Abstract:
Said device for mounting an electric propulsion assembly into the engine compartment of an electric vehicle includes a mounting member ( 4, 5 ) having a means for attaching onto the vehicle chassis and attachment means for an electrical machine ( 3 ), an electrical power unit ( 2 ), and a charging unit ( 1 ).

Description:
BACKGROUND 
     The invention relates generally to the electric engines of motor vehicles, and relates more particularly to the mounting of the electric engine in the engine compartment of the motor vehicle. 
     In an electric vehicle, the electric engine generally comprises an electric machine, an electronic power block and a charger block. These three elements are not fastened to one another in order to form one assembly as is the case for heat-powered vehicles. Linking these elements to the chassis then poses a problem. This is because, at the mounting stage, this implies, at first glance, linking each element to the chassis which increases the complexity of the mounting, dismantling and maintenance operations. 
     BRIEF SUMMARY 
     The aim of the invention is therefore to overcome these drawbacks by proposing an engine frame and electric engine assembly in the form of a single block facilitating the handling and mounting in the engine compartment of the vehicle. 
     In one embodiment, a device for mounting an electric propulsion assembly in the engine compartment of an electric vehicle comprises a mounting member having fastening means on the chassis of the vehicle and fastening means for an electric machine, an electronic power block and a charger block. The fastening means on the mounting member are, for example, a stud and nut assembly. 
     The mounting member can be divided into two portions and comprise a bottom securing module, such as a bottom frame, provided with a means for fastening to the chassis, a means for fastening the electric machine and a means for fastening the electronic power block, and a top securing module, such as a top frame, provided with a means for fastening the charger block and designed to be fastened onto the bottom securing module. The bottom securing module is linked to the chassis by fastening means in order to allow dismantling from above. The weight of the power electronic unit is such that, in effect, it has to be removed by lifting when dismantling the engine. 
     Advantageously, the bottom securing module comprises two transversal beams on which two fastening means enable a first beam of the top module to be fastened substantially attached to a first transversal beam of the bottom module and a second beam of the top module situated at a distance from a second transversal beam of the bottom module. The lack of space in the engine compartment is such that the lateral beams of the top securing module have to be recentered, thus partly covering at least the electronic power unit. 
     Preferably, the bottom securing module comprises lifting arms arranged on either side of its center of gravity. This position facilitates the handling of the electric motor assembly and its subsequent mounting in the engine compartment of an electric vehicle. 
     Advantageously, the device comprises fastening means suitable for fastening the auxiliary elements of the engine, such as a compressor or a water pump, to the bottom securing module. Thus, it is possible to dismantle the three elements of the engine while leaving the auxiliary elements in place. 
     According to another aspect, an electric propulsion assembly, intended to be mounted in the engine compartment of an electric vehicle, comprises an electric machine, an electronic power block and a charger block in which a mounting member has fastening means on the chassis of the vehicle and fastening means for the electric machine, the electronic power block and the charger block. 
     Preferably, the mounting member comprises a bottom securing module, such as a bottom frame, provided with a means for fastening to the chassis, a means for fastening the electric machine and a means for fastening the electronic power block, and a top securing module, such as a top frame, provided with a means for fastening the charger block and designed to be fastened to the bottom securing module. This assembly is then intended to be mounted in the engine compartment of an electric vehicle. The duly formed assembly can be conveyed in the various vehicle assembly factories. 
     According to yet another aspect, a method for mounting an electric propulsion assembly in the engine compartment of an electric vehicle comprises the following steps: an electric machine is fastened onto the bottom portion of a bottom securing module; an electronic power block is fastened onto the top portion of the bottom securing module; a charger block is fastened onto a top securing module; the top securing module is fastened onto the bottom securing module. Finally, the assembly is housed inside the engine compartment by advantageously fastening the bottom securing module to the chassis of the vehicle. Dismantling is then done in reverse. The first step is to remove the charger block, then the top securing module, making access to the electronic power unit possible, then the electric machine. 
     Preferably, auxiliary elements of the engine, such as a compressor or a water pump, are fastened to the bottom securing module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other aims, features and advantages of the invention will become apparent from reading the following description, given solely as a nonlimiting example, and with reference to the appended drawings, in which: 
         FIG. 1  illustrates an exploded view of a device according to the invention; 
         FIG. 2  illustrates an overview of a device according to the invention after assembly; and 
         FIG. 3  illustrates a plan view of a device according to the invention during assembly. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a mounting device in exploded view for an electric propulsion assembly according to the invention. The propulsion assembly comprises a charger block  1 , an electronic power unit  2 , and an electric machine  3 . These different elements of the propulsion assembly are fastened onto a mounting device comprising a mounting member consisting of a top frame  4  and a bottom frame  5 . The top frame  4  is, in the example illustrated, substantially rectangular. It has two longitudinal beams  6  and  7  and two transversal beams  8  and  9 . Conventionally, in the present description, the front portion of the device corresponds to the portion situated on the left of the figure and the rear portion is defined as being the portion situated on the right of the figure. Thus, the transversal beam  8  will hereinafter be called the “front” beam and the transversal beam  9  the “rear” beam of the top frame  4 . 
