Drive system
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-05
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026053013_13082026_PF_FP_ABST
Abstract
Description
[0001] DRIVE SYSTEM
[0002] TECHNICAL FIELD
[0003] The present disclosure relates to a drive system. Aspects of the invention relate to a drive system and to a vehicle comprising a drive system.
[0004] BACKGROUND
[0005] It is known to provide electric and hybrid vehicles that include two or more electric motors, where each electric motor provides torque to a respective output shaft of a drive system. In situations where a wheel connected to one of the output shafts experiences low friction (e.g. is in the air in an off road scenario), a wheel connected to the other output shaft may still receive torque from its respective electric motor so that the vehicle may still be propelled, albeit utilising torque from a single electric motor.
[0006] It is an aim of the present invention to address one or more of the disadvantages associated with the prior art.
[0007] SUMMARY OF THE INVENTION
[0008] Aspects and embodiments of the invention provide an drive system for an electric or hybrid vehicle, and to a vehicle comprising a drive system as claimed in the appended claims.
[0009] According to an aspect of the present invention there is provided a drive system for an electric or hybrid vehicle, comprising:
[0010] a first input shaft rotatable about a first input axis;
[0011] a second input shaft rotatable about a second input axis;
[0012] a first output shaft rotatable about a first output axis and arranged to receive torque from the first input shaft;
[0013] a second output shaft rotatable about a second output axis and arranged to receive torque from the second input shaft; and
[0014] a disconnect that is moveable between an open configuration and a closed configuration; wherein when the disconnect in in the closed configuration, the disconnect is arranged to transfer torque from either the first input shaft to the second output shaft, and / or from the second input shaft to the first output shaft.
[0015] According to another aspect of the present invention there is provided a drive system for an electric or hybrid vehicle, comprising:
[0016] a first input shaft rotatable about a first input axis;
[0017] a second input shaft rotatable about a second input axis;
[0018] a first output shaft rotatable about a first output axis;
[0019] a second output shaft rotatable about a second output axis;
[0020] a first gear assembly arranged to transfer torque from the first input shaft to the first output shaft;a second gear assembly arranged to transfer torque from the second input shaft to the second output shaft; and
[0021] a disconnect that is moveable between an open configuration and a closed configuration; wherein when the disconnect in in the closed configuration, the disconnect is arranged to transfer torque from either the first input shaft to the second output shaft, and / or from the second input shaft to the first output shaft.
[0022] In both of the above aspects, such a drive system is advantageous in that torque may be selectively transferred from the first input shaft to both of the first output shaft and the second output shaft, and similarly torque may be selectively transferred from the second input shaft to the both of the second output shaft and the first output shaft. Consequently, when a wheel driven by the first output shaft experiences low or substantially zero friction (e.g. if it is in the air in an off-road scenario), in which case the disconnect may be moved to the closed configuration so that some or all torque from the first electric motor may be directed to a wheel being driven by the second output shaft.
[0023] In an embodiment, the first input axis is parallel to the second input axis and the first input axis is not coaxial with the second input axis.
[0024] Such an arrangement may be referred to as a “tandem” arrangement and provides an effective way of arranging the components of the drive system in a space-efficient manner.
[0025] In an embodiment, the drive system comprises a third gear assembly arranged between the first input shaft and the second gear assembly, wherein the disconnect forms part of the third gear assembly.
[0026] The third gear assembly provides additional gearing between the first input shaft and the second gear assembly.
[0027] In an embodiment, the first input axis is parallel to the second input axis and the first input axis is coaxial with the second input axis.
[0028] Such an arrangement may be referred to as a “T-shaped” arrangement and provides an effective way of arranging the components of the drive system in a space-efficient manner.
[0029] In an embodiment, the drive system comprises a third gear assembly arranged between the first input shaft and the second input shaft, wherein the disconnect forms part of the third gear assembly.
[0030] The third gear assembly provides additional gearing between the first input shaft and the second gear assembly.In an embodiment, the drive system comprises one or more auxiliary disconnects, the one or more auxiliary disconnects being arranged to selectively transfer torque from one or more of:
[0031] the first input shaft to the first gear assembly;
[0032] the second input shaft to the first gear assembly; or
[0033] the second input shaft to the second gear assembly.
