Special-shaped centrifugal device damping mechanism and design method thereof

Abstract

This invention discloses a vibration damping mechanism for an irregularly shaped centrifuge device and its design method. The design method includes: establishing two balance reference planes corresponding to the upper and lower surfaces of the rotating module, respectively, and calculating the mass of the counterweight using the inertial force balance formula; determining the model of the vibration damping support based on the ratio of the interference frequency of the irregularly shaped centrifuge device to the natural frequency of the vibration damping mechanism being greater than a certain threshold; calculating the radial wall thickness of the suspended vibration damping sleeve based on the shear modulus of the material being prepared, and determining the axial length and outer diameter of the suspended vibration damping sleeve based on its installation inner diameter, thus obtaining the design parameters of the suspended vibration damping sleeve; after the vibration damping mechanism is assembled onto the irregularly shaped centrifuge device, using a dynamic balancing analyzer to test the vibration of the irregularly shaped centrifuge device at its rated speed to confirm the dynamic balancing effect. The design method of this invention is easier to operate and select, and through dynamic balancing verification analysis, it can effectively ensure the vibration damping and suppression effect of the vibration damping mechanism.

Description

Technical Field

[0001] This invention relates to the field of centrifugal equipment technology, and in particular to a vibration damping mechanism for an irregularly shaped centrifugal device and its design method. Background Technology

[0002] Centrifuges are commonly used equipment in various experiments and processing procedures. They separate liquids from solid particles or liquid-liquid mixtures using centrifugal force. Existing centrifuges typically achieve centrifugation by driving their centrifugal components at high speed with a motor, which in turn rotates the suspension. However, this high-speed rotation of the centrifugal components generates vibration. While some existing centrifuges are equipped with vibration damping structures, these typically only dampen vibrations in one or two directions. Since the vibration occurs along the centrifuge's perimeter during operation, existing damping structures cannot effectively counteract this vibration, leaving some degree of vibration remaining. Therefore, achieving efficient vibration damping for centrifuges has become a pressing issue. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a vibration reduction mechanism for irregularly shaped centrifugal devices and its design method, which has the advantages of achieving layered vibration reduction and improving the vibration reduction effect.

[0004] The objective of this invention is achieved through the following technical solution: According to a first aspect of the present disclosure, a vibration damping mechanism for an irregularly shaped centrifuge device is provided. The irregularly shaped centrifuge device includes: a centrifuge mounting frame, an irregularly shaped separation platform for loading materials to be centrifuged, a servo motor for providing rotational driving force, and a planetary gear module for transmitting the rotational driving force to the irregularly shaped separation platform. The planetary gear module includes: a transmission mounting column rotatably mounted on the centrifuge mounting frame, a central gear horizontally arranged and fixed on the transmission mounting column, and planetary gears vertically arranged and rotatably mounted on the transmission mounting column and meshing with the central gear. One side of the transmission mounting column is driven and connected to the servo motor, and the other side is fixed to the irregularly shaped separation platform. The vibration damping mechanism includes: The vibration damping support is disposed between the planetary gear module and the centrifugal mounting frame. The vibration damping support includes: a vibration damping mounting plate rotatably connected to the transmission mounting column, and a plurality of vibration damping feet arranged around the vibration damping mounting plate. The vibration damping feet are fixed to the centrifugal mounting frame. A suspension damping sleeve is fixed between the servo motor and the centrifugal mounting frame, and the bottom of the suspension damping sleeve is provided with a suspension mounting base for assembly with the centrifugal mounting frame; and, A counterweight block fixed to the transmission mounting column and disposed opposite to the planetary gear is used to balance the center of gravity of the planetary gear module and the irregular separation platform to a position close to the rotation axis.

[0005] To achieve the above technical solution, when the irregularly shaped centrifuge device is working, the driving force is provided by the servo motor and transmitted to the irregularly shaped separation platform through the planetary gear module to realize the centrifugation operation. The vibration generated during operation is first damped by the first layer of vibration reduction, which effectively suppresses the vibration of the centrifuge device under high-speed rotation. Then, the suspended damping sleeve provides a second layer of vibration reduction for the centrifuge device, which can effectively suppress the low-speed vibration / oscillation at the beginning of the servo motor's start-up acceleration and at the end of the deceleration. At the same time, the counterweight can balance the eccentric force generated by the planetary gear module during rotation, ensuring the vibration reduction effect of the damping mechanism, realizing the layered vibration reduction and suppression effect. The structure is simple, the cost is low, and the vibration reduction effect is excellent.

