HIGH-PERFORMANCE BALL SOCKET
A bearing shell for a ball and socket joint made of plastic as well as the ball and socket joint per se, wherein the bearing shell has first areas, which are subject to higher mechanical loads than the other areas of the bearing shell, wherein the material of the bearing shell forming the first areas is formed from a reinforced plastic, and the other areas are made of a less reinforced or unreinforced plastic.
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This application is a divisional under 37 CFR 1.53(b) of pending prior application Ser. No. 10/895,122 filed Jul. 20, 2004 and claims the benefit (35 U.S.C. § 120 and 365(c)) of International Application PCT/DE 2003/002387 of Jul. 16, 2003, which designated inter alia the United States and which claims the priority of German Application DE 102 33 489.7 of Jul. 24, 2002. The entire contents of each application is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTIONThe present invention pertains to a bearing shell made of plastic for a ball and socket joint, especially for motor vehicles as well as to the ball and socket joint per se.
BACKGROUND OF THE INVENTIONA bearing shell of this class for ball and socket joints, especially for motor vehicles, is known from DE 29722507 U1. DE 29722507 U1 discloses a bearing shell, which has slots for elastic deflection during the mounting of a joint ball in the bearing shell, the slots extend essentially in the direction of the central axis of the bearing shell. The inner walls of the bearing shell have groove-like depressions, which are used as grease depots for lubricating the ball and socket joint. Spacer nubs are provided on the outer walls of the bearing shell, which preset the position of the bearing shell in the ball and socket joint housing. The spacer nubs generate a pretension, however slight, after insertion into the ball and socket joint housing due to the additional material, which presses the bearing shell against the joint ball due to being supported on the ball and socket joint housing. Pretensioning of the bearing shell in certain areas is definitely desirable, because this makes it possible for the joint ball not to be lifted off from parts of the bearing shell even under load, so that the entire contact surface is available for the transmission of torques in the joint. However, the pretension brought about by the spacer nubs on the outer sides of the bearing shell acts on the entire bearing shell or the mounted joint ball and consequently also in areas in which such a pretension counteracts the actual task of the ball and socket joint, or leads to increased wear in certain areas, and thus shortens the service life of the ball and socket joint. At the same time, the space needed for installation is increased.
DE 19932789 A1 discloses a ball and socket joint in which the joint ball is enclosed in a manner adapted to the direction of the load to increase the transmission of forces without requiring a larger space for installation. The areas of the joint ball that are loaded more heavily due to the direction of the force, surround the bearing shell more than the less heavily loaded areas. However, the bearing shell must be lengthened in this embodiment to mount the joint ball in the bearing shell, which is equivalent to a great mounting effort as well as a high load on the material, which may lead to rupture of the bearing shell.
The bearing shells according to DE 19932789 A1 as well as DE 29722507 U1 are made homogeneously from a plastic by injection molding. This design leads in practice to the problem that if an inexpensive plastic is used, it is tribologically well suited in the unreinforced form but does not have sufficient strength, or it has good strength properties due to fiber reinforcement. Good strength properties are, however, equivalent to a loss of the tribological properties in case of inexpensive plastics. Pretensioning of the bearing shell to achieve better transmission of forces also cannot be achieved with these plastics because of the lack of flexibility.
SUMMARY OF THE INVENTIONThe object of the present invention is therefore to provide a bearing shell and a ball and socket joint having a bearing shell that have an increased service life due to their design.
This object is accomplished according to the present invention with a bearing shell having first areas, which are subject to higher mechanical loads than the other areas of the bearing shell, wherein the material of the bearing shell forming the first areas is made of a reinforced plastic, and the other areas are made of a less reinforced or unreinforced plastic.
Depending on the field of use of the ball bearing, the ball bearing according to the present invention and consequently also the bearing shell according to the present invention can be loaded more strongly either radially or also axially. Under a radial or axial load, the area of the bearing shell in which the joint ball is in contact because of the load (loading area) is compressed by the joint ball in the direction of the load.
If the bearing shell yields, the joint ball likewise moves in the loading direction by the amount by which the bearing shell yields. As a result, the joint ball can lift off from the area located opposite the loaded area of the bearing shell (opposite means here in a direction opposite the direction of load). The areas of the bearing shell that are loaded less heavily are therefore made according to the present invention from an unreinforced or less reinforced plastic. Due to the resulting increase in the flexibility of the plastic, the bearing shell is pretensioned during the mounting, as a result of which the joint ball cannot lift off from the bearing shell any longer, so that all contact surfaces of the bearing shell are in contact for transmitting forces even under a heavy load. At the same time, the risk of free clearance of the joint ball in the bearing shell, which may lead to deflection and consequently to failure of the joint, is reduced at the same time due to the pretensioning of the bearing shell, which is thus achieved. Areas that are exposed to higher loads have according to the present invention a reinforced core, which counteracts the deformation and wear occurring under load and thus reduces the amount by which the joint ball sinks under heavy load due to the compression of the plastic. A bearing shell thus designed makes it advantageously possible to design the bearing shell with a large contact surface in one piece and at the same time to make it from a highly fiber-reinforced material.
Another advantageous embodiment is obtained by means of a bearing shell that is additionally provided with webs and slots. Due to the advantageous arrangement of webs and slots on the bearing shell, the tolerance compensation achieved by the pretension can be additionally supported by the pretension being able to be coordinated even more accurately with the type of the stress. In addition, webs and slots make possible simple mounting without great stress of the reinforced, and consequently less expandable areas, due to a defined elastic expansion of the bearing shell. The risk of rupture of the bearing shell due to excessive expansion of the unelastic areas is thus advantageously reduced.