[0034] The provision of additional disconnects affords the drive system with additional configurations for transferring torque from the first input shaft and the second input shaft.
[0035] In an embodiment, the drive system comprises one or more auxiliary gear assemblies, wherein each of the one or more auxiliary disconnects forms part of one of the one or more auxiliary gear assemblies.
[0036] The auxiliary gear assemblies provide additional gearing in torque paths that include the one or more auxiliary disconnects.
[0037] In an embodiment, the disconnect comprises a clutch. A clutch is a particularly effective component for performing the required functions of the disconnect.
[0038] In an embodiment, the first input shaft is axially slidable along the first input axis between:
[0039] a first position in which the first input shaft is rotatably engaged with the first gear assembly and not rotatably engaged with the second gear assembly; and
[0040] a second position in which first input shaft is rotatably engaged with the second gear assembly and not rotatably engaged with the first gear assembly;
[0041] wherein the first input shaft comprises the clutch with the first position comprising the open configuration and the second position comprising the closed configuration.
[0042] This advantageously permits the slidable first input shaft to be the disconnect thereby negating the need for a separate disconnect component.
[0043] In an embodiment, the first input shaft is axially slidable along the first input axis to a third position in which the first input shaft is not rotatably engaged with the first gear assembly and not rotatably engaged with the second gear assembly.
[0044] In the third position, the first input shaft is disengaged from both of the first gear assembly and the second gear assembly. This may advantageously disengage an electric machine from torque paths towards either of thefirst output shaft and second output shaft (which may be desired if the electric machine is in a sub-optimal operating condition, e.g. high temperature).
[0045] In an embodiment, the second input shaft is axially slidable along the second input axis between:
[0046] a first position in which the second input shaft is rotatably engaged with the first gear assembly and not rotatably engaged with the second gear assembly; and
[0047] a second position in which second input shaft is rotatably engaged with the second gear assembly and not rotatably engaged with the first gear assembly.
[0048] This advantageously permits the slidable second input shaft to be the disconnect thereby negating the need for a separate auxiliary disconnect component.
[0049] In an embodiment, the second input shaft is axially slidable along the second input axis to a third position in which the second input shaft is not rotatably engaged with the second gear assembly and not rotatably engaged with the first gear assembly.
[0050] In the third position, the second input shaft is disengaged from both of the first gear assembly and the second gear assembly. This may advantageously disengage an electric machine from torque paths towards either of the first output shaft and second output shaft (which may be desired if the electric machine is in a sub-optimal operating condition, e.g. high temperature).
[0051] In an embodiment, the drive system comprises a first electric motor arranged to provide torque to the first input shaft and a second electric motor arranged to provide torque to the second input shaft.
[0052] The drive system is particularly well suited to have a first electric motor arranged to provide torque to the first input shaft and a second electric motor arranged to provide torque to the second input shaft.
[0053] In an embodiment, the first electric motor is different to the second electric motor.
[0054] In such embodiments, the disconnect may be used to provide torque to the first output shaft and the second output shaft selectively from the first electric motor and the second electric motor depending on which is most suited to provide the desired torque (which may depend on factors including but not limited to the required power or the operating conditions of the drive system).
[0055] In an embodiment, the first electric motor has a different power output compared to a power output of the second electric motor.In such embodiments, the electric motor with the lower power output of the two may exclusively or predominantly provide torque when only low torque is required, and the electric motor with the higher power output of the two may exclusively or predominantly provide torque when higher torque is required.
[0056] In an embodiment, the drive system comprises a park lock arranged to lock one or both of the first output shaft and the second output shaft.
[0057] In combination with the disconnect, the park lock may advantageously lock both of the first output shaft and the second output shaft.
[0058] According to another aspect of the present invention there is provided a vehicle comprising the drive system of any preceding claim.
[0059] Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in anyway and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner.
