A differential self-locking device

Abstract

The present invention discloses a differential self-locking device, which relates to the technical field of differential locks. It includes a differential housing and an internal half-shaft output gear set, an upper worm and worm gear mechanism, a lower worm and worm gear mechanism, a differential planet gear set, and a worm gear shaft arranged inside the differential housing. The self-locking torques of the upper worm and worm gear mechanism and the lower worm and worm gear mechanism have the lever amplification principle for locking the left and right half-shaft output gears, and at the same time, the left and right half-shaft output gears are automatically locked or released, and at the same time, the traction self-sensing torque distribution is realized to the left and right half-shaft output gears, improving the passing ability of the vehicle. The processing precision requirements and manufacturing costs of the parts of the differential self-locking device are not high, and the assembly process is also simple. The self-locking torque of the differential self-locking device has the lever amplification principle, which has obvious improvement in reducing weight and volume, significant optimization in reducing differential NVH, and great improvement in reducing wear of parts. It meets the economic benefits and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of differential locks, and particularly to a differential self-locking device. Background Art

[0002] A differential lock is a differential with an automatic locking function, and its function is to improve the passing ability of an automobile on a bad road surface. That is, when one driving axle of the automobile idles, the differential can be quickly locked, so that the two driving axles become rigidly connected.

[0003] For existing differential self-locking devices, basically a clutch device is added axially to the left and right half-shaft output gears, and a mechanical actuator or an electro-hydraulic actuator is used to operate the clutch device to lock the left and right half-shaft output gears and the differential housing, forcibly locking the differential of the left and right half-shaft output gears and the differential housing to solve the slipping problem. There is also a type (Torsen differential A) that uses a double worm and worm gear structure. It is the mutual meshing and interlocking of them and the structure of unidirectional torque transmission from the worm gear to the worm gear that realizes the differential locking function.

[0004] 1. The differential mechanism with a clutch device added axially to the left and right half-shaft gears is complex in structure, complex in control, has a delay in differential locking response, and is high in cost.

[0005] 2. The Torsen differential is a double worm and worm differential linear self-locking device; it consists of a left shaft worm, a right shaft worm, six worm gears, and each worm gear is equipped with two spur gears, for a total of twelve spur gears. Among them, three worm gears are meshed with the left shaft worm, and the other three worm gears are meshed with the right shaft worm, and the worm gears meshed with the left and right shaft worms are meshed with each other through spur gears. Such a meshing and assembly process has very high requirements for the dimensional accuracy and consistency of each worm gear, high requirements for the positioning and assembly process, large radial dimensions of the mechanism, large weight, high cost, poor NVH, and easy wear of parts. Summary of the Invention

[0006] To achieve the above object and improve the above deficiencies, the present invention provides the following technical solution: A differential self-locking device includes a differential housing and a half-shaft output gear set, an upper worm and worm gear mechanism, a lower worm and worm gear mechanism, a differential planet gear set, a worm gear shaft, a gasket, and a positioning bushing disposed inside the differential housing. The half-shaft output gear set includes a left half-shaft output gear and a right half-shaft output gear symmetrically disposed inside the differential housing. The upper worm and worm gear mechanism and the lower worm and worm gear mechanism are rotationally symmetrically disposed. Both the upper worm and worm gear mechanism and the lower worm and worm gear mechanism are engaged with the left half-shaft output gear and the right half-shaft output gear. The differential planet gear set is located between the upper worm and worm gear mechanism and the lower worm and worm gear mechanism and is engaged with the upper worm and worm gear mechanism, the lower worm and worm gear mechanism, the left half-shaft output gear, and the right half-shaft output gear. The worm gear shaft is located between the left half-shaft output gear and the right half-shaft output gear, and the worm gear shaft is coaxially connected to the worm gears of the upper worm and worm gear mechanism and the lower worm and worm gear mechanism.

[0007] As a preferred technical solution of the present invention, the upper worm and worm gear mechanism includes an upper worm gear disposed between the left half-shaft output gear and the right half-shaft output gear, and an upper worm one and an upper worm two rotationally symmetrically disposed on both sides of the upper worm gear and both engaged with the upper worm gear.

[0008] As a preferred technical solution of the present invention, gears respectively engaged with the right half-shaft output gear and the left half-shaft output gear are disposed at one ends of the upper worm one and the upper worm two.

