Built-in valve type magnetorheological damper based on blade paddle structure

Abstract

The invention discloses a built-in valve type magneto-rheological damper based on a blade paddle structure, and relates to the technical field of dampers, the damper is characterized in that a blade paddle and a rotor are coaxially arranged in a magneto-rheological damper cylinder barrel, a liquid backflow channel is arranged in a main shaft, and the blade paddle and the rotor are driven to move together by means of active torque provided by the main shaft; a built-in valve type working mode and a shear type working mode are formed in the damper to act together, two damping moments are generated at the same time to form resultant moments of the magnetorheological damper, the resultant moments comprise mechanical damping moments TM under high-speed rotation of blade paddles and coulomb damping moments TC of rotors under different magnetic field intensities, and according to different application occasions, the mechanical damping moments TM and the coulomb damping moments TC are different. The axial proportion sizes of different blade paddles and the rotor can be selected, and different ratios of mechanical torque to coulomb torque are provided.

Description

Technical Field

[0001] The invention relates to the technical field of magnetorheological dampers, and in particular to a high-performance magnetorheological damper based on a blade paddle structure to increase the transmission torque. Background Art

[0002] With the continuous development of mechanical transmission technology, the operational stability and safety of mechanical systems have become particularly important. Rotary magnetorheological dampers are semi-active damping components filled with magnetorheological fluid. Under the action of a magnetic field, the magnetorheological fluid produces a rheological output with controllable damping torque. It has the advantages of a wide damping torque output range, fast response speed, and good controllability. It has good application prospects in rotating conditions. However, most of the current rotary magnetorheological dampers face the problems of insufficient output damping torque, a single working mode, or excessive volume; and the temperature accumulation in the damper caused by the viscous dissipation of the magnetorheological fluid in the damper and the heating of the excitation coil affects the working performance of the magnetorheological fluid and reduces the service life of the damper.

[0003] At present, in the structural design process of rotating magnetorheological dampers, on the one hand, the main thing is to change the structure of the damper, such as T-type rotating magnetorheological damper, and on the other hand, to increase the number of disks or cylinders of the rotating magnetorheological damper, such as multi-disc magnetorheological damper; the purpose is to increase the effective damping area, thereby increasing the output damping torque. However, the working mode of these dampers is single and cannot be flexibly selected according to the use conditions. Therefore, in view of the different working conditions of the existing magnetorheological dampers, and when in a long-term working condition, the output torque is insufficient, the internal heat is large, and the performance of the magnetorheological fluid is reduced, and the service life is shortened. A built-in valve magnetorheological damper based on a blade paddle structure is proposed, which can effectively increase the damping torque. Summary of the invention

[0004] In view of this, the present invention provides a built-in valve magnetorheological damper based on a blade paddle structure, comprising a stator part, a rotor part, an excitation coil, a magnetorheological fluid and a sealing component part, wherein the stator part comprises a left end cover (2), an inner magnetic cylinder (6), an outer heat-conducting cylinder (8) and a right end cover (13); the rotor part comprises a main shaft (1), a rotor (7) and a blade paddle (5); the magnetorheological fluid is respectively filled between the inner magnetic cylinder (6) and the rotor (7), and between the blade paddle (5) and the inner magnetic cylinder (7); the main shaft (1 ) is provided with an external thread and is connected to the rotor (7) by a thread, and is also provided with a keyway and is connected to the blade propeller (5) by a key; the sealing part includes an O-ring (19) used between the left end cover (2) and the inner magnetic cylinder (6) and between the right end cover (13) and the inner magnetic cylinder (6); the inner magnetic cylinder (6) is connected to the left and right end covers inside the outer heat-conducting cylinder (8) by bolts; the left end cover (2) is provided with two oil injection holes (4); the outer heat-conducting cylinder (8) is provided with a water injection hole (11); the excitation coil (9) is wound inside the rotor (7);

[0005] The blade propeller principle of the centrifugal pump is used to increase the blade propeller structure. The high-speed rotation of the blade propeller promotes the continuous circulation of the magnetorheological fluid in the damper. There are two working modes: shear valve type. While promoting the heat dissipation efficiency of the damper, the mechanical damping torque mainly affected by the speed is generated to provide the transmission torque of the main system. Compared with the traditional magnetorheological damper, the torque of the damper is increased, and the working mode of the damper is increased, which broadens the scope of application of the magnetorheological damper.