[0006] In some exemplary embodiments, the vibration damping feet are arranged in 3-6 groups around the vibration damping mounting plate.

[0007] In some exemplary embodiments, the transmission mounting column has mounting holes for mounting planetary gears, and the counterweight is disposed on the upper and / or lower side of the mounting holes.

[0008] In some exemplary embodiments, the vibration damping support is bell-shaped or bell-like, and the suspension damping sleeve is inverted frustum-shaped and hollow.

[0009] According to a second aspect of the present disclosure, a method for designing a vibration damping mechanism for an irregularly shaped centrifuge device as described in the first aspect is provided, comprising: Two balance reference planes are established, corresponding to the upper and lower surfaces of the rotating module, respectively. The mass of the counterweight is calculated according to the inertial force balance formula. The ratio of the interference frequency of the irregularly shaped centrifuge device to the natural frequency of the vibration damping mechanism is greater than... To determine the model of the vibration damping support, the selection criteria are used; The radial wall thickness of the suspension damping sleeve is calculated based on the shear modulus of the material being prepared, and the axial length and outer diameter of the suspension damping sleeve are determined based on the installation inner diameter of the suspension damping sleeve, thus obtaining the design parameters of the suspension damping sleeve. After the vibration damping mechanism is assembled onto the irregularly shaped centrifuge, a dynamic balance analyzer is used to test the vibration of the irregularly shaped centrifuge at its rated speed to confirm the dynamic balance effect.

[0010] In some exemplary embodiments, the step of establishing two balance reference planes corresponding to the upper and lower surfaces of the rotating module, respectively, and calculating the mass of the counterweight according to the inertial force balance formula specifically includes: Based on the principle of equilibrium of inertial force and inertial force couple, two equilibrium reference surfaces corresponding to the upper and lower surfaces of the rotating module are determined and established respectively. The centrifugal inertial force of the rotating module is decomposed onto the equilibrium reference plane and equilibrium calculation is performed according to the inertial force equilibrium formula; A three-dimensional model of the irregular centrifuge device was established, the mass and centroid coordinates of each part of the rotating module were determined, and the first equilibrium parameters were obtained. Based on the first balance parameters, the required balance mass and centroid coordinates of the balance reference plane are calculated to finally obtain the mass of the counterweight.

[0011] In some exemplary embodiments, the inertial force balance formula is: ; ; ; ; ; ; in, For the quality of the irregular separation platform, For the quality of the planetary gear module, The rotational speed of the centrifuge device. For the eccentric mass radius, To balance the mass within the reference plane, The distance from the lower surface to the upper surface of the rotating module. The distance is the projection of the center of mass of the rotating module onto the upper surface along the rotation axis. The distance is the projection from the center of mass axis of the planetary gear module onto the upper surface.

[0012] In some exemplary embodiments, the ratio of the interference frequency of the irregularly shaped centrifuge device to the natural frequency of the vibration damping mechanism is greater than... The specific criteria for determining the model of the vibration damping support include: The static force that each vibration damping support needs to withstand is determined based on the total weight of the centrifuge and the number of vibration damping supports. The interference frequency is determined based on the rotational speed of the centrifuge. The required natural frequency of the vibration damping support is calculated based on the ratio of the interference frequency to the required frequency to meet the predetermined vibration isolation target; Based on the static force and the natural frequency, the product load-natural frequency diagram is used to determine the vibration damping support model that meets the requirements; Calculate the actual frequency ratio and vibration transmissibility to verify the model of the vibration damping support.

[0013] In some exemplary embodiments, when verifying the model of the vibration damping foot, the horizontal safety factor of the vibration damping foot is also calculated to verify the horizontal stability, wherein the horizontal safety factor = (allowable load × stiffness ratio) / horizontal force.

[0014] In some exemplary embodiments, the formula for calculating the radial wall thickness of the suspension damping sleeve based on the shear modulus of the material used in its preparation is as follows: ,in, The radial stiffness of the material used to prepare the suspension damping sleeve The shear modulus of the material used to prepare the suspension damping sleeve. The effective bearing area of ​​the suspension damping sleeve. The radial wall thickness is the radial wall thickness of the suspension damping sleeve; When determining the axial length and outer diameter of the suspension damping sleeve based on its mounting inner diameter, use L / Adjust the axial length of the suspension damping sleeve within the reference range of 0.8~2.0. 2×t is the design formula for calculating the outer diameter of the suspension damping sleeve, where L is the axial length of the suspension damping sleeve. This refers to the mounting inner diameter of the suspension damping sleeve. The outer diameter of the suspension damping sleeve; And in the initial determination Afterwards, verification Check if it is less than the maximum allowable installation outer diameter. If not, iteratively adjust the G or L value.

