Totally enclosed type tension pulley

Abstract

The utility model discloses a kind of full-sealed type tensioning wheels, it is related to engine transmission technical field.The tensioning wheel includes swing arm, bearing and pulley, swing arm is connected by bolt with bearing, pulley is sleeved in bearing outer. To solve the problem that bearing is easy to enter water and dust under harsh working condition, pulley one end surface is equipped with sealing cover, sealing structure is equipped between the other end surface and swing arm, and the outer wall of bearing outer ring is equipped with plugging ring. Sealing structure includes annular groove on swing arm and the rubber sealing ring arranged in, sealing ring is equipped with convex part with triangular section, is blocked in pulley inner hole wall and groove. Pulley is also equipped with let slot, and annular groove edge forms "n" shape barrier gap. The utility model passes through multiple sealing structure, effectively blocks the water, dust invasion path, significantly improves the sealing property and service life of tensioning wheel, and is applicable to engineering machinery and wade engine.

Description

Technical Field

[0001] This utility model relates to the technical field of engine accessory transmission systems, and in particular to a fully sealed tensioner for use in harsh working conditions. Background Technology

[0002] The tensioner pulley is a key component in engine timing belt or accessory belt drive systems, primarily used to maintain belt tension and prevent belt slippage or jump. Existing tensioners typically consist of a swing arm, a bearing, and a pulley. The pulley is mounted on the swing arm via the bearing, and the swing arm is connected to the mounting base via a torsion spring.

[0003] However, in harsh operating conditions such as construction machinery, agricultural machinery, or vehicles wading through water, existing tensioners have significant drawbacks: First, traditional tensioner bearings lack effective sealing and protection measures, allowing contaminants such as mud, dust, and water to easily penetrate the bearing through the gaps between the inner and outer rings, leading to grease failure, raceway wear, and severely impacting bearing rotational performance and service life. Second, when the pulley is submerged in water or subjected to high-pressure washing, water can easily seep in through the connection gap between the pulley and the swing arm, further accelerating the corrosion and damage of internal components. Once bearing performance deteriorates, it will lead to reduced belt drive efficiency, abnormal noise, or even breakage, causing serious equipment failure.

[0004] Therefore, there is an urgent need for a fully sealed tensioner with multiple sealing protection structures to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a fully sealed tensioning wheel to solve the technical problems of poor sealing performance and easy water and dust ingress into the tensioning wheel under harsh working conditions, which can lead to bearing damage.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A fully sealed tensioning wheel includes a rocker arm, a bearing, and a pulley. The rocker arm has a mounting hole, and a bolt passes through the bearing and is threaded into the mounting hole. A sealing cap is provided on one end face of the pulley, which covers the bearing. A sealing structure is provided between the other end face of the pulley and the end face of the rocker arm. The bearing includes an inner ring and an outer ring. Sealing rings are provided at both ends of the inner wall of the outer ring, and the sealing rings seal the gap between the inner ring and the outer ring.

[0008] Furthermore, the sealing structure includes an annular groove on the end face of the swing arm, a matching rubber sealing ring is provided in the annular groove, and an annular protrusion is provided on one end face of the rubber sealing ring, which seals the gap between the annular groove and the inner wall of the pulley.

[0009] Preferably, the cross-sectional shape of the protrusion is triangular.

[0010] Preferably, the lower end face of the pulley is provided with an annular relief groove, and the upper edge of the annular groove is placed in the relief groove to form an "n"-shaped barrier gap.

[0011] Preferably, the inner wall of the pulley is provided with an annular bearing mounting groove, the outer ring of the bearing is tightly inserted into the bearing mounting groove, and a retaining ring is provided at the port of the bearing mounting groove.

[0012] Preferably, a bushing is also provided between the bolt and the inner ring of the bearing.

[0013] Preferably, the other end of the swing arm is connected to the cover-shaped mounting base via a spiral planar spring.

[0014] The beneficial effects of this utility model are as follows: Compared with the prior art, this utility model has the following advantages:

[0015] 1. A multi-layered composite sealing system is adopted, consisting of "axial end face seal + radial labyrinth seal + bearing self-sealing". By setting a sealing cover at one end of the pulley and a sealing structure consisting of a rubber sealing ring and an annular groove at the other end of the pulley, combined with the sealing rings at both ends of the inner wall of the bearing outer ring, the path for external water and dust to enter the bearing is completely cut off, achieving full-seal protection.

[0016] 2. The triangular cross-section protrusion on the rubber sealing ring can generate greater contact pressure, tightly fitting the inner wall of the pulley and effectively blocking impurities; at the same time, the "n"-shaped barrier gap formed by the relief groove on the pulley and the edge of the annular groove on the swing arm increases the path length and resistance of water or dust intrusion, achieving a labyrinth seal effect and significantly improving the waterproof and dustproof level.

[0017] 3. The overall structure is compact and easy to install, making it particularly suitable for harsh working environments such as engineering machinery, ships and water engines, which greatly extends the service life of the tensioner and improves transmission stability.

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0019] Figure 1 This is a perspective view of a specific embodiment of the present utility model;

[0020] Figure 2 This is a partial cross-sectional view of a specific embodiment of the present utility model;

[0021] Figure 3 This is a perspective view of the rubber sealing ring in a specific embodiment of the present utility model;

[0022] Figure 4 This is a cross-sectional view of the bearing in a specific embodiment of this utility model.

