Interference-type torque split differential

An interference-type torque split differential includes a differential housing, a first differential gear and an interference-type torque split module. The first differential gear is provided in the differential housing. The interference-type torque split module is provided outside the differential housing and has a second differential gear, a first brake source and a second brake source. The second differential gear is connected with the first differential gear. The first brake source and the second brake source are at two sides of the second differential gear, respectively. The first brake source or the second brake source provides multiple stages of clamping force for performing torque split.

CROSS-REFERENCE TO RELATED APPLICATION

The present disclosure is based on, and claims priority from, Taiwan Application Number 106136126, filed Oct. 20, 2017, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to torque split differentials, and, more particularly, to an interference-type torque split differential.

2. Description of Related Art

Referring toFIG. 1, a schematic diagram of a standard differential1mounted on a vehicle according to the prior art is shown. The standard differential1includes a power input shaft11, a power input gear12, a power output gear121, a differential housing13, a first differential gear14, a first output gear15a, a second output gear15b, a first output shaft16a, a second output shaft16band a gearbox housing17. The power input shaft11provides power to sequentially drive the power input gear12, the power output gear121, the differential housing13and the first differential gear14, and the first output gear15a(the second output gear15b) and the first output shaft16a(the second output shaft16b).

However, one of the drawbacks of the standard differential1is that the general differential1cannot achieve torque split. In other words, torque cannot be correctly distributed to the wheels on either side of a vehicle when the vehicle slips. Further, when the wheels on either side of the vehicle travel or turn on a road having different coefficients of friction, the vehicle tends to have poor driving stability or a reduced transmission performance. Therefore, there is a need for a solution that addresses the aforementioned issues in the prior art.

SUMMARY

The present disclosure provides an interference-type torque split differential that maintains the functionality of a standard differential while achieving torque split.

An interference-type torque split differential according to the present disclosure may include: a differential housing; a first differential gear provided in the differential housing; and an interference torque split module provided outside the differential housing and including: a second differential gear connected with the first differential gear; and a first brake source and a second brake source providing multiple stages of clamping force for performing torque split.

Another interference-type torque split differential of the present disclosure may include: a differential housing; a first differential gear provided in the differential housing; and an interference torque split module provided outside the differential housing and including: a second differential gear connected with the first differential gear; and a driving source providing multiple stages of driving force for performing torque split.

DETAILED DESCRIPTION

The present disclosure is described by the following specific embodiments. Those with ordinary skills in the arts can readily understand other advantages and functions of the present disclosure after reading the disclosure of this specification. The present disclosure may also be practiced or applied with other different implementations. Based on different contexts and applications, the various details in this specification can be modified and changed without departing from the spirit of the present disclosure.

It should be noted that inFIG. 2A, 4A, 5A, or7A, only the upper and lower portions of components, such as a first differential gear14, a gearbox housing17, a second differential gear21, a first brake source23a, a second brake source23b, an interference wheel24, a first interference wheel24aor a second interference wheel24b, are shown, with the middle portion thereof omitted. Therefore, each of these components is one in number, not two.

FIGS. 2A, 2B, 3A and 3Bare schematic diagrams depicting an interference-type torque split differential2in accordance with a first embodiment of the present disclosure, whereinFIG. 2Bis a block diagram ofFIG. 2A, andFIGS. 3A and 3Billustrate different torque split modes of the interference-type torque split differential2ofFIG. 2A.

As shown inFIGS. 2A to 2B, the interference-type torque split differential2may include a power input shaft11, a power input gear12, a power output gear121, a differential housing13, a first differential gear14, a first output gear15a, a second output gear15b, a first output shaft16a(e.g., a right output shaft), a second output shaft16b(e.g., a left output shaft) and a gearbox housing17, similar to those shown inFIG. 1.

The power input gear12is connected to the power input shaft11. The power output gear121has gears engaged with gears of the power input gear12. The differential housing13is connected with the power output gear121. The first differential gear14is provided in the differential housing13and connected with the differential housing13via a turning shaft22. The turning shaft22is rotated by the differential housing13, which is in turn driven by a power source (not shown). The first output gear15aand the first differential gear14have their gears engaged, and the second output gear15band the first differential gear14also have their gears engaged. The first output shaft16aand the second output shaft16bare connected with the first output gear15aand the second output gear15b, respectively.

The power input shaft11provides power to sequentially drive the power input gear12, the power output gear121, the differential housing13and the first differential gear14, the first output gear15a(and the second output gear15b), and the first output shaft16a(and the second output shaft16b).

The interference-type torque split differential2may further include an interference torque split module20. The interference torque split module20is provided outside the differential housing13, and includes a second differential gear21, a first brake source23aand a second brake source23b. The second differential gear21can be fixed to or in rigid connection with the first differential gear14via the turning shaft22. The first brake source23aor the second brake source23bcan be a clamping device or a clutch device having different levels of clamping forces for performing torque split.

