Linear motor shock absorber

Abstract

The invention belongs to the technical field of automobile shock absorbers, and particularly relates to a linear motor shock absorber which comprises an electromagnetic coil, a permanent magnet, a mandrel and a sleeve on the outer side of the electromagnetic coil, one of the electromagnetic coil and the permanent magnet is connected to the outer side wall of the mandrel, and the other one of the electromagnetic coil and the permanent magnet is arranged on the inner side wall of the sleeve. The device further comprises a displacement sensor. The upper end of the sleeve is provided with a guide sleeve, and the lower end of the sleeve is provided with a lower limiting plate. A first sliding bearing and a sealing ring located on the top face of the first sliding bearing are arranged between the mandrel and the guide sleeve, and the first sliding bearing and the sealing ring are both fixedly arranged on the inner side wall of the guide sleeve. The first sliding bearing and the sealing ring are in sealing contact with the outer side wall of the mandrel and are in axial sliding fit with the outer side wall of the mandrel. The electromagnetic coil and the permanent magnet are located in the sleeve all the time, the sealing ring and the mandrel are matched to seal the through hole in the guide sleeve, impurities are prevented from entering the sleeve to damage the electromagnetic coil and the permanent magnet, and the working reliability of the linear motor shock absorber is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile shock absorbers, and in particular relates to a linear motor shock absorber. Background Art

[0002] With the rapid development of the automotive industry, consumers are increasingly demanding on vehicle performance, with ride comfort and driving stability becoming key indicators of vehicle quality. Shock absorbers, as a crucial component of the vehicle chassis, have a direct impact on the driving experience and safety of the vehicle.

[0003] Traditional shock absorbers include cylinder-type hydraulic shock absorbers, pneumatic hydraulic shock absorbers, and spring-hydraulic composite shock absorbers. The damping characteristics of these passive shock absorbers are determined during the design phase and cannot be dynamically adjusted based on actual driving conditions. This not only affects ride comfort but can also damage the vehicle's suspension system and components. To adjust shock absorber damping during driving, existing technologies employ methods such as incorporating movable valves within the shock absorber to adjust the size of the damping oil flow channel and employing electromagnetic coils and magnetorheological fluid to generate a magnetic field and change the viscosity of the magnetorheological fluid. However, due to their structure and control methods, these shock absorbers still struggle to respond quickly to sudden vibrations. When a vehicle suddenly encounters a large obstacle or brakes at high speed, semi-active shock absorbers are unable to instantly adjust the damping force to the appropriate value, compromising driving safety. Furthermore, during operation, friction between mechanical components and the flow resistance of the hydraulic fluid in passive shock absorbers generate significant energy losses, reducing the vehicle's energy efficiency.

[0004] Compared to the aforementioned shock absorbers, linear motor shock absorbers offer faster response, higher adjustment precision, and greater adaptability. They can quickly and flexibly adjust their damping capacity based on the vehicle's driving status and road conditions. Linear motor shock absorbers have various implementations. For example, Chinese patent application number 202411860231.X describes a linear motor shock absorber that integrates a linear motor with a hydraulic shock absorber, creating a novel linear motor shock absorber. The upper end of the hydraulic shock absorber's piston rod is equipped with a motor housing that sleeves around the outer periphery of an oil reservoir. The motor housing is external and moves relative to the oil reservoir along its axial direction. The inner wall of the motor housing is provided with a motor coil, and the outer wall of the oil reservoir is connected to a permanent magnet, located inside the motor coil and spaced apart from the outer wall of the oil reservoir. When energized, the motor coil generates a magnetic field. Under the influence of this magnetic field, the magnets are subjected to electromagnetic force, driving the oil reservoir in linear motion. By varying the magnitude and direction of the current, the damping capacity of the entire shock absorber can be actively and precisely controlled. However, the lower end of the space enclosed by the oil storage cylinder and the motor housing is open, and impurities such as road gravel, dust and rainwater can easily enter the motor housing through the opening, affecting the service life of the motor coil and even the entire linear motor shock absorber.

[0005] Generally speaking, a retractable dust cover can be provided at the opening to prevent road impurities from entering the motor housing. Chinese utility model patent application number 202322289169.0, entitled "A Linear Motor, Electromagnetic Shock Absorber, and Vehicle," discloses a linear motor comprising an iron core and a sleeve sleeved around the outer periphery of the iron core. One of the winding and the magnet is provided on the iron core, and the other is provided on the sleeve. The space enclosed by the iron core and the winding is open at the top. The winding is protected from dust and water by providing a dust cover on the outside of the end of the winding extending upward from the magnet. One end of the dust cover is connected to the iron core, and the other end is connected to the sleeve. The dust cover should be axially retractable with the relative movement of the winding and the magnet. The dust cover generally adopts an accordion rubber sleeve structure. The provision of an accordion rubber sleeve structure not only increases the outer diameter of the entire linear motor shock absorber and affects the layout of other components on the suspension system, but can also break and fail due to impact from flying sand and gravel on the road or aging over time. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a linear motor damper that prevents impurities from entering the sleeve and damaging the electromagnetic coil and permanent magnet, thereby improving the working reliability of the linear motor damper.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a linear motor vibration absorber, comprising an electromagnetic coil, a permanent magnet, a core shaft and a sleeve sleeved on the outside of the electromagnetic coil, wherein one of the electromagnetic coil and the permanent magnet is sleeved and connected to the outer wall of the core shaft, and the other is arranged on the inner wall of the sleeve, and the electromagnetic coil and the permanent magnet are spaced apart in the radial direction of the core shaft; further comprising a displacement sensor for monitoring the axial relative displacement of the electromagnetic coil and the permanent magnet; a guide sleeve is provided at the upper end of the sleeve, and a lower limit plate is provided at the lower end of the sleeve for sealing its lower port, the electromagnetic coil and the permanent magnet are both located between the guide sleeve and the lower limit plate, and the core shaft is located on the inner side of the guide sleeve and protrudes upward from the guide sleeve;

