Vehicle transmission

Abstract

The present invention provides a vehicle transmission with a configuration featuring two engagement mechanisms that is easy to miniaturize while ensuring durability. [Solution] The first rotating element E1 is connected to the input member 1, the third rotating element E3 is connected to the output member 2, the first rotating element E1 and the fourth rotating element E4 are connected, the fifth rotating element E5 is connected to the second rotating element E2 or the third rotating element E3, the first engagement mechanism 5 changes between an engaged state in which the second rotating element E2 is fixed to the non-rotating member NR and a released state in which the second rotating element E2 is rotatable, the second engagement mechanism 6 changes between an engaged state in which the sixth rotating element E6 is fixed to the non-rotating member NR and a released state in which the sixth rotating element E6 is rotatable, the planetary gear mechanisms 3,4 and the engagement mechanisms 5,6 are arranged coaxially, the first planetary gear mechanism 3 is positioned on the first axial side L1 relative to the second planetary gear mechanism 4, and the engagement mechanisms 5,6 are positioned on the second axial side L2 relative to the second planetary gear mechanism 4.

Description

[Technical Field]

[0001] The present invention relates to a vehicle transmission comprising: an input member drivingly coupled to a drive source; an output member drivingly coupled to wheels; a planetary gear mechanism; and an engagement mechanism. [Background Art]

[0002] An example of such a vehicle transmission is disclosed in Patent Document 1 below. In the following description of the background art, reference signs in Patent Document 1 are cited in parentheses.

[0003] The vehicle transmission (10) of Patent Document 1 includes a first engagement mechanism (3) and a second engagement mechanism (4) arranged coaxially side by side. The first engagement mechanism (3) is configured as a friction clutch that connects and disconnects power transmission between two rotating elements (E5, E6). The second engagement mechanism (4) is configured as a brake that selectively fixes the rotating element (E5) to a non-rotating member (NR). Either one of two shift speeds can be established by controlling the engagement states of the first engagement mechanism (3) and the second engagement mechanism (4). [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2024 / 166899 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] In the above-described vehicle transmission (10), the first engagement mechanism (3) comprises a first support member (33) that rotates integrally with one rotating element (E5), a second support member (34) that rotates integrally with the other rotating element (E6), a first friction engagement element (31) supported by the first support member (33), and a second friction engagement element (32) supported by the second support member (34). The first engagement mechanism (3) is engaged when the first friction engagement element (31) and the second friction engagement element (32) are pressed in the axial direction (L) so as to engage with each other.

[0006] Thus, because both the first friction engagement element (31) and the second friction engagement element (32) are rotating members, the power transmission structure in the first engagement mechanism (3) becomes complex, leading to a decrease in the durability of the first engagement mechanism (3). To improve the durability of the first engagement mechanism (3), for example, it is conceivable to increase the radial dimensions of the first friction engagement element (31) and the second friction engagement element (32), as well as the thrust bearings that support the thrust load generated when they are pressed, but this is disadvantageous in that it leads to an increase in the size of the first engagement mechanism (3).

[0007] Therefore, there is a need for a vehicle transmission with a configuration that includes two engagement mechanisms, which can be easily miniaturized while ensuring durability. [Means for solving the problem]

[0008] In light of the above, the characteristic configuration of a vehicle transmission is: An input member connected to a drive source, An output member that is driven and connected to the wheel, A first planetary gear mechanism comprising a first rotating element, a second rotating element, and a third rotating element, A second planetary gear mechanism comprising a fourth rotation element, a fifth rotation element, and a sixth rotation element, First engagement mechanism, A vehicle transmission comprising a second engagement mechanism, The first rotating element is connected to the input member so as to rotate integrally with it. The third rotating element is connected to the output member so as to rotate integrally with it. The first rotating element and the fourth rotating element are connected so as to rotate as a whole. The fifth rotating element is connected to the second rotating element or the third rotating element so as to rotate integrally with it. The first engagement mechanism is configured to be able to change between an engaged state in which the second rotating element is fixed to the non-rotating member and a released state in which the second rotating element is rotatable. The second engagement mechanism is configured to be able to change between an engaged state in which the sixth rotating element is fixed to the non-rotating member and a released state in which the sixth rotating element is rotatable. The first planetary gear mechanism, the second planetary gear mechanism, the first engagement mechanism, and the second engagement mechanism are arranged coaxially. One side in the axial direction is designated as the axial first side, and the other side in the axial direction is designated as the axial second side. The first planetary gear mechanism is positioned on the first axial side relative to the second planetary gear mechanism. The first engagement mechanism and the second engagement mechanism are positioned on the second axial side with respect to the second planetary gear mechanism.

[0009] According to this characteristic configuration, both the first and second engagement mechanisms for achieving two-speed shifting are configured as brakes that fix the rotating elements to non-rotating members. This makes it easier to simplify the power transmission structure in the engagement mechanism and ensure the durability of the engagement mechanism compared to a case where at least one of the first and second engagement mechanisms is configured as a friction-type clutch that disconnects and reconnects power transmission between the two rotating elements. Therefore, it is easier to miniaturize the vehicle transmission while ensuring the durability of the vehicle transmission. Furthermore, according to this characteristic configuration, the first planetary gear mechanism, the second planetary gear mechanism, the first engagement mechanism, and the second engagement mechanism are arranged coaxially. This makes it easier to keep the radial dimensions of the vehicle transmission small. Further, according to this characteristic configuration, the first planetary gear mechanism is disposed on a first axial side with respect to the second planetary gear mechanism, and the first engagement mechanism and the second engagement mechanism are disposed on a second axial side with respect to the second planetary gear mechanism. This easily simplifies the configuration for connecting the first rotating element of the first planetary gear mechanism to the input member and connecting the third rotating element of the first planetary gear mechanism to the output member. Accordingly, it is easy to achieve size reduction of the vehicle transmission. [Brief Description of the Drawings]

