GB2529175A

GB2529175A - Vehicle suspension

Info

Publication number: GB2529175A
Application number: GB1414248.3A
Authority: GB
Inventors: James John Alexander Dowle
Original assignee: NORMAN TRUST
Current assignee: NORMAN TRUST
Priority date: 2014-08-12
Filing date: 2014-08-12
Publication date: 2016-02-17
Anticipated expiration: 2034-08-12
Also published as: ZA201505733B; CN105365510A; CN105365510B; BR102015019082A2; GB201414248D0; GB2529175B

Abstract

A suspension assembly for a vehicle comprising a suspension arm 3 having attachment points 5, 7 at one end thereof for securing the arm to a vehicle, an upright assembly 13 comprising a wheel hub 15 and having upper and lower mounting points to allow rotation of the assembly around a substantially vertical axis, the upright assembly is connected to the arm at its upper and lower mounting points via a bracket 25 being a distinct part from the suspension arm but attached thereto. The bracket is attachable to the suspension arm in two alternative orientations thereby permitting fitment of the assembly on a left or right side of the vehicle. Thereby providing an interchangeable suspension arm arrangement suited to the steerable front wheels of a vehicle, which also provides a minimal number of unique parts but allows for those parts to be assembled into a left or right-hand unit. The bracket may receive one of the upper and the lower mounting points, and the suspension arm receives the other. Thus, the arm and the bracket define the mounting points for the rotatable upright assembly.

Description

Vehicle Suspension

FIELD OF THE INVENTION

The present invention relates to a vehicle suspension.

BACKGROUND ART

Vehicles need a suspension system in order to keep the wheels in contact with the surface over which the vehicle is being driven, and to insulate the vehicle body from at least some of the undulations in that surface. The former requirement is necessary in order to ensure the safe and effective handling of the vehicle, and the latter is necessary in order to provide the necessary level of ride comfort. Generally, these two requirements act in opposite directions, and a suspension system is therefore a compromise between the two.

A range of suspension systems are known.

The MacPherson strut suspension, often used for the front suspension, comprises a wishbone or a substantial compression link stabilized by a secondary link, which provides a bottom mounting point for a wheel hub or axle. This lower arm system provides both lateral and longitudinal location of the wheel. The upper part of the hub is rigidly fixed to the inner part of a sprung and damped strut, which extends upwards directly to a mounting in the body shell of the vehicle.

Double wishbone suspension locates the wheel through the use of two (upper and lower) arms, each in the shape of an "A" or a wishbone. Each arm has two mounting points on the chassis and one joint at the hub, or knuckle. A shock absorber and coil spring are mounted to the wishbones to control vertical movement. Double wishbone designs allow the engineer to carefully control the motion of the wheel throughout suspension travel, controlling such parameters as camber angle, caster angle, toe pattern, roll centre height, scrub radius, scuff and more.

A multi-link suspension uses three or more lateral arms, together with one or more longitudinal arms, to define and constrain the movement of the wheel hub. These arms do not have to be of equal length, and may be angled away from their obvious' direction.

Typically each arm has a spherical joint (ball joint) or rubber bushing at each end, and therefore react loads along their own length, in tension and compression, but not in bending. Some multi-links also use a trailing arm or wishbone, which has two bushings at one end.

All have relative advantages and disadvantages, typically reflecting a variation in the level of ride comfort or handling that is achievable against the cost and complexity of the system.

SUMMARY OF THE INVENTION

All the above forms of suspension use components that are "handed", i.e. suited only to the left-or right-hand side of the vehicle. Double-wishbone arrangements also typically have non-identical upper and lower arms. Multi-link arrangements may have several individually-designed arms, all of which are handed and different. Whilst this is beneficial in terms of the suspension performance that is obtained, it means that a large parts inventory must be maintained and that field repairs are problematic. For off-road and expedition vehicles where the finer qualities of ride & handling are less crucial, it would be beneficial to adopt a suspension having a substantially lower number of unique parts.

The present invention therefore provides a suspension assembly for a vehicle, comprising a suspension arm having at least one attachment point at one end thereof for securing the arm to a vehicle, an upright assembly comprising a wheel hub and having upper and lower mounting points, each allowing rotation of the assembly around a substantially vertical axis, the upright assembly being connected to the suspension arm at its upper and lower mounting points, via a bracket being a distinct part from the suspension arm but attached thereto, the bracket being attachable to the suspension arm in two alternative orientations thereby permitting fitment of the assembly on a left side or a right side of the vehicle. In this way, the interchangeable suspension arm arrangement is provided, especially suited to the steerable front wheels of a vehicle, which also provides a minimal number of unique parts but allows for those parts to be assembled into a left-or right-hand unit.

