Filling opening for wheel hub lubricant for heavy commercial vehicles

Abstract

Wheel head assembly comprising an improved wheel hub (200) and a pair of bearings (230, 232) mounted on a spindle of an axle of a heavy commercial vehicle, wherein the wheel hub (200) is rotatably mounted on the bearings (230, 232) and a lubricant cavity (210) is formed in the wheel head assembly between the bearings (230, 232), characterized in that: a lubricant filling opening (216) is formed in the wheel hub (200), the lubricant filling opening (216) extends axially inwards and radially inwards from the outer surface (254) of the improved wheel hub (200) at a predetermined angle (A) through an outer wall (226) of the lubricant cavity (210) to the lubricant cavity (210) and provides for fluid communication between the outer surface (254) of the wheel hub (200) and the lubricant cavity (210), thereby facilitating the filling and refilling of the lubricant cavity (210) with semi-liquid lubricant; and a plug (218) is located in the lubricant filling opening (216) between the lubricant cavity (210) and the outer surface (254) of the wheel hub (200).

Description

Cross-reference to related registration

[0001] This application claims priority over the preliminary US patent application serial no. 62 / 247,814 filed on October 29, 2015. Background of the invention; Field of the invention

[0002] The invention relates to wheel hub assemblies, and in particular to wheel hub assemblies for driven or non-driven, steerable or non-steerable axles of heavy commercial vehicles, such as trucks, tractors, semi-trailers, or trailers. In particular, the invention relates to a wheel hub of a driven or non-driven, steerable or non-steerable axle of a wheel hub assembly of a heavy commercial vehicle, wherein the wheel hub comprises a lubricant filling opening which extends axially inwards and radially inwards from an outer surface of the wheel hub at a predetermined angle to a wheel hub lubricant cavity, thereby facilitating the filling and refilling of the wheel hub lubricant cavity with semi-liquid lubricant. State of the art

[0003] For many years, the heavy-duty vehicle industry has used wheel hub assemblies, typically mounted at each end of one or more driven or non-driven, steerable or non-steerable axles. Each wheel hub assembly typically comprises a hub rotatably mounted on a bearing assembly, which includes an inner bearing and an outer bearing, which in turn are fixedly mounted to the outer end of the axle, commonly known as the axle spindle. As is well known to those skilled in the art, the bearing assembly and surrounding components must be lubricated with oil or grease for the wheel hub assembly to operate normally. Therefore, the wheel hub assembly must be sealed to prevent lubricant leakage and also to prevent contaminants from entering the assembly, both of which could be detrimental to its performance.In particular, a wheel cap is mounted on the outer end of the wheel hub, and a main seal is rotatably mounted on the inner end of the hub, and the bearing assembly abuts the axle spindle, resulting in a closed or sealed wheel head assembly.

[0004] On driven or non-driven axles, such as truck, tractor, or trailer axles, it is desirable to retain a predetermined amount of lubricant in the wheel hub assembly. This increases the service life of the bearing assembly and, in turn, reduces the costs of its maintenance and / or replacement. Historically, oil has been used as a lubricant for bearing assemblies, but it may not be the optimal lubricant for achieving the goal of increased bearing assembly service life. In particular, if the main seal on the wheel hub assembly fails, there is a tendency for the oil to leak out of the assembly due to its relatively low viscosity compared to other lubricants. When oil leaks, the bearing assembly may be insufficiently lubricated, reducing its service life. Furthermore, in the event of such an oil leak, the main seal usually needs to be repaired or replaced.If oil leaks from the wheel hub assembly, it can also run onto components of an associated braking system, such as the brake shoes, which then require repair, thus increasing the costs associated with the oil leak. Such potential disadvantages associated with oil leakage have led to the increasing use of semi-fluid lubricants as a replacement for oil as a lubricant for bearing assemblies in wheel hub assemblies on driven or non-driven axles.

[0005] The higher viscosity of semi-fluid lubricant means it does not flow as easily as oil, which is advantageous in reducing potential leakage, but also necessitates alternative methods for filling the wheel hub assembly with lubricant. Specifically, oil typically has a hole in the hub cap, allowing the oil to be poured into the sealed wheel hub assembly through the cap using known techniques. However, semi-fluid lubricant does not flow easily to both the inner and outer bearings and the hub area near the bearings when using such a hub cap fill hole. Therefore, various prior art methods have been developed to fill the wheel hub assembly with the correct amount of semi-fluid lubricant and / or other types of lubricants.

[0006] Most prior art methods for filling the wheel hub assembly with semi-fluid lubricant are associated with non-steerable axles. For example, one prior art method involves mounting only the inner bearing of the bearing assembly onto the axle spindle before adding semi-fluid lubricant to the wheel hub. In this prior art method, the inner bearing is mounted onto the axle spindle, and the wheel hub is mounted onto the inner bearing without the outer bearing and without a lock nut, the lock nut typically being used to secure the position of the bearings and hub on the axle spindle. A nozzle is inserted into the gap between the axle spindle and the hub, and a pre-measured quantity of the semi-fluid lubricant is pumped into the gap against the inner bearing.Once the lubricant is added, the outer bearing is mounted on the axle spindle, and the lock nut is installed and tightened on the axle spindle.

