Vehicle transmission

Abstract

A planetary gear mechanism (P) comprises a first rotating element (E1), a second rotating element (E2), and a third rotating element (E3). The first rotating element (E1) rotates integrally with an input member (I), and the second rotating element (E2) rotates integrally with an output member (O). A switching mechanism (S) comprises: a fourth rotating element (E4) that is disposed on a first axis (X1) on which the planetary gear mechanism (P) is disposed, and rotates integrally with the first rotating element (E1) or the second rotating element (E2); a fifth rotating element (E5) that is disposed on a second axis (X2) different from the first axis (X1), and rotates in an interlocking manner with the third rotating element (E3); a sixth rotating element (E6) that is disposed on the second axis (X2), and rotates in an interlocking manner with the fourth rotating element (E4); a first engagement mechanism (3) that connects and disconnects transmission of power between the fifth rotating element (E5) and the sixth rotating element (E6); and a second engagement mechanism (4) that selectively fixes the fifth rotating element (E5) to a non-rotating member (NR).

Description

Technical Field

[0001] The present invention relates to a vehicle transmission provided with an input member drivingly connected to a drive source, an output member drivingly connected to a wheel, a planetary gear mechanism, and a switching mechanism for switching the state of the planetary gear 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, the reference numerals in Patent Document 1 are cited within parentheses.

[0003] In the vehicle transmission disclosed in Patent Document 1, the planetary gear mechanism (22) includes a sun gear (51a), a carrier (55), a first ring gear (53), and a second ring gear (54). The carrier (55) supports a large-diameter pinion gear (52a) that meshes with both the sun gear (51a) and the first ring gear (53), and a small-diameter pinion gear (52b) that meshes with the second ring gear (54) so that they rotate integrally.

[0004] The switching mechanism (23) includes a first engagement mechanism (23a) for disconnecting and connecting between the first ring gear (53) and a non-rotating member (42), and a second engagement mechanism (23b) for disconnecting and connecting between the second ring gear (54) and the non-rotating member (42). When the first engagement mechanism (23a) is in the released state and the second engagement mechanism (23b) is in the engaged state, a first gear stage (low speed stage) with a relatively large gear ratio is formed. When the first engagement mechanism (23a) is in the engaged state and the second engagement mechanism (23b) is in the released state, a second gear stage (high speed stage) with a relatively small gear ratio is formed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] In the vehicle transmission disclosed in Patent Document 1, the first engagement mechanism (23a) and the second engagement mechanism (23b) are coaxial with the planetary gear mechanism (22) and are arranged radially outward relative to the planetary gear mechanism (22). As a result, the radial dimensions of the first engagement mechanism (23a) and the second engagement mechanism (23b) tend to be large, and consequently, the overall size of the vehicle transmission tends to increase radially.

[0007] Therefore, in a configuration that includes a planetary gear mechanism and a switching mechanism for switching the state of the planetary gear mechanism, it is desirable to realize a vehicle transmission in which at least a part of it can be easily miniaturized in the radial direction. [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 planetary gear mechanism comprising a first rotating element, a second rotating element, and a third rotating element, configured such that the rotational speeds of the first rotating element, the second rotating element, and the third rotating element are in the order described above, A vehicle transmission comprising a switching mechanism for switching the state of the planetary gear mechanism, The first rotating element is connected to the input member so as to rotate integrally with it. The second rotating element is connected to the output member so as to rotate integrally with it. The aforementioned switching mechanism is A fourth rotating element is positioned on the first axis, which is the axis on which the planetary gear mechanism is arranged, and is connected to the first rotating element or the second rotating element so as to rotate integrally with it. A fifth rotating element is positioned on a second axis, which is a different axis from the first axis, and rotates in conjunction with the third rotating element, A sixth rotating element is positioned on the second axis and rotates in conjunction with the fourth rotating element, A first engagement mechanism for disconnecting and connecting power transmission between the fifth rotating element and the sixth rotating element, The distinguishing feature is the inclusion of a second engagement mechanism for selectively fixing the fifth rotating element to a non-rotating member.

[0009] With this characteristic configuration, by engaging the first engagement mechanism and disengaging the second engagement mechanism, the fifth and sixth rotating elements rotate together, and a first gear stage can be formed that reduces the rotation of the input member and transmits it to the output member while the ratio of the rotational speeds of the first and third rotating elements remains constant. Furthermore, by disengaging the first engagement mechanism and engaging the second engagement mechanism, the fifth rotating element is fixed to the non-rotating member, and a second gear stage can be formed that reduces the rotation of the input member and transmits it to the output member. Furthermore, according to this characteristic configuration, the first rotating element of the planetary gear mechanism is connected to rotate integrally with the input member, and the second rotating element of the planetary gear mechanism is connected to rotate integrally with the output member. Therefore, the input member and the output member are arranged on the first axis. The fifth and sixth rotating elements of the switching mechanism are arranged on the second axis. The first engagement mechanism of the switching mechanism disconnects and connects the power transmission between the fifth and sixth rotating elements, and the second engagement mechanism of the switching mechanism is configured to selectively fix the fifth rotating element to the non-rotating member. Thus, with this characteristic configuration, an input member and output member arranged coaxially with the planetary gear mechanism, and a switching mechanism, part of which is arranged on a different axis from the planetary gear mechanism, can be used to selectively form the first and second gear stages. Therefore, in a configuration that includes a planetary gear mechanism and a switching mechanism for switching the state of the planetary gear mechanism, it is easier to miniaturize at least a part of the vehicle transmission in the radial direction. [Brief explanation of the drawing]

[0010] [Figure 1] Cross-sectional view of a vehicle drive system equipped with a vehicle transmission according to the first embodiment. [Figure 2] Skeleton diagram of a vehicle drive system equipped with a vehicle transmission according to the first embodiment. [Figure 3] Partial enlarged view of a cross-sectional view of a vehicle transmission according to the first embodiment [Figure 4] Velocity diagram of the planetary gear mechanism of a vehicle transmission according to the first embodiment [Figure 5] Cross-sectional view of a vehicle drive device equipped with a vehicle transmission according to the second embodiment [Figure 6] Skeleton diagram of a vehicle drive device equipped with a vehicle transmission according to the second embodiment [Figure 7] Cross-sectional view of a vehicle drive device equipped with a vehicle transmission according to the third embodiment [Figure 8] Skeleton diagram of a vehicle drive device equipped with a vehicle transmission according to the third embodiment [Figure 9] Cross-sectional view of a vehicle drive device equipped with a vehicle transmission according to the fourth embodiment [Figure 10] Skeleton diagram of a vehicle drive device equipped with a vehicle transmission according to the fourth embodiment [Figure 11] Partial enlarged view of a cross-sectional view of a vehicle transmission according to the fourth embodiment [Figure 12] Cross-sectional view of a vehicle drive device equipped with a vehicle transmission according to the fifth embodiment [Figure 13] Skeleton diagram of a vehicle drive device equipped with a vehicle transmission according to the fifth embodiment [Figure 14] Cross-sectional view of a vehicle drive device equipped with a vehicle transmission according to the sixth and seventh embodiments [Figure 15] Cross-sectional view of a vehicle drive device equipped with a vehicle transmission according to the sixth embodiment [Figure 16] Skeleton diagram of a vehicle drive device equipped with a vehicle transmission according to the sixth embodiment <00,00094>Cross-sectional view of a vehicle drive device equipped with a vehicle transmission according to the seventh embodiment [Figure 18] Skeleton diagram of a vehicle drive device equipped with a vehicle transmission according to the seventh embodiment

Embodiments for Carrying Out the Invention

[0011] 1. First Embodiment In the following description, a vehicle transmission 10 according to the first embodiment will be explained with reference to Figures 1 to 4. The vehicle transmission 10 is provided in the vehicle drive unit 100.

[0012] As shown in Figures 1 and 2, in this embodiment, the vehicle drive unit 100 includes, in addition to the vehicle transmission 10, a rotating electric machine MG as a drive source, and a case CS (see Figure 1) that houses the vehicle transmission 10 and the rotating electric machine MG.

[0013] The vehicle transmission 10 includes an input member I that is driven and connected to a drive source (in this case, a rotating electric machine MG), an output member O that is driven and connected to a wheel W (see Figure 2), a planetary gear mechanism P, and a switching mechanism S that switches the state of the planetary gear mechanism P. In this embodiment, the vehicle transmission 10 further includes a differential gear mechanism DF that distributes the rotation transmitted from the rotating electric machine MG to a pair of wheels W.

[0014] 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 the planetary gear mechanism P, it refers to a state in which they are connected to each other without the need for other rotating elements.