[0008] A first sliding bearing and a sealing ring located on the top surface of the first sliding bearing are provided between the core shaft and the guide sleeve. The first sliding bearing and the sealing ring are both fixedly arranged on the inner side wall of the guide sleeve; the first sliding bearing and the sealing ring are both in sealing contact with the outer side wall of the core shaft and axially slidingly fitted.

[0009] Furthermore, the electromagnetic coil is sleeved and connected to the outer wall of the core shaft, and the permanent magnet is coaxially arranged on the inner wall of the sleeve;

[0010] An axial length of the electromagnetic coil is smaller than an axial length of the permanent magnet.

[0011] Furthermore, a guide hole with a downward opening and a depth arranged along the axial direction of the core shaft is provided on the bottom wall of the core shaft, a guide column is provided on the top surface of the lower limit plate, and a second sliding bearing is provided between the guide column and the side wall of the guide hole; the second sliding bearing is fixedly arranged on the side wall of the guide hole, and the second sliding bearing is sleeved on the outside of the guide column and the two are axially slidingly matched;

[0012] The guide hole is provided with a lower limit block protruding inwardly from its side wall. The lower limit block is located below the second sliding bearing. The lower limit block and the outer side wall of the guide column are arranged at intervals.

[0013] Furthermore, a cooling cavity is provided in the core shaft, and the length of the cooling cavity in the axial direction of the core shaft should be greater than the length of the electromagnetic coil in the axial direction of the core shaft; the liquid inlet and liquid outlet of the cooling cavity are both located at the upper end of the core shaft.

[0014] Furthermore, a heat dissipation layer is provided on the outer wall of the sleeve, and the heat dissipation layer includes a plurality of heat dissipation fins, and the plurality of heat dissipation fins are evenly distributed on the outer wall of the sleeve.

[0015] Furthermore, an upper buffer pad is provided on the bottom surface of the guide sleeve, and a lower buffer pad is provided on the top surface of the lower limit plate;

[0016] The upper buffer pad and the lower buffer pad are annular pad structures with the same shape and size. The upper buffer pad is sleeved on the outside of the core shaft, and the lower buffer pad is sleeved on the outside of the guide column; the top surface of the upper buffer pad abuts the bottom surface of the first sliding bearing, and the upper buffer pad is axially slidably matched with the core shaft and the two are in sealed contact.

[0017] Furthermore, the displacement sensor is a magnetic grating displacement sensor; the displacement sensor includes a read head and a scale arranged inside the sleeve, the read head is arranged at the lower end of the core shaft, and the scale is arranged on the inner wall of the sleeve;

[0018] The cross section of the scale is a fan-shaped ring structure or a ring structure coaxial with the core shaft.

[0019] Furthermore, the sleeve includes an upper barrel section and a lower barrel section that are coaxially connected, the outer diameter of the upper barrel section is larger than the outer diameter of the lower barrel section, and the inner diameter of the upper barrel section is larger than the inner diameter of the lower barrel section; the scale is installed on the inner side wall of the lower barrel section.

[0020] Furthermore, a read head limit plate is provided at the lower end of the outer side wall of the core shaft, and the bottom surface of the read head is fitted with the top surface of the read head limit plate; a scale limit plate is provided at the lower end of the inner side wall of the sleeve, and the bottom surface of the scale is fitted with the top surface of the scale limit plate.

[0021] Furthermore, the electromagnetic coil is sleeved and connected to the outer wall of the core shaft, and the permanent magnet is coaxially arranged on the inner wall of the sleeve;

[0022] A support ring plate is provided between the upper barrel section and the lower barrel section, wherein the inner side wall of the support ring plate is connected to the outer side wall of the upper end of the lower barrel section, and the outer side wall of the support ring plate is connected to the inner side wall of the lower end of the upper barrel section; the top surface of the support ring plate abuts against the bottom wall of the permanent magnet; when the core shaft is at the lower limit position, the bottom surface of the electromagnetic coil abuts against the top surface of the support ring plate;

[0023] An upper limit ring is provided on the ground of the guide sleeve, the outer wall of the upper limit ring is sealed with the inner wall of the sleeve, and the bottom surface of the sleeve is in contact with the top surface of the permanent magnet.

