An integrated sealing structure for a steering shaft

Abstract

An integrated steering shaft sealing structure is provided with multiple sealing parts, which can achieve reliable sealing. It is also provided with multiple oil storage cavities, which can extend the maintenance cycle and service life. The structure is optimized and integrated without changing the original layout space size, and the installation is simple. It can reduce after-sales maintenance costs, extend the service life of the bushing and thrust tapered roller bearing, effectively save resources and avoid environmental pollution.

Description

Technical Field

[0001] The present invention relates to the field of commercial vehicle manufacturing, and particularly to an integrated sealing structure for a steering shaft. Background Art

[0002] With the increasingly strict national environmental protection requirements, the sealing requirements for the steering shafts of commercial vehicles, especially water-wading engineering vehicles, are getting higher and higher. The kingpin bushings and thrust tapered roller bearings of the steering shaft have very high requirements for the cleanliness of the friction contact surfaces during operation. Poor sealing, improper maintenance and lubrication will cause abnormal wear, ablation and low service life of the kingpin bushings and thrust tapered roller bearings, which may further cause problems such as tire wear, vehicle shaking and deviation, resulting in losses to customers.

[0003] At present, the structures at this position of the steering shaft are mostly independent seals or partial seals. For the independent seal structure, the kingpin bushings and thrust bearings each have their own set of filling and sealing systems, with independent grease nipples, which are not related to each other, having a complex structure, high cost and being difficult to assemble. For the partial seal structure, the sealing reliability at the contact between the lower end face of the thrust bearing and the steering knuckle is not high. Due to the vibration of the steering shaft during operation and the existence of axial clearance, impurities may still enter here and contaminate the interior of the bushings and bearings under complex working conditions, causing early failure. Summary of the Invention

[0004] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides an integrated sealing structure for a steering shaft that solves the sealing blind spots and improves the reliability and overall performance.

[0005] The technical solution adopted by the present invention to overcome its technical problems is as follows:

[0006] An integrated sealing structure for a steering shaft, including a steering knuckle, a front beam and a kingpin provided on the front beam, further comprising:

[0007] A bushing is inserted into the hole of the steering knuckle, and the lower end of the kingpin is inserted into the hole of the bushing;

[0008] An end cover is installed at the bottom of the steering knuckle through bolts. The end cover seals the bottom of the hole of the steering knuckle, and a grease nipple is provided on the end cover;

[0009] A thrust tapered roller bearing, the lower end of its raceway is provided with a boss matching the inner diameter of the hole of the steering knuckle. The raceway is inserted into the upper end of the hole of the steering knuckle through the boss. The kingpin is inserted into the inner race of the thrust tapered roller bearing, and a circular shell is fixed around the inner race. The raceway is located inside the shell;

[0010] A closed oil storage cavity Ⅰ is formed between the end cover and the lower end face of the kingpin. An oil passage Ⅰ is spirally wound around the inner wall of the bushing from top to bottom. A closed oil storage cavity Ⅱ is formed between the upper end face of the bushing and the lower end face of the seat ring. The lower end of the oil passage Ⅰ is communicated with the oil storage cavity Ⅰ, and its upper end is communicated with the oil storage cavity Ⅱ. An oil passage Ⅱ is arranged along the vertical direction on the inner wall of the seat ring. A closed oil storage cavity Ⅲ is formed among the upper end face of the seat ring, the lower end face of the shaft ring and the inner wall of the housing. The lower end of the oil passage Ⅱ is communicated with the oil storage cavity Ⅱ, and its upper end is communicated with the oil storage cavity Ⅲ.

[0011] To improve the sealing performance, an O-ring Ⅰ is arranged between the end cover and the hole of the steering knuckle.

[0012] To adjust the clearance, a gasket is further included. The upper end face of the gasket contacts with the lower end face of the front beam, and the lower end face of the gasket contacts with the upper end face of the shaft ring.

[0013] To improve the sealing performance, an O-ring Ⅲ is arranged between the above-mentioned boss and the hole of the steering knuckle.

[0014] To improve the sealing performance, an O-ring Ⅱ is arranged between the shaft ring and the kingpin.

[0015] To improve the sealing performance, a double-lip one-way seal ring clamped between the shaft ring and the seat ring and a single-lip one-way seal ring arranged between the seat ring and the housing are further included. The outer wall of the double-lip one-way seal ring contacts with the inner wall of the housing. The two one-way lips of the double-lip one-way seal ring are attached to the upper surface of the seat ring. The lip of the single-lip one-way seal ring contacts with the inner wall of the housing.

[0016] To improve the sealing performance, a closed oil storage cavity Ⅳ is formed among the double-lip one-way seal ring, the single-lip one-way seal ring and the inner wall of the housing.

