Tesla valve structure magnetorheological damper

Abstract

This invention discloses a Tesla valve structure magnetorheological damper, belonging to the technical field of damping devices. In this structure, the cylinder contains a magnetorheological fluid chamber filled with magnetorheological fluid; the piston assembly includes a piston rod, an excitation coil, and a piston housing. The excitation coil is located at one end of the piston rod extending into the magnetorheological fluid chamber, and the piston housing is located outside the excitation coil. The piston rod end, the excitation coil, and the piston housing together form a piston head. When a damper flow channel is formed between the piston housing and the excitation coil, or between the piston housing and the side wall of the magnetorheological fluid chamber, a first axial Tesla valve structure is correspondingly provided on the inner or outer side wall of the piston housing, and the first Tesla valve structure is located within the damper flow channel. This invention can achieve asymmetric damping force, and has the advantages of improving vibration reduction effect, enhancing support force, and extending structural fatigue life.

Description

Technical Field

[0001] This invention relates to the field of damping device technology, and in particular to a Tesla valve structure magnetorheological damper. Background Technology

[0002] A magnetorheological damper is an active / semi-active vibration control device based on smart materials. Its core utilizes the field-induced rheological properties of magnetorheological fluid to achieve real-time and precise control of the damping force. The magnetorheological fluid consists of micron-sized soft magnetic particles suspended in a carrier liquid. Without a magnetic field, it exhibits Newtonian fluid characteristics; upon applying a magnetic field, the particles are instantly magnetized and align along the magnetic field lines in a chain-like structure, transforming the fluid into a solid-like state, causing a dramatic increase in viscosity and generating a controllable damping force; after the magnetic field is removed, the solid-like state immediately returns to a liquid state, achieving stepless adjustment of the damping force.

[0003] In automotive suspension damper systems, load conditions are asymmetrical. When the damper compresses, the piston rod shortens, generating bumps; while recovery occurs when the damper extends, and the suspension returns to normal. These two phases typically require different damping characteristics to achieve ride comfort, system handling, and stability; therefore, asymmetrical force output is necessary. Asymmetrical force output allows magnetorheological dampers to implement differentiated damping strategies based on the direction of motion: providing lower damping force during compression to enhance comfort, and applying higher damping force during rebound to suppress excessive structural recovery, thus preventing excessive oscillation. Typically, compression damping is softer to allow the suspension to absorb road irregularities; recovery damping is usually stiffer to control how the suspension returns to its original position and prevent oscillations. Magnetorheological dampers can actively alter this behavior through electronic control, achieving good performance in both compression and recovery directions. However, magnetorheological dampers still need further enhancements to improve damping effectiveness, support capacity, and structural fatigue life, as well as to improve their adaptability in complex engineering applications. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to propose a Tesla valve structure magnetorheological damper that can achieve asymmetric damping force output, adjust and broaden the damping range, enhance vibration reduction effect, increase support force, and extend structural fatigue life.

[0005] According to an embodiment of the Tesla valve structure magnetorheological damper of the present invention, it includes: A cylinder body, wherein the cylinder body has a magnetorheological fluid chamber filled with magnetorheological fluid; A piston assembly includes a piston rod, an excitation coil, and a piston housing. The excitation coil is located at one end of the piston rod that extends into the magnetorheological fluid chamber. The piston housing is located outside the excitation coil. One end of the piston rod, the excitation coil, and the piston housing together form a piston head. When a damper flow channel is formed between the piston housing and the excitation coil or between the piston housing and the side wall of the magnetorheological fluid chamber, a first Tesla valve structure is provided on the inner side wall or the outer side wall of the piston housing, and the first Tesla valve structure is located in the damper flow channel.

[0006] The Tesla valve structure magnetorheological damper of this invention has the following advantages: First, it widens the damping range and enhances the shock absorption effect. For example, during the recovery process, when the piston assembly moves upward, the magnetorheological fluid flows back into the first Tesla valve structure, causing the magnetorheological fluid to be subjected to greater damping. Combined with the magnetic field generated by the excitation coil, it produces a larger recovery damping force, quickly dissipating the vibration energy of the car during vibration (such as when passing through a speed bump). Second, it enhances the support force. The curved structure of the first Tesla valve structure itself prolongs the residence time of the magnetorheological fluid in the damping channel, increasing the output force of the Tesla valve structure magnetorheological damper to provide stronger support. Third, it extends the fatigue life of the structure. The first Tesla valve structure is a fixed geometric structure set on the piston shell, with no relatively moving parts, avoiding mechanical wear. At the same time, the stable force output of the first Tesla valve structure can extend the fatigue life of the Tesla valve structure magnetorheological damper.

[0007] In some embodiments, a floating piston is further included, which is disposed in the cylinder and divides the internal space of the cylinder into the magnetorheological fluid chamber and a compensation gas chamber filled with compensation gas.