[0060] BRIEF DESCRIPTION OF THE DRAWINGS
[0061] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
[0062] FIG. 1 schematically shows a drive system in accordance with an embodiment of the present invention; FIG. 2 schematically shows the drive system of FIG. 1 with the disconnect in the open configuration;
[0063] FIG. 3 schematically shows the drive system of FIG. 1 with the disconnect in the closed configuration;
[0064] FIG. 4 schematically shows the drive system of FIG. 1 in another arrangement with the disconnect in the closed configuration;
[0065] FIG. 5 schematically shows a drive system in accordance with another embodiment of the present invention; FIG. 6 schematically shows a drive system in accordance with another embodiment of the present invention; and
[0066] FIG. 7 schematically shows a variation of the drive system of FIG. 6 in accordance with an embodiment of the present invention;
[0067] FIG. 8 schematically shows a drive system in accordance with another embodiment of the present invention; and
[0068] FIG. 9 shows a vehicle in accordance with an embodiment of the invention.DETAILED DESCRIPTION
[0069] FIG. 1 schematically shows a drive system 100 for an electric or hybrid vehicle in accordance with an embodiment of the present invention. The drive system 100 includes a first input shaft 102 that is drivable by a first electric motor 126 such that the first input shaft 102 is rotatable about a first input axis 104. Similarly, the drive system 100 includes a second input shaft 112 that is drivable by a second electric motor 128 such that the second input shaft 112 is rotatable about a second input axis 114.
[0070] The drive system 100 further includes a first output shaft 106 that is rotatable about a first output axis 108 and a second output shaft 116 that is rotatable about a second output axis 118. A first gear assembly 110 is provided and is arranged to transfer torque (i.e. along a torque path) from the first input shaft 102 to the first output shaft 106. Similarly, a second gear assembly 120 is provided to transfer torque (i.e. along a torque path) from the second input shaft 112 to the second output shaft 116.
[0071] In the non-limiting embodiment shown in FIG. 1 , the first input axis 104 is parallel to the second input axis 114 but the first input axis 104 is not coaxial with the second input axis 114. Such an arrangement may be referred to as a “tandem” arrangement. Additionally, the first output axis 108, the second output axis 118, and the second input axis 114 are coaxially aligned with one another. In other embodiments, any or all of the first input axis 104, second input axis 114, first output axis 108 and second output axis 118 may be arranged differently relative to one another.
[0072] A third gear assembly 122 is provided and comprises a disconnect 124 that is moveable between an open configuration and a closed configuration. In other embodiments, the disconnect 124 may be provided without the third gear assembly 122. In the non-limiting embodiment of FIG. 1 , the disconnect 124 may selectively provide a torque path between the first input shaft 102 and the second gear assembly 120. When in the closed configuration, the third gear assembly 122 is arranged to transfer torque from either the first input shaft 102 to the second output shaft 116, and / or from the second input shaft 112 to the first output shaft 106. That is, when the disconnect 124 is in the closed configuration, the first electric motor 126 may drive the second output shaft 116 and / or the second electric motor 128 may drive the first output shaft 106.
[0073] In an illustrative example, such an arrangement may be advantageous when a wheel driven by the first output shaft 106 experiences low or substantially zero friction (e.g. if it is in the air in an off-road scenario), in which case the disconnect 124 may be moved to the closed configuration so that some or all torque from the first electric motor 126 may be directed to a wheel being driven by the second output shaft 116.
[0074] In certain embodiments, when the disconnect 124 is in the open configuration, torque may not be transferred from the first input shaft 102 to the second output shaft 116 nor from the second input shaft 112 to the first output shaft 106. An example of such an arrangement is shown in FIG. 2 which is described further below.
[0075] FIG. 2 schematically shows the drive system 100 of FIG. 1 with the disconnect 124 in the open configuration. In this arrangement, torque, which is received from the first electric motor 126, is transferred from the first input shaft 102 to the first output shaft 106 via the first gear assembly 110 along a first torque path 130. Similarly,torque, which is received from the second electric motor 128, is transferred from the second input shaft 112 to the second output shaft 116 via the second gear assembly 120 along a second torque path 132. In this arrangement, torque is not transferred from the first input shaft 102 to the second output shaft 116 and torque is not transferred from the second input shaft 112 to the first output shaft 106 due to the disconnect 124 being in the open configuration.
[0076] FIG. 3 schematically shows the drive system 100 of FIG. 1 and FIG. 2 with the disconnect 124 in the closed configuration. In the depicted arrangement, a wheel (not shown) connected to the second output shaft 116 may be in the air and therefore not experiencing any friction, whilst a wheel (not shown) connected to the first output shaft 106 may be engaged with the ground. Additionally, the drive system 100 comprises a limited slip differential, a torque distribution mechanism, or a similar mechanism that prevents torque passing to either of the first output shaft 106 or the second output shaft 116 when a wheel connected to that output shaft is in the air (or otherwise in a low traction condition). In certain embodiments, the limited slip differential, torque distribution mechanism, or similar mechanism may form part of the first gear assembly 110 and / or the second gear assembly 120.
