Spring devices – Vehicle – Comprising compressible fluid
Reexamination Certificate
1999-12-14
2001-09-11
Schwartz, Christopher P. (Department: 3613)
Spring devices
Vehicle
Comprising compressible fluid
C267S064240
Reexamination Certificate
active
06286820
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a pneumatic spring with a vibration damper.
2. Discussion of the Prior Art
German reference DE 197 55 549 A1 describes a pneumatic spring having a vibration damper. Frequently, a pneumatic spring and a vibration damper are installed separately in a vehicle as individual subassemblies. There is an important reason for this method of construction. The structural space within the chassis is so confined that a pneumatic spring of sufficiently large dimensions cannot always be installed concentrically with the vibration damper.
In order to eliminate axial structural space problems in the case of vibration dampers, some solutions are known in which the connecting members of the vibration damper have been specially designed. For example, German reference DE 196 25 106 A1 describes a vibration damper in which at least two laterally mounted bearings have been produced. The gain in axial structural space corresponds to the structural height of a bearing.
A further problem resides in the fact that, during operation of vibration dampers, waste heat is produced due to the operating principle, caused by the throttling of a damping medium within the vibration damper. This waste heat is adequately removed by the slipstream. The container pipe of the vibration damper represents a heat exchanger with the ambient air. In the event of deficient heat removal, the sealing of the vibration damper may be damaged, which would result in a functional failure of the whole vibration damper.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to find a solution for the confined structural space of a pneumatic spring with a vibration damper. A further object lies in ensuring heat removal for the vibration damper. In addition, adequate angular mobility of the vibration damper within the chassis is to be guaranteed.
The object regarding the structural space is achieved, according to the invention, in that the connecting bearing is arranged in the region of the outer surface of the container pipe, the connecting bearing being of circular design and possessing a sealing ring which seals the spring chamber.
First, advantageously, a substantial saving of axial structural space is achieved. A further essential advantage resides in the fact that a conventional elastic bearing element, in addition to its anti-vibration insulation function, also performs a sealing function for the spring chamber. The bearing element is of such large dimensions that a correspondingly large sealing surface and sealing gap lengths are present, which ensure reliable sealing of the spring chamber of the pneumatic spring.
In a further embodiment, the connecting bearing possesses a radial prestress sleeve whose prestress force is active toward the container pipe. The effect of this is that the connecting bearing or the sealing ring of the connecting bearing is not dependent on its own prestress to perform its function.
To absorb the tensile forces acting on the vibration damper, the prestress sleeve possesses a base which represents an axial prestress surface for the connecting bearing. Furthermore, the connecting bearing possesses a fixing disk which prestresses the sealing ring axially to the base of the prestress sleeve. As a result, the sealing ring is guided on all sides within the prestress sleeve between the base and the fixing disk. Said components form an independent structural unit.
To transmit forces from the container pipe to the connecting bearing, the sealing ring possesses a support ring actively connected to the container pipe. In this arrangement, the support ring is at least axially enclosed by the sealing ring.
In an embodiment of the invention, that the connecting bearing possesses a sealing ring for sealing the spring chamber and a bearing ring for absorbing the damping support forces. A bearing ring may also have to meet other specific requirements, which for example demand a different material. The use of two ring elements may therefore be entirely logical.
In order, furthermore, to obtain a compact pneumatic spring/vibration damper structural unit, the sealing ring and the bearing ring are supported on the support ring.
With regard to the partial object of particularly smooth angular movement between the vibration damper and the pneumatic spring, the connecting bearing is designed according to the invention as a pivot bearing, possessing at least one universal ball joint in connection with a ball socket.
In order for the connecting bearing to be simple to install, the ball socket is of divided design in the axial direction of the pneumatic spring.
It has proven highly advantageous here if the sealing ring is inserted within the running surface of the ball socket. In this area, the sealing ring has a constant prestress.
In a further embodiment, the sealing ring is inserted between ball socket shells which form the ball socket. The sealing ring is thus able to undertake a sealing function at its inner and its outer diameters.
In order for the radial structural space requirement to remain low, the ball socket shells are radially held by the prestress sleeve.
The further components of the connecting bearing are likewise used for guidance, the ball socket shells being axially held by the base of the prestress sleeve and/or by the fixing disk.
With appropriate numbers of units, provision may be made for the fixing disk and a ball socket shell to be of integral design. Consequently, the prestress sleeve may also be designed integrally with a ball socket shell.
It is envisaged that at least one of the parts, prestressing the sealing ring, of the connecting bearing is connected to the chassis. The spring force of the pneumatic spring is thus decoupled from the vibration damper. The container pipe may be produced with thin walls. A small structural space can also be provided for the bearing, since only the damping forces now have to be supported.
In yet another embodiment, the prestress sleeve possesses a dimension extending beyond the connecting bearing with a connection to the chassis. The prestress sleeve can easily be produced with fairly thick walls, so that sufficient structural space exists, for example, for a screw connection to the chassis.
In a further embodiment of the pneumatic spring, a stop buffer is arranged in the spring chamber and moves relative to the container pipe of the vibration damper. The pneumatic spring possesses an impact surface which is held by the prestress sleeve in a fixed position relative to the connecting bearing. The compressive forces of the stop buffer which arise are directly supported on the chassis. For this purpose, cylindrical pipe-end caps are generally used which form the impact surface in order to protect the sensitive seal of the piston rod of the vibration damper. This expense is completely eliminated by the present invention.
With a sufficiently large number of units of the pneumatic spring according to the invention, it is possible to arrange for the impact surface to be designed integrally with the prestress sleeve. In order not to waste any structural space, the impact surface of the prestress sleeve is formed by the back of the base.
To achieve the partial object of the invention relating to heat removal, the pneumatic spring is assigned an air direction device which produces a targeted air flow onto the container pipe. A heat build-up critical for the vibration damper is thus prevented.
In this arrangement, the air direction device is formed by a spoiler. The spoiler may be a simple molding of metal or plastic which deflects the air flow at the chassis.
The shaping of the air direction device is selected so that the air direction device is directed toward the connecting bearing. A critical component is thus specially protected.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specif
Eichenmüller Thomas
Kolb Wolfgang
Lutz Dieter
Raulf Mathias
Cohen & Pontani, Lieberman & Pavane
Mannesmann Sachs AG
Schwartz Christopher P.
LandOfFree
Pneumatic spring with a vibration damper does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pneumatic spring with a vibration damper, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pneumatic spring with a vibration damper will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2484026