A function-integrated hub bearing unit

Abstract

The application relates to a function-integrated hub bearing unit which mainly comprises a wheel valve assembly, a hub assembly, an inner ring torque transmission shaft, an outer side bearing rolling ring, an outer ring support shaft, an inner side bearing rolling ring and an auxiliary function integration block; the end cover of the wheel valve assembly is fixedly connected with the left end surface of the hub assembly; the inner ring torque transmission shaft is connected by a reducer main frame and a wheel shaft supporting the inner ring of a bearing; the hub assembly is fixedly connected with the reducer main frame; the outer surface of the wheel shaft is in interference fit with the inner ring of the outer side bearing rolling ring and the inner side bearing rolling ring; the outer ring support shaft is provided with a bearing outer raceway and is connected with the outer side bearing rolling ring and the inner side bearing rolling ring in a matched mode. The application utilizes the hollow space available in a high-power inner rotor hub motor, adopts a structure mode of function reuse, space reuse and overlap, realizes torque transmission and load bearing compatibility, improves the optimization of the electric drive wheel bearing structure, and makes the axial dimension shorter.

Description

Technical Field

[0001] This invention belongs to the field of hub motor technology, specifically relating to a functionally integrated hub bearing unit. Background Technology

[0002] With the rapid development of ground equipment systems towards modularity, intelligence, and autonomy, distributed drive technology based on hub motors is a significant trend in the development of next-generation wheeled vehicles. Because multi-wheel drive systems offer optimized degrees of freedom in dynamic control, they facilitate the implementation of various complex dynamic control functions, making them one of the recognized best solutions for enhancing the all-terrain capabilities of wheeled vehicles. High-power hub motor drive systems, by introducing motors within the tires, integrate functions such as driving, braking, deceleration, support, and control, resulting in a structure significantly different from traditional wheel-side drive systems. Existing hub bearings for high-power heavy-duty vehicle electric drive wheels largely retain traditional bearing support structures, using paired tapered roller or angular contact ball bearings, which are independently installed and adjusted.

[0003] Existing high-power electric drive wheel hub bearings employ conventional end or reducer end bearing arrangements, resulting in a large axial space occupation. The introduction of hub motors further lengthens the axial dimension of the electric drive wheel, which is detrimental to the overall layout and suspension assembly. Some designs, while employing simple bearing integration structures, fail to consider the characteristics of electric drive wheels (i.e., the addition of hub motors compared to traditional designs), merely integrating the inner and outer bearing rings. Furthermore, their placement near the hub-rim mating surface causes an offset in the force exerted on the tire centerline by the vehicle load, negatively impacting bearing lifespan. Additionally, hub bearings are not designed for high integration with other electric drive wheel components or for functional modularization, resulting in low space utilization. This does not align with the future development direction of integrated, lightweight, and modular electric drive wheels, and thus lacks long-term application potential. Summary of the Invention

[0004] This invention provides a functionally integrated wheel hub bearing unit, overcoming the shortcomings of existing technologies.

[0005] To address the above technical problems, this invention provides a functionally integrated wheel hub bearing unit, characterized by: primarily composed of a wheel valve assembly 2, a wheel hub assembly 3, an inner ring torque transmission shaft 4, an outer bearing ring 5, an outer ring support shaft 6, an inner bearing ring 7, and an auxiliary function integrated block 8; the end cap of the wheel valve assembly 2 is fixedly connected to the left end face of the wheel hub assembly 3; the inner ring torque transmission shaft 4 is formed by connecting the reducer main frame 23 and the wheel axle 25 supporting the inner ring of the bearing; the wheel hub assembly 3 is fixedly connected to the reducer main frame; the outer surface 32 of the wheel axle 25 is interference-fitted with the inner rings of the outer bearing ring 5 and the inner ring of the inner bearing ring 7; the outer ring support shaft 6 is provided with an outer bearing raceway, which is respectively connected to the outer bearing ring 5 and the inner bearing ring 7; the inner hole at the right end of the outer ring support shaft 6 is provided with an auxiliary function integrated block 8 for a central inflation / deflation system.

