Unit

Abstract

[Problem] To reduce the step ratio during gear shifting in a unit having a power transmission mechanism therein. [Solution] This unit comprises: an input element; an output element; and a gear device which is configured by connecting the rotating elements of a first planetary gear mechanism and a second planetary gear mechanism to each other at two locations, and in which a first rotating part, a second rotating part, a third rotating part, and a fourth rotating part are arranged in this order on a speed diagram. The input element is connectable to the first rotating part and connectable to the second rotating part, the output element is connected to the third rotating part, and the fourth rotating part can be switched between a rotating state and a non-rotating state.

Description

Technical Field

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

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, as the gear ratio of the first speed increases, the torque amplification effect due to deceleration becomes higher. Therefore, as the gear ratio of the first speed increases, the maximum torque of the motor can be reduced, and a motor with a smaller size can be selected. On the other hand, for the second speed, the lower the 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 based on the above design concept, the step ratio (= gear ratio of the first speed / gear ratio of the second speed) when switching between the first speed and the second speed becomes large, resulting in a large shift shock.

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

Means for Solving the Problems

[0008] According to an aspect of the present invention, an input element, an output element, a gear device configured by connecting the rotating elements of a first planetary gear mechanism and a second planetary gear mechanism to each other at two locations, and on a speed diagram, a first rotating portion, a second rotating portion, a third rotating portion, and a fourth rotating portion are arranged in this order, is provided, the input element can be connected to the first rotating portion and can be connected to the second rotating portion, the output element is connected to the third rotating portion, the fourth rotating portion can switch between a rotating state and a non-rotating state, a unit is provided.

Effects of the Invention

[0009] According to the above aspect, by switching the connection destination of the input element (either one or both of the first rotating portion and the second rotating portion) and the rotating state of the fourth rotating portion, three shift stages can be realized. Since the step ratio becomes small, an appropriate gear ratio can be set according to the speed range. In addition, since the gear ratio becomes 1 at the third speed, the power transmission loss caused by the differential rotation between the rotating portions can be reduced.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] 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.

[0012] The “unit” means an entire device 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 speed reduction unit, and the like.

[0013] The "transmission 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 within the unit.

[0014] The "ratio between steps" is the value obtained by dividing the larger (for low speed) transmission ratio by the smaller (for high speed) transmission ratio for two transmission ratios achieved by the unit.

[0015] 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.

[0016] 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 the case for housing the motor, the case for housing the inverter, and the case for housing the power transmission mechanism are integrally formed is called "3in1".

[0017] The "motor" means a rotating electrical machine having a motor function, and may also have a generator function in addition to the motor function.

[0018] "Element A is connected to element B" means that element A is connected to element B, which is upstream or downstream, in a manner that enables 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 connected to element B via another member, and may be connected via a clutch or the like.

[0019] "Element A is coupled to element B" means that element A and element B are directly or indirectly connected via another member, and means a state in which element A and element B are integrated. In other words, it can also be said to be a state in which element A and element B rotate integrally. Also, it means a state in which element A and element B are connected without passing through a brake or a clutch, and can also be said to be a state in which element A and element B are constantly connected.

[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 where they at least partially overlap. It is synonymous with "element A and element B overlap in a predetermined direction". When element A and element B overlap in an 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 a drawing, it means that element A and element B overlap in a 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 portion. 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 a drawing, it means that element A and element B do not overlap in a predetermined direction view.

[0023] "Element A is disposed 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 element B, element A, and element 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. In the axial direction view, element A does not necessarily overlap with elements B and C. 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 disposed outside the axial direction of element B" means that element A is disposed on one side or the other side of the axial direction of element B, including cases where the radial positions of element A and element B are different and element A and element B do not overlap, in addition to the case where element A and element B overlap in the axial direction view.

[0025] "Element A is disposed outside (or inside) the radial direction of element B" means that the radial position of element A is outside (or inside) the radial position of element B, including cases where the axial positions of element A and element B are different and element A and element B do not overlap, in addition to the case where element A and element B overlap in the radial direction view.