[0010] [Figure 1] Skeleton diagram of a vehicle drive device including the vehicle transmission according to the first embodiment [Figure 2] Speed diagram of the first planetary gear mechanism and the second planetary gear mechanism according to the first embodiment [Figure 3] Cross-sectional view showing an example of the configuration of the first engagement mechanism and the second engagement mechanism [Figure 4] Cross-sectional view showing another example of the configuration of the first engagement mechanism and the second engagement mechanism [Figure 5] Skeleton diagram of a vehicle drive device including the vehicle transmission according to the second embodiment [Figure 6] Skeleton diagram of a vehicle drive device including the vehicle transmission according to the third embodiment [Figure 7] Speed diagram of the first planetary gear mechanism and the second planetary gear mechanism according to the third embodiment [Figure 8] Skeleton diagram of a vehicle drive device including the vehicle transmission according to the fourth embodiment [Figure 9] Speed diagram of the first planetary gear mechanism and the second planetary gear mechanism according to the fourth embodiment [Figure 10] Skeleton diagram of a vehicle drive device including the vehicle transmission according to the fifth embodiment [Figure 11] Speed diagram of the first planetary gear mechanism and the second planetary gear mechanism according to the fifth embodiment [Mode for Carrying Out the Invention]

[0011] 1. First Embodiment Hereinafter, a vehicle transmission 10 according to a first embodiment will be described with reference to FIGS. 1 to 3. The vehicle transmission 10 is provided in a vehicle drive device 100.

[0012] As shown in FIG. 1, in the present embodiment, the vehicle drive device 100 includes a rotating electric machine MG, a differential gear mechanism DF, and a case CS.

[0013] The rotating electric machine MG has a function as a motor (electric motor) that generates power upon receiving power supply, and a function as a generator that generates power upon receiving power supply. The rotating electric machine MG includes a stator ST and a rotor RT. The stator ST is fixed to a non-rotating member NR (here, the case CS). The rotor RT is rotatably supported relative to the stator ST.

[0014] The differential gear mechanism DF is configured to distribute rotation transmitted from the rotating electric machine MG side to a pair of wheels W. The differential gear mechanism DF is disposed on a second axis X2 different from a first axis X1 which is the rotation axis of the rotor RT. The differential gear mechanism DF includes a differential input gear G.

[0015] The case CS accommodates the vehicle transmission 10, the rotating electric machine MG, and the differential gear mechanism DF.

[0016] The vehicle transmission 10 includes an input member 1, an output member 2, a first planetary gear mechanism 3, a second planetary gear mechanism 4, a first engagement mechanism 5, and a second engagement mechanism 6.

[0017] The input member 1 is a member drivingly coupled to a drive source D. In the present embodiment, the drive source D is the rotating electric machine MG.

[0018] Herein, in this application, "drive connection" refers to a state in which two rotating elements are connected in a manner that can transmit driving force, and includes a state in which the two rotating elements are connected so as to rotate as a whole, or a state in which the two rotating elements are connected in a manner that can transmit driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a variable speed, such as shafts, gear mechanisms, belts, chains, etc. In addition, the transmission members may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices, meshing engagement devices, etc. However, when referring to "drive connection" for each rotating element of a planetary gear mechanism, it refers to a state in which they are connected to each other without the need for other rotating elements.

[0019] Furthermore, in the following explanation, the direction along the first axis X1 will be referred to as "axial direction L". One side of axial direction L will be referred to as "first axial direction L1", and the other side of axial direction L will be referred to as "second axial direction L2". Also, the direction perpendicular to the first axis X1 will be referred to as "radial direction R".

[0020] In this embodiment, the input member 1 is an input shaft 11 connected to the rotor RT so as to rotate integrally with it. The input shaft 11 is a shaft member formed to extend along the axial direction L. The input shaft 11 is positioned on the first axis X1.

[0021] The output member 2 is a member that is driven and connected to the wheel W. In this embodiment, the output member 2 is an external-toothed output gear 21. The output gear 21 meshes with the differential input gear G. The output gear 21 is located on the first axis X1.

[0022] The first planetary gear mechanism 3, the second planetary gear mechanism 4, the first engagement mechanism 5, and the second engagement mechanism 6 are all arranged on the first axis X1. In other words, the first planetary gear mechanism 3, the second planetary gear mechanism 4, the first engagement mechanism 5, and the second engagement mechanism 6 are all arranged coaxially.

[0023] The first planetary gear mechanism 3 is positioned on the first axial side L1 relative to the second planetary gear mechanism 4. In this embodiment, the rotating electric machine MG is positioned on the first axial side L1 relative to the first planetary gear mechanism 3.

[0024] The first engagement mechanism 5 and the second engagement mechanism 6 are positioned on the second axial side L2 relative to the second planetary gear mechanism 4. In this embodiment, the first engagement mechanism 5 and the second engagement mechanism 6 are positioned side by side in the axial direction L.

[0025] The first planetary gear mechanism 3 is a planetary gear mechanism comprising a first rotating element E1, a second rotating element E2, and a third rotating element E3. In this embodiment, the first planetary gear mechanism 3 is configured such that the rotational speeds of the first rotating element E1, the second rotating element E2, and the third rotating element E3 are in the order described above.

[0026] The second planetary gear mechanism 4 is a planetary gear mechanism comprising a fourth rotating element E4, a fifth rotating element E5, and a sixth rotating element E6. In this embodiment, the second planetary gear mechanism 4 is configured such that the rotational speeds of the fourth rotating element E4, the fifth rotating element E5, and the sixth rotating element E6 are in the order described above.

[0027] Here, "order of rotational speeds" refers to the order of rotational speeds of each rotating element in its rotational state. The rotational speed of each rotating element changes depending on the state of the planetary gear mechanism, but the order of high and low rotational speeds of each rotating element is constant because it is determined by the structure of the planetary gear mechanism. The order of rotational speeds of each rotating element is equal to the arrangement order of each rotating element in its velocity diagram (see Figure 2). Here, "arrangement order of each rotating element in its velocity diagram" refers to the order in which the axes corresponding to each rotating element in the velocity diagram are arranged along the direction perpendicular to that axis. The arrangement direction of the axes corresponding to each rotating element in the velocity diagram differs depending on how the velocity diagram is drawn, but the arrangement order is constant because it is determined by the structure of the planetary gear mechanism.

[0028] The first rotating element E1 is connected to the input member 1 so as to rotate integrally with it. The third rotating element E3 is connected to the output member 2 so as to rotate integrally with it.

[0029] In this embodiment, the first rotating element E1 is the first sun gear SG1. The second rotating element E2 is the first carrier CR1. The third rotating element E3 is the internally toothed first ring gear RG1. In this embodiment, the externally toothed output gear 21 is positioned radially outward from the third rotating element E3, which is the internally toothed first ring gear RG1, and overlaps with the third rotating element E3 in a radial view along the radial direction R.

