DE102011087345B4 - Joint and / or link arrangement - Google Patents

Abstract

Joint and / or bearing arrangement (1) with a multi-part (7; 8) bearing shell (4) which at least partially surrounds a joint ball (5), characterized in that each part (7; 8) of the bearing shell (4) on its the surface facing the joint ball (5) has a metallic cast material, the respective part (7; 8) of the joint and / or bearing shell (4) being formed entirely from a metallic cast material, the cast material at least on its joint ball (5) facing surface is nitrided and that the joint ball (5) is nitrided on its surface facing the joint and / or bearing shell (4).

Description

The invention relates to a joint and / or bearing arrangement according to the preamble of claim 1.

It is known to equip particularly highly stressed joints with a joint shell made of steel, which can be surface-treated, e.g. hard chrome-plated, to form a hard surface. The joint ball, which is movable with respect to the joint socket, can then, for example, be pressed into a joint socket designed in this way. Then, however, there is only support in the central area of the joint ball, so that such a joint cannot be loaded axially, but only radially.

A joint and / or bearing arrangement of the type mentioned is from DE 10 2008 041 619 A1 known. To support the joint ball, a first bearing shell part and a second bearing shell part are arranged in a housing, the first bearing shell part made of a plastic and the second bearing shell part made of sintered metal, sheet metal or a high-strength plastic.

The invention is based on the problem of achieving an alternative and / or an improvement here.

The invention solves this problem by a joint and / or bearing arrangement with the features of claim 1 and by a motor vehicle with the features of claim 12. With regard to advantageous configurations and developments of the invention, reference is made to the further claims 2 to 11.

By virtue of the fact that the surface of the joint and / or bearing shell facing the joint ball has a metallic cast material, this surface already has a high level of pressure stability. However, the nitriding causes a considerable increase in the surface hardness and at the same time corrosion protection of the joint ball surface is achieved. With the multi-part joint and / or bearing shell, an extensive enclosure of the joint ball is also made possible, as a result of which large axial forces can also be introduced into such a joint and / or bearing arrangement. Nevertheless, an overall low overall height of the joint and / or bearing arrangement can be achieved.

To increase the surface hardness and to protect against corrosion, it is advantageous to nitride the cast material on its surface facing the joint ball.

Nitriding is a surface hardening process using nitrogen. A surface layer is created that is resistant up to around 500 ° Celsius. Possible processes are e.g. bath nitriding, gas nitriding or plasma nitriding.

The process is usually carried out at temperatures around (500 ... 570) ° C for treatment times of 1 to 100 hours, whereby the core of the material remains ferritic and the formation of austenite near the surface due to the diffusion of nitrogen is avoided. A very hard superficial connection layer (ε- and y'-iron nitride) forms on the workpiece surface due to the diffusion of nitrogen or carbon into the workpiece, which, depending on the treatment time, can be (10 ... 30) µm thick and more or less thick has pronounced pore seams on the surface, which in turn can be used as a carrier of, for example, lubricants. The diffusion zone, in which the nitrogen is stored up to a certain depth in the ferritic metal matrix, is located under the connecting layer. This nitrogen stored in solid solution leads to an increase in strength.

In order to increase the corrosion protection of these layers, it is also possible to oxidize the connecting layer. This is usually done by applying steam, which corrodes the iron components and thus forms a protective oxide layer.

Common processes are salt bath nitriding, gas nitriding, gas nitrocarburizing and plasma nitriding. With salt bath nitriding, partial immersion of the workpieces is possible; with plasma nitriding, for example, you can mechanically cover with a clamping device or a protective paste and thus also achieve partial nitriding. Gas nitrocarburization is advantageous compared to gas nitriding in a shorter time, e.g. 2 to 5 hours at a temperature of around 570 ° C, which is higher than gas nitriding, and thus ensures a shorter throughput time in production.

The part of the joint shell and / or bearing shell that has the cast surface is formed entirely from a cast material, so that the material is homogeneous. A separate formation of the surface is then not necessary.