[0007] This method has a significant disadvantage because the lack of an external bearing during lubricant introduction requires a person to maintain a relatively horizontal position of the wheel hub to prevent damage to the main seal of the wheel head assembly. That is, without the external bearing in place, there is a tendency for the outer end of the wheel hub to drop onto the axle spindle, which in turn can kink or damage the main seal at the inner end of the wheel hub. Furthermore, while this prior art method can be used reasonably efficiently during the initial assembly of the wheel head assembly by factory-trained fitters, it is much less practical for later use, such as during wheel head assembly maintenance, since the wheel head assembly would have to be at least partially disassembled just to add lubricant.As is well known in engineering, it is desirable to carry out the lubrication of a wheel head assembly with as little disassembly as possible during later use.

[0008] Another prior art method involves a wheel hub comprising a radially oriented filling port formed in the hub wall between the inner and outer bearings, and pumping a pre-measured quantity of semi-liquid lubricant through this port into the wheel head assembly. After the lubricant has been added, a threaded plug is installed in the port to prevent the lubricant from escaping the wheel hub during operation. Specifically, the plug may comprise an interfering pipe thread, or it may comprise a standard thread that compresses an O-ring, thus sealing the port.This method is preferred over the first prior art method described above because the main seal and bearing assembly can be installed with the correct orientation before the lubricant is added, so that the main seal is typically not damaged during the filling of the lubricant.

[0009] The radially oriented design of the filler opening is well-known in engineering for non-driven, non-steerable axles and is relatively easy to manufacture, provided the wheel hub wall has sufficient thickness to allow the formation of an adequate number of threads to secure the threaded plug described above. However, when high-strength, thin-walled wheel hub designs are used, a radially oriented filler opening formed in the wheel hub wall is not practical, as such a hub may not have sufficient wall thickness to form enough threads to secure a threaded plug. Furthermore, forming the radially oriented opening involves an additional manufacturing step, which undesirably increases the cost of the wheel hub.

[0010] There is another prior art structure and method for adding lubricant to a wheel assembly, but this structure and method are applicable only to driven axles and not to non-driven axles. Specifically, to transmit drive torque to a drive wheel, a drive axle and wheel assembly typically comprises a rotating drive shaft extending over a non-rotating axle spindle. A wheel hub is rotatably mounted on the axle spindle via a bearing assembly, and a group of axially aligned holes is formed in the outer end of the wheel hub. The drive shaft is connected at its outer end to an outer plate or flange in which holes are formed that are aligned with the holes in the wheel hub. Drive pins extend through the holes in the plate and into the aligned holes in the wheel hub, where they are held by an interference fit.In this way, drive torque is transferred from the drive axle via the plate to the drive pins and to the wheel hub, which rotates around the axle spindle on the bearing assembly to turn the vehicle's wheels.

[0011] In the prior art lubrication method for such a drive axle wheel hub assembly, one of the holes in the wheel hub, which typically has a fairly large diameter, is drilled further inwards until it penetrates a cavity formed in the wheel hub between the inner and outer bearings. An oil-type lubricant is then introduced into the wheel hub cavity, allowing the lubricant to reach the bearings. Once the correct amount of oil has been added, the press-fit drive pin is installed in the wheel hub, and a nut is installed on the outer end of the pin to secure the connection between the plate and the wheel hub. However, this method cannot be applied to wheel hub assemblies for non-drive axles because such wheel hub assemblies lack the structure of drive axle wheel hubs, and in particular the outer plate drive pin assembly and the associated holes formed in the wheel hub.Furthermore, in this state-of-the-art process, as described above, oil is used as a lubricant instead of semi-liquid lubricant.

[0012] Another prior art method for filling a wheel hub assembly of a non-driven, non-steerable axle with semi-liquid lubricant is known. This prior art method is of the type described and shown in US Patent US 7,585,031 B2, which belongs to the applicant of the present invention, Hendrickson USALLC. In this method, a wheel hub of a non-steerable axle comprises an axially oriented filling opening that extends from a hubcap bolt opening into the lubricant cavity. Semi-liquid lubricant is introduced through the axially oriented opening into the lubricant cavity, and then the opening is closed with an internal threaded plug and the hubcap bolt.Such a method and structure cannot be used on a steerable axle due to the structural differences between the wheel hub of a steerable axle and that of a non-steerable axle. For example, the hubcap bolt openings in many steerable axle wheel hubs are not axially aligned with the lubricant cavity. Furthermore, there are significant space constraints in a steerable axle wheel hub that limit the creation of a lubricant filler opening compared to a non-steerable axle wheel hub.WO 98 / 32 618 A1 and US 6 203 114 B1 each disclose a wheel head assembly comprising an improved wheel hub and a pair of bearings mounted on a spindle of an axle of a heavy commercial vehicle, wherein the wheel hub is rotatably mounted on the bearings and a cavity is formed in the wheel head assembly next to the bearings, wherein an opening is formed in the wheel hub and the opening extends axially inward and radially inward from an outer surface of the improved wheel hub at a predetermined angle to the cavity, and wherein a plug is located in the opening between the cavity and the outer surface of the wheel hub.

[0013] Consequently, there is a need in engineering for a structure and a method for filling a wheel hub of a steerable or non-steerable, driven or non-driven axle of a wheel assembly of a heavy commercial vehicle with semi-liquid lubricant, which overcomes the disadvantages described above. The axle wheel hub of a wheel assembly of a heavy commercial vehicle with a lubricant filling opening according to the present invention fulfills this need. Brief description of the invention

[0014] One objective of the present invention is to provide an axle wheel hub that can be filled with semi-liquid lubricant without removing the outer bearing.

[0015] Another objective of the present invention is to provide an axle wheel hub that can be easily filled with semi-liquid lubricant and that is economical to manufacture.