[0017] The beneficial effects of the present invention are as follows: It solves the sealing blind spots, and has high reliability. At the same time, it systematically considers the integrated sealing, lubrication and maintenance problems of the bushing and the bearing, improves the overall performance, can reduce the failure rate of the bushing and the thrust tapered roller bearing, improves the product quality and service life, and greatly reduces the replacement and maintenance costs of customers. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the front view sectional structure schematic diagram of the present invention;

[0019] Figure 2 It is the structure schematic diagram of the shaft ring and seat ring parts of the present invention;

[0020] Figure 3 It is the structure schematic diagram of the seat ring part of the present invention;

[0021] In the figure, 1. front beam; 2. steering knuckle; 3. kingpin; 4. gasket; 5. thrust tapered roller bearing; 6. bushing; 7. end cover; 8. grease nipple; 9. bolt; 10. O-ring I; 11. oil storage cavity I; 12. oil passage I; 13. oil storage cavity II; 14. oil storage cavity III; 15. O-ring II; 16. double-lip one-way seal ring; 17. single-lip one-way seal ring; 18. O-ring III; 19. oil storage cavity IV; 20. oil passage II; 51. shaft ring; 52. seat ring; 53. housing; 521. boss. Detailed implementation mode

[0022] The following will further describe the present invention in conjunction with Figure 1 , Figure 2 , Figure 3 the accompanying drawings.

[0023] A one-piece sealing structure for a steering shaft includes a steering knuckle 2, a front beam 1, and a kingpin 3 disposed on the front beam 1. It further includes: a bushing 6 inserted into a hole of the steering knuckle 2, and the lower end of the kingpin 3 is inserted into a hole of the bushing 6; an end cover 7 mounted on the bottom of the steering knuckle 2 through a bolt 9, and the end cover 7 seals the bottom of the hole of the steering knuckle 2, and a grease nipple 8 is provided on the end cover 7; a thrust tapered roller bearing 5, the lower end of its seat ring 52 is provided with a boss 521 matching the inner diameter of the hole of the steering knuckle 2, and the seat ring 52 is inserted into the upper end of the hole of the steering knuckle 2 through the boss 521, the kingpin 3 is inserted into the shaft ring 51 of the thrust tapered roller bearing 5, and a circular housing 53 is fixed on the periphery of the shaft ring 51, and the seat ring 52 is located inside the housing 53; a closed oil storage cavity I 11 is formed between the end cover 7 and the lower end face of the kingpin 3, and an oil passage I 12 is spirally wound around the inner wall of the bushing 6 from top to bottom, a closed oil storage cavity II 13 is formed between the upper end face of the bushing 6 and the lower end face of the seat ring 52, the lower end of the oil passage I 12 is communicated with the oil storage cavity I 11, and its upper end is communicated with the oil storage cavity II 13, an oil passage II 20 is arranged vertically along the inner wall of the seat ring 52, and a closed oil storage cavity III 14 is formed among the upper end face of the seat ring 52, the lower end face of the shaft ring 51 and the inner wall of the housing 53, the lower end of the oil passage II 20 is communicated with the oil storage cavity II 13, and its upper end is communicated with the oil storage cavity III 14. Grease is injected through the grease nipple 8 and first enters the oil storage cavity I 11. After the oil storage cavity I 11 is filled with grease, the grease rises through the spiral oil passage I 12 and enters the oil storage cavity II 13. After the oil storage cavity II 13 is filled with grease, it enters the oil storage cavity III 14 through the oil passage II 20. Preferably, the gap between the kingpin 3 and the seat ring 52 is 0.3 - 0.5 mm. The width of the oil passage II 20 is 4 mm and its depth is 0.3 mm.

[0024] This integrated sealing structure is provided with multiple sealing parts, which can achieve reliable sealing. It is also provided with multiple oil storage cavities, which can extend the maintenance cycle and service life. The structure is optimized and integrated without changing the original layout space size, and the installation is simple. It can reduce the after-sales maintenance cost, extend the service life of the bushing 6 and the thrust tapered roller bearing 5, effectively save resources, and avoid environmental pollution.

[0025] In an embodiment of the present invention, an O-ring I 10 is provided between the end cover 7 and the hole of the steering knuckle 2. The O-ring I 10 can improve the sealing performance between the end cover 7 and the hole of the steering knuckle 2.

[0026] In an embodiment of the present invention, a gasket 4 is further included. The upper end surface of the gasket 4 is in contact with the lower end surface of the front beam 1, and the lower end surface of the gasket 4 is in contact with the upper end surface of the shaft ring 51. The gasket 4 can match the gap between the front beam 1 and the shaft ring 51, improving the convenience during assembly.

[0027] In an embodiment of the present invention, an O-ring III 18 is provided between the boss 521 and the hole of the steering knuckle 2. An O-ring II 15 is provided between the shaft ring 51 and the kingpin 3. By setting the O-ring III 18, the sealing performance between the seat ring 52 and the hole of the steering knuckle 2 can be improved, and by setting the O-ring II 15, the sealing performance between the shaft ring 51 and the kingpin 3 can be improved.

