Top-suspended centrifuge scraper device

Abstract

The invention belongs to the technical field of centrifugal machines, and particularly discloses a top suspension type centrifugal machine scraper device which comprises a scraper assembly and a driving mechanism, and the driving mechanism is meshed with or separated from an upper bevel gear and a lower bevel gear through a bevel gear shaft capable of axially moving. And the scraper assembly is controlled to be switched between a discharging mode (the scraper and the rotary drum rotate reversely) and a high-speed separation mode (the scraper and the rotary drum rotate synchronously). According to the invention, direct transmission is realized through end face teeth in a separation mode, a transmission chain is extremely short, no-load energy consumption and heat are extremely low, the whole structure is simplified, and the operation reliability is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of centrifuges, in particular to a scraper device of an upper suspension type centrifuge. BACKGROUND

[0002] The upper suspension type scraper discharge centrifuge is a classic separation equipment for solid-liquid separation by using centrifugal force and intermittent operation. The whole equipment adopts a suspension type structure, has the characteristics of stable operation, convenient discharge, small damage to material crystals, etc., and is widely used in high-standard industrial fields such as fine chemical industry, pharmaceutical industry, food industry, etc.

[0003] A core functional requirement of this machine type is that the scraper operation must be reliably switched between the discharge and separation states. Specifically: (1) in the high-speed separation working condition: the scraper assembly and the drum must rotate absolutely synchronously, and there is no relative motion between them. This is the key prerequisite for ensuring stable sedimentation of the material liquid in the drum, not producing disturbance, thereby obtaining high-purity separation effect and maintaining stable operation of the equipment; (2) in the low-speed discharge working condition: controllable relative motion (usually differential reverse rotation) must be generated between the scraper and the drum, so that the scraper blade can effectively scrape and discharge the solid sediment deposited on the drum wall.

[0004] In order to realize the switching of the above two modes, the traditional upper suspension type centrifuge usually adopts a complex differential transmission system (such as a planetary gear differential). During separation, the main motor drives the drum to rotate at high speed, and the whole differential system is idle; during discharge, the brake or auxiliary motor controls a certain component of the differential to output differential torque to drive the scraper. However, this traditional scheme has several significant inherent defects:

[0005] 1. High energy consumption and serious heating: During the separation stage, which accounts for most of the working cycle, the huge differential system (such as planetary gear train) must idle at high speed with the main shaft, which will generate huge oil stirring loss and gear meshing friction, resulting in a sharp increase in energy consumption and a large amount of heat, which requires an additional cooling system.

[0006] 2. Complex structure and high cost: The precision differential such as planetary gear requires extremely high manufacturing precision and complex assembly process, resulting in high cost and maintenance cost of the whole machine.

[0007] 3. Reliability challenge: The high-speed idle gear system is in a high-temperature and high-load state for a long time, which is harsh for lubrication and sealing, and has a relatively high risk of failure, affecting the continuous operation ability of the equipment. SUMMARY

[0008] The present application provides an upper suspension type centrifuge scraper device with low energy consumption, simple structure and high reliability.

[0009] The application relates to a scraper device of an upper-suspension type centrifuge, which is installed at an upper cover of a centrifuge drum, the center of the upper cover is rotationally matched with a hollow main shaft, and the scraper device comprises a scraper assembly and a driving mechanism; the scraper assembly comprises a scraper shaft and a scraper, the scraper shaft penetrates through the main shaft and extends into the drum, the free end of the scraper shaft is connected with the scraper; the driving mechanism comprises an upper bevel gear, a scraper driving gear plate, a lower bevel gear and a bevel gear shaft as a main rotating driving source; an expansion sleeve is fixed on the scraper shaft, the upper bevel gear and the scraper driving gear plate are fixed in an integrated mode and are sleeved on the expansion sleeve and can move axially along the expansion sleeve, the upper bevel gear is in sliding fit with the expansion sleeve, and the scraper driving gear plate is in spline fit with the expansion sleeve; the lower bevel gear is fixedly connected with the shaft end of the main shaft in a coaxial mode, the tooth surfaces of the upper bevel gear and the lower bevel gear are oppositely arranged, and the scraper driving gear plate is located between the upper bevel gear and the lower bevel gear; the axis of the bevel gear shaft is perpendicular to the main shaft, the bevel gear shaft can be moved to be engaged with or disengaged from the upper bevel gear and the lower bevel gear at the same time.