[0026] "Are disposed in proximity" means that two elements have a portion that overlaps in the axial direction view or the radial direction view, and there is no other element sandwiched between the two elements. For example, "two engaging elements are disposed in proximity" means that there is no planetary gear mechanism or the like disposed 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 disposed in proximity.

[0027] The "one side of the engaging element" and the "other side of the engaging element" refer to 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. The "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, the "one side of the engaging element" means either one of the "one side of the engaging element" and the "other side of the engaging element".

[0028] Other terms will be defined as appropriate in the text of the specification.

[0029] 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 an electric vehicle with three forward speeds that changes the rotation input to input element IN from a motor as a power source (not shown) at a gear ratio corresponding to the gear position and transmits it from output element OUT to a drive wheel (not shown). Input element IN and output element OUT are each composed of a gear, a rotating shaft, etc. Since the motor can switch between forward rotation and reverse rotation, unit 100 clearly differs in design concept from a unit for a vehicle using an internal combustion engine as the power source in that it does not have a reverse gear.

[0030] Unit 100 is a so-called 3-in-1 unit that houses input element IN, gear device 2, first to third engaging elements CL1, CL2, B1, output element OUT, a motor (not shown), and an inverter in housing 1. Housing 1 is fixedly non-rotatable with respect to the vehicle.

[0031] One end of input element IN is connected to the output shaft of the motor, and input element IN rotates by the power input from the motor. The rotational speed of input element IN is the input rotational speed of unit 100. The motor is electrically connected to a battery (not shown) outside unit 100 via an inverter, receives power supply from the battery, and functions as an electric motor. Also, the motor can function as a generator.

[0032] The gear device 2 is configured by arranging the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 in proximity and connecting their rotating elements at two locations.

[0033] 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.

[0034] 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.

[0035] The S in parentheses beside the reference signs PG1 and PG2 in the figure indicates that the planetary gear mechanism is a single pinion planetary gear mechanism. Although not appearing in this embodiment, when the planetary gear mechanism is a double pinion planetary gear mechanism, the D in parentheses shall be attached beside PG1 and PG2.

[0036] The first sun gear S1 is connected to the second sun gear S2. The first carrier C1 is connected to the second ring gear R2 and the output element OUT. By connecting the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 at two locations in this way, the first rotating part P1 is composed of the first sun gear S1 and the second sun gear S2, the second rotating part P2 is composed of the second carrier C2, the third rotating part P3 is composed of the first carrier C1 and the second ring gear R2, and the fourth rotating part P4 is composed of the first ring gear R1.

[0037] The rotational speed of the output element OUT is the output rotational speed of the unit 100.

[0038] The first engagement element CL1 is a hydraulic or electric clutch. When the first engagement element CL1 is in the engaged state, if the two parts of the first engagement element CL1 to be engaged are defined as one side and the other side, one side is connected to the input element IN via a connecting member M passing through the inner peripheral side of the gear device 2, and the other side is connected to the second rotating part P2 constituted by the second carrier C2. Thus, if the first engagement element CL1 is engaged, the input element IN can be connected to the second rotating part P2 constituted by the second carrier C2.

[0039] The second engagement element CL2 is a hydraulic or electric clutch. When the second engagement element CL2 is in the engaged state, if the two parts of the second engagement element CL2 to be engaged are defined as one side and the other side, one side is connected to the input element IN, and the other side is connected to the first rotating part P1 constituted by the first sun gear S1 and the second sun gear S2. Thus, if the second engagement element CL2 is engaged, the input element IN can be connected to the first rotating part P1 constituted by the first sun gear S1 and the second sun gear S2.

[0040] By connecting one side of the first engagement element CL1 to the input element IN via the connecting member M passing through the inner peripheral side of the gear device 2, the first engagement element CL1 and the second engagement element CL2 can be arranged and dispersed on both axial sides with respect to the gear device 2, that is, the gear device 2 can be arranged between the first engagement element CL1 and the second engagement element CL2 in a radial view.

[0041] When the first engagement element CL1 and the second engagement element CL2 are arranged on the same axial side with respect to the gear device 2, one will be arranged on the inner peripheral side of the other, and the necessity of adopting an actuator (such as a hydraulic actuator that supplies hydraulic pressure from a control valve unit) that is less subject to layout constraints increases.

