BEARING ARRANGEMENT FOR SUPPORTING A TRUNNION OF AN UNIVERSAL JOINT
A bearing arrangement for supporting a universal joint trunnion in an outer cup includes a radial bearing having cylindrical rolling elements disposed between the trunnion and the outer cup, and a resistance member made of a material to allow elastic deformation and bearing upon a confronting surface area of an end surface of the trunnion. The resistance member and the trunnion are hereby so configured either alone or in combination as to form a large lubricant reservoir. Disposed at a distance to the end surface of the trunnion is a stop member to define an axial gap, whereby the stop member inhibits an axial movement of the trunnion after the trunnion has moved in axial direction to close the gap.
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This application is a divisional of prior filed copending U.S. application Ser. No. 10/800,401, filed Mar. 12, 2004, the priority of which is hereby claimed under 35 U.S.C. §120 and which in turn is a continuation of prior filed PCT International application no. PCT/EP02/09054, filed Aug. 13, 2002, which designated the United States and on which priority is claimed under 35 U.S.C. §120 and which claims the priority of German Patent Application, Serial No. 101 45 536.4, filed Sep. 14, 2001, pursuant to 35 U.S.C. 119(a)-(d). The content of U.S. application Ser. No. 10/800,401 is incorporated herein by reference in its entirety as if fully set forth herein.
BACKGROUND OF THE INVENTIONThe present invention relates, in general, to a bearing arrangement, and more particularly to a bearing arrangement for supporting a trunnion of a Cardan type universal joint pr the like.
German utility model DE 73 02 217 G describes a bearing arrangement for universal joints, which includes an axial bearing having a closed washer which is made of plastic. The washer forms in the center a contact surface in a direction of the trunnion and has a collar disposed in concentric surrounding relationship to the contact surface and has a shorter length than the contact surface so that a gap is defined between the collar and the end surface of the trunnion. Between the central contact surface and the peripheral collar, the washer is provided on the trunnion-facing side with recesses for introduction of lubricant. The so-formed lubricant reservoir is thus limited between the central contact surface and the peripheral collar to a narrow annular gap which is capable of receiving only a very small amount of lubricant.
It would therefore be desirable and advantageous to provide an improved bearing arrangement for a universal joint to obviate prior art shortcomings and to realize a greater lubricant reservoir.
SUMMARY OF THE INVENTIONAccording to one aspect of the present invention, a bearing arrangement for supporting a universal joint trunnion in an outer cup includes a radial bearing having cylindrical rolling elements disposed between the trunnion and the cup, and an axial bearing having a resistance member provided with a central axial projection for support of an end surface of the trunnion and having an outer surface resting against a bottom wall of the cup, wherein the resistance member is formed with openings or recesses spaced partially about its circumference for defining spaces for lubricant alone or in combination with a configuration of the end surface of the trunnion, and wherein the resistance member is provided about its circumference with first stop members projecting axially toward the end surface of the trunnion and defined by a length which is shorter than a length of the axial projection as to define a gap between the stop members and a confronting portion of the end surface of the trunnion.
According to another aspect of the present invention, a bearing arrangement for supporting a universal joint trunnion in an outer cup includes a radial bearing having cylindrical rolling elements disposed between the trunnion and the cup, and an axial bearing having a resistance member disposed in concentric surrounding relationship to a central flange of the trunnion for support thereof and having an outer surface resting against a bottom wall of the cup, wherein the resistance member is formed with first stop members projecting axially toward the end surface of the trunnion and defined by a length which is shorter than a length of the flange as to define an axial gap between the stop members and a confronting portion of the end surface of the trunnion, and wherein the resistance member defines in combination with a configuration of the end surface of the trunnion spaces for introduction of lubricant.
The present invention resolves prior art problems by a novel and inventive configuration of the end surface of the trunnion and the use of an resistance member which is made, preferably, of elastic material. As a result, the space for receiving lubricant is increased within the cup. The resistance member is hereby provided with circumferentially spaced-apart openings, pockets or recesses which are formed continuously or unilaterally in the resistance member, and the trunnion is configured such as to significantly enlarge the space for introduction of lubricant. The resistance member defines a lubricant reservoir which extends axially from the end surface of the trunnion to at least the bottom wall of the cup and is bounded in radial direction by the central projection of the resistance member and partly by the inner wall of the cup. This configuration thus greatly increases the available lubricant volume so as to positively affect the service life of the cup.
The provision of stop members of shorter length compared to the central projection so as to define a gap between the trunnion and the stop members results in at least a two-phased, progressive support of the trunnion, when subjected to an increased axial force, and thus enables the bottom wall of the cup to transmit a greater axial force while the bottom wall of the cup can have a relatively small stiffness in the lower load range. The trunnion abuts at slight load in mid-section of the thin-walled and thus elastic bottom wall of the cup. As the load increases, the configuration of the resistance member enables a radial support in the peripheral and more rigid marginal zone of the end wall.
