A ball screw shock absorption device based on a spherical motor

Abstract

The present invention discloses a ball screw shock absorption device based on a spherical motor, which includes an upper suspension ear, a cylinder barrel, a lower suspension ear, a coil permanent magnet, a permanent magnet, a ball screw mechanism, a motor connecting piece, a control mechanism, and a flywheel. The ball screw mechanism is fixedly connected to one end of the upper suspension ear and is installed inside the cylinder barrel, and the other end of the upper suspension ear is hinged to the sprung mass; the motor connecting piece is arranged inside the cylinder body, the coil permanent magnet is fixedly installed on the ball screw mechanism, the permanent magnet is fixedly installed on the inner wall of the motor connecting piece, the flywheel is connected to the ball screw mechanism, the flywheel is installed inside the motor connecting piece, the control mechanism is arranged below the motor connecting piece, one end of the control mechanism is connected to the motor connecting piece, and the other end is connected to the cylinder barrel; the beneficial effect is that by utilizing the characteristics of the multi-degree-of-freedom movement of the spherical motor, it can effectively avoid the working failure and other situations caused by the bending deformation of the shock absorption device, realize efficient fault tolerance work, and make the suspension in the best working state.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle vibration isolation, and particularly to a ball screw shock absorption device based on a spherical motor. Background Art

[0002] An electromechanical inertial actuator designed by coupling a mechanical inertial actuator and a traditional motor has the advantage that the motor in the electromechanical inertial actuator can be used to actively control the suspension system to achieve effective control of the ideal output. In the application of the inertial actuator, Professor Wang Fuzheng applied the inertial actuator to the suspension of a railway locomotive, and investigated the beneficial effects of the inertial actuator through indicators such as critical speed, stabilization time, and ride comfort. Compared with the traditional passive suspension of the locomotive, its ride comfort, dynamic performance, and stability have been effectively improved; Chinese Patent CN104309438B discloses a multi-condition vehicle suspension. By controlling the current in the coil of the coil permanent magnet and the excitation coil in the electromagnetic piston, the controllability of the stiffness and damping of the suspension or the combined controllability of the stiffness and damping can be achieved. However, when the suspension equipped with the electromechanical inertial actuator is subjected to a force at a certain angle, an eccentricity of θ angle will occur. It is prone to roll and pitch during turning or braking, and the eccentricity of the device is extremely likely to cause the suspension to malfunction. The higher the θ, the higher the failure rate; moreover, the eccentricity of the spherical motor stator and the spherical motor rotor inside the linear motor will cause bearing wear and shaft bending of the motor, resulting in misalignment of the fixed spherical motor rotor and uneven air gap distribution. In addition, the eccentricity will increase the order and frequency components of the motor vibration noise, leading to an increase in the overall noise and vibration of the electric vehicle. Different eccentricity forms when the spherical motor rotor is eccentric will have different effects on the electromagnetic force, the excitation source of electromagnetic vibration, and thus affect the vibration and noise performance and torque output performance of the electric vehicle; based on this, there is an urgent need for a technical solution that can solve the eccentricity problem existing when the electromechanical inertial actuator composed of a linear motor and a mechanical inertial actuator operates. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention proposes a ball screw shock absorption device based on a spherical motor, which can effectively avoid situations such as the failure of the shock absorption device due to bending deformation, achieve efficient fault-tolerant operation, and keep the suspension in the best working state.

[0004] To achieve the above object, the technical solution of the present invention is a ball screw shock absorber based on a spherical motor, which includes an upper suspension ear, a cylinder barrel, a lower suspension ear, a coil permanent magnet, and a permanent magnet. The upper suspension ear is arranged at the upper end of the cylinder barrel. One end of the lower suspension ear is arranged at the lower end of the cylinder barrel and is fixedly connected thereto. The other end of the lower suspension ear is hinged to the unsprung mass. The coil permanent magnet and the permanent magnet are arranged inside the cylinder barrel. It further includes a ball screw mechanism, a motor connecting piece, a control mechanism, and a flywheel. The ball screw mechanism is fixedly connected to one end of the upper suspension ear and is installed inside the cylinder barrel. The other end of the upper suspension ear is hinged to the sprung mass. The motor connecting piece is arranged inside the cylinder body, and the ball screw mechanism makes a linear reciprocating motion up and down inside the motor connecting piece. The coil permanent magnet and the permanent magnet are arranged inside the motor connecting piece. The coil permanent magnet is fixedly installed on the ball screw mechanism, and the permanent magnet is fixedly installed on the inner wall of the motor connecting piece. The flywheel is connected to the ball screw mechanism and is installed inside the motor connecting piece. The control mechanism is arranged below the motor connecting piece. One end of the control mechanism is connected to the motor connecting piece, and the other end is connected to the cylinder barrel.