[0042] On the other hand, when the first engagement element CL1 and the second engagement element CL2 are dispersedly arranged on both axial sides of the gear device 2, a layout in which one is not arranged on the inner peripheral side of the other can be adopted. Thereby, it becomes easier to adopt an actuator that is likely to be subject to layout constraints as the actuator for the first engagement element CL1 and the second engagement element CL2 (such as an electric actuator that needs to be fixed to the housing 1 or the like due to the relationship of reaction force and connected to a power cable, or a hydraulic actuator that needs to attach a hydraulic supply unit to the housing 1 or the like and be connected to the hydraulic supply unit by piping), and the degree of freedom in selecting the actuator used for the first engagement element CL1 and the second engagement element CL2 is improved.

[0043] In addition, since one side of the first engagement element CL1 and one side of the second engagement element CL2 are both connected to the input element IN and rotate integrally, they can be shared, that is, configured as an integral part. For example, in the case where the first engagement element CL1 and the second engagement element CL2 are each configured by a multi-plate clutch in which a plurality of friction plates are arranged between a drum and a hub, by forming the other hub on the outer periphery of one drum, it is possible to configure them as an integral part. Thereby, the number of parts of the unit 100 can be reduced.

[0044] The third engagement element B1 is a hydraulic or electric brake. When the two parts of the third engagement element B1 that will be engaged when the third engagement element B1 is in the engaged state are defined as one side and the other side, one side is connected to the fourth rotating part P4 constituted by the first ring gear R1, and the other side is fixed to the housing 1. Thereby, when the third engagement element B1 is engaged, the fourth rotating part P4 constituted by the first ring gear R1 can be fixed to the housing 1.

[0045] Since the third engagement element B1 is arranged radially outside the first engagement element CL1 and the second engagement element CL2, as the third engagement element B1, either an actuator that is not easily subject to layout constraints or an actuator that is easily subject to layout constraints can be adopted.

[0046] The third engagement element B1 may be constituted by a selectable one-way clutch. The selectable one-way clutch is constituted by a pair of ratchet mechanisms whose operating state can be switched by an electric actuator and whose restricted rotation directions are different. When only one of the pair of ratchet mechanisms is operated, it becomes a one-way clutch state, and when both of the pair of ratchet mechanisms are operated, it becomes an engaged state.

[0047] By providing these first to third engagement elements CL1, CL2, and B1, by engaging one of the first engagement element CL1 and the second engagement element CL2 and releasing the other, the input element IN can be selectively connected to the first rotating part P1 composed of the first sun gear S1 and the second sun gear S2, or the second rotating part P2 composed of the second carrier C2. Also, by engaging both the first engagement element CL1 and the second engagement element CL2, the input element IN can be connected to the first rotating part P1 and the second rotating part P2.

[0048] Also, by changing the engagement state of the third engagement element B1, the fourth rotating part P4 composed of the first ring gear R1 can be switched between a rotating state and a non-rotating state.

[0049] Also, in a radial view, the first to third engagement elements CL1, CL2, and B1 are arranged outside the axial direction of the gear device 2. Since no engagement element is arranged between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the layout freedom of the first to third engagement elements CL1, CL2, and B1 is increased, and the axial dimension of the unit 100 can be reduced.

[0050] Also, in an axial view, the first to third engagement elements CL1, CL2, and B1 can be overlapped with the gear device 2. When these are overlapped, the radial dimension of the unit 100 can be reduced.

[0051] FIG. 2 is an engagement table showing the relationship between the engagement states of the first to third engagement elements CL1, CL2, B1 and the gear positions realized in the unit 100. In the table, black circles indicate the engaged state, and no mark indicates the released state.

[0052] As shown in the engagement table, the first gear is realized by engaging the second engagement element CL2 and the third engagement element B1 and releasing the first engagement element CL1. The second gear is realized by engaging the first engagement element CL1 and the third engagement element B1 and releasing the second engagement element CL2. The third gear is realized by engaging the first engagement element CL1 and the second engagement element CL2 and releasing the third engagement element B1.

