Technical Field

The present invention relates to a motorization unit for vehicles.

Background Art

With particular but not exclusive reference to quadricycles, applications of motorization units for vehicles are known composed of thermal and/or electric motors, intended to vary the speed of rotation of the tires of the quadricycle as well as to distribute the total power to each wheel.

The motorization unit, in actual facts, must be able to set all of the vehicle’s axle shafts and wheels in rotation regardless of whether one is driving along a substantially rectilinear or curved path.

In the latter circumstance, in particular, the problem arises of making the axle shafts rotate at different speeds from each other, whatever the radius of curvature of cornering.

This is due to the fact that each tire must cover an arc of curvature having a length proportional to the radius of curvature, and each arc must be covered in the same amount of time, making it inevitable that some tires and their axle shafts must rotate at different speeds than others; in particular, the wheels on the outer side of cornering cover a wider arc of circumference than the wheels on the inner side of the cornering and, therefore, must rotate faster.

Failure to do so would result in undesirable wheel slippage which, in addition to endangering the drive and driver, would cause premature tire wear.

The use of mechanical differentials in this regard is well known.

These devices are typically positioned between the motorization unit and the axle shafts and are composed, in their most traditional form, of a metal cage inside which a set of gears is housed which can be coupled in various ways to allow several driving conditions.

Such conditions, generally, are the rectilinear motion, cornering motion and lack of grip.

Under conditions of rectilinear motion, the driving force of the motorization unit is equally distributed over the two axle shafts, which are set in rotation at the same angular velocity.

Under conditions of cornering motion, the motive power of the motorization unit is distributed over the two axle shafts in such a way that the speed of rotation of the wheels on the outer side of the cornering is greater than the speed of rotation of the wheels on the inner side of the cornering.

Conditions of lack of grip, on the other hand, can occur when the vehicle is on slippery surfaces or if one wheel of the same is stuck in a pothole, and results in one or more tires slipping without actively contributing to vehicle’s traction.

The mechanical differentials belonging to the prior art respond to this drawback with the self-locking function, which allows to completely exclude one or more axle shafts in order to convey the power delivered by the motorized unit to the only wheels in contact with the ground and able to generate traction.

In order to properly perform all of the functions described, traditional mechanical differentials require that the gears be continuously lubricated by an oil bath in order to slow the wear thereof and to control the operating temperature.

This necessity, however, frequently leads to oil leaks from the metal cage, with the inconvenient consequences of having to replace the oil, risking damage to the gears due to poor lubrication, being forced to periodically overhaul the vehicle and, last but not least, causing environmental pollution due to uncontrolled oil leakage while driving.

It should also be borne in mind that the mechanical differentials belonging to the prior art are mechanisms of high constructive complexity, require particularly tight dimensional tolerances and involve considerable assembly work.

Last but not least, traditional mechanical differentials have considerable volumetric dimensions largely due to the non-negligible number of components used.

These overall dimensions are inconveniently connected to a corresponding increased weight of the vehicle, with negative consequences on consumption, as well as representing a potential risk of damage to the differential itself while driving, precisely because of its size.

Finally, it should be borne in mind that, in the general context of the motorized units for vehicles belonging to the prior art, such units are manufactured to effectively operate on a very specific type of vehicle, being inadequate, on the contrary, on vehicles having different characteristics, such as electric traction, vehicle weight and wheel size, unless substantial modifications are made that are inconveniently complex and important.

Description of the Invention

The main aim of the present invention is to devise a motorization unit for vehicles which can distribute motive power to the wheels of vehicles in a convenient and easy manner.

Another object of the present invention is to devise a motorization unit for vehicles capable of operating without complex mechanical devices.

One object of the present invention is to devise a motorization unit for vehicles which is arranged to be mounted on a plurality of vehicles having different technical characteristics.

A further object of the present invention is to devise an assembly kit for the practical and fast replacement of pre-existing mechanical differentials with a motorization unit for vehicles with exclusively electric propulsion.

An additional object of the present invention is to devise a motorization unit for vehicles which allows the mentioned drawbacks of the prior art to be overcome within a simple, rational, easy and effective to use as well as affordable solution.

