Protective ring, sealing arrangement and journal cross assembly

Abstract

A protective ring for a sealing arrangement of a bearing bushing of a journal cross assembly. The protective ring has an annular sleeve segment, which is concentric to a longitudinal axis, an annular seat segment which extends radially inward at a rear axial end of the sleeve segment, and at least one protrusion, which protrudes radially inward at a front axial end region of the sleeve segment. The protective ring also has a plurality of webs, which are distributed over the circumference and which protrude axially from the seat segment and are arranged inside the sleeve segment.

Claims

1. A sealing arrangement, comprising: a bearing bushing for a journal cross assembly of a universal joint, wherein the bearing bushing has a journal receptacle for receiving a journal of a journal cross; a seal, wherein at least a portion of the seal is disposed within the bearing bushing; a protective ring, which rests on an open end of the bearing bushing and has the following: an annular sleeve segment, formed concentrically to a longitudinal axis; an annular seat segment, extending at a rear axial end of the sleeve segment radially inwards; at least one protrusion, projecting at a front axial end portion of the sleeve segment radially inwards; a plurality of webs, arranged distributedly along the circumference projecting axially from the seat segment and arranged within the sleeve segment, wherein the bearing bushing is axially supported on the webs; a circumferential end face facing axially away from the seat segment, which end face is arranged on the front axial end portion of the sleeve segment; wherein adjacent to the end face of the protective ring in the transition between the end face and the at least one protrusion of the protective ring a concave recess is arranged ensuring a gap between the outer circumferential face of the bearing bushing and the inner circumferential face of the protective ring, avoiding capillary forces during a varnishing step of the journal cross assembly after the assembly of the protective ring on the bearing bushing; wherein the at least one protrusion of the protective ring rests in an outer circumferential groove in the outer circumferential face of the bearing bushing locking the protective ring therein; and a radial gap is formed between the bearing bushing and the sleeve segment of the protective ring.

2. The sealing arrangement according to claim 1, wherein the webs are respectively arranged in a transitional area between the sleeve segment and the seat segment.

3. The sealing arrangement according to claim 1, wherein a plurality of protrusions is arranged distributedly along the circumference.

4. The sealing arrangement according to claim 3, wherein in an inner circumferential face of the sleeve segment axially extending grooves are arranged, which separate the protrusions from each other.

5. The sealing arrangement according to claim 3, wherein the protrusions project differently far radially inwards along the circumference.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A preferred embodiment is described in detail in the following by using the Figures. Herein it shows

(2) FIG. 1 a half-sectional view of a universal joint shaft,

(3) FIG. 2 a perspective representation of the journal cross assembly of FIG. 1,

(4) FIG. 3 a first longitudinal sectional view through one of the journals of FIG. 2,

(5) FIG. 4 an enlarged representation of the protective ring according to the detail IV in FIG. 3,

(6) FIG. 5 a further longitudinal sectional view through a journal of FIG. 2,

(7) FIG. 6 an enlarged representation of the protective ring according to the detail VI in FIG. 5,

(8) FIG. 7 a perspective representation of the protective ring of FIG. 2,

(9) FIG. 8 a top view of the protective ring of FIG. 7,

(10) FIG. 9 the representation of the cross-sectional contour along the intersection line IX-IX of FIG. 8,

(11) FIG. 10 the representation of the cross-sectional contour along the intersection line X-X of FIG. 8,

(12) FIG. 11 the representation of the cross-sectional contour along the intersection line XI-XI of FIG. 8.

DETAILED DESCRIPTION TO THE DISCLOSURE

(13) FIG. 1 shows a universal joint shaft with the two universal joints 1, 1. Each of the universal joints 1, 1 has a first joint yoke 2, provided with a flange 3. Furthermore, a second joint yoke 4 is provided for each universal joint 1, 1. Both joint yokes 2, 4 are connected to each other by a journal cross assembly 5 such, that the first joint yoke 2 can carry out pivot movements around the longitudinal axis 8 and the assembly of the first joint yoke 2 and of the journal cross assembly 5 can carry out a pivot movement relative to the second joint yoke 4 around the second longitudinal axis 7. The journal cross assembly 5 comprises a journal cross 6 with four journals 17, to each of which one bearing arrangement is assigned, comprising a bearing bushing 9 received in the yoke bore 10 of the respective joint yoke 2, 4.

