RU184894U1 - Grain thrower trimmer coil - Google Patents

Abstract

The coil of the grain thrower trimmer block belongs to the agricultural industry, namely to the main unit - the trimmer block, which allows to disperse and throw the grain in the right direction to the maximum distance. The trimmer block consists of a prefabricated housing, in which the tension and drive drums are mounted on the axes, covered by an endless tape, to which a coil with two flanges on the disks connected by four blades, made in the form of cycloid semi-arcs emanating from the axis of rotation of the coil and directed by the convex side, is pressed towards the direction of rotation. The simplicity of the design and the use of the properties of the cycloid — brachistochronism (Greek brachist — shortest, + chronos — time) allows the coil blades, made in the form of cycloid semi-arches, to completely free from it during the throwing of a portion of grain in order to capture a new full-fledged portion of grain , i.e. increase the productivity of the grain thrower.

Description

The utility model relates to the agricultural industry, namely to grain throwers.

Known grain thrower (RU 2419583 C1, 05.27.2011), the trimmer block of which consists of a prefabricated housing, including two sidewalls, a cover and walls, in which are mounted on the axes of the tension and drive drums, covered by an endless belt, a coil with two flanges on disks connected by a distance pipe with a diameter smaller than the flanges by the height of a rectangular window formed by the cylindrical surface of the distance pipe and the cylindrical surface of the envelope of an endless tape with a width equal to the gap between have rim flanges. On the cylindrical surface of the remote pipe, the coils are welded parallel to the axis uniformly around the circumference of a metal strip, eight plate-brackets with four holes each, on which are mounted nozzles from a thick rubberized belt.

The use of a distance pipe in the coil design of a given grain thrower makes it impossible to capture a sufficient volume of grain to achieve a productivity of, for example, over 90 t / h. So, for example, when installing a loading conveyor equipped with two scraper chains, this is not achieved.

Also known is another grain thrower taken as a prototype (RU 140818 U1, 01/30/2014) a combined coil which consists of a shaft with two disks with flanges mounted on it, characterized in that the disks have grooves for installing three or more blades that have protrusions, for precise mating, the groove is the protrusion, removable, height-adjustable rigid, elastic pads or brushes are installed on the blades, and additionally contains metal inserts that create a metal core.

The design of the combined coil of this grain thrower has a number of significant drawbacks, namely:

1. The coil is not universal, but unjustifiably multivariant, because has height-adjustable rigid, elastic pads or brushes and additionally contains metal inserts that create a metal core, which requires the consumer to have sufficient qualifications or incur additional costs for inviting a specialist to correctly adjust the height of the above nodes and parts.

2. The protruding mounting bolts and nuts, grooves and edges of the pads, the increased coefficient of friction of grain against rubber, brushes and metal, and in the most dynamic zone, do not create sparing conditions for the seed material.

3. The productivity of a grain thrower with a combined coil is reduced due to the non-rational use of energy of throwing grain (energy costs for turbulent movement of grain and due to the increased coefficient of friction of grain on the blades, pads, rubber, brushes). As a result of this, part of the grain, especially from the zone near the axis of rotation of the coil at the time of throwing, does not have time to fly out of the coil, remaining between the blades and occupying the volume intended for throwing the next portion of grain. And this process increases until equilibrium is established, when the reduced volume of a portion of grain captured by the blades with overlays is equal to the volume of a portion of ejected grain. Moreover, the quality of adjustment significantly affects the decrease in productivity, range and throwing height of the grain thrower.

The purpose of the utility model is to increase productivity while simplifying the design and maintenance of the grain thrower.

This goal is achieved by the fact that in the proposed utility model, consisting of a shaft with two disks with flanges mounted on it, four blades are made in the form of semi-arches cycloid emanating from the axis of rotation of the coil and directed convex side in the direction of rotation.

The graphic part is presented in the form of 4 figures, namely:

In FIG. 1 depicts a grain thrower trimmer block.

In FIG. 2 shows a section AA of the trimmer trimmer.

In FIG. 3 shows the coil of the trimmer block of the grain thrower.

In FIG. 4 depicts the construction of the cycloid arch, with a remote semi-arch.

Works block trimmer grain thrower (see Fig. 1) as follows. Grain flows by gravity from estrus - pos. 1 through the trimmer funnel - pos. 2 on an endless tape - pos. 3 into the window bounded on the side by cheeks - pos. 4. Then it falls into the volume limited outgoing from the tension drum - pos. 5 endless ribbons - pos. 3 on the side of the coil disks - pos. 6 and two shoulder blades - pos. 7 and - pos. 8, made in the form of semi-arches cycloid directed convex side in the direction of rotation. Then the back shoulder blade - pos. 7 in motion closes the collected portion of grain by switching the flow of grain to the set of the next portion. Then on the radius section of the endless ribbon - pos. 3, envelope coil - pos. 9, the grain is pressed against an endless belt under the action of centrifugal forces, and when moving to a straight section and a portion of grain captured by adjacent blades, the grain opens and the grain flies (the throwing process takes place) tangentially to the drive drum - pos. 10 into the guide tube - pos. 9, while the back shoulder blade reveals a portion of grain that can be removed, starting from the area near the shaft, the grain slides along the blade and, as if with an overlap, completes the throwing operation, while simultaneously opening the next portion of grain.

