Differential transmission assembly and vehicle

Abstract

This invention discloses a differential transmission assembly and a vehicle, relating to the field of vehicle transmission technology. The differential transmission assembly includes: a power input shaft; an output assembly including a differential mechanism, a first output shaft section, and a second output shaft section; a first gear pair, a second gear pair, and a third gear pair, each including meshing input gears and output gears, with each input gear disposed on the power input shaft, and the output gear of the second gear pair being drive-connected to the differential mechanism; a first one-way transmission member drive-connected between the output gear of the first gear pair and the first output shaft section; and a second one-way transmission member drive-connected between the output gear of the third gear pair and the second output shaft section. By adding two sets of side gear pairs and two sets of one-way transmission members to an existing open differential, the above-mentioned differential transmission assembly enables the side gear pairs to participate in the transmission of the corresponding output shaft sections under specific relative speed conditions, which helps to improve the problem of wheel slippage.

Description

Technical Field

[0001] This invention relates to the field of vehicle transmission technology, and in particular to a differential transmission assembly and a vehicle. Background Technology

[0002] The vehicle's powertrain system transmits power from the power source to the wheels to drive the vehicle. The differential is a crucial component of the vehicle's powertrain system; it is typically located in the drive axle and is used to allow the left and right wheels to rotate at different speeds when the vehicle is turning or when there is a difference in the resistance of the left and right wheels, thereby improving the vehicle's ride smoothness and maneuverability.

[0003] Open differentials, commonly used in existing vehicles, are characterized by their relatively simple structure and direct transmission, making them widely applicable in vehicle transmission systems. However, under conditions such as rainy or snowy roads, slippery roads, or high turning speeds, differences in the traction conditions of the left and right wheels can easily arise. The power distribution characteristics of an open differential may cause one wheel to spin or slip.

[0004] To address these issues, existing technologies include Torsen differentials, multi-plate clutch limited-slip differentials, viscous coupling limited-slip differentials, and electronically controlled differential locks. However, these structures typically involve numerous transmission, locking, or control components, resulting in high overall structural complexity. Consequently, existing differential transmission structures struggle to balance structural simplicity with the ability to suppress wheel slippage. Summary of the Invention

[0005] The purpose of this invention is to provide a differential transmission assembly and vehicle that solves the problem that existing differential transmission structures cannot simultaneously achieve structural simplicity and the ability to suppress wheel slippage.

[0006] To achieve the above objectives, the present invention provides a differential transmission assembly, comprising: a power input shaft; an output assembly including a differential mechanism and a first output shaft segment and a second output shaft segment respectively drivenly connected to the differential mechanism; a first gear pair, a second gear pair, and a third gear pair, each including a meshing input gear and an output gear, each of the input gears being disposed on the power input shaft, and the output gear of the second gear pair being drivenly connected to the differential mechanism; a first one-way transmission member drivenly connected between the output gear of the first gear pair and the first output shaft segment; and a second one-way transmission member drivenly connected between the output gear of the third gear pair and the second output shaft segment; wherein the transmission ratios of the first gear pair and the third gear pair are different from the transmission ratio of the second gear pair.

[0007] Preferably, the transmission ratio of the first gear pair is the same as that of the third gear pair.

[0008] Preferably, the first output shaft segment and the second output shaft segment are coaxially arranged, and along the axial direction of the first output shaft segment and the second output shaft segment, the output gear of the first gear pair and the output gear of the third gear pair are respectively arranged on both sides of the differential mechanism.

[0009] Preferably, the number of teeth on the input gear of the first gear pair is the same as the number of teeth on the input gear of the third gear pair, and both are less than the number of teeth on the input gear of the second gear pair; the number of teeth on the output gear of the first gear pair is the same as the number of teeth on the output gear of the third gear pair, and both are greater than the number of teeth on the output gear of the second gear pair.

[0010] Preferably, the number of teeth on the input gear of the first gear pair is the same as the number of teeth on the input gear of the third gear pair, and both are greater than the number of teeth on the input gear of the second gear pair; the number of teeth on the output gear of the first gear pair is the same as the number of teeth on the output gear of the third gear pair, and both are less than the number of teeth on the output gear of the second gear pair.

