A horizontal scraper discharge centrifuge with adjustable differential speed

Abstract

This invention discloses a horizontal scraper centrifuge with adjustable differential speed, belonging to the technical field of coal preparation equipment. It includes a casing, feed pipe, screen basket, scraper, screen frame, and transmission system. The transmission system uses a dual-frequency conversion motor combined with a dual-axis input adjustable cycloidal pinwheel differential, enabling independent adjustment of the screen basket speed and the speed difference between the screen basket and the scraper. Operating parameters can be adjusted in real time without stopping the machine, according to the feeding conditions and discharge requirements. This invention effectively solves the technical problems of existing horizontal scraper centrifuges, such as non-adjustable differential speed, poor adaptability to operating conditions, and high energy consumption. It offers advantages such as flexible adjustment, stable operation, high transmission efficiency, low energy consumption, and good matching between dewatering effect and processing capacity. It can adapt to complex and changing material conditions, improve dewatering stability, and reduce operating and maintenance costs. It is suitable for coarse coal slime dewatering in coal preparation plants and solid-liquid separation operations of similar materials.

Description

Technical Field

[0001] This invention belongs to the technical field of coal preparation equipment, specifically relating to a horizontal scraper discharge centrifuge with adjustable differential speed. Background Technology

[0002] With the widespread application of underground mining equipment and the mining of thin coal seams, the crushing rate of raw coal is getting higher and higher, resulting in a year-on-year increase in the amount of coarse coal slime fed into coal washing plants. Horizontal scraper unloading coal slime centrifuges have become a new generation of high-capacity coarse coal slime dewatering equipment favored by many coal preparation plants. It is mainly used for coarse coal slime dewatering or solid-liquid separation of similar materials in coal preparation plants. It adopts a single motor and single belt pulley drive, and realizes the speed difference between the spiral scraper and the screen basket through a planetary cycloidal pinwheel differential with a fixed differential ratio.

[0003] The high-speed rotation of the screen basket provides centrifugal force, and the screen basket's rotational speed determines the magnitude of this centrifugal force, directly affecting the product's moisture content. A speed difference exists between the scraper and the screen basket; the scraper uses this speed difference to scrape off the material adhering to the inner wall of the screen basket for discharge. The magnitude of this speed difference determines the discharge speed, directly affecting processing capacity and dewatering time. The dewatering time and centrifugal factor are key parameters determining the centrifuge's dewatering effect. Currently, the fixed-ratio planetary cycloidal pinwheel differential cannot freely adjust the rotational speeds and speed difference between the screen basket and the scraper, hindering the optimization of key process parameters.

[0004] Currently used horizontal scraper-discharge coal slime centrifuges employ a single motor and single pulley drive. A planetary cycloidal pinwheel differential transmission is used to achieve the rotation and speed difference between the scraper and the screen basket. Because the transmission ratio of the planetary cycloidal pinwheel differential is fixed, when a fixed-frequency motor is selected, the screen basket speed and scraper speed are constant, and the speed difference is constant, making it impossible to adjust the screen basket speed and the speed difference between the screen basket and scraper. Even when a variable-frequency motor is used, due to the fixed transmission ratio of the planetary cycloidal pinwheel differential, the speeds of the screen basket and scraper increase or decrease proportionally; that is, the screen basket speed and the speed difference between the screen basket and scraper can only increase or decrease proportionally, failing to achieve a perfect match between the two and thus failing to achieve the dual goals of optimal product moisture content and processing capacity.

[0005] Patent publication number CN116459954A mentions a dual-shaft direct-drive horizontal scraper centrifuge in an adaptive adjustment coarse coal slime dewatering test system. This centrifuge eliminates the differential and uses a dual-shaft dual-frequency conversion motor drive system with both hollow and solid shafts. The speeds of the scraper and screen basket are freely adjustable, achieving arbitrary speeds and differential speeds, thus achieving the dual goals of superior dewatering effect and discharge speed. However, the elimination of the differential and the replacement of the variable frequency motor with a belt-driven direct drive results in a large and unstable load in actual production, inaccurate differential speed control, and high energy consumption due to the large power of both motors. While suitable for test systems, it is not suitable for actual production. Summary of the Invention

[0006] The purpose of this invention is to provide a horizontal scraper centrifuge with adjustable differential speed, which solves the technical problems of existing horizontal scraper centrifuges, such as non-adjustable differential speed, poor adaptability to working conditions, and high energy consumption.

