A rice grading and sorting apparatus

Abstract

The utility model belongs to rice screening technology field, concretely is a kind of rice grading screening equipment, including frame, drive source, driving shaft, friction wheel and drum screen, be equipped with drive source on the frame, several friction wheels are power connected with driving shaft on the drive source output end, the friction wheel is used to drive drum screen rotation and realizes screening, the drum screen is cylindrical structure, the drum screen both ends are equipped with feed inlet and discharge port respectively, the drum screen is evenly laid screen hole on circumference, the inner wall of the drum screen is equipped with the thread band of protruding inner wall, several joint vibrators are installed on the driving shaft, and the joint vibrator intermittently impacts driving drum screen in the drum screen rotation screening process, and it is added circumferential intermittent impact when drum screen rotates by driving shaft integration joint vibrator. It directly solves the screen hole circumferential jam problem in background art.

Description

Technical Field

[0001] This utility model relates to the field of rice sieving technology, specifically a rice grading and screening device. Background Technology

[0002] In the grain processing industry, especially in the refining of rice, drum grading screens are commonly used to classify rice grains by size. Drum screens are widely used due to their relatively simple structure, large processing capacity, and stable grading effect. However, a significant technical problem exists in the long-term operation of this equipment: screen clogging.

[0003] Screen clogging is mainly caused by the following factors: irregular rice grain shape (mostly slender ovals), the presence of fine rice bran dust on the surface, fluctuations in material moisture content, and particle size being close to the screen aperture size. During the rotation of the screen cylinder, particles can easily become stuck at the edge of the screen aperture at a specific angle (e.g., horizontally placed), or combine with dust to form adhesive blockages. Clogging is particularly severe when screening critically sized particles or processing materials with high powder content and slightly high moisture content. Once clogging occurs, the material's ability to pass through the screen aperture decreases, leading to a reduction in grading output or the need to extend the screening time. Clogging prevents some small grains or broken rice that should pass through the screen aperture from being screened out in time, mixing with qualified products, or causing large grains of rice to be incorrectly screened, affecting the grade and quality of the final product. Accumulated clogging also forces frequent equipment shutdowns for manual cleaning and maintenance, increasing the labor intensity of workers and reducing the continuous operating efficiency of the production line. Utility Model Content

[0004] To address the shortcomings of existing technologies, there is an urgent need for a technical means that is relatively simple in structure, easy to implement, and can effectively alleviate circumferential blockage, improve screening efficiency, and extend the stable operating time of the equipment. This utility model provides a rice grading and screening device, including a frame, a drive source, a drive shaft, friction wheels, and a drum screen. The frame is equipped with a drive source, and several friction wheels are poweredly connected to the output end of the drive source via the drive shaft. The friction wheels are used to drive the drum screen to rotate and achieve screening. The drum screen has a cylindrical structure, with an inlet and an outlet at both ends. The drum screen has screen holes evenly distributed around its circumference, and the inner wall of the drum screen has a threaded band protruding from the inner wall. Several combined vibrators are installed on the drive shaft, and during the rotation and screening process of the drum screen, the combined vibrators intermittently impact and drive the drum screen.

[0005] Preferably, the combined vibrator includes: an intermittent gear, a rack, and a spring. The intermittent gear is poweredly connected to a drive shaft. The rack and the intermittent gear are meshed together. A spring is connected to the rack to push the rack toward the drum screen. The rotation direction of the intermittent gear is the direction that pushes the rack away from the drum screen. The intermittent gear includes an intermittent part and a toothed part.

[0006] Preferably, each of the racks is rotatably mounted with an elastic rotating ring at the end near the drum screen.

[0007] Preferably, a vibrating ring is installed at the contact position between the drum screen and the elastic rotating ring to enhance the torsional strength of the drum screen.

[0008] Preferably, the vibrating ring has material dropping slopes on both sides, and the two material dropping slopes are connected to a connecting plate. The connecting plate and the two material dropping slopes form a trapezoidal structure that is larger at the bottom and smaller at the top.

[0009] Preferably, the vibrating ring has a trapezoidal cavity inside that corresponds to its shape.

[0010] Preferably, the gears of the intermittent gears in the plurality of combined vibrators are all different.

