Cantilever type centrifugal machine capable of balancing mass in real time

Abstract

The utility model discloses a cantilever type centrifugal machine capable of balancing mass in real time, which belongs to the technical field of centrifugal machines and is mainly used for balancing materials of the cantilever type centrifugal machine. The technical problem to be solved by the utility model is to provide a cantilever type centrifugal machine capable of balancing the mass in real time, which comprises a supporting seat, a rotating arm, a centrifugal machine main shaft, a driving motor, a piezoelectric ceramic sensor, an electromagnet assembly and a circuit board, and the piezoelectric ceramic sensor surrounds the centrifugal machine main shaft, is arranged on the upper surface of the supporting seat and is connected with the circuit board through a wire; the electromagnetic assembly comprises an electromagnet arranged at the end of the rotating arm, the electromagnet is connected with the circuit board through a wire so as to control the magnitude of current input into the electromagnet, a strip-shaped cavity formed in the length direction of the rotating arm is formed in the rotating arm, the strip-shaped cavity is filled with a movable magnetic medium, and the circuit board is arranged on the driving motor. In the working process of the centrifugal machine, materials at the two ends of the cantilever type centrifugal machine can be rapidly trimmed without adjusting the material quality, material balance is guaranteed, and the centrifugal machine is protected.

Description

TECHNICAL FIELD

[0001] The utility model relates to centrifuge technical field especially a cantilever type centrifuge of quality real -time matching. BACKGROUND

[0002] The centrifuge is a machine for separating liquid and solid particles or liquid and liquid mixture by centrifugal force. Figure 1 The centrifuge is used for separating solid particles and liquid in the suspension or separating two liquids with different density and mutually insoluble in the emulsion in the laboratory. The utility model provides a cantilever type centrifuge of quality real -time matching, which is mainly used for material matching of the cantilever type centrifuge, so that the material at both ends of the cantilever type centrifuge can be quickly matched without adjusting the material quality during the working process of the centrifuge, the balance of the material on the cantilever of the centrifuge is ensured, and the centrifuge is protected.

[0003] The utility model solves the technical problem of providing a cantilever type centrifuge of quality real -time matching, which is mainly used for material matching of the cantilever type centrifuge, so that the material at both ends of the cantilever type centrifuge can be quickly matched without adjusting the material quality during the working process of the centrifuge, the balance of the material on the cantilever of the centrifuge is ensured, and the centrifuge is protected.

[0004] The utility model discloses a cantilever type centrifuge of quality real -time matching, including support seat, swing arm, centrifuge main shaft and with the transmission of centrifuge main shaft lower extreme drive motor, the one end of centrifuge main shaft is away from drive motor and is connected with swing arm through support seat, be equipped with bearing in the junction of centrifuge main shaft and support seat, swing arm is symmetrical with centrifuge main shaft and is arranged on centrifuge main shaft, swing arm is equipped with the object table for placing material in the one end of centrifuge main shaft far away, still include piezoelectric ceramic sensor, electromagnet subassembly and controller, piezoelectric ceramic sensor is set up on the upper surface of support seat around centrifuge main shaft, piezoelectric ceramic sensor and controller wire connection, electromagnetic subassembly includes electromagnet, the electromagnet sets up in the end of swing arm and with controller wire connection to control the current size of input electromagnet, every swing arm is equipped with the strip cavity of setting along swing arm length direction, the one end of strip cavity is filled with the magnetic medium of movable along strip cavity close to centrifuge main shaft, the controller sets up on drive motor.

[0005] Further, the signal transmission nodes of the piezoelectric ceramic sensor are circularly arranged on the support seat around the centrifuge main shaft, and the signal transmission nodes of each electromagnet are respectively arranged at the junction of the swing arm and the centrifuge main shaft around the centrifuge main shaft.

[0006] Further, the top of the centrifuge main shaft is a permanent magnet.

[0007] Further, the utility model also includes a gravity sensor, which is arranged at the end of the swing arm and below the object table, and is electrically connected with the controller.

[0008] Further, the electromagnet is arranged on the swing arm and between the gravity sensor and the centrifuge main shaft.