[0007] To achieve the above objectives, embodiments of the present invention provide a horizontal scraper discharge centrifuge with adjustable differential speed, including a casing, a feed pipe, a screen basket, a scraper, a screen frame, and a transmission system. The transmission system is disposed inside the casing and includes a main motor, a speed regulating motor, a drive pulley, a speed regulating pulley, and a dual-axis input adjustable differential. The drive pulley is driven by the input shaft of the adjustable differential, the speed regulating pulley is driven by the speed regulating shaft of the adjustable differential, the scraper shaft of the adjustable differential is connected to the speed regulating shaft through the transmission component inside the adjustable differential, and the sieve shaft of the adjustable differential is connected to the input shaft through the needle housing of the adjustable differential. The adjustable differential is configured to independently adjust the rotational speed of the sieve basket shaft and the speed difference between the sieve basket shaft and the scraper shaft.

[0008] In one possible implementation, the adjustable differential is a cycloidal pinwheel differential, and the transmission components include a cycloidal disc, an eccentric sleeve, and a cycloidal pin. The input shaft is a hollow shaft, and the speed regulating shaft is coaxially inserted into the inner hole of the input shaft; One end of the input shaft is fixedly connected to the needle housing, and the other end of the input shaft is fixedly connected to the drive pulley; One end of the speed regulating shaft is fixedly connected to the eccentric sleeve, and the other end of the speed regulating shaft is fixedly connected to the speed regulating pulley.

[0009] In one possible implementation, the scraper shaft is a solid shaft, one end of the scraper shaft is fixedly connected to the scraper, and the other end of the scraper shaft is provided with a pin disc; The sieve basket shaft is a hollow shaft. One end of the sieve basket shaft is fixedly connected to the sieve base, and the other end of the sieve basket shaft is fixedly connected to the needle shell. A needle roller bearing and an oil seal are provided between the scraper shaft and the screen basket shaft, and a needle roller bearing and an oil seal are provided between the input shaft and the speed regulating shaft.

[0010] In one possible implementation, the cycloidal disk is a double cycloidal disk structure, with the two cycloidal disks arranged 180° opposite each other via the eccentric sleeve; The outer periphery of the cycloidal disc is provided with cycloidal teeth, which mesh with the needle teeth inside the needle shell; The cycloidal disc has multiple pin holes evenly distributed along its circumference, and the cycloidal pins are fitted into the pin holes.

[0011] In one possible implementation, the needle housing is cylindrical, and a support frame is provided inside the needle housing; A support bearing is installed in the center hole of the support frame, and the inner ring of the support bearing is engaged with the scraper shaft or the pin disc. The support frame has multiple through holes evenly distributed along the circumference, and the needle teeth are installed in the through holes.

[0012] In one possible implementation, the speed regulating shaft is a hollow shaft, and the speed regulating shaft has an axial oil supply channel inside; The rear end of the speed regulating shaft is connected to a rotary joint, and the speed regulating shaft has radial oil holes at the positions corresponding to the needle roller bearings.

[0013] In one possible implementation, both the main motor and the speed-regulating motor are variable frequency motors; The centrifuge also includes a controller, which is located outside the casing and electrically connected to both the main motor and the speed-regulating motor. The controller is used to adjust the speed of the main motor and the speed-regulating motor. The rotational speed of the sieve basket is set to 400-800 r / min, and the rotational speed difference between the sieve basket and the scraper is set to 5-20 r / min.

[0014] In one possible implementation, the rotational speed of the sieve basket shaft is n1, the rotational speed of the speed regulating shaft is n2, and the number of needle teeth in the needle housing is n. The rotational speed difference Δn between the scraper shaft and the sieve basket shaft satisfies: Δn=(n1-n2) / (n-1).

[0015] In one possible implementation, the input torque of the speed-regulating motor is 1 / (n-1) of the input torque of the main motor, and the power of the speed-regulating motor is less than the power of the main motor.

[0016] In one possible implementation, the cycloidal pin includes a pin shaft and a pin sleeve. One end of the pin shaft is fixedly connected to the pin shaft disc, and the pin sleeve is sleeved on the outside of the pin shaft. The difference between the outer diameter of the pin sleeve and the inner diameter of the pin hole of the cycloidal disc is equal to the eccentricity of the eccentric sleeve.