[0011] Preferably, the differential mechanism includes a differential housing, a planetary bevel gear, a first half-shaft bevel gear, and a second half-shaft bevel gear. The planetary bevel gear is rotatably disposed on the differential housing. Both the first half-shaft bevel gear and the second half-shaft bevel gear mesh with the planetary bevel gear. The first output shaft segment is circumferentially fixed to the first half-shaft bevel gear, and the second output shaft segment is circumferentially fixed to the second half-shaft bevel gear.

[0012] Preferably, a first clutch is provided between the power input shaft and the input gear of the first gear pair, and a second clutch is provided between the power input shaft and the input gear of the third gear pair.

[0013] Preferably, both the first one-way transmission component and the second one-way transmission component are overrunning clutches. The overrunning clutch includes an inner ring, an outer ring, and a locking component disposed between the inner ring and the outer ring. One of the inner ring and the outer ring is circumferentially fixed to the corresponding output gear, and the other is circumferentially fixed to the corresponding output shaft segment.

[0014] Preferably, the axis of the power input shaft is arranged parallel to the axis of the first output shaft segment, and the first gear pair, the second gear pair and the third gear pair are all cylindrical gear pairs.

[0015] The present invention also provides a vehicle including wheels and a differential drive assembly as described in any of the preceding claims, the differential drive assembly being drive-connected to the wheels.

[0016] Compared to the aforementioned background technology, the differential transmission assembly provided by this invention has the following beneficial effects: This invention, by setting up a first gear pair, a second gear pair, and a third gear pair, and connecting the output gear of the second gear pair to the differential mechanism, enables the power input shaft to transmit power to the differential mechanism through the second gear pair, thereby meeting the conventional differential output requirements of the first and second output shaft segments. The output gear of the first gear pair is connected to the first output shaft segment via a first one-way transmission member, and the output gear of the third gear pair is connected to the second output shaft segment via a second one-way transmission member. Furthermore, the transmission ratios of the first and third gear pairs are different from the transmission ratio of the second gear pair. When the relative speed between the first or second output shaft segment and the corresponding output gear meets the engagement condition of the corresponding one-way transmission member, torque is transmitted between the corresponding side output gear and the corresponding output shaft segment through the one-way transmission member; when the relative speed does not meet the engagement condition, the corresponding one-way transmission member causes the side gear pair to disengage from the corresponding output shaft segment. While retaining the conventional differential function of the differential mechanism, selective transmission is achieved to the corresponding output shaft segments through gear pairs on both sides. This improves the problem of insufficient output power on one side and easy wheel slippage when turning or when the adhesion of the left and right wheels is inconsistent. Furthermore, the overall structure is mainly composed of gear pairs and one-way transmission components, making the structure relatively simple. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 This is a three-dimensional structural diagram of the differential transmission assembly provided in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached drawings: 10-Power input shaft; 110-First clutch; 120-Second clutch; 20-First gear pair; 21-First input gear; 22-First output gear; 30-Second gear pair; 31-Second input gear; 32-Second output gear; 40-Third gear pair; 41-Third input gear; 42-Third output gear; 50-Output assembly; 51-Differential mechanism; 511-Differential housing; 512-Planetary bevel gear; 513-First half-shaft bevel gear; 514-Second half-shaft bevel gear; 52-First output shaft section; 53-Second output shaft section; 60-First one-way transmission component; 70-Second one-way transmission component. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] It should be noted that the transmission ratio of the gear pair in this application can be understood as the speed transmission relationship between the input gear and the output gear in the gear pair, or determined by the tooth number relationship between the input gear and the output gear. The first gear pair 20 and the third gear pair 40 can also be called side gear pairs, and the second gear pair 30 can be called an intermediate gear pair; wherein, the input gear in the first gear pair 20 is the first input gear 21, and the output gear is the first output gear 22; the input gear in the second gear pair 30 is the second input gear 31, and the output gear is the second output gear 32; the input gear in the third gear pair 40 is the third input gear 41, and the output gear is the third output gear 42.

