Front frame structure for an electric vehicle with longitudinal beams and associated support element for mounting an electric motor, as well as an electric vehicle with such a frame structure

Abstract

A front frame structure (10) for an electric vehicle chassis (12) is described, comprising at least two longitudinal members (14); a cross member (16) connecting the two longitudinal members (14) in the vehicle width direction; and at least two support elements (20) assigned to a respective longitudinal member (14) and connected to the cross member (16) and / or to the respective longitudinal member (14). A gap (AB, ABv) is provided between an inner surface (14i) of the respective longitudinal member (14) and the respective support element (20), such that a bearing section (22) of an electric motor (18) can be inserted between the support element (20) and the respective longitudinal member (14) and can be attached to the support element (20) and the longitudinal member (14) by means of a screw connection (24), wherein an axis of rotation of the screw connection (24) runs essentially in the vehicle width direction (Y).Furthermore, an electric vehicle with such a front frame structure (10) is described.

Description

The invention relates to a front frame structure for a chassis of an electric vehicle, having at least two longitudinal members; a cross member connecting the two longitudinal members in the vehicle width direction; at least two support elements which are assigned to a respective longitudinal member and are connected to the cross member and / or to the respective longitudinal member. The invention further relates to an electric vehicle having such a front frame structure and to an electric motor for a front frame structure according to the preamble of claim 9.Such a front frame structure is known, for example, from the generic DE 10 2019 201 145 A1, wherein an integrated bearing for an electric motor is provided in each case on the longitudinal beams of the frame structure.DE 10 2017 206 391 A1 discloses a vehicle with a body support structure in which an electric motor is supported on an auxiliary frame via a four-point bearing. In this case, a base body of a rear unit support can act as a mechanical pressure stop, wherein in a design position it is spaced apart from the opening edge region of the vehicle body-side bearing receptacle of the rear unit bearing by an clearance.For further details, reference is made to DE 10 2011 102 322 A1, DE 10 2017 217 931 A1 and DE 10 2014 201 619 A1.In the known front frame structure, the engine bearings are firmly integrated into the longitudinal supports, which are usually designed to be very stable or rigid. Accordingly, the manufacture of the longitudinal members with motor bearings and of the electric motors must meet very high requirements with respect to low assembly tolerances.The object on which the invention is based is to specify a front frame structure which, in particular during assembly, enables greater tolerances which, however, no longer exhibit any effect in the fully assembled state.This object is achieved by a front frame structure and an electric vehicle having the features of the independent patent claims 1, 6 and 9.A front frame structure for a chassis of an electric vehicle is therefore proposed, having at least two longitudinal members; a cross member connecting the two longitudinal members in the vehicle width direction; and at least two support elements which are assigned to a respective longitudinal member and are connected to the cross member and / or to the respective longitudinal member. In this case, it is provided that a distance is formed between an inner side of the respective longitudinal member and the respective support element in such a way that a respective bearing section of an electric motor can be introduced between the support element and the respective longitudinal member and can be fastened or fastened to the support element and the longitudinal member by means of a screw connection, wherein an axis of rotation of the screw connection runs substantially in the vehicle width direction.In other words, the bearing section is not integrated into the longitudinal member, but is provided on the electric motor. During assembly, the bearing supports of the electric motor are each inserted between the relevant support element and the relevant longitudinal support and tightened by means of the screw connection. In this case, the distance can be selected such that the bearing section can be inserted with high reliability between the support element and the longitudinal member without abutting against the latter or possibly damaging the latter.In the front frame structure, the support element can be designed such that, in an assembled state of the electric motor, it is moved towards the inner side of the longitudinal member with a tightened screw connection, such that the distance to the inner side of the respective longitudinal member is smaller than in a state before the assembly of the electric motor. This allows a good and dimensionally tolerant introduction of the bearing sections, wherein a secure and stable mounting of the electric motor is ensured in the assembled state.In the front frame structure, the support member may be welded to the cross member. In other words, the bearing sections of the electric motor or the electric motor are not only mounted on the longitudinal supports, but also on the cross support by means of the support element. As a result, the loads are distributed optimally to longitudinal and cross members.In the front frame structure, a threaded section, in particular a weld nut, can be arranged on the support element, which threaded section can be brought into engagement or is standing with a screw guided through the longitudinal member. As a result, it is possible during assembly to easily plug a screw through the longitudinal member and the bearing section of the electric motor from a lateral position and then to screw and tighten it in the threaded section already present on the support section.In the front frame structure, the support element can be designed to be elastically or plastically deformable in such a way that it is movable to the inner side of the longitudinal member when the screw connection is tightened. In other words, the support element can be pulled or deformed in the direction of the relevant longitudinal member. In this case, the support element can be movable in the region of the screw connection by, for example, 0.5 to 2.0 mm with respect to the relevant longitudinal member. In other words, the distance between the supporting element and the longitudinal member before assembly can be about 0.5 to 2.0 mm greater than after tightening the screw connection.An electric vehicle having a front frame structure described above and having an electric motor which is fastened to the front frame structure is furthermore proposed, wherein at least two bearing sections are formed on the electric motor, with a respective bearing core which is accommodated between the inner side of the respective longitudinal member and the respective supporting element.In the electric vehicle, the bearing sections can be connected to a housing of the electric motor in a materially bonded and / or force-fit manner or the bearing sections