[0006] In order to achieve the above-mentioned purpose, the internal valve type magnetorheological damper based on the blade paddle structure provided by the present invention adopts the following technical solutions:

[0007] When the structural parameters of the magnetorheological damper are as follows:

[0008] Table 1 Structural parameters of the built-in valve magnetorheological damper based on the blade propeller structure

[0009]

[0010] Substitute into formula (1.2) and calculate the relationship between the damping torque of the blade propeller and its speed with and without a magnetic field: Figure 3 As shown: a built-in valve-type magnetorheological damper based on a blade paddle structure, characterized in that the damper has a valve-type working mode due to the circulation of magnetorheological fluid driven by the blade paddle. Under zero magnetic field conditions, the mechanical torque increases with the influence of the rotational speed, and its value is small. However, under magnetic field conditions, its mechanical torque increases significantly with the influence of the rotational speed, and its value is large.

[0011] The Coulomb torque of the rotor part depends largely on the performance of the magnetorheological fluid. The greater the shear yield stress of the magnetorheological fluid under magnetic field conditions, the greater the Coulomb torque output by the rotor. Figure 4 As shown, it can be concluded that the magnetic induction intensity of the magnetorheological fluid increases with the increase of the magnetic field intensity, and its yield stress is changing with the increase of the magnetic induction intensity. When the magnetic induction intensity reaches 0.6T, the magnetorheological fluid has an obvious saturation trend, and the relationship between the magnetic field intensity and the magnetic induction intensity is also the same. The relationship between the shear yield stress and the magnetic induction intensity is fitted by the origin with a fifth-order polynomial, and the relationship between the approximate dynamic shear yield stress and the magnetic induction intensity of the magnetorheological fluid is obtained as follows:

[0012] τ(B)=a0+a1B+a2B 2 +a3B 3 +a4B 4 +a5B 5 (0.1)

[0013] Where:

[0014] a0, a1, a2, a3, a4, a5—polynomial fitting curve.

[0015] Substituting equation (1.5) into equation (1.1), we can obtain the Coulomb torque of the rotor as shown in the figure below:

[0016] A built-in valve magnetorheological damper based on a blade paddle structure, Figure 5 As shown, the rotor generates Coulomb damping torque due to the shear yield stress of the magnetorheological fluid, and the magnitude of the torque increases with the increase of the magnetic field strength. When the magnetic field strength is greater than 150kA / m, the damping torque tends to be flat, and the damping torque cannot be increased by applying the magnetic field strength. At this time, a larger damping torque can be provided by the valve working mode increased by the blade propeller structure.

[0017] from Figures 6 to 10 It can be seen that compared with the traditional shear-type magnetorheological damper, the damping torque of the built-in valve-type magnetorheological damper based on the blade paddle structure increases significantly with the increase of the speed. The reason is that the addition of the blade paddle structure inside the magnetorheological damper forms a circulating flow loop through the liquid flow channel inside the main shaft and the magnetorheological fluid gap, thereby forming a valve-type working mode. Its torque is manifested as the mechanical damping torque of the blade paddle, which increases with the increase of the speed. According to different working requirements, if used under high-speed conditions, in order to increase the effect of the valve-type working mode, the axial length of the blade paddle can be appropriately increased.

[0018] A built-in valve magnetorheological damper based on a blade propeller structure. The axial length of the blade propeller and the rotor is a key factor affecting its design. The relationship between the blade propeller and the rotor with different axial lengths and the output damping torque is given below.

[0019] Depend on Fig.12 — Fig.13 It can be obtained that: when the axial length ratio of the rotor increases, its Coulomb damping torque increases accordingly; when the axial length ratio of the blade propeller increases, its mechanical torque also increases accordingly; when the axial length ratio of the rotor and the blade propeller is different, its total damping torque also changes accordingly. Therefore, different axial length ratios of the rotor and the blade propeller can be designed according to different application scenarios.