In a preferred arrangement, the bracket receives one of the upper and the lower mounting points, and the suspension arm receives the other. Thus, the arm and the bracket define the mounting points for the rotatable upright assembly. A separate steering arm can be connected to the upright assembly in order to control its rotation and steer the vehicle as desired.

The bracket can be attached to the suspension arm by one or more bolts, which is convenient even in the field, and allows for an assembled suspension to be dismantled and re-assembled in an opposite configuration. A suitable form for the bracket is a C-arm, one end of which can then be attached to the suspension arm, and the other end of which can be adapted to receive one of the upper and the lower mounting points.

The suspension arm preferably has two attachment points, spaced laterally with respect to each other. They can be adapted to allow rotation of the suspension arm relative to the vehicle around a common rotation axis. That axis is ideally level (relative to the vehicle), allowing the arm to move such that its remote end has the necessary vertical articulation to provide a useful suspension travel.

It should be noted that we describe the upright assembly as having a "substantially vertical" axis, about which the assembly can be rotated in order to steer the vehicle. In practice, of course, this axis will rarely be truly vertical as most steered wheels in the automotive field have a degree of caster andJor camber which will cause the axis to depart from perfect verticality in longitudinal and lateral directions (respectively). Thus, "substantially vertical" should be interpreted so as to take account of these normal variations.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described by way of example, with reference to the accompanying figures in which; Figures 1A and lB are plan views of first embodiments of vehicle suspension assemblies for the left and right hand sides of a vehicle respectively; Figures 2A and 2B are perspective views of the assemblies of Figures 1A and lB respectively; S Figures 3A and 3B are plan views of the assemblies of Figures 1A and lB showing a wheel attached thereto; Figures 4A and 4B are perspective views of the assemblies of Figures 1A and lB respectively; Figure 5 is an exploded schematic view of part of the suspension assembly of Figures 1A and 2A; Figures GA and 6B are plan views of second embodiments of vehicle suspension assemblies for the left and right hand sides of a vehicle respectively; Figures 7A and 7B are perspective views of the assemblies of Figures GA and GB respectively, and Figure 8 is an exploded schematic view of the suspension assembly of Figures GA and 7A.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the drawings, like reference numerals are used in the different drawings to indicate the same elements; further, the assemblies shown are "handed", those in Figures with the suffix "A" are for the left hand side of a vehicle and, substantially, mirror images of those in Figures with the suffix "B", which are for the right hand side of a vehicle.

In Figures 1A and 1B, in accordance with a first embodiment of the invention, a suspension assembly 1 has a suspension arm 3 with, at one end, outer and inner attachment points 5, 7 for mounting to the vehicle body or chassis (not shown); each of these attachment points comprises a bracket 9 (see Figure 2A) which is mounted to the vehicle, the suspension arm 3 having bearings 11 with a common axis A (see Figure 5) by which the suspension arm 3 is connected to the bracket 9 so as to allow it to rotate about the axis A as shown by the arrow R in Figure 5.

Mounted to the other end of the suspension arm 3 is an upright assembly 13 comprising a wheel hub 15 with wheel studs 17 (by which in use a wheel 19 (see Figures 3 and 4) is connected), and a brake disc 21 and a brake caliper 23 which are conventional in design. The upright assembly 13 is mounted to the suspension arm by way of C-arm 25, which will be described further below in connection with Figure 5, which allows rotation of the upright assembly about a substantially vertical axis (i.e. substantially perpendicular to the plane of Figures 1A and 1B). Also mounted to upright assembly 13 is a conventional steering arm 27, by which the wheel assembly can be rotated about the substantially vertical axis so as to steer the vehicle.

As shown more clearly in Figures 2A and 2B, a conventional MacPherson strut damper assembly 29, comprising a coil spring 31 coaxially enclosing a shock absorber, or damper 33, is mounted at one of its ends to the suspension arm 3 by way of a damper mounting bracket 35 and at its other end 37 to the vehicle body or chassis. The damper assembly 29 is, in use, conventional, however it will be noted that the design of the suspension assembly is such that the axis of the damper assembly 29 is slightly transversely distanced from the steering axis of the upright assembly 13 (described further below in connection with Figure 5).