[0006] Beneficial Effects: This invention utilizes the available space within the hollow of a high-power internal rotor hub motor, employing a functional reuse and space-sharing overlapping structure to achieve compatibility between torque transmission and load-bearing. This optimizes the load-bearing structure of the electric drive wheel, resulting in a shorter axial dimension. Furthermore, the invention integrates functional components such as a central inflation / deflation system, ABS speed measurement, and a transmission breather. By converting the operating characteristics of the inner and outer ring modules, it forms a hub bearing unit suitable for different vehicle variants. This provides a reliable, lightweight, and functionally integrated hub bearing unit for the electric drive wheels of high-power wheeled special electric transmission vehicles. Compared to existing technologies, this invention achieves a compact, lightweight, high-space-utilization, and highly reliable support and torque transmission bearing unit structure. Attached Figure Description

[0007] Figure 1 Schematic diagram of the structure of this invention;

[0008] Figure 2 Schematic diagram of wheel valve assembly;

[0009] Figure 3 Schematic diagram of wheel hub assembly structure;

[0010] Figure 4 Schematic diagram of the inner ring torsion shaft structure;

[0011] Figure 5 Schematic diagram of the outer ring support shaft structure;

[0012] Figure 6 Schematic diagram of the auxiliary function integration block structure. Detailed Implementation

[0013] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below.

[0014] The present invention proposes a functionally integrated wheel hub bearing unit 1, which mainly consists of a wheel valve assembly 2, a wheel hub assembly 3, an inner ring torsion transmission shaft 4, an outer bearing ring 5, an outer ring support shaft 6, an inner bearing ring 7, an auxiliary function integrated block 8, and a locking nut 9.

[0015] The hub motor, reduction gear, and brake are located in the center of the integrated bearing unit 1, specifically on the hub assembly 3 and the outer ring support shaft 6 with end flanges. The inner ring torsion shaft 4 and the outer ring support shaft 6 pass through the central hole available to the hub motor. The inner ring torsion shaft 4 is a rotating shaft, while the outer ring support shaft 6 is a fixed shaft. The outer bearing ring 5 and the inner bearing ring 7 can be selected at appropriate distances according to the vehicle and tire offset requirements to meet the overall vehicle usage requirements, resulting in more reasonable bearing load and higher reliability.

[0016] The wheel valve assembly 2 includes an end cap 10, bolts 11, a wheel valve 12, an end cap stop 13, and an O-ring groove 14. The outer shell of the wheel valve 12 is integrated with the end cap 10. The end cap 10 is positioned by transition fit with the wheel hub assembly 3 through the end cap stop 13, and then fixedly connected to the wheel hub assembly 3 by 6 bolts 11. The wheel valve 12 connects the tire to the inflation / deflation air passage 24. It is opened by air pressure during inflation, deflation, and testing, and automatically closes when the operation ends.

[0017] An O-ring 15 is installed in the O-ring groove 14 on the end face of the end cap 10, which forms an end face seal with the wheel hub assembly 3 to prevent oil leakage. The wheel valve assembly 2 has functions such as inflation / deflation, sealing, and fixing.

[0018] The wheel assembly 3 includes a wheel hub 16 and tire bolts 17. The wheel hub 16 is made of high-strength titanium alloy to meet lightweight requirements. The tire bolts 17 have a straight edge at the end, with the straight edge 18 facing the arc 19 of the wheel hub 16 and being interference-fitted with the hole 20 in the wheel hub 16. The wheel hub 16 has a rectangular spline 21 with an inner diameter centering and an oil drain hole 22.

[0019] The inner ring torsion shaft 4 is provided with a reducer main frame 23, an air passage 24, a wheel axle 25 supporting the inner ring of the bearing, a locking nut thread 26 at the end, an oil and gas seal mating surface 27 at the small end, and an external spline 28 connected to the hub assembly 3.

[0020] The main frame 23 of the reducer is provided with an oil inlet arc hole 29, a pin hole 30, and a connection hole 31 with the reducer sub-frame, mainly serving to lubricate and connect the various parts of the reducer. The air passage 24 is a straight through hole with a diameter of not less than 8mm running from left to right. The outer surface 32 of the right side of the wheel axle 25 is interference-fitted with the inner rings of the outer bearing ring 5 and the inner bearing ring 7. The external spline 28 is an inner diameter centering spline with 6 threaded holes 33 on its end face, which is fixedly connected to the wheel hub assembly 3 by bolts 11, forming a three-in-one structure of wheel hub, reducer, and wheel axle, reducing the axial dimension. At the same time, it meets the torque transmission requirements.

