阅读说明：本技术 一种高耐磨多层密封式汽车轮毂轴承 (High-wear-resistance multilayer sealed automobile hub bearing ) 是由 萧月军 于 2021-09-07 设计创作，主要内容包括：本发明涉及汽车轴承技术领域。目的在于提供一种高耐磨多层密封式汽车轮毂轴承,包括法兰盘和轴承组件,所述法兰盘包括盘体和设置在盘体一面中心的盘轴；所述轴承组件包括由内至外依次套设在盘轴外的内圈、中圈和外圈,所述内圈与中圈之间、外圈与中圈之间均设置有滚子,所述内圈和外圈均与法兰盘固接；所述中圈的内外侧壁上均设置有横截面呈V形的凹部,所述内圈和外圈面向中圈的侧壁上设置有与凹部相配合的V形的凸部；所述凹部与凸部V字形的两斜面之间对应滚子的数量形成有若干滚动槽,所述滚子通过保持架维持在滚动槽内。本发明能够有效的分摊轴向荷载,降低轴承组件在轴向上的窜动风险,提高了稳定性,延长了使用寿命。(The invention relates to the technical field of automobile bearings. The high-wear-resistance multilayer sealed automobile hub bearing comprises a flange plate and a bearing assembly, wherein the flange plate comprises a disc body and a disc shaft arranged in the center of one surface of the disc body; the bearing assembly comprises an inner ring, a middle ring and an outer ring which are sequentially sleeved outside the disc shaft from inside to outside, rollers are arranged between the inner ring and the middle ring and between the outer ring and the middle ring, and the inner ring and the outer ring are fixedly connected with the flange plate; the inner side wall and the outer side wall of the middle ring are both provided with concave parts with V-shaped cross sections, and the side walls of the inner ring and the outer ring facing the middle ring are provided with V-shaped convex parts matched with the concave parts; and a plurality of rolling grooves are formed between the two V-shaped inclined planes of the concave part and the convex part corresponding to the number of the rollers, and the rollers are maintained in the rolling grooves through a retainer. The invention can effectively share the axial load, reduce the risk of axial play of the bearing assembly, improve the stability and prolong the service life.)

1. A high-wear-resistance multilayer sealed automobile hub bearing comprises a flange plate and a bearing assembly, wherein the flange plate comprises a disc body (1) and a disc shaft (2) arranged in the center of one surface of the disc body (1); the bearing assembly comprises an inner ring (3), a middle ring (4) and an outer ring (5) which are sequentially sleeved outside the disc shaft (2) from inside to outside, rollers (6) are arranged between the inner ring (3) and the middle ring (4) and between the outer ring (5) and the middle ring (4), and the inner ring (3) and the outer ring (5) are fixedly connected with a flange plate;

the method is characterized in that: the inner side wall and the outer side wall of the middle ring (4) are both provided with a concave part (7) with a V-shaped cross section, and the side walls of the inner ring (3) and the outer ring (5) facing the middle ring (4) are provided with a V-shaped convex part (8) matched with the concave part (7); a plurality of rolling grooves (10) are formed between the two V-shaped inclined planes of the concave part (7) and the convex part (8) corresponding to the number of the rollers (6), and the rollers (6) are maintained in the rolling grooves (10) through a retainer (9).

2. The highly wear-resistant multilayer sealed automobile hub bearing according to claim 1, characterized in that: stepped end platforms (11) are arranged at two ends of the convex part (8), an outer bearing sealing cover (12) is arranged between the end platforms (11) at two ends of the convex part (8) of the outer ring (5) and the middle ring (4), and an inner bearing sealing cover (13) is arranged between the end platforms (11) at two ends of the convex part (8) of the inner ring (3) and the middle ring (4).

3. The highly wear-resistant multilayer sealed automobile hub bearing according to claim 2, characterized in that: the rollers (6) are cylindrical rollers which are symmetrically distributed on two sides along the center line of the V-shaped tip.

4. The highly wear-resistant multilayer sealed automobile hub bearing according to claim 3, characterized in that: the roller (6) is a ball roller.

5. The highly wear-resistant multilayer sealed automobile hub bearing according to claim 4, characterized in that: the two end faces of the middle ring (4) are provided with weight reduction ring grooves (14) with arc-shaped sections, and the cross section of the middle ring (4) is X-shaped.