Figures 3 and 4 show the assemblies of Figures 1 and 2 with a wheel 19 mounted to wheel studs 17.

Moving to Figure 5, one end of C-arm 25 and damper mounting bracket 35 are mounted to the suspension arm 3 by bolts 39, those for the C-arm 25 being received in holes 41 and those for the damper mounting bracket in holes 43. The end of the suspension arm 3 distant from the bearings 11 is provided with a lower mounting point 45, which in use receives a lower pivot point (not shown) of the upright assembly; the upright assembly also has an upper pivot point (not shown) which is received by an upper mounting point 47, which is provided at the end of the other end of the C-arm 25 (i.e. the end distant from the end which is mounted to the suspension arm 3). The C-arm 25 and the holes 41 in the suspension arm are configured and disposed so that the lower and upper mounting points 45, 47 define the substantially vertical axis about which the upright assembly 13 can rotate, for steering the vehicle, with the upper and lower pivot points which form part of the upright assembly 13 being held between the lower and upper mounting points 45, 47 so that they have only a single degree of freedom of movement, being able to rotate about the vertical axis. Alternatively, the pivot points may be ball joints that can move with two degrees of freedom, allowing the pivot points to allow for up and down movement of the suspension in use and the steering swivel.

As will be appreciated, the mounting arrangements shown in Figure 5, in particular the mounting points 45, 47 and damper mounting bracket 35, preclude the axis of the damper assembly 29 being coaxial with the axis about which the upright assembly 3 can rotate for steering, the steering pivot axis, however these mounting arrangements allow for easy and independent removal and replacement of parts for repair or maintenance.

Preferably the damper mounting bracket is mounted so as to allow the end of the damper assembly 29 to be as close to the steering pivot axis as possible, so as to minimise non-vertical forces on the damper assembly 29. It will also be appreciated that, although the elements illustrated in Figure 5 are arranged for mounting on the left hand side of the vehicle (i.e. as shown in Figure 1A), they can easily be used on the opposite side of the vehicle by inverting them, with the only additional item to be provided being the provision of holes on the underside of the suspension arm 3 to accept the bolts 39 so as to mount damper mounting bracket 35 to the opposite side of suspension arm 3 to that shown in Figure 5 (or, holes 43 may simply pass right through suspension arm 3 and be secured by nuts 43', in which case reversal of the arm 3 for use on the opposite side of the vehicle is simple and straightforward).

Figures 6 to 8 show a second embodiment of a suspension assembly 201 in accordance with the invention. There is a suspension arm 203 with, at one end, outer and inner attachment points 205, 207 for mounting to the vehicle body or chassis (not shown); each of these attachment points comprises a bracket 209 (see Figure 7A) which is mounted to the vehicle, the suspension arm 203 having bearings 211 with a common axis A (see Figure 8) by which the suspension arm 203 is connected to the bracket 209 so as to allow it to rotate about the axis A, as in the first embodiment.

Mounted to the other end of the suspension arm 203 is an upright assembly 213 having mounted to it (by suitable releasable fixings, not shown) a wheel hub 215 with wheel studs 217 (by which in use a wheel is connected), and a brake disc 221 and a brake caliper 223 which are conventional in design. The upright assembly 213 is mounted to the suspension arm 203 by way of upper and lower ball joints 224, 226 which engage with upper socket 228 forming part of inverted U-shaped arm 230 (which will be described further below in connection with Figure 8) and lower socket 232 respectively, which allows rotation of the upright assembly 213 about a substantially vertical axis (i.e. substantially perpendicular to the plane of Figures GA and GB). Also mounted to upright assembly 213 is a conventional steering arm 227, by which the wheel assembly can be rotated about the substantially vertical axis so as to steer the vehicle.

As shown more clearly in Figures 7A and 7B, there is a conventional MacPherson strut damper assembly 229, comprising a coil spring 231 coaxially enclosing a shock absorber, or damper 233. The lower end 234 of damper 229 is mounted to the U-shaped arm 230 by a pin or bolt (not shown), which is releasably insertable into socket 236 formed in arm 230, and at its other end 237 to the vehicle body or chassis. The damper assembly 229 is, in use, conventional, however it will be noted that it is shorter than that shown in the first embodiment, and that the design of the suspension assembly is such that the axis of the damper assembly 229 is slightly inwardly (i.e. transversely relative to the vehicle's direction of forward motion) distanced from the steering axis of the upright assembly 213, as in the first embodiment.

