Semi-trailing arm suspension for a motor vehicle

Abstract

An independent rear suspension of a motor vehicle with an electrical drivetrain. The independent rear suspension including a left semi-trailing arm and a right semi-trailing arm, each of which can be articulated with an end on the body side to a chassis of the motor vehicle and are fixedly connectable to a wheel carrier on an end on the wheel carrier side, and also a transverse leaf spring for the suspension of the rear wheels. The transverse leaf spring is attached on the end side to the ends of the semi-trailing arms on the wheel carrier side, so that between the semi-trailing arms and the transverse leaf spring is formed an open installation space for receiving at least part of the electrical drivetrain.

Claims

1. A motor vehicle, comprising a left and a right semi-trailing arm, each pivotally attached to a chassis of the vehicle and extending rearwardly therefrom; a left and a right wheel carrier mounted to the left and right semi-trailing arms respectively, the wheel carriers defining respective wheel rotational axes; a transverse leaf spring attached to/between the respective first and second semi-trailing arms at respective points rearward of the respective wheel rotational axes; and an electric motor fastened to the chassis of the motor vehicle and located forward of the leaf spring between the left and right wheel carriers and in alignment with the wheel rotational axes.

2. The motor vehicle of claim 1, wherein left and right stub shafts extend from left and right sides of the electric motor and are coaxial with the respective wheel rotational axes.

3. The motor vehicle of claim 1, further comprising a left and a right shock absorber attached to the respective semi-trailing arm.

4. The motor vehicle of claim 3, wherein the shock absorbers act on the respective semi-tailing arms at respective locations forward of respective attachment points of the leaf spring to the semi-trailing arms.

5. A vehicle suspension, comprising: left and right semi-trailing arms attached to a vehicle chassis at respective pivot axes and extending rearwardly from the pivot axes; left and right wheel carriers mounted to the respective semi-trailing arms and defining respective wheel rotational axes; a transverse leaf spring having left and right ends attached to the respective semi-trailing arms at points rearward of the respective wheel rotational axes; and an electric motor fixed to the chassis and located forward of the leaf spring between the left and right wheel carriers and in alignment with the wheel rotational axes.

6. The suspension of claim 5, further comprising a left and a right shock absorber attached to the respective semi-trailing arm.

7. The suspension of claim 6, wherein the shock absorbers act on the respective semi-tailing arms at respective locations forward of respective attachment points of the leaf spring to the semi-trailing arms.

8. The suspension of claim 5, wherein left and right stub shafts extend from left and right sides of the electric motor and are coaxial with the respective wheel rotational axes.

9. A vehicle suspension, comprising: left and right semi-trailing arms, each having a forward end pivotally attached to a vehicle chassis; a transverse leaf spring having opposite ends attached to the respective semi-trailing arms adjacent rear ends thereof; and left and right wheel carriers mounted to the respective semi-trailing arms and defining respective wheel rotational axes forward of the leaf spring, the wheel carriers having respective left and right wheels rotatably mounted thereto; and an electric motor fastened to the chassis and located forward of the leaf spring between the left and right wheel carriers and in alignment with the wheel rotational axes, wherein left and right articulation shafts extend from left and right sides of the electric motor and provide power to the respective left and right wheels.

10. The suspension of claim 9, further comprising a left and a right shock absorber attached to the respective semi-trailing arm.

11. The suspension of claim 10, wherein the shock absorbers act on the respective semi-tailing arms at respective locations forward of respective attachment points of the leaf spring to the semi-trailing arms.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic representation of an independent rear suspension of a motor vehicle according to the invention with an electrical drivetrain in an installation state in plan view.

DETAILED DESCRIPTION

(2) As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

(3) FIG. 1 shows a schematic plan-view representation of an exemplary embodiment of an independent rear suspension 10 of a motor vehicle with an electrical drivetrain 60. A forward driving direction 68 of the motor vehicle is shown in FIG. 1.

(4) The independent rear suspension 10 has a left semi-trailing arm 14 and a right semi-trailing arm, each having an outer shape that substantially corresponds to the shape of a tapered equilateral triangle. The semi-trailing arms 14, 28 may be made of steel or other high-strength materials, wherein light metal alloys or composite materials, also fiber-reinforced plastics, are contemplated.

(5) Each of the two semi-trailing arms 14, 28 has a first or forward end (corresponding to the base of the equilateral triangle) which is articulated to an auxiliary carrier (not shown) of the motor vehicle or directly to the chassis, frame, or sub-frame (not shown) of the motor vehicle. The first or forward ends of the semi-trailing arms 14, 28 are generally fork-shaped and are each is fitted with two separate bushings 16, 18, 30, 32 for articulating connection to the vehicle, so that the left semi-trailing arm 14 is pivotably mounted about a left pivot axis 20 oriented obliquely relative to the vehicle longitudinal axis (X-axis) and the right semi-trailing arm 28 is pivotably mounted about a right pivot axis 34 oriented obliquely relative to the vehicle longitudinal axis (X-axis). Between its two bushings 16, 18, 30, 32 each of the semi-trailing arms 14, 28 may be define a recess 22, 36 (circular segment-shaped in the depicted embodiment) for weight saving.