[0016] Another objective of the present invention is to provide an axle wheel hub that provides a visual indicator when there is a leakage of the semi-liquid lubricant.

[0017] These objectives and advantages are achieved by the improved wheel hub of the present invention. In an exemplary embodiment of the invention, a wheel head assembly comprises the improved wheel hub and a pair of bearings mounted on a spindle of an axle of a heavy-duty vehicle. The improved wheel hub is rotatably mounted on the bearings, and a cavity is formed in the wheel head assembly adjacent to the bearings. The improved wheel hub includes an opening formed within the improved wheel hub, and the opening extends axially inward and radially inward from an outer surface of the improved wheel hub at a predetermined angle to the cavity to facilitate filling and refilling the cavity with semi-liquid lubricant. A plug is located in the opening of the improved wheel hub.

[0018] These objectives and others are also achieved by the method for introducing semi-fluid lubricant into a wheel hub assembly mounted on an axle of a heavy-duty vehicle according to the present invention. In an exemplary embodiment, the method comprises providing a wheel hub assembly. The wheel hub assembly includes an improved wheel hub and a pair of bearings mounted on a spindle of the axle. The improved wheel hub is rotatably mounted on the bearings, and a cavity is formed in the wheel hub assembly adjacent to the bearings. An opening is formed in the improved wheel hub, extending axially inward and radially inward from an outer surface of the improved wheel hub at a predetermined angle to the cavity. A nozzle is inserted into the opening to be in fluid communication with a source of the semi-fluid lubricant.This causes the semi-liquid lubricant to flow through the nozzle into the opening and then into the cavity of the wheel hub assembly. The flow of the semi-liquid lubricant stops when a predetermined quantity has been introduced into the wheel hub assembly. After the flow of the semi-liquid lubricant has stopped, a plug is inserted into the opening. Brief description of the multiple views of the drawings

[0019] The preferred embodiment of the present invention, which illustrates the best way in which the applicants wish to see the principles applied, is set out in the following description and shown in the drawings, and is further detailed and precisely set out in the attached claims. Fig. Figure 1 is a fragmentary longitudinal sectional view of part of a first non-steerable axle and axle spindle and wheel head assembly of the prior art, including a wheel hub of the prior art formed with a radially oriented lubricant filling opening, and shows a device inserted into the filling opening to introduce semi-liquid lubricant into the wheel head assembly; Fig. Figure 2 is a fragmentary longitudinal sectional view of part of a second non-steerable axle and axle spindle and wheel head assembly of the prior art, including a wheel hub of the prior art formed with an axially oriented lubricant filling opening; Fig. Figure 3 is a fragmentary longitudinal sectional view of an exemplary embodiment of an axle wheel hub with a lubricant filling opening of the present invention; and Fig. 4 is an external top view of the in Fig. 3 axle wheel hubs with lubricant filling opening shown.

[0020] In all drawings, identical numbers refer to similar parts. Description of the preferred embodiment

[0021] To better understand the wheel hub of the present invention, it is necessary to Fig. Figure 1 shows and now describes a first wheel hub of a non-driven, non-steerable axle of the prior art, which is installed in a non-steerable axle spindle and wheel head assembly for a heavy commercial vehicle. The non-steerable axle 10 is suspended from the trailer of a heavy tractor unit (not shown) and extends transversely over it. A typical heavy tractor unit comprises one or more axles 10 suspended from the trailer, each axle having a wheel head assembly 12 mounted at each end of the axle. For clarity, only one axle end and one wheel head assembly 12 are described here. The axle 10 comprises a central tube 14, and an axle spindle 16 is integrally connected to each end of the central tube by some suitable means, such as welding. The central tube of the axle 14 is essentially tubular and forms an internal cavity 18.The axle spindle 16 tapers and is formed with a correspondingly tapered inner cavity 20.

[0022] The wheel head assembly 12 comprises a bearing assembly with an inner bearing 22 and an outer bearing 24, which are fixedly mounted at the outer end of the axle spindle 16. That is, the inner bearing 22 is mounted on the outer diameter of the axle spindle 16, with its inwardly facing surface abutting a shoulder 26 formed on the axle spindle. The outer bearing 24 is mounted near the outer end of the axle spindle 16 and, due to the tapered shape of the axle spindle, has a smaller inner diameter than the inner bearing 22.

[0023] A wheel hub 42 is rotatably mounted on the inner and outer bearings 22, 24 in a manner well known to those skilled in the art. A cavity 36 is defined in the wheel hub 42 between the inner and outer bearings 22, 24 and the axle spindle 16. A correspondingly tapered bearing spacer 28 is optionally located in the cavity 36 between the bearings 22, 24 to conveniently maintain the correct distance between the bearings. A nut assembly comprising an inner nut 30, a locking washer 32, an outer nut 34, and an adjusting screw 35 engages the outer end of the axle spindle 16 via a thread and holds the bearings 22, 24 and the bearing spacer 28 in place.

[0024] A wheel cover (not shown) is mounted to the outer end of the hub 42 by a plurality of bolts, each bolt passing through one of a plurality of openings formed in the wheel cover and threaded into one of a plurality of aligned threaded openings 44 formed in the hub. In this way, the wheel cover closes the outer end of the wheel head assembly 12. A continuous main seal 46 is rotatably mounted to the inner end of the wheel head assembly 12 and closes the inner end of the assembly. In particular, the seal 46 is suitably mounted to the wheel head assembly 12 and radially bridges the hub 42 and the axle spindle 16 to seal the cavity 36.The hub 42 is formed with a radially extending wheel mounting flange 52, which accommodates a plurality of press-fit pins 48 (only one shown) used to mount a brake drum, a rim, and one or more tires (not shown) to the wheel head assembly 12. Ideally, a vertical load line (not shown) of the one or more tires is located outside the wheel mounting flange 52 and between the inner and outer bearings 22, 24.

