Unit

Abstract

[Problem] To reduce a gear ratio during gear shifting in a unit that has a power transmission mechanism inside. [Solution] This unit comprises: an input element; an output element; first to third engagement elements; a first planetary gear mechanism in which first to third rotational elements are arranged side by side in this order on the collinear chart; and a second planetary gear mechanism in which fourth to sixth rotational elements are arranged side by side in this order on the collinear chart. The input element is connected to the first rotational element, the output element is connected to the second rotational element and the sixth rotational element, one side of the first engagement element is connected to the fifth rotational element, the other side of the first engagement element is fixed, one side of the second engagement element is connected to the third rotational element and the fourth rotational element, the other side of the second engagement element is fixed, and the third engagement element connects two rotational elements selected, from the first to sixth rotational elements, that are not connected to each other.

Description

Technical Field

[0001] The present invention relates to a unit having a power transmission mechanism inside.

Background Art

[0002] Patent Document 1 discloses an automatic transmission unit for an electric vehicle with two forward speeds. In this unit, by switching the engagement state of two friction clutches, a first speed and a second speed with a gear ratio (= input rotational speed / output rotational speed) smaller than the first speed can be realized.

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

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] In an automatic transmission unit for an electric vehicle with two forward speeds, the greater the first speed gear ratio, the higher the torque amplification effect due to deceleration. Therefore, the greater the first speed gear ratio, the smaller the maximum torque of the motor can be, and a smaller-sized motor can be selected. On the other hand, the smaller the second speed gear ratio, the lower the rotational speed of the motor when achieving a certain vehicle speed, which is advantageous during high-speed cruising.

[0006] However, when setting the gear ratios of the first speed and the second speed respectively based on the above design concept, the step ratio (= first speed gear ratio / second speed gear ratio) when switching between the first speed and the second speed becomes large, and the acceleration and deceleration speed of the output rotation during gear shifting becomes large.

[0007] The present invention has been made in view of such technical problems, and aims to reduce the step ratio during gear shifting in a unit having a power transmission mechanism inside.

Means for Solving the Problems

[0008] According to an aspect of the present invention, the unit includes an input element, an output element, a first engaging element, a second engaging element, a third engaging element, a first planetary gear mechanism in which a first rotating element, a second rotating element, and a third rotating element are arranged in this order on a collinear diagram, 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 collinear diagram. The input element is connected to the first rotating element, The output element is connected to the second rotating element and the sixth rotating element, One side of the first engaging element is connected to 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 fourth rotating element, The other side of the second engaging element is fixed, The third engaging element connects two non-connected rotating elements selected from the first to sixth rotating elements.

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 shift speeds can be realized. As a result, the ratio between shift speeds becomes smaller compared to a two-forward-speed unit, and the acceleration and deceleration rates of the output rotation during shifting can be suppressed to be smaller than those of the two-forward-speed unit. Also, more appropriate gear ratios can be set for each shift speed.

[0010] Further, when the first and second engagement elements are disengaged and the third engagement element is engaged, the gear ratio becomes 1, and all the rotating elements constituting the first and second planetary gear mechanisms rotate at the same rotational speed. Therefore, the power transmission loss due to the differential rotation between the rotating elements can be reduced.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 5C

Figure 5D

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The definitions of the terms used in this specification are as follows.

[0013] The "unit" means all devices having 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 reduction gear unit, and the like.

[0014] The "gear ratio" is the value obtained by dividing the input rotational speed of the unit by the output rotational speed. The "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 "step ratio" is the value obtained by dividing the larger gear ratio (for low speed) by the smaller gear ratio (for high speed) for two gear ratios realized by the unit.

[0016] The "axial direction" means the axial direction of the rotation axis of the components constituting the unit. The components are a motor, a gear mechanism, a differential gear mechanism, etc. The "radial direction" means the radial direction from the central axis of the rotation axis.

[0017] The "housing" means a container that houses a motor, an inverter, and a power transmission mechanism, and is composed of one or more cases. A mode in which a case for housing a motor, a case for housing an inverter, and a case for housing a power transmission mechanism are integrally formed is called "3in1".

[0018] The "motor" means a rotating electrical machine having a motor function, and may also have a generator function in addition to the motor function.

