JPH06249302A - Gear transmission for electric automobile - Google Patents

Abstract

PURPOSE:To select a starting gear stage without hydraulic pressure and to make a smooth speed change to a high speed stage by means of a hydraulic- pressure operated clutch. CONSTITUTION:When a dog-clutch D/C is put on a first speed position, the rotation of a shaft 1 is transferred to a shaft 2 via a one-way clutch OWC, first speed gear trains 4, 6, and the clutch D/C, thereby entering a first speed selected state. Here, since no hydraulic pressure is needed for switching of the clutch D/C, even if no hydraulic pressure is generated because of a stoppage of a motor while an automobile stops, the automobile can be started as soon as the accelerating operation is performed. A speed change to a second speed is carried out by joining a hydraulic-pressure operated clutch O/C and releasing the clutch OWC. Accordingly, a smooth speed-change can be conducted only by having control over the working hydraulic pressure of the clutch O/C, and, even if a gear transmission is mounted, the electric automobile is free from a speed-change shock.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear transmission used in an electric vehicle using an electric motor as a power source, the gear transmission being used by being interposed between the electric motor and driving wheels.

[0002]

2. Description of the Related Art As a gear transmission for use in this type of application, for example, the one described in Japanese Utility Model Laid-Open No. 59-172853 is known.

By the way, in an electric vehicle, the speed of the electric motor is usually controlled by a driver's accelerator operation between a rotation stopped state and a maximum speed rotation state. Then, the gear transmission functions to input the rotation from the electric motor whose speed is thus controlled to the input shaft, change the speed of the rotation, and transmit the rotation to the output shaft drivingly coupled to the wheels.

However, all of the conventional gear transmissions represented by the above-mentioned documents are based on the same concept as that of a vehicle equipped with an internal combustion engine and are hydraulically actuated such as hydraulically actuated clutches and hydraulically actuated brakes. A structure in which a predetermined gear is selected by selectively engaging friction elements, or a predetermined gear is selected by selectively shifting a switching clutch such as a dog clutch in a corresponding direction Since it has been customary to configure so as to select, the following problems have occurred.

[0005]

That is, in the former gear transmission in which the predetermined gear stage is selected by selectively engaging the hydraulically actuated friction element, the pump for generating the hydraulic fluid is used as described above. When it is attempted to be driven by the electric motor, the electric motor is stopped in the stopped state in which the accelerator pedal is released, as is apparent from the above-mentioned condition. Does not occur. For this reason, the vehicle cannot be started unless the electric motor is operated by operating the accelerator pedal at the time of starting, and the start delay cannot be avoided. For this reason, another dedicated electric motor that constantly drives the pump is required, which is not only disadvantageous in terms of cost, but also causes a definite problem that power consumption increases and the traveling distance of the vehicle is sacrificed.

On the other hand, in the latter gear transmission in which the predetermined shift speed is selected by selectively shifting the shift clutch in the corresponding direction, a comparatively large shift shock occurs, and the greatest feature of the electric vehicle. The advantage that there is no gear change shock is largely lost in exchange for improvement of power performance by mounting the gear transmission. Above all, this type of gear transmission has a problem that automation of gear shifting is very difficult, and it is almost impossible to configure it as an automatic transmission.

It is an object of the present invention to provide a gear transmission that solves the above problems peculiar to electric vehicles.

[0008]

To this end, the present invention provides an input shaft to which rotation is input from an electric motor whose speed can be controlled between a rotation stopped state and a maximum speed rotation state by a driver's accelerator operation. , And an output shaft drivingly connected to the wheels and capable of changing the transmission ratio between these input and output shafts, in a gear shift device of an electric vehicle at a starting gear stage via a switching clutch and a one-way clutch arranged in series with each other For high-speed transmission of power from the input shaft to the output shaft via a gear transmission system for starting, which transmits power from the input shaft to the output shaft, and a hydraulic clutch that is arranged in parallel with this starting transmission system. And a gear transmission system.

[0009]

The speed of the electric motor is controlled between the rotation stopped state and the maximum speed rotation state by the driver's accelerator operation, and the rotation from the electric motor is transmitted to the input shaft of the gear transmission.
Then, the gear transmission shifts the input rotation at a gear ratio according to the selected shift speed and transmits it to the wheels from the output shaft.

