KR100559760B1 - Automotive Hybrid Transmission - Google Patents

Abstract

The invention relates in particular to transmissions (15; 15a; 15b; 15c) used in motor vehicles, which include two planetary gears (16; 16c, 17; 17c) and ring gears (18) of said planetary gears; 18c, 19 are connected to the crankshaft 11 (11a; 11c) of the internal combustion engine by the crown gear 12. Each planetary gear 16 (16c, 17) is coupled to a gear shaft (31, 32), on which the input gear wheels (1E to 5E, RE) for various transmission ratios are arranged. The input gear wheels 1E to 5E, RE engage with the output gear wheels 1A to 5A, RA arranged on the output shafts 40; 40a; 40c. According to the invention each planetary gear 16; 16c, 17 is coupled, for example, with an electrical machine 26, 27 connected to the sun wheels 23; 23a, 24; 24a of the planetary gears 16; 16c, 17. do. Through the above configuration, it is possible to obtain a relatively high overall efficiency and a continuously adjustable speed ratio, particularly when used in a hybrid vehicle.

Transmission, ring gear, crown gear, crankshaft, planetary gear, input gear wheel, output shaft, output gear wheel, sun wheel, electric machine, hybrid car

Description

Hybrid transmission, especially for motor vehicles}

The present invention relates to a transmission for an automobile according to the preamble of claim 1.

Such transmissions are described in the article "Development of the Toyota Hybrid System" (Technical Prospect 47, No. 2, April 2, 1998). In this known hybrid vehicle transmission, a single planetary gear is provided. The ring gear of the planetary gear connected to the output shaft is coupled to the first electric machine, while the sun wheel is connected to the second electric machine. The planetary gear is introduced with a driving moment via a planetary carrier connected to the drive shaft or crankshaft of the internal combustion engine. By varying the rotational speed of the sun wheel coupled to the second electric machine, the arbitrary rotation speed is adjusted for the rotation of the predetermined planetary wheel in the ring gear generated by the internal combustion engine, so that the ring gear and the output shaft and the internal combustion Any speed ratio can be obtained between the engines. The rotation moment is always divided at a fixed rate by the planetary gear between the internal combustion engine, the output shaft and the second electric machine. For a given rotational moment and specific transmission ratio of the internal combustion engine, the rotational speed and the required rotational moment of the second electric machine are also fixed. If the number of revolutions required in the second electric machine changes, the power of this electric machine also changes. The output generated during generator operation of the second electrical machine is output back to the first electrical machine and vice versa when the motor of the second electrical machine is operated. In general, this process is called electrical power branching. However, such a power branch has a problem that a loss occurs.

For this reason, so-called SEL-transmissions (compared to the mechanical-electric vehicle transmissions described on page 551 of VDI-Report 1393, published in 1998 by VDI Publisher, Dusseldorf, by Pe. . Here, after the planetary set of planetary gears, a third gear is further arranged, which reduces the rotational dispersion of the electric machine. However, there are disadvantages such as relatively complicated gear arrangements and hydraulic pressure required to convert lamination clutches and brakes.

On the other hand, the transmission according to the present invention having the features of claim 1, in particular an automobile transmission, has the advantage that it can be installed relatively simply mechanically and has good efficiency. These advantages are obtained by reducing the power flow of both electric machines by means of two planetary trains connected to each of the electric machines according to the features of claim 1, thereby for example on-board during generator operation. Only the power required for the network is generated by both electric machines.

Other advantages and other preferred embodiments of the transmission, in particular of the automobile transmission, according to the invention are described in the dependent claims and in the description.

The clutch according to the prior art can be omitted by coupling both electric machines to one gear shaft and using planetary trains. Both electric machines can also replace starting devices, generators necessary for starting the internal combustion engine, and synchronization devices for converting individual gears. In addition, by using two gear shafts, the gears can be changed without interrupting the tension. By using both electric machines, it is possible to carry out continuously variable speed in the area between the two gear stages.

An embodiment of the present invention is shown in the drawings and described in detail below.

1 schematically shows a first transmission according to the invention;
2 to 4 schematically show a transmission modified compared to FIG. 1.

