A linear motor damper

Abstract

The utility model belongs to the technical field of automobile shock absorber, specifically relates to a linear motor shock absorber, which comprises an electromagnetic coil, a permanent magnet, a core shaft and a sleeve outside the electromagnetic coil, one of the electromagnetic coil and the permanent magnet is connected on the outer side wall of the core shaft, and the other is arranged on the inner side wall of the sleeve, further comprises a displacement sensor, the upper end of the sleeve is equipped with a guide sleeve, the lower end of the sleeve is equipped with a lower limit plate, the core shaft is located inside the guide sleeve and protrudes upwards, a first sliding bearing and a sealing ring located on the top surface of the first sliding bearing are arranged between the core shaft and the guide sleeve, the first sliding bearing and the sealing ring are fixedly arranged on the inner side wall of the guide sleeve, and the first sliding bearing and the sealing ring are in sealed contact with the outer side wall of the core shaft and axially slide. The electromagnetic coil and the permanent magnet are always located in the sleeve, the sealing ring and the core shaft are matched to seal the through hole on 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] This utility model belongs to the field of automotive shock absorber technology, specifically relating to a linear motor shock absorber. Background Technology

[0002] With the rapid development of the automotive industry, consumers have increasingly stringent requirements for vehicle performance, among which ride comfort and driving stability have become key indicators for measuring vehicle quality. As an important component of the vehicle chassis, the performance of shock absorbers directly affects the driving experience and driving safety.

[0003] Traditional shock absorbers include telescopic 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 according to actual driving conditions. This not only affects ride comfort but may also damage the vehicle's suspension system and components. To make shock absorber damping adjustable during vehicle operation, existing technologies adjust the damping force by using movable valves inside the shock absorber to regulate the flow of damping oil, or by using electromagnetic coils and magnetorheological fluids to generate a magnetic field and change the viscosity of the magnetorheological fluid. However, these shock absorbers, due to their structure and control methods, still struggle to respond quickly to sudden vibrations. When a car suddenly encounters a large obstacle or brakes suddenly at high speed, semi-active shock absorbers cannot instantly adjust the damping force to a suitable value, affecting driving safety. Furthermore, during operation, friction between mechanical components and the flow resistance of hydraulic oil in passive shock absorbers generate significant energy loss, reducing the vehicle's energy efficiency.

[0004] Compared to the aforementioned shock absorbers, linear motor shock absorbers offer faster response, higher adjustment precision, and stronger adaptability. They can quickly and flexibly adjust their damping capacity based on the vehicle's actual driving status and road conditions. Linear motor shock absorbers have various embodiments. For example, Chinese Patent Application No. 202411860231.X describes a linear motor shock absorber that integrates a linear motor into a hydraulic shock absorber, forming a novel type of linear motor shock absorber. The upper end of the piston rod of the hydraulic shock absorber is equipped with a motor housing fitted around the outer periphery of the oil reservoir. The motor moves relative to the oil reservoir along its axial direction. A motor coil is located on the inner wall of the motor housing, and a permanent magnet is connected to the outer wall of the oil reservoir. The permanent magnet is located inside the motor coil and the two are arranged at intervals. When the motor coil is energized, it generates a magnetic field. Under the influence of this magnetic field, the magnet experiences electromagnetic force, causing the oil reservoir to move linearly. By changing the magnitude and direction of the current, the damping capacity of the entire shock absorber can be actively and precisely controlled. However, the lower opening of the space enclosed by the oil reservoir and the motor housing allows impurities such as sand, dust, and rainwater from the road surface to easily enter the motor housing, affecting the service life of the motor coils and even the entire linear motor vibration damper.

[0005] Generally, a retractable dust cover at the opening can prevent road debris from entering the motor housing. Chinese utility model patent application number 202322289169.0, entitled "A Linear Motor, Electromagnetic Vibration Damper, and Vehicle," discloses a linear motor including an iron core and a sleeve fitted around the iron core. One of the windings and the magnet is located in the iron core, and the other in the sleeve. The space enclosed by the iron core and the windings is open at the top. A dust cover is installed on the outside of the end of the winding extending upwards from the magnet to protect the winding from dust and water. 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 expandable and contractible with the relative movement of the windings and the magnet. A bellows rubber sleeve structure is generally used for the dust cover. However, the bellows rubber sleeve structure not only increases the outer diameter of the entire linear motor vibration damper and affects the layout of other components in the suspension system, but it can also fail due to impacts from flying gravel or aging over time. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a linear motor vibration 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 vibration damper.

