Differential lock device and vehicle with same

Abstract

The invention provides a differential lock device and a vehicle with the same. The differential lock device comprises a first friction piece and a second friction piece, the first friction piece is connected with the movable gear sleeve, the first friction piece can slide relative to the movable gear sleeve in the axial direction of the first driving shaft, and the first friction piece is provided with a first matching end face arranged towards the side where the second driving shaft is located; the second friction piece and the first friction piece are oppositely arranged in the axial direction of the first driving shaft, the second friction piece is connected with the combined teeth, and the second friction piece is provided with a second matching end face arranged towards the first friction piece; wherein the first matching end face and the second matching end face are each provided with a plurality of first coating areas and a plurality of second coating areas, the first coating areas and the second coating areas are alternately arranged in the circumferential direction, and the friction coefficient of coating materials of the first coating areas is larger than that of coating materials of the second coating areas. According to the scheme, the problem that a padlock of a differential lock structure in the prior art is prone to tooth abutting is solved.

Description

Technical Field

[0001] This invention relates to the field of vehicle drive technology, and more specifically, to a differential lock device and a vehicle having the same. Background Technology

[0002] With the rapid development of new energy vehicles and rugged off-road vehicles, higher demands are being placed on their ability to overcome obstacles and their passability. Differential locks, as a key component, are widely used in the drive axle reducers of these vehicles. When a vehicle is traveling on rough terrain such as mud, snow, or sand, if one drive wheel slips and spins freely, the differential lock can forcibly lock the differential, making the left and right half-shafts a rigid unit, transmitting power to the wheels that still have traction, thus ensuring normal vehicle traction.

[0003] Currently, most mainstream differential lock structures employ a splined gear sleeve engagement type. Its basic working principle is as follows: an actuator (such as a motor or cylinder) drives a shift fork, pushing a gear sleeve with internal splines axially to engage with an external splined gear ring fixed on the other half-shaft, thus achieving locking. However, during the locking process, due to the speed difference between the two half-shafts of the differential and the lack of an effective synchronization mechanism between the gear sleeve and the gear ring, a "tooth collision" phenomenon easily occurs. That is, the end faces of the internal spline teeth of the gear sleeve and the external spline teeth of the gear ring collide head-on just before engagement, instead of smoothly sliding into the tooth groove. This phenomenon can lead to the following consequences:

[0004] 1) Padlock failure: The actuator thrust is insufficient to overcome the axial force caused by the top tooth, resulting in the gear sleeve being unable to engage and the differential lock function failing.

[0005] 2) Impact and noise: The top gear will generate a huge impact force and a harsh metallic clanging sound, which will seriously reduce the driving comfort and premium feel of the vehicle.

[0006] 3) Parts wear: Frequent impacts from the top teeth can cause severe wear on the ends of the spline teeth, and even cause tooth breakage, which reduces the service life and reliability of the differential lock in the long run.

[0007] There is currently no effective solution to the aforementioned technical problems. Summary of the Invention

[0008] The main objective of this invention is to provide a differential lock device and a vehicle having it, so as to solve the problem of tooth breakage in the padlock structure of the differential lock in the prior art.

[0009] To achieve the above objectives, according to one aspect of the present invention, a differential lock device is provided, comprising a movable gear sleeve disposed on a first drive shaft of a differential and a engaged tooth disposed on a second drive shaft of a differential. The differential lock device further comprises: a first friction member connected to the movable gear sleeve and slidably disposed relative to the movable gear sleeve along the axial direction of the first drive shaft; the first friction member having a first mating end face facing the side where the second drive shaft is located; and a second friction member disposed opposite to the first friction member along the axial direction of the first drive shaft, the second friction member being connected to the engaged tooth and having a second mating end face facing the first friction member; wherein both the first and second mating end faces are provided with a plurality of first coating areas and a plurality of second coating areas. The coating area is divided into two circumferentially alternating areas. The friction coefficient of the coating material in the first coating area is greater than that in the second coating area. When the movable toothed sleeve is in its initial state, the first friction element is in its initial position, and the first mating end face protrudes from the movable toothed sleeve along the axial direction of the first drive shaft. During the padlocking process, the movable toothed sleeve moves toward the engaged tooth. The contact between the first mating end face and the second mating end face precedes the contact between the movable toothed sleeve and the engaged tooth. When the first coating area of ​​the first mating end face and the first coating area of ​​the second mating end face come into contact with each other, the frictional torque generated by the first mating end face and the second mating end face can cause the first drive shaft and the second drive shaft to perform a pre-alignment action. The pre-alignment action occurs before the engagement action of the movable toothed sleeve and the engaged tooth.

[0010] Furthermore, the movable gear sleeve also has an installation space. The differential lock device further includes: an axial preload mechanism, which is located within the installation space and is movably arranged along the radial direction of the movable gear sleeve, so that the axial preload mechanism has a limiting position and a clearance position. When the axial preload mechanism is in the limiting position, at least a portion of the axial preload mechanism is located outside the installation space. When the movable gear sleeve is in its initial state, the first friction element is located on the side of the axial preload mechanism facing the second drive shaft, and the axial preload mechanism is in the limiting position. During the padlock process, the axial preload mechanism... As the movable toothed sleeve moves synchronously toward the tooth to be engaged, during the pre-alignment process, the axial preload mechanism applies a first axial force toward the side where the second drive shaft is located to ensure that the first friction element is in contact with the second friction element. After the pre-alignment is completed, the axial preload mechanism moves from the limiting position to the clearance position so that the first friction element moves away from the second friction element, thereby disengaging from the second friction element. During the engagement of the movable toothed sleeve with the tooth to be engaged, the axial preload mechanism moves from the clearance position to the limiting position to limit the first friction element to the side of the axial preload mechanism away from the second friction element.