[0009] As a preferred mode, the utility model also includes a temperature sensor, which is arranged at the bottom of both ends of the swing arm and below the object table, and is electrically connected with the controller.

[0010] The utility model has the advantages that: by arranging the piezoelectric ceramic sensor, the electromagnetic assembly and the controller, when the centrifuge is working, the collision contact between the centrifuge rotating shaft and the piezoelectric ceramic sensor can be used to judge whether the masses of the materials placed on the centrifuge are equal, then the controller can identify the signals transmitted by the piezoelectric ceramic sensor and supply power to the electromagnet arranged at the end of the swing arm, so as to adjust the weights on both sides of the swing arm by adsorbing the magnetic medium, achieve the balance of the materials at both ends of the swing arm without adjusting the mass of the materials, ensure the balance of the materials on the swing arm of the centrifuge, and protect the centrifuge. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 : the structure diagram of prior cantilever type centrifuge;

[0012] Figure 2 The utility model provides a cantilever type centrifuge structure schematic view of quality real -time matching,

[0013] Figure 3 The utility model relates to special circuit structure,

[0014] Figure 4 The utility model's plan view,

[0015] Reference Signs: 1 - cantilever type centrifuge;11 - support seat;12 - swing arm;121 - object table;13 - centrifuge spindle;14 - drive motor;15 - main machine cover;2 - piezoelectric ceramic sensor;21 - piezoelectric ceramic sensor's signal transmission node;3 - electromagnet assembly;31 - electromagnet;311 - electromagnet's signal transmission node;32 - strip cavity;33 - magnetic medium;34 - permanent magnet;4 - controller;5 - gravity sensor;6 - temperature sensor. DETAILED DESCRIPTION

[0016] The utility model is further explained below.

[0017] The utility model provides a cantilever type centrifuge of quality real -time matching mainly be used for cantilever type centrifuge's material matching, including support seat 11, swing arm 12, centrifuge spindle 13 and with centrifuge spindle 13 lower end transmission connection's drive motor 14, centrifuge spindle 13 is away from drive motor 14 one end passes through support seat 11 and is connected with swing arm 12, the junction of centrifuge spindle 13 with support seat 11 is equipped with bearing, swing arm 12 is away from centrifuge spindle 13 one end and is equipped with the object table 121 for placing sample;Still include piezoelectric ceramic sensor 2, electromagnet assembly 3 and controller 4, piezoelectric ceramic sensor 2 is set up in the upper surface of support seat 11 and surrounds centrifuge spindle 13;Piezoelectric ceramic sensor 2 is connected with controller 4 wire;Electromagnetic assembly includes electromagnet 31, electromagnet 31 sets up in the end of swing arm 12 and is connected with controller 4 wire to control the current size of input electromagnet 31, every swing arm 12 is equipped with the strip cavity 32 of setting along swing arm 12 length direction, the one end of strip cavity 32 near centrifuge spindle 13 fills with the magnetic medium 33 that can move along strip cavity 32, controller 4 sets up on drive motor 14.

