Multi-choice full-time four-wheel drive distributor structure

Abstract

The utility model discloses a kind of multi-selection full-time four-wheel drive divider structure, both can realize different drive mode such as two-wheel drive, four-wheel drive, also have the differential adaptation ability of front and rear axle under four-wheel drive mode, in addition, when needed, the rotational speed locking between vehicle front axle and vehicle rear axle can be realized, in the process of switching different mode, switching action is smooth, impact is small, overall structure is relatively compact, layout is reasonable.In the present application, including gear shift tooth cover, input shaft, rear output shaft and front input sprocket, the sprocket joint is fixed on the front input sprocket, further including lock ring type synchronizer and planetary gear type differential, gear shift tooth cover is adapted with lock ring type synchronizer, planetary gear type differential includes differential housing, differential carrier, differential sun gear, differential ring gear and a plurality of differential planetary gears, differential planetary gear is engaged with differential sun gear, differential planetary gear is engaged with differential ring gear.

Description

Technical Field

[0001] This utility model belongs to the field of vehicle transmission and transfer case technology, and in particular relates to a multi-select all-time four-wheel drive transfer case structure. Background Technology

[0002] A transfer case is a power distribution device unique to four-wheel drive (4WD) or all-wheel drive (AWD) vehicles, typically mounted behind the transmission. The transfer case has two main functions: first, to distribute power to the front and rear axles, receiving power from the transmission and distributing it to the front and rear drive shafts respectively, thus driving all four wheels; second, to provide additional gear ratios, further amplifying engine torque and improving climbing and off-road capabilities. Utility Model Content

[0003] This utility model provides a multi-select full-time four-wheel drive transfer case structure that can realize different driving modes such as two-wheel drive and four-wheel drive. In four-wheel drive mode, it also has the ability to adapt to the differential speed between the front and rear axles. In addition, when needed, it can lock the speed between the front axle and the rear axle of the vehicle. The switching action is smooth and the impact is small during the switching of different modes. The overall structure is relatively compact and the layout is reasonable.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A multi-select full-time four-wheel drive transfer case structure includes a shift sleeve, an input shaft, a rear output shaft arranged coaxially with the input shaft, and a front input sprocket rotatably connected to the rear output shaft; The front input sprocket is fixed with sprocket teeth, and also includes a locking ring synchronizer sleeved on the rear output shaft and a planetary gear differential sleeved on the rear output shaft. The locking ring synchronizer includes a synchronizer hub rotatably connected to the rear output shaft and a synchronizer ring for pressing the sprocket teeth. The shifting teeth are sleeved on the locking ring synchronizer and are adapted to the locking ring synchronizer. The planetary gear differential includes a differential housing fixed to the input shaft, a differential planetary carrier that rotates synchronously with the differential housing, a differential sun gear that rotates synchronously with the synchronizer hub, a differential ring gear that rotates synchronously with the rear output shaft, and a plurality of differential planetary gears that are rotatably connected to the differential planetary carrier. The differential planetary gears mesh with the differential sun gear, and the differential planetary gears mesh with the differential ring gear. The planetary gear differential, synchronizer hub and front input sprocket are arranged sequentially along the input shaft axis. The shift sleeve can be slidably connected to the differential housing and the shift sleeve can be slidably connected to the sprocket teeth.

[0005] Preferably, the planetary gear differential further includes a first friction ring sleeved on the rear output shaft and a second friction ring sleeved on the rear output shaft. The differential gear ring includes a gear ring base and an internal gear ring arranged coaxially. One end face of the first friction ring is a first friction front face for contacting the differential housing, and the other end face of the first friction ring is a first friction rear face for contacting the gear ring base. The first friction front face, the first friction rear face, the gear ring base, the second friction ring, and any differential planet gear are arranged sequentially along the input shaft axis.

[0006] Preferably, the differential ring gear and the rear output shaft can slide relative to each other, the differential ring gear is a helical ring gear, and the differential planetary gears are slidably connected to the differential planetary carrier.

[0007] Preferably, the planetary gear differential further includes a third friction ring sleeved on the rear output shaft and a fourth friction ring sleeved on the rear output shaft. One end face of the fourth friction ring is a fourth front end face for contacting the differential sun gear, and the other end face of the fourth friction ring is a fourth rear end face for contacting the differential planetary carrier. The rear output shaft is provided with a rear axle cam. The rear axle cam, the third friction ring, the differential sun gear, the fourth front end face, and the fourth rear end face are arranged sequentially along the input shaft axial direction.

[0008] Preferably, the differential sun gear is slidably connected to the synchronizer hub, the differential sun gear is a helical gear, and the differential planetary gears are helical gears.