[0030] Here, regarding the arrangement of the two elements, "overlapping in a specific viewing direction" means that when a virtual line parallel to the line of sight is moved in each direction perpendicular to that virtual line, there exists at least a portion of the region where the virtual line intersects both elements.

[0031] In this embodiment, the first planetary gear mechanism 3 is a single-pinion type planetary gear mechanism. Therefore, the first carrier CR1 rotatably supports the first pinion gear PG1, which meshes with both the first sun gear SG1 and the first ring gear RG1. The first pinion gear PG1 rotates (rotates) around its axis and also rotates (revolves) together with the first carrier CR1 around the first axis X1.

[0032] The fourth rotating element E4 is connected to the first rotating element E1 so as to rotate integrally with it. The fifth rotating element E5 is connected to the second rotating element E2 or the third rotating element E3 so as to rotate integrally with it. In this embodiment, the fifth rotating element E5 is connected to the second rotating element E2 so as to rotate integrally with it.

[0033] In this embodiment, the fourth rotating element E4 is the second sun gear SG2. The fifth rotating element E5 is the second carrier CR2. The sixth rotating element E6 is the internally toothed second ring gear RG2.

[0034] In this embodiment, the second planetary gear mechanism 4 is a single-pinion type planetary gear mechanism. Therefore, the second carrier CR2 rotatably supports the second pinion gear PG2, which meshes with both the second sun gear SG2 and the second ring gear RG2. The second pinion gear PG2 rotates (rotates) around its axis and also rotates (revolves) around the first axis X1 together with the second carrier CR2.

[0035] The first engagement mechanism 5 is configured to change between an engaged state in which the second rotating element E2 is fixed to the non-rotating member NR, and a released state in which the second rotating element E2 is rotatable. In this embodiment, the first engagement mechanism 5 switches between the engaged state and the released state by selectively fixing the fifth rotating element E5, which is connected to rotate integrally with the second rotating element E2, to the non-rotating member NR.

[0036] The second engagement mechanism 6 is configured to be able to change between an engaged state in which the sixth rotating element E6 is fixed to the non-rotating member NR, and a released state in which the sixth rotating element E6 is rotatable.

[0037] Figure 2 is a velocity diagram of the first planetary gear mechanism 3 and the second planetary gear mechanism 4 according to this embodiment. In the velocity diagram of Figure 2, the vertical lines correspond to the rotational speed of each rotating element of the first planetary gear mechanism 3 and the second planetary gear mechanism 4. The symbols shown above the multiple vertical lines are the symbols of the corresponding rotating elements of the first planetary gear mechanism 3 and the second planetary gear mechanism 4. The symbols shown below the multiple vertical lines are the symbols of the elements driven and connected to the rotating elements corresponding to the symbols shown above. The same method of notation is used for velocity diagrams other than those in Figure 2.

[0038] As shown in Figure 2, when the first engagement mechanism 5 is in the disengaged state and the second engagement mechanism 6 is in the engaged state, the second rotating element E2 (here, the first carrier CR1) is rotatable and the sixth rotating element E6 (here, the second ring gear RG2) is fixed to the non-rotating member NR, and the first gear stage S1 is formed. When the first gear stage S1 is formed, the rotation transmitted from the input member 1 to the first rotating element E1 (here, the first sun gear SG1) is reduced by a relatively large reduction ratio in both the first planetary gear mechanism 3 and the second planetary gear mechanism 4, and output from the third rotating element E3 (here, the first ring gear RG1) to the output member 2.

[0039] In this embodiment, the second rotating element E2 (here, the first carrier CR1) and the third rotating element E3 (here, the first ring gear RG1) rotate in opposite directions to each other. In other words, in this embodiment, the first planetary gear mechanism 3 and the second planetary gear mechanism 4 are configured such that when the first engagement mechanism 5 is in the disengaged state, the second engagement mechanism 6 is in the engaged state, and the input member 1 is rotating, the rotation directions of the second rotating element E2 and the third rotating element E3 are opposite.

[0040] When the first engagement mechanism 5 is engaged and the second engagement mechanism 6 is disengaged, the second rotating element E2 (here, the first carrier CR1) is fixed to the non-rotating member NR, and the sixth rotating element E6 (here, the second ring gear RG2) is rotatable, forming the second gear stage S2. When the second gear stage S2 is formed, the rotation transmitted from the input member 1 to the first rotating element E1 (here, the first sun gear SG1) is reduced by a relatively small reduction ratio in the first planetary gear mechanism 3 and output from the third rotating element E3 (here, the first ring gear RG1) to the output member 2.

[0041] Figure 3 is a cross-sectional view showing an example of the configuration of the first engagement mechanism 5 and the second engagement mechanism 6. As shown in Figure 3, in this embodiment, the first engagement mechanism 5 is positioned on the second axial side L2 relative to the second engagement mechanism 6. The first engagement mechanism 5 comprises a first engagement element 51, a second engagement element 52, a first support member 53, and a second support member 54. The second engagement mechanism 6 comprises a third engagement element 61, a fourth engagement element 62, a third support member 63, and a fourth support member 64.

[0042] The first engaging element 51 and the second engaging element 52 are configured to engage with each other. The first support member 53 is a member that supports the first engaging element 51. The second support member 54 is a member that supports the second engaging element 52.

[0043] The third engaging element 61 and the fourth engaging element 62 are configured to engage with each other. The third support member 63 is a member that supports the third engaging element 61. The fourth support member 64 is a member that supports the fourth engaging element 62.

[0044] In this embodiment, the first engaging element 51 and the second engaging element 52 are arranged to face each other in the axial direction L. The first engaging element 51 and the second engaging element 52 engage with each other by friction when pressed against each other in the axial direction L. In addition, multiple first engaging elements 51 and second engaging elements 52 are provided, and these are arranged alternately along the axial direction L.

[0045] In this embodiment, the third engaging element 61 and the fourth engaging element 62 are arranged to face each other in the axial direction L. The third engaging element 61 and the fourth engaging element 62 engage with each other by friction when pressed against each other in the axial direction L. Multiple third engaging elements 61 and multiple fourth engaging elements 62 are provided, and these are arranged alternately along the axial direction L.