     The parallelepipedal charger block  1  is fastened onto the top frame  4  by four screws  10  passing through four orifices  11  situated in the vicinity of its corners and four corresponding orifices  12  situated in the vicinity of the four corners of the top frame  4 . Three of these screws  10  are fastened onto three fastening elements  13 ,  14 ,  15  situated on the bottom frame  5 , thus enabling the charger block  1  to be fastened to the top frame  4  and the top frame  4  to the bottom frame  5 . The remaining screw is fastened, for example using a nut, in an orifice  12  of the top frame  4 , thus creating a means for fastening the charger block  1  to the top frame  4 . The top frame  4  also comprises a fixing tab  16 , including an orifice  17  and fastened at the corner between the longitudinal beam  6  and the rear beam  9  of the top frame  4 . This fixing tab  16  is fastened using a screw  17   a  onto a fastening element  18  of the bottom frame  5 . 
     The bottom frame  5  comprises a horizontal rectangular frame  5   a  comprising two longitudinal beams  19  and  20 , a front transversal beam  21  and a rear transversal beam  22 . The bottom frame  5  also comprises a rectangular mounting element  23 , mounted perpendicularly on the front transversal beam  21 . The mounting element  23  comprises two lateral uprights  24  and  25  and two longitudinal uprights  26  and  27 . 
     The bottom frame  5  comprises two reinforcing arms  28  and  29  fastened by one of their ends, for example by welding, respectively onto the lateral uprights  24  and of the mounting element  23 . The first reinforcing arm  28  is fastened by its other end onto the fastening means  18  of the bottom frame  5  and the second reinforcing arm  29  is fastened by its other end onto the longitudinal beam  20  of the horizontal frame  5   a.    
     A first lifting arm  30  is positioned vertically on the longitudinal beam  20  of the horizontal frame  5   a . A second lifting arm  31  is attached to the lateral upright  24  of the mounting element  23 , thus forming a diagonal of the bottom frame  5  with the first lifting arm. This second arm is positioned vertically toward the outside of the bottom frame  5 . The first lifting arm  30  is situated at two thirds of the longitudinal beam  20  of the frame  5   a  and the second lifting arm  31  is situated in the vicinity of the longitudinal beam  20  and the front transversal beam  21 , thus forming a diagonal with the first lifting arm  30 . Furthermore, these lifting arms  30  and  31  are situated on either side of the center of gravity of the propulsion assembly so as to facilitate the handling of the device. 
     The top frame  4  is fastened onto the bottom frame  5  via the four screws  10  and  17   a  cooperating with the four fastening elements  13 ,  14 ,  15  and  18  situated on the bottom frame  5 . 
     The bottom frame  5  comprises a first fastening element fastened, for example by welding, onto the first lifting arm  30 , said lifting arm  30  being positioned on the longitudinal beam  20  of the bottom frame  5 . The bottom frame  5  comprises a second fastening element  14  fastened, for example by welding, onto a lateral upright  25  of the mounting element  23  of the bottom frame  5 . The bottom frame  5  comprises a third fastening element  15  fastened, for example by welding, onto the first reinforcing arm  28  of the bottom frame  5 . The bottom frame  5  comprises a fourth fastening element  18  fastened, for example by welding, onto the longitudinal beam  19  of the horizontal frame  5   a  of the bottom frame  5 . These fastening elements  13 ,  14 ,  15  and  18  comprise tapped orifices  32  cooperating with the screws  10  and  17   a  for fastening the top frame  4  onto the bottom frame  5 . 
     The bottom frame  5  is linked to the chassis by a first fastening means  33  and a second fastening means  34  respectively fastened onto the front and rear transversal beams  21  and  22  of the horizontal frame  5   a . Preferably, these fastening means comprise elastic parts, such as parts made of rubber, making it possible to avoid the transmission of the vibrations from the electric machine  3  and other elements mounted in the mounting device to the chassis. 
     The parallelepipedal electronic power unit  2  comprises four fixing tabs  35  in the vicinity of its corners making it possible to fasten it to four of the corresponding fixing tabs  36  fastened in pairs inside the longitudinal beams  19  and  20  of the horizontal frame  5   a . Four screws  37  pass through the orifices  38  of the fixing tabs  35  of the electronic power unit  2  and through the orifices  39  of the fixing tabs  36  of the bottom frame  5  and are tightened using a nut for example making it possible to fasten the electronic power unit  2  to the bottom frame  5 . 