[0015] In summary, compared with the prior art, the present invention has the following beneficial effects: This invention provides a vibration damping mechanism and its design method for an irregularly shaped centrifuge device. During operation, the centrifuge device is driven by a servo motor, which transmits the driving force to the irregularly shaped separation platform via a planetary gear module to achieve centrifugal operation. Regarding the vibration damping mechanism, a counterweight is initially used to balance most of the eccentricity or imbalance. However, due to structural design limitations, the counterweight cannot balance all imbalances, especially at high speeds. These unbalanced imbalances significantly affect the dynamic balance of the centrifuge device. Therefore, during operation, a vibration damping support is used for the first layer of vibration damping, effectively suppressing the vibration of the centrifuge device at high speeds. Finally, a suspended vibration damping sleeve provides a second layer of vibration damping, effectively suppressing low-speed vibration / oscillation during the initial acceleration of the servo motor and the final deceleration, ensuring the vibration damping effect of the mechanism and achieving a layered vibration damping and suppression effect. The structure is simple, low-cost, and provides excellent vibration damping. Furthermore, the design method of this invention is easier to operate and select, and through dynamic balance verification analysis, it effectively guarantees the vibration damping and suppression effect of the mechanism. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the vibration damping mechanism of the irregular centrifugal device in an embodiment of the present invention.

[0017] Figure 2 This is a cross-sectional view of the vibration damping mechanism of the irregular centrifugal device in an embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of the connection structure between the servo motor and the suspension damping sleeve in an embodiment of the present invention.

[0019] Figure 4 This is a schematic diagram illustrating the inertial force balancing process in an embodiment of the present invention.

[0020] The numbers and letters in the diagram represent the names of the corresponding components: 10. Centrifuge mounting frame; 20. Irregularly shaped separation platform; 30. Servo motor; 31. Coupling; 41. Transmission mounting column; 42. Central gear; 43. Planetary gear; 50. Vibration damping support; 51. Vibration damping mounting plate; 52. Vibration damping foot; 60. Suspension damping sleeve; 61. Suspension mounting seat; 63. Support plate; 64. First mounting shaft; 65. Second mounting shaft; 70. Counterweight. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figures 1 to 3 As shown, the first aspect of the present invention provides a vibration damping mechanism for an irregularly shaped centrifuge device. The irregularly shaped centrifuge device includes: a centrifuge mounting frame 10, an irregularly shaped separation platform 20 for loading materials to be centrifuged, a servo motor 30 for providing rotational driving force, and a planetary gear 43 module for transmitting the rotational driving force to the irregularly shaped separation platform 20. The planetary gear 43 module includes: a transmission mounting column 41 rotatably mounted on the centrifuge mounting frame 10, a central gear 42 horizontally arranged and fixed on the transmission mounting column 41, and a planetary gear 43 vertically arranged and rotatably mounted on the transmission mounting column 41 and meshing with the central gear 42. One side of the transmission mounting column 41 is drivenly connected to the servo motor 30, and the other side is fixed to the irregularly shaped separation platform 20.

[0023] A coupling 31 is typically configured between the servo motor 30 and the planetary gear 43 module. This coupling 31 is preferably a diaphragm-type high-rigidity clamping coupling 31, with its main body made of aluminum alloy and featuring a double diaphragm design with the diaphragms made of stainless steel. It has the characteristics of high torsional stiffness, high torque, and zero backlash, and can be well adapted to the use environment of irregular centrifugal structures, large rotating weight, and low speed and high torque. It is understood that the planetary gear 43 module is configured with a rotating shaft and bearings to accommodate its rotational installation. In order to ensure its own rigidity, two tapered roller bearings are preferably selected in a face-to-face installation manner as radial fixation of the rotating shaft. The specific structure of the irregular centrifugal device can adopt the setting method in the prior art, which will not be elaborated here. The vibration damping mechanism of this application is adaptively designed based on the structural characteristics of the irregular centrifugal device.

