A vibration reduction device for a motor

Abstract

The present invention discloses a vibration reduction device, which has a lever amplifying transmission unit, which can amplify the radial vibration force transmitted outward by the bearing to increase the displacement generated in the polarization direction of the piezoelectric component. When the rotor system is running, the radial vibration force generated in all directions of the bearing ring, no matter how small it is, can always be amplified by the lever amplifying transmission unit, thereby generating a larger pressure to squeeze the piezoelectric component, fully converting the radial vibration force into mechanical energy, and having a strong mechanical structure coupling ability. Therefore, the device does not require too many piezoelectric components to achieve a good vibration reduction effect, has a simple structure, small additional mass, and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of motor vibration reduction, and in particular to a vibration reduction device for a motor. Background Art

[0002] With the advancement of the new energy vehicle craze, the NVH performance of electric drive assemblies has received more and more attention.

[0003] The electric drive system includes a drive motor and a transmission device, in which a rotor system consisting of rotating parts such as shafts, bearings, and gears is installed. When the torque pulsation caused by the tangential electromagnetic force of the drive motor is transmitted to the gear of the transmission device through the shaft, the gear pair generates meshing vibration, which is transmitted to the housing through the shaft and bearings, causing vibration of the housing, and finally causing secondary vibration of the frame through the suspension system, affecting the riding comfort of passengers.

[0004] At present, piezoelectric shunt damping technology is usually used for vibration reduction of rotor systems. In a typical mechanism, the butterfly connectors in the device are evenly arranged in the grooves where the inner ring and the outer ring of the vibration reduction ring are aligned along the circumferential direction, aiming to achieve vibration reduction and noise reduction effects in all directions along the circumferential direction. However, the device has the following problems:

[0005] First, there are many parts and the structure is complicated. The vibration damping ring device includes an inner ring, an outer ring, an inner ring end cover, an outer ring end cover, a butterfly connector, bolts and screws, etc. The increase in parts will increase the processing and assembly time and cost, and the failure of one part will cause the entire device to fail, and the overall reliability of the device will decrease.

[0006] Second, it is difficult to ensure assembly accuracy. The inner ring of the vibration damping ring is matched with the outer ring of the bearing, and the outer ring is matched with the support seat. Therefore, higher requirements are placed on the coaxiality between the inner and outer rings of the vibration damping ring. The inner and outer rings are assembled and connected by a butterfly-shaped connection frame and screws. Moreover, the butterfly-shaped connection frame will bend and deform under the action of radial vibration force, so it is difficult to ensure assembly accuracy. The low installation accuracy causes the axis to deviate from the correct position, and the motion accuracy of the shaft supported on the bearing is damaged.

[0007] Third, the coupling effect of piezoelectric ceramics cannot be fully utilized. The device evenly arranges 8 piezoelectric stacks and butterfly-shaped connectors along the circumference, and uses the butterfly-shaped connection frame to transmit radial vibration force to the piezoelectric ceramics. However, when the rotor system is running, the magnitude and direction of the vibration force in the circumferential direction change over time. When the larger radial vibration force is transmitted to the position between two adjacent piezoelectric ceramics, the radial deformation of the butterfly-shaped connection frame is small, and the vibration force transmitted to the piezoelectric ceramics through the butterfly-shaped connection frame is also small, resulting in unsatisfactory vibration reduction and noise reduction effects.

[0008] How to overcome at least one of the above-mentioned defects is a technical problem that needs to be solved urgently by technicians in this field. Summary of the invention

[0009] The object of the present invention is to provide a vibration reduction device with good vibration reduction effect and simple process.

[0010] The present invention provides a vibration reduction device, characterized in that it includes an annular main body with a central through hole, the annular main body is provided with an installation cavity for installing a piezoelectric material, and also includes a lever amplification transmission unit integrally formed with the annular main body, located between the peripheral wall of the central through hole and the piezoelectric component, and used for transmitting the deformation of the peripheral wall to the piezoelectric component.

[0011] Optionally, the peripheral wall of the central through hole has an arc groove coaxial with the central through hole, and an arc wall is formed between the arc groove and the central through hole. The lever amplification transmission unit includes a primary lever, and the primary lever has a first fulcrum connected to the annular body, and the primary lever abuts against the outer wall of the arc wall.

[0012] Optionally, it further includes a radial section extending radially along the annular body, the primary lever abuts against the outer wall of the arc-shaped wall through the radial section, and the primary lever is arranged perpendicular to the radial section.

[0013] Optionally, the first fulcrum and the radial segment are respectively located at two ends of the primary lever.

[0014] Optionally, the two side surfaces of the root where the primary lever is connected to the annular body have recessed portions, and the first fulcrum is formed between the two recessed portions.