[0053] Any gear position is realized by engaging two of the first to third engagement elements CL1, CL2, B1, and the released engagement element is one. When the released engagement element is in a released state like a multi-plate clutch and the parts generating relative rotation come into contact with each other to generate drag torque, the fewer the number of released engagement elements in realizing a gear position, the more the mechanical loss can be reduced. In this embodiment, since the released engagement element is one in any gear position, even when using an engagement element that generates drag torque as the first to third engagement elements CL1, CL2, B1, the mechanical loss can be suppressed and the electricity cost of the vehicle equipped with the unit 100 can be improved.

[0054] FIG. 3 is a speed diagram of the unit 100. On the speed diagram, the first to fourth rotating parts P1 to P4 are arranged in this order, and vertical lines l1 to l4 correspond to the respective rotating parts.

[0055] Since the first planetary gear mechanism PG1 is a single-pinion planetary gear mechanism, the first carrier C1 is arranged between the first sun gear S1 and the first ring gear R1. Since the second planetary gear mechanism PG2 is also a single-pinion planetary gear mechanism, the second carrier C2 is arranged between the second sun gear S2 and the second ring gear R2.

[0056] When the first engaging element CL1 is engaged and the second engaging element CL2 is released, the input element IN is connected to the second rotating part P2, so the vertical line l2 corresponds to the input element IN. Conversely, when the first engaging element CL1 is released and the second engaging element CL2 is engaged, the input element IN is connected to the first rotating part P1, so the vertical line l1 corresponds to the input element IN.

[0057] Since the output element OUT is connected to the third rotating part P3, the vertical line l3 corresponds to the output element OUT.

[0058] When the interval between the vertical line l1 and the vertical line l3 is set to 1, the interval α1 between the vertical line l3 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. Also, when the interval between the vertical line l1 and the vertical line l2 is set to 1, the interval 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.

[0059] In the speed diagram, straight lines L1 to L3 corresponding to each gear stage are drawn. The rotational speeds of the respective rotating parts P1 to P4 in each gear stage 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.

[0060] In the first gear, the second engaging element CL2 and the third engaging element B1 are engaged, and the first engaging element CL1 is released. As a result, the rotational speeds of the input element IN and the first rotating part P1 become equal, and the rotational speed of the fourth rotating part P4 becomes zero. Therefore, the straight line L1 corresponding to the first gear is a straight line passing through the point X3 and the point X2. The rotational speed of the output element OUT is r1, which is the vertical coordinate of the intersection of the straight line L1 and the vertical line l3. Therefore, when the rotational speed of the input element IN is rin, the gear ratio in the first gear is rin / r1.

[0061] In the second speed, the first engaging element CL1 and the third engaging element B1 are engaged, and the second engaging element CL2 is released. As a result, the rotational speeds of the input element IN and the second rotating part P2 become equal, and the rotational speed of the fourth rotating part P4 becomes zero. Therefore, the straight line L2 corresponding to the second speed is a straight line passing through the points X1 and X2 and having a larger slope than the straight line L1. The rotational speed of the output element OUT is r2, which is the ordinate of the intersection of the straight line L2 and the vertical line l3. Therefore, the gear ratio in the second speed is rin / r2 when the rotational speed of the input element IN is rin. Since r2 is larger than r1, the gear ratio in the second speed is smaller than the gear ratio in the first speed.

[0062] In the third speed, the first engaging element CL1 and the second engaging element CL2 are engaged, and the third engaging element B1 is released. As a result, the rotational speeds of the input element IN, the first to fourth rotating parts P1 to P4, and the output element OUT become equal. Therefore, the straight line L3 corresponding to the third speed is a straight line with a zero slope passing through the points X3 and X1. Since the rotational speeds of the input element IN and the output element OUT are equal, the gear ratio in the third speed is 1, which is smaller than the gear ratios in the first and second speeds.

[0063] Therefore, in the unit 100, three gear stages can be realized. Compared with a two-forward-speed unit, the ratio between gear stages is smaller, and the shock during gear shifting can be suppressed to be smaller than that of a two-forward-speed unit. Also, since the first to third speeds can be used as low speed, medium speed, and high speed respectively, an appropriate gear ratio can be set according to the speed range.