The interference torque split module20may further include a first interference wheel24aprovided between the second differential gear21and the first brake source23a. The first brake source23ais able to adjust the rotating speed of the first interference wheel24ato provide multiple stages of speed. For example, the first brake source23ais able to reduce the rotating speed of the first interference wheel24ato put it in several different reduced speeds. The first brake source23abrakes and interferes with the second differential gear21via the first interference wheel24afor performing torque split.

The interference torque split module20may further include a second interference wheel24bprovided between the second differential gear21and the second brake source23b. The second brake source23bis able to adjust the rotating speed of the second interference wheel24bto provide multiple stages of speed. For example, the second brake source23bis able to reduce the rotating speed of the second interference wheel24bto put it in several different reduced speeds. The second brake source23bbrakes and interferes with the second differential gear21via the second interference wheel24bfor performing torque split.

The interference-type torque split differential2includes the gearbox housing17, which can be fixed to or in rigid connection with the first brake source23aand the second brake source23b.

The interference-type torque split differential2includes the first output gear15aand the first output shaft16a. The first output gear15ais provided in the differential housing13. The first output gear15ahas gears engaged with gears of the first differential gear14, and the first output shaft16ais connected with the first output gear15a.

The interference-type torque split differential2includes the second output gear15band the second output shaft16b. The second output gear15bis provided in the differential housing13. The second output gear15bhas gears engaged with gears of the first differential gear14, and the second output shaft16bis connected with the second output gear15b.

For example, as shown inFIG. 3A, in terms of the torque split mode of the interference-type torque split differential2, when the first brake source23ais used to brake and interfere with the first interference wheel24a, the first interference wheel24adrives the second differential gear21, the second differential gear21drives the first differential gear14, the first differential gear14simultaneously drives the first output gear15aand the second output gear15b, and the first output gear15aand the second output gear15bdrive the first output shaft16aand the second output shaft16b, respectively.

Therefore, according to the right hand rule, the second differential gear21and the first differential gear14rotate in a clockwise direction R1and a clockwise direction R2(shown as left arrows) around a Z axis, respectively, the first output gear15aand the first output shaft16aboth rotate in an anticlockwise direction R3around an X axis (shown as a downward arrow), while the second output gear15band the second output shaft16bboth rotate in a clockwise direction R4around the X axis (shown as an upward arrow). As such, a driving force and torque split range T1of the first output shaft16ais reduced, while a driving force and torque split range T2of the second output shaft16bis increased, thereby achieving driving force and torque split.

On the contrary, as shown inFIG. 3B, in terms of the torque split mode of the interference-type torque split differential2, when the second brake source23bis used to brake and interfere with the second interference wheel24b, the second interference wheel24bdrives the second differential gear21, the second differential gear21drives the first differential gear14, the first differential gear14simultaneously drives the first output gear15aand the second output gear15b, and the first output gear15aand the second output gear15bdrive the first output shaft16aand the second output shaft16b, respectively.

Therefore, according to the right hand rule, the second differential gear21and the first differential gear14rotate in an anticlockwise direction R1and an anticlockwise direction R2(shown as right arrows) around the Z axis, respectively, the first output gear15aand the first output shaft16aboth rotate in a clockwise direction R3around an X axis (shown as an upward arrow), while the second output gear15band the second output shaft16bboth rotate in an anticlockwise direction R4around the X axis (shown as a downward arrow). As such, the driving force and torque split range T1of the first output shaft16ais increased, and the driving force and torque split range T2of the second output shaft16bis reduced, thereby achieving driving force and torque split.

Furthermore, when the first brake source23aand the second brake source23bare not in action, the first interference wheel24aand the second interference wheel24bare free to turn and do not interfere with the second differential gear21, such that the interference-type torque split differential2acts like or similar to the standard differential1inFIG. 1, but is not limited to this.

FIGS. 4A and 4Bare schematic diagrams depicting an interference-type torque split differential2in accordance with a second embodiment of the present disclosure, whereinFIG. 4Bis a block diagram ofFIG. 4A. The interference-type torque split differential2shown inFIGS. 4A and 4Bis similar to that shown inFIGS. 2A and 2B, with the major differences described as follow and the rest of the interference-type torque split differential2already described with respect toFIGS. 2A and 2Babove.

InFIGS. 4A and 4B, the first interference wheel24aand the second interference wheel24bofFIGS. 2A and 2Bare omitted from the interference-type torque split differential2. Therefore, the first brake source23aor the second brake source23bdirectly brakes and interferes with the second differential gear21for performing torque split.