     The parallelepipedal electric machine  3 , schematically represented in  FIG. 1 , is associated with a reduction gear  40 . It comprises a tapped orifice  41  so as to allow for the tightening of a screw  42 . The bottom frame  5  comprises a fixing tab  43  on the longitudinal beam  19  comprising an orifice  44  corresponding to the orifice  41  of the electric machine  3  making it possible, by tightening the screw  42 , to create a means for fastening the electric machine  3  onto the bottom frame  5 . The electric machine  3  also comprises at least one fastening element  45  complementing at least one fastening element  46  fastened under the longitudinal beam  19  of the bottom frame  5  representing another means for fastening the electric machine  3  onto the bottom frame  5 . Other fastening means, not represented in  FIG. 1 , make it possible to complete the fastening of the electric machine  3  onto the bottom frame  5 . 
     The bottom frame  5  can have all kinds of auxiliary elements easily fastened to it, such as the compressor, the vacuum pump or even the water pump, as well as other elements such as beam fastening members, not represented in  FIG. 1 , which remain attached to the chassis via the bottom frame  5 . 
       FIG. 2 , in which the elements that are identical to those of  FIG. 1  are given the same references, is a representation of the device described previously when the propulsion assembly comprising the charger block  1 , the electronic power unit  2  and the electric machine are assembled with the mounting member comprising the top frame  4  and the bottom frame  5 . The charger block  1  is fastened onto the top portion of the top frame  4 . The electronic power unit  2  is fastened onto the bottom frame  5  and most of this electronic power unit  2  is located under the bottom frame  5 . As for the electric machine  3 , this is fastened to the underside of the bottom frame  5 . 
     Via the two lifting arms  30  and  31  positioned balanced relative to the center of gravity of the propulsion assembly and the mounting member assembled, all these elements together can be assembled in one place then easily transported to another place with a view to mounting in the engine compartment of a motor vehicle. 
       FIG. 3 , in which the elements that are identical to those of  FIG. 1  are given the same references, is a plan view of the device according to the invention during assembly. The top frame  4  is already fastened onto the bottom frame  5  by the screws  10  and  17   a  and the bottom frame  5  is here already fastened to the chassis of the vehicle via the fastening means  33  and  34 . The electronic power unit  2  is already fastened onto the bottom frame  5  via the screws  37 . 
     The mounting member of the device comprises two distinct frames, a bottom frame  5  and a top frame  4 , in order to overcome the lack of space in the engine compartment, which is such that the front and rear beams  8  and  9  of the top frame  4  have to be recentered. Thus, the front beam  8  of the top frame  4  is attached to the front beam  21  of the bottom frame  5  and the rear beam  9  of the top frame  4  is situated at a distance from the rear beam  22  of the bottom frame  5 , blocking access to the rear fastening screws  37  fastening the electronic power unit to the bottom frame  5 . When the top frame  4  is not dismantled, access to the rear fastening screw  37  of the electronic power unit  2  is masked. Now, the significance of the weight of the electronic power unit requires upward displacement for mounting and dismantling. This is made possible only when the top frame  4  is dismantled. 
     There now follows a description of the various steps in mounting an electric propulsion assembly on the mounting member described previously with reference to  FIGS. 1 and 3 . The first step is to fasten the bottom frame  5  onto the electric machine  3 , the electronic power block  2  is then fastened onto the bottom frame  5 , the top frame  4  is fastened onto the bottom frame  5  and finally the charger block is fastened to the top frame  4 . 
     It is also possible to begin by fastening the charger block to the top frame  4 , then fastening the electronic power unit  2  to the bottom frame  5 . The top frame  4  is then fastened to the bottom frame  5  and the electric machine is fastened to the bottom frame  5 . The bottom frame  5  is then fastened to the chassis of the motor vehicle. 
     When the assembly is mounted, as represented in  FIG. 2 , it can be handled and positioned, by supporting it using the two lifting arms  30  and  31  in order to lower it into the engine compartment of the vehicle and fasten it to the chassis of the vehicle via the bottom frame  5 . 
     It is thus possible to easily and individually dismantle, for servicing or repair for example, the charger block  1  and the electronic power unit  2 . It is also possible to dismantle or have access to the charger block  1 , to the electronic power unit  2  and to the electric machine by removing only the top frame  4  without having to dismantle the bottom frame  5 . Thus, the auxiliary elements, such as the compressor, the vacuum pump, the water pump, can remain in place in the engine compartment of the vehicle when dismantling the electric engine assembly. 
     It should be noted that, if the architectural constraints of the engine compartment permit, a mounting member comprising only a single portion could be used instead of two separate, bottom and top, frames. 
     Furthermore, the frames of the mounting device are preferably made of mechanically welded steel, which has the advantage of making the mounting device more resistant to impacts: in practice, in the event of an impact, the mounting device will be deformed without breaking. It should also be noted that the arrangement of the propulsion elements in this mounting device, which also makes it possible to fasten connector or cable protectors, makes these propulsion elements less vulnerable to the impacts than if they were fastened in the usual manner in the compartments more directly fastened to the chassis.