[0018] As Figure 1 , Figure 2As shown, the centrifuge comprises a support seat 11, a rotating arm 12, a centrifuge spindle 13 and a driving motor 14 connected with the lower end of the centrifuge spindle 13. The side of the centrifuge spindle 13 away from the driving motor 14 penetrates through the support seat 11 and is fixedly connected with the rotating arm 12. A bearing is arranged between the centrifuge spindle 13 and the support seat 11, so that the centrifuge spindle 13 can rotate without affecting the support seat 11. The rotating arm 12 is fixedly connected with the centrifuge spindle 13 to rotate with the centrifuge spindle 13, thereby processing the materials arranged on the material tables 121 at both ends of the rotating arm 12, such as Figure 4As shown, the rotating arm 12 is 4, with the centrifuge main shaft 13 as the symmetry axis, symmetrically arranged on the side of the centrifuge main shaft 13, and placed on the material loading platform 121 of the rotating arm 12 as symmetrically as possible to ensure the preliminary balance of the rotating arm 12 after placing the material. The cantilever type centrifuge with real-time mass balancing is also provided with a piezoelectric ceramic sensor 2, an electromagnet assembly 3 and a controller 4. The controller 4 is arranged on the driving motor 14 and is connected with the piezoelectric ceramic sensor 2 and the electromagnet 31 by wires. The above-mentioned controller 4 can adopt an existing PLC controller. The piezoelectric ceramic sensor 2 is arranged on the upper surface of the supporting seat 11 around the centrifuge main shaft 13. It is used to monitor the contact vibration between the centrifuge main shaft 13 and the supporting seat 11 during rotation and convert the vibration signal into an electric signal to be transmitted to the controller 4 for processing. The electromagnetic assembly includes an electromagnet 31 arranged at the end of the rotating arm 12 and connected with the controller 4 by wires to control the current input to the electromagnet 31. The magnetic force of the electromagnet 31 is adjusted by adjusting the current. The controller 4 will energize the electromagnet 31 while adjusting the current according to the electric signal fed back by the piezoelectric ceramic sensor 2 to indirectly adjust the magnetic force. The greater the magnetic force, the more magnetic medium 33 it can attract to increase the mass. The smaller the magnetic force, the less magnetic medium 33 it can attract to increase the mass. Thus, the mass is controlled by controlling the magnetic force. Each of the rotating arms 12 is provided with a strip-shaped cavity 32 arranged along the length direction of the rotating arm 12. The strip-shaped cavity 32 is filled with a magnetic medium 33 which can move along the strip-shaped cavity 32. Specifically, the strip-shaped cavity 32 is arranged inside the rotating arm 12, and the magnetic medium 33 is filled in one end of the strip-shaped cavity 32 close to the centrifuge main shaft 13. The magnetic medium 33 can adopt existing strong magnetic substances such as iron, nickel, cobalt and their alloys. Such substances have high density and can compress the volume to balance more mass in a limited space, and have low loss and high stability, i.e. without worrying about demagnetization and loss caused by heat energy generated by high-speed rotation during use.In the process of the device running, when the centrifuge spindle 13 deflects due to the inconsistent sample mass at the end of the rotating arm 12, the centrifuge spindle 13 will press the piezoelectric ceramic sensor 2 arranged on the support seat 11, at which time the piezoelectric ceramic sensor 2 will transmit a signal to the controller 4, and after the controller 4 processes the signal, it will energize the electromagnet 31 on the rotating arm 12 in the direction opposite to the deflection direction of the centrifuge spindle 13, and use the electromagnet 31 to adsorb the magnetic medium 33 arranged on the centrifuge spindle 13 to increase the mass of the rotating arm 12 on the side of the energized electromagnet 31, so as to balance the mass and eliminate the imbalance of the centrifuge spindle 13 in the working state of the centrifuge; by arranging the piezoelectric ceramic sensor 2, the electromagnetic assembly and the controller 4, when the centrifuge is working, the collision contact between the centrifuge spindle 13 and the piezoelectric ceramic sensor 2 can be used to judge whether the mass of the material placed on the centrifuge is equal, and then the controller 4 can recognize the signal transmitted by the piezoelectric ceramic sensor 2 and supply power to the electromagnet 31 arranged at the end of the rotating arm 12, so as to adjust the weight on both sides of the rotating arm 12 by adsorbing the magnetic medium 33, so as to achieve the balance of the materials at both ends of the rotating arm 12 without adjusting the mass of the materials, ensure the balance of the materials on the rotating arm 12 of the centrifuge and protect the centrifuge.