The bearing shell according to the present invention advantageously has reinforced, and unreinforced or less reinforced areas. The reinforced areas being manufactured, e.g., by means of a multicomponent system. The multicomponent system is composed of reinforced plastics, and less reinforced and/or unreinforced plastics. The reinforced area comprises a core component and a jacket component. Due to corresponding additives, e.g., fibers, mica, minerals, fillers or beads, the core component forms the reinforcement, whose degree of reinforcement can be set variably by varying the type and the amount of the reinforcing additives used. The jacket component is formed by a tribologically suitable plastic. It surrounds the core component in the sections in which there may be increased risk for wear due to friction effects because of corresponding reinforcing additives, e.g., between the core component and the joint ball, and the susceptibility to wear of the ball and socket joint thus decreases. The material costs can be lowered due to the use of the above-described plastics and the bearing shell can thus be manufactured at a lower cost.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings,
The bearing shell according to
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
Claims
1. A bearing shell for a ball and socket joint, the bearing shell comprising:
- a first and a second area made of plastic, said first area being made of a reinforced plastic more reinforced than a plastic of said second area.
2. A bearing shell in accordance with claim 1, wherein said bearing shell has a one-part design.
3. A bearing shell in accordance with claim 1, wherein one part of the bearing shell is a basic body and has a reinforcing core in areas in which higher loads occur and is reinforced less or is unreinforced in other areas.
4. A bearing shell in accordance with claim 3, wherein another part of the bearing shell is a bearing shell part and is shaped to surround a joint ball, said bearing shell part being fastened to said basic body.
5. A bearing shell in accordance with claim 3, wherein said bearing shell part is made in one piece with said basic body.
6. A bearing shell in accordance with claim 5, wherein said bearing shell part is connected with said basic body of the bearing shell via at least one web which is especially elastic.
7. A bearing shell in accordance with claim 5, wherein said bearing shell part has a reinforcing core in areas in which high loads occur on the contact surfaces, and other areas of said bearing shell part are less reinforced or unreinforced.
8. A bearing shell in accordance with claim 5, wherein said bearing shell part defines openings shaped to facilitate elastic expansion of the bearing shell during mounting.
9. A bearing shell for a ball and socket joint, the bearing shell comprising:
- a first bearing shell section;
- a second bearing shell section having a reinforcing core and a jacket component completely jacketing the entire outer surface of said core, said core being composed of a first plastic material uniformly reinforced with one of fibers, mica, minerals or beads, said jacket component being composed of a second plastic material either unreinforced or reinforced with one of fibers, mica, minerals or beads, said first material being more reinforced than said second material, said first bearing shell section being connected to said second bearing shell section to form an integral bearing shell structure for receiving a joint ball of the ball and socket joint.
10. A bearing shell in accordance with claim 9, further comprising:
- an elastic web;
- a basic body element integrally connected to said bearing shell structure via said elastic web, said basic body having a basic body reinforcing core in areas in which higher loads occur, said basic body being reinforced less or unreinforced in other areas.
11. A bearing shell in accordance with claim 10, wherein said basic body has a basic body jacket component completely jacketing the outer surface of said basic body reinforcing core, said basic body reinforcing core being composed of a first basic body plastic material uniformly reinforced with one of fibers, mica, minerals or beads, said basic body jacket component being composed of a second basic body plastic material either unreinforced or reinforced with one of fibers, mica, minerals or beads, said first basic body material being more reinforced than said second basic body material.
12. A bearing shell in accordance with claim 9, wherein said integral bearing shell structure defines one of a slot and a web, said web including an elastic plastic, said web and said slot making possible one of axial and radial elastic expansion of said integral bearing shell structure during mounting as well as pretensioning and/or tolerance compensation of said integral bearing shell structure.
13. A bearing shell in accordance with claim 11, wherein said first basic body plastic material is the same as said first plastic material of said second bearing shell section and said second basic body plastic material is the same as said second plastic material of said second bearing shell section.
14. A bearing shell for a ball and socket joint, the bearing shell comprising:
- a first bearing shell section;
- a second bearing shell section having a reinforcing core and a jacket component completely jacketing the entire outer surface of said core, said core being composed of a first plastic material uniformly reinforced with one of fibers, mica, minerals or beads, said jacket component being composed of a second plastic material either unreinforced or reinforced with one of fibers, mica, minerals or beads, said first material being more reinforced than said second material, said first bearing shell section being integrally connected to said second bearing shell section to form an integral bearing shell part, said bearing shell part defining an opening for receiving a joint ball of the ball and socket joint;
- a connection element;
- a basic body element integrally connected to said bearing shell part via said connection element.
15. A bearing shell in accordance with claim 14, wherein said basic body has a first section and a second section, said first section having a basic body reinforcing core and a basic body jacket component completely covering the outer surface of said basic body reinforcing core, said basic body reinforcing core being composed of a first basic body plastic material uniformly reinforced with one of fibers, mica, minerals or beads, said basic body jacket component being composed of a second basic body plastic material either unreinforced or reinforced with one of fibers, mica, minerals or beads, said first basic body material being more reinforced than said second basic body material.
16. A bearing shell in accordance with claim 14, wherein said bearing shell part defines a slot, said connection element being composed of an elastic plastic, said connection element and said slot making possible one of axial and radial elastic expansion of said integral bearing shell structure during mounting as well as pretensioning and/or tolerance compensation of said integral bearing shell structure.
17. A bearing shell in accordance with claim 15, wherein said first basic body plastic material is the same as said first plastic material of said second bearing shell section and said second basic body plastic material is the same as said second plastic material of said second bearing shell section.
Type: Application
Filed: Nov 9, 2007
Publication Date: Mar 13, 2008
Applicant:
Inventor: Frank BUDDE (Damme)
Application Number: 11/937,656
International Classification: F16C 11/06 (20060101);