A wheel hub assembly structure of a waterproof single-row conical roller bearing for a front steering axle

Abstract

The utility model discloses a wheel hub assembly structure of waterproof single row tapered roller bearing for front steering axle, contain wheel hub, wheel hub outer bearing, wear -reducing baffle, axle head locking nut, wheel hub end cover, wheel hub inner bearing, waterproof oil seal and steering knuckle, wheel hub end cover and wheel hub junction department establish first sealing structure, constitute by the first annular groove of wheel hub end face and the first O type ring embedded in it, when wheel hub end cover locking, first O type ring is compressed between the flanging press -fitting portion and first annular groove, wheel hub inner bearing inner race and steering knuckle junction department establish second sealing structure, constitute by the second annular groove of wheel hub inner bearing inner race outer circular surface and second O type ring, and second O type ring is compressed between second annular groove and steering knuckle journal after installation. The structure passes through double O type ring sealing, effectively solves the problem of water entry of engineering vehicle wheel hub, avoids the emulsification of lubricating grease to cause early damage.

Description

Technical Field

[0001] This utility model belongs to the field of automotive wheel hub assembly technology, and particularly relates to a wheel hub assembly structure with a waterproof single-row tapered roller bearing for the front steering axle. Background Technology

[0002] As a key component of the front steering axle of automobiles, the reliability of the wheel hub assembly's sealing performance directly affects the service life of the bearings and the overall vehicle uptime. For construction vehicles such as dump trucks and mixer trucks, the working conditions are extremely harsh, and frequent water crossings (such as crossing water pools when leaving a construction site) are commonplace, which places extremely high demands on the waterproof sealing capabilities of the wheel ends.

[0003] Currently, there are two main sealing solutions for the front steering axle wheel ends of commercial vehicles: one is to use four screws to fasten the wheel hub end cap and supplement it with a sealing gasket or sealant; the other is to use a threaded wheel hub cap and apply sealant to the threads. The inside of the wheel hub generally relies on a single waterproof oil seal to prevent water ingress. However, in practical applications, these existing solutions all have significant drawbacks. First, the inner ring of the bearing inside the wheel hub has a small clearance fit with the steering knuckle. Under wading conditions, high-pressure water can easily penetrate through this mating surface, causing the grease to emulsify and fail, leading to premature bearing damage. Second, the sealing of the wheel hub end cap heavily relies on manually applied sealant, the uniformity of which is difficult to guarantee, and gaps in the sealant may exist. Furthermore, the performance of the sealant is greatly affected by ambient temperature; it may not solidify properly at low temperatures, leading to seal failure and water ingress from the end cap.

[0004] Chinese utility model patent application CN113320331A discloses a front axle wheel hub bearing unit for automobiles. It compensates for wear and maintains stable clearance by using an intermediate spacer sleeve, and employs combined seals and O-rings (such as seal 06 and seal O-ring 07) to improve sealing performance. However, the sealing design of this patent primarily aims to prevent internal grease leakage and block external dust and impurities from entering. Its application scenario and the technical problem it addresses differ from that of this utility model. This solution does not provide an effective solution to the problem of external sewage actively intruding into the wheel hub under high-pressure wading conditions for engineering vehicles. Its sealing structure is not designed to address the two main water ingress paths: the fit gap between the inner bearing ring and the steering knuckle, and the sealing weakness of the threaded end cap.

[0005] Therefore, the existing wheel hub assembly structure cannot meet the stringent requirements of engineering vehicles that frequently wade through water. Water ingress into the wheel hub leads to premature damage to bearings and oil seals, and there is an urgent need for a new and more targeted high-sealing wheel hub assembly structure to solve this industry pain point. Utility Model Content

[0006] To address the problems existing in the prior art, this utility model provides a hub assembly structure for a waterproof single-row tapered roller bearing for a front steering axle.

[0007] This utility model is implemented as follows: a hub assembly structure for a front steering axle with a waterproof single-row tapered roller bearing, comprising a hub, an outer hub bearing, a friction-reducing baffle, a shaft end lock nut, a hub end cap, an inner hub bearing, a waterproof oil seal, and a steering knuckle, characterized in that: The hub end cap and the hub are provided with a first sealing structure. The first sealing structure includes a first annular groove formed on the end face of the hub and a first O-ring embedded in the first annular groove. When the hub end cap is locked, the first O-ring is compressed between the flange pressing part of the hub end cap and the first annular groove. The inner ring of the inner bearing in the wheel hub is provided with a second sealing structure at the joint between the inner ring and the steering knuckle. The second sealing structure includes a second annular groove formed on the outer cylindrical surface of the inner ring of the inner bearing in the wheel hub and a second O-ring embedded in the second annular groove. The second O-ring is compressed between the second annular groove and the journal of the steering knuckle after the wheel hub assembly is installed on the steering knuckle.