[0025] To maintain proper lubrication and operation of the inner and outer bearings 22, 24, an appropriate quantity of lubricant (not shown) is introduced into the cavity 36. For example, in the prior art, a radially oriented opening 49 is formed in the hub 42 between the inner and outer bearings 22, 24. A nozzle 50, which is in fluid communication with a tank (not shown) containing semi-liquid lubricant, is inserted into the radial opening 49 to pump the semi-liquid lubricant into the cavity 36. Once the correct quantity of lubricant has been introduced into the cavity 36, a plug (not shown) is inserted into the opening 49 and secured by mating threads (not shown) formed in the plug and the connection.As described above, the plug may include an interfering pipe thread, or it may include a standard thread that compresses an O-ring (not shown) which seals the opening 49 to prevent lubricant from escaping from the wheel head assembly 12.

[0026] If, as mentioned above, high-strength materials are used to form the hub 42, which allows for the use of a thinner wall to desirablely reduce the hub's weight, there may not be enough wall thickness to form sufficient threads in the radially oriented opening 49 to secure the threaded plug. Furthermore, forming the opening 49 requires an additional manufacturing step, which increases the cost of the hub 42.

[0027] We now turn Fig. 2. Shown is a second non-driven, non-steerable wheel hub 118 of the prior art, which is installed in a non-steerable axle spindle 100 and wheel head assembly 102. The wheel hub 118 is of the type described and shown in US Patent No. 7,585,031, which belongs to the applicant of the present invention, Hendrickson USALLC. The wheel head assembly 102 comprises a bearing assembly with an inner bearing 104 and an outer bearing 106, which are immovably mounted on the outer end of the axle spindle 100. In particular, the inner bearing 104 is mounted on the outer diameter of the axle spindle 100, with its inwardly facing surface abutting a shoulder 108 formed on the axle spindle. The external bearing 106 is mounted near the outer end of the axis spindle on the outer diameter of the axis spindle 100, as is known in engineering.

[0028] The wheel hub 118 is rotatably mounted on the inner and outer bearings 104, 106 in a manner well known to those skilled in the art. A cavity 116 is defined in the wheel hub 118 between the inner and outer bearings 104, 106 and the axle spindle 100. A bearing spacer (not shown) is optionally located between the bearings 104, 106 in the cavity 116 to conveniently maintain the correct distance between the bearings. A nut assembly (not shown) engages the outer end of the axle spindle 100 via a thread and holds the bearings 104, 106 and, optionally, the bearing spacer in place.

[0029] A wheel cap (not shown) is secured by a plurality of wheel cap bolts 140, each of which passes through one of a plurality of openings (not shown) formed in the wheel cap and engages threadedly with one of a plurality of aligned threaded openings 124 formed in projections 119 of the hub. Each wheel cap bolt opening 124 includes threads 123 formed therein to facilitate the threaded engagement of one of the plurality of wheel cap bolts 140. In this way, the wheel cap seals the outer end of the wheel head assembly 102. A continuous main seal 126 is rotatably mounted on the inner end of the wheel head assembly 102 and seals the inner end of the assembly. In particular, the seal 126 is suitably mounted on the wheel head assembly 102 and radially bridges the hub 118 and the axle spindle 100 to seal the cavity 116.The hub 118 is formed with a radially extending wheel mounting flange 132, which accommodates a plurality of threaded bolts 128 used to mount a brake drum, a rim, and one or more tires (not shown) to the wheel head assembly 102. Ideally, a vertical load line (not shown) of the one or more tires is located outside the wheel mounting flange 132 and between the inner and outer bearings 104, 106.

[0030] An axially oriented opening 121 is formed in the hub 118 so that a suitable quantity of semi-liquid lubricant (not shown) can be introduced into the cavity 116 to maintain proper lubrication and operation of the inner and outer bearings 104, 106. In particular, one of the wheel cap bolt openings 124' is drilled deeper inwards into the cavity 116 than the other wheel cap bolt openings 124 to form the filling opening 121. In this way, an axially oriented filling opening 121 extends substantially parallel to an imaginary central axis 130 of the hub 118, so that a through opening is formed between an outer surface 154 of the wheel hub and the cavity 116.To fill the wheel head assembly 102 with lubricant, a nozzle in fluid communication with a container of semi-liquid lubricant (not shown) is inserted into the outer end of the filler opening 121, and a metered quantity of semi-liquid lubricant is injected through the opening into the hub cavity 116. The filler opening 121 is provided with a thread 123' extending sufficiently deep from its outer end to allow sufficient space for the installation of an internal threaded plug 125 to seal the filler opening 121, and for the external installation of a wheel cap bolt 140' with respect to the internal threaded plug 125.