[0020] When the number of blades changes:

[0021] like Fig.14 The figure shows the change of the damping torque brought by the blades when the number of blades is 2, 4, 6, 8, and 10. As can be seen from the figure, as the number of blades increases, the torque generated by the blades also increases, but the increase is slightly smaller. This is because the increase in the number of blades mainly affects the shape resistance torque of the blades, but the contribution of the shape damping torque of the blades is relatively small, so the increase in the number of blades has little effect on the damping torque.

[0022] When the angle between the blade propeller and the horizontal plane of the main shaft changes, such as Fig.15 As shown in the figure, as the angle α between the blade propeller and the main shaft increases, its torque increases. The reason is that as the angle α between the blade propeller and the main shaft increases, the viscous friction torque increases, and the total torque increases. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation method of the present application or the technical solution in the prior art, the drawings required for use in the specific implementation method or the prior art description are briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0025] Figure 2 Schematic diagram of the relationship between the rotation speed and the blade damping torque under zero magnetic field conditions

[0026] Figure 3 Schematic diagram of the relationship between the rotation speed and the blade damping torque under 80kA / m magnetic field conditions

[0027] Figure 4 Magnetorheological fluid performance curve

[0028] Figure 5 Schematic diagram of the relationship between magnetic field strength and rotor damping torque

[0029] Figure 6 Schematic diagram of the torque of the built-in valve type and traditional shear type dampers based on the blade paddle structure at a speed of 100r / min

[0030] Figure 7 Schematic diagram of the torque of the built-in valve type and traditional shear type dampers based on the blade paddle structure at a speed of 200r / min

[0031] Figure 8 Schematic diagram of the torque of the built-in valve type and traditional shear type dampers based on the blade propeller structure at a speed of 300r / min

[0032] Fig. 9 Schematic diagram of the torque of the built-in valve type and traditional shear type dampers based on the blade paddle structure at a speed of 400r / min

[0033] Fig.10 Schematic diagram of the torque of the built-in valve type and traditional shear type dampers based on the blade paddle structure at a speed of 500r / min. Fig.11 Under the same magnetic field conditions, the influence of the axial length of the blade propeller on the damping torque at different speeds. Fig.12 The influence of the axial length of the rotor on the damping torque at different current intensities under the same speed conditions. Fig.13 When the magnetic field strength and speed are constant, the relationship between the axial length ratio a / b of the rotor and the blade and the damping torque

[0034] Fig.14 Relationship between number of blades and blade torque

[0035] Fig.15 The influence of the angle α between the blade and the main shaft on the mechanical torque

[0036] Fig.16 Magnetorheological fluid performance curve

[0037] Fig.17 Schematic diagram of the relationship between the rotation speed and the blade damping torque under zero magnetic field conditions

[0038] Fig.18 Schematic diagram of the relationship between the rotation speed and the blade damping torque under 80kA / m magnetic field conditions

[0039] Fig.19 Schematic diagram of the torque of the built-in valve type and traditional shear type dampers based on the blade paddle structure at a speed of 500r / min

[0040] Fig. 20 Schematic diagram of the change of damping torque under different scale sizes

[0041] Description of reference numerals:

[0042] 1. Spindle; 2. Left end cover; 3. Oiling nozzle; 4. Oiling hole; 5. Blade; 6. Magnetic cylinder; 7. Rotor; 8. Heat-conducting cylinder; 9. Lead hole; 10. Excitation coil; 11. Water injection hole; 12. Rotor; 13. Right end cover; 14 Liquid flow hole; 15. Wire outlet hole; 16. Liquid flow hole; 17. Bearing; 18. Skeleton oil seal; 19. O-ring; 20. Bolt. DETAILED DESCRIPTION

[0043] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the items in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0044] According to the application requirements, taking high-speed application conditions as an example, the magnetorheological damper needs to work more in valve mode. When the axial length ratio of the rotor to the blade is 2:1, the torque provided by the blade and the torque provided by the rotor are calculated respectively:

[0045] The structural parameters of the magnetorheological damper are as follows:

[0046] Table 2 Structural parameters of magnetorheological damper based on blade propeller structure

[0047]

[0048] Magnetorheological fluid properties such as Fig.16 :

[0049] The relationship between the shear yield stress and the magnetic induction intensity is fitted by a fifth-order polynomial through origin, and the relationship between the approximate dynamic shear yield stress and the magnetic induction intensity of the magnetorheological fluid is obtained as follows:

[0050] τ(B)=a0+a1B+a2B 2 +a3B 3 +a4B 4 +a5B 5 (0.2)

[0051] Where:

[0052] a0, a1, a2, a3, a4, a5—polynomial fitting curve parameters.

[0053] Substitute into formula (1.2) and calculate the relationship between the damping torque of the blade propeller and its speed with and without a magnetic field: Figure 17-18As shown in the figure: when the axial ratio of the blade propeller to the rotor is 2:1, the blade damping torque is more obviously affected by the rotational speed. Under the magnetic field condition, when the rotational speed is high, the output damping is large, and under the zero magnetic field condition, the output damping is also small, which has little effect on the damping of the magnetorheological damper under zero field.

[0054] Depend on Fig.19 It can be seen that when the speed is 500r / min, the built-in valve damper based on the blade paddle structure is more than twice that of the traditional shear damper under low current. Under high current intensity, its damping output is also significantly higher than that of the traditional shear damper.

[0055] Depend on Fig. 20 Analysis shows that as the axial length of the blade propeller and the rotor increases, the damping torque output increases accordingly. Therefore, according to the application conditions, blade propellers and rotors with different axial length ratios can be selected to adapt to high and low speed application scenarios.

Claims

1. A built-in valve magnetorheological damper based on a blade paddle structure, characterized in that: The damper consists of a blade propeller and a rotor coaxially placed inside the cylinder of the magnetorheological damper, and a liquid reflux channel is provided inside the main shaft. The active torque provided by the main shaft drives the blade propeller and the rotor to move together, forming two working modes, a built-in valve type and a shear type, which work together inside the damper; under magnetic field conditions, when the rotor moves, Coulomb damping is generated by the shear yield stress of the magnetorheological fluid, and at the same time, the blade propeller drives the magnetorheological fluid to move, forming a built-in valve type liquid flow circuit inside the damper, thereby generating mechanical damping, and at the same time, the two types of damping act together on the magnetorheological damper.

2. According to the built-in valve magnetorheological damper based on the blade paddle structure of claim 1, when the rotor moves at high speed under the magnetic field condition, the shear yield stress of the magnetorheological fluid generates a Coulomb damping torque, which is calculated by the following formula: in: T C is the Coulomb damping torque; L e is the axial length of the cylinder; τ H is the circumferential shear stress of the magnetorheological fluid; R1 is the outer diameter of the rotor; R2 is the inner diameter of the outer cylinder; η is the viscosity at zero magnetic field intensity; ω is the angular velocity of the rotor.

3. According to the built-in valve-type magnetorheological damper based on the blade-paddle structure of claim 1, the rotor drives the magnetorheological fluid to form a circulating flow loop in the damper cylinder when rotating at high speed, and the mechanical damping torque in the valve-type working mode is calculated by the following formula: in: T M Represents the mechanical damping torque; L b is the axial length of the cylinder; ρ represents the density of the magnetorheological fluid; ω is the angular velocity of the rotor; r1 is the radius of the shaft of the blade propeller; r2 is the outer diameter of the blade propeller; is the valve switch function; α is the angle between the blade propeller and the horizontal plane of the main shaft α∈[0,90); n is the number of blade propellers; τ H is the shear stress of the magnetorheological fluid under magnetic field; τ0 is the shear stress of the magnetorheological fluid under zero magnetic field.

4. According to the built-in valve magnetorheological damper based on the blade paddle structure of claim 1, the resultant moment is composed of the sum of the Coulomb damping moment and the mechanical damping moment, which can be calculated by the following formula:

5. The ratio of the Coulomb moment to the mechanical moment according to claim 4 is λ, which can be calculated by the following formula: The value range of λ is [0.01,300].

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