Wheel hub / bearing arrangement

Abstract

Wheel hub / bearing assembly (10) comprising a rotatable flanged inner ring (20), a fixed outer ring (30) forming a gap (11) with the inner ring (20); and a sealing device (50) formed integrally with a tubular shoulder (32) of the outer ring (30) and itself provided with a shield (51) axially attached to the tubular shoulder (32), and with a sealing fluid (55) applied in an application area (Z) arranged between the tubular shoulder (32) and the shield (51); an element (80) for collecting and accumulating the sealing fluid (55) connected to the sealing device (50) and arranged on the outside of the application area (Z) to collect the sealing fluid (55) that may escape from the application area (Z).

Description

Technical area of ​​the invention

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

[0002] In particular, the present invention relates to a wheel hub / bearing arrangement of the driven type, namely a wheel hub / bearing arrangement for driven wheels of vehicles, and which is not provided with a half-shaft running along an axis of rotation of the wheel hub / bearing arrangement, and in the following text express reference is made to these wheel hub / bearing arrangements without thereby losing the general character. State of the art

[0003] The known wheel hub / bearing arrangements of the driven type are inserted between a vehicle axle stub and a corresponding wheel and comprise a rotatable flanged inner ring, a stationary outer ring which forms a gap with the inner ring, and several rolling elements which are inserted into the gap between the two inner and outer rings, so that the inner ring can rotate in relation to the outer ring.The flanged inner ring is provided with a mounting flange for the vehicle's wheel, while the outer ring is also provided with a corresponding mounting flange for its connection to the vehicle's steering knuckle and with a tubular shoulder located axially in front of the flange. This shoulder is bounded radially outward by a cylindrical mounting surface that can be inserted into a mounting seat formed in the steering knuckle, and radially inward by a cylindrical engagement surface that is coaxial with the cylindrical mounting surface. The tubular shoulder is also bounded axially outward by an annular stop surface located between the cylindrical mounting surface and the cylindrical engagement surface.

[0004] To prevent the ingress of environmentally contaminating materials (water, mud, dirt, etc.) into the gap, the wheel hub / bearing assembly of the type described above further comprises a sealing device, such as that described, for example, in Italian patent application No. 102015000056435 filed on behalf of the applicant. This sealing device is integral with the tubular bearing assembly and engages in the cylindrical contact surface so that it bears axially against the annular contact surface. The known sealing device is provided with a more or less shell-shaped sheet metal shield, which includes - a cylindrical lateral mounting wall, which is forcibly fitted into the cylindrical mounting surface of the shoulder with radial interference and is formed from two completely folded sheet metal layers, - an essentially radial circular base wall, which is integral with the cylindrical side mounting wall and is arranged radially on the inside of the cylindrical side mounting wall, and - a ring-shaped, annular stop edge extending in a ring shape, which is integral with the cylindrical side mounting wall and is arranged radially on the outside of the cylindrical side mounting wall and rests axially against the annular contact surface of the shoulder.

[0005] The sealing device of the type described above further comprises a sealing fluid formed by a liquid adhesive, a varnish or other liquid or semi-liquid sealant or by a polymerized silicone with a rubber-like consistency, and intended to be applied to the cylindrical lateral mounting wall of the shield or to the annular stop edge to assist the metallic seal between the shield and the assembly and to prevent the ingress of water and contaminants, and in particular to prevent unintentional detachment of the sealing device during the movement of the wheel hub / bearing assembly.

[0006] Although the methods for applying the sealing fluid have since been technically developed and refined to such an extent that only a very thin film is applied in precisely the right amount for the purpose described above, it has unfortunately been shown that in some cases, due to the axial pressure between the annular stop surface and the annularly extending stop edge, this sealing fluid has nevertheless leaked out outside the sealing device, particularly outside the annular stop edge, contaminating the cylindrical mounting surface and the mounting flange of the outer ring, and has also led to some problems in handling the shield and the wheel hub / bearing assembly.Furthermore, in some cases the leakage of sealing fluid from the application area also leads to the spread of flakes of sticky material which, when distributed along the production channels, cause a number of disadvantages, such as the contamination of the associated wheel hubs / bearing assembly, the impairment of the function of the control devices and the devices for moving the wheel hubs / bearing assemblies along the production channels. Summary of the invention

[0007] The object of the present invention is therefore to provide a wheel hub / bearing arrangement that does not have the disadvantages described above.

