Direct drive type electro-hydraulic power unit, magneto-rheological valve group, suspension system and method

Abstract

The invention relates to a direct drive type electro-hydraulic power unit, a magneto-rheological valve group, a suspension system and a method, the electro-hydraulic power unit comprises a motor assembly, a magneto-rheological valve group, a magneto-rheological valve group and a magneto-rheological valve group, the motor assembly comprises a motor shell, a motor stator and a motor rotor, and the stator is fixed in the motor shell; the mechanical transmission assembly is arranged in the motor assembly and comprises a lead screw and a nut which are matched with each other; the hydraulic pumping assembly is fixedly connected with the motor shell or integrally formed with the motor shell and comprises at least one piston cylinder and a piston located in the piston cylinder. A motor rotor is fixedly connected with one of the lead screw or the nut to drive the lead screw or the nut to rotate; the rotation freedom degree of the other one of the lead screw and the nut is limited, only the axial movement freedom degree is reserved, and the other one is in transmission connection with the piston. According to the fluid output structure, the piston divides the piston cylinder into at least one sealing cavity for containing transmission fluid, the sealing cavity comprises a first oil cavity and a second oil cavity, and a fluid oil port used for being communicated with an external load is formed in the sealing cavity.

Description

Technical Field

[0001] This invention relates to the field of electro-hydraulic transmission technology, and in particular to a direct-drive electro-hydraulic power unit, a magnetorheological valve assembly, a suspension system, and a method. Background Technology

[0002] As vehicles become increasingly intelligent, the requirements for ride comfort, handling stability, and off-road capability are becoming more stringent. Active suspension systems, which can proactively adjust vehicle height, stiffness, and damping according to road conditions, have become one of the core technologies of high-end intelligent chassis.

[0003] Existing active hydraulic suspension systems for vehicles typically use a servo motor and a rotary hydraulic pump as their power source. The motor drives the hydraulic pump to draw oil from the tank, build up high pressure, and then distribute it to the hydraulic cylinders through a complex servo valve assembly to achieve vehicle attitude control. However, this traditional rotary pump-valve control architecture has significant limitations: First, it suffers from low system integration and insufficient energy efficiency. It not only includes numerous components such as a motor, pump, tank, and filter, resulting in complex piping, but also relies on throttle or relief valves for control, leading to significant throttling and relief losses, and generally low system energy utilization. Second, it has extremely high requirements for the cleanliness of the medium, limiting the application of smart fluids. Rotary hydraulic pumps rely on precisely matched moving parts to build pressure, making them extremely sensitive to the cleanliness of the hydraulic oil. This directly prevents the use of smart fluids containing micron-sized solid particles—such as magnetorheological fluids—in such systems. Even in existing electro-hydraulic actuators (EHA) commonly used in ball screw direct-drive pumps, if magnetorheological fluid is used directly as the working medium, magnetic particles will infiltrate the raceways of the screw and nut assembly, leading to severe abrasive wear and jamming. This is the core technical bottleneck that currently hinders the expansion of magnetorheological technology from "vibration dampers" to "pump-controlled circulation systems." Once magnetorheological fluid is pumped into a rotary pump, magnetic particles will rapidly cause abrasive wear on the pump's internal components, leading to internal leakage or even jamming.

[0004] CN116901636A discloses a vehicle vibration damping control system and method based on magnetorheological hydro-pneumatic springs. However, despite the progress made by the aforementioned prior art at the fluid logic control level, unresolved technical bottlenecks remain at the "power source" level. First, this solution is essentially still a semi-active or passive interconnected system. The flow of fluid within the system mainly relies on road excitation causing wheel bounce, thereby compressing / stretching the hydro-pneumatic spring to generate a pressure difference, or on the passive release of energy from an accumulator. It lacks a power unit that can actively and continuously inject large-flow, high-pressure fluid into the system. Therefore, this system is difficult to achieve large-range active and rapid raising and lowering of the vehicle body height, and it cannot actively adjust the vehicle body posture when stationary. Second, although this solution uses magnetorheological fluid, it avoids the "pumping" problem. As mentioned earlier, since existing rotary hydraulic pumps cannot deliver magnetorheological fluid, current magnetorheological suspension systems are mostly limited to the level of shock absorbers or interconnected valves, and cannot build a true pump-controlled active magnetorheological suspension.

[0005] Therefore, the industry urgently needs a new type of electro-hydraulic power unit and suspension architecture. This architecture must eliminate the wear sensitivity of traditional rotary pumps, enabling direct pumping of intelligent fluids such as magnetorheological fluids; it must also possess the high precision and high energy efficiency of direct drive by servo motors, thus achieving "pump-controlled cylinder" type active adjustment without relying on complex valve control circuits.

[0006] Furthermore, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making this invention, but due to space limitations, not all details and contents were listed in detail. However, this does not mean that the present invention does not possess the features of these prior art. On the contrary, the present invention already possesses all the features of the prior art, and the applicant reserves the right to add relevant prior art to the background art. Summary of the Invention

[0007] To address the limitations and shortcomings of the motor and hydraulic pump solutions mentioned in the background section, this invention proposes an integrated, direct-drive technical solution: an electro-hydraulic power unit based on a motor and hydraulic cylinder, a suspension system, and a vehicle equipped with the electro-hydraulic power unit and suspension system.

[0008] This invention relates to an electro-hydraulic power unit for a vehicle suspension system, comprising: a motor assembly including a motor housing, a motor stator, and a motor rotor, the motor stator being fixed inside the motor housing; a mechanical transmission assembly disposed inside the motor assembly, including a lead screw and a nut that cooperate with each other; a hydraulic pumping assembly fixedly connected to or integrally formed with the motor housing, including at least one piston cylinder and a piston located within the piston cylinder; a motion conversion structure, wherein the motor rotor is fixedly connected to one of the lead screw or nut to drive its rotation; the other of the lead screw or nut has its rotational freedom restricted and only retains its axial movement freedom, and the other is drively connected to the piston; a fluid output structure, wherein the piston divides the piston cylinder into at least one sealed chamber for containing a transmission fluid, the sealed chamber including a first oil chamber and a second oil chamber, and the sealed chamber is provided with a fluid port for communicating with an external load, the fluid port including a first oil port and a second oil port; the motor assembly drives the mechanical transmission assembly to directly push the piston to perform reciprocating linear motion within the piston cylinder, thereby outputting or drawing in pressurized transmission fluid through the first oil port and the second oil port.

[0009] According to a preferred embodiment, the threaded transmission pair formed by the screw and nut fitting together is a rolling thread pair, which is selected from a ball screw pair or a roller screw pair; the piston is provided with a first seal and a second seal to seal the first oil chamber and the second oil chamber.

[0010] According to a preferred embodiment, the motion conversion structure adopts a rotor direct-drive nut configuration: the motor rotor is coaxially fixed to the nut and drives the nut to rotate; the lead screw is restricted from rotating, and one or both ends of the lead screw are fixed to the piston; the lead screw moves linearly along the axial direction under the drive of the nut and drives the piston to move.

[0011] According to a preferred embodiment, the electro-hydraulic power unit has a horizontally opposed structure, and the hydraulic pumping assembly includes a first piston cylinder and a second piston cylinder coaxially arranged on both sides of the motor assembly; the two ends of the lead screw are respectively connected to the first piston and the second piston; the first piston and the second piston move synchronously to change the volume of the first oil chamber and the second oil chamber respectively.

[0012] According to a preferred embodiment, the motion conversion structure adopts a rotor direct-drive screw configuration: the motor rotor is coaxially fixed to the screw and drives the screw to rotate; the nut is restricted from rotating, and the nut is directly or through a hollow piston rod to drive the piston; the nut moves linearly along the axial direction under the drive of the screw and drives the piston to move.

[0013] According to a preferred embodiment, it further includes an anti-rotation device, which is an anti-rotation pin or groove disposed inside the piston cylinder or the motor housing, used to limit the rotational freedom of the lead screw or nut about its central axis.

[0014] According to a preferred embodiment, the motor assembly further includes a support bearing, which includes a first bearing, a second bearing, a third bearing, or a fourth bearing, for supporting the rotational movement of the motor rotor or lead screw and bearing axial reaction force; the support bearing is confined within a bearing shoulder of the motor housing or piston cylinder.

[0015] According to a preferred embodiment, it further includes a motor driver, which is integrated with or independently arranged with the motor housing, and is used to control the intensity and direction of the electromagnetic field generated by the motor stator.

[0016] According to a preferred embodiment, the transmission fluid includes hydraulic oil, magnetorheological fluid, or electrorheological fluid; when the transmission fluid is magnetorheological fluid, the first seal between the piston and the inner wall of the piston cylinder is made of wear-resistant material, and the lead screw and nut are physically isolated from the magnetorheological fluid.

[0017] According to a preferred embodiment, the motor housing coincides with the central axis of the piston cylinder; the piston, lead screw, and motor rotor share a common central axis.

[0018] The electro-hydraulic power unit provided by this invention adopts a direct-drive structure where the motor directly drives the piston via a lead screw and nut transmission pair. Volumetric pumping is achieved through the linear reciprocating motion of the piston within the cylinder. This design eliminates the complex rotating friction pairs found in traditional rotary hydraulic pumps (such as gear pumps and piston pumps), fundamentally solving the wear and internal leakage problems that easily occur when rotary pumps transport fluids containing solid particles (such as magnetorheological fluids). This allows the power unit to be compatible with hydraulic oils requiring high cleanliness and intelligent fluids containing micron-sized magnetic particles. In particular, this invention uses a piston seal to divide the piston cylinder into a "fluid chamber" and a "mechanical chamber," confining the magnetorheological fluid within the fluid chamber while placing precision transmission components such as the lead screw, nut, and bearings within the mechanical chamber for physical isolation. This structure cleverly solves the industry problem of magnetorheological fluid particle wear on mechanical transmission pairs, making it possible to actively pump magnetorheological fluids without sacrificing lifespan. Meanwhile, this unit highly integrates the motor, transmission mechanism and hydraulic cylinder, eliminating the oil tank, filter and redundant pipelines in traditional hydraulic stations. This not only significantly reduces the size and weight and improves the power density, but also eliminates dead zone and nonlinearity by utilizing the high controllability of the servo motor, achieving efficient and high-precision hydraulic energy output without throttling loss.

[0019] Another aspect of the present invention relates to a vehicle active suspension system, comprising the aforementioned electro-hydraulic power unit; a hydraulic actuator connected between the vehicle body and the wheels, selected from an electronically controlled hydraulic cylinder, a magnetorheological damper, or an electronically controlled damper; a fluid transmission circuit connecting the first and second ports of the electro-hydraulic power unit to the working chamber of the hydraulic actuator via hydraulic pipelines; and system control logic, wherein the electro-hydraulic power unit acts as a hydraulic volume generator of the system, directly adjusting the volume of fluid entering or leaving the hydraulic actuator by changing the position of the piston in the piston cylinder, thereby actively changing the relative height or force between the vehicle body and the wheels; wherein the transmission fluid circulates in a closed loop formed between the electro-hydraulic power unit and the hydraulic actuator.

[0020] According to a preferred embodiment, the suspension system is an independent active suspension system, the first oil port of the electro-hydraulic power unit is connected to the hydraulic actuator corresponding to the left wheel, and the second oil port of the electro-hydraulic power unit is connected to the hydraulic actuator corresponding to the right wheel or the right air tank.

[0021] According to a preferred embodiment, the suspension system is an interconnected active suspension system, including a left electro-hydraulic cylinder and a right electro-hydraulic cylinder; the electro-hydraulic power unit controls the fluid flow between the rod-side or rodless side chambers of the left and right electro-hydraulic cylinders through hydraulic lines to achieve cross-adjustment or synchronous adjustment of the vehicle height.

[0022] According to a preferred embodiment, the system also includes an energy storage device, which is a left gas storage tank, a right gas storage tank, or a bellows-type energy storage device, used to compensate for fluid volume changes or provide back pressure within the system; the energy storage device is connected to the fluid transmission loop via a pipeline.

[0023] According to a preferred embodiment, the fluid transmission circuit also integrates a left first electrically controlled damping valve, a right first electrically controlled damping valve, a left second electrically controlled damping valve, a right second electrically controlled damping valve, or an electro-hydraulic valve group, for changing the on / off state of the pipeline or adjusting the fluid damping characteristics.