[0015] In the following explanation, the direction along the first axis X1, which is the axis on which the planetary gear mechanism P is located, will be referred to as the "axial direction L". One side of the axial direction L will be referred to as the "first axial direction L1", and the other side of the axial direction L will be referred to as the "second axial direction L2". Furthermore, the direction perpendicular to each of the multiple axes, including the first axis X1, will be referred to as the "radial direction R" relative to each axis. Note that if it is not necessary to distinguish which axis is the reference axis, or if it is clear which axis is the reference axis, it may simply be written as "radial direction R".

[0016] The rotating electric machine MG comprises a stator ST and a rotor RT. The stator ST is fixed to a non-rotating member NR. In this embodiment, the stator ST is fixed to a case CS which is the non-rotating member NR. The rotor RT is rotatably supported relative to the stator ST. In this embodiment, the rotating electric machine MG is positioned on a first axis X1. The rotating electric machine MG is positioned axially on the first side L1 with respect to the planetary gear mechanism P.

[0017] In this application, the term "rotating electric machine" is used as a concept that includes motors, generators, and motor-generators that perform both motor and generator functions as needed.

[0018] The input member I is positioned on the first axis X1. In this embodiment, the input member I is a rotor shaft 1 connected to the rotor RT so as to rotate integrally with it. The rotor shaft 1 is a shaft member formed to extend along the axial direction L. In this embodiment, the rotor shaft 1 is formed in a cylindrical shape with the first axis X1 as its axis.

[0019] The planetary gear mechanism P comprises a first rotating element E1, a second rotating element E2, and a third rotating element E3. The planetary gear mechanism P 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. The planetary gear mechanism P functions as a reducer that reduces the rotation of the input member I and transmits it to the output member O.

[0020] 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 rotational state of the planetary gear mechanism P, 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 P. 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 4). 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 P.

[0021] The first rotating element E1 is connected to the input member I so as to rotate integrally with it. The second rotating element E2 is connected to the output member O so as to rotate integrally with it. In this embodiment, the first rotating element E1 is a sun gear SG, the second rotating element E2 is a carrier CR, and the third rotating element E3 is an internally toothed ring gear RG.

[0022] In this embodiment, the planetary gear mechanism P is a single-pinion type planetary gear mechanism. Therefore, the pinion gear PG, which is rotatably supported by the carrier CR, meshes with both the sun gear SG and the ring gear RG. The pinion gear PG rotates (rotates) around its axis and also rotates (revolves) around the first axis X1 together with the carrier CR. Multiple pinion gears PG are provided spaced apart from each other along their orbital trajectory.

[0023] In this embodiment, the differential gear mechanism DF is located on the first axis X1. Furthermore, in this embodiment, the differential gear mechanism DF is a bevel gear type differential gear mechanism comprising a differential case 21, a pair of differential pinion gears 22, a first side gear 23 and a second side gear 24.

[0024] The differential case 21 houses a pair of differential pinion gears 22, as well as a first side gear 23 and a second side gear 24. The differential case 21 is rotatably supported relative to the case CS. In this embodiment, the differential case 21 is connected to rotate integrally with the second rotating element E2 (here, the carrier CR) of the planetary gear mechanism P. In other words, in this embodiment, the differential case 21 functions as the output member O.

[0025] The pair of differential pinion gears 22 are arranged facing each other in the radial direction R. The pair of differential pinion gears 22 are mounted on a pinion shaft 22a that is supported to rotate integrally with the differential case 21. Each of the pair of differential pinion gears 22 is configured to be rotatable (rotate) about the pinion shaft 22a and to be rotatable (revolve) about the rotation axis of the differential case 21 (in this case, the first axis X1).

[0026] The first side gear 23 and the second side gear 24 mesh with a pair of differential pinion gears 22. The first side gear 23 is positioned on the first axial side L1 with respect to the pinion shaft 22a. The second side gear 24 is positioned on the second axial side L2 with respect to the pinion shaft 22a.

[0027] In this embodiment, the first side gear 23 is connected to the first wheel connecting shaft 25 so as to rotate integrally with it. The first wheel connecting shaft 25 is a shaft member that rotates integrally with the wheel W on the first axial side L1 via the drive shaft. The first wheel connecting shaft 25 is arranged to extend from the first side gear 23 to the first axial side L1. In this embodiment, the first wheel connecting shaft 25 is located on the first axis X1. The first wheel connecting shaft 25 is located radially R inward from the rotor shaft 1 so as to penetrate the rotor shaft 1 in the axial direction L.

[0028] Furthermore, in this embodiment, the second side gear 24 is connected to the second wheel connecting shaft 26 so as to rotate integrally with it. The second wheel connecting shaft 26 is a shaft member that rotates integrally with the wheel W on the second axial side L2 via the drive shaft. The second wheel connecting shaft 26 is arranged to extend from the second side gear 24 to the second axial side L2. In this embodiment, the second wheel connecting shaft 26 is located on the first axis X1.

[0029] The switching mechanism S comprises a fourth rotating element E4, a fifth rotating element E5, a sixth rotating element E6, a first engaging mechanism 3, and a second engaging mechanism 4.

[0030] The fourth rotating element E4 is positioned on the first axis X1. The fourth rotating element E4 is connected to the first rotating element E1 or the second rotating element E2 of the planetary gear mechanism P so as to rotate integrally with it. In this embodiment, the fourth rotating element E4 is connected to the first rotating element E1 so as to rotate integrally with it. In this embodiment, the fourth rotating element E4 is the first gear G1. In this embodiment, the first gear G1 is an external gear positioned adjacent to the sun gear SG, which is the first rotating element E1, on the first axial side L1. In the example shown in Figure 1, the first gear G1 and the sun gear SG are formed on the outer circumferential surface of the rotor shaft 1. Also, the first gear G1 and the sun gear SG are formed to the same diameter.

[0031] The fifth rotating element E5 is positioned on the second axis X2, which is a different axis from the first axis X1. The fifth rotating element E5 is configured to rotate in conjunction with the third rotating element E3 of the planetary gear mechanism P. Here, with respect to the two rotating elements, "rotating in conjunction" includes both configurations in which they rotate at the same speed as each other and configurations in which they rotate synchronously with a constant gear ratio. In this example, the second axis X2 is positioned parallel to the first axis X1.

[0032] In this embodiment, the fifth rotating element E5 is the second gear G2. The second gear G2 is configured to mesh with the fourth gear G4. The fourth gear G4 is an external gear that rotates integrally with the ring gear RG, which is the third rotating element E3. In this embodiment, the fourth gear G4 is positioned outside the ring gear RG in the radial direction R and overlaps with the ring gear RG in a radial view along the radial direction R. Alternatively, the fourth gear G4 may be positioned offset from the ring gear RG in the axial direction L. In this case, the fourth gear G4 may be positioned overlapping with the ring gear RG in an axial view along the axial direction L, or it may be positioned inside the ring gear RG in the radial direction R. Here, regarding the arrangement of the two elements, "overlapping in a specific direction" means that when a virtual line parallel to the line of sight is moved in each direction perpendicular to the virtual line, there is at least a portion of the region where the virtual line intersects both elements.

[0033] The sixth rotating element E6 is positioned on the second axis X2. The sixth rotating element E6 is configured to rotate in conjunction with the fourth rotating element E4. In this embodiment, the sixth rotating element E6 is the third gear G3. The third gear G3 is configured to mesh with the first gear G1, or with a gear that meshes with the first gear G1. In this embodiment, the third gear G3 meshes with the first idler gear IG1, which meshes with the first gear G1. In other words, in this embodiment, the third gear G3 and the first gear G1 mesh with the first idler gear IG1 at mutually different positions in the circumferential direction of the first idler gear IG1. Also, in this embodiment, the third gear G3 is positioned adjacent to the second gear G2 on the first axial side L1.

[0034] The first engagement mechanism 3 is configured to disconnect and reconnect power transmission between the fifth rotating element E5 and the sixth rotating element E6. The second engagement mechanism 4 is configured to selectively fix the fifth rotating element E5 to the non-rotating member NR. In this embodiment, the first engagement mechanism 3 and the second engagement mechanism 4 are arranged side by side on the second axis X2. In the example shown in Figure 1, the first engagement mechanism 3 is positioned adjacent to the second engagement mechanism 4 on the first axial side L1. Also in this embodiment, the first engagement mechanism 3 and the second engagement mechanism 4 are positioned on the second axial side L2 with respect to the second gear G2.