The aforementioned objects are achieved by the present motorization unit for vehicles having the characteristics of claim 1.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become more apparent from the description of some preferred, but not exclusive, embodiments of a motorization unit for vehicles, illustrated by way of an indicative, yet non-limiting example in the accompanying tables of drawings wherein: Figure 1 is an exploded view of an embodiment of the unit according to the invention;

Figure 2 is an axonometric view, in partial transparency, of the same embodiment of the unit according to the invention;

Figure 3 is an axonometric view of another embodiment of the unit according to the invention;

Figure 4 is an axonometric view of yet another embodiment of the unit according to the invention;

Figure 5 is a cross-sectional view of the latter embodiment of the unit according to the invention;

Embodiments of the Invention

With reference to these figures, reference numeral 1 globally indicates a motorization unit for vehicles.

With particular reference to Figure 1 and Figure 2, the unit 1 comprises: at least one basic frame 2; at least a first electric motor 3, associated with the basic frame 2 and provided with a first drive shaft 4 rotatable around a first motor axis Ml; at least a first transmission unit 5, comprising: at least a first outlet element 6 mounted on the basic frame 2 in a rotatable manner around a first outlet axis U1 substantially parallel to the first motor axis Ml, the first outlet element 6 being configured to associate with a first axle shaft 7 of a vehicle; and first transmission means 8 for transferring the motion between the first drive shaft 4 and the first outlet element 6; at least a second electric motor 9, associated with the basic frame 2 and provided with a second drive shaft 10 rotatable around a second motor axis M2 substantially parallel to the first motor axis Ml; at least a second transmission unit 11, comprising: at least a second outlet element 12 mounted on the basic frame 2 in a rotatable manner around a second outlet axis U2 substantially parallel to the second motor axis M2 and substantially aligned with the first outlet axis Ul, the second outlet element 12 being configured to associate with a second axle shaft 13 of a vehicle; and second transmission means 14 for transferring the motion between the second drive shaft 10 and the second outlet element 12; at least one electronic processing and control unit 15 electronically connected to the electric motors 3, 9 and adapted to adjust the operation thereof.

Conveniently, the electronic processing and control unit 15 is configured to control the rotational speed of the individual electric motors 3, 9 by causing the first electric motor 3 to generate a possibly different amount of power than that generated by the second electric motor 9, so as to cause the first outlet element 6 and the second outlet element 12 to rotate at rotational speeds that may also differ from each other (e.g., when cornering or under conditions of lack of grip). Conveniently, the basic frame 2 comprises at least a first plate 16 and at least a second plate 17, substantially parallel to each other and substantially orthogonal to the first motor axis Ml and to the second motor axis M2, wherein the first plate 16 is positioned between the first electric motor 3 and the first transmission unit 5 and the second plate 17 is positioned between the second electric motor 9 and the second transmission unit 11.

Conveniently, the first plate 16 comprises: at least a first main face 18; at least a first secondary face 19, opposite the first main face 18; at least a first opening 20 made through; wherein the first electric motor 3 is arranged on the side of the first main face 18, the first transmission unit 5 is arranged on the side of the first secondary face 19 and the first drive shaft 4 is arranged to pass through the first opening 20.

In particular, the first opening 20 is substantially circular in shape and extends between the first main face 18 and the first secondary face 19.

Conveniently, the first plate 16 is substantially triangular in shape with rounded corners. Usefully, the first plate 16 comprises a first connection hole 21 obtained through, substantially circular in shape and provided with a first axis of connection Cl.

Usefully, the first opening 20 and the first connection hole 21 are obtained in the proximity of two vertices of the first plate 16 with a substantially triangular shape.

In the particular embodiment shown in Figures 1 and 2, the second electric motor 9 is associated with the first main face 18, for example such that the first axis of connection Cl is substantially coincident with the second motor axis M2.

Conveniently, the second plate 17 comprises: at least a second main face 22; at least a second secondary face 23, opposite the second main face 22; at least a second opening 24 made through; wherein the second electric motor 9 is arranged on the side of the second main face 22, the second transmission unit 11 is arranged on the side of the second secondary face 23 and the second drive shaft 10 is arranged to pass through the second opening 24.

In particular, the second opening 24 is substantially circular in shape and extends between the second main face 22 and the second secondary face 23. Preferably, the second plate 17 is substantially triangular in shape with rounded corners.

Usefully, the second plate 17 comprises a second connection hole 25 formed through, substantially circular in shape and provided with a second axis of connection C2.

Usefully, the second opening 24 and the second connection hole 25 are obtained in the proximity of two vertices of the second plate 17 of substantially triangular shape.

