Dynamic sealing structure and rocker arm cutting head of coal mining machine

Abstract

The present invention relates to a dynamic sealing structure and a rocker arm cutting head for a coal mining machine. The dynamic sealing structure includes a radially inner sealing assembly and a radially outer sealing assembly. Each sealing assembly includes a sealing seat, an elastic ring, a sealing ring, and a positioning seat arranged in sequence from front to back in the axial direction. The elastic ring is elastically compressed between the corresponding sealing ring and the sealing seat to form a static seal. In the installed state, the outer cylindrical surface of the sealing ring of the inner sealing assembly contacts the inner cylindrical surface of the sealing ring of the outer sealing assembly to form a dynamic sealing pair. The bearing seat of the rocker arm cutting head of the coal mining machine is fixedly connected to the rocker arm housing. The front of the planetary carrier is rotatably supported in the inner hole of the bearing seat by a large bearing. The roller connecting sleeve is sleeved on the front outward end of the planetary carrier and is splined to the planetary carrier. The radially inner sealing assembly and the radially outer sealing assembly are respectively fixed to the roller connecting sleeve and the bearing seat. The present invention solves the problem of frequent oil leakage in the rocker arm cutting head of the coal mining machine and improves the reliability of the rocker arm cutting head of the coal mining machine.

Description

Technical Field

[0001] The invention relates to a dynamic sealing structure and a coal mining machine rocker arm cutting head applying the dynamic sealing structure. Background Art

[0002] Existing shearer rocker cutting heads often experience oil leakage. In severe cases, this can lead to major faults such as high-temperature gear seizure in the rocker arm's transmission system, bearing lock, and gear knocking, severely impacting the quality of the shearer and reducing mining production, resulting in significant economic losses. This is because existing electric shearer rocker cutting heads utilize a floating oil seal structure with an end-face axial seal (see Chinese Utility Model Patent No. 201420208096.6, entitled "Shearer Rocker Arm and Novel Sealing Structure of DO-Type Floating Oil Seal for Shearer Rocker Arm"). This requires a stable working gap and contact pressure, which is difficult to achieve. If the working gap decreases, the contact pressure of the floating oil seal ring increases, increasing frictional resistance and temperature. In severe cases, this can lead to fracturing of the floating oil seal ring and shortening its lifespan. If the working gap increases, the contact pressure decreases, impairing the sealing effect and causing oil leakage, leading to serious problems such as gear seizure in the rocker arm's transmission system or high-temperature bearing lockup.

[0003] In actual operation, the working clearance can vary. For example, due to the complex operating conditions and frequent vibrations of the shearer, components in the rocker arm cutting head often become loose, ultimately increasing the working clearance of the floating oil seal structure, resulting in poor sealing performance and oil leakage from the rocker arm cutting head. Another example is when the shearer is making an oblique cut into the fully mechanized working face, the shearer drum is subjected to a large axial load, which exerts a significant force on the rocker arm cutting head, causing it to significantly deform. This reduces the working clearance of the floating oil seal structure, increases the temperature of the floating oil seal, accelerates the aging of the elastic ring, and can even cause the floating oil seal ring to fracture, resulting in failure of the floating oil seal dynamic seal and premature oil leakage from the rocker arm cutting head.

[0004] In addition, the dynamic sealing effect of the floating oil seal structure is closely related to the assembly quality. When assembling the floating oil seal, special tools are required. The elastic ring needs to be pressed in slowly, which is quite laborious. At the same time, the elastic ring must not be twisted. Otherwise, the elastic ring will tear prematurely, the floating oil seal will be damaged, and oil leakage will occur in the rocker arm cutting head. It can be seen that the installation of the existing floating oil seal structure has relatively high assembly quality requirements. When underground workers replace the floating oil seal, they do not have special tools. Even if they have special tools, underground assembly is difficult. Or due to the harsh environment or the difficulty in ensuring the assembly quality of workers, oil leakage often occurs again shortly after replacement, causing frequent failures of the rocker arm cutting head, affecting the operating rate of the coal mining machine and the mine production. Summary of the Invention

[0005] The present invention aims to provide a dynamic sealing structure and a rocker arm cutting head of a coal shearer, so as to solve the problem of frequent oil leakage of the rocker arm cutting head of the coal shearer and improve the reliability of the rocker arm cutting head of the coal shearer.