[0046] Thus, in this embodiment, the first engagement mechanism 5 and the second engagement mechanism 6 are both friction-type engagement mechanisms. A friction-type engagement mechanism is configured such that the engagement state (engaged state / released state) is controlled according to the engagement pressure of a pair of engagement elements. In a friction-type engagement mechanism, the engagement state includes a "direct engagement state" and a "slip engagement state". The direct engagement state is a state in which a pair of engagement elements are engaged without differential rotation. The slip engagement state is a state in which a pair of engagement elements are engaged with differential rotation.

[0047] In this embodiment, the first support member 53 supports the first engaging element 51 so that it cannot rotate relative to the first engaging element 51, but can slide in the axial direction L. The first support member 53 is formed in a cylindrical shape with the first axis X1 as its axis. The first support member 53 supports the first engaging element 51 from the outside in the radial direction R. In the illustrated example, multiple spline teeth extending in the axial direction L are formed on the inner circumference of the first support member 53 and are dispersed in the circumferential direction. On the other hand, similar spline teeth are formed on the outer circumference of the first engaging element 51 and are dispersed in the circumferential direction. These spline teeth are engaged with each other.

[0048] Furthermore, in this embodiment, the first support member 53 is supported by the case CS, which is a non-rotating member NR, so as to be unable to rotate relative to it and to be slidable in the axial direction L. In the illustrated example, a plurality of spline teeth extending in the axial direction L are formed on the outer circumference of the first support member 53 and are dispersed in the circumferential direction. On the other hand, similar spline teeth are formed on the inner circumference of the case CS and are dispersed in the circumferential direction. These spline teeth are engaged with each other.

[0049] In this embodiment, the second support member 54 supports the second engaging element 52 so that it can slide in the axial direction L, and rotates integrally with the second engaging element 52. The second support member 54 is formed in a cylindrical shape with the first axis X1 as its axis. The second support member 54 supports the second engaging element 52 from the inside in the radial direction R. In the illustrated example, multiple spline teeth extending in the axial direction L are formed on the outer circumference of the second support member 54 and are dispersed in the circumferential direction. On the other hand, similar spline teeth are formed on the inner circumference of the second engaging element 52 and are dispersed in the circumferential direction. These spline teeth are engaged with each other.

[0050] Furthermore, in this embodiment, the second support member 54 is connected to the second carrier CR2, which serves as the fifth rotating element E5, via a first axial member 541 that extends along the axial direction L, so as to rotate integrally with it.

[0051] In this embodiment, the third support member 63 supports the third engaging element 61 so that it cannot rotate relative to the third engaging element 61, but can slide in the axial direction L. The third support member 63 is formed in a cylindrical shape with the first axis X1 as its axis. The third support member 63 supports the third engaging element 61 from the outside in the radial direction R. In the illustrated example, multiple spline teeth extending in the axial direction L are formed on the inner circumference of the third support member 63, distributed in the circumferential direction. On the other hand, similar spline teeth are formed on the outer circumference of the third engaging element 61, also distributed in the circumferential direction. These spline teeth are engaged with each other.

[0052] Furthermore, in this embodiment, the third support member 63 is supported with respect to the case CS, which is a non-rotating member NR, in a manner that prevents relative rotation and allows sliding in the axial direction L. In the illustrated example, the third support member 63 is formed integrally with the case CS.

[0053] In this embodiment, the fourth support member 64 supports the fourth engaging element 62 so that it can slide in the axial direction L, and rotates integrally with the fourth engaging element 62. The fourth support member 64 is formed in a cylindrical shape with the first axis X1 as its axis. The fourth support member 64 supports the fourth engaging element 62 from the inside in the radial direction R. In the illustrated example, multiple spline teeth extending in the axial direction L are formed on the outer circumference of the fourth support member 64 and are dispersed in the circumferential direction. On the other hand, similar spline teeth are formed on the inner circumference of the fourth engaging element 62 and are dispersed in the circumferential direction. These spline teeth are engaged with each other.

[0054] Furthermore, in this embodiment, the fourth support member 64 is connected to the second ring gear RG2, which serves as the sixth rotating element E6, via a second axial member 641 that extends along the axial direction L, so as to rotate integrally with it.

[0055] As described above, the first gear stage S1 is formed when the first engagement mechanism 5 is in a disengaged state and the second engagement mechanism 6 is in an engaged state. The second gear stage S2 is formed when the first engagement mechanism 5 is in an engaged state and the second engagement mechanism 6 is in a disengaged state. Since the reduction ratio of the first gear stage S1 is larger than that of the second gear stage S2, the engagement torque of the second engagement mechanism 6 for forming the first gear stage S1 needs to be greater than the engagement torque of the first engagement mechanism 5 for forming the second gear stage S2. Therefore, in this embodiment, the second shaft member 641 is formed in a cylindrical shape with the first axis X1 as its axis, and is positioned to cover the first shaft member 541 from the outside in the radial direction R. In this way, the strength of the second shaft member 641 connected to the fourth support member 64 of the second engagement mechanism 6, which has a relatively large engagement torque for forming the first gear stage S1, is increased.

[0056] In this embodiment, the first engagement mechanism 5 further comprises a first pressure-receiving member 55. The first pressure-receiving member 55 is a member that supports the first engagement element 51 and the second engagement element 52 in the axial direction L when the first engagement element 51 and the second engagement element 52 are pressed in the axial direction L. In this embodiment, the first pressure-receiving member 55 is positioned on the second axial side L2 with respect to the first engagement element 51 and the second engagement element 52. In the illustrated example, the first pressure-receiving member 55 is formed in an annular shape with a first axis X1 as its axis. The first pressure-receiving member 55 is fixed to the case CS via a support shaft member 551 that is formed to extend along the axial direction L.

[0057] Furthermore, in this embodiment, the second engagement mechanism 6 further comprises a second pressure-receiving member 65. The second pressure-receiving member 65 is a member that supports the third engagement element 61 and the fourth engagement element 62 in the axial direction L when the third engagement element 61 and the fourth engagement element 62 are pressed in the axial direction L. In this embodiment, the second pressure-receiving member 65 is positioned on the first axial side L1 with respect to the third engagement element 61 and the fourth engagement element 62. In the illustrated example, the second pressure-receiving member 65 is formed in an annular shape with the first axis X1 as its axis. The second pressure-receiving member 65 is formed integrally with the case CS.