[0077] Therefore, in the depicted arrangement, torque, which is received from the first electric motor 126, is transferred from the first input shaft 102 to the first output shaft 106 via the first gear assembly 110 along the first torque path 130. Additionally, torque, which is received from the second electric motor 128, is transferred from the second input shaft 112 to the first output shaft 106 along a third torque path 134. The third torque path 134 passes from the second input shaft 112, through part of second gear assembly 120, through the third gear assembly 122 (and its closed disconnect 124), through the first input shaft 102 and the first gear assembly 110 to the first output shaft 106.
[0078] In the non-limiting embodiment shown in FIG. 3, no torque is transferred from the second input shaft 112 to the second output shaft 116 via the second gear assembly 120 due to the limited slip differential (or torque distribution mechanism or similar mechanism) and given that the wheel connected to the second output shaft 116 is in the air (or otherwise in a low traction condition). Consequently, in such a scenario, all of the torque available from the first electric motor 126 and the second electric motor 128 may be passed to the first output shaft 106 which has a wheel connected thereto that is engaged with the ground. In alternative embodiments, no limited slip differential, torque distribution mechanism or similar mechanism may be present, and the second input shaft 112 may drive the second output shaft 116 via the second gear assembly 120, causing the second output shaft 116 (and the wheel attached thereto) to rotate. However, if the wheel is in the air (or otherwise in a low traction condition), there will be no reaction force from the ground and torque will not be transferred by the wheel. Thus, the result is the same as described above (i.e. when a limited slip differential, torque distribution mechanism or similar mechanism is present) and all of the torque available from the first electric motor 126 and the second electric motor 128 may be passed to the first output shaft 106 which has a wheel connected thereto that is engaged with the ground.
[0079] FIG. 4 schematically shows the same drive system 100 of FIG. 3 with the disconnect 124 in the closed configuration. However, in contrast to the arrangement described above in relation to FIG. 3, in thearrangement of FIG. 4 the wheel connected to the second output shaft 116 is engaged with the ground whilst the wheel connected to the first output shaft 106 may be in the air (or otherwise in a low traction condition) and therefore not experiencing any (or low) friction.
[0080] Torque, which is received from the second electric motor 128, is transferred from the second input shaft 112 to the second output shaft 116 along the second torque path 132. Additionally, torque, which is received from the first electric motor 126 is transferred to the second output shaft 116 along a fourth torque path 136. The fourth torque path 136 passes from the first input shaft 102 through the third gear assembly 122 (and its closed disconnect 124), through a part of the second gear assembly 120 to the second output shaft 116.
[0081] In the non-limiting embodiment shown in FIG. 4, no torque is transferred from the first input shaft 102 to the first output shaft 106 via the first gear assembly 110 due to the limited slip differential (or torque distribution mechanism or similar mechanism) and given that the wheel connected to the first output shaft 106 is in the air (or otherwise in a low traction condition). Consequently, in such a scenario, all of the torque available from the first electric motor 126 and the second electric motor 128 may be passed to the second output shaft 116 which has a wheel connected thereto that is engaged with the ground.
[0082] Therefore, in the embodiments described above, when the disconnect 124 is in the closed configuration, torque may be transferred from both the first input shaft 102 and the second input shaft 112 to one of the output shafts (first output shaft 106 and second output shaft 116) but not the other output shaft.
[0083] In other embodiments, when the disconnect 124 is in the closed configuration, torque from the first input shaft 102 (received from the first electric motor 126) may be transferred to both the first output shaft 106 and the second output shaft 116 simultaneously and / or torque from the second input axis 114 (received from the second electric motor 128) may be transferred to both of the second output shaft 116 and the first output shaft 106 simultaneously.