[0011] Furthermore, the axial preload mechanism includes: a shaped limiting block, which is connected to the bottom of the installation space via an elastic element. The shaped limiting block has a first inclined surface and a second inclined surface that are arranged opposite to each other along the axial direction of the first drive shaft, with the first inclined surface facing the side where the second drive shaft is located. When the movable toothed sleeve is in its initial state, the first friction element is positioned close to the first inclined surface. During the pre-alignment operation, the first inclined surface applies a first axial force toward the side where the second drive shaft is located to the first friction element to ensure that the first friction element contacts the second friction element. After the pre-alignment operation is completed, the first friction element passes over the top of the shaped limiting block and moves away from the second friction element along the first inclined surface. During the engagement of the movable toothed sleeve with the engaged tooth, the first friction element is positioned close to the second inclined surface, and the second inclined surface applies a second axial force away from the side where the second drive shaft is located to limit the first friction element to the side of the shaped limiting block away from the second friction element.

[0012] Furthermore, the differential lock device also includes: a housing, a movable gear sleeve, a engaged gear, a first friction element, a second friction element, and an axial preload mechanism, all located within the housing; and a baffle, which is disposed within the housing and connected to the housing, and is located on the side of the first friction element opposite to the second friction element, and partially obscures the first friction element along the axial direction of the first drive shaft.

[0013] Furthermore, the movable gear sleeve includes a first driving section and a first engaging section. The first engaging section is disposed near the side where the second driving shaft is located. Along the radial direction of the first driving shaft, the first engaging section and the first driving shaft are disposed at a distance. A first internal spline is provided on the inner circumferential surface of the first engaging section facing the first driving shaft. The engaged tooth includes a second driving section and a second engaging section. The second engaging section is disposed near the side where the first driving shaft is located. A first external spline is provided on the outer circumferential surface of the second engaging section. When the first internal spline and the first external spline mesh, the movable gear sleeve engages with the engaged tooth. The first friction element and the axial preload mechanism are both disposed on the first engaging section.

[0014] Furthermore, one of the first external spline and the first internal spline is a tooth groove, and the other is a spline tooth, with the width of the tooth groove being greater than the width of the spline tooth.

[0015] Furthermore, the second mating end face is flush with the end face of the tooth being mated.

[0016] Furthermore, a second external spline is provided on the outer circumferential surface of the movable gear sleeve, and a second internal spline is provided on the first friction element. The first friction element and the movable gear sleeve are slidably connected through the second internal spline and the second external spline.

[0017] Furthermore, the first mating end face is configured identically to the second mating end face.

[0018] According to another aspect of the present invention, a vehicle is provided, including a differential lock device, wherein the differential lock device is the differential lock device described above.

[0019] By applying the technical solution of this invention, during the padlock process, the movable toothed sleeve moves towards the direction of the engaged tooth. The contact between the first mating end face and the second mating end face occurs before the movable toothed sleeve contacts the engaged tooth. When the first coating area of ​​the first mating end face and the first coating area of ​​the second mating end face come into contact with each other, the frictional torque generated by the high friction coefficient area can cause the first drive shaft and the second drive shaft to perform a pre-alignment action. Since the pre-alignment occurs before the actual engagement action of the movable toothed sleeve and the engaged tooth, the speed difference between the two drive shafts is eliminated or significantly reduced, ensuring that the phase of the movable toothed sleeve and the engaged tooth is aligned when they contact each other, thereby avoiding tooth-pinning phenomenon. This solves the problem of tooth-pinning that easily occurs in differential lock structure padlocks in the prior art, achieving a smooth and impact-free padlock, improving the success rate of the padlock. At the same time, the smooth implementation of the padlock process also significantly reduces the impact and noise during the padlock process, reduces wear, improves the user experience, and extends the service life of the differential lock. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 A schematic diagram of an embodiment of the differential lock device according to the present invention is shown;

[0022] Figure 2 It shows Figure 1 An enlarged schematic diagram of part A in the middle;

[0023] Figure 3 A schematic diagram of an embodiment of the differential lock device according to the present invention is shown;

[0024] Figure 4 A schematic diagram of an embodiment of the first mating end face of the first friction member according to the present invention is shown.

[0025] The above figures include the following reference numerals:

[0026] 1. First drive shaft;

[0027] 2. Second drive shaft;

[0028] 3. Movable gear sleeve;

[0029] 4. Elastic components;

[0030] 5. Irregularly shaped limiting blocks;

[0031] 6. First friction component; 61. First coating area; 62. Second coating area;

[0032] 7. Second friction component;

[0033] 8. The teeth being engaged;

[0034] 9. Shift fork;

[0035] 10. Baffle. Detailed Implementation

[0036] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0040] Combination Figures 1 to 4As shown, according to another specific embodiment of this application, a differential lock device is provided.

