unit

Abstract

[Problem] To reduce the gear ratio during gear shifting in a unit having an internal power transmission mechanism. [Solution] A unit has an input element, an output element, first to third engaging elements, a first planetary gear mechanism in which first to third rotating elements are arranged in this order on a collinear diagram, and a second planetary gear mechanism in which fourth to sixth rotating elements are arranged in this order on the collinear diagram. The input element is connected to the fourth rotating element, the output element is connected to the first rotating element, one side of the first engaging element is connected to the second rotating element and the fifth rotating element, the other side of the first engaging element is fixed, one side of the second engaging element is connected to the third rotating element and the sixth rotating element, the other side of the second engaging element is fixed, and the third engaging element connects two rotating elements that are selected from the first to sixth rotating elements and are not connected to each other.

Description

[Technical Field]

[0001] The present invention relates to a unit having a power transmission mechanism therein. [Background technology]

[0002] Patent Document 1 discloses a two-speed automatic transmission unit for an electric vehicle, which can achieve first speed and second speed, which has a smaller gear ratio (= input rotation speed / output rotation speed) than first speed, by switching the engagement state of two friction clutches.

[0003] Similar units are also disclosed in Patent Documents 2 to 4. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] German Patent No. 102019107517 [Patent Document 2] German Patent Application Publication No. 102019119947 [Patent Document 3] German Patent Application Publication No. 102019119949 [Patent Document 4] Chinese Utility Model No. 207333597 Summary of the Invention [Problem to be solved by the invention]

[0005] In an automatic transmission unit for an electric vehicle with two forward speeds, the larger the first-speed gear ratio, the greater the torque amplification effect due to deceleration, so the larger the first-speed gear ratio, the smaller the maximum torque of the motor can be, allowing a smaller motor to be selected.In contrast, the smaller the second-speed gear ratio, the lower the motor rotation speed when achieving a certain vehicle speed, which is advantageous for high-speed cruising.

[0006] However, if the gear ratios for first and second gears are set based on the above design concept, the gear ratio (= gear ratio for first gear / gear ratio for second gear) when switching between first and second gears becomes large, and the acceleration / deceleration of the output rotation when changing gears becomes large.

[0007] The present invention has been made in view of these technical problems, and has as its object to reduce the gear ratio during gear change in a unit having a power transmission mechanism therein. [Means for solving the problem]

[0008] According to one aspect of the present invention, the unit comprises: An input element; An output element; A first engagement element; A second engagement element; A third engagement element; a first planetary gear mechanism in which a first rotation element, a second rotation element, and a third rotation element are arranged in this order on a nomographic diagram; and a second planetary gear mechanism in which a fourth rotating element, a fifth rotating element, and a sixth rotating element are arranged in this order on the nomographic diagram. the input element is connected to the fourth rotational element; the output element is connected to the first rotating element; one side of the first engagement element is connected to the second rotation element and the fifth rotation element, The other side of the first engagement element is fixed, one side of the second engagement element is connected to the third rotation element and the sixth rotation element, The other side of the second engagement element is fixed, The third engagement element connects two rotation elements selected from the first to sixth rotation elements that are not connected to each other. [Effects of the Invention]

[0009] According to the above aspect, by changing the engagement states of the first to third engagement elements, three or more gear stages can be realized. This reduces the inter-stage ratio compared to a unit with two forward speeds, and the acceleration / deceleration of the output rotation during gear changes can be kept lower than in a unit with two forward speeds. Also, a more appropriate gear ratio can be set for each gear stage.

[0010] Furthermore, when the first and second engaging elements are disengaged and the third engaging element is engaged, the gear ratio becomes 1 and all of the rotating elements that make up the first and second planetary gear mechanisms rotate at the same rotational speed, thereby reducing power transmission loss caused by differential rotation between the rotating elements. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a skeleton diagram of a unit according to an embodiment of the present invention. [Figure 2] FIG. 2 is an engagement table showing the engagement state of each engagement element at each gear position. [Figure 3] Figure 3 is a collinear diagram of the unit. [Figure 4A] FIG. 4A is a skeleton diagram of a modified example of the unit. [Figure 4B] FIG. 4B is a skeleton diagram of a modified example of the unit. [Figure 4C] FIG. 4C is a skeleton diagram of a modified example of the unit. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The definitions of terms used in this specification are as follows.