[0028] In an embodiment of the present invention, a double-lip one-way seal ring 16 clamped between the shaft ring 51 and the seat ring 52 and a single-lip one-way seal ring 17 provided between the seat ring 52 and the housing 53 are further included. The outer wall of the double-lip one-way seal ring 16 is in contact with the inner wall of the housing 53, and the outer wall of the single-lip one-way seal ring 17 is in contact with the inner wall of the housing 53. A closed oil storage cavity IV 19 is formed between the double-lip one-way seal ring 16, the single-lip one-way seal ring 17 and the inner wall of the housing 53. After the grease forms a certain pressure in the oil storage cavity III 14, it overflows along the two one-way lip joint parts of the seat ring 52 and the double-lip one-way seal ring 16 and enters the oil storage cavity IV 19 inside the housing 53. Since a sealing material is coated on the outside of the skeleton of the double-lip one-way seal ring 16, after installation, it cooperates with the housing 53 to form the oil storage cavity IV 19, preventing the grease from overflowing upward in the oil storage cavity IV 19 and at the same time preventing external impurities from entering. After the oil storage cavity IV 19 is filled with grease, the grease overflows along the joint of the lip of the single-lip one-way seal ring 17 and the housing 53, completing the process of filling grease. During after-sales maintenance, new grease is gradually injected from the grease nipple 8, and the old grease and abrasives are gradually extruded from the one-way seal ring 17, facilitating the quick update of the internal grease without disassembly for maintenance.

[0029] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An integrated sealing structure for a steering shaft, comprising a knuckle (2), a front beam (1), and a kingpin (3) provided on the front beam (1), characterized in that, It further includes: A bushing (6) inserted into the hole of the knuckle (2), and the lower end of the kingpin (3) is inserted into the hole of the bushing (6); An end cover (7) installed at the bottom of the knuckle (2) through bolts (9). The end cover (7) seals the bottom of the hole of the knuckle (2), and a grease nipple (8) is provided on the end cover (7); A thrust tapered roller bearing (5), a boss (521) matching the inner diameter of the hole of the knuckle (2) is provided at the lower end of its raceway (52). The raceway (52) is inserted into the upper end of the hole of the knuckle (2) through the boss (521). The kingpin (3) is inserted into the inner ring (51) of the thrust tapered roller bearing (5). A circular shell (53) is fixed on the periphery of the inner ring (51), and the raceway (52) is located inside the shell (53); A closed oil storage chamber Ⅰ (11) is formed between the end cover (7) and the lower end face of the kingpin (3). An oil passage Ⅰ (12) is spirally wound around the inner wall of the bushing (6) from top to bottom. A closed oil storage chamber Ⅱ (13) is formed between the upper end face of the bushing (6) and the lower end face of the raceway (52). The lower end of the oil passage Ⅰ (12) is communicated with the oil storage chamber Ⅰ (11), and its upper end is communicated with the oil storage chamber Ⅱ (13). An oil passage Ⅱ (20) is arranged along the vertical direction on the inner wall of the raceway (52). A closed oil storage chamber Ⅲ (14) is formed among the upper end face of the raceway (52), the lower end face of the inner ring (51) and the inner wall of the shell (53). The lower end of the oil passage Ⅱ (20) is communicated with the oil storage chamber Ⅱ (13), and its upper end is communicated with the oil storage chamber Ⅲ (14).

2. The one-piece seal structure of the steering shaft according to claim 1, wherein: An O-ring Ⅰ (10) is arranged between the end cover (7) and the hole of the knuckle (2).

3. The integrated seal structure of the steering shaft according to claim 1, characterized in that: It further includes a gasket (4). The upper end face of the gasket (4) is in contact with the lower end face of the front beam (1), and the lower end face of the gasket (4) is in contact with the upper end face of the inner ring (51).

4. The integrated seal structure of the steering shaft according to claim 1, wherein: An O-ring Ⅲ (18) is arranged between the boss (521) and the hole of the knuckle (2).

5. The integrated seal structure of the steering shaft according to claim 1, characterized in that: An O-ring Ⅱ (15) is arranged between the inner ring (51) and the kingpin (3).

6. The integrated seal structure of the steering shaft according to claim 1, characterized in that: It further includes a double-lip one-way seal ring (16) clamped between the inner ring (51) and the raceway (52) and a single-lip one-way seal ring (17) arranged between the raceway (52) and the shell (53). The outer wall of the double-lip one-way seal ring (16) is in contact with the inner wall of the shell (53). The two one-way lips of the double-lip one-way seal ring (16) are attached to the upper surface of the raceway (52). The lip of the single-lip one-way seal ring (17) is in contact with the inner wall of the shell (53).

7. The integrated seal structure of the steering shaft according to claim 6, characterized in that: A closed oil storage chamber Ⅳ (19) is formed among the double-lip one-way seal ring (16), the single-lip one-way seal ring (17) and the inner wall of the shell (53).

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