Cassette seal for a bearing and bearing

Abstract

A box-type seal for a bearing and a bearing, the box-type seal comprising a first ring and a second ring capable of relative rotation. A radial gap (3a) is provided between the first ring and the second ring, and a groove (3b) is provided on the outer peripheral wall of the radial gap (3a). The axial inner end (3c) of the groove (3b) is closed, and the axial outer end (3d) of the groove (3b) is open. The bottom surface (3e) of the groove (3b) extends radially outward while extending from the axial inner end (3c) to the axial outer end (3d).

Description

Cartridge seals for bearings and bearings Technical Field

[0001] This application relates to the field of sealing, and particularly to a box-type seal for bearings and a bearing. Background Technology

[0002] Chinese invention patent application CN107387570A discloses a box-type sealing device and a bearing including the box-type sealing device. A pumping section is formed on the inclined wall, and an annular groove is formed between the centrifugal lip and the pumping section. When mud or water enters the annular groove, the pumping section can pump the mud or water away from the sealing device, thereby keeping the mud or water away from the sealing device. However, when the cover plate is in a non-rotating state, mud or water easily deposits in the annular groove under the action of gravity, which reduces the sealing performance of the box-type sealing device.

[0003] Summary of the Invention

[0004] This application is made in view of the state of the prior art described above. The object of this application is to provide a cartridge seal for bearings and a bearing that can overcome or mitigate at least one of the disadvantages described in the background art.

[0005] To achieve the above objectives, this application adopts the following technical solution.

[0006] This application provides a box seal for a bearing, comprising a first ring and a second ring that are rotatable relative to each other, a radial gap being provided between the first ring and the second ring, a groove being provided on the outer peripheral wall of the radial gap, the inner axial end of the groove being closed and the outer axial end of the groove being open, and the bottom surface of the groove extending radially outward while extending from the inner axial end to the outer axial end.

[0007] In one alternative embodiment, the groove includes a first side and a second side, which are arranged in a mirror-symmetrical manner about a plane of symmetry that coincides with the central axis of the box seal.

[0008] In another alternative, the radial depth of the groove gradually increases from the inner axial end to the outer axial end.

[0009] In another alternative, the circumferential width of the groove gradually increases from the inner axial end to the outer axial end.

[0010] In another alternative, the radial clearance is less than or equal to 1.5 mm.

[0011] In another alternative embodiment, the ratio of the circumferential width of the inner axial end to the circumferential width of the outer axial end is less than or equal to 0.8.

[0012] In another alternative embodiment, the first ring body includes an elastic portion having one or more sealing lips and a plurality of said grooves, the plurality of said grooves being evenly spaced apart in the circumferential direction of the box seal.

[0013] In another alternative embodiment, the first ring body includes a first axial portion, and the second ring body includes a second axial portion, the first axial portion and the second axial portion being arranged radially opposite to each other in the box seal and together defining the radial clearance.

[0014] In another alternative embodiment, the outer peripheral wall of the radial gap is formed by the first axial portion, the inner peripheral wall of the radial gap is formed by the second axial portion, and the axial length of the groove is less than the axial length of the second axial portion.

[0015] This application also provides a bearing comprising an outer ring and an inner ring, characterized in that the bearing further comprises the aforementioned box-type seal, wherein the first ring body is fixedly installed on the outer ring, and the second ring body is fixedly installed on the inner ring.

[0016] By adopting the above technical solution, and by setting a radial gap and a bottom surface, the radial gap can collect dirt such as mud and water into the groove under the action of gravity. The mud and water collected in the groove can leave the groove along the bottom surface under the action of gravity, so that the mud and water can be discharged from the radial gap when the vehicle is parked, thereby improving the sealing performance of the box seal and extending the service life of the bearing. Attached Figure Description

[0017] Figure 1 shows a partial cross-sectional view of a bearing according to an embodiment of this application.

[0018] Figure 2 shows a schematic diagram of the bearing in Figure 1 mounted on the outer ring.

[0019] Figure 3 shows a schematic diagram of the groove of the bearing in Figure 1. Detailed Implementation

[0020] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaust all possible methods of this application, nor to limit the scope of this application.