[0008] More preferably, the hub end cap is connected to the hub by threads, and thread-fastening adhesive is applied to the threaded portion.

[0009] More preferably, the waterproof oil seal is a box-type waterproof oil seal, which is disposed between the wheel hub and the inner ring of the inner bearing of the wheel hub.

[0010] More preferably, the inner bearing of the wheel hub is a single-row tapered roller bearing.

[0011] More preferably, the first O-ring and the second O-ring are made of nitrile rubber or fluororubber.

[0012] The advantages and technical effects of this utility model are as follows: The core technical effect of this utility model lies in its innovative double O-ring sealing structure, which fundamentally solves the problem of water ingress into the wheel hubs of engineering vehicles under wading conditions. A first O-ring seal is installed at the mating surface of the wheel hub end cover, replacing the traditional unreliable sealant. Through mechanical compression, a stable and temperature-independent static seal is formed, completely eliminating the risk of water ingress from this point. More importantly, a second O-ring seal is added at the mating clearance between the inner bearing ring and the steering knuckle inside the wheel hub, actively blocking the most important water ingress path. Together with the original oil seal, it forms a composite barrier system of "dynamic seal + static seal," enclosing the bearing system in a dry cavity. This design greatly improves sealing reliability and bearing life, effectively avoids premature damage caused by grease emulsification due to water ingress, significantly improves vehicle uptime, and reduces maintenance costs. It has outstanding advantages such as ingenious structure, low modification cost, and ease of promotion. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall result of this utility model; Figure 2 This is a 3D view of the wheel hub end cap.

[0014] In the diagram: 1. Wheel hub; 2. Outer bearing of wheel hub; 3. First O-ring; 4. Anti-friction baffle; 5. Shaft head lock nut; 6. Wheel hub end cover; 61. Flanged pressing part; 7. Inner bearing of wheel hub; 8. Waterproof oil seal; 9. Second O-ring; 10. Steering knuckle. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0016] Please see Figure 1 and Figure 2 A hub assembly structure for a waterproof single-row tapered roller bearing for a front steering axle includes a hub 1, an outer hub bearing 2, a friction-reducing baffle 4, a shaft head lock nut 5, a hub end cover 6, an inner hub bearing 7, a waterproof oil seal 8, and a steering knuckle 10, characterized in that: A first sealing structure is provided at the joint between the hub end cover 6 and the hub 1. The first sealing structure includes a first annular groove formed on the end face of the hub 1 and a first O-ring 3 embedded in the first annular groove. When the hub end cover 6 is locked, the first O-ring 3 is compressed between the flange pressing part 61 of the hub end cover 6 and the first annular groove. The locking torque of the hub end cover (6) is 100 N·m. A second sealing structure is provided at the junction of the inner ring of the inner bearing 7 and the steering knuckle 10. The second sealing structure includes a second annular groove formed on the outer cylindrical surface of the inner ring of the inner bearing 7 and a second O-ring 9 embedded in the second annular groove. The second O-ring 9 is compressed between the second annular groove and the journal of the steering knuckle 10 after the wheel hub assembly is installed on the steering knuckle 10.

[0017] This solution constitutes a dual active sealing barrier. The first sealing structure, through the elastic compression of the O-ring, completely solves the water ingress risks associated with uneven sealing and temperature-dependent failure inherent in traditional wheel hub end caps, which rely on manual application of sealant. The second sealing structure directly blocks the primary water ingress channel—the clearance between the inner bearing ring and the steering knuckle within the wheel hub. Working in conjunction with the waterproof oil seal 8, it encloses the bearing system in a dry environment, fundamentally preventing grease failure and premature bearing damage caused by water ingress, and significantly improving the uptime and reliability of engineering vehicles under harsh operating conditions.

[0018] Preferably, the hub end cap 6 is threadedly connected to the hub 1, and thread-locking adhesive is applied to the threaded portion. The threaded connection provides a strong axial locking force, ensuring that the first O-ring 3 receives uniform and stable compression, guaranteeing the durability of the seal. Applying thread-locking adhesive effectively prevents the hub end cap 6 from loosening due to vibrations during vehicle operation, avoiding seal failure caused by loosening, thus achieving dual protection against thread loosening and end-face sealing.

[0019] Preferably, the waterproof oil seal 8 is a box-type waterproof oil seal, located between the wheel hub 1 and the inner ring of the inner bearing 7. As a third line of defense, the box-type waterproof oil seal's multi-lip and rigid shell structure effectively prevents the intrusion of external mud, water, and dust. Combined with the static seal formed by the second O-ring 9, it constitutes a composite sealing system of "dynamic seal + static seal," significantly enhancing the overall sealing protection level of the wheel hub's internal cavity.