[0019] That "element A is connected to element B" means that element A is connected to the upstream or downstream element B in a manner capable of power transmission between element A and element B. The power input side is upstream and the power output side is downstream. It is not limited to the mode in which element A is directly or indirectly connected to element B via another member, and it may be connected via a clutch or the like.

[0020] "Element A is fixed to element B" includes both the mode in which element A is directly fixed to element B and the mode in which element A is fixed to element B via an element C other than elements A and B. "Element A is fixed" means that element A is fixed to another element and is in a non-rotatable state.

[0021] "Element A and element B overlap in a predetermined direction view" means that element A and element B are arranged in a predetermined direction (axial direction, radial direction, gravitational direction, etc.), and when observed from the predetermined direction, element A and element B are in a state of at least partially overlapping. It is synonymous with "element A and element B overlap in a predetermined direction". When element A and element B overlap in the axial direction view, element A and element B are coaxial. When element A and element B are drawn side by side in a predetermined direction in the drawing, it means that element A and element B overlap in the predetermined direction view.

[0022] On the contrary, "element A and element B do not overlap in a predetermined direction view" means that element A and element B are not arranged in a predetermined direction (axial direction, radial direction, gravitational direction, vehicle traveling direction, etc.), and when observed from the predetermined direction, element A and element B do not have a overlapping part. It is synonymous with "element A and element B do not overlap in a predetermined direction". When element A and element B are drawn so as not to be arranged in a predetermined direction in the drawing, it means that element A and element B do not overlap in the predetermined direction view.

[0023] "Element A is located between element B and element C in a predetermined direction view" means that when observed from a predetermined direction (axial direction, radial direction, gravitational direction, etc.), it is observed that element A is between element B and element C. For example, when elements B, A, and C are arranged in this order along the axial direction, since it is observed that element A is between element B and element C in the radial direction view, it can be said that element A is located between element B and element C. Element A does not need to overlap with elements B and C in the axial direction view. When element A is drawn between element B and element C in the drawing, it means that element A is located between element B and element C in the predetermined direction view.

[0024] "Element A is located radially outside (or radially inside) of element B" means that the radial position of element A is outside (or inside) of the radial position of element B. In addition to the case where element A and element B have an overlapping portion in the radial view, it also includes the case where the axial positions of element A and element B are different and element A and element B do not have an overlapping portion.

[0025] "Arranged in proximity" means a state in which two elements have an overlapping portion in the axial view or the radial view, and no other element is sandwiched between the two elements. For example, "two engaging elements are arranged in proximity" means that no planetary gear mechanism or the like is arranged between the two engaging elements. When no other element is drawn between element A and element B in the drawing, it means that element A and element B are arranged in proximity.

[0026] "One side of the engaging element" and "the other side of the engaging element" mean two elements included in the engaging element that become non-rotatable relative to each other when the engaging element is in the engaged state and become rotatable relative to each other when in the released 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. Generally, the former is called a clutch and the latter is called a brake. Also, "one side of the engaging element" means either one of "one side of the engaging element" and "the other side of the engaging element".

[0027] Other terms will be appropriately defined in the main text of the specification.

[0028] FIG. 1 is a skeleton diagram showing the basic structure of unit 100 according to an embodiment of the present invention. Unit 100 is an automatic transmission unit for a hybrid vehicle that shifts the rotation input to input element In from motor MTR and / or engine ENG as a power source at a gear ratio corresponding to the gear stage and transmits it from output element Out to a drive wheel (not shown). In this example, input element In is a rotating shaft and output element Out is a gear.

[0029] Unit 100 is a unit that houses an input element In, first and second planetary gear mechanisms PG1, PG2, first to fourth engagement elements B1, B2, CL1, CL2, an output element Out, and a motor MTR within a housing 1. The housing 1 is fixedly secured to be non-rotatable with respect to the vehicle. Note that the unit 100 may also be a 3-in-1 unit that houses an inverter INV in the housing 1 as well.

[0030] One end of the input element In is connected to the output shaft of the motor MTR, and the input element In rotates by the power input from the motor MTR. The rotational speed of the input element In is the input rotational speed of the unit 100. The motor MTR is electrically connected to a battery (not shown) outside the unit 100 via the inverter INV, receives power supply from the battery, and functions as an electric motor. Also, the motor MTR can function as a generator.

