A mechanical locking limited slip differential

Abstract

The present invention discloses a mechanical locking limited slip differential, which belongs to the technical field of differentials. The differential adds a mechanical locking mechanism to the existing limited slip differential. The mechanical locking mechanism includes an electromagnetic coil and an elastic locking pin. The electromagnetic coil is arranged on the outside of the hollow shaft opposite to the end face of the gear hub. The elastic locking pin includes a locking pin and an elastic member. The locking pin is arranged in a limiting hole axially opened in the gear hub. When the electromagnetic coil is energized, the locking pin moves toward the electromagnetic coil side and is inserted into the locking hole on the inner wall of the hollow shaft to achieve differential locking of the differential. When the electromagnetic coil is de-energized, the locking pin moves out of the locking hole under the action of the elastic member, and the differential function of the differential is restored. The present invention cleverly achieves the locking and disengagement of the locking pin by setting the locking pin as an integral locking pin structure or a split locking pin structure and utilizing its axial movement in the limiting hole of the gear hub. The structure is simple, the design is reasonable, the torque transmission capacity is strong, and the requirements of the vehicle's extreme escape ability are met, making it highly competitive in the market.

Description

Technical Field

[0001] The present invention relates to the technical field of differentials, and in particular to a mechanical locking limited slip differential. Background Art

[0002] A car's differential is a mechanism that enables the left and right (or front and rear) drive wheels to rotate at different speeds. This allows the left and right wheels to roll at different speeds when turning or driving on uneven surfaces. This ensures that the drive wheels on both sides perform pure rolling motion, ensuring that the car's rotational speeds are essentially the same when driving in curves. An open differential evenly distributes the torque transmitted by the reducer to the left and right wheels. However, when a vehicle is on a patchy surface and one wheel loses traction, the other wheel cannot receive sufficient torque, rendering the vehicle unable to escape. When turning at high speed, the vehicle tends to camber outward, reducing pressure on the inside wheel and resulting in reduced traction torque on the inside wheel. Simultaneously, the outside wheel cannot receive sufficient torque, making the vehicle prone to understeer, which affects its handling.

[0003] Current limited-slip differentials (LSDs) maintain a certain speed difference between the drive wheels, ensuring normal cornering and other driving performance, while also providing a certain degree of escape capability. However, they are insufficient for the extreme escape scenarios encountered by vehicles, resulting in the risk of ablation and failing to meet these requirements.

[0004] As can be seen from this, the existing differentials mentioned above still have inconveniences and defects in their structure, methods, and use, and are in urgent need of further improvement. The industry is currently seeking to develop a new mechanically locked limited-slip differential that integrates a mechanical locking mechanism with existing limited-slip differentials, providing a mechanical locking function that can overcome the shortcomings of conventional friction plate limited-slip differentials, such as insufficient capacity and susceptibility to corrosion, while enhancing the vehicle's ultimate escape capability. Furthermore, the industry is currently seeking to develop a new mechanically locked limited-slip differential that combines an integrated design, space savings, a simple structure, and low cost. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a mechanical locking limited slip differential, which has a mechanical locking function by adding a mechanical locking mechanism, thereby compensating for the shortcomings of insufficient capacity and easy ablation of the existing ordinary friction plate limited slip differential, enhancing the vehicle's ultimate escape ability, and having an integrated design, saving space, simple structure and low cost, thereby overcoming the shortcomings of the existing differential.

[0006] To solve the above technical problems, the present invention provides a mechanical locking limited-slip differential. The limited-slip differential includes an intermediate shaft, a hollow shaft, and a friction plate type limited-slip mechanism. The two ends of the intermediate shaft are respectively connected to the differential side gear and one side wheel. The hollow shaft is sleeved on the outer periphery of the intermediate shaft. One end of the hollow shaft is used for fixedly connecting with the differential housing, and the other end is fixedly connected with the friction plate group housing. The friction plate type limited-slip mechanism includes a friction plate group housing, a friction plate group, a gear hub, a piston, and a power mechanism for driving the piston to move. The friction plate group includes a pressure plate connected to the friction plate group housing and a friction plate connected to the gear hub. The pressure plate and the friction plate are arranged at intervals. The inner side of the gear hub is splined to the middle part of the intermediate shaft. A mechanical locking mechanism is also included. The mechanical locking mechanism includes an electromagnetic coil and an elastic locking pin. The electromagnetic coil is arranged on the outer side of the hollow shaft opposite to the end face of the gear hub. The elastic locking pin includes a locking pin and an elastic member. The locking pin is arranged in a limiting hole axially opened in the gear hub, and one end of the locking pin corresponds to the electromagnetic coil, and the other end is matched with the elastic member. When the electromagnetic coil is energized, the locking pin moves towards the side of the electromagnetic coil and inserts into a locking hole on the inner side wall of the hollow shaft to realize differential locking of the differential. When the electromagnetic coil is de-energized, the locking pin moves out of the locking hole under the action of the elastic member to restore the differential function of the differential.