[0009] Preferably, the synchronizer hub is rotatably connected to the rear output shaft via a first bearing, the inner ring of the first bearing is coaxially fixed to the rear output shaft, and the outer ring of the first bearing is coaxially fixed to the synchronizer hub. The front input sprocket is rotatably connected to the rear output shaft via a second bearing, the inner ring of the second bearing is coaxially fixed to the rear output shaft, and the outer ring of the second bearing is coaxially fixed to the front input sprocket.

[0010] Preferably, each tooth on the shift sleeve is a shift engagement tooth, and all shift engagement teeth together form an inner ring engagement tooth set. The differential housing is provided with an outer ring tooth hub for engaging with the inner ring engagement tooth set. The end of the shift engagement tooth facing the differential housing has a chamfered bevel for contacting the outer ring tooth hub, and the angle between the chamfered bevel and the end face of the shift sleeve is 25 to 60 degrees.

[0011] Preferably, in the axial direction of the input shaft: the distance between the outer ring gear hub and the synchronizer gear hub is L, where L≤2cm.

[0012] The beneficial effects of this utility model are: it can realize different driving modes such as two-wheel drive and four-wheel drive, and it has the ability to adapt to the differential speed between the front and rear axles in four-wheel drive mode. In addition, when needed, it can lock the speed between the front axle and the rear axle of the vehicle. The switching action is smooth and the impact is small during the switching of different modes. The overall structure is relatively compact and the layout is reasonable. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 yes Figure 1 Enlarged view of point A in the middle; Figure 3 yes Figure 1 Enlarged view of point B in the middle; Figure 4 This is a partial structural schematic diagram of the present invention.

[0014] Reference numerals: 1. Shift sleeve; 101. Shift engagement tooth; 101a. Chamfered bevel; 2. Rear output shaft; 3. Front input sprocket; 301. Sprocket connecting tooth; 4. Locking ring synchronizer; 401. Synchronizer hub; 402. Synchronizer ring gear; 501. Differential housing; 501.1. Outer ring hub; 502. Differential planetary carrier; 503. Differential sun gear; 504. Differential ring gear; 504.1. Ring gear base; 504.2. Inner ring gear; 505. Differential planetary gears; 506.1. First friction ring; 506.2. Second friction ring; 506.3. Fourth friction ring; 506.4. Rear spline; 6. Spline neck; 601. First bearing; 701. Second bearing; 702. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0016] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, A multi-select full-time four-wheel drive transfer case structure includes a shift sleeve 1, an input shaft, a rear output shaft 2 arranged coaxially with the input shaft, and a front input sprocket 3 rotatably connected to the rear output shaft 2; The front input sprocket 3 is fixed with sprocket teeth 301, and also includes a locking ring synchronizer 4 sleeved on the rear output shaft 2 and a planetary gear differential sleeved on the rear output shaft 2. The locking ring synchronizer 4 includes a synchronizer hub 401 rotatably connected to the rear output shaft 2 and a synchronizer ring 402 for pressing the sprocket teeth 301. The shift sleeve 1 is provided on the locking ring synchronizer 4 and is adapted to the locking ring synchronizer 4. The planetary differential includes a differential housing 501 fixed to the input shaft, a differential planet carrier 502 that rotates synchronously with the differential housing 501, a differential sun gear 503 that rotates synchronously with the synchronizer hub 401, a differential ring gear 504 that rotates synchronously with the rear output shaft 2, and a plurality of differential planet gears 505 that are rotatably connected to the differential planet carrier 502. The differential planet gears 505 mesh with the differential sun gear 503, and the differential planet gears 505 mesh with the differential ring gear 504. The planetary gear differential, synchronizer ring 402 and front input sprocket 3 are arranged sequentially along the input shaft axis. The shift sleeve 1 can be slidably connected to the differential housing 501 and the shift sleeve 1 can be slidably connected to the sprocket connecting teeth 301.

[0017] In this invention, when the shift sleeve 1 is engaged with the differential housing 501 (sliding connection) and the shift sleeve 1 is separated from the sprocket connecting teeth 301 (the shift sleeve 1 is always engaged with the locking ring synchronizer 4), the vehicle is in two-wheel drive mode. The power transmission route is input shaft, differential housing 501, differential planetary carrier 502, differential planetary gear 505, differential ring gear 504, and rear output shaft 2. Thus, the rear wheels of the vehicle have power.