[0006] The main technical solutions of the present invention are:

[0007] The cam is pressed against the cam face and the cam face is pressed against the cam face, and the cam face is pressed against the cam face, so that the cam face is pressed against the cam face, and the cam face is pressed against the cam face, so that the cam face is pressed against the cam face, and the cam face is pressed against the cam face.

[0008] The inner sealing seat and the inner positioning seat, as well as the outer sealing seat and the outer positioning seat, are fixedly connected via a plurality of bayonet pins spaced circumferentially, and the bayonet pins extend radially.

[0009] The radial inner and outer edges of the inner sealing ring are both provided with forward protrusions, and the surface between the two edge protrusions that contacts the inner elastic ring is a conical surface with a radial size larger at the front and smaller at the back; the radial inner and outer edges of the outer sealing ring are both provided with forward protrusions, and the surface between the two edge protrusions that contacts the outer elastic ring is a conical surface with a radial size smaller at the front and larger at the back.

[0010] The inner positioning seat includes a circular inner bottom plate and an inner rib located at the radial inner ring edge of the inner bottom plate, the inner rib extends forward, an inner oil storage tank is provided on the inner bottom plate near the root of the inner rib, and a plurality of inner oil holes penetrating the inner bottom plate are provided at the bottom of the inner oil storage tank; the outer positioning seat includes a circular outer bottom plate and an outer rib located at the radial outer ring edge of the outer bottom plate, the outer rib extends forward, an outer oil storage tank is provided on the outer bottom plate near the root of the outer rib, and a plurality of outer oil holes penetrating the outer bottom plate are provided at the bottom of the outer oil storage tank.

[0011] The inner sealing seat includes an inner ring-shaped inner top plate and an inner rib located at the radial inner ring edge of the inner top plate, the inner rib extends rearward, and the inner rib of the inner sealing seat and the inner rib of the inner positioning seat are overlapped and fixed to each other; the outer sealing seat includes an outer ring-shaped outer top plate and an outer rib located at the radial outer ring edge of the outer top plate, the outer rib extends rearward, and the outer rib of the outer sealing seat and the outer rib of the outer positioning seat are overlapped and fixed to each other.

[0012] The surface of the inner sealing seat in contact with the inner elastic ring is a conical surface with a radial dimension larger at the front and smaller at the back, and a radial outer edge of the conical surface is provided with a rearward protrusion; the surface of the outer sealing seat in contact with the outer elastic ring is a conical surface with a radial dimension smaller at the front and larger at the back, and a radial inner edge of the conical surface is provided with a rearward protrusion.

[0013] The inner rib of the inner sealing seat is located on the inner side of the inner rib of the inner positioning seat, and the outer rib of the outer sealing seat is located on the outer side of the outer rib of the outer positioning seat.

[0014] The rear part of the outer cylindrical surface of the inner sealing ring is preferably configured as an outer conical surface with a larger radial dimension at the front and a smaller radial dimension at the rear, and the rear part of the inner cylindrical surface of the outer sealing ring is preferably configured as an inner conical surface with a smaller radial dimension at the front and a larger radial dimension at the rear, and the outer conical surface and the inner conical surface form a V-shaped gap.