[0023] like Figure 1As shown, to achieve the above objectives, the present invention provides a differential transmission assembly, comprising: a power input shaft 10; an output assembly 50, including a differential mechanism 51 and a first output shaft section 52 and a second output shaft section 53 respectively drivenly connected to the differential mechanism 51; a first gear pair 20, a second gear pair 30, and a third gear pair 40, each including a meshing input gear and an output gear, each of the input gears being disposed on the power input shaft 10, and the output gear of the second gear pair 30 being drivenly connected to the differential mechanism 51; a first one-way transmission member 60, drivenly connected between the output gear of the first gear pair 20 and the first output shaft section 52; and a second one-way transmission member 70, drivenly connected between the output gear of the third gear pair 40 and the second output shaft section 53; wherein the transmission ratios of the first gear pair 20 and the third gear pair 40 are different from the transmission ratio of the second gear pair 30. Specifically, the power input shaft 10 is used for transmission connection with a power source, which is an engine or a drive motor. When the power input shaft 10 rotates, it can drive the input gear in the three sets of gear pairs to rotate synchronously. The second output gear 32 is transmission connected to the differential mechanism 51, so that the power input shaft 10 can input power to the differential mechanism 51 through the second gear pair 30, and then the differential mechanism 51 distributes it to the first output shaft section 52 and the second output shaft section 53, so as to retain the conventional differential function of the differential mechanism 51. The first output gear 22 forms a selective transmission relationship with the first output shaft section 52 through the first one-way transmission member 60, and the third output gear 42 forms a selective transmission relationship with the second output shaft section 53 through the second one-way transmission member 70. When the relative speed between the corresponding output gear and the corresponding output shaft section meets the engagement condition, the corresponding side gear pair can transmit power to the corresponding output shaft section. When the relative speed does not meet the engagement condition, the corresponding side gear pair can overtake and disengage relative to the corresponding output shaft section. The transmission ratios of the first gear pair 20 and the third gear pair 40 are different from those of the second gear pair 30, which makes the output speed relationship formed by the side gear pairs different from that of the intermediate differential transmission path. This provides a speed difference basis for the first one-way transmission component 60 and the second one-way transmission component 70 to engage or disengage according to the relative speed change, which is beneficial to improve the problem of insufficient output power on one side when turning or when the adhesion state of the left and right wheels is inconsistent.

[0024] In some embodiments of the present invention, the transmission ratio of the first gear pair 20 is the same as that of the third gear pair 40. Specifically, the first gear pair 20 and the third gear pair 40 correspond to the first output shaft segment 52 and the second output shaft segment 53, respectively. By setting the transmission ratio of the two gear pairs to be the same, the first output shaft segment 52 and the second output shaft segment 53 obtain the same or substantially the same side transmission response conditions, thereby improving the transmission consistency of the differential transmission assembly under left and right turning conditions. The first gear pair 20 and the third gear pair 40 may use gear sets with the same module, the same tooth width, and the same tooth number relationship. Alternatively, gear sets with different tooth widths or different materials may be used, provided that the transmission ratio is the same, to adapt to the vehicle chassis space, load-bearing capacity, or processing and assembly requirements.

[0025] In some embodiments of the present invention, the first output shaft segment 52 and the second output shaft segment 53 are coaxially arranged. Along the axial direction of the first output shaft segment 52 and the second output shaft segment 53, the output gears of the first gear pair 20 and the third gear pair 40 are respectively arranged on both sides of the differential mechanism 51. Specifically, the first output shaft segment 52 and the second output shaft segment 53 are coaxially arranged so that they can respectively form the left and right half shafts, which facilitates cooperation with the vehicle drive axle structure. The first output gear 22 and the third output gear 42 are respectively located on both sides of the differential mechanism 51, which can shorten the transmission connection distance between the side output gears and the corresponding output shaft segments, and make the one-way transmission components on the left and right sides symmetrically arranged around the differential mechanism 51 to reduce the risk of off-center loading. This facilitates the addition of side gear pairs and one-way transmission components on the basis of the existing open differential structure, and also facilitates assembly, maintenance and lubrication.

[0026] In one embodiment of the present invention, the number of teeth on the input gear of the first gear pair 20 is the same as the number of teeth on the input gear of the third gear pair 40, and both are less than the number of teeth on the input gear of the second gear pair 30; the number of teeth on the output gear of the first gear pair 20 is the same as the number of teeth on the output gear of the third gear pair 40, and both are greater than the number of teeth on the output gear of the second gear pair 30. Specifically, this tooth number relationship corresponds to a first transmission ratio configuration. Since the number of teeth on the first input gear 21 and the third input gear 41 is less than the number of teeth on the second input gear 31, and the number of teeth on the first output gear 22 and the third output gear 42 is greater than the number of teeth on the second output gear 32, at the same power input shaft 10 speed, the side output gears form a speed relationship different from that of the output gear of the second gear pair 30. When the vehicle is traveling in a straight line, the first output shaft section 52 and the second output shaft section 53 mainly obtain power through the differential mechanism 51. The corresponding side output gear can rotate relative to the corresponding output shaft section under the action of the one-way transmission member. When the vehicle turns or the left and right adhesion states change, the speed of a certain output shaft section relative to the corresponding side output gear decreases and the engagement conditions of the corresponding one-way transmission member are met, the corresponding side output gear transmits power to the output shaft section through the one-way transmission member.