(14) On the second joint yoke 4, belonging to the joint 1, a tube 11 is rigidly connected. Latter carries a plunging sleeve 12, having a central bore and a wall with a splined toothing 13 with teeth extending parallel to an axis of rotation D of the universal joint shaft. In this, a sliding stubshaft 14, which has on the outside a splined toothing 15, is received in a longitudinally displaceable manner. The sliding stubshaft 14 is rigidly connected to the second joint yoke 4 of the universal joint 1. Thus, in the longitudinal displacement, which comprises the sliding stubshaft 14 and the plunging sleeve 12, length changes, which result from the change of the position of the universal joint shaft and thus the angulation at the two universal joints 1, 1 can be compensated. The longitudinal displacement is provided with a protective tube 16, which is fixed to the second joint yoke 4 of the universal joint 1 at one end and covers the outer surface of the plunging sleeve 12 and has at its other end a seal for sealing relative to this outer face. The two flanges 3 serve for connection to a driving or a driven part of a drive train, into which the universal joint shaft is incorporated.

(15) FIG. 2 shows a perspective representation of the journal cross assembly 5, as it is shown in FIG. 1. The journal cross assembly 5 comprises a journal cross 6 with a central base body 18, from which four journals 17 project, of which one is described exemplary with FIG. 2. Respectively two of the four journals 17 are arranged on a common longitudinal axis 7, 8 and are directed in opposite directions, wherein the two longitudinal axes 7, 8 intersect at a right angle each other.

(16) Onto the journals 17 a sealing arrangement with a bearing bushing 9 and a protective ring 19 is pushed. The protective ring 19 serves for sealing the bearing chamber or the journal receptacle within the bearing bushing 9 and/or serves for the protection of a main seal arranged in the bearing bushing 9.

(17) FIGS. 3 to 11 show the sealing arrangement and the protective ring 19 in different representations and are described in the following together.

(18) FIG. 3 shows a detail of the journal cross assembly 5 of FIG. 2 in a half-sectional view with an sectional plane, extending through the longitudinal axis 7. A part of the journal cross 6 with the journal 17 of FIG. 2 is shown. The journal 17 has an end face 20 and starting therefrom initially a cylindrical bearing surface 21 in direction towards the base body 18. Starting from the end face 20 a reservoir 22 for receiving lubricant is provided. Alternative to the reservoir 22, a lubricant channel can be provided, which is connected to lubricant channels of all journals 17 and to a lubricant nipple provided in the base body 18 for lubricating.

(19) To the cylindrical bearing face 21, a sealing face 23 is connected, which merges in direction towards the base body 18 in a seat face 24. The sealing face 23 serves as a sealing face for a seal 51 and which rests in the bearing bushing 9. The seal 51 is inserted into an open end 25 of the bearing bushing 9 and is held non-rotationally to the bearing bushing 9 and has sealing lips 52, held in abutment to the sealing face 23, wherein a relative movement is carried out between the sealing face 23 of the journal 17 and the sealing lips 52, when the joint is articulated and a rotational movement is produced between the bearing bushing 9 and the journal 17.

(20) The protective ring 19 is mounted and non-rotationally held on the seat face 24. For this, the protective ring 19 is oversized. This means, a central accommodation bore 26 of the protective ring 19 has an inner diameter, which is smaller than an outer diameter of the seat face 24. In FIGS. 3 to 6 the support ring 19 is shown not deformed, to illustrate the oversize.

(21) The bearing bushing 9 has a hollow cylindrical envelope 27, which has a cylindrical inner face 28 and a cylindrical outer face 29. The cylindrical outer face 29 serves for receiving the bearing bushing 9 in the yoke bore in the joint yoke. Furthermore, the bearing bushing 9 has a bottom 30 with a bottom inner face 31 facing to the open end 25 of the bearing bushing 9 and which covers the end face 20 of the journal 17. Between the inner face 28 of the bearing bushing 9 and the bearing face 21 of the journal 17 an annular gap is formed, in which a ring of rolling members 32 in form of needles or rollers is arranged. The rolling bearings 32 roll thus on the bearing face 21 of the journal 17 and on the inner face 28 of the envelope 27 and enable a rotational movement of the bearing bushing 9 relative to the journal 17 around the longitudinal axis 7.