In selecting the starting shift speed, the rotation of the input shaft is transmitted to the output shaft via the starting clutch and the one-way clutch by setting the switching clutch to the corresponding position. Select the start gear position.

When shifting to a high speed, the hydraulic clutch is engaged to induce self-release of the one-way clutch, and power is transmitted from the input shaft to the output shaft via the hydraulic clutch. As a result, the gear transmission is brought into the high speed stage selected state.

By the way, when selecting the starting gear,
Since this is executed by operating the switching clutch, hydraulic pressure is not required when starting. Therefore, even when the electric motor is stopped and no hydraulic pressure is generated while the vehicle is stopped,
It is possible to start at the same time as the accelerator operation. For this reason, a dedicated electric motor that constantly drives the pump as if hydraulic pressure is being generated from the time of start is not required, which is advantageous in terms of cost and contributes to the reduction of power consumption and therefore the extension of traveling distance.

Further, when shifting to a high speed stage, the hydraulic actuating clutch is engaged, or the self-release of the one-way clutch is induced to do so. Therefore, only the hydraulic pressure control of the hydraulic actuating clutch is performed. Smooth gear shifting is easily possible, and even if the gear transmission of the present invention is mounted, gear shifting shocks hardly pose a problem. Moreover, the speed change by the hydraulically operated clutch is easy to automate the speed change, which is adopted in a normal automatic transmission, and the gear transmission of the present invention can be easily configured as an automatic transmission.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows an embodiment of a gear transmission according to the present invention, where 1 is an input shaft and 2 is an output shaft. The input shaft 1 is connected to an electric motor (not shown) at the right end in the figure, and the output shaft 2 is juxtaposed in parallel with the input shaft 1. Intermediate shaft 3 coaxial with input shaft 1
Are provided in a butt relationship, and these two shafts are connected by a one-way clutch OWC. The one-way clutch is arranged in a direction in which the rotation of the electric motor can be transmitted from the input shaft 1 to the intermediate shaft 3.

A one-way clutch OW is mounted on the intermediate shaft 3.
The first speed input gear 4 and the reverse input gear 5 are sequentially connected from the side farther from C, and the output shaft 2 is aligned with these gears 4 and 5.
A first speed output gear 6 and a reverse output gear 7 are rotatably supported on the upper side. The first speed output gear 6 is directly meshed with the first speed input gear 4, and the reverse output gear 7 is meshed with the reverse input gear 5 through the idler gear 8.

A 1-R dog clutch D / C serving as a switching clutch is interposed between the gears 6 and 7, and the dog clutch has a well-known structure. When the coupling sleeve is in the neutral position indicated by N, both gears 6 are provided. , 7 are not connected to the output shaft 2 and are moved leftward to the 1st speed position, the 1st speed output gear 6
Is connected to the output shaft 2 and when the reverse position R is set, the reverse output gear 7 is connected to the output shaft 2.

On the output shaft 2, a parking gear 9 and a second speed output gear 10 are further connected, aligned with the second speed output gear 10, and a second speed input gear 11 is rotatably supported on the input shaft 1. . The input shaft 1 is further provided with a hydraulically operated clutch O / O in order to appropriately drive-connect the second speed input gear 11 to the input shaft 1.
Provide C.

A differential gear 12 is provided in parallel with the output shaft 2, and the differential gear 12 is drivingly coupled to the output shaft 2 via a final drive gear set 13. Then, the axles 14L and 14R are extended from the differential gear 12, and these axles are respectively coupled to the left and right wheels not shown.

The operation of the above embodiment will be described below. The gear transmission of this example can select the forward first and second speeds and the reverse speed by engaging the clutch as shown in the logical table of FIG.

To bring the transmission into a neutral state where power cannot be transmitted, the dog clutch D / C is set to the N position and the hydraulic clutch O / C is deactivated (released). Here, the rotation from the electric motor to the input shaft 1 is caused by the dog clutch D.
/ C and hydraulically operated clutch O / C, the transmission to the output shaft 2 is interrupted, and the transmission may be in a neutral state in which power transmission is not performed in a predetermined manner.