As can be seen in Figure 8, the ends of the U-shaped arm 230 are mounted to the suspension arm 203 at brackets 238 using bolts (not shown) or other suitable releasable fixings. The U-shaped arm 230 and the suspension arm 203 are configured and disposed so that the upper and lower sockets 228, 232 define a substantially vertical axis about which the upright assembly 213 can rotate, for steering the vehicle, with the upper and lower ball joints 224, 226 which form part of the upright assembly 213 being held between the upper and lower sockets 228, 232 so that they can move with two degrees of freedom, allowing for up and down movement of the suspension in use and also for the upright assembly 213 to swivel, or rotate about the defined vertical axis, for steering purposes. The U-shaped arm 230 when mounted to the suspension arm 203 defines an opening through which a drive shaft (not shown) can pass to drive the wheel hub 215; the U-shaped arm 230 is shaped and dimensioned so that this opening is sufficient to allow for the drive shaft to pivot freely in a substantially vertical plane as may be necessary to allow the travel of the suspension in use. It will be appreciated that the lower side of the suspension arm 203, which is not visible in any of the Figures, is a mirror image of the side which is visible, so that suspension arm 203 may be used on either side of the vehicle; U-shaped arm is symmetrical about a plane which is parallel to axis A in Figure 8, so that it too may be used on either side of the vehicle. Preferably, the upright assembly 213, steering arm 227 and brake caliper 223 are also reversible so that they too can be used on either side of the vehicle; brake disc 221 and strut assembly are not handed, and therefore can also be used on either side of the vehicle.

It will of course be understood that many variations may be made to the above-described embodiment without departing from the scope of the present invention. For example, although the bushings are shown disposed transversely relative to the direction of motion of the vehicle, in some applications it may be beneficial for the two brackets to be mounted at different positions on the vehicle; in this case, the axes of the two bearings 11, 211 could be staggered vertically and/or longitudinally relative to the vehicle, provided that there is a common rotational axis. The axis about which the upright assembly 3, 203 can rotate for steering, the steering pivot axis, is described as substantially vertical; those skilled in the art will understand that modifying the assembly to allow for various degrees of caster and/or camber can be accomplished simply, in the first embodiment by modifying one or more of the shape and configuration of the C-arm 25 and the orientation and/or location of the holes 41 relative to the lower mounting point 45, and in the second embodiment by modifying one or more of the shape and configuration of the U-shaped arm 230 and the orientation and/or location of the upper socket 228 relative to the brackets 238 and/or the lower socket 232 relative to the brackets 238 and/or the relative locations of the upper and lower ball joints 224, 226. Furthermore, where different variations or alternative arrangements are described above, it should be understood that embodiments of the invention may incorporate such variations and/or alternatives in any suitable combination.

Claims

CLAIMS1. A suspension assembly for a vehicle, comprising; a suspension arm having at least one attachment point at one end thereof for securing the arm to a vehicle; S an upright assembly comprising a wheel hub and having upper and lower mounting points, each allowing rotation of the assembly around a substantially vertical axis; the upright assembly being connected to the suspension arm at its upper and lower mounting points, via a bracket being a distinct part from the suspension arm but attached thereto; the bracket being attachable to the suspension arm in two alternative orientations thereby permitting fitment of the assembly on a left side or a right side of the vehicle.
2. A suspension assembly according to claim 1 in which the bracket receives one of the upper and the lower mounting points, and the suspension arm receives the other.
3. A suspension assembly according to claim 1 or claim 2 in which the bracket is attached to the suspension arm by one or more bolts.
4. A suspension assembly according to claim 2 or claim 3 in which the bracket is a C-arm, one end of which is attached to the suspension arm, and the other end of which is adapted to receive one of the upper and the lower mounting points.
5. A suspension assembly according to any one of the preceding claims in which the suspension arm has two attachment points, spaced laterally with respect to each other.
6. A suspension assembly according to claim 5 in which the two attachment points are adapted to allow rotation of the suspension arm relative to the vehicle around a common rotation axis.
7. A suspension assembly for a vehicle substantially as herein described with reference to and/or as illustrated in the accompanying figures.