[0058] As shown in Figure 3, in this embodiment, the vehicle transmission 10 further includes a drive mechanism 7. The drive mechanism 7 is configured to drive both the first engagement mechanism 5 and the second engagement mechanism 6. In other words, the first engagement mechanism 5 and the second engagement mechanism 6 are driven by a common drive mechanism 7.

[0059] The drive mechanism 7 comprises an engaging member 71 and a drive device 72. In this embodiment, the drive mechanism 7 further comprises a linear motion conversion mechanism 73.

[0060] The engaging member 71 is a member that operates to selectively engage either the first engaging mechanism 5 or the second engaging mechanism 6. In this embodiment, the engaging member 71 is connected to the first support member 53 so as to move integrally with it in the axial direction L. The engaging member 71 also includes a pressing portion 711 that presses the first engaging element 51 and the second engaging element 52 toward the second axial direction L2, and presses the third engaging element 61 and the fourth engaging element 62 toward the first axial direction L1.

[0061] The drive unit 72 is configured to output a driving force to move the engaging member 71 in the axial direction L. In this embodiment, the drive unit 72 is an electric motor that outputs a predetermined rotational driving force.

[0062] The linear motion conversion mechanism 73 comprises a screw shaft 74, a nut member 75, and a transmission mechanism 76.

[0063] The screw shaft 74 is formed in a cylindrical shape extending along the axial direction L. Screw threads are formed on the outer circumference of the screw shaft 74. The screw shaft 74 is rotatably supported with respect to the non-rotating member NR. In this embodiment, the screw shaft 74 is positioned on the first axis X1 such that it covers the support shaft member 551 from the outside in the radial direction R. The screw shaft 74 is rotatably supported with respect to the support shaft member 551.

[0064] The nut member 75 is configured to be screwed onto the screw shaft 74. That is, a groove is formed on the inner circumference of the nut member 75 that engages with the threads of the screw shaft 74. The nut member 75 is supported relative to the non-rotating member NR so as to be immobile relative to it and movable in the axial direction L. In this embodiment, the nut member 75 is connected integrally with the first support member 53 so as to move axially L. That is, in this embodiment, the nut member 75 is supported via the first support member 53 so as to be immobile relative to the case CS, which is the non-rotating member NR, and movable in the axial direction L. In this way, as the screw shaft 74 rotates, the nut member 75 performs linear motion along the axial direction L according to the direction of rotation and the orientation of the threads of the screw shaft 74.

[0065] The transmission mechanism 76 is configured to transmit the rotational driving force of the drive unit 72, which is an electric motor, to the screw shaft 74. In this embodiment, the transmission mechanism 76 includes a first transmission gear 761, a second transmission gear 762, and a third transmission gear 763.

[0066] The first transmission gear 761 is connected to the output element of the drive unit 72, which is an electric motor, so as to rotate integrally with it.

[0067] The second transmission gear 762 meshes with the first transmission gear 761. The second transmission gear 762 is an idler gear and is rotatably supported relative to the case CS.

[0068] The third transmission gear 763 meshes with the second transmission gear 762. The third transmission gear 763 is connected to the screw shaft 74 so as to rotate integrally with it.

[0069] In this embodiment, the number of teeth of the third transmission gear 763 is greater than the number of teeth of the first transmission gear 761. Therefore, in this embodiment, the rotation transmitted from the drive unit 72 to the first transmission gear 761 is reduced in speed between the first transmission gear 761 and the third transmission gear 763, which are connected via the second transmission gear 762, and then transmitted to the screw shaft 74. In other words, in this embodiment, the transmission mechanism 76 is configured to reduce the rotation of the drive unit 72 and transmit it to the screw shaft 74.

[0070] In this embodiment, when the drive unit 72 is rotated toward the first side, the rotational driving force of the drive unit 72 is transmitted to the screw shaft 74 via the transmission mechanism 76, and the nut member 75 moves toward the second axial side L2. Consequently, the engaging member 71 moves toward the second axial side L2 via the first support member 53 connected to the nut member 75. As a result, the first engaging element 51 and the second engaging element 52 are pressed in the axial direction L between the pressing portion 711 of the engaging member 71 and the first pressure receiving member 55, and the first engaging mechanism 5 becomes engaged. At the same time, the pressing of the third engaging element 61 and the fourth engaging element 62 between the pressing portion 711 and the second pressure receiving member 65 is released, and the second engaging mechanism 6 becomes disengaged.

[0071] On the other hand, when the drive unit 72 rotates toward the second side opposite to the first side, the rotational driving force of the drive unit 72 is transmitted to the screw shaft 74 via the transmission mechanism 76, and the nut member 75 moves toward the first side L1 in the axial direction. Consequently, the engaging member 71 moves toward the first side L1 in the axial direction via the first support member 53 connected to the nut member 75. As a result, the third engaging element 61 and the fourth engaging element 62 are pressed in the axial direction L between the pressing portion 711 of the engaging member 71 and the second pressure receiving member 65, and the second engaging mechanism 6 becomes engaged. At the same time, the pressing of the first engaging element 51 and the second engaging element 52 between the pressing portion 711 and the first pressure receiving member 55 is released, and the first engaging mechanism 5 becomes open.

[0072] Thus, in this embodiment, the first engagement mechanism 5 is engaged and the second engagement mechanism 6 is released by driving the engagement member 71 toward either side of the axial direction L using the driving force of the drive device 72. Then, the first engagement mechanism 5 is released and the second engagement mechanism 6 is engaged by driving the engagement member 71 toward the other side of the axial direction L using the driving force of the drive device 72.

[0073] In the above embodiment, a configuration in which the first engagement mechanism 5 and the second engagement mechanism 6 are both friction-type engagement mechanisms was described as an example, but the configuration is not limited to this. For example, as shown in Figure 4, the first engagement mechanism 5 and the second engagement mechanism 6 may each be mesh-type engagement mechanisms.

[0074] In the example shown in Figure 4, the first engaging element 51 and the second engaging element 52 are formed to interlock with each other. In this example, the engaging member 71 does not have a pressing portion 711, and is integrally formed with the first support member 53 that supports the first engaging element 51 and the second support member 54 that supports the second engaging element 52. The first engaging element 51 is positioned on the second axial side L2 relative to the engaging member 71, and the second engaging element 52 is positioned on the first axial side L1 relative to the engaging member 71.