[0007] The technical solution adopted by this utility model to solve the technical problem is as follows: a linear motor vibration damper, including an electromagnetic coil, a permanent magnet, a spindle, and a sleeve sleeved on the outside of the electromagnetic coil. One of the electromagnetic coil and the permanent magnet is sleeved and connected to the outer wall of the spindle, and the other is disposed on the inner wall of the sleeve. The electromagnetic coil and the permanent magnet are arranged radially spaced on the spindle. It also includes a displacement sensor for monitoring the axial relative displacement of the electromagnetic coil and the permanent magnet. 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 that seals its lower port. The electromagnetic coil and the permanent magnet are both located between the guide sleeve and the lower limiting plate. The spindle is located inside 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 mandrel and the guide sleeve. The first sliding bearing and the sealing ring are both fixedly disposed 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 axially slidingly engaged.

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

[0010] The axial length of the electromagnetic coil is less than the axial length of the permanent magnet.

[0011] Furthermore, the bottom wall of the mandrel is provided with a guide hole with the opening facing downward and the depth arranged along the axial direction of the mandrel. A guide post is provided on the top surface of the lower limiting plate. A second sliding bearing is provided between the guide post and the side wall of the guide hole. The second sliding bearing is fixedly installed on the side wall of the guide hole. The second sliding bearing is sleeved on the outside of the guide post and the two slide in axial direction.

[0012] The guide hole is provided with a lower limiting block that protrudes inward from its side wall. The lower limiting block is located below the second sliding bearing, and the lower limiting block and the outer side wall of the guide post are arranged at intervals.

[0013] Furthermore, the mandrel has a cooling cavity, the length of which in the axial direction should be greater than the length of the electromagnetic coil in the axial direction; the inlet and outlet of the cooling cavity are both located at the upper end of the mandrel.

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

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

[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 mandrel, and the lower buffer pad is sleeved on the outside of the guide post. The top surface of the upper buffer pad abuts against the bottom surface of the first sliding bearing. The upper buffer pad and the mandrel slide in an axial manner and are in sealed contact.

[0017] Furthermore, the displacement sensor is a magnetic grating displacement sensor; the displacement sensor includes a reading head and a grating scale disposed inside the sleeve, the reading head being disposed at the lower end of the mandrel, and the grating scale being disposed on the inner wall of the sleeve;

[0018] The cross-section of the grating ruler is a fan-shaped annular structure or annular structure coaxial with the mandrel.

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

[0020] Furthermore, a reading head limiting plate is provided at the lower end of the outer side wall of the mandrel, and the bottom surface of the reading head is in contact with the top surface of the reading head limiting plate; a grid ruler limiting plate is provided at the lower end of the inner side wall of the sleeve, and the bottom surface of the grid ruler is in contact with the top surface of the grid ruler limiting plate.

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

[0022] A support ring plate is provided between the upper cylinder section and the lower cylinder section. The inner sidewall of the support ring plate is connected to the outer sidewall of the upper end of the lower cylinder section, and the outer sidewall of the support ring plate is connected to the inner sidewall of the lower end of the upper cylinder section. The top surface of the support ring plate abuts against the bottom wall of the permanent magnet. When the mandrel is in the lower limit position, the bottom surface of the electromagnetic coil abuts against the top surface of the support ring plate.

[0023] The guide sleeve is provided with an upper limit ring, the outer wall of the upper limit ring is sealed to the inner wall of the sleeve, and the bottom surface of the sleeve abuts against the top surface of the permanent magnet.

