JP2001138752A - Power device for series hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of component items and improve productivity by rationalizing arrangement of a power generator, an electric motor and a reduction gear mechanism in a series hybrid vehicle. SOLUTION: In this power device, the power generator 4 and the motor 3 provided on the extension of an engine main shaft 20 are adjacently housed in a common case 12. A pair of bearing parts oppositely extended from both ends of the case 12 respectively cantilevers a power generator rotor 19 and a motor rotor 18 to dispense with an intermediate wall for the bearings. A differential gear device 8 constituting a vehicle drive system is deposed in a side part of the case 12, and motor rotation is transmitted to a drive shaft of the vehicle though a reduction gear 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a power unit for a series hybrid vehicle.

[0002]

2. Description of the Related Art In a series type hybrid vehicle, a generator is driven by an engine to generate electric power, and an electric motor for traveling drive is driven by the generated electric power or an output of a battery storing the electric power. . As a power unit for a hybrid vehicle of this kind, for example,
There is one disclosed in Japanese Patent Publication No. 01003. In this case, the motor and the speed reducer constitute a separate unit from the generator, and the output of the speed reducer is transmitted to the drive wheels via the drive shaft.

However, when the generator, the motor, and the speed reducer constitute an independent unit as described above, a case and a mount are required for each unit, and the total length of the strong electric harness connected to each unit is increased. However, there is a drawback in that the number of parts increases, for example, the length of the cable becomes longer and a number of harness fixing brackets are required. In addition, when the generator or the electric motor is to be cooled with water, it is necessary to prepare a cooling jacket and a cooling water pipe for each case, so that the structure becomes complicated.

The present invention has been made in view of such conventional problems, and provides a power unit for a series-type hybrid vehicle which has a simple structure, a small number of parts, is easy to manufacture, and is compact. It is intended to be.

[0005]

In order to solve the above problem, according to the first aspect of the present invention, a generator driven by an engine and an electric motor for generating a running driving force of a vehicle based on the power generated by the generator. In the series-type hybrid vehicle provided with the above, the generator and the electric motor are arranged in a common case that accommodates the respective stators adjacent to each other in the axial direction.

According to a second aspect of the present invention, in the first aspect of the present invention, the case is disposed at an axial end of the engine block such that the generator rotor is located on an extension of the engine main shaft.

According to a third aspect of the present invention, in the first aspect of the present invention, the generator rotor is supported on one of a pair of bearing portions extending opposite from the cover portions at both ends of the case, and the motor rotor is supported on the other. did.

According to a fourth aspect of the present invention, in each of the above-mentioned inventions, the differential gear device of the vehicle drive system is arranged in parallel with the case, and the output of the motor is transmitted to the differential gear device via the reduction gear. I did it.

According to a fifth aspect of the present invention, the speed reducer according to the fourth aspect of the present invention is constituted by a gear mechanism for transmitting rotational force between a plurality of shafts arranged in parallel.

According to a sixth aspect of the present invention, there is provided a speed reducer according to the fourth aspect of the present invention, wherein the planetary gear revolves in a fixed internal gear coaxially provided around the gear provided on the motor rotor as a sun gear. The planetary gear mechanism is provided, and the carrier rotation of the planetary gear is transmitted as an output to the differential gear device.

According to a seventh aspect of the present invention, in the fourth aspect of the present invention, the generator is disposed on a side close to the engine, and the electric motor is disposed on a side separated from the engine with the generator therebetween. The motor rotor protruding from the end of the separated case and the differential gear device arranged on the side of the generator were connected via a speed reducer comprising a gear mechanism arranged in parallel with these. A power unit for a series hybrid vehicle according to claim 4.

According to an eighth aspect of the present invention, in the above fourth aspect, the motor rotor has a hollow structure, and the engine rotation is transmitted to the generator rotor via an input shaft penetrating the hollow shaft. .

According to a ninth aspect of the present invention, in the eighth aspect of the present invention, a connecting portion with the speed reducer is provided at an end of the motor rotor on the engine side.

According to a tenth aspect of the present invention, the case of the first to third aspects of the present invention is such that a common refrigerant jacket is formed for the generator and the electric motor.