[0009] As a preferred technical solution of the present invention, the lower worm and worm gear mechanism includes a lower worm gear disposed between the left half-shaft output gear and the right half-shaft output gear, and a lower worm one and a lower worm two rotationally symmetrically disposed on both sides of the lower worm gear and both engaged with the lower worm gear.

[0010] As a preferred technical solution of the present invention, gears respectively engaged with the left half-shaft output gear and the right half-shaft output gear are disposed at one ends of the lower worm one and the lower worm two.

[0011] As a preferred technical solution of the present invention, the differential planetary gear set includes a left half shaft planetary gear I, a right half shaft planetary gear I, a right half shaft planetary gear II, and a left half shaft planetary gear II. The left half shaft planetary gear I and the right half shaft planetary gear I are respectively meshed with a left half shaft output gear and a right half shaft output gear. The right half shaft planetary gear II and the left half shaft planetary gear II are respectively meshed with the right half shaft output gear and the left half shaft output gear. The left half shaft planetary gear I and the right half shaft planetary gear I are respectively meshed with an upper worm I and a lower worm I. The right half shaft planetary gear I and the left half shaft planetary gear II are respectively meshed with an upper worm II and a lower worm II. The left half shaft planetary gear I and the right half shaft planetary gear I are connected by gear meshing transmission. The right half shaft planetary gear II and the left half shaft planetary gear II are connected by gear meshing transmission.

[0012] As a preferred technical solution of the present invention, the worm shaft is disposed inside the upper worm wheel and the lower worm wheel, and gaskets are further arranged on the top and bottom of the upper worm wheel and the lower worm wheel on the worm shaft;

[0013] The gasket is one of a copper sheet or a friction sheet;

[0014] A positioning sleeve is further arranged on the worm shaft between the upper worm wheel and the lower worm wheel, and the upper worm wheel, the lower worm wheel, the gasket and the positioning sleeve are coaxially arranged.

[0015] As a preferred technical solution of the present invention, the gear parameter of the meshing between the upper worm I, the upper worm II, the lower worm I, the lower worm II, the left half shaft planetary gear I, the right half shaft planetary gear I, the right half shaft planetary gear II, the left half shaft planetary gear II and the left half shaft output gear and the right half shaft output gear are the same.

[0016] As a preferred technical solution of the present invention, the gear helix angle characteristic parameter of the upper worm and worm wheel mechanism is opposite to that of the lower worm and worm wheel mechanism.

[0017] Compared with the prior art, the present invention provides a differential self-locking device, which has the following beneficial effects:

[0018] The differential self-locking device includes a differential housing and a half-shaft output gear set, an upper worm and worm gear mechanism, a lower worm and worm gear mechanism, a differential planetary gear set, and a worm shaft disposed inside the differential housing. By designing a simple upper worm and worm gear mechanism, a lower worm and worm gear mechanism, a differential planetary gear set, and a worm shaft inside the differential housing, the self-locking torque of the upper worm and worm gear mechanism and the lower worm and worm gear mechanism has a lever amplification principle for locking the left and right half-shaft output gears. At the same time, the left and right half-shaft output gears are automatically locked or released, and the traction self-sensing torque is distributed to the left and right half-shaft output gears. The passing ability of the vehicle is improved. The differential self-locking device has obvious improvements in reducing weight and volume, significant optimization in reducing differential NVH, and great improvement in reducing component wear. It is cost-effective and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 FIG. is a schematic structural diagram of a differential self-locking device proposed by the present invention;

[0020] Figure 2 FIG. is an exploded structural view of a differential self-locking device proposed by the present invention;

[0021] Figure 3 FIG. is a side view of the half-shaft output gear set structure of a differential self-locking device proposed by the present invention;

[0022] Figure 4 FIG. is a sectional view of the structure of a differential self-locking device proposed by the present invention.