[0031] The structure of the filling opening 121 cannot be used on a steerable axle due to the size and structural differences between a wheel hub of a steerable axle and a wheel hub 118 of a non-steerable axle. In terms of size, a steerable axle wheel hub assembly is generally smaller, thinner, and / or lighter than a non-steerable axle wheel hub assembly, including drive axle or non-drive axle wheel hub assemblies, due to differences in function and location. A steerable axle wheel hub assembly is installed in a relatively confined, essentially horizontal space near a non-steerable axle of a trailer and in a relatively confined, essentially vertical space below the trailer frame.Furthermore, a steerable axle and its hub assembly, unlike a non-steerable axle and its hub assembly, are typically designed to be raised towards the trailer frame, thus limiting both the vertical and horizontal space available for installing the steerable axle and its hub assembly. Structurally, a steerable axle hub assembly also differs from a non-steerable axle hub assembly. For example, the hubcap bolt holes in many steerable axle hubs are not axially aligned with the lubrication cavity. Additionally, a steerable axle hub has significant space constraints that limit the formation of a lubrication filler opening compared to a non-steerable axle hub.

[0032] In other hub designs of the prior art, which do not have a radially oriented opening 49 ( Fig. 1) or axially aligned opening 121 ( Fig. 2) In this case, the hub is mounted without the outer bearing or the nut assembly on the inner bearing so that lubricant can be pumped into the hub cavity. Once the correct amount of lubricant has been introduced into the hub cavity, the outer bearing and nut assembly are installed. However, the lack of support at the outer end of the hub during filling increases the likelihood that the outer end of the hub will fall onto the axle spindle, which in turn can kink or damage the main seal at the inner end of the wheel hub.

[0033] The disadvantages described above led to a need in engineering for a structure and a method for filling a wheel hub of a driven or non-driven, steerable or non-steerable axle of a wheel assembly of a heavy commercial vehicle with semi-liquid lubricant. The axle wheel hub of a wheel assembly of a heavy commercial vehicle with a lubricant filling opening according to the present invention fulfills this need, as described below.

[0034] We now turn to the Fig. 3 and Fig. 4. An exemplary embodiment of an axle wheel hub of a wheel head assembly of a heavy commercial vehicle with a lubricant filling opening according to the present invention is generally designated by 200. The wheel hub 200 comprises an axially extending wall 202 and a radially extending wheel mounting flange 204, as is known in the art. The mounting flange 204 is preferably located on the outside with respect to a vertical load line (not shown) from one or more tires mounted on the flange 204. In a preferred case, the vertical load line is located axially between an outer bearing 230 (only bearing shell shown) and an inner bearing 232 (only bearing shell shown). In less preferred cases, the vertical load line may be located axially on the outside with respect to the outer bearing 230 or axially on the inside with respect to the inner bearing 232.An outer bearing cavity 206 is formed in the hub 200 and accommodates the outer bearing 230, which is press-fitted into the outer bearing cavity 206. An inner bearing cavity 208 is also formed in the hub 200 and accommodates the inner bearing 232, which is press-fitted into the inner bearing cavity. A lubricant cavity 210 is formed between the outer bearing cavity 206 and the inner bearing cavity 208 to retain lubricant, such as a semi-liquid lubricant (not shown), between and near the outer bearing 230 and inner bearing 232. A variety of threaded bolts 212 are used to mount a rim and tire (not shown) onto the wheel hub 200.

[0035] The hub 200 comprises an outer surface 254. A lubricant filling opening 216 is formed in the hub 200 and extends from the outer surface 254 of the hub through an outer wall 226 of the lubricant cavity 210, thus providing fluid communication between the outer surface of the hub and the lubricant cavity. The lubricant filling opening 216 is preferably formed by drilling or milling the hub 200. An outer end 222 of the filling opening 216 is preferably also threaded to receive a removable plug 218, thereby sealing the filling opening and retaining the lubricant in the lubricant cavity 210. The filling opening 216 comprises an inner end 224 adjacent to and in fluid communication with the lubricant cavity 210.

[0036] How best to Fig. As shown in Figure 4, the outer surface 254 of the hub is formed with a plurality of circumferentially spaced threaded openings 220 to receive wheel cap bolts (not shown). The wheel cap bolt openings 220 form a wheel cap bolt opening circle 228, and the outer end 222 of the filling opening 216 is located radially outside with respect to the wheel cap bolt opening circle 228. The outer end 222 of the filling opening 216 is preferably located at a position on the circumference that lies between a pair of wheel cap bolt openings 220 to create a free space between the filling opening and the bolt openings. The filling opening 216 extends axially inward from its outer end 222 to its inner end 224 and bends radially inward from its outer end to its inner end at an angle A relative to an axial centerline CL of the hub 200.The angle A is preferably between about 4 degrees and about 30 degrees relative to the axial centerline CL of the hub, and is particularly preferably between about 9 degrees and about 25 degrees relative to the axial centerline CL of the hub. For example, the angle A is in . Fig. Figure 3 shows an angle of approximately 14 degrees relative to the axial centerline CL of the hub. The filling opening 216 therefore begins radially outward from the wheel cap bolt opening circle and extends axially inward and radially inward within the hub 200 at a predetermined angle A, towards the wheel cap bolt circle 228, to the lubricant cavity 210.

[0037] In this way, the filling opening 216 creates a structure in the wheel hub 200 that facilitates the lubrication of the hub with semi-liquid lubricant. In comparison, the wheel hub 200 differs in structure from the wheel hubs for non-driven, non-steerable axles 42 ( Fig. 1) and 118 ( Fig. 2) of the prior art. Since, in particular, the mounting surface of the wheel mounting flange 204 is located in axial alignment with, or outside of, the outer surface of the hub 254, there is less space on the outer surface of the wheel hub 200 than in the wheel hubs for non-steerable axles 42 and 118 of the prior art.