The resistance members may be guided on their outside directly upon the inner wall or a bottom wall portion of the cup. The resistance member may extend across the entire area of the bottom wall of the cup and cover the end surface of the trunnion at the same time, so that the trunnion is indirectly supported by the bottom wall of the cup. As an alternative, the resistance member may be supported directly upon the bottom wall of the cup, whereby the resistance member is disposed here in concentric surrounding relationship to a central, axial flange of the trunnion.
According to another feature of the present invention, the trunnion may have a bore in the end surface of the trunnion, with the axial projection being constructed for engagement in the bore of the trunnion. One option involves an engagement of the axial projection with clearance in the bore of the trunnion to thereby form a circular ring shaped space for use a lubricant reservoir. Another option involves a press-fitting engagement of the axial projection in the bore of the trunnion. It is also possible to configure the end surface of the trunnion in a stepped shape, whereby the axial projection of the resistance member is press-fitted in the stepped bore with smallest diameter. This construction simplifies assembly as the resistance member is held captive on the trunnion.
According to another feature of the present invention, the resistance member allows a two-step support of the trunnion upon the bottom wall, when the trunnion is acted upon by an axial force. Suitably, the resistance member may have second stop members disposed in alternating relationship to the first stop members, whereby the first and second stop members have different lengths. In this way, the trunnion can be borne by a three-phased support upon the resistance member and the bottom wall of the cup in dependence on the applied axial force of the trunnion. This construction subjects the bottom wall of the cup to less stress thereby increasing the service life of the cup.
The resistance member can be guided and centered on the inner wall of the cup. This configuration allows the resistance member to form an axial stop for the rolling elements.
According to another feature of the present invention, the bottom wall of the cup may be made without material removal with a gradation which ends in an axial surface area of a size that corresponds to a size of a surface area of the confronting axial projection. The gradation, resembling a crimp, improves the stiffness and thus the strength of the bottom wall which thus lasts longer without changing the wall thickness.
According to another feature of the present invention, the bottom wall of the cup has a side distal to the end surface of the trunnion, whereby this side of the bottom wall may be formed with a stepped configuration. The resistance member can hereby be centered at the step where the bottom wall is of smallest diameter, whereby the axial projection of the resistance member has an axial length which is greater than a vertical dimension of the step so as to provide a support surface for the trunnion. In addition, the axial projection is arranged so that a gap is established between the end surface of the trunnion and a step of the bottom wall. This construction results in a stepped support of the trunnion in dependence on the applied axial force.
Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.
Turning now to the drawing, and in particular to
The bearing arrangement includes a radial bearing, generally designated by reference numeral 3 and having a plurality of cylindrical rolling elements 7 which are disposed in an annular gap 6 as bounded by a wall 5 of the outer cup 2 and an outer surface area 6 of the trunnion 1. In addition, the bearing arrangement includes a thrust bearing, generally designated by reference numeral 8 and including a substantially disk-shaped resistance member 10 which rests flatly against a bottom wall 9 of the cup 2 and is centered by the wall 5 of the cup 2. The resistance member 10 is formed with a central axial projection 11 which is received in a bore 12 of the trunnion 1. The trunnion 1 has here a substantially U-shaped end configuration with an axially recessed base 14 and an end surface 13, with the axial projection 11 abutting against an end surface 19 of the base 14. The bore 12 has a diameter which is greater than a diameter of the projection 11 so that an enclosing ring space 15 is formed.
About its periphery, the resistance member 10 has a collar 16 which extends in the direction of the rolling elements 7 to provide an axial stop for the rolling elements 7. The collar 16 further demarcates a ring-shaped recess 17 which is established between the projection 11 and the collar 16.
As further indicated by a dashed line, plural stop members 18 (only one is shown here) extend radially inwardly from the collar 16 in spaced-apart relation about the circumference of the collar 16. The stop members 18 are sized such that a gap s is defined between the end surface 13 of the trunnion 1 and the stop member 18, when the bearing arrangement is assembled. The gap s allows an indexed support of the trunnion 1 in the outer cup 2. In other words, when the trunnion 1 is exposed to an axial force in the direction of arrow A, an elastic deformation of the projection 11 takes place first as a result of the abutting relationship between the projection 11 and the trunnion 1. After moving in axial direction far enough to close the gap s, the trunnion 1 abuts with its end surface 13 against the stop members 18 of the resistance member 10. Thus, the bottom wall 9 is not exposed to an inadmissible excessive central load and the trunnion 1 is supported across a greater area by the bottom wall 9 of the cup 2. The ring space 15 in the trunnion 1 and the recess 17 in the resistance member 10 define together spaces or chambers that can be utilized as lubricant reservoirs. The size of these spaces can be large enough to eliminate the need for re-lubrication of the cup 2. In other words, a maintenance-free outer cup 2 can be implemented.