[0041] Specifically, the differential lock device includes a movable gear sleeve 3 disposed on the first drive shaft 1 of the differential and a engaged tooth 8 disposed on the second drive shaft 2 of the differential. The differential lock device further includes: a first friction member 6, which is connected to the movable gear sleeve 3 and is slidably disposed relative to the movable gear sleeve 3 along the axial direction of the first drive shaft 1; the first friction member 6 has a first mating end face facing the side where the second drive shaft 2 is located; and a second friction member 7, which is disposed opposite to the first friction member 6 along the axial direction of the first drive shaft 1 and is connected to the engaged tooth 8; the second friction member 7 has a second mating end face facing the first friction member 6. Both the first and second mating end faces are provided with multiple first coating areas 61 and multiple second coating areas 62. The first coating area 61 is circumferentially alternated with the second coating area 62. The coefficient of friction of the coating material in the first coating area 61 is greater than that in the second coating area 62. When the movable toothed sleeve 3 is in its initial state, the first friction element 6 is in its initial position, and the first mating end face protrudes from the movable toothed sleeve 3 along the axial direction of the first drive shaft 1. During the padlock process, the movable toothed sleeve 3 moves toward the engaged tooth 8. The contact between the first mating end face and the second mating end face precedes the contact between the movable toothed sleeve 3 and the engaged tooth 8. When the first coating area 61 of the first mating end face and the first coating area 61 of the second mating end face come into contact with each other, the frictional torque generated by the first mating end face and the second mating end face can cause the first drive shaft 1 and the second drive shaft 2 to perform a pre-alignment action. The pre-alignment action occurs before the engagement action of the movable toothed sleeve 3 and the engaged tooth 8.

[0042] Applying the technical solution of this embodiment, during the padlock process, the movable toothed sleeve 3 moves towards the engaged tooth 8. The contact between the first mating end face and the second mating end face occurs before the movable toothed sleeve 3 contacts the engaged tooth 8. When the first coating area 61 of the first mating end face and the first coating area 61 of the second mating end face contact each other, the frictional torque generated by the high friction coefficient area can cause the first drive shaft 1 and the second drive shaft 2 to perform a pre-alignment action. Since the pre-alignment occurs before the actual engagement action of the movable toothed sleeve 3 and the engaged tooth 8, the speed difference between the two drive shafts is eliminated or significantly reduced, ensuring that the phase of the movable toothed sleeve 3 and the engaged tooth 8 is aligned when they contact each other, thereby avoiding tooth tipping. This solves the problem of tooth tipping that easily occurs in differential lock structure padlocks in the prior art, achieving a smooth and impact-free padlock, improving the success rate of the padlock. At the same time, the smooth implementation of the padlock process also significantly reduces the impact and noise during the padlock process, reduces wear, and improves the user experience and the service life of the differential lock.

[0043] Furthermore, the movable gear sleeve 3 also has an installation space. The differential lock device also includes an axial preload mechanism, which is located within the installation space. The axial preload mechanism is movably arranged along the radial direction of the movable gear sleeve 3, so that the axial preload mechanism has a limiting position and a clearance position. When the axial preload mechanism is in the limiting position, at least part of the axial preload mechanism is located outside the installation space. When the movable gear sleeve 3 is in the initial state, the first friction member 6 is located on the side of the axial preload mechanism facing the second drive shaft 2, and the axial preload mechanism is in the limiting position. During the padlock process, the axial preload mechanism follows the movable gear sleeve 3. The sleeve 3 moves synchronously toward the engaged tooth 8. During the pre-alignment process, the axial preload mechanism applies a first axial force toward the side where the second drive shaft 2 is located to the first friction member 6 to ensure that the first friction member 6 contacts the second friction member 7. After the pre-alignment is completed, the axial preload mechanism moves from the limiting position to the avoidance position so that the first friction member 6 moves away from the second friction member 7, thereby disengaging from the second friction member 7. During the engagement of the movable tooth sleeve 3 with the engaged tooth 8, the axial preload mechanism moves from the avoidance position to the limiting position to limit the first friction member 6 to the side of the axial preload mechanism away from the second friction member 7.

[0044] In this embodiment, during the pre-alignment process of the padlock, the axial preload mechanism moves synchronously toward the engaged tooth 8 along with the movable toothed sleeve 3. By applying an axial force to the first friction member 6, it maintains contact with the second friction member 7 until the pre-alignment is completed. Subsequently, the axial preload mechanism moves from the limiting position to the clearance position, allowing the first friction member 6 to move away from the second friction member 7 and eventually disengage from it. When the movable toothed sleeve 3 continues to move and engages with the engaged tooth 8, the axial preload mechanism returns from the clearance position to the limiting position, confining the first friction member 6 to the side of the axial preload mechanism opposite to the second friction member 7. The position switching process of the axial preload mechanism ensures the effective release time of the first friction element 6 and the second friction element 7 during the padlock process, as well as the timely separation after phase synchronization. This ensures the smooth realization of the phase alignment process on both sides during pre-synchronization, effectively avoiding tooth-biting phenomena. At the same time, it automatically disengages after locking, preventing the first friction element 6 and the second friction element 7 from continuing to abut after pre-synchronization, which may hinder the movement of the movable tooth sleeve 3. This reduces unnecessary frictional losses and improves the reliability and service life of the differential lock.

[0045] Specifically, the axial preload mechanism includes a shaped limiting block 5, which is connected to the bottom of the installation space via an elastic member 4. The shaped limiting block 5 has a first inclined surface and a second inclined surface that are arranged opposite each other along the axial direction of the first drive shaft 1. The first inclined surface is arranged towards the side where the second drive shaft 2 is located. When the movable tooth sleeve 3 is in its initial state, the first friction member 6 is arranged close to the first inclined surface. During the pre-alignment operation, the first inclined surface applies a first axial force towards the side where the second drive shaft 2 is located to the first friction member 6 to ensure that the first friction member 6 contacts the second friction member 7. After the pre-alignment operation is completed, the first friction member 6 passes over the top of the shaped limiting block 5 and moves away from the second friction member 7 along the first inclined surface. During the engagement of the movable tooth sleeve 3 with the engaged tooth 8, the first friction member 6 is arranged close to the second inclined surface, and the second inclined surface applies a second axial force away from the side where the second drive shaft 2 is located to limit the first friction member 6 to the side of the shaped limiting block 5 away from the second friction member 7.