[0017] The significant technical effects of the embodiments of the present invention are as follows: This invention employs a cycloidal pinwheel differential with adjustable speed in conjunction with a dual-frequency conversion motor drive. This allows for independent adjustment of the screen basket speed and the speed difference between the screen basket and the scraper. It enables real-time, non-stop adjustment of operating parameters based on feed rate, feed moisture content, and discharge moisture content, achieving optimal matching of dewatering effect, processing capacity, and energy consumption. Simultaneously, the speed-adjustable motor requires minimal power, significantly reducing overall equipment energy consumption. The differential has a compact structure, stable operation, high torque capacity, and high transmission efficiency, effectively adapting to feed fluctuations and coal quality changes. It solves the problem of unstable dewatering of coarse coal slime, improving dewatering effect while reducing wear on vulnerable parts, lowering power consumption per ton of coal and equipment maintenance costs, and significantly expanding the application range and adaptability of the horizontal scraper centrifuge. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a differential speed adjustable horizontal scraper discharge centrifuge according to one embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the main motor and speed-regulating motor; Figure 3 for Figure 1 A schematic diagram of the adjustable differential.

[0020] In the diagram: 1. Scraper shaft, 2. Screen basket shaft, 3. Needle roller bearing, 4. Needle housing, 5. Cycloidal disc, 6. Pin shaft, 7. Pin sleeve, 8. Eccentric bearing, 9. Drive pulley, 10. Speed ​​regulating pulley, 11. Input shaft, 12. Rotary joint, 13. Speed ​​regulating shaft, 14. Eccentric sleeve, 15. Support bearing, 16. Support frame, 17. Needle tooth pin, 18. Needle tooth sleeve, 19. Feed pipe, 20. Machine housing, 21. Screen basket, 22. Scraper, 23. Screen frame, 24. Adjustable differential, 25. Main motor, 26. Speed ​​regulating motor. Detailed Implementation

[0021] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0023] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0026] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation", "connection", "linking", and "fixing" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components.

[0028] Please see Figures 1-3 This invention illustrates a differentially adjustable horizontal scraper discharge centrifuge according to one embodiment of the present invention. The invention enables independent adjustment of the rotational speed of the screen basket 21, the rotational speed of the scraper 22, and the differential speed between the two. The entire machine mainly consists of a feed pipe 19, a casing 20, a screen basket 21, a scraper 22, a screen frame 23, an adjustable differential 24, a drive pulley 9, a speed regulating pulley 10, a rotary joint 12, a main motor 25, and a speed regulating motor 26.

[0029] This embodiment replaces the traditional single-motor drive with a dual-motor drive, and changes the differential from a single-axis input to a dual-axis input. A speed-regulating motor 26 and a speed-regulating pulley 10 are also added. Material enters the scraper 22 through the feed pipe 19, passes through the opening on the scraper 22 cone, and enters the gap between the scraper 22 and the screen basket 21, rotating at high speed along with the screen basket 21. Under strong centrifugal force, water and fine particles pass through the screen openings of the screen basket 21 into the filtrate chamber and are discharged from the drain port. A speed difference provided by the adjustable differential 24 is formed between the scraper 22 and the screen basket 21. The material moves slowly forward under the spiral conveying action of the scraper 22, and the dewatered material falls into the discharge chamber and is discharged outside the machine. The entire process is continuous, achieving continuous dewatering of the material.

[0030] This embodiment employs an adjustable differential 24, which adopts a cycloidal pinwheel structure. It mainly includes a scraper shaft 1, a sieve basket shaft 2, a needle roller bearing 3, a needle housing 4, a cycloidal disc 5, a pin shaft 6, a pin sleeve 7, an eccentric bearing 8, a drive pulley 9, a speed regulating pulley 10, an input shaft 11, a rotary joint 12, a speed regulating shaft 13, an eccentric sleeve 14, a support bearing 15, a support frame 16, a needle tooth pin 17, and a needle tooth sleeve 18. The scraper shaft 1 is a solid shaft, with its front end fixedly connected to the scraper 22 via a key and bolts. A pin disc, circular in shape with 6-12 evenly distributed pin holes, is located at the rear of the scraper shaft 1. The sieve basket shaft 2 is a hollow shaft, with its front end connected to the sieve seat via a key and bolts. A flange is located at the rear, which is fixedly connected to the needle housing 4 via bolts. Bearings are fitted between the sieve basket shaft 2 and the housing 20 or the differential housing to ensure reliable support and flexible rotation. To ensure smooth differential rotation and stable support between the scraper shaft 1 and the screen basket shaft 2, and between the input shaft 11 and the speed regulating shaft 13, while saving installation space, needle roller bearings 3 are arranged between the scraper shaft 1 and the screen basket shaft 2, and between the input shaft 11 and the speed regulating shaft 13. Oil seals are fitted on the outside of the needle roller bearings 3 to achieve sealing protection.