[0008] In some embodiments, an axial second Tesla valve structure is provided on the sidewall of the compensation air chamber.

[0009] In some embodiments, the first Tesla valve structure makes the magnetorheological fluid flow smoothly through the damper channel during compression but difficult to flow through the damper channel during recovery.

[0010] In some embodiments, during compression, the magnetorheological fluid flows through the damper channel in the opposite direction to compression. When the magnetorheological fluid passes through the first Tesla valve structure, it splits into two parts at each loop opening, and then converges again at the next junction, achieving accelerated flow. During recovery, the magnetorheological fluid flows through the damper channel in the opposite direction to recovery. When the magnetorheological fluid flows back into the first Tesla valve structure, it also splits into two paths at the first junction and converges again at the second junction. The flow directions of the two fluids are opposite, forming a large resistance, thereby providing a large recovery damping force.

[0011] In some embodiments, the working principle of the compensating gas flow in the compensating gas chamber is the same as the working principle of the magnetorheological fluid in the magnetorheological fluid chamber.

[0012] In some embodiments, there are multiple first Tesla valve structures, and the multiple first Tesla valve structures are distributed at equal intervals along the circumference.

[0013] In some embodiments, there are multiple second Tesla valve structures, which are distributed at equal intervals along the circumference.

[0014] In some embodiments, the excitation coil is a single-stage or multi-stage coil.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a Tesla valve structure magnetorheological damper according to an embodiment of the present invention; Figure 2 yes Figure 1 Enlarged view of point A in the middle; Figure 3 This is a schematic diagram of the flow of magnetorheological fluid in the first Tesla valve structure during the compression process in an embodiment of the present invention; Figure 4 This is a schematic diagram of the flow of magnetorheological fluid in the first Tesla valve structure during the restoration process in an embodiment of the present invention; Figure 5 This is a schematic diagram of the second Tesla valve structure in an embodiment of the present invention.

[0017] Figure Labels Tesla valve structure magnetorheological damper 1000; cylinder 1; magnetorheological fluid chamber 101; compensating air chamber 102; piston assembly 2; piston head 20; piston rod 201; excitation coil 202; piston shell 203; damper flow channel 204; floating piston 3; first Tesla valve structure 41; second Tesla valve structure 42; magnetorheological fluid 5. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0019] The following is combined Figures 1 to 5 The Tesla valve structure magnetorheological damper 1000 of the present invention is described in this embodiment.

[0020] like Figures 1 to 5 As shown, the Tesla valve structure magnetorheological damper 1000 of the first aspect of the present invention can be used in automotive suspension to achieve asymmetric damping force output, thereby improving comfort, handling, and stability. The Tesla valve structure magnetorheological damper 1000 of the first aspect of the present invention includes a cylinder 1 and a piston assembly 2.

[0021] The cylinder 1 contains a magnetorheological fluid chamber 101 filled with magnetorheological fluid 5. When no magnetic field is applied, the magnetorheological fluid 5 exhibits Newtonian fluid characteristics. When a magnetic field is applied, the magnetorheological fluid transforms into a solid-like substance, its viscosity increases dramatically, and it generates a controllable damping force according to the magnitude of the magnetic field. After the magnetic field is removed, the solid-like substance immediately returns to the liquid state, thus achieving stepless adjustment of the damping force.

[0022] Piston assembly 2 includes piston rod 201, excitation coil 202, and piston housing 203. The excitation coil 202 is located at one end of piston rod 201 that extends into magnetorheological fluid chamber 101. Piston housing 203 is located outside the excitation coil 202. The piston rod 201, excitation coil 202, and piston housing 203 together form piston head 20. When piston housing 203 is positioned between excitation coil 202 and piston housing 203 (see reference...),... Figures 2 to 4 When a damper flow channel 204 is formed between the piston housing 203 and the side wall of the magnetorheological fluid chamber 101 (not shown in the figure), correspondingly, the inner side wall of the piston housing 203 (see reference) Figures 2 to 4 The piston housing 203 has an axial first Tesla valve structure 41 on its outer side wall, and the first Tesla valve structure 41 is located in the damper flow channel 204.

[0023] When the piston assembly 2 reciprocates axially, the piston head 20 inside the cylinder 1 drives the magnetorheological fluid 5 to flow through the damper channel 204 in the opposite direction to the piston head's movement. For example, refer to... Figure 1 During the compression process, when the piston rod 201 and piston head 20 move downward synchronously, the magnetorheological fluid 5 flows from the lower end of the damper channel 204 under the pressure of the piston head 20 and flows out from the upper end of the damper channel 204. During the recovery process, when the piston rod 201 and piston head 20 move upward synchronously, the magnetorheological fluid 5 flows from the upper end of the damper channel 204 under the pressure of the piston head 20 and flows out from the lower end of the damper channel 204.