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1 shows a portion of an automobile drive train. This drive train comprises in particular a crankshaft 11 of an internal combustion engine, not shown, wherein one end of the crankshaft is arranged with a crown gear 12. The crankshaft 11 also interacts with the engine brake 13. The crown gear 12 may be coupled to a transmission 15 formed as a three-shaft transmission in this embodiment.
The transmission 15 preferably has the same two planetary trains, in particular two planetary gear sets 16, 17. Each planetary gear set 16, 17 has a ring gear 18 with inner teeth, a ring gear 19 with outer teeth, a plurality of planet wheels 21, 22, and a sun wheel, as is known, respectively. 23, 24). The transmission 15 is coupled to the crown gear 12 via the outer teeth of the ring gears 18, 19 of the planetary gear sets 16, 17. Each sun wheel 23, 24 on the side of the planetary gear sets 16, 17 facing the crankshaft 11 is coupled to one electric machine 26, 27. For example, via intermediate electrical circuits, electrical machines 26 and 27 that are also connected to the on-board battery of a motor vehicle are provided with electronic output components for four quadrant operation. The planetary carriers 28, 29 of the planetary gear sets 16, 17 are connected to the gear shafts 31, 32 on the side opposite to the electric machines 26, 27.

Two gear shafts 31, 32 support the input gear wheels 1E to 5E, RE of the five-gear manual transmission. Input gear wheels 2E, 4E; 1E, 3E; 5E, RE for connecting the input gear wheels 1E to 5E, RE disposed separately to the gear shafts 31 and 32 to the gear shafts 31 and 32. Each one of the gear wheels 33, 34, 35 is disposed so as not to rotate. The gear wheels 33, 34, 35 are engaged with the respective input gear wheels 1E to 5E, RE by claw coupling with electrically actuating sliding cuffs 36, 37, 38. Therefore, it can be connected non-positively.

The input gear wheels 1E to 5E, RE are engaged with the output gear wheels 1A to 5A, RA which are rotatably disposed on the output shaft 40, wherein between the input gear wheels RE and the output gear wheels RA. The intermediate gear wheel 41 is disposed. The output shaft also interacts with the brake 42 to block or fix the output shaft 40. The brake 42 may be a driving brake of an automobile.

In the following, various operating states which can be implemented by the transmission 15 described above are described. The internal combustion engine as well as the transmission 15 are controlled and regulated by an electronic control device and the brake 42 is activated to start the internal combustion engine of the vehicle when the vehicle is at rest, ie the output shaft 40. Is blocked. In addition, for both gear shafts 31 and 32, one gear, for example a first gear and a second gear, is selected, for which the sliding cuffs 37 and 38 correspond to the corresponding input gear wheels 1E and 2E. ) By selecting one gear on each gear shaft 31, 32, the planetary carriers 28, 29 of the planetary gear set 16, 17 are fixed, ie these planet carriers are connected via the sun wheels 23, 24. It may not rotate when the starting moment is introduced. Both electrical machines 26 and 27 are motorized by an on-board battery. At this time, the rotation moment introduced from the electric machine 26, 27 to the sun wheels 23, 24 rotates the respective ring gears 18, 19 through the rotated planet wheels 21, 22, which in turn rotate. Since the crown gear 12 of the crankshaft 11 is driven at the required starting speed, the internal combustion engine is started.

The construction of suitable conventional planetary gear sets 16, 17 results in a starting transmission ratio of about 4: 1. Assuming that the starting moment required for the internal combustion engine is about 200 Nm, about 25 Nm should be provided for the electric machines 26, 27 acting as electric motors. This required rotational moment also simultaneously determines the structural size and output stage of the electrical machine 26, 27.

It should be mentioned here that both electric machines 26, 27 are driven by the internal combustion engine through the crown gear 12 after the start of the internal combustion engine, in the start-up mode, ie with the planetary carriers 28, 29. Based on the speed ratio of the planetary gear sets 16 and 17 described above, the electric machines 26 and 27 are driven at engine speed four times that of the internal combustion engine. In order to ensure that the electric machines 26, 27 do not exceed the limit speed, the engine speed of the internal combustion engine should be limited during the start mode in this case.