[0064] Also, in the third speed, the gear ratio is 1. That is, since all the rotating parts P1 to P4 constituting the gear device 2 rotate at the same rotational speed, the power transmission loss caused by the differential rotation between the rotating parts can be reduced. Since the third speed for high-speed cruising is frequently used, a high power saving effect can be obtained by realizing a gear ratio of 1 in the third speed.

[0065] Subsequently, a modification of the embodiment of the present invention will be described.

[0066] FIG. 4A is a skeleton diagram of the unit 100 according to the modified example.

[0067] The first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are single-pinion planetary gear mechanisms, the same as the unit 100 shown in FIG. 1.

[0068] In this unit 100, the first rotating part P1 is formed by connecting the first sun gear S1 and the second sun gear S2, the second rotating part P2 is formed by the second carrier C2, the third rotating part P3 is formed by connecting the first carrier C1 and the second ring gear R2, and the fourth rotating part P4 is formed by the first ring gear R1.

[0069] Then, one side of the first engaging element CL1 is connected to the input element IN, the other side of the first engaging element CL1 is connected to the second carrier C2 as the second rotating part P2, one side of the second engaging element CL2 is connected to the input element IN, the other side of the second engaging element CL2 is connected to the first sun gear S1 and the second sun gear S2 as the first rotating part P1, one side of the third engaging element B1 is connected to the first ring gear R1 as the fourth rotating part P4, and the other side of the third engaging element B1 is fixed to the housing 1.

[0070] As shown in FIG. 4B, one side of the second engaging element CL2 may be connected to the input element IN via a connecting member M passing through the inner peripheral side of the gear device 2.

[0071] According to the modified examples shown in FIGS. 4A and 4B, since the first to third engaging elements CL1, CL2, and B1 are respectively arranged outside the axial direction of the gear device 2, the layout freedom of the first to third engaging elements CL1, CL2, and B1 is increased, and the axial dimension of the unit 100 can be reduced.

[0072] Also, in the axial view, the first to third engaging elements CL1, CL2, and B1 can be overlapped with the gear device 2. When these are overlapped, the radial dimension of the unit 100 can be reduced.

[0073] In addition, one side of the first engaging element CL1 and one side of the second engaging element CL2 can be shared (integrated into one part), thereby reducing the number of components of the unit 100.

[0074] The engagement table is the same as that shown in FIG. 2, and three shift speeds can be realized by changing two of the engaged first to third engaging elements CL1, CL2, and B1. Since the ratio between shifts becomes smaller, an appropriate gear ratio can be set according to the speed range. Also, since the gear ratio is 1 in the third speed, the power transmission loss caused by the differential rotation between the rotating parts can be reduced.

[0075] Since there is only one disengaged engaging element in any shift speed, even when using engaging elements that generate drag torque as the first to third engaging elements CL1, CL2, and B1, mechanical losses can be suppressed and the power consumption of the vehicle in which the unit 100 is mounted can be improved.

[0076] Also, according to the modification shown in FIG. 4B, a layout can be adopted in which the first engaging element CL1 and the second engaging element CL2 are distributed and arranged on both axial sides with respect to the gear device 2, and the second engaging element CL2 is not arranged on the inner peripheral side of the first engaging element CL1. As a result, it becomes easier to adopt an actuator that is easily subject to layout constraints as the actuators of the first to third engaging elements CL1, CL2, and B1, and the degree of freedom in selecting the actuator is improved.

[0077] The speed diagram is the same as that shown in FIG. 3.

[0078] FIG. 5A is a skeleton diagram of the unit 100 according to another modification.

[0079] Unlike the unit 100 shown in FIG. 1, the first planetary gear mechanism PG1 is a double pinion planetary gear mechanism. That is, the first carrier C1 rotatably supports a plurality of inner pinion gears (not shown) that mesh with the first sun gear S1 and a plurality of outer pinion gears (not shown) that mesh with the first ring gear R1, and further, the plurality of inner pinion gears and the plurality of outer pinion gears mesh with each other. The second planetary gear mechanism PG2 is a single pinion planetary gear mechanism, the same as the unit 100 shown in FIG. 1.

