Hub / bearing assembly

Abstract

A hub / bearing assembly (10) is provided with: a rotatable flanged inner ring (20); a fixed outer ring (30) defining a gap (11) together with the inner ring (20); and a sealing device (50) integral with the tubular end collar (32) of the outer ring (30) and provided with, in its own, a shield (51) mounted in an axial abutment against the tubular end collar (32); and a sealing fluid (55), the sealing fluid (55) being applied in an application zone (Z) between the tubular end collar (32) and the shield (51); an element (80) for collecting and accumulating said sealing fluid (55), associated with said sealing means (50) and arranged outside said application zone (Z), in order to collect sealing fluid (55) that may escape from said application zone (Z).

Description

Technical Field

[0001] The present invention relates to a hub / bearing assembly.

[0002] In particular, the present invention relates to a hub / bearing assembly of a driven type, i.e., a hub / bearing assembly for a non-driven wheel of a vehicle and which hub / bearing assembly is not provided with a half-shaft passing along the axis of rotation of the hub / bearing assembly, and the following text will explicitly describe these hub / bearing assemblies without thereby losing their general character. Background Art

[0003] A known driven-type wheel hub / bearing assembly is interposed between a vehicle upright and a corresponding wheel, and includes a rotatable flanged inner ring, a stationary outer ring defining a gap together with the inner ring, and a plurality of rolling bodies interposed in the gap between the two inner rings and the outer ring to allow the inner ring to rotate relative to the outer ring. The flanged inner ring is provided with a mounting flange for the vehicle wheel, while the outer ring is also provided with a corresponding mounting flange for connecting the outer ring to the upright of the vehicle, and the outer ring is provided with a tubular end collar, which is located axially in front of the flange and is defined radially outward by a cylindrical mounting surface that can be inserted into a mounting seat formed in the upright, and the tubular end collar is defined radially inward by a cylindrical engagement surface coaxial with the cylindrical mounting surface. The tubular end collar is also defined axially toward the outside by an annular abutment surface arranged between the cylindrical mounting surface and the cylindrical engaging surface.

[0004] In order to prevent any environmental contamination and the intrusion of contaminating materials (water, mud, dirt, etc.) into the gap, a hub / bearing assembly of the above-mentioned type also comprises a sealing device, of the type described, for example, by Italian patent application No. 102015000056435 filed in the name of the present applicant, which is integral with the tubular end collar and engages in the cylindrical engagement surface so as to be arranged in axial abutment against the annular engagement surface. The known sealing device is provided with a more or less cup-shaped sheet-metal shield comprising:

[0005] a cylindrical lateral mounting wall forcibly keyed in a radial interference manner into the cylindrical engagement surface of the collar and formed by two sheet-metal layers completely folded onto each other,

[0006] - a substantially radially extending circular bottom wall, integral with the cylindrical lateral mounting wall and arranged radially on the inside of said cylindrical lateral mounting wall; and

[0007] - an annularly extending annular stop edge, integral with the cylindrical lateral mounting wall and arranged radially on the outside of said cylindrical lateral mounting wall and bearing axially against the annular abutment surface of the collar.

[0008] A sealing device of the above type also comprises a sealing fluid, which is formed by a liquid adhesive, a varnish or another liquid or semi-liquid sealing substance or by a polymeric silicone with a rubber consistency and is designed to be applied to the cylindrical lateral mounting wall of the shield or the annularly extending annular stop edge so as to assist the metal-to-metal sealing action between the shield and the collar, prevent the penetration of water and contaminants, and prevent any accidental detachment of the sealing device, especially during the movement of the hub / bearing assembly.

[0009] Although the methods for applying the sealing fluid have now been technically advanced and refined so that only a very thin film is applied in just the right amount for the above-mentioned purpose, it has unfortunately been found that in some cases, due to the axial compression between the annular abutment surface and the annularly extending annular stop edge, such sealing fluid still leaks out of the sealing device, in particular out of the annular stop edge, thereby contaminating the cylindrical mounting surface and the mounting flange of the outer ring and also causing some problems in the handling of the shield and the hub / bearing assembly. Moreover, in some cases, the escape of the sealing liquid from the application zone also leads to the proliferation of flakes of viscous material, which are dispersed along the production channel, causing many disadvantages, such as contaminating the associated hub / bearing assembly, damaging the functioning of the control device and the device for moving the hub / bearing assembly along the production channel. Summary of the invention

[0010] The present invention therefore aims to provide a hub / bearing assembly which does not have the above-mentioned disadvantages.