[0084] Again, in alternative embodiments, no limited slip differential, torque distribution mechanism or similar mechanism may be present, and the first input shaft 102 may drive the first output shaft 106 via the first gear assembly 110, causing the first output shaft 106 (and the wheel attached thereto) to rotate. However, if the wheel is in the air (or otherwise in a low traction condition), there will be no reaction force from the ground and torque will not be transferred by the wheel. Thus, the result is the same as described above (i.e. when a limited slip differential, torque distribution mechanism or similar mechanism is present) and all of the torque available from the first electric motor 126 and the second electric motor 128 may be passed to the second output shaft 116 which has a wheel connected thereto that is engaged with the ground.
[0085] FIG. 5 shows a drive system 200 according to another embodiment of the present invention. The drive system 200 largely comprises the same components as the drive system 100 described above and identical reference numerals are used to refer to corresponding features. Unlike the “tandem” arrangement described above with reference to FIGs. 1-4, in the drive system 200 of FIG. 5, the first input axis 104 and the second input axis 114are both parallel and coaxial with one another. Such an arrangement may be referred to as a T-shaped arrangement.
[0086] In the drive system 200 of FIG. 5, the third gear assembly 122 is disposed between the first input shaft 102 and the second input shaft 112. Therefore the disconnect 124 may selectively provide a torque path between the first input shaft 102 and the second input shaft 112. In particular, when the disconnect 124 is in the open configuration, no torque may be transferred between the first input shaft 102 and the second input shaft 112. When the disconnect 124 is in the closed configuration, torque may be transferred between the first input shaft 102 and the second input shaft 112.
[0087] Therefore, when the disconnect 124 is in the closed configuration, torque may be transferred from both the first input shaft 102 and the second input shaft 112 to one of the output shafts (first output shaft 106 and second output shaft 116) but not the other output shaft.
[0088] In other embodiments, when the disconnect 124 is in the closed configuration, torque from the first input shaft 102 (received from the first electric motor 126) may be transferred to both the first output shaft 106 and the second output shaft 116 simultaneously and / or torque from the second input shaft 112 (received from the second electric motor 128) may be transferred to both of the second output shaft 116 and the first output shaft 106 simultaneously.
[0089] FIG. 5 depicts a non-limiting arrangement in which no torque from the first input shaft 102 is transferred to the first output shaft 106. As described above, this may be due to the presence of a limited slip differential (or torque distribution mechanism or similar mechanism) and because a wheel connected to the first output shaft 106 is not engaged with the ground (e.g. it is in the air) (or otherwise in a low traction condition) and so is experiencing substantially zero friction. Instead, torque from the first input shaft 102 is transferred along a fifth torque path 138 to the second output shaft 116. The fifth torque path 138 passes from the first input shaft 102, through the third gear assembly 122 (and its closed disconnect 124), through the second input shaft 112, through the second gear assembly 120 to the second output shaft 116. Simultaneously, torque from the second input shaft 112 is transferred to the second output shaft 116 along the second torque path 132. Consequently, torque from both the first input shaft 102 and the second input shaft 112 (received from the first electric motor 126 and the second electric motor 128, respectively) is transferred exclusively to the second output shaft 116, and no torque is transferred to the first output shaft 106.
[0090] In alternative embodiments, no limited slip differential, torque distribution mechanism or similar mechanism may be present, and the first input shaft 102 may drive the first output shaft 106 via the first gear assembly 110, causing the first output shaft 106 (and the wheel attached thereto) to rotate. However, if the wheel is in the air (or otherwise in a low traction condition), there will be no reaction force from the ground and torque will not be transferred by the wheel. Thus, the result is the same as described above (i.e. when a limited slip differential, torque distribution mechanism or similar mechanism is present) and all of the torque available from the first electric motor 126 and the second electric motor 128 may be passed to the second output shaft 116 which has a wheel connected thereto that is engaged with the ground.FIG. 6 shows a drive system 300 according to another embodiment of the present invention. The drive system 300 comprises the same components as the drive system 100 described above and identical reference numerals are used to refer to corresponding features.
[0091] In addition, the drive system 300 comprises additional auxiliary gear assemblies 140 and additional auxiliary disconnects 142. In particular, one auxiliary gear assembly 140 having an auxiliary disconnect 142 is provided to selectively transfer torque from the first input shaft 102 to the first gear assembly 110. One auxiliary gear assembly 140 having an auxiliary disconnect 142 is provided to selectively transfer torque from the second input shaft 112 to the first gear assembly 110. One auxiliary disconnect 142 is provided to selectively transfer torque from the second input shaft 112 to the second gear assembly 120.