6. The highly wear-resistant multilayer sealed automobile hub bearing according to claim 5, characterized in that: the outer peripheries of the outer ring (5) and the inner ring (3) close to one end of the disc body (1) are both provided with an annular edge (15), one surface of the annular edge (15) facing the disc body (1) is provided with a connecting rod (16), and the end part of the connecting rod (16) is provided with threads and is matched with a fastening nut (17); a rod hole (18) is formed in the disc body (1) corresponding to the fastening nut (17), the connecting rod (16) penetrates through the rod hole (18), and the annular edge (15) and the disc body (1) are locked through the fastening nut (17); the outer side of one end of the disc body (1) is far away from the middle ring (4) is provided with an outer connecting ring (19), a plurality of outer connecting lugs (20) are uniformly distributed on the circumferential surface of the outer connecting ring (19), and outer connecting holes (21) are formed in the outer connecting lugs (20).

7. The highly wear-resistant multilayer sealed automobile hub bearing according to claim 6, characterized in that: the inner side of one end, far away from the disc body (1), of the middle ring (4) is provided with an inner connecting ring (22), a plurality of inner connecting lugs (23) are uniformly distributed on the circumferential surface of the inner connecting ring (22), and inner connecting holes (24) are formed in the inner connecting lugs (20).

8. The highly wear-resistant multilayer sealed automobile hub bearing according to claim 7, characterized in that: two rings of limiting rings (25) are further arranged on one surface, close to the disc shaft (2), of the disc body (1), and the two rings of limiting rings (25) are respectively matched with the ring edge (15) of the inner ring (3) and the ring edge (15) of the outer ring (5) and sleeved outside the ring edge (15); the inner side wall of the limiting ring (25) is provided with first clamping teeth (26), the outer peripheral surface of the ring edge (15) is provided with second clamping teeth, and the first clamping teeth (26) are meshed with the second clamping teeth.

9. The highly wear-resistant multilayer sealed automobile hub bearing according to claim 8, characterized in that: the middle ring (4) is formed by splicing an inner section (28) and an outer section (29), and a splicing seam of the inner section (28) and the outer section (29) is positioned at the V-shaped bottom of the V-shaped concave part (7); a plurality of splicing holes (30) penetrating through the weight-reducing ring grooves (14) at two ends are formed in the middle ring (4), the splicing holes (30) extend along the length direction of the middle ring (4), and the splicing holes (30) are uniformly distributed in the weight-reducing ring grooves (14) in an annular shape;

the split type ring is characterized in that a matched split type rod (31) penetrates through the split type hole (30), threads are arranged at two ends of the split type rod (31) and are matched with split type nuts (32), and the inner section (28) and the outer section (29) of the middle ring (4) are locked through the split type rod (31) and the split type nuts (32).

10. The highly wear-resistant multilayer sealed automobile hub bearing according to claim 9, characterized in that: the opposite ends of the inner section (28) and the outer section (29) are respectively provided with a step groove (33) and a step edge (34) which are mutually meshed.

Technical Field

The invention relates to the technical field of automobile bearings, in particular to a high-wear-resistance multilayer sealed automobile hub bearing.

Background

The hub bearing is applied to the end part of an automobile shaft, is used for providing support for the hub and providing accurate guide for the rotation of the hub, bears axial load and radial load, and is an important component part for the load and rotation of the automobile. Through development for many years, the automobile hub bearing forms various types such as an integrated type, a combined type, a single-layer type and a double-layer type, the single-layer type hub bearing has the advantages of being simple in structure, low in manufacturing cost and the like, is suitable for being applied to light small-load vehicles, and the double-layer type or even multi-layer type bearing has the advantages of being large in load bearing capacity and high in strength and is suitable for being applied to medium-heavy large-load vehicles. In practice and research for many years, the inventor finds that the axial load of the conventional double-layer hub bearing is increased due to the influence of factors such as steering and collision during application, the double-layer hub bearing is easy to deform during long-term use, and the service life of the hub bearing is shortened, and the phenomenon is more remarkable particularly for heavy vehicles running on pothole bumpy road sections for a long time.

Disclosure of Invention

The invention aims to provide a high-wear-resistance multilayer sealed automobile hub bearing which is long in service life and capable of preventing movement.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows: a high-wear-resistance multilayer sealed automobile hub bearing comprises a flange plate and a bearing assembly, wherein the flange plate comprises a disc body and a disc shaft arranged in the center of one surface of the disc body; the bearing assembly comprises an inner ring, a middle ring and an outer ring which are sequentially sleeved outside the disc shaft from inside to outside, rollers are arranged between the inner ring and the middle ring and between the outer ring and the middle ring, and the inner ring and the outer ring are fixedly connected with the flange plate;

the inner side wall and the outer side wall of the middle ring are both provided with concave parts with V-shaped cross sections, and the side walls of the inner ring and the outer ring facing the middle ring are provided with V-shaped convex parts matched with the concave parts; and a plurality of rolling grooves are formed between the two V-shaped inclined planes of the concave part and the convex part corresponding to the number of the rollers, and the rollers are maintained in the rolling grooves through a retainer.