[0008] The present invention is provided with a wheel hub / bearing arrangement having the features specified in the attached claims. Brief description of the drawings

[0009] The invention will now be described with reference to the accompanying drawings, which show non-limiting embodiments of the invention, in which: - Fig. 1 is a view in axial section of a first preferred embodiment of a wheel hub / bearing arrangement according to the present invention; - Fig. 2 and Fig. Three enlarged views with sectional views and, for clarity, removed parts of a detail of the arrangement. Fig. 1 in the respective operating states of the arrangement; - Fig. 4 an enlarged view of a detail of a second preferred embodiment of the arrangement in Fig. Figure 1 shows parts in section and parts have been removed for clarity; and - Fig. 5 an enlarged view of a detail of a third preferred embodiment of the arrangement in Fig. Figure 1 shows parts in section and parts have been removed for clarity. Detailed description

[0010] With reference to Fig. 1 designates 10 in general as a first preferred embodiment of a wheel hub / bearing arrangement which is intended to be inserted between a steering knuckle of a vehicle and a corresponding wheel, wherein the steering knuckle, the wheel and the vehicle are known and not shown, and comprises - a flanged inner ring 20 which is rotatable about a rotation axis A; - a stationary outer ring 30 which forms a gap 11 with the inner ring 20, and - several rolling elements 40 which are inserted into the gap 11 between the two rings, the inner ring 20 and the outer ring 30, so that the inner ring 20 can rotate in relation to the outer ring 30.

[0011] The outer ring 30 is provided with a mounting flange 31 for its connection to the steering knuckle of the vehicle and with a tubular shoulder 32, which is located axially in front of the flange 31 and is bounded radially outwards by a cylindrical mounting surface 33 that can be inserted into the steering knuckle, and radially inwards by a cylindrical engagement surface 34 that is coaxial with the cylindrical mounting surface 33. The tubular shoulder 32 is also bounded axially outwards by an annular contact surface 35, which is arranged between the cylindrical mounting surface 33 and the cylindrical engagement surface 34 perpendicular to axis A and is connected to the cylindrical engagement surface 34 by a conical surface 36 that is open towards the annular contact surface 35.

[0012] To prevent any ingress of environmentally harmful and polluting materials (water, mud, dirt, etc.) into the gap 11, the wheel hub / bearing assembly 10 further comprises a sealing device 50 which is integral with the tubular shoulder 32 and engages in the cylindrical engagement surface 34, so that it is arranged in axial contact with the annular contact surface 35.

[0013] As in the Fig. 2 and Fig. As shown in Figure 3, the sealing device 50 is provided with a shield 51, which is preferably, but not necessarily, made of sheet metal more or less in the form of a shell and comprises the following: - a cylindrical lateral mounting wall 52 which engages in the cylindrical engagement surface 34 of the shoulder 32 with radial interference and is formed from two sheet layers 52' and 52" which are essentially folded completely over each other at an angle of 180° and each has an essentially equal thickness, - a substantially radial circular base wall 53, which is integral with the layer 52' ​​of the cylindrical mounting side wall 52 and is arranged radially on the inside of the cylindrical mounting side wall 52; and - a ring-shaped annular stop edge 54, which is integral with the layer 52" of the cylindrical lateral mounting wall 52 and is arranged radially on the outside of the cylindrical lateral mounting wall 52 and rests axially against the annular contact surface 35 of the shoulder 32.

[0014] The circular base wall 53 and the annular stop edge 54 each form a right angle with the cylindrical side mounting wall 52. However, while the circular base wall 53 is a wall shaped to essentially replicate the axial outer shape of the inner ring 20, the annular stop edge 54 runs transversely to the axis A and is located, as shown in particular in Fig. 2 shown, on the annular mounting surface 35 and flush with the cylindrical mounting surface 33.

[0015] The sealing device 50 further comprises a sealing fluid 55, which is formed by a liquid adhesive, a varnish or another liquid or semi-liquid sealant or by a polymerized silicone with a rubber-like consistency and is applied in an application area Z of the annular stop edge 54 to support the metal-to-metal seal between the shield 51 and the shoulder 32 and to prevent the ingress of water and contaminants.The application area Z is located between the shoulder 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 with defined and fully enclosed dimensions, namely smaller than the radial dimensions of both the annular contact surface 35 and the annular stop edge 54, which, moreover, define an axial contact area Z' between the shoulder 32 and the shield 51, namely the annular stop edge 54.