[0011] Compared with the prior art, the present invention provides a rice grading and screening device, which has the following beneficial effects:

[0012] The core of this application lies in integrating a combined vibrator with a drive shaft to apply intermittent circumferential impacts during the rotation of the drum screen. This directly solves the problem of circumferential jamming in the screen holes in the prior art: vibration energy is transmitted along the tangential direction of the drum, causing the rice grains stuck in the screen holes to gain lateral acceleration, disrupting their mechanical equilibrium and causing them to fall out. Compared to traditional axial vibration, this design better suits the kinematic characteristics of the drum. Attached Figure Description

[0013] Fig. 1 This is a three-dimensional structural diagram of the present invention;

[0014] Fig. 2 This is a schematic diagram of the principle and structure of the combined vibrator of this utility model;

[0015] Fig. 3 This is a three-dimensional structural diagram of the vibration ring of this utility model;

[0016] Fig. 4 This is a schematic diagram of the internal structure of the vibration ring of this utility model.

[0017] In the diagram: 1. Drum screen; 101. Screen hole; 102. Threaded belt; 2. Drive source; 3. Friction wheel; 4. Feed inlet; 5. Discharge outlet; 6. Frame; 7. Combined vibrator; 701. Intermittent gear; 702. Rack; 703. Spring; 704. Intermittent section; 705. Tooth section; 706. Elastic rotating ring; 8. Drive shaft; 9. Vibrating ring; 901. Material drop slope; 902. Cavity. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Example

[0020] The following is combined with Figs. 1 to 4 This application introduces a rice grading and screening device, including a frame 6, a drive source 2, a drive shaft 8, friction wheels 3, and a drum screen 1. The frame 6 is equipped with the drive source 2, and the output end of the drive source 2 is poweredly connected to several friction wheels 3 through the drive shaft 8. The friction wheels 3 are used to drive the drum screen 1 to rotate and achieve screening. The drum screen 1 has a cylindrical structure, and the two ends of the drum screen 1 are respectively provided with a feed inlet 4 and a discharge outlet 5. The drum screen 1 has screen holes 101 evenly distributed around its circumference, and the inner wall of the drum screen 1 is provided with a threaded band 102 protruding from the inner wall. The device is characterized in that several combined vibrators 7 are installed on the drive shaft 8, and the combined vibrators 7 intermittently impact and drive the drum screen 1 during the rotation and screening process. The core design lies in integrating a combined vibrator 7 into the drive shaft 8, applying intermittent circumferential impact as the drum screen 1 rotates. This directly solves the circumferential jamming problem of the screen holes 101 in the background technology without adding a drive source 2: the vibration energy is transmitted along the tangential direction of the drum, giving the rice grains stuck in the screen holes 101 lateral acceleration, disrupting their mechanical equilibrium and causing them to fall off. Compared to traditional axial vibration, this design better suits the kinematic characteristics of the drum.

[0021] The combined vibrator 7 includes an intermittent gear 701, a rack 702, and a spring 703. The intermittent gear 701 is poweredly connected to the drive shaft 8. The rack 702 is meshed with the intermittent gear 701. A spring 703 is connected to the rack 702 to push the rack 702 toward the drum screen 1. The rotation direction of the intermittent gear 701 is the direction that pushes the rack 702 away from the drum screen 1. The intermittent gear 701 includes an intermittent section 704 and a toothed section 705. A transmission mechanism linking the intermittent gear 701, rack 702, and spring 703 achieves precise vibration timing control: when the intermittent gear 701's toothless section 704 rotates to the rack 702, the spring 703 pushes the rack 702 to impact the screen at high speed; when the intermittent gear 701 and the rack 702's toothed section 705 mesh, the energy is reset and stored. This mechanical triggering structure is highly reliable, requires no additional control circuit, and automatically matches the impact frequency with the drum speed (vibration frequency = drive shaft speed × number of gear teeth), avoiding excessive vibration that could cause rice grains to break.

[0022] Each rack 702 has an elastic rotating ring 706 rotatably mounted at one end near the drum screen 1. The design of the elastic rotating ring 706 enables flexible transmission of impact force, its rotational characteristics reduce scratch damage to the screen, and the elastomer absorbs high-frequency shock waves to prevent local deformation of the screen. A combination of a metal rotating base and a polyurethane coating layer can be used.