[0015] A rocker arm cutting head of a coal mining machine, comprising a rocker arm housing, a planetary carrier, a large bearing, a bearing seat, a roller connecting sleeve, an end cover, a pressure cover, a pressure plate and the dynamic sealing structure. The bearing seat is fixedly connected to the rocker arm housing, and the front of the planetary carrier is rotatably supported in the inner hole of the bearing seat by the large bearing. The pressure cover is detachably fixedly connected to the front end of the bearing seat to axially limit the outer ring of the large bearing. The pressure plate is detachably fixedly connected to the front of the pressure cover. The pressure plate is cantilevered radially toward the axis of the axis relative to the pressure cover. The steps on the pressure plate and the pressure cover form an annular groove with an opening facing the axis of the planetary carrier. The radial outer seal component of the dynamic sealing structure is embedded in the annular groove, and the radial outer seal component and the annular groove are connected. The bottom surface of the groove has an interference fit, the roller connecting sleeve is sleeved on the front outward end of the planetary carrier and is splined to the planetary carrier, the roller connecting sleeve covers the bearing seat, large bearing, pressure cover and pressure plate from the front, and axially limits the inner ring of the large bearing, the radial inner sealing component of the dynamic sealing structure is coaxially installed with the roller connecting sleeve through a stop fitting structure and fixedly connected by a fixing pin, the radial inner sealing component rotates synchronously with the roller connecting sleeve, the end cover is coaxially fixed to the front end of the planetary carrier, and presses the roller connecting sleeve axially backward, and axial static seals are provided between the radial inner sealing component and the roller connecting sleeve, between the radial outer sealing component and the pressure cover, and between the pressure cover and the bearing seat.

[0016] Furthermore, the outer cylindrical surface of the inner sealing ring and the inner cylindrical surface of the outer sealing ring have the same axial size or the former is larger than the latter.

[0017] The beneficial effects of the present invention are:

[0018] The working clearance K value of the dynamic sealing structure of the present invention is not affected by the axial relative displacement of the radially inner sealing component and the radially outer sealing component, so the dynamic sealing effect is guaranteed.

[0019] The dynamic sealing structure of the present invention does not require special tools during installation, which facilitates on-site operation, and the elastic ring will not be twisted, so it is easy to ensure assembly quality and conducive to ensuring the sealing effect.

[0020] By setting the rear ends of the two dynamic sealing surfaces into conical surfaces and forming a V-shaped gap at the rear of the dynamic sealing pair, the capillary action and centrifugal action can be utilized to facilitate the injection of lubricating oil into the dynamic sealing surfaces, thereby achieving infiltration and cooling effects and preventing the dynamic sealing surfaces from overheating and sintering.

[0021] Due to the adoption of the dynamic sealing structure, the shearer rocker arm cutting head of the present invention has good sealing and no longer leaks oil frequently, thereby improving working reliability, reducing maintenance workload and use costs, and increasing mine production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the structure of an embodiment of the dynamic sealing structure of the present invention;

[0023] Figure 2 for Figure 1 A top view of the inner positioning seat;

[0024] Figure 3 for Figure 2 AA section view;

[0025] Figure 4 It is a structural schematic diagram of an embodiment of a rocker arm cutting head for a coal mining machine according to the present invention;

[0026] Figure 5 for Figure 4 B is a partial enlarged view of .

[0027] Reference numerals:

[0028] 1. Roller connecting sleeve; 2. Pressure cover; 3. Sealing ring; 4. Pressure plate; 5. Dynamic sealing structure; 51. Outer elastic ring; 52. Outer sealing ring; 53. Inner sealing seat; 54. Inner elastic ring; 55. Inner sealing ring; 56. Inner positioning seat; 561. Inner oil storage tank; 562. Inner oil hole; 57. Outer positioning seat; 58. Bayonet pin; 59. Outer sealing seat; 6. Sealing ring; 7. End cover; 8. Fixing pin; 9. Sealing ring; 10. Bearing seat; 11. Large bearing; 12. Planet carrier. DETAILED DESCRIPTION

[0029] The present invention discloses a dynamic sealing structure 5, such as Figure 1-5As shown, it includes a radial inner seal component and a radial outer seal component. The radial inner seal component includes an inner seal seat 53, an inner elastic ring 54, an inner seal ring 55 and an inner positioning seat 56, which are arranged in sequence from front to back in the axial direction. The inner seal seat and the inner positioning seat are interlocked and fixedly connected to form an inner ring groove with a radial outer opening. The inner seal ring and the inner elastic ring are installed in the inner ring groove. The inner elastic ring is elastically compressed to form a static seal between the inner seal ring and the inner seal seat. The radial outer seal component includes an outer seal seat 59, an outer elastic ring 51, an outer seal ring 52 and an outer positioning seat, which are arranged in sequence from front to back in the axial direction. The outer seal seat and the outer positioning seat are interlocked and fixedly connected to form an outer ring groove with a radial inner opening. The outer seal ring and the outer elastic ring are installed in the outer ring groove. The outer elastic ring is elastically compressed to form a static seal between the outer seal ring and the outer seal seat.