[0046] In this embodiment, the axial preload mechanism employs a shaped limiting block 5, which is connected to the bottom of the installation space via an elastic element 4. The shaped limiting block 5 has a first inclined surface and a second inclined surface opposite each other along the axial direction of the first drive shaft 1, with the first inclined surface facing the side where the second drive shaft 2 is located. Initially, the first friction element 6 is positioned close to the first inclined surface. During pre-alignment, the first inclined surface applies a first axial force to the first friction element 6 towards the second drive shaft 2, causing the first friction element 6 and the second friction element 7 to come into close contact, achieving synchronization. After pre-alignment, the first friction element 6 passes the top of the shaped limiting block 5. During the engagement of the movable gear sleeve 3 and the engaged gear 8, the first friction element 6 is positioned close to the second inclined surface. At this time, the second inclined surface applies a second axial force towards the side away from the second drive shaft 2, limiting the first friction element 6 to the side of the shaped limiting block 5 away from the second friction element 7, ensuring that the synchronization mechanism does not interfere with the normal gear sleeve engagement operation. The technical solution of this embodiment utilizes the relative positional change of the inclined plane and the friction component to achieve precise control and smooth transition of the synchronization process, effectively avoiding the tooth-biting phenomenon during the padlock process, and improving the success rate of the padlock and the service life of the differential lock.

[0047] In other embodiments, the axial preload mechanism may also take the form of spring steel balls, hydraulic linear actuators, solenoid valves, etc., to adapt to a wider range of application scenarios and needs.

[0048] Furthermore, the differential lock device also includes a housing and a baffle 10. The movable gear sleeve 3, the engaged gear 8, the first friction element 6, the second friction element 7, and the axial preload mechanism are all located inside the housing. The baffle 10 is disposed inside the housing and connected to the housing. The baffle 10 is located on the side of the first friction element 6 away from the second friction element 7 and partially blocks the first friction element 6 along the axial direction of the first drive shaft 1.

[0049] In this embodiment, the housing serves to enclose and support the movable toothed sleeve 3, the engaged tooth 8, the first friction element 6, the second friction element 7, and the axial preload mechanism, ensuring the stability of the overall structure and the precise alignment between components. The baffle 10 is located on one side of the second friction element 7 of the first friction element 6. The baffle 10 partially obstructs the first friction element 6, causing it to move a certain distance away from the second friction element 7 before contacting the baffle 10. This prevents the first friction element 6 from moving further, ensuring that it accurately returns to its initial position during the unlocking process, ready for the next use of the padlock.

[0050] Specifically, the movable gear sleeve 3 includes a first driving section and a first engaging section. The first engaging section is located near the side where the second driving shaft 2 is located. Along the radial direction of the first driving shaft, the first engaging section is spaced apart from the first driving shaft 1. A first internal spline is provided on the inner circumferential surface of the first engaging section facing the first driving shaft 1. The engaged tooth 8 includes a second driving section and a second engaging section. The second engaging section is located near the side where the first driving shaft 1 is located. A first external spline is provided on the outer circumferential surface of the second engaging section. When the first internal spline and the first external spline mesh, the movable gear sleeve 3 engages with the engaged tooth 8. The first friction element 6 and the axial preload mechanism are both located on the first engaging section.

[0051] In this embodiment, the movable gear sleeve 3 includes a first driving section and a first engaging section. The first engaging section is located adjacent to the second driving shaft 2 and is radially spaced from the first driving shaft 1. The inner circumferential surface of the first engaging section facing the first driving shaft 1 is provided with a first internal spline. The engaged tooth 8 is composed of a second driving section and a second engaging section. The second engaging section is close to the first driving shaft 1, and its outer circumferential surface is provided with a first external spline that matches the first internal spline. When the first internal spline and the first external spline accurately mesh, the movable gear sleeve 3 and the engaged tooth 8 form a locked state, realizing the differential lock function. The first friction element 6 and the axial preload mechanism are both mounted on the first engaging section of the movable gear sleeve 3. This ensures that before the differential lock is engaged, the friction of the first friction element 6 and the axial preload mechanism work together to automatically adjust and eliminate the speed difference between the two half-shafts, ensuring precise alignment of the internal and external splines. This allows the locking action to be completed smoothly and without impact under the actuator's push. In addition, the axial preload mechanism causes the first friction element 6 to quickly disengage after successful padlocking, avoiding damage to the mechanism caused by continuous friction and ensuring the efficiency and smoothness of the padlocking and unlocking process.

[0052] Preferably, one of the first external spline and the first internal spline is a groove and the other is a spline tooth, with the width of the groove being greater than the width of the spline tooth.

[0053] In this embodiment, the width of the tooth groove is greater than the width of the spline tooth. This allows the tooth sleeve to more easily find the correct engagement point with the tooth ring during padlock operation, even in cases of speed differences and phase misalignment, thus significantly reducing tooth tipping. The dimensional difference between the tooth groove and the spline tooth provides sufficient space, enabling rapid synchronization through relative sliding on both sides during the initial stage of padlock operation, even if the splines of the tooth sleeve and the tooth ring are not ideally aligned. Furthermore, this design helps to reduce spline tooth wear and extend the overall service life of the differential lock.