[0016] Since at the in the Fig. 1, Fig. 2 and Fig. In the preferred embodiment of the present invention shown in Figure 3, where the sealing fluid 55 is applied to the shield 51 and not to the shoulder 32, the application area Z forms part of an axial surface 54' of the annular stop edge 54 facing the shoulder 32. If the sealing fluid 55 were applied to the shoulder 32 instead of the shield 51, the application area Z would form part of the annular stop surface 35. Both solutions are entirely alternative and equivalent to each other, depend essentially on the described method for manufacturing the wheel hub / bearing assembly 10, and thus fall within the scope of the present invention. In the following description, reference is made to an application area Z that forms part of the axial surface 54'.

[0017] If the shielding 51 in one of its in Fig. In the 3 operating states shown before assembly, i.e., at least with the annular contact surface 35 of the shoulder 32 and the annular stop edge 54 axially spaced apart from each other, the 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 figures the thickness is emphasized in order to show the sealing fluid 55) and a radial width that is completely contained in the area Z.

[0018] However, if the shielding 51 in one of its in Fig. 2 arrangements shown, i.e. when the annular contact surface 35 of the shoulder 32 and the surface 54' of the annular stop edge 54 are in direct contact with each other, the sealing fluid 55 is still axially compressed despite the reduced axial thickness of the associated continuous annular film and tends to expand radially and flow out of the region Z.

[0019] Therefore, in order to prevent the sealing fluid 55 compressed between the shoulder 32 and the annular edge 54 from possibly escaping from the contact area Z' between the shoulder 32 and the annular stop edge 54, the arrangement 10 includes a channel 80 for catching and collecting the sealing fluid 55.

[0020] The channel 80 is associated with the sealing device 50, serves to collect and retain the sealing fluid 55, and is formed radially on the outside of the application area Z by the surface 54' in order to collect any sealing fluid 55 that may escape from this application area Z. In the Fig. 1, Fig. 2 and Fig. In the preferred embodiment shown in Figure 3, the channel 80 is formed by an annular groove which extends through and over the entire surface 54' around the axis A and has an inner diameter with larger dimensions than the dimensions of an outer diameter of the application area Z.

[0021] If the shield 51 is arranged in the operational assembly state such that the shoulder 32 and the annular stop edge 54 are in direct contact with each other, the sealing fluid 55 could, as a result of compression, expand outside the application area Z despite a continuous annular film with reduced axial thickness and, in this case, be collected by the channel 80 into which it can flow without spreading further radially, i.e., without even escaping from the contact area Z' between the shoulder 32 and the annular stop edge 54 and thus without contaminating the cylindrical mounting surface 33 and also the mounting flange 31 of the outer ring 30, and without causing problems in handling the shield 51 and the wheel hub / bearing assembly 10.

[0022] The above described and in Fig. 4. The alternative embodiment of the wheel hub / bearing arrangement 10 shown relates to a wheel hub / bearing arrangement 10' which differs from the wheel hub / bearing arrangement 10 in that the channel 80 is still associated with the sealing device 50 and serves to catch and collect the sealing fluid 55, but is formed by the annular contact surface 35 of the shoulder 32 instead of in the annular stop edge 54, but is still radially outside the application area Z in order to catch the sealing fluid 55 that may escape from this application area Z.

[0023] By forming the channel 80 through the annular contact surface 35 of the shoulder 32, it is possible to avoid the mechanical processing of the shielding 51, since the thickness of the annular stop edge 54 is reduced. However, the two solutions are alternatives.

[0024] The further alternative embodiment of the wheel hub / bearing arrangement 10, as described above and in Fig. Figure 5 refers to a wheel hub / bearing assembly 10", which differs from the wheel hub / bearing assembly 10 in that it includes a second channel 80', which is still connected to the sealing device 50 and is formed by the annular contact surface 35 of the shoulder 32 in a position axially in front of the channel 80 and radially outside the application area Z, in order to collect any sealing fluid 55 that may escape from this application area Z. The second channel 80' may be necessary if the manufacturing, operating, and / or application conditions of the wheel hub / bearing assembly 10" require a sealing fluid 55 that is applied in such a quantity that it still forms a continuous annular film over the entire surface 54', but whose axial thickness is no longer significantly reduced.