[0075] Furthermore, in this example, the first engagement mechanism 5 does not include the first pressure-receiving member 55. And the second engagement mechanism 6 does not include the second pressure-receiving member 65.

[0076] 2. Second Embodiment In the following description, a vehicle drive system 100 equipped with a vehicle transmission 10 according to the second embodiment will be explained with reference to Figure 5. In this embodiment, the configuration of the first planetary gear mechanism 3 and the second planetary gear mechanism 4 differs from that of the first embodiment. In the following description, the differences from the first embodiment will be the main focus. Unless otherwise specified, the same applies as in the first embodiment.

[0077] As shown in Figure 5, in this embodiment, the first rotating element E1 and the fourth rotating element E4 are integrally configured. Therefore, in this embodiment, the second sun gear SG2 is not provided, and the first sun gear SG1 functions as both the first rotating element E1 and the fourth rotating element E4.

[0078] In this embodiment, the first pinion gear PG1 and the second pinion gear PG2 are connected so as to rotate integrally. The first pinion gear PG1 is formed to have a larger diameter than the second pinion gear PG2.

[0079] In this embodiment, similar to the first embodiment, when the first gear stage S1 is formed, the rotation transmitted from the input member 1 to the first rotating element E1 is reduced by a relatively large reduction ratio in both the first planetary gear mechanism 3 and the second planetary gear mechanism 4, and output from the third rotating element E3 to the output member 2. Also, when the second gear stage S2 is formed, the rotation transmitted from the input member 1 to the first rotating element E1 is reduced by a relatively small reduction ratio in the first planetary gear mechanism 3, and output from the third rotating element E3 to the output member 2.

[0080] 3. Third Embodiment In the following description, a vehicle drive system 100 equipped with a vehicle transmission 10 according to the third embodiment will be explained with reference to Figures 6 and 7. In this embodiment, the position of the output member 2, the positions of the first engagement mechanism 5 and the second engagement mechanism 6, and the configuration of the first planetary gear mechanism 3 and the second planetary gear mechanism 4 differ from those of the first embodiment. In the following description, the differences from the first embodiment will be the main focus. Points that are not specifically explained will be the same as those of the first embodiment.

[0081] As shown in Figure 6, in this embodiment, the output gear 21, which is the output member 2, is positioned on the first axial side L1 relative to the first planetary gear mechanism 3. The output gear 21 is connected to the first carrier CR1 so as to rotate integrally with it.

[0082] In this embodiment, the first engagement mechanism 5 is positioned on the first axial side L1 relative to the second engagement mechanism 6.

[0083] In this embodiment, the first rotating element E1 is the first sun gear SG1. The second rotating element E2 is the first ring gear RG1. The third rotating element E3 is the first carrier CR1.

[0084] In this embodiment, the fourth rotating element E4 is the second sun gear SG2. The fifth rotating element E5 is the second ring gear RG2. The sixth rotating element E6 is the second carrier CR2.

[0085] In this embodiment, the first carrier CR1 is connected to the output member 2 so as to rotate integrally with it. The first ring gear RG1 and the second ring gear RG2 are also connected so as to rotate integrally with each other. The first ring gear RG1 and the second ring gear RG2 are connected to the first engagement mechanism 5. The second carrier CR2 is also connected to the second engagement mechanism 6.

[0086] As shown in Figure 7, in this embodiment, the first planetary gear mechanism 3 is configured such that the rotational speeds of the first rotating element E1, the third rotating element E3, and the second rotating element E2 are in the order described. The second planetary gear mechanism 4 is configured such that the rotational speeds of the fourth rotating element E4, the sixth rotating element E6, and the fifth rotating element E5 are in the order described.

[0087] 4. Fourth Embodiment In the following description, a vehicle drive system 100 equipped with a vehicle transmission 10 according to the fourth embodiment will be explained with reference to Figures 8 and 9. In this embodiment, the position of the output member 2 and the configuration of the first planetary gear mechanism 3 and the second planetary gear mechanism 4 differ from those of the first embodiment. In the following description, the differences from the first embodiment will be the main focus. Unless otherwise specified, the same applies as in the first embodiment.

[0088] As shown in Figure 8, in this embodiment, the output gear 21, which is the output member 2, is positioned on the first axial side L1 relative to the first planetary gear mechanism 3. The output gear 21 is connected to the first carrier CR1 so as to rotate integrally with it.

[0089] In this embodiment, the first rotating element E1 is the first sun gear SG1. The second rotating element E2 is the first ring gear RG1. The third rotating element E3 is the first carrier CR1.

[0090] In this embodiment, the fourth rotating element E4 is the second sun gear SG2. The fifth rotating element E5 is the second carrier CR2. The sixth rotating element E6 is the second ring gear RG2.

[0091] In this embodiment, the second planetary gear mechanism 4 is a double pinion type planetary gear mechanism. Therefore, the second carrier CR2 rotatably supports the third pinion gear PG3, which meshes with the second sun gear SG2, and the fourth pinion gear PG4, which meshes with the third pinion gear PG3 and the second ring gear RG2.

[0092] Furthermore, in this embodiment, the first carrier CR1 is connected to the output member 2 so as to rotate integrally with it. Also, the first ring gear RG1 and the second carrier CR2 are connected so as to rotate integrally with each other. The first ring gear RG1 and the second carrier CR2 are connected to the first engagement mechanism 5. The second ring gear RG2 is connected to the second engagement mechanism 6.

[0093] As shown in Figure 9, in this embodiment, the first planetary gear mechanism 3 is configured such that the rotational speeds of the first rotating element E1, the third rotating element E3, and the second rotating element E2 are in the order described. The second planetary gear mechanism 4 is configured such that the rotational speeds of the fourth rotating element E4, the sixth rotating element E6, and the fifth rotating element E5 are in the order described.

[0094] 5. Fifth Embodiment In the following description, a vehicle drive system 100 equipped with a vehicle transmission 10 according to the fifth embodiment will be explained with reference to Figures 10 and 11. In this embodiment, the positions of the first engagement mechanism 5 and the second engagement mechanism 6, and the configuration of the first planetary gear mechanism 3 and the second planetary gear mechanism 4 differ from those of the first embodiment. In the following description, the differences from the first embodiment will be the main focus. Points that are not specifically explained will be the same as those of the first embodiment.

