Unit

Abstract

[Problem] To reduce the step ratio when shifting gears in a unit having a power transmission mechanism therein. [Solution] This unit has an input element, an output element, first through third engaging elements, a first planetary gear mechanism having first through third rotary elements arranged in this order in a nomograph, and a second planetary gear mechanism having fourth through sixth rotary elements arranged in this order in said nomograph. The input element is connected to the third rotary element. The output element is connected to the second rotary element and the sixth rotary element. One side of the first engaging element is connected to the fifth rotary element, and the other side of the first engaging element is fixed. One side of the second engaging element is connected to the first rotary element and the fourth rotary element, and the other side of the second engaging element is fixed. The third engaging element connects two rotary elements that are selected from among the first through sixth rotary elements and are not connected to one another.

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, and a second planetary gear mechanism in which a fourth rotating element, a fifth rotating element, and a sixth rotating element are arranged in this order on the collinear diagram. The input element is connected to the third 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 first 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-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 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 caused by the differential rotation between the rotating elements can be reduced.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 4E

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 "ratio between steps" is the value obtained by dividing the larger (for low speed) gear ratio by the smaller (for high speed) gear ratio for two gear ratios realized by the unit.

[0016] The "axial direction" means the axial direction of the rotation axis of the parts constituting the unit. The parts 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. The mode in which the case that houses the motor, the case that houses the inverter, and the case that houses the power transmission mechanism are integrally formed is called "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 in which power can be transmitted 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 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 at least partially overlap when observed from the predetermined direction. 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 do not have a portion where they overlap when observed from the predetermined direction. 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 side by side 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 it is observed that element A is between element B and element C when observed from a predetermined direction (axial direction, radial direction, gravitational direction, etc.). 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 necessarily 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 elements A and B have an overlapping portion in the radial view, it also includes the case where the axial positions of elements A and B are different and elements A and B do not have an overlapping portion.

[0025] "Arranged in proximity" means that two elements have an overlapping portion in the axial view or the radial view, and there is no other element 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 elements A and B in the drawing, it means that elements A and 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] For other terms, they will be defined as appropriate 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 an electric vehicle that shifts the rotation input to input element IN from a motor as a power source (not shown) 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, both input element IN and output element OUT are rotating shafts.

[0029] Unit 100 is a so-called 3-in-1 unit that houses an input element IN, first and second planetary gear mechanisms PG1, PG2, first to third engagement elements B1, B2, CL, an output element OUT, a motor (not shown), and an inverter inside a housing 1. The housing 1 is fixedly secured to the vehicle so as not to rotate.

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

[0031] 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.

[0032] 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.

[0033] The first sun gear S1 is connected to the second sun gear S2. The first carrier C1 is connected to the output element OUT and the second ring gear R2 via the inner peripheral sides of the first sun gear S1 and the second sun gear S2 by a member M disposed on the inner peripheral side of the first sun gear S1 and the second sun gear S2. The first ring gear R1 is connected to the input element IN.

[0034] The rotational speed of the output element OUT is the output rotational speed of the unit 100.

[0035] The first engagement element B1 is a brake. The first engagement element B1 is constituted by a hydraulic or electric clutch. When the two parts of the first engagement element B1 that are to be engaged when the first engagement 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 engagement element B1 is engaged, the second carrier C2 can be fixed to the housing 1.

[0036] The second engagement element B2 is a brake. The second engagement element B2 is constituted by a hydraulic or electric clutch. When the two parts of the second engagement element B2 that are to be engaged when the second engagement element B2 is in the engaged state are taken as one side and the other side, one side is connected to the first sun gear S1 and the second sun gear S2, and the other side is fixed to the housing 1. Thereby, if the second engagement element B2 is engaged, the first sun gear S1 and the second sun gear S2 can be fixed to the housing 1.

[0037] The third engagement element CL is a clutch. The third engagement element CL is constituted by an electric multi-plate clutch.

[0038] The third engagement element CL includes a hub 11, inner friction plates 12 and outer friction plates 13 arranged alternately, a drum 14, and an electric actuator 15.