[0027] In another embodiment of the present invention, the number of teeth on the input gear of the first gear pair 20 is the same as the number of teeth on the input gear of the third gear pair 40, and both are greater than the number of teeth on the input gear of the second gear pair 30; the number of teeth on the output gear of the first gear pair 20 is the same as the number of teeth on the output gear of the third gear pair 40, and both are less than the number of teeth on the output gear of the second gear pair 30. Specifically, this tooth number relationship corresponds to a second transmission ratio configuration, the tooth number relationship being the opposite of the first transmission ratio configuration. In this embodiment, the locking directions of the first one-way transmission member 60 and the second one-way transmission member 70 are adapted to the transmission ratio configuration, so that when the relative rotational speeds between the first output gear 22 and the first output shaft segment 52, and between the third output gear 42 and the second output shaft segment 53, meet the engagement conditions, a transmission connection on the corresponding side can be formed. This is used for vehicle platforms that require an overtaking direction opposite to the first configuration or different transmission responses, and the specific number of teeth is matched according to the vehicle wheel track, tire radius, or differential ratio.

[0028] In some embodiments of the present invention, the differential mechanism 51 includes a differential housing 511, a planetary bevel gear 512, a first half-shaft bevel gear 513, and a second half-shaft bevel gear 514. The planetary bevel gear 512 is rotatably disposed on the differential housing 511. The first half-shaft bevel gear 513 and the second half-shaft bevel gear 514 both mesh with the planetary bevel gear 512. The first output shaft section 52 is circumferentially fixed to the first half-shaft bevel gear 513, and the second output shaft section 53 is circumferentially fixed to the second half-shaft bevel gear 514. Specifically, the differential mechanism 51 adopts an open differential structure. The differential housing 511 is used to support the planetary bevel gear 512. The first half-shaft bevel gear 513 and the second half-shaft bevel gear 514 mesh with the planetary bevel gear 512 respectively, and are circumferentially fixed to the first output shaft section 52 and the second output shaft section 53 respectively. When the vehicle is traveling in a straight line and the resistance of the left and right wheels is similar, the first half-shaft bevel gear 513 and the second half-shaft bevel gear 514 rotate synchronously with the differential housing 511. When the vehicle turns, the planetary bevel gear 512 can rotate relative to the differential housing 511, causing a speed difference between the first half-shaft bevel gear 513 and the second half-shaft bevel gear 514. The differential mechanism 51 is a bevel gear type open differential, but it can also be other gear-type differential mechanisms that can distribute power to the two output shaft segments and allow a speed difference between the two output shaft segments.

[0029] It should be noted that the output gear of the second gear pair 30 is circumferentially fixed to the differential housing 511. Specifically, the second output gear 32 serves as an intermediate transmission gear. After being circumferentially fixed to the differential housing 511, the power input shaft 10 can directly drive the differential housing 511 to rotate through the second gear pair 30, thus making the differential mechanism 51 a conventional power transmission path. The second output gear 32 is fixed to the differential housing 511 by bolts or keys, or it can be integrally formed with the differential housing 511 to improve coaxiality and transmission rigidity. This structure facilitates the placement of an intermediate output gear on the outer periphery of an open differential, and the arrangement of the first gear pair 20 and the third gear pair 40 on both sides of the differential mechanism 51.