[0035] As shown in Figure 3, the first engagement mechanism 3 comprises a first engagement element 31 and a second engagement element 32 configured to engage with each other. The second engagement mechanism 4 comprises a third engagement element 41 and a fourth engagement element 42 configured to engage with each other.

[0036] In this embodiment, the first engagement mechanism 3 and the second engagement mechanism 4 are both friction-type engagement mechanisms. The 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.

[0037] In this embodiment, the first engaging element 31 and the second engaging element 32 are arranged to face each other in the axial direction L. The first engaging element 31 and the second engaging element 32 engage with each other by friction when pressed against each other in the axial direction L. In addition, multiple first engaging elements 31 and second engaging elements 32 are provided, and these are arranged alternately along the axial direction L.

[0038] In this embodiment, the third engaging element 41 and the fourth engaging element 42 are arranged to face each other in the axial direction L. The third engaging element 41 and the fourth engaging element 42 engage with each other by friction when pressed against each other in the axial direction L. Multiple third engaging elements 41 and multiple fourth engaging elements 42 are provided, and these are arranged alternately along the axial direction L.

[0039] In this embodiment, the first engagement mechanism 3 further comprises a first support member 33 that supports the first engagement element 31 and a second support member 34 that supports the second engagement element 32.

[0040] The first support member 33 supports the first engaging element 31 so that it can slide in the axial direction L, and rotates integrally with the first engaging element 31. In this embodiment, the first support member 33 is formed in a cylindrical shape with the second axis X2 as its axis. The first support member 33 supports the first engaging element 31 from the outside in the radial direction R. In this example, multiple spline teeth extending in the axial direction L are formed on the inner circumference of the first support member 33, distributed in the circumferential direction. On the other hand, similar spline teeth are also formed on the outer circumference of the first engaging element 31, distributed in the circumferential direction. These spline teeth are engaged with each other.

[0041] The second support member 34 supports the second engaging element 32 so that it can slide in the axial direction L, and rotates integrally with the second engaging element 32. In this embodiment, the second support member 34 is coaxial with the first support member 33 and is formed in a cylindrical shape with a smaller diameter than the first support member 33. The second support member 34 supports the second engaging element 32 from the inside in the radial direction R. In this example, a plurality of spline teeth extending in the axial direction L are formed on the outer circumference of the second support member 34 and are dispersed in the circumferential direction. On the other hand, similar spline teeth are also formed on the inner circumference of the second engaging element 32 and are dispersed in the circumferential direction. These spline teeth are engaged with each other.

[0042] As shown in Figures 1 and 2, the first support member 33 is connected to the fifth rotating element E5 so as to rotate integrally with it. In this embodiment, the first support member 33 is connected to the second gear G2, which is the fifth rotating element E5, via the first connecting shaft 35. The first connecting shaft 35 is a shaft member that extends along the axial direction L. In this embodiment, the first connecting shaft 35 is formed in a cylindrical shape with the second axis X2 as its axis.

[0043] The second support member 34 is connected to the sixth rotating element E6 so as to rotate integrally with it. In this embodiment, the second support member 34 is connected to the third gear G3, which is the sixth rotating element E6, via the second connecting shaft 36. The second connecting shaft 36 is a shaft member that extends along the axial direction L. In this embodiment, the second connecting shaft 36 is located on the second axis X2. The second connecting shaft 36 is located radially R inward of the first connecting shaft 35 so as to penetrate the first connecting shaft 35 in the axial direction L.

[0044] When the first engaging element 31 and the second engaging element 32 are engaged without differential rotation and the first engaging mechanism 3 is in a direct engagement state, the fifth rotating element E5 and the sixth rotating element E6 rotate together. On the other hand, when the first engaging element 31 and the second engaging element 32 are not engaged with each other and the first engaging mechanism 3 is in a disengaged state, or when the first engaging element 31 and the second engaging element 32 are engaged with differential rotation and the first engaging mechanism 3 is in a slip engagement state, the fifth rotating element E5 and the sixth rotating element E6 rotate relative to each other.

[0045] As shown in Figure 3, in this embodiment, the second engagement mechanism 4 further comprises a third support member 43 that supports the third engagement element 41 and a fourth support member 44 that supports the fourth engagement element 42.

[0046] The third support member 43 supports the third engaging element 41 so that it can slide in the axial direction L, and rotates integrally with the third engaging element 41. In this embodiment, the third support member 43 is formed in a cylindrical shape with the second axis X2 as its axis. The third support member 43 supports the third engaging element 41 from the outside in the radial direction R. In this example, multiple spline teeth extending in the axial direction L are formed on the inner circumference of the third support member 43, distributed in the circumferential direction. On the other hand, similar spline teeth are also formed on the outer circumference of the third engaging element 41, distributed in the circumferential direction. These spline teeth are engaged with each other.

[0047] The fourth support member 44 supports the fourth engagement element 42 so that it cannot rotate relative to it in the circumferential direction and can slide in the axial direction L. In this embodiment, the fourth support member 44 is coaxial with the third support member 43 and is formed in a cylindrical shape with a smaller diameter than the third support member 43. The fourth support member 44 supports the fourth engagement element 42 from the inside in the radial direction R. In this example, multiple spline teeth extending in the axial direction L are formed on the outer circumference of the fourth support member 44 and are dispersed in the circumferential direction. On the other hand, similar spline teeth are also formed on the inner circumference of the fourth engagement element 42 and are dispersed in the circumferential direction. These spline teeth are engaged with each other.

[0048] The third support member 43 is connected to the fifth rotating element E5 so as to rotate integrally with it. In this embodiment, the third support member 43 is connected to the first support member 33 so as to rotate integrally with it. Therefore, in this embodiment, the third engaging element 41 supported by the third support member 43 and the first engaging element 31 supported by the first support member 33 rotate integrally with each other.

[0049] The fourth support member 44 is fixed to the non-rotating member NR. In this embodiment, the case CS, which is the non-rotating member NR, includes a first support wall portion 91 formed to extend along the radial direction R. The fourth support member 44 is fixed to the first support wall portion 91. In the example shown in Figure 3, the first support wall portion 91 is positioned to cover the second engagement mechanism 4 from the axial second side L2. The fourth support member 44 is formed to protrude from the first support wall portion 91 in the axial first side L1.

[0050] When the third engaging element 41 and the fourth engaging element 42 are engaged without differential rotation and the second engaging mechanism 4 is in a direct engagement state, the fifth rotating element E5 is fixed to the non-rotating member NR. On the other hand, when the third engaging element 41 and the fourth engaging element 42 are not engaged with each other and the second engaging mechanism 4 is in a disengaged state, or when the third engaging element 41 and the fourth engaging element 42 are engaged with differential rotation and the second engaging mechanism 4 is in a slip engagement state, the fifth rotating element E5 rotates relative to the non-rotating member NR.

[0051] In the vehicle transmission 10 configured as described above, when the first engagement mechanism 3 is engaged (in this case, in a direct engagement state) and the second engagement mechanism 4 is disengaged, the fifth rotating element E5 and the sixth rotating element E6 rotate together, and a first gear stage S1 is formed that reduces the rotation of the input member I and transmits it to the output member O while the ratio of the rotational speeds of the first rotating element E1 and the third rotating element E3 remains constant. Furthermore, when the first engagement mechanism 3 is disengaged and the second engagement mechanism 4 is engaged (in this case, in a direct engagement state), the fifth rotating element E5 is fixed to the non-rotating member NR, and a second gear stage S2 is formed that reduces the rotation of the input member I and transmits it to the output member O.

[0052] As described above, the vehicle transmission 10 is An input member I is connected to a drive source (in this case, a rotating electric machine MG), An output member O is driven and connected to the wheel W, A planetary gear mechanism P comprising a first rotating element E1, a second rotating element E2, and a third rotating element E3, 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, A vehicle transmission 10 comprising a switching mechanism S for switching the state of a planetary gear mechanism P, The first rotating element E1 is connected to the input member I so as to rotate integrally with it. The second rotating element E2 is connected to the output member O so as to rotate integrally with it. The switching mechanism S is, A fourth rotating element E4 is positioned on the first axis X1, which is the axis on which the planetary gear mechanism P is located, and is connected to the first rotating element E1 or the second rotating element E2 so as to rotate integrally with it. A fifth rotational element E5 is positioned on a second axis X2, which is a different axis from the first axis X1, and rotates in conjunction with the third rotational element E3. A sixth rotation element E6 is positioned on the second axis X2 and rotates in conjunction with the fourth rotation element E4, A first engagement mechanism 3 disconnects and connects the power transmission between the fifth rotating element E5 and the sixth rotating element E6, The system includes a second engagement mechanism 4 that selectively fixes the fifth rotating element E5 to the non-rotating member NR.