In selecting the first forward speed, the dog clutch D / C is set to the first speed position, but the hydraulically actuated clutch O / C is maintained in the released state. Here, the rotation of the input shaft 1 reaches the output shaft 2 via the one-way clutch OWC, the first speed gear sets 4, 6 and the dog clutch D / C, and the first speed (starting speed stage) is selected. The rotation of the output shaft 2 then reaches the left and right wheels via the final drive gear set 13 and the differential gear 12. However, in the second speed, the power is transmitted through the one-way clutch OWC, so engine braking (regenerative braking) cannot be obtained.

By the way, when the first speed is selected with the desire to start, the selection is made by switching the dog clutch D / C from the neutral position to the first speed position. No pressure is needed. Therefore,
Even when the electric motor is stopped and no hydraulic pressure is generated while the vehicle is stopped, it is possible to start at the same time as the accelerator operation. For this reason, a dedicated electric motor that constantly drives the pump as if hydraulic pressure is being generated from the time of start is not required, which is advantageous in terms of cost and contributes to the reduction of power consumption and therefore the extension of traveling distance.

When shifting from the first speed to the second speed, which is a high speed stage, the hydraulic pressure is supplied to the hydraulically actuated clutch O / C in the first speed selected state and the clutch is engaged. This allows input shaft 1
Rotation of the clutch O / C and the gear set 11, 1
0, and further, it is transmitted to the differential gear 12 via the output shaft 2 and the gear set 13, and the shift to the second forward speed can be performed. Here, the intermediate shaft 3 is naturally the first
Although it rotates at a higher speed than at high speed, the one-way clutch OWC releases and allows this high-speed rotation, so that the gear shift is not hindered.

By the way, when shifting to the second speed, which is the high speed stage, by engaging the hydraulic clutch O / C and inducing the self-release of the one-way clutch OWC, this is done. Smooth gear shifting can be easily performed only by controlling the hydraulic pressure of the pressure-actuated clutch O / C, and even if the gear transmission of this example is mounted, gear-shift shock hardly poses a problem. Moreover, the gear shift by the hydraulically operated clutch O / C is easy to automate, and the gear transmission of this example can be easily configured as an automatic transmission.

To select another starting shift speed, that is, reverse, the dog clutch D / C is set to the R position, but the hydraulically operated clutch O / C is maintained in the released state. Here, the rotation of the input shaft 1 reaches the output shaft 2 in the reverse direction via the one-way clutch OWC, the reverse gear sets 5, 8, and 7 and the dog clutch D / C to enter the reverse (starting gear) selection state. The rotation of the output shaft 2 then reaches the left and right wheels via the final drive gear set 13 and the differential gear 12. However, in this reverse movement, power is transmitted through the one-way clutch OWC, so engine braking (regenerative braking) cannot be obtained.

By the way, when the vehicle is desired to start and the reverse is selected, the selection is made by switching the dog clutch D / C from the neutral position to the reverse position. Therefore, no hydraulic pressure is required. Is. Therefore, even when the electric motor is stopped and the hydraulic pressure is not generated while the vehicle is stopped, the vehicle can start at the same time as the accelerator operation. For this reason, a dedicated electric motor that constantly drives the pump as if hydraulic pressure is being generated from the time of start is not required, which is advantageous in terms of cost and contributes to the reduction of power consumption and therefore the extension of traveling distance.

FIG. 2 is a substantive block diagram of the gear transmission in FIG. 1. Only corresponding parts are designated by the same reference numerals, and repeated description is avoided, but an oil pump for generating hydraulic fluid pressure of the clutch O / C is shown. The O / P is driven via the input shaft 1 in the same manner as a normal automatic transmission, and as a result, this pump is driven by the electric motor connected to the input shaft 1.

FIG. 3 shows another example of the gear transmission of the present invention. In this example, the one-way clutch OWC is added to the device of FIG.
Switchable overrun clutch OR
It is configured by adding / C. In the configuration of this example, the overrun clutch O is selected in the first speed and reverse selection states.
By setting the R / C to the engagement position and not releasing the one-way clutch OWC, engine braking (regenerative braking) can be obtained even at these shift speeds.