[0024] In some embodiments, a movable platform may be provided at the bottom of the centrifuge mounting frame 10, and the bottom of the movable platform may be equipped with rollers to facilitate the movement of the centrifuge device.

[0025] The vibration damping mechanism includes: a vibration damping support 50 disposed between the planetary gear 43 module and the centrifugal mounting frame 10, the vibration damping support 50 including: a vibration damping mounting plate 51 rotatably connected to the transmission mounting column 41, and a plurality of vibration damping legs 52 disposed around the vibration damping mounting plate 51, the vibration damping legs 52 being fixed to the centrifugal mounting frame 10; a suspended vibration damping sleeve 60 fixed between the servo motor 30 and the centrifugal mounting frame 10, the bottom of the suspended vibration damping sleeve 60 being provided with a suspended mounting seat 61 for assembly with the centrifugal mounting frame 10; and a counterweight 70 fixed to the transmission mounting column 41 and disposed opposite to the planetary gear 43, the counterweight 70 being used to balance the center of gravity of the planetary gear 43 module and the irregular separation platform 20 to a position close to the rotation axis.

[0026] Specifically, 3-6 sets of vibration damping feet 52 are arranged around the vibration damping mounting plate 51. In this embodiment, 3 sets of vibration damping feet 52 are arranged. Typically, 3 sets of outwardly protruding connecting lugs are provided on the vibration damping mounting plate 51. The top of the vibration damping feet 52 is fixed to the connecting lugs by screws, while the bottom sides of the vibration damping feet 52 are provided with connecting flanges. The vibration damping feet 52 are fixed to the centrifugal mounting frame 10 by screws locked into the connecting flanges. Preferably, the vibration damping feet 52 are bell-shaped or bell-like, which is more conducive to achieving the vibration damping effect.

[0027] The transmission mounting column 41 has mounting holes for mounting the planetary gear 43. It can be understood that the mounting hole is used to assemble the rotating shaft and bearings of the planetary gear 43. The counterweight 70 is set on the upper and / or lower side of the mounting hole to achieve a better counterweight balance effect.

[0028] The suspension damping sleeve 60 is in the shape of an inverted frustum and is hollow. In some embodiments, the suspension damping sleeve 60 is preferably configured as an inverted gourd shape, so that its stiffness increases sharply when it is compressed and closed, playing a "progressive limiting" role. Typically, a support plate 63 is provided at the bottom of the servo motor 30, and a first mounting shaft 64 is provided at the bottom of the support plate 63. A second mounting shaft 65 is provided at the top of the suspension mounting seat 61. The upper end of the suspension damping sleeve 60 is sleeved on the first mounting shaft 64, and the lower end of the suspension damping sleeve 60 is sleeved on the second mounting shaft 65. The first mounting shaft 64 and the second mounting shaft 65 abut and fix the suspension damping sleeve 60.

[0029] When the irregularly shaped centrifuge is working, the servo motor 30 provides the driving force, which is transmitted to the irregularly shaped separation platform 20 through the planetary gear 43 module to realize the centrifugation operation. For the vibration damping mechanism, the counterweight 70 first balances most of the eccentricity or imbalance. However, due to the limitations of the structural design, the counterweight 70 cannot balance all the imbalance, especially under high-speed rotation. These unbalanced imbalances will have a great impact on the dynamic balance of the centrifuge. Therefore, during operation, the vibration damping support performs the first layer of vibration damping for most of the vibration, effectively suppressing the vibration of the centrifuge under high-speed rotation. Finally, the suspended vibration damping sleeve 60 performs the second layer of vibration damping for the centrifuge, which can effectively suppress the low-speed vibration / oscillation at the beginning of the servo motor 30's start-up acceleration and the end of the shutdown deceleration, ensuring the vibration damping effect of the vibration damping mechanism, realizing the layered vibration damping and suppression effect. The structure is simple, the cost is low, and the vibration damping effect is excellent.

[0030] A second aspect of this invention provides a design method for a vibration damping mechanism of an irregularly shaped centrifuge device as described in the first aspect, comprising: S100. Establish two balance reference surfaces corresponding to the upper and lower surfaces of the rotating module respectively, and calculate the mass of the counterweight according to the inertial force balance formula.

[0031] Specifically, S100 includes: S101. Based on the principle of balancing inertial force and inertial torque, two balance reference planes are determined and established, corresponding to the upper and lower surfaces of the rotating module, respectively. For the irregular centrifugal device targeted by this application, since its mass distribution is not in the same plane of rotation, the centrifugal force generated by the rotating components such as the irregular separation platform and planetary gear module forms a spatial force system, which requires the simultaneous balancing of inertial force and inertial torque.