can be formed integrally with the housing. In other words, the bearing sections can be fastened as separate components to the electric motor or to its housing or they can be formed integrally with the housing during casting.In the electric vehicle, the bearing sections can be screwed to the respective longitudinal member, wherein the screw connection is arranged behind a wheel brake device and in front of an end wall cross member in the longitudinal direction of the electric vehicle.Furthermore, an electric motor for a front frame structure described above is also proposed, wherein the electric motor has at least three bearing sections, of which two bearing sections are arranged at the top at the rear with respect to an installation position of the electric motor in an electric vehicle, with a bearing alignment in the width direction of the electric vehicle, wherein it is provided that the two rear bearing sections are connected to a housing of the electric motor in a materially bonded and / or force-fit manner or that the rear bearing sections are formed integrally with the housing.Further advantages and details of the invention are evident from the following description of embodiments with reference to the figures. The following shows: FIG. 1 is a simplified and schematic perspective view of a front frame structure; FIG. 2 shows a simplified and schematic perspective view of a mounting of an electric motor by means of support element of the front frame structure; FIG. 3 shows a simplified and schematic sectional view corresponding to the section line III-III of FIG. 2 after assembly of the electric motor; FIG. 4 shows a simplified and schematic sectional view corresponding to the section line III-III of FIG. 2 during or during the assembly of the electric motor.FIG. 1 is a simplified and schematic illustration of a perspective partial view of a front frame structure 10 for a chassis of an electric vehicle 12 illustrated as a dash-dotted rectangle.The front frame structure 10 comprises at least two longitudinal members 14. The two longitudinal members 14 are connected, in particular in the region in front of a vehicle cabin, not shown, to cross members 16 running in the vehicle width direction Y. The cross member 16 may also be part of a partition wall 16 tbetween the engine compartment and the vehicle cabin.An electric motor 18 is arranged between the longitudinal beams 14 and is also mounted or fastened thereto, which is described in more detail below with reference to FIGS. 2 and 3.The front frame structure 10 comprises at least two support elements 20.In the example shown in FIG. 2, the support element 20 is welded to the cross member 16. The support element 20 protrudes substantially forwards from the cross member 16 in the longitudinal direction X.It can also be seen from FIG. 2 that a distance AB is formed between an inner side 14 iof the longitudinal member 14 and the support element 20, such that a bearing section 22 of the electric motor 18 can be introduced between the support element 20 and the longitudinal member 14 and can be fastened or is fastened to the support element 20 and the longitudinal member 14 by means of a screw connection 24. Here, a rotation axis of the screw joint 24 extends substantially in the vehicle width direction Y.FIG. 3 shows a simplified and schematic sectional view of the support element 20, the bearing section 22 and the longitudinal support 14 of FIG. 2 approximately according to the section line III-III. FIG. 3 illustrates a mounted state of the electric motor 18 on the longitudinal member 14 and the support element 20.FIG. 4 is a sectional view substantially the same as FIG. 3, illustrating a state during mounting of the electric motor 18 before tightening of the screw joint 24.It can be seen from the overview of FIGS. 3 and 4 that the support element 20 is designed such that, in the assembled state (FIG. 3 of the electric motor 18 with the screw connection 24 tightened, it is moved towards the inner side 14 iof the longitudinal member 14 such that the distance ABto the inner side 14 iof the longitudinal member 14 is smaller than in a state before or during the assembly of the electric motor 18.In FIG. 3 and also in FIG. 2, the smaller distance AB is illustrated, while in FIG. 4 the somewhat larger distance ABv is illustrated before the mounting or before the tightening of the screw connection 24.The support element 20 can thus be designed to be elastically or plastically deformable, so that it is moved to the inner side 14 iof the longitudinal member 14 when the screw connection 24 is tightened.In this case, the support element 20 can be movable in the region of the screw connection 24 by, for example, 0.5 to 2.0 mm with respect to the relevant longitudinal member 14. In other words, the distance ABv between the support element 20 and the longitudinal member 14 before assembly can be approximately 0.5 to 2.0 mm greater than after the tightening of the screw connection 24.It can also be seen from FIGS. 2, 3 to 4 that a threaded section 24 g, in particular a weld nut, is arranged on the support element 20, which threaded section can be or is capable of being brought into engagement with a screw 24 srouted through the longitudinal member.It can also be seen from the sectional views of FIGS. 3 and 4 that the bearing section 22 has a bearing core 22 k, which is only shown in simplified form here and is accommodated between the inner side 14 iof the longitudinal member 14 and the support element 20.As already explained above with reference to FIG. 1, in the electric vehicle 12, the electric motor 18 is fastened to the front frame structure 10, wherein at least two bearing sections 22 are formed on the electric motor 18, with a respective bearing core 22 k(FIGS. 3 and 4 ) which is accommodated between the inner side 14 iof the respective longitudinal member 14 and the respective support element 20.The bearing sections 22 can be connected to a housing 18 g(FIGS. 1 and 2 ) of the electric motor in a materially bonded and / or force-fit manner. Alternatively, the bearing portions 22 may be formed integrally with the housing 18 g.In the electric vehicle 12, the bearing sections 22 can be screwed to the respective longitudinal member 14, wherein the screw connection is arranged in the longitudinal direction X of the electric vehicle 12 behind a wheel brake device, not shown here, and in front of the bulkhead cross member 16.The electric motor 18 is further supported or mounted in a front, lower region of the frame structure 10 on a further cross member 26, which is likewise evident from FIG. 1. For this purpose, the electric motor 18 can be fastened to the cross member 26 by means of a further bearing section 28.The electric motor 18 for the above-described front frame structure 10 can have at least three bearing sections 22, 28, of which two bearing sections 22 are arranged at the top rear with respect to an installation position of the electric motor 18 in the electric vehicle 12, with a bearing orientation in the width direction Y of the electric vehicle 12, wherein it is provided that the two rear bearing sections 22 are connected to the housing 18 gof the electric motor 18 in a materially bonded and / or force-fit manner or that the rear bearing sections 22 are formed integrally with the housing 18 g.