[0030] To accommodate reverse gear operation, a first clutch 110 is provided between the power input shaft 10 and the input gear of the first gear pair 20, and a second clutch 120 is provided between the power input shaft 10 and the input gear of the third gear pair 40. Specifically, the first clutch 110 is provided between the power input shaft 10 and the first input gear 21, and the second clutch 120 is provided between the power input shaft 10 and the third input gear 41. The first clutch 110 and the second clutch 120 are either dog clutches or friction clutches. When the vehicle is in forward gear, the first clutch 110 and the second clutch 120 are engaged, allowing the first gear pair 20 and the third gear pair 40 to operate according to a preset operating logic. When the vehicle is in reverse gear, the first clutch 110 and the second clutch 120 are disengaged, disconnecting the first gear pair 20 and the third gear pair 40 from the power input shaft 10. The reverse gear power is transmitted through the second gear pair 30 and the differential mechanism 51, avoiding interference between the first one-way transmission member 60 and the second one-way transmission member 70, which are arranged in the forward direction, and the reverse gear transmission. The first clutch 110 and the second clutch 120 can be controlled by the shift mechanism or by the vehicle controller according to the gear position signal.

[0031] In some embodiments of the present invention, both the first one-way transmission member 60 and the second one-way transmission member 70 are overrunning clutches. Each overrunning clutch includes an inner ring, an outer ring, and a locking member disposed between the inner and outer rings. One of the inner and outer rings is circumferentially fixed to the corresponding output gear, and the other is circumferentially fixed to the corresponding output shaft segment. Specifically, an overrunning clutch, also known as a one-way clutch, can transmit torque in one relative rotational direction and allow two connected objects to rotate relative to each other in another relative rotational direction. The locking member is a roller, and the inner and outer rings can be circumferentially fixed to their corresponding components via splines. Taking the first one-way transmission member 60 as an example, the inner ring is circumferentially fixed to the first output shaft segment 52, and the outer ring is circumferentially fixed to the first output gear 22; alternatively, the inner ring can be circumferentially fixed to the first output gear 22, and the outer ring to the first output shaft segment 52. Similarly, the second one-way transmission member 70 adopts the same structure as the first one-way transmission member 60.

[0032] To mitigate the impact on the output shaft segment generated during the engagement of the first gear pair 20 and the third gear pair 40, a first torsional vibration damper is provided between the outer ring of the first output gear 22 and the first one-way transmission member 60, and a second torsional vibration damper is provided between the outer ring of the third output gear 42 and the second one-way transmission member 70. Specifically, the first torsional vibration damper is driven between the outer ring of the first output gear 22 and the first one-way transmission member 60, and the second torsional vibration damper is driven between the outer ring of the third output gear 42 and the second one-way transmission member 70. Both the first and second torsional vibration dampers are spring-type or rubber-elastic torsional vibration dampers, designed to absorb some of the torsional impact when the corresponding output gear and the corresponding one-way transmission member switch from an overrunning disengagement state to a transmission engagement state. When the first gear pair 20, where the first input gear 21 and the first output gear 22 are located, begins to participate in the transmission, or when the third gear pair 40, where the third input gear 41 and the third output gear 42 are located, begins to participate in the transmission, the first torsional damper or the second torsional damper can buffer the instantaneous torque fluctuation between the corresponding output gear and the corresponding one-way transmission component, reduce the impact on the output shaft section at the moment of gear pair engagement, make the power output more stable and continuous, and help reduce the impact wear of gears, one-way transmission components and output shaft section.

[0033] In some embodiments of the present invention, the axis of the power input shaft 10 is arranged parallel to the axis of the first output shaft segment 52, and the first gear pair 20, the second gear pair 30, and the third gear pair 40 are all cylindrical gear pairs. Specifically, after the power input shaft 10 is arranged parallel to the output shaft segment, the first gear pair 20, the second gear pair 30, and the third gear pair 40 adopt parallel shaft cylindrical gear transmission, and the cylindrical gear pairs are spur cylindrical gear pairs or helical cylindrical gear pairs; when using spur cylindrical gear pairs, the structure is simple and easy to manufacture, and when using helical cylindrical gear pairs, the meshing smoothness is better and the noise is lower. The power input shaft 10 is supported by bearings on the axle housing or gearbox housing outside the differential housing 511, and the first output shaft segment 52 and the second output shaft segment 53 can be supported by bearings respectively to ensure gear meshing accuracy and transmission stability.

[0034] The working principle of this invention is as follows: the power input shaft 10 is connected to an engine, drive motor or other power source, and rotates under the drive of the power source. The power input shaft 10 drives the first input gear 21, the second input gear 31 and the third input gear 41 to rotate synchronously, wherein the second output gear 32 drives the differential mechanism 51, and the differential mechanism 51 then distributes the power to the first output shaft section 52 and the second output shaft section 53.