In the particular embodiment shown in Figures 1 and 2, the first electric motor 3 is associated with the second main face 22, for example in a such way that the second axis of connection C2 is substantially coincident with the first motor axis Ml.

Usefully, the basic frame 2 comprises at least a first supporting body 26 for the rotary support of the first outlet element 6, the first supporting body 26 being associated with the first plate 16 by interposition of first position adjustment means 27 of the first outlet axis U1 with respect to the first motor axis Ml and to the second motor axis M2.

In particular, the first supporting body 26 abuts against the first main face 18 and can creep with respect thereto by the action of the first position adjustment means 27.

Conveniently, the first position adjustment means 27 comprise a first sliding pocket 31 formed in the first plate 16 and wherein the first supporting body 26 is housed in a sliding manner.

More in detail, the first sliding pocket 31 is substantially a through hole formed between the first main face 18 and the first secondary face 19 and is oriented along a first direction of sliding SI substantially orthogonal to the lying plane of the first motor axis Ml and of the second motor axis M2.

The first position adjustment means 27 also comprise a first adjustment screw 30 coupled to the first plate 16 (e.g., to a first appendage 16a of the first plate itself) and to the first supporting body 26.

In particular, the first adjustment screw 30 is located inside the first sliding pocket 31 and is rotatable around an axis of rotation substantially coincident with the first direction of sliding S 1.

Therefore, by operating on the first adjustment screw 30, it is possible to move the first supporting body 26 along the first direction of sliding SI and, consequently, to adjust the position of the first outlet element 6 connected thereto.

The first sliding pocket 31 is arranged in the proximity of a vertex of the first plate 16 having a substantially triangular shape; in this way, the first axis of connection Cl, the first motor axis Ml, and the first outlet axis U1 are arranged in the proximity of the three vertices of the first plate 16, thereby reducing the overall dimensions of the unit 1 all other conditions being equal. Preferably, the basic frame 2 comprises at least a second supporting body 28 for the rotary support of the second outlet element 12, the second supporting body 28 being associated with the second plate 17 by interposition of second position adjustment means 29 of the second outlet axis U2 with respect to the first motor axis Ml and to the second motor axis M2.

In particular, the second supporting body 28 abuts against the second main face 22 and can creep with respect thereto due to the action of the second position adjustment means 29.

Conveniently, the second position adjustment means 29 comprise a second sliding pocket 33 formed in the second plate 17 and wherein the second supporting body 28 is housed in a sliding manner.

More in detail, the second sliding pocket 33 is substantially a through hole obtained between the second main face 22 and the second secondary face 23 and is oriented along a second direction of sliding S2 substantially orthogonal to the lying plane of the first motor axis Ml and of the second motor axis M2.

The second position adjustment means 29 also comprise a second adjustment screw 32 coupled to the second plate 17 (e.g., to a second appendage 17a of the second plate itself) and to the second supporting body 28.

In particular, the second adjustment screw 32 is located inside the second sliding pocket 33 and is rotatable around an axis of rotation substantially coincident with the second direction of sliding S2.

By operating on the second adjustment screw 32, it is therefore possible to move the second supporting body 28 along the second direction of sliding S2 and, consequently, to adjust the position of the second outlet element 12 connected thereto.

The second sliding pocket 33 is arranged in the proximity of a vertex of the second plate 17 having a substantially triangular shape; in this way, the second axis of connection C2, the second motor axis M2 and the second outlet axis U2 are arranged in the proximity of the three vertices of the second plate 17, thereby reducing the overall dimensions of the unit 1 all other conditions being equal. Preferably, the first drive shaft 4 comprises at least a first drive pulley 34, the first outlet element 6 comprises at least a first outlet pulley 35 and the first transmission means 8 comprise at least a first flexible element 36 closed on itself in a loop and wrapped at least partly around the first drive pulley 34 and around the first outlet pulley 35.

Conveniently, the second drive shaft 10 comprises at least a second drive pulley 37, the second outlet element 12 comprises at least a second outlet pulley 38 and the second transmission means 14 comprise at least a second flexible element 39 closed on itself in a loop and wrapped at least partly around the second drive pulley 37 and around the second outlet pulley 38.

Preferably, the first flexible element 36 and the second flexible element 39 are cog belts.

Further different embodiments cannot however be ruled out, wherein, for example, the first flexible element 36 and the second flexible element 39 consist of chains, ropes, flat belts or the like.