[0024] Compared with the prior art, the beneficial effects of this utility model are as follows: It provides a linear motor vibration damper in which the electromagnetic coil and permanent magnet are always located inside the sleeve. The sealing ring and the mandrel cooperate to seal the through hole on the guide sleeve, preventing impurities such as road dust, gravel, and rainwater from entering the sleeve and damaging the electromagnetic coil and permanent magnet, thus improving the working reliability of the linear motor vibration damper. Even if dust, gravel, or other impurities adhere to the outer wall of the mandrel exposed to air, the mandrel slides relative to the sealing ring during its downward movement. The sealing ring scrapes the impurities on the side wall of the mandrel upwards, leaving them outside the sleeve, preventing the mandrel from bringing the attached impurities into the sleeve, further improving the working reliability of the linear motor vibration damper. Even if the sealing ring is damaged or falls off, the first sliding bearing can still replace the sealing ring to scrape the impurities on the side wall of the mandrel upwards, leaving them outside the sleeve, further improving the reliability of the linear motor vibration damper described in this utility model. The dustproof structure of the electromagnetic coil and permanent magnet in this invention is simple and has a better dustproof effect, making the entire shock absorber safer and more reliable. Furthermore, the shock absorber of this invention has a smaller radial dimension, facilitating the installation of other parts on the suspension. By setting the displacement sensor as a magnetic grating displacement sensor and placing its reading head and grating ruler inside the sleeve, damage to the displacement sensor from road debris impacts or water ingress is avoided. By setting the grating ruler to a fan-shaped or circular annular cross-section, the reading head can still sense the displacement change of the grating ruler relative to it when the sleeve and spindle rotate relative to each other, improving the working stability and monitoring accuracy of the displacement sensor. This, in turn, allows the vehicle controller to more accurately and promptly adjust the shock absorber to the appropriate damping force for the vehicle, improving ride comfort and safety. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the axial cross-sectional structure of this utility model;

[0026] Figure 2 yes Figure 1 Enlarged structural diagram of section A in the middle;

[0027] Figure 3 yes Figure 1 Enlarged structural diagram of section B in the middle;

[0028] Figure 4 yes Figure 1 Enlarged structural diagram of section C;

[0029] Figure 5 This utility model is based on Figure 1 A schematic diagram of the sectional structure after cutting along the direction of the mid-section line of sight DD;

[0030] Figure 6 This utility model is based on Figure 1 A schematic diagram of the cross-sectional structure after the central section line of sight EE is cut along the direction of the cross section;

[0031] Reference numerals: 1-Electromagnetic coil; 11-Iron core; 12-Winding; 2-Permanent magnet; 21-Housing; 3-Mandrel; 31-Adapter shaft section; 32-Guide hole; 33-Cooling chamber; 331-Inlet; 332-Outlet; 333-Inlet column cavity; 334-Outlet column cavity; 335-Annular connecting groove; 34-Reader head limiting plate; 35-Upper section of mandrel; 36-Lower section of mandrel; 4-Sleeve; 41-Guide sleeve; 411-Upper limit position 42-Lower limit plate; 43-Sealing ring; 44-Guide post; 45-Heat dissipation layer; 46-Grid ruler 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-Reader head; 62-Grid ruler; 71-Upper buffer pad; 72-Lower buffer pad; 91-Body body adapter; 92-Fasting bolt; 93-Wheel adapter. Detailed Implementation

[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 construed as limiting the present invention.

[0033] As attached Figure 1-6As shown, a linear motor vibration damper includes an electromagnetic coil 1, a permanent magnet 2, a spindle 3, and a sleeve 4 sleeved on the outside of the electromagnetic coil 1. One of the electromagnetic coil 1 and the permanent magnet 2 is sleeved and connected to the outer wall of the spindle 3, and the other is disposed on the inner wall of the sleeve 4. The electromagnetic coil 1 and the permanent magnet 2 are arranged radially spaced apart on the spindle 3. It also includes a displacement sensor 6 for monitoring the axial relative displacement of the electromagnetic coil 1 and the permanent magnet 2. The sleeve 4 is characterized by having a guide sleeve 41 at its upper end and a sealed lower port at its lower end. The lower limiting plate 42 is provided, with the electromagnetic coil 1 and the permanent magnet 2 both located between the guide sleeve 41 and the lower limiting plate 42. The mandrel 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 mandrel 3 and the guide sleeve 41. The first sliding bearing 51 and the sealing ring 43 are both fixedly mounted on the inner wall of the guide sleeve 41. The first sliding bearing 51 and the sealing ring 43 are in sealing contact with the outer wall of the mandrel 3 and are axially slidingly fitted. The length of the electromagnetic coil 1 or the permanent magnet 2 mounted on the mandrel 3 in the axial direction of the mandrel 3 should be less than the distance between the limiting sleeve 21 and the lower limiting plate 42, so that it can reciprocate axially within the sleeve 4.

