Thrust wheel

Abstract

The utility model provides a thrust wheel, which belongs to the technical field of engineering machinery and comprises a wheel body, a wheel shaft and two side covers, two ends of the wheel body are respectively provided with a mounting cavity and a sealing cavity which are sequentially communicated along the axial direction, the inner diameter of the sealing cavity is larger than that of the mounting cavity, the mounting cavity is used for accommodating a rolling bearing, and the wheel body is in running fit with the wheel shaft by means of the rolling bearing; the sealing cavity is used for containing a framework seal of a double-layer lip opening, and the framework seal is arranged on the outer side of the axle in a sleeving mode through a round nut. The sealing cavity is filled with butter; the side cover is of an integrated structure without an oil injection hole. According to the thrust wheel provided by the utility model, the mode of combining the rotating bearing and the framework seal is adopted, the rotating bearing is in contact with the wheel shaft, so that the frictional wear is reduced, and meanwhile, the problem of oil leakage is solved through the matching of the framework seal and the butter; in addition, due to the semi-solid property of the butter, the butter is matched with the side cover without the oil filler hole to form a closed lubricating system, the production difficulty of the side cover is reduced, and meanwhile the oil leakage risk caused by the oil filler hole is avoided.

Description

Technical Field

[0001] This utility model belongs to the field of engineering machinery technology, and more specifically, it relates to a support roller. Background Technology

[0002] As a core component of excavators and tank chassis, the performance of track rollers directly affects the reliability and working efficiency of the entire machine.

[0003] Existing track rollers typically consist of a track roller body, a track roller shaft passing through a cavity within the body, bearing seats at both ends of the shaft, a floating oil seal at the connection between the track roller body and the bearing seats, and a metal sleeve fitted over the outer side of the shaft. The track roller body rotates through this metal sleeve, simultaneously engaging with both the shaft and bearing seats. During rotation, sliding friction occurs between the track roller body / shaft seats and the metal sleeve, resulting in high frictional force. The metal sleeve is prone to wear and tear during operation, leading to gaps and loosening, which affects the overall sealing performance of the track roller and causes lubricant leakage. Furthermore, the floating oil seals are filled with liquid lubricant, posing a risk of leakage, and wear on the metal sleeve increases this risk, further impacting the track roller's performance. Utility Model Content

[0004] The purpose of this invention is to provide a support roller that addresses the problem of metal sleeves being prone to wear and increasing the risk of oil leakage.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A support roller is provided, comprising a wheel body, a wheel axle, and two side covers. Both ends of the wheel body have an axially connected mounting cavity and a sealing cavity, the inner diameter of which is larger than the inner diameter of the mounting cavity. The mounting cavity is used to accommodate a rotating bearing, and the wheel body rotates with the wheel axle via the rotating bearing. The sealing cavity is used to accommodate a double-lip skeleton seal, which is fitted onto the outside of the wheel axle by a round nut. The sealing cavity is filled with grease. The two side covers are respectively installed at both ends of the wheel body to seal the end faces of the wheel body, and the side covers are integral structures without grease injection holes.

[0006] In another embodiment of this application, the rotating bearing is a cylindrical roller bearing or a tapered roller bearing.

[0007] In another embodiment of this application, the mounting cavity has two parallel rotating bearings.

[0008] In another embodiment of this application, when the rotating bearing is a tapered roller bearing, the two tapered roller bearings are arranged back to back.

[0009] In another embodiment of this application, the sealing cavity has an annular limiting step at one end near the mounting cavity, the end face of the skeleton seal abuts against the limiting step, the round nut is located inside the skeleton seal, and the round nut is in contact with the end face of the rotating bearing.

[0010] In another embodiment of this application, the sidewall of the mounting cavity is connected to the limiting step of the sealing cavity by means of an inclined transition surface.

[0011] In another embodiment of this application, the skeleton seal is an assembled FZ type skeleton seal.

