JP2001287556A - Power transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size, weight and cost of a power transmission. SOLUTION: In this power transmission, first torque transmission paths 2, 3, 13 for transmitting torque of an electric motor 1 to a wheel 23 and second torque transmission paths 2, 17, 13 are arranged in parallel, and these torque transmission paths are provided with a first transmission mechanism for forward stage high speed, a second transmission mechanism for a forward stage low speed, and a third transmission mechanism for a backward stage. The power transmission is provided with a two-way clutch 18 for selectively transmitting the torque of the electric motor 1 to two torque transmission paths, the first torque transmission paths 2, 3, 13 are provided with a first transmission mechanism Hi, and the second torque transmission paths 2, 17, 13 are provided with the second transmission mechanism Lo and the third transmission mechanism Lo, the parts of which are made in common.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device provided with two torque transmission paths for transmitting the torque of an electric motor to wheels.

[0002]

2. Description of the Related Art In recent years, a vehicle using an electric motor as a driving force source of the vehicle has been proposed in order to reduce noise and exhaust gas. An example of a gear transmission used in such a vehicle is described in Japanese Patent Application Laid-Open No. 6-249302. In this publication, an input shaft and a hollow shaft are arranged concentrically, and the input shaft and the hollow shaft are connected via a one-way clutch. An output shaft is provided in parallel with the input shaft and the hollow shaft. A first speed drive gear provided on the hollow shaft and a first speed drive gear provided on the output shaft are provided.
The speed driven gear is meshed. Further, a reverse drive gear provided on the hollow shaft and a reverse driven gear provided on the output shaft are connected via an intermediate gear. Further, a dog clutch is provided for selectively engaging and disengaging the hollow shaft and the first speed driven gear or the reverse gear. On the other hand, a second-speed drive gear provided on the input shaft and a second-speed driven gear provided on the output shaft are engaged. Further, a hydraulic clutch for selectively engaging and disengaging the input shaft and the second speed drive gear is provided.

When the first speed of the forward gear is set, the one-way clutch is engaged, and the first speed driven gear and the output shaft are engaged by the dog clutch. Then, the torque of the electric motor is transmitted to the first speed drive gear via the input shaft and the hollow shaft, and the torque is transmitted to the output shaft via the first speed driven gear. When the second speed of the forward gear is set, the hydraulic clutch is engaged, the torque of the electric motor is transmitted from the input shaft to the second speed drive gear, and the torque is transmitted to the second speed driven gear. Is transmitted to the output shaft via the output shaft. On the other hand, when setting the reverse gear, the one-way clutch is engaged, and the driven gear for reverse gear and the output shaft are engaged by the dog clutch. Then, the torque of the electric motor is transmitted to the reverse drive gear via the input shaft and the hollow shaft, and the torque is transmitted to the output shaft via the intermediate gear and the reverse driven gear.

[0004]

By the way, in the gear transmission described in the above publication, the first gear in the forward gear is used.
A separate one-way clutch and a hydraulic clutch are provided to set the speed and the second speed. For this reason, the number of parts of the gear transmission mechanism is increased, which causes a problem that the device is increased in size and weight, and the manufacturing cost is increased. Further, since the gear train dedicated to the reverse gear is provided to set the reverse gear, the above problem tends to be further exacerbated.

The present invention has been made in view of the above circumstances, and has as its object to provide a power transmission device capable of reducing the size, weight, and cost of the device.

[0006]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, a first torque transmission path and a second torque transmission path for transmitting torque of an electric motor to wheels are provided. A first transmission mechanism for a high-speed forward stage, a second transmission mechanism for a low-speed forward stage, and a third transmission mechanism for the reverse stage are provided in parallel with each other in these torque transmission paths. A power transmission device, a two-way clutch for selectively transmitting torque of the electric motor to two torque transmission paths is provided, and the first transmission mechanism or the first transmission mechanism is provided in the first torque transmission path. A second speed change mechanism is provided, and a second speed transmission mechanism is provided with a speed change mechanism for a forward gear that is not provided in the first torque transmission path and the third speed change mechanism. And The one in which the second part of the transmission mechanism for forward gear provided on the torque transmission path and part of the third transmission mechanism is characterized in that it is shared.

