GB2257773A

GB2257773A - Universal joint spider with interlocking seal

Info

Publication number: GB2257773A
Application number: GB9211998A
Authority: GB
Inventors: Brian J Thoele; Andrew M Madonia; Bret S Olson
Original assignee: Rockford Powertrain Inc
Current assignee: Rockford Powertrain Inc
Priority date: 1991-07-18
Filing date: 1992-06-05
Publication date: 1993-01-20
Also published as: GB9211998D0; ITMI921489A0; IT1259004B; ITMI921489A1; DE4222689A1; JPH05187454A

Description

2 23 77 7i UNIVERSAL JOINT SPIDER WITH INTERLOCKING SEAL The present

invention relates to a spider of the type used in the universal joint of an off-road vehicle or the like which operates under severe environmental conditions. Such a spider includes angularly spaced trunnions, bearing blocks, and needle bearings for rotatably journaling the trunnions in the bearing blocks.

If excessive wear is to be prevented, the bearings must be adequately lubricated and protected against contamination. An annular rubber seal typically is employed to retain lubricant in the bearing block and exclude contamination. Also, an outer dust shield usually is associated with the seal to prevent abrasive material from impinging on the seal.

Means must be provided to captivate the bearing blocks and the needle bearings axially on the spider during shipping and handling of the spider. In some prior arrangements, a wire is welded across the bearing blocks in order to hold the blocks on the trunnions.

Crane, Jr. et al United States Patent 4,810,233 discloses a seal and dust shield which coact to retain a bearing block axially on a trunnion. The patented combination, however, requires three components and, in addition to requiring a press fit between the seal and the bearing block, requires a press fit between the dust shield and the trunnion.

Summarv of the Invention The general aim of the present invention is to provide a sealldust shield combination which is capable of axially retaining a bearing block on the trunnion of a universal joint spider while requiring fewer components and while lending itself to easier assembly than prior arrangements of the same general type.

1 A more detailed object of the invention is to achieve the foregoing by providing a seal and a dust shield which are manufactured as a unitary assembly adapted to be assembled with the spider by press-fitting the dust shield into the bearing block and by slipping the seal into axially interlocking relation with the trunnion.

The invention also resides in the provision of a seal having a unique bead adapted to interlock with a circumferentially extending groove in the trunnion.

These and other objects and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

FIGURE 1 is an elevational view of a universal joint utilizing the present invention.

FIG. 2 is an elevational view, partially in crosssection of the spider for the universal joint.

FIG. 3 is an enlarged fragmentary cross-section taken axially through one of the trunnions and bearing blocks of the spider and showing the new and improved sealldust shield of the invention.

FIG. 4 is an enlarged fragmentary perspective view of the components shown in FIG. 3.

Detailed Description of the Preferred Embodiment

For purposes of illustration, the invention has been shown in the drawings in conjunction with a universal or cardan joint 10 interconnecting two rotatable shafts 11 and 12, one of which drives the other through the universal joint. The latter includes a pair of yokes 13 and 14 suitably secured to the ends of the shafts 11 and 12, respectively.

2 As shown in FIG. 2, a spider 15 includes a central cross member 16 having four equally spaced trunnions 17, on which are mounted four bearing assemblies 18; each bearing assembly comprising a bearing block 21 or 22 rotatably mounted on its associated trunnion 17 by a plurality of needle bearings 19. The yoke 13 is secured to a pair of oppositely disposed bearing blocks 21, 21 while the yoke 14 is secured to the other pair of blocks 22, 22 spaced 900 from the first pair.

In accordance with the present invention, lubricant is sealed in each bearing block 21, 22 and contaminants are excluded from the block by a two-component seal/dust shi,eld combination 25, 26 which also captivates the bearing block axially on the trunnion 17 during shipping and handling. The seal/dust shield combination not only is characterized by its relatively simple and low cost construction but also by the ease with which it may be assembled with the bearing block and the trunnion.

more specifically, the seal 25 is an annular member made of rubber or other elastomeric material and formed with inner and outer lips 27 and 28 for engaging the trunnion 17 near the base thereof in order to seal in lubricant. The dust shield 30 is a sleeve made of a suitable metal.