[0080] In this unit 100, the first rotating part P1 is configured by connecting the first sun gear S1 and the second sun gear S2, the second rotating part P2 is configured by the first carrier C1, the third rotating part P3 is configured by connecting the first ring gear R1 and the second ring gear R2, and the fourth rotating part P4 is configured by the second carrier C2.

[0081] Then, one side of the first engaging element CL1 is connected to the input element IN, the other side of the first engaging element CL1 is connected to the first carrier C1 as the second rotating part P2, one side of the second engaging element CL2 is connected to the input element IN, the other side of the second engaging element CL2 is connected to the first sun gear S1 and the second sun gear S2 as the first rotating part P1, one side of the third engaging element B1 is connected to the second carrier C2 as the fourth rotating part P4, and the other side of the third engaging element B1 is fixed to the housing 1.

[0082] According to the modification shown in FIG. 5A, since the first to third engaging elements CL1, CL2, and B1 are respectively arranged outside the axial direction of the gear device 2, the layout freedom degree of the first to third engaging elements CL1, CL2, and B1 is increased, and the axial dimension of the unit 100 can be reduced.

[0083] Also, in the axial view, the first to third engaging elements CL1, CL2, and B1 can be overlapped with the gear device 2. When these are overlapped, the radial dimension of the unit 100 can be reduced.

[0084] In addition, one side of the first engaging element CL1 and one side of the second engaging element CL2 can be shared (integrated into one part), thereby reducing the number of components of the unit 100.

[0085] The engagement table is the same as that shown in FIG. 2, and three shift speeds can be realized by changing two of the engaged first to third engaging elements CL1, CL2, and B1. Since the ratio between shifts becomes smaller, an appropriate gear ratio can be set according to the speed range. Also, in the third gear, the gear ratio becomes 1, so the power transmission loss caused by the differential rotation between the rotating parts can be reduced.

[0086] Since there is only one disengaged engaging element in any shift speed, even when using an engaging element that generates drag torque as the first to third engaging elements CL1, CL2, and B1, mechanical losses can be suppressed and the power consumption of the vehicle on which the unit 100 is mounted can be improved.

[0087] FIG. 5B is a speed diagram of the modification shown in FIG. 5A. Since the first planetary gear mechanism PG1 is a double pinion planetary gear mechanism, on the speed diagram, the first ring gear R1 will be arranged between the first sun gear S1 and the first carrier C1. That is, it is the reverse of the case where the second and third rotating elements are a single pinion planetary gear mechanism.

[0088] Although the rotating elements constituting the first to fourth rotating parts P1 to P4 and the intervals between the vertical lines l1 to l4 are different from those shown in FIG. 3, since the connection relationships between the first to fourth rotating parts P1 to P4 and the first to third engaging elements CL1, CL2, and B1 are the same, substantially the same speed diagram can be obtained.

[0089] Next, the functions and effects of the embodiments of the present invention will be described.

[0090] (1) In the embodiments of the present invention, In the examples shown in FIGS. 1, 4A, 4B, and 5A, the unit 100 includes an input element IN and, an output element OUT, and The gear device 2 (Figs. 3, 4C, 5B) is configured by connecting the rotational elements of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 to each other at two locations, and on the speed diagram, the first rotational part P1, the second rotational part P2, the third rotational part P3, and the fourth rotational part P4 are arranged in this order, and is provided with. The input element IN can be connected to either one or both of the first rotational part P1 and the second rotational part P2, The output element OUT is connected to the third rotational part P3, The fourth rotational part P4 can be switched between a rotating state and a non-rotating state.

[0091] According to the present embodiment, by switching the connection destination of the input element IN (either one or both of the first rotational part P1 and the second rotational part P2) and the rotational state of the fourth rotational part P4, three shift speeds can be realized. Since the ratio between the shift speeds becomes small, an appropriate gear ratio can be set according to the speed range, and since the gear ratio becomes 1 in the third speed, the power transmission loss due to the differential rotation between the rotational parts can be reduced.