[0013] "Unit" refers to a device in general that has a power transmission mechanism such as a gear mechanism or a differential gear mechanism inside, and includes a motor unit having a motor and a power transmission mechanism, an automatic transmission unit, a reducer unit, etc.

[0014] The "gear ratio" is the value obtained by dividing the input rotation speed of a unit by the output rotation speed. "Input rotation" includes not only the rotation input to the unit from a power source outside the unit, but also the rotation input to the unit from a power source inside the unit.

[0015] The "gear ratio" is the value obtained by dividing the larger (low speed) gear ratio by the smaller (high speed) gear ratio of the two gear ratios realized by the unit.

[0016] "Axial direction" refers to the axial direction of the rotating shaft of the parts that make up the unit. The parts are motors, gear mechanisms, differential gear mechanisms, etc. "Radial direction" refers to the radial direction from the central axis of the rotating shaft.

[0017] "Housing" refers to a container that houses the motor, inverter, and power transmission mechanism, and is composed of one or more cases. An embodiment in which the case that houses the motor, the case that houses the inverter, and the case that houses the power transmission mechanism are integrally formed is called "3-in-1."

[0018] The term "motor" refers to a rotating electric machine having a motor function, and may have a generator function in addition to the motor function.

[0019] "Element A is connected to element B" means that element A is connected to element B upstream or downstream in a manner that allows power transmission between element A and element B. The power input side is upstream, and the power output side is downstream. Element A is not limited to being connected to element B directly or via another member, and may be connected via a clutch or the like.

[0020] "Element A is fixed to element B" includes both a state in which element A is directly fixed to element B and a state in which element A is fixed to element B via an element C other than elements A and B. "Element A is fixed" means a state in which element A is fixed to another element and cannot rotate.

[0021] "Element A and element B overlap when viewed in a specified direction" refers to a state in which element A and element B are aligned in a specified direction (axial direction, radial direction, gravity direction, etc.) and at least partially overlap when observed from the specified direction. This is synonymous with "element A and element B overlap in a specified direction." When element A and element B overlap when viewed in the axial direction, element A and element B are coaxial. When element A and element B are drawn aligned in a specified direction in a drawing, this means that element A and element B overlap when viewed in the specified direction.

[0022] In contrast, "element A and element B do not overlap when viewed in a specified direction" refers to a state in which element A and element B are not aligned in a specified direction (axial direction, radial direction, gravity direction, vehicle running direction, etc.), and there is no overlapping portion between element A and element B when observed from the specified direction. This is synonymous with "element A and element B do not overlap in a specified direction." When element A and element B are depicted in a drawing so that they are not aligned in a specified direction, this means that element A and element B do not overlap when viewed in the specified direction.

[0023] "Element A is located between element B and element C when viewed in a specified direction" means that element A is observed to be located between element B and element C when viewed from a specified direction (axial direction, radial direction, gravity direction, etc.). For example, if elements B, A, and C are lined up in this order along the axial direction, element A is observed to be located between element B and element C when viewed in the radial direction, and therefore element A can be said to be located between element B and element C. Element A does not need to overlap with elements B and C when viewed in the axial direction. When element A is depicted between element B and element C in a drawing, this means that element A is located between element B and element C when viewed in the specified direction.

[0024] "Disposed closely together" means that two elements have an overlapping portion when viewed in the axial direction or the radial direction, and no other elements are sandwiched between the two elements. For example, "two engaging elements are disposed closely together" means that a planetary gear mechanism or the like is not disposed between the two engaging elements. If no other elements are depicted between element A and element B in the drawing, this means that element A and element B are disposed closely together.