[0010] The application is characterized in that a mode-switchable composite transmission mechanism is designed, the mechanism creatively integrates the differential transmission of the bevel gear and the function of the face gear clutch, and synchronous control is realized through axial movement of a bevel gear shaft. Specifically, the upper bevel gear and the scraper driving gear plate are fixed in an integrated mode and form an axially movable "power switching valve", the lower bevel gear is fixed to the main shaft and serves as a power input end of the main shaft, and the bevel gear shaft serves as a main driving source and a mode switching execution member: when the bevel gear shaft is axially moved to be engaged with the upper and lower bevel gears, the system enters the unloading mode and realizes differential reverse scraping; when the bevel gear shaft is axially moved out, the "power switching valve" is moved downward under the action of gravity, and at the moment, the main shaft power is directly transmitted to the scraper through the face gear engagement, and the system is seamlessly switched to the high-speed separation mode.

[0011] The "one movement and two states" design makes the transmission system free of complex relative motion gear pairs in the dominant separation condition, and only relies on the rigid combination of the face gear to transmit power, so that extremely low no-load energy consumption and minimum heat generation are realized; the transmission chain is extremely short in the separation mode, the moving parts are few, and the fault points are reduced; the unloading mode is driven by an independent motor, and the load is clear. The overall structure reduces the requirements for lubrication and sealing, is more reliable in operation and more convenient in maintenance. Meanwhile, the whole mechanism is compact in structure, replaces the traditional planetary gear box, and brings about significant cost reduction and qualitative leap in operation reliability.

[0012] Further, the diameter of the small end of the bevel gear shaft is greater than the thickness of the gear plate of the scraper driving gear plate. The beneficial effect is that through simple geometric size design, the logical interlocking of mode switching is ensured: when the bevel gear shaft is engaged, the gear plate assembly can be necessarily lifted to be disengaged from the lower bevel gear, interference between the two transmission paths is avoided, and reliable linkage of "engagement and switching" is realized.

[0013] Furthermore, the expansion sleeve includes a smooth section and an external spline section. The upper bevel gear slides into the smooth section, and the scraper drive gear plate engages with the external spline end. Beneficial effects: It achieves separation of transmission and guiding functions; the spline section ensures reliable torque transmission from the scraper drive gear plate to the expansion sleeve and scraper shaft; the smooth section provides a smooth axial movement track for the upper bevel gear and the entire gear plate assembly, serving as a key structural foundation for mode switching.

[0014] Furthermore, the upper bevel gear is bolted to the scraper drive gear plate. Beneficial effects: simple structure, reliable connection, and convenient assembly and disassembly. By fixing two key transmission components together as a whole, it ensures consistent action during axial movement and power transmission, allowing them to function as a single unit and simplifying assembly.

[0015] Furthermore, it also includes a switching drive structure, which is connected to the bevel gear shaft drive and is used to drive the bevel gear shaft to perform axial movement and rotational motion. Beneficial effects: It can simultaneously complete the axial movement (for engagement / disengagement) and rotational motion (for driving) of the bevel gear shaft, simplifying the external drive configuration and providing precise and reliable control.

[0016] Furthermore, the lower ends of the scraper shaft and the main shaft are both located inside the drum, and the blade of the scraper contacts the inner wall of the drum, ensuring that the scraper can effectively scrape off the filter residue on the inner wall of the drum, which is a basic guarantee for the unloading function to be realized.

[0017] Furthermore, the number of scrapers is three, and the included angle between adjacent scrapers is 120°. Beneficial effects: The three scrapers are evenly distributed circumferentially, ensuring balanced force on the scraper shaft and smooth operation. Simultaneously, they efficiently and evenly scrape away filter residue from the entire circumference of the inner wall of the drum, preventing uneven unloading or equipment vibration. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a top-suspended centrifuge scraper device;

[0019] Figure 2 for Figure 1 A three-dimensional structural diagram (excluding the switching drive structure and coupling);

[0020] Figure 3 for Figure 1 A schematic diagram of the structure of the scraper drive gear disc. Detailed Implementation

[0021] The following detailed description illustrates the specific implementation method:

[0022] The reference signs in the drawings of the specification include: main shaft 1, lower bevel gear 2, scraper driving gear 3, feed pipe 4, fixed frame 5, scraper shaft 6, expansion sleeve 7, upper bevel gear 8, bevel gear shaft 9, switching driving structure 10, coupling 11.

[0023] The upper suspension type centrifuge described in the embodiment includes a hollow main shaft 1 and a drum driven to rotate by the main shaft 1, and the main shaft 1 is externally connected with a main shaft motor. The feed pipe 4 is fixedly installed on the fixed frame 5, so as to be kept stationary during the operation of the upper suspension type centrifuge, and the feed pipe 4 penetrates the main shaft 1 from top to bottom.

[0024] As shown in Figure 1 , Figure 2 and Figure 3 , the scraper device of the upper suspension type centrifuge in the embodiment is located at the upper cover of the drum and includes a driving mechanism and a scraper assembly.

