DE10132610A1 - Motor vehicle drive, has electric motor integrated into wheel with rotor mounted on wheel hub - Google Patents

Abstract

The motor vehicle drive has an electric motor mounted in a wheel hub with the axle mounting (2) supporting the motor stator. The motor rotor is mounted on the wheel hub (1). The magnetic field sources (9-11) for the motor are positioned in a gap defined between the wheel bearings and the hub. The magnets can be formed integrally with the axis.

Description

The invention relates to a vehicle drive, in particular for a small motor vehicle an electric motor integrated into a wheel of the vehicle.

Electric motors that act directly on a vehicle wheel as the drive for vehicles z. B. from WO 91/13779 and EP-A-0 224 144 known. WO 91/13779 describes one such, modified for rotary movements linear motor, in which a wheel rim load-bearing element for the rotor, while for the stator, which is only part of the Extends rotor circle circumference, a separate, rotatably arranged on the inside of the wheel Carrier element is provided. EP-A-0 224 144 relates to the inside of the wheel arranged, provided as an additional drive for a vehicle wheel hub motor, the Rotor is firmly connected to the wheel hub. Avoid drives with directly on the wheel attacking drive motors transmission losses through motor and wheel connecting Drive elements. Such losses can exceed 20% in conventional motor vehicles the engine power.

The present invention has for its object a new, especially for To create small motor vehicle usable vehicle drive of the type mentioned, which, compared to known drives of this type, has a reduced production outlay requires.

The vehicle drive according to the invention which achieves this object is characterized in that that an axle part connectable to the vehicle is a supporting element of the stator and a against the axle part rotatable wheel hub a supporting element of the rotor of the electric motor forms.

According to this solution of the invention, wheel bearing and drive merge into one Functional unit in which both the axle part and the wheel hub have a double function. Separate parts forming a carrier housing of the drive motor are omitted.

The axle part can be inserted into the wheel hub with the Wheel suspension of a motor vehicle connected axle journal or a receiving the wheel hub Act axle bushing.

In a preferred embodiment of the invention, the field-generating elements of the Electric motor, i.e. conductor windings, magnetizable parts and, if necessary, permanent magnets the axle part and the wheel hub in one through the axle part and the wheel hub and on the front arranged by wheel bearings limited annular space, which is preferably cylindrical, however could also have a gradation.

The wheel bearings are preferably made use of the axial length of the wheel hub and axle part provided at the axial end of the axle part or the wheel hub. In addition to their wheel bearing function the wheel bearings take over the mutual rotary mounting of the rotor and stator. From one Ordinary wheel bearing differs from such a component only by the coaxial field-generating elements enclosed between the wheel hub and the axle part.

In the preferred embodiment of the invention, the electric motor is part of one of the other wheel releasable, having devices for connection to the vehicle Unit. It lends itself to such a z. B. prepared for mounting on a motor vehicle Completely prefabricate unit at an electric motor manufacturer and one To supply vehicle manufacturers. On the other hand, one would focus on the production of Wheel bearings specialist manufacturers with the installation of the field-generating elements not a big one Additional expenses arise.

It would even be conceivable to make such a unit compatible with an alternative, e.g. B. by train a gasoline engine, powered vehicle, e.g. B. to the vehicle with a electrical auxiliary drive or convert to electric drive.

In a further advantageous embodiment of the invention, the field generation is used Elements of the electric motor are formed in one piece with the axle part and / or the wheel hub. This can be, in particular, protruding from the wheel hub or the axle part, act magnetizable coil cores or magnetizable teeth. It advantageously reduces hereby the number of parts forming the engine and thus ultimately the Production expense. Finally, such a construction bears in terms of material continuous transitions between the relevant field-generating elements and the wheel hub or the axis part are formed, also to the mechanical stability of the drive.

In the preferred embodiment of the invention, the electric motor is a transverse flux or / and reluctance machine. Both electrical machines are characterized by relatively simple structure and a high power density, which in particular allows powerful drives in the dimensions of conventional motor vehicles used to manufacture wheel bearings formed by the wheel hub and axle part. Transversal flux machines get by with relatively few coils that are expensive to manufacture. Reluctance machines do not require permanent magnets. Especially at Reluctance motors are the ones that can be magnetized to interact with the stator Form teeth in one piece with the axle part or the wheel hub.