According to the first aspect of the present invention, by switching the two-way clutch, the electric motor is selectively transmitted to the first transmission mechanism or the second transmission mechanism, and one of the forward gears. And the component of the third speed change mechanism for setting the reverse gear are shared. Accordingly, the number of devices for selectively switching the torque transmission path connected to the electric motor is reduced, and there is no need to provide a transmission mechanism dedicated to the reverse gear.

According to a second aspect of the present invention, a first torque transmission path and a second torque transmission path for transmitting the torque of an electric motor to wheels are provided in parallel, and the first torque transmission path is In a power transmission device provided with a first transmission mechanism for high-speed gears and a first transmission mechanism for low-speed forward gears provided in the second torque transmission path,
A torque converter is provided at a position closer to the electric motor than the first speed change mechanism for setting the high-speed gear in the first torque transmission path.

According to the second aspect of the present invention, the torque is transmitted via the second speed change mechanism in the low speed stage where the high torque is transmitted, and the torque converter and the first stage are transmitted in the high speed stage where the low torque is transmitted. Torque is transmitted via the speed change mechanism. Therefore, the torque to be transmitted by the torque converter can be reduced.

[0010]

Next, the present invention will be specifically described with reference to the drawings. FIG. 1 is a skeleton diagram showing a schematic configuration of a vehicle to which the present invention is applied. An electric motor 1 serving as a driving force source of the vehicle is mounted, and the electric motor 1 can switch its rotation direction at the time of driving to either forward or reverse. A converter drive shaft 2 is connected to an output side of the electric motor 1. A converter output shaft 3 is provided concentrically with the converter drive shaft 2. A torque converter 4 for transmitting torque (in other words, transmitting power) between the converter drive shaft 2 and the converter output shaft 3 is provided.

The torque converter 4 is a so-called fluid transmission device capable of transmitting power by a working fluid. The torque converter 4 includes a pump impeller 6 connected to the converter drive shaft 2 via a front cover 5, a turbine runner 7 connected to the converter output shaft 3, a front cover 5 and the converter output shaft 3. A lock-up clutch 8 for controlling a torque transmission state between the two and a stator 9 are provided.

Although not shown, a plurality of guide blades are formed on each of the pump impeller 6, the turbine runner 7, and the stator 9. The capacity coefficient of the torque converter 4 is determined based on various factors such as the shape of the pump impeller 6 or the turbine runner 7, the angle of the guide blades of the pump impeller 6 or the turbine runner 7, and the amount of the working fluid in the flow circuit. Is determined.

On the other hand, an oil pump 10 driven by the converter drive shaft 2 is provided, and a hydraulic control device 11 for using the discharge oil pressure of the oil pump 10 as a base pressure of a hydraulic circuit is provided. The hydraulic control device 11 controls engagement / disengagement / release of the lock-up clutch 8.
An electromagnetic valve (not shown) for controlling the hydraulic pressure acting on the slip and lock-up clutch 8 is provided.

In the above configuration, the torque of the electric motor 1 is
Converter drive shaft 2 and front cover 5
To the pump impeller 6. Here, when the lockup clutch 8 is released (that is, turned off), the torque of the pump impeller 6 is transmitted to the turbine runner 7 by the hydraulic oil. In this case, a predetermined rotation speed difference occurs between the pump impeller 6 and the turbine runner 7 torque converter, and the ratio of the rotation speed of the pump impeller 6 to the rotation speed of the turbine runner 7, that is, the speed ratio is equal to or less than a predetermined value. In some cases, the torque transmitted between pump impeller 6 and turbine runner 7 is amplified by the stator. When the speed ratio exceeds a predetermined value, the torque transmitted between the pump impeller 6 and the turbine runner 7 is not amplified.

Specifically, when the speed ratio between the pump impeller 6 and the turbine runner 7 is within a predetermined range or less (torque converter range), the torque ratio of the torque converter 4 exceeds "1". It has the characteristic that the torque ratio decreases as the speed ratio increases. In other words, the torque converter 4 has a characteristic that the power transmission efficiency increases as the speed ratio increases. When the speed ratio has reached a predetermined value, that is, when the coupling point has been reached, the torque ratio is set to "1".