[0024] Compared with the prior art, the present invention has the following advantages: a linear motor damper is provided, wherein the electromagnetic coil and permanent magnet are always located within the sleeve, and the sealing ring and core shaft cooperate to seal the through-hole of the guide sleeve, preventing impurities such as road dust, gravel, and rainwater from entering the sleeve and damaging the electromagnetic coil and permanent magnet, thereby improving the operating reliability of the linear motor damper. Even if impurities such as dust, gravel, and rainwater adhere to the outer wall of the core shaft exposed to air, the core shaft slides relative to the sealing ring during downward movement, and the sealing ring scrapes the impurities on the side wall of the core shaft upward, retaining them outside the sleeve, preventing the core shaft from carrying impurities attached to it into the sleeve, further improving the operating reliability of the linear motor damper. Even if the sealing ring is damaged or dropped, the first sliding bearing can still replace the sealing ring to scrape impurities on the side wall of the core shaft upward, retaining them outside the sleeve, further improving the reliability of the linear motor damper of the present invention. The dustproof structure of the electromagnetic coil and permanent magnet in the present invention is simple, the dustproof effect is better, and the entire damper is safer and more reliable. In addition, the damper of the present invention has a small radial dimension, which facilitates the layout and installation of other parts on the suspension. By configuring the displacement sensor as a magnetic grating displacement sensor and positioning its reader head and scale inside the sleeve, damage to the displacement sensor from road rock impact or water intrusion is prevented. By configuring the scale with a sectoral or circular cross-section, the reader head can still sense the scale's displacement relative to the sleeve when the sleeve and spindle rotate relative to each other, improving the displacement sensor's operational stability and monitoring accuracy. This, in turn, enables the vehicle controller to more accurately and promptly adjust the shock absorber to the appropriate damping force for the vehicle, enhancing both ride comfort and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the axial cross-sectional structure of the present invention;

[0026] Figure 2 yes Figure 1 A schematic diagram of the enlarged structure of the middle part A;

[0027] Figure 3 yes Figure 1 A schematic diagram of the enlarged structure of the middle part B;

[0028] Figure 4 yes Figure 1 Schematic diagram of the enlarged structure of the middle C part;

[0029] Figure 5 For the present invention Figure 1 Schematic diagram of the cross-sectional structure after cutting in the direction of the middle section line DD;

[0030] Figure 6 For the present invention Figure 1 Schematic diagram of the cross-sectional structure after cutting in the direction of the middle cross-sectional line EE;

[0031] Figure numerals: 1-electromagnetic coil; 11-iron core; 12-winding; 2-permanent magnet; 21-housing; 3-core; 31-adapter shaft section; 32-guide hole; 33-cooling chamber; 331-liquid inlet; 332-liquid outlet; 333-liquid inlet column chamber; 334-liquid outlet column chamber; 335-annular connecting groove; 34-reader limit plate; 35-core shaft upper section; 36-core shaft lower section; 4-sleeve; 41-guide sleeve; 411-upper limit Ring; 42-lower limit plate; 43-sealing ring; 44-guide column; 45-heat dissipation layer; 46-scale limit plate; 47-upper cylinder section; 48-lower cylinder section; 49-support ring plate; 51-first sliding bearing; 52-second sliding bearing; 53-lower limit block; 6-displacement sensor; 61-reading head; 62-scale; 71-upper buffer pad; 72-lower buffer pad; 91-body adapter; 92-fastening bolts; 93-wheel adapter. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0033] As attached Figure 1-6As shown, a linear motor vibration absorber includes an electromagnetic coil 1, a permanent magnet 2, a core shaft 3 and a sleeve 4 sleeved on the outside of the electromagnetic coil 1, wherein one of the electromagnetic coil 1 and the permanent magnet 2 is sleeved and connected to the outer wall of the core shaft 3, and the other is arranged on the inner wall of the sleeve 4, and the electromagnetic coil 1 and the permanent magnet 2 are spaced apart in the radial direction of the core shaft 3; and further includes a displacement sensor 6 for monitoring the axial relative displacement of the electromagnetic coil 1 and the permanent magnet 2; and is characterized in that: the upper end of the sleeve 4 is provided with a guide sleeve 41, and the lower end of the sleeve 4 is provided with a sealing lower port thereof. The lower limit plate 42, the electromagnetic coil 1 and the permanent magnet 2 are both located between the guide sleeve 41 and the lower limit plate 42, and the core shaft 3 is located inside the guide sleeve 41 and protrudes upward from the guide sleeve 41; a first sliding bearing 51 and a sealing ring 43 located on the top surface of the first sliding bearing 51 are provided between the core shaft 3 and the guide sleeve 41, and the first sliding bearing 51 and the sealing ring 43 are both fixedly arranged on the inner side wall of the guide sleeve 41; the first sliding bearing 51 and the sealing ring 43 are both in sealing contact with the outer side wall of the core shaft 3 and axially slidingly fit. The axial length of the electromagnetic coil 1 or permanent magnet 2 arranged on the core shaft 3 should be less than the distance between the limit sleeve 21 and the lower limit plate 42, so that it can axially reciprocate in the sleeve 4.

[0034] When the present invention is applied to a vehicle, the upper end of the core shaft 3 is connected to the vehicle body, the lower end of the sleeve 4 is connected to the wheel frame, the displacement sensor 6 is electrically connected to the vehicle controller, and the electromagnetic coil 1 is electrically connected to the vehicle power supply. During vehicle operation, the vehicle body and wheel drive undergo relative displacement in the vertical direction, causing the core shaft 3 and sleeve 4 to move relative to each other in the vertical direction. The displacement sensor 6 transmits the detected relative displacement data of the core shaft 3 and sleeve 4 to the vehicle controller. The vehicle controller adjusts the current intensity and direction of the power supply to the electromagnetic coil 1 based on the signal returned by the displacement sensor 6, causing the electromagnetic coil 1 to generate electromagnetic fields of varying intensities and directions. This in turn causes the permanent magnet 2 to move upward or downward according to the changes in the direction and intensity of the electromagnetic coil 1's magnetic field, thereby offsetting the vibration of the vehicle body.