[0032] This application specifically balances the inertial force and the moment of inertial couple according to the following set of equations: ; ; Where u(z) is the distribution function of the unbalance on the Z-axis. Let j be the j-th balancing mass, and n be the number of balancing masses.

[0033] Solving the above equations reveals that when n=2, the equations have a unique solution. This means that any unbalanced mass of the rigid rotor can be balanced by adding or subtracting corrective mass on two correction surfaces perpendicular to the axis of rotation. Furthermore, the deformation of the rigid rotor itself is negligible during rotation, meaning the rigid rotor axis of rotation can be considered a fixed spatial axis, and its unbalance does not change with the rotational speed. Therefore, if the rigid rotor is in dynamic equilibrium at a certain rotational speed, and the system stiffness is sufficient, the rigid rotor can still maintain a balanced state.

[0034] Based on the above operating principle, when designing a vibration damping mechanism, a counterweight can be set on the transmission mounting column to pull the overall center of gravity of the device back to the vicinity of the rotation axis. Subsequently, by repeatedly adjusting the position, size, and volume of the counterweight, the distance between the center of gravity and the rotation axis can be reduced as much as possible.

[0035] S102. Decompose the centrifugal inertial force of the rotating module onto the equilibrium reference plane and perform equilibrium calculations according to the inertial force equilibrium formula. The rotating module specifically includes an irregularly shaped separation platform and a planetary gear module. Since the rotation center of the rotating module will deviate from the center circumference during the operation of the centrifuge, the dynamic balance analysis and design of the centrifuge mainly involves balancing the eccentric mass of the rotating module. During balancing, equilibrium reference planes corresponding to the upper and lower surfaces of the rotating module are selected, as shown in the equilibrium diagram below. Figure 4 As shown.

[0036] Specifically, the inertial force balance formula is as follows: ; ; ; ; ; ; in, The mass (kg) of the irregularly shaped separation platform The mass (kg) of the planetary gear module. The rotational speed of the centrifuge is rad / s. For the eccentric mass radius, To balance the mass within the reference plane, The distance (mm) between the lower and upper surfaces of the rotating module. The distance (mm) is the projection of the center of mass of the rotating module onto the upper surface on the axis of rotation. The distance (mm) is the projection of the planetary gear module's center of mass shaft onto the upper surface.

[0037] S103. Establish a three-dimensional model of the irregular centrifuge device, determine the mass and centroid coordinates of each part of the rotating module, and obtain the first equilibrium parameters; the three-dimensional model can be imported into ADAMS or other similar software for model processing.

[0038] S104. Based on the first balance parameters, calculate the balance mass and centroid coordinates required for the balance reference plane to finally obtain the mass of the counterweight. The first balance parameters can be imported into MATLAB or other similar software for calculation and solution. Then, the counterweight can be designed and improved using the obtained balance mass and centroid coordinates.

[0039] S200, the ratio of the interference frequency of the irregularly shaped centrifuge device to the natural frequency of the vibration damping mechanism is greater than... To select the appropriate type of vibration-damping support, the purpose of adding vibration-damping supports to the centrifuge unit is to form a vibration isolation system. The core condition for effective vibration isolation is that, while meeting load-bearing requirements, the interference frequency of the centrifuge unit must be within acceptable limits. f With the natural frequency of the vibration isolation system The ratio is greater than The larger the ratio, the better the vibration isolation effect. The vibration isolation effect can be measured by the vibration transmissibility. The better the vibration isolation effect, the lower the vibration transmissibility. The lower.

[0040] Specifically, S200 includes: S201. Based on the total weight of the centrifuge and the number of vibration-damping supports, determine the static force that each vibration-damping support needs to withstand. The formula for calculating the static force of each vibration-damping support is as follows: =Total weight of the device / Number of support points As this is a static force, it is necessary to ensure during the design phase that... ≤ Product allowable load, with sufficient safety margin.

[0041] S202. Determine the interference frequency based on the rotational speed of the centrifuge, wherein the interference frequency is... f = Rotational speed / 60. By calculation, the most significant interference frequency can be obtained, such as the interference frequency of a servo motor.