In the following, the normal operation of a vehicle in which the vehicle runs at a constant or variable speed is described. Also in this case one gear, for example a second gear and a third gear, is selected for both gear shafts 31 and 32 of the transmission 15. Corresponding gear wheels 2E, 3E are connected non-positively with gear wheels 2A, 3A of the output shaft 40. The specified ratio between the revolutions of both planet carriers 28 and 29 corresponds to the transmission ratio between the second and third gears, where the planet carrier 28 of the second gear is larger than the third planet carrier 29 Rotate to numbers The rotation speed of the output shaft 40 is also proportional to the running speed of the vehicle. When the planetary gear sets 16 and 17 are the same, since the ring gears 18 and 19 driven by the internal combustion engine rotate at the same rotational speed, the sun wheel 23 coupled to the electric machine 26, 27, The designated number of revolutions of 24) occurs. When the rotational speed levels of both electric machines 26 and 27 change, when the rotational speed of the internal combustion engine is constant, the ratio between the engine rotational speed of the internal combustion engine and the output shaft 40 rotational speed also changes. That is, the change in the rotational speed level of the electric machine 26, 27 may change the speed ratio (unauthorized) when the gears are fixedly selected on the gear shafts 31, 32.

At the moment of rotation given by the internal combustion engine and the drive moment required at the output shaft 40, both electric machines 26 and 27 produce a fixed total rotation moment. In addition, the rotation moment of the internal combustion engine and the total rotation moment in both electric machines 26 and 27 are always present at a constant rate unless the brake is actuated. Therefore, the actual rotation moment of the internal combustion engine is very accurately derived from the total rotation moment of the electric machines 26, 27 (known from its control). Knowing the actual moment of rotation of the internal combustion engine is advantageous for coordinated drive train control and engine control or such control can be simplified or improved.

By branching the rotation moment through both gear shafts 31, 32, the total rotation moment of both electrical machines 26, 27 can be arbitrarily distributed between the gear shafts. Since both electric machines 26 and 27 have different rotational speeds based on differently selected gears in both gear shafts 31 and 32, the output of the electric machine also changes.

In particular, it is desirable for both electric machines 26 and 27 to function as generators which generate only the energy or output required for the on-board network in normal operation. This also adjusts the specific speed level at both electric machines 26, 27 and thus the transmission ratio of the transmission 15 at the particular power required at both electric machines. Unauthorized changes in transmission ratios possible within certain limits via the electrical machines 26, 27 diverge between both electrical machines 26, 27 where the power required by the on-board network is acting as a generator, It can only be achieved that the resulting output branch does not occur between both electrical machines 26 and 27.

It is sufficient to cover an area where the spread of the transmission ratio possible by both electric machines 26 and 27 is relatively small, because the gear ratio can be greatly changed by gear change. For example, at low on-board network outputs, if there is not enough dispersion for one gear, allow for (lossy) output flow between both electrical machines 26, 27, or allow on-board battery charging. The dispersion can be increased by increasing the power for the circuit beyond the actual on-board network requirements.

The following describes the conversion process of the transmission 15, which is necessary, for example, to change the transmission ratio when the internal combustion engine is required to produce a high running speed when at a certain rotational speed and correspondingly high load. Here, it is assumed that the second gear shaft 32 should be converted from the third gear to the fifth gear, while in the first gear shaft 31 the fourth gear should remain selected. Before the actual conversion process, the electrical machine 27 assigned to the second gear shaft 32 for this process is converted into a no-load state, so that the moment in the second gear shaft 32 reduces the small moment from the mass inertia of the part. It is 0 except for that. In this state, the flow of force is generated only by the first gear shaft 31, and the electric machine 26 assigned to the first gear shaft supports a part of the driving moment and can operate as a motor or a generator. As soon as the second gear shaft 32 is in the no-load state, the selected third gear can be separated by the removal of the claw coupling and the movement of the sliding cuff 37. The electrical machine 27 of the second gear shaft 32 then generates the required synchronization speed, with the second gear shaft 32 being the gear wheel 5E of the fifth gear driven by the output shaft 40. Rotate at a speed that matches the number of revolutions. In this case, the sliding cuff 38 moves between the second gear shaft 32 and the gear wheel 5E so that a force flow occurs. At this time, the control unit of the transmission 115 may detect the rotation speed necessary for the synchronization of the second gear shaft 32, using the rotation speed of the electric machine 26 and the internal combustion engine. Thus, no additional sensor for detecting the rotation speed of the gear shafts 31 and 32 is necessary.

Other shift changes during high gear shift or low gear shift occur correspondingly, and for all shift shifts, between the crankshaft 11 and the output shaft 40 of the internal combustion engine, one of the two gear shafts 31 and 32 is used. The force flow always occurs, so the conversion processes can take place without disturbing the tensile force.