[0024] According to a preferred embodiment, the hydraulic actuator is a magnetorheological damper, which includes an internally integrated electromagnet, a springback channel, and a compression channel; the magnetorheological damper has a semi-active damping mode and an active height adjustment mode.

[0025] According to a preferred embodiment, in the active height adjustment mode, the rebound channel and compression channel inside the magnetorheological damper are restricted from flowing under the action of a magnetic field, and the magnetorheological fluid pumped in by the electro-hydraulic power unit drives the left piston rod of the magnetorheological damper to extend and retract.

[0026] According to a preferred embodiment, the device further includes a hydraulic lock device, which includes a first hydraulically controlled check valve and a second hydraulically controlled check valve, disposed between the electro-hydraulic power unit and the hydraulic actuator, for maintaining the suspension height when the motor stops working.

[0027] According to a preferred embodiment, the device further includes an electrically controlled high-speed switching valve connected between the rod-side and rodless sides of the hydraulic actuator for rapidly switching the fluid communication path.

[0028] According to a preferred embodiment, it further includes a left safety valve or a right safety valve, which are respectively disposed inside the piston of their respective hydraulic cylinders.

[0029] The active suspension system provided by this invention utilizes an electro-hydraulic power unit as the core volume generator to construct a closed-loop fluid circulation circuit, enabling active adjustment of vehicle height and attitude. Compared with traditional valve control systems, this system does not rely on throttle valves or servo valves for pressure distribution. Instead, it directly controls the fluid volume entering the actuator to change the vehicle's attitude, eliminating throttling and overflow losses and significantly improving system energy efficiency. Furthermore, the system architecture supports independent or interconnected layouts. Flexible piping connections and simple on / off control enable energy coupling between wheels (such as anti-roll and anti-pitch), greatly improving vehicle handling stability and passability while ensuring ride comfort. The system response speed is primarily limited by the motor response, achieving millisecond-level rapid adjustment capabilities.

[0030] Another aspect of the present invention relates to a fluid control valve assembly based on magnetorheological effect, which is applied to the aforementioned vehicle active suspension system, comprising: a fluid channel network including a fluid inlet, a fluid outlet, and at least two parallel branches connecting the inlet and outlet; a magnetorheological valve unit including a first magnetorheological valve, a second magnetorheological valve, a third magnetorheological valve, and a fourth magnetorheological valve, respectively arranged in the parallel branches, the magnetorheological valve unit being filled with magnetorheological fluid; a magnetic field generating device independently configured in each magnetorheological valve unit for applying a variable magnetic field to the corresponding magnetorheological fluid; and a logic control unit for adjusting the magnetic field strength of the magnetic field generating device, causing the magnetorheological valve unit to switch between a conduction mode and a clamping mode; wherein, in the clamping mode, the magnetic field strength reaches a critical value, causing the magnetorheological fluid to form a solid plug with yield stress inside the valve, thereby physically blocking the fluid flow in that branch; the logic control unit controls the flow direction of the fluid in the fluid channel network by combining the conduction and clamping states of the magnetorheological valve units on different branches, thereby replacing the reversing function of a mechanical directional valve.

[0031] According to a preferred embodiment, the operating modes of the first magnetorheological valve, the second magnetorheological valve, the third magnetorheological valve, and the fourth magnetorheological valve also include a shearing mode, a valve mode, and a compression mode.

[0032] According to a preferred embodiment, the fluid channel network includes a first group of magnetorheological valves and a second group of magnetorheological valves. The first group of magnetorheological valves includes a first magnetorheological valve and a second magnetorheological valve, and the second group of magnetorheological valves includes a third magnetorheological valve and a fourth magnetorheological valve, forming a bridge-type loop structure.

[0033] According to a preferred embodiment, the fluid control valve assembly has a first operating mode: the third and fourth magnetorheological valves are in a clamping mode to stop the flow, and the first and second magnetorheological valves are in a conducting mode to allow the fluid to flow in a first direction.

[0034] According to a preferred embodiment, the fluid control valve assembly has a second operating mode: the first and second magnetorheological valves are in a clamping mode to stop the flow, and the third and fourth magnetorheological valves are in a conducting mode to allow the fluid to flow in a second direction.

[0035] According to a preferred embodiment, the fluid control valve assembly has a third operating mode: the first magnetorheological valve, the second magnetorheological valve, the third magnetorheological valve, and the fourth magnetorheological valve are all in a clamping mode, which completely shuts off the fluid channel network and achieves fluid interlocking.

[0036] According to a preferred embodiment, the fluid channel network further includes a third group of magnetorheological valves, which includes a fifth magnetorheological valve and a sixth magnetorheological valve, and cooperates with the first group of magnetorheological valves and the second group of magnetorheological valves to form a multi-path switching structure.

[0037] According to a preferred embodiment, a magnetorheological valve unit is connected in series with a check valve to form a left first electrically controlled damping valve and a left second electrically controlled damping valve with unidirectional flow control function.

[0038] According to a preferred embodiment, the fluid control valve assembly is used to control the cross-connection or independent control between the rod-side and rodless sides of the left and right electro-hydraulic cylinders in the vehicle's active suspension system.

[0039] According to a preferred embodiment, the magnetorheological fluid contains micron-sized magnetic particles, and the critical magnetic field strength generated by the magnetic field generator is sufficient to enable the magnetic particles to form a chain-like structure capable of withstanding the system's operating pressure.

[0040] The fluid control valve assembly based on magnetorheological effect provided by this invention innovatively utilizes the "pinch mode" generated by magnetorheological fluid under a critical magnetic field to form a solid plug with yield stress, thereby achieving physical shut-off of the fluid channel. This "no moving parts" valve body design completely replaces traditional mechanical directional valves (such as slide valves and seat valves), completely eliminating the failure risk caused by wear, jamming, or fatigue of mechanical valve cores, and greatly improving the reliability and service life of the valve assembly. At the same time, through the combination and adjustment of the magnetic field strength of different branches by the logic control unit, the valve assembly can flexibly construct a Wheatstone bridge-type fluid circuit to achieve rapid switching of flow direction and logical control, and has extremely fast response speed and continuously adjustable damping characteristics, providing a highly integrated, highly responsive, and wear-resistant intelligent solution for fluid control systems.

[0041] Another aspect of the present invention relates to an active method for adjusting vehicle body height, based on the aforementioned electro-hydraulic power unit. The method includes the following steps: Command receiving step: receiving a vehicle body height adjustment signal and determining the target adjustment direction as raising or lowering; Motor driving step: according to the target adjustment direction, controlling the stator of the electro-hydraulic power unit to generate an electromagnetic field, driving the motor rotor to rotate clockwise or counterclockwise; Motion conversion step: utilizing the threaded engagement of the lead screw and nut, converting the rotational motion of the motor rotor into the axial linear feed motion of the piston within the piston cylinder; Volumetric pumping step: the linear feed motion of the piston directly compresses the transmission fluid within the piston cylinder, causing it to flow into or out of the hydraulic actuator connected to the wheel via the first oil port; Height changing step: utilizing the incompressibility of the transmission fluid, the volume of the flowing or flowing fluid directly pushes the hydraulic actuator to extend or retract, thereby changing the vehicle body height.

[0042] According to a preferred embodiment, in the motor drive step, the piston's movement speed is adjusted by controlling the motor's rotational speed, thereby controlling the rate of vehicle height adjustment.

[0043] According to a preferred embodiment, in the height change step, when it is necessary to raise the vehicle body, the electro-hydraulic power unit pumps transmission fluid into the rodless or rod-type chamber of the hydraulic actuator to do work against the weight of the vehicle body and / or the pressure of the energy storage device, which is a bellows-type energy storage device or an air tank.

[0044] According to a preferred embodiment, during the height-changing step, when it is necessary to lower the vehicle body, the electro-hydraulic power unit rotates in the reverse direction, allowing the transmission fluid to flow back to the piston cylinder under the action of the vehicle body's gravity or the pressure of the energy storage device, and recovering part of the gravitational potential energy.

[0045] According to a preferred embodiment, the method further includes a position holding step: when the vehicle body reaches the target height, for short-term holding, the magnetorheological valve group can be controlled to enter the clamping mode or the motor can be controlled to generate holding torque; for long-term holding, the pipeline is closed by using the first hydraulic check valve and the second hydraulic check valve to keep the piston in a fixed position, thereby avoiding the slight creep leakage of the magnetorheological fluid under high pressure differential.

[0046] According to a preferred embodiment, the method is applied to an interconnected active suspension system and includes a cross-control step: controlling the electro-hydraulic power unit to move the transmission fluid from the left hydraulic actuator to the right hydraulic actuator, thereby raising one side of the vehicle body while lowering the other side.

[0047] According to a preferred embodiment, the method further includes a semi-active vibration reduction step: when no height adjustment is performed, the electro-hydraulic power unit is controlled to stop working, and the road surface vibration is attenuated by utilizing the damping characteristics of the hydraulic actuator itself or by adjusting the external left first electro-hydraulic damping valve.

[0048] According to a preferred embodiment, the transmission fluid is a magnetorheological fluid, and the method includes a valve group control step: while adjusting the height, controlling the magnetorheological valve group to enter a clamping mode or a conducting mode to selectively connect a specific fluid circuit.

[0049] According to a preferred embodiment, the method utilizes the yield stress characteristics of magnetorheological fluid to achieve pressure holding and locking of the hydraulic system by controlling the magnetorheological valve assembly in a clamping mode.

[0050] According to a preferred embodiment, the instruction receiving step further includes receiving vehicle sensor signals and automatically calculating the target adjustment direction and adjustment amount based on the vehicle's pitch and roll states.

[0051] The vehicle height active adjustment method provided by this invention precisely controls the rotation angle and speed of the motor rotor, converting this into a quantitative linear displacement of the piston via a precision lead screw drive. Utilizing the incompressibility of liquids, it achieves precise control of the extension and retraction of the suspension actuator. This method decouples the complex vehicle attitude control task into a precisely measurable volumetric pumping process, resulting in a smooth, shock-free height adjustment process that is easily integrated with vehicle dynamics algorithms. Furthermore, this method supports on-demand energy allocation, consuming electrical energy only when height adjustment is needed. When maintaining height, it utilizes the self-locking characteristics of mechanical transmission pairs or a hydraulic lock to achieve zero-energy pressure maintenance. Compared to traditional continuous oil supply control strategies, this significantly reduces the overall vehicle energy consumption and heat generation.

[0052] Another aspect of the present invention relates to a wear-resistant magnetorheological fluid circulation drive system, comprising: a transmission medium, which is a magnetorheological fluid containing micron-sized magnetic particles; a direct-drive pump source, including a motor stator, a lead screw, a nut, and a piston; a magnetorheological actuator, which forms a closed circulation loop with the direct-drive pump source through a pipeline; the direct-drive pump source adopts a non-rotating positive displacement pumping structure, and the motor stator drives the piston to make linear motion through the lead screw and nut to pump the magnetorheological fluid; a first seal is provided between the piston and the cylinder wall, and the linear motion of the piston directly pumps the magnetorheological fluid into the magnetorheological actuator, while the lead screw and nut are physically isolated from the magnetorheological fluid; thereby realizing the circulation flow and pressure transmission of the magnetorheological fluid in the system without using a rotary hydraulic pump.

[0053] According to a preferred embodiment, the piston divides the inner cavity of the direct-drive pump source into a first oil cavity and a mechanical cavity, the magnetorheological fluid is only filled in the first oil cavity, and the lead screw and nut are located in the mechanical cavity.

[0054] According to a preferred embodiment, a magnetorheological valve group or a left first electrically controlled damping valve is provided on the pipeline between the direct-drive pump source and the magnetorheological actuator to control the flow resistance or on / off state of the magnetorheological fluid.

[0055] According to a preferred embodiment, the magnetorheological actuator is a magnetorheological damper, which has an electromagnet inside for changing the apparent viscosity of the magnetorheological fluid.

[0056] According to a preferred embodiment, the system further includes a bellows-type accumulator for accommodating changes in magnetorheological fluid volume caused by temperature variations or system operation, and for isolating external gases from the magnetorheological fluid.

[0057] According to a preferred embodiment, the direct-drive pump source has a dual-rod or dual-piston structure to ensure the flow balance of the pumped and sucked magnetorheological fluid, or to compensate for the flow difference through an accumulator.