[0025] "One side of the engaging element" and "the other side of the engaging element" refer to two elements included in the engaging element that are unable to rotate relative to each other when the engaging element is in an engaged state and are able to rotate relative to each other when the engaging element is in a disengaged state. "One side of the engaging element" and "the other side of the engaging element" may be a combination of rotating elements, or a combination of a rotating element and a non-rotating element; the former is generally called a clutch and the latter a brake. Also, "one side of the engaging element" means either "one side of the engaging element" or "the other side of the engaging element."

[0026] Other terms will be defined as appropriate throughout the specification.

[0027] 1 is a skeleton diagram showing the basic structure of a unit 100 according to an embodiment of the present invention. The unit 100 is a three-speed automatic transmission unit for an electric vehicle that changes the speed of rotation input to an input element IN from a motor (not shown) as a power source at a gear ratio corresponding to the gear position and transmits the rotation from an output element OUT to drive wheels (not shown). In this example, both the input element IN and the output element OUT are rotating shafts.

[0028] The unit 100 is a so-called 3-in-1 unit that accommodates an input element IN, first and second planetary gear mechanisms PG1 and PG2, first to third engagement elements B1, B2, and CL, an output element OUT, and a motor and inverter (not shown) within a housing 1. The housing 1 is fixed to the vehicle so as not to be rotatable.

[0029] One end of the input element IN is connected to the output shaft of the motor, and the input element IN rotates due to the power input from the motor. The rotational speed of the input element IN is the input rotational speed of the unit 100. The motor is electrically connected to a battery (not shown) outside the unit 100 via an inverter, and receives power from the battery to function as an electric motor. The motor can also function as a generator.

[0030] The first planetary gear mechanism PG1 is a single-pinion planetary gear mechanism having a first sun gear S1 as a first rotating element, a plurality of first pinion gears (not shown), a first carrier C1 as a second rotating element that rotatably supports the plurality of first pinion gears, and a first ring gear R1 as a third rotating element. The first sun gear S1 meshes with the plurality of first pinion gears, and the plurality of first pinion gears mesh with the first ring gear R1.

[0031] The second planetary gear mechanism PG2 is a single-pinion planetary gear mechanism having a second sun gear S2 as a fourth rotating element, a plurality of second pinion gears (not shown), a second carrier C2 as a fifth rotating element that rotatably supports the plurality of second pinion gears, and a second ring gear R2 as a sixth rotating element. The second sun gear S2 meshes with the plurality of second pinion gears, and the plurality of second pinion gears mesh with the second ring gear R2.

[0032] The first sun gear S1 is connected to the output element OUT. The first carrier C1 is connected to the second carrier C2. The first ring gear R1 is connected to the second ring gear R2. The second sun gear S2 is connected to the input element IN.

[0033] The rotational speed of the output element OUT is the output rotational speed of the unit 100 .

[0034] The first engaging element B1 is a brake. The first engaging element B1 is configured with a hydraulic or electric clutch. If the two portions of the first engaging element B1 that are engaged when the first engaging element B1 is in an engaged state are referred to as one side and the other side, one side is connected to the first carrier C1 and the second carrier C2, and the other side is fixed to the housing 1. As a result, when the first engaging element B1 is engaged, the first carrier C1 and the second carrier C2 can be fixed to the housing 1.

[0035] The second engaging element B2 is a brake. The second engaging element B2 is configured with a hydraulic or electric clutch. If the two portions of the second engaging element B2 that are engaged when the second engaging element B2 is in an engaged state are referred to as one side and the other side, one side is connected to the first ring gear R1 and the second ring gear R2, and the other side is fixed to the housing 1. As a result, when the second engaging element B2 is engaged, the first ring gear R1 and the second ring gear R2 can be fixed to the housing 1.

[0036] The third engagement element CL is a clutch, and is configured as an electric multi-plate clutch.

[0037] The third engagement element CL includes a hub 11, inner friction plates 12 and outer friction plates 13 arranged alternately, a drum 14, and an electric actuator 15.

[0038] An inner friction plate 12 is spline-fitted to the outer periphery of the hub 11, and the inner friction plate 12 is displaceable in the axial direction but is non-rotatable relative to the hub 11. The hub 11 is also spline-fitted to the input element IN, and is non-rotatable relative to the input element IN.

