Front axle subframe with a bearing for a drive unit

Abstract

Front axle subframe (100) for mounting a drive unit (101) of a vehicle with a first longitudinal beam (L1) and a second longitudinal beam (L2) aligned along a vehicle longitudinal axis (x), a first crossbeam (Q1) and a second crossbeam (Q2) aligned along a vehicle transverse axis (y), wherein the first crossbeam (Q1) is arranged in front of the second crossbeam (Q2) when viewed in a direction of travel (+x), wherein a three-point bearing (110, 120, 130) for the drive unit (101) is provided on the crossbeams (Q1, Q2), characterized by that the first cross member (Q1) is attached to the longitudinal members (L1, L2) adjacent to mounting bushings (B1) of the front axle subframe (100) for the arrangement of the front axle subframe (100) on a vehicle body such that bearings (110, 120) of the three-point mounting (110, 120, 130) of the first cross member (Q1) are arranged with respect to a vehicle vertical axis (z) at the same height (H) as the mounting bushings (B1) and above a central area of ​​the first cross member (Q1) along the vehicle transverse axis (y).

Description

[0001] The invention relates to a front axle subframe for mounting a drive unit of a vehicle according to the preamble of independent claim 1.

[0002] Such a front axle subframe is known from EP 1 386 827 A2. Further front axle subframes or rear axle subframes, which are technically more distant, are known from DE 19909945 C1 and DE 10 2006 013 550 A1, DE 10 2014 220 312 A1, US 2017 / 0057550 A1, EP 2578473 A1, DE 10 2008 057 196 A1 and DE 10 2013 020 565 B3.

[0003] Front axle subframes for mounting drive units in vehicles are generally known. These known front axle subframes are designed with special mounting bearings, such as metal-rubber bearings, which serve to decouple the movements of the drive unit relative to the vehicle body. During rapid changes in speed, such as during acceleration or braking, the drive units move back and forth along the vehicle's longitudinal axis due to their inertia. In a front-transverse engine configuration, this results in oscillations of the drive units around a transverse vehicle axis. Therefore, it is important that the drive unit mountings absorb and dampen these oscillations.Furthermore, the mounting of the drive unit affects driving safety, ride comfort, and the service life of chassis, bearing, and body components. Additionally, improper mounting of the drive unit can lead to disruptive noises.

[0004] Another exemplary front axle subframe is known from DE 10 2016 000 670 B3, which forms a frame-like subframe with two longitudinal members and two transverse members. A four-point mounting for the drive unit is provided at the corners of the subframe. However, a disadvantage has been found to be that the four-point mounting is too overdetermined for vibration decoupling of the drive unit from the body, at least in the horizontal plane. With such a four-point mounting, pendulum movements of the drive unit can only be absorbed around the vehicle's transverse axis. For this to be effective, the two front bearings must be aligned exactly parallel to the vehicle's transverse axis and be exactly the same distance from the rear bearings. The rear bearings must also have exactly parallel axes.Otherwise, even small mounting tolerances can lead to pendulum movements of the drive unit that cannot be absorbed by the bearings.

[0005] Therefore, it is an object of the present invention to overcome at least one disadvantage known from the prior art, at least in part. In particular, it is an object of the present invention to provide a front axle subframe for mounting a vehicle's drive unit, which has a simple and compact design and is suitable for absorbing and reducing the vibrations of the drive unit, especially along the vehicle's longitudinal axis, and the oscillations of the drive unit, especially about the vehicle's transverse axis. Furthermore, it is an object of the invention to provide a front axle subframe for mounting a vehicle's drive unit with a mounting that advantageously decouples the drive unit from the vehicle body with respect to vibration.

[0006] The aforementioned problem is solved by a front axle subframe for mounting a drive unit of a vehicle, comprising the features of independent claim 1, in particular the characterizing part. Preferred embodiments of the invention are listed in the dependent claims. Features disclosed with respect to the individual embodiments of the front axle subframe according to the invention can be combined in such a way that the disclosures relating to the embodiments of the invention always refer to each other.

