IT202000014032A1 - Electric motor - Google Patents

Description

?Electric motor?

DESCRIPTION

The present invention relates to an electric motor, in particular the electric propulsion motor of an electric vehicle.

The mobility? electricity has the problem of reducing energy waste. Currently the electric motors are not sized for all speeds? of the vehicle, but for a speed? well above normal use. This involves a great waste of electricity because? the stator, the rotor and the coils are oversized, and to work from low speeds? up to the medium-high require more? energy than necessary (despite the use of sophisticated inverters).

Main purpose of the invention? propose a new electric motor.

Another purpose of the invention? solve or at least mitigate at least one of the above problems.

These and other objects are achieved by what is reported in the attached claims; advantageous technical characteristics are defined in the dependent claims.

A first aspect of the invention relates to an electric motor comprising:

? a first, second and third component, where

the first component? mounted inside the second component and the second component ? mounted inside the third component,

all components are mounted coaxially e

two of said components are mounted to be able to rotate around the same axis while the remaining component? fixed (one stator);

? windings configured to generate

a torque for relatively rotating the first and second components, e

a torque to rotate the second and third components relatively.

Another aspect of the invention relates to an electric motor comprising:

? N components, N > 3, where

the components are mounted one inside the other,

all components are mounted coaxially e

N-1 components are mounted to be able to rotate around the same axis while the remaining component ? fixed (one stator);

? windings configured to generate

a torque to rotate one component relative to an adjacent component.

The couple can be driving, to generate mechanical power with the engine, or resistant, to make two of said components integral with each other.

The fixed component can? be the most external or the pi? internal, but not necessarily. In the general case of N components such as the aforementioned, N > 3, by managing the torque produced by the windings, K components can be made integral with each other, 0 < K < N, and the remaining N-K components can be made integral with each other. The group of K integral components rotates relative to the group of N-K integral components to generate mechanical power outside the engine. That is, by managing the torque produced by the windings, you can? make the first component integral with the second component or the second component with the third component. The loose components rotate relatively to generate mechanical power outside the engine.

Thanks to this system, by establishing the K value in real time, energy waste can be reduced, consequently increasing autonomy and lowering pollution (product for the production of energy).

because the windings can be sized differently, from time to time you can? select and exploit for the propulsion those windings which give the best efficiency.

Another advantage? the reduction of the heat produced, in terms of speed? low and intermediate, the engine is more? small.

The number of said N engine components pu? vary, gradually adding an external component that contains all the others. This procedure can be repeated indefinitely at the expense of weight and space. As a preferred compromise, e.g. the electric motor can? foresee four components, which in fact form three electric motors inserted one inside the other. Then the three motors can be sized for different speeds, for example:

a first engine, pi? internal and formed by the first component and the second component, for low speeds? from 0 km/h to about 60 km/h;

an engine, intermediate and formed by the second component and the third component, for medium speeds? from 60 km/h to about 120 km/h;

an engine, more external and formed by the third component and the fourth component, for high speeds? from 120 km/h to about 150 km/h.

To lock the relative rotation of said two adjacent components you can? use a resistive torque generated via the windings, or preferably the motor comprises means, e.g. mounted between two adjacent components, to mechanically connect one component with the other.

In the previous example, if the third motor works (rotary cooperation between the fourth and third components), the first and second motors are locked together and form a single rotor, i.e. the first, second and third components are joined together to rotate together , while the fourth component remains fixed.

Said connecting means can be of various types. e.g. a disc clutch, a magnetic brake, a hydraulic system, a worm screw system (which, by screwing or unscrewing itself, thanks to an electric impulse or a hydraulic system, couples or uncouples the two said components from each other), or a system geared.

Said means can also act as a brake.

To manage the operation of the electric motor, ? preferable to use an electronic processor, e.g. a microprocessor. If with a single microprocessor you are unable to manage the whole process quickly, you can use more? parallel processors.

The processor ? programmed with software, which e.g. takes into account more parameters at the same time and thanks to these parameters calculates which is the engine pi? efficient to use in every situation and correspondingly controls the electric power supply in the windings, and/or said means for connecting, in order to dynamically configure the motor, that is? establish which elements are integral with each other and with respect to which element held fixed they rotate.

In particular situations, for example at speed? low proceeding in an uphill road, no ? said that the engine pi? small is the most? efficient. Why? to have maximum efficiency in any condition, it is advisable for the software to have various parameters to consider, such as e.g. one or each of:

the torque delivered by the engine,

engine rpm,

the current absorption of the motor,

the voltage of the motor,

the speed? of the vehicle,

the vehicle's position (e.g. taken with a gyroscope),

steering degrees,

the friction/impact of the air,

the frequency of the inverter,

the voltage of the inverter,

the amperage of the inverter,

the time taken to change the engine configuration;

the outside temperature,

the weather conditions.