[0035] During the axial relative movement of the core shaft 3 and the sleeve 4, the core shaft 3 drives one of the electromagnetic coil 1 and the permanent magnet 2 thereon to move axially relative to the other within the sleeve 4. The other of the electromagnetic coil 1 and the permanent magnet 2 is fixedly mounted on the inner sidewall of the sleeve 4. When the core shaft 3 moves relative to the sleeve 4 to the lower limit position, the bottom surface of the core shaft 3 abuts against the top surface of the lower limit plate 42, limiting the core shaft 3. The electromagnetic coil 1 or permanent magnet 2 on the core shaft 3 is always located within the sleeve 4. The sealing ring 43 cooperates with the core shaft 3 to seal the through hole in the guide sleeve 41, preventing impurities such as road dust, gravel, and rainwater from entering the sleeve 4 and damaging the electromagnetic coil 1 and permanent magnet 2, thereby improving the operating reliability of the linear motor vibration damper. Even if impurities such as dust, gravel, and rainwater adhere to the outer wall of the core shaft 3 exposed to the air, the core shaft 3 slides relative to the sealing ring 43 during its downward movement, and the sealing ring 43 scrapes the impurities on the side wall of the core shaft 3 upward, leaving them outside the sleeve 4, preventing the core shaft 3 from carrying impurities attached to it into the sleeve 4, further improving the operating reliability of the linear motor vibration damper. Even if the sealing ring 43 is damaged or falls off, the first sliding bearing 51 can still replace the sealing ring 43 to scrape the impurities on the side wall of the core shaft 3 upward, leaving them outside the sleeve 4, further improving the reliability of the linear motor vibration damper described in the present invention. Compared to linear motor shock absorbers that use retractable accordion rubber sleeves for dust protection, the dust-proof structure of the electromagnetic coil 1 and permanent magnet 2 in the present invention is simpler and more effective, making the entire shock absorber safer and more reliable. Furthermore, the shock absorber's smaller radial dimensions facilitate the placement and installation of other suspension components.

[0036] The electromagnetic coil 1 is used to generate a magnetic field after being energized to drive the permanent magnet 2 to move axially relative to each other, thereby driving the core shaft 3 and the sleeve 4 to move axially relative to each other. The electromagnetic coil 1 generally includes an iron core 11 with winding slots and a winding 12 wound in the winding slots of the iron core 11; the winding 12 is provided with a plurality of windings 12 and the plurality of windings 12 are evenly distributed along the axial direction of the iron core 11. The iron core 11 has an axially through-going mounting hole. The permanent magnet 2 is generally made of magnetic steel and is bonded to the core shaft 3 or the sleeve 4 through a cylindrical shell plate 21. The axial length of the electromagnetic coil 1 can be greater than, equal to, or less than the length of the permanent magnet 2. The electromagnetic coil 1 is generally wound on the iron core 11 with winding slots. There are two layout methods for the electromagnetic coil 1 and the permanent magnet 2, as shown below:

[0037] In the first embodiment, the electromagnetic coil 1 is coaxially arranged on the inner wall of the sleeve 4 , and the permanent magnet 2 is sleeved and connected to the outer wall of the core shaft 3 .

[0038] In the second embodiment, the electromagnetic coil 1 is sleeved and connected to the outer wall of the core shaft 3 , and the permanent magnet 2 is coaxially arranged on the inner wall of the sleeve 4 .

[0039] To ensure the stability of the relative movement between the electromagnetic coil 1 and the permanent magnet 2, when using embodiment 1, the axial length of the electromagnetic coil 1 is greater than the axial length of the permanent magnet 2; when using embodiment 2, the axial length of the electromagnetic coil 1 is less than the axial length of the permanent magnet 2.

[0040] The core shaft 3 is used to connect the upper end of the shock absorber to the vehicle body. Generally speaking, the core shaft 3 needs to be connected to the vehicle body via a vehicle body adapter 91. The vehicle body adapter 91 is an existing mechanical component that is generally connected to the bottom surface of the vehicle body via bolts. Specifically, the top surface of the core shaft 3 is provided with an adapter shaft section 31 having an outer diameter smaller than that of the core shaft 3. The vehicle body adapter 91 is sleeved on the outside of the adapter shaft section 31. The upper end of the adapter shaft section 31 protrudes from the top surface of the vehicle body adapter 91 and is threadedly connected to a fastening bolt 92. The top surface of the core shaft 3 abuts the bottom surface of the vehicle body adapter 91, and the bottom surface of the fastening bolt 92 abuts the top surface of the vehicle body adapter 91. The bottom surface of the fastening bolt 92 and the top surface of the core shaft 3 cooperate to fasten the vehicle body connector 91 to the adapter shaft section 31.

[0041] The core shaft 3 can have a straight axis structure or a stepped axis structure; it can have a solid cylindrical structure or a hollow cylindrical structure. Preferably, a guide hole 32 is provided on the bottom wall of the core shaft 3, with its opening facing downward and its depth arranged along the axial direction of the core shaft 3. A guide post 44 is provided on the top surface of the lower limit plate 42. The guide post 44 is positioned within the guide hole 32 and the two are axially slidingly engaged. The guide post 44 and the guide hole 32 cooperate to further ensure the axial movement of the core shaft 3, thereby improving the movement reliability of the core shaft 3.