[0011] The present invention provides a hub / bearing assembly having the features set out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The invention will now be described with reference to the accompanying drawings, which show non-limiting embodiments of the invention, in which:

[0013] - Figure 1 is an axial cross-sectional view of a first preferred embodiment of a hub / bearing assembly made in accordance with the present innovation;

[0014] - Figure 2 and Figure 3 yes Figure 1 an enlarged scale view of a detail of the components in the corresponding operating assembly conditions, wherein the parts are in section and a portion is removed for clarity;

[0015] - Figure 4 yes Figure 1 an enlarged scale view of a detail of a second preferred embodiment of the assembly in which the parts are in cross section and with portions removed for clarity; and

[0016] - Figure 5 yes Figure 1 0026] An enlarged scale view of a detail of a third preferred embodiment of the assembly in FIG. 1 with parts in cross section and with parts removed for clarity. DETAILED DESCRIPTION

[0017] Reference Figure 1 , 10 generally represents a first preferred embodiment of a hub / bearing assembly, the hub / bearing assembly being designed to be interposed between an upright and a corresponding wheel of a vehicle, the upright, wheel and vehicle being known and not shown, and comprising:

[0018] - a flanged inner ring 20 rotatable about an axis of rotation A;

[0019] a stationary outer ring 30 which defines, together with the inner ring 20, the gap 11, and

[0020] A plurality of rolling elements 40 are interposed in the gap 11 between the two inner rings 20 and the outer ring 30 to allow the inner ring 20 to rotate relative to the outer ring 30 .

[0021] The outer ring 30 is provided with a mounting flange 31 for connecting the outer ring 30 to an upright of the vehicle, and with a tubular end collar 32, which is located axially in front of the flange 31 and is delimited radially toward the outside by a cylindrical mounting surface 33 that can be inserted into the upright, and radially toward the inside by a cylindrical engagement surface 34 that is coaxial with the cylindrical mounting surface 33. The tubular end collar 32 is also delimited axially toward the outside by an annular abutment surface 35 that is arranged between the cylindrical mounting surface 33 and the cylindrical engagement surface 34, perpendicular to the axis A, and connected to the cylindrical engagement surface 34 by a tapered surface 36 that is open toward the annular abutment surface 35.

[0022] In order to prevent any environmental pollution and contaminating materials (water, mud, dirt, etc.) from intruding into the gap 11, the hub / bearing assembly 10 also includes a sealing device 50, which is integral with the tubular end collar 32 and is engaged in the cylindrical engagement surface 34 so as to be arranged in axial abutment against the annular abutment surface 35.

[0023] Also like Figure 2 and Figure 3 As shown, the sealing device 50 is provided with a shield 51, which is preferably but not necessarily made of a more or less cup-shaped metal plate and comprises:

[0024] a cylindrical lateral mounting wall 52, force-keyed in a radial interference manner into the cylindrical engagement surface 34 of the collar 32 and formed by two sheet metal layers 52' and 52", which are completely folded onto each other at an angle of substantially 180° and each of which has substantially the same thickness,

[0025] a substantially radially extending circular bottom wall 53 , integral with the layer 52 ′ of the cylindrical lateral mounting wall 52 and arranged radially on the inside of said cylindrical lateral mounting wall 52 ; and

[0026] - an annularly extending annular stop edge 54 , integral with the layer 52 ″ of the cylindrical lateral mounting wall 52 and arranged radially at the outside of said cylindrical lateral mounting wall 52 and bearing axially against the annular abutment surface 35 of the collar 32 .

[0027] The circular bottom wall 53 and the annular stop edge 54 both form corresponding right angles with the cylindrical lateral mounting wall 52, but when the circular bottom wall 53 is a wall shaped in a manner that substantially replicates the axial outer shape of the inner ring 20, the annular stop edge 54 is transverse to the axis A and is Figure 2 As specifically shown in FIG. 3 , the annular abutment surface 35 extends against the annular abutment surface 35 and is flush with the cylindrical mounting surface 33 .

[0028] The sealing device 50 also comprises a sealing fluid 55, formed by a liquid adhesive, a varnish or another liquid or semi-liquid sealing substance, or by a polymeric silicone with a rubber consistency, and applied in an application zone Z of the annular stop edge 54 to assist the metal-to-metal sealing action between the shield 51 and the collar 32, thereby preventing the penetration of water and contaminants. The application zone Z is located between the collar 32 and the annular stop edge 54, extends angularly around the entire circumference of the annular stop edge 54, and has a radial width L of defined and completely contained dimensions, i.e., a radial width L that is smaller than the radial dimensions of both the annular abutment surface 35 and the annular stop edge 54, which, incidentally, define an axial contact zone Z' between the collar 32 and the shield 51 (i.e., the annular stop edge 54).