For the detection of the aforementioned parameters, the motor e.g. includes a related sensor.

To improve the electronic management of the engine, preferably the microprocessor executes at least two decision algorithms for each pair of elements. Each algorithm reads all or some of the sensors mentioned, processes them and d? in output a decision datum that expresses the condition for the pair of elements: integral or in relative rotation to generate torque.

The outputs of all algorithms will then be evaluated and processed by a final downstream algorithm to establish in real time the actual relative configuration of the elements, e.g. piloting said means for connecting and/or power inverters which feed the windings (by varying their voltage and/or current and/or output frequency).

Having eg. three decision algorithms for each electric motor, you create nine outputs to evaluate. Each algorithm ? specialized for calculating a maximum efficiency result based on certain criteria and calculated for the current situation. The final algorithm chooses, among all the outputs, the most? efficient and provide to configure the elements to adapt the engine to the selected configuration.

It is preferable that the algorithms have default configurations, for example for starting the engine.

Another aspect of the invention relates to a vehicle including an engine as per any of the preceding variants.

Preferably, is the microprocessor system in the vehicle ? scheduled for

collect vehicle-related data in real time from sensors,

processing the data to determine a configuration for the means for blocking according to an efficiency criterion for the engine;

driving the blocking means to achieve the determined configuration.

Pi? preferably in the vehicle the microprocessor system ? programmed to determine this configuration

calculating, for each possible configuration of the means to block, a plurality? of mathematical formulas that have as argument all or some of the data coming from the sensors,

then selecting, on the basis of an energy efficiency criterion of the engine and/or vehicle, a result among all the results of the mathematical formulas,

using the selected result to drive the means to block and cos? configure the rotating structure of the engine.

Another aspect of the invention relates to a method for driving an electric motor comprising:

? N components, N > 3, where

the components are mounted one inside the other,

all components are mounted coaxially e

one of the components? fixed (a stator) while the remaining components are mounted to be able to rotate around the same axis;

? windings configured to generate torque to rotate each component relative to its adjacent component,

in which K components are joined together, 0 < K < N,

which the remaining N-K components join together, e

rotate the K components relative to the N-K components.

Preferably the K components are made integral with each other, and the remaining N-K components through a torque generated with the motor windings.

Preferably, the K components and the remaining N-K components are made integral with each other by means of a selectively connectable mechanical constraint.

Further advantages will become clear from the following description, which refers to a preferred embodiment of an engine in which:

- figure 1 shows a schematic front view of an engine;

- figure 2 shows a schematic side view of the engine,

- figure 3 shows a flowchart for an engine management program.

Like numbers in the figures indicate like or substantially like parts.

An electric motor 10 ? schematically shown in figs. 1-2, and comprises a first rotating element 20, a second rotating element 22, a third rotating element 24, and a fourth fixed element 26, which can be defined as a stator.

In particular, the first rotating element 20 ? the most internal, and ? integral with an output shaft 30. The second rotating element 22 surrounds and contains the first rotating element 20. The third rotating element 24 surrounds and contains the second rotating element 22. The fourth element 26, the furthest? outer, surrounds and contains the third rotating element 24.

The three elements 20, 22, 24 are mounted coaxially to be able to rotate independently around a common axis X, e.g. thanks to windings (not shown) configured in a known way to generate a torque between two adjacent rotating elements. You can use eg. the known construction technologies of brushless motors. Element 26 ? fixed and remains rotationally immobile.

Note that the number of rotating elements 20, 22, 24, 26 of the motor 10 can vary, having to be at least three.

Also note that the fixed element does not necessarily have to be the most? external 26, being able to be e.g. the most internal 20 and connecting the shaft 30 to the element 26.

The motor 10 comprises means 40 (indicated generally with broken lines) for blocking the relative rotation of two adjacent rotating elements (that is, between an element which contains one and the contained element). The means 40 allow one rotating element to be mechanically connected to the other, making them integral or not.

The means 40 can be of various types. e.g. a disc clutch, a magnetic brake, a hydraulic system, a worm screw system.

The means 40 can also act as a brake.

In the illustrated example, it is understood that the engine 10 is then composed of three concentric and independent sub-engines: a sub-engine formed by the interaction of elements 20, 22; a sub-engine formed by the interaction of elements 22, 24; and a sub-engine formed by the interaction of elements 24, 26.

By controlling the means 40, the electric motor 10 can? be configured to run only one of its sub-engines at a time. The mechanical torque generated by the active sub-motor? always transferred outside from? shaft 30, which can? also be sympathetic to a different, e.g. to the element pi? external 26.

Since the sub-motors can be sized for different speeds, energy waste can be reduced, consequently increasing autonomy and efficiency, by making the sub-motor work faster. suitable e.g. at the speed of the vehicle.