[0095] As shown in Figure 10, in this embodiment, the first engagement mechanism 5 is positioned on the first axial side L1 relative to the second engagement mechanism 6.

[0096] In this embodiment, the fifth rotating element E5 is connected to the third rotating element E3 so as to rotate integrally with it. As described above, in the first to fourth embodiments, the fifth rotating element E5 is connected to the second rotating element E2 so as to rotate integrally with it. In other words, the fifth rotating element E5 is connected to the second rotating element E2 or the third rotating element E3 so as to rotate integrally with it.

[0097] In this embodiment, the first rotating element E1 and the fourth rotating element E4 are integrally configured. Therefore, in this embodiment, the second sun gear SG2 is not provided, and the first sun gear SG1 functions as both the first rotating element E1 and the fourth rotating element E4.

[0098] In this embodiment, the second rotating element E2 is the first ring gear RG1. The third rotating element E3 is the first carrier CR1. The fifth rotating element E5 is the second carrier CR2. The sixth rotating element E6 is the second ring gear RG2.

[0099] In this embodiment, the first pinion gear PG1 and the second pinion gear PG2 are connected so as to rotate integrally. The first pinion gear PG1 is formed to have a larger diameter than the second pinion gear PG2.

[0100] Furthermore, in this embodiment, the first carrier CR1 and the second carrier CR2 are connected so as to rotate integrally with the output member 2. The first ring gear RG1 is connected to the first engagement mechanism 5, and the second ring gear RG2 is connected to the second engagement mechanism 6.

[0101] As shown in Figure 11, in this embodiment, the first planetary gear mechanism 3 is configured such that the rotational speeds of the first rotating element E1, the third rotating element E3, and the second rotating element E2 are in the order described. The second planetary gear mechanism 4 is configured such that the rotational speeds of the fourth rotating element E4, the fifth rotating element E5, and the sixth rotating element E6 are in the order described.

[0102] 6. Other Embodiments (1) In the above embodiment, the vehicle drive unit 100 was described as having a differential gear mechanism DF, and the differential gear mechanism DF was described as having a differential input gear G that meshes with an output gear 21 which is an output member 2. However, the vehicle drive unit 100 is not limited to such a configuration, and for example, the vehicle drive unit 100 may not have a differential gear mechanism DF, and the output member 2 may be an output shaft that rotates integrally with the wheel W.

[0103] (2) In the above embodiment, a configuration in which the first engagement mechanism 5 and the second engagement mechanism 6 are driven by a common drive mechanism 7 was described as an example. However, the invention is not limited to such a configuration, and the first engagement mechanism 5 and the second engagement mechanism 6 may be driven by separate drive mechanisms.

[0104] (3) The configurations disclosed in each of the embodiments described above can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. With regard to other configurations, the embodiments disclosed herein are merely illustrative in all respects. Therefore, various modifications can be made as appropriate without departing from the spirit of this disclosure.

[0105] 7. Summary of this embodiment The following describes the vehicle transmission (10) as explained above.

[0106] The vehicle transmission (10) is An input member (1) is connected to the drive source (D), An output member (2) is driven and connected to the wheel (W), A first planetary gear mechanism (3) comprising a first rotating element (E1), a second rotating element (E2), and a third rotating element (E3), A second planetary gear mechanism (4) comprising a fourth rotation element (E4), a fifth rotation element (E5), and a sixth rotation element (E6), First engagement mechanism (5), A vehicle transmission (10) comprising a second engagement mechanism (6), The first rotating element (E1) is connected to the input member (1) so as to rotate integrally with it. The third rotating element (E3) is connected to the output member (2) so as to rotate integrally with it. The first rotating element (E1) and the fourth rotating element (E4) are connected so as to rotate together as a single unit. The fifth rotating element (E5) is connected to the second rotating element (E2) or the third rotating element (E3) so as to rotate integrally with it. The first engagement mechanism (5) is configured to be able to change between an engaged state in which the second rotating element (E2) is fixed to the non-rotating member (NR) and a released state in which the second rotating element (E2) is rotatable. The second engagement mechanism (6) is configured to be able to change between an engaged state in which the sixth rotating element (E6) is fixed to the non-rotating member (NR), and a released state in which the sixth rotating element (E6) is rotatable. The first planetary gear mechanism (3), the second planetary gear mechanism (4), the first engagement mechanism (5), and the second engagement mechanism (6) are arranged coaxially. Let one side in the axial direction (L) be the axial first side (L1), and the other side in the axial direction (L) be the axial second side (L2), The first planetary gear mechanism (3) is positioned on the first axial side (L1) relative to the second planetary gear mechanism (4), The first engagement mechanism (5) and the second engagement mechanism (6) are arranged on the second axial side (L2) relative to the second planetary gear mechanism (4).

[0107] In this configuration, both the first engagement mechanism (5) and the second engagement mechanism (6) for achieving two-speed shifting are configured as brakes that fix the rotating element to the non-rotating member (NR). This makes it easier to simplify the power transmission structure in the engagement mechanism and ensure the durability of the engagement mechanism compared to the case where at least one of the first engagement mechanism (5) and the second engagement mechanism (6) is configured as a friction clutch that disconnects and reconnects the power transmission between the two rotating elements. Therefore, it is easier to miniaturize the vehicle transmission (10) while ensuring the durability of the vehicle transmission (10). Furthermore, in this configuration, the first planetary gear mechanism (3), the second planetary gear mechanism (4), the first engagement mechanism (5), and the second engagement mechanism (6) are arranged coaxially. This makes it easier to keep the radial (R) dimension of the vehicle transmission (10) small. Furthermore, in this configuration, the first planetary gear mechanism (3) is positioned on the first axial side (L1) relative to the second planetary gear mechanism (4), and the first engagement mechanism (5) and the second engagement mechanism (6) are positioned on the second axial side (L2) relative to the second planetary gear mechanism (4). This makes it easier to simplify the configuration for connecting the first rotating element (E1) of the first planetary gear mechanism (3) to the input member (1), and for connecting the third rotating element (E3) of the first planetary gear mechanism (3) to the output member (2). Therefore, it is easier to miniaturize the vehicle transmission (10).