FIGS. 5A, 5B, 6A and 6Bare schematic diagrams depicting an interference-type torque split differential2in accordance with a third embodiment of the present disclosure, whereinFIG. 5Bis a block diagram ofFIG. 5A, andFIGS. 6A and 6Billustrate different torque split modes of the interference-type torque split differential2ofFIG. 5A.

As shown inFIGS. 5A to 5B, the interference-type torque split differential2may include a power input shaft11, a power input gear12, a power output gear121, a differential housing13, a first differential gear14, a first output gear15a, a second output gear15b, a first output shaft16a, a second output shaft16b, and a gearbox housing17, similar to those in the standard differential1shown inFIG. 1.

The power input gear12is connected to the power input shaft11, and the differential housing13is connected with the power output gear121. The first differential gear14is provided in the differential housing13and connected with the differential housing13via the turning shaft22. The first output gear15aand the first differential gear14have their gears engaged, and the second output gear15band the first differential gear14also have their gears engaged. The first output shaft16aand the second output shaft16bare connected with the first output gear15aand the second output gear15b, respectively.

The power input shaft11provides power to sequentially drive the power input gear12, the differential housing13and the first differential gear14, the first output gear15a(and the second output gear15b), and the first output shaft16a(and the second output shaft16b).

The interference-type torque split differential2may further include an interference torque split module20. The interference torque split module20is provided outside the differential housing13, and includes a second differential gear21, and a driving source23. The second differential gear21can be fixed to or in rigid connection with the first differential gear14via the turning shaft22. The driving source23can be a driving motor with driving forces for performing torque split. The driving motor can be a motor without resistance upon reverse input. When the interference-type torque split differential2is provided with the driving source23, the first brake source23aand the second brake source23bas shown inFIG. 2A, for example, can be omitted, but the present disclosure is not limited as such.

The interference torque split module20may further include an interference wheel24provided between the second differential gear21and the driving source23. The driving source23is used for adjusting or switching the rotating direction or rotating speed of the interference wheel24. The driving source23drives to interfere with the second differential gear21via the interference wheel24to achieve torque split.

The interference-type torque split differential2includes the first output gear15aand the first output shaft16a. The first output gear15ais provided in the differential housing13. The first output gear15ahas gears engaged with gears of the first differential gear14, and the first output shaft16ais connected with the first output gear15a.

The interference-type torque split differential2includes the second output gear15band the second output shaft16b. The second output gear15bis provided in the differential housing13. The second output gear15bhas gears engaged with gears of the first differential gear14, and the second output shaft16bis connected with the second output gear15b.

For example, as shown inFIG. 6A, in terms of the torque split mode of the interference-type torque split differential2, when the driving source23drives the interference wheel24in a clockwise direction, the interference wheel24drives the second differential gear21, the second differential gear21drives the first differential gear14, the first differential gear14simultaneously drives the first output gear15aand the second output gear15b, and the first output gear15aand the second output gear15bdrive the first output shaft16aand the second output shaft16b, respectively.

Therefore, according to the right hand rule, the second differential gear21and the first differential gear14rotate in a clockwise direction R1and a clockwise direction R2(shown as left arrows) around the Z axis, respectively, the first output gear15aand the first output shaft16aboth rotate in an anticlockwise direction R3around the X axis (shown as a downward arrow), while the second output gear15band the second output shaft16bboth rotate in a clockwise direction R4around the X axis (shown as an upward arrow). As such, the driving force and torque split range T1of the first output shaft16ais reduced, and the driving force and torque split range T2of the second output shaft16bis increased, thereby achieving driving force and torque split.

On the contrary, as shown inFIG. 6B, in terms of the torque split mode of the interference-type torque split differential2, when the driving source23drives to interfere with the interference wheel24, the interference wheel24drives the second differential gear21, the second differential gear21drives the first differential gear14, the first differential gear14simultaneously drives the first output gear15aand the second output gear15b, and the first output gear15aand the second output gear15bdrive the first output shaft16aand the second output shaft16b, respectively.

Therefore, according to the right hand rule, the second differential gear21and the first differential gear14rotate in an anticlockwise direction R1and an anticlockwise direction R2(shown as right arrows) around the Z axis, respectively, the first output gear15aand the first output shaft16aboth rotate in a clockwise direction R3around an X axis (shown as an upward arrow), while the second output gear15band the second output shaft16bboth rotate in an anticlockwise direction R4around the X axis (shown as a downward arrow). As such, the driving force and torque split range T1of the first output shaft16ais increased, and the driving force and torque split range T2of the second output shaft16bis reduced, thereby achieving driving force and torque split.

Furthermore, when the driving source23is not in action, the interference-type torque split differential2acts like or similar to the standard differential1inFIG. 1, but is not limited to this.