Preferably, stepped end platforms are arranged at two ends of the convex part, outer bearing sealing covers are arranged between the end platforms at two ends of the convex part of the outer ring and the middle ring, and inner bearing sealing covers are arranged between the end platforms at two ends of the convex part of the inner ring and the middle ring.

Preferably, the roller is a cylindrical roller, and the cylindrical rollers are symmetrically distributed on two sides along the center line of the V-shaped tip.

Preferably, the roller is a ball roller.

Preferably, the two end faces of the middle ring are provided with weight reduction ring grooves with arc-shaped sections, and the cross section of the middle ring is X-shaped.

Preferably, the outer peripheries of the outer ring and the inner ring close to one end of the tray body are both provided with annular edges, one surface of each annular edge facing the tray body is provided with a connecting rod, and the end part of each connecting rod is provided with threads and is matched with a fastening nut; a rod hole is formed in the disc body corresponding to the fastening nut, the connecting rod penetrates through the rod hole, and the ring edge and the disc body are locked through the fastening nut; the outer side of the middle ring far away from one end of the disc body is provided with an outer connecting ring, a plurality of outer connecting lugs are uniformly distributed on the circumferential surface of the outer connecting ring, and outer connecting holes are formed in the outer connecting lugs.

Preferably, the inner side of the middle ring, which is far away from one end of the tray body, is provided with an inner connecting ring, a plurality of inner connecting lugs are uniformly distributed on the circumferential surface of the inner connecting ring, and the inner connecting lugs are provided with inner connecting holes.

Preferably, one surface of the disc body, which is close to the disc shaft, is also provided with two rings of limiting rings, and the two rings of limiting rings are respectively matched with the ring edge of the inner ring and the ring edge of the outer ring and are sleeved outside the ring edges; the limiting ring is characterized in that first clamping teeth are arranged on the inner side wall of the limiting ring, second clamping teeth are arranged on the outer peripheral surface of the ring edge, and the first clamping teeth are meshed with the second clamping teeth.

Preferably, the middle ring is formed by splicing an inner section and an outer section, and the splicing seam of the inner section and the outer section is positioned at the V-shaped bottom of the V-shaped concave part; a plurality of splicing holes penetrating through the weight-reducing ring grooves at two ends are formed in the middle ring, the splicing holes extend along the length direction of the middle ring, and the splicing holes are uniformly distributed in the weight-reducing ring grooves in an annular shape;

the matched splicing rod penetrates through the splicing hole, threads are arranged at two ends of the splicing rod and are matched with the splicing nuts, and the inner section and the outer section of the middle ring are locked through the splicing rod and the splicing nuts.

Preferably, the opposite ends of the inner section and the outer section are respectively provided with a stepped groove and a stepped edge which are meshed with each other.

The beneficial effects of the invention are concentrated and expressed as follows: axial load can be effectively shared, the axial play risk of the bearing assembly is reduced, the stability is improved, and the service life is prolonged. Specifically, the bearing assembly comprises an outer ring, a middle ring and an inner ring, wherein the outer ring and the inner ring are fixedly connected with a flange plate, the middle ring can be connected with a mounting foundation such as a bogie, and the like, so that the integral shaft support effect of the double-layer support structure is better, and the support strength is higher. Meanwhile, the rollers are arranged in the rolling grooves formed between the V-shaped convex parts and the V-shaped concave parts, the V-shaped rolling support structure can effectively limit axial movement among rings, and after the inner and outer double-layer V-shaped rollers are adopted for supporting, axial runout can be limited in a very small range, so that abrasion among the rings is reduced. When the vehicle wheel bears external forces such as steering, collision, extrusion and the like, the bearing assembly can be ensured not to be out of position, the supporting strength of the bearing assembly to the hub part is ensured, and the service life is effectively prolonged.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is a right side view of the flange of FIG. 1;

FIG. 4 is a left side view of the middle ring of FIG. 1;

FIG. 5 is a schematic view of a split bar;

FIG. 6 is a cross-sectional view of a split rod, split nut, and abutment cap.