FIG. 4 shows still another example of the gear transmission of the present invention, and the same parts as those in FIG. In this example, the intermediate shaft 3 in FIG. 1 is omitted, and the first speed input gear 4 and the reverse input gear 5 are connected to the input shaft 1. The first speed output gear 6 and the reverse output gear 7 rotatably supported on the output shaft 2 in relation to the input gears 4 and 5.
Of these, the first speed output gear 6 is the forward dog clutch D / C.
(F) allows the output shaft 2 to be appropriately coupled via the forward one-way clutch OWC / F, and the reverse output gear 7 can be appropriately output via the reverse dog clutch D / C (R) via the reverse one-way clutch OWC / R. Can be combined with 2. These one-way clutches OWC / F, O
It goes without saying that the WC / Rs are arranged so that the rotations of the corresponding output gears 6 and 7 can be transmitted to the output shaft 2. Also, the dog clutches D / C (F) and D / C
(R) is a normal one that is switched between a release position and an engagement position.

The operation of the gear transmission according to this embodiment will be described below. The gear transmission of the present example is configured such that the forward first speed and the second speed can be set by engaging the clutches as shown in the logical table of FIG.
In addition, the reverse gear can be selected.

In setting the transmission in a neutral state where power cannot be transmitted, the dog clutches D / C (F) and D /
C (R) is released and the hydraulic clutch O / C is deactivated (released). Here, from the motor to the input shaft 1
Rotation to dog clutch D / C (F), D / C (R)
Also, the transmission to the output shaft 2 is cut off at the location of the hydraulically actuated clutch O / C, and the transmission may be in a neutral state in which power is not transmitted as prescribed.

In selecting the first forward speed, the forward dog clutch D / C (F) is set to the engagement position, but the reverse dog clutch D / C (R) is kept in the disengagement position, and the hydraulically actuated clutch is operated. Keep O / C open. Here, the rotation of the input shaft 1 is the first speed gear set 4, 6, the forward dog clutch D / C (F) and the forward one-way clutch OW.
First speed (starting gear) reaching the output shaft 2 via C / F
The selected state is set. The rotation of the output shaft 2 then reaches the left and right wheels via the final drive gear set 13 and the differential gear 12. However, in this first speed, power is transmitted through the one-way clutch OWC / F,
The engine brake (regenerative brake) cannot be obtained.

By the way, when the first speed is selected with the desire to start, the dog clutch D / C (F) is switched from the disengaged position to the engaged position to make the selection. Therefore, no hydraulic pressure is required. Therefore, even when the electric motor is stopped and the hydraulic pressure is not generated while the vehicle is stopped, the vehicle can start at the same time as the accelerator operation. For this reason, a dedicated electric motor that constantly drives the pump as if hydraulic pressure is being generated from the time of start is not required, which is advantageous in terms of cost and contributes to the reduction of power consumption and therefore the extension of traveling distance.

When shifting from the first speed to the second speed, which is a high speed stage, the hydraulic pressure is supplied to the hydraulic actuating clutch O / C in the first speed selected state, and the clutch is engaged. This allows input shaft 1
Rotation of the clutch O / C and the gear set 11, 1
0, and further, it is transmitted to the differential gear 12 via the output shaft 2 and the gear set 13, and the shift to the second forward speed can be performed. Here, the output shaft 2 is naturally the first
Although it rotates at a higher speed than at high speed, the one-way clutch OWC / F releases and allows this high speed rotation, so that the gear shift is not hindered.

When shifting to the second speed, which is a high speed stage, by engaging the hydraulically operated clutch O / C and inducing self-release of the one-way clutch OWC / F,
Since this is performed, smooth gear shifting can be easily performed only by controlling the hydraulic pressure of the hydraulic clutch O / C, and even if the gear transmission of this example is mounted, a gear shift shock hardly occurs. . Moreover, the shift operation by the hydraulically actuated clutch O / C is easy to automate, and
The gear transmission of this example can be easily configured as an automatic transmission.

To select another starting shift speed, that is, reverse, the dog clutch D / C (R) is moved from the disengaged position to the engaged position, and the dog clutch D / C (F) is kept in the disengaged position. , Keep the hydraulically operated clutch O / C in the released state. Here, the rotation of the input shaft 1 causes the reverse gear sets 5, 8,
7. The reverse (starting gear) selection state is reached in which the output shaft 2 is rotated in the reverse direction via the reverse dog clutch D / C (R) and the reverse one-way clutch OWC / R. The rotation of the output shaft 2 then reaches the left and right wheels via the final drive gear set 13 and the differential gear 12. However, in this reverse movement, the power is transmitted via the one-way clutch OWC / R, so that engine braking (regenerative braking) cannot be obtained.