[0034] When this invention is applied to a vehicle, the upper end of the spindle 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 relative displacement between the vehicle body and the wheels in the vertical direction causes the spindle 3 and sleeve 4 to move relative to each other in the vertical direction. The displacement sensor 6 transmits the monitored relative displacement data of the spindle 3 and sleeve 4 to the vehicle controller. Based on the signal returned by the displacement sensor 6, the vehicle controller adjusts the current intensity and direction supplied to the electromagnetic coil 1 to generate electromagnetic fields of different intensities and directions. This causes the permanent magnet 2 to move upward or downward according to the changes in the magnetic field direction and intensity of the electromagnetic coil 1, thus counteracting the vibration of the vehicle body.

[0035] During the axial relative movement of the mandrel 3 and the sleeve 4, the mandrel 3 drives one of its electromagnetic coil 1 and permanent magnet 2 to move axially relative to the other within the sleeve 4. The other of the electromagnetic coil 1 and permanent magnet 2 is fixedly installed on the inner side wall of the sleeve 4. When the mandrel 3 moves to the lower limit position relative to the sleeve 4, the bottom surface of the mandrel 3 abuts against the top surface of the lower limit plate 42, limiting the mandrel 3. The electromagnetic coil 1 or permanent magnet 2 on the spindle 3 is always located inside the sleeve 4. The sealing ring 43 and the spindle 3 cooperate to seal the through hole on 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, thus improving the working reliability of the linear motor vibration damper. Even if impurities such as dust, gravel, and rainwater adhere to the outer wall of the spindle 3 exposed to the air, the spindle 3 slides relative to the sealing ring 43 during its downward movement. The sealing ring 43 scrapes the impurities on the side wall of the spindle 3 upwards, leaving them outside the sleeve 4, preventing the spindle 3 from bringing the impurities attached to it into the sleeve 4, further improving the working 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 spindle 3 upwards, leaving them outside the sleeve 4, further improving the reliability of the linear motor vibration damper described in this utility model. Compared to linear motor vibration dampers that use retractable accordion rubber sleeves for dust protection, the dust-proof structure of the electromagnetic coil 1 and permanent magnet 2 in this invention is simpler and has a better dust-proof effect, making the entire vibration damper safer and more reliable. Furthermore, the vibration damper of this invention has a smaller radial dimension, facilitating the layout and installation of other parts on the suspension.

[0036] The electromagnetic coil 1 generates a magnetic field after being energized, driving the permanent magnet 2 to move axially relative to each other, thereby driving the mandrel 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 windings 12 wound within the winding slots of the iron core 11; multiple windings 12 are provided and evenly distributed along the axial direction of the iron core 11. The iron core 11 has axially penetrating mounting holes. The permanent magnet 2 is generally a magnetic steel and is bonded to the mandrel 3 or sleeve 4 via 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 around the iron core 11 with winding slots. The electromagnetic coil 1 and the permanent magnet 2 have two arrangement methods, as shown below:

[0037] In Example 1, the electromagnetic coil 1 is coaxially disposed on the inner wall of the sleeve 4, and the permanent magnet 2 is sleeved and connected to the outer wall of the mandrel 3.

[0038] Example 2: The electromagnetic coil 1 is sleeved and connected to the outer wall of the mandrel 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 motion between the electromagnetic coil 1 and the permanent magnet 2, in Embodiment 1, the axial length of the electromagnetic coil 1 is greater than the axial length of the permanent magnet 2; in Embodiment 2, the axial length of the electromagnetic coil 1 is less than the axial length of the permanent magnet 2.

[0040] The spindle 3 is used to connect the upper end of the shock absorber to the vehicle body. Generally, the spindle 3 needs to be connected to the vehicle body via a body adapter 91. The body adapter 91 is an existing mechanism, which is generally bolted to the bottom of the vehicle body. Specifically, the top surface of the spindle 3 has an adapter section 31 with an outer diameter smaller than that of the spindle 3. The body adapter 91 is fitted onto the outer side of the adapter section 31. The upper end of the adapter section 31 protrudes from the top surface of the body adapter 91 and is threaded with a fastening bolt 92. The top surface of the spindle 3 abuts against the bottom surface of the body adapter 91, and the bottom surface of the fastening bolt 92 abuts against the top surface of the body adapter 91. The bottom surface of the fastening bolt 92 and the top surface of the spindle 3 cooperate to fasten the body adapter 91 to the adapter section 31.