[0039] An outer friction plate 13 is spline-fitted to the inner periphery of the drum 14, and the outer friction plate 13 is displaceable but not rotatable relative to the drum 14. The drum 14 is also connected to one side of the first engagement element B1, the first carrier C1, and the second carrier C2.

[0040] The electric actuator 15 is an actuator that drives the third engagement element CL. When a motor built into the electric actuator 15 is driven, the piston 15p is advanced in the axial direction, and the inner friction plate 12 and the outer friction plate 13 are pressed together, preventing relative rotation, and the third engagement element CL is brought into an engaged state. The electric actuator 15 applies a mechanical force to the piston 15p and receives a reaction force from the piston 15p, so that the electric actuator 15 is fixed to the housing 1.

[0041] Furthermore, when the motor built into the electric actuator 15 is driven in the reverse direction, the piston 15p moves backward, the inner friction plate 12 and the outer friction plate 13 move away from each other, and the third engagement element CL enters a disengaged state.

[0042] It is also possible to use a hydraulic actuator that hydraulically pushes out the piston 15p instead of the electric actuator 15. Oil may be supplied to the hydraulic actuator by a hydraulic supply unit attached to the housing 1 or the like, or by a control valve unit including a spool, a solenoid valve, and the like.

[0043] If the two portions of the third engaging element CL that are engaged when the third engaging element CL is in an engaged state are defined as one side (hub 11) and the other side (drum 14), one side is connected to the input element IN and the second sun gear S2, and the other side is connected to one side of the first engaging element B1, the first carrier C1, and the second carrier C2. As a result, when the third engaging element CL is engaged, the input element IN and the second sun gear S2 are connected to the first carrier C1 and the second carrier C2.

[0044] Since the other side of the third engagement element CL is connected to one side of the first engagement element B1, these can be made into a common part (integrated part), and this allows the number of parts of the unit 100 to be reduced.

[0045] Furthermore, by connecting the second sun gear S2 and the second carrier C2 with the third engagement element CL, the third engagement element CL does not need to be disposed between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, making layout design easier.

[0046] Actuators that can be used for the third engagement element CL include actuators that are subject to layout constraints (such as electric actuators that need to be fixed to the housing 1 or the like due to reaction forces, and hydraulic actuators that require a hydraulic supply unit to be attached to the housing 1 or the like), and actuators that are not subject to layout constraints (such as hydraulic actuators that supply hydraulic pressure from a control valve unit).When using the former type of actuator, if the third engagement element CL needs to be disposed between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the difficulty of layout design increases.

[0047] In this regard, the arrangement shown in FIG. 1 allows for easy layout design regardless of the type of actuator, and increases the degree of freedom in selecting the actuator that drives the third engagement element CL.

[0048] Furthermore, by arranging the first planetary gear mechanism PG1 on one axial side of the second planetary gear mechanism PG2 and the third engaging element CL on the other axial side of the second planetary gear mechanism PG2, the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are arranged close to each other, which increases the degree of freedom in the layout of the other elements and also enables the axial dimension of the unit 100 to be reduced.

[0049] The third engagement element CL is disposed coaxially with the first and second planetary gear mechanisms PG1 and PG2, and has a portion overlapping with the first planetary gear mechanism PG1 and a portion overlapping with the second planetary gear mechanism PG2 when viewed in the axial direction, thereby enabling the radial dimension of the unit 100 to be reduced.

[0050] 2 is an engagement table showing the relationship between the engagement states of the first to third engagement elements B1, B2, and CL and the gear positions achieved in the unit 100. In the table, black circles indicate the engaged state, and no marks indicate the disengaged state.

[0051] As shown in the engagement table, first gear is achieved by engaging the first engagement element B1 and disengaging the second and third engagement elements B2 and CL. Second gear is achieved by engaging the second engagement element B2 and disengaging the first and third engagement elements B1 and CL. Third gear is achieved by engaging the third engagement element CL and disengaging the first and second engagement elements B1 and B2.