[0035] Taking the first type of tooth number relationship as an example, when the vehicle is traveling straight, due to the different transmission ratios of the side gear pair and the middle gear pair, and the fact that the first one-way transmission member 60 and the second one-way transmission member 70 are allowed to overtake and disengage, the first output gear 22 and the third output gear 42 idle relative to their corresponding output shaft segments, and the power is mainly transmitted through the second gear pair 30 and the differential mechanism 51. When the vehicle turns left, the left side is the inside, and the speed of the first output shaft segment 52 decreases relative to the first output gear 22. If the relative speeds of the two satisfy the engagement condition of the first one-way transmission member 60, then the first output gear 22 no longer idles relative to the first output shaft segment 52, but instead drives the first output shaft segment 52 to rotate through the first one-way transmission member 60; when the vehicle turns right or the right output shaft segment meets the engagement condition relative to the third output gear 42, the third output gear 42 drives the second output shaft segment 53 to rotate through the second one-way transmission member 70. After the turn ends or the relative speed relationship is restored, the corresponding one-way transmission component is in the overrunning separation state again, the side gear pair starts to idle again, and the power mainly returns to the transmission path of the second gear pair 30 and the differential mechanism 51.

[0036] In another tooth count relationship, the first gear pair 20 and the third gear pair 40 have opposite tooth counts to the second gear pair 30, and are used in conjunction with a unidirectional transmission component adapted to the locking direction. This embodiment still uses the relative rotational speed between the corresponding output gear and the corresponding output shaft segment satisfying the engagement condition as the trigger for power transmission, rather than using the absolute rotational speed change of one wheel as the sole criterion. In this way, the differential transmission assembly can form different selective transmission modes under different gear ratio configurations.

[0037] It should be noted that, based on the rotational speed relationship between the differential housing 511 and the first half-shaft bevel gear 513 and the second half-shaft bevel gear 514, the preset rotational speed ratios of the first output gear 22 and the third output gear 42 relative to the differential housing 511 are determined. This sets the preset intervention boundaries of the first one-way transmission member 60 and the second one-way transmission member 70, ensuring that the differential mechanism 51 maintains normal operation within the normal differential speed range. When the actual rotational speed ratio between the corresponding output shaft segment and the differential housing 511 reaches the preset rotational speed ratio, the corresponding side gear pairs limit the further expansion of the rotational speed difference between the two output shaft segments. For an open differential where the first half-shaft bevel gear 513 and the second half-shaft bevel gear 514 have the same number of teeth, ignoring transmission errors, the sum of the rotational speeds of the first output shaft segment 52 and the second output shaft segment 53 is equal to twice the rotational speed of the differential housing 511. Based on this relationship, the tooth configuration of the first gear pair 20, the second gear pair 30, and the third gear pair 40 is determined. When the actual speed ratio between the corresponding output shaft segment and the differential housing 511 reaches the preset speed ratio, the relative speed relationship between the corresponding output shaft segment and the corresponding output gear reaches the engagement condition of the corresponding one-way transmission component, and the corresponding gear pair begins to transmit torque, limiting the actual speed ratio between the corresponding output shaft segment and the differential housing 511 from continuing to deviate from the normal differential range.

[0038] In practical applications, assuming the maximum permissible ratio of the outer wheel speed to the inner wheel speed during normal vehicle operation is 1.41:1, and setting the speed of the differential housing 511 as N0, the speeds of the first output shaft segment 52 and the second output shaft segment 53 are N1 and N2 respectively. According to the open differential's speed relationship of N1 + N2 = 2N0, when the differential housing 511 rotates one revolution, the output shaft segment corresponding to the inner wheel rotates approximately 0.83 revolutions, and the output shaft segment corresponding to the outer wheel rotates approximately 1.17 revolutions. The first gear pair 20 and the third gear pair 40 are configured according to a preset speed ratio of 0.83:1 between the output shaft segment and the differential housing 511 to limit the minimum speed of the corresponding output shaft segment. Alternatively, they can be configured according to a preset speed ratio of 1.17:1, and in conjunction with a one-way transmission component with opposite locking directions, to limit the maximum speed of the corresponding output shaft segment. The first gear pair 20, the second gear pair 30, and the third gear pair 40 use the same module, and the corresponding transmission ratio is obtained by adjusting the number of teeth on each input gear and output gear. This limits the further increase of the speed difference between the first output shaft section 52 and the second output shaft section 53 without affecting the vehicle's normal differential speed operation. The above preset speed ratio is only an example; the actual preset speed ratio can be determined based on the vehicle's maximum steering angle, wheelbase, track width, and wheel rolling radius.