[0031] The other end of the input element In is connected to an engine ENG outside the unit 100 via the fourth engagement element CL2. By engaging the fourth engagement element CL2, the input element In can be rotated by the input from the engine ENG. A generator GEN is connected to the output shaft of the engine ENG, and the generator GEN can generate electricity using a part of the power of the engine ENG.

[0032] 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 P1, a first carrier C1 as a second rotating element that rotatably supports the plurality of first pinion gears P1, and a first ring gear R1 as a third rotating element. The first sun gear S1 meshes with the plurality of first pinion gears P1, and the plurality of first pinion gears P1 mesh with the first ring gear R1.

[0033] 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 P2, a second carrier C2 as a fifth rotating element for rotatably supporting the plurality of second pinion gears P2, and a second ring gear R2 as a sixth rotating element. The second sun gear S2 meshes with the plurality of second pinion gears P2, and the plurality of second pinion gears P2 mesh with the second ring gear R2.

[0034] The first sun gear S1 is connected to the input element In. The first carrier C1 is connected to the second ring gear R2 and the output element Out. The first ring gear R1 is connected to the second sun gear S2.

[0035] The rotational speed of the output element Out is the output rotational speed of the unit 100.

[0036] The first engaging element B1 is a brake. The first engaging element B1 is here constituted by a selectable one-way clutch that can select between a one-way clutch state and an engaged state by an electric actuator. The first engaging element B1 may be constituted by a hydraulic or electric clutch. When the two parts of the first engaging element B1 that are to be engaged when the first engaging element B1 is in the engaged state are taken as one side and the other side, one side is connected to the second carrier C2 and the other side is fixed to the housing 1. Thereby, if the first engaging element B1 is engaged, the second carrier C2 can be fixed to the housing 1.

[0037] The second engaging element B2 is a brake. The second engaging element B2 is constituted by a hydraulic or electric clutch. When the two parts of the second engaging element B2 that are to be engaged when the second engaging element B2 is in the engaged state are taken as one side and the other side, one side is connected to the first ring gear R1 and the second sun gear S2, and the other side is fixed to the housing 1. Thereby, if the second engaging element B2 is engaged, the first ring gear R1 and the second sun gear S2 can be fixed to the housing 1.

[0038] The third engaging element CL1 is a clutch. The third engaging element CL1 is constituted by a hydraulic or electric clutch. When the third engaging element CL1 is in the engaged state, taking the two parts of the third engaging element CL1 that will be engaged as one side and the other side, one side is connected to the input element In and the first sun gear S1, and the other side is connected to the output element Out, the first carrier C1 and the second ring gear R2. Thus, when the third engaging element CL1 is engaged, the input element In and the first sun gear S1 are connected to the output element Out, the first carrier C1 and the second ring gear R2.

[0039] FIG. 2 is an engagement table showing the relationship between the engagement states of the first to third engaging elements B1, B2, CL1 and the gear shift stages realized in the unit 100. In the table, black circles indicate the engaged state and no marks indicate the released state.

[0040] As shown in the engagement table, the first gear is realized by engaging the first engaging element B1 and releasing the second and third engaging elements B2, CL1. The second gear is realized by engaging the second engaging element B2 and releasing the first and third engaging elements B1, CL1. The third gear is realized by engaging the third engaging element CL1 and releasing the first and second engaging elements B1, B2.

[0041] Also, FIG. 3 is a collinear diagram of the unit 100. In the figure, the vertical lines l1 to l4 correspond to the respective rotating elements of the first and second planetary gear mechanisms PG1, PG2. Regarding the first planetary gear mechanism PG1, the first sun gear S1, the first carrier C1, and the first ring gear R1 are arranged in this order from the left side in the figure. Regarding the second planetary gear mechanism PG2, the second sun gear S2, the second carrier C2, and the second ring gear R2 are arranged in this order from the right side in the figure.

[0042] Since the first carrier C1 and the second ring gear R2 are connected to each other, the same vertical line l2 corresponds to them. Similarly, since the first ring gear R1 and the second sun gear S2 are also connected to each other, the same vertical line l4 corresponds to them. When the distance between the vertical line l1 and the vertical line l2 is set to 1, the distance α1 between the vertical line l2 and the vertical line l4 is the value obtained by dividing the number of teeth of the first sun gear S1 by the number of teeth of the first ring gear R1. When the distance between the vertical line l3 and the vertical line l4 is set to 1, the distance α2 between the vertical line l2 and the vertical line l3 is the value obtained by dividing the number of teeth of the second sun gear S2 by the number of teeth of the second ring gear R2.