[0038] In other words, the wheel mounting flange 204 of the hub 200 extends radially outward from substantially near the outer surface 254 of the hub 200. In contrast, the wheel mounting flanges 52 of the hub 42 or 132 of the hub 118 extend radially outward from between the inner surfaces 56, 156 and outer surfaces 54, 154, respectively, of the axially extending hub wall, and the mounting surfaces of the wheel mounting flanges 52, 132 are neither aligned with nor outside the outer surface 54, 154 of the hub. Due to the different location of the wheel hub mounting flange 204 of the wheel hub 200, there is less space on the outer surface 254 of the axle wheel hub 200 than in wheel hubs for non-steerable axles 42 and 118 of the prior art to position a lubricant filling opening.

[0039] Furthermore, a wheel mounting flange 204, which is preferably located axially outwards relative to the vertical load line of one or more tires mounted on the wheel mounting flange 204, enables the positioning of the vertical load line axially between the outer bearing 230 and the inner bearing 232, thereby distributing the tire loads of the outer bearing 230 and the inner bearing 232.

[0040] When applied specifically to a steerable hub, the formation of the wheel mounting flange 204 axially near the hub's outer surface 254, thus providing an axially outward and radially outward-facing gap essentially between the wheel mounting flange 204 and the inner surface 256 along the outer surface of the hub wall 202, allows the wheel hub 200 to accommodate steering components (not shown), such as a steering knuckle, steering arm, etc., within this outer gap. Of particular importance is the fact that, as is well known in engineering, a steerable wheel hub should generally have a smaller diameter and lower weight than a non-steerable wheel hub, and therefore manufacturing a wheel hub with a thin and lightweight axle wall helps to achieve this goal.Thus, positioning the lubricant filling port 216 in the hub's outer surface 254, rather than in the axially extending wall 202, allows the use of a thin, axially extending wall with high strength to reduce the weight and cost of the hub 200, in contrast to the heavier, thicker wall of the first wheel hub for a non-steerable axle 42 of the prior art. Furthermore, the lubricant filling port 216 allows direct fluid communication with the lubricant cavity 210, unlike the filling port 121, which extends axially from a selected opening 124' of the second wheel hub for a non-steerable axle of the prior art, and which may not be aligned with the lubricant cavity in the wheel hub 200.

[0041] The position and structure of the lubricant filler opening 216 of the wheel hub 200 also allows the filler opening to lead directly from the hub's outer surface 254 to the lubricant cavity 210, while maintaining a distance to the outer bearing cavity 206 and the outer bearing 230, thus preserving the structural integrity of the hub and its associated components. In particular, the fact that the outer end 222 of the filler opening 216 is located radially outside the wheel cap bolt circle 228 and the outer bearing cavity 206 preserves the structural integrity of the hub and its associated components, while maintaining the structural strength of the hub. Preferably, positioning the outer end of the filler opening 222 circumferentially between a pair of wheel cap bolt openings 220 also preserves the structural integrity of the hub and its associated components, while maintaining the structural strength of the hub.Furthermore, the lubricant filling opening 216 allows the wheel hub 200 to be filled with lubricant, while both the inner bearing 232 and the outer bearing 230 support the hub, thus preventing damage to the main seal 126 (. Fig. 2), which occurs in state-of-the-art wheel hubs where the outer bearing has to be removed for filling, is prevented.

[0042] The lubricant filling opening 216 also enables economical maintenance by providing a lubricant filling opening which, compared to a filling opening 121 of the state of the art ( Fig. 2) is separated from a wheel cap bolt opening 140' and a wheel cap (not shown). In particular, if the wheel hub 118 receives a strong impact, the wheel cap, the wheel cap bolt opening 124', the wheel cap bolt 140', the plug 125 and / or the hub projection 119 may break or be damaged, potentially resulting in lubricant leakage. Furthermore, due to the possible damage caused by the strong impact, the impacted wheel cap, the wheel cap bolt 140', the wheel cap bolt opening 124' and / or the opening of the filler opening 121 may result in a deteriorated fastening or seal between the wheel cap and the hub 118.A weakened bolt fastening of the opening of the filler opening 121 can, in turn, result in a disproportionate fastening load on the other wheel cap bolts 140, leading to poor fastening between the wheel cap and the hub in general, which can impair the performance of the wheel head assembly. A strong impact against the hub 118 or the wheel cap can also potentially destroy or damage the filler opening 121 and cause lubricant to leak into the threads 123' of the wheel cap bolt opening 124', which can loosen the threaded seat between the wheel cap bolt 140' and the threads 123' and between the plug 125 and the threads 123', thereby weakening the fastening between the wheel cap and the hub. In contrast, the lubricant filler opening 216 of the wheel hub 200 of the present invention is formed separately from the wheel cap bolt openings 220.Since the lubricant filling opening 216 has its own access to the cavity 210, independent of any wheel cap bolt opening 220, there is no potential weakening of the fastening between the wheel cap and the hub 200 caused by improper installation of the wheel cap bolt 140', nor is there any risk of damage to the wheel cap, wheel cap bolt 140', hub projection 119, and / or wheel cap bolt opening 124' due to a strong impact. Therefore, there is no risk of such undesirable effects on the performance of the wheel head assembly hub 200 of the present invention in the event of a strong impact against the wheel cap, the wheel cap bolts, the hub projection, and / or the wheel cap bolt openings.

[0043] The wheel hub 200 can therefore be easily filled or refilled with semi-liquid lubricant during the initial assembly of the wheel head assembly (not shown) or during subsequent maintenance of the wheel head assembly using the lubricant filling port 216. To fill or refill the wheel hub 200 with semi-liquid lubricant, a nozzle (not shown), which is in fluid communication with a tank or other container of semi-liquid lubricant, is inserted into the outer end 222 of the filling port 216, and then a metered quantity of the semi-liquid lubricant is injected into the lubricant cavity 210. After the lubricant has been injected, the nozzle is removed, and the plug 218 is screwed into the outer end 222 of the filling port 216 to seal the port and the lubricant cavity 210.