[0042] The guide post 44 and the guide hole 32 can be directly connected by a clearance fit to achieve a sliding connection. As a further preferred feature, a second sliding bearing 52 is provided between the guide post 44 and the sidewall of the guide hole 32. The second sliding bearing 52 is fixedly mounted on the sidewall of the guide hole 32 and sleeved onto the outside of the guide post 44, with the two axially slidingly engaging with each other. A lower stopper 53 is provided on the guide hole 32, protruding inwardly from the sidewall. The lower stopper 53 is located below the second sliding bearing 52 and spaced apart from the outer wall of the guide post 44. The lower stopper 53 is used to support the second sliding bearing 52 upward, thereby retaining it within the guide hole 32. The provision of the second sliding bearing 52 facilitates the axial relative movement between the core shaft 3 and the guide post 44, preventing wear caused by friction between the guide post 44 and the wall of the guide hole 32, and improving the reliability of the linear motor vibration damper. The lower limit block 53 can be a bolt or a pin arranged along the radial direction of the core shaft 3 , or can be a ring plate structure connected to the inner wall of the guide hole 32 .

[0043] Taking into account that a certain amount of heat is generated during the operation of the shock absorber, as a further preferred embodiment, a cooling chamber 33 is provided in the core shaft 3, and the liquid inlet 331 and the liquid outlet 332 of the cooling chamber 33 are both located at the upper end of the core shaft 3. The cooling chamber 33 is filled with coolant, which enters the cooling chamber 33 through the liquid inlet 331 and is discharged from the liquid outlet 332 to carry away the heat generated during the operation of the shock absorber. The cooling equipment is generally a water cooler. The length of the cooling chamber 33 in the axial direction of the core shaft 3 should be greater than the length of the electromagnetic coil 1 in the axial direction of the core shaft 3, so that the coolant can better absorb the heat generated by the electromagnetic coil 1.

[0044] The cooling chamber 33 can be a spiral channel structure, a plurality of interconnected annular channel structures, or a plurality of interconnected columnar cavity structures. Since the core shaft 3 is a slender hollow shaft structure, it is easier to process the cooling chamber by setting it as a plurality of interconnected columnar cavity structures. If the core shaft 3 is an integral structure formed in one piece, it is difficult to realize the processing and manufacturing of the interconnected columnar cavity structures on it. Preferably, the core shaft 3 includes an upper core shaft section 35 and a lower core shaft section 36 that are adjacent to each other and coaxially arranged, and the guide hole 32 is located on the upper core shaft section 35; the lower core shaft section 36 is a cylindrical structure and its inner side wall protrudes inwardly from the side wall of the guide hole 32, and the part of the lower core shaft section 36 that protrudes inwardly from the guide hole 32 is the lower limit block 53; the cooling chamber 33 includes a liquid inlet column chamber 333, a liquid outlet column chamber 334 and an annular connecting groove 335 arranged on the top surface of the lower core shaft section 36; the liquid inlet column chamber 333 and the liquid outlet column chamber 334 are both along the axial direction of the core shaft 3. Through the mandrel upper section 35, the upper end of the liquid inlet column cavity 333 serves as the liquid inlet 331, and the upper end of the liquid outlet column cavity 334 serves as the liquid outlet 332. Multiple liquid inlet column cavities 333 and multiple liquid outlet column cavities 334 are provided, evenly distributed along the circumference of the mandrel 3. The upper end surface of the mandrel lower section 36 is seal-welded to the lower end surface of the mandrel upper section 35. The lower ends of the liquid inlet column cavity 333 and the lower ends of the liquid outlet column cavity 334 are connected via the annular connecting groove 335. The interconnected liquid inlet column cavity 333 and liquid outlet column cavity 334 form a cooling circuit. The coolant in the cooling device enters the liquid inlet column chamber 333 from the liquid inlet 331 and then enters the liquid outlet column chamber 334 through the annular connecting groove 335. Finally, the coolant that has absorbed the heat of the shock absorber is returned to the cooling device by the liquid outlet 332 on the liquid outlet column chamber 334 for cooling. The core shaft 3 is configured as a welded assembly formed by welding the core shaft upper section 35 and the core shaft lower section 36, which facilitates the processing and manufacturing of the liquid inlet column chamber 333, the liquid outlet column chamber 334 and the annular connecting groove 335. By providing multiple liquid inlet column chambers 333 and liquid outlet column chambers 334, multiple cooling circuits are formed that are evenly distributed on the core shaft 3, thereby increasing the cooling area of the core shaft 3 and achieving uniform and rapid cooling of the shock absorber. The axial length of the liquid inlet column chamber 333 and the liquid outlet column chamber 334 in the core shaft 3 should be greater than the axial length of the electromagnetic coil 1 in the core shaft 3 so that the coolant can better absorb the heat generated by the electromagnetic coil 1.

[0045] Sleeve 4 is used to connect the lower end of the shock absorber to the wheel frame. It is typically connected to the wheel frame's suspension arm via a conventional wheel adapter 93. Specifically, the wheel adapter 93 is provided on the bottom surface of the sleeve 4. This wheel adapter 93 comprises a connecting shaft and a U-shaped plate disposed at the lower end of the connecting shaft. The U-shaped groove on the U-shaped plate faces downward. The connecting shaft of the wheel adapter 93 is welded to the lower limit plate 42 and arranged coaxially with the guide post 44. The U-shaped plate on the wheel adapter 93 is typically connected to the suspension arm via bolts perpendicular to its sidewalls.