According to an eleventh aspect of the present invention, in each of the first to third aspects, the outer diameter of each of the stators of the generator and the motor and the inner diameter of the case in which they are fitted are set to be the same.

[0016]

According to the above inventions, the generator and the motor are arranged in a common case in which the respective stators are housed adjacent to each other in the axial direction. The number of components required when individually provided can be greatly reduced, and the length of the high-power harness can be minimized.

Further, when the motor or the generator is cooled with water, the common cooling jacket may be formed in the case as shown in the tenth aspect of the present invention, so that the casting structure of the case and the structure of the cooling system are simplified. Can be

Further, as set forth in the eleventh aspect of the present invention, the workability of the case can be further improved by setting the outer diameter of each of the stators of the generator and the motor and the inner diameter of the case in which they are fitted to be the same. .

The case where the generator and the motor are integrated can be laid out separately from the engine. However, as shown in the second aspect of the invention, the generator rotor is mounted on the extension of the engine main shaft. By placing the case at the axial end of the engine block so that it is located,
It can be compactly assembled as a power unit including an engine.

In a configuration in which the generator and the motor are integrated in a common case, a pair of oppositely extending pairs of the cover portions at both ends of the case are provided as described above. A cantilever support structure in which the generator rotor is supported on one side of the bearing and the motor rotor is supported on the other side can eliminate the need to provide an intermediate wall for providing a bearing between the generator and the motor. Thus, the structure of the case can be further simplified.

On the other hand, as shown in the fourth aspect of the present invention, the differential gear device of the vehicle drive system is arranged in parallel with the case, and the output of the motor is transmitted to the differential gear device via the reduction gear. With this configuration, it is possible to reduce the size of the drive unit including the differential gear device, and it is possible to obtain a drive unit particularly suitable for an FF type vehicle in which the engine is mounted laterally with respect to the vehicle body.

As the above-mentioned speed reducer, a gear mechanism for transmitting a rotational force between a plurality of shafts arranged in parallel as described in the invention of claim 5 and a planetary gear mechanism as described in the invention of claim 6 are used. Can be adopted. In particular, when a planetary gear mechanism is applied, a compact and efficient reduction gear can be configured. The speed reducer is not limited to these gear mechanisms, and a rotation transmission mechanism using a silent chain, a metal belt, or the like may be employed depending on the load or application.

In addition, as shown in the seventh aspect of the present invention, an electric motor rotor protruding from an end of the case separated from the engine and a differential gear device arranged on the side of the generator are arranged in parallel with these. It is also possible to adopt a configuration in which the generator rotor is located near the engine because of the torsional rigidity of the shaft system that drives the generator because the generator rotor is located near the engine. Therefore, it is not always necessary to take a countermeasure against vibration by a torsional damper or the like. In addition, since the length of the reduction gear shaft connecting the motor rotor and the differential gear device is increased, the distance between the fulcrums of the gear shaft can be increased to reduce the inclination of the gear, thereby suppressing generation of gear noise. There is also the advantage that you can.

Further, as shown in the eighth aspect of the present invention, the motor rotor may have a hollow structure and the engine rotation may be transmitted to the generator rotor via an input shaft penetrating the hollow shaft. In this case, as shown in the ninth aspect of the present invention, the motor rotor can be provided with a connection portion with the speed reducer at the engine side end, so that the structure of the speed reducer can be simplified. The whole can be made smaller.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a series hybrid vehicle to which an embodiment of the present invention is applied. This is an example of application to a vehicle in which the engine 1 is mounted laterally with respect to the vehicle body, and the reduction gear 2, the electric motor 3, and the generator 4 are arranged so as to be located on the main shaft extension of the engine 1. .
The output of the generator 4 driven by the engine is supplied to the battery 6 or the electric motor 3 via the inverter 5. The input and output of power by the inverter 5 at this time are controlled by the controller 7 according to the operating state such as the charging state of the battery 6 and the required output at that time.