[0053] With this configuration, by engaging the first engagement mechanism 3 and disengaging the second engagement mechanism 4, the fifth rotating element E5 and the sixth rotating element E6 rotate together, and a first gear stage S1 can be formed that reduces the rotation of the input member I and transmits it to the output member O while the ratio of the rotational speeds of the first rotating element E1 and the third rotating element E3 remains constant. Furthermore, by disengaging the first engagement mechanism 3 and engaging the second engagement mechanism 4, the fifth rotating element E5 is fixed to the non-rotating member NR, and a second gear stage S2 can be formed that reduces the rotation of the input member I and transmits it to the output member O. Furthermore, in this configuration, the first rotating element E1 of the planetary gear mechanism P is connected to rotate integrally with the input member I, and the second rotating element E2 of the planetary gear mechanism P is connected to rotate integrally with the output member O. Therefore, the input member I and the output member O are positioned on the first axis X1. The fifth rotating element E5 and the sixth rotating element E6 of the switching mechanism S are positioned on the second axis X2. The first engagement mechanism 3 of the switching mechanism S disconnects and connects the power transmission between the fifth rotating element E5 and the sixth rotating element E6, and the second engagement mechanism 4 of the switching mechanism S is configured to selectively fix the fifth rotating element E5 to the non-rotating member NR. Thus, with this configuration, the input member I and output member O arranged coaxially with the planetary gear mechanism P, and the switching mechanism S, part of which is arranged on a different axis from the planetary gear mechanism P, make it possible to selectively form a first gear stage S1 and a second gear stage S2. Therefore, in a configuration that includes a planetary gear mechanism P and a switching mechanism S for switching the state of the planetary gear mechanism P, it is easier to miniaturize at least a part of the vehicle transmission 10 in the radial direction R.

[0054] Furthermore, as described above, in this embodiment, the first rotating element E1 is a sun gear SG. The second rotational element E2 is the carrier CR, The third rotating element E3 is an internally geared ring gear RG. The switching mechanism S is, The first gear G1 as the fourth rotational element E4, The second gear G2 as the fifth rotation element E5, The third gear G3 as the sixth rotation element E6, It comprises a fourth gear G4 with external teeth that rotates integrally with the ring gear RG, The second gear G2 is configured to mesh with the fourth gear G4. The third gear G3 is configured to mesh with the first gear G1, or with a gear that meshes with the first gear G1 (in this case, the first idler gear IG1).

[0055] This configuration makes it possible to realize a vehicle transmission 10 with a small radial radius (R) using a simple design.

[0056] As shown in Figure 4, in this embodiment, with the first engagement mechanism 3 in the engaged state and the second engagement mechanism 4 in the disengaged state (i.e., the first gear stage S1 is formed), and the input member I is rotating, the power transmission path between the third rotating element E3 and the fifth rotating element E5, which rotates in conjunction with the third rotating element E3, is configured such that the third rotating element E3 rotates in the opposite direction to the first rotating element E1, and the power transmission path between the fourth rotating element E4, which is connected to rotate integrally with the first rotating element E1, and the sixth rotating element E6, which rotates in conjunction with the fourth rotating element E4. To elaborate, the gear ratio relationship between the power transmission path between the third rotating element E3 and the fifth rotating element E5 and the power transmission path between the fourth rotating element E4 and the sixth rotating element E6 is set such that, with the input member I rotating, the third rotating element E3 rotates in the opposite direction to the first rotating element E1.

[0057] In this configuration, the gear ratio of the first gear stage S1, formed when the first engagement mechanism 3 is engaged and the second engagement mechanism 4 is disengaged, is greater than the gear ratio of the second gear stage S2, formed when the first engagement mechanism 3 is disengaged and the second engagement mechanism 4 is engaged. Furthermore, in this configuration, the planetary gear mechanism P has a configuration in which the second gear stage S2 requires fewer rotating elements to constitute the power transmission path than the first gear stage S1. Therefore, the second gear stage S2, which is used more frequently when traveling at high speeds compared to the first gear stage S1, has higher power transmission efficiency. Consequently, this configuration makes it easier to improve the energy efficiency when driving a vehicle.

[0058] Figure 4 is a velocity diagram of the planetary gear mechanism P according to this embodiment. In the velocity diagram of Figure 4, the vertical lines correspond to the rotational speed of each rotating element of the planetary gear mechanism P. Each of the multiple vertical lines arranged in parallel corresponds to each rotating element of the planetary gear mechanism P. In addition, in the velocity diagram of Figure 4, the symbols shown above the multiple vertical lines are the symbols of the corresponding rotating elements of the planetary gear mechanism P. The symbols shown below the multiple vertical lines are the symbols of elements that rotate integrally with the rotating elements corresponding to the symbols shown above.

[0059] As shown in Figure 3, in this embodiment, the switching mechanism S further comprises a first drive mechanism 5. The first drive mechanism 5 is configured to drive both the first engagement mechanism 3 and the second engagement mechanism 4. In other words, the first engagement mechanism 3 and the second engagement mechanism 4 are driven by a common first drive mechanism 5. The first drive mechanism 5 comprises a first engagement member 51, a first drive motor 52, and a first linear motion conversion mechanism 53.

[0060] The first engaging member 51 is an "engaging member" that operates to selectively engage either the first engaging mechanism 3 or the second engaging mechanism 4. The first drive motor 52 is a "drive motor" that outputs a predetermined rotational driving force. The first linear motion conversion mechanism 53 is a screw-type "linear motion conversion mechanism" that converts the rotational driving force of the first drive motor 52 into a driving force in the direction along the second axis X2 (in this case, the axial direction L) and transmits it to the first engaging member 51.

[0061] In this embodiment, the first engaging member 51 includes a first pressing portion 511 and a second pressing portion 512.

[0062] The first pressing portion 511 is configured to press the first engaging element 31 and the second engaging element 32 of the first engaging mechanism 3 in the axial direction L. In this embodiment, the first pressing portion 511 is formed to extend along the radial direction R. The first pressing portion 511 is positioned to press the first engaging element 31 and the second engaging element 32 from the second axial side L2. In this embodiment, the first pressing portion 511 is supported by the first support member 33 of the first engaging mechanism 3 so as to be movable relative to it in the axial direction L, but not so as to be rotatable relative to it in the circumferential direction.

[0063] The second pressing portion 512 is configured to press the third engaging element 41 and the fourth engaging element 42 of the second engaging mechanism 4 in the axial direction L. In this embodiment, the second pressing portion 512 is formed to extend along the radial direction R. The second pressing portion 512 is positioned to press the third engaging element 41 and the fourth engaging element 42 from the first axial side L1. In this embodiment, the second pressing portion 512 is made of a separate component from the first pressing portion 511 and is positioned opposite the first pressing portion 511 in the axial direction L. The second pressing portion 512 is supported relative to the first pressing portion 511 via a thrust bearing B1 so as to be rotatable relative to it. Therefore, in this embodiment, the first pressing portion 511 and the second pressing portion 512 are configured to be interlocked in the axial direction L while being able to rotate relative to each other.

[0064] In this embodiment, the first linear motion conversion mechanism 53 includes a first screw shaft 54, a first nut member 55, and a first transmission mechanism 56.

[0065] The first screw shaft 54 ​​is rotatably supported with respect to the non-rotating member NR. Screw threads are formed on the outer circumference of the first screw shaft 54. The first screw shaft 54 ​​is formed to extend along the axial direction L. In this embodiment, the first screw shaft 54 ​​is positioned on the second axis X2. Furthermore, in this embodiment, the first screw shaft 54 ​​is positioned radially R inward from the fourth support member 44 of the second engagement mechanism 4, and overlaps with the fourth support member 44 in a radial view along the radial direction R.

[0066] The first nut member 55 is configured to be screwed onto the first screw shaft 54. That is, a groove is formed on the inner circumference of the first nut member 55 that engages with the threads of the first screw shaft 54. The first nut member 55 is supported so as to be relatively movable in the axial direction L with respect to the non-rotating member NR, but not so as to be relatively rotatable in the circumferential direction. In this embodiment, the first nut member 55 is positioned radially R inward with respect to the fourth support member 44. The first nut member 55 is connected to the fourth support member 44 by a first connecting member 55a positioned between the outer circumference of the first nut member 55 and the inner circumference of the fourth support member 44 in the radial direction R, so as to be relatively movable in the axial direction L with respect to the case CS, which is the non-rotating member NR, but with relative rotation restricted. In this way, the first nut member 55 performs linear motion along the axial direction L according to the direction of rotation and the orientation of the threads of the first screw shaft 54 ​​as the first screw shaft 54 ​​rotates.