[0018] The locking ring synchronizer 4 and the front input sprocket 3 are both existing technologies. The locking ring synchronizer 4 can "adapt the speeds of the two gear transmission structures before they engage, thereby reducing shift shock and improving smoothness". The front input sprocket 3 is linked to the front wheels of the vehicle (the front input sprocket 3 will be driven by the front output sprocket fixed on the front output shaft through a chain, and the front output shaft outputs power to the front wheels of the vehicle).

[0019] When the shift sleeve 1 (from its position in two-wheel drive mode) moves to the point where "the shift sleeve 1 engages with the differential housing 501 (sliding connection) and the shift sleeve 1 engages with the sprocket teeth 301", the vehicle is in four-wheel drive lock-up mode. During the aforementioned movement, initially, there is a large speed difference between the differential housing 501 (linked to the rear axle and rear wheels) and the sprocket teeth 301 (linked to the front axle and front wheels). If the shift sleeve 1 directly engages with the sprocket teeth 301, a large impact will occur due to the large speed difference. At this time, the locking ring synchronizer 4 can be fully utilized to allow the speeds of the differential housing 501 and the sprocket teeth 301 to approach each other first, and then engage (as mentioned earlier, this is the function of the existing "locking ring synchronizer 4"), thereby greatly improving the smoothness of shifting.

[0020] The four-wheel drive lock-up mode has two power transmission routes. The first route is: input shaft, differential housing 501, differential planetary carrier 502, differential planetary gears 505, differential ring gear 504, and rear output shaft 2. The second route is: input shaft, differential housing 501, shift sleeve 1, sprocket coupling gear 301, and front input sprocket 3 (the front input sprocket 3 is linked to the front output shaft). In this mode, the front and rear wheels of the vehicle always rotate at the same speed.

[0021] When the shift sleeve 1 (from its position in four-wheel drive lock mode) moves to the point where "the shift sleeve 1 separates from the differential housing 501 and engages with the sprocket teeth 301," the vehicle is in full-time four-wheel drive mode. During this movement, the sprocket teeth 301 do not need to re-engage with any transmission structure, thus avoiding impact. In this mode, the front and rear wheel speeds may differ, but for the vehicle to drive normally, the front and rear wheel speeds should remain the same most of the time. Therefore, a planetary differential is used. In a planetary differential, the differential housing 501 is linked to the rear output shaft 2 (i.e., linked to the rear wheels of the vehicle) via the differential planetary carrier 502, differential planetary gears 505, and differential ring gear 504. The differential sun gear 503 is linked to the front output shaft (i.e., linked to the front wheels of the vehicle) via the locking ring synchronizer 4, shift sleeve 1, sprocket coupling 301, and front output sprocket. The differential sun gear 503 meshes with the differential planetary gears 505. When the front and rear wheels of the vehicle rotate at different speeds due to factors such as turning or vehicle bouncing (this speed difference is usually small), the differential planetary gears 505 will "revolve" around the differential sun gear 503, thereby eliminating the negative impact of the speed difference between the front and rear wheels. When the vehicle returns to normal straight driving, the speeds of the front and rear wheels will return to the same.

[0022] The planetary gear differential also includes a first friction ring 506.1 and a second friction ring 506.2 sleeved on the rear output shaft 2. The differential gear ring 504 includes a gear ring base 504.1 and an internal gear ring 504.2 arranged coaxially. One end face of the first friction ring 506.1 is a first friction front face for contacting the differential housing 501, and the other end face of the first friction ring 506.1 is a first friction rear face for contacting the gear ring base 504.1. The first friction front face, the first friction rear face, the gear ring base 504.1, the second friction ring 506.2, and any differential planet gear 505 are arranged sequentially along the input shaft axis.

[0023] The differential gear ring 504 can slide relative to the rear output shaft 2. The differential gear ring 504 is a helical gear ring. The differential planetary gear 505 is slidably connected to the differential planetary carrier 502.

[0024] The planetary gear differential also includes a third friction ring 506.3 and a fourth friction ring 506.4 sleeved on the rear output shaft 2. One end face of the fourth friction ring 506.4 is a fourth front end face for contacting the differential sun gear 503, and the other end face of the fourth friction ring 506.4 is a fourth rear end face for contacting the differential planetary carrier 502. The rear output shaft 2 is provided with a rear spline 6 that is slidably connected to the differential ring gear 504. The rear spline 6 is provided with a spline neck 601. The spline neck 601, the third friction ring 506.3, the differential sun gear 503, the fourth front end face, and the fourth rear end face are arranged sequentially along the input shaft axis.

[0025] The differential sun gear 503 is slidably connected to the synchronizer hub 401. The differential sun gear 503 is a helical gear, and the differential planetary gear 505 is a helical gear.