[0058] According to a preferred embodiment, the first seal is made of a wear-resistant polymer material and is configured as a lip seal or a combination seal to prevent micron-sized magnetic particles from entering the area where the lead screw and nut are located.

[0059] According to a preferred embodiment, the motor in the direct-drive pump source is a servo motor, which achieves stepless adjustment of the magnetorheological fluid flow rate by precisely controlling the rotation angle and speed.

[0060] According to a preferred embodiment, the circulation loop does not include a rotary hydraulic pump component, thus avoiding wear of the rotating blades or gears by magnetic particles and sedimentation or deterioration of the magnetorheological fluid under high-speed shear.

[0061] According to a preferred embodiment, the system is applied to a vehicle suspension, driving the vehicle body to rise and fall by pumping magnetorheological fluid, and achieving stiffness and damping adjustment by magnetic field control.

[0062] The anti-wear magnetorheological fluid circulation drive system provided by this invention specifically solves the industry problem of the difficulty in long-term stable application of magnetorheological fluid in active circulation systems. By adopting a non-rotating direct-drive volumetric pumping structure and combining it with elastic seals on the piston to achieve physical isolation between the magnetorheological fluid and the precision mechanical transmission pairs (lead screw, nut), the system successfully prevents micron-sized hard magnetic particles from intruding into the transmission area and causing abrasive wear. This design allows the vehicle suspension system to simultaneously utilize the "intelligent variable damping characteristics" and "hydraulic transmission characteristics" of the magnetorheological fluid, achieving a perfect integration of fully active power control and semi-active damping adjustment, breaking through the technical bottleneck of existing technologies where magnetorheological fluid can only be used in shock absorbers and not in pump-controlled circulation systems.

[0063] In this invention, the motor directly drives the piston rod and / or piston of the hydraulic cylinder via a mechanical transmission mechanism. The hydraulic cylinder in this solution primarily functions as a compact hydraulic volume generator, rather than a traditional actuator. This solution offers the following advantages:

[0064] 1) The system has a simplified structure, mainly consisting of a motor, transmission mechanism, and hydraulic cylinder, eliminating the need for an oil tank and most valves. Furthermore, it has a very compact structure, is easy to modularly design, has few leakage points, and an aesthetically pleasing appearance.

[0065] 2) High mechanical efficiency, no throttling or overflow losses, the motor only consumes energy when it needs to operate, and the system efficiency can reach 80%-90% or even higher.

[0066] 3) Thanks to the high-precision position / speed control of the servo motor and the high thrust characteristics of the lead screw drive, the system can overcome the static friction caused by the high-pressure seal, easily achieve micron-level displacement control and smooth low-speed motion, and has a fast response.

[0067] 4) The motor starts and stops on demand, with low noise; low energy loss and low heat generation.

[0068] 5) The transmission fluid can be a liquid containing magnetic particles, such as magnetorheological fluid or electrorheological fluid.

[0069] According to a preferred embodiment, an electro-hydraulic power unit of the present invention includes: a motor, a hydraulic cylinder, a lead screw, a nut, and a bearing; the motor is used to output rotational torque, which can be transmitted and drive the nut or lead screw to rotate; the motor includes at least one pair of motor rotors and motor stators, a motor housing and bearings for mounting the motor, and a circuit board or driver for controlling the motor.

[0070] Specifically, the circuit board or driver controlling the motor can be integrated with the electro-hydraulic power unit or placed in other positions in the vehicle suspension system; the lead screw and nut are fitted together to form a threaded transmission pair, and either the lead screw or the nut can be directly or indirectly mechanically connected to the motor rotor. Thus, the motor rotor rotates under the action of electromagnetic force, which can drive the lead screw or nut to rotate.

[0071] Specifically, when the lead screw rotates, it can drive the nut to move linearly; conversely, when the nut rotates, it can also drive the lead screw to move linearly.

[0072] Threaded drive pairs can be sliding thread pairs or rolling thread pairs. Rolling thread pairs can be composed of "ball screws and ball nuts" or "roller screws and roller nuts".

[0073] At least one hydraulic cylinder includes at least one piston cylinder, piston rod, piston, and seals; the piston is used to push the transmission fluid in the piston cylinder, forcing the transmission fluid to flow into or out of the piston cylinder; the transmission fluid is contained in the piston cylinder inner chamber separated by the piston, and the inner chamber has several fluid ports that communicate with external fluid devices.

[0074] Specifically, transmission fluids are used to transmit mechanical energy. Hydraulic oil, magnetorheological fluid, and electrorheological fluid can all be used as transmission fluids for electrohydraulic power units.

[0075] Preferably, the screw-nut threaded transmission pair can be a rolling thread pair, wherein the rolling thread pair can be composed of a ball screw and a ball nut, or it can be composed of a roller screw and a roller nut.

[0076] According to a preferred embodiment, the motor rotor can be kept relatively fixed to the nut, so that when the rotor rotates, it can drive the nut to rotate around the axis.

[0077] Specifically, the nut and the lead screw are a set of threaded transmission pairs, and when the motor rotor and the nut can only rotate together, the lead screw can only move linearly along its central axis.

[0078] According to a preferred embodiment, the motor rotor can also be kept relatively fixed to the lead screw, and when the motor rotor rotates, it drives the lead screw to rotate around the axis. When the motor rotor and the lead screw can only rotate together, the nut can only move linearly along its central axis.

[0079] Specifically, the lead screw or nut is provided with several anti-rotation grooves, which restrict its rotational movement around the axis by several anti-rotation devices fixed inside the piston cylinder.

[0080] According to a preferred embodiment, the piston cylinder and the motor housing are designed as a single unit, the piston rod is a hollow piston rod, and the motor stator is fixed to the motor housing to maintain relative fixation or fixed inside the piston cylinder.

[0081] The piston's movement within the piston cylinder compresses the hydraulic fluid, forcing it to flow in or out of the cylinder. The hydraulic fluid is housed in a piston cylinder chamber separated by the piston, and this chamber has several fluid ports connecting to external hydraulic systems.

[0082] The motor housing and the piston cylinder have one or more relative positional relationships, and the motor rotor has one or more relative positional relationships with the lead screw and nut.

[0083] Preferably, the motor housing is designed to coincide with the central axis of the piston cylinder, using the central axis of the piston cylinder as a reference. Similarly, the motor rotor is designed to coincide with the central axes of the lead screw and nut, using the central axis of the motor rotor as a reference.

[0084] Preferably, when the piston and the lead screw are fixedly connected, the motor rotor drives the nut to rotate around their common central axis, while the lead screw moves linearly along its central axis. Furthermore, under the "push-pull" force of the lead screw, the piston also moves linearly along its central axis.

[0085] When the piston and nut are fixed together, the motor rotor drives the lead screw to rotate around their common central axis, while the nut moves linearly along its central axis. Consequently, under the "push-pull" force of the nut, the piston also moves linearly along its central axis.

[0086] According to a preferred embodiment, the bearing is used to limit the linear motion of the motor rotor, nut, or lead screw along its central axis.

[0087] According to a preferred embodiment, the present invention provides a suspension system comprising an electro-hydraulic power unit as described above, and an electronically controlled shock absorber, a magnetorheological shock absorber, or a hydraulic cylinder connected to a hydraulic cylinder in the electro-hydraulic power unit.

[0088] Specifically, the electro-hydraulic power unit can work together with the elastic elements in the suspension system to control the motion state of the suspension. Electronically controlled shock absorbers, magnetorheological shock absorbers, or hydraulic cylinders can selectively achieve various forms of connection, coupling, or decoupling modes through pipelines, hydraulic valve groups or magnetorheological valve groups, energy storage devices, and other auxiliary components.

[0089] According to a preferred embodiment, a magnetorheological valve assembly includes one or more magnetorheological valves; specifically, the operating modes of the magnetorheological valves include pinch mode, direct-shear mode, valve mode, and squeeze mode; preferably, a magnetorheological valve having a pinch mode is selected.

[0090] Magnetorheological valves are used to restrict the flow state of transmission fluids, especially the viscosity and flow or circulation state of magnetorheological fluids in electrohydraulic power units;

[0091] Magnetorheological valves can be combined into magnetorheological valve assemblies to replace "multi-position, multi-pass" directional valves such as hydraulic directional valves, hydraulic proportional valves, and hydraulic servo valves in hydraulic systems.

[0092] Magnetorheological valve assemblies have different operating modes for changing the connection between the rodless and rod chambers of one or more electronically controlled vibration dampers, magnetorheological vibration dampers, or hydraulic cylinders.

[0093] The connection methods include: connection between rod-shaped cavities or connection between rod-shaped cavities and rodless cavities.

[0094] According to a preferred embodiment, the present invention provides a vehicle comprising any of the above-mentioned electro-hydraulic power unit, suspension system, magnetorheological valve, and magnetorheological directional valve. The vehicle may be, but is not limited to, amphibious vehicles, land vehicles, flying vehicles, and rail vehicles, or other types of vehicles. Attached Figure Description

[0095] Figure 1 This is a schematic diagram of the preferred horizontally opposed electro-hydraulic power unit of the present invention.

[0096] Figure 2 This is a schematic diagram of the preferred structure of a direct-drive electro-hydraulic power unit of the present invention;

[0097] Figure 3 This is a schematic diagram of a preferred independent active suspension system based on an electro-hydraulic power unit according to the present invention.

[0098] Figure 4 This is a schematic diagram of a preferred embodiment of the interconnected active suspension system based on an electro-hydraulic power unit according to the present invention.

[0099] Figure 5 This is a schematic diagram of a preferred embodiment of the interconnected and releasable active suspension system based on an electro-hydraulic power unit according to the present invention.

[0100] Figure 6 This is a schematic diagram of the preferred independent active suspension system of the present invention, which integrates a magnetorheological damper and an electro-hydraulic power unit.

[0101] Figure 7 This is a schematic diagram of the preferred independent active suspension system of the present invention, which integrates an external dual magnetorheological valve actuator and an electro-hydraulic power unit.

[0102] Figure 8 This is a schematic diagram of the preferred embodiment of the present invention: an interconnected active suspension system integrating a magnetorheological damper and an electro-hydraulic power unit.

[0103] Figure 9 This is a schematic diagram of the preferred embodiment of the present invention: an interconnected active suspension system integrating an external dual magnetorheological valve actuator and an electro-hydraulic power unit.

[0104] Figure 10 This is a schematic diagram of a preferred active suspension system with a hydraulic lock and a high-speed switching valve according to the present invention.

[0105] Figure 11 A schematic diagram of a preferred embodiment of the present invention, which is based on two sets of magnetorheological valves and has three working modes, is shown.

[0106] Figure 12 The diagram shows a preferred embodiment of the present invention, which is a magnetorheological valve assembly with four operating modes based on three sets of magnetorheological valves.

[0107] List of reference numerals

[0108] 101: Motor housing; 102: Motor stator; 103: Motor rotor; 104: Motor driver; 201: Piston cylinder; 201a: First piston cylinder; 201b: Second piston cylinder; 202: Piston; 202a: First piston; 202b: Second piston; 203a: First seal; 203b: Second seal; 203c: Third seal; 204a: First oil chamber; 204b: Second oil chamber; 205a: First oil port; 205b: Second oil port; 205c: Left second pipeline branch; 205d: Left first pipeline branch; 205e: Right second pipeline branch; 205f: Right first pipeline branch; 301: Lead screw; 302: Nut; 303: Hollow actuator Plug rod; 303a: First bearing; 303b: Second bearing; 304: Anti-rotation pin; 304a: Third bearing; 304b: Fourth bearing; 401a: Left electro-hydraulic cylinder; 4011: Left magnetorheological damper; 401b: Right electro-hydraulic cylinder; 4012: Right magnetorheological damper; 401c: Left compression chamber; 401d: Left spring chamber; 401e: Right spring chamber; 401f: Right compression chamber; 402a: Left piston rod; 402b: Right piston rod; 402c: Left power supply line; 402d: Right power supply line; 403a: Left piston; 403b: Right piston; 403c: Left floating piston; 403d: Right floating piston; 404a: Left safety valve; 404b: Right safety valve; 404c: Left compression channel; 404d: Left electromagnet; 404e: Left springback channel; 404f: Right springback channel; 404g: Right electromagnet; 404h: Right compression channel; 405: Bellows accumulator; 405a: Left air tank; 405b: Right air tank; 405c: Left internal air tank; 405d: Left bellows accumulator; 405e: Right bellows accumulator; 409a: First hydraulically controlled check valve; 409b: Second hydraulically controlled check valve; 409c: First hydraulically controlled pipeline; 409d: Second hydraulically controlled pipeline; P1: First oil circuit; P2: Second oil circuit; P3: Third oil circuit; P4: Fourth oil circuit; 501: Left first electrically controlled damping valve 502: Right first electro-hydraulic damping valve; 503: Left second electro-hydraulic damping valve; 504: Right second electro-hydraulic damping valve; 505: Electro-hydraulic valve assembly; 505n: Magnetorheological valve assembly; 505a: First magnetorheological valve; 505b: Second magnetorheological valve; 505c: Third magnetorheological valve; 505d: Fourth magnetorheological valve; 505e: Fifth magnetorheological valve; 505f: Sixth magnetorheological valve; 506: Electro-controlled high-speed switching valve; 506a: Left first electro-hydraulic high-speed switching valve; 506b: Right first electro-hydraulic high-speed switching valve; 601a: Left load-bearing unit; 601b: Right load-bearing unit; 602a: Left side of the vehicle body; 602b: Right side of the vehicle body; 603a: Left wheel; 603b: Right wheel. Detailed Implementation

[0109] The following is a detailed explanation with reference to the accompanying drawings.