On the other hand, when the lock-up clutch 8 is engaged (that is, turned on), the torque of the front cover 5 is transmitted directly (in other words, mechanically) to the converter output shaft 3. It should be noted that control for half-engaging (slipping) the lock-up clutch 8 may be performed so that a predetermined rotational speed difference is generated between the front cover 5 and the converter output shaft 3.

A high speed drive gear 12 is formed on the converter output shaft 3. Further, an output shaft 13 parallel to the converter drive shaft 2 and the converter output shaft 3 is provided. On the output shaft 13, a high-speed driven gear 14, a low-speed driven gear 15, and an output gear 16 are formed. The high-speed drive gear 12 and the high-speed driven gear 14 mesh with each other. In the embodiment of FIG. 1, the value obtained by dividing the number of teeth of the high-speed driven gear 14 by the number of teeth of the high-speed drive gear 12, that is, the gear ratio is “1”.
Is set to The high-speed drive gear 12 and the high-speed driven gear 14 form a high-speed gear train Hi.

On the other hand, the oil pump 10 and the torque converter 4 on the outer periphery of the converter drive shaft 2
The hollow shaft 17 is mounted between the two. The hollow shaft 17 and the converter drive shaft 2 are configured to be relatively rotatable. Further, a two-way clutch 18 for controlling a torque transmission state between the converter drive shaft 2 and the hollow shaft 17 is provided.

The two-way clutch 18 is capable of controlling the rotational speed of the converter drive shaft 2 (in other words, the rotational speed) and the rotational speed of the hollow shaft 17 regardless of whether the converter drive shaft 2 rotates in the forward or reverse direction. , The torque of the converter drive shaft 2 is transmitted to the hollow shaft 17. Specifically, when the rotation speed of converter drive shaft 2 is higher than the rotation speed of hollow shaft 17, the two-way clutch is engaged (on), and the torque of converter drive shaft 2 is reduced. It is configured to be transmitted to.

On the other hand, when the rotation speed of the hollow shaft 17 is higher than the rotation speed of the converter drive shaft 2, the two-way clutch is released (off). The hollow shaft 17 is formed with a low-speed drive gear 19, and the low-speed drive gear 19 and the low-speed driven gear 15 are meshed with each other. In the embodiment of FIG. 1, a value obtained by dividing the number of teeth of the low speed driven gear 15 by the number of teeth of the low speed drive gear 19, that is, the gear ratio is set to a value larger than "1". This low speed drive gear 19
And the low-speed driven gear 15 form the low-speed gear train L
o is configured.

Further, a final reduction gear 20 is provided,
The final reduction gear 20 includes a ring gear 21, a differential case (not shown) that rotates integrally with the ring gear 21, and a pinion gear (not shown) mounted in the differential case.
And a side gear (not shown) meshing with the pinion gear, and a drive shaft 22 connected to the side gear.
And The torque of the drive shaft 22 is transmitted to the wheels 23.

Further, an integrated control device 24 for controlling the vehicle
Is provided. The general control device 24 includes a microcomputer mainly including an arithmetic processing unit (CPU or MPU), a storage device (RAM and ROM), and an input / output interface.
Then, a signal of the accelerator opening sensor 25, a signal of the brake switch 26, a vehicle speed sensor (a rotation speed sensor of the output shaft 13) 27
, The signal of the shift position sensor 28, and the like. An operation of a shift device (not shown) such as a shift lever is detected by the shift position sensor 28.

In this embodiment, by operating the shift device, for example, R (reverse) position, N (neutral position), D (drive) position, etc. can be selectively switched. Here, the D position is a position for moving the vehicle forward, and R
The position is a position for moving the vehicle backward. The rotation direction of the electric motor 1 is controlled based on the signal of the shift position sensor 28.

The required driving force for the vehicle is determined based on the vehicle speed and the accelerator opening, and the output of the electric motor 1 is controlled based on the determination result. Further, the general control device 24 stores a lock-up clutch control map. This lockup clutch control map
This is for controlling engagement / disengagement / slip of the lock-up clutch 8 based on the vehicle speed and the accelerator opening.