(22) Towards the bottom 30 of the bearing bushing 9 the rolling members 32 are supported axially on a thrust washer 33, which is arranged between the bottom inner face 31 and the end face 20 and projects radially relative to the longitudinal axis 7 into the annular gap, in which the rolling members 32 are arranged.

(23) A movement of the rolling members 32 parallel to the longitudinal axis 7 away from the end face 20 in direction to the base body 18 is limited by a stop disc 34, which is pushed onto the journal 17 and is supported on a shoulder in the transition from the bearing face 21 to the sealing face 23 axially in direction to the base body 18. The stop disc 34 has internal axially extending grooves 35 (FIG. 4). These serve for transporting lubricant from the area of the annular gap, in which the rolling members 32 are arranged, in direction to the protective ring 19. Between the stop disc 34 and the protective ring 19 a main seal 51 is arranged, which, as already explained, is inserted into the open end 25 and is held non-rotationally there.

(24) The protective ring 19 has a sleeve segment 36, which is formed essentially cylindrically and coaxially to the longitudinal axis 7. The sleeve segment 36 encloses the outer face 29 of the envelope 27 of the bearing bushing 9 in the area of the open end 25. At a rear axial end, facing away from the bottom 30 of the bearing bushing 9 and facing the base body 18 of the journal cross 6, the protective ring 19 has an annular seat segment 37, formed approximately flange-like and which projects from the sleeve segment 36 radially inwards relative to the longitudinal axis 7. The seat segment 37 forms the accommodation bore 36, with which the protective ring 19 is arranged on the seat face 24 of the journal 17. The seat segment 37 covers an end face 38, directed to the base body 18, of the envelope 27 of the bearing bushing 9 and the annular gap between the envelope 27 of the bearing bushing 9 and the journal 17. Thus, a main seal 51, arranged between the protective ring 19 and the stop disc 34 is protected from external influences. Furthermore, the protective ring 19 has itself already a sealing effect and acts a preseal.

(25) The sleeve segment 36 has at a front axial end, facing away from the seat segment 37, protrusions 39, 40 facing radially inwards. The protrusions 39, 40 extend respectively along a portion of the circumference around the longitudinal axis 7 and are separated from each other by grooves 43, extending axially parallel to the longitudinal axis 7 and are arranged in an inner circumferential groove 44 of the sleeve segment 36.

(26) As especially visible in FIG. 8 and the cross-sectional representations of FIGS. 10 and 11, several first protrusions 39 and second protrusions 40 are arranged distributedly along the circumference, wherein the first protrusions 39 and the second protrusions 40 alternate. The first protrusions 39 project further from the inner circumferential face 44 radially inwards than the second protrusions 40. All protrusions 39, 40 serve for securing the protection ring 19 on the bearing bushing 9, insofar, as the protrusions 39, 40 engage in an outer circumferential groove 41 of the bearing bushing 9. During the assembly, the protection ring 19 is pushed in direction of the longitudinal axis 7 onto the open end 25 of the bearing bushing 9, wherein the protrusions 39, 40 abut a stop face 45 at the open end 25 of the bearing bushing 9. The stop face 45 is formed like a truncated cone, so that when pushing on the protection ring 19 the sleeve segment 36 is radially deformed outwards and expanded, till the protrusions 39, 40 snap into the outer circumferential face 41. Because of the lower second protrusions 40 or as these project to smaller extent radially inwards from the inner circumferential face 44, the deformation of the sleeve segment 36 is reduced during the mounting of the protection ring 19, without compromising the holding function.

(27) The protrusions 39, 40 arranged distributedly along the circumference can project with different extent radially inwards. Thus, all protrusions 39, 40 can engage in the outer circumferential groove of the bearing bushing 9 and can lock the protective ring 19 therein. Further, some of the protrusions 39, 40 can project with a smaller extension radially inwards, to facilitate the assembly of the protective ring 19 on the bearing bushing 9. During the pushing-on of the protective ring 19 onto the bearing bushing 9, namely the sleeve segment 36 is deformed radially outwards until the protrusions 39, 40 snap into the outer circumferential groove 41 of the bearing bushing 9. If some of the protrusions 39, 40 have a smaller radial extension inwards, the sleeve segment 36 does not have to be deformed so far as in an embodiment with protrusions 39, 40, which project all identically radially inwards.