[0052] 3 is a collinear diagram of unit 100. In the diagram, vertical lines 11 to 14 correspond to the respective rotational elements of first and second planetary gear mechanisms PG1 and PG2, with the first planetary gear mechanism PG1 having a first sun gear S1, first carrier C1, and first ring gear R1 arranged in this order from the left in the diagram, and the second planetary gear mechanism PG2 having a second sun gear S2, second carrier C2, and second ring gear R2 arranged in this order from the left in the diagram.

[0053] The first carrier C1 and the second carrier C2 are connected to each other, so they share the same vertical line l3. Similarly, the first ring gear R1 and the second ring gear R2 are connected to each other, so they share the same vertical line l4. When the distance between vertical lines l3 and l4 is 1, the distance between vertical lines l2 and l3 and the distance between vertical lines l1 and l3 are 1 / α1 and 1 / α2, respectively, where α1 is the number of teeth of the first sun gear S1 divided by the number of teeth of the first ring gear R1, and α2 is the number of teeth of the second sun gear S2 divided by the number of teeth of the second ring gear R2.

[0054] The alignment chart depicts straight lines L1 to L3 corresponding to each gear position. The rotational speed of each rotating element is represented by the ordinate of the intersection of the straight lines L1 to L3 corresponding to each gear position with the vertical lines l1 to l4.

[0055] In first gear, by engaging the first engagement element B1, the first carrier C1 and the second carrier C2 are fixed to the housing 1 and the rotational speed of the first carrier C1 and the second carrier C2 becomes zero, so the straight line L1 corresponding to first gear becomes a straight line passing through point X1.

[0056] If the rotational speed of the first sun gear S1 is r1 and the rotational speed of the second sun gear S2 is r4, the input rotational speed rin of the unit 100 is equal to the rotational speed r4 of the second sun gear S2, and the output rotational speed rout is equal to the rotational speed r1 of the first sun gear S1, so the gear ratio in first gear is rin / rout = r4 / r1.

[0057] In addition, in second gear, by engaging the second engagement element B2, the first ring gear R1 and the second ring gear R2 are fixed to the housing 1, and the rotational speed of the first ring gear R1 and the second ring gear R2 becomes zero, so the straight line L2 corresponding to second gear becomes a straight line passing through point X2.

[0058] If the rotational speed of first sun gear S1 is r2 and the rotational speed of second sun gear S2 is r4, the input rotational speed rin of unit 100 is equal to the rotational speed r4 of second sun gear S2, and the output rotational speed rout is equal to the rotational speed r2 of first sun gear S1, so the gear ratio in second gear is rin / rout = r4 / r2. Because r2 is greater than r1, the gear ratio in second gear is smaller than the gear ratio in first gear.

[0059] In third gear, the third engagement element CL is engaged, connecting the input element IN and second sun gear S2 to the first carrier C1 and second carrier C2, so that the rotational speeds of all the rotational elements are equal (r3). As a result, the input rotational speed rin and the output rotational speed rout are also equal, and the gear ratio in third gear is 1, which is smaller than that in second gear.

[0060] Therefore, in unit 100, three gear stages can be realized, including third stage, where the gear ratio is 1, so the interstage ratio is smaller than in a unit with two forward stages, and the acceleration / deceleration of the output rotation during gear changes can be kept smaller than in a unit with two forward stages. Also, first to third stages can be used as low, medium, and high speeds, respectively, so an appropriate gear ratio can be set according to the speed range.

[0061] In addition, in third gear, the gear ratio is 1. In other words, all of the rotating elements that make up the first and second planetary gear mechanisms PG1, PG2 rotate at the same rotation speed, which reduces power transmission loss caused by differential rotation between the rotating elements.

[0062] Next, a modified example of the unit 100 will be described.

[0063] 4A to 4C are skeleton diagrams of modified examples of the unit 100. The position of the third engagement element CL differs from that shown in Fig. 1. The same elements as those in the skeleton diagram shown in Fig. 1 are denoted by the same reference numerals.