[0030] The outer cylindrical surface of the inner sealing ring is the dynamic sealing surface, which extends outwardly beyond the outer cylindrical surface of the inner sealing seat; the inner cylindrical surface of the outer sealing ring is the dynamic sealing surface, which extends inwardly beyond the inner cylindrical surface of the outer sealing seat. In the assembled state, the outer cylindrical surface of the inner sealing ring contacts the inner cylindrical surface of the outer sealing ring (at a diameter of D) and squeezes each other to produce a slight elastic deformation, forming a dynamic sealing pair, generating a certain specific pressure on the contact surface, and achieving a dynamic sealing effect. The radial gap between the outer cylindrical surface of the inner sealing seat 53 and the inner cylindrical surface of the outer sealing seat 59 is the working gap K of the dynamic sealing structure. The value of K determines the dynamic sealing contact specific pressure between the outer sealing ring and the inner sealing ring, which affects the dynamic sealing effect. The cross-sectional diameter specifications of the inner elastic ring and the outer elastic ring are preferably the same, and the compression amount of the inner elastic ring and the outer elastic ring in the assembled state should also be the same.

[0031] During installation, first place the inner elastic ring concentrically onto the inner sealing ring, then install the inner elastic ring and inner sealing ring together onto the inner locating seat, and finally secure the inner locating seat and inner sealing seat. Place the outer elastic ring concentrically onto the outer sealing ring, then install the outer elastic ring and outer sealing ring together onto the outer locating seat, and finally secure the outer locating seat and outer sealing seat. This makes installation quick and easy without requiring specialized tools for installing the inner and outer elastic rings, and prevents distortion of the inner and outer elastic rings.

[0032] The inner sealing seat and the inner positioning seat, and the outer sealing seat and the outer positioning seat are fixedly connected by a plurality of bayonet pins 58 arranged at intervals in the circumferential direction, and the bayonet pins extend in the radial direction. Figure 1 、 3 The compression of the inner and outer elastic rings can be adjusted by adjusting the E value in the diagram. Usually, the compression of the inner and outer elastic rings needs to be adjusted simultaneously. To do this, simply replace the outer and inner seal seats with the other bayonet hole positions.

[0033] The inner and outer radial edges of the inner sealing ring are each equipped with forward-facing protrusions. The surface between these two protrusions, which contacts the inner elastic ring, is a conical surface with a larger radial dimension at the front and a smaller radial dimension at the back. The outer sealing ring also has forward-facing protrusions on its radial inner and outer edges. The surface between these two protrusions, which contacts the outer elastic ring, is a conical surface with a smaller radial dimension at the front and a larger radial dimension at the back. The conical surfaces generate axial and radial force components when the inner and outer elastic rings are squeezed. The axial force achieves a static sealing effect and generates static friction to prevent rotation between the inner elastic ring and the inner sealing ring, as well as between the outer elastic ring and the outer sealing ring. The protrusions on the inner and outer sealing rings prevent displacement of the inner and outer elastic rings. When the dynamic sealing structure is subjected to an unbalanced load, the specific pressure on the dynamic sealing surface is locally high and locally low. The radial force acts as a counteracting force, balancing the contact specific pressures on the dynamic sealing surface and thus promoting uniform wear.

[0034] The axial dimensions of the outer cylindrical surface of the inner sealing ring and the inner cylindrical surface of the outer sealing ring may be equal or unequal. When the radial outer sealing assembly is subject to axial movement in actual use, the axial dimension of the outer cylindrical surface of the inner sealing ring may be smaller than the axial dimension of the inner cylindrical surface of the outer sealing ring. Conversely, when the radial inner sealing assembly is subject to axial movement in actual use, the axial dimension of the outer cylindrical surface of the inner sealing ring is preferably larger than the axial dimension of the inner cylindrical surface of the outer sealing ring.