[0041] The mandrel 3 can be a smooth shaft structure or a stepped shaft structure; it can be a solid cylinder structure or a hollow cylindrical structure. Preferably, the bottom wall of the mandrel 3 has a guide hole 32 with its opening facing downwards and its depth arranged along the axial direction of the mandrel 3. The top surface of the lower limiting plate 42 has a guide post 44, which is located 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 that the mandrel 3 moves along its axial direction and improve the reliability of the mandrel 3's movement.

[0042] The guide post 44 and the guide hole 32 can be directly slidably connected with a clearance fit. As a further preferred embodiment, a second sliding bearing 52 is provided between the sidewalls of the guide post 44 and the guide hole 32. The second sliding bearing 52 is fixedly mounted on the sidewall of the guide hole 32, and is sleeved on the outside of the guide post 44 with axial sliding engagement. A lower limiting block 53 protruding inward from its sidewall is provided on the guide hole 32. The lower limiting block 53 is located below the second sliding bearing 52, and is spaced apart from the outer sidewall of the guide post 44. The lower limiting block 53 supports the second sliding bearing 52 upward, keeping it always within the guide hole 32. By providing the second sliding bearing 52, the axial relative movement between the spindle 3 and the guide post 44 becomes smoother, avoiding wear caused by friction between the guide post 44 and the hole wall of the guide hole 32, thus improving the operational reliability of the linear motor vibration damper. The lower limit block 53 can be a bolt or pin arranged radially along the mandrel 3, or it can be a ring plate structure connected to the inner wall of the guide hole 32.

[0043] Considering that the vibration damper generates heat during operation, as a further preferred embodiment, the mandrel 3 has a cooling chamber 33, with both the inlet 331 and outlet 332 of the cooling chamber 33 located at the upper end of the mandrel 3. The cooling chamber 33 is filled with coolant, which enters through the inlet 331 and exits through the outlet 332, carrying away the heat generated during the vibration damper's operation. The cooling equipment is generally a water chiller. The axial length of the cooling chamber 33 on the mandrel 3 should be greater than the axial length of the electromagnetic coil 1 on the mandrel 3, so that the coolant can better absorb the heat generated by the electromagnetic coil 1.

[0044] The cooling cavity 33 can be a spiral channel structure, a structure of multiple interconnected annular channels, or a structure of multiple interconnected cylindrical cavities. Since the mandrel 3 is a slender hollow shaft structure, it is easier to manufacture the cooling cavity as a structure of multiple interconnected cylindrical cavities. If the mandrel 3 is a one-piece molded structure, it is difficult to manufacture the interconnected cylindrical cavities. Preferably, the mandrel 3 includes an upper section 35 and a lower section 36 arranged coaxially and adjacent to each other. The guide hole 32 is located on the upper section 35. The lower section 36 is a cylindrical structure with its inner wall protruding inward from the sidewall of the guide hole 32. The portion of the lower section 36 protruding inward from the guide hole 32 is the lower limiting block 53. The cooling cavity 33 includes an inlet column cavity 333, an outlet column cavity 334, and an annular connecting groove 335 disposed on the top surface of the lower section 36. Both the inlet column cavity 333 and the outlet column cavity 334 extend along the axial direction of the mandrel 3. The upper port of the liquid inlet chamber 333 is the liquid inlet 331, and the upper port of the liquid outlet chamber 334 is the liquid outlet 332, both connected to the upper section 35 of the mandrel. Multiple liquid inlet chambers 333 and multiple liquid outlet chambers 334 are evenly distributed circumferentially along the mandrel 3. The upper end face of the lower section 36 of the mandrel is sealed and welded to the lower end face of the upper section 35 of the mandrel. The lower ports of the liquid inlet chambers 333 and the lower ports of the liquid outlet chambers 334 are connected through the annular connecting groove 335. The interconnected liquid inlet chambers 333 and liquid outlet chambers 334 form a cooling circuit. The coolant in the cooling equipment enters the inlet column cavity 333 through the inlet port 331, then flows through the annular connecting groove 335 into the outlet column cavity 334. Finally, the coolant that has absorbed the heat from the vibration damper is returned to the cooling equipment through the outlet port 332 on the outlet column cavity 334 for further cooling. The mandrel 3 is designed as a welded assembly composed of the upper section 35 and the lower section 36, facilitating the fabrication of the inlet column cavity 333, the outlet column cavity 334, and the annular connecting groove 335. By setting multiple inlet columns 333 and outlet columns 334, multiple cooling circuits are formed evenly distributed on the mandrel 3, increasing the cooling area of ​​the mandrel 3 and achieving uniform and rapid cooling of the vibration damper. The axial length of the inlet column cavity 333 and the outlet column cavity 334 on the mandrel 3 should be greater than the axial length of the electromagnetic coil 1 on the mandrel 3, so that the coolant can better absorb the heat generated by the electromagnetic coil 1.