By the way, when the vehicle is desired to start and the reverse is selected, the dog clutch D / C (R) is switched from the disengaged position to the engaged position to make the selection. No hydraulic pressure is required. Therefore, even when the electric motor is stopped and the hydraulic pressure is not generated while the vehicle is stopped, the vehicle can start at the same time as the accelerator operation.
For this reason, a dedicated electric motor that constantly drives the pump as if hydraulic pressure is being generated from the time of start is not required, which is advantageous in terms of cost and contributes to the reduction of power consumption and therefore the extension of traveling distance.

FIG. 5 is a substantive block diagram of the gear transmission in FIG. 4, and the corresponding parts are shown by the same reference numerals, and duplicate explanation is avoided, but an oil pump for generating hydraulic fluid pressure of the clutch O / C is shown. In this example, the O / P is driven via the input shaft 1 as in the above-described example, and as a result, this pump is driven by the electric motor coupled to the input shaft 1.

[0039]

As described above, the gear shift device for an electric vehicle according to the present invention selects the starting shift speed (the first forward speed and the reverse shift speed in the illustrated example) as described in claim 1.
Since the configuration is such that this is performed by operating the switching clutch (dog clutch in the illustrated example), hydraulic pressure is not required when starting, and therefore even when the motor is stopped and no hydraulic pressure is generated while the vehicle is stopped. , It is possible to start at the same time as the accelerator operation. For this reason, a dedicated electric motor that constantly drives the pump as if hydraulic pressure is being generated from the time of start is not required, which is advantageous in terms of cost and contributes to the reduction of power consumption and therefore the extension of traveling distance.

Further, when shifting to the high speed stage (second forward speed in the illustrated example), the hydraulically operated clutch is engaged, and the one-way clutch is self-released, so that this is done. The smooth shift can be easily performed only by controlling the hydraulic pressure of the hydraulic clutch, and the gear shift device of the present invention hardly causes a shift shock even when it is mounted.

Moreover, the speed change by the hydraulically operated clutch is easy to automate the speed change, which is adopted in a normal automatic transmission, and the gear transmission of the present invention can be easily configured as an automatic transmission. it can.

[Brief description of drawings]

FIG. 1 is a skeleton diagram diagrammatically showing an embodiment of a gear transmission for an electric vehicle according to the present invention.

FIG. 2 is a detailed cross-sectional view showing the actual configuration of a gear transmission for an electric vehicle according to the same example.

FIG. 3 is a skeleton diagram similar to FIG. 1 showing another example of the device of the present invention.

FIG. 4 is a skeleton diagram diagrammatically showing still another example of the gear transmission for an electric vehicle according to the present invention.

FIG. 5 is a detailed cross-sectional view showing the actual configuration of a gear transmission for an electric vehicle according to the same example.

[Explanation of symbols]

 1 input shaft 2 output shaft 3 intermediate shaft 4 1st speed input gear 5 reverse input gear 6 1st speed output gear 7 reverse output gear 8 idler gear 10 2nd speed output gear 11 2nd speed input gear 12 differential gear 13 final drive gear 14L axle 14R axle D / C dog clutch (switching clutch) OWC one-way clutch O / C hydraulically operated clutch OR / C overrun clutch D / C (F) forward dog clutch (switching clutch) D / C (R) reverse dog clutch (switching clutch) ) OWC / F Forward one-way clutch OWC / R Reverse one-way clutch O / P Oil pump

Claims (1)

[Claims] 1. An input shaft for inputting rotation from an electric motor capable of speed control between a rotation stopped state and a maximum speed rotation state by a driver's accelerator operation, and an output shaft drive-coupled to wheels. In a gear transmission for an electric vehicle that can change the transmission ratio between these input and output shafts, a start transmission that transmits power from an input shaft to an output shaft at a shift speed via a switching clutch and a one-way clutch that are arranged in series with each other And a high-speed gear transmission system for transmitting power from the input shaft to the output shaft via a hydraulically operated clutch arranged in parallel with the starting transmission system. Gear transmission of electric vehicle.