[0092] (2) The gear device 2 can be configured as shown in Figs. 1, 4A, and 4B. In the example shown in Figs. 1, 4A, and 4B, The first planetary gear mechanism PG1 includes a first sun gear S1, a first carrier C1, and a first ring gear R1, and is a single pinion planetary gear mechanism in which the first carrier C1 is arranged between the first sun gear S1 and the first ring gear R1 on the speed diagram (Fig. 3). The second planetary gear mechanism PG2 includes a second sun gear S2, a second carrier C2, and a second ring gear R2, and is a single pinion planetary gear mechanism in which the second carrier C2 is arranged between the second sun gear S2 and the second ring gear R2 on the speed diagram (Fig. 3). The first rotational part P1 is configured by connecting the first sun gear S1 and the second sun gear S2, The second rotational part P2 is configured by the second carrier C2, The third rotational part P3 is configured by connecting the first carrier C1 and the second ring gear R2, The fourth rotating part P4 is composed of the first ring gear R1.

[0093] In the example shown in FIG. 5A, The first planetary gear mechanism PG1 includes a first sun gear S1, a first carrier C1, and a first ring gear R1, and is a single pinion planetary gear mechanism in which the first carrier C1 is arranged between the first sun gear S1 and the first ring gear R1 on the speed diagram (FIG. 5B). The second planetary gear mechanism PG2 includes a second sun gear S2, a second ring gear R2, and a second carrier C2, and is a double pinion planetary gear mechanism in which the second ring gear R2 is arranged between the second sun gear S2 and the second carrier C2 on the speed diagram (FIG. 5B). The first rotating part P1 is composed of the first sun gear S1 and the second sun gear S2 being coupled together, The second rotating part P2 is composed of the first carrier C1, The third rotating part P3 is composed of the first ring gear R1 and the second ring gear R2 being coupled together, The fourth rotating part P4 is composed of the second carrier C2.

[0094] (3) The connection destination of the input element IN and the switching of the rotation state of the fourth rotating part P4 can be realized by the first to third engagement elements CL1, CL2, and B1.

[0095] In the examples shown in FIGS. 1, 4A, 4B, and 5A, The unit 100 includes the first engagement element CL1, the second engagement element CL2, the third engagement element B1, and. One side of the first engagement element CL1 is connected to the input element IN, The other side of the first engagement element CL1 is connected to the second rotating part P2, One side of the second engagement element CL2 is connected to the input element IN, The other side of the second engagement element CL2 is connected to the first rotating part P1, One side of the third engagement element B1 is connected to the fourth rotating part P4, The other side of the third engaging element B1 is fixed.

[0096] According to this configuration, in the axial view, the first to third engaging elements CL1, CL2, and B1 can overlap with the gear device 2. When these are overlapped, the radial dimension of the unit 100 can be reduced.

[0097] (4) In the examples shown in FIGS. 1, 4A, 4B, and 5A, the first to third engaging elements CL1, CL2, and B1 are respectively arranged on the outer side in the axial direction of the gear device 2. Thereby, the degree of freedom in the layout of the first to third engaging elements CL1, CL2, and B1 is increased, and the axial dimension of the unit 100 can be reduced.

[0098] (5) In the examples shown in FIGS. 1 and 4B, one side of the first engaging element CL1 or one side of the second engaging element CL2 is connected to the input element IN via a connecting member M passing through the inner peripheral side of the gear device 2. Thereby, a layout can be adopted in which the first engaging element CL1 and the second engaging element CL2 are dispersed and arranged on both axial sides with respect to the gear device 2, and one is not arranged on the inner peripheral side of the other. It becomes easier to adopt an actuator that is likely to be subject to layout constraints as the actuator for the first to third engaging elements CL1, CL2, and B1, and the degree of freedom in selecting the actuator is improved.

[0099] (6) In the examples shown in FIGS. 1, 4A, 4B, and 5A, three shift speeds are realized by changing two engaging elements out of the first to third engaging elements CL1, CL2, and B1 (FIG. 2). Since there is one disengaged engaging element in any shift speed, even when using an engaging element that generates drag torque as the first to third engaging elements CL1, CL2, and B1, mechanical losses can be suppressed and the power consumption of the vehicle on which the unit 100 is mounted can be improved.