[0067] In this embodiment, the first nut member 55 is connected to the second pressing portion 512 of the first engaging member 51 so as to move integrally with it in the axial direction L. In the example shown in Figure 3, the first nut member 55 and the second pressing portion 512 are integrally formed such that the second pressing portion 512 extends radially outward from the first nut member 55 in the radial direction R.

[0068] The first transmission mechanism 56 is configured to transmit the rotational driving force of the first drive motor 52 to the first screw shaft 54. In this embodiment, the first transmission mechanism 56 reduces the rotation of the first drive motor 52 and transmits it to the first screw shaft 54. In this embodiment, the first transmission mechanism 56 includes a first transmission gear 561 and a first connecting body 562.

[0069] The first transmission gear 561 is driven and connected to the first drive motor 52 via at least one gear (not shown). In this embodiment, the first transmission gear 561 is positioned on the second axis X2. The first transmission gear 561 is connected to the first coupling body 562 via a first shaft portion 563 so as to rotate integrally with it. The first shaft portion 563 is formed in an axial shape that extends along the axial direction L. In this embodiment, the first shaft portion 563 is formed to extend from the first transmission gear 561 toward the first axial side L1.

[0070] The first connecting body 562 connects the first transmission gear 561 and the first screw shaft 54 ​​so that they rotate together as a single unit. In this embodiment, the first connecting body 562 is connected so as to rotate together with the first screw shaft 54, with the first screw shaft 54 ​​protruding from the first connecting body 562 in the axial direction L1. In this embodiment, the first connecting body 562 is formed in a cylindrical shape with an opening on the axial direction second side L2. The first connecting body 562 is connected so as to rotate together with the first shaft portion 563, with the first shaft portion 563 positioned radially R inward relative to the first connecting body 562.

[0071] In this embodiment, when the first drive motor 52 rotates toward the first side, the rotational driving force of the first drive motor 52 is transmitted to the first screw shaft 54 ​​via the first transmission mechanism 56, and the first nut member 55 moves toward the first axial side L1. As described above, in this embodiment, a thrust bearing B1 is positioned between the first pressing portion 511 and the second pressing portion 512 in the axial direction L. Therefore, in this embodiment, when the first nut member 55 moves toward the first axial side L1, the second pressing portion 512 moves toward the first axial side L1 via the first nut member 55, and the first pressing portion 511 also moves toward the first axial side L1 via the thrust bearing B1. As a result, the first engaging element 31 and the second engaging element 32 are pressed by the first pressing part 511, and the first engaging mechanism 3 becomes engaged, while the pressing of the third engaging element 41 and the fourth engaging element 42 by the second pressing part 512 is released, and the second engaging mechanism 4 becomes disengaged.

[0072] On the other hand, when the first drive motor 52 rotates toward the second side opposite to the first side, the rotational driving force of the first drive motor 52 is transmitted to the first screw shaft 54 ​​via the first transmission mechanism 56, and the first nut member 55 moves toward the second side L2 in the axial direction. Consequently, the second pressing part 512 moves toward the second side L2 in the axial direction via the first nut member 55. As a result, the third engaging element 41 and the fourth engaging element 42 are pressed by the second pressing part 512, and the second engaging mechanism 4 becomes engaged, while the pressing of the first engaging element 31 and the second engaging element 32 by the first pressing part 511 is released, and the first engaging mechanism 3 becomes open.

[0073] Thus, in this embodiment, the first engagement mechanism 3 and the second engagement mechanism 4 are arranged side by side on the second axis X2 and are driven by a common first drive mechanism 5. The first drive mechanism 5 includes a first engaging member 51 that operates to selectively engage either the first engaging mechanism 3 or the second engaging mechanism 4, a first drive motor 52, and a screw-type first linear motion conversion mechanism 53 that converts the rotational driving force of the first drive motor 52 into a driving force in the direction along the second axis X2 (here, the axial direction L) and transmits it to the first engaging member 51. When the first drive motor 52 rotates toward the first side, the first engagement mechanism 3 is engaged and the second engagement mechanism 4 is released. When the first drive motor 52 rotates toward the second side opposite to the first side, the second engagement mechanism 4 is engaged and the first engagement mechanism 3 is released.

[0074] With this configuration, the first drive mechanism 5 that drives the first engagement mechanism 3 and the second engagement mechanism 4 is composed of a first drive motor 52 and a screw-type first linear motion conversion mechanism 53, making it easier to miniaturize the vehicle transmission 10 compared to when a hydraulic drive mechanism is used.

[0075] 2. Second Embodiment In the following description, the vehicle transmission 10 according to the second embodiment will be explained with reference to Figures 5 and 6. In this embodiment, the position of the differential gear mechanism DF is different 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.

[0076] As shown in Figures 5 and 6, in this embodiment, the differential gear mechanism DF is located on a third axis X3, which is a different axis from the first axis X1 and the second axis X2. The differential gear mechanism DF includes a differential input gear 28, which distributes the rotation of the differential input gear 28 to a pair of wheels W (see Figure 6). The differential input gear 28 is connected to rotate integrally with the differential case 21. The differential input gear 28 is formed to protrude radially outward from the differential case 21 in the direction R. In this embodiment, the differential input gear 28 meshes with an output gear 27 located on the first axis X1. In this example, the third axis X3 is located parallel to the first axis X1.

[0077] The output gear 27 is connected to the second rotating element E2 (here, the carrier CR) of the planetary gear mechanism P so as to rotate integrally with it. Therefore, in this embodiment, the output gear 27 functions as the output member O. In addition, in this embodiment, the output gear 27 is positioned adjacent to the planetary gear mechanism P on the second axial side L2.

[0078] Furthermore, in this embodiment, the first wheel connecting shaft 25 is not positioned radially inward relative to the rotor shaft 1, but rather in a region radially outward relative to the rotating electric machine MG. This allows the radial dimension R of the rotor shaft 1 to be kept small, and therefore the outer diameter of the sun gear SG provided on the rotor shaft 1 can also be kept small. Consequently, it is easier to secure a large reduction ratio for the planetary gear mechanism P.

[0079] 3. Third Embodiment In the following description, a vehicle transmission 10 according to the third embodiment will be explained with reference to Figures 7 and 8. In this embodiment, the configuration of the planetary gear mechanism P 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 principles apply as in the first embodiment.

[0080] As shown in Figures 7 and 8, in this embodiment, the pinion gear PG of the planetary gear mechanism P comprises a first gear portion PG1 that meshes with the sun gear SG and a second gear portion PG2 that meshes with the ring gear RG.

[0081] The first gear section PG1 and the second gear section PG2 are connected so as to rotate integrally with each other. In this embodiment, the first gear section PG1 is formed to have a larger diameter than the second gear section PG2. Furthermore, the first gear section PG1 is positioned axially on the first side L1 relative to the second gear section PG2.

[0082] 4. Fourth Embodiment In the following description, the vehicle transmission 10 according to the fourth embodiment will be explained with reference to Figures 9 to 11. In this embodiment, the configuration of the switching mechanism S 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.

[0083] As shown in Figures 9 and 10, in this embodiment, the switching mechanism S further comprises a friction-type third engagement mechanism 6 that selectively fixes the fourth rotating element E4 to the non-rotating member NR.

[0084] With this configuration, when shifting (upshifting) from a gear with a large gear ratio to a gear with a small gear ratio, where the rotational speed of the input member I is lower at the same vehicle speed, even if the drive source (in this case, the rotating electric machine MG) cannot output negative torque, the rotational speed of the input member I can be reduced by putting the third engagement mechanism 6 into a slip engagement state, thereby enabling a rapid gear change. Furthermore, with this configuration, by engaging either the first engagement mechanism 3 or the second engagement mechanism 4 with the third engagement mechanism 6, it can also function as a parking brake.

[0085] As shown in Figure 11, the third engagement mechanism 6 includes a fifth engagement element 61 and a sixth engagement element 62 configured to engage with each other. In this embodiment, the fifth engagement element 61 and the sixth engagement element 62 are arranged to face each other in the axial direction L. The fifth engagement element 61 and the sixth engagement element 62 engage with each other by friction when pressed against each other in the axial direction L. In addition, multiple fifth engagement elements 61 and sixth engagement elements 62 are provided, and these are arranged alternately along the axial direction L.