[0025] 1, scraper assembly

[0026] The scraper assembly includes a scraper shaft 6 and scrapers, wherein the scraper shaft 6 is a hollow shaft, the scraper shaft 6 penetrates the main shaft 1 and is externally sleeved on the feed pipe 4, so that the feed pipe 4, the scraper shaft 6 and the main shaft 1 form a coaxial multi-layer nested layout. The upper ends of the feed pipe 4, the scraper shaft 6 and the main shaft 1 are all higher than the upper cover of the drum, and the spacing between the upper ends of the three and the upper cover is: feed pipe 4> scraper shaft 6> main shaft 1.

[0027] The lower ends of the scraper shaft 6, the feed pipe 4 and the main shaft 1 are all located in the drum, three scrapers are installed at the lower end of the scraper shaft 6, the included angle between adjacent scrapers is 120°, and the cutting edge of the scraper is in contact with the inner wall of the drum.

[0028] 2, driving mechanism

[0029] The driving mechanism includes, from top to bottom, an expansion sleeve 7, an upper bevel gear 8, a scraper driving gear 3, a bevel gear shaft 9 and a lower bevel gear 2.

[0030] (1) The expansion sleeve 7 includes a sleeve body with a shaft hole in the center, the expansion sleeve 7 is sleeved on the scraper shaft 6 and is in interference fit with the scraper shaft 6, and the rotation of the expansion sleeve 7 can drive the scraper shaft 6 to rotate. The sleeve body of the expansion sleeve 7 is divided into a smooth section and an external spline section from top to bottom.

[0031] The upper bevel gear 8 has a circular hole in the center, the upper bevel gear 8 is sleeved on the smooth section of the expansion sleeve 7 and is in sliding fit with the expansion sleeve 7, and the lower end surface of the upper bevel gear 8 is a downwardly inclined bevel gear surface.

[0032] The scraper drive gear 3 and the upper conical gear 8 are attached to each other and fixed together by bolts; the center of the scraper drive gear 3 is the inner spline part, and the scraper drive gear 3 is engaged with the outer spline section of the expansion sleeve 7. The rotation of the scraper drive gear 3 can drive the expansion sleeve 7 to rotate, thereby driving the scraper shaft 6 to rotate; the lower surface of the scraper drive gear 3 is the end tooth surface.

[0033] The assembly consisting of the scraper drive gear 3 and the upper conical tooth 8 can move axially within a certain range along the expansion sleeve 7. The rotation of either the scraper drive gear 3 or the upper conical tooth 8 can drive the scraper shaft 6 to rotate through the expansion sleeve 7.

[0034] (2) The lower conical tooth 2 has a circular hole in the center. The lower conical tooth 2 is sleeved on the upper end of the main shaft 1 and locked by bolts. The outer circle of the upper end face of the lower conical tooth 2 is an upwardly inclined conical tooth surface. The conical tooth surfaces of the upper conical tooth 8 and the lower conical tooth 2 are opposite to each other. The end tooth surface of the scraper drive tooth disk 3 can mesh with or disengage from the conical tooth surface of the lower conical tooth 2.

[0035] (3) The bevel gear shaft 9 is arranged in a direction perpendicular to the main shaft 1 (e.g., Figure 1 (In the horizontal position), the bevel gear shaft 9 is located between the upper bevel gear 8 and the lower bevel gear 2. The bevel gear shaft 9 is driven by the switching drive structure 10 to perform axial movement and rotation. Specifically, the power end of the bevel gear shaft 9 is connected to a linear drive mechanism through a coupling 11. This linear drive mechanism is connected to a rotary motor. The aforementioned linear drive mechanism and rotary motor constitute the switching drive structure 10.

[0036] The diameter of the small end of the bevel gear shaft 9 is greater than the thickness of the scraper drive gear disk 3. This causes the scraper drive gear disk 3 to disengage from the lower bevel gear 2 when the bevel gear shaft 9 is simultaneously engaged with the upper bevel gear 8 and the lower bevel gear 2. After the bevel gear shaft 9 disengages from the upper bevel gear 8 and the lower bevel gear 2, the scraper drive gear disk 3 moves down due to its own weight and engages with the lower bevel gear 2.

