AU603948B2 - Bearing device for an axle of a vehicle - Google Patents

Description

~L o s. (4 8 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION NAME ADDRESS OF APPLICANT: Koyo Seiko Co., Ltd 2, Unagidani Nishino-cho, Minami-ku Osaka-shi Osaka-fu Japan p S NAME(S) OF INVENTOR(S): Tooru MIYOSHI I. his document oins the 49and e under ian d is correct for lilt in ADDRESS FOR SERVICE:

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DAVIES COLLISON Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: Bearing device for an axle of a vehicle The following statement is a full description of this invention, including the best method of performing it known to me/us:- 1A- 00 .0 0e 0 0o a 0 00 00 00 a 00 00o 0 0o a* o o oe 0 0 4, The present invention relates to a bearing device for an axle of a vehicle which seals the inside of a bearing.

According to a conventional bearing device for an axle of a vehicle of the present type as shown in Fig. 2, a double-row roller bearing which is provided between a backing ring 51 fit on a shoulder 70a that is a radiused portion of an axle 70, and a end cap 53 affixed at multiple 1 locations by bolts 52 in the axial direction at an end of the axLe 70 is sealed by seal members 60, 60 and a pair of seal retaining rings 57, 58 for retaining the seal members 60, 60 with the object of preventing water and dust from the outside from penetrating to the inside of the 1 double-row roller bearing 55. The seal retaining rings 57, 58 are provided on both sides in the axial direction of and tight to outer ring 56 of the double-row roller bearing and the seal members 60, 60 are fusion-bonded to respective seal retaining portions 57a, 58a of the pair of seal retain- 20 ing rings 57, 58. The seal membersg.0, 60 have dust seals and lips 60a forced to the inside in the radial direction by springs 59 in sliding contact with outer peripheral surfaces 54a of sleeves 54 provided on both sides of the double-row roller bearing 25 However, when this conventional bearing dev3ce is used on vehicles driven in atypical regions, including areas

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-2" characterised by heavy precipitation or desert regions having much dust and sand, then water, sand, and other foreign matter may penetrate the aforementioned doublerow roller bearing through the route indicated by an arrow in the figure because the sealing of the said conventional bearing device is done only by the seal members 60, 60 each having the one lip 60a and one dust seal 60b between the seal retaining portions 57a, 58a of the seal retaining rings 57, 58 and the sleeves 54. This results in improper lubrication at a rolling contact portion of said bearing and thus in damage to the rollers and raceway surface, and as a result inhibits the maintenance of a long service life of the bearing device.

Therefore, a preferred object of the present invention is to provide a bearing device for an axle of a vehicle with excellent seal characteristics and to which, ooo0 even when used in atypical regions, including areas o characterised by heavy precipitation or desert regions "ao 0 having much dust and sand, foreign matter such as water o O* 20 and sand do not penetrate, and which can therefore maintain a long service life.

According to the present invention there is provided a bearing device for an axle of a vehicle which ,o00 comprises: 25 a backing ring fitted over a step portion of an axle a aO o of a vehicle and having an annular groove on an end «a surface thereof; S* A" an end cap provided on an end of the axle and having an annular groove on an end surface thereof, this end S 30 surface being opposite to the end surface of the backing t s C ring; t t a pair of sleeves fitted to the end cap and backing ring; a double-row roller bearing fitted over the axle between the end cap and backing ring by way of the pair of sleeves; a pair of seal retaining rings affixed on both sides -3in the axial direction of an outer ring of the double-row roller bearing and located between the double-row roller bearing and the end cap and between the double-row roller bearing and the backing ring; and a pair of seal members affixed to respective seal retaining portions of the seal retaining rings in such a manner as to seal the double-row roller bearing in cooperation with the seal retaining rings, wherein a surface defining an outer side in the radial direction of each of said annular grooves forms a cylindrical surface, and each of the seal members has a main lip which slides in contact with an outer peripheral surface of the sleeve, and a complementary lip which generally projects in a radial direction of the sleeve and is inclined so as to extend toward the double-row *roller bearing, the ends of the complementary lips of the seal members slide in contact with the cylindrical surfaces of the annular grooves in the backing ring and 0e f the end cap, respectively.