[0035] The inner locating seat includes an annular inner base plate and an inner rib located at the radial inner edge of the inner base plate. The inner rib extends forward, and the radial cross-section of the inner locating seat is L-shaped. An inner oil reservoir 561 is provided on the front surface of the inner base plate near the root of the inner rib. The bottom of the inner oil reservoir is provided with a plurality of inner oil holes 562 that extend through the inner base plate. In other words, the inner oil reservoir and the inner oil holes are located at the inner corner of the inner locating seat. Similarly, the outer locating seat includes an annular outer base plate and an outer rib located at the radial outer edge of the outer base plate. The outer rib extends forward, and the radial cross-section of the outer locating seat is L-shaped. An outer oil reservoir is provided on the front surface of the outer base plate near the root of the outer rib. The bottom of the outer oil reservoir is provided with a plurality of outer oil holes that extend through the outer base plate. In other words, the outer oil reservoir and the outer oil holes are located at the inner corner of the outer locating seat. Inner and outer oil storage tanks and inner and outer oil holes are provided to facilitate the oil in the oil pool to flow into the inner cavity formed by the inner sealing ring, inner elastic ring and inner sealing seat, as well as into the outer cavity formed by the outer sealing ring, outer elastic ring and outer sealing seat, so as to play a role in infiltration and cooling the inner and outer static seals.

[0036] The inner seal seat includes an inner ring-shaped inner top plate and an inner rib located at the radial inner edge of the inner top plate. The inner rib extends rearward, and the inner seal seat has an L-shaped radial cross-section. The inner rib of the inner seal seat overlaps the inner rib of the inner positioning seat, and a set of bayonet pins passes through the overlap to secure the inner seal seat and the inner positioning seat. The outer seal seat includes an outer ring-shaped outer top plate and an outer rib located at the radial outer edge of the outer top plate. The outer rib extends rearward, and the outer seal seat has an L-shaped radial cross-section. The outer rib of the outer seal seat overlaps the outer rib of the outer positioning seat, and another set of bayonet pins passes through the overlap to secure the outer seal seat and the outer positioning seat. Each set of bayonet pins includes multiple bayonet pins, which are evenly spaced circumferentially.

[0037] The inner sealing seat, inner positioning seat, outer sealing seat, and outer positioning seat are each provided with a bayonet hole for installing a bayonet. In order to ensure that the compression of the inner and outer elastic rings is equal without complicating the structure, the thickness of the inner bottom plate of the inner positioning seat is usually equal to the thickness of the outer bottom plate of the outer positioning seat. In the assembled state, the rear end face of the inner bottom plate of the inner positioning seat is flush with the rear end face of the outer bottom plate of the outer positioning seat, and the bayonet hole on the inner positioning seat and the bayonet hole on the outer positioning seat are axially aligned, that is, the distance E between the bayonet holes on both and the rear end faces of the inner and outer bottom plates is the same. Of course, the axial dimensions of the bayonet hole on the inner sealing seat and the inner top plate, as well as the axial dimensions of the bayonet hole on the outer sealing seat and the outer top plate, also need to be coordinated.

[0038] The surface of the inner seal seat that contacts the inner elastic ring is a conical surface with a larger radial dimension at the front and a smaller radial dimension at the rear. A rearward-facing protrusion is provided on the radial outer edge of this conical surface. The surface of the outer seal seat that contacts the outer elastic ring is a conical surface with a smaller radial dimension at the front and a larger radial dimension at the rear. A rearward-facing protrusion is provided on the radial inner edge of this conical surface to prevent the elastic ring from shifting or falling out. In the embodiment shown in the drawings, this protrusion is configured as a conical surface.

[0039] The inner rib of the inner sealing seat is preferably located inside the inner rib of the inner positioning seat, and the outer rib of the outer sealing seat is preferably located outside the outer rib of the outer positioning seat.