[0007] The invention provides a front axle subframe for mounting a vehicle's drive unit, comprising a first longitudinal member and a second longitudinal member, which are oriented substantially along a longitudinal axis of the vehicle, and a first cross member and a second cross member, which are oriented substantially along a transverse axis of the vehicle, wherein the first cross member is arranged in front of the second cross member when viewed in a direction of travel. For this purpose, it is provided that a three-point mounting for the drive unit is provided on the cross members.

[0008] A drive unit according to the invention may preferably be an electric drive unit, particularly one that can be operated as an auxiliary unit. The vehicle according to the invention may preferably be an electric vehicle, which is preferably designed with a rear-wheel drive, preferably electric, as its main drive. The front axle subframe according to the invention may particularly be a frame-like subframe.

[0009] The inventive concept lies in creating a three-point mounting on the frame-like front axle subframe to support the drive unit and optimally decouple it from the vehicle body in terms of vibration. A three-point mounting creates a plane in which vibrations of the drive unit in any direction passing through two bearings are absorbed. Furthermore, a three-point mounting can absorb pendulum movements in any direction passing through two bearings. The bearings do not necessarily need to be positioned at exact points with zero tolerance, since three points always form a plane. Preferably, this plane can lie in the horizontal plane. In the three-point mounting according to the invention, it is also conceivable that two bearings are arranged on the first or front crossmember and one bearing on the second or rear crossmember.This allows the rear bearing to advantageously absorb pendulum movements of the drive unit around a transverse vehicle axis or around the axis running through the two front bearings, particularly during acceleration maneuvers. At the front, for example, two bushings can be provided, and at the rear, a pot bearing, a conical bearing, or a round bearing. A special bearing housing can be provided in the respective crossmember for each bearing. A special support for the drive unit can also be attached to each bearing. The front bushings can be pressed or bolted into the first crossmember. In addition to housing the bearings, the front crossmember also stiffens the front axle subframe in the transverse direction of the vehicle. Furthermore, the front crossmember can serve as a mounting point for an air conditioning compressor. The air conditioning compressor can be mounted between the bushings.The first crossmember can be attached to the front subframe at the same height and near the subframe mounting brackets, i.e., where the front subframe is stiffest. The rear bearing can be attached to the second, or rear, crossmember, for example, by bolting it. Besides mounting the bearing, the rear crossmember also stiffens the front subframe laterally. The rear crossmember can also accommodate utility lines, such as water and / or electrical lines, and at least partially protect them. Furthermore, appropriate pumps and valves for these utility lines can be mounted on the rear crossmember. The rear crossmember can have corresponding guides and / or holes for these lines.In the three-point mounting system according to the invention, it is possible to represent different orientations of the bearings in the front crossmember, e.g., along a longitudinal, a transverse, or a vertical axis of the vehicle. Thus, an improved front axle subframe for mounting the drive unit can be provided, which has a simple and compact design and is suitable for optimally absorbing and reducing the vibrations and pendulum movements of the drive unit in different directions, so that the drive unit can be advantageously decoupled from the vehicle body in terms of vibration.

[0010] According to the invention, the first cross member is attached to the longitudinal members with respect to a vehicle vertical axis at the same height as and adjacent to the mounting bushings of the front axle subframe to a vehicle body. Thus, the first cross member can be attached to the vehicle body at the stiffest point of the front axle subframe, thereby improving the force distribution between the front axle subframe and the vehicle body as a result of changes in speed, e.g., during acceleration or braking maneuvers, or even in a crash.

[0011] Furthermore, the invention can provide that, in a front axle subframe, the first crossmember is positioned higher than the second crossmember with respect to the vehicle's vertical axis. This allows the rear crossmember to be positioned lower, particularly where, for example, there is limited space along the vehicle's vertical axis in the footwell. The drive unit can be mounted suspended from the two front bearings and supported by a pendulum-like mechanism at the rear bearing. This also allows for certain pendulum movements around the axis passing through the two front bearings. By permitting these pendulum movements, the bearings can selectively absorb unforeseen pendulum movements resulting from unintentionally incorrect bearing positioning.

[0012] Furthermore, the invention can provide that, in the case of a front axle subframe, the first crossmember is designed to accommodate an air conditioning compressor. This expands the functionality of the first crossmember. The first crossmember can thus be used not only to stiffen the front axle subframe and to mount the drive unit, but also to support the air conditioning compressor. This also allows for advantageous utilization of the installation space in the front of the vehicle.