[0039] The inner friction plate 12 is spline-fitted to the outer periphery of the hub 11, and the inner friction plate 12 is axially relatively displaceable and non-rotatable relative to the hub 11. Further, the hub 11 is spline-fitted to the outer periphery of the first ring gear R1, and thereby is non-rotatably connected to the first ring gear R1 and the input element IN.

[0040] On the inner circumference of the drum 14, an outer friction plate 13 is spline-fitted, and the outer friction plate 13 is displaceable relative to the drum 14 and non-rotatable relative to the drum 14. Further, the drum 14 is connected to one side of the first sun gear S1, the second sun gear S2, and the second engaging element B2.

[0041] The electric actuator 15 is an actuator that drives the third engaging element CL. When the motor built in the electric actuator 15 is driven, the piston 15p is extended in the axial direction, the inner friction plate 12 and the outer friction plate 13 are pressed against each other to become non-rotatable relative to each other, and the third engaging element CL enters an engaged state. Since the electric actuator 15 mechanically applies a force to the piston 15p and receives the reaction force from the piston 15p, the electric actuator 15 is fixed to the housing 1.

[0042] When the motor built in the electric actuator 15 is driven in the reverse direction, the piston 15p retracts, the inner friction plate 12 and the outer friction plate 13 are separated, and the third engaging element CL enters a released state.

[0043] Note that instead of the electric actuator 15, a hydraulic actuator that pushes out the piston 15p hydraulically can also be used. The supply of oil to the hydraulic actuator may be performed by a hydraulic supply unit attached to the housing 1 or the like, or may be performed by a control valve unit including a spool, a solenoid valve, or the like.

[0044] When the two parts of the third engaging element CL that are to be engaged when the third engaging element CL is in the engaged state are defined as one side (hub 11) and the other side (drum 14), respectively, one side is connected to the input element IN and the first ring gear R1, and the other side is connected to one side of the first sun gear S1, the second sun gear S2, and the second engaging element B2. Thereby, when the third engaging element CL is engaged, the input element IN and the first ring gear R1 are connected to one side of the first sun gear S1, the second sun gear S2, and the second engaging element B2.

[0045] Since the other side of the third engaging element CL is connected to one side of the second engaging element B2, they can be made into a shared part (integrated part). As a result, the number of parts of the unit 100 can be reduced.

[0046] Also, by connecting the first sun gear S1 and the first ring gear R1 with the third engaging element CL, it is not necessary to arrange the third engaging element CL between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, and the first engaging element B1, the second engaging element B2, and the third engaging element CL can be aggregated in one place. As a result, it is also possible to arrange the first engaging element B1, the second engaging element B2, and the third engaging element CL close to each other by effectively using the space outside the radial direction of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2. Furthermore, in the arrangement shown in FIG. 1, the third engaging element CL overlaps with the first planetary gear mechanism PG1 in the radial view, and thereby, the axial dimension of the unit 100 can be reduced.

[0047] Also, as the actuator that can be used for the third engaging element CL, there are an actuator that is likely to be subject to layout constraints (an electric actuator that needs to be fixed to the housing 1 or the like due to the relationship of the reaction force, a hydraulic actuator that needs to attach a hydraulic supply unit to the housing 1 or the like, etc.) and an actuator that is less likely to be subject to layout constraints (a hydraulic actuator that supplies hydraulic pressure from a control valve unit, etc.). When using the former actuator, if it is necessary to arrange the third engaging element CL between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the difficulty of layout design increases.

[0048] Regarding this point, in the arrangement shown in FIG. 1, the third engaging element CL can be arranged outside the radial direction of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, and it is also easy to fix the third engaging element CL to the housing 1. Therefore, the layout design is easy regardless of the type of actuator. Therefore, according to the arrangement shown in FIG. 1, the degree of freedom in selecting the actuator that drives the third engaging element CL can be increased.

[0049] Further, by connecting the first carrier C1 to the second ring gear R2 via the inner circumferential sides of the first sun gear S1 and the second sun gear S2, the connection between the first carrier C1 and the second ring gear R2 becomes easier and the layout design becomes easier as compared with the case of connecting via the radially outer sides of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2.