[0023] In the figure: 1. Differential housing; 2. Internal half-shaft output gear set; 21. Left half-shaft output gear; 22. Right half-shaft output gear; 3. Upper worm and worm gear mechanism; 31. Upper worm gear; 32. First upper worm; 33. Second upper worm; 4. Lower worm and worm gear mechanism; 41. First lower worm; 42. Second lower worm; 43. Lower worm gear; 5. Differential planetary gear set; 51. First left half-shaft planetary gear; 52. First right half-shaft planetary gear; 53. Second right half-shaft planetary gear; 54. Second left half-shaft planetary gear; 6. Worm shaft; 7. Gasket; 8. Positioning bushing. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0025] Please refer to Figures 1-4, A differential self-locking device, comprising a differential housing 1 and components disposed on the differential housing 1, a half-axle output gear set 2, an upper worm and worm gear mechanism 3, a lower worm and worm gear mechanism 4, a differential planet gear set 5, a worm shaft 6, brake pads 7, and a positioning bushing 8. The half-axle output gear set 2 includes a left half-axle output gear 21 and a right half-axle output gear 22 symmetrically disposed inside the differential housing 1. The upper worm and worm gear mechanism 3 and the lower worm and worm gear mechanism 4 are rotationally symmetrically arranged. Both the upper worm and worm gear mechanism 3 and the lower worm and worm gear mechanism 4 are meshed with the left half-axle output gear 21 and the right half-axle output gear 22. The differential planet gear set 5 is located between the upper worm and worm gear mechanism 3 and the lower worm and worm gear mechanism 4 and is meshed with the upper worm and worm gear mechanism 3, the lower worm and worm gear mechanism 4, the left half-axle output gear 21, and the right half-axle output gear 22. The worm shaft 6 is located between the left half-axle output gear 21 and the right half-axle output gear 22, and the worm shaft 6 is coaxially connected to the worms of the upper worm and worm gear mechanism and the lower worm and worm gear mechanism.

[0026] As a specific technical solution of this embodiment, the upper worm and worm gear mechanism 3 includes an upper worm wheel 31 disposed between the left half-axle output gear 21 and the right half-axle output gear 22, an upper worm one 32 and an upper worm two 33 that are rotationally symmetrically arranged on both sides of the upper worm wheel 31 and are both meshed with the upper worm wheel 31. Gears meshing with the right half-axle output gear 22 and the left half-axle output gear 21 respectively are disposed at one ends of the upper worm one 32 and the upper worm two 33. The lower worm and worm gear mechanism 4 includes a lower worm wheel 43 disposed between the left half-axle output gear 21 and the right half-axle output gear 22, a lower worm one 41 and a lower worm two 42 that are rotationally symmetrically arranged on both sides of the lower worm wheel 43 and are both meshed with the lower worm wheel 43. Gears meshing with the left half-axle output gear 21 and the right half-axle output gear 22 respectively are disposed at one ends of the lower worm one 41 and the lower worm two 42. Due to the transmission from the upper worm wheel 31 to the upper worm one 32 and the upper worm two 33, and the transmission from the lower worm wheel 43 to the lower worm one 42 and the lower worm two 43 having the magnitude of (i.e., the internal frictional torque of the worm and worm gear), it has the characteristics of automatically locking or releasing, thereby achieving automatic locking or releasing. That is, when the relative speed difference between the left and right half-axles of the half-axle output gear set 2 is small, the internal frictional force of the upper worm and worm gear mechanism 3 and the lower worm and worm gear mechanism 4 is also small. The relative speed difference between the left half-axle output gear 21 and the right half-axle output gear 22 is absorbed through the relative movement inside the upper worm mechanism 3 and the lower worm 4 to achieve the normal driving differential function. When the speed difference between the left half-axle output gear 21 and the right half-axle output gear 22 is too large, the inside of the upper worm mechanism 3 and the lower worm and worm gear mechanism 4 will automatically lock. Since the upper worm and worm gear mechanism 3, the lower worm and worm gear mechanism 4 and the half-axle output gear set 2 are meshed in a deceleration relationship, the self-locking torque of the upper worm and worm gear mechanism and the lower worm and worm gear mechanism has the lever amplification principle to lock the left and right half-axle output gears.