[0023] In some embodiments, a vibration ring 9 is installed at the contact position between the drum screen 1 and the elastic rotating ring 706 to enhance the torsional strength of the drum screen 1. The vibration ring 9, as a local reinforcement structure, solves the problem of insufficient torsional stiffness of traditional screens under repeated impacts. Its annular topology transforms point impact loads into circumferential stress distribution, preventing deformation of the screen holes 101. The vibration ring 9 is preferably made of the same material as the screen, typically 304 or 316 stainless steel, and is welded or riveted to ensure structural continuity and minimize weight.

[0024] The vibrating ring 9 has two inclined surfaces 901 on both sides, and a connecting plate is connected to the end faces of the two inclined surfaces 901. The connecting plate and the two inclined surfaces 901 form a trapezoidal structure that is larger at the bottom and smaller at the top. The trapezoidal inclined surfaces 901 constitute a self-cleaning guide channel: during vibration, rice grains stuck in the ring gap slide down the inclined surface under the action of gravity and vibration, preventing material accumulation and adhesion. The structure that is larger at the bottom and smaller at the top ensures the contact area between the connecting plate and the elastic rotating ring 706, and can evenly bear the load and transmit the impulse.

[0025] The vibrating ring 9 has a trapezoidal cavity 902 inside, corresponding to its shape. The trapezoidal cavity 902 achieves lightweighting and dynamic balance optimization: while maintaining the bending section modulus, it reduces weight by 40% compared to a solid structure, lowering drive energy consumption; the symmetrical layout of the cavity 902 ensures uniform distribution of rotational inertia, reducing equipment vibration amplitude by 35%. In the preferred embodiment, the intermittent gears 701 in the multiple combined vibrators 7 are all different, and this differentiated gear design achieves vibration phase misalignment: by setting intermittent gears 701 with different numbers of teeth, the impact actions of multiple vibrators are evenly distributed in the circumferential direction. This design eliminates the vibration superposition effect. The tooth configuration of the intermittent gears 701 follows the prime number principle (e.g., 3 teeth, 5 teeth, 7 teeth, etc.) to avoid periodic resonance as much as possible.

[0026] Finally, it should be noted that the above are merely preferred embodiments of this utility model and are not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A rice grading and screening device, comprising a frame (6), a drive source (2), a drive shaft (8), friction wheels (3), and a drum screen (1), wherein the frame (6) is provided with a drive source (2), and a plurality of friction wheels (3) are poweredly connected to the output end of the drive source (2) via the drive shaft (8), the friction wheels (3) being used to drive the drum screen (1) to rotate to achieve screening, the drum screen (1) having a cylindrical structure, the drum screen (1) having an inlet (4) and an outlet (5) at both ends respectively, the drum screen (1) having screen holes (101) evenly distributed circumferentially, and the inner wall of the drum screen (1) having a threaded band (102) protruding from the inner wall, characterized in that: Several combined vibrators (7) are installed on the drive shaft (8). During the rotation and screening process of the drum screen (1), the combined vibrators (7) intermittently impact the drive drum screen (1).

2. The rice grading and screening device according to claim 1, characterized in that: The combined vibrator (7) includes an intermittent gear (701), a rack (702), and a spring (703). The intermittent gear (701) is poweredly connected to the drive shaft (8). The rack (702) and the intermittent gear (701) are meshed together. A spring (703) is connected to the rack (702) to push the rack (702) toward the drum screen (1). The rotation direction of the intermittent gear (701) is the direction that pushes the rack (702) away from the drum screen (1). The intermittent gear (701) includes an intermittent part (704) and a tooth part (705).

3. The rice grading and screening device according to claim 2, characterized in that: Each of the racks (702) has an elastic rotating ring (706) rotatably mounted at one end near the drum screen (1).

4. The rice grading and screening device according to claim 3, characterized in that: A vibrating ring (9) is installed at the contact position between the drum screen (1) and the elastic rotating ring (706) to enhance the torsional strength of the drum screen (1).

5. The rice grading and screening device according to claim 4, characterized in that: The vibrating ring (9) has material dropping slopes (901) on both sides. The two material dropping slopes (901) are connected to a connecting plate. The connecting plate and the two material dropping slopes (901) form a trapezoidal structure with a larger bottom and a smaller top.

6. The rice grading and screening device according to claim 5, characterized in that: The vibrating ring (9) has a trapezoidal cavity (902) inside that corresponds to its shape.

7. The rice grading and screening device according to claim 2, characterized in that: The gears of the intermittent gears (701) in the multiple combined vibrators (7) are all different.

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