[0092] In the embodiment of FIG. 6, selective movement of the disconnect 124 and the three auxiliary disconnects 142 between their respective open configurations and closed configurations may permit a range of torque paths to be utilised. For example, if each of the disconnect 124 and the three auxiliary disconnects 142 are in their closed configuration, torque from each of the first input shaft 102 and the second input shaft 112 (received from the first electric motor 126 and the second electric motor 128, respectively) may be transferred to both of the first output shaft 106 and the second output shaft 116. Therefore, each of the wheels connected to the first output shaft 106 and the second output shaft 116 may be driven by both of the first electric motor 126 and the second electric motor 128 simultaneously.
[0093] Moreover, selective pairs from the disconnect 124 and the three auxiliary disconnects 142 may be moved to their open configuration to isolate either the first input shaft 102 or the second input shaft 112 from torque paths that provide torque to either of the first output shaft 106 and the second output shaft 116. That is, either or both of the first electric motor 126 and the second electric motor 128 may be prevented from providing torque to either of the first output shaft 106 or the second output shaft 116. Such isolation may be useful if either of the first electric motor 126 or the second electric motor 128 develops a fault or satisfies an undesirable operating condition (e.g. its temperature exceeds a predetermined temperature threshold). Alternatively, the first electric motor 126 and the second electric motor 128 may be different from one another (e.g. having differing efficiencies and / or power outputs) and it may be desirable to use the first electric motor 126 and the second electric motor 128 in various combinations in dependence on certain conditions (e.g. the terrain being driven on). Selective opening of the disconnect 124 and the three auxiliary disconnects 142 may therefore permit either of the first electric motor 126 and the second electric motor 128 to be used exclusively to drive the wheels connected to the first output shaft 106 and the second output shaft 116, or in combination to drive both or either one of the wheels (e.g. with the other wheel not being driven).
[0094] FIG. 7 shows the drive system 300 of FIG. 6 with an additional park lock 700. The park lock 700 may be in accordance with known park lock arrangements and is actuatable to selectively prevent rotation of a shaft or gear (e.g. in response to a user instruction and / or an instruction that depends on certain vehicle conditions being met). In the non-limiting embodiment of FIG. 7, the park lock 700 is arranged on the auxiliary gear assembly 140 that is disposed between the first input shaft 102 to the first gear assembly 110. In use, the parklock 700 is actuated to prevent the auxiliary gear assembly 140 from being capable of transmitting torque from the first input shaft 102 to the first gear assembly 110. Since the first gear assembly 110 is permanently rotationally coupled to the first output shaft 106, actuation of the park lock 700 locks (i.e. prevents rotation) of the first output shaft 106.
[0095] Furthermore, if selective pairs from the disconnect 124 and the three auxiliary disconnects 142 are closed so as to provide a closed torque path between the (locked) auxiliary gear assembly 140 and the second output shaft 116, then the park lock 700 simultaneously has the effect of locking (i.e. preventing rotation) of the second output shaft 116. Therefore, in dependence on the configuration of the disconnect 124 and the three auxiliary disconnects 142, a single park lock 700 may be utilized to selectively and simultaneously lock both of the first output shaft 106 and the second output shaft 116. In alternative embodiments, the park lock 700 may be positioned anywhere along the torque path to either the first output shaft 106 or the second output shaft 116 to provide an ability to lock the respective output shaft. Utilisation of the disconnect 124 and the three auxiliary disconnects 142 then ensures that the other output shaft is simultaneously also locked at the same time.
[0096] Use of a park lock 700 may be similarly used to provide the ability to simultaneously lock both the first output shaft 106 and the second output shaft 116 in other embodiments of the present invention. In particular, with reference to the drive system 100 of FIG.1 , a park lock 700 may be positioned anywhere along the torque path to either the first output shaft 106 or the second output shaft 116 to provide an ability to lock the respective output shaft. Utilisation of the disconnect 124 then ensures that the other output shaft is simultaneously also locked at the same time.
[0097] With reference to the drive system 200 of FIG. 5, a park lock 700 may be positioned anywhere along the torque path to either the first output shaft 106 or the second output shaft 116 to provide an ability to lock the respective output shaft. Utilisation of the disconnect 124 then ensures that the other output shaft is simultaneously also locked at the same time.