As shown in Fig. 3, the dust shield 26 is telescoped over and is bonded to the seal 25. Preferably, the dust shield is insert molded with the seal and thus becomes bonded to the seal as an incident to molding the seal. Flanges 30 and 31 at the inner and outer ends, respectively, of the seal extend outwardly across the ends of the dust shield to help hold the seal and the dust shield in unitary relation.

Pursuant to the invention, the dust shield 26 is sized to telescope with a tight press fit into a counterbore 33 (FIG. 3) formed in the bearing block 21, 22; the outer end of the seal engaging the axially facing end of the counterbore. Thus, the seal 25 and the dust shield 3 26 may be assembled as a unit with the bearing block simply by pressing the dust shield into the counterbore.

Further in carrying out the invention, the trunnion 17 and the seal 25 are formed with means which interlock axially with one another as an incident to slipping the seal onto the trunnion. Herein, these means comprise an annular groove 35 formed in and extending circumferentially around the base of the trunnion at a position located inwardly of the area where the lip 27 contacts the trunnion. Formed integrally with and extending around the inner side of the lower end portion of the seal is a bead 36 which projects radially inwardly into the groove. The bead is generally semi-circular in cross-section while the groove is curved on a somewhat larger radius. The diameter of the groove is somewhat larger than the diameter of the bead when the elastomeric material of the bead is in a relaxed condition and thus the bead is contracted around and resiliently grips the surface of the groove when the bead is received in the groove.

Assembly and installation are effected by placing the needle bearings 19 in the bearing block 21, 22 and press-fitting the dust shield 26 with the bonded seal 25 into the counterbore 33. Thereafter, the subassembly simply is slipped onto the trunnion 17. As an incident thereto, the bead flexes past an enlarged diameter shoulder 40 at the outer end of the groove 35 and then snaps into the groove upon clearing the shoulder. The bead interlocks with the groove and engages the shoulder to retain the bearing block 21, 22 axially on the trunnion during shipping of the spider 15 and prior to attachment of the yokes 13 and 14 to the spider.

From the foregoing, it will be apparent that the present invention brings to the art a new and improved universal joint 10 in which each bearing block 21, 22 is both sealed with respect to and is axially captivated on a trunnion 17 by a simple and compact two-component unit 4 consisting of a seal 25 and a dust shield 26. The ability to simply slip the bead 36 of the seal into interlocking relation with the groove 35 of the trunnion significantly simplifies assembly of the bearing block with the trunnion.

6

Claims

CLAIMS:

1. A universal joint spider having at least one trunnion with an outer side and having a bearing block rotatably journalled on said trunnion, and means for establishing a seal between said block and said trunnion while captivating the block axially on the trunnion, said means comprising a metallic sleeve telescoped into said block with a press fit, a sealing ring made of elastomeric material and secured within said sleeve whereby said sleeve and said sealing ring constitute a unitary assembly, said sealing ring having an inner side engaging the outer side of said trunnion to establish said seal, and coacting bead and groove means on the outer side of said trunnion and the inner side of said ring and interlocking with one another to captivate said block axially on said trunnion.

2. A universal joint spider as claimed in claim 1 in which said bead and groove means comprise an annular bead formed integrally with and projecting inwardly from the inner side of said sealing ring, and an annular groove formed in and extending circumferentially around the outer side of said trunnion and receiving said bead.

3. A universal-jOint spider as claimed in claims 1 or 2 in which said groove and said bead are of such diameters that said bead resiliently grips said trunnion when said bead is disposed in said groove.

4. A universal joint spider as claimed in claims 1, 2 or 3, further including annular flanges formed integrally with and projecting radially outwardly from 7 the ends of said ring and projecting across the ends of said sleeve.

5. 3 A universal joint spider as claimed in claims 1, 2, or 4, in which said sealing ring is bonded to said sleeve.