[0026] In full-time four-wheel drive mode, as mentioned earlier, "when the front and rear wheels of the vehicle rotate at different speeds due to factors such as turning or vehicle bouncing (this speed difference is usually small), the differential planetary gear 505 will revolve around the differential sun gear 503, thereby eliminating the negative impact of the speed difference between the front and rear wheels. When the vehicle returns to normal straight-line driving, the speeds of the front and rear wheels will return to the same." Therefore, when the front and rear wheels rotate at different speeds, because "the differential ring gear 504 is a helical ring gear, the differential sun gear 503 is a helical gear, and the differential planetary gear 505 is a helical gear," and "the differential ring gear 504 can slide relative to the rear output shaft 2, the differential planetary gear 505 is slidably connected to the differential planetary carrier 502, and the differential sun gear 503 is slidably connected to the synchronizer hub 401," therefore, with... Figure 1 , Figure 2 , Figure 3Taking a perspective example, if the differential ring gear 504 moves to the left, it will rub against the first friction ring 506.1; if it moves to the right, it will rub against the second friction ring 506.2. Similarly, if the differential sun gear 503 moves to the left, it will rub against the third friction ring 506.3; and if it moves to the right, it will rub against the fourth friction ring 506.4. Therefore, regardless of the type of friction, the axial movement of the differential ring gear 504 or the differential sun gear 503 can be suppressed (when the front and rear wheels of the vehicle rotate at the same speed, the differential ring gear 504 or the differential sun gear 503 will not move axially; when they do move axially, it indicates that the front and rear wheels of the vehicle rotate at different speeds), thus accelerating the process of restoring the front and rear wheel speeds to the same level.

[0027] The synchronizer hub 401 is rotatably connected to the rear output shaft 2 via a first bearing 701. The inner ring of the first bearing 701 is coaxially fixed with the rear output shaft 2, and the outer ring of the first bearing 701 is coaxially fixed with the synchronizer hub 401. The front input sprocket 3 is rotatably connected to the rear output shaft 2 via a second bearing 702. The inner ring of the second bearing 702 is coaxially fixed with the rear output shaft 2, and the outer ring of the second bearing 702 is coaxially fixed with the front input sprocket 3.

[0028] The first bearing 701 and the second bearing 702 assist the synchronizer hub 401 and the front input sprocket 3 in working stably and reliably.

[0029] Each tooth on the shift sleeve 1 is a shift engagement tooth 101. All shift engagement teeth 101 together form an inner ring engagement tooth set. The differential housing 501 is provided with an outer ring hub 501.1 for engaging with the inner ring engagement tooth set. The end of the shift engagement tooth 101 facing the differential housing 501 has a chamfered bevel 101a for contacting the outer ring hub 501.1. The angle between the chamfered bevel 101a and the end face of the shift sleeve 1 is 25 to 60 degrees.

[0030] On the input shaft axis: the distance between the outer ring gear hub 501.1 and the synchronizer gear hub 401 is L, where L≤2cm.

[0031] As mentioned earlier, "in full-time four-wheel drive mode, when the front and rear wheels of the vehicle rotate at different speeds, the speed difference is usually small, and when the vehicle returns to normal straight driving, the speeds of the front and rear wheels will return to the same." This means that the speed difference between the differential housing 501 (linked to the front wheels) and the shift sleeve 1 (linked to the rear wheels) is either small or the same. Therefore, unlike the situation when switching from "four-wheel drive lock mode to full-time four-wheel drive mode," the locking ring synchronizer 4 is not required when switching from "full-time four-wheel drive mode to four-wheel drive lock mode." In this utility model, utilizing the aforementioned characteristics, only a chamfered bevel 101a for guiding and reducing impact needs to be arranged at the end of the shift engagement gear 101 facing the differential housing 501. This can reduce impact and improve shift smoothness (smoothness), without the need for an additional, relatively large and costly locking ring synchronizer 4, thus saving overall space and ensuring the rationality of the layout.

[0032] Furthermore, designing a smaller gap between the outer ring gear hub 501.1 and the synchronizer gear hub 401 further enhances shift smoothness. To explain: when a driver selects to switch from "full-time four-wheel drive mode to four-wheel drive lock mode," the shifting operation is usually not performed when the vehicle is unstable or the front and rear wheel speeds differ significantly. More often, it's done when the vehicle is moving smoothly or stationary and about to enter low-traction surfaces such as mud, sand, or ice. At these times, the front and rear wheel speeds are usually the same. The probability of a sudden increase in the front and rear wheel speed difference immediately after shifting is low. If the shift completion time can be further shortened, the possibility of encountering a large difference in front and rear wheel speeds becomes even less. A smaller gap between the outer ring gear hub 501.1 and the synchronizer gear hub 401 (i.e., L mentioned earlier) results in a shorter shifting time, naturally ensuring smoother shifting. Moreover, in this shifting scenario, the aforementioned chamfered bevel 101a is clearly sufficient to handle it (the shifting impact in this scenario is already very small).