FIGS. 7A and 7Bare schematic diagrams depicting an interference-type torque split differential2in accordance with a fourth embodiment of the present disclosure, whereinFIG. 7Bis a block diagram ofFIG. 7A. The interference-type torque split differential2shown inFIGS. 7A and 7Bis similar to that shown inFIGS. 2A and 2B, with the major differences described as follow and the rest of the interference-type torque split differential2already described with respect toFIGS. 5A and 5Babove.

InFIGS. 7A and 7B, the interference wheel24ofFIGS. 5A and 5Bis omitted from the interference-type torque split differential2. Therefore, the driving source23directly connects to and drives to interfere with the second differential gear21for performing torque split. Moreover, the driving source23may have gear- or belt-driven type transmission.

FIG. 8Ais a graph depicting a comparison between the driving forces on wheels of the interference-type torque split differential2ofFIGS. 2A and 2Band the prior-art standard differential1ofFIG. 1, andFIG. 8Bis a graph depicting a comparison between the driving forces on wheels of the interference-type torque split differential2ofFIGS. 5A and 5Band the prior-art standard differential1ofFIG. 1, wherein the unit of the vertical axis is in Newton (N), and the unit of the horizontal axis is in seconds (S).

For example, as shown inFIGS. 8A and 8BandFIG. 1of the prior art, take 0.5 second inFIG. 8Aas an example, the driving forces on wheels of the first output shaft16a(e.g., the right output shaft) of the standard differential1after location P1on a curve A1and the driving forces on wheels of the second output shaft16b(e.g., the left output shaft) after location P1on a curve A2are both between about 680 to 700 N. Thus, the standard differential1cannot achieve effective driving force (torque) split.

On the contrary, as shown inFIG. 8AandFIGS. 2A and 2Bof the present disclosure, take 0.5 second inFIG. 8Aas an example, the driving forces on wheels of the first output shaft16a(e.g., the right output shaft) of the interference-type torque split differential2of the present disclosure after location P2on a curve B1are roughly between 550 to 570 N, and the driving forces on wheels of the second output shaft16b(e.g., the left output shaft) after location P3on a curve B2are roughly between about 740 to 760 N. Therefore, the driving forces on wheels of the second output shaft16bare significantly greater than those on the first output shaft16a. In other words, the interference-type torque split differential2according to the present disclosure is able to distribute some of the driving force (or torque) from the first output shaft16ato the second output shaft16bto achieve effective driving force (or torque) split. However, in other embodiments, the present disclosure may also distribute some of the driving force (or torque) from the second output shaft16bto the first output shaft16ato achieve effective driving force (or torque) split.

Similarly, as shown inFIG. 8BandFIGS. 5A and 5Bof the present disclosure, take 0.5 second inFIG. 8Bas an example, the driving forces on wheels of the first output shaft16a(e.g., the right output shaft) of the interference-type torque split differential2of the present disclosure after location P2on a curve B1are roughly between 610 to 630 N, and the driving forces on wheels of the second output shaft16b(e.g., the left output shaft) after location P3on a curve B2are roughly between about 810 to 830 N. Therefore, the driving forces on wheels of the second output shaft16bare significantly greater than those on the first output shaft16a. In other words, the interference-type torque split differential2according to the present disclosure is able to distribute some of the driving force (or torque) from the first output shaft16ato the second output shaft16bto achieve effective driving force (or torque) split. However, in other embodiments, the present disclosure may also distribute some of the driving force (or torque) from the second output shaft16bto the first output shaft16ato achieve effective driving force (or torque) split.

It can be understood from the above that the interference-type torque split differential according to the present disclosure adds components, such as a second differential gear, interference wheel(s), brake sources or a driving source, onto the standard differential. These components are modularized into an interference torque split module that is provided outside the differential housing. As a result, the interference-type torque split differential according to the present disclosure not only maintains the functionality of a standard differential, but also achieves effective torque (or driving force) split through the interference torque split module. The interference torque split module further provides numerous benefits such as easy assembly and maintenance and low complexity.

When the interference-type torque split differential according to the present disclosure is installed on a vehicle, for example, the interference-type torque split differential is capable of achieving torque (or driving force) split between the first output shaft (e.g., the right output shaft) and the second output shaft (e.g., the left output shaft). This increases steering and stability of the vehicle and overcomes poor stability or reduced transmission performance when the wheels at either side of the vehicle are traveling or turning on a road with different coefficients of friction.

The above embodiments are only used to illustrate the principles of the present disclosure, and should not be construed as to limit the present disclosure in any way. The above embodiments can be modified by those with ordinary skill in the art without departing from the scope of the present disclosure as defined in the following appended claims.