[0013] Furthermore, the invention can provide that, in the case of a front axle subframe, the first crossmember has at least one, preferably integrally formed, mounting bushing for an air conditioning compressor. This simplifies the mounting of the air conditioning compressor to the first crossmember. Thus, a complete front axle subframe, which supports the drive unit and the air conditioning compressor, can be provided during pre-assembly. The assembly of the vehicle can therefore be significantly simplified and reduced in time.

[0014] Furthermore, the invention can provide that, in the case of a front axle subframe, the second crossmember is designed to accommodate at least one service line, such as a water line and / or an electrical line, a pump, or a valve. This expands the functionality of the second crossmember. The second crossmember can thus be used not only to stiffen the front axle subframe along a transverse axis of the vehicle and to mount the drive unit, but also to accommodate and guide service lines and to house corresponding pumps and valves. The service lines can therefore be routed section by section along the second crossmember, protected from being left hanging freely. This also allows for advantageous use of the available space in the front of the vehicle.

[0015] Furthermore, the invention can provide that, in the case of a front axle subframe, the second crossmember has at least one, preferably integrally formed, guide for at least one service cable. This facilitates the routing of the service cable on the second crossmember and provides intuitive guidance for the installer. Moreover, a complete front axle subframe, supporting the drive unit and the service cable, can thus be provided during pre-assembly. This significantly simplifies and reduces the time required for vehicle assembly.

[0016] Furthermore, the invention can provide that, in the case of a front axle subframe, the first cross member has a first bearing receptacle for receiving a first bearing and a second bearing receptacle for receiving a second bearing, which are designed to support the drive unit on the front axle subframe. This simplifies the pre-assembly of the drive unit on the front axle subframe.

[0017] Furthermore, the invention can provide that, in the case of a front axle subframe, the first bearing receptacle and the second bearing receptacle of the first cross member are designed as sleeve-shaped bearing bushings. Mounting bushings of the drive unit can advantageously be received in the sleeve-shaped bearing receptacles, e.g., pressed or screwed in.

[0018] Furthermore, the invention can provide that, in the case of a front axle subframe, the first bearing receptacle and the second bearing receptacle are positively and / or force-fitted to the first crossmember. It is conceivable that the bearing receptacles are manufactured separately and subsequently attached to the first crossmember. Thus, even conventional crossmembers can be upgraded. Alternatively, it is conceivable that the first bearing receptacle and the second bearing receptacle in the first crossmember can be formed from a single material and / or monolithically, in particular as a single injection-molded part. In this way, vibrations can advantageously be dissipated within the bearings, without any play between the bearing receptacles and the crossmembers potentially contributing to the generation of disruptive noise.

[0019] Furthermore, the invention can provide, in the case of a front axle subframe, that a first bearing of the drive unit is pressed and / or bolted into a first bearing housing and a second bearing of the drive unit is pressed and / or bolted into a second bearing housing. This allows for simple and quick assembly of the bearings within the bearing housings. With pressed-in bearings within the bearing housings, it can be advantageous that the propagation of disruptive noises, e.g., in the form of rattling noises, between the bearings and the bearing housings due to fastening tolerances is avoided.

[0020] Furthermore, the invention can provide, in the case of a front axle subframe, that a first bearing and a second bearing of the drive unit are designed as mounting bushings, as metal-rubber bearings, or as spring bearings. The rubber or spring within the bearings can advantageously serve to dampen vibrations. It is also conceivable that the bearings may have certain stops in the direction of vibration absorption.

[0021] Furthermore, the invention can provide, in the case of a front axle subframe, that the three-point mounting is designed such that a first bearing receptacle and a second bearing receptacle for supporting the drive unit on the front axle subframe can be selectively aligned along a longitudinal axis of the vehicle, along a transverse axis of the vehicle, or along a vertical axis of the vehicle. The three-point mounting according to the invention advantageously allows for flexible, model-specific alignment of the front bearings. By aligning the front bearings along the longitudinal axis of the vehicle, the vibrations of the drive unit along the longitudinal axis can be absorbed directly in the front bearings. By aligning the front bearings along the transverse axis of the vehicle, the vibrations of the drive unit along the longitudinal axis can be absorbed as pendulum movements in the area of ​​the third bearing.By aligning the bearings along the vehicle's vertical axis, the vibrations of the drive unit along the vehicle's longitudinal axis can be distributed between the front and rear bearings.