[0021] The outer ring support shaft 6 has bearing outer raceways 34 and 35 that mate with the outer bearing raceway 5 and the inner bearing raceway 7, respectively. A keyway hole 36 is located at the right end, mates with the central inflation / deflation system air duct functional integrated block 8, and is protected against radial rotation via a radial keyway 37 within the keyway hole 36. A retaining ring groove 38 is located on the right side of the keyway hole 36, used to assemble a retaining ring to fix the integrated block 8 and prevent axial movement. A large flange 39 with a set of fixing holes 40 is located on the right side of the outer ring support shaft 6, allowing for bolt-connected fixing to the hub motor and supporting the hub motor. A set of elongated arc-shaped holes 41 is also provided for heat dissipation, weight reduction, and reinforcement. The right end of the outer ring support shaft 6 has 10 threaded holes 42 and a stop 43 for connecting the steering knuckle suspension.

[0022] The outer bearing ring 5 and the inner bearing ring 7 are non-standard. Alternatively, standard tapered roller bearings without outer rings can also be used.

[0023] The auxiliary function integrated block 8 consists of a plug 44, a breather 45, an ABS sensor 46, a large retaining ring 47, an O-ring 48, an oil seal 49, an air seal 50, and a small retaining ring 51. The oil seal 49 has a pressure resistance of not less than 0.5 MPa, the air seal 50 has a pressure resistance of not less than 1 MPa, and the maximum operating speed range is between 400 r / min and 1500 r / min; the breather 45 has a pressure resistance of not less than 0.3 MPa.

[0024] The plug 44 is made of high-strength aluminum and is a cylindrical structure with a radial key 52. ​​The radial key 52 mates with the radial keyway 37 of the outer ring support shaft 6 and is axially positioned by a large retaining ring 47. A groove is provided at the left end for installing an O-ring 48 to radially seal the oil. The end of the plug 44 has a central air intake port 53 for the air filling system. The outer rings of the oil seal 49 and air seal 50 are connected through the mounting inner hole 54 of the plug 44, and the lip mates with the oil-air seal mating surface 27, and is axially positioned by a small retaining ring 51. The air intake port 53, air seal 50, mounting inner hole 54, and oil-air seal mating surface 27 form a closed air chamber 55. Air for the central air filling system enters the air chamber 55 through the air intake port 53, passes through the air passage 24, and enters the wheel valve 12, providing an air source for the central air filling system.

[0025] The auxiliary function integration block 8 is also equipped with a breather 45 to balance the internal and external air pressure of the transmission part, meet the requirements for wading, and can be used to check the oil level; it is also equipped with an ABS sensor for mechanical structure to determine tire speed. The function integration block 8 integrates multiple functional requirements to meet the realization of electric drive wheel auxiliary functions.

[0026] The locking nut 9 is a self-locking nut, whose main function is to axially lock the outer bearing race 5 and the inner bearing race 7. Its main assembly feature is to tighten the locking nut according to the required torque according to the thread specification, and then turn it back at an angle of 15 to 35 degrees. Then it is locked again to prevent loosening (this can be achieved by using a washer or deformation of the tail of the locking nut).

[0027] This invention achieves compatibility between the torsion transmission and load-bearing functions of the bearing unit by employing a functional reuse and space-sharing overlapping structural integration method. This optimizes the load-bearing structure of the electric drive wheel, resulting in a shorter axial dimension. It also integrates functional components such as a central inflation / deflation system, ABS speed measurement, and transmission ventilation. Furthermore, by converting the operating characteristics of the inner and outer ring modules, it forms a wheel hub bearing unit suitable for the needs of different vehicle variants. This invention provides a reliable, lightweight, and functionally integrated wheel hub bearing unit for the electric drive wheels of high-power wheeled special electric transmission vehicles. Compared to existing technologies, it achieves a compact, lightweight, high-space-utilization, and highly reliable support and torsion transmission bearing unit structure.