[0110] Example 1

[0111] According to a preferred embodiment, such as Figure 1 As shown, this invention discloses a horizontally opposed electro-hydraulic power unit. This embodiment is based on an innovative design with a dual-piston hydraulic cylinder and an integrated motor, combined with a mechanical transmission assembly consisting of a lead screw and a nut, to achieve the function of synchronous and active movement of the two pistons inside the piston cylinder. The specific mechanical design is described below:

[0112] The motor stator 102 is fixedly installed inside the motor housing 101 and is coaxially and fixedly connected to the first piston cylinder 201a and the second piston cylinder 201b. The direct-drive electro-hydraulic power unit has a motor assembly, a mechanical transmission assembly and a hydraulic pumping assembly. The motor assembly and the mechanical transmission assembly form a coaxial nested structure within the drying mechanical cavity defined by the motor housing 101, which gives the drying mechanical cavity the characteristic of physically isolating the magnetorheological fluid. This is fundamentally different from the existing technology such as FP1531039A2, where the motor and hydraulic parts are arranged separately and cannot handle fluids containing particles. Specifically, the motor assembly includes a motor housing 101, a motor stator 102, a motor rotor 103, and a first bearing 303a and a second bearing 303b. The first bearing 303a and the second bearing 303b can establish a radial rigid support relationship when the motor stator 102 is energized, so that the motor rotor 103 is stably fixed to the bearing shoulder of the inner wall of the motor housing 101 in a rotatable posture, thereby ensuring that a constant electromagnetic air gap is maintained between the motor rotor 103 and the motor stator 102.

[0113] Furthermore, the motor rotor 103 is connected to the outside of the nut 302 with an internal circulating raceway via an interference fit or key connection. The nut 302 is axially abutted against the first bearing 303a, restricting its axial displacement, allowing the nut 302 to undergo a rotational-linear motion conversion with the lead screw 301 passing through it. The lead screw 301 has a first piston 202a and a second piston 202b fixedly connected to its ends. The first piston 202a and the second piston 202b can establish an axially synchronized feed relationship when the nut 302 is in a rotationally driven state, allowing the lead screw 301 and its connecting components to suspend within the mechanical cavity as purely linear motion components.

[0114] The first piston 202a is in a reciprocating linear motion position within the first piston cylinder 201a, allowing the first oil chamber 204a and the mechanical chamber to undergo complementary volume changes. The first seal 203a is in a dynamically sealed position in the presence of micron-sized magnetic particles, physically isolating the magnetorheological fluid from the precision threaded transmission pair. In this configuration, the electro-hydraulic power unit converts the mechanical energy generated by the motor rotation into the hydraulic energy of the magnetorheological fluid; the first seal 203a prevents particle intrusion; and the mechanical transmission assembly transmits thrust. Specifically, when the motor rotor 103 rotates at high speed, it coaxially transmits torque with the nut 302 under the condition of the first bearing 303a. When the magnetorheological fluid is pumped at high pressure, the first seal 203a, due to its wear-resistant material properties, scrapes and seals against the inner wall of the piston cylinder 201. And / or, when the lead screw 301 is subjected to axial reaction force, the nut 302 transmits thrust to the lead screw 301 without lateral force according to rolling friction.

[0115] A first seal 203a is installed on the first piston 202a to ensure that a first oil chamber 204a is generated after the first piston 202a and the first piston cylinder 201a cooperate. The first oil chamber 204a is located on the side of the first piston 202a away from the lead screw 301, utilizing the complete end face of the first piston 202a as the effective pressure-bearing area. A first oil port 205a is provided on the first oil chamber 204a. A second seal 203b is installed on the second piston 202b to ensure that a second oil chamber 204b is generated after the second piston 202b and the second piston cylinder 201b cooperate. Similarly, the second oil chamber 204b utilizes the complete end face of the second piston 202b as the effective pressure-bearing area. Since the first piston 202a and the second piston 202b have the same diameter and both use rodless side pumping, a natural balance between the suction and discharge flow rates is ensured, avoiding the area difference problem of conventional single-rod hydraulic cylinders. A second oil port 205b is provided on the second oil chamber 204b. The first oil chamber 204a and the second oil chamber 204b can respectively contain a certain volume of hydraulic oil, magnetorheological fluid, or electrorheological fluid. In particular, when the transmission fluid is magnetorheological fluid, the first seal 203a and the second seal 203b are made of wear-resistant polymer material, which confines the magnetorheological fluid containing magnetic particles within the first oil chamber 204a and the second oil chamber 204b, physically isolating it from the mechanical chambers where the motor rotor 103, the lead screw 301, and the nut 302 are located, thereby achieving wear-resistant magnetorheological fluid circulation drive.

[0116] The working principle is as follows: When the motor stator 102 is energized, it generates electromagnetic force to drive the motor rotor 103 to rotate. Due to the fixed assembly method, the motor rotor 103 drives the nut 302 to rotate around its central axis. According to the working principle of the "ball screw-ball nut" transmission pair, the rotational motion of the nut 302 is transmitted through the internal balls, which can then be converted into linear motion of the screw 301. Due to the fixed assembly method, the screw 301 can drive the first piston 202a and the second piston 202b to perform linear motion. When the motor driver 104 ( Figure 1 Not shown, please refer to Figure 3 When a control signal is received requiring a reduction in the volume of the first oil chamber 204a, the motor drives the lead screw and the first piston 202a and the second piston 202b to move to the left. At this time, the hydraulic oil in the first oil chamber 204a is forced out of the first oil port 205a, and the hydraulic oil in the external hydraulic system flows into the second oil chamber 204b to replenish the changed volume. When a control signal requires a reduction in the volume of the second oil chamber 204b, the second piston 202b and the first piston 202a move to the right. At this time, the hydraulic oil in the second oil chamber 204b is forced out of the second oil port 205b, and the hydraulic oil in the external hydraulic system flows into the first oil chamber 204a to replenish the changed volume.

[0117] Example 2

[0118] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be described again.

[0119] According to a preferred embodiment, such as Figure 2 As shown, this invention discloses a direct-drive electro-hydraulic power unit. This embodiment is based on an innovative design of a double-rod hydraulic cylinder with a hollow piston rod and an integrated motor. Combined with the classic "ball screw-ball nut" transmission pair (screw-nut transmission pair), it achieves the function of a single piston actively moving inside the piston cylinder. The specific mechanical design is described below:

[0120] The motor stator 102 is fixedly installed inside the motor housing 101 and is coaxially connected to the piston cylinder 201. The motor rotor 103 is coaxially installed with the motor stator 102. One end of the motor rotor 103 is supported on the third bearing 304a, and the other end is supported on the fourth bearing 304b. The third bearing 304a and the fourth bearing 304b are restricted from axial movement by the bearing shoulders inside the motor housing 101. After the lead screw 301 is engaged with the nut 302, one end is fixed to the third bearing 304a, and the other end passes through the nut 302 and is inserted into the hollow piston rod 303. A first seal 203a is installed on the piston 202. A second seal 203b and a third seal 203c are installed at the contact position between the hollow piston rod 303 and the piston cylinder 201 to ensure that a first oil chamber 204a and a second oil chamber 204b are generated after the piston 202 and the piston cylinder 201 cooperate. A first oil port 205a is opened on the first oil chamber 204a, and a second oil port 205b is opened on the second oil chamber 204b. The first oil chamber 204a and the second oil chamber 204b can respectively contain a certain volume of hydraulic oil or magnetorheological fluid. The inner cavity of the hollow piston rod 303 forms an independent mechanical chamber, which encloses the lead screw 301 and the nut 302. The first seal 203a, the second seal 203b, and the third seal 203c achieve physical isolation between the first oil chamber 204a and the second oil chamber 204b and the mechanical chamber, preventing particles in the liquid from entering the lead screw drive pair.

[0121] The working principle is as follows: When the motor stator 102 is energized, it generates electromagnetic force to drive the motor rotor 103 to rotate. Due to the fixed assembly method, the motor rotor 103 drives the lead screw 301 to rotate around its central axis. According to the working principle of the "ball screw-ball nut" transmission pair, the rotational motion of the lead screw 301 is transmitted through the internal balls, which can then be converted into linear motion of the nut 302; wherein, the nut 302 is restricted in its rotational freedom (for example, by being fixed to the piston rod and cooperating with an anti-rotation structure). Due to the fixed assembly method, the nut 302 can drive the hollow piston rod 303 to move linearly. Due to the fixed assembly method, the hollow piston rod 303 pushes the piston 202 to move linearly. When the control signal requires the volume of the first oil chamber 204a to decrease, the piston 202 moves to the left under the drive of the hollow piston rod 303. At this time, the hydraulic oil in the first oil chamber 204a is forced out of the first oil port 205a, and the hydraulic oil in the external hydraulic system flows into the second oil chamber 204b to replenish the changed volume. When the control signal requires the volume of the second oil chamber 204b to decrease, the piston 202 moves to the right under the drive of the hollow piston rod 303. At this time, the hydraulic oil in the second oil chamber 204b is forced out of the second oil port 205b, and the hydraulic oil in the external hydraulic system flows into the first oil chamber 204a to replenish the changed volume.

[0122] Example 3

[0123] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be described again.

[0124] According to a preferred embodiment, such as Figure 3 As shown, the independent active suspension system based on an electro-hydraulic power unit of the present invention includes the horizontally opposed electro-hydraulic power unit described in Embodiment 1, a left electro-hydraulic cylinder 401a, a left piston rod 402a, a left piston 403a, a left safety valve 404a, a left air tank 405a and a right air tank 405b (the air tank can also be replaced by a bellows-type accumulator or a piston-type accumulator), a left first electro-hydraulic damping valve 501, a left second electro-hydraulic damping valve 503, and an electro-hydraulic valve group 505. The upper ends of the left piston rod 402a and the left load-bearing unit 601a are connected to the left side of the vehicle body 602a, and the lower end of the left electro-hydraulic cylinder 401a is connected to the left wheel 603a. The horizontally opposed electro-hydraulic power unit pumps hydraulic oil into or out of the first oil chamber 204a and the second oil chamber 204b through hydraulic pipelines, the first oil port 205a and the second oil port 205b. The electro-hydraulic valve assembly 505 can change the on / off state of the two hydraulic lines in accordance with the commands issued by the motor driver 104. The system also includes a controller (not shown) for receiving vehicle height adjustment signals or sensor signals and sending control commands to the motor driver 104.