[0021] Figures 1 to 3 illustrate a partial structure of a bearing according to an embodiment of this application, particularly a wheel hub bearing suitable for trucks. Of course, the application scenarios of the bearing of this application are not limited to this.

[0022] Referring to Figure 1, the bearing may include an outer ring 1 (an example of a rotating ring), an inner ring 2 (an example of a stationary ring), and a box seal 3.

[0023] The box seal 3 may include a ring 31 (an example of a first or second ring), a ring 32 (an example of a second or first ring), and a spring 33. The rings 31 and 32 may be disposed between an outer ring 1 and an inner ring 2. The ring 31 may be coaxially and fixedly mounted to the outer ring 1, and the ring 32 may be coaxially and fixedly mounted to the inner ring 2. The ring 31 may include an axial portion 311 (an example of the outer peripheral wall of a first axial portion and radial clearance 3a) and a radial portion 312 fixed to each other. The ring 32 may include an axial portion 321 (an example of the inner peripheral wall of a second axial portion and radial clearance 3a), a radial portion 322, and an axial portion 323 fixed to each other. The axial portion 321 may be disposed radially outside the axial portion 323 and connected to the axial portion 323 via the radial portion 322. The axial portion 311 can be coaxially fitted onto the axial portion 321. An annular radial clearance 3a can be provided between the axial portions 311 and 321. For example, the radial height of the radial clearance 3a can be less than or equal to 1.5 mm (excluding the radial depth of the groove 3b). In other words, the radial clearance 3a can be defined by both the axial portions 311 and 321. The radial portion 312 can be disposed between the radial portion 322 and the rollers of the bearing (not shown in the figure), that is, the radial portion 312 can be closer to the axial inner side of the bearing than the radial portion 322.

[0024] The ring 31 can be formed by joining a rigid portion 313 and an elastic portion 314. The rigid portion 313 can be made of metal, and the elastic portion 314 can be made of rubber. The rigid portion 313 and the elastic portion 314 can be vulcanized and bonded together. The elastic portion 314 can be provided with a centrifugal lip 315 (an example of a sealing lip), a main lip 316 (an example of a sealing lip), and a dustproof lip 317 (an example of a sealing lip). The centrifugal lip 315 can extend from the radial portion 312 generally along the axial direction A and abut against the radial portion 322. The main lip 316 can extend from the radial portion 312 generally along the axial direction A and abut against the axial portion 323. The dustproof lip 317 can extend from the radial portion 312 generally along the radial direction R and abut against the inner ring 2. It is understood that one or more of the centrifugal lip 315, the main lip 316, and the dustproof lip 317 can be bent. A spring 33 can be fitted onto the main lip 316 and bias the main lip 316 toward the axial portion 323. Referring to Figure 1, it should be noted that the overlapping portions of the centrifugal lip 315, the main lip 316, and the dustproof lip 317 with other components only indicate a contact relationship, and do not mean that they enter the material of other components.

[0025] Referring to Figures 1 to 3, the ring body 1 can be provided with multiple trapezoidal grooves 3b. The inner circumference of the axial portion 311 can be formed by an elastic portion 314, and the grooves 3b can be provided in the portion of the elastic portion 314 corresponding to the radial clearance 3a. The multiple grooves 3b can be evenly arranged at intervals in the circumferential direction C. The axial inner end 3c of the groove 3b (the end near the axial middle position of the bearing) can be closed, and the axial outer end 3d of the groove 3b (the end near the axial outer side of the bearing) can be open. The bottom surface 3e of the groove 3b can extend radially outward while extending from the axial inner end 3c to the axial outer end 3d, such that the bottom surface 3e is inclined in the direction away from the radial clearance 3a. The radial depth of the groove 3b can gradually increase from the axial inner end 3c to the axial outer end 3d, such that the ratio of the radial depth H1 of the axial inner end 3c to the radial depth H2 of the axial outer end 3d is less than 1 (H1 / H2 < 1). The side surface 3f (example of the first or second side surface) and side surface 3g (example of the second or first side surface) of the groove 3b can extend from the axial inner end 3c to the axial outer end 3d, and are mirror-symmetric about a virtual plane of symmetry 3h. The plane of symmetry 3h can coincide with the central axis of the box seal 3, and the side surface 3f and side surface 3g of each groove 3b can be mirror-symmetric about different planes of symmetry 3h. The circumferential width of the groove 3b can gradually increase from the axial inner end 3c to the axial outer end 3d, for example, the ratio of the circumferential width L1 of the axial inner end 3c to the circumferential width L2 of the axial outer end 3d can be less than or equal to 0.8 (L1 / L2≤0.8). The axial length of the groove 3b can be less than the axial length of the axial portion 321.