[0040] The rear portion of the outer cylindrical surface of the inner sealing ring can be further configured as an outer conical surface with a radial dimension that is larger at the front and smaller at the back. At the same time, the rear portion of the inner cylindrical surface of the outer sealing ring can be further configured as an inner conical surface with a radial dimension that is smaller at the front and larger at the back. The outer conical surface and the inner conical surface form a V-shaped seam. The opening of the V-shaped seam faces the direction of the inner and outer positioning seats. Through capillary action and centrifugal action, lubricating oil can be easily injected into the dynamic sealing surface through the V-shaped seam, which plays a role in infiltration and cooling, and avoids the dynamic sealing surface from overheating and sintering. In addition, the V-shaped seam also has a sealing compensation function, which can extend the service life of the dynamic sealing structure. With the increase of wear on the dynamic sealing surface, especially under heavy load or severe overload conditions, the conical surfaces forming the V-shaped seam can be partially in contact with each other through elastic deformation, which is equivalent to temporarily increasing the axial length of the dynamic sealing pair, thereby ensuring the sealing performance.

[0041] The present invention also discloses a rocker arm cutting head for a coal mining machine, such as Figure 4 、 5 As shown, it includes a rocker housing, a planetary carrier 12, a large bearing 11, a bearing seat 10, a roller connecting sleeve 1, an end cover 7, a pressure cover 2, a pressure plate 4 and the dynamic sealing structure 5. The bearing seat is fixedly connected to the rocker housing. The front part of the planetary carrier is rotatably supported in the inner hole of the bearing seat through the large bearing. The pressure cover 2 is detachably fixedly connected to the front end of the bearing seat to axially limit the outer ring of the large bearing. The pressure plate 4 is detachably fixedly connected (for example, by screw connection) in front of the pressure cover, and the pressure plate is cantilevered radially toward the axis of the planetary carrier relative to the pressure cover. The steps on the pressure plate and the pressure cover form an annular groove with an opening facing the axis of the planetary carrier. The radial outer sealing component of the dynamic sealing structure is embedded in the annular groove, and the radial outer sealing component is interference fit with the bottom surface of the annular groove. The pressure plate presses the radial outer sealing component, Figure 4 、 5 Specifically, the outer seal seat of the radial outer seal assembly is interference-fitted with the bottom surface of the annular groove, and the outer seal seat 59 is prevented from rotating by static friction resistance. The roller connecting sleeve 1 is sleeved on the front outward end of the planetary carrier and is spline-connected to the planetary carrier. The roller connecting sleeve rotates synchronously with the planetary carrier. The roller connecting sleeve covers the bearing seat, large bearing, pressure cover and pressure plate from the front, and axially limits the inner ring of the large bearing. The radial inner seal assembly of the dynamic seal structure is coaxially installed with the roller connecting sleeve through a stopper matching structure and is fixedly connected by a fixing pin 8. Figure 4 、 5 Specifically, the inner seal seat of the radially inner seal assembly is fixedly connected to the roller sleeve, with a retaining pin extending radially along the roller sleeve. An end cap 7 is coaxially fixed to the front end of the planetary carrier and axially compresses the roller sleeve backward. Axial static seals are provided between the radially inner seal assembly and the roller sleeve, between the radially outer seal assembly and the gland, and between the gland and the bearing seat to prevent leakage of gear oil from the rocker arm cutting head through the joints of the relevant parts. In the embodiment shown in the accompanying drawings, these static seals are respectively provided by seal rings 6, 3, and 9. The radially outer seal assembly is fixed relative to the rocker arm housing and is a stationary ring, while the radially inner seal assembly rotates synchronously with the roller sleeve and is a dynamic ring.

[0042] When the rocker motor's power is transferred to the planetary carrier 12 in the planetary mechanism via a gear transmission system, the planetary carrier synchronously rotates the roller coupling sleeve 1, end cap 7, and the inner seal assembly in the dynamic seal structure 5. The roller coupling sleeve then rotates with the shearer's drum to cut coal. The dynamic seal pair, consisting of the outer and inner seal rings in the dynamic seal structure 5, provides a dynamic seal, preventing oil leakage from the shearer's internal gears and preventing external coal dust, water, and other substances from entering the shearer as it cuts the coal seam, thereby preventing oil contamination and even major bearing seizure.