[0086] In this embodiment, the third engagement mechanism 6 is positioned on a fourth axis X4, which is a different axis from the first axis X1 to the third axis X3. Furthermore, in this embodiment, the third engagement mechanism 6 further comprises a fifth support member 63 that supports the fifth engagement element 61 and a sixth support member 64 that supports the sixth engagement element 62. In this example, the fourth axis X4 is positioned parallel to the first axis X1.

[0087] The fifth support member 63 supports the fifth engaging element 61 so that it can slide in the axial direction L, and rotates integrally with the fifth engaging element 61. In this embodiment, the fifth support member 63 is formed in a cylindrical shape with the fourth axis X4 as its axis. The fifth support member 63 supports the fifth engaging element 61 from the outside in the radial direction R. In this example, multiple spline teeth extending in the axial direction L are formed on the inner circumference of the fifth support member 63 and are dispersed in the circumferential direction. On the other hand, similar spline teeth are also formed on the outer circumference of the fifth engaging element 61 and are dispersed in the circumferential direction. These spline teeth are engaged with each other.

[0088] The sixth support member 64 supports the sixth engaging element 62 so that it can slide in the axial direction L, and rotates integrally with the sixth engaging element 62. In this embodiment, the sixth support member 64 is coaxial with the fifth support member 63 and is formed in a cylindrical shape with a smaller diameter than the fifth support member 63. The sixth support member 64 supports the sixth engaging element 62 from the inside in the radial direction R. In this example, a plurality of spline teeth extending in the axial direction L are formed on the outer circumference of the sixth support member 64 and are dispersed in the circumferential direction. On the other hand, similar spline teeth are also formed on the inner circumference of the sixth engaging element 62 and are dispersed in the circumferential direction. These spline teeth are engaged with each other.

[0089] As shown in Figures 9 and 10, the fifth support member 63 is connected to the fifth gear G5 so as to rotate integrally with it. The fifth gear G5 meshes with the second idler gear IG2, which meshes with the first gear G1, which is the fourth rotating element E4 connected to the first rotating element E1 of the planetary gear mechanism P so as to rotate integrally with it. In other words, the fifth gear G5 and the first gear G1 mesh with the second idler gear IG2 at mutually different positions in the circumferential direction of the second idler gear IG2. Also, the first idler gear IG1 and the second idler gear IG2 mesh with the first gear G1 at mutually different positions in the circumferential direction of the first gear G1. Therefore, the fifth gear G5 rotates in conjunction with the first rotating element E1 (here, the sun gear SG) of the planetary gear mechanism P.

[0090] In this embodiment, the fifth gear G5 is positioned on the fourth axis X4. Furthermore, the fifth gear G5 is positioned on the first axial side L1 with respect to the third engagement mechanism 6.

[0091] As shown in Figure 11, the sixth support member 64 is fixed to the non-rotating member NR. In this embodiment, the case CS, which is the non-rotating member NR, includes a second support wall portion 92 formed to extend along the radial direction R. The sixth support member 64 is fixed to the second support wall portion 92. In the example shown in Figure 11, the second support wall portion 92 is positioned to cover the third engagement mechanism 6 from the axial second side L2. The sixth support member 64 is formed to protrude from the second support wall portion 92 toward the axial first side L1.

[0092] When the fifth engaging element 61 and the sixth engaging element 62 are engaged without differential rotation and the third engaging mechanism 6 is in a direct engagement state, the fifth gear G5 is fixed to the non-rotating member NR. As a result, the first rotating element E1, which rotates in conjunction with the fifth gear G5, is fixed to the non-rotating member NR. On the other hand, when the fifth engaging element 61 and the sixth engaging element 62 are not engaged with each other and the third engaging mechanism 6 is in a disengaged state, or when the fifth engaging element 61 and the sixth engaging element 62 are engaged with differential rotation and the third engaging mechanism 6 is in a slip engagement state, the first rotating element E1 rotates relative to the non-rotating member NR.

[0093] As shown in Figure 11, in this embodiment, the switching mechanism S further includes a second drive mechanism 7 that drives the third engagement mechanism 6. The second drive mechanism 7 includes a second engagement member 71, a second drive motor 72, and a second linear motion conversion mechanism 73.

[0094] The second engaging member 71 is configured to switch the engagement state of the third engaging mechanism 6. The second drive motor 72 is configured to output a predetermined rotational driving force. The second linear motion conversion mechanism 73 is a screw-type linear motion conversion mechanism that converts the rotational driving force of the second drive motor 72 into a driving force in the direction along the fourth axis X4 (in this case, the axial direction L) and transmits it to the second engaging member 71.

[0095] In this embodiment, the second engaging member 71 is configured to press the fifth engaging element 61 and the sixth engaging element 62 in the axial direction L. In this embodiment, the second engaging member 71 is formed to extend along the radial direction R. The second engaging member 71 is positioned to press the fifth engaging element 61 and the sixth engaging element 62 from the first axial side L1.

[0096] In this embodiment, the second linear motion conversion mechanism 73 includes a second screw shaft 74, a second nut member 75, and a second transmission mechanism 76.

[0097] The second screw shaft 74 is rotatably supported with respect to the non-rotating member NR. Screw threads are formed on the outer circumference of the second screw shaft 74. The second screw shaft 74 is formed to extend along the axial direction L. In this embodiment, the second screw shaft 74 is located on the fourth axis X4. Furthermore, in this embodiment, the second screw shaft 74 is located radially R inward from the sixth support member 64 of the third engagement mechanism 6, and is positioned to overlap with the sixth support member 64 in a radial view along the radial direction R.

[0098] The second nut member 75 is configured to screw onto the second screw shaft 74. That is, a groove is formed on the inner circumference of the second nut member 75 that engages with the threads of the second screw shaft 74. The second nut member 75 is supported so as to be movable relative to the non-rotating member NR in the axial direction L, but not so as to be rotatable relative to the circumferential direction. In this embodiment, the second nut member 75 is positioned radially R inward relative to the sixth support member 64. The second nut member 75 is connected to the sixth support member 64 by a second connecting member 75a positioned between the outer circumference of the second nut member 75 and the inner circumference of the sixth support member 64 in the radial direction R, so as to be movable relative to the case CS, which is the non-rotating member NR, in the axial direction L, but with relative rotation restricted. In this way, the second 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 second screw shaft 74 as the second screw shaft 74 rotates.

[0099] In this embodiment, the second nut member 75 is connected to the second engaging member 71 so as to move integrally with it in the axial direction L. In the example shown in Figure 11, the second nut member 75 and the second engaging member 71 are integrally formed such that the second engaging member 71 extends radially outward from the second nut member 75 in the radial direction R.

[0100] The second transmission mechanism 76 is configured to transmit the rotational driving force of the second drive motor 72 to the second screw shaft 74. In this embodiment, the second transmission mechanism 76 reduces the rotation of the second drive motor 72 and transmits it to the second screw shaft 74. In this embodiment, the second transmission mechanism 76 includes a second transmission gear 761 and a second connecting body 762.

[0101] The second transmission gear 761 is driven and connected to the second drive motor 72 via at least one gear (not shown). In this embodiment, the second transmission gear 761 is located on the fourth axis X4. The second transmission gear 761 is connected to the second connecting body 762 via a second shaft portion 763 so as to rotate integrally with it. The second shaft portion 763 is formed in an axial shape that extends along the axial direction L. In this embodiment, the second shaft portion 763 is formed to extend from the second transmission gear 761 toward the first axial direction L1.

[0102] The second connecting body 762 connects the second transmission gear 761 and the second screw shaft 74 so that they rotate together as a single unit. In this embodiment, the second connecting body 762 is connected so that it rotates together with the second screw shaft 74, with the second screw shaft 74 protruding from the second connecting body 762 in the axial direction first side L1. In this embodiment, the second connecting body 762 is formed in a cylindrical shape with an opening on the axial direction second side L2. The second connecting body 762 is connected so that it rotates together with the second shaft portion 763, with the second shaft portion 763 positioned radially R inward relative to the second connecting body 762.

[0103] In this embodiment, when the second drive motor 72 rotates toward the first side, the rotational driving force of the second drive motor 72 is transmitted to the second screw shaft 74 via the second transmission mechanism 76, causing the second nut member 75 to move toward the first axial direction L1. Consequently, the second engaging member 71 also moves toward the first axial direction L1 via the second nut member 75. As a result, the pressure on the fifth engaging element 61 and the sixth engaging element 62 by the second engaging member 71 is released, and the third engaging mechanism 6 becomes open.