(28) In the area of the front axial end of the sleeve segment 36, this has an end face 50, which is facing away from the seat segment 37. In the transition from the end face 50 to the protrusions 39, 40, concave recesses 46, 47 are formed. These form in the outer circumferential groove 41 respectively a gap 48, 49, by means of which it is prevented, that during the later varnishing of the journal cross assembly 5 capillary forces are produced, which pull varnish into the intermediate gap between the outer face 29 of the bearing bushing 9 and the inner circumferential face 44 of the sleeve segment 36. Generally, a radial gap 53 is provided between the bearing bushing 9 and the sleeve segment 36 of the protective ring 19, to enable a relative movement between the protective ring 19 connected rigidly to the journal 17 and the bearing bushing 9 held rotationally relative to the journal 17.

(29) The concave recess 46, 47 ensures a sufficient gap 48, 49 between the outer circumferential face of the bearing bushing and the inner circumferential face 44 of the protective ring 19. Thus, it is prevented, that during the varnishing process after the assembly of the protective ring 19 on the bearing bushing 9 capillary forces are produced, which pull the applied varnish into the radial gap 48, 49 between the sleeve segment 36 and the bearing bushing 9. This would lead to the fact, that, when the varnish is hardened, the protective ring 19 is connected rigidly to the bearing bushing 9. The support ring 19 should however rest non-rotationally on the journal 17 and a relative movement should be enabled between the protective ring 19 and the bearing bushing 9.

(30) Furthermore, the protective ring 19 has webs 42 arranged distributedly along the circumference and projecting from the seat segment 37 axially in direction to the longitudinal axis 7 and, at the same time, being integrally connected to the sleeve segment 36 projecting radially therefrom. The webs 42 are, thus, arranged in the transition between the sleeve segment 36 and the seat segment 37. In this case, the sleeve segment 36, the seat segment 37 as well as the webs 42 are formed integrally, i.e. as one piece. The protection ring 19 is supported via the webs 42 radially on the end face 38 of the bearing bushing 9. During the assembly of the bearing bushing 9, initially the thrust washer 33, the rolling members 32, the stop disc 34, a main seal 51, as well as the protection ring 19 are mounted in the bearing bushing. This unit is then pushed onto the journal 17 axially in direction of the longitudinal axis 7 towards the base body 18 onto the journal 17. As soon as the protection ring 19 has reached the seat face 24 of the journal 17, an increased axial force is produced for pushing-on the protection ring 17 with the accommodation bore 26 onto the portion of the journal 17 having a larger diameter, in the area of the seat face 24. In this case, the protection ring 19 is supported axially via the webs 42 on the bearing bushing 9.

(31) As the webs 42 are arranged distributedly along the circumference, lubricant can exit from the annular gap between the envelope 27 of the bearing bushing 9 and the bearing face 21 of the journal 17 between the webs 42 and through the radial gap 53 between the sleeve segment 36 and the envelope 27 in circumferential direction during the lubrication of the bearing.

REFERENCE NUMERALS LIST

(32) 1, 1 universal joint shaft

(33) 2 first joint yoke

(34) 3 flange

(35) 4 second joint yoke

(36) 5 journal cross assembly

(37) 6 journal cross

(38) 7 longitudinal axis

(39) 8 longitudinal axis

(40) 9 bearing bushing

(41) 10 yoke bore

(42) 11 tube

(43) 12 plunging sleeve

(44) 13 spline toothing

(45) 14 sliding stubshaft

(46) 15 spline toothing

(47) 16 protective tube

(48) 17 journal

(49) 18 base body

(50) 19 protective ring

(51) 20 end face

(52) 21 bearing surface

(53) 22 reservoir

(54) 23 sealing face

(55) 24 seat face

(56) 25 open end

(57) 26 accommodation bore

(58) 27 envelope

(59) 28 inner face

(60) 29 outer face

(61) 30 bottom

(62) 31 bottom inner face

(63) 32 rolling members

(64) 33 thrust washer

(65) 34 stop disc

(66) 35 groove

(67) 36 sleeve segment

(68) 37 seat segment

(69) 38 end face

(70) 39 first protrusion

(71) 40 second protrusion

(72) 41 outer circumferential groove

(73) 42 web

(74) 43 groove

(75) 44 inner circumferential face

(76) 45 stop face

(77) 46 recess

(78) 47 recess

(79) 48 gap

(80) 49 gap

(81) 50 end face

(82) 51 seal or main seal

(83) 52 sealing lips

(84) 53 radial gap

(85) D axis of rotation