the case of using the mill for dry grinding, it is advisable to make the shaft of the working body hollow, i.e. with a through central hole to allow material to flow through it into the chamber.

The essence of the solution is illustrated by an example of a specific implementation and drawings, where

in FIG. 1 shows a General diagram of the device;

in FIG. 2 is a view A from FIG. 1, bottom view of a carrier with rods (for clarity, springs and support plates are not shown);

in FIG. 3 shows an example of a specific embodiment of a device with a partial section.

The implementation of the invention

The laboratory mill contains (see Fig. 1) a grinding chamber in the form of a cup 1 having the shape of an inverted truncated cone with a vertical axis of rotation, and a working body coaxially placed in it, including a shaft 2 connected to a rotation drive 3, and grinding bodies in the form cylindrical springs 4, worn on the rods 5, rigidly connected with its upper end to the carrier 6, mounted on the shaft 2.

The rods 5 are placed around the shaft 2 and at an angle to it. The distance between the shaft 2 and the upper end of any rod is R _in . The distance between the shaft 2 and the lower end of the rods 5 is R _n , and R _in > R _n (see Fig. 2).

The rods 5 are threaded at the upper end so that they can be fixed after installation in the holes of the carrier 6. At the lower end of the rods 5, a plate 7 can be fixed to support the lower end of the spring 4, the upper end of which abuts against the carrier 6.

The carrier 6 can be made in the form of a disk, cone or crosspiece with a central landing hole for the shaft and peripheral holes for the rods.

To increase the reliability of the joints, it is advisable that the surface of the carrier in which the hole for installing the rod is made is perpendicular to the axis of the rod installed in the hole (see Fig. 3).

The glass 1 is worn on the bottom of the working body and is drawn to it by the hinged stop 8. The working body, the hinged stop 8 and a rotation drive including an electric motor 9 connected to the shaft 2 by means of a belt drive 10 are mounted on one bearing frame 11.

The device operates as follows.

The source material is poured into the cup 1 before installation or the material is fed into the installed cup through the hollow shaft 2. The engine 9 is turned on, which transmits rotation to the shaft 2 through the belt drive 10.

In the process of rotation of the shaft 2, the springs 4 are pressed against the inner surface of the grinding chamber by centrifugal forces and, under the action of the rods pushing them 5, perform a complex rotation around the shaft 2 with simultaneous rotation around the rod 5 carrying them in the direction opposite to the pressure of this rod. There is abrasion of the material between the walls of the chamber and the springs. At the same time, due to the difference in diameters in the upper and lower parts of the cup 1, the lower coil of the spring 4 lags behind its upper coil, the spring is twisted. In this case, elastic forces arise, which increase as the spring stretches, and when a critical value is reached, they trigger by pulling the lagging part of the coils and leveling their position. As a result, the spring not only rolls, but also periodically stretches and contracts, slipping along the walls of the glass, while the material falling into the space between the walls of the glass and the coil of the spring is subjected to intense destructive action. As a result, the grinding intensity increases significantly.

To unload the crushed material, turn off the engine 9, recline the stop 8 and remove the glass 1.

The mill allows dry grinding of various bulk materials with a fraction of up to 2 mm, as well as wet grinding and activation of various mixtures.

Claims (4)

1. A laboratory mill containing a grinding chamber and a working body coaxially placed in the chamber, including a shaft connected to a rotation drive, and grinding media in the form of cylindrical springs in contact with the inner surface of the chamber, worn on rods placed around the shaft parallel to the inner walls of the chamber and rigidly connected to the shaft by means of a carrier mounted on the shaft, characterized in that the grinding chamber with the working body are oriented vertically, the rods are connected to the upper end mounted on the shaft of the carrier, and p positioned with respect to the shaft at an angle so that their ends connected to the carrier are removed from the shaft by a distance greater than their opposite ends, while the inner surface of the chamber is made in the form of a conical surface. 2. The mill according to claim 1, characterized in that the grinding chamber is made in the form of a removable cup in the form of an inverted truncated cone, worn from below on the working body and pushed to it by means of a folding stop. 3. The mill according to claim 1, characterized in that the working body, the rotation drive and the folding stop are mounted on one supporting frame. 4. The mill under item 1, characterized in that the shaft is made with a through hole for loading into the chamber of the crushed material.

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