[0024] The excitation coil 202 is connected to an external power source and generates an adjustable magnetic field parallel to the direction of movement of the piston assembly 2 through current control. During the compression motion of the piston head 20, the excitation coil 202 can generate a smaller magnetic field by not being energized or by passing a smaller current, making the magnetorheological fluid 5 more fluid and with less damping force compared to the recovery process. During the recovery process, the excitation coil 202 is usually energized or by passing a larger current to generate a larger magnetic field, making the magnetorheological fluid 5 more viscous and with increased damping force compared to the compression process.

[0025] When fluid flows through the first Tesla valve structure from different directions, it generates different levels of resistance. For example... Figure 3 In the first Tesla valve structure 41, when the magnetorheological fluid 5 passes through the first Tesla valve structure 41 from below, the magnetorheological fluid 5 will split into two parts at each loop opening, and then converge again at the next confluence opening, achieving accelerated flow. At this time, the magnetorheological fluid 5 flows smoothly through the first Tesla valve structure, outputting a small damping force; such as Figure 4 As shown, when the magnetorheological fluid 5 flows into the first Tesla valve structure 41 in the reverse direction, the magnetorheological fluid 5 will also split into two streams at the first junction and converge again at the second junction. The flow directions of the two streams are opposite, forming a large damping force. Therefore, the first Tesla valve structure can generate asymmetric damping force in the magnetorheological fluid in both the compression and recovery directions. Thus, by adding the first Tesla valve structure to the existing magnetorheological damper, the damping range can be broadened.

[0026] The Tesla valve structure magnetorheological damper 1000 of this invention has the following advantages: First, it widens the damping range and enhances the shock absorption effect. For example, during the recovery process, when the piston assembly 2 moves upward (refer to...) Figure 1Firstly, by setting the first Tesla valve structure 41, the magnetorheological fluid 5 flows into the first Tesla valve structure 41 in the reverse direction, causing the magnetorheological fluid 5 to be subjected to greater damping. Combined with the magnetic field generated by the excitation coil 202, this produces a greater restoring damping force, rapidly dissipating the vibration energy of the vehicle during vibrations (such as when passing speed bumps). Secondly, it enhances the supporting force. The curved structure of the first Tesla valve structure 41 itself prolongs the residence time of the magnetorheological fluid 5 in the damping channel 204, increasing the output force value of the Tesla valve structure magnetorheological damper 1000 to provide stronger supporting force. Thirdly, it extends the structural fatigue life. The first Tesla valve structure 41 is a fixed geometric structure set on the piston housing 203, with no relatively moving parts, avoiding mechanical wear. At the same time, the stable force output of the first Tesla valve structure 41 can extend the fatigue life of the Tesla valve structure magnetorheological damper 1000.

[0027] In some embodiments, a floating piston 3 is also included. The floating piston 3 is disposed within the cylinder body 1, dividing the internal space of the cylinder body 1 into a magnetorheological fluid chamber 101 and a compensation gas chamber 102 filled with compensation gas. The magnetorheological fluid chamber 101 contains the magnetorheological fluid 5, and the compensation gas chamber 102 is filled with high-pressure compensation gas (such as nitrogen). The floating piston 3 is slidable within the cylinder body 1. By providing the floating piston 3, when the piston rod 201 extends into the cylinder body 1 causing a volume change, the floating piston 3 automatically compensates for the volume difference, ensuring a constant pressure within the magnetorheological fluid chamber 101, thereby ensuring the stability of the damping force output and extending its service life.

[0028] In some embodiments, an axial second Tesla valve structure 42 is provided on the sidewall of the compensation gas chamber 102. The first Tesla valve structure 41 is responsible for regulating the asymmetric flow of the magnetorheological fluid 5, while the second Tesla valve structure 42 is responsible for regulating the asymmetric flow of the compensation gas. This forms a "dual Tesla valve structure," which on the one hand prolongs the residence time of the magnetorheological fluid 5 in the damping channel 204, increasing the output force value; on the other hand, the device structure synchronously integrates the asymmetric channel, so that the resistance is minimal when the magnetorheological fluid 5 flows forward with the compensator (piston compression process), but the resistance increases sharply when flowing in the reverse direction (piston assembly 2 recovery process), thereby achieving the purpose of asymmetric output and enhancing the damping effect.

[0029] In some embodiments, the first Tesla valve structure 41 makes the magnetorheological fluid 5 flow smoothly through the damper channel 204 during the compression process and difficult to flow through the damper channel 204 during the recovery process. This arrangement is reasonable and enhances the shock absorption effect.