Detailed Description

As shown in fig. 1-6, compared with a conventional hub bearing, the multilayer sealed hub bearing with high wear resistance also comprises a flange plate and a bearing assembly, wherein the flange plate comprises a plate body 1 and a plate shaft 2 arranged in the center of one surface of the plate body 1, the plate body 1 is used for connecting a hub, and the plate shaft 2 is used for connecting a wheel shaft to realize power transmission, and the multilayer sealed hub bearing with high wear resistance can be butted with the wheel shaft in key connection, flange connection and other ways. The bearing assembly comprises an inner ring 3, a middle ring 4 and an outer ring 5 which are sequentially sleeved outside a disc shaft 2 from inside to outside, wherein the inner ring 3 is sleeved on the disc shaft 2, the middle ring is sleeved outside the inner ring 3, and the outer ring 5 is sleeved outside the middle ring 4. The roller bearing is characterized in that rollers 6 are arranged between the inner ring 3 and the middle ring 4 and between the outer ring 5 and the middle ring 4, and the rollers 6 can be single-row ball rollers, double-row or multi-row ball rollers or cylindrical rollers. The inner ring 3 and the outer ring 5 are fixedly connected with a flange plate, the middle ring 4 is connected with a bogie, a frame and other installation bases, and the specific selection is adjusted according to the type of the vehicle.

Compared with the traditional hub bearing, the invention has the following differences: the V-shaped layout of the rollers 6, as shown in fig. 2 and 3, the inner and outer side walls of the middle ring 4 are each provided with a concave portion 7 with a V-shaped cross section, and the side walls of the inner ring 3 and the outer ring 5 facing the middle ring 4 are provided with a V-shaped convex portion 8 matched with the concave portion 7. The concave part 7 and the convex part 8 form an installation space of the roller 6, in order to limit the roller 6, a plurality of rolling grooves 10 are formed between two V-shaped inclined surfaces of the concave part 7 and the convex part 8 corresponding to the number of the rollers 6, the roller 6 is maintained in the rolling groove 10 through a retainer 9, the specific form of the retainer 9 is more, and the retainer can be adapted by referring to various retainers 9 which are commercially available.

The bearing assembly comprises an outer ring, a middle ring and an inner ring, wherein the outer ring 5 and the inner ring 3 are fixedly connected with a flange plate, the middle ring 4 can be connected with a mounting foundation such as a bogie, and the like, so that the integral shaft support effect of the double-layer support structure is better, and the support strength is higher. Meanwhile, the rollers 6 are arranged in the rolling grooves 10 formed between the V-shaped convex parts 8 and the V-shaped concave parts 7, the V-shaped rolling support structure can effectively limit axial movement among rings, after the inner and outer double-layer V-shaped rollers are adopted for supporting, axial runout can be limited in a tiny range, and abrasion among the rings is reduced. When the vehicle wheel bears external forces such as steering, collision, extrusion and the like, the bearing assembly can be ensured not to be out of position, the supporting strength of the bearing assembly to the hub part is ensured, and the service life is effectively prolonged.

In order to prevent dust, foreign matters and the like from entering between the rings of the bearing assembly and ensure the integral sealing performance of the bearing, the invention needs to form sealing between the rings, and usually a bearing sealing cover or a sealing ring is selected for sealing, when the bearing sealing cover is adopted, because the sealing gap of the bearing assembly is multilayer, particularly two layers, in order to facilitate the installation of the bearing sealing cover, as shown in fig. 2, two ends of the convex part 8 are provided with step-shaped end platforms 11, an outer bearing sealing cover 12 is arranged between the end platforms 11 at two ends of the convex part 8 of the outer ring 5 and the middle ring 4, and an inner bearing sealing cover 13 is arranged between the end platforms 11 at two ends of the convex part 8 of the inner ring 3 and the middle ring 4.

As mentioned above, the roller 6 of the present invention can be selected in many forms, but it is preferable to use a cylindrical roller, that is, the roller 6 of the present invention is preferably a cylindrical roller, in this case, the cylindrical rollers are symmetrically distributed along the center line of the V-shaped tip in order to ensure the forces on both sides of the V-shape are balanced. On the basis, in order to reduce the overall weight, as shown in fig. 2, for the middle ring 4, weight-reducing ring grooves 14 with arc-shaped sections may be arranged on both end faces of the middle ring 4, and the cross section of the middle ring 4 is in an X shape as a whole. Of course, besides the lightening holes and the lightening slots arranged on the middle ring 4, under the condition of meeting the design requirement, the lightening holes and the lightening slots are also feasible to be additionally arranged on the disk body 1, the disk shaft 2, the inner ring 3, the outer ring 5 and other parts.