[0046] The sleeve 4 has a variety of structural forms. It can be a straight cylindrical structure with equal axial diameters, or a stepped cylindrical structure with unequal axial diameters; the outer contour of its cross section can be a circular, rectangular, triangular, regular hexagonal structure, etc. In order to facilitate processing and manufacturing, the sleeve 4 is generally a cylindrical structure. Preferably, a heat dissipation layer 45 is provided on the outer wall of the sleeve 4, and the heat dissipation layer 45 includes a plurality of heat dissipation fins, and the plurality of heat dissipation fins are evenly arranged on the outer wall of the sleeve 4. The heat dissipation fins should be made of a metal material with a high thermal conductivity, and two adjacent heat dissipation fins should be arranged at intervals. By providing heat dissipation fins to increase the surface area of the sleeve 4, it is more conducive to the heat conduction of the sleeve 4. The shock absorber can not only dissipate heat through the circulation of the coolant in the cooling chamber 33, but also dissipate heat through the heat dissipation fins on the sleeve 4, thereby avoiding damage to the shock absorber due to overheating and improving the working reliability of the shock absorber.

[0047] The guide sleeve 41 should be sealed with the inner wall of the sleeve 4. The two can be welded, or connected by a sealing thread with a raw tape, or the joint between the two can be filled with sealant after being connected by thread. The guide sleeve 41 at the upper end of the sleeve 4 is used to guide the movement of the core shaft 3 and also cooperates with the core shaft 3 to seal the upper end of the sleeve 4. The lower limit plate 42 at the lower end of the sleeve 4 is used to seal the lower end of the guide sleeve 4 and limit the axial position of the core shaft 3. Preferably, the bottom surface of the guide sleeve 41 is provided with an upper buffer pad 71, and the top surface of the lower limit plate 42 is provided with a lower buffer pad 72. This avoids the core shaft 3 from rigidly colliding with the guide sleeve 41 when it moves to the upper limit position, and from rigidly colliding with the lower limit plate 42 when it moves to the lower limit position, thereby reducing the probability of damage to the core shaft 3, the guide sleeve 41 and the lower limit plate 42, and extending the service life of the shock absorber.

[0048] The cross-sections of the upper and lower buffer pads 71 and 72 can be any shape, such as circular, annular, or square. Preferably, the upper and lower buffer pads 71 and 72 are annular pads of identical shape and size. The upper buffer pad 71 is sleeved on the outside of the core shaft 3, while the lower buffer pad 72 is sleeved on the outside of the guide post 44. The top surface of the upper buffer pad 71 abuts the bottom surface of the first sliding bearing 51, and the upper and lower buffer pads 71 and the core shaft 3 slide axially in sealing contact. The upper and lower buffer pads 71 and 72 have the same structure, facilitating fabrication. The upper buffer pad 71 also supports the first sliding bearing 51, preventing it from sliding down and falling off. Furthermore, the upper buffer pad 71 seals against the core shaft 3 to further prevent impurities attached to the core shaft 3 from entering the sleeve 4. The upper and lower buffer pads 71 and 72 can be made of elastic rubber pads such as nitrile rubber, silicone, or polyurethane, or they can be a combination of springs and plates. The upper buffer pad 71 is generally bonded to the guide sleeve 41 , and the lower buffer pad 72 is bonded to the lower limit plate 42 .

[0049] The sealing ring 43 is used to seal the gap between the core shaft 3 and the guide sleeve 41. When the core shaft 3 moves axially, it is also used to scrape the attachments attached to the outer wall of the core shaft 3 to the outside of the sleeve 4 to prevent impurities from entering the sleeve 4 and contaminating the electromagnetic coil 1 and the permanent magnet 2. The sealing ring 43 is an elastic sealing ring, and its material can be elastic rubber such as silicone, nitrile rubber, polyurethane, etc. Under the clamping action of the inner wall of the guide sleeve 41 and the outer wall of the core shaft 3, the sealing ring 43 should always be in an elastic compression state. The sealing ring 43 can be fixed to the guide sleeve 41 by bonding, or an annular groove can be set on the inner wall of the guide sleeve 41, and the sealing ring 43 is clamped in the annular groove. The first sliding bearing 51 is in sliding cooperation with the core shaft 3 to make the axial movement of the core shaft 3 smoother.

[0050] The displacement sensor 6 is used to monitor the axial relative displacement of the electromagnetic coil 1 and the permanent magnet 2, and the axial relative displacement of the core shaft 3 and the sleeve 4, thereby realizing the detection of the axial displacement between the vehicle body and the wheel. The displacement sensor 6 can be installed on the outside of the sleeve 4, or it can be set on the inside of the sleeve 4. The displacement sensor 6 can be selected from an inductive displacement sensor, a Hall effect sensor, a grating sensor or a magnetic grating displacement sensor. Preferably, the displacement sensor 6 is a magnetic grating displacement sensor; the displacement sensor 6 includes a reader 61 and a scale 62 arranged on the inside of the sleeve 4, the reader 61 is arranged at the lower end of the core shaft 3, and the scale 62 is arranged on the inner wall of the sleeve 4. Installing the displacement sensor 6 on the inside of the sleeve 4 prevents the displacement sensor 6 from being damaged by sand, dust and rainwater splashed from the road surface, thereby extending its service life. The length direction of the scale 62 is arranged along the axial direction of the core shaft 3.