The electric motor is expediently a brushless motor with conductor leads exclusively to the stator. In this case, fixed, functionally more reliable than sliding contacts Make contacts between the motor windings and the conductor leads. Apart from the bearings neither wear nor require such an engine Maintenance.

The entire length, predetermined by the function as a wheel bearing, is expedient Wheel hub and axle part used to create a field-generating motor file between the wheel hub and To accommodate the axle part and to achieve the highest possible power density. You can do this a plurality of ring arrangements of field-generating elements, each generating a torque for itself Be formed elements that are laterally adjacent to each other.

It would even be conceivable for ring arrangements to correspond to different types of Electric motors are provided to mutually advantageous motor properties combine, e.g. B. Properties of the reluctance machine with properties of the Transversal flow.

The electric motor is expediently a multi-phase motor with one Single phase motor improved concentricity.

Preferably when using the drive in a passenger car Control device for field switching and / or for load control of the electric motor depending on a power request or / and from a sensor signal processing Control program provided. In particular, this control device can be used to connect the Electric motor with an operating voltage source that controls time Circuit breaker device include.

Such a circuit breaker device can be used, for example, to phase one Impulse the multi-phase motor with the voltage of a battery, load control can take place over the pulse width.

The sensor is preferably the rotational position of the rotor detecting sensor, which also at least the first time derivative of the rotational position, d. H. the Rotation speed of the rotor, determined. While such a rotational position sensor for Control of field switching z. B. can serve in the operation of a reluctance motor, supplies he in the preferred embodiment of the invention further output values for a Control program that serves the driving stability of the vehicle and in particular slip and Blocked wheels prevented. The changes to the required according to the control program Torque attacking the wheels is directly affected by appropriate changes brought about the wiring of the motor with the operating voltage. The Control device sensor information of the electric motors of several wheels of the vehicle to process.

The invention will now be based on exemplary embodiments and the accompanying these exemplary drawings are explained in more detail. Show it:

Fig. 1 shows a first embodiment of an inventive vehicle drive with an electric motor, the field-generating elements are arranged between a wheel hub and an axle sleeve,

Fig. 2 shows a second embodiment of a vehicle drive according to the invention with an electric motor, the field-generating elements are arranged between a wheel hub and an axle journal,

Fig. 3 is a cross sectional view of a usable in the drive of Fig. 1 the transverse flux motor,

Fig. 4 is a cross sectional view of a usable in the drive of Fig. 2 the transverse flux motor,

Fig. 5 is a cross sectional view of a usable in the drive of Fig. 1 reluctance motor,

Fig. 6 is a cross-sectional view of a usable in the embodiment of FIG. 2 reluctance motor, and

FIG. 7 shows a schematic illustration of a vehicle equipped with drive units according to FIG. 1.

The reference numeral 1 in FIG. 1, a hub is called a motor vehicle, which coaxially engages an axle bush. 2 The axle box 2 is integrally connected to parts 3 and 4 of the wheel suspension via which the axle box 2 is connected in known manner-bearing parts of a vehicle body (not shown) with. On its end facing away from the vehicle and provided with a flange 5 , the wheel hub can be screwed to a wheel.

Between the wheel hub 1 and the axle bushing 2 , ball or roller bearings 6 and 7 are arranged, each bearing laterally against an annular shoulder formed on the outer circumference of the wheel hub or the inner circumference of the axle bushing. The bearing 7 is secured on the wheel hub 1 on the side facing the vehicle by a spring ring 8 .

An annular space, which is delimited by the wheel hub 1 , the axle bushing 2 and on the end face by the bearings 6 and 7 , contains field-generating elements of an electric motor. As such field-generating elements, teeth 9 rigidly connected to the wheel hub 1 are distributed over the circumference of the wheel hub 1 . The teeth 9 consist of either a magnetizable or a permanent magnetic material. In the case of permanent magnets, teeth forming the north and south poles alternate with one another.