[0028] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A functionally integrated hub bearing unit, characterized in that: The assembly includes a wheel valve assembly (2), a wheel hub assembly (3), an inner ring torsion transmission shaft (4), an outer bearing ring (5), an outer ring support shaft (6), an inner bearing ring (7), and an auxiliary function integrated block (8). The end cap of the wheel valve assembly (2) is fixedly connected to the left end face of the wheel hub assembly (3). The inner ring torsion transmission shaft (4) is formed by connecting the main frame of the reducer (23) and the wheel axle (25) supporting the inner ring of the bearing. The wheel hub assembly (3) is fixedly connected to the main frame of the reducer. The outer surface (32) of the wheel axle (25) is interference-fitted with the inner rings of the outer bearing ring (5) and the inner ring of the inner bearing ring (7). The outer ring support shaft (6) is provided with an outer bearing raceway, which is connected to the outer bearing ring (5) and the inner bearing ring (7) respectively. The inner hole of the right end of the outer ring support shaft (6) is provided with an auxiliary function integrated block (8) for the central inflation / deflation system. The auxiliary function integrated block (8) includes a plug (44) and a vent (45) and an ABS sensor (46) installed on the plug; the central hole of the plug is provided with an oil seal and an air seal, wherein the oil seal has a pressure of not less than 0.5MPa and the air seal has a pressure of not less than 1MPa, and the maximum operating speed range is between 400r / min and 1500r / min. The wheel valve assembly (2) includes an end cap (10) and a wheel valve (12). The outer shell of the wheel valve (12) is integrated with the end cap (10). The end cap (10) is positioned by transition fit with the wheel hub assembly (3) through the end cap stop (13), and then fixedly connected to the wheel hub assembly (3) by bolts (11). The wheel valve (12) connects the tire to the inflation / deflation air passage. The wheel hub assembly (3) includes a wheel hub (16) and tire bolts (17). The wheel hub (16) is provided with a rectangular spline (21) with an inner diameter center and an oil drain hole (22). The tire bolts (17) are evenly distributed on the end face of the wheel hub along the circumference.

2. The integrated wheel hub bearing unit according to claim 1, characterized in that: An O-ring (15) is installed in the O-ring groove (14) on the end face of the end cap (10), forming an end face seal with the hub assembly (3).

3. The integrated wheel hub bearing unit according to claim 1, characterized in that: The wheel hub (16) is made of high-strength titanium alloy; the tire bolts have a structure with straight edges at the ends, and the straight edge part (18) is installed facing the arc (19) of the wheel hub (16).

4. The integrated wheel hub bearing unit according to claim 1, characterized in that: The main frame (23) of the reducer is provided with an oil inlet arc hole (29), a pin hole (30), and a connection hole (31) with the sub-frame of the reducer.

5. The integrated wheel hub bearing unit according to claim 1, characterized in that: The main frame of the reducer is connected to the hub assembly (3) via an external spline.

6. The integrated wheel hub bearing unit according to claim 1, characterized in that: The outer ring support shaft (6) has a large flange (39) and a set of fixing holes (40) on the right side for fixed connection with the hub motor; the right end of the outer ring support shaft (6) is connected to the steering knuckle suspension.

7. The integrated wheel hub bearing unit according to claim 1, characterized in that: The ventilator (45) has a pressure rating of not less than 0.3 MPa.

8. The integrated wheel hub bearing unit according to claim 7, characterized in that: The plug (44) is made of high-strength aluminum and is a cylindrical structure with a radial key (52). Its radial key (52) is connected to the radial keyway (37) of the outer ring support shaft (6) and is axially positioned by a large retaining ring (47). A groove is provided at the left end of the plug (44) for installing an O-ring (48). The end of the plug (44) is provided with a central air inlet (53) for the air filling and deflation system. The outer ring of the skeleton of the oil seal (49) and the air seal (50) is provided through the plug (44). The mounting inner hole (54) is fitted and connected, and the lip is fitted and connected to the oil-gas seal mating surface (27), and is axially positioned by the small retaining ring (51); the air inlet (53), the gas seal (50), the mounting inner hole (54), and the oil-gas seal mating surface (27) form a closed air chamber (55). The air used by the central air filling and deflation system enters the air chamber (55) through the air inlet (53), passes through the air passage (24), and enters the wheel valve (12) to provide an air source for the central air filling and deflation system.

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