[0051] The read head 61 and the scale 62 should be located on the same radial line of the core shaft 3 to ensure that the read head 61 can sense changes in the magnetic pole of the scale 62. Considering that the core shaft 3 and the sleeve 4 may deflect relative to each other due to vibration or other factors during vehicle operation, this may cause the spacing between the read head 61 and the scale 62 to change, affecting the detection accuracy of the displacement sensor 6. Preferably, the cross-section of the scale 62 is a sector ring structure or an annular structure coaxial with the core shaft 3. Even if the core shaft 3 and the sleeve 4 deflect relative to each other, causing the read head 61 and the scale 62 to rotate relative to each other, the read head 61 can still sense changes in the magnetic pole of the scale 62, thereby improving the accuracy and reliability of the displacement sensor 6. The read head 61 can also accurately and in real time transmit information about the axial relative movement of the core shaft 3 and the sleeve 4 back to the vehicle controller, allowing the vehicle controller to accurately and in real time adjust the current direction and intensity of the electromagnetic coil 1, thereby timely and accurately adjusting the damping capacity of the entire shock absorber, adapting the damping capacity of the shock absorber to the vehicle's operating state, and improving the comfort and safety of the vehicle. During vehicle travel, the deflection angle of the core shaft 3 and the sleeve 4 is generally around 10°. Therefore, the central angle corresponding to the scale 62 is required to be above 10° to ensure the detection accuracy of the displacement sensor 6.

[0052] If the sleeve 4 is a straight cylinder, due to the small outer diameter of the electromagnetic coil 1, directly mounting the read head 61 on the core shaft 3 and the scale 62 on the sleeve 4 would result in a large gap between the read head 61 and the scale 62, potentially preventing the read head 61 from sensing changes in the magnetic poles of the scale 62. Preferably, the sleeve 4 includes a coaxially arranged upper section 47 and a lower section 48. The outer diameter of the upper section 47 is larger than that of the lower section 48, and the inner diameter of the upper section 47 is larger than that of the lower section 48. The scale 62 is mounted on the inner sidewall of the lower section 48. Reducing the gap between the read head 61 and the scale 62 improves the reliability of the displacement sensor 6.

[0053] Preferably, a read head limit plate 34 is provided at the lower end of the outer wall of the core shaft 3, and the bottom surface of the read head 61 is aligned with the top surface of the read head limit plate 34; a scale limit plate 46 is provided at the lower end of the inner wall of the sleeve 4, and the bottom surface of the scale 62 is aligned with the top surface of the scale limit plate 46. The read head limit plate 34 is used to install the read head 61 and simultaneously limit the read head 61 axially downward to prevent it from sliding down; the scale limit plate 46 is used to limit the scale 62 axially downward to prevent it from sliding down. This ensures the sensing accuracy of the relative displacement between the read head 61 and the scale 62, improves the monitoring accuracy of the displacement sensor 6, and thereby ensures that the vehicle controller can more accurately adjust the buffering capacity of the shock absorber, thereby improving vehicle driving comfort.

[0054] The upper barrel section 47 and the lower barrel section 48 are generally connected by a ring plate. Preferably, the electromagnetic coil 1 is sleeved and connected to the outer wall of the core shaft 3, and the permanent magnet 2 is coaxially arranged on the inner wall of the sleeve 4. A support ring plate 49 is provided between the upper barrel section 47 and the lower barrel section 48. The inner wall of the support ring plate 49 is connected to the outer wall of the upper end of the lower barrel section 48, and the outer wall of the support ring plate 49 is connected to the inner wall of the lower end of the upper barrel section 47. The top surface of the support ring plate 49 abuts against the bottom wall of the permanent magnet 2. When the core shaft 3 is at the lower limit position, the bottom surface of the electromagnetic coil 1 abuts against the top surface of the support ring plate 49. The guide sleeve 41 is provided with an upper limit ring 411 on the ground. The outer wall of the upper limit ring is sealed with the inner wall of the sleeve 4, and the bottom surface of the sleeve 4 abuts against the top surface of the permanent magnet 2. The support ring plate 49 connects the upper and lower barrel sections 47 and 48 and seals the joint therebetween. The outer wall of the upper limit ring 411 cooperates with the inner wall of the sleeve 4 to secure the guide sleeve 41 to the upper end of the sleeve 4 and seal the upper end of the sleeve 4. Furthermore, the upper limit ring 411 and the support ring plate 49 cooperate to axially position the permanent magnet 2, preventing axial slippage after the permanent magnet 2 falls off and affecting the induction strength between the permanent magnet 2 and the electromagnetic coil 1, thereby ensuring the control accuracy and stability of the shock absorber.

[0055] The embodiments of this specific implementation method are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

[0056] In the description of the present invention, the terms "upper", "lower", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the figures. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationships in the figures are only used for illustrative purposes and cannot be understood as limitations on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

Claims

1. A linear motor vibration damper, comprising an electromagnetic coil (1), a permanent magnet (2), a core shaft (3), and a sleeve (4) sleeved on the outside of the electromagnetic coil (1), wherein one of the electromagnetic coil (1) and the permanent magnet (2) is sleeved and connected to the outer wall of the core shaft (3), and the other is arranged on the inner wall of the sleeve (4), and the electromagnetic coil (1) and the permanent magnet (2) are spaced apart in the radial direction of the core shaft (3); further comprising a displacement sensor (6) for monitoring the axial relative displacement of the electromagnetic coil (1) and the permanent magnet (2); characterized in that: The upper end of the sleeve (4) is provided with a guide sleeve (41), and the lower end of the sleeve (4) is provided with a lower limit plate (42) for sealing the lower end thereof; the electromagnetic coil (1) and the permanent magnet (2) are both located between the guide sleeve (41) and the lower limit plate (42); and the core shaft (3) is located inside the guide sleeve (41) and protrudes upward from the guide sleeve (41); A first sliding bearing (51) and a sealing ring (43) located on the top surface of the first sliding bearing (51) are provided between the core shaft (3) and the guide sleeve (41); the first sliding bearing (51) and the sealing ring (43) are both fixedly arranged on the inner side wall of the guide sleeve (41); the first sliding bearing (51) and the sealing ring (43) are both in sealing contact with the outer side wall of the core shaft (3) and are axially slidably matched.