[0022] Furthermore, the invention can provide that, in the case of a front axle subframe, the second crossmember has a third bearing receptacle for supporting the drive unit on the front axle subframe, wherein the third bearing receptacle is designed to accommodate a third bearing in the form of a cup bearing, a conical bearing, or a cylindrical bearing. Such a bearing helps to absorb vibrations in different directions and transmit them into the bearing receptacle. In addition, such a bearing is suitable for absorbing shear forces, thereby advantageously compensating for any fastening and / or manufacturing tolerances. It is also conceivable that the third bearing receptacle is integrally formed with the second crossmember, or forms a section of the second crossmember to which the third bearing can be attached, for example, by positive locking and / or frictional locking.

[0023] Furthermore, within the scope of the invention, it is possible for a third bearing receptacle of the second cross member to support the drive unit on the front axle subframe to be aligned along a vehicle vertical axis. This makes it possible to advantageously transfer the weight of the drive unit into the second cross member.

[0024] Further measures improving the invention are described in more detail below with reference to the figures and the preferred embodiments of the invention. The features mentioned in the claims and in the description can be essential to the invention individually or in any combination. It should be noted that the figures are for descriptive purposes only and are not intended to limit the invention in any way. They show: Fig. 1 a view of a front axle subframe according to the invention with a drive unit from above, Fig. 2 a perspective view of a front axle subframe according to the invention without the drive unit, Fig. 3a a perspective view of a first cross member for a front axle subframe according to the invention, Fig. 3b a perspective view of a second cross member for a front axle subframe according to the invention, Fig. 4 a possible embodiment of a front axle subframe according to the invention, Fig. 5 another possible embodiment of a front axle subframe according to the invention, and Fig. 6 another possible embodiment of a front axle subframe according to the invention.

[0025] In the following figures, identical reference numerals are used for the same technical features even for different embodiments.

[0026] The Fig. 1 and Fig. Figure 2 shows a front axle subframe 100 according to the invention, which serves to mount a drive unit 101 of a vehicle. The drive unit 101 shown is preferably an electric, and in particular an auxiliary, drive unit 101, which is installed in the front of the vehicle and is operated auxiliaryly to a main drive unit that is installed in the rear of the vehicle. Consequently, the vehicle according to the invention is an electric vehicle. As the Fig. 1 and Fig. Figure 2 further illustrates that the front axle subframe 100 forms a frame-like structure essentially in the shape of a rectangle. The front axle subframe 100 comprises a first longitudinal member L1 and a second longitudinal member L2, which are aligned essentially along a longitudinal axis x of the vehicle, as well as a first cross member Q1 and a second cross member Q2, which are aligned essentially along a transverse axis y of the vehicle. The first cross member Q1 is located in front of the second cross member Q2 when viewed in a driving direction +x. According to the invention, a three-point mounting 110, 120, 130 for the drive unit 101 is provided on the cross members Q1 and Q2.

[0027] The three-point mounting 110, 120, 130 according to the invention serves to mount the drive unit 101 and to optimally decouple it from the vehicle body (not shown) with respect to vibrations. During strong changes in speed, e.g., during acceleration or braking maneuvers, the drive unit 101 is moved forward or backward along the vehicle's longitudinal axis x due to its inertia. In this process, the drive unit 101 can pivot at least about the vehicle's transverse axis y. With an unfavorable mounting, vibrations about other geometric axes can occur. The three-point mounting 110, 120, 130 according to the invention allows vibrations of the drive unit 101 relative to the vehicle body to be optimally absorbed during vehicle operation, specifically about different geometric axes, but at least about the vehicle's transverse axis y.

[0028] The two front bearings 10, 20 for the drive unit 101, which can be designed, for example, in the form of bearing bushings, as shown by the Fig. Figure 3a shows that the bearings can be attached to the first crossbeam Q1, e.g., by bolting, or pressed directly into the first crossbeam Q1. For this purpose, corresponding bearing receptacles 110, 120, e.g., sleeve-shaped, can be provided on the first crossbeam Q1. The front bearing receptacles 110, 120 can, in turn, be attached to the first crossbeam Q1, e.g., by bolting, or be formed directly in the first crossbeam Q1, e.g., molded directly with the first crossbeam Q1.