[0007] Further improvement, the locking pin includes a first annular structure, a second annular structure, and a plurality of connecting pin rods connecting the first annular structure and the second annular structure. The limiting hole includes a plurality of through holes for the connecting pin rods to pass through, and a first annular groove and a second annular groove respectively arranged at both ends of the plurality of through holes. The first annular structure is located in the first annular groove, the second annular structure is located in the second annular groove. The elastic member is sleeved on the outer periphery of the connecting pin rod. One end of the elastic member abuts against the second annular structure, and the other end abuts against the bottom of the second annular groove. And the first annular structure is arranged as a gear-shaped structure with a plurality of protrusions. The locking hole is also arranged as a gear-shaped groove structure corresponding to the first annular structure. When the electromagnetic coil is energized, the first annular structure inserts into the locking hole to realize differential locking of the differential. When the electromagnetic coil is de-energized, the first annular structure moves out of the locking hole under the action of the elastic member to restore the differential function of the differential.

[0008] Further improvement, the depth of the locking hole is less than the thickness of the first annular structure.

[0009] Further improvement, the depth of the second annular groove is greater than the thickness of the second annular structure.

[0010] For further improvement, the locking pin is arranged in a dumbbell-shaped structure including a first locking piece and a second locking piece. The limiting hole is arranged as a through-hole structure with counterbores at both ends corresponding to the dumbbell-shaped structure. The first locking piece is located in the first counterbore, and the second locking piece is located in the second counterbore. The depth of the second counterbore is greater than the thickness of the second locking piece. The elastic member is sleeved on the outer circumference of the middle connecting rod of the locking pin, with one end abutted against the bottom of the second counterbore and the other end abutted against the inner side of the second locking piece. The locking pin axially moves along the limiting hole under the action of the energized electromagnetic coil. The first locking piece is inserted into the locking hole and, when the electromagnetic coil is de-energized, moves out of the locking hole under the action of the elastic member to realize the reset of the locking pin.

[0011] For further improvement, the depth of the locking hole is less than the thickness of the first locking piece.

[0012] For further improvement, at least two limiting holes are circumferentially formed in the gear hub, and one locking pin is arranged in each limiting hole. Locking holes corresponding to the number of the locking pins are arranged on the inner side wall of the hollow shaft.

[0013] For further improvement, the piston is arranged on the rear end side of the friction plate group away from the electromagnetic coil, and the friction plate group is pressed through the power mechanism.

[0014] For further improvement, the power mechanism includes a plunger pump connected to the piston, a motor for controlling the flow rate of the plunger pump, and a controller for controlling the rotation speed of the motor.

[0015] After adopting such a design, the present invention has at least the following advantages:

[0016] 1. The mechanical locking type limited slip differential of the present invention can, when the vehicle is in an extreme situation of getting stuck, energize the electromagnetic coil, make the locking pin move towards the electromagnetic coil side and insert into the locking hole, forming a rigid connection between the hollow shaft and the gear hub, realizing the differential locking of the differential and preventing differential. After the vehicle gets out of trouble, the electromagnetic coil is de-energized, and the locking pin moves out of the locking hole under the action of the elastic member, restoring the differential function of the differential. This mechanical locking mechanism can make up for the deficiencies of ordinary friction plate type differentials, such as insufficient capacity and easy ablation. And the original integrated design of this mechanical locking mechanism integrates and adds the mechanical locking function on the basis of not changing the overall structure of the existing limited slip differential. The structure is simple and the design is reasonable. Compared with the independent installation of a differential lock, it saves space and greatly reduces the cost.