The output of the electric motor 3 is transmitted to a drive shaft 9 and drive wheels 10 constituting a vehicle drive system via a speed reducer 2 and a differential gear device 8 arranged in parallel with the speed reducer 2. As described above, a series-type hybrid vehicle runs only with the driving force of the electric motor 3, and the engine 1 drives only the generator 4.

Next, an embodiment of a power unit applied to the hybrid vehicle will be described with reference to FIGS. First, an outline will be described with reference to FIG. 2. In this embodiment, an electric motor 3 is arranged on a main shaft extension of the engine 1,
The generator 4 provided adjacent to the electric motor 3 is driven by the engine by the input shaft 11 penetrating the electric motor rotor. The generator 3 and the electric motor 4 are housed in a common case 12 connected to the end of the cylinder block of the engine 1. The reduction gear 3 takes out the motor rotor output from an intermediate portion between the motor 4 and the engine 1,
It is composed of a gear mechanism for transmitting to a differential gear device 8 arranged in parallel with the electric motor 4.

Next, details of the power unit will be described with reference to FIG. In the figure, reference numeral 13 denotes a case set in which the power unit is unitized, and its end (bell housing) is axially connected to the engine block. The case set 13 mainly includes a bell housing 14, a housing cover 15, a bearing support (first cover) 16, a case 12, and a side cover (second cover).
The case set 13 includes a motor 3, a generator 4, a gear reducer 2, and a differential gear device 8.

The bearing support 16 and the cover 17 attached to the end of the case 12 on the engine side and the opposite side, respectively, have cylindrical bearings 16a facing each other.
17a are extended, and these bearing portions 16a, 17a
Each has a motor rotor 1 via a ball bearing.
8. The generator rotor 19 is supported. The motor rotor 18 has a hollow structure, and the rotational force of the engine crankshaft 20 is transmitted to the generator rotor 19 by the input shaft 11 loosely fitted in the hollow portion. Also,
Inside the case 12, a stator 22 of the electric motor 3 and a stator 23 of the generator 4 are respectively fitted and fixed by press fitting or the like.

Between the bell housing 14 and the bearing support 16, the reduction gear shaft 2 is arranged in parallel with the motor rotor 18.
1 is supported. The reduction gear shaft 21 has a reduction gear 18 a formed at the engine-side end of the motor rotor 18.
A gear 2a that meshes with the gear 2b and a gear 2b that transmits the rotation of the gear 2a to the ring gear 8a of the differential gear device 8 are attached. That is, in this case, the rotational force of the electric motor 3 is
The transmission is transmitted to the differential gear device 8 by two-stage reduction of the speed by the gear 18a and the gear 2a and the reduction by the gear 2b and the ring gear 8a.

As shown, the case 12 has no intermediate wall separating the motor 3 and the generator 4, and the inner surface is formed by a single cylindrical surface. Therefore, as compared with the case where there is an intermediate wall, not only the material is reduced, but also the inner surface can be processed at one time, so that there is little variation in coaxiality and inner diameter, and high accuracy can be easily obtained. In addition, since both end faces are open and there are no end face walls, machining is possible from both the left and right, and it is easy to obtain machining accuracy because it is not necessary to machine deep holes. It is easy to assemble and easy to check after assembling.

The structure without the intermediate wall in the case 12 is such that the motor rotor 18 and the generator rotor 19 are cantilevered by the bearing support 16 and the side cover 17, respectively, as described above. It depends. When the motor 3 and the generator 4 are adjacent to each other in the axial direction, an intermediate wall is not required between the rotors 16 and 18 by adopting the above-mentioned cantilever support structure.
The size can be reduced accordingly. In a vehicle with a horizontal engine, the axial dimension is a factor that determines the maximum width of the vehicle. Therefore, a small axial dimension increases the degree of freedom in determining the maximum width of the vehicle.