A graphite cast is used particularly favorably, which has a high lubricity due to the embedded graphite components, so that emergency lubrication of the joint and / or bearing arrangement is guaranteed even when the actual lubricant has already been used up.

The use of spheroidal graphite cast iron, such as GGG 60, represents a good compromise between the required high strength on the one hand and sufficiently high ductility on the other hand. The well-known abbreviation GGG stands for Graphite Guss Globular.

The gas nitrocarburizing process can be adjusted by sufficient dwell time (e.g. 2-5 hours) and appropriate pressure and temperature parameters (e.g. 570 ° C) so that a nitriding depth of at least 0.15 millimeters is achieved, so that a high stability of the nitrided Surface is present.

For easy running of the joint and / or bearing arrangement and to remove small surface defects, it is also advantageous to polish the surface mentioned - and possibly also the surface of the joint ball.

For a good axial load capacity, a lower bearing shell part opposite a shaft of a held joint ball can encompass the joint ball approximately up to its equatorial plane. This can be followed by an upper bearing shell part through which a shaft extends as a hinge closure. In order to hold this, a pressure element that braces the bearing shell parts against one another can advantageously be provided, for example a resilient and / or elastic ring body.

In addition, a sensor device can be provided, for example by means of piezo elements, by means of which the magnitude of the axial preload can be determined, whereby wear can be determined in continuous operation.

In order to keep the wear as low as possible, it is also advantageous to nitride and / or polish the joint ball on its surface. The polished surface can extend over the shaft to the approach of a dirt-sealing bellows.

A motor vehicle with at least one joint and / or bearing arrangement according to the invention is claimed separately. Such vehicles can be designed as cars or commercial vehicles or construction machines.

Further advantages and features of the invention emerge from the exemplary embodiments of the subject matter of the invention shown in the drawing and described below.

• 1 eine die wesentlichen Elemente einer Gelenk- und/oder Lageranordnung nach Anspruch 1 zeigende und teilweise aufgeschnittene Ansicht,
• 1a eine Detailansicht des in 1 mit Ia gekennzeichneten Bereichs
• 2 eine Gelenk- und/oder Lageranordnung ähnlich wie in 1, hier eingesetzt in eine Baueinheit mit zwei V-förmig aufeinander zulaufenden Lenkern, in deren Zentrum die Gelenkanordnung gehalten ist,
• 3 eine Detailansicht etwa entsprechend dem Detail III in 2,
• 4 die Baueinheit nach 2 in Draufsicht,
• 5 einen perspektivischen und schematischen Ausschnitt eines Nutzkraftwagens im Bereich einer Gelenkanordnung zur Verbindung eines im Differentialbereich erweiterten Achskörpers, wobei hier die Baueinheit nach 2 ff. zur Abstützung des Achskörpers vorgesehen ist.

In the drawing shows:

• 1 a partially cut-away view showing the essential elements of a joint and / or bearing arrangement according to claim 1,
• 1a a detailed view of the in 1 area marked with Ia
• 2 a joint and / or bearing arrangement similar to that in FIG 1 , here used in a structural unit with two V-shaped connecting rods, in the center of which the joint arrangement is held,
• 3 a detailed view roughly corresponding to the detail III in 2 ,
• 4th the unit according to 2 in plan view,
• 5 a perspective and schematic section of a utility vehicle in the area of an articulated arrangement for connecting an axle body expanded in the differential area, the structural unit according to FIG 2 ff. is intended to support the axle body.

In the 1 The schematically illustrated joint and / or bearing arrangement is designed here as a joint arrangement which can be seen both in the radial direction (arrow 2 ) as well as in the axial direction (arrow 3 ) can be charged.