[0125] The working principle is as follows: This embodiment demonstrates an active method for adjusting the vehicle body height. In the command receiving step, the controller receives a descent signal. In the motor driving step, when the left side of the vehicle body 602a needs to be lowered, the motor driver 104, which is fixedly integrated with the electro-hydraulic power unit, sends a command signal to the electro-hydraulic power unit to drive the motor. After the motor stator 102 is energized, it generates electromagnetic force and electromagnetic torque to drive the motor rotor 103 to rotate. In turn, the motor rotor 103 drives the nut 302 to rotate coaxially, and due to the fixed connection, they have the same speed. In the motion conversion step, nut 302 and lead screw 301 form a classic "threaded transmission pair". The rotational motion of nut 302 transmits axial driving force to lead screw 301 through its internal balls. Therefore, lead screw 301 moves along its axial centerline towards the left side of the vehicle body 602a. In the volumetric pumping step, the first piston 202a moves with the lead screw, thus reducing the volume of the first oil chamber 204a. The hydraulic fluid inside is forced out through the first oil port 205a and flows through the hydraulic pipeline into the rod chamber of the left electro-hydraulic cylinder 401a and the left air tank 405a filled with high-pressure gas. At the same time, the high-pressure gas in the right air tank 405b expands, discharging the hydraulic fluid in the hydraulic pipeline and replenishing the second oil chamber 204b through the second oil port 205b. Since the high-pressure gas in the left air tank 405a is difficult to compress and generates a high-pressure reaction force in the hydraulic pipeline, this force ultimately acts on the left piston 403a, subjecting it to a downward pressure. Ultimately, under the action of downforce, the goal of lowering the left side of the vehicle body 602a was achieved during the height change process.

[0126] Example 4

[0127] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be described again.

[0128] According to a preferred embodiment, such as Figure 4As shown, the interconnected active suspension system based on an electro-hydraulic power unit of the present invention includes the horizontally opposed electro-hydraulic power unit described in Embodiment 1, and interconnected components via hydraulic lines: a left electro-hydraulic cylinder 401a and a right electro-hydraulic cylinder 401b, a left piston rod 402a and a right piston rod 402b, a left piston 403a and a right piston 403b, a left safety valve 404a and a right safety valve 404b, a left air tank 405a and a right air tank 405b, a left first electro-hydraulic damping valve 501, a left second electro-hydraulic damping valve 503, a right first electro-hydraulic damping valve 502, a right second electro-hydraulic damping valve 504, and an electro-hydraulic valve assembly 505. The electro-hydraulic valve assembly 505 can change the on / off state of the two hydraulic lines in conjunction with commands issued by the motor driver 104 or the circuit board. The upper ends of the left piston rod 402a and the left load-bearing unit 601a are respectively connected to the left side of the vehicle body 602a, and the upper ends of the right piston rod 402b and the right load-bearing unit 601b are respectively connected to the right side of the vehicle body 602b. The lower ends of the left electro-hydraulic cylinder 401a and the right electro-hydraulic cylinder 401b are respectively connected to the left wheel 603a and the right wheel 603b. The horizontally opposed electro-hydraulic power unit pumps hydraulic oil into or out of the first oil chamber 204a and the second oil chamber 204b through hydraulic pipelines, the first oil port 205a and the second oil port 205b, thereby controlling the fluid flow between the rod-side or rodless chambers of the left and right electro-hydraulic cylinders through a fluid transmission circuit.

[0129] The working principle is as follows: This embodiment implements the cross-control step. When the left side of the vehicle body 602a needs to be raised and the right side of the vehicle body 602b needs to be lowered, the motor driver 104 sends a command signal to the electro-hydraulic power unit to drive the motor to work. After the motor stator 102 is energized, it generates electromagnetic force and electromagnetic torque to drive the motor rotor 103 to rotate. In turn, the motor rotor 103 drives the nut 302 to rotate coaxially together, and due to the fixed connection, they have the same speed. The nut 302 and the lead screw 301 are a classic "threaded transmission pair". The rotational motion of the nut 302 transmits axial driving force to the lead screw 301 through its internal balls. Therefore, the lead screw 301 moves along its axial center line towards the right side 602b. As a result, the volume of the second oil chamber 204b decreases. The hydraulic fluid inside is forced out through the second oil port 205b and flows through the hydraulic pipeline into the rodless chamber of the left electro-hydraulic cylinder 401a, the rod chamber of the right electro-hydraulic cylinder 401b, and the right air tank 405b filled with high-pressure gas. Because the high-pressure gas inside the right air tank 405b is difficult to compress and generates a high-pressure reaction force in the hydraulic lines, this force ultimately acts on the left piston 403a and the right piston 403b. Specifically, the left piston 403a experiences an upward lifting force, while the right piston 403b experiences a downward pressure. Ultimately, under the action of these two forces, the goal of raising the left side of the vehicle body 602a and lowering the right side of the vehicle body 602b is achieved.

[0130] The horizontally opposed electro-hydraulic power unit, together with the load-bearing unit in the active suspension system, controls the vehicle's motion. The electro-hydraulic cylinders are connected and coupled through hydraulic pipelines, hydraulic valve groups, hydraulic accumulators, and other hydraulic accessories to transport hydraulic fluid, realizing the flow and conversion of energy between multiple fields: electrical energy → mechanical energy → hydraulic energy → mechanical energy. Through this structure, the system supports multiple interconnected control modes such as anti-roll and anti-pitch.

[0131] Example 5

[0132] According to a preferred embodiment, such as Figure 5 As shown, this invention preferably presents an interconnected, releasable active suspension system based on an electro-hydraulic power unit. The following content focuses on explaining three significant differences between this embodiment and Embodiment 4; repeated details will not be elaborated upon.

[0133] The first difference lies in the connection of the electronically controlled damping valves: the left first electronically controlled damping valve 501 and the left second electronically controlled damping valve 503 are connected through the third oil circuit P3, and the right first electronically controlled damping valve 502 and the right second electronically controlled damping valve 504 are connected through the fourth oil circuit P4. The second difference lies in the installation of the gas storage tanks: the left gas storage tank 405a is installed between the left first electronically controlled damping valve 501 and the left second electronically controlled damping valve 503, and the right gas storage tank 405b is installed between the right first electronically controlled damping valve 502 and the right second electronically controlled damping valve 504. The third difference lies in the installation of the left first electronically controlled high-speed switching valve 506a and the right first electronically controlled high-speed switching valve 506b between the first oil circuit P1 and the second oil circuit P2.

[0134] When the left first electrically controlled high-speed switch valve 506a and the right first electrically controlled high-speed switch valve 506b are in the closed working position, the first oil circuit P1 and the second oil circuit P2 are not interconnected, corresponding to the active mode in this embodiment; when the left first electrically controlled high-speed switch valve 506a and the right first electrically controlled high-speed switch valve 506b are energized and in the open working position, the first oil circuit P1 and the second oil circuit P2 are interconnected, corresponding to the passive or semi-active mode in this embodiment.

[0135] Example 6

[0136] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be described again.

[0137] According to a preferred embodiment, such as Figure 6As shown, the present invention discloses an independent active suspension system integrating a magnetorheological damper and an electro-hydraulic power unit, namely a wear-resistant magnetorheological fluid circulation drive system. It includes the horizontally opposed electro-hydraulic power unit (as a direct-drive pump source) described in Example 1, a left magnetorheological damper 4011 (as a magnetorheological actuator), a left rebound chamber 401d, a left compression chamber 401c, a left piston rod 402a, a left power supply line 402c, a left piston 403a, a left floating piston 403c, a left rebound channel 404e, a left compression channel 404c, a left electromagnet 404d, and a left internal air tank 405c. The horizontally opposed electro-hydraulic power unit pumps magnetorheological fluid containing magnetic particles into or out of the first oil chamber 204a and the second oil chamber 204b through pipelines, a first oil port 205a, and a second oil port 205b. The independent active suspension system described in this embodiment has at least two operating modes: semi-active mode and active mode.

[0138] The working principle is as follows: In the semi-active damping step, in semi-active mode, the electro-hydraulic power unit is inactive, and the first piston 202a and the second piston 202b are held in a predetermined position or area (e.g., by the holding torque of the motor). When the left side of the vehicle body 602a moves downward relative to the left wheel 603a, the left piston rod 402a and the left piston 403a move downward together, and the left magnetorheological damper 4011 is in compression condition. At this time, after the left electromagnet 404d is energized, it generates a changing magnetic field in the left compression channel 404c, thereby changing the viscosity (flow velocity) of the magnetorheological fluid inside the left rebound chamber 401d and the left compression chamber 401c, ultimately generating a changing damping force. This changing damping force is controlled in real time by the controller according to the motion state of the vehicle body, and is used to attenuate the real-time changing vibration and impact between the vehicle body and the wheel. The left floating piston 403c moves up and down with the left piston 403a under the action of compressed gas inside the left built-in air tank 405c, which is used to ensure that the output changing damping force is continuous and stable.

[0139] In the active height adjustment step, in active mode, the electro-hydraulic power unit is in operation, and the first piston 202a and the second piston 202b reciprocate linearly within the first piston cylinder 201a and the second piston cylinder 201b, respectively. At this time, the fluid flow inside the left magnetorheological damper 4011 is restricted; that is, under the influence of the magnetic field generated by the left electromagnet 404d, only a very small amount of magnetorheological fluid is allowed to flow between the left rebound chamber 401d and the left compression chamber 401c. This arrangement results in near isolation between the left rebound chamber 401d and the left compression chamber 401c. Taking raising the vehicle body as an example, when the left side of the vehicle body 602a needs to be raised, the second piston 202b moves to the right under the push of the lead screw 301. The magnetorheological fluid inside the second oil chamber 204b flows into the left compression chamber 401c through the pipeline. Due to the incompressible nature of the magnetorheological fluid and the pre-filled high-pressure gas in the left internal gas tank 405c, the magnetorheological fluid pumped in by the electro-hydraulic power unit will push the left piston 403a and the left piston rod 402a upward together. Ultimately, the left side of the vehicle body 602a moves upward under the combined lifting force of the left piston rod 402a and the left load-bearing unit 601a.

[0140] This embodiment only illustrates the differences from the above embodiments; repeated content will not be repeated here.

[0141] Example 7

[0142] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be described again.

[0143] According to a preferred embodiment, such as Figure 7As shown, the present invention describes an independent active suspension system integrating an external dual magnetorheological valve actuator and an electro-hydraulic power unit. This embodiment differs significantly from the above embodiment in two aspects. The first difference is that the left gas tank 405a and the right gas tank 405b are replaced with a bellows-type accumulator 405 (or a piston-type accumulator or a diaphragm-type accumulator); the second difference is that the left first electrically controlled damping valve 501 and the left second electrically controlled damping valve 503 are composed of a magnetorheological valve and a check valve with the working mode of Pinch mode. Among them, the magnetorheological valve with the working mode of Pinch mode has two functions: (1) the flow channel inside the magnetorheological valve can change the size of the flow cross section according to the strength of the magnetic field, thereby controlling the speed of the magnetorheological fluid flowing through the flow channel, and finally obtaining a real-time variable and controllable damping force. At this time, the flow channel of the magnetorheological valve, operating in valve mode or direct-shear mode (2), can generate reversible blockage when the magnetic field strength reaches a critical value (critical magnetic field), forming a solid plug with yield stress, thereby forming a fluid lock-in effect that can resist system pressure, greatly increasing the flow resistance to cut off or slightly cut off the fluid flow of the branch, and finally realizing the "open-close" function of the hydraulic switching valve. The independent active suspension system described in this embodiment has at least two working modes: semi-active mode and active mode.

[0144] To avoid repetition, the following description only explains the working principles of the left first electrically controlled damping valve 501 and the left second electrically controlled damping valve 503. In semi-active mode, the electro-hydraulic power unit is inactive. Magnetorheological fluid flows out from the rod chamber of the left magnetorheological damper 4011, flows into the left second electrically controlled damping valve 503 through the left second pipeline branch 205c. The left second electrically controlled damping valve 503 generates a changing damping force under the action of the magnetic field. At the same time, the magnetorheological fluid in the bellows accumulator 405 flows through the check valve and magnetorheological valve inside the left first electrically controlled damping valve 501 under the action of the rebound force of the high-pressure gas, and is replenished to the rodless chamber of the left magnetorheological damper 4011 through the left first pipeline branch 205d. Conversely, the magnetorheological fluid flows out from the rodless chamber of the left magnetorheological damper 4011, flows into the left first electrically controlled damping valve 501 through the left first pipeline branch 205d. The first left electrically controlled damping valve 501 generates a changing damping force under the action of a magnetic field. At the same time, the magnetorheological fluid in the bellows accumulator 405 flows through the check valve and magnetorheological valve inside the second left electrically controlled damping valve 503 under the action of the rebound force of the high-pressure gas, and is replenished to the rod chamber of the left magnetorheological vibration damper 4011 through the second left pipeline branch 205c.