A so-called hybrid vehicle having not only an electric motor but also an internal combustion engine can be particularly preferably operated by the transmission 15. The operation of the motor vehicle, for example by means of an electric motor used in urban areas for air purification reasons, is realized by both electric machines 26, 27 receiving the necessary energy from the on-board battery. Ring gears 18, 19 of planetary gear sets 16, 17 to support rotational moments introduced into gear shafts 31, 32 via planetary carriers 28, 29 via electrical machines 26, 27. ) Must be fixed. This is done simply by the operation of the engine brake 13, which acts on the ring gears 18, 19 via the crown gear 12.

If a restart is required while the internal combustion engine is running completely electrically only, the second gear and the reverse gear are selected in the transmission 15. The electric machine 27 reversely rotates, ie reversely rotates in the direction of rotation necessary for starting the engine, while the electric machine 26 is driven forward. Thus by both electric machines 26, 27 a uniform drive rotation moment is introduced into the output shaft 40. Since the speed ratio between the selected second gear and the reverse gear is different, the second electric machine 27 assigned to the reverse gear passes through the gear ring 19 to the crown gear 12, rather than through the ring gear 20. Delivers a higher rotational moment (supported by engine brake 13). Therefore, it is sufficient to release the engine brake 13 for substantial starting, so that the crown gear 12 and the crankshaft 11 move the gear ring 19 of the second electric machine 27 in the starting direction required by the internal combustion engine. Is rotated through. When the internal combustion engine is started, the reverse gear is disconnected from the second gear shaft 32 corresponding to the gear change mentioned above, and the first gear or the third gear is selected instead.

In addition, during start-up of the internal combustion engine, the driver can feel bucking due to the rotational moment introduced by the internal combustion engine into the drive train, which corresponds to the corresponding control via both electric machines 26, 27. It can be compensated by the method.

As described above, the driving of the vehicle using only the electric machines 26 and 27 inevitably takes relatively high energy from the on-board battery. In order to limit the required capacity of the on-board battery or to allow recharging during internal combustion engine operation, both electrical machines 26 and 27, as already mentioned, operate as generators. In order to operate the electrical machines 26, 27 as generators, it is particularly desirable to utilize the rolling energy stored in the motor vehicle during the movement operation. To this end, the internal combustion engine is converted to an overrunning operating state (no load state) and the engine brake 13 is activated. Thus, the sun wheels 23, 24 coupled to the electrical machines 26, 27 are driven by rotating planet carriers 28, 29.

The transmission 15 described above can be modified in many ways. Thus, for example, additional brakes 43, 43a need to be provided on at least one of both electric machines 26, 27. This allows the vehicle to be started at high power from the stop. This is explained by the rotation ratio of approximately 4: 1 planetary gear sets 16 and 17 already mentioned by both electric machines 26 and 27 when the car is at rest, rotating at approximately four times the motor speed. do. If a relatively high starting moment is introduced to the crankshaft 11 by the internal combustion engine at start-up, the starting moment must be supported by the electric machine 26, 27, which inevitably is a short time in the electric machine 26, 27. To draw very high power. By using at least one additional brake 43, 43a which interacts with the at least one electric machine 26, 27, the starting moment can be received by the brakes 43, 43a and converted into frictional operation. . The brakes 43 and 43a may be formed as mechanically actuated friction brakes (shoe brakes or lamination brakes). However, the brakes 43 and 43a are particularly preferably formed as vortex brakes. This vortex brake can additionally be used as a part of a heating system (such as for a water-cooled generator) and can support very high moments in a short time.

In this embodiment, the transmission 15 is shown and described as a planetary gear. However, other types of planetary trains may be used instead of planetary gears. When using planetary gears, it is also possible to consider different couplings of the individual elements to parts of the planetary gears. Thus, for example, an internal combustion engine can introduce its rotational moment into the planetary carrier, while gear shafts can be coupled to ring gears.

Three other modifications are shown in FIGS. 2 shows a transmission 15a, which is formed as a hollow shaft transmission instead of the three-shaft transmission shown in FIG. The crankshaft 11a coupled to the planet carriers 28a and 29a is surrounded by the hollow gear shaft 44 and on which the input gear wheels RE, 1E, 3E and 5E are arranged, In the extension of the crankshaft 11a the gear shaft 45 supports the input gear wheels 4E and 2E. Input gear wheels 1E to 5E, RE interact with output gear wheels 1A to 5A, RA, which output gear wheels are hollow gear shaft 44, crankshaft 11a, gear shaft 45 Is disposed on an output shaft 40a extending in parallel to. The transmission 15a shown in FIG. 2 has in particular an advantage that it can be formed structurally narrow.