[0044] Furthermore, the lubricant filling opening 216 of the wheel hub 200 provides a visual indicator if the semi-liquid lubricant leaks out. Particularly due to the centrifugal force generated when the heavy commercial vehicle is in motion and the wheels are rotating, the plug 218 may tend to retract from the lubricant filling opening 216 if it is not installed or not installed correctly. If, in a first wheel hub for a non-steerable axle 42 of the prior art ( Fig. 1) When the plug (not shown) retracts from the radially oriented filling opening 49, the centrifugal force causes semi-liquid lubricant to spray out of the filling opening. The position of the filling opening 49, i.e., facing outwards with respect to the wheel mounting flange 52, means that this escaped semi-liquid lubricant comes into contact with the wheel surface. Since the wheel surface is easily visible, semi-liquid lubricant on the wheel surface is a visual indicator for the driver or technician that the plug is missing. Similarly, in the case of the second wheel hub for a non-steerable axle 118 of the prior art ( Fig. 2) When the plug (not shown) retracts from the axially oriented filler opening 121, the centrifugal force causes semi-liquid lubricant to spray out of the filler opening, and the position of the filler opening 121, which is located externally with respect to the wheel mounting flange 132, causes this escaped semi-liquid lubricant to come into contact with the wheel surface. Since the wheel surface is easily visible, this again provides a visual indicator to the driver or a technician that the plug is missing.

[0045] In contrast, the wheel mounting flange 204 of the wheel hub 200 is axially aligned with or outside the hub's outer surface 254, making it more difficult to provide a visual indicator if the plug 218 is missing. For example, a radially oriented filler opening formed in the axially extending wall 202 of the wheel hub 200 would be positioned behind the wheel, so that any leaked semi-liquid lubricant would not come into contact with the wheel in an area easily visible to an operator or technician. However, the structure of the lubricant filler opening 216 described above allows for optimal positioning of the filler opening to provide a visual indicator in the event that the plug 218 retracts from the filler opening.The axial and radial position of the outer end 222 of the lubricant filler opening 216 allows any leaked semi-liquid lubricant to escape from the outer end of the filler opening and come into contact with the surface of the respective wheel (not shown). Since the wheel surface is easily visible, the semi-liquid lubricant on the wheel surface is a visual indicator to the driver or technician that the plug 218 is missing. The driver or technician can then take measures to check the amount of semi-liquid lubricant in the wheel hub 200, thereby maintaining the function of the bearings 230, 232 and optimizing their service life.

[0046] The present invention also comprises a method for introducing and filling a wheel hub of a driven or non-driven, steerable or non-steerable axle of a wheel head assembly of a heavy commercial vehicle with semi-liquid lubricant using a lubricant filling port. The semi-liquid lubricant can be introduced into the axle wheel hub after the bearings have been mounted on the axle, which can take place during the initial assembly of the wheel head assembly or during subsequent maintenance of the wheel head assembly. The method comprises steps as described above and in the Fig. 3-4 is shown.

[0047] It should be understood that the structure and / or location of the wheel hub 200 of a wheel head assembly of a heavy commercial vehicle with lubricant filling opening 216 described above can be modified or rearranged, or that certain components can be omitted or added, without affecting the overall concept or implementation of the invention. Furthermore, the wheel hub 200 of a wheel head assembly of a heavy commercial vehicle with lubricant filling opening 216 according to the present invention can also be used with other types of axles, wheel head assemblies, axle / suspension systems, and / or brake systems than those shown and described above, without affecting the overall concept or implementation of the invention.

[0048] It should also be understood that the present invention applies to all types of wheel hubs of driven or non-driven, steerable or non-steerable axles and associated axle spindles and wheel head assemblies known to those skilled in the art, including types other than those shown and described herein, without affecting the concept or embodiment of the invention. Furthermore, while reference has been made generally to a heavy commercial vehicle for convenience, this reference is understood to encompass trucks, tractors and their trailers, as well as all other types of heavy commercial vehicles.Furthermore, it is envisaged that the present invention can be applied in single-wheel or twin-wheel configurations, wherein the vertical load line with respect to the wheel mounting flange on which the wheel rim or rims / the tire or tires are mounted is preferably located on the inside.

[0049] The present invention has been described with reference to a particular embodiment. It is clear that this description and illustration are exemplary and in no way limiting. Potential modifications and alterations will occur to others upon reading and understanding this disclosure, and it is clear that the invention encompasses all such modifications and alterations and their equivalents.

[0050] Accordingly, the axle wheel hub of a wheel head assembly of a heavy commercial vehicle with lubricant filling opening of the present invention is simplified, provides an effective, safe, cost-effective and efficient structure that achieves all the listed objectives, eliminates the difficulties encountered in prior art wheel hubs, solves problems and obtains new results in the technology.

[0051] In the above description, certain terms have been used for the sake of brevity, clarity, and understanding; however, no unnecessary restrictions beyond the requirements of the prior art should be inferred from this, since these terms are used for descriptive purposes and are intended to be interpreted broadly. Furthermore, the description and illustration of the present invention are exemplary, and the scope of the present invention is not limited to the exact details shown or described.