[0043] In the collinear diagram, straight lines L1 to L3 corresponding to each gear stage are drawn. The rotational speeds of each rotating element are represented by the vertical coordinates of the intersections of the straight lines L1 to L3 corresponding to each gear stage and the vertical lines l1 to l4.

[0044] In the first gear, by engaging the first engaging element B1, the second carrier C2 is fixed to the housing 1, and the rotational speed of the second carrier C2 becomes zero. Therefore, the straight line L1 corresponding to the first gear is a straight line passing through the point X1.

[0045] Let the rotational speed of the first sun gear S1 be r1, and the rotational speeds of the first carrier C1 and the second ring gear R2 be r4. Then, the input rotational speed rin of the unit 100 is equal to the rotational speed r1 of the first sun gear S1, and the output rotational speed rout is equal to the rotational speeds r4 of the first carrier C1 and the second ring gear R2. Therefore, the gear ratio in the first gear is rin / rout = r1 / r4.

[0046] Also, in the second gear, by engaging the second engaging element B2, the first ring gear R1 and the second sun gear S2 are fixed to the housing 1, and the rotational speeds of the first ring gear R1 and the second sun gear S2 become zero. Therefore, the straight line L2 corresponding to the second gear is a straight line passing through the point X2.

[0047] When the rotational speed of the first sun gear S1 is r2 and the rotational speeds of the first carrier C1 and the second ring gear R2 are r4, the input rotational speed rin of the unit 100 is equal to the rotational speed r2 of the first sun gear S1, and the output rotational speed rout is equal to the rotational speeds r4 of the first carrier C1 and the second ring gear R2. Therefore, the gear ratio at the second speed is rin / rout = r2 / r4. Since r2 is smaller than r1, the gear ratio at the second speed is smaller than that at the first speed.

[0048] Also, at the third speed, by engaging the third engagement element CL1, the input element In and the first sun gear S1 are connected to the output element Out, the first carrier C1, and the second ring gear R2. As a result, the rotational speeds of all the rotational elements become equal, r3. Consequently, the input rotational speed rin and the output rotational speed rout also become equal, and the gear ratio at the third speed becomes 1, which is smaller than that at the second speed.

[0049] Therefore, in the unit 100, three gear stages including the third speed with a gear ratio of 1 can be realized. Compared with a two-forward-speed unit, the ratio between stages becomes smaller, and the acceleration and deceleration speed of the output rotation during gear shifting can be suppressed to be smaller than that of the two-forward-speed unit. Also, since the first to third speeds can be used for low speed, medium speed, and high speed respectively, an appropriate gear ratio can be set according to the speed range.

[0050] Moreover, at the third speed, the gear ratio is 1. That is, all the rotational elements constituting the first and second planetary gear mechanisms PG1 and PG2 rotate at the same rotational speed, so the power transmission loss due to the differential rotation between the rotational elements can be reduced. In addition, the input element In and the output element Out are connected, and the power transmission path from the input element In to the output element Out becomes the shortest, further reducing the power transmission loss.

[0051] FIG. 4 shows a cross section of a specific configuration example of the unit corresponding to the skeleton diagram of FIG. 1. The same reference numerals are assigned to the elements already described.

[0052] Since the connection relationships of the rotating elements, input element In, and output element Out of the first and second planetary gear mechanisms PG1 and PG2 are the same as the skeleton diagram of FIG. 1, the description thereof is omitted here, and the specific configurations of the first to third engaging elements B1, B2, and CL1, which do not appear in the skeleton diagram of FIG. 1, will be mainly described.

[0053] In this configuration example, the first engaging element B1 is a selectable one-way clutch. The first engaging element B1 is composed of a pair of ratchet mechanisms that can be switched in operating state by an electric actuator (not shown) and have different restricted rotation directions. A receiving portion 41 is provided on the outer edge of the second carrier C2, and a plurality of recesses for receiving the claws of the pair of ratchet mechanisms of the first engaging element B1 are provided side by side in the circumferential direction on the outer periphery of the receiving portion 41.