The joint arrangement drawn here 1 has a multi-part - here two-part - joint or bearing shell 4th who have favourited a joint ball 5 at least partially surrounds. Overall, a three-part structure is drawn here, in which the joint shell 4th one with the joint ball 5 coherent shaft 6th opposite lower joint or bearing shell 7th and one from the shaft 6th penetrated upper joint or bearing shell 8th having. The lower bearing shell 7th can in a housing 9 pressed in or otherwise held in it. Alternatively, it is also possible that the lower bearing shell 7th integral with the housing 9 is trained. The last-mentioned solution is, however, possibly more expensive in the case of nitriding, which is described in more detail below. A pre-assembly of a completely usable joint 1 is possible and cheap.

The upper bearing shell 8th can for example be kept floating, with a receptacle, for example an annular groove, for one of the bearing shell parts 7th , 8th biasing element axially biasing against each other 10 , formed here as an annular pressure element, in the upper bearing shell 8th can be formed. Specifically, the prestressing element 10 be designed for example as a rubber ring or disc spring. When using a rubber element, in addition to the effect of an axial preload, it also has a shock-absorbing effect.

In addition, a sensor device 20th be provided, by means of which a detection of the size of the axial preload is possible. For this purpose, for example, piezo elements can be provided that measure the axial pressure and thereby contribute to If the pressure falls below a minimum, signal a lack of axial preload. Adjustability to compensate for wear can be possible.

The sensor device can be assigned to an evaluation unit which, when a piezo element is used, detects the voltage and uses a suitable instrument 21st can display. The voltage can also be forwarded to a control unit or saved for evaluation purposes.

Behind the biasing element 10 can be a lock ring 11 or similar position securing and the housing 9 closing closure be provided. It is also possible to use the housing for a stable finish and enclosure of the parts 7th , 8th the bearing shell 4th to roll.

On the shaft 6th opposite end can be the housing 9 , as drawn here, must be closed and a storage room 12th for lubricants include. The lower bearing shell 7th is at the pole of the joint ball 5 except. Alternatively, such a storage space can also be inside the lower bearing shell 7th be provided. Overall, such a joint arrangement 1 maintenance free.

It is also possible that the housing 9 on the shaft 6th opposite area can be opened with a screw cap or the like, whereby the very flat and cheap design can be retained. The cover that can be opened can also make it possible to refill lubricant.

At least part of the joint and / or bearing shell 4th shows, among other things, a high surface hardness with good corrosion protection at the same time on the joint ball 5 facing surface on a nitrided metallic cast material. This achieves high pressure stability and good corrosion protection. In terms of production, the respective part is simple here 7th , 8th the joint and / or bearing shell 4th Completely formed from a metallic cast material. A graphite cast, in particular a spheroidal graphite cast, is used as the casting material. For example, a GGG 60 or a material with similar strength and elongation properties can be considered as the material. The GGG 60 achieves a higher strength than, for example, a GGG 40, although the elongation properties are still sufficiently good. The joint arrangement created in this way 1 thus forms a three-part, spherically shaped cast steel or cast-cast bearing.

It is particularly favorable if the cast material of the bearing shell parts 7th , 8th at least on his the joint ball 5 facing surface is nitrided, for example via a gas nitrocarburizing. The immigration depth of the nitrogen, i.e. the nitriding depth, should be sufficiently large in order to be able to ensure a high surface quality even with surface defects. This can be easily achieved by long exposure to the process. The nitrided sliding surfaces therefore do not lose their properties, which have been improved by the nitriding, even after a long period of use.

For a high surface quality, that of the joint ball 5 facing surface of the joint and / or bearing shell parts 7th , 8th also be polished.

The joint ball 5 , which itself can consist of steel or also a cast material, on its joint and / or bearing shell 4th facing surface also be nitrided and / or polished. When polishing, it is beneficial to keep the polished surface on the shaft 6th at the approach of a sealing bellows 13th to continue. Even if as a pretensioning element 10 a rubber ring is inserted, this is through the bellows 13th completely free of sealing tasks. The joint and / or bearing arrangement is thus insensitive to dirt.