[0031] Furthermore, the needle housing 4 has a cylindrical structure with a threaded hole at the front, which is bolted to the rear flange of the screen basket shaft 2. The rear also has a threaded hole, which is bolted to the front flange of the input shaft 11. A support frame 16 is installed inside the needle housing 4, which is integrally cast or welded. The needle housing 4 has n needle teeth evenly distributed circumferentially. This invention employs a double cycloidal disk 5 structure. The two cycloidal disks 5 are arranged 180° opposite each other via an eccentric sleeve 14, making the equipment operation more stable and smooth. The cycloidal disks 5 are assembled outside the eccentric bearing 8, and are positioned and fixed axially using components such as a distance sleeve, retaining ring, and spacer ring. The outer circumference of the cycloidal disk 5 has n-1 cycloidal teeth evenly distributed, which mesh with the needle teeth inside the needle housing 4. The cycloidal disk 5 has evenly distributed pin holes circumferentially, with the pin hole diameter larger than the outer diameter of the pin sleeve 7, and the radius difference between the two is consistent with the eccentricity of the eccentric sleeve 14. Pin 6 and pin sleeve 7 together form a cycloidal pin, with 6-12 sets in total. The front end of pin 6 is inserted into the pin hole on the pin disk and rigidly connected to the pin disk. Pin sleeve 7 is fitted outside pin 6. The two are clearance-fitted to allow relative rotation. The inner ring of eccentric bearing 8 is connected to eccentric sleeve 14, and the outer ring is connected to the inner hole of cycloidal disk 5. It is used to support cycloidal disk 5 and realize relative rotation between cycloidal disk 5 and eccentric sleeve 14.

[0032] It should be noted that the input shaft 11 adopts a hollow shaft structure, with the speed regulating shaft 13 coaxially fitted inside. The front of the input shaft 11 has a flange, which is fixedly connected to the needle housing 4 by bolts. The flange has n blind holes evenly distributed around its circumference for fixing the needle pins 17. The rear of the input shaft 11 is connected to the drive pulley 9 by a key and bolts. The drive pulley 9, input shaft 11, needle housing 4, and sieve shaft 2 form a rigid connection, rotating synchronously during operation. Bearings are fitted between the input shaft 11 and the housing 20 or differential housing to achieve support and flexible rotation. The speed regulating shaft 13 also adopts a hollow shaft structure, with an eccentric sleeve 14 fitted at the front end and the rear end extending out of the input shaft 11 and connected to the speed regulating pulley 10 by a key and bolts. The central hole of the speed regulating shaft 13 serves as an oil supply channel, and a rotary joint 12 is horizontally installed at the outermost end. The lower interface of the rotary joint 12 is connected to the oil supply pipe, and radial oil holes are opened on the speed regulating shaft 13 at the corresponding positions of the rear needle roller bearing 3. The eccentric sleeve 14 has a double cam structure, with two cams arranged 180° opposite each other. It is mounted on the front end of the speed regulating shaft 13 via a flat key and can be a split eccentric wheel structure or an integrated structure. The drive pulley 9 is mounted on the rear end of the input shaft 11 by a stop and bolt fastening, and the speed regulating pulley 10 is mounted on the rear end of the speed regulating shaft 13 by a stop and bolt fastening.

[0033] Furthermore, the support frame 16 inside the needle housing 4 is rigidly connected to the needle housing 4 or is an integrally formed structure. A bearing seat is provided in the center hole of the support frame 16 for assembling the support bearing 15. The outer ring of the support frame 16 has n evenly distributed through holes for installing the needle tooth pins 17. The outer ring of the support bearing 15 is assembled inside the support frame 16, and the inner ring is fitted onto the outside of the scraper shaft 1 or the pin disc, achieving stable support for the scraper shaft 1 and the pin disc. The needle teeth consist of needle tooth pins 17 and needle tooth sleeves 18. The needle tooth sleeves 18 are fitted onto the outside of the needle tooth pins 17, and the two are clearance-fitted and can rotate relative to each other. The front end of the needle tooth pin 17 is inserted into the through hole of the support frame 16, and the front end is pressed and positioned by the flange of the input shaft 11. The needle teeth can rotate synchronously with the needle housing 4. The rotary joint 12 adopts a one-way flow structure. The outlet is connected to the internal thread of the center hole at the rear end of the speed regulating shaft 13 through an external thread, and the inlet is connected to the lubrication system through a rubber tube. When the speed regulating shaft 13 rotates, the outlet of the rotary joint 12 rotates synchronously with the speed regulating shaft 13, while the main body and the inlet remain stationary, ensuring that the lubricating oil enters the differential stably to lubricate the moving parts.