[0033] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A multi-select full-time four-wheel drive transfer case structure, comprising a shift sleeve, an input shaft, a rear output shaft coaxially arranged with the input shaft, and a front input sprocket rotatably connected to the rear output shaft; characterized in that, The front input sprocket is fixed with sprocket teeth, and also includes a locking ring synchronizer sleeved on the rear output shaft and a planetary gear differential sleeved on the rear output shaft. The locking ring synchronizer includes a synchronizer hub rotatably connected to the rear output shaft and a synchronizer ring for pressing the sprocket teeth. The shifting teeth are sleeved on the locking ring synchronizer and are adapted to the locking ring synchronizer. The planetary gear differential includes a differential housing fixed to the input shaft, a differential planetary carrier that rotates synchronously with the differential housing, a differential sun gear that rotates synchronously with the synchronizer hub, a differential ring gear that rotates synchronously with the rear output shaft, and a plurality of differential planetary gears that are rotatably connected to the differential planetary carrier. The differential planetary gears mesh with the differential sun gear, and the differential planetary gears mesh with the differential ring gear. The planetary gear differential, synchronizer hub and front input sprocket are arranged sequentially along the input shaft axis. The shift sleeve can be slidably connected to the differential housing and the shift sleeve can be slidably connected to the sprocket teeth.

2. The multi-choice full-time four-wheel drive power distribution structure according to claim 1, characterized in that, The planetary gear differential also includes a first friction ring sleeved on the rear output shaft and a second friction ring sleeved on the rear output shaft. The differential gear ring includes a gear ring base and an internal gear ring arranged coaxially. One end face of the first friction ring is a first friction front face for contacting the differential housing, and the other end face of the first friction ring is a first friction rear face for contacting the gear ring base. The first friction front face, the first friction rear face, the gear ring base, the second friction ring, and any differential planet gear are arranged sequentially along the input shaft axis.

3. A multiple selection full-time four-wheel drive transfer structure according to claim 2, characterized in that, The differential ring gear and the rear output shaft can slide relative to each other. The differential ring gear is a helical ring gear, and the differential planetary gears are slidably connected to the differential planetary carrier.

4. The multi-choice full-time four-wheel drive power distribution structure according to claim 2, characterized in that, The planetary gear differential also includes a third friction ring and a fourth friction ring sleeved on the rear output shaft. One end face of the fourth friction ring is a fourth front end face for contacting the differential sun gear, and the other end face of the fourth friction ring is a fourth rear end face for contacting the differential planetary carrier. The rear output shaft is provided with a rear axle cam. The rear axle cam, the third friction ring, the differential sun gear, the fourth front end face, and the fourth rear end face are arranged sequentially along the input shaft axis.

5. A multiple selection full-time four-wheel drive transfer structure according to claim 4, characterized in that, The differential sun gear is slidably connected to the synchronizer hub, and the differential sun gear is a helical gear, as are the differential planetary gears.

6. A multiple full-time four-wheel drive transfer structure according to claim 1 or 2 or 3 or 4 or 5, characterized in that, The synchronizer hub is rotatably connected to the rear output shaft via a first bearing. The inner ring of the first bearing is coaxially fixed with the rear output shaft, and the outer ring of the first bearing is coaxially fixed with the synchronizer hub. The front input sprocket is rotatably connected to the rear output shaft via a second bearing. The inner ring of the second bearing is coaxially fixed with the rear output shaft, and the outer ring of the second bearing is coaxially fixed with the front input sprocket.

7. The multi-select full-time four-wheel drive transfer case structure according to claim 1, characterized in that, Each tooth on the shift sleeve is a shift engagement tooth, and all shift engagement teeth together form an inner ring engagement tooth set. The differential housing is provided with an outer ring tooth hub for engaging with the inner ring engagement tooth set. The end of the shift engagement tooth facing the differential housing has a chamfered bevel for contacting the outer ring tooth hub, and the angle between the chamfered bevel and the end face of the shift sleeve is 25 to 60 degrees.

8. The multi-select full-time four-wheel drive transfer case structure according to claim 7, characterized in that, On the input shaft axis: the distance between the outer ring gear hub and the synchronizer gear hub is L, where L≤2cm.

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