[0019] In order to ensure the transmission and timeliness of the electric signal between the piezoelectric ceramic sensor 2, the electromagnet 31 and the controller 4, and ensure that the controller 4 can accurately input the current to the electromagnet 31 on the side where the weight needs to be increased, the controller 4 is connected to the piezoelectric ceramic sensor 2 and the electromagnet 31 through a signal line and a power line. Figure 3As shown, the signal transmission nodes 21 of the piezoelectric ceramic sensors are arranged in a circle on the support seat 11 around the centrifuge main shaft 13, and the signal transmission nodes 311 of each electromagnet are respectively arranged at the joint of the rotating arm 12 and the centrifuge main shaft 13 around the centrifuge main shaft 13; after the centrifuge starts to operate, the centrifuge main shaft 13 will not collide violently with the piezoelectric ceramic sensors 2 in the normal operation process, so the electric signal received by the piezoelectric ceramic sensors 2 at this time can be ignored; but when the mass of the material arranged on the rotating arm 12 is uneven, the centrifuge main shaft 13 will be unbalanced during operation and will deviate to the side with more mass during rotation, causing the centrifuge main shaft 13 to collide with the piezoelectric ceramic sensors 2 arranged on the support seat 11, generating a strong electric signal which is transmitted to the controller 4 through the wire, and since the signal is very strong and cannot be filtered out, and the signal nodes of the electromagnet 31 rotate with the centrifuge main shaft 13, at this time, the signal transmission node of one of the electromagnets moves to the lower side of the piezoelectric ceramic sensor that collides, and the signal transmission node of the other electromagnet moves to the opposite side of the piezoelectric ceramic sensor that collides, so we only need to determine the direction of the smaller mass side of the rotating arm 12 according to the position of the signal at this time, and then activate the nodes of the electromagnets 31 in the direction to electrify the electromagnets 31 to generate a magnetic force to attract the magnetic medium 33 to increase the mass balance of the two sides of the suspended arm, which can remove the centrifuge main shaft 13 from the unbalanced state.

[0020] In order to avoid the magnetic medium 33 moving in the strip-shaped cavity 32 due to the centrifugal force of the centrifuge rotation when the electromagnet 31 is not electrified and the centrifuge starts to rotate, as shown, Figure 4 As shown, the top end of the centrifuge main shaft 13 is a permanent magnet 34 which uses the permanent magnet 34 to adsorb and fix the magnetic medium 33, and when the electromagnet 31 is electrified, its magnetic attraction force is greater than that of the permanent magnet 34, thereby adsorbing the magnetic medium 33 to the electromagnet 31 at the end of the rotating arm 12 to adjust the mass at the end of the rotating arm 12. In order to ensure that the magnetic medium 33 adsorbed on the electromagnet 31 can return to the end of the rotating arm 12 close to the centrifuge main shaft 13 after the use of the centrifuge is finished, the permanent magnet 34 is used to re-adsorb the magnetic medium 33 to the end of the strip-shaped cavity 32 close to the centrifuge main shaft 13, and the above-mentioned permanent magnet 34 can be made of samarium-cobalt (SmCo) permanent magnet material, which has extremely strong anti-demagnetization ability, an intrinsic coercive force of 2388kA / m, and can well maintain the stability of the internal magnetic field; at the same time, it also has high temperature stability, with an upper limit of working temperature of 350℃ and a magnetic flux temperature coefficient of only -0.03% / ℃, which will not cause demagnetization due to overheating; in addition, it has excellent mechanical strength, with a compressive strength of 1100MPa, and will not disintegrate or deform during high-speed rotation.

[0021] In order to facilitate real-time measurement and recording of the mass of the sample and obtain the corresponding experimental parameters, as shown, Figure 2As shown, the quality real-time balancing cantilever centrifuge further comprises a gravity sensor 5 arranged at the end of the rotating arm 12 and below the object table 121, and the gravity sensor 5 is electrically connected with the controller 4; the gravity sensor 5 is arranged at the end of the rotating arm 12 and below the object table 121 to monitor the mass of the sample, and the gravity sensor 5 is electrically connected with the controller 4 to transmit the measured data to the controller 4, and the controller 4 will energize the electromagnet 31 while adjusting the size of the current according to the size of the mass measured by the gravity sensor 5, indirectly adjusting the size of the magnetic force - the larger the magnetic force, the more magnetic medium 33 can be attracted to increase the mass, the smaller the magnetic force, the less magnetic medium 33 can be attracted to increase the mass, and then the size of the magnetic force is controlled to control the adjusted mass.