Here, the correspondence between the configuration of this embodiment and the configuration of the present invention will be described. The converter drive shaft 2, the converter output shaft 3, and the output shaft 13 form the first torque transmission of the present invention. The converter drive shaft 2, the hollow shaft 17, and the output shaft 13 correspond to a second torque transmission path according to the present invention, and the high-speed gear train Hi corresponds to the first forward high-speed gear according to the present invention. And the low-speed gear train Lo corresponds to the forward-speed low-speed second speed change mechanism and the reverse-speed third speed change mechanism of the present invention.

A high-speed gear train Hi and a low-speed gear train Lo are provided in parallel. In the embodiment of FIG. 1, the low-speed gear train is set so that the value obtained by dividing the gear ratio of the low-speed gear train Lo by the gear ratio of the high-speed gear train Hi is greater than “1”. The gear ratio of Lo and the gear ratio of the high-speed gear train Hi are set.

Next, the case where the D position is selected and the vehicle travels forward will be described. First, the electric motor 1 is rotated in a predetermined direction. Here, the output characteristics of the electric motor 1 will be described based on the diagram of FIG. The diagram in FIG. 2 shows the relationship between the rotation speed of the electric motor 1 and the maximum torque at that rotation speed. When the rotation speed of the electric motor 1 is between zero and a predetermined value, the maximum torque is substantially constant. is there. Further, when the rotation speed of the electric motor 1 exceeds a predetermined value, the motor 1 has a low output characteristic in which the maximum torque decreases as the rotation speed increases. When the vehicle starts moving, the running resistance is large, so that the electric motor 1 is controlled to a state corresponding to the region A1 where the torque is relatively large. When the vehicle starts moving, the lock-up clutch 8 is released.

For this reason, in the torque converter 4, the pump impeller 6 and the turbine runner 7 rotate relative to each other, that is, slip. Further, when the vehicle starts moving, the required driving force is relatively large, so that the slip ratio of the torque converter 4 is large, in other words, the first value which is a value obtained by dividing the rotation speed of the turbine runner 7 by the rotation speed of the pump impeller 6. The speed ratio becomes relatively small.

In this way, when the torque of the pump impeller 6 is transmitted to the pump impeller 7 by the fluid, the gear ratio of the high-speed gear train Hi is set to “1” and the low-speed gear is set. Since the gear ratio of the gear train Lo is set to a value larger than “1”, the rotation speed of the converter drive shaft 2 is higher than the rotation speed of the hollow shaft 17. As a result, a state where the two-way clutch 18 is engaged and the torque of the converter drive shaft 2 is transmitted to the output shaft 13 mainly via the low-speed gear train Lo, that is, a so-called low-speed stage is set.

As described above, after the vehicle starts in a state where the low gear is set, when the rotation speed of the electric motor 1 increases and enters the region B1, the maximum torque of the electric motor 1 gradually decreases. Further, as the vehicle speed increases, the slip ratio of the torque converter 4 gradually decreases, in other words, the first speed ratio gradually increases, and the torque of the turbine runner 7 is changed by the torque of the pump impeller 6. The divided value, that is, the first torque ratio gradually decreases. Here, the torque transmission capacity of the torque converter 4 is proportional to the square of the rotation speed of the converter drive shaft 2.

When the rotation speed of the hollow shaft 17 becomes higher than the rotation speed of the converter drive shaft 2, the two-way clutch 18 is released, and the torque of the converter drive shaft 2 is mainly reduced to the high speed gear. A state of transmission to the output shaft 13 via the row Hi, that is, a so-called high-speed stage is set. When the high-speed stage is set in this way, the torque is amplified by the torque converter 4. When the speed ratio becomes equal to or more than the predetermined value, the first torque ratio is maintained at "1". The lock-up clutch 8 is set based on the vehicle speed and the accelerator opening.
Is engaged, the first speed ratio becomes "1".