[0042] S203. Based on the ratio of the interference frequency to the required frequency, calculate the required natural frequency of the vibration damping support to meet the predetermined vibration isolation target. The vibration isolation target can be determined by setting the vibration transmissibility. To determine the required intrinsic frequency < f / Required frequency ratio; Typically, to achieve good vibration isolation, the vibration transmissibility is set. For example, it can be set to the desired intrinsic frequency. The required natural frequency should at least satisfy .

[0043] S204. Based on the static force and the natural frequency, find the product load-natural frequency diagram to determine the vibration damping foot model that meets the requirements. The determined vibration damping foot model must simultaneously meet the requirements of static force and natural frequency. In some embodiments, the spring constant can also be calculated for subsequent verification. The spring constant K ≈ ( ) / δ, where δ is the static deformation.

[0044] S205. Calculate the actual frequency ratio and vibration transmissibility to verify the vibration damping support model. The actual frequency ratio is... Vibration transmissibility The actual frequency ratio must be guaranteed. .

[0045] In some embodiments, when verifying the model of the vibration damping support, the horizontal safety factor of the vibration damping support is also calculated to verify the horizontal stability, wherein the horizontal safety factor = (allowable load × stiffness ratio) / horizontal force, and the risk of overturning is determined by verifying the horizontal stability.

[0046] S300. Calculate the radial wall thickness of the suspension damping sleeve based on the shear modulus of the material being prepared. Determine the axial length and outer diameter of the suspension damping sleeve based on its installation inner diameter, thus obtaining the design parameters of the suspension damping sleeve. Typically, natural rubber is selected as the material for preparing the suspension damping sleeve, which has the characteristics of high elasticity, low heat generation, and excellent fatigue life. The hardness of rubber is usually in the range of 40°A to 70°A. Low-hardness rubber has the characteristics of low modulus and low stiffness, but it is prone to instability under large deformation conditions. High-hardness rubber, on the other hand, has the characteristics of high modulus and high stiffness, but its vibration isolation effect may be reduced.

[0047] Furthermore, when installing the suspension damping sleeve, a certain amount of pre-compression needs to be applied to it to improve load-bearing stability, suppress low-frequency large-amplitude swaying, and also change its dynamic and static stiffness characteristics.

[0048] Specifically, the formula for calculating the radial wall thickness of the suspension damping sleeve based on the shear modulus of the prepared material is as follows: ,in, The radial stiffness of the material used to prepare the suspension damping sleeve The shear modulus of the material used to prepare the suspension damping sleeve. The effective bearing area of ​​the suspension damping sleeve. The radial wall thickness is the radial wall thickness of the suspension damping sleeve.

[0049] radial stiffness It mainly depends on the shear deformation and shear modulus of the material being prepared. It mainly depends on the formulation and hardness of the material used, and the effective load-bearing area. Approximately the inner surface area of ​​the suspension damping sleeve ,in, The mounting inner diameter of the suspension damping sleeve is determined based on the shaft diameter that mates with the suspension damping sleeve. L This refers to the axial length of the suspension damping sleeve.

[0050] Based on target stiffness The hardness of the initial selected materials (corresponding to) G (value) and , L Given the installation dimensions, the required wall thickness t can be deduced; meanwhile, during the design process, the wall thickness t is usually within the installation inner diameter. The wall thickness should be between 10% and 25%. If the wall thickness is too thin, it will make the process difficult, the stress high, and the material vulnerable. If the wall thickness is too thick, it will result in poor heat dissipation, large internal constraints, and an inability to achieve the ideal shearing state.

[0051] When determining the axial length and outer diameter of the suspension damping sleeve based on its mounting inner diameter, use L / Adjust the axial length of the suspension damping sleeve within the reference range of 0.8~2.0. 2×t is the design formula for calculating the outer diameter of the suspension damping sleeve, where L is the axial length of the suspension damping sleeve. This refers to the mounting inner diameter of the suspension damping sleeve. This refers to the outer diameter of the suspension damping sleeve.

[0052] Axial length L directly affects the effective bearing area This, in turn, affects the radial stiffness. This will also affect the yaw stiffness and axial stiffness. When designing the axial length, the following should be considered: increasing the axial length L can reduce the stress on the suspension damping sleeve and improve durability, but it occupies a lot of space and may affect the yaw stiffness; reducing the axial length L can save space, but stress concentration may occur and fatigue life may decrease.

[0053] outer diameter Due to the limited installation space, in the initial determination Afterwards, verification is required. Check if it is smaller than the maximum allowable installation outer diameter. If not, iteratively adjust the G or L value until the size installation requirements are met.