[0015] Optionally, the number of the arc-shaped grooves is at least two, which are spaced and evenly arranged along the circumference of the central through hole.

[0016] Optionally, the lever amplification transmission unit also includes a secondary lever, which has a second fulcrum connected to the annular body, the secondary lever is parallel to the primary lever and transmission is transmitted between the two through a connecting section, and the secondary lever also has a resting section that rests against the piezoelectric material.

[0017] Optionally, the second fulcrum of the secondary lever and the connecting section are located at two ends of the secondary lever, and the abutting section is close to the second fulcrum.

[0018] Optionally, the primary lever and the secondary lever and at least part of the rod segments are radially overlapped, and the second fulcrum is close to one side of the radial segment;

[0019] Alternatively or alternatively, the piezoelectric material comprises a piezoelectric ceramic stack, and the piezoelectric ceramic stack is bonded to the abutting section of the secondary lever.

[0020] Optionally, or / and, the annular body and the lever amplifying transmission unit are integrally formed by an electric spark cutting process or a casting process.

[0021] Optionally, it also includes a resistor and an inductor, which are connected in series or in series-parallel to form an external circuit, and the external circuit is connected to both ends of the piezoelectric material.

[0022] The vibration reduction device for the motor provided by the present invention is provided with a lever amplification transmission unit, which can amplify the radial vibration force transmitted outward from the bearing ring installed on the motor to increase the displacement generated in the polarization direction of the piezoelectric component. When the rotor system connected to the motor is running, the radial vibration force generated in all directions of the bearing ring, no matter how small, can always be amplified by the lever amplification transmission unit, thereby generating a larger pressure to squeeze the piezoelectric component, fully converting the radial vibration force into mechanical energy, and having a strong mechanical structure coupling ability. Therefore, the device does not require too much piezoelectric material to achieve a good vibration reduction effect, has a simple structure, small additional mass, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a three-dimensional structure of a vibration reduction device for a motor in one embodiment of the present invention;

[0024] Figure 2 for Figure 1 Schematic diagram of the structure;

[0025] Figure 3 for Figure 2 The structural diagram at A in the middle;

[0026] Figure 4 for Figure 1 The amplification principle of the lever amplification transmission unit shown;

[0027] Figure 5 This is the enlarged schematic diagram of the first-level lever.

[0028] in, Figures 1 to 3 middle:

[0029] 1- annular body, 13- mounting cavity, 12- arc groove, 11- center through hole;

[0030] 2-lever amplification transmission unit, 21-primary lever; C-first fulcrum; 21a-recessed portion; 22-first radial section; 23-radial section; 24-secondary lever; F-second fulcrum; 25-abutting section;

[0031] 3- Piezoelectric components. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. Without loss of generality, this article takes the application of the vibration reduction device to the rotor system of the motor as an example to introduce the technical effects and technical solutions. Those skilled in the art should understand that the vibration reduction device described herein can also be applied to other systems that require vibration reduction.

[0033] Please refer to Figures 1 to 5 The present invention proposes a vibration reduction device for a motor system, including an annular body 1 with a central through hole 11. The annular body 1 is provided with a mounting cavity 13 for mounting a piezoelectric component 3. The mounting cavity 13 may be a hole structure. The piezoelectric component 3 may be a piezoelectric stack, such as a piezoelectric ceramic stack. The figure shows that the piezoelectric component 3 includes a stack structure formed by four piezoelectric ceramic sheets. Of course, the piezoelectric component 3 may also be other materials and is not limited to the piezoelectric ceramic stack. The vibration reduction device also includes a lever amplification transmission unit 2 formed inside the annular body 1, located between the peripheral wall of the central through hole 11 and the piezoelectric component 3, and used to transmit the deformation of the peripheral wall to the piezoelectric component 3. Taking the lever amplification transmission unit 2 having only a primary lever 21 as an example, by using F in *L1=F out * The principle of L2 is to set L1 larger than L2 to obtain a ratio of F in Big F out . Among them, F in is the radial vibration force on the peripheral wall of the central through hole 11, F out In order to use the above principle to reduce the force F acting on the peripheral wall of the central through hole 11 in , and obtain the amplified force. The lever amplification transmission unit 2 includes at least one level of lever 21, and of course can also include two levels or more than two levels of levers. The following text will take the lever amplification transmission unit 2 as a two-level lever as an example to specifically introduce the technical solution and technical solution.