[0145] In active mode, the working principle of the left first electronically controlled damping valve 501 and the left second electronically controlled damping valve 503 is summarized as follows: Taking the vehicle body lifting as an example, when the left side of the vehicle body 602a needs to be raised, the second piston 202b moves to the right under the push of the lead screw 301. The magnetorheological fluid inside the second oil chamber 204b flows into the rodless chamber of the left magnetorheological damper 4011 through the pipeline. Furthermore, the pinch mode magnetorheological valve inside the left first electronically controlled damping valve 501 is controlled by the critical magnetic field to enter the clamping mode, causing the magnetorheological fluid to be unable to flow from the left first pipeline branch 205d into the bellows-type accumulator 405. Due to the incompressible nature of the magnetorheological fluid, it will push the left piston 403a and the left piston rod 402a upwards together. Simultaneously, the Pinch mode magnetorheological valve within the left second electronically controlled damping valve 503 increases the flow channel cross-section (in conduction or adjustment mode), causing a portion of the magnetorheological fluid in the rod chamber of the left magnetorheological damper 4011 to flow into the bellows-type accumulator 405. Ultimately, the left side of the vehicle body 602a moves upward under the combined lifting force of the left piston rod 402a and the left load-bearing unit 601a.

[0146] This embodiment only illustrates the differences from the above embodiments; repeated content will not be repeated here.

[0147] Example 8

[0148] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be described again.

[0149] According to a preferred embodiment, such as Figure 8 As shown, the interconnected active suspension system integrating a magnetorheological damper and an electro-hydraulic power unit of the present invention includes the horizontally opposed electro-hydraulic power unit described in Embodiment 1, a right magnetorheological damper 4012 (as a magnetorheological actuator), a right rebound chamber 401e, a right compression chamber 401f, a right piston rod 402b, a right power supply line 402d, a right piston 403b, a right floating piston 403d, a right rebound channel 404f, a right compression channel 404h, a right electromagnet 404g, and a right air tank 405b. This system differs significantly from Embodiment 4 in three aspects. The first difference is that the transmission fluid filled inside this system is magnetorheological fluid, and the electro-hydraulic power unit adopts an anti-wear magnetorheological fluid circulation drive system architecture to ensure physical isolation between the magnetorheological fluid and the motor and transmission pair; the second difference is that the electro-hydraulic cylinder is replaced by a magnetorheological damper; the third difference is that the electro-hydraulic valve group 505 is replaced by the electro-magnetorheological valve group 505n. The magnetorheological valve assembly 505n will be described in detail in Examples 10 and 11.

[0150] This embodiment is a further extension based on the above embodiments. It is basically the same as the above embodiments in terms of structural composition and functional principle. Only the differences from the above embodiments are described here, and the repeated content will not be repeated here.

[0151] Example 9

[0152] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be described again.

[0153] According to a preferred embodiment, such as Figure 9 As shown, the interconnected active suspension system integrating an external dual magnetorheological valve actuator and an electro-hydraulic power unit described in this invention differs from Embodiment 7 in three significant ways. The first difference is that the magnetorheological damper is replaced by an electro-hydraulic cylinder; the second difference is that the left air tank 405a and right air tank 405b are replaced by a left bellows-type accumulator 405d and a right bellows-type accumulator 405e; the third difference is that the left first electro-hydraulic damping valve 501, the left second electro-hydraulic damping valve 503, the right first electro-hydraulic damping valve 502, and the right second electro-hydraulic damping valve 504 are composed of a magnetorheological valve and a check valve operating in pinch mode, thus replacing the mechanical check valve in the traditional hydraulic system. The flow direction of the magnetorheological fluid in the right first electrically controlled damping valve 502, the right second electrically controlled damping valve 504, and the right second pipeline branch 205e and the right first pipeline branch 205f connecting the two can be found in the relevant description of the left electrically controlled damping valve and the left pipeline branch in Example 7, and will not be repeated here.

[0154] This embodiment is a further extension based on the above embodiments. It is basically the same as the above embodiments in terms of structural composition and functional principle. Only the differences from the above embodiments are described here, and the repeated content will not be repeated here.

[0155] Example 10

[0156] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be described again.

[0157] According to a preferred embodiment, such as Figure 10As shown, this invention discloses an active suspension system equipped with a hydraulic lock and a high-speed switching valve. The diagram illustrates the system in active lifting mode. In this mode, the rod chambers of the left electro-hydraulic cylinder 401a and the right electro-hydraulic cylinder 401b are connected via pipelines using the electro-hydraulic valve assembly 505 described in embodiments 3 and 4. The rodless chambers of the left electro-hydraulic cylinder 401a and the right electro-hydraulic cylinder 401b are also connected via pipelines. The diagram is for illustrative purposes only; therefore, the electro-hydraulic valve assembly 505 is omitted. This embodiment differs significantly from the previous embodiments in two aspects. The first difference lies in that the horizontally opposed electro-hydraulic power unit described in Embodiment 1 is externally connected to a hydraulic lock device. This hydraulic lock device includes a first hydraulically controlled check valve 409a, a second hydraulically controlled check valve 409b, a first hydraulically controlled pipeline 409c, and a second hydraulically controlled pipeline 409d, used to achieve the position holding step. The second difference lies in that an electrically controlled high-speed switching valve 506 is connected between the pipelines connecting the rod-side and rodless sides of the electro-hydraulic cylinder for rapid bypass flow. Since the active suspension system in the illustrated configuration can actively change the vehicle's rising and falling motion states, the working principle of the active suspension system equipped with a hydraulic lock and a high-speed switching valve in different modes will be specifically described below.

[0158] Lifting Mode: Hydraulic oil in the second oil chamber 204b flows through the second hydraulic check valve 409b under the push of the second piston 202b, and then flows into the rodless chamber of the left electro-hydraulic cylinder 401a and the rodless chamber of the right electro-hydraulic cylinder 401b. Simultaneously, the hydraulic oil also flows through the second hydraulic control line 409d and then pushes open the first hydraulic check valve 409a. At this time, the hydraulic oil inside the rod chamber of the left electro-hydraulic cylinder 401a and the rod chamber of the right electro-hydraulic cylinder 401b flows back to the first oil chamber 204a. Due to the incompressible nature of hydraulic oil, the hydraulic oil inside the rodless chamber of the left electro-hydraulic cylinder 401a and the rodless chamber of the right electro-hydraulic cylinder 401b pushes the left piston 403a and left piston rod 402a, and the right piston 403b and right piston rod 402b to move upwards synchronously, thereby completing the lifting of the left side of the vehicle body 602a and the right side of the vehicle body 602b.

[0159] Descent Mode: Hydraulic oil in the first oil chamber 204a flows through the first hydraulic check valve 409a under the push of the first piston 202a, and then flows into the rod chamber of the left electro-hydraulic cylinder 401a and the rod chamber of the right electro-hydraulic cylinder 401b. Simultaneously, the hydraulic oil also flows through the first hydraulic control line 409c and then pushes open the second hydraulic check valve 409b. At this time, the hydraulic oil inside the rodless chamber of the left electro-hydraulic cylinder 401a and the rodless chamber of the right electro-hydraulic cylinder 401b flows back to the second oil chamber 204b. Due to the incompressible nature of hydraulic oil, the hydraulic oil inside the rod chamber of the left electro-hydraulic cylinder 401a and the rod chamber of the right electro-hydraulic cylinder 401b pushes the left piston 403a and left piston rod 402a, and the right piston 403b and right piston rod 402b to move downwards synchronously, thereby completing the descent of the left side vehicle body 602a and the right side vehicle body 602b.

[0160] The vehicle's active suspension system includes a hydraulic lock device for locking the suspension height when the motor stops. The hydraulic lock device has a first hydraulically controlled check valve 409a, a second hydraulically controlled check valve 409b, and a control oil circuit connecting them. The first hydraulically controlled check valve 409a and the second hydraulically controlled check valve 409b can establish a reverse conduction relationship when the control oil circuit is under pilot pressure, giving the hydraulic lock device a bidirectional controllable unlocking characteristic.

[0161] The motor assembly features a fine torque control mode, a position holding mode, and a reverse pilot mode. In the reverse pilot mode, the motor assembly and the hydraulic pump assembly constitute a pressure generation source, enabling the closed loop to actively establish unlocking pressure. Specifically, the first hydraulically controlled check valve 409a is connected to the fluid transmission loop, which has a second hydraulically controlled pipeline 409d and is in communication with the second oil chamber 204b, via a hydraulically controlled opening mechanism, allowing the first hydraulically controlled check valve 409a to be connected to the return oil path.

[0162] During active adjustment, the electro-hydraulic power unit pumps fluid and establishes pilot pressure; the hydraulic lock device opens and closes the main oil circuit; and the controller issues adjustment commands. Specifically, upon receiving a gravity-induced descent command, the motor rotor 103, under the condition of outputting a small reverse torque, slightly retracts from the lead screw 301 to establish pilot pressure in the second oil chamber 204b. When the pilot pressure reaches the opening threshold, the second hydraulically controlled check valve 409b, under the condition of controlling the pressure transmitted in the oil circuit, unlocks and connects with the return oil circuit, and / or, under the influence of the vehicle's gravity, the transmission fluid, according to the gravitational potential energy release relationship, undergoes a controlled return flow relationship with the hydraulic pumping components. This process effectively resolves the technical contradiction in the prior art where gravity alone cannot open the high-pressure side hydraulically controlled check valve.

[0163] Example 11

[0164] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be described again.

[0165] According to a preferred embodiment, such as Figure 11 As shown, the present invention discloses a magnetorheological valve group 505n (i.e., a fluid control valve group based on magnetorheological effect) with three operating modes, based on two sets of magnetorheological valves. The magnetorheological valve group 505n can be used in Embodiments 7 and 8 to change the connection relationship between the four chambers of the left electro-hydraulic cylinder 401a (rod chamber, rodless chamber) and the right electro-hydraulic cylinder 401b (rod chamber, rodless chamber). As described in the previous embodiments, the first magnetorheological valve 505a and the second magnetorheological valve 505b constitute the first set of magnetorheological valves, and the third magnetorheological valve 505c and the fourth magnetorheological valve 505d constitute the second set of magnetorheological valves, forming a bridge-type circuit structure. The first magnetorheological valve 505a, the second magnetorheological valve 505b, the third magnetorheological valve 505c, and the fourth magnetorheological valve 505d are all magnetorheological clamping valves operating in pinch mode. The system is equipped with a logic control unit (not shown) to adjust the magnetic field strength of the magnetic field generator corresponding to each magnetorheological valve. Utilizing the reversible blocking property of this type of valve, the "open-close" function of the hydraulic switching valve is ultimately achieved.

[0166] The magnetorheological valve assembly 505n is used to replace the traditional mechanical directional valve to control the flow direction of fluid between the left and right actuators; the first magnetorheological valve 505a is used to control the opening and closing of the first branch; the magnetic field generating device is used to generate a solid plug effect, wherein, in the case of cross-connection where the left side of the vehicle body needs to be raised and the right side of the vehicle body needs to be lowered, the first magnetorheological valve 505a has a low-damping conduction relationship with the fluid under the condition of zero magnetic field; in the case of system position pressure holding, the third magnetorheological valve 505c has a yield stress cutoff relationship with the fluid under the condition of critical magnetic field strength; and / or in the case of semi-active vibration damping, each magnetorheological valve has a variable damping relationship with the fluid according to a continuous adjustment relationship.

[0167] The magnetorheological valve assembly 505n includes a first magnetorheological valve 505a, a second magnetorheological valve 505b, a third magnetorheological valve 505c, and a fourth magnetorheological valve 505d. The first magnetorheological valve 505a and the second magnetorheological valve 505b can establish a logical flow path relationship when their parallel branches are in a bridge-like connection, allowing the magnetorheological valve assembly 505n to be fixed in the fluid transmission circuit between the rod-side and rodless sides of the left electro-hydraulic cylinder 401a. The first magnetorheological valve 505a is connected in series or parallel to a valve body base integrated with a fluid channel network and equipped with a magnetic field generator, enabling the magnetorheological valve assembly 505n to switch between multiple modes with an external load.