[0020] Preferably, the inner bearing 7 of the wheel hub is a single-row tapered roller bearing. Using a single-row tapered roller bearing provides sufficient load-bearing capacity to meet the heavy-duty requirements of engineering vehicles, and its standardized structure facilitates machining to create the second annular groove, ensuring the feasibility and economy of the second sealing structure. This allows the waterproofing solution to be easily implemented on a conventional bearing structure.

[0021] Preferably, the first O-ring 3 and the second O-ring 9 are made of nitrile rubber or fluororubber. Nitrile rubber has good oil resistance and elasticity, and is moderately priced; fluororubber has excellent high-temperature resistance, oil resistance, and chemical resistance. Selecting appropriate materials based on different operating environments and cost requirements ensures that the O-rings maintain stable sealing performance and a long service life under complex and harsh working conditions.

[0022] In summary, the wheel hub assembly structure of the waterproof single-row tapered roller bearing for the front steering axle described in this utility model, through its innovative dual active sealing design, fundamentally solves the long-standing technical problem of water ingress into the wheel hub of engineering vehicles under severe wading conditions, achieving significant technical progress and multiple positive effects.

[0023] First, a qualitative leap has been achieved in sealing reliability. This utility model abandons the passive sealing method of relying on manual application of sealant in traditional solutions, and creatively sets up a mechanical seal structure based on O-rings at the two key water inlet paths. First, a first seal (first O-ring 3) is set at the mating surface of the wheel hub end cover. The axial clamping force of the end cover flange causes the O-ring to elastically deform, forming a continuous, stable, and temperature-independent annular sealing band, completely eliminating the risk of seal failure caused by poor sealant curing or uneven application. Second, a second seal (second O-ring 9) is set at the most important water inlet channel—the mating gap between the inner ring of the wheel hub bearing 7 and the steering knuckle 10. This design directly blocks the intrusion channel of high-pressure water flow, and together with the original waterproof oil seal 8, it constructs a composite barrier system of "dynamic seal (oil seal) + static seal (O-ring)," making the inside of the wheel hub a nearly completely sealed dry cavity, greatly improving the overall sealing protection level.

[0024] Secondly, this invention offers significant practical and economic value. By substantially improving sealing reliability, it effectively prevents grease from emulsifying and failing due to water ingress, thereby avoiding premature abnormal wear and damage to bearings and oil seals. This not only extends the service life of the wheel hub assembly to match its design life but, more importantly, greatly improves the uptime and operational efficiency of engineering vehicles such as dump trucks and mixer trucks, reduces downtime losses caused by frequent maintenance, significantly lowers users' subsequent maintenance and operating costs, and enhances customer satisfaction.

[0025] Finally, the structural design of this utility model is ingenious and easy to implement. Its core sealing element (O-ring) is a standard part, which is inexpensive and easy to install. The improvement of the inner bearing of the wheel hub only requires machining an annular groove in its inner ring, without changing other main structures. The modification cost is low, the processability is good, and it is very conducive to promotion and application in existing models, with broad market prospects.

[0026] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hub assembly structure for a waterproof single-row tapered roller bearing for a front steering axle, comprising a hub (1), an outer hub bearing (2), a friction-reducing baffle (4), a shaft end lock nut (5), a hub end cap (6), an inner hub bearing (7), a waterproof oil seal (8), and a steering knuckle (10), characterized in that: A first sealing structure is provided at the joint between the hub end cap (6) and the hub (1). The first sealing structure includes a first annular groove opened on the end face of the hub (1) and a first O-ring (3) embedded in the first annular groove. When the hub end cap (6) is locked, the first O-ring (3) is compressed between the flange pressing part (61) of the hub end cap (6) and the first annular groove. A second sealing structure is provided at the joint between the inner ring of the inner bearing (7) and the steering knuckle (10). The second sealing structure includes a second annular groove formed on the outer cylindrical surface of the inner ring of the inner bearing (7) and a second O-ring (9) embedded in the second annular groove. The second O-ring (9) is compressed between the second annular groove and the journal of the steering knuckle (10) after the wheel hub assembly is installed on the steering knuckle (10).

2. The hub assembly structure of a waterproof single-row tapered roller bearing for a front steering axle according to claim 1, characterized in that: The hub end cap (6) is connected to the hub (1) by threads, and thread fastening adhesive is applied to the threaded part.

3. The hub assembly structure of a waterproof single-row tapered roller bearing for a front steering axle according to claim 1, characterized in that: The waterproof oil seal (8) is a box-type waterproof oil seal, which is located between the hub (1) and the inner ring of the inner bearing (7) of the hub.

4. The hub assembly structure of a waterproof single-row tapered roller bearing for a front steering axle according to claim 1, characterized in that: The inner bearing (7) of the wheel hub is a single-row tapered roller bearing.

5. The hub assembly structure of a waterproof single-row tapered roller bearing for a front steering axle according to claim 1, characterized in that: The first O-ring (3) and the second O-ring (9) are made of nitrile rubber or fluororubber.

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