[0025] It should be noted here that in all three preferred and alternative embodiments of the wheel hub / bearing arrangement of the present invention, the cylindrical lateral mounting wall 52, or even better, the folded sheet metal layer 52'', and the annularly extending annular stop edge 54 on the conical surface 36 define an annular space 81 which has a substantially triangular shape in axial section. This space 81, which essentially limits the application area Z radially downwards, can also have the same functions as the channel 80 for collecting and accumulating the sealing fluid 55.However, since the cylindrical side wall 52 of the shield 51 has a total thickness that is essentially twice the thickness of the annular stop edge 54, this side wall 52 is also stiffer than the annular stop edge 54, so that the annular stop edge 54 deforms elastically during the assembly of the shield 51 in the shoulder 32 and opens radially outwards, i.e. causing the annular stop edge 54 to compress the sealing fluid 55 from the smaller diameters to the larger diameters of the application area Z and thus direct the sealing fluid 55 more outwards, i.e. to the channel 80 or to the channels 80 and 80', than to the space 81.

[0026] Furthermore, all three preferred and alternative embodiments of the wheel hub / bearing arrangement of the present invention are particularly advantageous if the axial contact area Z' between the shoulder 32 and the shield 51, namely the annular stop edge 54, has quite small radial dimensions due to a small size of the wheel hub / bearing arrangement.

[0027] Finally, the presence of the channel 80 for collecting and storing the sealing fluid 55, or of the double channel 80 and 80' for collecting and storing the sealing fluid 55, not only allows for a sealing device 50 that is highly effective in sealing and protecting the gap 11, because it also enables better distribution of the sealing fluid 55 in the application area Z and across its entire circumference, but it also allows for the optimization of the wheel hub / bearing assembly manufacturing process by making it essentially independent of the limits imposed by the settling times of the sealing fluid 55. Furthermore, this independence can be further increased by modulating the dimensions of the collecting and storage channel.

[0028] In addition to the embodiments of the invention described above, numerous other variants are of course possible. It should also be clear that these embodiments are merely exemplary and do not limit the scope of the invention, its applications, or its possible configurations. On the contrary, although the description provided above enables a person skilled in the art to implement the present invention at least according to one exemplary embodiment, it is self-evident that numerous variations of the described components can be invented without thereby departing from the scope of the invention as defined in the attached claims, either literally and / or according to their legal equivalents. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] IT 102015000056435

[0004]

Claims

[1] Wheel hub / bearing assembly (10)(10')(10'') comprising: - a rotatable flanged inner ring (20), - a fixed outer ring (30) defining a gap (11) with the inner ring (20) and provided with a tubular end shoulder (32) which is axially outwardly delimited by an annular bearing surface (35); and - a sealing device (50) integral with the tubular shoulder (32) and provided with a shield (51) which in turn comprises a cylindrical lateral mounting wall (52) fixed in the tubular shoulder (32), and an annular stop edge (54) integral with the cylindrical lateral mounting wall (52) and axially abutting the annular stop surface (35); wherein the sealing device (50) is also provided with a sealing liquid (55) applied in an application area (Z) located between the tubular shoulder (32) and the annularly extending annular stop edge (54), and the wheel hub / bearing assembly (10)(10')(10'') characterized byis that it comprises means (80)(80') for collecting and accumulating the sealing liquid (55), which are associated with the sealing device (50) and arranged outside the application area (Z) in order to collect the sealing liquid (55) which may leak from this application area (Z). [2] Wheel hub / bearing arrangement according to claim 1, characterized by that the means (80)(80') for catching and collecting the sealing fluid (55) have smaller radial dimensions which are larger than larger radial dimensions of the application area (Z). [3] Wheel hub / bearing arrangement according to claim 2, characterized by that the means (80)(80') for catching and collecting are formed by an annular groove extending around the axis A around the application area (Z). [4] Wheel hub / bearing arrangement according to claim 3, characterized bythat the annular groove (80) is formed in the annularly extending annular stop edge (54). [5] Wheel hub / bearing arrangement according to claim 3 or 4, characterized by that the annular groove (80') is formed in the tubular end shoulder (32).

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