[0168] This valve assembly design, based on rheological properties, utilizes the chain-forming mechanism of magnetic particles under the influence of a magnetic field to achieve fluid reversal without mechanical moving parts, completely avoiding the failure risk caused by particle jamming in traditional slide valves or seat valves in existing technologies such as CN202597325U. Furthermore, when the first piston 202a moves to the left, the first port 205a is in a high-pressure output position, allowing a pressure differential distribution relationship between the first magnetorheological valve 505a and the third magnetorheological valve 505c. Meanwhile, when the second piston 202b moves to the left, the second port 205b is in a low-pressure suction position, allowing a return flow convergence relationship between the fourth magnetorheological valve 505d and the second magnetorheological valve 505b, thereby completing the reconfiguration of the fluid logic within milliseconds.

[0169] The working principle of the 505n magnetorheological valve group in achieving three working modes will be explained in detail below.

[0170] Mode 1 (also known as the first operating mode): In this mode, the third magnetorheological valve 505c and the fourth magnetorheological valve 505d in the second group of magnetorheological valves are in a blocked state (clamping mode) under the action of the critical magnetic field, while the first magnetorheological valve 505a and the second magnetorheological valve 505b in the first group of magnetorheological valves are in an open state (conducting mode) under the action of the magnetic field. Therefore, the magnetorheological fluid can flow from both sides of the first magnetorheological valve 505a or from both sides of the second magnetorheological valve 505b, thereby realizing the illustrated function of the hydraulic directional valve in Mode 1.

[0171] Mode 2 (also known as the second operating mode): In this mode, the first magnetorheological valve 505a and the second magnetorheological valve 505b in the first group of magnetorheological valves are in a blocked state (clamping mode) under the action of the critical magnetic field, while the third magnetorheological valve 505c and the fourth magnetorheological valve 505d in the second group of magnetorheological valves are in an open state (conducting mode) under the action of the magnetic field. Therefore, the magnetorheological fluid can flow from both sides of the third magnetorheological valve 505c or from both sides of the fourth magnetorheological valve 505d, thereby realizing the illustrated function of the hydraulic directional valve in Mode 2.

[0172] Mode 3 (also known as the third operating mode): In this mode, the first magnetorheological valve 505a and the second magnetorheological valve 505b in the first set of magnetorheological valves are blocked under the influence of the critical magnetic field (clamping mode); the third magnetorheological valve 505c and the fourth magnetorheological valve 505d in the second set of magnetorheological valves are also blocked under the influence of the critical magnetic field (clamping mode). Therefore, the magnetorheological fluid cannot flow through the two sets of magnetorheological valves, thus preventing the connection between the rod-side and rodless-side chambers of the left and right magnetorheological dampers. Ultimately, the magnetorheological fluid will flow directly between the rod-side and rodless-side chambers of the left magnetorheological damper 4011 and the right magnetorheological damper 4012, achieving fluid interlocking.

[0173] Example 12

[0174] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be described again.

[0175] According to a preferred embodiment, such as Figure 12 As shown, the present invention discloses a magnetorheological valve group 505n based on three sets of magnetorheological valves, having four operating modes. As described in the previous embodiments, the first magnetorheological valve 505a and the second magnetorheological valve 505b form the first set of magnetorheological valves; the third magnetorheological valve 505c and the fourth magnetorheological valve 505d form the second set of magnetorheological valves; and the fifth magnetorheological valve 505e and the sixth magnetorheological valve 505f form the third set of magnetorheological valves, forming a multi-path switching structure. This magnetorheological valve group 505n differs from the magnetorheological valve group 505n in Embodiment 9 in that it adds a fifth magnetorheological valve 505e and a sixth magnetorheological valve 505f. This magnetorheological valve group 505n can achieve four operating modes, of which modes 5, 6, and 7 are the same as modes 1, 2, and 3 in Embodiment 9, and will not be described again here. The following describes the operating principle of the magnetorheological valve group 505n in mode 4.

[0176] Mode 4: In this mode, the first magnetorheological valve 505a and the second magnetorheological valve 505b in the first group of magnetorheological valves, and the third magnetorheological valve 505c and the fourth magnetorheological valve 505d in the second group of magnetorheological valves are in a blocked state (clamping mode) under the action of the critical magnetic field. The fifth magnetorheological valve 505e and the sixth magnetorheological valve 505f in the third group of magnetorheological valves are in an open state (conducting mode) under the action of the magnetic field. Therefore, the magnetorheological fluid can flow from both sides of the fifth magnetorheological valve 505e or from both sides of the sixth magnetorheological valve 505f, thereby realizing the illustrated function of the hydraulic directional valve in Mode 4.

[0177] According to a preferred embodiment, the four-wheeled vehicle of the present invention includes any one of the electro-hydraulic power units in Embodiments 1 and 2 above, as well as any one of the active suspension systems based on the electro-hydraulic power unit described in Embodiments 3 to 8, and any one of the magnetorheological valve groups 505n with multiple working modes described in Embodiments 9 and 10.

[0178] It should be noted that the specific embodiments described above are exemplary. Those skilled in the art can devise various solutions inspired by the disclosure of this invention, and these solutions all fall within the scope of this invention and its protection. Those skilled in the art should understand that this specification and its accompanying drawings are illustrative and not intended to limit the scope of the claims. The scope of protection of this invention is defined by the claims and their equivalents. This specification contains multiple inventive concepts; terms such as "preferredly," "according to a preferred embodiment," or "optionally" indicate that the corresponding paragraph discloses an independent concept. The applicant reserves the right to file divisional applications based on each inventive concept.

Claims

1. An electro-hydraulic power unit for a vehicle suspension system, characterized in that, include: The motor assembly includes a motor housing (101), a motor stator (102), and a motor rotor (103), wherein the motor stator (102) is fixed inside the motor housing (101); A mechanical transmission assembly, disposed inside the motor assembly, includes a lead screw (301) and a nut (302) that cooperate with each other; The hydraulic pumping assembly is fixedly connected to or integrally formed with the motor housing (101), and includes at least one piston cylinder (201) and a piston (202) located in the piston cylinder (201); A motion conversion structure wherein the motor rotor (103) is fixedly connected to one of the lead screw (301) or the nut (302) to drive its rotation; The other of the lead screw (301) or the nut (302) is restricted in rotational freedom and retains only axial movement freedom, and the other is connected to the piston (202) in a transmission connection. The fluid output structure is provided in which the piston (202) divides the piston cylinder (201) into at least one sealed chamber for containing transmission fluid. The sealed chamber includes a first oil chamber (204a) and a second oil chamber (204b). The sealed chamber is provided with a fluid port for communicating with an external load. The fluid port includes a first oil port (205a) and a second oil port (205b). The motor assembly drives the mechanical transmission assembly, directly pushing the piston (202) to reciprocate linearly within the piston cylinder (201), thereby outputting or drawing in pressurized transmission fluid through the first oil port (205a) and the second oil port (205b).

2. The electro-hydraulic power unit according to claim 1, characterized in that, The threaded transmission pair formed by the screw (301) and the nut (302) fitting together is a rolling thread pair, which is selected from a ball screw pair or a roller screw pair; the piston (202) is provided with a first seal (203a) and a second seal (203b) to seal the first oil chamber (204a) and the second oil chamber (204b).

3. The electro-hydraulic power unit according to claim 1 or 2, characterized in that, The motion conversion structure adopts a rotor direct-drive nut configuration: the motor rotor (103) is coaxially fixed to the nut (302) and drives the nut (302) to rotate; the lead screw (301) is restricted from rotation, and one or both ends of the lead screw (301) are fixed to the piston (202); the lead screw (301) moves linearly along the axial direction under the drive of the nut (302) and drives the piston (202) to move.

4. The electro-hydraulic power unit according to any one of claims 1 to 3, characterized in that, The electro-hydraulic power unit is a horizontally opposed structure. The hydraulic pumping assembly includes a first piston cylinder (201a) and a second piston cylinder (201b) coaxially arranged on both sides of the motor assembly. The two ends of the lead screw (301) are respectively connected to the first piston (202a) and the second piston (202b). The first piston (202a) and the second piston (202b) move synchronously to change the volume of the first oil chamber (204a) and the second oil chamber (204b) respectively.

5. The electro-hydraulic power unit according to any one of claims 1 to 4, characterized in that, The motion conversion structure adopts a rotor direct drive screw configuration: the motor rotor (103) is coaxially fixed to the screw (301) and drives the screw (301) to rotate; the nut (302) is restricted from rotation, and the nut (302) is directly or through the hollow piston rod (303) connected to the piston (202); the nut (302) moves linearly along the axial direction under the drive of the screw (301) and drives the piston (202) to move.

6. The electro-hydraulic power unit according to any one of claims 1 to 5, characterized in that, It also includes an anti-rotation device, which is an anti-rotation pin (304) or a groove disposed inside the piston cylinder (201) or the motor housing (101) to limit the rotational freedom of the lead screw (301) or the nut (302) about its central axis.

7. The electro-hydraulic power unit according to any one of claims 1 to 6, characterized in that, The motor assembly also includes a support bearing, which includes a first bearing (303a), a second bearing (303b), a third bearing (304a), or a fourth bearing (304b) for supporting the rotational movement of the motor rotor (103) or the lead screw (301) and bearing axial reaction force; the support bearing is confined within a bearing shoulder of the motor housing (101) or the piston cylinder (201).

8. The electro-hydraulic power unit according to any one of claims 1 to 7, characterized in that, It also includes a motor driver (104), which is integrated with or independently arranged with the motor housing (101) and is used to control the intensity and direction of the electromagnetic field generated by the motor stator (102).

9. The electro-hydraulic power unit according to any one of claims 1 to 8, characterized in that, The transmission fluid includes hydraulic oil, magnetorheological fluid, or electrorheological fluid; when the transmission fluid is magnetorheological fluid, the first seal (203a) between the piston (202) and the inner wall of the piston cylinder (201) is made of wear-resistant material, and the lead screw (301) and nut (302) are physically isolated from the magnetorheological fluid.

10. The electro-hydraulic power unit according to any one of claims 1 to 9, characterized in that, The motor housing (101) coincides with the central axis of the piston cylinder (201); the piston (202), the lead screw (301), and the motor rotor (103) share a common central axis.

11. A vehicle active suspension system, characterized in that, include: The electro-hydraulic power unit as described in any one of claims 1 to 10; The hydraulic actuator, connected between the vehicle body and the wheels, is selected from an electro-hydraulic cylinder, a magnetorheological damper, or an electro-hydraulic damper. The fluid transmission circuit connects the first oil port (205a) and the second oil port (205b) of the electro-hydraulic power unit to the working chamber of the hydraulic actuator via hydraulic pipelines; The system control logic states that the electro-hydraulic power unit, as the system's hydraulic volume generator, directly adjusts the volume of liquid entering or flowing out of the hydraulic actuator by changing the position of the piston (202) within the piston cylinder (201), thereby actively changing the relative height or force between the vehicle body and the wheels; wherein the transmission fluid circulates in a closed loop formed between the electro-hydraulic power unit and the hydraulic actuator.

12. The vehicle active suspension system according to claim 11, characterized in that, The suspension system is an independent active suspension system. The first port (205a) of the electro-hydraulic power unit is connected to the hydraulic actuator corresponding to the left wheel, and the second port (205b) of the electro-hydraulic power unit is connected to the hydraulic actuator corresponding to the right wheel or the right air tank (405b).

13. The vehicle active suspension system according to claim 11 or 12, characterized in that, The suspension system is an interconnected active suspension system, including a left electro-hydraulic cylinder (401a) and a right electro-hydraulic cylinder (401b); the electro-hydraulic power unit controls the fluid flow between the rod-side or rodless side of the left electro-hydraulic cylinder (401a) and the right electro-hydraulic cylinder (401b) through hydraulic lines to achieve cross-adjustment or synchronous adjustment of vehicle height.

14. The vehicle active suspension system according to any one of claims 11 to 13, characterized in that, It also includes an energy storage device, which is a left gas storage tank (405a), a right gas storage tank (405b), or a bellows-type energy storage device (405), used to compensate for fluid volume changes in the system or to provide back pressure; the energy storage device is connected to the fluid transmission circuit through a pipeline.