[0026] When the vehicle is in motion, the groove 3b can pump contaminants such as mud and water away from the radial gap 3a. For mud and water entering the radial gap 3a, the narrow radial gap 3a creates flow resistance, allowing the mud and water to remain briefly within the radial gap 3a. The mud and water remaining in the radial gap 3a can enter the groove 3b. When the groove 3b rotates clockwise with the outer ring 1 (viewed from the right side of Figure 1), the side 3f can squeeze the mud and water, causing it to move towards the axially outer end 3d, thereby throwing the mud and water out of the groove 3b. When the groove 3b rotates counterclockwise with the outer ring 1 (viewed from the right side of Figure 1), the side 3g can squeeze the mud and water, causing it to move towards the axially outer end 3d, thereby leaving the groove 3b.

[0027] When the vehicle is parked, mud and water can leave the radial clearance 3a under the influence of gravity. Typically, the bearing's central axis is roughly parallel to the horizontal plane, causing the radial clearance 3a to extend approximately horizontally. This allows mud and water entering the radial clearance 3a to converge circumferentially (on the circumferential C) towards the lowest point of the radial clearance 3a under gravity, rather than flowing deeper into the radial clearance 3a (the portion closer to the left in Figure 1). Near the lowest point, mud and water can enter the groove 3b and flow along the bottom surface 3e towards the axially outer end 3d under gravity, thus leaving the groove 3b. Between the highest and lowest points of the radial clearance 3a (on the circumferential C), mud and water can also flow along the side surface 3f or 3g towards the axially outer end 3d under gravity, thus leaving the groove 3b. In cases of low mud and water levels, mud and water can also collect by dripping under gravity. For example, near the highest position of the radial gap 3a, the mud and water adhering to the bottom surface 3e can drip onto the outer peripheral surface of the axial part 321, and the mud and water dripping onto the outer peripheral surface can slide along the circumferential direction C to near the lowest position of the radial gap 3a.

[0028] The bearing of this embodiment has at least the following advantages.

[0029] (i) By setting a radial gap 3a and a bottom surface 3e, the radial gap 3a can collect mud and water into the groove 3b under the action of gravity. The mud and water collected in the groove 3b can leave the groove 3b along the bottom surface 3e under the action of gravity, so that the mud and water can be discharged from the radial gap 3a in the parked state, thereby improving the sealing performance of the box seal 3 and extending the service life of the bearing.

[0030] (ii) By arranging the sides 3f and 3g in a mirror symmetrical manner, the vehicle can pump mud and water when moving forward and backward, so that the box seal 3 can have a good sealing effect when moving forward and backward.

[0031] (iii) By gradually increasing the circumferential width of the groove 3b from the inner axial end 3c to the outer axial end 3d, the mud and water are less likely to be blocked by the opposite side during the process of being thrown out by one side, so that the groove 3b can pump mud and water efficiently.

[0032] (iv) By arranging multiple grooves 3b evenly spaced on the circumferential C, the grooves 3b are likely to be near the lowest position of the radial gap 3a when the vehicle is parked, which is conducive to the discharge of mud and water from the radial gap 3a.

[0033] (v) By making the axial length of the groove 3b less than the axial length of the axial portion 321, the mud and water dripping from the groove 3b are less likely to drip outside the axial portion 321, so that the mud and water can be fully collected by the axial portion 321.

[0034] It should be understood that the above embodiments are merely exemplary and are not intended to limit this application. Those skilled in the art can make various modifications and changes to the above embodiments under the teachings of this application without departing from the scope of this application.

[0035] (i) The groove 3b is not limited to being provided in the elastic part 314, but may be provided in the rigid part 313 for example.