[0034] Furthermore, the main motor 25 drives the drive pulley 9 to rotate via a belt. The drive pulley 9, needle housing 4, and screen basket shaft 2 form a rigid whole, rotating synchronously at a speed n1. If no torque or constraint is applied to the speed regulating pulley 10, the cycloidal disk 5 and needle housing 4 only maintain meshing without relative rotation, and they rotate at the same speed. The cycloidal disk 5 drives the scraper shaft 1 to rotate synchronously via the pin shaft 6, and drives the speed regulating shaft 13 to rotate at the same speed via the eccentric bearing 8 and eccentric sleeve 14. At this time, the scraper 22 and screen basket 21 maintain the same speed. The working requirement of the horizontal scraper discharge centrifuge is that the speed of the scraper 22 is greater than that of the screen basket 21 to achieve the spiral conveying and unloading of materials. Therefore, it is necessary to apply torque to the speed regulating pulley 10 to adjust the speed difference between the screen basket 21 and the scraper 22. When the needle housing 4 is fixed, the speed regulating pulley 10 drives the speed regulating shaft 13 to rotate, and the eccentric sleeve 14 rotates synchronously. Under the action of the cycloidal pinwheel transmission characteristics, the cycloidal disk 5 rotates in the opposite direction along the needle tooth meshing direction while rotating on its own axis. For each rotation of the cycloidal disk 5, it rotates in the opposite direction by an angle corresponding to one needle tooth, thereby driving the scraper shaft 1 to rotate in the opposite direction by the corresponding angle, realizing the differential speed operation of the scraper 22 and the sieve basket 21. At this time, the transmission ratio between the speed regulating shaft 13 and the sieve basket shaft 2 is: The speed regulating pulley 10 rotates in the opposite direction to the sieve shaft 2.

[0035] Furthermore, the main motor 25 drives the drive pulley 9 to rotate via a belt. The drive pulley 9, needle housing 4, and sieve basket shaft 2 are rigid bodies and rotate together at the same speed, set to n1. If the speed regulating pulley 10 does not apply torque or fixed constraint, the cycloidal disk 5 and needle housing 4 only mesh but do not rotate, meaning the cycloidal disk 5 and needle housing 4 do not rotate relative to each other and rotate at the same speed. The cycloidal disk 5 drives the scraper shaft 1 to rotate at the same speed via the pin 6, and drives the speed regulating shaft 13 to rotate at the same speed via the eccentric bearing 8 and eccentric sleeve 14. At this time, the scraper 22 and sieve basket 21 rotate at the same speed.

[0036] The principle of the horizontal scraper discharge centrifuge is to use the scraper 22 to rotate at a speed greater than that of the screen basket 21 to convey and discharge the material by screw conveying. This requires applying torque to the speed regulating pulley 10 to adjust the speed difference between the screen basket 21 and the scraper 22.

[0037] Assuming the needle housing 4 is fixed, the speed-regulating pulley 10 drives the speed-regulating shaft 13 to rotate, and the eccentric sleeve 14 rotates at the same speed. According to the characteristics of the cycloidal pinwheel differential, while the cycloidal disk 5 rotates at its own speed, the cycloidal teeth revolve in the opposite direction along the needle teeth. For each rotation of the cycloidal disk 5, it revolves in the opposite direction by the angle of one needle tooth, which drives the scraper shaft 1 to rotate in the opposite direction by the angle of one needle tooth, thus achieving the differential speed between the scraper 22 and the sieve basket 21. At this time, the transmission ratio between the speed-regulating shaft 13 and the sieve basket shaft 2 is... It should be noted that, through the transmission of this differential, the rotation direction of the speed regulating pulley 10 is opposite to that of the screen shaft 2.