[0037] Work process:

[0038] 1. Unloading mode

[0039] When the main spindle 1 motor is turned off and the drive mechanism is started, the rotary motor drives the bevel gear shaft 9 to rotate at low speed through the coupling. At this time, the main spindle 1 decelerates clockwise due to inertia, and the bevel gear shaft 9 also rotates clockwise. Simultaneously, the linear drive mechanism pushes the bevel gear shaft 9 forward towards the scraper drive gear disk 3. When the bevel gear shaft 9 enters between the upper bevel gear 8 and the lower bevel gear 2 and begins to mesh with them, since the diameter of the small end of the bevel gear shaft 9 is greater than the thickness of the scraper drive gear disk 3, the scraper drive gear disk 3 and the upper bevel gear 8 move upward, and the scraper drive gear disk 3 disengages from the lower bevel gear 2. Finally, the bevel gear shaft 9 meshes with the upper bevel gear 8 and the lower bevel gear 2 simultaneously.

[0040] The rotating power of the bevel pinion 9 is transmitted to the lower bevel gear 2 and the upper bevel gear 8, and the direction of the power transmitted to the lower bevel gear 2 is clockwise.

[0041] The power transmitted to the upper bevel gear 8 is counterclockwise, and after passing through the upper bevel gear 8 and the expansion sleeve 7, it is transmitted to the scraper shaft 6. At this time, the main shaft 1 and the scraper assembly produce relative motion with the same speed and opposite directions under the control of the bevel pinion 9, and the scraper scrapes the filter residue on the drum wall, completing the unloading.

[0042] 2. High-speed separation mode

[0043] The bevel pinion 9 moves away from the scraper driving gear 3 under the drive of the linear push mechanism, and is disengaged from the lower bevel gear 2 and the upper bevel gear 8. At this time, the expansion sleeve 7, the upper bevel gear 8 and the scraper driving gear 3 move downward under the action of gravity, so that the end face teeth of the scraper driving gear 3 mesh with the lower bevel gear 2.

[0044] The main shaft 1 rotates to drive the lower bevel gear 2 to rotate, and then drives the scraper driving gear 3 to rotate, thereby driving the expansion sleeve 7, and finally driving the scraper shaft 6 and the scraper to rotate. At this time, the main shaft 1 and the scraper assembly rotate synchronously and in the same direction, and the equipment performs high-speed separation.

[0045] The above is only an embodiment of the present application, and the specific technical solutions and / or common knowledge of characteristics in the scheme are not described in detail. It should be noted that for those skilled in the art, without departing from the technical solutions of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, and these will not affect the effect and practicality of the present application. The protection scope claimed in the present application should be subject to the content of its claims, and the specific implementation mode and the like in the specification can be used to explain the content of the claims.

Claims

1. A top-suspended centrifuge scraper device, installed on the upper cover of the centrifuge drum, wherein a hollow main shaft is rotatably fitted at the center of the upper cover, characterized in that, Includes scraper assembly and drive mechanism; The scraper assembly includes a scraper shaft and a scraper. The scraper shaft coaxially extends through the main shaft into the drum, and its free end is connected to the scraper. The drive mechanism includes an upper bevel gear, a scraper drive gear disc, a lower bevel gear, and a bevel gear shaft as the main rotation drive. An expansion sleeve is fixed to the scraper shaft. The upper bevel gear and the scraper drive gear disc are integrally fixed and sleeved on the expansion sleeve, and can move axially along the expansion sleeve. The upper bevel gear slides into the expansion sleeve, and the scraper drive gear disc splines into the expansion sleeve. The lower bevel gear is coaxially fixed to the end of the main shaft, and the tooth surfaces of the upper and lower bevel gears are opposite to each other. The scraper drive gear disc is located between the upper and lower bevel gears. The axis of the bevel gear shaft is perpendicular to the main shaft, and the bevel gear shaft can move to engage or disengage simultaneously with the upper and lower bevel gears.

2. The top-suspended centrifuge scraper device according to claim 1, characterized in that: The diameter of the small end of the bevel gear shaft is greater than the thickness of the scraper drive gear.

3. The scraper device for an overhead centrifuge according to claim 2, characterized in that: The expansion sleeve includes a smooth section and an external spline section. The upper bevel tooth slides in engagement with the smooth section, and the scraper drive toothed disc engages with the external spline end.

4. The top-suspended centrifuge scraper device according to claim 3, characterized in that: The upper bevel gear is bolted to the scraper drive gear disc.

5. The top-suspended centrifuge scraper device according to claim 4, characterized in that: It also includes a switching drive structure, which is connected to the bevel gear shaft drive and is used to drive the bevel gear shaft to perform axial movement and rotation.

6. The scraper device for an overhead centrifuge according to claim 5, characterized in that: The lower ends of the scraper shaft and the main shaft are both located inside the rotating drum, and the blade of the scraper is in contact with the inner wall of the rotating drum.

7. The top-suspended centrifuge scraper device according to claim 6, characterized in that: The number of scrapers is three, and the included angle between adjacent scrapers is 120°.

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