[0054] Meanwhile, since the end area of ​​the suspension damping sleeve is a stress concentration point, the end of the suspension damping sleeve is usually set with a rounded corner to significantly reduce the stress peak and extend the fatigue life. The radius of the rounded corner is usually not less than 20%-30% of the rubber wall thickness.

[0055] Furthermore, the inner diameters of the upper and lower ends of the suspension damping sleeve are usually set to be slightly smaller than the shaft diameter of the loading shaft, forming a radial interference fit. The interference will generate assembly prestress, improve the initial stiffness, and prevent loosening during use.

[0056] S400. After the vibration damping mechanism is assembled onto the irregular centrifuge, a dynamic balance analyzer is used to test the vibration of the irregular centrifuge at the rated speed to confirm the dynamic balance effect. The test shall comply with GB / T 9239.21-2019. For example, in a specific embodiment of the vibration damping mechanism, the test is carried out at a rated speed of 3000 rpm, and the maximum vibration is less than 6.3 mm / s, and the remaining unbalance is better than G 6.3 level.

[0057] In addition, the reason for conducting dynamic balancing effect testing is that, due to the process of selecting the required frequency ratio and vibration damping support model in the aforementioned steps, as well as the empirical judgments in each calculation formula, there may be slight deviations. Therefore, further testing and verification are required. According to the test results of the dynamic balancing analyzer, it can indicate whether it is necessary to add counterweights to certain phases. In actual execution, it may be necessary to add a few grams or a fraction of a gram of counterweight to improve the dynamic balance and further enhance the vibration damping effect.

[0058] The design method of this invention is easier to operate and select. At the same time, through dynamic balance verification analysis, it can effectively ensure the vibration reduction and suppression effect of the vibration damping mechanism. In addition, the design method of this invention strictly follows the steps of calculating the mass of the counterweight, selecting the vibration damping support, and calculating the size of the suspension damping sleeve, so as to first balance most of the unbalance, so that the dynamic balance reaches the optimal level. Then, the vibration damping support provides the first layer of vibration damping for most of the vibration, effectively suppressing the vibration of the centrifuge device under high-speed rotation. Finally, the suspension damping sleeve provides the second layer of vibration damping for the centrifuge device, effectively suppressing the low-speed vibration / oscillation during the initial acceleration of the servo motor and the final deceleration of the servo motor, achieving a better vibration reduction and suppression effect.

[0059] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These are all equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of these fall within the protection scope of the present invention.

Claims

1. A vibration damping mechanism for an irregularly shaped centrifuge device, characterized in that, The irregularly shaped centrifuge device includes: a centrifuge mounting frame, an irregularly shaped separation platform for loading the material to be centrifuged, a servo motor for providing rotational driving force, and a planetary gear module for transmitting the rotational driving force to the irregularly shaped separation platform. The planetary gear module includes: a transmission mounting column rotatably mounted on the centrifuge mounting frame, a central gear horizontally arranged and fixed on the transmission mounting column, and planetary gears vertically arranged and rotatably mounted on the transmission mounting column and meshing with the central gear. One side of the transmission mounting column is driven and connected to the servo motor, and the other side is fixed to the irregularly shaped separation platform. The vibration damping mechanism includes: The vibration damping support is disposed between the planetary gear module and the centrifugal mounting frame. The vibration damping support includes: a vibration damping mounting plate rotatably connected to the transmission mounting column, and a plurality of vibration damping feet arranged around the vibration damping mounting plate. The vibration damping feet are fixed to the centrifugal mounting frame. A suspension damping sleeve is fixed between the servo motor and the centrifugal mounting frame, and the bottom of the suspension damping sleeve is provided with a suspension mounting base for assembly with the centrifugal mounting frame; and, A counterweight block fixed to the transmission mounting column and disposed opposite to the planetary gear is used to balance the center of gravity of the planetary gear module and the irregular separation platform to a position close to the rotation axis.

2. The vibration damping mechanism of the irregularly shaped centrifuge device according to claim 1, characterized in that, The vibration damping support feet are arranged in 3-6 sets around the vibration damping mounting plate.

3. The vibration damping mechanism of the irregularly shaped centrifuge device according to claim 1, characterized in that, The transmission mounting column has mounting holes for mounting planetary gears, and the counterweight is provided on the upper and / or lower side of the mounting holes.