[0038] In this embodiment of a differential speed adjustable horizontal scraper discharge centrifuge, the needle housing 4 and the screen basket 21 rotate together with the drive pulley 9. Let the drive pulley 9 rotate in the forward direction, with a speed of n1, and the speed of the speed regulating pulley 10 be n2 (positive for forward rotation and negative for reverse rotation). According to the design principle of the horizontal scraper discharge centrifuge, the scraper 22 rotates faster than the screen basket 21. At this time, the speed regulating pulley 10 rotates in the opposite direction relative to the drive pulley 9, meaning the speed regulating pulley 10 is slower than or rotates in the opposite direction to the drive pulley 9. At this time, the speed difference between the screen basket shaft 2 and the scraper shaft 1... Since the drive pulley 9 rotates in the positive direction and n1 is a positive number, when n1 > n2 (including the case where the speed regulating pulley 10 rotates in the opposite direction and n2 is a negative number), the scraper shaft 1 rotates faster than the sieve basket shaft 2, which meets the operating conditions of the horizontal scraper centrifuge.

[0039] This embodiment of a differential speed adjustable horizontal scraper discharge centrifuge is driven by two motors (main motor 25 and speed regulating motor 26) to rotate the drive pulley 9 and the speed regulating pulley 10 through pulleys and belts respectively. The two motors are frequency conversion motors, and the speed can be adjusted in real time by the centrifuge control system.

[0040] When the output moisture content is too high and cannot meet the requirements, it is necessary to improve the dewatering effect. By increasing the speed of n1 by the main motor 25, the centrifugal force is increased, and by increasing the speed of n2 by the speed regulating motor 26, the speed difference between the screen basket 21 and the scraper 22 is reduced, the pushing speed is slowed down, and the dewatering time of the material is increased, which can effectively improve the dewatering effect.

[0041] When the output moisture content is low enough to meet the requirements, the dewatering effect can be appropriately reduced. This is achieved by reducing the speed of the main motor 25 (n1) to decrease centrifugal force, and by reducing the speed of the variable-speed motor 26 (n2). The speed difference between the screen basket 21 and the scraper 22 is adjusted according to the feed rate, thus adjusting the dewatering time to meet the requirements of both the feed rate and the output moisture content. This method reduces the speed while maintaining the required processing capacity and output moisture content, thereby mitigating wear on vulnerable parts, reducing motor power consumption, and achieving energy conservation and cost reduction.

[0042] When the feed rate increases or the feed moisture content rises, the output moisture content will be too high. For adjustment methods, please refer to the section on "When the output moisture content is too high".

[0043] When the feed rate decreases or the feed moisture content decreases, the output moisture content will be too low. For adjustment methods, please refer to When the Output Moisture Content is Too Low.

[0044] Of course, regardless of the adjustments, processing capacity and output moisture content are interdependent and mutually influential. As a single unit for dewatering coarse coal slime, the horizontal scraper centrifuge 22 has limited processing capacity. To ensure the equipment's service life, the rotation speed cannot be increased indefinitely. Therefore, a reasonable range of rotation speed should be set in the electrical control system, generally 400–800 r / min, and the differential speed between the screen basket 21 and the scraper 22 should generally be 5–20 r / min.

[0045] Since the scraper 22 and the screen basket 21 + screen frame 23 have similar weights, diameters, and rotational speeds, the torques of the screen basket shaft 2 and the scraper shaft 1 are approximately equal, which is equal to the torque of the drive pulley 9. According to the differential structure, the output torque of the scraper shaft 1 is input via the speed regulating shaft 13. Assuming the differential transmission efficiency is 1, the pulley torque is adjusted by reverse calculation based on "output torque = input torque × transmission ratio". ,Right now This indicates that the direction is opposite to the torque direction of the drive pulley 9, and the torque of the pulley is adjusted to be equal to the torque of the drive pulley 9. Calculations show that the torque of the adjusting pulley is very small, far less than the torque of the driving pulley (9), indicating that the power of the speed regulating motor (26) is very small, approximately one-third of the power of the main motor (25). .

[0046] Based on the above structure, in this embodiment, a horizontal scraper discharge centrifuge with adjustable differential speed adopts a drive pulley 9 to directly drive the screen basket 21 to rotate, and a speed regulating pulley 10 to indirectly control the speed difference between the screen basket 21 and the scraper 22.

[0047] That is, the speed difference between the sieve basket 21 and the scraper 22 = The speed difference between the drive pulley 9 and the speed regulating pulley 10. The speed of the speed regulating pulley 10 can be calculated by reversing the speed of the scraper 22 and the screen basket 21.