As described above, in the embodiment of FIG. 1, the torque transmitted to the output shaft 13 is changed by switching from the state in which the low-speed gear is set to the state in which the high-speed gear is set. The value divided by the torque of the shaft 2, that is, the second torque ratio is automatically switched. FIG. 3 is a diagram showing input / output characteristics of torque transmitted from converter drive shaft 2 to output shaft 13. Specifically, the relationship between the second speed ratio and the second torque ratio is shown.
The second speed ratio refers to a value obtained by dividing the rotation speed of the output shaft 13 (in other words, the rotation speed) by the rotation speed of the converter drive shaft 2. As shown in FIG. 3, the characteristic shows that the second torque ratio gradually decreases as the second speed ratio increases. Also, the second torque ratio does not become smaller than its reduction ratio.

FIG. 4 is a diagram showing the relationship between the torque input to converter drive shaft 2 and the second torque ratio. The diagram of FIG. 4 also assumes that the characteristics of the torque converter 4 and the configurations of the low-speed gear train Lo and the high-speed gear train Hi are the same as described above. When the low-speed stage is set, the second torque ratio becomes substantially constant even when the torque input to converter drive shaft 2 decreases as shown in FIG. And
When the speed is switched from the low speed stage to the high speed stage, a torque transmission state is established by the torque converter 4, so that the second torque ratio decreases as the input torque decreases. When the rotational speed of the electric motor 1 gradually decreases from the state where the high-speed stage is set, the rotational speed of the electric motor 1 is set to 2 based on the rotational speed relationship between the converter drive shaft 2 and the hollow shaft 17.
The way clutch 18 is released, and the gear is switched to the low speed stage.

Next, the case where the R position is selected by operating the shift device will be described. When the R position is selected, the electric motor 1 rotates in a direction opposite to the case where the vehicle moves forward. Even if the torque of the electric motor 1 is transmitted to the converter drive shaft 2, the torque converter 4 has almost no function of transmitting torque due to structural reasons, and the rotational speed of the converter drive shaft 2 is smaller than that of the hollow shaft 17. It becomes faster than the rotation speed, and the two-way clutch 18 is engaged. Therefore, the electric motor 1
Is transmitted to the output shaft 13 via the low-speed gear train Lo.

Thus, in the embodiment of FIG.
When the vehicle having a relatively large required driving force starts, the torque of the electric motor 1 is applied to the output shaft 13 via the low-speed gear train Lo regardless of whether the vehicle moves forward or backwards. Is transmitted. That is,
Power loss is small because torque is transmitted by gear transmission.

On the other hand, as the vehicle starts and the rotation speed of the electric motor 1 increases, the speed is switched from the low speed stage to the high speed stage, and the power is transmitted by the torque converter 4. That is, in a state where the first speed ratio is relatively small and the power transmission efficiency is low, the torque converter 4 mainly transmits the torque by the low-speed gear train Lo, while the first When the speed ratio is relatively large and the power transmission efficiency is high, the torque is transmitted mainly via the high-speed gear train Hi. For this reason, heat generation and reduction in durability due to slippage of the torque converter 4 are suppressed. In addition, when the lock-up clutch 8 is engaged, slippage of the torque converter 4 and transmission loss of power do not occur, so that fuel efficiency is improved and the maximum speed can be increased as much as possible.

The torque transmitted mainly by the torque converter 4 depends on the state in which the high-speed stage is set,
That is, since the torque is relatively low corresponding to the region B1 in FIG. 2, the specifications of the torque converter 4 may be designed so that the torque transmission capacity of the torque converter 4 is relatively small. Therefore, the size, weight and cost of the torque converter 4 can be reduced. further,
The switching of the power transmission path for setting the low-speed gear and the high-speed gear is achieved by engagement / disengagement of the single two-way clutch 18. For this reason, an increase in the number of parts is suppressed, and the size, weight, and cost of the power transmission device can be reduced.

The engagement and disengagement of the two-way clutch 18 is automatically switched based on the correspondence between the rotation speed of the converter drive shaft 2 and the rotation speed of the hollow shaft 17. For this reason, special systems and components for controlling the engagement and disengagement, such as a wet multi-disc clutch, for example, a complicated hydraulic circuit and a high-pressure large-capacity oil pump, or a large number of clutch discs and clutch plates There is no need to provide such components, and the power transmission device can be further reduced in size, weight, and cost.