(6) A left wheel carrier 48 is fixedly connected to the left semi-trailing arm 14 adjacent to a rear end thereof. In the manner of a mirror image, a right wheel carrier 54 is fixedly connected to the right semi-trailing arm 28 adjacent to a rear end thereof. In this way, the left rear wheel 50, the left wheel carrier 48, and the left semi-trailing arm 14 attached to the left wheel carrier 48 are mounted pivotably about the left pivot axis 20 and independently of the right rear wheel 56 which is attached to the right wheel carrier 54 and is pivotably mounted along with the right semi-trailing arm 28 about the right pivot axis 34.

(7) The left rear wheel 50 and the right rear wheel 56 are attached in a manner known in the art to the corresponding wheel carrier 48, 54, such that the wheels 50, 56 are rotatably mounted about a left rotational axis 52 and a right rotational axis 58 respectively.

(8) In a state wherein the independent rear suspension 10 is loaded only with the static vehicle weight, the rear ends of the semi-trailing arms 14, 28 are disposed below the rotational axes 52, 58 of the rear wheels 50, 56 and the first or forward or body-attachment ends of the semi-trailing arms 14, 18 are disposed above the rotational axes 52, 58.

(9) The independent rear suspension 10 according to the invention further comprises a transverse leaf spring 42. The transverse leaf spring 42 may advantageously comprise a predominant proportion of more than 95% by vol. of a composite material, made of a fiber-reinforced plastic in this special embodiment. The fiber-reinforced plastic may be realized as a glass-fiber-reinforced epoxy resin (GRE). The transverse leaf spring 42 in the installation state depicted in FIG. 1 in a vertical plane (YZ plane) which is arranged perpendicularly to the straight-ahead direction of travel 68. The transverse leaf spring 42 may have a substantially rectangular cross section which varies along its length, as required to achieve a predetermined spring characteristic curve.

(10) The transverse leaf spring 42 is fixedly connected to the chassis of the motor vehicle, for example by means of two spring clips 44, 46 disposed on either side of a center axis 70 of the motor vehicle.

(11) The outboard left and right ends of the transverse leaf spring 42 are attached to the semi-trailing arm 14, 28. The attachment between the transverse leaf spring 42 and the semi-trailing arms 14, 28 is located rearwardly (along the vehicle longitudinal axis or X-axis) of the respective rear wheel rotational axes 52, 58. The attachments between the opposite/outboard ends of the transverse leaf spring 42 and the respective left and right semi-trailing arm 14, 28 is effected by means of two couplings 24, 38, the which are screwed or otherwise attached to the respective end of the transverse leaf spring 42 and the semi-trailing arm 14, 28. The couplings 24, 38 permit relative movements (within predefined limits) between the ends of the transverse leaf spring 42 and the respective semi-trailing arms 14, 28 in the XY plane (horizontal, assuming the vehicle is sitting on a level surface). In this way, the second/rear ends of the semi-trailing arms 14, 28 are connected, via the leaf spring 42, in a sprung manner to the chassis of the motor vehicle.

(12) Shock absorbers 26, 40 are operatively connected at their lower ends to the respective semi-trailing arms 14, 28 and extend generally upward (along the vehicle Z-axis), with upper ends of the shock absorbers attached to the vehicle chassis or body (not shown) in a manner well known in the art. The shock absorbers 26, 40 may (as shown) make contact with and act on the semi-trailing arms at locations relatively close to the respective locations 24, 38 where the leaf spring is connected to the semi-trailing arms.

(13) As can be seen from FIG. 1, the left semi-trailing arm 14, the right semi-trailing arm 28, and the transverse leaf spring 42 are arranged in such a manner that an open installation space 12 is defined between those components. The open installation space 12 is ideally located to receiving part of the electrical drivetrain 60 of the motor vehicle which may be located directly between the left and right semi-trailing arms 14, 48 and in alignment with the wheel rotational axes 52, 58. In this context, in alignment with may mean in coaxial alignment with the axes or it may mean somewhat above or below the axes.

(14) The electrical drivetrain 60 of the motor vehicle generally comprises, among other things, an electric motor 62 and a left stub shaft 64 and a right stub shaft 66 which may advantageously be configured as articulation shafts. The electric motor 62 may have an elongate form and be arranged transversely (parallel with the vehicle Y-axis) in the open installation space 12, most optimally in a central region thereof, between the semi-trailing arms 14, 28 and forward of the transverse leaf spring 42, and be secured to the chassis of the motor vehicle. The motor 62 is therefore located on or in alignment with the left and right wheel rotational axes 52, 58. Each of the stub shafts 64, 66 may optimally be disposed generally co-axially with its respective rear wheel rotational axis 52, 58, starting from either transverse side of the electric motor 62, when the independent rear suspension 10 is a state wherein it is only statically loaded with the vehicle body load. The two stub shafts 64, 66 are, as is well known in the art, operatively connected to one of the rear wheels 50, 56 for transmission of drive and/or regenerative braking torque. The articulation shafts permit the necessary degree of movements of the rear wheels 50, 56 relative to the electric motor 62 during operation of the motor vehicle.

(15) While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.