[0050] FIG. 2 is an engagement table showing the relationship between the engagement states of the first to third engagement elements B1, B2, and CL and the gear shift stages realized in the unit 100. In the table, black circles indicate the engaged states and blanks indicate the released states.

[0051] As shown in the engagement table, the first gear is realized by engaging the first engagement element B1 and releasing the second and third engagement elements B2 and CL. The second gear is realized by engaging the second engagement element B2 and releasing the first and third engagement elements B1 and CL. The third gear is realized by engaging the third engagement element CL and releasing the first and second engagement elements B1 and B2.

[0052] FIG. 3 is a collinearity 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 and PG2. For 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. For 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 left side in the figure.

[0053] Since the first sun gear S1 and the second sun gear S2 are connected to each other, the same vertical line l1 corresponds to them. Similarly, since the first carrier C1 and the second ring gear R2 are also connected to each other, the same vertical line l3 corresponds to them. When the interval between the vertical lines l1 and l3 is set to 1, the interval α1 between the vertical lines l3 and 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 lines l1 and l2 is set to 1, the interval α2 between the vertical lines l2 and 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.

[0054] In the alignment chart, straight lines L1 to L3 corresponding to each gear stage are drawn. The rotational speeds of the respective rotating elements 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.

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

[0056] Assuming that the rotational speed of the first ring gear R1 is r4 and the rotational speeds of the first carrier C1 and the second ring gear R2 are r1, the input rotational speed rin of the unit 100 is equal to the rotational speed r4 of the first ring gear R1, and the output rotational speed rout is equal to the rotational speeds r1 of the first carrier C1 and the second ring gear R2. Therefore, the gear ratio in the first gear is rin / rout = r4 / r1.

[0057] Also, in the second gear, by engaging the second engaging element B2, the first sun gear S1 and the second sun gear S2 are fixed to the housing 1, and since the rotational speeds of the first sun gear S1 and the second sun gear S2 become zero, the straight line L2 corresponding to the second gear is a straight line passing through the point X2.

[0058] Assuming that the rotational speed of the first ring gear R1 is r4 and the rotational speeds of the first carrier C1 and the second ring gear R2 are r2, the input rotational speed rin of the unit 100 is equal to the rotational speed r4 of the first ring gear R1, and the output rotational speed rout is equal to the rotational speeds r2 of the first carrier C1 and the second ring gear R2. Therefore, the gear ratio in the second gear is rin / rout = r4 / r2. Since r2 is greater than r1, the gear ratio in the second gear is smaller than the gear ratio in the first gear.

[0059] Also, in the third gear, by engaging the third engaging element CL, the first ring gear R1 is connected to the first sun gear S1 and the second sun gear S2, so the rotational speeds of all the rotating elements become equal to r3. As a result, the input rotational speed rin and the output rotational speed rout also become equal, and the gear ratio in the third gear is 1, which is smaller than that in the second gear.

[0060] Therefore, in unit 100, since three gear stages including the third gear stage with a gear ratio of 1 can be realized, the ratio between gear stages becomes smaller compared to the two-forward-speed unit, and the acceleration and deceleration rates of the output rotation during gear shifting can be suppressed to be smaller than those of the two-forward-speed unit. Also, since the first to third gears can be used for low speed, medium speed, and high speed respectively, an appropriate gear ratio can be set according to the speed range.

[0061] Also, in the third gear, the gear ratio is 1. That is, since all the rotating elements constituting the first and second planetary gear mechanisms PG1 and PG2 rotate at the same rotational speed, the power transmission loss caused by the differential rotation between the rotating elements can be reduced.

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

[0063] Figures 4A to 4E are skeleton diagrams of a modified example of unit 100. The position of the third engagement element CL is different from the skeleton diagram shown in FIG. 1. The same elements as those in the skeleton diagram shown in FIG. 1 are labeled with the same reference numerals.