It is easy to appreciate that the transmission ratio between the motor shafts and the outlet elements may be changed and adapted to the construction requirements in an extremely simple manner, e.g. by changing the diameter of the pulleys as required.

Usefully, at least one of either the first electric motor 3 or the second electric motor 9 comprises at least one detecting sensor 40 adapted to detect the angular position of at least one of either the first drive shaft 4 or the second drive shaft 10.

Conveniently, the detecting sensor 40 is provided with a gear wheel 41 mounted on at least one of either the first or the second drive shafts 4, 10.

In particular, the gear wheel 41 is connected to a control device not shown in the figures which allows associating the rotation of the gear wheel 41 itself with the angular position of at least one of either the first drive shaft 4 or the second drive shaft 10.

In the embodiment shown in Figures 1 and 2, only one detecting sensor 40 is shown for detecting the position of the first motor shaft 4 but a similar detecting sensor 40 is also provided on the second electric motor 9.

In the embodiment shown in Figures 1 and 2, the first main face 18 and the second main face 22 face each other and mutually define a space wherein both electric motors 3, 9 are housed; this makes it possible to obtain a compact solution, to optimize the overall dimensions and to install the unit 1 in a plurality of different types of quadricycles depending on the availability of space on board the same.

Figure 3 shows a second embodiment which is provided with plates 16, 17, electric motors 3, 9 and transmission units 5, 11 similar to the embodiment shown in Figures 1-2, to the detailed description of which reference is made, except that the plates 16, 17 are arranged differently.

Indeed, in this embodiment, the first plate 16 and the second plate 17 are associated with each other by means of connecting elements 46 such that the first secondary face 19 and the second secondary face 23 face each other and mutually define a space wherein both transmission units 5, 11 are housed.

The unit 1 according to this second embodiment allows obtaining a compact solution which optimizes the space available and is suitable in those circumstances where, for physical and/or geometric reasons, the unit 1 according to the first embodiment cannot be installed on board the vehicles. Figure 4 and Figure 5 show a third embodiment which is provided with plates 16, 17 and transmission units 5, 11 similar to the embodiment shown in Figures 1-2, a detailed description of which is referred to herein.

The third embodiment differs from the first embodiment by the fact that a plurality of electric motors 3, 9 is provided connected in series.

With particular reference to Figure 4 and Figure 5, in fact, the unit 1 comprises: a plurality of first electric motors 3 connected in series to form a first common electric motor 42, the first drive shafts 4 of the first electric motors 3 being integrally associated with each other to form a first common drive shaft 43 rotatable around the first motor axis Ml; a plurality of second electric motors 9 connected in series to form a second common electric motor 44, the second drive shafts 10 of the second electric motors 9 being integrally associated with each other to form a second common drive shaft 45 rotatable around the second motor axis M2.

In particular, the first common electric motor 42 is composed of two first electric motors 3 arranged on opposite sides of the second plate 17, with the first common drive shaft 43 being arranged passing through the second connection hole 25.

Similarly, the second common electric motor 44 is composed of two second electric motors 9 arranged on opposite sides of the first plate 16, with the second common drive shaft 45 being arranged passing through the first connection hole 21.

Alternative embodiments cannot however be ruled out wherein, for example: the plates 16, 17 are spaced apart from each other by a greater distance than that shown in Figures 4 and 5 and both first electric motors 3 and both second electric motors 9 are arranged in the space defined between the plates 16, 17; a different number of electric motors 3, 9 is provided, in the space between the plates 16, 17 and/or on opposite sides with respect to the plates 16, 17.

In other words, in the third embodiment, the electric motors 3 are connected to each other as a stack, assembling them in series in a modular manner and in different numbers according to the needs; this allows varying the value of the power delivered in a simple, fast and reversible way, making it possible to manufacture different models of units 1 easily adaptable to a wide range of vehicles with different traction needs.

It has in practice been ascertained that the described invention achieves the intended objects.

In particular, the fact is emphasized that the peculiar solution of adjusting the power delivered by the electric motors by means of electronic control by the electronic processing and control unit allows the motorization unit for vehicles to distribute the total power independently to each axle shaft, effectively achieving the differential and self-locking function without introducing any additional components.

It should also be pointed out that the particular expedient of including sliding pockets and a plurality of outlet pulleys having different diameters makes it possible to adapt the same motorization unit to a plurality of vehicle types that require very different transmission ratios.