A bearing device according to one embodiment of the present invention operates as follows.

i a cc 1 LLI~I~ -4- 0 0 0 0 0000 00 0 00 4 a D 04 When the axle turns, the backing ring, end cap, the pair of sleeves, and an inner ring of the double-row roller bearing turn together. On the other hand, the outer ring of the double-row roller bearing, the pair of seal retaining rings affixed on both sides of the outer ring, and each of the seal members provided at the seal retaining portion of said seal retaining ring are stationary. The main lips of the seal members slide in contact with the outer circumference of said sleeves while the complementary 0 lips slide in contact with the cylindrical surface of the annular grooves of the backing ring and end cap. Thus, the double-row tapered roller bearing seals the space between the seal retaining portion of said pair of seal retaining rings and the outside circumference of the sleeve by means 15 of the main lip portion of the seal member on either side, and moreover seals the space, which corresponds to the upstream side of a penetration path for water and other foreign matter, between the seal retaining portion of said pair of seal retaining rings and the cylindrical surface of 20 said backing ring and end cap, and thus completely seals the inside of the double-row tapered roller bearing during a rotation of the axle; thus, water, sand or dust does not penetrate the inside of the double-row tapered roller bearing even when used in special regions, including regions with extremely heavy precipitation or desert regions in 0004 4o 0 to 4 0 04 41

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a oo 0 0 0 00 0000 0 0000 00 6 0 0 0 0 o 00 00 00 a *O 00 0 a 0 0000 0 0 0 00 0 0 0 which there is much sand, dust and water, and there is no decrease in the life of the bearing.

The complementary lips of said seal members are housed inside the annular grooves provided on the backing ring and end cap, respectively. Thus, the dimension in the axial direction of this bearing device can be made short and small.

Furthermore, due to a direction of the slope of complementary lips that approaches the double-row roller 0 bearing, when the bearing device is being assembled the assembly proceeds more smoothlyp and there is no inversion or reversing of the complementary lips during assembly.

Furthermore, because the complementary lips are adapted to be in contact with the cylindrical surface of a 15 certain width of the annular grooves provided on the end cap and backing ring, even if assembly error in the axial direction occurs during assembly of the bearing device, a positive seal can be constantly assured irrespective of assembly error.

20 Furthermore, because an annular gutter-like channel is formed by a circumferential surface including the cylindrical surface of the the backing ring and the end cap, a face of the complementary lip on the double-row tapered roller bearing side, and the side of the seal retaining ring, water from the outside, including rain water, is conducted along said channel and flows out below. Thus, oa 0 0 00 00 00 0 0 0 -6water does not collect inside said channel or in the proximity of said complementary lip.

An embodiment of the invention will now be described, by way of example only with reference to the accompanying drawings in which:- Fig. 1 is a vertical cross section of a preferred embodiment of a bearing device for an axle of a vehicle according to the present invention; and Fig. 2 is a vertical cross section of a prior art bearing device for an axle of a vehicle.

In Fig. 1, reference number 1 is an axle which has a shoulder or a step portion 4 having a radiused surface between large diameter part 2 and small diameter part 3 of axle 1. To shoulder 4 is fitted an annular backing ring 10, the inner circumference surface of which is t* formed of a radiused surface 11 flush with the radius S' face of said shoulder 4, a tapered surface 12, the cross sectioni of which is wider at the bottom than at the top St: 4 in a manner similar to the base of a cone opening in the i direction of large diameter part 2, and a cylindrical S* surface 13, with said radiused surface 11 in contact with the radiused surface of et o 94 9 c Qocc 0 00 900824,gnspe.003,ky32348spe,6 c 7 i- 7 the aforementioned shoulder 4. Thus, a ring-shaped space which in cross section has a wedge shape is formed between this tapered surface 12 and cylindrical surface 13 and radiused surface of shoulder 4 of the axle 1. The backing ring 10 is provided with an annular groove or channel 17 of a spec.fied depth and having a cylindrical face 16 of a specified diameter on the outer side in the radial direction at its end face 14. This channel 17 is n comprised of said cylindrical face 16, chamfer 18 provided o oo 0 oao i0 between cylindrical face 16 and end face 14, bottom 19 0000 00 o0 continuing from cylindrical face 16, circumference face o o0 o°o on the inside in the radial direction at a specified dis- 00, o tance from and in opposition to said cylindrical face 16, o 0 and end face 21 continuing from circumference face 0 oo 15 parallel to end face 14 and at a specified distance in the 00 o o°00 o axial direction from end face 14. The end face 21 has an annular fitting portion 22 of a rectangular cross section 0 open to cylindrical surface 13 on the inside in the radial direction of end face 21. Grease supply holes 24 penetrata0.,'o 20 ing in the radial direction are provided at specific posi- 00 IC Stions through the backing ring 10, and communicate outer circumference face 23 to space 25a formed on the side of tapered surface 12.