[0029] Because in Figure 1 , Figure 2 and Figure 3 In the preferred embodiment of the invention shown in , the sealing fluid 55 is applied to the shield 51 instead of the collar 32, so that the application zone Z forms part of the axial surface 54' of the annular stop edge 54 facing the collar 32. As a further alternative, if the sealing fluid 55 is applied to the collar 32 instead of the shield 51, the application zone Z will form part of the annular abutment surface 35. These two solutions are absolutely alternatives and equivalents to each other, depend essentially on the process used to produce the described hub / bearing assembly 10, and therefore fall within the scope of the invention: the following description will illustrate the application zone Z forming part of the axial surface 54'.

[0030] When the shield 51 is configured in one of its operating pre-assembly conditions ( Figure 3), i.e., at least the annular abutment surface 35 of the collar 32 and the annular stop edge 54 are axially spaced apart from each other, a sealing fluid 55 is applied directly to the annular stop edge 54 so that a continuous annular film is formed over the entire surface 54', the film having a reduced axial thickness (in the accompanying drawings, the thickness is highlighted (accentuated) to be able to show the sealing fluid 55) and a radial width that is completely contained within zone Z.

[0031] However, when the shield 51 is disposed in one of its operational assembly conditions ( Figure 2 ), i.e., the annular abutment surface 35 of the collar 32 and the surface 54' of the annular stop edge 54 are in direct contact with each other, and although the axial thickness of the associated continuous annular film is reduced, the sealing fluid 55 is still compressed in the axial direction, tending to expand in the radial direction and flow out of zone Z.

[0032] Therefore, in order to prevent that the sealing fluid 55 compressed between the collar 32 and the annular edge 54 could possibly escape even from the contact zone Z′ between the collar 32 and the annular stop edge 54 , the assembly 10 comprises a channel 80 for collecting and accumulating the sealing fluid 55 .

[0033] A channel 80 is associated with the sealing device 50 for collecting and accumulating the sealing fluid 55 and is formed through the surface 54 ′ radially outside the application zone Z to collect the sealing fluid 55 that may escape from said application zone Z. Figure 1 , Figure 2 and Figure 3 In the preferred embodiment shown in , the channel 80 is formed by an annular groove extending through the entire surface 54 ′ around the axis A and having an inner diameter greater than the outer diameter of the application zone Z.

[0034] When the shield 51 is configured to be in an operational assembly condition (wherein the collar 32 and the annular stop edge 54 are in direct contact with each other), the sealing fluid 55, although composed of a continuous annular film with reduced axial thickness, may still expand beyond the application zone Z due to compression. In this case, the sealing fluid 55 will be intercepted by the channel 80, and the sealing fluid 55 can be injected into the channel 80 without further flowing in the radial direction, i.e., it will not escape from the contact zone Z' between the collar 32 and the annular stop edge 54 at all, and therefore will not contaminate the cylindrical mounting surface 33 and the mounting flange 31 of the outer ring 30, and will not cause any problems in the operation of the shield 51 and the hub / bearing assembly 10.

[0035] As mentioned above and Figure 4The alternative embodiment of the hub / bearing assembly 10 shown in the figure relates to a hub / bearing assembly 10', which differs from the hub / bearing assembly 10 in that the channel 80 is still associated with the sealing device 50 for collecting and accumulating the sealing fluid 55, but the channel 80 is formed through the annular abutment surface 35 of the ring 32 instead of being formed in the annular stop edge 54, but is still located radially outside the application zone Z to collect the sealing fluid 55 that may escape from the application zone Z.

[0036] Forming the channel 80 through the annular abutment surface 35 of the collar 32 makes it possible to avoid having to machine the shield 51 to the extent that the thickness of the annular stop edge 54 is reduced. However, these two solutions are alternatives.

[0037] As mentioned above and Figure 5 Another alternative embodiment of the hub / bearing assembly 10 shown in relates to a hub / bearing assembly 10', which differs from the hub / bearing assembly 10 in that the hub / bearing assembly 10' comprises a second channel 80', which is still associated with the sealing device 50 and is formed through the annular abutment surface 35 of the collar 32 at a position axially in front of the channel 80 and still radially outside the application zone Z to collect the sealing fluid 55 that may escape from the application zone Z. The second channel 80' may be necessary if the production, operation ( / working) and / or application conditions of the hub / bearing assembly 10' require the application of the sealing fluid 55 in an amount such that a continuous annular film is still formed over the entire surface 54', but the axial thickness is no longer significantly reduced.