[0005] As a further supplement to the above technical solution, the ball screw mechanism includes a lead screw and a ball screw nut connected to the lead screw. The lead screw passes through the upper surface of the motor connecting piece and makes a linear reciprocating motion up and down inside it. The ball screw nut is sleeved on the outer surface of the lead screw. The outer surface of the ball screw nut is fixedly connected to the motor connecting piece. The flywheel is fixedly connected to the outer surface of the ball screw nut. The upper end of the lead screw is fixedly connected to the upper suspension ear. The coil permanent magnet is fixedly connected to the outer surface of the lead screw.

[0006] As a further supplement to the above technical solution, a limit block is also sleeved on the lead screw. The limit block is arranged above the motor connecting piece and the ball screw nut and is fixedly installed on the lead screw.

[0007] As a further supplement to the above technical solution, the control mechanism includes a spherical motor stator connected to the lower end of the motor connecting piece, a spherical motor rotor installed on the cylinder barrel, and a plurality of bull's-eye bearings fixedly connected to the spherical motor stator. One end of the bull's-eye bearing is installed on the spherical motor stator, and the other end faces the spherical motor rotor.

[0008] As a further supplement to the above technical solution, a plurality of tooth grooves are provided on the spherical motor stator, and a coil is installed inside it.

[0009] As a further supplement to the above technical solution, the motor connecting piece and the ball screw nut are welded into one body.

[0010] As a further supplement to the above technical solution, the flywheel and the ball screw nut are welded into one body.

[0011] For further supplement to this technical solution, the electromechanical inertor is connected to the external circuit through a spherical motor, realizing the following three modes:

[0012] Energy harvesting mode: When the motor connecting piece drives the spherical motor stator to make a rotational motion, the alternating electromotive force induced in the armature coil recovers and stores the vibration energy of the system through the external circuit and is used as the energy input for other energy-consuming systems;

[0013] Passive control mode: The external circuit is a passive network composed of resistors, inductors and capacitors. When the terminal voltage acts on the passive network, the impedance of the passive network is equivalent to the mechanical impedance of the mechanical network, further attenuating the vibration of the system;

[0014] Active control mode: When an external power supply supplies power to the linear motor, the controller controls the magnitude of the current input according to the corresponding control strategy to control the output force of the motor, realizing active tuning control of the vibration system. At the same time, according to the vehicle body height sensor, when the vehicle body height is too low, the output force of the motor is controlled to prevent the suspension from hitting the limit block.

[0015] Its beneficial effects are as follows: 1. The present invention utilizes the characteristics of the multi-degree-of-freedom motion of the spherical motor, which can effectively avoid the working failure and other situations caused by the bending deformation of the shock absorber, realize efficient fault tolerance work, and make the suspension in the best working state;

[0016] 2. By selecting different spherical motors for power generation or motion control, the shock absorber can work in three modes: "energy harvesting mode", "passive control mode" and "active control". Description of the Drawings

[0017] Figure 1 is a sectional view of a ball screw electromechanical device based on a control mechanism;

[0018] Figure 2 is an axonometric view of the connection part between the spherical motor stator and the spherical motor rotor of this technical solution;

[0019] Figure 3 is a schematic diagram of the eccentric state of the linear motor stator and rotor in the prior art;

[0020] Figure 4 is an eccentric structure diagram of the electromechanical inertor installed on the MacPherson suspension;

[0021] In the figure, 1 is the upper suspension ear; 2 is the cylinder barrel; 3 is the limit block; 4 is the ball screw nut; 5 is the flywheel; 6 is the coil permanent magnet; 7 is the permanent magnet; 8 is the screw rod; 9 is the motor connecting piece; 10 is the lower suspension ear; 11 is the spherical motor rotor; 12 is the spherical motor stator; 13 is the bull's eye bearing; 14 is the electromechanical inertial capacitor; 15 is the positioning arm; 16 is the lower swing arm; 17 is the brake disc; 18 is the brake caliper. Specific implementation mode

[0022] First, the design intention of the present invention is to solve the problem of eccentricity during the operation of the electromechanical inertial capacitor composed of a linear motor and a mechanical inertial capacitor in the traditional sense. Based on this, the present invention proposes a ball screw shock absorption device based on a spherical motor. By combining the ball screw mechanism with the control mechanism, it can effectively avoid situations such as the failure of the shock absorption device due to bending deformation, achieve efficient fault tolerance operation, and keep the suspension in the best working state.