[0048] In summary, existing horizontal scraper centrifuges use a fixed differential speed ratio differential, meaning the rotational speed of the screen basket 21 and the differential speed between the screen basket 21 and the scraper 22 cannot be adjusted independently. The speed can only be changed by replacing pulleys of different diameters, and the rotational speeds of the screen basket 21 and the scraper 22 can only be increased or decreased proportionally. Furthermore, the equipment operates at a constant speed, meaning that increasing the feed rate or feed moisture content cannot improve the dewatering effect, and decreasing the feed rate or feed moisture content cannot reduce the speed to save energy. In contrast, the dual-shaft direct-drive horizontal scraper discharge centrifuge in the comparative document uses dual shafts and dual motors to directly drive the scraper shaft 1 and the screen basket shaft 2. Both motors have high power and high energy consumption. This invention, however, uses a differentially adjustable cycloidal pinwheel. The differential gear, in conjunction with the variable frequency motor, allows for independent adjustment of the rotational speed of the screen basket 21 and the differential rotational speed between the screen basket 21 and the scraper 22. This achieves an optimal balance between dewatering effect, processing capacity, and motor power consumption. The centrifuge's electronic control system can adjust the rotational speed of the screen basket 21 and the speed difference between the screen basket 21 and the scraper 22 in real time based on the feed rate, feed moisture content, and discharge moisture content, enabling online adjustment without shutting down the machine. Simultaneously, the speed-regulating motor 26 has very low power consumption, significantly saving energy. When the feed rate increases or the feed moisture content rises, the rotational speed can be increased to ensure dewatering effect; when the feed rate decreases or the feed moisture content decreases, the rotational speed can be reduced while meeting the discharge moisture requirements. This achieves energy saving and consumption reduction, reduces wear on vulnerable parts, and lowers the cost per ton of coal. The purpose of this invention is to reduce power consumption and equipment maintenance costs. This invention offers the following advantages: Since the rotational speed of the screen basket 21 determines the centrifugal intensity, and the speed difference between the scraper 22 and the screen basket 21 determines the dewatering time, both of which jointly affect the dewatering effect and processing capacity, this invention employs an adjustable differential cycloidal pinwheel differential to separately adjust the rotational speed of the screen basket 21 and the speed difference between the scraper 22 and the screen basket 21. This achieves the optimal match between dewatering effect, processing capacity, and motor power consumption. This differential has a simple and compact structure, small size, stable operation, low noise, high transmission efficiency, large torque capacity, good stability, and long service life. The centrifuge's electrical control system can control the variable speed based on parameters such as feed rate, feed moisture content, and discharge moisture content. The high-frequency motor adjusts the rotation speed of the screen basket 21 and the speed difference between the screen basket 21 and the scraper 22 in real time, achieving dynamic adjustment without stopping the machine. The rotation speed of the screen basket 21 and the speed difference can be adjusted arbitrarily within the design range, enabling the centrifuge to adapt to different feed concentrations, feed amounts, and different output moisture requirements. It effectively addresses the problem of coarse coal slime dewatering caused by large fluctuations in feed and frequent changes in coal quality in coal washing plants, thus broadening the application range of the horizontal scraper 22 centrifuge. At the same time, when the feed amount increases or the feed moisture increases, the rotation speed can be increased to ensure the dewatering effect, and when the feed amount decreases or the feed moisture decreases, the rotation speed can be decreased to save energy and reduce wear on vulnerable parts, further reducing the power consumption per ton of coal and the equipment maintenance cost.

[0049] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of protection of the claims of the present invention.

Claims

1. A differential speed adjustable horizontal scraper discharge centrifuge, comprising a casing (20), a feed pipe (19), a screen basket (21), a scraper (22), a screen frame (23), and a transmission system, characterized in that, The transmission system is located inside the housing (20) and includes a main motor (25), a speed regulating motor (26), a drive pulley (9), a speed regulating pulley (10), and a dual-axis input adjustable differential (24). The drive pulley (9) is connected to the input shaft (11) of the adjustable differential (24), the speed regulating pulley (10) is connected to the speed regulating shaft (13) of the adjustable differential (24), the scraper shaft (1) of the adjustable differential (24) is connected to the speed regulating shaft (13) through the transmission component inside the adjustable differential (24), and the sieve shaft (2) of the adjustable differential (24) is connected to the input shaft (11) through the needle housing (4) of the adjustable differential (24). The adjustable differential (24) is configured to independently adjust the rotational speed of the sieve basket shaft (2) and the speed difference between the sieve basket shaft (2) and the scraper shaft (1).