[0098] Indeed, in accordance with certain embodiments of the present invention, a single park lock may be provided in a drive system that includes a first input shaft, a second input shaft, a first output shaft and a second output shaft, to allow for simultaneous locking of both the first output shaft and the second output shaft.
[0099] FIG. 8 shows a drive system 400 according to another embodiment of the present invention. The drive system 400 largely comprises the same components as the drive system 300 and identical reference numerals are used to refer to corresponding features. FIG. 8 additionally schematically shows a frame 144 that supports various components on the drive system 400 and a wheel 402 connected to each of the first output shaft 106 and the second output shaft 116.
[0100] In the drive system 400 of FIG. 8, the first input shaft 102 is slidable axially along the first input axis 104 between three positions labelled -1 , 0, and 1. Similarly, the second input shaft 112 is slidable axially along the second input axis 114 between three positions labelled -1 , 0, and 1. In doing so, the slidable first input shaft 102 serves as the disconnect 124 and the slidable second input shaft 112 serves as an auxiliary disconnect142. In certain embodiments, one or more actuators may be provided to cause the first input shaft 102 and the second input shaft 112 to slide along their respective axes.
[0101] When the first input shaft 102 is in position 1 (a first position of the first input shaft 102), torque may be transferred from the first input shaft 102 to the first gear assembly 110 and then to the first output shaft 106. When the first input shaft 102 is in position -1 (a second position of the first input shaft 102), torque may be transferred from the first input shaft 102 to the second gear assembly 120 and then to the second output shaft 116. When the first input shaft 102 is in position 0 (a third position of the first input shaft 102), the first input shaft 102 is isolated from any torque path that is connected to either of the first output shaft 106 and the second output shaft 116. In the first position, the first input shaft 102 serves as the disconnect 124 in the open configuration. In the second position, the first input shaft 102 serves as the disconnect 124 in the closed configuration.
[0102] When the second input shaft 112 is in position -1 (a second position of the second input shaft 112), torque may be transferred from the second input shaft 112 to the second gear assembly 120 and then to the second output shaft 116. When the second input shaft 112 is in position 1 (a first position of the second input shaft 112), torque may be transferred from the second input shaft 112 to the first gear assembly 110 and then to the first output shaft 106. When the second input shaft 112 is in position 0 (a third position of the second input shaft 112), the second input shaft 112 is isolated from any torque path than is connected to either of the first output shaft 106 and the second output shaft 116.
[0103] Therefore six configurations are possible depending on the respective axial positions of the first input shaft 102 and the second input shaft 112.
[0104] When the first input shaft 102 is in position 1 and the second input shaft 112 is in position -1 (as shown in FIG.
[0105] 8), the wheel 402 connected to the first output shaft 106 is driven exclusively by the first electric motor 126 and the wheel 402 connected to the second output shaft 116 is driven exclusively by the second electric motor 128.
[0106] When the first input shaft 102 is in position -1 and the second input shaft 112 is in position 1 , the wheel 402 connected to the first output shaft 106 is driven exclusively by the second electric motor 128 and the wheel 402 connected to the second output shaft 116 is driven exclusively by the first electric motor 126.
[0107] When the first input shaft 102 is in position -1 and the second input shaft 112 is in position -1 , the wheel 402 connected to the second output shaft 116 is driven by both the first electric motor 126 and the second electric motor 128, and the wheel 402 connected to first output shaft 106 is not driven by either of the first electric motor 126 or the second electric motor 128.
[0108] When the first input shaft 102 is in position 1 and the second input shaft 112 is in position 1 , the wheel 402 connected to the first output shaft 106 is driven by both the first electric motor 126 and the second electricmotor 128, and the wheel 402 connected to the second output shaft 116 is not driven by either of the first electric motor 126 or the second electric motor 128.
[0109] When both of the first input shaft 102 and the second input shaft 112 are in position 0, the drive system 400 is in a neutral configuration, and neither wheel 402 is driven by either of the first electric motor 126 or the second electric motor 128. That is, both the first electric motor 126 and the second electric motor 128 are isolated from any torque path connected to either wheel 402.