[0104] On the other hand, when the second drive motor 72 rotates toward the second side opposite to the first side, the rotational driving force of the second drive motor 72 is transmitted to the second screw shaft 74 via the second transmission mechanism 76, and the second nut member 75 moves toward the second side L2 in the axial direction. Consequently, the second engaging member 71 moves toward the second side L2 in the axial direction via the second nut member 75. As a result, the fifth engaging element 61 and the sixth engaging element 62 are pressed by the second engaging member 71, and the third engaging mechanism 6 becomes engaged.

[0105] 5. Fifth Embodiment In the following description, the vehicle transmission 10 according to the fifth embodiment will be explained with reference to Figures 12 and 13. The vehicle transmission 10 according to this embodiment differs from the vehicle transmission 10 according to the second embodiment in that it is equipped with the third engagement mechanism 6 of the fourth embodiment. In the following description, the differences from the second embodiment will be explained in detail. Points that are not specifically explained will be the same as those of the second embodiment.

[0106] As shown in Figures 12 and 13, in this embodiment, the fifth gear G5 meshes with the third idler gear IG3, which meshes with the first gear G1. In other words, the fifth gear G5 and the first gear G1 mesh with the third idler gear IG3 at different positions in the circumferential direction of the third idler gear IG3.

[0107] 6. Sixth Embodiment In the following description, a vehicle transmission 10 according to the sixth embodiment will be explained with reference to Figures 14 to 16. In this embodiment, the configuration of the planetary gear mechanism P and the switching mechanism S differs from that of the second embodiment. In the following description, the differences from the second embodiment will be the main focus. Unless otherwise specified, the same applies as in the second embodiment.

[0108] As shown in Figures 14 to 16, in this embodiment, the fourth rotating element E4 does not rotate integrally with the first rotating element E1, but is connected to rotate integrally with the second rotating element E2. In other words, in this embodiment, the first gear G1 does not rotate integrally with the sun gear SG, but is connected to rotate integrally with the carrier CR. Also, in this embodiment, the first gear G1 is an external gear that meshes with the differential input gear 28. In other words, the output gear 27 that rotates integrally with the carrier CR and meshes with the differential input gear 28 in the second embodiment is not provided in this embodiment. Therefore, in this embodiment, the first gear G1 as the fourth rotating element E4 functions as the output member O.

[0109] As shown in Figures 15 and 16, in this embodiment, the third gear G3 meshes with the first idler gear IG1, which meshes with the first gear G1. In other words, in this embodiment, the third gear G3 and the first gear G1 mesh with the first idler gear IG1 at different positions in the circumferential direction of the first idler gear IG1.

[0110] 7. Seventh Embodiment In the following description, the vehicle transmission 10 according to the seventh embodiment will be explained with reference to Figures 17 and 18. This embodiment shares the same configuration as the sixth embodiment as shown in Figure 14. On the other hand, the configuration of the switching mechanism S in this embodiment differs from that of the sixth embodiment. In the following description, the differences from the sixth embodiment will be explained in detail. Points that are not specifically explained are the same as those in the sixth embodiment.

[0111] As shown in Figures 17 and 18, in this embodiment, the first idler gear IG1 is not provided. The third gear G3 meshes with the differential input gear 28. Also in this embodiment, as in the sixth embodiment described above, the first gear G1 meshes with the differential input gear 28. Therefore, in this embodiment, the third gear G3 and the first gear G1 mesh with the differential input gear 28 at different positions in the circumferential direction of the differential input gear 28. In this embodiment, the differential input gear 28 corresponds to the "gear that meshes with the first gear G1".

[0112] 8. Other Embodiments (1) In the above embodiment, a configuration in which the third gear G3 meshes with the first idler gear IG1 which meshes with the first gear G1 was described as an example. However, the configuration is not limited to such a configuration, and the third gear G3 may mesh directly with the first gear G1. In this configuration, the first engagement mechanism 3 is in an engaged state, the second engagement mechanism 4 is in an unengaged state (i.e., the first gear stage S1 is formed), and the input member I is rotating, while the third rotating element E3 rotates in the same direction as the first rotating element E1. The gear ratio of the first gear stage S1 formed when the first engagement mechanism 3 is in an engaged state and the second engagement mechanism 4 is in an unengaged state is smaller than the gear ratio of the second gear stage S2 formed when the first engagement mechanism 3 is in an unengaged state and the second engagement mechanism 4 is in an engaged state.

[0113] (1) In the above embodiment, a configuration in which the drive source is a rotating electric machine MG was described as an example. However, the configuration is not limited to such a configuration, and for example, the drive source may be an internal combustion engine.

[0114] (2) In the above embodiment, a configuration in which the first linear motion conversion mechanism 53 and the second linear motion conversion mechanism 73 are each screw-type linear motion conversion mechanisms was described as an example. However, the invention is not limited to such a configuration, and for example, at least one of the first linear motion conversion mechanism 53 and the second linear motion conversion mechanism 73 may be configured to include a rail and a sliding member that slides along the rail.

[0115] (3) In the first embodiment described above, a configuration in which the planetary gear mechanism P is a single-pinion type planetary gear mechanism was explained as an example. However, the planetary gear mechanism P is not limited to such a configuration, and may be a double-pinion type planetary gear mechanism. In this case, for example, the first rotating element E1 may be a sun gear SG, the second rotating element E2 may be a ring gear RG, and the third rotating element E3 may be a carrier CR.

[0116] (4) 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.

[0117] [Summary of this embodiment] The following describes the vehicle transmission (10) as explained above.

[0118] The vehicle transmission (10) is An input member (I) is connected to a drive source (MG), An output member (O) is driven and connected to the wheel (W), A planetary gear mechanism (P) comprising a first rotating element (E1), a second rotating element (E2), and a third rotating element (E3), 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, A vehicle transmission (10) comprising a switching mechanism (S) for switching the state of the planetary gear mechanism (P), The first rotating element (E1) is connected to the input member (I) so as to rotate integrally with it. The second rotating element (E2) is connected to the output member (O) so as to rotate integrally with it. The aforementioned switching mechanism (S) is A fourth rotating element (E4) is positioned on the first axis (X1), which is the axis on which the planetary gear mechanism (P) is located, and is connected to the first rotating element (E1) or the second rotating element (E2) so as to rotate integrally with it. A fifth rotation element (E5) is positioned on a second axis (X2), which is a different axis from the first axis (X1), and rotates in conjunction with the third rotation element (E3), A sixth rotating element (E6) is positioned on the second axis (X2) and rotates in conjunction with the fourth rotating element (E4), A first engagement mechanism (3) disconnects and connects the power transmission between the fifth rotating element (E5) and the sixth rotating element (E6), The device comprises a second engagement mechanism (4) for selectively fixing the fifth rotating element (E5) to the non-rotating member (NR).

[0119] With this configuration, by engaging the first engagement mechanism (3) and disengaging the second engagement mechanism (4), the fifth rotating element (E5) and the sixth rotating element (E6) are made to rotate together, and a first gear stage (S1) can be formed that reduces the rotation of the input member (I) and transmits it to the output member (O) while the ratio of the rotational speeds of the first rotating element (E1) and the third rotating element (E3) remains constant. Furthermore, by disengaging the first engagement mechanism (3) and engaging the second engagement mechanism (4), the fifth rotating element (E5) is made to be fixed to the non-rotating member (NR), and a second gear stage (S2) can be formed that reduces the rotation of the input member (I) and transmits it to the output member (O). Furthermore, in this configuration, the first rotating element (E1) of the planetary gear mechanism (P) is connected to the input member (I) so as to rotate integrally with it, and the second rotating element (E2) of the planetary gear mechanism (P) is connected to the output member (O) so as to rotate integrally with it. Therefore, the input member (I) and the output member (O) are arranged on the first axis (X1). In addition, the fifth rotating element (E5) and the sixth rotating element (E6) of the switching mechanism (S) are arranged on the second axis (X2). The first engagement mechanism (3) of the switching mechanism (S) is configured to disconnect and reconnect the power transmission between the fifth rotating element (E5) and the sixth rotating element (E6), and the second engagement mechanism (4) of the switching mechanism (S) is configured to selectively fix the fifth rotating element (E5) to the non-rotating member (NR). Thus, with this configuration, an input member (I) and an output member (O) arranged coaxially with the planetary gear mechanism (P), and a switching mechanism (S) partly arranged on a different axis from the planetary gear mechanism (P), make it possible to selectively form a first gear stage (S1) and a second gear stage (S2). Therefore, in a configuration that includes a planetary gear mechanism (P) and a switching mechanism (S) for switching the state of the planetary gear mechanism (P), it is easier to miniaturize at least a part of the vehicle transmission (10) in the radial direction (R).