[0054] When only one of the pair of ratchet mechanisms is operated, the first engaging element B1 is in a one-way clutch state, and the second carrier C2 can rotate only in one direction. When both of the pair of ratchet mechanisms are operated, the first engaging element B1 is in an engaged state, and the second carrier C2 is fixed to the housing 1 via the first engaging element B1.

[0055] Since the first engaging element B1 is an engaging element that is engaged when realizing the first speed, that is, an engaging element for which there are few scenes where control of the engaging capacity (also referred to as "torque capacity" in the sense of transmissible torque; the same applies hereinafter) is required, even if the first engaging element B1 is configured as a one-way clutch, smooth starting performance can be ensured. In addition, compared with the case of using a multi-plate clutch, the configuration of the unit 100 can be simplified.

[0056] In addition, by configuring the first engaging element B1 so that not only the one-way clutch state but also the engaged state can be selected, it becomes possible to use the first speed as the reverse gear when the motor MTR is rotated reversely to make the vehicle travel backward.

[0057] Incidentally, the first engaging element B1 may be further configured to be selectable in a released state. Also, the first engaging element B1 may be configured by a hydraulic or electric multi-plate clutch like other engaging elements.

[0058] In this configuration example, the second engaging element B2 is a hydraulic multi-plate clutch. The second engaging element B2 includes a hub 21, a plurality of inner friction plates 22 and outer friction plates 23 arranged alternately, a drum 24, a return spring 25, and a hydraulic actuator 26.

[0059] The hub 21 has a bottomed cylindrical shape composed of a base portion 21a and a cylindrical portion 21b extending axially from the outer edge of the base portion 21a. An inner friction plate 22 is spline-fitted to the outer periphery of the cylindrical portion 21b, and the inner friction plate 22 is axially displaceable and non-rotatable relative to the cylindrical portion 21b. The inner periphery of the base portion 21a is spline-fitted to a connecting portion 51 extending axially from the second sun gear S2, whereby the hub 21 and the second sun gear S2 are non-rotatable relative to each other.

[0060] The drum 24 has a cylindrical shape composed of a cylindrical portion 24a. An outer friction plate 23 is spline-fitted to the inner periphery of the cylindrical portion 24a so as to be axially movable, and the outer friction plate 23 is axially displaceable and non-rotatable relative to the cylindrical portion 24a.

[0061] One end of the drum 24 is fixed to an intermediate wall 2 serving as a wall portion extending inward from the housing 1. In this example, the drum 24 and the intermediate wall 2 are integrally formed.

[0062] The intermediate wall 2 has a portion located between the first engaging element B1 and the second engaging element B2 in a radial view. By fixing the drum 24 of the second engaging element B2 to such an intermediate wall 2, the second engaging element B2 can be reasonably fixed to the housing 1 while making use of the empty space in the housing 1. Further, the intermediate wall 2 has an opening on the inner peripheral side through which the input element In, a connecting portion 34c of the drum 34 of the third engaging element CL1 described later, an intermediate member 52, and a connecting portion 51 of the second sun gear S2 are inserted.

[0063] The hydraulic actuator 26 is an actuator that drives the second engagement element B2. The hydraulic actuator 26 is connected via a flexible pipe 61 to an electric hydraulic supply unit (not shown). The hydraulic supply unit is attached to the outer periphery of the housing 1 or the like. When oil is supplied from the hydraulic supply unit to the oil chamber 261, the piston 262 is pushed out in the axial direction, the inner friction plate 22 and the outer friction plate 23 are pressed against each other and become non-rotatable relative to each other, and the second engagement element B2 is brought into an engaged state.

[0064] A return spring 25 is disposed between the piston 262 and the intermediate wall 2. When oil is not supplied to the oil chamber 261, the piston 262 is pushed back by the spring force of the return spring 25, the inner friction plate 22 and the outer friction plate 23 are separated, and the second engagement element B2 is brought into a released state.

[0065] In this configuration example, the third engagement element CL1 is a hydraulic multi-plate clutch. The third engagement element CL1 includes a hub 31, a plurality of inner friction plates 32 and outer friction plates 33 arranged alternately, a drum 34, a return spring 35, and a hydraulic actuator 36.

