Patent Application
20180304896
The present invention relates to a driving apparatus for vehicle and a vehicle.
Patent Literature 1 discloses a discontinuous change of a speed reduction ratio produced by using a combination of a continuously variable transmission and a two-speed sub-transmission at the time of switching between two stages of high and low speeds.
PTL 1: Japanese Patent No. 4660583
However, according to the above conventional art which produces a discontinuous change of a speed reduction ratio by using a combination of a continuously variable transmission and a two-speed sub-transmission at the time of switching between high and low speeds, there has been arising an issue of discomfort felt by a user as a result of speed change shock, or a discontinuous change of acceleration, at the time of absorption of energy corresponding to a relative rotation speed difference produced by the discontinuous change of the speed reduction ratio.
Accordingly, an object of the present invention is to solve the aforementioned issue by providing a driving apparatus for vehicle and a vehicle each preventing discomfort felt by a user as a result of speed change shock, or a discontinuous change of acceleration.
In accomplishing these and other objects, according to an aspect of the present invention, there is provided a driving apparatus for vehicle, the apparatus comprising:
a Ravigneaux planetary gear;
a friction clutch; and
a friction brake,
wherein
input paths of two systems and an output path of one system are provided for the Ravigneaux planetary gear, and
continuously variable adjustment of output of the one system is achieved by adjusting each input from the two systems connected to the Ravigneaux planetary gear in an opened state of each of the friction clutch and the friction brake.
In accomplishing these and other objects, according to a different aspect of the present invention, there is provided a vehicle comprising:
a driving apparatus for vehicle that includes a Ravigneaux planetary gear, a friction clutch, and a friction brake, wherein input paths of two systems and an output path of one system are provided for the Ravigneaux planetary gear; and
a controller provided on the vehicle to perform continuously variable control of output of the one system by controlling a rotation direction, a rotation speed, and torque of each input from the two systems connected to the Ravigneaux planetary gear in an opened state of each of the friction clutch and the friction brake.
According to the aspect of the present invention, continuously variable adjustment of output of one system is achievable by adjusting each input of two systems. Accordingly, discomfort felt by a user as a result of speed change shock or a discontinuous change of acceleration is avoidable.
These and other objects and features of the present invention will become apparent in the light of following description relating to preferred embodiments describing the accompanying drawings. In the drawings:
Embodiments according to the present invention are hereinafter described in detail with reference to the drawings.
As illustrated in
According to the first embodiment, a continuously variable sub-transmission is adopted instead of the two-speed sub-transmission to solve the conventional issue. This point is hereinafter detailed.
The Ravigneaux planetary gear 501 includes a first sun gear 504, a second sun gear 505, a first pinion gear 506, a second pinion gear 507, a ring gear 508, and a pinion carrier 509.
Relative rotations of the second pinion gear 507 and the first pinion gear 506 are regulated by the identical pinion carrier 509.
The first sun gear 504 engages with the first pinion gear 506 via the second pinion gear 507.
The second sun gear 505 engages with the first pinion gear 506. The first pinion gear 506 is a gear elongated in the axial direction, and engages with the second sun gear 505 on the downstream side of an engagement portion between the first pinion gear 506 and the second pinion gear 507.
The first pinion gear 506 and the ring gear 508 engage with each other. The ring gear 508 is disposed outside the first pinion gear 506.
A first input path of the input paths of the two systems is connected to the second sun gear 505, while a second input path is connected to the first sun gear 504. The output path of the one system is connected to the ring gear 508.
In an example, the first input path of the input passes of the two systems in
A stator 511b for the rotor 511a of the electric motor 511 is fixed to a fixed end (case of driving apparatus for vehicle 513) 520. The rotor 511a rotates relative to the stator 511b.
The friction clutch 502 and the friction brake 503 are also connected to the rotation shaft 516 integrally rotating with the rotor 511a of the electric motor 511. Accordingly, driving is achievable by closing of the friction clutch 502 or the friction brake 503 only with the engine 510 even when electric input from the electric motor 511 becomes zero as a result of no supply of power from a battery.