Further, there is no need to perform complicated control when switching between the low speed stage and the high speed stage, and the electronic control unit 24
Is simplified. Furthermore, the engagement / disengagement is automatically switched based on the correspondence between the rotation speed of the converter drive shaft 2 and the rotation speed of the hollow shaft 17. For this reason, unlike the case of using a wet multi-plate clutch or the like, there is no shock accompanying the engagement, and shift shock is unlikely to occur.

Further, the forward gear and the reverse gear can be switched only by switching the rotation direction of the electric motor 1, and the low-speed gear train Lo has a function of setting the low gear and the reverse gear. Therefore, a gear dedicated to the reverse gear is not required. Therefore, an increase in the number of components is suppressed, and the size, weight, and cost of the power transmission device can be reduced. Since the low-speed gear train Lo also has a function of setting the low-speed stage and the reverse speed, if the torque of the electric motor 1 is the same, the driving force generated at the low-speed stage during forward driving and the reverse The generated driving force is the same.

FIG. 5 is a skeleton diagram showing another embodiment in which a part of the configuration of the embodiment of FIG. 1 is changed. In the embodiment of FIG. 5, a first high speed drive gear 29 and a second high speed drive gear 30 are formed on the converter output shaft 3. Here, the number of teeth of the second high speed drive gear 30 is set to be greater than the number of teeth of the first high speed drive gear 29.

On the other hand, a gear 31 is formed on the output shaft 13, and hollow shafts 32 and 33 are attached to both sides of the gear 31 in the output shaft 13 in the axial direction. The output shaft 13 and the hollow shafts 32 and 33 are configured to be relatively rotatable. The hollow shaft 32 has a first high-speed driven gear 34 and a gear 35.
Are formed. The first high-speed drive gear 29 and the first high-speed driven gear 34 mesh with each other.

The hollow shaft 33 is formed with a second high speed driven gear 36 and a second gear 37. The second high-speed drive gear 30 and the second high-speed driven gear 3
6 are engaged with each other. Further, it is meshed with the gear 31,
Further, a hub sleeve 38 that is movable in the axial direction of the output shaft 13 is provided. The hub sleeve 38 and the gear 31 are spline-fitted. The hub sleeve 38 is moved in the axial direction of the output shaft 13 by the hydraulic control device 11 or another actuator (not shown).
Is selectively meshed with the gear 35 or the gear 37. That is, the configuration of the gear 31, the gears 35 and 37, the hub sleeve 38, and the like corresponds to a known synchronous meshing mechanism.

The second high-speed drive gear 30 and the second high-speed drive gear 36 have a higher gear ratio than the first high-speed drive gear 29 and the first high-speed driven gear 34. The number of teeth of each gear is set so that the gear ratio becomes smaller. In this embodiment, the gear ratio between the first high speed drive gear 29 and the first high speed driven gear 34 is set to “1”.

The first high-speed drive gear 29 and the first high-speed driven gear 34 constitute a first high-speed gear train Hi 1, and the second high-speed drive gear 30 and the second high-speed drive gear 30. The second high speed driven gear 36 constitutes a second high speed gear train Hi2. As described above, in the embodiment of FIG. 5, the first high-speed gear train Hi1 and the second high-speed gear train Hi2, and the low-speed gear train Lo are provided.
And are provided in parallel. The gear ratio of the first high-speed gear train Hi1 and the second high-speed gear train Hi2
Is set smaller than the gear ratio of the low-speed stage gear train Lo. The other configuration in FIG. 5 is the same as the configuration in FIG.

In the embodiment of FIG. 5, the operation of the hub sleeve 38 is controlled so that the first high-speed driven gear 34 or the second high-speed driven gear 36 and the output shaft 13 transmit torque. It is possible.
That is, the first high-speed driven gear 34 and the output shaft 13 are connected by the hub sleeve 38 so that torque can be transmitted, and the first high-speed gear is set. In addition, the second high-speed driven gear 36 and the output shaft 13
Are connected by a hub sleeve 38 so that torque can be transmitted, and a second high speed stage is set.