[0043] Preferably, the axial dimensions of the outer cylindrical surface of the inner sealing ring are equal to those of the inner cylindrical surface of the outer sealing ring, or the former is larger than the latter.

[0044] When high-intensity axial loads such as the shearer's oblique cutting feed or the drum's long-term coal loading cause the drum connecting sleeve to axially creep or loosen, it is possible that the radial inner seal component and the radial outer seal component will slide relative to each other. However, the working clearance K value of the dynamic seal structure remains unchanged, and when the axial dimension of the dynamic sealing surface on the inner seal ring is larger than that on the outer seal ring, a stable contact pressure ratio and sealing effect can be guaranteed on the dynamic seal contact surface. After working for a period of time, the dynamic seal surface will have some wear, but the cone seal compensation function at the V-shaped seam can extend the service life of the dynamic seal structure.

[0045] As can be seen, the working clearance K value is independent of the axial relative movement between the radially inner and radially outer seal assemblies. Therefore, axial relative movement between the radially inner and radially outer seal assemblies does not affect the contact pressure ratio and sealing effectiveness of the dynamic seal pair. This solves the problem of premature failure and oil leakage caused by axial clearance variations in the floating oil seal end face seal structure used in rocker arm cutting heads. Furthermore, the dynamic seal structure of the present invention facilitates assembly and avoids the elastic ring distortion associated with existing floating oil seal structures, ensuring assembly quality and ultimately performance.

[0046] The before and after mentioned in this article Figure 1 、 4 The up and down directions under the viewing angle are consistent, which is a relative orientation, not a limitation of the absolute orientation.

Claims

1. A dynamic sealing structure, characterized in that: The cam is pressed against the cam face and pressed against the outside of the cam, and the cam is pressed against the outside of the cam face, so that the cam face is pressed against the outside of the cam face and the cam face is locked.

2. The dynamic sealing structure according to claim 1, wherein: The inner sealing seat and the inner positioning seat, as well as the outer sealing seat and the outer positioning seat, are fixedly connected via a plurality of bayonet pins spaced circumferentially, and the bayonet pins extend radially.

3. The dynamic sealing structure according to claim 2, wherein: The radial inner and outer edges of the inner sealing ring are both provided with forward protrusions, and the surface between the two edge protrusions that contacts the inner elastic ring is a conical surface with a radial size larger at the front and smaller at the back; the radial inner and outer edges of the outer sealing ring are both provided with forward protrusions, and the surface between the two edge protrusions that contacts the outer elastic ring is a conical surface with a radial size smaller at the front and larger at the back.

4. The dynamic sealing structure according to claim 1, 2 or 3, characterized in that: The inner positioning seat includes a circular inner bottom plate and an inner rib located at the radial inner ring edge of the inner bottom plate, the inner rib extends forward, an inner oil storage tank is provided on the inner bottom plate near the root of the inner rib, and a plurality of inner oil holes penetrating the inner bottom plate are provided at the bottom of the inner oil storage tank; the outer positioning seat includes a circular outer bottom plate and an outer rib located at the radial outer ring edge of the outer bottom plate, the outer rib extends forward, an outer oil storage tank is provided on the outer bottom plate near the root of the outer rib, and a plurality of outer oil holes penetrating the outer bottom plate are provided at the bottom of the outer oil storage tank.

5. The dynamic sealing structure according to claim 4, characterized in that: The inner sealing seat includes an inner ring-shaped inner top plate and an inner rib located at the radial inner ring edge of the inner top plate, the inner rib extends rearward, and the inner rib of the inner sealing seat and the inner rib of the inner positioning seat are overlapped and fixed to each other; the outer sealing seat includes an outer ring-shaped outer top plate and an outer rib located at the radial outer ring edge of the outer top plate, the outer rib extends rearward, and the outer rib of the outer sealing seat and the outer rib of the outer positioning seat are overlapped and fixed to each other.

6. The dynamic sealing structure according to claim 5, characterized in that: The surface of the inner sealing seat in contact with the inner elastic ring is a conical surface with a radial dimension larger at the front and smaller at the back, and a radial outer edge of the conical surface is provided with a rearward protrusion; the surface of the outer sealing seat in contact with the outer elastic ring is a conical surface with a radial dimension smaller at the front and larger at the back, and a radial inner edge of the conical surface is provided with a rearward protrusion.