[0045] The sleeve 4 is used to connect the lower end of the shock absorber to the wheel frame, which is generally connected to the suspension arm of the wheel frame via an existing wheel adapter 93. Specifically, the bottom surface of the sleeve 4 is provided with a wheel adapter 93, which includes a connecting shaft and a U-shaped plate disposed at the lower end of the connecting shaft. The U-shaped groove opening on the U-shaped plate faces downward. The connecting shaft of the wheel adapter 93 is welded to the lower limiting plate 42 and is coaxially arranged with the guide post 44. The U-shaped plate on the wheel adapter 93 is generally connected to the suspension arm by bolts perpendicular to its sidewall.

[0046] The sleeve 4 has various structural forms, including a straight cylindrical structure with a uniform axial diameter and a stepped cylindrical structure with unequal axial diameters; its cross-sectional outer contour can be circular, rectangular, triangular, or regular hexagonal. For ease of 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, the heat dissipation layer 45 including multiple heat dissipation fins, which are evenly distributed on the outer wall of the sleeve 4. The heat dissipation fins should be made of a metal with a high thermal conductivity, and adjacent heat dissipation fins are spaced apart. By setting heat dissipation fins, the surface area of ​​the sleeve 4 is increased, which is more conducive to heat conduction. The vibration damper can dissipate heat not only through the circulation of coolant in the cooling chamber 33 but also through the heat dissipation fins on the sleeve 4, preventing overheating and damage to the vibration damper and improving its operational reliability.

[0047] The guide sleeve 41 should be sealed to the inner wall of the sleeve 4. The two can be welded, connected by a sealing thread using PTFE tape, or connected by threading and then filled with sealant at the joint. The guide sleeve 41 at the upper end of the sleeve 4 guides the movement of the spindle 3 and also seals the upper port of the sleeve 4 in conjunction with the spindle 3. The lower limit plate 42 at the lower end of the sleeve 4 seals the lower port of the guide sleeve 4 and axially limits the spindle 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 rigid collisions between the spindle 3 and the guide sleeve 41 when it moves to the upper limit position, and between the spindle 3 and the lower limit plate 42 when it moves to the lower limit position, reducing the probability of damage to the spindle 3, guide sleeve 41, and lower limit plate 42, and extending the service life of the vibration damper.

[0048] The cross-sections of the upper buffer pad 71 and the lower buffer pad 72 can be any shape, such as circular, annular, or square. Preferably, 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 mandrel 3, and 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 against the bottom surface of the first sliding bearing 51, and the upper buffer pad 71 slides axially with the mandrel 3 and the two are in sealed contact. The upper buffer pad 71 and the lower buffer pad 72 have the same structure, which is convenient for processing and manufacturing. The upper buffer pad 71 also supports the first sliding bearing 51 and prevents the first sliding bearing 51 from sliding down and falling off. In addition, the upper buffer pad 71 is also sealed with the mandrel 3 to further prevent impurities attached to the mandrel 3 from entering the sleeve 4. The materials of the upper buffer pad 71 and the lower buffer pad 72 can be elastic rubber pad structures such as nitrile rubber, silicone, and polyurethane, or they can be combined structures assembled from 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 mandrel 3 and the guide sleeve 41. When the mandrel 3 moves axially, it also scrapes any adhering material from the outer wall of the mandrel 3 to the outside of the sleeve 4, preventing 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, or polyurethane. Under the clamping action of the inner wall of the guide sleeve 41 and the outer wall of the mandrel 3, the sealing ring 43 should always be in an elastically compressed state. The sealing ring 43 can be fixed to the guide sleeve 41 by adhesive bonding, or an annular groove can be provided on the inner wall of the guide sleeve 41, and the sealing ring 43 can be engaged in the annular groove. The sliding fit between the first sliding bearing 51 and the mandrel 3 ensures smoother axial movement of the mandrel 3.

