Land vehicles – Wheeled – Running gear
Reexamination Certificate
1999-11-12
2001-07-10
Rice, Kenneth R. (Department: 3611)
Land vehicles
Wheeled
Running gear
C267S068000
Reexamination Certificate
active
06257604
ABSTRACT:
BACKGROUND OF INVENTION
The present invention concerns the suspension of vehicles and, more specifically, the guidance of a vehicle wheel in relation to the chassis of that vehicle, as well as control of deflection of the wheel in relation to the chassis.
It is known that a wheel is mounted on a hub, and that the hub is mounted on a wheel carrier by means of a bearing defining the axis of rotation of the wheel. Guidance of the wheel consists of making possible a displacement of the wheel carrier in relation to the vehicle to an extent sufficient for the suspension of the vehicle. At the same time, guidance of the wheel should be such that control of the path of the vehicle is ensured with the utmost care. The deflection movement sought is very wide vertically. It may be desired to permit a slight movement longitudinally, while ideally it is sought to prevent any relative transverse movement. Furthermore, the steering and camber variations that might induce all these movements have to be strictly contained, which also puts a constraint on design that the expert has to take into account.
If the plane perpendicular to the axis of rotation of the wheel is called wheel “plane,” passing through the middle of the wheel, or more precisely through the center of the area of contact with the road of a pneumatic tire or non-pneumatic tire mounted on said wheel (generally referred to below as “tire”), control of the deflection movement actually means that guidance has to ensure a strictly controlled position of the wheel plane relative to the chassis.
In addition to the guidance aspect of the wheel plane, the suspension also has to ensure weight transfer of the vehicle on the wheel and control of the amplitude of movements allowed by guidance. That is the role ordinarily played by the springs and shock absorbers or parts combining the functions of spring (flexibility) and shock absorption (preventing the maintenance of oscillations).
All of the suspensions used at the present time on vehicles have the common characteristic of being rather cumbersome. The suspension arms must have a certain length for their angular movement and not be accompanied, for example, by overly great tracking variations (suspension diagrams). Even the MacPherson strut, the growing use of which is known to be due to the greater space it leaves for installing a motor power unit in transverse position, introduces some problems, including its height dimension.
Furthermore, the search for an ever better compromise between suspension comfort and handling leads to proposing so-called active or semiactive suspensions, control of which is now rendered possible by the progress of electronics. In general, that leads to making installation of the suspension on the vehicle even more cumbersome, by increasing the space occupied by springs and/or shock absorbers, not to mention adding extra elements forming the spring or shock absorber.
SUMMARY OF THE INVENTION
The object of the invention is to propose a complete suspension assembly, easy to integrate with a vehicle, while permitting a suspension whose elasticity and shock absorption characteristics are well controlled.
The invention proposes a suspension assembly of a motor vehicle, said assembly containing a hub designed to support a wheel, said wheel containing a disk and a tire and defining a wheel plane through the center of the area of contact with the road of a tire mounted on the wheel, said wheel containing:
a support comprising mounting means for making possible mounting of the support on the chassis of a vehicle, said support being intended to be locked on vertical deflection relative to the chassis;
a guide member locked on vertical deflection relative to the support;
a single elongated bar, guided in relative translation by the guide member and sliding inside said guide member, mounted in rotation on the sliding axle locked in relation to the guide member;
a wheel carrier mounted on the bar at both ends of the latter, said wheel carrier defining the axis of rotation of said hub, means for supporting the weight of the vehicle transmitted by the support to the wheel carrier, said means for supporting the weight comprising a spring acting between two points of application of the stress of the spring, one integral with the wheel carrier and the other integral with the guide member.
The invention thus proposes an assembly making it possible, in a preferred embodiment, to integrate the guidance necessary for wheel deflection and the elements making it possible to ensure the necessary flexibility and control of deflection inside the wheel. In that way, it is possible for the essential functions of the suspension (guidance of the wheel plane, degree of freedom in the desired direction and control of deflection movements) to be integrated in the actual interior space of the wheel. It is thus possible very simply to mount that assembly to the chassis of the vehicle in any suitable manner and, notably, rigidly. In the latter case, the guide member plays a support role for suspension and is integrated with the chassis, which makes very simple use possible. The support being intended to be locked in vertical deflection relative to the chassis and the guide member being mounted locked in vertical deflection relative to the support, the guide member is therefore locked in vertical deflection relative to the chassis.
Preferably, in order to radically reduce the space occupied, the invention aims at installing as many parts useful to the suspension as possible in the space available inside the wheel, that is to say, on one side of the wheel disk and radially inside the wheel.
The electronic automatic control means available at the present time make it possible to run an electric motor more rapidly and more directly than a hydraulic or pneumatic component. That is why, in a particularly advantageous variant, the invention proposes using a linear or rotary electric motor for controlling the deflection movements of the wheel. An arrangement is thus proposed which makes it possible to house such a motor in the assembly according to the invention, while remaining roughly within the interior space limits of the wheel. The invention thus has the advantage of lending itself particularly well to active control of the suspension characteristics and, more specifically, to direct electric control of the suspension characteristics.
Let us note that, when translation guidance of the bar is “friction-free,” that is, involving as little friction as possible, control of the deflection movement is thereby facilitated, for it is not distorted by parasite frictions, the extent of which is often variable. Roller guidance is very appropriate. Rollers cooperating with roller ways provided on the bar can be used, the rollers being mounted rotating on the guide member. Relative sliding contact surfaces could thus be imagined, insofar as they involve appropriate treatment or insofar as they are sufficiently lubricated. For example, a fluid bearing can be used. That variant lends itself particularly well to control of deflection essentially by means of an electromechanical machine that can be run for that purpose, for the absence of boundary friction simplifies its operation and improves overall performances.
The invention is applicable to steering wheels as well as to driving wheels and to steering and driving wheels at the same time. It makes it possible to install a pivot and to install the steering angle control point. It makes it possible, in the case of steering wheels, to place the pivot axis of the wheel in the wheel plane defined above and on a diameter, that is, so as to be able to adopt the so-called “pivot-in-axis” solution, that is to say, an arrangement in which the axis about which the wheel can steer is perpendicular to the axis of rotation of the wheel, the assembly being so arranged in order that said axis about which the wheel steers is secant to the tire foot print substantially in the middle of the foot print. Hence in a very advantageous design variant, the bar axis and the pivot axis of
Laurent Daniel
Walser Daniel
Baker & Botts L.L.P.
Conception et Developpement - Michelin S.A.
Rice Kenneth R.
LandOfFree
Assembly containing a wheel and a suspension integrated with... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Assembly containing a wheel and a suspension integrated with..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Assembly containing a wheel and a suspension integrated with... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2526625