[0017] 2. By setting the lock pin into an integral lock pin structure or a split lock pin structure, and utilizing its axial movement in the limiting hole of the gear hub, the locking and disengagement of the lock pin can be simply and conveniently achieved. It has a reasonable structure and strong torque transmission capability, ensuring the realization of the mechanical locking function, enhancing the vehicle's cornering and dynamic performance, meeting the vehicle's ultimate escape capability, and being highly competitive in the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0019] Figure 1 It is a structural cross-sectional view of the mechanical locking limited slip differential of the present invention.

[0020] Figure 2 It is a partial enlarged view of the lock pin structure in the mechanical locking limited slip differential of the present invention.

[0021] Figure 3 It is a structural schematic diagram of an integral locking pin in the mechanical locking limited slip differential of the present invention.

[0022] Among them: 1. intermediate shaft; 2. hollow shaft; 21. locking hole; 3. electromagnetic coil; 4. friction plate group housing; 5. friction plate group; 51. pressure plate; 52. friction plate; 6. gear hub; 61. first annular groove; 62. second annular groove; 63. through hole; 7. locking pin; 71. first annular structure; 72. second annular structure; 73. connecting pin; 8. elastic member; 9. piston; 10. outer shell; 11. controller; 12. motor; 13. plunger pump. DETAILED DESCRIPTION

[0023] This invention improves upon existing multi-plate clutch limited-slip differentials by adding a mechanical locking function. This addresses the performance deficiencies of open differentials on slippery roads or curves, while also eliminating the risk of friction plate erosion under high-torque conditions, providing the vehicle with enhanced escape capabilities. Specific embodiments are as follows.

[0024] Refer to the attached Figure 1 and 2 As shown, the mechanical locking limited slip differential of this embodiment is an improvement on the existing limited slip differential, wherein the limited slip differential comprises an intermediate shaft 1, a hollow shaft 2, a friction plate limited slip mechanism and an outer shell 10.

[0025] Both ends of the intermediate shaft 1 are respectively connected to the differential half shaft gear and a wheel on one side. The hollow shaft 2 is sleeved on the outer periphery of the intermediate shaft 1, one end of which is used for fixed connection with the differential housing through splines, and the other end is fixedly connected with the friction plate group housing 4 through splines. The friction plate type limited slip mechanism includes a friction plate group housing 4, a friction plate group 5, a hub 6, a piston 9, and a power mechanism for driving the piston 9 to move. The friction plate group 5 includes a pressure plate 51 connected to the friction plate group housing 4 and a friction plate 52 connected to the hub 6, and the pressure plate 51 and the friction plate 52 are arranged at intervals. The hub 6, that is, the Hub shaft, is connected to the middle part of the intermediate shaft 1 through splines on the inner side. The piston 9 is arranged on the rear end side of the friction plate group 5, and the friction plate group 5 is pressed through the power mechanism to adjust the friction force of the friction plate group 5. The power mechanism includes a plunger pump 13 connected to the piston 9, a motor 12 for controlling the flow rate of the plunger pump 13, and a controller 11 for controlling the rotation speed of the motor 12.

[0026] When the vehicle turns normally and the differential needs to differential, the intermediate shaft 1 and the hollow shaft 2 rotate relative to each other, and a slip occurs between the pressure plate 51 and the friction plate 52 of the friction plate group 5. When the vehicle needs to limit the differential of the differential, the controller 11 controls the rotation speed of the motor 12, thereby adjusting the flow rate of the plunger pump 13, and then controlling the pressure of the piston 9 to press the friction plate group 5, suppressing the slip generated in the friction plate group 5, playing a limited slip role, and its limited slip ability depends on the torque capacity of the friction plate group 5.

[0027] The improvement of this embodiment lies in that it further includes a mechanical locking mechanism. The mechanical locking mechanism includes an electromagnetic coil 3 and an elastic locking pin. The electromagnetic coil 3 is arranged on the outer side of the hollow shaft 2 opposite to the end face of the hub 6, forming an electromagnet structure for attracting the elastic locking pin. The elastic locking pin includes a locking pin 7 and an elastic member 8.

[0028] Refer to the appendix Figure 3 As shown, the locking pin 7 of this embodiment adopts an integral locking pin structure. The integral locking pin structure is arranged in the hub 6 and can move axially along the hub 6. A locking hole 21 for inserting the locking pin 7 is provided on the inner side wall of the hollow shaft 2.