[0066] The hub 31 is a bottomed cylindrical shape composed of a base portion 31a and a cylindrical portion 31b extending axially from the outer edge of the base portion 31a. An inner friction plate 32 is spline-fitted to the outer periphery of the cylindrical portion 31b, and the inner friction plate 32 is axially displaceable and non-rotatable relative to the cylindrical portion 31b. The inner periphery of the base portion 31a is spline-fitted to the input element In, whereby the hub 31 and the input element In are non-rotatable relative to each other.

[0067] The drum 34 is a stepped cylindrical shape composed of a base portion 34a, a cylindrical portion 34b extending axially from the outer edge of the base portion 34a, and a connecting portion 34c extending from the inner edge of the base portion 34a in a direction opposite to the cylindrical portion 34b. An outer friction plate 33 is spline-fitted to the inner periphery of the cylindrical portion 34b so as to be axially movable, and the outer friction plate 33 is axially displaceable and non-rotatable relative to the cylindrical portion 34b.

[0068] The connecting portion 34c is spline-fitted non-rotatably relative to one end of an intermediate member 52 disposed between the input element In and the second sun gear S2. The other end of the intermediate member 52 is spline-fitted non-rotatably relative to a connecting portion 53 extending axially from the first carrier C1. Thus, the drum 34 and the first carrier C1 are non-rotatable relative to each other.

[0069] The hydraulic actuator 36 is an actuator that drives the third engaging element CL1. The hydraulic actuator 36 is connected via a flexible pipe 62 to an electric hydraulic supply unit (not shown). The hydraulic supply unit is attached to the outer periphery of the housing 1 or the like. When oil is supplied from the hydraulic supply unit to the oil chamber 361, the piston 362 is pushed out axially, the inner friction plate 32 and the outer friction plate 33 are pressed against each other to become non-rotatable relative to each other, and the third engaging element CL1 is brought into an engaged state.

[0070] A return spring 35 is disposed between the piston 362 and the hub 31. In a state where no oil is supplied to the oil chamber 361, the piston 362 is pushed back by the spring force of the return spring 35, the inner friction plate 32 and the outer friction plate 33 are separated, and the third engaging element CL1 is brought into a released state.

[0071] In the example shown in FIG. 4, the supply of oil to the oil chambers 261 and 361 is controlled by electric hydraulic supply units respectively. However, a control valve unit including a spool, a solenoid valve, etc. may be provided to control the supply of oil to the oil chambers 261 and 361 by the control valve unit.

[0072] Also, instead of the hydraulic actuators 26 and 36, an electric actuator that drives the piston with a motor may be provided. In this case, since the electric actuator mechanically applies a force to the piston, an equal reaction force will be received from the piston. Therefore, when using an electric actuator, the electric actuator should be fixed at a position where it can receive the reaction force, such as the housing 1.

[0073] Also, the relative positional relationships of the first to third engaging elements B1, B2, and CL1 are as follows.

[0074] The first engaging element B1 is arranged radially outward as viewed from the second planetary gear mechanism PG2 and has a portion that overlaps the second planetary gear mechanism PG2 in a radial view. Thereby, the axial dimension of the unit 100 can be reduced.

[0075] Also, the second engaging element B2 is arranged radially outward of the third engaging element CL1 and has a portion that overlaps the third engaging element CL1 in a radial view. Thereby, the axial dimension of the unit 100 can be reduced.

[0076] Also, the hydraulic actuator 26 of the second engaging element B2 is arranged radially outward as viewed from the hydraulic actuator 36 of the third engaging element CL1 and has a portion that overlaps the hydraulic actuator 36 in a radial view. Thereby, the axial dimension of the unit 100 can be reduced.

[0077] Also, according to this arrangement, the second engaging element B2, the third engaging element CL1, and the hydraulic actuators 26 and 36 are closely arranged together in one place, and the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 can be efficiently laid out. That is, an inefficient layout in which the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are arranged closely and other elements such as engaging elements and actuators are arranged between them can be avoided.

[0078] Subsequently, a modified example of the unit 100 will be described.

[0079] Figs. 5A to 5D are skeleton diagrams of a modified example of the unit 100. The position of the third engaging element CL1 is different from that in the skeleton diagram shown in Fig. 1. The same reference numerals are given to the same elements as those in the skeleton diagram shown in Fig. 1.