[0064] Since the third engagement element CL only needs to be able to realize a gear ratio of 1 when engaged, the position of the third engagement element CL may be other than the position shown in FIG. 1.

[0065] Specifically, in the collinearity diagram shown in FIG. 3, to realize 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.

[0066] 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 sun gear S1 and the second sun gear S2, the first carrier C1 and the second ring gear R2), a combination of two non-connected rotating elements is selected, and these two rotating elements are connected.

[0067] In the modification shown in FIG. 4A, the third engagement element CL is disposed at a position where the output element OUT, the first carrier C1, and the second ring gear R2 can be connected to the first sun gear S1 and the second sun gear S2. Specifically, one side (hub 11) of the third engagement element CL is connected to one side of the first sun gear S1, the second sun gear S2, and the second engagement element B2, and the other side (drum 14) is connected to the output element OUT, the first carrier C1, and the second ring gear R2.

[0068] In this arrangement, since the third engagement element CL is disposed radially inside the member connecting the first carrier C1 and the output element OUT, as the actuator for driving the third engagement element CL, it is preferable to use a hydraulic actuator 16 that supplies hydraulic pressure from a control valve unit with fewer layout constraints.

[0069] Further, by connecting the first carrier C1 to the second ring gear R2 via the inner circumferential sides of the first sun gear S1 and the second sun gear S2, compared with the case of connecting via the radially outer sides of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the connection between the first carrier C1 and the second ring gear R2 becomes easier, and the layout design becomes easier.

[0070] Further, the third engagement element CL is disposed coaxially with the first and second planetary gear mechanisms PG1, PG2, and in an axial view, has a portion overlapping with the first planetary gear mechanism PG1 and a portion overlapping with the second planetary gear mechanism PG2. Thereby, the radial dimension of the unit 100 can be reduced.

[0071] Also, since one side (hub 11) of the third engagement element CL is connected to one side of the second engagement element B2, these can be made into common parts (integral parts). Thereby, the number of parts of the unit 100 can be reduced.

[0072] In the modification shown in FIG. 4B, the third engagement element CL is arranged at a position where the input element IN and the first ring gear R1 can be connected to the first carrier C1, the second ring gear R2, and the output element OUT. Specifically, one side (hub 11) of the third engagement element CL is connected to the first carrier C1, the second ring gear R2, and the output element OUT, and the other side (drum 14) is connected to the input element IN and the first ring gear R1.

[0073] In this arrangement, since the third engagement element CL is arranged between the member connecting the input element IN and the first ring gear R1 and the member connecting the first carrier C1 and the output element OUT, as the actuator for driving the third engagement element CL, it is preferable to use a hydraulic actuator 16 that supplies hydraulic pressure from a control valve unit with few layout constraints.

[0074] Further, by connecting the first carrier C1 to the second ring gear R2 via the inner circumferential sides of the first sun gear S1 and the second sun gear S2, compared with the case of connecting via the radially outer sides of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the connection between the first carrier C1 and the second ring gear R2 becomes easier, and the layout design becomes easier.

[0075] Further, the third engagement element CL is arranged coaxially with the first and second planetary gear mechanisms PG1, PG2, and in the axial view, it has a portion overlapping with the first planetary gear mechanism PG1 and a portion overlapping with the second planetary gear mechanism PG2. Thereby, the radial dimension of the unit 100 can be reduced.

[0076] Further, when the third engagement element CL is engaged, in addition to being able to achieve a gear ratio of 1, since 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.

[0077] In the modification shown in FIG. 4C, the third engagement element CL is arranged at a position where the second carrier C2 can be connected to the second ring gear R2, the first carrier C1, and the output element OUT. Specifically, one side (hub 11) of the third engagement element CL is connected to one side of the second carrier C2 and the first engagement element B1, and the other side (drum 14) is connected to the second ring gear R2, the first carrier C1, and the output element OUT.

[0078] In this arrangement, since the third engagement element CL is arranged radially inside the member connecting the second ring gear R2 and the output element OUT, as an actuator for driving the third engagement element CL, it is preferable to use a hydraulic actuator 16 that supplies hydraulic pressure from a control valve unit with fewer layout constraints.