[0023] For the convenience of those skilled in the art to understand this technical solution more clearly, the following will be combined with the attached Figures 1-4 Describe the specific structures and principles of the above-mentioned various mechanisms:

[0024] As Figure 1 shown, a ball screw shock absorption device based on a spherical motor includes an upper suspension ear 1, a cylinder barrel 2, a lower suspension ear 10, a coil permanent magnet 6, a permanent magnet 7, a ball screw 8 mechanism, a motor connecting piece 9, a control mechanism, and a flywheel 5. The upper suspension ear 1 is arranged at the upper end of the cylinder barrel 2. One end of the lower suspension ear 10 is arranged at the lower end of the cylinder barrel 2 and is fixedly connected thereto. The other end of the lower suspension ear 10 is hinged to the unsprung mass; the coil permanent magnet 6 and the permanent magnet 7 are arranged inside the cylinder barrel 2. The ball screw mechanism is fixedly connected to one end of the upper suspension ear 1 and is installed inside the cylinder barrel 2. The other end of the upper suspension ear 1 is hinged to the sprung mass; the motor connecting piece 9 is arranged inside the cylinder body, and the ball screw mechanism makes a linear reciprocating motion up and down inside the motor connecting piece 9. The coil permanent magnet 6 and the permanent magnet 7 are arranged inside the motor connecting piece 9. The coil permanent magnet 6 is fixedly installed on the ball screw mechanism, and the permanent magnet 7 is fixedly installed on the inner wall of the motor connecting piece 9. The flywheel 5 is connected to the ball screw mechanism, and the flywheel 5 is installed inside the motor connecting piece 9. The control mechanism is arranged below the motor connecting piece 9. One end of the control mechanism is connected to the motor connecting piece 9, and the other end is connected to the cylinder barrel 2.

[0025] Next, the structure of the ball screw mechanism will be elaborated in detail. As Figure 1As shown in the figure, the ball screw mechanism includes a lead screw 8 and a ball screw nut 4 connected to the lead screw 8. The lead screw 8 passes through the upper surface of the motor connecting piece 9 and makes a linear reciprocating motion up and down inside it. The ball screw nut 4 is sleeved on the outer surface of the lead screw 8, and the outer surface of the ball screw nut 4 is fixedly connected to the motor connecting piece 9. The flywheel 5 is fixedly connected to the outer surface of the ball screw nut 4. The upper end of the lead screw 8 is fixedly connected to the upper suspension ear 1, and the coil permanent magnet 76 is fixedly connected to the outer surface of the lead screw 8. Among them, the motor connecting piece 9 and the ball screw nut 4 are welded into one body; the flywheel 5 and the ball screw nut 4 are welded into one body.

[0026] In order to further limit the suspension, a limit block 3 is also sleeved on the lead screw 8. The limit block 3 is arranged above the motor connecting piece 9 and the ball screw nut 4, and the limit block 3 is fixedly installed on the lead screw 8.

[0027] The mechanism of the control mechanism will be elaborated in detail below, as Figures 1-2 As shown in the figure, the control mechanism includes a spherical motor stator 12 connected to the lower end of the motor connecting piece 9, a spherical motor rotor 11 installed on the cylinder barrel 2, and a plurality of bull's-eye bearings 13 fixedly connected to the spherical motor stator 12. One end of the bull's-eye bearing 13 is installed on the spherical motor stator 12, and the other end is arranged towards the spherical motor rotor 11. The spherical motor stator 12 and the spherical motor rotor 11 are curve-matched and its cross-section is arc-shaped. Among them, a plurality of tooth grooves are provided on the spherical motor stator 12 and a coil is installed inside it. The bull's-eye bearing 13 mainly plays a role in fixing the spherical motor rotor 11 during the working process.