In FIG. 2 shows a section AA of the block of the trimmer of the grain thrower where the coil also falls, which includes the shaft - pos. 11, two flanges - pos. 12, two disks - pos. 6, four shoulder blades - pos. 7, made in the form of semi-arches cycloid emanating from the axis of rotation of the coil and directed convex side in the direction of direction of rotation.

In FIG. 3 shows the coil of the trimmer block of the grain thrower. The fifth straight shoulder blade - pos. 13, which is not in the design of the coil, but it is depicted conditionally, for a clear comparative analysis of the direction of the vector of forces acting on the grain with a blade in different zones under the same conditions.

The notation in FIG. 3:

F _CB - centrifugal force directed from the center of rotation acting on the grain located in the area of the shaft and at the end of the blade - pos. 7;

G _mg - normal force of action of the scapula - pos. 7 by grain in the area of the shaft and at the end of the blade, equal to the product of mass and acceleration;

P is the total force vector acting on the grain with a spatula - pos. 7;

F _{CB *} - centrifugal force directed from the center of rotation acting on the grain located in the shaft area and at the end of the blade - pos. 13;

G _{mg *} - normal force of action of the scapula - pos. 13 by grain in the area of the shaft and the end of the blade equal to the product of mass and acceleration;

P * - the total force vector acting on the grain with a spatula - pos. 13;

Comparing the directions of the total force vectors - P and - P * acting on the grain by the blades - pos. 7 and - pos. 13 (see Fig. 3) it is noteworthy that, under equal conditions, the total force vector - P is directed from the shoulder blade - pos. 4, and the total force vector - P * is directed to the shoulder blade - pos. 13, thereby creating additional resistance to the movement of grain and the energy costs of its throwing. The use of a combined coil (RU 140818 U1) with blades on which elastic pads or brushes are mounted can change their shape, but the energy of throwing grain is spent on acquiring this shape, thereby reducing the distance, height and volume of the grain being thrown. It is no accident that the profile of the blade is selected in the form of a half-arch of cycloids (see Fig. 4) - a curved line described by a point of a circle that rolls without sliding in a straight line. After all, a coil, the flanges of which are circles, “roll” relative to an endless tape without slipping, and each point of the flanges (circles) describes cycloids on a conditionally straightened endless tape. But the most important property of a cycloid is that this curve is a curve of the shortest descent, i.e. - brachistochronous (Greek, brahisto - shortest, + chronos - time), and this allows the coil blades, made in the form of cycloid semi-arches, while throwing a portion of grain in the shortest possible time to be completely released from it, then to capture a new full portion, t. e. improve grain throwing performance. Even more confidence in the stability of this process will be given by more accurate manufacturing of the coil body with blades made in the form of cycloid semi-arches on a 3D printer from a polymer antifriction material, for example, polyurethane, which will further reduce the coefficient of friction of grain on the blades. But, understanding that this can only be done in the development process due to the high cost of manufacturing coils on a 3D printer (program preparation, dimensions, small initial order volume), we suggest using a coil of this design at the first stage in a prefabricated version, and with minimal costs, verify the effectiveness of the proposed coil for which:

1. Since coils, as a rule, are made with a diameter of 350 mm, so that the blades made in the form of cycloid semi-arches fit in, select B = 89 mm (see Fig. 3) and build a cycloid arch (see Fig. 4) and a semi-arch of pos. 15 we endure.

2. We select the radius of the circle that most closely matches the cycloid semi-arch. Choose R = 150 mm. And then we roll a sheet with a thickness of 2 mm and a width equal to the distance between the disks under this radius and cut out blades with a length of C = 159 mm (see Fig. 3).

3. At the beginning, make a coil according to the template or markings with the installation parameters of the blades - B = 89 mm, R = 150 mm and C = 159 mm (see Fig. 3), ie cycloids close to the semi-arch. Test the grain thrower, making sure that the proposed coils are efficient, and only then proceed with the manufacture of the proposed coils on a 3D printer from a polymer antifriction / material, for example, polyurethane.

Claims (2)

1. Coil of the block of the trimmer of the grain thrower, consisting of a shaft with two disks with flanges and four blades mounted on it, characterized in that the blades are made in the form of cycloid semi-arches emanating from the axis of rotation of the coil and directed convex side in the direction of rotation. 2. The coil according to claim 1, characterized in that its housing is made on a 3D printer from a polymer antifriction material, for example polyurethane.

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