[0050] The displacement sensor 6 is used to monitor the axial relative displacement between the electromagnetic coil 1 and the permanent magnet 2, and the axial relative displacement between the spindle 3 and the sleeve 4, thereby detecting the axial displacement between the vehicle body and the wheels. The displacement sensor 6 can be installed on the outside of the sleeve 4 or on the inside of the sleeve 4. The displacement sensor 6 can be an inductive displacement sensor, a Hall effect sensor, an optical grating sensor, or a magnetic grating displacement sensor, etc. Preferably, the displacement sensor 6 is a magnetic grating displacement sensor; the displacement sensor 6 includes a read head 61 and a grating scale 62 disposed on the inside of the sleeve 4. The read head 61 is disposed at the lower end of the spindle 3, and the grating scale 62 is disposed 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, thus extending its service life. The length direction of the grating scale 62 is arranged along the axial direction of the spindle 3.

[0051] The reading head 61 and the grating ruler 62 should be located on the same radial straight line as the spindle 3 to ensure that the reading head 61 can sense the magnetic pole change of the grating ruler 62. Considering that during vehicle operation, the spindle 3 and the sleeve 4 may undergo relative deflection due to vibration or other reasons, which may lead to changes in the distance between the reading head 61 and the grating ruler 62 and affect the detection accuracy of the displacement sensor 6, preferably, the cross-section of the grating ruler 62 is a fan-shaped annular structure or annular structure coaxial with the spindle 3. Even if the relative deflection of the spindle 3 and the sleeve 4 causes the reading head 61 and the grating ruler 62 to rotate relative to each other, the reading head 61 can still sense the magnetic pole change of the grating ruler 62, improving the accuracy and reliability of the displacement sensor 6. It can transmit the axial relative movement information of the spindle 3 and the sleeve 4 back to the vehicle controller in real time and accurately, so that the vehicle controller can adjust the current direction and intensity of the electromagnetic coil 1 in real time and accurately, thereby timely and accurately adjusting the damping capacity of the entire shock absorber, making the damping capacity of the shock absorber match the vehicle's operating state, and improving the comfort and safety of the vehicle ride. During vehicle operation, the deflection angle of spindle 3 and sleeve 4 is generally around 10°. Therefore, the central angle corresponding to the grid ruler 62 is required to be above 10° to ensure the detection accuracy of displacement sensor 6.

[0052] When the sleeve 4 has a straight cylindrical structure, because the outer diameter of the electromagnetic coil 1 is relatively small, directly mounting the reading head 61 on the spindle 3 and the grating ruler 62 on the sleeve 4 would result in a large gap between the reading head 61 and the grating ruler 62, making it impossible for the reading head 61 to sense changes in the magnetic poles of the grating ruler 62. Preferably, the sleeve 4 includes an upper cylindrical section 47 and a lower cylindrical section 48 arranged coaxially. The outer diameter of the upper cylindrical section 47 is larger than the outer diameter of the lower cylindrical section 48, and the inner diameter of the upper cylindrical section 47 is larger than the inner diameter of the lower cylindrical section 48. The grating ruler 62 is mounted on the inner wall of the lower cylindrical section 48. Reducing the gap between the reading head 61 and the grating ruler 62 improves the operational reliability of the displacement sensor 6.

[0053] Preferably, a reading head limiting plate 34 is provided at the lower end of the outer side wall of the mandrel 3, and the bottom surface of the reading head 61 is in contact with the top surface of the reading head limiting plate 34; a grid ruler limiting plate 46 is provided at the lower end of the inner side wall of the sleeve 4, and the bottom surface of the grid ruler 62 is in contact with the top surface of the grid ruler limiting plate 46. The reading head limiting plate 34 is used to install the reading head 61 and simultaneously limit the reading head 61 axially downward to prevent the reading head 61 from sliding down; the grid ruler limiting plate 46 is used to limit the grid ruler 62 axially downward to prevent the grid ruler 62 from sliding down. This ensures the sensing accuracy of the relative displacement between the reading head 61 and the grid ruler 62, improves the monitoring accuracy of the displacement sensor 6, and thus ensures that the vehicle controller can more accurately control the damper's buffering capacity, thereby improving the vehicle's ride comfort.