[0012] In another embodiment of this application, the end face of the wheel body is provided with a limiting groove extending along the axial direction. The bottom of the limiting groove is in communication with the sealing cavity. The inner diameter of the limiting groove is larger than the inner diameter of the sealing cavity. The side wall of the limiting groove forms a supporting step on the side close to the sealing cavity. The end of the side cover extends into the limiting groove and covers the sealing cavity.

[0013] In another embodiment of this application, the side cover is provided with a pin hole, and the side cover is connected to the end of the wheel axle by means of a flexible cylindrical pin.

[0014] The beneficial effects of the support roller provided by this utility model are as follows: Compared with the prior art, the support roller of this utility model adopts a combination of rotating bearing and frame seal. The rotating bearing contacts the wheel axle, reducing friction and wear. At the same time, the cooperation between the frame seal and grease solves the oil leakage problem. In addition, the design of the rotating bearing reduces the thickness of the wheel body end, reducing the wheel body weight and simplifying the wheel body production. The semi-solid nature of the grease and the side cover without oil injection hole form a closed lubrication system, reducing the production difficulty of the side cover and avoiding the risk of oil leakage caused by oil injection hole. It also reduces the machining accuracy requirements of the side cover and shaft. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the support roller provided in the first embodiment of the present invention;

[0017] Figure 2 A side view of the support roller provided in an embodiment of this utility model;

[0018] Figure 3This is a schematic diagram of the support roller provided in the second embodiment of the present invention.

[0019] In the diagram: 1. Side cover; 2. Axle; 3. Round nut; 4. Wheel body; 5. Rotary bearing; 6. Skeleton seal; 7. Flexible cylindrical pin. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0021] Please see Figure 1 and Figure 3 The support roller provided by this utility model will now be described. The support roller includes a wheel body 4, a wheel axle 2, and two side covers 1. Both ends of the wheel body 4 have an installation cavity and a sealing cavity that are connected sequentially along the axial direction. The inner diameter of the sealing cavity is larger than the inner diameter of the installation cavity. The installation cavity is used to accommodate a rotating bearing 5. The wheel body 4 is rotatably engaged with the wheel axle 2 by means of the rotating bearing 5. The sealing cavity is used to accommodate a double-lip skeleton seal 6. The skeleton seal 6 is sleeved on the outside of the wheel axle 2 by means of a round nut 3. The sealing cavity is filled with grease. The two side covers 1 are respectively installed at both ends of the wheel body 4 to seal the end face of the wheel body 4. The side covers 1 are integral structures without oil injection holes.

[0022] In the existing technology, track rollers mostly adopt a copper bushing + floating oil seal combination. The copper bushing is prone to wear during operation, resulting in oil leakage. The floating oil seal is filled with liquid lubricating oil, which is prone to leakage. Therefore, the machining accuracy requirements of the side cover 1 and the wheel axle 2 are high, and the side cover 1 needs to retain an oil filling hole to facilitate the subsequent filling of lubricating oil into the floating oil seal.

[0023] To address the aforementioned problem of easy lubricant leakage, the present invention proposes a structure in which a rotating bearing 5 is combined with a frame seal 6 to form a support roller.

[0024] The above structural changes have the following effects: (1) First, the inner cavity structure at both ends of the wheel body 4 is divided into two parts: the mounting cavity and the sealing cavity. The rotating bearing 5 is fixed in the mounting cavity. The rotating bearing 5 replaces the traditional sliding friction structure of the metal sleeve, which greatly reduces friction and wear and extends service life. In addition, the use of the rotating bearing 5 can reduce the force on the outside of the wheel body 4 and reduce the thickness of the wheel body 4 at the location of the mounting cavity. Under the same size requirements of the wheel body 4, the thickness on both sides of the wheel body 4 is reduced and the mass of the wheel body 4 is reduced. At the same time, the forging process of the wheel body 4 is simpler.

[0025] (2) An independent sealing cavity is set on one side of the rotating bearing 5 to accommodate the skeleton seal 6 with double lips. The skeleton seal 6 with double lips effectively isolates external dust and prevents grease leakage through the dual functions of the main lip sealing grease and the secondary lip dust prevention, thus solving the oil leakage problem of the traditional floating oil seal and liquid lubricating oil combination.