While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein:
Claims
1. A bearing arrangement for supporting a universal joint trunnion in an outer cup, comprising:
- a radial bearing having cylindrical rolling elements disposed between the trunnion and the cup; and
- an axial bearing having a resistance member disposed in concentric surrounding relationship to a central flange of the trunnion for support thereof and having an outer surface resting against a bottom wall of the cup, wherein the resistance member is formed with first stop members projecting axially toward the end surface of the trunnion and defined by a length which is shorter than a length of the flange as to define an axial gap between the stop members and a confronting portion of the end surface of the trunnion, and wherein the resistance member defines in combination with a configuration of the end surface of the trunnion spaces for introduction of lubricant.
2. The bearing arrangement of claim 1, wherein the resistance member of the axial bearing is constructed to allow a multi-stepped support of the trunnion, when the trunnion is acted upon by an axial force.
3. The bearing arrangement of claim 1, wherein the resistance member forms an axial stop for the rolling elements.
4. The bearing arrangement of claim 1, wherein the bottom wall of the cup is formed without material removal with a gradation which ends in an axial surface area of a size that corresponds to a size of a surface area of the confronting axial projection.
5. In combination:
- a universal joint having a trunnion; and
- a bearing arrangement for supporting the trunnion, said bearing arrangement comprising;
- an outer cup disposed in surrounding relationship of the trunnion;
- a radial bearing having cylindrical rolling elements disposed between the trunnion and the outer cup; and
- a resistance member made of a material to allow elastic deformation and bearing upon a confronting surface area of an end surface of the trunnion, and
- a stop member maintaining an axial distance of the end surface of the trunnion in relation to the resistance member to thereby form part of a lubricant reservoir and defining an axial gap with the end surface of the trunnion, said stop member inhibiting an axial movement of the trunnion after the trunnion has moved in axial direction to close the gap.
6. The combination of claim 5, wherein the end surface of the trunnion has a substantially U-shaped configuration to define a base, said resistance member having an end wall, which abuts against a bottom wall of the outer cup, and including a central portion to rest against the confronting surface area of the base to thereby demarcate a space forming another part of the lubricant reservoir.
7. The combination of claim 6, wherein the resistance member has a collar in a peripheral area of the resistance member for abutment against the rolling elements.
8. The combination of claim 7, wherein the stop member extends radially inwardly from the collar.
9. The combination of claim 5, wherein the end surface of the trunnion has a beveled edge.
10. The combination of claim 5, wherein the end surface of the trunnion has a substantially U-shaped configuration to define a base, said outer cup having a gradation, said resistance member having an end wall, which abuts against a bottom wall of the outer cup, and including a central portion press-fitted into the confronting surface area of the trunnion and bearing upon the gradation of the outer cup to thereby demarcate a space forming another part of the lubricant reservoir.
11. The combination of claim 7, wherein the collar and the central portion are separate parts.
12. The combination of claim 5, wherein the end surface of the trunnion has a cylindrical configuration.
13. The combination of claim 12, wherein the outer cup has a bottom wall which is formed at a peripheral area with a first step to provide the stop member, said resistance member having an end wall, which abuts against a bottom wall of the outer cup, and including a central portion to rest against the confronting surface area of the end surface of the trunnion, said collar and said first step demarcating the lubricant reservoir.
14. The combination of claim 13, wherein the bottom wall of the outer cup is formed with a second step which bears upon the rolling elements.
15. The combination of claim 12, wherein the trunnion includes a flange projecting in axial direction from the end surface, said outer cup being formed with a gradation which ends in an axial surface area of a size that corresponds to a size of a surface area of the flange, said resistance member having an end wall, which abuts against a bottom wall of the outer cup, and is formed with a collar bearing upon the rolling elements, said collar and said flange demarcating the lubricant reservoir, said stop member extending radially inwardly from the collar.
16. The combination of claim 12, wherein the trunnion includes a flange projecting in axial direction from the end surface, said resistance member having an end wall, which abuts against a bottom wall of the outer cup, and including a central portion bearing upon the confronting surface area of the flange, and a collar disposed in a peripheral area of the resistance member and bearing upon the rolling elements, said collar and said flange demarcating the lubricant reservoir, said stop member including a first stop extending radially inwardly from the collar, and a second stop connected to a cup-distal side of the end wall of the disk in an area between the first stop and the central portion.
17. The combination of claim 16, wherein the first and second stops have a different axial length.
Type: Application
Filed: Jan 10, 2007
Publication Date: May 8, 2008
Applicant: INA-SCHAEFFLER KG (Herzogenaurach)
Inventor: Martin Kruppa (Herzogenaurach)
Application Number: 11/621,774
International Classification: F16D 3/16 (20060101); F16C 21/00 (20060101);