Here, the correspondence between the configuration of the embodiment of FIG. 5 and the configuration of the present invention will be described. The first high-speed gear train Hi1 and the second high-speed gear train Hi2 correspond to the present invention. Corresponds to the first speed change mechanism for high speed of the forward gear. In addition,
The correspondence between the other configurations in FIG. 5 and the configuration of the present invention is the same as the correspondence between the configuration in FIG. 1 and the configuration of the present invention.

In the embodiment shown in FIG. 5, when the D position is selected and the vehicle moves forward, the hub sleeve 38 and the gear 35 are engaged. Then, the torque of the electric motor 1 is transmitted through the torque converter 4 to the converter output shaft 3.
The two-way clutch 18 is engaged by the same operation as in FIG. 1 to set the low gear. Then, as the rotational speed of the electric motor 1 increases, the two-way clutch 18 is disengaged and the first high-speed stage is set by the same operation as in FIG. As a result, the torque of the electric motor 1 is transmitted to the output shaft 13 mainly via the first high-speed gear train Hi1.

Thereafter, when the required driving force for the vehicle further changes, the operation of the hub sleeve 18 switches from the first high speed stage to the second high speed stage. As a result, the torque of the electric motor 1 is mainly changed to the second high-speed gear train Hi2.
Through the output shaft 13. In the embodiment of FIG. 5, the operation when the R position is set is the same as that of the embodiment of FIG. As described above, also in the embodiment of FIG. 5, for the same reason as in the embodiment of FIG. 1, the same effect as the embodiment of FIG. 1 can be obtained.

In the case where a fluid coupling having no torque amplifying function is used in place of the torque converter 4 of the embodiment shown in FIG. 1 and the embodiment shown in FIG. And the reverse gear, and the low-speed gear train Lo can set the low gear and the reverse gear. "

Although the torque converter 4 of the fluid transmission type is used in the embodiment shown in FIGS. 1 and 5, an electric torque converter may be used instead of the torque converter 4. This electric torque converter is a known one having a planetary gear mechanism and an electric motor. When this electric torque converter is used, the speed ratio between the rotation speed of the converter drive shaft 2 and the rotation speed of the converter output shaft 3 is controlled by controlling the current value of the electric power supplied to the electric motor. be able to. Even when this electric torque converter is used, the torque of the electric torque converter to be transmitted in the high-speed stage can be reduced, so that the rating of the motor is reduced or the gear tooth thickness of the planetary gear mechanism is reduced. By reducing the thickness of the power transmission device, the torque transmission capacity of the electric torque converter can be reduced. As a result, the power transmission device can be reduced in size, weight, and cost.

Further, in the embodiment shown in FIGS. 1 and 5, the electric motor 1 is driven by a clutch other than the two-way clutch.
Even when a configuration for selectively connecting the first torque transmission path or the second torque transmission path is adopted, the description “by suppressing the torque transmitted to the torque converter,
By reducing the torque transmission capacity, the power transmission device can be reduced in size, weight, and cost. " Note that the embodiment of FIGS. 1 and 2 and the above-described modified examples are either an electric vehicle using only the electric motor 1 as a driving force source or a hybrid vehicle using the electric motor 1 and an engine (not shown) as a driving force source. It can also be applied to

Here, the characteristic configurations of the present invention disclosed based on the above specific examples are listed as follows. That is, the first characteristic configuration is such that a first torque transmission path and a second torque transmission path for transmitting torque of an electric motor to wheels are provided in parallel, and these torque transmission paths are provided with a forward gear. In a power transmission device provided with a first transmission mechanism for a high speed, a second transmission mechanism for a low speed forward step, and a third transmission mechanism for a reverse step, the torque of the electric motor is transmitted through two torque transmission paths. A first transmission mechanism or the second transmission mechanism is provided in the first torque transmission path, and a second torque transmission path is provided in the second torque transmission path. A forward speed change mechanism that is not provided in the first torque transmission path and the third speed change mechanism are provided, and a forward speed change mechanism that is provided in the second torque transmission path is provided. of A part of the speed mechanism and a part of the third transmission mechanism are shared, and a torque converter is provided at a position closer to the electric motor than the transmission mechanism in the first torque transmission path. Power transmission device.