The selection of which sub-engine to enable in real time ? made by a microprocessor system, whose preferred architecture ? the following (see fig.3).

For each Q-th sub-engine (Q>=2), N algorithms (N>=1) evaluate data emitted by on-board sensors 200 (such as, for example, those listed above) and each calculate an efficiency datum 96 for this sub-engine according to a specific criterion or formula.

In the example of fig.2, N = 3 and Q = 3, and the algorithms for each Q-th sub-engine are indicated with 90, 92, 94.

Then all the 3 * N efficiency data are processed by a general algorithm 98, which effectively selects in real time which of the Q sub-engines to activate in each circumstance. To do this, the general algorithm 98 evaluates among all the data 96 the one which determines a greater efficiency in real time, and consequently generates a signal 100 for e.g. control the means 40 and establish in real time the relative dynamic configuration of the elements 20, 22, 24, 26.

As said, the values of Q and N can vary from what is illustrated.

Below is an example for the algorithms 90, 92, 94, where all the values are detected by the sensors 100. A sensor detects the speed? current of the vehicle, and a sensor detects the power Pa delivered by the engine, in the example 80 kW at that speed?. Assume that the residual voltage of the supply battery in the vehicle is V = k * Vfull, 0 <= k <= 1, where Vfull ? the voltage with fully charged battery, while I indicates the current supplied to the motor by the inverters.

It is valid in general

Pa = (V * I *1.73 * cos?)/1000, (1)

where in the calculations it is considered cos? = 0.94.

Algorithm 90 calculates the I in formula (1) three times by imposing a V with K about 0.3; then about 0.6 and finally about 0.95. A default value Pa1 is considered as the value of Pa.

Algorithm 92 calculates the I in formula (1) three times by imposing a V with K about 0.3; then about 0.6 and finally about 0.95. A default value Pa2 is considered as the value of Pa.

Algorithm 94 calculates the I in formula (1) three times by imposing a V with K about 0.3; then about 0.6 and finally about 0.95. A default value Pa3 is considered as the value of Pa.

It is Pa1 < Pa2 < Pa3.

The general algorithm 98 receives in input the data V, I of each algorithm 90, 92, 94 and calculates each time the coefficient c = V/I, which user? then to determine the configuration (V, I) pi? efficient among the various algorithms. Choosing the configuration (V, I) pi? efficient, the inverters will be controlled accordingly. In combination with the aforementioned calculations, the final algorithm 90 compares the current value of Pa with Pa1, Pa2, Pa3 and chooses the configuration of the motor with Pa pi? low, resulting in less waste of energy. Once the configuration of the engine has been chosen, the final algorithm 90 realizes it by commanding the means 40.

Claims (10)

1. Electric motor (10) comprising: - a first, second and third component (20, 22, 26), where the first component (20) ? mounted inside the second component (22) and the second component ? mounted inside the third component (26), all components are mounted coaxially around an axis (X), e two of said components (20, 22) are mounted to be able to rotate about said axis (X) while the remaining component (26) ? fixed; - windings configured to generate a torque for relatively rotating the first and second components, and a torque for relative rotating the second and third components; 2. A motor according to claim 1, wherein the locking means comprises an electronic circuit for driving the windings to generate a torque resisting the relative rotation of two adjacent components. 3. An engine according to claim 1 or 2, wherein the means for locking comprises means which is mounted between two adjacent components and configured to mechanically connect one component to the other in response to an external electrical signal. The engine according to claim 3, wherein the means for locking comprise a disc clutch and/or a magnetic brake and/or a hydraulic system and/or a worm system and/or a gear system. 5. Motor according to any preceding claim, comprising a microprocessor system for managing the power supply of the windings and/or the means for blocking by sending said electrical signal. 6. An engine according to claim 5, wherein the microprocessor system is programmed to detect engine data in real time from sensors, processing the data to determine a configuration for the means to block according to an energy efficiency criterion for the motor; driving the blocking means to achieve the determined configuration. 7. Motor according to any preceding claim, comprising means (40) for selectively blocking the relative rotation of two adjacent components1. 8. Vehicle comprising an engine according to any one of the preceding claims. 9. Vehicle according to claim 8, wherein the microprocessor system is programmed to detect vehicle-related data in real time from sensors, processing the data to determine a configuration for the means for blocking according to an efficiency criterion for the engine; driving the blocking means to achieve the determined configuration. 10. Vehicle according to claim 9 or 10, wherein the microprocessor system is programmed to determine this configuration calculating, for each possible configuration of the means to block, a plurality? of mathematical formulas that have as argument all or some of the data coming from the sensors, then selecting, on the basis of an energy efficiency criterion of the engine and/or vehicle, a result among all the results of the mathematical formulas, using the selected result to drive the means to block and cos? configure the rotating structure of the engine.