Compared with the traditional hub bearing, the invention has the second difference in the fixed connection form of the inner ring 3, the outer ring 5 and the flange plate and the fixed connection form of the middle ring 4 and the installation foundation. Specifically, as shown in fig. 1 and 3, the outer ring 5 and the inner ring 3 are provided with a ring edge 15 on the outer peripheral surface of one end close to the disc body 1, a connecting rod 16 is provided on one surface of the ring edge 15 facing the disc body 1, and the end of the connecting rod 16 is provided with a thread and is adapted with a fastening nut 17. A rod hole 18 is formed in the disc body 1 at a position corresponding to the fastening nut 17, the connecting rod 16 penetrates through the rod hole 18, and the ring edge 15 and the disc body 1 are locked through the fastening nut 17. Of course, in order to avoid the fastening nut 17 protruding out of the disc surface of the disc body 1 and interfering with the mounting of the hub, it is better if the end of the rod hole 18 remote from the bearing assembly is provided with a large-sized receiving hole 27, and the fastening nut 17 is located in the receiving hole 27. Regarding the connection form of the middle ring 4, as shown in fig. 1, an outer connection ring 19 is arranged on the outer side of one end of the middle ring 4 away from the disc body 1, a plurality of outer connection lugs 20 as shown in fig. 4 are uniformly distributed on the circumferential surface of the outer connection ring 19, and outer connection holes 21 are arranged on the outer connection lugs 20. On this basis, in order to further improve the connection stability of the middle ring 4, as shown in fig. 1, an inner connecting ring 22 is disposed on the inner side of the middle ring 4, which is far away from one end of the plate body 1, a plurality of inner connecting lugs 23 are uniformly distributed on the circumferential surface of the inner connecting ring 22, and an inner connecting hole 24 is disposed on the inner connecting lug 20. The inner connecting ring 22 has a smaller diameter than the outer connecting ring 19, and the inner connecting ring 22 and the inner and outer connecting lugs on the outer link ring 19 are fixed in a double mode, so that the stability is better.

After the installation form is adopted, the bearing assembly is sleeved in from the disc shaft 2, so that the inner ring 3 is sleeved outside the disc shaft 2 to form radial limit. Of course, it is better to combine the existing key connection to carry out circumferential limit on the inner ring 3 and the disc shaft 2. And then the ring edges 15 at the ends of the inner ring 3 and the outer ring 5 are fixedly connected with the plate body 1 of the flange plate by using the fastening nuts 17. On one hand, the matching of the connecting rod 16 and the rod hole 18 has the positioning function and is very convenient to install. On the other hand, the double-deck bolt fastening connection structure of interior outer lane tip, including the cup joint connection structure of inner circle 3, well circle 4 and outer lane 5 itself, can form many three-dimensional atress supports for holistic joint strength obtains very big promotion.

In addition, in order to further improve the positioning accuracy of connection, two rings of limiting rings 25 are further arranged on one surface of the disk body 1 close to the disk shaft 2, and the two rings of limiting rings 25 are respectively matched with the ring edge 15 of the inner ring 3 and the ring edge 15 of the outer ring 5 and sleeved outside the ring edge 15. In order to further reduce the transverse shearing force applied to the connecting rod 16, a first latch 26 is arranged on the inner side wall of the limiting ring 25, a second latch is arranged on the outer peripheral surface of the annular edge 15, and the first latch 26 is meshed with the second latch.

As shown in the foregoing, after the invention adopts the form of the inner ring 3, the middle ring 4 and the outer ring 5, the middle ring 4 of the bearing assembly is limited by the convex parts 8 due to the existence of the convex parts 8 and the concave parts 7, and the weight-reducing ring grooves 14 with arc-shaped cross sections are arranged on the two end surfaces of the middle ring 4, and the cross section of the middle ring 4 is in an X shape. The middle ring 4 cannot be directly inserted between the inner ring 3 and the outer ring 5, and in order to realize the assembly, another difference of the present invention is that, as shown in fig. 2, the middle ring 4 is formed by splicing an inner section 28 and an outer section 29, and the splicing seam of the inner section 28 and the outer section 29 is located at the V-shaped bottom of the V-shaped recess 7. That is, the inner section 28 and the outer section 29 are butted at the center of the V-shape. A plurality of splicing holes 30 penetrating through the weight reducing ring grooves 14 at two ends are formed in the middle ring 4, the splicing holes 30 extend along the length direction of the middle ring 4, and the splicing holes 30 are uniformly distributed in the weight reducing ring grooves 14 in an annular mode. In this way, the inner section 28 and the outer section 29 can be closed from both ends, avoiding the influence of the protrusion 8. The matched splicing rod 31 penetrates through the splicing hole 30, threads are arranged at two ends of the splicing rod 31 and are matched with the splicing nuts 32, and the inner section 28 and the outer section 29 of the middle ring 4 are locked through the splicing rod 31 and the splicing nuts 32.