The transmission 15b shown in FIG. 3 is characterized in that both electric machines 26, 27 are arranged side by side and both planetary gear sets 16b, 17b are arranged reflectively symmetrically with each other (as in the transmission 15a). Especially different from the gearbox shown in. Also, as in the transmission 15a, both electric machines 26 and 27 and the planetary gear sets 16b and 17b form a series structure, so that a relatively compact transmission can be achieved.

The transmission 15c shown in FIG. 4 is a particularly preferred variant. This transmission differs from the transmission 15a in that the planetary gear 16c and the planetary wheel 21c are formed in double and connected to the rigid shaft. The first planet wheel 21c disposed on the left side of the planet carrier 28c meshes with the sun wheel 23c connected to the electric machine 26, and on the right side of the planet carrier 28c, the second planet wheel 21c is driven. Meshes with the ring gear 18c of the device. Thus, a very compact transmission structurally similar to the current manual transmission can be obtained, wherein the electric machine takes the space required for the clutch in a conventional manual transmission.

Of course, corresponding to the transmission 15 according to FIG. 1, it is also conceivable to install at least one additional brake 43, 43a on the transmissions 15a, 15b, 15c.

Claims (10)

As a transmission (15; 15a; 15b; 15c) used in a motor vehicle, the transmission introduces a rotation moment of the internal combustion engine and is coupled to an input shaft (11) coupled to at least one planetary train (16; 16c; 17; 17c). 11a; 11c, an output shaft 40; 40a; 40c coupled to at least one planetary train 16; 16c, 17; 17c, and at least one planetary train 16; 16c, 17; 17c; Two electrical machines 26, 27 are arranged interactively, which are coupled to the input shafts 11; 11a; 11c and the output shafts 40; 40a; 40c. In the transmission in which the rotation speeds of the electric machines 26 and 27 can be changed independently of each other, Both electric machines 26, 27 are each coupled to one separate planetary train 16; 16c, 17; 17c, the planetary trains 16, 17 interacting with an output shaft 40; 40a. Transmission characterized in that it is coupled to a separate gear shaft (31, 32) arranged in a manner. 2. The output gear wheels 1A to 5A according to claim 1, wherein input gear wheels 1E to 5E and RE are arranged on each of the gear shafts 31 and 32 and the wheels are arranged on the output shafts 40 and 40a. Gearbox characterized in that it meshes with RA). 3. The non-positive input according to claim 2, wherein the input gear wheels 1E to 5E, RE and the output gear wheels 1A to 5A, RA are non-positive to the gear shafts 31 and 32 and the output shafts 40 and 40a. Parts 34 to 38 are provided for connection Wherein both gear shafts (31, 32) and output shafts (40; 40a) are always connected in a non-positive manner, with the exception of the conversion pose. 4. Transmission according to any of the preceding claims, characterized in that the gear shaft is formed as a hollow shaft (44) comprising an input shaft (11a). 4. The planetary train according to any one of claims 1 to 3, wherein the planetary train is a planetary gear (16, 17), and the ring gears (18, 19) are connected to the input shaft (11), the sun wheel (23); 23a, 24; 24a are coupled to the electrical machine 26, 27, the planet carriers 28, 29 are coupled to the gear shaft 31, 32, or the planet carriers 28, 29 are the input On the shaft 11, its sun wheels 23, 23a, 24, 24a are coupled to the electric machine 26, 27, and the ring gears 18, 19 are coupled to the gear shafts 31, 32. Transmission characterized in that. 4. Transmission according to any one of the preceding claims, characterized in that the electrical machines (26, 27) are arranged in a straight line with one another in the axial direction. 4. Transmission according to any one of the preceding claims, characterized in that the number of revolutions of both electric machines (26, 27) can be varied to obtain a continuously variable ratio. 4. Transmission according to any of the preceding claims, characterized in that the input shaft (11) and the output shaft (40; 40a) each have one brake device (13, 42). 4. Transmission according to any one of the preceding claims, characterized in that at least one said electrical machine (26, 27) is arranged to interact with the brake device (43, 43a). delete

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