15. The vehicle active suspension system according to any one of claims 11 to 14, characterized in that, The fluid transmission circuit also integrates a left first electrically controlled damping valve (501), a right first electrically controlled damping valve (502), a left second electrically controlled damping valve (503), a right second electrically controlled damping valve (504), or an electro-hydraulic valve group (505) for changing the on / off state of the pipeline or adjusting the fluid damping characteristics.

16. The vehicle active suspension system according to any one of claims 11 to 15, characterized in that, The hydraulic actuator is a magnetorheological damper, which includes an internally integrated electromagnet, a springback channel, and a compression channel; the magnetorheological damper has a semi-active damping mode and an active height adjustment mode.

17. The vehicle active suspension system according to any one of claims 11 to 16, characterized in that, In the active height adjustment mode, the rebound channel and compression channel inside the magnetorheological damper are restricted from flowing under the action of a magnetic field, and the magnetorheological fluid pumped in by the electro-hydraulic power unit drives the left piston rod (402a) of the magnetorheological damper to extend and retract.

18. The vehicle active suspension system according to any one of claims 11 to 17, characterized in that, It also includes a hydraulic locking device, which includes a first hydraulically controlled check valve (409a) and a second hydraulically controlled check valve (409b), and is disposed between the electro-hydraulic power unit and the hydraulic actuator to maintain the suspension height when the motor stops working.

19. The vehicle active suspension system according to any one of claims 11 to 18, characterized in that, It also includes an electrically controlled high-speed switching valve (506) connected between the rod-side and rodless sides of the hydraulic actuator for rapidly switching the fluid communication path.

20. The vehicle active suspension system according to any one of claims 11 to 19, characterized in that, It also includes a left safety valve (404a) or a right safety valve (404b), which are respectively located inside the piston of their respective hydraulic cylinders.

21. A fluid control valve assembly based on magnetorheological effect, characterized in that, Applied to the vehicle active suspension system according to any one of claims 11 to 20, comprising: A fluid channel network includes a fluid inlet, a fluid outlet, and at least two parallel branches connecting the inlet and the outlet; The magnetorheological valve unit includes a first magnetorheological valve (505a), a second magnetorheological valve (505b), a third magnetorheological valve (505c), and a fourth magnetorheological valve (505d), which are respectively arranged in the parallel branch. The magnetorheological valve unit is filled with magnetorheological fluid. A magnetic field generating device is independently configured in each of the magnetorheological valve units, used to apply a variable magnetic field to the corresponding magnetorheological fluid; A logic control unit is used to adjust the magnetic field strength of the magnetic field generator, so that the magnetorheological valve unit switches between the conduction mode and the clamping mode. In the clamping mode, the magnetic field strength reaches a critical value, causing the magnetorheological fluid to form a solid plug with yield stress inside the valve, thereby physically blocking the fluid flow in that branch; the logic control unit controls the flow direction of the fluid in the fluid channel network by combining the conduction and clamping states of the magnetorheological valve units on different branches, thereby replacing the reversing function of the mechanical reversing valve.

22. The fluid control valve assembly according to claim 21, characterized in that, The operating modes of the first magnetorheological valve (505a), the second magnetorheological valve (505b), the third magnetorheological valve (505c), and the fourth magnetorheological valve (505d) also include shear mode, valve mode, and extrusion mode.

23. The fluid control valve assembly according to claim 21 or 22, characterized in that, The fluid channel network includes a first group of magnetorheological valves and a second group of magnetorheological valves. The first group of magnetorheological valves includes a first magnetorheological valve (505a) and a second magnetorheological valve (505b). The second group of magnetorheological valves includes a third magnetorheological valve (505c) and a fourth magnetorheological valve (505d), forming a bridge-type loop structure.

24. The fluid control valve assembly according to any one of claims 21 to 23, characterized in that, It has a first working mode: the third magnetorheological valve (505c) and the fourth magnetorheological valve (505d) are in clamping mode to stop the flow, and the first magnetorheological valve (505a) and the second magnetorheological valve (505b) are in conducting mode to allow the fluid to flow in a first direction.

25. The fluid control valve assembly according to any one of claims 21 to 24, characterized in that, It has a second operating mode: the first magnetorheological valve (505a) and the second magnetorheological valve (505b) are in clamping mode to stop the flow, and the third magnetorheological valve (505c) and the fourth magnetorheological valve (505d) are in conducting mode to allow the fluid to flow in a second direction.

26. The fluid control valve assembly according to any one of claims 21 to 25, characterized in that, It has a third working mode: the first magnetorheological valve (505a), the second magnetorheological valve (505b), the third magnetorheological valve (505c), and the fourth magnetorheological valve (505d) are all in clamping mode, which completely shuts off the fluid channel network and achieves fluid lockout.

27. The fluid control valve assembly according to any one of claims 21 to 26, characterized in that, The fluid channel network also includes a third group of magnetorheological valves, which includes a fifth magnetorheological valve (505e) and a sixth magnetorheological valve (505f), and together with the first group of magnetorheological valves and the second group of magnetorheological valves, form a multi-path switching structure.

28. The fluid control valve assembly according to any one of claims 21 to 27, characterized in that, The magnetorheological valve unit is connected in series with the check valve to form a left first electrically controlled damping valve (501) and a left second electrically controlled damping valve (503) with unidirectional flow control function.

29. The fluid control valve assembly according to any one of claims 21 to 28, characterized in that, The fluid control valve group is used to control the cross-connection or independent control of the rod-side and rodless sides of the left electro-hydraulic cylinder (401a) and the right electro-hydraulic cylinder (401b) in the vehicle's active suspension system.

30. The fluid control valve assembly according to any one of claims 21 to 29, characterized in that, The magnetorheological fluid contains micron-sized magnetic particles, and the critical magnetic field strength generated by the magnetic field generator is sufficient to enable the magnetic particles to form a chain-like structure capable of withstanding the system's operating pressure.

31. A method for actively adjusting the height of a vehicle body, characterized in that, Based on the electro-hydraulic power unit as described in any one of claims 1 to 10, the method includes the following steps: Command receiving steps: Receive the vehicle height adjustment signal and determine whether the target adjustment direction is to raise or lower; Motor driving steps: According to the target adjustment direction, control the motor stator (102) of the electro-hydraulic power unit to generate an electromagnetic field, drive the motor rotor (103) to rotate clockwise or counterclockwise; Motion conversion steps: By utilizing the threaded engagement relationship between the lead screw (301) and the nut (302), the rotational motion of the motor rotor (103) is converted into the axial linear feed motion of the piston (202) within the piston cylinder (201); Volumetric pumping step: The linear feed motion of the piston (202) directly squeezes the transmission fluid in the piston cylinder (201), causing it to flow into or out of the hydraulic actuator connected to the wheel through the first oil port (205a). Height change procedure: Utilizing the incompressibility of the transmission fluid, the volume of the fluid flowing in or out directly drives the hydraulic actuator to extend or retract, thereby changing the vehicle height.

32. The method according to claim 31, characterized in that, In the motor drive step, the moving speed of the piston (202) is adjusted by controlling the rotational speed of the motor, thereby controlling the rate of vehicle height adjustment.

33. The method according to claim 31 or 32, characterized in that, In the height change step, when it is necessary to raise the vehicle body, the electro-hydraulic power unit pumps transmission fluid into the rodless or rod-type chamber of the hydraulic actuator to do work against the weight of the vehicle body and / or the pressure of the energy storage device, which is a bellows-type energy storage device (405) or an air tank.

34. The method according to any one of claims 31 to 33, characterized in that, During the height change step, when it is necessary to lower the vehicle body, the electro-hydraulic power unit rotates in the opposite direction, allowing the transmission fluid to flow back to the piston cylinder (201) under the action of the vehicle body's gravity or the pressure of the energy storage device, and recovering part of the gravitational potential energy.

35. The method according to any one of claims 31 to 34, characterized in that, The method also includes a position holding step: when the vehicle body reaches the target height, the motor is controlled to generate a holding torque or the pipeline is closed by using the first hydraulic check valve (409a) and the second hydraulic check valve (409b) to keep the piston (202) in a fixed position.

36. The method according to any one of claims 31 to 35, characterized in that, Applied to an interconnected active suspension system, the method includes a cross-control step: controlling the electro-hydraulic power unit to move, causing the transmission fluid to flow from the left hydraulic actuator to the right hydraulic actuator, thereby raising one side of the vehicle body while lowering the other side.

37. The method according to any one of claims 31 to 36, characterized in that, The method also includes a semi-active vibration reduction step: when no height adjustment is performed, the electro-hydraulic power unit is controlled to stop working, and the road vibration is attenuated by the damping characteristics of the hydraulic actuator itself or by adjusting the external left first electrically controlled damping valve (501).

38. The method according to any one of claims 31 to 37, characterized in that, The transmission fluid is a magnetorheological fluid, and the method includes a valve group control step: while adjusting the height, the magnetorheological valve group (505n) is controlled to enter the clamping mode or the conduction mode to selectively connect a specific fluid circuit.

39. The method according to claim 38, characterized in that, By utilizing the yield stress characteristics of magnetorheological fluid, the pressure holding and locking of the hydraulic system are achieved by controlling the magnetorheological valve assembly (505n) to be in clamping mode.

40. The method according to any one of claims 31 to 39, characterized in that, The instruction receiving step also includes receiving vehicle sensor signals and automatically calculating the target adjustment direction and adjustment amount based on the vehicle's pitch and roll states.

41. A wear-resistant magnetorheological fluid circulation drive system, characterized in that, include: The transmission medium is a magnetorheological fluid containing micron-sized magnetic particles; The direct-drive pump source includes a motor stator (102), a lead screw (301), a nut (302), and a piston (202); The magnetorheological actuator and the direct-drive pump source form a closed loop through pipelines; The direct-drive pump source adopts a non-rotating volumetric pumping structure. The motor stator (102) drives the piston (202) to move linearly through the lead screw (301) and nut (302) to pump the magnetorheological fluid. A first seal (203a) is provided between the piston (202) and the cylinder wall. The linear motion of the piston directly pumps the magnetorheological fluid into the magnetorheological actuator. The lead screw (301) and nut (302) are physically isolated from the magnetorheological fluid. Thus, the circulation and pressure transmission of the magnetorheological fluid in the system can be achieved without using a rotary hydraulic pump.

42. The system according to claim 41, characterized in that, The piston (202) divides the inner cavity of the direct-drive pump source into a first oil cavity (204a) and a mechanical cavity. The magnetorheological fluid is only filled in the first oil cavity (204a), and the lead screw (301) and nut (302) are located in the mechanical cavity.

43. The system according to claim 41 or 42, characterized in that, A magnetorheological valve group (505n) or a left first electrically controlled damping valve (501) is installed on the pipeline between the direct-drive pump source and the magnetorheological actuator to control the flow resistance or on / off state of the magnetorheological fluid.

44. The system according to any one of claims 41 to 43, characterized in that, The magnetorheological actuator is a magnetorheological vibration damper, which contains an electromagnet to change the apparent viscosity of the magnetorheological fluid.

45. The system according to any one of claims 41 to 44, characterized in that, The system also includes a bellows-type accumulator (405) for accommodating changes in the volume of the magnetorheological fluid caused by temperature changes or system operation, and for isolating external gases from the magnetorheological fluid.

46. ​​The system according to any one of claims 41 to 45, characterized in that, The direct-drive pump source has a dual-rod or dual-piston structure to ensure the flow balance of the pumped and sucked magnetorheological fluid, or to compensate for the flow difference through an accumulator.

47. The system according to any one of claims 41 to 46, characterized in that, The first seal (203a) is made of wear-resistant polymer material and is configured as a lip seal or a combination seal to prevent micron-sized magnetic particles from entering the area where the lead screw (301) and nut (302) are located.

48. The system according to any one of claims 41 to 47, characterized in that, The motor in the direct-drive pump source is a servo motor, which achieves stepless adjustment of the magnetorheological fluid flow rate by precisely controlling the rotation angle and speed.

49. The system according to any one of claims 41 to 48, characterized in that, The circulation loop does not contain a rotary hydraulic pump component, thus avoiding wear of the rotating blades or gears by magnetic particles and sedimentation or denaturation of the magnetorheological fluid under high-speed shear.

50. The system according to any one of claims 41 to 49, characterized in that, The system is applied to vehicle suspension, driving the vehicle body to rise and fall by pumping magnetorheological fluid, and adjusting stiffness and damping by magnetic field control.

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