To fitting portion 22 is fit an end portion of a ring-shaped sleeve 26 having in cross section a simplified J-shape. The other end portion of the ring-shaped sleeve 26 7 8 is fit tightly to small diameter part 3 of axle 1. The inside diameter of this sleeve at a cylindrical portion thereof is larger by a specific dimension than the diameter of small diameter part 3 of axle 1, and thus a cylindrically shaped space 25b is formed between sleeve 26 and small diameter part 3 of axle 1. Sleeve 26 is provided with holes 26e open in the radial direction to the space 25b at specific positions in the circumferential direction. Thus, grease o o 1 supplied from grease supply holes 24 passes through space 0 00 0ooo 0 25a, space 25b, and holes 26e, and is supplied to double- O0 0000 o00 0 row tapered roller bearing 34 to be described hereinafter.

ao0 0 Double-row tapered roller bearing 34 is located 0 o00 0 of 0 adjacently to sleeve 26 and comprised of paired inner rings a t 28, 29 comprised of raceways 28a, 29a and arrayed symmetrio 0 15 cally to each other and fit over small diameter part 3 of 00 4 o0*, axle 1, inner ring spacer 30 similarly fit over small 0O diameter part 3 and positioned between the paired inner rings 28, 29, outer ring 31 comprised of a pair of raceways 31a, 31b on an inside circumference, tapered rollers 32, 32 ^se 20 arrayed at even intervals in two series in the circumferenec S' tial direction between raceways 28a, 31a and raceways 29a, 31b, and cages 33, 33 retaining said tapered rollers 32, S2 at even intervals.

The end of said sleeve 26 is in contact with one end 28b of inner ring 28. In addition, one end 29b of the 9 0 00f 00 0O 0 00 0006 0 0000 Or oO OS t 0 t 0 C 0 00 t t B t e tc i: iT 1 other inner ring 29 is in contact with another sleeve 35 of the same shape and dimension as said sleeve 26.

Double-row tapered roller bearing 34 is mounted to axle 1 by sandwiching backing ring 10, sleeve 26, inner ring 28, inner ring spacer 30, inner ring 29, and the other sleeve 35 between shoulder 4 of axle 1 and fitting portion 36 of end cap 37 which has in section a simplified U-shape and includes annular groove or channel 17 and fitting portion 36 having a rectangular shape in cross section, 10 these annular channel 17 and fitting portion 36 being paired with annular channel 17 and fitting portion 22 of backing ring 10. Said end cap 37 has the same cross sectional configuration as backing ring 10 at a portion on the side of double-row tapered roller bearing 34. This sandwich mount 15 is accomplished by means of bolts 38 passed through bolt holes 37b provided in the axial direction at three specified locations in bottom 37a of the end cap, and threaded into screw holes in axle end 5 of axle 1 provided in the axial direction at positions corresponding to the aforementionad 2 positions of bolts 38.

When end cap 37 is bolted into position, there is a gap of a specific dimension between bottom 37a thereof and axle end 5, thus forming space 39. Said space 39 is open to space 25b between sleeve 35 and small diameter part 3 of axle 1, and to holes 35e of sleeve 35, thus forming a passage for grease supplied from a grease supply hole not CCCrl 1 fr r G I

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00 00 ao o0 oo 0 0 o o 00 0 0 0 0 0 00 00 0 0 04 00 4 0 0 Sa t p 0C 0 4C 0 a 4 shown in the figure and provided in end cap 37. Said outer ring 31 is mounted to a chassis of a vehicle (not shown) by means of adapter A.

At both end portions of the inside circumference of outer ring 31 are provided mounting portions 40. Each of mounting portions 40 is comprised of smooth cylindrical face and channel 40b of a specific dimension and configuration and provided at an inmost part of smooth cylindrical face 40a. To each of said mounting members 40 are fit seal 10 retaining rings 41 having a smooth outer peripheral surface, said seal retaining rings 41 comprised of a large diameter portion 42 which is flexible, a small diameter portion 43, and seal retaining portion 44, thus the cross section of said seal retaining rings 41 being of a stepped shape. Said 15 saal retaining rings 41 are fit to fitting portions 40 of outer ring 31 with said large diameter portion 42 fit in place. This fitting of seal retaining rings 41 is accomplished by means of flexibly fitting enlarged diameter portion 42a (see the bottom left part of Fig. 1) provided at 20 the end of large diameter portion 42 into channels 40b of said mounting portions 40. At this time, because cylindrical faces 40a and the outside circumference of large diameter portion 42 are smooth, cylindrical faces 40a and the outside circumference of large diameter portion 42 are completely tight when seal retaining rings 41 are mounted.