Opposite the teeth 9 there are at least one coil or a plurality of coils 10 and pole teeth 11 which can be magnetized by the coil or coils 10 and which are firmly connected to the rotationally fixed axle bushing 2 .

In the exemplary embodiment of FIG. 2, parts that are the same or have the same effect are designated with the same reference number as in the previous exemplary embodiment, the reference number being in each case followed by the letter a.

Instead of the axle bushing 2 , in which the wheel hub 1 engages, an axle journal 2 a is inserted into a wheel hub 1 a in the embodiment of FIG. 2. Between the wheel hub 1 a and the axle journal 2 a, bearings 6 a and 7 a are arranged, each of which bears laterally against an annular shoulder formed on the wheel hub 1 a and the axle journal 2 a. The bearing 6 a is secured on its outer side facing away from the vehicle on the journal 2 a by a spring ring 8 a.

The wheel hub 1 a and the axle journal 2 a form an annular space which is delimited on the end side by the bearings 6 a and 7 a and in which the elements 9 to 11 corresponding field-generating elements 9 a to 11 a with coils 10 a on the rotationally fixed axle journal 2 a are accommodated.

Conductor feeds for the coils 10 and 10 a are not shown in FIGS. 1 and 2.

As can be seen in FIGS. 1 and 2, the wheel hub 1 or 1 a, the axle bushing 2 or the axle journal 2 a and the bearings 6 , 7 or 6 a, 7 a each perform a double function. The parts mentioned are used on the one hand for wheel bearings. On the other hand, they form load-bearing, mutually rotatable housing elements of an electric motor.

The structural units shown in FIGS. 1 and 2 can be assembled and disassembled on the vehicle as a whole. A defective drive motor can be easily replaced.

The dimensions of the wheel hubs and axle parts correspond to the dimensions of the Such parts conventionally used in small vehicles with internal combustion engines.

Reference is now made to FIGS. 3 and 4, where field-generating elements which can be used in the exemplary embodiments of FIGS. 1 and 2 are shown in cross section.

From Fig. 3 field generating elements will be apparent to a transverse flux machine with internal rotor. Magnetizable pole teeth 11 ′ of the stator formed by laminated cores are connected to a carrier ring 13 . A coil 10 'serves to magnetize the teeth 11 ', the conductor of which extends mainly in the circumferential direction of the stator according to the construction principle of the transverse flux machine. Permanent teeth 9 ', which are held on a carrier ring 14 , are arranged on the rotor radially opposite the teeth 11 '. The tangential distance between the permanent magnets 9 'alternating in polarity corresponds to the tangential length of the teeth 11 '. There is an air gap between the rotor and the stator. In the drive of Fig. 1, the carrier ring 13 with the axle sleeve 2 and the support ring 14 with the hub wheel 1 is connected.

FIG. 4 shows field-generating elements of a transverse flux motor with an internal rotor, as can be used in the drive of FIG. 2. Permanent magnet 9 a 'changing in polarity are held on a carrier ring 14 a of the rotor. A carrier ring 13 a of the stator is connected in one piece with magnetizable teeth 11 a '. A coil 10 a 'serves to magnetize the teeth 11 a'.

In Fig. 5 field generating elements of a reluctance motor shown, which can be used in the drive of Fig. 1,. A carrier ring 15 of the rotor is connected to magnetizable teeth 9 ″. Opposite magnetizable pole teeth 11 ″ are integrally attached to a carrier ring 16 of the stator. The teeth 11 "can each be magnetized by a coil 10 ".

Fig. 6, finally, shows field generating elements of a reluctance motor, such as are used in the drive of FIG. 2. A coil 10 a "magnetizable pole teeth 11 a" are formed on a support ring 16 a of the stator. From a carrier ring 15 a of the rotor protrudes integrally connected magnetizable teeth 10 a ".

In the reluctance motors of Figs. 5 and 6 the number of magnetizable teeth 10 "and 10 a" is smaller than the number of these teeth facing teeth. As a result, an offset promoting the concentricity of the motor is formed between the pole teeth and the magnetizable teeth.