The cantilever support structure also has the following advantages. That is, the cantilever support structure is the rotor 16 or 1
In order to arrange the bearing on one side of the support surface of the rotor 8, when lubricating the bearing, the lubricating oil is spread on the support surface of the rotor and does not reach the middle of the two rotors. On the other hand, if an intermediate wall is provided to support both ends, oil lubrication of the bearing provided on the intermediate wall requires an oil passage for feeding the lubricating oil to the vicinity of the dead-path-shaped intermediate wall. In addition, since the lubricating oil is spread on the support surface of the rotor, a discharge passage for the lubricating oil must be provided. As a result, dimensions for securing these passages in the case and the intermediate wall are required, and not only the shaft dimension becomes long, but also complicated drilling is required. That is,
In the case of the cantilever support structure, since the two bearings are adjacent to each other, the passage for lubricating the two bearings may be located at one place in the middle of the two bearings.
Although a total of two lubrication passages may be used for 18, a dual support structure requires at least three lubrication passages at each of the right, left, and middle positions.

On the other hand, when the motor 3 and the generator 4 are cooled, it is only necessary to form a common cold soot jacket 24 in the case 12 as shown in the figure, whereby the motor and the generator are separately provided. The configuration of the cooling system can be greatly simplified as compared with the configuration. From the manufacturing point of view, the cost can be reduced because only one jacket 24 is required when casting the case 12. In that case, each stay evening 2
Since the outer diameters of 2 and 23 are common, the jacket 24 has a simpler structure. If the stator outer diameter is different, the jacket also becomes uneven, which not only causes an increase in cost, but also complicates the flow of the refrigerant, makes it difficult to ensure uniform cooling, and makes design difficult. Further, if the above-mentioned intermediate wall exists, the jacket 24 has a more complicated shape because the lubrication path is provided at the intermediate portion of the jacket.

In a series-type hybrid vehicle, for example, when the remaining battery power is low, the power generated by the generator 4 may be directly supplied to the motor 3 to secure the driving power. The electric motor 3 has substantially the same power (wattage) setting. That is, the conditions are such that the respective stators 22 and 23 are likely to have the same outer diameter. The stator has a coil formed by coiling a magnetic steel sheet with a copper wire. By matching the outer diameter, the inner diameter is also matched, and by matching the number of slots, the magnetic steel sheet is completely identical between the motor 3 and the generator 4. It will be.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 shows the outline and FIG. 5 shows the details. This embodiment differs from the first embodiment in that a planetary gear mechanism is applied as the speed reducer 2. The same parts as those in the first embodiment are denoted by the same reference numerals.

In the figure, a planetary gear mechanism constituting the speed reducer 2 includes a gear 18 a formed at one end of a motor rotor 18.
Is a sun gear, a planetary gear 2d that revolves around it,
Internal ring fixed ring gear 2 meshing with planetary gear 2d
The planetary gear 2d is supported by a planetary gear carrier 2e provided to rotate coaxially with the motor rotor 18. Inside the fixed ring gear 2c, the planetary gear 2
d revolves around gear 18a. The rotation of the planetary gear carrier 2e at this time is transmitted to the ring gear 8a of the differential gear device 8 by the gear 2f formed on the planetary gear carrier 2e.

The advantage of this configuration is that the gear 1 which is a sun gear
In 8a, the radial load is canceled and only the thrust load is applied, and the supporting bearing reduces the load by the radial load and improves the durability. In addition, a compact structure can be used because a smaller bearing can be used. It is becoming. From this and the reduction in the number of shafts, bearing friction can be reduced, and transmission efficiency is also improved.

FIG. 6 is a schematic diagram showing a third embodiment of the present invention. This is the case 1 where the motor 3 and the generator 4 are shared.
2 and each rotor is cantilevered, but the generator 4 is provided adjacent to the engine 1, and the electric motor 3 is disposed between the generator 4 and the engine 4. It differs from 1 in that it is opposite.

In this embodiment, the generator rotor 19 can be connected to the engine crankshaft 20 with relatively high rigidity. In the first embodiment, the generator rotor 19 is connected via the input shaft 11 passing through the hollow portion of the motor rotor 18.
In this case, considering a torsional vibration model in which the input shaft 11 is a torsion spring and the rotor 19 has an inertia rate, if the torsional stiffness of the input shaft 11 is small, the natural frequency will be low and the engine operating range will be low. Therefore, vibration may occur during operation in this frequency band, giving the driver an uncomfortable feeling. In order to prevent this, it is necessary to add a torsional damper for further reducing the torsional spring constant so that the frequency becomes lower than the operating range of the engine (idle rotation or less). This means an increase in the number of parts, an increase in cost, an increase in weight, and an increase in shaft dimensions.