[0026] (3) Due to the semi-solid nature of grease, the side cover 1 of the support roller adopts an integrated structure without oil injection holes. After the side cover 1 is installed, the side cover 1 and the skeleton seal 6 in the sealing cavity form a closed lubrication system, which simplifies the design structure of the side cover 1 and avoids the leakage risk caused by the oil injection hole; it improves the strength and production efficiency of the side cover 1.

[0027] (4) The skeleton seal 6 is fixed by the round nut 3 to ensure the stability of the skeleton seal 6 under dynamic load; the round nut 3, in conjunction with the layered cavity design, further optimizes the pressure distribution in the sealing cavity and prevents the grease from being lost due to mechanical vibration or temperature rise.

[0028] (5) The skeleton seal 6 structure of the grease-coated oil seal has lower requirements for the machining accuracy of the side cover 1 and the shaft compared with the floating oil seal, which can further improve production efficiency and yield and reduce production difficulty.

[0029] Compared with the prior art, the support roller provided by this utility model adopts a combination of rotating bearing 5 and skeleton seal 6. The rotating bearing 5 contacts the wheel axle 2, reducing friction and wear. At the same time, the cooperation between the skeleton seal 6 and grease solves the oil leakage problem. In addition, the design of the rotating bearing 5 reduces the thickness of the end of the wheel body 4, reducing the weight of the wheel body 4 and simplifying its production. The semi-solid nature of the grease and the side cover 1 without oil injection holes form a closed lubrication system, reducing the production difficulty of the side cover 1 and avoiding the risk of oil leakage caused by oil injection holes. It also reduces the machining accuracy requirements of the side cover 1 and the shaft.

[0030] In some possible embodiments, please refer to Figure 1 The rotating bearing 5 is a cylindrical roller bearing or a tapered roller bearing.

[0031] Rotary bearing 5 uses a roller bearing. Compared to traditional ball bearings, the rolling elements and raceways of a roller bearing have line contact, resulting in a larger contact area than the point contact of a ball bearing. Therefore, it can withstand higher radial or axial loads. For example, the radial load capacity of a cylindrical roller bearing can be more than 1.5 times that of a ball bearing of the same size, making it more suitable for the extreme load requirements of tracked machinery. Furthermore, the roller structure is more stable under impact loads or vibrations, and is less prone to deformation or failure. Under heavy loads or frequent start-stop conditions, roller bearings wear more evenly, and their lifespan may be longer than that of ball bearings.

[0032] Roller bearings include cylindrical roller bearings and tapered roller bearings. Both cylindrical roller bearings and tapered roller bearings can be used with skeleton seals.

[0033] During installation, the inner wall of the wheel body 4 at the end of the mounting cavity near the center has an inwardly extending annular protrusion. The inner end of the rotating bearing 5 along the axial direction abuts against the annular protrusion, and the outer end of the rotating bearing 5 along the axial direction faces the sealing cavity and abuts against the round nut 3 inside the sealing cavity.

[0034] In some possible embodiments, the mounting cavity has two parallel rotating bearings 5.

[0035] To meet the requirements of the support roller, multiple pairs of rotary bearings 5 ​​can be arranged within the roller body 4 to form a distributed support structure. Simultaneously, by arranging parallel rotary bearings 5 ​​within the same mounting cavity, the radial load can be shared. This method is suitable for applications involving extremely heavy radial loads. The parallel rotary bearings 5 ​​ensure a more even load distribution, preventing premature failure due to overload of a single bearing. Furthermore, the parallel rotary bearings 5 ​​reduce shaft bending deformation under stress, improve transmission accuracy, and extend service life.

[0036] Optionally, when both radial and axial combined loads need to be borne simultaneously, two parallel tapered roller bearings can be used, arranged back-to-back. When the axial space of the mounting cavity is limited, double-row cylindrical roller bearings can be selected. The integrated design of double-row cylindrical roller bearings can reduce the risk of installation errors.

[0037] During installation, due to the symmetrical structure of the wheel body 4, identical rotary bearings 5 ​​are installed in the mounting cavities at both ends of the wheel body 4. If the rotary bearings 5 ​​are tapered roller bearings, then the tapered roller bearings in the mounting cavities on both sides are required to be symmetrically distributed.