Claims

Front frame structure (10) for a chassis of an electric vehicle (12), having at least two longitudinal members (14); a cross member (16) connecting the two longitudinal members (14) in the vehicle width direction; at least two support elements (20) which are assigned to a respective longitudinal member (14) and are connected to the cross member (16) and / or to the respective longitudinal member (14), characterized in that a distance (AB, ABv) is formed between an inner side (14i) of the respective longitudinal member (14) and the respective support element (20) in such a way that a respective bearing section (22) of an electric motor (18) can be introduced between the support element (20) and the respective longitudinal member (14) and can be fastened or is fastened to the support element (20) and the longitudinal member (14) by means of a screw connection (24), wherein an axis of rotation of the screw connection (24) runs in the vehicle width direction (Y).Front frame structure (10) according to Claim 1, characterized in that the supporting element (20) is designed such that, in an assembled state of the electric motor (18), it is moved towards the inner side (14i) of the longitudinal member (14) with the screw connection (24) tightened, such that the distance (AB, ABv) to the inner side (14i) of the respective longitudinal member (14) is smaller than in a state before the assembly of the electric motor (18).Front frame structure (10) according to claim 1 or 2, characterised in that the support element (20) is welded to the cross member (16)Front frame structure (10) according to one of the preceding claims, characterized in that a threaded section (24g) is arranged on the support element (20), which threaded section can be brought into or is in engagement with a screw (24s) guided through the longitudinal member (14).Front frame structure (10) according to one of the preceding claims, characterized in that the support element (20) is designed to be elastically or plastically deformable in such a way that it is movable towards the inner side (14i) of the longitudinal member (14) when the screw connection (24) is tightened.Electric vehicle (12) having a front frame structure (10) according to one of the preceding claims and having an electric motor (18) which is fastened to the front frame structure (10), wherein at least two bearing sections (22) are formed on the electric motor (18), with a respective bearing core (22k) which is accommodated between the inner side (14i) of the respective longitudinal member (14) and the respective supporting element (20).Electric vehicle (12) according to Claim 6, characterized in that the bearing sections (22) are connected to a housing (18g) of the electric motor (18) in a materially bonded and / or force-fit manner, or in that the bearing sections (22) are formed integrally with the housing (18g).Electric vehicle (12) according to Claim 6 or 7, characterized in that the bearing sections (22) are screwed to the respective longitudinal member (14), wherein the screw connection is arranged in the longitudinal direction of the electric vehicle (12) behind a wheel brake device and in front of an end wall cross member (16).Electric motor (18) for a front frame structure (10) according to one of Claims 1 to 5, wherein the electric motor (18) has at least three bearing sections (22, 28), of which two bearing sections (22) are arranged at the top at the rear, with respect to an installation position of the electric motor in an electric vehicle, with a bearing orientation in the width direction (Y) of the electric vehicle (12), characterized in that the two rear bearing sections (22) are connected to a housing (18g) of the electric motor (18) in a materially bonded and / or force-fit manner, or in that the rear bearing sections (22) are formed integrally with the housing (18g).

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