[0054] Furthermore, the second mating end face is flush with the end face of the mating tooth 8.

[0055] In this embodiment, the second mating end face is flush with the end face of the tooth 8 being engaged, so that the first mating end face protruding from the end face of the first drive shaft can contact the second mating end face within a small stroke range, ensuring pre-synchronization before the two drive shafts engage.

[0056] Furthermore, a second external spline is provided on the outer peripheral surface of the movable gear sleeve 3, and a second internal spline is provided on the first friction member 6. The first friction member 6 and the movable gear sleeve 3 are slidably connected through the second internal spline and the second external spline.

[0057] In this embodiment, the outer peripheral surface of the movable toothed sleeve 3 is provided with a second external spline, while the first friction member 6 is equipped with a second internal spline. Through the sliding connection between the second internal spline and the second external spline, the first friction member 6 can achieve axial sliding on the movable toothed sleeve 3 while maintaining coaxiality. This ensures that the relative movement between the friction member and the toothed sleeve is smooth, guarantees the stability and reliability of the friction member during the synchronization process, and effectively improves the success rate of the differential lock padlock and the durability of the entire system.

[0058] Furthermore, the first mating end face is configured identically to the second mating end face.

[0059] In this embodiment, the first mating end face and the second mating end face are set in the same way to ensure that the friction coefficient changes in the same way during the relative movement of the two. Thus, in the padlock and unlocking operation, the contact of the high friction coefficient area can be quickly found and maintained, so as to achieve rapid synchronization and accurate positioning.

[0060] It should be understood that the first mating end face and the second mating end face being the same means that the area size, alternation pattern and coating material of the first coating area 61 and the second coating area 62 on the two end faces are the same, and the size of the first mating end face and the second mating end face are the same.

[0061] This application also provides a preferred embodiment of a differential lock device.

[0062] Specifically, the differential lock device in this embodiment is a differential lock mechanism with active synchronization function. Based on the traditional differential lock mechanism (including gear sleeve, shift fork 9 and actuator), it introduces a phase self-addressing friction synchronization device. The core of the synchronization device consists of a movable end friction component (i.e. the aforementioned first friction component 6, referred to as the movable end in the following description), a fixed end friction component (i.e. the aforementioned second friction component 7, referred to as the fixed end in the following description), and a limiting spring slider mechanism (i.e. the aforementioned axial preload mechanism, referred to as the spring limiting block in the following description, including spring and slider).

[0063] The specific structure of the synchronization device is as follows: the movable end friction component is coaxially fixed with the gear sleeve and can undergo limited relative axial displacement; the fixed end friction component is fixedly mounted on the differential housing or a component connected to the target gear ring, and is arranged opposite to the movable end friction component. On the opposing surfaces of the movable end friction component and the fixed end friction component, alternating fan-shaped friction areas are arranged according to the pitch of their circumferential splines. These areas are of two types:

[0064] High friction coefficient region (μmax): Made of carbon fiber composite materials, powder metallurgy friction materials or special coatings, it has a large friction coefficient.

[0065] Low friction coefficient region (μmin): This is a smooth surface or coating with a very small friction coefficient.

[0066] This special arrangement causes the effective coefficient of friction between the two friction surfaces to change with their relative circumferential positions.

[0067] The working principle of the synchronization device is as follows:

[0068] 1) Padlock process (synchronization and engagement):

[0069] When the actuator pushes the toothed sleeve to move in the engagement direction through the shift fork, the toothed sleeve first causes the moving end friction component to press against the fixed end friction component.

[0070] Phase self-addressing stage: At initial contact, if the two parts happen to be in opposite positions within the low friction coefficient region, due to the very small frictional torque, relative slippage will occur between the moving end and the fixed end driven by any tiny difference in rotational speed on both sides. This slippage process is actually an automatic process of finding the optimal engagement phase.

[0071] Synchronization Phase: When the relative rotations reach the high-friction coefficient region and are directly opposite each other, the resulting frictional torque increases dramatically. At this point, the limit spring-slider mechanism begins to function. This mechanism provides an axial preload that increases with displacement on the mating surface between the gear sleeve and the moving end friction component, ensuring that the moving end is firmly pressed against the fixed end. The resulting huge frictional torque can quickly eliminate the speed difference between the gear sleeve and the gear ring, achieving forced synchronization. Furthermore, since the phase of the sector region and the spline tooth groove is precisely matched, the instant the high-friction region is in complete contact means that the inner spline of the gear sleeve and the outer spline of the gear ring are also aligned.

[0072] Engagement and Disengagement Phase: After synchronization is complete, the shift fork 9 continues to push the gear sleeve axially. The gear sleeve smoothly slides into the gear ring to complete engagement without any impact noise. At the same time, the moving end friction component, driven by the gear sleeve, overcomes the pressure of the limit spring slider and passes its highest point. Subsequently, the diameter of the hole that mates with the slider increases, the slider resets under the action of the spring, and the moving end friction component loses its axial constraint. Under the reaction force, it quickly separates from the fixed end friction component, thus ceasing to participate in the work after locking, avoiding unnecessary friction wear and power loss.