[0079] In addition, by connecting the first carrier C1 to the second ring gear R2 via the inner circumferential sides of the first sun gear S1 and the second sun gear S2, compared with the case of connecting via the radially outer sides of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the connection between the first carrier C1 and the second ring gear R2 becomes easier, and the layout design becomes easier.

[0080] In addition, the third engagement element CL is arranged coaxially with the first and second planetary gear mechanisms PG1 and PG2, and in the axial direction view, it has a portion overlapping with the first planetary gear mechanism PG1 and a portion overlapping with the second planetary gear mechanism PG2. Thereby, the radial dimension of the unit 100 can be reduced.

[0081] In addition, since one side (hub 11) of the third engagement element CL is connected to one side of the first engagement element B1, these can be made into common parts (integral parts). Thereby, the number of parts of the unit 100 can be reduced.

[0082] In the modification shown in FIG. 4D, the third engagement element CL is arranged at a position where the first sun gear S1 and the second sun gear S2 can be connected to the second ring gear R2, the first carrier C1, and the output element OUT. Specifically, one side (hub 11) of the third engagement element CL is connected to one side of the first sun gear S1, the second sun gear S2, and the second engagement element B2, and the other side (drum 14) is connected to the second ring gear R2, the first carrier C1, and the output element OUT.

[0083] In this arrangement, since the third engagement element CL is arranged radially inside the member connecting the second ring gear R2 and the output element OUT, as the actuator for driving the third engagement element CL, it is preferable to use a hydraulic actuator 16 that supplies hydraulic pressure from a control valve unit with fewer layout constraints.

[0084] Also, by connecting the first carrier C1 to the second ring gear R2 via the inner peripheral sides of the first sun gear S1 and the second sun gear S2, compared with the case of connecting via the radially outer sides of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the connection between the first carrier C1 and the second ring gear R2 becomes easier, and the layout design becomes easier.

[0085] Further, the third engagement element CL is arranged coaxially with the first and second planetary gear mechanisms PG1 and PG2, and in the axial view, it has a portion overlapping with the first planetary gear mechanism PG1 and a portion overlapping with the second planetary gear mechanism PG2. Thereby, the radial dimension of the unit 100 can be reduced.

[0086] Also, since one side (hub 11) of the third engagement element CL is connected to one side of the second engagement element B2, these can be made into a common part (integrated part). Thereby, the number of parts of the unit 100 can be reduced.

[0087] In the modification shown in FIG. 4E, the third engaging element CL is arranged at a position where the first sun gear S1 and the second sun gear S2 can be connected to the second carrier C2. Specifically, one side (hub 11) of the third engaging element CL is connected to one side of the first sun gear S1, the second sun gear S2, and the second engaging element B2, and the other side (drum 14) is connected to one side of the second carrier C2 and the first engaging element B1.

[0088] In this arrangement, since the third engaging element CL is arranged radially inside the member connecting the second ring gear R2 and the output element OUT, as the actuator for driving the third engaging element CL, it is preferable to use a hydraulic actuator 16 that supplies hydraulic pressure from a control valve unit with few layout constraints.

[0089] Also, by connecting the first carrier C1 to the second ring gear R2 via the inner peripheral sides of the first sun gear S1 and the second sun gear S2, compared with the case of connecting via the radially outer sides of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the connection between the first carrier C1 and the second ring gear R2 becomes easier, and the layout design becomes easier.

[0090] Also, the third engaging element CL is arranged coaxially with the first and second planetary gear mechanisms PG1 and PG2, and in the axial view, it has a portion overlapping with the first planetary gear mechanism PG1 and a portion overlapping with the second planetary gear mechanism PG2. Thereby, the radial dimension of the unit 100 can be reduced.

[0091] Also, since one side (hub 11) of the third engaging element CL is connected to one side of the second engaging element B2, and the other side (drum 14) is connected to one side of the first engaging element B1, these can be made into common parts (integral parts). Thereby, the number of parts of the unit 100 can be reduced.