[0022] As shown in the accompanying drawings, Figure 2 As shown, the electromagnet 31 is arranged on the rotating arm 12 and between the gravity sensor 5 and the centrifuge main shaft 13, and by such arrangement, the electromagnet 31 can be closer to the rotating shaft to avoid the collision between the attracted magnetic medium 33 and the material placed on the object table 121.

[0023] As a preferred mode, in order to monitor the temperature of the sample and real-time monitor the state of the sample, as shown in the accompanying drawings, Figure 2 As shown, the quality real-time balancing cantilever centrifuge further comprises a temperature sensor 6 arranged at the bottom of both ends of the rotating arm 12 and below the object table 121, and the temperature sensor 6 is electrically connected with the controller 4; the above-mentioned controller 4 can be externally connected with a display and an operation platform to record the data monitored by various sensors and operate them; the gravity sensor 5 and the temperature sensor 6 installed below the object table 121 can realize the measurement of the temperature and mass of the sample, can meet and adapt to more application scenarios, and can be connected with the controller 4 through wires, so as to balance the mass according to the difference in mass of both ends of the rotating arm 12, and simplify the mass balancing step before using the centrifuge.

[0024] In order to ensure that the controller 4 and the piezoelectric ceramic sensor 2, the electromagnet 31, the gravity sensor 5 and the temperature sensor 6 will not affect each other and will not be disturbed by the external environment when connected and communicated, the communication between the piezoelectric ceramic sensor 2, the electromagnet 31, the gravity sensor 5, the temperature sensor 6 and the controller 4 can be realized through various wires; and the main cover 15 of the device can be made of a transparent shell to facilitate real-time observation of the internal use of the centrifuge.

[0025] As a specific embodiment, the above-mentioned scheme of adjusting the size of the magnetic force according to the size of the current specifically is that: Figure 2The rotating arm 12 located on the left side of the centrifuge main shaft 13 is set as rotating arm 12b, and the rotating arm 12 located on the right side of the centrifuge main shaft 13 is set as rotating arm 12c. Assuming that the permanent magnet is a samarium-cobalt (SmCo) permanent magnet, the magnetic medium is pure iron, the magnetic medium is 1 cm away from the permanent magnet, the magnetic medium is 5 cm away from the electromagnet, and the electromagnet itself has the following properties: the coil radius is 5 cm, the number of turns is 5000 turns, the silicon steel sheet is inserted, and the current is 1A; the centrifuge speed is 5000 revolutions per minute; the magnetic pole area A is 1 cm 2 ;

[0026] The magnetic field strength B generated by the permanent magnet is side :

[0027]

[0028] Where: P c —Permeability;

[0029] η—Edge effect coefficient;

[0030] B di —Effective residual magnetism, T;

[0031] μ rec —Recovery permeability of samarium-cobalt (SmCo) permanent magnet, H / m;

[0032] At this time, the magnetic attraction force F1 of 0.1g of magnetic medium received by the permanent magnet is:

[0033]

[0034] Where, A—Magnetic pole area, cm 2 ;

[0035] B side —Magnetic field strength of permanent magnet, T;

[0036] μ0—Vacuum permeability, (T·m) / A;

[0037] The centrifugal force F2 received by 0.1g of magnetic medium is:

[0038]

[0039] Where, m—Mass of magnetic medium, kg; r—Radius, m; ω—Angular velocity, rad / s;

[0040] The magnetic attraction force F3 of 0.1g of magnetic medium received by the electromagnet is:

[0041] First step: the internal magnetic field B of the electromagnet core core:

[0042]

[0043] Where: the core is annular, radius R = 0.05m, cross-sectional area A = πR 2 ≈0.00785m 2 ;

[0044] l - length of magnetic circuit, l = 2πR ≈ 0.314m;

[0045] μ r - relative permeability of silicon steel, μ r = 2000;

[0046] μ0 - vacuum permeability, μ0 = 4π x 10 -7 ;

[0047] N - number of turns of coil;

[0048] I - current;

[0049] But the saturation magnetic induction B sat of silicon steel = 1.8T; so after saturation of silicon steel, B core ≤ 1.8T, the excess magnetic motive force (NI = 5000A\cdotp turns) will significantly increase the leakage.