On the other hand, in the present embodiment, since the input shaft 11 is not provided, the torsional rigidity is sufficiently large, and the torsional resonance point of the generator rotor 19 can be easily set to be higher than the maximum engine speed. There is no need to take measures against vibrations such as shoal dampers. Further, since the output of the electric motor 3 located on the end side is transmitted to the differential gear device 8 arranged on the side of the generator 4, the reduction gear shaft 21 naturally becomes long, so that its supporting rigidity is increased. Gear 2
The inclination of a and 2b can be reduced, and the effect of reducing gear noise can be expected.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an example of a series hybrid vehicle to which the present invention can be applied.

FIG. 2 is a schematic explanatory diagram of the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of the first embodiment.

FIG. 4 is a schematic explanatory view of a second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of the second embodiment.

FIG. 6 is a schematic explanatory view of a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Reduction gear 3 Electric motor 4 Generator 5 Inverter 6 Battery 7 Controller 8 Differential gear device 9 Drive shaft 10 Drive wheel 11 Input shaft 12 Case 13 Case set 14 Bell housing 15 Case cover 16 Bearing support (first cover) 16a Bearing part 17 Side cover (second cover) 17a Bearing part 18 Motor rotor 19 Generator rotor 20 Engine crankshaft 21 Reduction gear shaft 22 Motor stator 23 Generator stator 24 Refrigerant jacket

Claims (11)

[Claims] 1. A series hybrid vehicle comprising: a generator driven by an engine; and an electric motor that generates a driving force for driving the vehicle based on electric power generated by the generator. A power unit for a series hybrid vehicle in which a stator is disposed in a common case that is housed adjacently in the axial direction. 2. The power unit according to claim 1, wherein the case is arranged at an axial end of the engine block such that the generator rotor is positioned on an extension of the engine main shaft. 3. The power of a series hybrid vehicle according to claim 1, wherein a generator rotor is supported on one of a pair of bearing portions extending from the cover portions at both ends of the case and a motor rotor is supported on the other. apparatus. 4. A differential gear device for a vehicle drive system is arranged in parallel with a case, and an output of a motor is transmitted to the differential gear device via a speed reducer.
A power unit for a series hybrid vehicle according to any one of the above. 5. The power unit of a series hybrid vehicle according to claim 4, wherein the speed reducer is constituted by a gear mechanism for transmitting a rotational force between a plurality of shafts arranged in parallel. 6. The speed reducer is constituted by a planetary gear mechanism having a planetary gear revolving in a fixed internal gear coaxially provided around a gear provided on a motor rotor as a sun gear. 5. The apparatus according to claim 4, wherein the carrier rotation is transmitted as an output to the differential gear device.
A power unit for a series-type hybrid vehicle according to item 1. 7. An electric motor rotor having a generator disposed on a side close to the engine and an electric motor disposed on a side separated from the engine with the generator interposed therebetween, and a motor rotor protruding from a case end side separated from the engine. 5. The power plant for a series hybrid vehicle according to claim 4, wherein the differential gear device arranged on the side of the generator is connected to the differential gear device via a speed reducer including a gear mechanism arranged in parallel with the generator. 8. The power unit for a series hybrid vehicle according to claim 4, wherein the motor rotor has a hollow structure, and the engine rotation is transmitted to the generator rotor via an input shaft penetrating the hollow shaft. . 9. A power unit for a series-type hybrid vehicle according to claim 8, wherein a connection portion with a reduction gear is provided at an end of the motor rotor on the engine side. 10. The power unit for a series hybrid vehicle according to claim 1, wherein the case has a refrigerant jacket common to the generator and the electric motor. 11. The power unit for a series hybrid vehicle according to claim 1, wherein the outer diameter of the stator of each of the generator and the electric motor and the inner diameter of the case in which they are fitted are set to be the same.