[0092] The engagement table and the collinearity diagram of the modifications shown in FIGS. 4A to 4E are the same as those of the skeleton diagram of FIG. 1 shown in FIGS. 2 and 3.

[0093] Next, the effects of the embodiments of the present invention will be described.

[0094] (1) The unit 100 according to the embodiment of the present invention includes an input element IN, an output element OUT, a first engagement element B1, a second engagement element B2, a third engagement element CL, a first planetary gear mechanism PG1 in which a first sun gear S1, a first carrier C1, and a first ring gear R1 are arranged in this order on a collinear diagram, and a second planetary gear mechanism PG2 in which a second sun gear S2, a second carrier C2, and a second ring gear R2 are arranged in this order on a collinear diagram. The input element IN is connected to the first ring gear R1, The output element OUT is connected to the first carrier C1 and the second ring gear R2, One side of the first engagement element B1 is connected to the second carrier C2, The other side of the first engagement element B1 is fixed, One side of the second engagement element B2 is connected to the first sun gear S1 and the second sun gear S2, The other side of the second engagement element B2 is fixed, The third engagement element CL 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.

[0095] According to this configuration, by changing the engagement states of the first to third engagement elements B1, B2, and CL, three or more shift stages can be realized. As a result, the ratio between shift 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 a two-speed forward unit. In addition, a more appropriate gear ratio can be set for each shift stage.

[0096] Further, when the first and second engagement elements B1 and B2 are disengaged and the third engagement element CL 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, it is possible to reduce the power transmission loss caused by the differential rotation between the rotating elements.

[0097] (2) Also, in the example shown in FIG. 1, the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are single pinion planetary gear mechanisms, and the third engagement element CL connects the first sun gear S1 and the first ring gear R1.

[0098] According to this configuration, it is not necessary to dispose the third engagement element CL between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, and the first engagement element B1, the second engagement element B2, and the third engagement element CL can be concentrated in one place. Thereby, it is also possible to dispose the first engagement element B1, the second engagement element B2, and the third engagement element CL in proximity by effectively using the space outside the radial direction of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2.

[0099] Also, the third engagement element CL can be disposed outside the radial direction of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, and it is easy to fix the third engagement element CL to the housing 1. Therefore, according to this configuration, the degree of freedom in selecting an actuator for driving the third engagement element CL can be increased.

[0100] (3) Also, in the examples shown in FIGS. 1, 4A, 4C to 4E, one side (hub 11 or drum 14) of the third engagement element CL is connected to one side of the first engagement element B1 or one side of the second engagement element B2.

[0101] According to this configuration, one side of the third engagement element CL and one side of the first engagement element B1 or one side of the second engagement element B2 can be made into a common part (integral part), thereby reducing the number of parts of the unit 100.

[0102] (4) Also, in the examples shown in FIGS. 1 and 4A to 4E, the first carrier C1 is connected to the second ring gear R2 via the inner circumferential sides of the first sun gear S1 and the second sun gear S2.

[0103] According to this configuration, compared with the case of connecting via the radially outer sides of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2, the connection between the first carrier C1 and the second ring gear R2 becomes easier, and the layout design becomes easier.

[0104] As described above, the embodiments of the present invention have been explained. 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.

[0105] For example, the skeleton diagrams shown in FIGS. 1 and 4A to 4E 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 to these.

[0106] In addition, although the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are each a single pinion planetary gear mechanism, they may be double pinion planetary gear mechanisms.

Explanation of Reference Numerals

[0107] 1: Housing 100: Unit B1: First engaging element B2: Second engaging element CL: Third engaging 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 third 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 first 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 first planetary gear mechanism and the second planetary gear mechanism are single-pinion planetary gear mechanisms, the third engaging element is a unit that connects the first rotating element and the third rotating element.

3. In the unit according to Claim 1, one side of the third engaging element is connected to one side of the first engaging element or one side of the second engaging element.

4. In the unit according to any one of Claims 1 to 3, the second rotating element is connected to the sixth rotating element via the inner peripheral sides of the first rotating element and the second rotating element.

Images