[0080] Since the third engaging element CL1 only needs to be able to achieve a gear ratio of 1 when engaged, the position of the third engaging element CL1 may be other than the position shown in FIG. 1.

[0081] Specifically, in the collinearity diagram shown in FIG. 3, to achieve a gear ratio of 1, it is only necessary for the straight line L3 corresponding to the third gear to be horizontal. Therefore, any two of the four vertical lines can be selected, and the rotating elements corresponding to the selected two lines can be connected to each other.

[0082] In other words, from all the combinations of selecting two rotating elements from the six rotating elements S1, C1, R1, S2, C2, and R2 of the first and second planetary gear mechanisms PG1 and PG2, excluding the already connected combinations (the first carrier C1 and the second ring gear R2, the first ring gear R1 and the second sun gear S2), a combination of two non-connected rotating elements is selected and these two rotating elements are connected.

[0083] In the modification shown in FIG. 5A, the third engaging element CL1 is arranged at a position where it can connect the input element In and the first sun gear S1 to the first ring gear R1 and the second sun gear S2.

[0084] In the modification shown in FIG. 5B, the third engaging element CL1 is arranged at a position where it can connect the second carrier C2 to the output element Out, the first carrier C1, and the second ring gear R2.

[0085] In the modification shown in FIG. 5C, the third engaging element CL1 is arranged at a position where it can connect the first ring gear R1 and the second sun gear S2 to the output element Out, the first carrier C1, and the second ring gear R2.

[0086] In the modification shown in FIG. 5D, the third engaging element CL1 is arranged at a position where it can connect the first ring gear R1 and the second sun gear S2 to the second carrier C2.

[0087] According to these arrangements, since one side of the third engaging element CL1 is connected to one side of the first engaging element B1 or one side of the second engaging element B2, they can be made into common parts (integrated parts). As a result, the number of parts of the unit 100 can be reduced.

[0088] The engagement table and the collinearity diagram of the modification shown in FIGS. 5A to 5C are the same as those of the skeleton diagram of FIG. 1 shown in FIGS. 2 and 3.

[0089] Subsequently, the operation and effect of the embodiment of the present invention will be described.

[0090] (1) The unit 100 according to the embodiment of the present invention includes an input element In, an output element Out, a first engaging element B1, a second engaging element B2, a third engaging element CL1, 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 the collinearity 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 collinearity diagram. The input element In is connected to the first sun gear S1, the output element Out is connected to the first carrier C1 and the second ring gear R2, one side of the first engaging element B1 is connected to the second carrier C2, the other side of the first engaging element B1 is fixed, one side of the second engaging element B2 is connected to the first ring gear R1 and the second sun gear S2, the other side of the second engaging element B2 is fixed, the third engaging element CL1 connects two rotating elements 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, which are not connected to each other.

[0091] According to this configuration, by changing the engagement states of the first to third engagement elements B1, B2, and CL1, three or more speed stages can be realized. As a result, the ratio between speed stages becomes smaller compared to a two-speed forward unit, and the acceleration and deceleration rates of the output rotation during shifting can be suppressed to be smaller than those of the two-speed forward unit. Also, more appropriate gear ratios can be set for each speed stage.

[0092] Further, when the first and second engagement elements B1 and B2 are disengaged and the third engagement element CL1 is engaged, the gear ratio becomes 1, and all the rotating elements constituting the first and second planetary gear mechanisms PG1 and PG2 rotate at the same rotational speed. Therefore, the power transmission loss due to the differential rotation between the rotating elements can be reduced.

[0093] (2) Also, in the example shown in FIG. 1, the third engagement element CL1 connects the input element In and the output element Out.

[0094] According to this configuration, when the third engagement element CL1 is engaged, the input element In and the output element Out are connected. The power transmission path from the input element In to the output element Out becomes the shortest, and the power transmission loss can be further reduced.

[0095] (3) Also, in the example shown in FIG. 4, the first engagement element B1 is configured to be able to select between a one-way clutch state and an engaged state, the second engagement element B2 is constituted by a multi-plate clutch, and the third engagement element CL1 is constituted by a multi-plate clutch.

[0096] Since the first engagement element B1 is an engagement element that is engaged when realizing the first speed, that is, an engagement element for which there are few scenes where control of the engagement capacity is required, if the first engagement element B1 is constituted by a one-way clutch, smooth starting performance can be ensured while simplifying the configuration of the unit 100.