[0038] In some possible embodiments, please refer to Figure 1 The sealing cavity has an annular limiting step at one end near the mounting cavity. The end face of the skeleton seal 6 abuts against the limiting step. The round nut 3 is located inside the skeleton seal 6 and fits against the end face of the rotating bearing 5.

[0039] The sealing cavity is connected to the mounting cavity, and the inner diameter of the sealing cavity is larger than that of the mounting cavity. The sealing cavity and the mounting cavity are coaxial. Therefore, the sealing cavity has an annular limiting step on the side near the mounting cavity. This limiting step is formed by the inner wall of the wheel body 4. The sealing cavity and the mounting cavity form a stepped transition structure.

[0040] The skeleton seal 6 is installed inside the sealing cavity, with its axial end face abutting against the limiting step. A round nut 3 is connected radially to the inner side of the skeleton seal 6, and the round nut 3 is sleeved onto the wheel axle 2. The end face of the round nut 3 abuts against the end face of the rotating bearing 5, limiting the rotation of the bearing 5. Specifically, the skeleton seal 6 is embedded into the sealing cavity using an interference fit on its outer ring, with its axial end face tightly fitted to the limiting step, and the sealing lip facing the mounting cavity side, forming the first dynamic sealing interface. The round nut 3 is connected to the wheel axle 2 via a threaded pair, and its end face is clearance-fitted with the bearing's outer ring end face, achieving precise adjustment and limiting of the bearing's axial clearance; the clearance fit between the end face of the round nut 3 and the bearing provides space for thermal expansion compensation.

[0041] To facilitate the installation of the rotating bearing 5, the side wall of the mounting cavity and the limiting step of the sealing cavity are connected by an inclined transition surface. The inclined transition surface forms a flared opening at the opening end of the mounting cavity, so that the rotating bearing 5 can smoothly enter the mounting cavity through the flared opening during installation.

[0042] Optionally, the transition surface can be inclined at 15°, and the transition surface and the limiting step surface of the sealing cavity are smoothly connected by a 2mm radius corner to form a flared guide structure. This flared guide structure enables a self-aligning effect during bearing press-fitting: when the bearing is introduced along the flared opening, its outer ring is guided by the conical surface to automatically correct coaxiality deviations, avoiding raceway damage caused by hard impacts.

[0043] Optionally, the skeleton seal 6 is an assembled FZ type skeleton seal.

[0044] The main lip of the skeleton seal 6 forms a contact seal with the wheel axle 2, while the secondary lip forms a non-contact labyrinth seal with the inner wall of the sealing cavity, thus forming double protection: the main sealing layer is a contact lip seal that can block more than 80% of pollutants from entering; the secondary sealing layer is a labyrinth structure that further reduces the permeability through the lipid film viscosity effect.

[0045] The arrangement of the sealing cavity and the mounting cavity, through the coordinated design of the stepped cavity and the limiting step, realizes the modular assembly of the bearing-sealing assembly and improves the axial positioning accuracy; the horn-shaped guide structure reduces the dependence on special tooling and improves the assembly efficiency; the dual-stage sealing system can achieve long-term maintenance-free operation under IP67 protection level, significantly extending the service life of the support roller under harsh working conditions such as sand, gravel and mud.

[0046] In some possible embodiments, please refer to Figure 1The end face of the wheel body 4 has a limiting groove extending axially. The bottom of the limiting groove communicates with the sealing cavity. The inner diameter of the limiting groove is larger than the inner diameter of the sealing cavity. The side wall of the limiting groove forms a supporting step on the side near the sealing cavity. The end of the side cover 1 extends into the limiting groove and covers the sealing cavity. The side cover 1 has a pin hole, and the side cover 1 is connected to the end of the wheel axle 2 by means of an elastic cylindrical pin 7.

[0047] The limiting groove, sealing cavity, and mounting cavity are connected in sequence to form a three-stage stepped cavity structure with the inner diameter increasing from the inside to the outside along the axial direction, forming a coaxial channel with a smaller inner diameter and a larger outer diameter.