[0029] Specifically, the integral locking pin structure includes a first annular structure 71, a second annular structure 72, and a plurality of connecting pins 73 connecting the first annular structure 71 and the second annular structure 72. The gear hub 6 is provided with a limiting hole structure corresponding to the integral locking pin structure. The limiting hole structure includes a plurality of through holes 63 for the connecting pins 73 to pass through, and a first annular groove 61 and a second annular groove 62 respectively arranged at both ends of the plurality of through holes 63, that is, the first annular structure 71 is located in the first annular groove 61, and the second annular structure 72 is located in the second annular groove 62. The depth of the second annular groove 62 is greater than the thickness of the second annular structure 72. The elastic member 8 is sleeved on the outer periphery of the connecting pin 73, with one end abutting against the inner side of the second annular structure 72 and the other end abutting against the bottom of the second annular groove 62. Furthermore, the first annular structure 71 is configured as a gear-type structure with a plurality of protrusions 711, and the locking hole 21 is also configured as a gear-type groove structure corresponding to the first annular structure 71, so that after the first annular structure 71 is inserted into the locking hole 21, a stable connection between the gear hub 6 and the hollow shaft 2 can be formed. When the vehicle is in an extreme escape situation, a limited slip torque greater than the torque capacity of the friction plate group is required. At this time, the electromagnetic coil 3 is energized, the locking pin 7 moves toward the electromagnetic coil 3, and the first annular structure 71 is inserted into the gear-type groove structure of the locking hole 21, forming a rigid connection between the hollow shaft 2 and the gear hub 6, achieving differential locking of the differential and preventing differential operation. After the vehicle escapes, the electromagnetic coil 3 loses power, and the first annular structure 71 moves out of the locking hole 21 under the action of the elastic member 8, restoring the differential function of the differential.

[0030] In a preferred embodiment, the depth of the locking hole 21 is less than the thickness of the first annular structure 71, and more preferably is 50% of the thickness of the first annular structure 71. In this way, when the first annular structure 71 is inserted into the locking hole 21, half of it is engaged with the hollow shaft 2 and the other half is engaged with the gear hub 6, thereby improving the torque transmission capability and achieving a better mechanical locking effect.

[0031] Of course, the lock pin 7 can also adopt a split lock pin structure, such as a split dumbbell-shaped lock pin. The lock pin is configured as a dumbbell-shaped structure including a first locking plate and a second locking plate. The limiting hole corresponding to the dumbbell-shaped structure is configured as a through-hole structure with countersunk holes at both ends. The first locking plate is located in the first countersunk hole, and the second locking plate is located in the second countersunk hole. The depth of the second countersunk hole is greater than the thickness of the second locking plate. The elastic member is sleeved on the middle connecting rod of the lock pin, with one end abutting against the bottom of the second countersunk hole and the other end abutting against the inner side of the second locking plate. Similarly, the lock pin 7 moves axially along the limiting hole under the action of the energized electromagnetic coil. The first locking plate is inserted into the locking hole. When the electromagnetic coil is de-energized, it moves out of the locking hole under the action of the elastic member to achieve the reset of the lock pin.

[0032] The gear hub is provided with two or more limiting holes in a circumferential direction, each limiting hole is provided with a split locking pin, and the inner side wall of the hollow shaft is provided with locking holes corresponding in number to the locking pins.

[0033] The mechanical locking limited-slip differential of the present invention, by adding a mechanical locking mechanism, can compensate for the shortcomings of conventional friction plate differentials, such as insufficient capacity and susceptibility to corrosion. Furthermore, the unique integrated design of the mechanical locking mechanism adds a mechanical locking function without changing the overall structure of existing limited-slip differentials. This results in a simple structure and strong torque transmission capability. Compared to independently provided differential locks, this mechanical locking limited-slip differential saves space and significantly reduces costs. The mechanical locking limited-slip differential of the present invention also enables intelligent control of limited-slip torque, enhancing the vehicle's cornering and dynamic performance, meeting the vehicle's ultimate escape capability, and strengthening its market competitiveness.

[0034] In the description of the present invention, it should be noted that the terms "front", "rear", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Those skilled in the art can make some simple modifications, equivalent changes or modifications based on the technical content disclosed above, which all fall within the scope of protection of the present invention.