[0064] The third engagement element CL may be positioned at a position other than that shown in FIG. 1, as long as it is possible to realize a speed ratio of 1 by engaging the third engagement element CL.

[0065] Specifically, to achieve a gear ratio of 1 in the alignment chart shown in FIG. 3, the line L3 corresponding to third gear must be horizontal, so any two of the four vertical lines can be selected and the rotating elements corresponding to the selected two lines can be connected together.

[0066] In other words, from all the combinations of two rotating elements selected from the six rotating elements S1, C1, R1, S2, C2, R2 of the first and second planetary gear mechanisms PG1 and PG2, it is only necessary to select combinations of two rotating elements that are not connected to each other, excluding combinations that are already connected (first carrier C1 and second carrier C2, first ring gear R1 and second ring gear R2), and then connect these two rotating elements.

[0067] 4A, the third engagement element CL is disposed at a position that allows connection of the input element IN and the second sun gear S2 with the first ring gear R1 and the second ring gear R2. Specifically, one side (hub 11) of the third engagement element CL is connected to the input element IN and the second sun gear S2, and the other side (drum 14) is connected to one side of the second engagement element B2, the first ring gear R1, and the second ring gear R2.

[0068] This arrangement is suitable for a layout design in which the third engaging element CL is not disposed between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2. Furthermore, by not disposing the third engaging element CL between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the degree of freedom in selecting the actuator that drives the third engaging element CL can be increased.

[0069] The actuator that drives the third engagement element CL may be the same electric actuator 15 as in the example shown in Figure 1, or a hydraulic actuator that supplies hydraulic pressure from a hydraulic pressure supply unit or control valve unit attached to the housing 1, etc.

[0070] Furthermore, the first planetary gear mechanism PG1 is disposed on one axial side of the second planetary gear mechanism PG2, and the third engagement element CL is disposed on the other axial side of the second planetary gear mechanism PG2.

[0071] Since the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are disposed close to each other, the degree of freedom in the layout of other elements increases, and the axial dimension of the unit 100 can be reduced.

[0072] Furthermore, since one side of the third engagement element CL (the drum 14) and one side of the second engagement element B2 are connected, these can be made into a common part (integrated part), thereby reducing the number of parts of the unit 100.

[0073] The third engagement element CL is disposed coaxially with the first and second planetary gear mechanisms PG1 and PG2, and has a portion overlapping with the first planetary gear mechanism PG1 and a portion overlapping with the second planetary gear mechanism PG2 when viewed in the axial direction, thereby enabling the radial dimension of the unit 100 to be reduced.

[0074] 4B, the third engagement element CL is disposed at a position that allows the input element IN and the second sun gear S2 to be connected to the first sun gear S1 and the output element OUT. Specifically, one side (hub 11) of the third engagement element CL is connected to the input element IN and the second sun gear S2, and the other side (drum 14) is connected to the first sun gear S1 and the output element OUT.

[0075] In this arrangement, the third engagement element CL is arranged between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, so it is preferable to use a hydraulic actuator 16 that supplies hydraulic pressure from a control valve unit, which has fewer layout restrictions, as the actuator that drives the third engagement element CL.

[0076] Furthermore, when the third engagement element CL is engaged, not only can a gear ratio of 1 be achieved, but the input element IN and the output element OUT are connected, thereby shortening the power transmission path from the input element IN to the output element OUT and further reducing power transmission loss.

[0077] The third engagement element CL is disposed coaxially with the first and second planetary gear mechanisms PG1 and PG2, and has a portion overlapping with the first planetary gear mechanism PG1 and a portion overlapping with the second planetary gear mechanism PG2 when viewed in the axial direction, thereby enabling the radial dimension of the unit 100 to be reduced.

[0078] 4C, the third engagement element CL is disposed at a position that allows the input element IN and the second sun gear S2 to be connected to the first carrier C1 and the second carrier C2. Specifically, one side of the third engagement element CL (hub 11) is connected to the input element IN and the second sun gear S2, and the other side (drum 14) is connected to one side of the first engagement element B1, the first carrier C1, and the second carrier C2.