Transversal flux machines, as described with reference to FIGS. 3 and 4, go z. B. from DE 195 32 614 A1, DE 198 11 075 A1 and DE 35 36 538 A1. Reluctance machines are described for example in DE 198 43 924 A1, PCT / US 99/22502 and DE 198 32 876 C1.

The transverse flux machines and which can be operated with continuous field switching Reluctance motors are characterized by a high power density. The rotating masses are low. The construction is simple, the production is therefore inexpensive. at Reluctance motors dispense with magnets. It is especially important to remember here that the magnetizable Form teeth in one piece with the hub or the axle bush.

Reference is now made to FIG. 7, where a vehicle with four wheels 17 is shown schematically, each having a drive according to FIG. 1. A three-phase motor with three conductor leads 18 is integrated in each of the wheels 17 .

The three conductor leads 18 are each connected to a circuit breaker unit 19 which, with a time delay, pulsates the individual phases of the drive motors with an operating voltage source 20 , e.g. B. a battery or fuel cell connects.

The circuit breaker unit 19 is connected to a control device 21 comprising a computer circuit, which determines the switching times of the circuit breaker unit.

The control device 21 receives signals from four rotational position sensors 22 which are installed in the four drive motors. By means of a differentiation device formed by the control device 21 , the rotational speed and rotational acceleration can be determined from the time-dependent rotational positions.

The control device 21 is also connected to an input device for load requests indicated at 24 .

The control device 21 , on the one hand, ensures normal motor operation by controlling the continuous field switching of the motors depending on the rotational position and rotational speed in accordance with different load requirements. On the other hand, the control device contains the programs, which automatically control the load and serve to improve driving stability, which, in particular by means of direct control of the engine torque, prevent wheels from locking, slip or critical situations arising when cornering. In this case, the control device 21 can control the four motors independently of one another and process sensor information from a plurality of wheels for comparison.

Claims (12)

1. Vehicle drive, in particular for a small motor vehicle, with an electric motor integrated into a wheel ( 17 ) of the vehicle, characterized in that an axle part ( 2 ; 2 a) which can be connected to the vehicle is a load-bearing element of the stator and a wheel hub which can be rotated against the axle part ( 1 ; 1 a) forms a supporting element of the rotor of the electric motor. 2. Drive according to claim 1, characterized in that the field-generating elements ( 9-11 ; 9 a- 11 a) of the electric motor on the axle part ( 2 ; 2 a) and the wheel hub ( 1 ; 1 a) in one by the axle part ( 2 ) and the wheel hub ( 1 ) and on the end face by wheel bearings ( 6 , 7 ) delimited annular space. 3. Drive according to claim 1 or 2, characterized, that the field generating elements of the electric motor integrally with the Axle part and / or the wheel hub are formed. 4. Drive according to one of claims 1 to 3, characterized in that the electric motor is part of a, preferably detachable from the rest of the wheel, devices ( 3 , 4 ; 3 a, 4 a) for connection to the vehicle unit. 5. Drive according to one of claims 1 to 4, characterized, that the assembly for the suspension of an alternatively powered vehicle is compatible. 6. Drive according to one of claims 1 to 5, characterized, that the electric motor comprises a transverse flux or / and reluctance machine. 7. Drive yet one of claims 1 to 6, characterized, that the electric motor is a motor free of sliding contacts with conductor leads to the stator only. 8. Drive according to one of claims 1 to 7, characterized, that several ring arrangements, each generating a torque for itself field-generating elements are provided. 9. Drive according to claim 8, characterized, that ring arrangements corresponding to different types of electric motors are provided. 10. Drive according to one of claims 1 to 9, characterized, that a control unit for field switching and / or for load control of the Electric motor depending on a power requirement and / or a sensor signals processing control program is provided. 11. Drive according to claim 10, characterized in that the control unit ( 22 ) comprises a circuit breaker device ( 21 ) which controls the line connection of the electric motor to an operating voltage source. 12. Drive according to claim 10 of 11, characterized, that the control program is one of the driving stability of the vehicle, in particular the Prevention of slipping and locking of the wheels is the service program.