[0097] In addition, the second and third engagement elements B2 and CL1, for which control of the engagement capacity is required during gear shifting, are configured as multi-plate clutches capable of controlling the engagement capacity, so that the acceleration and deceleration rates of the output rotation during gear shifting to the second and third speeds can be suppressed to a small value.

[0098] In addition, by configuring the first engagement element B1 so that not only the one-way clutch state but also the engaged state can be selected, it becomes possible to use the first speed as the reverse gear when the motor MTR is rotated in the reverse direction to cause the vehicle to travel backward.

[0099] (4) Also, in the example shown in FIG. 4, in a radial view, the second engagement element B2 has a portion that overlaps with the third engagement element CL1.

[0100] According to this configuration, the axial dimension of the unit 100 can be reduced.

[0101] (5) Also, in the example shown in FIG. 4, in a radial view, the hydraulic actuator 26 that drives the second engagement element B2 has a portion that overlaps with the hydraulic actuator 36 that drives the third engagement element CL1.

[0102] According to this configuration, the axial dimension of the unit 100 can be reduced.

[0103] Moreover, by providing both the configurations of (4) and (5), the second engagement element B2, the third engagement element CL1, and the hydraulic actuators 26 and 36 can be arranged together in one place, and the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 can be efficiently laid out. That is, it is possible to avoid an inefficient layout in which the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are arranged closely and the component parts of the engagement elements are arranged between them.

[0104] (6) Also, in the example shown in FIG. 4, in a radial view, the first engagement element B1 has a portion that overlaps with the second planetary gear mechanism PG2.

[0105] According to this configuration, the axial dimension of the unit 100 can be reduced.

[0106] (7) Also, in the example shown in FIG. 4, the other side of the second engagement element B2 is fixed to the intermediate wall 2, and the intermediate wall 2 has a portion located between the first engagement element B1 and the second engagement element B2.

[0107] According to this configuration, while making use of the empty space in the housing 1, the second engagement element B2 can be reasonably fixed to the housing 1.

[0108] As described above, embodiments of the present invention have been described. However, the above embodiments are merely application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0109] For example, the skeleton diagrams shown in FIGS. 1, 5A to 5C are part of the application examples of the present invention, and the skeleton diagrams of the unit to which the present invention is applied are not limited to these.

[0110] Also, in the above embodiment, the unit 100 has been described as being for a hybrid vehicle, but it can also be used for an electric vehicle without an engine ENG.

[0111] Also, the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are each a single pinion planetary gear mechanism, but they may also be double pinion planetary gear mechanisms.

Explanation of Reference Numerals

[0112] 1: Housing 2: Intermediate wall (wall portion) 26: Hydraulic actuator (actuator) 36: Hydraulic actuator (actuator) 100: Unit B1: First engagement element B2: Second engagement element CL1: Third engagement element CL2: Fourth engagement element S1: First sun gear (first rotating element) C1: First carrier (second rotating element) R1: First ring gear (third 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 engaging element, a second engaging element, a third engaging element, a first planetary gear mechanism in which a first rotating element, a second rotating element, and a third rotating element are arranged in this order on a collinear diagram, 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 collinear diagram, the input element is connected to the first rotating element, the output element is connected to the second rotating element and the sixth rotating element, one side of the first engaging element is connected to 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 fourth rotating element, the other side of the second engaging element is fixed, the third engaging element is a unit that connects two non-connected rotating elements selected from the first to sixth rotating elements.

2. In the unit according to claim 1, the third engaging element is a unit that connects the input element and the output element.

3. In the unit according to claim 1, the first engaging element is configured to be able to select between a one-way clutch state and an engaged state, the second engaging element is composed of a multi-plate clutch, the third engaging element is composed of a multi-plate clutch.

4. In the unit according to claim 1, in a radial view, the second engaging element has a portion that overlaps with the third engaging element.

5. In the unit according to claim 4, in a radial view, the actuator that drives the second engaging element has a portion that overlaps with the actuator that drives the third engaging element.

6. In the unit according to claim 1, in a radial view, the first engaging element has a portion that overlaps with the second planetary gear mechanism.

7. In the unit according to claim 1, the other side of the second engaging element is fixed to a wall portion, the wall portion has a portion located between the first engaging element and the second engaging element.

Images