[0079] In this arrangement, the third engagement element CL is arranged between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, so it is preferable to use a hydraulic actuator 16 that supplies hydraulic pressure from a control valve unit, which has fewer layout restrictions, as the actuator that drives the third engagement element CL.

[0080] The third engagement element CL is disposed coaxially with the first and second planetary gear mechanisms PG1 and PG2, and has a portion overlapping with the first planetary gear mechanism PG1 and a portion overlapping with the second planetary gear mechanism PG2 when viewed in the axial direction, thereby enabling the radial dimension of the unit 100 to be reduced.

[0081] Furthermore, since one side of the third engagement element CL (the drum 14) and one side of the first engagement element B1 are connected, these can be made into a common part (integrated part), thereby reducing the number of parts of the unit 100.

[0082] The engagement table and alignment chart of the modified example shown in FIGS. 4A to 4C are the same as those of the skeleton diagram of FIG. 1 shown in FIGS.

[0083] Next, the effects of the embodiment of the present invention will be described.

[0084] (1) The unit 100 according to the embodiment of the present invention is An input element IN; an output element OUT; A first engagement element B1, A second engagement element B2, A third engagement element CL; a first planetary gear mechanism PG1 in which a first sun gear S1, a first carrier C1, and a first ring gear R1 are arranged in this order on a collinear diagram; and a second planetary gear mechanism PG2 in which a second sun gear S2, a second carrier C2, and a second ring gear R2 are arranged in this order on the nomographic diagram. The input element IN is connected to the second sun gear S2, The output element OUT is connected to the first sun gear S1. One side of the first engaging element B1 is connected to the first carrier C1 and the second carrier C2, The other side of the first engagement element B1 is fixed, One side of the second engagement element B2 is connected to the first ring gear R1 and the second ring gear R2, The other side of the second engagement element B2 is fixed, The third engagement element CL connects two rotating elements that are not connected to each other and are selected from the first sun gear S1, the first carrier C1, the first ring gear R1, the second sun gear S2, the second carrier C2, and the second ring gear R2.

[0085] According to this configuration, by changing the engagement states of the first to third engagement elements B1, B2, and CL, three or more gear stages can be realized. As a result, the inter-stage ratio is smaller than that of a unit with two forward speeds, and the acceleration / deceleration of the output rotation during gear changes can be kept smaller than that of a unit with two forward speeds. Also, a more appropriate gear ratio can be set for each gear stage.

[0086] Furthermore, when the first and second engaging elements B1, B2 are disengaged and the third engaging element CL is engaged, the gear ratio becomes 1 and all of the rotating elements that make up the first and second planetary gear mechanisms PG1, PG2 rotate at the same rotational speed, thereby reducing power transmission loss caused by differential rotation between the rotating elements.

[0087] (2) In the example shown in FIG. 1, the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are single-pinion planetary gear mechanisms, and the third engagement element CL connects the second sun gear S2 and the second carrier C2.

[0088] This arrangement is suitable for a layout design in which the third engaging element CL is not disposed between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2. Furthermore, by not disposing the third engaging element CL between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the degree of freedom in selecting the actuator that drives the third engaging element CL can be increased.

[0089] (3) In the example shown in FIG. 1, the first planetary gear mechanism PG1 is disposed on one axial side of the second planetary gear mechanism PG2, and the third engagement element CL is disposed on the other axial side of the second planetary gear mechanism PG2.

[0090] According to this configuration, the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are disposed close to each other, which increases the degree of freedom in the layout of other elements and also enables the axial dimension of the unit 100 to be reduced.

[0091] (4) In the example shown in FIG. 4A, the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are single-pinion planetary gear mechanisms, and the third engagement element CL connects the second sun gear S2 and the second ring gear R2.

[0092] This arrangement is suitable for a layout design in which the third engaging element CL is not disposed between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2. Furthermore, by not disposing the third engaging element CL between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the degree of freedom in selecting the actuator that drives the third engaging element CL can be increased.