[0036] (ii) The ratio of radial depth H1 to radial depth H2 is not limited to less than 1, for example, it can be equal to 1.

[0037] (iii) The sealing lip is not limited to being provided on the ring body 31; for example, at least part of the sealing lip may be provided on the ring body 32.

[0038] (iv) The groove 3b is not limited to being trapezoidal; for example, it can be triangular or rectangular.

[0039] (v) Side 3f and side 3g are not limited to being arranged in a mirror symmetry; for example, they can be arranged asymmetrically.

[0040] (vi) The elastic part 314 is not limited to being made of rubber; for example, the elastic part may also include plastic. In particular, the elastic part may include polytetrafluoroethylene (PTFE).

[0041] List of reference numerals

[0042] 1 Outer ring

[0043] 2 Inner circle

[0044] 3. Box-type seals

[0045] 31 Ring body

[0046] 311 Axial section

[0047] 312 Radial section

[0048] 313 Rigid Part

[0049] 314 Elastic part

[0050] 315 Centrifugal Lips

[0051] 316 main lip

[0052] 317 Dustproof Lip

[0053] 3a Radial clearance

[0054] 3b Groove

[0055] 3c Axial inner end

[0056] 3d Axial Outer End

[0057] 3e bottom surface

[0058] 3F Side View

[0059] 3g side

[0060] 3h symmetry plane

[0061] 32 rings

[0062] 321 Axial section

[0063] 322 Radial section

[0064] 323 Axial section

[0065] 33 Springs

[0066] H1 Radial Depth

[0067] H2 radial depth

[0068] L1 circumferential width

[0069] L2 circumferential width

[0070] Axial

[0071] R radial

[0072] C Zhou Xiang

Claims

1. A box-type seal for a bearing, comprising a first ring body and a second ring body capable of relative rotation, characterized in that, A radial gap (3a) is provided between the first ring body and the second ring body. A groove (3b) is provided on the outer peripheral wall of the radial gap (3a). The inner axial end (3c) of the groove (3b) is closed, and the outer axial end (3d) of the groove (3b) is open. The bottom surface (3e) of the groove (3b) extends radially outward while extending from the inner axial end (3c) to the outer axial end (3d).

2. The box-type seal according to claim 1, characterized in that, The groove (3b) includes a first side and a second side, which are arranged in a mirror-symmetric manner about a plane of symmetry (3h) that coincides with the central axis of the box seal (3).

3. The box-type seal according to claim 1, characterized in that, The radial depth of the groove (3b) gradually increases from the inner axial end (3c) to the outer axial end (3d).

4. The box-type seal according to claim 1, characterized in that, The circumferential width of the groove (3b) gradually increases from the inner axial end (3c) to the outer axial end (3d).

5. The box-type seal according to any one of claims 1 to 4, characterized in that, The radial clearance (3a) is less than or equal to 1.5 mm.

6. The box-type seal according to any one of claims 1 to 4, characterized in that, The ratio of the circumferential width of the inner axial end (3c) to the circumferential width of the outer axial end (3d) is less than or equal to 0.

8.

7. The box-type seal according to any one of claims 1 to 4, characterized in that, The first ring body includes an elastic portion, which is provided with one or more sealing lips and a plurality of grooves (3b), which are evenly spaced on the circumferential (C) side of the box seal.

8. The box-type seal according to any one of claims 1 to 4, characterized in that, The first ring body includes a first axial portion, and the second ring body includes a second axial portion. The first axial portion and the second axial portion are arranged opposite each other in the radial direction (R) of the box seal (3) and together define the radial gap (3a).

9. The box-type seal according to claim 8, characterized in that, The outer peripheral wall of the radial gap (3a) is formed by the first axial portion, the inner peripheral wall of the radial gap (3a) is formed by the second axial portion, and the axial length of the groove (3b) is less than the axial length of the second axial portion.

10. A bearing comprising an outer ring (1) and an inner ring (2), characterized in that, The bearing further includes a box-type seal (3) as described in any one of claims 1 to 9. The first ring is fixedly installed on the outer ring (1), and the second ring is fixedly installed on the inner ring (2).

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