[0050] Step 2: Estimation of external magnetic field (5cm):

[0051] When the core is saturated, the magnetic field mainly spreads outward through the air path (leakage),

[0052]

[0053] Where: R = 0.05m; z = 0.05m; B sat = 1.8T; i.e. B external = 12.7mT;

[0054] Although the number of turns is increased to 5000 (the number of ampere turns is 5000), the saturation of the core causes the magnetic field to be unable to grow linearly. The actual leakage ratio may be slightly higher due to different magnetic circuit designs, but the magnetic field at 5cm is still limited to about 15-25mT.

[0055] Step 3: Assuming the magnetic field is uniformly distributed at the cross-section of the electromagnet,

[0056] Therefore, the above 0.1g of magnetic medium receives a magnetic attraction force F3 of the electromagnet of 6.14N;

[0057] When the magnetic attraction F3 of the magnetic medium by the electromagnet is 6.14 N, and the centrifugal force F2 is 1.92 N, the magnetic attraction F1 of the magnetic medium by the permanent magnet is 7.36 N, so F1 < F2 + F3, that is, the magnetic medium can be attracted to the end of the rotating arm by the electromagnet, so as to realize the balance of the material on the rotating arm of the centrifugal machine and protect the centrifugal machine.

[0058] Since the magnetic medium 33 and the electromagnet 31 adopt different types of materials, the same current can cause the medium to move different distances, which needs to be adjusted according to the specific situation.

Claims

1. A cantilever centrifuge for mass real-time balancing, comprising a support base (11), a rotating arm (12), a centrifuge main shaft (13) and a driving motor (14) in driving connection with the lower end of the centrifuge main shaft (13), the centrifuge main shaft (13) passing through the support base (11) at the end away from the driving motor (14) and being connected with the rotating arm (12), a bearing being arranged at the connection between the centrifuge main shaft (13) and the support base (11), and a sample placing platform (121) being arranged at the end of the rotating arm (12) away from the centrifuge main shaft (13); characterized in that: It also includes a piezoelectric ceramic sensor (2), an electromagnet assembly (3), and a controller (4), wherein the piezoelectric ceramic sensor (2) is arranged on the upper surface of the support seat (11) around the centrifuge main shaft (13); the piezoelectric ceramic sensor (2) is connected to the controller (4) by wires; the electromagnetic assembly includes an electromagnet (31) arranged at the end of the rotating arm (12) and connected to the controller (4) by wires to control the current size of the input electromagnet (31), each rotating arm (12) is provided with a strip-shaped cavity (32) arranged along the length direction of the rotating arm (12), and the strip-shaped cavity (32) is filled with a magnetic medium (33) movable along the strip-shaped cavity (32) at one end close to the centrifuge main shaft (13), and the controller (4) is arranged on the driving motor (14). ​ 2. The mass real-time trim balance cantilever centrifuge of claim 1, wherein: The signal transmission node (21) of the piezoelectric ceramic sensor is circularly arranged on the support seat (11) around the centrifuge main shaft (13), and the signal transmission node (311) of each electromagnet is arranged at the joint of the rotating arm (12) and the centrifuge main shaft (13) respectively.

3. The mass real-time trim balance cantilever centrifuge of claim 1, wherein: The top of the centrifuge main shaft (13) is a permanent magnet (34).

4. The mass real-time trim balance cantilever centrifuge of claim 1, wherein: It also includes a gravity sensor (5) arranged at the end of the rotating arm (12) below the object table (121), and the gravity sensor (5) is electrically connected to the controller (4).

5. The mass real-time trim balance cantilever centrifuge of claim 4, wherein: The electromagnet (31) is arranged on the rotating arm (12) between the gravity sensor (5) and the centrifuge main shaft (13).

6. The mass real-time trim balance cantilever centrifuge of claim 4, wherein: It also includes a temperature sensor (6) arranged at the bottom of both ends of the rotating arm (12) below the object table (121), and the temperature sensor (6) is electrically connected to the controller (4).

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