[0110] When either of the first input shaft 102 orthe second input shaft 112 are in position 0 and the other is in position -1 or 1 , the drive system 400 is in a semi-neutral configuration in which one of the first input shaft 102 and the second input shaft 112 is isolated from any torque path connected to either wheel 402.
[0111] In embodiments of the present invention, the disconnect 124 (and any auxiliary disconnects 142 present) may be any mechanical connection that is moveable between an open configuration and a closed configuration so as to be capable of selectively transferring torque. Non-limiting examples of such mechanical connections include, but are not limited to, clutches (which include sliding shafts).
[0112] FIG. 9 shows a vehicle 902 in accordance with an embodiment of the present invention. The vehicle 902 is an electric or hybrid vehicle and includes wheels 402 that are driven by a drive system 100 as described above. In certain embodiments, the vehicle 902 may comprise more than one drive system 100 (e.g. one drive system 100 arranged to provide torque to a first pair of wheels 402, and another drive system 100 arranged to provide torque to a second pair of wheels 402).
[0113] It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.
Claims
CLAIMS1. A drive system for an electric or hybrid vehicle, comprising:a first input shaft rotatable about a first input axis;a second input shaft rotatable about a second input axis;a first output shaft rotatable about a first output axis;a second output shaft rotatable about a second output axis;a first gear assembly arranged to transfer torque from the first input shaft to the first output shaft;a second gear assembly arranged to transfer torque from the second input shaft to the second output shaft; anda disconnect that is moveable between an open configuration and a closed configuration; wherein when the disconnect in in the closed configuration, the disconnect is arranged to transfer torque from either the first input shaft to the second output shaft, and / or from the second input shaft to the first output shaft.
2. A drive system according to claim 1 , wherein the first input axis is parallel to the second input axis and the first input axis is not coaxial with the second input axis.
3. A drive system according to claim 2, comprising a third gear assembly arranged between the first input shaft and the second gear assembly, wherein the disconnect forms part of the third gear assembly.
4. A drive system according to claim 1 , wherein the first input axis is parallel to the second input axis and the first input axis is coaxial with the second input axis.
5. A drive system according to claim 4, comprising a third gear assembly arranged between the first input shaft and the second input shaft, wherein the disconnect forms part of the third gear assembly.
6. A drive system according to any preceding claim, comprising one or more auxiliary disconnects, the one or more auxiliary disconnects being arranged to selectively transfer torque from one or more of:the first input shaft to the first gear assembly;the second input shaft to the first gear assembly; orthe second input shaft to the second gear assembly.
7. A drive system according to claim 6, comprising one or more auxiliary gear assemblies, wherein each of the one or more auxiliary disconnects forms part of one of the one or more auxiliary gear assemblies.
8. A drive system according to any preceding claim, wherein the disconnect comprises a clutch.
9. A drive system according to claim 8 when dependent on claim 6 or 7, wherein the first input shaft is axially slidable along the first input axis between:a first position in which the first input shaft is rotatably engaged with the first gear assembly and not rotatably engaged with the second gear assembly; anda second position in which first input shaft is rotatably engaged with the second gear assembly and not rotatably engaged with the first gear assembly;wherein the first input shaft comprises the clutch with the first position comprising the open configuration and the second position comprising the closed configuration.
10. A drive system according to claim 9, wherein the first input shaft is axially slidable along the first input axis to a third position in which the first input shaft is not rotatably engaged with the first gear assembly and not rotatably engaged with the second gear assembly.
11. A drive system according to claim 9 or 10, wherein the second input shaft is axially slidable along the second input axis between:a first position in which the second input shaft is rotatably engaged with the first gear assembly and not rotatably engaged with the second gear assembly; anda second position in which second input shaft is rotatably engaged with the second gear assembly and not rotatably engaged with the first gear assembly.
12. A drive system according to claim 11 , wherein the second input shaft is axially slidable along the second input axis to a third position in which the second input shaft is not rotatably engaged with the second gear assembly and not rotatably engaged with the first gear assembly.
13. A drive system according to any preceding claim, comprising a first electric motor arranged to provide torque to the first input shaft and a second electric motor arranged to provide torque to the second input shaft.
14. A drive system according to claim 13, wherein the first electric motor is different to the second electric motor.
15. A vehicle comprising the drive system of any preceding claim.