[0034] The vibration reduction device for the motor of the present invention is provided with a lever amplifying transmission unit, which can amplify the radial vibration force transmitted outward from the bearing ring installed on the motor to increase the displacement generated in the polarization direction of the piezoelectric component. When the rotor system connected to the motor is running, the radial vibration force generated in all directions of the bearing ring, no matter how small, can always be amplified by the lever amplifying transmission unit 2, thereby generating a larger pressure to squeeze the piezoelectric component 3, and fully converting the radial vibration force into mechanical energy. The mechanical structure has a strong coupling ability. Therefore, the device does not require too many piezoelectric components 3 to achieve a good vibration reduction effect, and has a simple structure, small additional mass and low cost.

[0035] In a specific embodiment, the peripheral wall of the central through hole 11 has an arcuate groove 12 coaxial therewith, and an arcuate wall is formed between the arcuate groove 12 and the central through hole 11. The arcuate groove 12 can be a through hole extending longitudinally, and of course, it can also be not a through hole. The thickness of the arcuate wall can be determined according to the situation. The fact that the thickness of the arcuate wall is not disclosed herein does not hinder the understanding and implementation of the technical solution of this invention by those skilled in the art. The lever amplification transmission unit 2 includes a primary lever 21, and the primary lever 21 has a first fulcrum C connected to the annular body 1. The first fulcrum C can be located at one end of the primary lever 21, and of course, it can also be located at a non-end position of the primary lever 21. The primary lever 21 abuts against the outer wall of the arcuate wall, wherein a first radial section 22 can be set between the lever 21 and the arcuate wall, and the two transmit force through the first radial section 22.

[0036] Specifically, the lever amplification transmission unit 2 further includes a radial section 23 extending radially along the annular body 1, the primary lever 21 abuts against the outer wall of the arc wall through the radial section, and the primary lever 21 is arranged perpendicular to the radial section. This structure is simple and easy to implement.

[0037] In the above embodiments, the first fulcrum C and the radial segment 23 are respectively located at two ends of the primary lever 21 .

[0038] Specifically, the two sides of the root where the primary lever 21 is connected to the annular body 1 have recessed parts 21a, and the first fulcrum C is formed between the two recessed parts 21a. This can improve the flexibility of lever rotation and has a relatively simple structure. Similarly, the second fulcrum of the secondary lever described later can also be achieved in the above manner.

[0039] There are at least two arc grooves 12, which are spaced and evenly arranged along the circumference of the central through hole 11. The figure shows a specific embodiment of setting four arc grooves 12, which are evenly arranged along the axial direction of the central through hole 11, so that the vibrations corresponding to the central through hole 11 and the four arc grooves 12 can be transmitted to the piezoelectric component 3 by the corresponding lever amplification transmission unit 2, and then weakened.

[0040] Of course, a greater number of arc-shaped grooves 12 is more conducive to vibration reduction, but the complexity of the annular body 1 will also increase accordingly.

[0041] In a specific embodiment, the lever amplification transmission unit 2 also includes a secondary lever, which has a second fulcrum F connected to the annular body 1, and the secondary lever is parallel to the primary lever 21 and the transmission is transmitted through a connecting section. The secondary lever also has a supporting section 25 that abuts against the piezoelectric component 3.

[0042] F in After being magnified by the first-stage lever 21 amplification mechanism, it is magnified F in-out , according to the lever principle F in-out =Fin (l1 + l2) / l2, the magnification factor is (l1 + l2) / l2, F in-out is the output force of the first-level lever 21 amplification mechanism and also the input force of the second-level lever amplification mechanism. Similarly, the force transmitted to the piezoelectric ceramic after passing through the second-level lever amplification mechanism is obtained by the lever principle as F out = F in-out (l3 + l4) / l4, the magnification factor is (l3 + l4) / l4. In summary, the output force F out and the input force F in The relationship between them is derived from the lever principle as F out = F in (l1 + l2)(l3 + l4) / l2l4. (l1 + l2)(l3 + l4) / l2l4 is the total magnification factor, l is the length of each force arm, and the magnification factor can be changed by changing the length of the force arm. Figure 5 In, point A moves to point A' under the action of the input force F in , and the movement displacement is h2. According to the principle of similar triangles, point B will move to point B' under the action of the output force F out , and the movement displacement is h1, h1 < h2. It can be seen that while this mechanism amplifies the vibration force, it will reduce the output displacement. Therefore, the vibration damping ring can achieve the transmission of a large vibration force with a very small vibration compression amount in the radial direction of the bearing, ensuring the movement accuracy of the shafting while achieving a good vibration damping effect. Among them Figure 4 and Figure 5 Point A in is the acting point of the bearing F in , point B and point D are respectively the contact points of the radial section with the first-level lever and the contact points of the radial section with the second-level lever, point C is the fulcrum of the first-level lever 21 (the above-mentioned first fulcrum), F is the fulcrum of the second-level lever (the above-mentioned second fulcrum), point E is the contact point of the abutting section with the second-level lever 24, and points A' and B' are not shown. l1 is the distance between A and C, l2 is the distance between B and C, l3 is the distance between D and F, and l4 is the distance between E and F.