4. The vibration damping mechanism of the irregularly shaped centrifuge device according to claim 1, characterized in that, The vibration damping support is bell-shaped or bell-like, and the suspension damping sleeve is inverted frustum shape and hollow.

5. A design method for a vibration damping mechanism of an irregularly shaped centrifuge device as described in any one of claims 1-4, characterized in that, include: Two balance reference planes are established, corresponding to the upper and lower surfaces of the rotating module, respectively. The mass of the counterweight is calculated according to the inertial force balance formula. The ratio of the interference frequency of the irregularly shaped centrifuge device to the natural frequency of the vibration damping mechanism is greater than... To determine the model of the vibration damping support, the selection criteria are used; The radial wall thickness of the suspension damping sleeve is calculated based on the shear modulus of the material being prepared, and the axial length and outer diameter of the suspension damping sleeve are determined based on the installation inner diameter of the suspension damping sleeve, thus obtaining the design parameters of the suspension damping sleeve. After the vibration damping mechanism is assembled onto the irregularly shaped centrifuge, a dynamic balance analyzer is used to test the vibration of the irregularly shaped centrifuge at its rated speed to confirm the dynamic balance effect.

6. The design method according to claim 5, characterized in that, The establishment of two balance reference planes corresponding to the upper and lower surfaces of the rotating module, respectively, and the calculation of the mass of the counterweight according to the inertial force balance formula specifically include: Based on the principle of equilibrium of inertial force and inertial force couple, two equilibrium reference surfaces corresponding to the upper and lower surfaces of the rotating module are determined and established respectively. The centrifugal inertial force of the rotating module is decomposed onto the equilibrium reference plane and equilibrium calculation is performed according to the inertial force equilibrium formula; A three-dimensional model of the irregular centrifuge device was established, the mass and centroid coordinates of each part of the rotating module were determined, and the first equilibrium parameters were obtained. Based on the first balance parameters, the required balance mass and centroid coordinates of the balance reference plane are calculated to finally obtain the mass of the counterweight.

7. The design method according to claim 6, characterized in that, The inertial force balance formula is as follows: ； ； ； ； ； ； in, For the quality of the irregular separation platform, For the quality of the planetary gear module, The rotational speed of the centrifuge device. For the eccentric mass radius, To balance the mass within the reference plane, The distance from the lower surface to the upper surface of the rotating module. The distance is the projection of the center of mass of the rotating module onto the upper surface along the rotation axis. The distance is the projection from the center of mass axis of the planetary gear module onto the upper surface.

8. The design method according to claim 5, characterized in that, The ratio of the interference frequency of the irregularly shaped centrifuge device to the natural frequency of the vibration damping mechanism is greater than... The specific criteria for determining the model of the vibration damping support include: The static force that each vibration damping support needs to withstand is determined based on the total weight of the centrifuge and the number of vibration damping supports. The interference frequency is determined based on the rotational speed of the centrifuge. The required natural frequency of the vibration damping support is calculated based on the ratio of the interference frequency to the required frequency to meet the predetermined vibration isolation target; Based on the static force and the natural frequency, the product load-natural frequency diagram is used to determine the vibration damping support model that meets the requirements; Calculate the actual frequency ratio and vibration transmissibility to verify the model of the vibration damping support.

9. The design method according to claim 8, characterized in that, When verifying the model of the vibration damping support, the horizontal safety factor of the vibration damping support is also calculated to verify the horizontal stability. The horizontal safety factor is calculated as (allowable load × stiffness ratio) / horizontal force.

10. The design method according to claim 5, characterized in that, The formula for calculating the radial wall thickness of the suspension damping sleeve based on the shear modulus of the prepared material is as follows: ,in, The radial stiffness of the material used to prepare the suspension damping sleeve The shear modulus of the material used to prepare the suspension damping sleeve. The effective bearing area of ​​the suspension damping sleeve. The radial wall thickness is the radial wall thickness of the suspension damping sleeve; When determining the axial length and outer diameter of the suspension damping sleeve based on its mounting inner diameter, use L / Adjust the axial length of the suspension damping sleeve within the reference range of 0.8~2.

0. 2×t is the design formula for calculating the outer diameter of the suspension damping sleeve, where L is the axial length of the suspension damping sleeve. This refers to the mounting inner diameter of the suspension damping sleeve. The outer diameter of the suspension damping sleeve; And in the initial determination Afterwards, verification Check if it is less than the maximum allowable installation outer diameter. If not, iteratively adjust the G or L value.

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