[0120] In this configuration, it is preferable that the power transmission path between the third rotating element (E3) and the fifth rotating element (E5), and the power transmission path between the fourth rotating element (E4) and the sixth rotating element (E6) are configured such that, when the first engaging mechanism (3) is engaged, the second engaging mechanism (4) is released, and the input member (I) is rotating, the third rotating element (E3) rotates in the opposite direction to the first rotating element (E1).

[0121] In this configuration, the gear ratio of the first gear stage (S1), formed when the first engagement mechanism (3) is engaged and the second engagement mechanism (4) is disengaged, is greater than the gear ratio of the second gear stage (S2), formed when the first engagement mechanism (3) is disengaged and the second engagement mechanism (4) is engaged. Furthermore, in this configuration, the planetary gear mechanism (P) has a configuration in which the second gear stage (S2) requires fewer rotating elements to constitute the power transmission path than the first gear stage (S1). Therefore, the second gear stage (S2), which is used more frequently when traveling at high speeds compared to the first gear stage (S1), has higher power transmission efficiency. Consequently, this configuration makes it easier to improve the energy efficiency when driving a vehicle.

[0122] Furthermore, the switching mechanism (S) preferably further comprises a friction-type third engagement mechanism (6) that selectively fixes the fourth rotating element (E4) to the non-rotating member (NR).

[0123] With this configuration, when shifting (upshifting) from a gear with a large gear ratio to a gear with a small gear ratio where the rotational speed of the input member (I) is lower at the same vehicle speed, even if the drive source (MG) cannot output negative torque, the rotational speed of the input member (I) can be reduced by putting the third engagement mechanism (6) into a slip engagement state, thereby enabling a rapid gear change. Furthermore, with this configuration, by engaging either the first engagement mechanism (3) or the second engagement mechanism (4) with the third engagement mechanism (6), it can also function as a parking brake.

[0124] Furthermore, the aforementioned first rotating element (E1) is a sun gear (SG), The aforementioned second rotating element (E2) is a carrier (CR), The third rotating element (E3) is an internally geared ring gear (RG), The aforementioned switching mechanism (S) is The first gear (G1) as the fourth rotating element (E4), The second gear (G2) as the fifth rotating element (E5), The third gear (G3) as the sixth rotating element (E6), It comprises a fourth gear (G4) with external teeth that rotates integrally with the ring gear (RG), The second gear (G2) is configured to mesh with the fourth gear (G4), Preferably, the third gear (G3) is configured to mesh with the first gear (G1), or with a gear (IG1) that meshes with the first gear (G1).

[0125] This configuration makes it possible to realize a vehicle transmission (10) with a small radial (R) dimension using a simple design.

[0126] In the above configuration, a differential gear mechanism (DF) is further provided, which is located on a third axis (X3) that is different from the first axis (X1) and the second axis (X2). The differential gear mechanism (DF) includes a differential input gear (28) and is configured to distribute the rotation of the differential input gear (28) to a pair of wheels (W). The first gear (G1) is an external gear that rotates integrally with the carrier (CR) and meshes with the differential input gear (28). Preferably, the third gear (G3) is configured to mesh with the gear (IG1) that meshes with the first gear (G1), or with the differential input gear (28).

[0127] With this configuration, even when the differential gear mechanism (DF) is located on a third axis (X3) that is different from the first axis (X1) and the second axis (X2), it is easy to keep the number of gears arranged on each axis low, and the configuration of the vehicle transmission (10) can be easily simplified.

[0128] Furthermore, the first engagement mechanism (3) and the second engagement mechanism (4) are arranged side by side on the second axis (X2) and are driven by a common drive mechanism (5). The drive mechanism (5) comprises an engaging member (51) that operates to selectively engage either the first engaging mechanism (3) or the second engaging mechanism (4), a drive motor (52), and a screw-type linear motion conversion mechanism (53) that converts the rotational driving force of the drive motor (52) into a driving force in a direction along the second axis (X2) and transmits it to the engaging member (51). When the drive motor (52) is rotated toward the first side, the first engagement mechanism (3) is engaged and the second engagement mechanism (4) is released. Preferably, the drive motor (52) is rotated to the second side opposite to the first side, thereby engaging the second engagement mechanism (4) and releasing the first engagement mechanism (3).

[0129] With this configuration, the drive mechanism (5) that drives the first engagement mechanism (3) and the second engagement mechanism (4) is made up of a drive motor (52) and a screw-type linear motion conversion mechanism (53), making it easier to miniaturize the vehicle transmission (10) compared to when a hydraulic drive mechanism is used. [Industrial applicability]

[0130] 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 a switching mechanism for switching the state of the planetary gear mechanism. [Explanation of symbols]

[0131] 10: Vehicle transmission, I: Input member, O: Output member, P: Planetary gear mechanism, E1: First rotating element, E2: Second rotating element, E3: Third rotating element, SG: Sun gear, CR: Carrier, RG: Ring gear, S: Switching mechanism, E4: Fourth rotating element, E5: Fifth rotating element, E6: Sixth rotating element, 3: First engagement mechanism, 4: Second engagement mechanism, 5: First drive mechanism (drive mechanism) ), 51: First engaging member (engaging member), 52: First drive motor (drive motor), 53: First linear motion conversion mechanism (linear motion conversion mechanism), 6: Third engaging mechanism, DF: Differential gear mechanism, G1: First gear, G2: Second gear, G3: Third gear, G4: Fourth gear, NR: Non-rotating member, MG: Rotating electric machine (drive source), W: Wheel, X1: First axis, X2: Second axis, X3: Third axis

Claims

1. An input member connected to a drive source, An output member that is driven and connected to the wheel, A planetary gear mechanism comprising a first rotating element, a second rotating element, and a third rotating element, configured such that the rotational speeds of the first rotating element, the second rotating element, and the third rotating element are in the order described above, A vehicle transmission comprising a switching mechanism for switching the state of the planetary gear mechanism, The first rotating element is connected to the input member so as to rotate integrally with it. The second rotating element is connected to the output member so as to rotate integrally with it. The aforementioned switching mechanism is A fourth rotating element is positioned on a first axis, which is the axis on which the planetary gear mechanism is arranged, and is connected to the first rotating element or the second rotating element so as to rotate integrally with it. A fifth rotating element is positioned on a second axis, which is a different axis from the first axis, and rotates in conjunction with the third rotating element, A sixth rotating element is positioned on the second axis and rotates in conjunction with the fourth rotating element, A first engagement mechanism for disconnecting and connecting power transmission between the fifth rotating element and the sixth rotating element, A vehicle transmission comprising a second engagement mechanism for selectively fixing the fifth rotating element to a non-rotating member.

2. The vehicle transmission according to claim 1, wherein a power transmission path between the third rotating element and the fifth rotating element and a power transmission path between the fourth rotating element and the sixth rotating element are configured such that, when the first engaging mechanism is engaged, the second engaging mechanism is disengaged, and the input member is rotating, the third rotating element rotates in the opposite direction to the first rotating element.

3. The vehicle transmission according to claim 1, wherein the switching mechanism further comprises a friction-type third engagement mechanism for selectively fixing the fourth rotating element to the non-rotating member.

4. The first rotating element is a sun gear, The aforementioned second rotating element is a carrier, The third rotating element is an internally geared ring gear, The aforementioned switching mechanism is The first gear as the fourth rotating element, The second gear, which is the fifth rotating element, The third gear, which is the sixth rotating element, It comprises a fourth gear with external teeth that rotates integrally with the ring gear, The second gear is configured to mesh with the fourth gear, The vehicle transmission according to any one of claims 1 to 3, wherein the third gear is configured to mesh with the first gear, or with a gear that meshes with the first gear.

5. The differential gear mechanism further comprises a third axis which is a different axis from the first and second axes, The differential gear mechanism comprises a differential input gear and is configured to distribute the rotation of the differential input gear to a pair of wheels. The first gear is an external gear that rotates integrally with the carrier and meshes with the differential input gear. The vehicle transmission according to claim 4, wherein the third gear is configured to mesh with a gear that meshes with the first gear, or with the differential input gear.

6. The first engagement mechanism and the second engagement mechanism are arranged side by side on the second axis 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, a drive motor, and a screw-type linear motion conversion mechanism that converts the rotational driving force of the drive motor into a driving force in the direction along the second axis and transmits it to the engaging member. When the drive motor is rotated toward the first side, the first engagement mechanism is engaged and the second engagement mechanism is released. The vehicle transmission according to any one of claims 1 to 3, wherein the drive motor is rotated to the second side opposite to the first side, thereby engaging the second engagement mechanism and disengaging the first engagement mechanism.

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