[0027] As a specific technical solution of this embodiment, the differential planetary gear set 5 includes a left half-shaft planetary gear 51, a right half-shaft planetary gear 52, a right half-shaft planetary gear 53 and a left half-shaft planetary gear 54. The left half-shaft planetary gear 51 and the right half-shaft planetary gear 52 are respectively engaged with the left half-shaft output gear 21 and the right half-shaft output gear 22. The right half-shaft planetary gear 53 and the left half-shaft planetary gear 54 are respectively engaged with the right half-shaft output gear 22 and the left half-shaft output gear 21. The left half-shaft planetary gear 51 and the right half-shaft planetary gear 52 are connected by gear meshing transmission. The right half-shaft planetary gear 53 and the left half-shaft planetary gear 54 are connected by gear meshing transmission. The left half-shaft planetary gear 51 and the upper worm 32 are connected by gear meshing transmission. The right half-shaft planetary gear 52 and the lower worm 41 are connected by gear meshing transmission. The right half-shaft planetary gear 53 and the upper worm 33 are connected by gear meshing transmission. The left half-shaft planetary gear 54 and the lower worm 42 are connected by gear meshing transmission. This setting enables the upper worm 32, the upper worm 33, the lower worm 41, the lower worm 42, the left half-shaft planetary gear 51, the right half-shaft planetary gear 52, the right half-shaft planetary gear 53, and the left half-shaft planetary gear 54 to jointly bear the torque from the differential housing 1, increasing the load-bearing capacity of the differential self-locking device and making the force more balanced.

[0028] As a specific technical solution of this embodiment, the worm shaft 6 passes through the upper worm gear 31 and the lower worm gear 43. Washers 7 are also provided on the worm shaft 6 at the top and bottom of the upper worm gear 31 and the lower worm gear 43. The washer 7 is one of a copper sheet or a friction sheet. A positioning shaft sleeve 8 is also provided on the worm shaft 6 between the upper worm gear 31 and the lower worm gear 43. The upper worm gear 31, the lower worm gear 43, the brake pad 7 and the positioning shaft sleeve 8 are coaxially arranged. Due to the axial force generated when the upper worm gear 31 and the lower worm gear 43 move, if it is necessary to increase the worm gear locking friction, the washer 7 is a friction sheet; if it is not necessary to increase the worm gear locking friction, the washer 7 is a copper sheet.

[0029] As a specific technical solution of this embodiment, the gear parameters of the meshing between the upper worm 32, the upper worm, the lower worm 41, the lower worm 42, the differential planetary gear set 5 and the left half-shaft output gear 21 and the right half-shaft output gear 22 are the same. Refer to Figure 3 ., the gear helix angle characteristic parameters of the upper worm and worm gear mechanism 3 are opposite to those of the lower worm and worm gear mechanism 4, and the generated axial forces are also opposite, while other characteristic parameters are the same.

[0030] This differential self-locking device can also perform linear locking and torque distribution by utilizing the high internal friction torque of the worm and worm gear drive for self-locking. The internal friction torque depends on the relative rotational speeds of the left half-shaft output gear 21 and the right half-shaft output gear 22, and more of the input torque of the differential housing 1 is distributed to the right half-shaft output gear 22 or the left half-shaft output gear 21. This differential self-locking device is a fully automatic pure mechanical differential self-locking device, which is reliable and durable, and has a rapid response. From certain perspectives, it is a very balanced design. It can respond to the torque difference generated between the driving wheels in a very short time, adjust the torque output to solve the wheel difference problem, and its self-locking characteristic is also very linear and can be adjusted within a relatively wide torque range without being affected by the structural space of the differential housing and restricting the exertion of its function.

[0031] This differential self-locking device realizes that the self-locking torques of the upper worm and worm gear mechanism and the lower worm and worm gear mechanism have the lever amplification principle for locking the left and right half-shaft output gears by designing a simple upper worm and worm gear mechanism, a lower worm and worm gear mechanism, a differential planet gear set and a worm shaft inside the differential housing. At the same time, it realizes automatic locking or unlocking, and at the same time realizes traction self-sensing torque distribution to the left and right half-shaft output gears, improving the passing ability of the vehicle. This differential self-locking device has obvious improvements in reducing weight and volume, significant optimizations in reducing differential NVH, and great improvements in reducing component wear. It meets economic benefits and has broad application prospects.