[0039] In one embodiment of the present invention, the first gear pair 20 and the third gear pair 40 are used to limit the minimum speed ratio between the corresponding output shaft segment and the differential housing 511. When the vehicle is traveling in a straight line or within the normal steering range, the first output shaft segment 52 and the second output shaft segment 53 are mainly driven by the second gear pair 30 and the differential mechanism 51. The actual speed ratio between the first output shaft segment 52 and the second output shaft segment 53 and the differential housing 511 is higher or lower than the corresponding preset minimum speed ratio, respectively. The first one-way transmission member 60 and the second one-way transmission member 70 are in an overrunning disengagement state, and the first gear pair 20 and the third gear pair 40 do not interfere with the normal differential speed of the differential mechanism 51. When one wheel is suspended or slips, and the rotational speed of the other wheel with traction and the corresponding output shaft segment gradually decreases, if the actual speed ratio between the first output shaft segment 52 and the differential housing 511 decreases to the corresponding preset minimum speed ratio, and the relative speed between the first output shaft segment 52 and the first output gear 22 meets the engagement condition of the first one-way transmission member 60, the first one-way transmission member 60 engages, and the power input shaft 10 drives the first output shaft segment 52 to rotate via the first input gear 21, the first output gear 22, and the first one-way transmission member 60; if the second output shaft segment 53 and the differential housing... The actual speed ratio between 511 is reduced to the corresponding preset minimum speed ratio, and the relative speed between the second output shaft section 53 and the third output gear 42 meets the engagement condition of the second one-way transmission member 70. The second one-way transmission member 70 is engaged, and the power input shaft 10 drives the second output shaft section 53 to rotate via the third input gear 41, the third output gear 42 and the second one-way transmission member 70, so as to mechanically limit the minimum speed ratio between the output shaft section corresponding to the wheel with traction and the differential housing 511, reducing the risk that the wheel on that side will not be able to obtain effective driving torque due to the other wheel spinning freely.

[0040] In another embodiment of the invention, the first gear pair 20 and the third gear pair 40 are used to limit the maximum speed ratio between the corresponding output shaft segment and the differential housing 511. When the vehicle is traveling straight or within the normal steering range, the actual speed ratio between the first output shaft segment 52 and the second output shaft segment 53 and the differential housing 511 is within the normal differential speed range of the vehicle. The first output gear 22 and the third output gear 42 rotate beyond the corresponding output shaft segment, and the two sets of side gear pairs do not restrict the normal operation of the differential mechanism 51. When one wheel is suspended and accelerates, causing the actual speed ratio between the corresponding output shaft segment and the differential housing 511 to reach the preset maximum speed ratio, the corresponding one-way transmission component engages, causing the output shaft segment to form a mechanical transmission relationship with the power input shaft 10 through the corresponding output gear and input gear, thereby limiting the further increase of the speed ratio between the corresponding output shaft segment of the suspended wheel and the differential housing 511. When the speed ratio of the output shaft segment corresponding to the suspended wheel is limited, and the speed of the corresponding output shaft segment is constrained by the side transmission path, it helps to keep the wheel with traction on the other side from obtaining driving torque, thereby limiting the speed of the suspended wheel from continuing to increase and improving the vehicle's ability to get out of low traction conditions.

[0041] A vehicle includes wheels and a differential transmission assembly as described in any of the foregoing embodiments, the differential transmission assembly being driveably connected to the wheels. Specifically, the vehicle is a passenger car or commercial vehicle, the wheels include a left wheel and a right wheel, a first output shaft section 52 and a second output shaft section 53 are driveably connected to the left wheel and the right wheel respectively, or are driveably connected to the corresponding wheels via half-shafts, universal joints and wheel-end reduction mechanisms. The differential transmission assembly is disposed in the vehicle's drive axle, or may be disposed in the transmission path between the gearbox and the half-shafts. When the vehicle uses this differential transmission assembly, while retaining conventional differential capability, it provides auxiliary transmission to the corresponding output shaft section through a side gear pair under corresponding relative speed conditions, thereby improving the problem of wheel slippage on wet or snowy roads or during cornering.