Such a joint arrangement 1 can be used at various points as a particularly heavy-duty joint and / or bearing arrangement within chassis parts 14th a motor vehicle be provided.

A motor vehicle with at least one of its chassis 14th associated joint and / or bearing arrangement according to one of claims 1 to 11 is therefore claimed here separately.

In 2 to 5 is a section of the landing gear 14th of a vehicle 15th , for example a commercial vehicle or an off-road vehicle. The arrangement shown there comprises two in a triangular link arrangement at an acute angle and V-shaped in plan view converging towards one another 16 , 17th . These grip the triangular tip formed in this way by means of a joint arrangement 1 on a vehicle axle 18th , here a rear axle. This is extended in the central area with respect to the vehicle transverse direction to accommodate a differential. The joint arrangement 1 can thus be on the upper end of this area of the rear axle that is expanded to accommodate a differential 18th be mountable and thus a transverse guide and longitudinal guide for this vehicle axle 18th form. The two supporting links here 16 , 17th can even in their upper ranges 19th be connected to load-bearing longitudinal frame parts, for example.

List of reference symbols

1

Joint and / or bearing arrangement,

2

radial direction,

3

axial direction,

4th

Joint or bearing shell,

5

Joint ball,

6th

Shaft,

7th

lower joint shell,

8th

upper joint shell,

9

Casing,

10

Pretensioning element,

11

Closure element,

12th

Storage room for lubricants,

13th

Bellows,

14th

Landing gear,

15th

Vehicle,

16

Handlebars,

17th

Handlebars,

18th

Axis,

19th

Connection of the handlebars

20th

Sensor device

21

Evaluation unit

Claims (12)

Joint and / or bearing arrangement (1) with a multi-part (7; 8) bearing shell (4) which at least partially surrounds a joint ball (5), characterized in that each part (7; 8) of the bearing shell (4) on its the surface facing the joint ball (5) has a metallic cast material, the respective part (7; 8) of the joint and / or bearing shell (4) being formed entirely from a metallic cast material, the cast material at least on its joint ball (5) facing surface is nitrided and that the joint ball (5) is nitrided on its surface facing the joint and / or bearing shell (4). Joint and / or bearing arrangement (1) according to Claim 1 , characterized in that the material is nitrided on the surface mentioned by gas nitrocarburizing. Joint and / or bearing arrangement (1) according to one of the Claims 1 to 2 , characterized in that the cast material is spheroidal graphite cast iron. Joint and / or bearing arrangement (1) according to Claim 3 , characterized in that the cast material is a GGG 60. Joint and / or bearing arrangement (1) according to one of the Claims 3 or 4th , characterized in that the nitriding depth, measured perpendicularly from said surface, is at least 0.15 millimeters. Joint and / or bearing arrangement (1) according to one of the Claims 1 to 5 , characterized in that the joint ball (5) facing surface of the joint and / or bearing shell (4) is polished. Joint and / or bearing arrangement (1) according to one of the preceding claims, characterized in that the joint and / or bearing shell (4) has a lower joint and / or bearing shell part (5) opposite a shaft (6) of a held joint ball (5). 7) and an upper bearing shell part (8) through which the shaft (6) extends. Joint and / or bearing arrangement (1) according to Claim 7 , characterized in that at least one pressure element (10) axially preloading the bearing shell parts (7; 8) against one another is provided. Joint and / or bearing arrangement (1) according to Claim 8 , characterized in that the pressure element (10) is a resilient and / or elastic ring body. Joint and / or bearing arrangement (1) according to one of the Claims 8 or 9 , characterized in that a sensor device (20) is provided for detecting the axial preload. Joint and / or bearing arrangement (1) according to one of the Claims 7 to 10 , characterized in that the upper bearing shell part (8) is held floating. Motor vehicle (15) with at least one joint and / or bearing arrangement (1) assigned to its chassis (14) according to one of the Claims 1 to 11 .

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