[0032] It should be noted that in this article, terms such as "including", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitations, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0033] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A differential self-locking device, comprising a differential case (1), and a half-shaft output gear set (2), an upper worm and worm gear mechanism (3), a lower worm and worm gear mechanism (4), a differential planet gear set (5), a worm gear shaft (6), a gasket (7), and a positioning bushing (8) arranged inside the differential case (1), characterized in that: The half - shaft output gear set (2) includes a left half - shaft output gear (21) and a right half - shaft output gear (22) symmetrically arranged on the differential housing (1). The upper worm - worm gear mechanism (3) and the lower worm - worm gear mechanism (4) are rotationally symmetrically arranged. Both the upper worm - worm gear mechanism (3) and the lower worm - worm gear mechanism (4) are meshed with the left half - shaft output gear (21) and the right half - shaft output gear (22). The differential planet gear set (5) is located between the upper worm - worm gear mechanism (3) and the lower worm - worm gear mechanism (4) and is meshed with the upper worm - worm gear mechanism (3), the lower worm - worm gear mechanism (4), the left half - shaft output gear (21), and the right half - shaft output gear (22). The worm shaft (6) is located between the left half - shaft output gear (21) and the right half - shaft output gear (22).

2. The differential self-locking device according to claim 1, characterized in that: The upper worm - worm gear mechanism (3) includes an upper worm gear (31) arranged between the left half - shaft output gear (21) and the right half - shaft output gear (22), and an upper worm one (32) and an upper worm two (33) rotationally symmetrically arranged on both sides of the upper worm gear (31) and both meshed with the upper worm gear (31).

3. The differential self-locking device according to claim 2, wherein: Gears meshing with the right half - shaft output gear (22) and the left half - shaft output gear (21) respectively are arranged at one ends of the upper worm one (32) and the upper worm two (33).

4. The differential self-locking device according to claim 3, characterized in that: The lower worm - worm gear mechanism (4) includes a lower worm gear (43) arranged between the left half - shaft output gear (21) and the right half - shaft output gear (22), and a lower worm one (41) and a lower worm two (42) rotationally symmetrically arranged on both sides of the lower worm gear (43) and both meshed with the lower worm gear (43).

5. The differential self-locking device according to claim 4, characterized in that: Gears meshing with the left half - shaft output gear (21) and the right half - shaft output gear (22) respectively are arranged at one ends of the lower worm one (41) and the lower worm two (42).

6. The differential self-locking device according to claim 5, characterized in that: Gears meshing with the left half - shaft planet gear one (51) and the right half - shaft planet gear two (53) respectively are arranged at one ends of the upper worm one (32) and the upper worm two (33). Gears meshing with the right half - shaft planet gear one (52) and the left half - shaft planet gear two (54) respectively are arranged at one ends of the lower worm one (41) and the lower worm two (42).

7. A differential self-locking device according to claim 6, characterized in that: The differential planet gear set (5) includes a left half - shaft planet gear one (51), a right half - shaft planet gear one (52), a right half - shaft planet gear two (53), and a left half - shaft planet gear two (54). The left half - shaft planet gear one (51) and the right half - shaft planet gear one (52) are meshed with the left half - shaft output gear (21) and the right half - shaft output gear (22) respectively. The right half - shaft planet gear two (53) and the left half - shaft planet gear two (54) are meshed with the right half - shaft output gear (22) and the left half - shaft output gear (21) respectively.

8. A differential self-locking device according to claim 6, wherein the left half-shaft planetary gear I (51) and the right half-shaft planetary gear I (52) are connected by gear meshing transmission, the right half-shaft planetary gear II (53) and the left half-shaft planetary gear II (54) are connected by gear meshing transmission, the left half-shaft planetary gear I (51) and the right half-shaft planetary gear I (52) are respectively meshed with the upper worm I (32) and the lower worm I (41) for transmission connection, and the right half-shaft planetary gear I (52) and the left half-shaft planetary gear II (54) are respectively meshed with the upper worm II (33) and the lower worm II (42) for transmission connection.

9. The differential self-locking device according to claim 1, characterized in that: The worm wheel shaft (6) is disposed inside the upper worm wheel (31) and the lower worm wheel (43), and gaskets (7) are further provided on the worm wheel shaft (6) at the top and bottom of the upper worm wheel (31) and the lower worm wheel (43); The gasket (7) is one of a copper sheet or a friction sheet; A positioning shaft sleeve (8) is further provided on the worm wheel shaft (6) between the upper worm wheel (31) and the lower worm wheel (43), and the upper worm wheel (31), the lower worm wheel (43), the gasket (7) and the positioning shaft sleeve (8) are coaxially arranged.

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