A second characteristic configuration is that a first torque transmission path and a second torque transmission path for transmitting torque of an electric motor to wheels are provided in parallel with each other, and
A first transmission mechanism for a forward-stage high speed is provided in a torque transmission path of the power transmission device, and a first transmission mechanism for a low-speed forward stage is provided in the second torque transmission path. A torque converter is arranged at a position closer to the electric motor than the first speed change mechanism for setting the high-speed gear in the first torque transmission path, and the torque of the electric motor is transmitted to the first torque transmission path or the first torque transmission path. A power transmission device comprising a two-way clutch for selectively transmitting a torque to a second torque transmission path.

[0055]

As described above, according to the first aspect of the present invention, the number of switching devices for selecting the torque transmission path connected to the electric motor is reduced, and a transmission mechanism dedicated to the reverse gear is provided. No need. Therefore, the number of components can be reduced, and the size, weight, and cost of the device can be reduced.

According to the second aspect of the present invention, the torque is transmitted through the second speed change mechanism in the low speed stage where the transmitted torque is large, and the torque converter is transmitted in the high speed stage where the transmitted torque is small. And torque is transmitted via the first transmission mechanism. Therefore, the torque converter can be designed so as to reduce its torque transmission capacity, and the device can be reduced in size, weight, and cost.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing one embodiment of a power transmission device of the present invention.

FIG. 2 is a diagram showing characteristics of the electric motor shown in FIG.

3 is a diagram showing a relationship between a speed ratio between a converter drive shaft and an output shaft shown in FIG. 1 and a torque ratio between the converter drive shaft and an output shaft.

FIG. 4 is a diagram showing a relationship between an input torque of the converter drive shaft shown in FIG. 1 and a torque ratio between the converter drive shaft and the output shaft.

FIG. 5 is a skeleton diagram showing another embodiment of the power transmission device of the present invention.

[Explanation of symbols]

1 ... motor, 2 ... converter drive shaft, 3
... converter output shaft, 4 ... torque converter,
Reference numeral 12: High-speed drive gear, 13: Output shaft, 14: High-speed driven gear, 15: Low-speed driven gear, 17, 32, 36: Hollow shaft, 18: 2-way clutch, 19: Low-speed drive Gears 23 Wheels 29 First high speed drive gear 30 Second high speed drive gears 31, 35, 37 Gears 34
... first high-speed driven gear, 36 ... second high-speed driven gear, Hi: high-speed gear train, Hi1: first high-speed gear train, Hi2: second high-speed gear train , L
o: Gear train for low speed.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16H 47/06 F16H 47/06 B F-term (Reference) 3D039 AA02 AA04 AB01 AC02 AC04 AC36 AC37 AC40 AC45 AC54 AC77 AD02 AD06 AD23 AD43 AD53 3J028 EA07 EA09 EA25 EB04 EB13 EB37 EB54 EB63 FA06 FB06 FC32 FC42 FC57 FC59 FC63 GA01 5H115 PG04 PU01 QH08 QN03 RB08 SE08 SJ12 SJ14 TB01 TO21 TO30

Claims (2)

[Claims] A first torque transmission path and a second torque transmission path for transmitting a torque of an electric motor to wheels are provided in parallel, and the first and second torque transmission paths are provided with a first forward speed high speed first transmission path. Transmission mechanism and second gear for forward low speed
And a two-way clutch for selectively transmitting the torque of the electric motor to two torque transmission paths. The first torque transmission path is provided with the first transmission mechanism or the second transmission mechanism, and the second torque transmission path is provided for a forward gear not provided in the first torque transmission path. And the third transmission mechanism are provided, and the parts of the transmission mechanism for the forward gear provided in the second torque transmission path and the parts of the third transmission mechanism are shared. A power transmission device characterized in that it is formed. 2. A first torque transmission path and a second torque transmission path for transmitting torque of an electric motor to wheels are provided in parallel with each other.
A power transmission device comprising: a first speed change mechanism for a forward-stage high speed; and a first speed change mechanism for a low-speed forward stage provided in the second torque transmission path. Wherein a torque converter is arranged at a position closer to the electric motor than the first speed change mechanism for setting the high-speed stage in the above.