[0073] 2) Unlocking process (reset):

[0074] When unlocking is required, the actuator drives the toothed sleeve to move in the opposite direction via the shift fork 9. The toothed sleeve first moves backward a short distance, and under the resistance of the spring limit block, it moves the moving end friction component backward as well. The moving end friction component stops after contacting a fixed limit structure, while the toothed sleeve continues to retract, causing the two to re-displace relative to each other. This relative displacement forces the moving end friction component to re-compress the limit spring slider and pass its highest point, finally being pushed back to the initial position at the very front of the toothed sleeve under the action of the spring force, preparing for the next padlock synchronization process.

[0075] Compared to traditional differential lock mechanisms, the differential lock device in this embodiment adds a synchronization structure. This synchronization structure consists of a moving end friction component and a fixed end friction component. This structure allows the gear sleeve to rotate synchronously before the inner and outer splines make contact. Furthermore, the surface of the synchronization structure is designed with fan-shaped regions matched to the phase positions of the spline teeth. Different regions are divided into friction surfaces with a large coefficient of friction μmax and smooth surfaces with a small coefficient of friction μmin. This ensures that when the gear sleeve spline is at the position of the top tooth during locking, the coefficient of friction between the two friction surfaces is relatively small due to the phase relationship of the synchronization structure. Under the influence of the speed difference on both sides, the two friction surfaces will rotate relative to each other. After rotating a certain angle, the materials with the larger coefficient of friction between the two friction surfaces come into contact and can transmit frictional torque. Simultaneously, a limiting spring slider exists at the mating point between the moving end friction component and the gear sleeve. As the differential lock actuator pushes the shift fork to move the gear sleeve forward, the limiting spring slider provides an axial force to the moving end friction component. This axial force gradually increases with displacement, ensuring that the moving end friction component and the fixed end friction component can generate sufficient frictional torque to prevent relative rotation on both sides of the differential lock gear sleeve. At this time, due to the friction surfaces with a larger coefficient of friction facing each other, the internal spline teeth and external spline grooves of the differential lock are aligned. As the shift fork continues to push forward, the differential lock gear sleeve can engage smoothly. At the same time, the moving end friction component fully presses the limiting spring slider into place and past the highest point of the slider. As the gear sleeve continues to move, the inner diameter of the mating part between the moving end friction component and the slider increases. Under the action of the slider spring force, the moving end friction component moves rapidly backward relative to the gear sleeve, causing the moving end friction surface to separate from the fixed end friction surface, and the gear sleeve engages normally.

[0076] When it is necessary to unlock, the gear sleeve drives the movable end friction component to move backward. After moving a certain distance, the movable end friction component contacts the fixed limit structure inside the reducer, ensuring that the movable end friction component can pass the limit spring slider and generate relative displacement with the gear sleeve, and move to the front end of the gear sleeve.

[0077] Figure 4This embodiment illustrates the control method for a phase-synchronized differential lock device. The differential lock is positioned between the left and right wheels of the vehicle. When the vehicle is in motion, the driver or vehicle controller issues a padlock command. The vehicle controller then identifies the vehicle speed signal. If the speed exceeds the maximum allowable padlock speed limit, the vehicle controller prompts the driver to reduce the speed, or the vehicle controller controls the drive motor to reduce the speed. The vehicle controller then determines if the vehicle is stationary. If stationary, it controls the drive motors of the left and right wheels to rotate slightly at opposite speeds. Once the vehicle speed falls within the allowable padlock speed range, the differential lock actuator performs the padlock action, controlling the shift fork and differential lock gear to move in the padlock direction. The differential lock controller continuously monitors the shift fork displacement signal. If the shift fork displacement reaches the successful padlock position, the actuator action terminates; otherwise, the padlock action continues.

[0078] Figure 1 , Figure 2 The structure of the phase-synchronized differential lock device in this embodiment is shown. The left wheel is connected to the first drive shaft 1, and the right wheel is connected to the second drive shaft 2. When locking is required, the differential lock actuator moves the drive fork 9 axially. The fork 9 drives the movable tooth sleeve 3 of the differential lock to move toward the engaged tooth 8. The movable tooth sleeve 3 is connected to the first drive shaft 1 through a spline and can slide axially on the first drive shaft 1. The engaged tooth 8 is interference-fitted with the second drive shaft 2 to keep it fixed and transmit torque normally. The movable tooth sleeve 3 has an internal spline structure on the side near the second drive shaft 2, which can mesh with the external spline of the engaged tooth 8. The spline tooth width of the engaged tooth 8 is much smaller than the spline groove width, ensuring that the engaging tooth is easier to engage. The fixed-end friction component is interference-fitted onto the engaged tooth 8 via a spline. The movable-end friction component is connected to the movable-end sleeve 3 via a spline. The movable-end friction component can slide axially on the movable-end sleeve 3. The movable-end sleeve 3 has a countersunk hole in its outer spline, in which a spring (i.e., the aforementioned elastic element 4) can be installed. The spring is connected to the irregularly shaped limiting block 5. When the shift fork 9 drives the movable-end sleeve 3 axially closer to the second drive shaft 2, the movable-end friction component, due to its axial position exceeding that of the movable-end sleeve 3, will first contact the fixed-end friction component. Subsequently, the movable-end friction component slides backward relative to the movable-end sleeve 3 under the axial force. The inner diameter on the left side of the movable-end friction component first contacts the irregularly shaped limiting block 5. The spring provides an upward thrust to the irregularly shaped limiting block 5. The contact position between the irregularly shaped limiting block 5 and the movable-end friction component provides axial pressure under the action of the inclined plane. Both the movable-end friction component and the fixed-end friction component have two types of friction materials on their surfaces: one is a friction material with a lower coefficient of friction, forming the second coating area 62; the other is a friction material with a higher coefficient of friction, forming the first coating area 61. See Figure 3As shown, during the padlocking process, there is a speed difference or slight rotation on the left and right sides. If the first coating area 61 and the second coating area 62 are in phase and in contact with each other, the frictional torque generated by the axial force is small. Under the influence of the inertia of the shaft system and gear system, they continue to rotate, causing the first coating area 61 with a larger friction coefficient to contact each other and provide a larger frictional torque. This allows the speed and phase of the left and right sides to quickly synchronize and align. As the shift fork 9 continues to push, the contact point between the moving end friction component and the irregularly shaped limiting block 5 passes the highest point, the axial force disappears, and the moving tooth sleeve 3 smoothly engages into the engaged tooth 8. Under the action of the reverse inclined surface of the irregularly shaped limiting block, the moving end friction component is subjected to a reverse axial force and quickly separates from the fixed end friction component, and the differential lock is successfully padlocked.