2. The linear motor vibration absorber according to claim 1, characterized in that: The electromagnetic coil (1) is sleeved and connected to the outer wall of the core shaft (3), and the permanent magnet (2) is coaxially arranged on the inner wall of the sleeve (4); The axial length of the electromagnetic coil (1) is smaller than the axial length of the permanent magnet (2).

3. The linear motor vibration absorber according to claim 1, characterized in that: A guide hole (32) with an opening facing downward and a depth arranged along the axial direction of the core shaft (3) is provided on the bottom wall of the core shaft (3); a guide column (44) is provided on the top surface of the lower limit plate (42); a second sliding bearing (52) is provided between the guide column (44) and the side wall of the guide hole (32); the second sliding bearing (52) is fixedly arranged on the side wall of the guide hole (32); the second sliding bearing (52) is sleeved on the outside of the guide column (44) and the two are axially slidingly matched; The guide hole (32) is provided with a lower limit block (53) protruding inwardly from its side wall. The lower limit block (53) is located below the second sliding bearing (52). The lower limit block (53) and the outer side wall of the guide column (44) are arranged at intervals.

4. The linear motor vibration absorber according to claim 3, characterized in that: The core shaft (3) has a cooling cavity (33) therein, and the length of the cooling cavity (33) in the axial direction of the core shaft (3) should be greater than the length of the electromagnetic coil (1) in the axial direction of the core shaft (3); the liquid inlet (331) and the liquid outlet (332) of the cooling cavity (33) are both located at the upper end of the core shaft (3).

5. The linear motor vibration absorber according to claim 4, characterized in that: A heat dissipation layer (45) is provided on the outer side wall of the sleeve (4), and the heat dissipation layer (45) includes a plurality of heat dissipation fins, and the plurality of heat dissipation fins are evenly distributed on the outer side wall of the sleeve (4).

6. The linear motor vibration absorber according to claim 4, characterized in that: The bottom surface of the guide sleeve (41) is provided with an upper buffer pad (71), and the top surface of the lower limit plate (42) is provided with a lower buffer pad (72); The upper buffer pad (71) and the lower buffer pad (72) are annular pad structures with the same shape and size. The upper buffer pad (71) is sleeved on the outside of the core shaft (3), and the lower buffer pad (72) is sleeved on the outside of the guide column (44); the top surface of the upper buffer pad (71) abuts against the bottom surface of the first sliding bearing (51), and the upper buffer pad (71) and the core shaft (3) are axially slidably matched and the two are in sealed contact.

7. The linear motor vibration absorber according to any one of claims 1 to 6, characterized in that: The displacement sensor (6) is a magnetic grating displacement sensor; the displacement sensor (6) comprises a reading head (61) and a grating scale (62) arranged inside the sleeve (4); the reading head (61) is arranged at the lower end of the core shaft (3), and the grating scale (62) is arranged on the inner wall of the sleeve (4); The cross section of the grating scale (62) is a fan-shaped ring structure or a ring structure coaxial with the core shaft (3).

8. The linear motor vibration absorber according to claim 7, characterized in that: The sleeve (4) includes an upper barrel section (47) and a lower barrel section (48) that are coaxially connected, the outer diameter of the upper barrel section (47) is larger than the outer diameter of the lower barrel section (48), and the inner diameter of the upper barrel section (47) is larger than the inner diameter of the lower barrel section (48); the scale (62) is installed on the inner side wall of the lower barrel section (48).

9. The linear motor vibration absorber according to claim 8, characterized in that: A reader limit plate (34) is provided at the lower end of the outer wall of the core shaft (3), and the bottom surface of the reader (61) is in contact with the top surface of the reader limit plate (34); a scale limit plate (46) is provided at the lower end of the inner wall of the sleeve (4), and the bottom surface of the scale (62) is in contact with the top surface of the scale limit plate (46).

10. The linear motor vibration absorber according to claim 9, characterized in that: The electromagnetic coil (1) is sleeved and connected to the outer wall of the core shaft (3), and the permanent magnet (2) is coaxially arranged on the inner wall of the sleeve (4); A support ring plate (49) is provided between the upper barrel section (47) and the lower barrel section (48); the inner side wall of the support ring plate (49) is connected to the outer side wall of the upper end of the lower barrel section (48), and the outer side wall of the support ring plate (49) is connected to the inner side wall of the lower end of the upper barrel section (47); the top surface of the support ring plate (49) abuts against the bottom wall of the permanent magnet (2); when the core shaft (3) is located at the lower limit position, the bottom surface of the electromagnetic coil (1) abuts against the top surface of the support ring plate (49); An upper limit ring (411) is provided on the ground of the guide sleeve (41), the outer wall of the upper limit ring is sealedly connected to the inner wall of the sleeve (4), and the bottom surface of the sleeve (4) is in contact with the top surface of the permanent magnet (2).

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