[0054] The upper cylinder section 47 and the lower cylinder section 48 are generally connected by a ring plate. Preferably, the electromagnetic coil 1 is sleeved and connected to the outer wall of the mandrel 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 cylinder section 47 and the lower cylinder section 48, the inner wall of the support ring plate 49 is connected to the outer wall of the upper end of the lower cylinder 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 cylinder section 47; the top surface of the support ring plate 49 abuts against the bottom wall of the permanent magnet 2; when the mandrel 3 is in 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 sealed to 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 cylinder section 47 and the lower cylinder section 48 and seals the joint between them. The outer wall of the upper limit ring 411 cooperates with the inner wall of the sleeve 4 to install the guide sleeve 41 at the upper port of the sleeve 4 and seal the upper port of the sleeve 4. In addition, the upper limit ring 411 and the support ring plate 49 cooperate to axially position the permanent magnet 2, preventing the permanent magnet 2 from sliding axially after falling off and affecting its induction intensity with the electromagnetic coil 1, thus ensuring the adjustment accuracy and stability of the vibration damper.

[0055] The embodiments described herein are preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape, and principle of this utility model should be included within the scope of protection of this utility model.

[0056] In the description of this utility model, the terms "upper," "lower," "top," "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figure. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe the positional relationship in the figure are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above-mentioned terms can be understood according to the specific circumstances.

Claims

1. A linear motor vibration damper, comprising an electromagnetic coil (1), a permanent magnet (2), a spindle (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 spindle (3), and the other is disposed on the inner wall of the sleeve (4), and the electromagnetic coil (1) and the permanent magnet (2) are arranged radially spaced on the spindle (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 limiting plate (42) that seals its lower port. The electromagnetic coil (1) and the permanent magnet (2) are both located between the guide sleeve (41) and the lower limiting plate (42). The spindle (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 mandrel (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 mandrel (3) and are axially slidingly engaged.

2. The linear motor vibration damper according to claim 1, characterized in that: The electromagnetic coil (1) is sleeved and connected to the outer wall of the mandrel (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 less than the axial length of the permanent magnet (2).

3. The linear motor vibration damper according to claim 1, characterized in that: The bottom wall of the mandrel (3) is provided with a guide hole (32) with the opening facing downward and the depth arranged along the axial direction of the mandrel (3). The top surface of the lower limiting plate (42) is provided with a guide post (44). A second sliding bearing (52) is provided between the guide post (44) and the side wall of the guide hole (32). The second sliding bearing (52) is fixedly installed on the side wall of the guide hole (32). The second sliding bearing (52) is sleeved on the outside of the guide post (44) and the two slide in axial direction. The guide hole (32) is provided with a lower limiting block (53) that protrudes inward from its side wall. The lower limiting block (53) is located below the second sliding bearing (52). The lower limiting block (53) and the outer side wall of the guide post (44) are arranged at intervals.

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

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

6. The linear motor vibration damper 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 limiting 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 mandrel (3), and 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 against the bottom surface of the first sliding bearing (51). The upper buffer pad (71) and the mandrel (3) slide axially and are in sealed contact.

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

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

9. The linear motor vibration damper according to claim 8, characterized in that: The lower end of the outer wall of the mandrel (3) is provided with a reading head limiting plate (34), and the bottom surface of the reading head (61) is in contact with the top surface of the reading head limiting plate (34); the lower end of the inner wall of the sleeve (4) is provided with a grid ruler limiting plate (46), and the bottom surface of the grid ruler (62) is in contact with the top surface of the grid ruler limiting plate (46).

10. The linear motor vibration damper according to claim 9, characterized in that: The electromagnetic coil (1) is sleeved and connected to the outer wall of the mandrel (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 cylinder section (47) and the lower cylinder section (48). The inner wall of the support ring plate (49) is connected to the outer wall of the upper end of the lower cylinder 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 cylinder section (47). The top surface of the support ring plate (49) abuts against the bottom wall of the permanent magnet (2). When the spindle (3) is in 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 to the inner wall of the sleeve (4). The bottom surface of the sleeve (4) abuts against the top surface of the permanent magnet (2).

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