According to the invention, the support strength of the whole bearing is enhanced by adopting a mode that the double-row rollers are arranged in a V shape, but the whole assembly difficulty is increased due to the existence of the concave part 7 and the convex part 8, so that the middle ring 4 is adjusted to be composed of the inner section 28 and the outer section 29, the split rods 31 are tightly taken from two ends by utilizing the split nuts 32, and the middle ring 4 is folded and clamped from two ends to form the assembly, thereby effectively solving the difficult problem of assembly difficulty. In the process that the middle ring 4 supports the inner ring 3 and the outer ring 5 to rotate, due to the stress on the two sides of the V shape, a transverse shearing force can be applied to the split rod 31, in order to protect the middle section of the split rod 31, better as shown in fig. 2, the opposite ends of the inner section 28 and the outer section 29 are respectively provided with a step groove 33 and a step edge 34 which are meshed with each other. The stepped groove 33 and the stepped edge 33 can reduce the transverse shearing force applied to the split rod 31, and the connection strength is further improved.

In addition, in order to facilitate the installation of the split nut 32, it is preferable that both ends of the split hole 30 are provided with large-sized counter bore sections 35, and the split nut 32 is located in the counter bore sections 35. For better fastening effect of the split nut 32, an elastic washer 36 is disposed at the split nut 32. The two split nuts 32 can be arranged in pairs and synchronously arranged at one end of the split rod 31 to realize mutual abutting, or the inner side wall of the counter bore section 35 is provided with threads, the counter bore section 35 is internally provided with the abutting cover 37, and the peripheral surface of the abutting cover 37 is provided with the threads and forms threaded fit with the counter bore section 35. The split nut 32 is held tightly within the counterbore section 35 by a holding cap 37.

The invention adopts a bearing structure with three rings, namely an outer ring, a middle ring and an inner ring, heat is generated due to friction in the rotation process of each ring, and the middle ring 4 forms rolling support with the outer ring 5 and the inner ring 3, so that the heat dissipation requirement is the largest. Therefore, a plurality of heat dissipation holes penetrating through the middle ring 4 along the length direction of the middle ring 4 are formed in the middle ring 4, and the heat dissipation holes are uniformly distributed on the middle ring 4 in an annular mode. According to the invention, the plurality of heat dissipation holes are formed in the middle ring 4 along the length direction of the middle ring, and the air convection in the heat dissipation holes can quickly carry away the heat of silt, so that the risk of heating deformation of the middle ring is reduced, the integral strength of the middle ring 4 is improved, and the structural stability between the middle ring 4 and the inner ring 3 and the outer ring 5 is further ensured. Along with seting up of louvre, the intensity of centre circle 4 has the reduction of certain degree, in order to keep its intensity, the radiating hole internal fixation is provided with pipy reinforcing steel core, the lumen of reinforcing steel core forms the louvre, and the reinforcing steel core can adopt multiple fixed forms such as threaded connection, end cover butt, joint to install in the radiating hole, and in order to promote the intensity of reinforcing steel core, the inside wall of reinforcing steel core is provided with a plurality of enhancement arris 38 of strengthening the extension of steel core length direction.

When the inner ring 4 adopts the inner and outer two-section structure, the split holes 4 are required to be arranged, so that the split holes 4 can be independently arranged, but the better way is to combine the heat dissipation holes and the split holes 4. In other words, the center of the split rod 31 is provided with a central through hole extending along the length direction of the split rod 31, the reinforcing steel core is formed by the split rod 31, and the heat dissipation holes are formed by the central through hole. Namely, the split rod 31 is used as a reinforcing steel core, and the inner hole thereof is used as a heat dissipation hole. On this basis, in order to avoid the blocking of the heat dissipation holes by the abutting cover 37 and at the same time facilitate the installation of the abutting cover 37, the split nut 32 abuts against the inside of the counterbore section 35 through the abutting cover 37. The center of the abutting cover 37 is provided with a hexagon socket.