[0029] The rear bearing 30 can preferably be aligned vertically along a vehicle vertical axis z and be designed, for example, in the form of a pot bearing, a conical bearing or a cylindrical bearing, as shown by the Fig. Figure 3b shows that a third bearing receptacle 130 can be provided, which, for example, can form a section of the second crossbeam Q2. The third bearing 30 can thus be screwed directly to the second crossbeam Q2.

[0030] Each bearing receptacle 110, 120, 130 can also be fitted with a special support 11, 21, 31 for the respective bearing 10, 20, 30 of the drive unit 101.

[0031] As it is Fig. Figure 1 further shows that, according to a particular advantage of the invention, the first cross member Q1 can be designed to accommodate an air conditioning compressor 102. For this purpose, the first cross member Q1 can have at least one, and in particular four, preferably integrally formed, receiving bushings K. Thus, the installation of the air conditioning compressor 102 in the front of the vehicle can be facilitated and already carried out during pre-assembly. In the view of the Fig. 1 A connecting rod 103 for the vehicle's wheels (not shown) can be seen between the drive unit 101 and the air conditioning compressor 102.

[0032] The Fig. Figure 2 further indicates that, according to another particular advantage of the invention, the second cross member Q2 can be configured to accommodate at least one consumer line (not shown), such as a water line, an electrical line, a pump, or a valve. For this purpose, the second cross member Q2 can have at least one, preferably integrally formed, guide V for the at least one consumer line. This significantly simplifies the assembly of the vehicle's front end.

[0033] Furthermore, the functionality of the first crossmember Q1 and the second crossmember Q2 can thus be expanded. The two crossmembers Q1 and Q2 can therefore be used not only to stiffen the front axle subframe 100 in the transverse direction of the vehicle and to mount the drive unit 101, but also to accommodate an air conditioning compressor 102 and the necessary service lines. This also allows for advantageous use of the installation space in the front of the vehicle.

[0034] Using the three-point mounting according to the invention 110, 120, 130, the two front bearings 10, 20 can be selectively aligned along a longitudinal axis x of the vehicle, along a transverse axis y of the vehicle or along a vertical axis z of the vehicle, as shown by the Fig. 4, Fig. 5 and Fig. Show 6 in succession.

[0035] The Fig. Figure 4 shows a possible embodiment of the front axle subframe 100 according to the invention, with the two front bearings 10, 20 aligned along the vehicle's longitudinal axis x. In this configuration, the vibrations of the drive unit 101 along the vehicle's longitudinal axis x can be directly compensated in the front bearings 10, 20.

[0036] The Fig. Figure 5 shows a possible embodiment of the front axle subframe 100 according to the invention, with the two front bearings 10, 20 aligned along the vehicle's transverse axis y. In this configuration, the vibrations of the drive unit 101 along the vehicle's longitudinal axis x can be compensated at the third bearing 30 as pendulum movements around the vehicle's transverse axis y, which essentially passes through the two front bearings 10, 20.

[0037] The Fig. Figure 6 shows a possible embodiment of the front axle subframe 100 according to the invention with an alignment of the two front bearings 10, 20 along the vehicle's vertical axis z. In this way, the vibrations of the drive unit 101 along the vehicle's longitudinal axis x can be compensated as pendulum movements about the vehicle's transverse axis y at both the two front bearings 10, 20, and at the third rear bearing 30.

[0038] Depending on the vehicle model and customer requirements, one or the other embodiment of the invention can be implemented according to one of the Fig. 4 to 6 would be advantageous.

[0039] As it is Fig. As shown in Figures 4 to 6 in the upper view, the first cross member Q1 is, according to the invention, attached to the longitudinal members L1, L2 with respect to the vehicle's vertical axis z at the same height H as and adjacent to the mounting bushings B1 of the front axle subframe 100 to a vehicle body, which corresponds to the stiffest point of the front axle subframe 100 to the vehicle body. Behind the second cross member Q2, further mounting bushings B2 can be provided between the longitudinal members L1, L2 and the vehicle body.