[0052] Having now described the features, results and principles of the present invention, the manner in which the axle wheel hub of a wheel head assembly of a heavy commercial vehicle with lubricant filling opening of the present invention is constructed, arranged and used, the features of the construction and arrangement and the advantageous new and useful results obtained, the new and useful structures, devices, elements, arrangements, methods, parts and combinations are set out in the appended claims.

Claims

[1] Wheel head assembly comprising an improved wheel hub (200) and a pair of bearings (230, 232) mounted on a spindle of an axle of a heavy commercial vehicle, wherein the wheel hub (200) is rotatably mounted on the bearings (230, 232) and a lubricant cavity (210) is formed in the wheel head assembly between the bearings (230, 232), characterized by , that: a lubricant filling opening (216) is formed in the wheel hub (200), the lubricant filling opening (216) extends axially inwards and radially inwards from the outer surface (254) of the improved wheel hub (200) at a predetermined angle (A) through an outer wall (226) of the lubricant cavity (210) to the lubricant cavity (210) and provides for fluid communication between the outer surface (254) of the wheel hub (200) and the lubricant cavity (210), thereby facilitating the filling and refilling of the lubricant cavity (210) with semi-liquid lubricant; and a plug (218) is located in the lubricant filling opening (216) between the lubricant cavity (210) and the outer surface (254) of the wheel hub (200). [2] Wheel head assembly according to claim 1, wherein an outer end (222) of the lubricant filling opening (216) is located circumferentially between a pair of wheel cap bolt openings (220). [3] Wheel head assembly according to claim 1, wherein an outer end (222) of the lubricant filling opening (216) is located radially outside with respect to a wheel cap bolt opening circle (228) formed by the wheel cap bolt openings (220). [4] Wheel head assembly according to claim 1, wherein the plug (218) is removable. [5] Wheel head assembly according to claim 1, wherein the lubricant filling opening (216) has a thread and the plug (218) is formed with a thread that fits the lubricant filling opening (216) having the thread. [6] Wheel head assembly according to claim 1, wherein the predetermined angle (A) is between 4 degrees and 30 degrees. [7] Wheel head assembly according to claim 1, wherein the predetermined angle (A) is between 9 degrees and 25 degrees. [8] Wheel head assembly according to claim 1, further comprising a visual indicator formed on an outer surface (254) of the wheel hub (200) to indicate the location of the lubricant filling opening (216). [9] Wheel head assembly according to claim 1, wherein the wheel hub (200) is a thin-walled wheel hub. [10] Wheel head assembly according to claim 1, wherein the wheel hub (200) comprises a wheel mounting flange (204) which is located on the outside with respect to a vertical load line of at least one tire that was mounted on the wheel hub (200). [11] Method for introducing semi-liquid lubricant into a wheel head assembly mounted on an axle of a heavy commercial vehicle, the method comprising the following steps: Providing a wheel head assembly comprising an improved wheel hub (200) and a pair of bearings (230, 232) mounted on a spindle of the axle, wherein the improved wheel hub (200) is rotatably mounted on the bearings (230, 232) and a lubricant cavity (210) is formed in the wheel head assembly between the bearings (230, 232); Forming a lubricant filling opening (216) in the improved wheel hub (200), wherein the lubricant filling opening (216) extends axially inwards and radially inwards from the outer surface (254) of the improved wheel hub (200) at a predetermined angle (A) through an outer wall (226) of the lubricant cavity (210) to the lubricant cavity (210) and provides for fluid communication between the outer surface (254) of the wheel hub (200) and the lubricant cavity (210); Inserting a nozzle into the lubricant filling opening (216), wherein the nozzle is in fluid communication with a source of the semi-liquid lubricant; Causing the semi-liquid lubricant to flow through the nozzle into the lubricant filling opening (216), thereby allowing the semi-liquid lubricant to flow into the lubricant cavity (210) of the wheel head assembly; Interrupting the flow of the semi-liquid lubricant when a predetermined quantity of the semi-liquid lubricant has been introduced into the wheel head assembly; and Inserting a plug (218) into the lubricant filling opening (216) after the flow of the semi-liquid lubricant has stopped. [12] Method for introducing semi-liquid lubricant into the wheel head assembly according to claim 11, wherein an outer end (222) of the lubricant filling opening (216) is located circumferentially between a pair of wheel cap bolt openings (220). [13] Method for introducing semi-liquid lubricant into the wheel head assembly according to claim 11, wherein an outer end (222) of the lubricant filling opening (216) is located radially outside with respect to a wheel cap bolt opening circle (228) formed by the wheel cap bolt openings (220). [14] Method for introducing semi-liquid lubricant into the wheel head assembly according to claim 11, wherein the plug (218) is removable. [15] Method for introducing semi-liquid lubricant into the wheel head assembly according to claim 11, wherein the lubricant filling opening (216) has a thread and the plug (218) has a thread that fits the lubricant filling opening (216) with the thread. [16] Method for introducing semi-liquid lubricant into the wheel head assembly according to claim 11, wherein the predetermined angle (A) is between 4 degrees and 30 degrees. [17] Method for introducing semi-liquid lubricant into the wheel head assembly according to claim 11, wherein the predetermined angle (A) is between 9 degrees and 25 degrees. [18] Method for introducing semi-liquid lubricant into the wheel head assembly according to claim 11, wherein the wheel hub (200) is a thin-walled wheel hub. [19] Method for introducing semi-liquid lubricant into the wheel head assembly according to claim 11, further comprising a visual indicator formed on an outer surface (254) of the wheel hub (200) to indicate the location of the lubricant filling opening (216).

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