[0043] In a specific embodiment, the second fulcrum of the second-level lever and the connecting section are located at both ends of the second-level lever, and the abutting section 25 is close to the second fulcrum. In this way, the amplification ability of the second-level lever is improved as much as possible.

[0044] The piezoelectric component 3 is bonded in the cavity at the end of the lever amplification transmission unit 2, which not only has strong electromechanical coupling ability, but also effectively protects the piezoelectric ceramic from tangential stress and torque, improving the service life of the piezoelectric ceramic.

[0045] Furthermore, at least part of the primary lever 21 and the secondary lever 24 are radially overlapped, and the second fulcrum is close to one side of the radial segment. That is, the first fulcrum C of the primary lever 21 is close to the free end of the secondary lever, and the free end of the primary lever 21 is located at the second fulcrum of the secondary lever. In this way, the lever amplification transmission unit 2 has a compact structure and occupies a small space.

[0046] The lever amplifying transmission unit 2 and the annular main body 1 can be integrally formed. The lever amplifying transmission unit 2 can be processed on the annular main body 1 by an electric spark cutting process, or the lever amplifying transmission unit 2 and the annular main body 1 can be integrally formed by a casting process. In particular, the electric spark cutting process is convenient and low-cost, and is more suitable for engineering applications.

[0047] The integrated structure has high equivalent stiffness and little change to the natural frequency of the system.

[0048] In addition, the integrated structure can firmly fix the bearing, has a compact structure, small deformation, and small assembly error. When the rotor system rotates at high speed, it does not increase the wear of the bearing. Therefore, the integrated structure has better environmental adaptability and higher reliability.

[0049] The integrated annular vibration reduction device utilizes the deformation of the lever to achieve the transmission of force and energy, reducing complex problems such as clearance, friction and wear existing in traditional rigid mechanisms. The mechanism requires less maintenance, has low cost, and has obvious advantages such as high precision and high performance.

[0050] The above is a detailed introduction to a vibration reduction device provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A vibration reduction device for a motor, characterized in that: It includes an annular body with a central through hole, the annular body is provided with an installation cavity for installing a piezoelectric component, and also includes a lever amplification transmission unit integrally formed with the annular body, located at the peripheral wall of the central through hole and the piezoelectric component, and used to transmit the deformation of the peripheral wall to the piezoelectric component; the peripheral wall of the central through hole has an arc groove coaxial with it, and an arc wall is formed between the arc groove and the central through hole, the lever amplification transmission unit includes a primary lever, the primary lever has a first fulcrum connected to the annular body, and the primary lever abuts against the outer wall of the arc wall; it also includes a radial section extending along the radial direction of the annular body, the primary lever abuts against the outer wall of the arc wall through the radial section, and the primary lever is arranged perpendicular to the radial section; the first fulcrum and the radial section are respectively located at two ends of the primary lever; The lever amplification transmission unit further comprises a secondary lever, the secondary lever having a second fulcrum connected to the annular body, the secondary lever being parallel to the primary lever and transmitting power through a connecting section, and the secondary lever also having abutting section against the piezoelectric component; The second fulcrum of the secondary lever and the connecting section are located at two ends of the secondary lever, and the abutting section is close to the second fulcrum.

2. The vibration reduction device for a motor according to claim 1, characterized in that: The two side surfaces of the root where the primary lever is connected to the annular body have recessed parts, and the first fulcrum is formed between the two recessed parts.

3. The vibration reduction device for a motor according to claim 1, characterized in that: The number of the arc-shaped grooves is at least two, and they are spaced and evenly arranged along the circumference of the central through hole.

4. The vibration reduction device for a motor according to claim 1, characterized in that: The first lever and the second lever have at least some rod sections overlapped in the radial direction, and the second fulcrum is close to one side of the radial section; Alternatively or alternatively, the piezoelectric component comprises a piezoelectric ceramic stack, and the piezoelectric ceramic stack is bonded to the abutting section of the secondary lever.

5. The vibration reduction device for a motor according to any one of claims 1 to 4, characterized in that: It also includes a resistor and an inductor, which are connected in series or in series-parallel to form an external circuit, and the external circuit is connected to both ends of the piezoelectric component; Alternatively or / and, the annular body and the lever amplifying transmission unit are integrally formed by an electric spark cutting process or a casting process.

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