The friction clutch 502 and the friction brake 503 are configured to be controlled (closed or opened) by closing control under the control mechanism 316. The control mechanism 316 herein is a hydraulic piston or an electric actuator, for example, which independently closes or opens the friction clutch 502 and/or the friction brake 503. For example, the friction clutch 502 transmits torque by an axial press against disks 341 and driven plates 343 alternately overlapped with each other. In this case, a pressing action is achievable by a direct press with a hydraulic piston or by a press with an electric actuator via a bearing. The friction brake 503 stops rotation by an axial press against disks 344 and driven plates 345 alternately overlapped on each other. In this case, a pressing action is achievable by a direct press with a hydraulic piston or by a press with an electric actuator via a bearing.
More specifically, the friction clutch 502 regulates relative rotations of the rotation shaft 516 and the pinion carrier 509 of the Ravigneaux planetary gear 501, while the friction brake 503 regulates relative rotations of the pinion carrier 509 of the Ravigneaux planetary gear 501 and the fixed end (case of driving apparatus for vehicle 513) 520.
The pinion carrier 509 is connected to a driving ring 342 described below.
More specifically, the friction clutch 502 and the friction brake 503 have following configurations as illustrated in
The annular disks 341 for the friction clutch 502 are connected to an outer surface of an input side member 340 which is concentrically connected to the rotation shaft 516 of the electric motor 511 and integrally rotates with the rotation shaft 516. The driving ring 342, whose rotation axis center is disposed concentrically with the rotation shaft 516, includes on the inner surface side thereof the annular driven plates 343 for the friction clutch 502 facing the disks 341. The driving ring 342 is restricted in the axial direction of the rotation shaft 516. The annular disks 344 for the friction brake 503 are connected to the outer surface side of the driving ring 342. The annular driven plates 345 for the friction brake 503 are connected to the inner circumferential surface of the fixed end (case of driving apparatus for vehicle 513) 520 at positions facing the annular disks 344. Note that the driven plates 345 are restricted in the rotation direction with respect to the fixed end 520, but are movable in the axial direction of the rotation shaft 516. In this manner, the annular disks 341 for the friction clutch 502 and the annular driven plates 343 for the friction clutch 502 are alternately disposed with a clearance left between each other. In addition, the annular disks 344 for the friction brake 503 and the annular driven plates 345 for the friction brake 503 are alternately disposed with a clearance left between each other. Accordingly, the disks 341 and the driven plates 343 disposed adjacent to each other for the friction clutch 502 are allowed to contact with each other with pressure or separate from each other to achieve relative rotation regulation by axial forward or backward movement using a hydraulic piston or an electric actuator, for example, under the closing control by the control mechanism 316. Simultaneously, the disks 344 and the annular driven plates 345 disposed adjacent to each other for the friction brake 503 are allowed to contact with each other with pressure or separate from each other to achieve relative rotation regulation. Note that the disks 344 and the driven plates 345 for the friction brake 503 are allowed to achieve forward and backward movement in the axial direction, while the driving ring 342 is restricted in the axial direction.
The friction clutch 502 is configured to regulate relative rotations of any two elements selected from the first sun gear 504, the second sun gear 505, the pinion carrier 509, and the ring gear 508. The friction brake 503 is configured to regulate relative rotations of the pinion carrier 509 and a fixed end (case of driving apparatus for vehicle 513) 520.
The expression “to regulate” herein refers to any action of forward or backward movement of components in the axial direction by driving of the control mechanism 316 to shift one of the components in the axial direction for contact with each other and thereby achieving connection between the components, to shift one of the components in the axial direction for separation from each other and thereby achieving disconnection between the components, or to shift one of the components in the axial direction for approach to each other and thereby achieving slip between the components with contact therebetween (half-clutch).
An operation of the driving apparatus for vehicle 513 having this configuration is now described.
Each of
When the transmission 512 is a CVT, the transmission 512 may be configured by a pair of pulleys 311b (only one of pulleys 311b is shown, and the other pulley is not shown) capable of adjusting a distance between opposed sheave surfaces 311a, and a band-shaped member 311c such as a belt or a chain laid between the pair of pulleys 311b.