Claims

1. A mechanical locking limited slip differential, the limited slip differential comprising an intermediate shaft, a hollow shaft and a friction plate type limited slip mechanism. The two ends of the intermediate shaft are respectively connected to a differential side gear and a wheel on one side. The hollow shaft is sleeved on the outer periphery of the intermediate shaft, one end of which is used for fixedly connecting with a differential housing, and the other end is fixedly connected with a friction plate group housing. The friction plate type limited slip mechanism comprises a friction plate group housing, a friction plate group, a tooth hub, a piston and a power mechanism for driving the piston to move. The friction plate group comprises a pressing plate connected to the friction plate group housing and a friction plate connected to the tooth hub. The pressing plate and the friction plate are arranged at intervals. The inner side of the tooth hub is in spline connection with the middle part of the intermediate shaft, and is characterized in that, It further includes a mechanical locking mechanism, which includes an electromagnetic coil and an elastic locking pin. The electromagnetic coil is arranged outside the hollow shaft opposite to the end face of the gear hub. The elastic locking pin includes a locking pin and an elastic member. The locking pin is arranged in a limiting hole axially opened in the gear hub, and one end of the locking pin corresponds to the electromagnetic coil, and the other end cooperates with the elastic member. When the electromagnetic coil is energized, the locking pin moves towards the electromagnetic coil side and inserts into a locking hole on the inner side wall of the hollow shaft to realize the differential locking of the differential. When the electromagnetic coil is de-energized, the locking pin moves out of the locking hole under the action of the elastic member to restore the differential function of the differential.

2. The mechanical locking limited slip differential according to claim 1, characterized in that, The locking pin includes a first annular structure, a second annular structure, and a plurality of connecting pin rods connecting the first annular structure and the second annular structure. The limiting hole includes a plurality of through holes for the connecting pin rods to pass through, and a first annular groove and a second annular groove respectively arranged at both ends of the plurality of through holes. The first annular structure is located in the first annular groove, the second annular structure is located in the second annular groove, the elastic member is sleeved on the outer periphery of the connecting pin rod, one end of which abuts against the second annular structure, and the other end abuts against the bottom of the second annular groove. And the first annular structure is arranged as a gear-shaped structure with several protrusions, and the locking hole is also arranged as a gear-shaped groove structure corresponding to the first annular structure. When the electromagnetic coil is energized, the first annular structure inserts into the locking hole to realize the differential locking of the differential. When the electromagnetic coil is de-energized, the first annular structure moves out of the locking hole under the action of the elastic member to restore the differential function of the differential.

3. The mechanical locking limited slip differential according to claim 2, wherein The depth of the locking hole is less than the thickness of the first annular structure.

4. The mechanical locking limited slip differential according to claim 3, wherein, The depth of the second annular groove is greater than the thickness of the second annular structure.

5. The mechanical locking limited slip differential according to claim 1, characterized in that, The locking pin is arranged as a dumbbell-shaped structure including a first locking piece and a second locking piece. The limiting hole is arranged as a through hole structure with counterbores at both ends corresponding to the dumbbell-shaped structure. The first locking piece is located in the first counterbore, the second locking piece is located in the second counterbore, and the depth of the second counterbore is greater than the thickness of the second locking piece. The elastic member is sleeved on the outer periphery of the middle connecting rod of the locking pin, one end of which abuts against the bottom of the second counterbore, and the other end abuts against the inner side of the second locking piece. The locking pin moves axially in the limiting hole under the action of the energized electromagnetic coil, and the first locking piece inserts into the locking hole, and when the electromagnetic coil is de-energized, it moves out of the locking hole under the action of the elastic member to realize the reset of the locking pin.

6. The mechanical locking limited slip differential according to claim 5, characterized in that, The depth of the locking hole is less than the thickness of the first locking piece.

7. The mechanical locking limited slip differential according to claim 6, characterized in that, At least two of the above-mentioned limiting holes are circumferentially opened in the gear hub, and each limiting hole is provided with a locking pin, and the inner side wall of the hollow shaft is provided with locking holes corresponding to the number of the locking pins.

8. The mechanical locking limited slip differential according to any one of claims 1 to 7, characterized in that, The piston is arranged on the rear end side of the friction plate group away from the electromagnetic coil, and the friction plate group is pressed through the power mechanism.

9. The mechanical locking limited slip differential according to claim 8, characterized in that The power mechanism includes a plunger pump connected to the piston, a motor for controlling the flow rate of the plunger pump, and a controller for controlling the rotational speed of the motor.

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