When mounted, outer surface 45a of step 45 (see the bottom 04 as~e 0 C 4j 11 o 00 0 0 0 o 00 0 000 0 0000 00 00 0 a a 0 0 00 0 o 0 0 0 00 0 a0 00 0 106 0 I0 Oi 0 0 a 00 left part of Fig. 1) formed between large diameter portion 42 and small diameter portion 43 is flush with end 31c of outer ring 31. Accordingly, said small diameter portion 43 protrudes from the end of outer ring 31 to the outside in the axial direction by a specific dimension, and flangeshaped seal retaining portion 44 extends to the inside in the radial direction from the end of small diameter portion 43. The diameter of said small diameter portion 43 is smaller by a specific dimension than the specified diameter 10 of cylindrical face 16 of backing ring 10 and of end cap 37, The outer surface of seal retaing portions 44 is flush with a borderline of chamfered surface 18 and cylindrical surface 16 of the end cap 37 and backing ring 10. Furthermore,, there is a specific gap between the edge of seal i5 retaining portions 44 and said sleeves 26, Seal members 46 are fusion-bonded onto an end portion of seal retaining portions 44. Said seal. members 46 are comprised of a mounting portion 47 having a channei fit to said seal retaining portion 44 of seal retaining rings 41, a main lip 48 provided on the inside of said mounting portion 47, an annular spring 49, and a complementary lip 50 provided on the outside of mounting portion 47 and projecting toward the outside in the radfl (Airection (see the bottom right of Fig. Said main lip 48 is comprised of a. main lip portion O8a and a seal portion 48b located inside of main lip portion 48a. This main lip ENIM NMMMMMPW.

*4 12 00 0 a oo 00 0 0 0 0 90 0 a0 0 0 0" 0 00 portion 48a has a wedge-shaped cross section the slope of which angles away from double-row tapered roller bearing 34 as it approaches the end. On the other hand, seal portion 48b has an annular groove on an outer circumferential Ssurface thereof for receiving said annular spring 49, and an inner circumferential surface of seal portion 48b is formed cef two faces forming a certain angle. By fitting annular spring 49 in said annular groove of the seal portion 48b, main lip portion 48a and seal portion 48b are forced to the 10 inside in the radial direction; main lip 48 is thus forced to the Inside in the radial direction at two locations along the entire circumference at a specific interval in the axial direction, spe-cifically the end of main lip portion 48a and the ridge line of the two faces forming the inner circumferential surface of seal, portion 48b.

Complementary lip 50 is comprised of a cylindrically shaped flange 50a which projects a specific length to the outside in the axial direction from the end of mounting portion 47, an annular lip base 50b projecting towards the outside in the radial direction from the end of said flange and a complementary lip portion 50c extending from the end of the lip base 50b and having a slope whi,-* approachan the doubla-row tapered roller bearing as it approaches its edge* this edge in forced to cylindrical face 16 of each channel 17 of backing ring 10 and end cap 37 due to the inherent elasticity of~ seal members 46.

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l- 13 0 0 00 0 a o 0 00 00 00 Q 0 0 0 oa o 0 0 0 on 00 0 0 00 4 0 00 000 0 0 0 0a 00 *0 00 04 0 e 0 In the bearing device for an axle of a vehicle as herebefore described, when axle 1 rotates, backing ring end cap 37, paired sleeves 26, 35, paired inner rings 28, 29 of double-row tapered roller bearing 34 and inner ring spacer 30 rotate together. On the other hand, outer ring 31 of said louble-row tapered roller bearing 34, paired seal retaining rings 41 mounted on mounting portions 40 on both sides of outer ring 31, and each of the seal members 46 mounted on seal retaining rings 41 are stationary.

During rotation of axle 1, main lips 48 of said seal members 46 slide in contact at the above-described two places along the entire circumference of outside circumference surfaces 26f, 35f of said sleeves 26, 35 which rotate together with axle 1, said two places being the edge of main 15 lip portion 48a and the ridge line of seal portion 48b.

Complementary lip portion 50c of each complementary lip 50 accommodated in channel 17 of backing ring and end cap 37 is forced toward the outside in the radial direction by the inherent elasticity of itself, and slides 20 in contact with cylindrical face 16 of said channel 17 during th6 rotation of axle 1.

Thus, the present bearing device for an axle of a vehicle seals the inside of double-row tapered roller bearing 34 by means of sealing tightly at four places with main lip portions 8a and seal poctions 48b of main lips 48 of seal members 46 the space between paired seal retaining 71 i I 14 rings 41 provided on outer ring 31 and paired sleeves 26, which are fit tightly to axle 1, and moreover by completely sealing with complementary lips 50 the space between seal retaining ring 41 and backing ring 10 and that between seal Sretaining ring 41 and end cap 37 in the upstream side of the penetration path from main lips 48 for water and other foreign matter shown by arrow B.