[0079] When unlocking is required, the shift fork 9 drives the movable gear sleeve 3 to move to the left. The reverse inclined surface of the irregular limiting block 5 first contacts the movable end friction component and drives it to move to the left together. Then, the movable end friction component first contacts the baffle 10 fixed inside the reducer housing. The shift fork 9 and the movable gear sleeve 3 continue to move to the left. The movable end friction component slides to the right relative to the irregular limiting block 5. After passing the highest point of the irregular limiting block 5, the movable end friction component moves to the rightmost end of the movable gear sleeve 3 under the axial force provided by the inclined surface of the irregular limiting block 5. A retaining ring (not shown in the figure) is installed on the outer spline of the movable gear sleeve 3, which can accurately limit the axial position of the movable end friction component on the movable gear sleeve 3.

[0080] It should be noted that the friction synchronization device in this embodiment is not limited to the specific size, arrangement position and friction coefficient of the friction plates mentioned above. The distribution of different friction materials of the synchronization friction mechanism corresponds to the number of teeth of the differential lock sleeve and the angle is designed accordingly.

[0081] It should be noted that the axial force providing mechanism of the friction synchronization device during engagement and disengagement is not limited to the spring limit block mentioned above, but may also include structures such as spring steel balls, hydraulic linear actuators, and solenoid valves.

[0082] Compared with traditional differential lock mechanisms, the traditional differential lock mechanism in this embodiment achieves the following beneficial effects:

[0083] 1) Extremely high padlock success rate and reliability: Through the "phase self-addressing" synchronization mechanism, the "tooth-hitting" phenomenon is fundamentally eliminated, ensuring that every padlock operation can successfully engage, greatly improving the reliability of the system.

[0084] 2) Smooth and shock-free, excellent user experience: The padlock process first synchronizes and then engages, achieving a smooth experience like shifting gears in a manual transmission, completely avoiding unpleasant shocks and metallic collision noises, and enhancing the overall premium feel and comfort of the vehicle.

[0085] 3) Intelligent and Adaptive: This synchronization process is achieved entirely passively and mechanically, without the need for additional sensors or electronic control systems. Its structure is ingenious and intelligent. It can automatically adapt to any initial phase and any speed difference, demonstrating strong adaptability.

[0086] 4) No additional power loss: The synchronization function only works for the moment the padlock is engaged. Once engaged, the synchronization mechanism automatically disengages. Like traditional differential locks, there is no additional friction loss when locked, resulting in high efficiency.

[0087] 5) Compact structure and easy integration: The synchronization mechanism can be integrated into the limited space of the existing differential lock without large-scale modification of the reducer housing, resulting in low modification cost and easy application to existing platforms.

[0088] The differential lock device in this embodiment, without significantly increasing structural complexity and cost, ensures that the differential lock gear sleeve can automatically eliminate the speed difference between the two sides and automatically align the phase of the inner and outer spline teeth before engaging with the gear ring, thereby completely eliminating tooth tipping and achieving smooth, silent, and high-success-rate padlock operation. Simultaneously, the mechanism must also be able to automatically retract after padlocking without affecting normal power transmission, and automatically reset upon unlocking for future use.

[0089] According to another specific embodiment of this application, a vehicle is provided, including a differential lock device, wherein the differential lock device is the differential lock device described above.

[0090] In this embodiment, the differential lock device can automatically eliminate the speed difference between the drive shafts and achieve precise alignment of the internal and external splines before locking. This makes the differential lock locking operation smoother and more successful when the vehicle is traversing complex road conditions such as mud, snow, and sand. It also reduces impact and noise, improving ride comfort and the durability of the differential lock. Under harsh driving conditions, the vehicle's ability to get out of trouble and its passability are significantly enhanced, thus providing users with a more reliable and smoother driving experience.

[0091] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0092] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this invention.