[0093] (5) In the example shown in FIG. 4A, the first planetary gear mechanism PG1 is disposed on one axial side of the second planetary gear mechanism PG2, and the third engagement element CL is disposed on the other axial side of the second planetary gear mechanism PG2.

[0094] According to this configuration, the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are disposed close to each other, which increases the degree of freedom in the layout of other elements and also enables the axial dimension of the unit 100 to be reduced.

[0095] 1 and 4A to 4C, the third engaging element CL has a portion that overlaps with the first planetary gear mechanism PG1 when viewed in the axial direction. The third engaging element CL also has a portion that overlaps with the second planetary gear mechanism PG2 when viewed in the axial direction.

[0096] This allows the radial dimension of the unit 100 to be reduced.

[0097] (7) In the examples shown in FIGS. 1, 4A, and 4C, one side of the third engagement element CL (the drum 14) is connected to one side of the first engagement element B1 or one side of the second engagement element B2.

[0098] According to this configuration, one side of the third engagement element CL and one side of the first engagement element B1 or one side of the second engagement element B2 can be made into a common part (integrated part), thereby reducing the number of parts of the unit 100.

[0099] Although the embodiments of the present invention have been described above, the above embodiments are merely application examples of the present invention, and the technical scope of the present invention is not intended to be limited to the specific configurations of the above embodiments.

[0100] For example, the skeleton diagrams shown in FIGS. 1 and 4A to 4C are only some of the application examples of the present invention, and skeleton diagrams of units to which the present invention is applied are not limited to these.

[0101] Furthermore, although the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are each a single-pinion planetary gear mechanism, they may also be double-pinion planetary gear mechanisms. [Explanation of symbols]

[0102] 1: Housing 100: Unit B1: 1st engagement element B2 :Second engagement element CL: Third engagement element S1: First sun gear (first rotating element) C1: First carrier (second rotating element) R1: 1st ring gear (3rd rotating element) S2: Second sun gear (fourth rotating element) C2: Second carrier (fifth rotating element) R2: Second ring gear (sixth rotating element) IN : Input element OUT: Output element PG1: First planetary gear mechanism PG2: Second planetary gear mechanism

Claims

1. An input element; An output element; A first engagement element; A second engagement element; A third engagement element; a first planetary gear mechanism in which a first rotation element, a second rotation element, and a third rotation element are arranged in this order on a nomographic diagram; a second planetary gear mechanism in which a fourth rotation element, a fifth rotation element, and a sixth rotation element are arranged in this order on the nomographic diagram, the input element is connected to the fourth rotational element; the output element is connected to the first rotating element; one side of the first engagement element is connected to the second rotation element and the fifth rotation element, The other side of the first engagement element is fixed, one side of the second engagement element is connected to the third rotation element and the sixth rotation element, The other side of the second engagement element is fixed, The third engagement element connects two rotation elements selected from the first to sixth rotation elements that are not connected to each other.

2. 2. The unit of claim 1, the first planetary gear mechanism and the second planetary gear mechanism are single-pinion planetary gear mechanisms, The third engagement element connects the fourth rotation element and the fifth rotation element.

3. 3. The unit according to claim 2, the first planetary gear mechanism is disposed on one axial side of the second planetary gear mechanism, the third engagement element is disposed on the other axial side of the second planetary gear mechanism.

4. 2. The unit of claim 1, the first planetary gear mechanism and the second planetary gear mechanism are single-pinion planetary gear mechanisms, The third engagement element connects the fourth rotation element and the sixth rotation element.

5. 5. The unit according to claim 4, the first planetary gear mechanism is disposed on one axial side of the second planetary gear mechanism, the third engagement element is disposed on the other axial side of the second planetary gear mechanism.

6. In the unit according to claim 3 or claim 5, When viewed in the axial direction, the third engagement element has a portion that overlaps with the first planetary gear mechanism, When viewed in the axial direction, the third engagement element has a portion that overlaps with the second planetary gear mechanism.

7. 2. The unit of claim 1, A unit, wherein one side of the third engagement element is connected to one side of the first engagement element or one side of the second engagement element.

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