2. The differential speed adjustable horizontal scraper discharge centrifuge according to claim 1, characterized in that, The adjustable differential (24) is a cycloidal pinwheel differential, and the transmission components include a cycloidal disc (5), an eccentric sleeve (14), and a cycloidal pin; The input shaft (11) is a hollow shaft, and the speed regulating shaft (13) is coaxially inserted into the inner hole of the input shaft (11); One end of the input shaft (11) is fixedly connected to the needle housing (4), and the other end of the input shaft (11) is fixedly connected to the drive pulley (9); One end of the speed regulating shaft (13) is fixedly connected to the eccentric sleeve (14), and the other end of the speed regulating shaft (13) is fixedly connected to the speed regulating pulley (10).

3. A horizontal scraper discharge centrifuge with adjustable differential speed according to claim 2, characterized in that, The scraper shaft (1) is a solid shaft. One end of the scraper shaft (1) is fixedly connected to the scraper (22), and the other end of the scraper shaft (1) is provided with a pin disc. The sieve basket shaft (2) is a hollow shaft. One end of the sieve basket shaft (2) is fixedly connected to the sieve seat, and the other end of the sieve basket shaft (2) is fixedly connected to the needle shell (4). A needle roller bearing (3) and an oil seal are provided between the scraper shaft (1) and the sieve shaft (2), and a needle roller bearing (3) and an oil seal are provided between the input shaft (11) and the speed regulating shaft (13).

4. A horizontal scraper discharge centrifuge with adjustable differential speed according to claim 2, characterized in that, The cycloidal disk (5) is a double cycloidal disk structure, and the two cycloidal disks (5) are arranged facing each other at 180° through the eccentric sleeve (14); The outer periphery of the cycloidal disk (5) is provided with cycloidal teeth, which mesh with the needle teeth inside the needle shell (4); The cycloidal disc (5) has multiple pin holes evenly distributed along its circumference, and the cycloidal pin is fitted into the pin holes.

5. A horizontal scraper discharge centrifuge with adjustable differential speed according to claim 2, characterized in that, The needle shell (4) is cylindrical, and a support frame (16) is provided inside the needle shell (4). A support bearing is installed in the center hole of the support frame (16), and the inner ring of the support bearing is engaged with the scraper shaft (1) or the pin disc. The support frame (16) has multiple through holes evenly distributed along the circumference, and the needle teeth are installed in the through holes.

6. A horizontal scraper discharge centrifuge with adjustable differential speed according to claim 2, characterized in that, The speed regulating shaft (13) is a hollow shaft, and the speed regulating shaft (13) has an axial oil supply channel inside; The rear end of the speed regulating shaft (13) is connected to a rotary joint (12), and the speed regulating shaft (13) has a radial oil hole at the position corresponding to the needle roller bearing (3).

7. A horizontal scraper discharge centrifuge with adjustable differential speed according to claim 1, characterized in that, Both the main motor (25) and the speed regulating motor (26) are variable frequency motors; The centrifuge also includes a controller, which is located outside the casing (20) and electrically connected to the main motor (25) and the speed regulating motor (26). The controller is used to adjust the speed of the main motor (25) and the speed regulating motor (26). The rotational speed of the sieve basket (21) is set to 400-800 r / min, and the rotational speed difference between the sieve basket (21) and the scraper (22) is set to 5-20 r / min.

8. A horizontal scraper discharge centrifuge with adjustable differential speed according to claim 2, characterized in that, The rotational speed of the sieve basket shaft (2) is n1, the rotational speed of the speed regulating shaft (13) is n2, and the number of needle teeth in the needle shell (4) is n. The speed difference Δn between the scraper shaft (1) and the sieve shaft (2) is: Δn=(n1-n2) / (n-1).

9. A horizontal scraper discharge centrifuge with adjustable differential speed according to claim 8, characterized in that, The input torque of the speed-regulating motor (26) is 1 / (n-1) of the input torque of the main motor (25), and the power of the speed-regulating motor (26) is less than the power of the main motor (25).

10. A horizontal scraper discharge centrifuge with adjustable differential speed according to claim 2, characterized in that, The cycloidal pin includes a pin shaft (6) and a pin sleeve (7). One end of the pin shaft (6) is fixedly connected to the pin shaft disc. The pin sleeve (7) is sleeved on the outside of the pin shaft (6). The difference between the outer diameter of the pin sleeve (7) and the inner diameter of the pin hole of the cycloidal disc (5) is equal to the eccentricity of the eccentric sleeve (14).

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