[0023] Explanation of reference numerals in the attached drawings: 1. Swing arm; 11. Annular groove; 2. Bearing; 21. Inner ring; 22. Outer ring; 23. Sealing ring; 3. Pulley; 31. Relief groove; 32. Bearing mounting groove; 4. Bolt; 5. Sealing cap; 6. Rubber sealing ring; 61. Protrusion; 7. Retaining ring; 8. Bushing. Detailed Implementation

[0024] The present invention will be specifically described below through embodiments, which are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention.

[0025] like Figure 1 — Figure 4 As shown, this embodiment provides a fully sealed tensioning wheel, whose structure mainly includes a swing arm 1, a bearing 2, and a pulley 3. The swing arm 1 has a mounting hole, and a bolt 4 passes through the bearing 2 and is threaded into the mounting hole, thereby fixing the pulley 3, bearing 2, and swing arm 1 together. The other end of the swing arm 1 is connected to a cover-shaped mounting base via a spiral planar spring to achieve an automatic tensioning function.

[0026] In terms of sealing structure design, this embodiment adopts multiple protections:

[0027] First, in terms of the bearing 2's own structure, the bearing 2 includes an inner ring 21 and an outer ring 22. The inner walls of the outer ring 22 are respectively provided with inwardly protruding sealing rings 23. The sealing rings 23 are closely attached to the outer walls of the inner ring 21, sealing the gap on both sides of the raceway between the inner ring 21 and the outer ring 22, thus preventing grease leakage and external contaminants from entering along the axial direction from the source.

[0028] Secondly, double end-face seals are provided at both axial ends of the pulley 3. A metal or plastic sealing cover 5 is disposed on the end face of the pulley 3 near the mounting base. The sealing cover 5 is fixed to the pulley 3 by interference fit or snap-fit ​​and covers the outer end face of the bearing 2. Specifically, the sealing cover 5 is spherical in shape, and its outer edge is provided with an upwardly bent elastic retaining ring, which is pressed into the end face groove of the pulley 3. A dynamic sealing structure is provided between the other end face (i.e., the lower end face) of the pulley 3 and the end face of the rocker arm 1. Specifically, an annular groove 11 is machined on the upper end face of the rocker arm 1, and an O-ring or a specially made rubber sealing ring 6 is installed in the annular groove 11. The upper end face of the rubber sealing ring 6 has an integrally formed annular protrusion 61. The cross-section of the protrusion 61 is designed as a triangle. Under the action of the installation preload, the tip of the triangular protrusion 61 tightly abuts against the inner wall of the pulley 3, forming a reliable radial seal.

[0029] To further enhance the waterproofing effect, an annular relief groove 31 is provided on the lower end face of the pulley 3. When the swing arm 1 is assembled with the pulley 3, the upper edge of the annular groove 11 is precisely placed in the relief groove 31, forming an "n"-shaped meandering gap between them. This structure increases the length and bend of the water flow path, forming a labyrinth seal that can effectively prevent the splashing intrusion of high-pressure water.

[0030] In addition, an annular bearing mounting groove 32 is machined on the inner wall of the pulley 3. The outer ring 22 of the bearing 2 is tightly fitted into the bearing mounting groove 32, and an elastic retaining ring 7 is provided at the end of the bearing mounting groove 32 to prevent the bearing 2 from moving axially. A bushing 8 is also provided between the bolt 4 and the inner ring 21 of the bearing 2 to protect the inner ring bore wall of the bearing and reduce wear.

[0031] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., 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 fully sealed tensioning wheel, comprising a swing arm (1), a bearing (2), and a pulley (3), wherein the swing arm (1) is provided with a mounting hole, and a bolt (4) passes through the bearing (2) and is threadedly connected to the mounting hole, characterized in that, A sealing cover (5) is provided on one end face of the pulley (3), which covers the bearing (2). A sealing structure is provided between the other end face of the pulley (3) and the end face of the swing arm (1). The bearing (2) includes an inner ring (21) and an outer ring (22). A sealing ring (23) is provided at both ends of the inner wall of the outer ring (22), which seals the gap between the inner ring (21) and the outer ring (22).

2. The fully sealed tensioner according to claim 1, characterized in that, The sealing structure includes an annular groove (11) provided on the end face of the swing arm (1), and a matching rubber sealing ring (6) is provided in the annular groove (11). One end face of the rubber sealing ring (6) is provided with an annular protrusion (61), which blocks the gap between the annular groove (11) and the inner wall of the pulley (3).

3. The fully sealed tensioner according to claim 2, characterized in that, The cross-sectional shape of the protrusion (61) is triangular or wedge-shaped.

4. The fully sealed tensioner according to claim 2, characterized in that, The lower end face of the pulley (3) is provided with an annular relief groove (31), and the upper edge of the annular groove (11) is placed in the relief groove (31) to form a meandering barrier gap.

5. The fully sealed tensioner according to claim 1, characterized in that, The inner wall of the pulley (3) is provided with an annular bearing mounting groove (32), the outer ring (22) of the bearing (2) is tightly inserted into the bearing mounting groove (32), and a retaining ring (7) is provided at the port of the bearing mounting groove (32).

6. The fully sealed tensioner according to claim 1, characterized in that, A bushing (8) is also provided between the bolt (4) and the inner ring (21) of the bearing (2).

7. The fully sealed tensioner according to claim 1, characterized in that, The other end of the swing arm (1) is connected to the cover-shaped mounting base via a spiral planar spring.

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