[0038] It is worth noting at this point that in all three preferred and alternative embodiments of the hub / bearing assembly of the invention, the cylindrical lateral mounting wall 52 or, better still, the folded sheet metal layer 52″ and the annularly extending annular stop edge 54 define, at the conical surface 36, an annular space 81 which has a substantially triangular shape in axial section. This space 81, which substantially delimits the application zone Z at the bottom in the radial direction, can also have the same function as the channel 80 for collecting and accumulating the sealing fluid 55. However, due to the circular shape of the shield 51 The total thickness of the cylindrical lateral wall 52 is substantially twice the thickness of the annular stop edge 54, and the lateral wall 52 is also more rigid than the annular stop edge 54, so that during the assembly of the shield 51 in the collar 32, the annular stop edge 54 is elastically deformed and opens radially toward the outside, that is, the annular stop edge 54 compresses the sealing fluid 55 from the smaller diameter of the application zone Z toward the larger diameter, and thus guides the sealing fluid 55 more toward the outside, that is, toward the channel 80 or the channels 80 and 80', rather than toward the space 81.

[0039] Furthermore, all three preferred and alternative embodiments of the hub / bearing assembly of the present invention are particularly advantageous when, due to the small size of the hub / bearing assembly, the axial contact zone Z' between the collar 32 and the shield 51 (i.e., the annular stop edge 54) has a fully accommodated radial dimension.

[0040] Finally, the presence of the channel 80 for collecting and accumulating the sealing fluid 55, or of the double channel 80 and 80' for collecting and accumulating the sealing fluid 55, not only makes it possible to have a sealing device 50 that is very effective in terms of sealing and protecting the gap 11, since it also allows a good distribution of the sealing fluid 55 in the application zone Z and around the entire circumference of the application zone Z, but also makes it possible to optimize the process for manufacturing the hub / bearing assembly, making it substantially independent of the limitations imposed by the deposition time of said sealing fluid 55. Furthermore, adjusting the dimensions of the collection and accumulation channels makes it possible to further increase this independence.

[0041] In addition to the embodiments of the present invention as described above, it should be understood that there are many other variations. It should also be understood that these embodiments are merely exemplary and do not limit the scope of the invention, the application of the invention, or the possible configurations of the invention. On the contrary, although the description provided above enables those skilled in the art to implement the invention according to at least one exemplary configuration of the invention, it should be understood that many variations of the described components may be suggested without thereby departing from the scope of the invention as defined in the appended claims, interpreted literally and / or according to their legal equivalents.

Claims

1. A hub / bearing assembly (10)(10')(10"), comprising: - a rotatable flanged inner ring (20), a fixed outer ring (30) which defines, together with the inner ring (20), a gap (11) and is provided with a tubular end collar (32) which is delimited axially towards the outside by an annular abutment surface (35); and - a sealing device (50) integral with the tubular end collar (32) and provided with a shield (51), the shield (51) for its part comprising a cylindrical lateral mounting wall (52) keyed into the tubular end collar (32) and an annularly extending annular stop edge (54) integral with the cylindrical lateral mounting wall (52) and bearing axially against the annular abutment surface (35); The sealing device (50) is also provided with a sealing fluid (55), which is applied in an application zone (Z) located between the tubular end collar (32) and the annularly extending annular stop edge (54), and the hub / bearing assembly (10) (10') (10") is characterized in that the hub / bearing assembly (10) (10') (10") includes a component (80) (80') for collecting and accumulating the sealing fluid (55), the component (80) (80') being associated with the sealing device (50) and being arranged outside the application zone (Z) to collect the sealing fluid (55) that may escape from the application zone (Z).

2. The hub / bearing assembly according to claim 1, characterized in that The smaller radial dimension of the means (80)(80') for collecting and accumulating the sealing fluid (55) is greater than the larger radial dimension of the application zone (Z).

3. The hub / bearing assembly according to claim 2, characterized in that: The collecting and accumulation means (80)(80') are formed by an annular groove extending around said axis A around said application zone (Z).

4. The hub / bearing assembly according to claim 3, characterized in that: The annular groove (80) is formed in the annularly extending annular stop edge (54).

5. The hub / bearing assembly according to claim 3 or 4, characterized in that: The annular groove (80') is formed in the tubular end collar (32).

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