[0030] In some embodiments, during compression, the magnetorheological fluid 5 flows through the damper channel 204 in the opposite direction to compression. When the magnetorheological fluid 5 passes through the first Tesla valve structure, it splits into two parts at each loop opening, and then converges again at the next junction, achieving accelerated flow. During recovery, the magnetorheological fluid 5 flows through the damper channel 204 in the opposite direction to recovery. When the magnetorheological fluid 5 flows back into the first Tesla valve structure, it again splits into two paths at the first junction and converges again at the second junction. The two fluids flow in opposite directions, creating significant resistance and thus providing a large recovery damping force. During compression, the magnetorheological fluid 5 and the compensator move downwards following the piston head 20 and the floating piston 3, respectively. At this time, the resistance of the first Tesla valve structure 41 is relatively small, and the magnetorheological fluid 5 can smoothly pass through the Tesla valve channel. During the recovery stroke, the kinetic energy of the magnetorheological fluid 5 is used to generate greater resistance. This enhances the damping effect, ensures the stability of the damping force output, and extends the structural fatigue life of the damper flow channel.

[0031] In some embodiments, the working principle of the compensating gas flow in the compensating gas chamber 102 is the same as the working principle of the magnetorheological fluid 5 in the magnetorheological fluid chamber 101. This setting is reasonable, can enhance the damping effect, ensure the stability of the damping force output, and extend the structural fatigue life of the damper flow channel.

[0032] In some embodiments, there are multiple first Tesla valve structures 41, which are distributed at equal intervals along the circumference. This ensures the smooth flow of the magnetorheological fluid 5, ensures uniform force around the piston head 20, and prevents the piston rod 201 from shifting during reciprocating motion.

[0033] In some embodiments, there are multiple second Tesla valve structures 42, which are distributed at equal intervals along the circumference to ensure that the floating piston 3 is subjected to uniform force when moving axially, and will not deviate, thereby improving stability.

[0034] In some embodiments, the excitation coil 202 is a single-stage or multi-stage coil. Single-stage coils have a simpler structure, while multi-stage coils (such as double-stage coils) have better shock resistance and can be selected according to different load requirements, making them highly adaptable.

[0035] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A Tesla valve-structured magnetorheological damper, characterized in that, include: A cylinder body, wherein the cylinder body has a magnetorheological fluid chamber filled with magnetorheological fluid; A piston assembly includes a piston rod, an excitation coil, and a piston housing. The excitation coil is located at one end of the piston rod that extends into the magnetorheological fluid chamber. The piston housing is located outside the excitation coil. One end of the piston rod, the excitation coil, and the piston housing together form a piston head. When a damper flow channel is formed between the piston housing and the excitation coil or between the piston housing and the side wall of the magnetorheological fluid chamber, a first Tesla valve structure is provided on the inner side wall or the outer side wall of the piston housing, and the first Tesla valve structure is located in the damper flow channel.

2. The Tesla valve structure magnetorheological damper according to claim 1, characterized in that, It also includes a floating piston, which is disposed in the cylinder and divides the internal space of the cylinder into the magnetorheological fluid chamber and the compensation gas chamber filled with compensation gas.

3. The Tesla valve structure magnetorheological damper according to claim 2, characterized in that, An axial second Tesla valve structure is provided on the side wall of the compensation air chamber.

4. The Tesla valve structure magnetorheological damper according to claim 3, characterized in that, The first Tesla valve structure makes the magnetorheological fluid flow smoothly through the damper channel during the compression process, but makes it difficult for it to flow through the damper channel during the recovery process.

5. The Tesla valve structure magnetorheological damper according to claim 4, characterized in that, During compression, the magnetorheological fluid flows through the damper channel in the opposite direction to compression. When the magnetorheological fluid passes through the first Tesla valve structure, it splits into two parts at each loop opening. The magnetorheological fluid then converges at the next junction, achieving accelerated flow. During recovery, the magnetorheological fluid flows through the damper channel in the opposite direction to recovery. When the magnetorheological fluid flows back into the first Tesla valve structure, it also splits into two paths at the first junction and converges again at the second junction. The two fluids flow in opposite directions, creating significant resistance and thus providing a large recovery damping force.

6. The Tesla valve structure magnetorheological damper according to claim 5, characterized in that, The working principle of the compensating gas flow in the compensating gas chamber is the same as the working principle of the magnetorheological fluid in the magnetorheological fluid chamber.

7. The Tesla valve structure magnetorheological damper according to claim 5, characterized in that, There are multiple first Tesla valve structures, and the multiple first Tesla valve structures are distributed at equal intervals along the circumference.

8. The Tesla valve structure magnetorheological damper according to claim 6, characterized in that, There are multiple second Tesla valve structures, which are distributed at equal intervals along the circumference.

9. The Tesla valve structure magnetorheological damper according to any one of claims 1-8, characterized in that, The excitation coil can be a single-stage or multi-stage coil.

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