[0100] (7) In the examples shown in FIGS. 1, 4A, 4B, and 5A, one side of the first engaging element CL1 and one side of the second engaging element CL2 may be configured as an integral part. Thereby, the number of parts of the unit 100 can be reduced.

[0101] The embodiments of the present invention have been described above. 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.

[0102] The skeleton diagrams shown in FIGS. 1, 4A, 4B, and 5A are part of the application examples of the present invention, and the skeleton diagrams of the units to which the present invention is applied are not limited thereto.

[0103] FIGS. 6 to 32 are examples of skeleton diagrams of units included in the technical scope of the inventions according to claims 1, 4, 7, and 8. The same elements as those shown in the embodiment of FIG. 1 are denoted by the same reference numerals. Each engagement table is the same as the engagement table shown in FIG. 2. Also, since the connection relationships between the first to fourth rotating parts P1 to P4 and the first to third engagement elements CL1, CL2, and B1 are the same for each speed diagram, it is substantially the same as FIG. 3.

[0104] Further, as the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, either a single pinion planetary gear mechanism or a double pinion planetary gear mechanism may be used.

Explanation of Reference Numerals

[0105] 1: Housing 2: Gear device 100: Unit CL1: First engagement element CL2: Second engagement element B1: Third engagement element S1: First sun gear S2: Second sun gear C1: First carrier C2: Second carrier R1: First ring gear R2: Second ring gear M: Connection member P1: First rotating part P2: Second rotating part P3: Third rotating part P4: Fourth rotating part 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 gear device configured by connecting the rotating elements of a first planetary gear mechanism and a second planetary gear mechanism at two locations, and having a first rotating part, a second rotating part, a third rotating part, and a fourth rotating part arranged in this order on a collinear diagram, and the input element is connectable to the first rotating part and also connectable to the second rotating part, the output element is connected to the third rotating part, the fourth rotating part is capable of switching between a rotating state and a non-rotating state, the first rotating part is composed of a first sun gear of the first planetary gear mechanism and a second sun gear of the second planetary gear mechanism, the third rotating part is composed of a first ring gear of the first planetary gear mechanism and a second ring gear of the second planetary gear mechanism, a unit.

2. The unit according to Claim 1, wherein the first planetary gear mechanism includes a first rotating element, a second rotating element, and a third rotating element, and is a planetary gear mechanism in which the second rotating element is arranged between the first rotating element and the third rotating element on a collinear diagram, the second planetary gear mechanism includes a fourth rotating element, a fifth rotating element, and a sixth rotating element, and is a planetary gear mechanism in which the fifth rotating element is arranged between the fourth rotating element and the sixth rotating element on a collinear diagram, the first rotating part is configured by connecting the first rotating element and the fourth rotating element, the second rotating part is composed of the fifth rotating element, the third rotating part is configured by connecting the second rotating element and the sixth rotating element, the fourth rotating part is composed of the third rotating element, a unit.

3. The unit according to Claim 1 or 2, including a first engaging element, a second engaging element, and a third engaging element, wherein one side of the first engaging element is connected to the input element, the other side of the first engaging element is connected to the second rotating part, one side of the second engaging element is connected to the input element, the other side of the second engaging element is connected to the first rotating part, one side of the third engaging element is connected to the fourth rotating part, and the other side of the third engaging element is fixed, a unit.

4. The unit according to Claim 3, wherein the first to third engaging elements are each arranged outside the axial direction of the gear device, a unit.

5. The unit according to Claim 3, ​ One side of the first engaging element or one side of the second engaging element is connected to the input element via a connecting member passing through the inner peripheral side of the gear device. Unit. **Claim 6** The unit according to claim 3, wherein three speed stages are realized by changing two engaging elements among the first to third engaging elements. Unit. **Claim 7** The unit according to claim 3, wherein one side of the first engaging element and one side of the second engaging element are formed as an integral part. Unit.

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