[0028] The working process of the present invention will be described in detail below: When the upper suspension ear 1 is forced upward, it moves upward through the lead screw 8. When the lead screw 8 moves upward, under the action of the ball screw nut 4, the flywheel 5 and the ball screw nut 4 can be made to rotate, generating inertial force. At the same time, since the ball screw nut 4 is fixedly connected to the motor connecting piece 9, when the ball screw nut 4 rotates, the motor connecting piece 9 and the spherical motor stator 12 on the motor connecting piece 9 can be made to rotate together, and an induced alternating electromotive force is generated in the armature coil in the spherical motor stator 12;

[0029] At the same time, the electromechanical inertial energy storage device is connected to the external circuit through the spherical motor to realize the following three modes, as follows:

[0030] Energy feeding mode: When the motor connecting piece 9 drives the spherical motor stator 12 to rotate, the induced alternating electromotive force in the armature coil recovers and stores the system vibration energy through the external circuit and is used as the energy input of other energy-consuming systems.

[0031] Passive control mode: The external circuit is a passive network composed of resistors, inductors, and capacitors. When the terminal voltage acts on the passive network, the impedance of the passive network is equivalent to the mechanical impedance of the mechanical network, further attenuating the vibration of the system.

[0032] Active control mode: When the external power supply supplies power to the linear motor, the controller (not shown in the figure) controls the magnitude of the current input according to the corresponding control strategy to control the output force of the motor, so as to realize the active tuning control of the vibration system. At the same time, according to the vehicle body height sensor, when the vehicle body height is too low, the output force of the motor is controlled to prevent the suspension from hitting the limit block 3.

[0033] In the prior art, when the shock absorber generates bending deformation, for example, in a vehicle using a MacPherson independent suspension, due to the eccentric design, it is extremely easy to cause the shock absorber to bend and deform. However, when using a ball screw shock absorber based on a spherical motor proposed by the present invention, making full use of the characteristics of the multi-degree-of-freedom movement of the spherical motor, it can effectively avoid situations such as the shock absorber failing to work due to bending deformation, realize efficient fault tolerance work, and make the suspension in the best working state; as Figure 4 shown, it is an eccentric structure diagram of an electromechanical inertance container installed on a MacPherson suspension, including an electromechanical inertance container 14, a positioning arm 15, a lower swing arm 16, a brake disc 17, and a brake caliper 18; when the MacPherson suspension equipped with the electromechanical inertance container 14 is subjected to a force at a certain angle, an eccentricity of θ angle is generated, and it is prone to roll and nod during turning or braking, and the eccentricity of the device is extremely likely to cause the MacPherson suspension to malfunction. The higher the θ, the higher the failure rate; as Figure 3 shown is the eccentricity of the stator and rotor of the linear motor. Another existing state of eccentricity lies inside the linear motor, causing bearing wear and shaft bending of the motor, resulting in misalignment of the linear motor stator and the linear motor rotor, uneven air gap distribution. Moreover, eccentricity will increase the order and frequency components of the motor vibration noise, leading to an increase in the overall noise and vibration of the electric vehicle. Different eccentricity forms when the linear motor rotor is eccentric will have different effects on the excitation source of electromagnetic vibration - electromagnetic force, and thus affect the vibration and noise performance and torque output performance of the electric vehicle.

[0034] When there is an eccentric angle θ in the shock absorber of the prior art, the induced electromotive force output is: U A =k e vcosθ;

[0035] When using a spherical motor to avoid eccentricity of the shock absorber, the induced electromotive force output is: U B =k e v;

[0036] Through experimental calculation, U A ≤U B ;

[0037] When the shock absorber is in an eccentric state, it will not only cause bending deformation but also affect its energy harvesting effect.

[0038] Take the induced electromotive force constant k e = 100, v = 2, I = 4. The corresponding induced electromotive force and power at different eccentric angles are as follows:

[0039]

[0040] Moreover, by controlling the magnitude of the current in the coil permanent magnet, the controllability of the stiffness and moment of inertia of the suspension can be achieved; the coil in the coil permanent magnet can generate an induced current during the reciprocating motion of the suspension, and this part of the electrical energy can be recovered and stored through an external circuit to achieve "energy storage"; when the magnitude of the current is changed, the electromagnetic force of the coil permanent magnet will change, thereby changing the torque and the moment of inertia.

[0041] The present invention utilizes the characteristics of the multi-degree-of-freedom motion of the spherical motor to solve the problems such as the bending deformation of the shock absorber caused by the eccentric design, resulting in the failure of the work. Moreover, by selecting different spherical motors for power generation or actuation control, the shock absorber can work in three modes: "energy harvesting mode", "passive control mode" and "active control mode", so that the suspension is in the best state; and by controlling the magnitude of the current in the coil permanent magnet, the controllability of the stiffness and moment of inertia of the suspension can be achieved, which is convenient for enterprises to promote and use.