[0048] The end of side cover 1 extends into the limiting groove, and the end face of side cover 1 fits against the support step within the limiting groove, covering the opening of the sealing cavity. The radial height of the support step is at least 3 mm. The clearance fit tolerance between the inner wall of the limiting groove and the end face of side cover 1 is ±0.02 mm, used for axial positioning of side cover 1 and dispersing external impact loads. The end face of side cover 1 extending into the limiting groove fits against the support step, forming an axial sealing structure to prevent external contaminants from entering.

[0049] The side cover 1, rotating bearing 5, axle 2, and wheel body 4 enclose the skeleton seal 6 within the sealing cavity, thus sealing the cavity. The grease filled within the sealing cavity has a dropping point of not less than 180°C.

[0050] Optionally, the butter can be a complex calcium-based grease, with graphene microparticles added, and a dropping point ≥220℃. A gap is left between the side cover 1, the supporting step, and the round nut 3 to compensate for the thermal expansion of the butter.

[0051] The pin hole of side cover 1 and the pin hole at the end of axle 2 must be machined coaxially, and the flexible cylindrical pin 7 used to connect the two must conform to GB / T 879.1-2000 standard. The flexible cylindrical pin 7 connects side cover 1 and axle 2, providing radial flexible constraint for both, allowing side cover 1 to float slightly under thermal expansion or vibration conditions, avoiding stress concentration caused by rigid connection.

[0052] The inlet end of the limiting groove is designed with a 20° guide cone surface, which matches the chamfered end of the side cover 1 to achieve self-guiding assembly. In addition, there is also a tapered transition surface between the limiting groove and the sealing cavity.

[0053] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements 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 support roller, characterized in that, The device includes a wheel body (4), a wheel axle (2), and two side covers (1). Both ends of the wheel body (4) have an axially connected mounting cavity and a sealing cavity. The inner diameter of the sealing cavity is larger than the inner diameter of the mounting cavity. The mounting cavity is used to accommodate a rotating bearing (5). The wheel body (4) rotates with the wheel axle (2) through the rotating bearing (5). The sealing cavity is used to accommodate a double-lip skeleton seal (6). The skeleton seal (6) is fitted onto the outside of the wheel axle (2) by means of a round nut (3). The sealing cavity is filled with grease. The two side covers (1) are respectively installed at both ends of the wheel body (4) to seal the end face of the wheel body (4). The side covers (1) are integral structures without oil injection holes.

2. The support roller as described in claim 1, characterized in that, The rotating bearing (5) is a cylindrical roller bearing or a tapered roller bearing.

3. The support roller as described in claim 2, characterized in that, The mounting cavity contains two parallel rotating bearings (5).

4. The support roller as described in claim 3, characterized in that, When the rotating bearing (5) is a tapered roller bearing, the two tapered roller bearings are arranged back to back.

5. The support roller as described in claim 1, characterized in that, The sealing cavity has an annular limiting step at one end near the mounting cavity. The end face of the skeleton seal (6) abuts against the limiting step. The round nut (3) is located inside the skeleton seal (6) and fits against the end face of the rotating bearing (5).

6. The support roller as described in claim 5, characterized in that, The sidewall of the mounting cavity is connected to the limiting step of the sealing cavity by means of an inclined transition surface.

7. The support roller as described in claim 1, characterized in that, The skeleton seal (6) is an assembled FZ type skeleton seal.

8. The support roller as described in claim 1, characterized in that, The end face of the wheel body (4) is provided with a limiting groove extending along the axial direction. The bottom of the limiting groove is connected to the sealing cavity. The inner diameter of the limiting groove is larger than the inner diameter of the sealing cavity. The side wall of the limiting groove forms a supporting step on the side close to the sealing cavity. The end of the side cover (1) extends into the limiting groove and covers the sealing cavity.

9. The support roller as described in claim 8, characterized in that, The side cover (1) has a pin hole, and the side cover (1) is connected to the end of the axle (2) by means of an elastic cylindrical pin (7).

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