In short, the bearing device of the present o invention is sealed in three places on either side by main e oO 0on 10 lip portion 48a and seal port&-, 48b of main lip 48 and 00 00 0 a complementary lip portion 50c of complementary lip 50, for a 00 0 0o total six places on both sides. Thus, this bearing device 00 O o for an axle of a vehicle, even when used in such special regions as previously described, is not penetrated by water, o" 0 3 15 sand or dust to the inside of double-row tapered roller o 0t 0 4 bearing 34.

ao Furthermore, because an annular "gutter"-like channel is formed in annular channel 17 on both sides of double-row tapered roller be4a ng 34 by small diameter S 20 portion 43 and seal retaining portion 44 of each of seal 0 t retaining rings 41, and the complementary lip 50 of each seal member 46, water entering said gutter-like channel as shown by arrow B in the figure is conducted by gravity along the gutter-like channel and thus flows out below, and water therefore does not collect inside the gutter-like channel.

Furthermore, because end cap 37 and backing ring 11 rotate I? 15 with axle 1, water which has flowed through said gutter-like channel and reaches chamfer 18 or cylindrical face 16 defining a part of the gutter-like channel is thrown off by centrifugal force, and can be smoothly thrown to the outside along said chamfer face 18.

Furthermore, the dimension of the present bearing device can be shortened in the axial direction because complementary lips 50 of seal members 46 are provided o o completely within annular channels 17 provided in backing coo 10 @o6 10 ring 10 and end cap 37. Furthermore, because complementary So lip portion 50c of complementary lip 50 has a slope which 0o O o o approaches duuble-row tapered roller bearing 34 as it 00 00 Sapproaches its end when assembling the bearing device, said slope is in tha direction of assembly, thereby making o, 15 o00" assembly smoother, and there occurs no inversion of comple- 0 Ot o000, mentary lip 50c during assembly.

~Moreover, seal members 46 seal with main lips 48 sliding in contact with outside circumference surfaces 26f, of sleeves 26, 35, and lip portions 50c of complementary 20 lips 50 sliding in contact with cylindrical faces 16 of channels 17 of front and rear caps 37 and 10. Namely, because both main lips 48 of seal members 46 and complementary lips 50 slide in contact with and seal the cylindrical surfaces of a width in the axial direction, even if there is assembly error in the axial direction during aasembly of the 16 bearing device, a constant seal can be assured irrespective of the assembly error.

The invention being thus described, it will be obvious that the same may be vazied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

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Claims (3)

1. A bearing device for an axle of a vehicle which comprises: an backing ring fitted over a step portion of an axle of a vehicle and having an annular groove on an end surface thereof; an end cap provided on an end of the axle and having an annular groove on an end surface thereof, this end surface being opposite to the end surface of the backing ring; a pair of sleeves fitted to the end cap and backing ring; a double-row roller bearing fitted over the axle between the end cap and backing ring by way of the pair of sleeves; a pair of seal retaining rings affixed on both sides in the axial direction of an outer ring of the double-row roller bearing and located between the double-row roller bearing and the end cap and between the double-row roller bearing and the backing ring; and a pair of seal members affixed to respective seal retaining portions of the seal retaining rings in such a manner as to seal the double-row roller bearing in cooperation with the seal retaining rings, wherein a surface defining an outer side in the radial direction of each of said annular grooves forms a cylindrical surface, and each of the seal members has a main lip which slides in contact with an outer peripheral surface of the sleeve, and a complementary lip which generally projects in a radial direction of the sleeve and is inclined so as to extend toward the double-row roller bearing, the ends of the complementary lips of the seal members slide in contact with the cylindrical surfaces of the annular grooves in the backing ring and the end cap, respectively. 0 00 0 0 OQ 00 000* 0 0000 00 Oo O 0 00 0 0 00 1 C C i ti i: i es0 1 44~ 0 40 ZV, L114A //UA 9W~824.03ky3248,spe,17 -18-

2. A bearing device as claimed in Claim 1, wherein each of the main lips of the seal members has a seal portion and a main lip portion which are in contact with the sleeve at a specific interval in the axial direction.

3. A bearing device substantially as hereinbefore described with reference to Figure 1 of the drawings. DATED this 24th day of August 1990 Koyo Seiko Co., Ltd. By Its Patent Attorneys DAVIES COLLISON eoo 00 0 0 00 0004 0000 00 00 0 0 L o S00 .B00