[0042] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Some changes that may be made by those skilled in the art to some parts thereof all reflect the principles of the present invention and are within the protection scope of the present invention.

Claims

1. A ball screw shock absorption device based on a spherical motor, comprising an upper suspension ear (1), a cylinder barrel (2), a lower suspension ear (10), a coil permanent magnet (6), and a permanent magnet (7). The upper suspension ear (1) is arranged at the upper end of the cylinder barrel (2). One end of the lower suspension ear (10) is arranged at the lower end of the cylinder barrel (2) and fixedly connected thereto. The other end of the lower suspension ear (10) is hinged to the unsprung mass. The coil permanent magnet (6) and the permanent magnet (7) are arranged inside the cylinder barrel (2), and it is characterized in that, It further includes a ball screw mechanism, a motor connecting member (9), a control mechanism, and a flywheel (5). The ball screw mechanism is fixedly connected to one end of the upper hanging ear (1) and is installed inside the cylinder barrel (2). The other end of the upper hanging ear (1) is hinged to the sprung mass. The motor connecting member (9) is disposed inside the cylinder body, and the ball screw mechanism makes a linear reciprocating motion up and down inside the motor connecting member (9). The coil permanent magnet (6) and the permanent magnet (7) are disposed inside the motor connecting member (9). The coil permanent magnet (6) is fixedly installed on the ball screw mechanism, and the permanent magnet (7) is fixedly installed on the inner wall of the motor connecting member (9). The flywheel (5) is connected to the ball screw mechanism and is installed inside the motor connecting member (9). The control mechanism is disposed below the motor connecting member (9). One end of the control mechanism is connected to the motor connecting member (9), and the other end is connected to the cylinder barrel (2). The control mechanism includes a spherical motor stator (12) connected to the lower end of the motor connecting member (9), a spherical motor rotor (11) installed on the cylinder barrel (2), and a plurality of bull's-eye bearings (13) fixedly connected to the spherical motor stator (12). One end of the bull's-eye bearing (13) is installed on the spherical motor stator (12), and the other end is disposed towards the spherical motor rotor (11). The spherical motor stator (12) is provided with a plurality of tooth grooves and a coil is installed inside it.

2. The ball screw shock absorption device based on a spherical motor according to claim 1, characterized in that, The ball screw (8) mechanism includes a screw (8) and a ball screw nut (4) connected to the screw (8). The screw (8) passes through the upper surface of the motor connecting member (9) and makes a linear reciprocating motion up and down inside it. The ball screw nut (4) is sleeved on the outer surface of the screw (8). The outer surface of the ball screw nut (4) is fixedly connected to the motor connecting member (9). The flywheel (5) is fixedly connected to the outer surface of the ball screw nut (4). The upper end of the screw (8) is fixedly connected to the upper hanging ear (1). The coil permanent magnet (6) is fixedly connected to the outer surface of the screw (8).

3. A ball screw shock absorption device based on a spherical motor according to claim 2, characterized in that, A limiting block (3) is further sleeved on the screw (8). The limiting block (3) is disposed above the motor connecting member (9) and the ball screw nut (4) and is fixedly installed on the screw (8).

4. A ball screw shock absorption device based on a spherical motor according to claim 2, characterized in that, The motor connecting member (9) and the ball screw nut (4) are welded into one body.

5. The ball screw shock absorption device based on a spherical motor according to claim 4, characterized in that, The flywheel (5) and the ball screw nut (4) are welded into one body.

6. The ball screw shock absorption device based on a spherical motor according to claim 5, characterized in that, The electromechanical inerter is connected to the external circuit through a spherical motor and realizes the following three modes: Energy feeding mode: When the motor connecting member (9) drives the spherical motor stator (12) to make a rotational motion, the alternating electromotive force induced in the armature coil recovers and stores the vibration energy of the system through the external circuit and is used as the energy input of other energy-consuming systems. Passive control mode: The external circuit is a passive network composed of a resistor, an indicator, and a capacitor. When the terminal voltage acts on the passive network, the impedance of the passive network is equivalent to the mechanical impedance of the mechanical network, further attenuating the vibration of the system. Active control mode: When an external power supply powers the linear motor, the controller controls the magnitude of the current input according to the corresponding control strategy to control the output force of the motor, so as to achieve active tuning control of the vibration system. At the same time, according to the vehicle body height sensor, when the vehicle body height is too low, the controller controls the output force of the motor to prevent the suspension from hitting the limit block (3).

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