[0042] In summary, this invention adds two sets of side gear pairs and two sets of one-way transmission components to the existing open differential, so that power can be transmitted through the intermediate gear pair and differential mechanism 51 under normal operating conditions. Under specific relative speed conditions, the side gear pairs can participate in the transmission of the corresponding output shaft segment, which helps to improve the problem of wheel slippage. Moreover, the overall structure is relatively simple.

[0043] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0044] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the technical solutions and core ideas of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A differential transmission assembly, characterized in that, include: Power input shaft (10); The output assembly (50) includes a differential mechanism (51) and a first output shaft segment (52) and a second output shaft segment (53) respectively drivenly connected to the differential mechanism (51); The first gear pair (20), the second gear pair (30) and the third gear pair (40) each include meshing input gears and output gears. Each input gear is located on the power input shaft (10). The output gear of the second gear pair (30) is connected to the differential mechanism (51) in a transmission. The first one-way transmission component (60) is connected between the output gear of the first gear pair (20) and the first output shaft segment (52); The second one-way transmission component (70) is connected between the output gear of the third gear pair (40) and the second output shaft segment (53); The transmission ratios of the first gear pair (20) and the third gear pair (40) are different from the transmission ratio of the second gear pair (30).

2. The differential transmission assembly according to claim 1, characterized in that, The transmission ratio of the first gear pair (20) is the same as that of the third gear pair (40).

3. The differential transmission assembly according to claim 1, characterized in that, The first output shaft segment (52) and the second output shaft segment (53) are coaxially arranged. Along the axial direction of the first output shaft segment (52) and the second output shaft segment (53), the output gear of the first gear pair (20) and the output gear of the third gear pair (40) are respectively arranged on both sides of the differential mechanism (51).

4. The differential transmission assembly according to claim 2, characterized in that, The number of teeth of the input gear of the first gear pair (20) is the same as the number of teeth of the input gear of the third gear pair (40), and both are less than the number of teeth of the input gear of the second gear pair (30); the number of teeth of the output gear of the first gear pair (20) is the same as the number of teeth of the output gear of the third gear pair (40), and both are greater than the number of teeth of the output gear of the second gear pair (30).

5. The differential transmission assembly according to claim 2, characterized in that, The number of teeth of the input gear of the first gear pair (20) is the same as the number of teeth of the input gear of the third gear pair (40), and both are greater than the number of teeth of the input gear of the second gear pair (30); the number of teeth of the output gear of the first gear pair (20) is the same as the number of teeth of the output gear of the third gear pair (40), and both are less than the number of teeth of the output gear of the second gear pair (30).

6. The differential transmission assembly according to any one of claims 1 to 5, characterized in that, The differential mechanism (51) includes a differential housing (511), a planetary bevel gear (512), a first half-shaft bevel gear (513), and a second half-shaft bevel gear (514). The planetary bevel gear (512) is rotatably disposed on the differential housing (511). The first half-shaft bevel gear (513) and the second half-shaft bevel gear (514) both mesh with the planetary bevel gear (512). The first output shaft segment (52) is circumferentially fixed to the first half-shaft bevel gear (513), and the second output shaft segment (53) is circumferentially fixed to the second half-shaft bevel gear (514).

7. The differential transmission assembly according to claim 1, characterized in that, A first clutch (110) is provided between the power input shaft (10) and the input gear of the first gear pair (20), and a second clutch (120) is provided between the power input shaft (10) and the input gear of the third gear pair (40).

8. The differential transmission assembly according to any one of claims 1 to 5, characterized in that, Both the first one-way transmission component (60) and the second one-way transmission component (70) are overrunning clutches. The overrunning clutch includes an inner ring, an outer ring, and a locking component disposed between the inner ring and the outer ring. One of the inner ring and the outer ring is circumferentially fixed to the corresponding output gear, and the other is circumferentially fixed to the corresponding output shaft segment.

9. The differential transmission assembly according to any one of claims 1 to 5, characterized in that, The axis of the power input shaft (10) is parallel to the axis of the first output shaft segment (52), and the first gear pair (20), the second gear pair (30) and the third gear pair (40) are all cylindrical gear pairs.

10. A vehicle, characterized in that, It includes wheels and a differential drive assembly as described in any one of claims 1 to 9, the differential drive assembly being drive-connected to the wheels.

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