[0093] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A differential lock device, characterized in that, The differential lock device includes a movable gear sleeve (3) disposed on the first drive shaft (1) of the differential and a engaged gear (8) disposed on the second drive shaft (2) of the differential. The differential lock device further includes: The first friction element (6) is connected to the movable toothed sleeve (3), and the first friction element (6) is slidably disposed relative to the movable toothed sleeve (3) along the axial direction of the first drive shaft (1). The first friction element (6) has a first mating end face disposed toward the side where the second drive shaft (2) is located. The second friction element (7) is disposed opposite to the first friction element (6) along the axial direction of the first drive shaft (1). The second friction element (7) is connected to the engaged tooth (8). The second friction element (7) has a second mating end face disposed toward the first friction element (6). The first mating end face and the second mating end face are each provided with a plurality of first coating areas (61) and a plurality of second coating areas (62). The first coating areas (61) and the second coating areas (62) are arranged alternately in the circumferential direction. The friction coefficient of the coating material of the first coating area (61) is greater than that of the coating material of the second coating area (62). When the movable toothed sleeve (3) is in the initial state, the first friction member (6) is in the initial position, and the first mating end face protrudes from the movable toothed sleeve (3) along the axial direction of the first drive shaft (1). During the padlock process, the movable tooth sleeve (3) moves toward the engaged tooth (8). The contact between the first mating end face and the second mating end face precedes the contact between the movable tooth sleeve (3) and the engaged tooth (8). When the first coating area (61) of the first mating end face and the first coating area (61) of the second mating end face come into contact with each other, the frictional torque generated by the first mating end face and the second mating end face can cause the first drive shaft (1) and the second drive shaft (2) to perform a pre-alignment action. The pre-alignment action occurs before the engagement action of the movable tooth sleeve (3) and the engaged tooth (8).

2. The differential lock device according to claim 1, characterized in that, The movable gear sleeve (3) also has an installation space, and the differential lock device further includes: An axial preload mechanism is located within the installation space. The axial preload mechanism is movably arranged along the radial direction of the movable toothed sleeve (3) so that the axial preload mechanism has a limiting position and a clearance position. When the axial preload mechanism is in the limiting position, at least a portion of the axial preload mechanism is located outside the installation space. When the movable toothed sleeve (3) is in the initial state, the first friction member (6) is located on the side of the axial preload mechanism facing the second drive shaft (2), and the axial preload mechanism is in the limiting position; During the padlock process, the axial preload mechanism moves synchronously toward the engaged tooth (8) along with the movable tooth sleeve (3). During the pre-alignment process, the axial preload mechanism applies a first axial force toward the side where the second drive shaft (2) is located to the first friction member (6) to ensure that the first friction member (6) contacts the second friction member (7). After the pre-alignment process is completed, the axial preload mechanism moves from the limiting position to the avoidance position so that the first friction member (6) moves away from the second friction member (7) and disengages from the second friction member (7). During the engagement of the movable tooth sleeve (3) with the engaged tooth (8), the axial preload mechanism moves from the avoidance position to the limiting position to limit the first friction member (6) to the side of the axial preload mechanism away from the second friction member (7).

3. The differential lock device according to claim 2, characterized in that, The axial preload mechanism includes: The irregularly shaped limiting block (5) is connected to the bottom of the installation space through an elastic member (4). The irregularly shaped limiting block (5) has a first inclined surface and a second inclined surface that are arranged opposite to each other along the axial direction of the first drive shaft (1). The first inclined surface is arranged towards the side where the second drive shaft (2) is located. When the movable toothed sleeve (3) is in its initial state, the first friction element (6) is positioned close to the first inclined surface; During the pre-alignment process, the first inclined plane applies a first axial force toward the side where the second drive shaft (2) is located to the first friction member (6) to ensure that the first friction member (6) contacts the second friction member (7); After the pre-alignment action is completed, the first friction member (6) passes the top of the irregular limiting block (5) and moves away from the second friction member (7) along the first inclined surface; During the engagement of the movable tooth sleeve (3) with the engaged tooth (8), the first friction member (6) is positioned close to the second inclined surface, and the second inclined surface applies a second axial force to the first friction member (6) away from the side where the second drive shaft (2) is located, so as to limit the first friction member (6) to the side of the irregular limiting block (5) away from the second friction member (7).

4. The differential lock device according to claim 2, characterized in that, The differential lock device also includes: The housing, the movable toothed sleeve (3), the engaged tooth (8), the first friction element (6), the second friction element (7), and the axial preload mechanism are all located inside the housing; A baffle (10) is disposed inside the housing and connected to the housing. The baffle (10) is located on the side of the first friction member (6) away from the second friction member (7) and partially blocks the first friction member (6) along the axial direction of the first drive shaft (1).

5. The differential lock device according to claim 2, characterized in that, The movable tooth sleeve (3) includes a first driving section and a first engaging section. The first engaging section is located near the side where the second driving shaft (2) is located. Along the radial direction of the first driving shaft, the first engaging section is spaced apart from the first driving shaft (1). A first internal spline is provided on the inner circumferential surface of the first engaging section facing the first driving shaft (1). The engaged tooth (8) includes a second driving section and a second engaging section. The second engaging section is located near the side where the first driving shaft (1) is located. A first external spline is provided on the outer circumferential surface of the second engaging section. When the first internal spline meshes with the first external spline, the movable tooth sleeve (3) engages with the engaged tooth (8). The first friction element (6) and the axial preload mechanism are both located on the first engaging section.

6. The differential lock device according to claim 5, characterized in that, One of the first external spline and the first internal spline is a tooth groove, and the other is a spline tooth. The width of the tooth groove is set to be greater than the width of the spline tooth.

7. The differential lock device according to claim 1, characterized in that, The second mating end face is flush with the end face of the mating tooth (8).

8. The differential lock device according to claim 1, characterized in that, The movable toothed sleeve (3) is provided with a second external spline on its outer peripheral surface, and the first friction member (6) is provided with a second internal spline. The first friction member (6) and the movable toothed sleeve (3) are slidably connected through the second internal spline and the second external spline.

9. The differential lock device according to claim 1, characterized in that, The first mating end face is configured identically to the second mating end face.

10. A vehicle, characterized in that, Includes a differential lock device, wherein the differential lock device is the differential lock device according to any one of claims 1-8.

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