[0108] Here, it is preferable that the first planetary gear mechanism (3) and the second planetary gear mechanism (4) are configured such that, when the first engagement mechanism (5) is in a disengaged state, the second engagement mechanism (6) is engaged, and the input member (1) is rotating, the rotation directions of the second rotating element (E2) and the third rotating element (E3) are opposite.

[0109] With this configuration, in a gear shift stage (S1) where the first engagement mechanism (5) is in a disengaged state and the second engagement mechanism (6) is in an engaged state, the rotation of the input member (1) can be reduced by a large reduction ratio and transmitted to the output member (2).

[0110] Furthermore, the first engagement mechanism (5) and the second engagement mechanism (6) are arranged side by side in the axial direction (L) and are driven by a common drive mechanism (7). The drive mechanism (7) includes an engaging member (71) that operates to selectively engage either the first engaging mechanism (5) or the second engaging mechanism (6), and a drive device (72) that outputs a driving force to move the engaging member (71) in the axial direction (L). By driving the engaging member (71) toward either side of the axial direction (L) using the driving force of the drive device (72), the first engaging mechanism (5) is engaged and the second engaging mechanism (6) is released. Preferably, the driving force of the drive device (72) drives the engaging member (71) toward the other side of the axial direction (L), thereby releasing the first engaging mechanism (5) and engaging the second engaging mechanism (6).

[0111] With this configuration, the first engagement mechanism (5) and the second engagement mechanism (6) can be driven by a common drive mechanism (7), making it easier to miniaturize and reduce the cost of the vehicle transmission (10).

[0112] Furthermore, the first rotating element (E1) and the fourth rotating element (E4) are sun gears (SG1, SG2), The second rotating element (E2) and the fifth rotating element (E5) are carriers (CR1, CR2), The third rotating element (E3) and the sixth rotating element (E6) are internally toothed ring gears (RG1, RG2), The output member (2) is preferably an external-toothed output gear (21) positioned radially (R) outward from the third rotating element (E3) and overlapping with the third rotating element (E3) in a radial view along the radial direction (R).

[0113] This configuration makes it possible to realize a vehicle transmission (10) having a gear stage (S1) with a relatively large reduction ratio achieved by combining the first planetary gear mechanism (3) and the second planetary gear mechanism (4), and a gear stage (S2) with a relatively small reduction ratio achieved by the first planetary gear mechanism (3) alone. Furthermore, according to this configuration, the output member is an externally toothed output gear (21) positioned radially (R) outward from the third rotating element (E3), which is an internally toothed ring gear (RG1), and overlapping with the third rotating element (E3) in a radial view. This makes it easier to keep the axial (L) dimension of the vehicle transmission (10) small. [Industrial applicability]

[0114] The technology disclosed herein can be used in a vehicle transmission comprising an input member driven to a drive source, an output member driven to a wheel, a planetary gear mechanism, and an engagement mechanism. [Explanation of symbols]

[0115] 10: Vehicle transmission, 1: Input member, 2: Output member, 21: Output gear, 3: First planetary gear mechanism, E1: First rotating element, E2: Second rotating element, E3: Third rotating element, SG1: First sun gear, CR1: First carrier, RG1: First ring gear, 4: Second planetary gear mechanism, E4: Fourth rotating element, E5: Fifth rotating element, E6: Sixth rotating element, SG2: Second sun gear, CR2: Second carrier, RG2: Second ring gear, 5: First engagement mechanism, 6: Second engagement mechanism, 7: Drive mechanism, 71: Engaging member, 72: Drive device, NR: Non-rotating member, D: Drive source, W: Wheel, L: Axial direction, L1: First axial side, L2: Second axial side, R: Radial direction

Claims

1. An input member connected to a drive source, An output member that is driven and connected to the wheel, A first planetary gear mechanism comprising a first rotating element, a second rotating element, and a third rotating element, A second planetary gear mechanism comprising a fourth rotation element, a fifth rotation element, and a sixth rotation element, First engagement mechanism, A vehicle transmission comprising a second engagement mechanism, The first rotating element is connected to the input member so as to rotate integrally with it. The third rotating element is connected to the output member so as to rotate integrally with it. The first rotating element and the fourth rotating element are connected so as to rotate as a whole. The fifth rotating element is connected to the second rotating element or the third rotating element so as to rotate integrally with it. The first engagement mechanism is configured to be able to change between an engaged state in which the second rotating element is fixed to the non-rotating member and a released state in which the second rotating element is rotatable. The second engagement mechanism is configured to be able to change between an engaged state in which the sixth rotating element is fixed to the non-rotating member and a released state in which the sixth rotating element is rotatable. The first planetary gear mechanism, the second planetary gear mechanism, the first engagement mechanism, and the second engagement mechanism are arranged coaxially. One side in the axial direction is designated as the first axial side, and the other side in the axial direction is designated as the second axial side. The first planetary gear mechanism is positioned on the first axial side relative to the second planetary gear mechanism. A vehicle transmission in which the first engagement mechanism and the second engagement mechanism are arranged on the second axial side with respect to the second planetary gear mechanism.

2. The vehicle transmission according to claim 1, wherein the first planetary gear mechanism and the second planetary gear mechanism are configured such that, when the first engagement mechanism is in a disengaged state, the second engagement mechanism is in an engaged state, and the input member is rotating, the directions of rotation of the second rotating element and the third rotating element are opposite.

3. The first engagement mechanism and the second engagement mechanism are arranged side by side in the axial direction and are driven by a common drive mechanism. The drive mechanism comprises an engaging member that operates to selectively engage either the first engaging mechanism or the second engaging mechanism, and a drive device that outputs a driving force for moving the engaging member in the axial direction. By driving the engaging member toward either side of the axial direction using the driving force of the drive device, the first engaging mechanism is put into an engaged state, and the second engaging mechanism is put into a disengaged state. The vehicle transmission according to claim 1 or 2, wherein the engaging member is driven toward the other side of the axial direction by the driving force of the drive device, thereby disengaging the first engaging mechanism and engaging the second engaging mechanism.

4. The first and fourth rotating elements are sun gears, The second and fifth rotating elements are carriers, The third and sixth rotating elements are internally geared ring gears. The vehicle transmission according to claim 1 or 2, wherein the output member is an external-toothed output gear positioned radially outward with respect to the third rotating element and overlapping with the third rotating element in a radial view along the radial direction.

Images