[0040] As can be seen from the Fig. 2 and the Fig. As can be seen in the lower view (4 to 6), the first crossmember Q1 can be positioned higher than the second crossmember Q2 with respect to the vehicle's vertical axis z. This can be particularly advantageous in the front of the vehicle, where installation space is severely limited in the footwell area.

[0041] The preceding description of the figures describes the present invention solely by way of examples. Naturally, individual features of the embodiments can be freely combined with one another, provided it is technically feasible, without departing from the scope of the invention. Reference symbol list 100 front axle subframes 101 Drive unit 102 Air conditioning compressor 103 Connecting rod 110 first stock assessment 120 second storage 130 third stock assessment Q1 first crossbeam Q2 second crossbeam L1 first longitudinal member L2 second longitudinal member 10 first camp 11 support 20 second camp 21 support 30 third camp 31 support B1 Mounting socket B2 Mounting socket H height K mounting socket for an air conditioning compressor V Lead for at least one consumer line x vehicle longitudinal axis y vehicle transverse axis z Vehicle vertical axis

Claims

[1] Front axle subframe (100) for mounting a drive unit (101) of a vehicle with a first longitudinal beam (L1) and a second longitudinal beam (L2) aligned along a vehicle longitudinal axis (x), a first crossbeam (Q1) and a second crossbeam (Q2) aligned along a vehicle transverse axis (y), wherein the first crossbeam (Q1) is arranged in front of the second crossbeam (Q2) when viewed in a direction of travel (+x), wherein a three-point bearing (110, 120, 130) for the drive unit (101) is provided on the crossbeams (Q1, Q2), characterized by , that the first cross member (Q1) is attached to the longitudinal members (L1, L2) adjacent to mounting bushings (B1) of the front axle subframe (100) for the arrangement of the front axle subframe (100) on a vehicle body such that bearings (110, 120) of the three-point mounting (110, 120, 130) of the first cross member (Q1) are arranged with respect to a vehicle vertical axis (z) at the same height (H) as the mounting bushings (B1) and above a central area of ​​the first cross member (Q1) along the vehicle transverse axis (y). [2] Front axle subframe (100) according to claim 1, characterized by , that the first crossbeam (Q1) is designed to accommodate an air conditioning compressor (102). [3] Front axle subframe (100) according to any one of the preceding claims, characterized by , that the first cross member (Q1) has at least one mounting socket (K) for an air conditioning compressor (102). [4] Front axle subframe (100) according to any one of the preceding claims, characterized by, that the second crossbeam (Q2) is designed to accommodate at least one consumer line, one water line, one power line, one pump or one valve. [5] Front axle subframe (100) according to any one of the preceding claims, characterized by that the second crossbeam (Q2) has at least one guide (V) for at least one consumer line. [6] Front axle subframe (100) according to any one of the preceding claims, characterized by , that the first cross member (Q1) has a first bearing receptacle (110) for receiving a first bearing (10) and a second bearing receptacle (120) for receiving a second bearing (20), which are designed to support the drive unit (101) on the front axle subframe (100), wherein the first bearing receptacle (110) and the second bearing receptacle (120) of the first cross member (Q1) are designed in a sleeve-like manner as bearing bushings. [7] Front axle subframe (100) according to the preceding claim, characterized by, that a first bearing (10) of the drive unit (101) is pressed into a first bearing receptacle (110) and a second bearing (20) of the drive unit (101) is pressed into a second bearing receptacle (120). [8] Front axle subframe (100) according to any one of the preceding claims, characterized by , that the three-point mounting (110, 120, 130) is designed such that a first bearing receptacle (110) and a second bearing receptacle (120) for supporting the drive unit (101) on the front axle subframe (100) can be oriented either along a longitudinal axis (x) of the vehicle, along a transverse axis (y) of the vehicle or along a vertical axis (z) of the vehicle. [9] Front axle subframe (100) according to any one of the preceding claims 6 to 8, characterized by , that the second cross member (Q2) has a third bearing receptacle (130) for supporting the drive unit (101) on the front axle subframe (100), wherein the third bearing receptacle (130) is designed to accommodate a third bearing (30) in the form of a pot bearing, a conical bearing or a cylindrical bearing.

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