According to the first embodiment as described above, the issue of speed change shock or a feeling of discontinuity of acceleration can be solved by making at least continuous (smooth) adjustment of input of the two systems. In other words, there occurs an issue of speed change shock or a feeling of discontinuity of acceleration at the time of rapid regulation of relative rotations by using elements allowing a slight slip but only producing substantially two states of on and off (i.e., discontinuous elements), such as a friction clutch and a friction brake. In this case, the user may be shocked, for example, at the time of an instantaneous stop (brake) of a driving electric motor, for example.
More specifically, in comparison with the two-speed sub-transmission which switches between high and low speeds in Patent Literature 3, the first embodiment adopting the continuously variable sub-transmission can eliminate speed change shock caused by a speed change of the sub-transmission, or discomfort felt by a user as a result of a discontinuous change of acceleration. Moreover, the driving apparatus for vehicle 513 functions as a continuously variable sub-transmission when combined with the existing transmission 512. Accordingly, a transmission gear ratio range (ratio coverage) of the existing transmission 512 expands, wherefore traveling performance and fuel consumption of the vehicle can improve. Moreover, the driving apparatus for vehicle 513 functioning as a continuously variable sub-transmission achieves smooth operation. Furthermore, addition of the electric motor 511 can improve fuel consumption of the vehicle.
In a modified example of the first embodiment, as illustrated in
In a different modified example illustrated in
According to this different modified example, following effects can be obtained. Generally, an electric motor is required to use a range of small load and low efficiency when necessary driving force is small during driving of a vehicle. In this case, either the first electric motor 511 or the second electric motor 531 is used as an electric motor for driving, while the other of the first and second electric motors 511 and 531 is used as a power generator, i.e., an electric motor for load. According to this configuration, the electric motor for driving is driven in a range of larger load and higher efficiency, while power exceeding driving force necessary for vehicle driving is generated by the other electric motor, and can be stored as electrical energy. The electrical energy stored herein can be used for subsequent vehicle driving. When necessary driving force for driving a vehicle is large in an opposite case, an electric motor is required to use a large load and low efficiency range. In this case, driving force is shared by the first electric motor 511 and the second electric motor 531 to lower each load of the electric motors and achieve driving in a high efficiency range.
In a further different modified example, as illustrated in
According to this different modified example, losses produced by corotation of the engine 510 (friction and pumping losses) can be eliminated when the vehicle is driven only by the electric motor 511, or when kinetic energy of the vehicle is regenerated into electrical energy by the electric motor 511. Accordingly, efficiency during driving and a regeneration quantity can improve.
Furthermore, following two combinations may be adopted as modified examples of the combination of any two elements selected from the first sun gear 504, the second sun gear 505, the pinion carrier 509, and the ring gear 508 in the first embodiment as a combination of relative rotations regulated by the friction clutch 502, as well as the combination of the first sun gear 504 and the pinion carrier 509 as described above.
According to the foregoing three configuration examples in total, i.e., the embodiment in
(1) According to the configuration example in
(2) According to the configuration example in
(3) According to the configuration example in
Summarizing above, the respective levels of the relative rotation speed difference have a relationship of: configuration example (2) in
Accordingly, in view of drag torque, the order of excellency of the respective configuration examples is considered as the configuration example (2) in
By properly combining the arbitrary embodiment(s) or modified example(s) of the aforementioned various embodiments and modified example(s), the effects possessed by the embodiment(s) or modified example(s) can be produced. Moreover, combinations of the embodiments, combinations of the working examples, and combinations of the embodiment(s) and the working example(s) may be made. Furthermore, combinations of the features included in the different embodiments or working examples may be made.
Although the present invention has been fully described in connection with the embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
A driving apparatus for vehicle and a vehicle according to the present invention prevent discomfort felt by a user as a result of speed change shock or a discontinuous change of acceleration, and are therefore useful when applied to various types of vehicle including a compact automobile.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-206491 | Oct 2015 | JP | national |
| 2016-183440 | Sep 2016 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/080395 | 10/13/2016 | WO | 00 |