7. The dynamic sealing structure according to claim 6, wherein: The inner rib of the inner sealing seat is located on the inner side of the inner rib of the inner positioning seat, and the outer rib of the outer sealing seat is located on the outer side of the outer rib of the outer positioning seat.

8. The dynamic sealing structure according to claim 1, 2 or 3, characterized in that: The rear part of the outer cylindrical surface of the inner sealing ring is configured as an outer conical surface with a larger radial dimension at the front and a smaller radial dimension at the rear, and the rear part of the inner cylindrical surface of the outer sealing ring is configured as an inner conical surface with a smaller radial dimension at the front and a larger radial dimension at the rear, and the outer conical surface and the inner conical surface form a V-shaped gap.

9. The dynamic sealing structure according to claim 4, wherein: The rear part of the outer cylindrical surface of the inner sealing ring is configured as an outer conical surface with a larger radial dimension at the front and a smaller radial dimension at the rear, and the rear part of the inner cylindrical surface of the outer sealing ring is configured as an inner conical surface with a smaller radial dimension at the front and a larger radial dimension at the rear, and the outer conical surface and the inner conical surface form a V-shaped gap.

10. The dynamic sealing structure according to claim 5, wherein: The rear part of the outer cylindrical surface of the inner sealing ring is configured as an outer conical surface with a larger radial dimension at the front and a smaller radial dimension at the rear, and the rear part of the inner cylindrical surface of the outer sealing ring is configured as an inner conical surface with a smaller radial dimension at the front and a larger radial dimension at the rear, and the outer conical surface and the inner conical surface form a V-shaped gap.

11. The dynamic sealing structure according to claim 6, wherein: The rear part of the outer cylindrical surface of the inner sealing ring is configured as an outer conical surface with a larger radial dimension at the front and a smaller radial dimension at the rear, and the rear part of the inner cylindrical surface of the outer sealing ring is configured as an inner conical surface with a smaller radial dimension at the front and a larger radial dimension at the rear, and the outer conical surface and the inner conical surface form a V-shaped gap.

12. The dynamic sealing structure according to claim 7, wherein: The rear part of the outer cylindrical surface of the inner sealing ring is configured as an outer conical surface with a larger radial dimension at the front and a smaller radial dimension at the rear, and the rear part of the inner cylindrical surface of the outer sealing ring is configured as an inner conical surface with a smaller radial dimension at the front and a larger radial dimension at the rear, and the outer conical surface and the inner conical surface form a V-shaped gap.

13. A rocker arm cutting head for a coal mining machine, characterized by: The invention comprises a rocker arm housing, a planetary carrier, a large bearing, a bearing seat, a roller connecting sleeve, an end cover, a pressure cover, a pressure plate and a dynamic sealing structure according to any one of claims 1 to 12, wherein the bearing seat is fixedly connected to the rocker arm housing, the front part of the planetary carrier is rotatably supported in the inner hole of the bearing seat by the large bearing, the pressure cover is detachably fixedly connected to the front end part of the bearing seat, and the outer ring of the large bearing is axially limited, the pressure plate is detachably fixedly connected to the front of the pressure cover, the pressure plate is cantilevered radially toward the axis relative to the pressure cover, the steps on the pressure plate and the pressure cover form an annular groove with an opening facing the axis of the planetary carrier, the radial outer sealing component of the dynamic sealing structure is embedded in the annular groove, and the radial outer seal The assembly has an interference fit with the bottom surface of the ring groove, the roller connecting sleeve is sleeved on the front outward end of the planetary carrier and is splined to the planetary carrier, the roller connecting sleeve covers the bearing seat, large bearing, pressure cover and pressure plate from the front, and axially limits the inner ring of the large bearing, the radial inner sealing assembly of the dynamic sealing structure and the roller connecting sleeve are coaxially installed through a stop fitting structure and fixedly connected by a fixing pin, the radial inner sealing assembly rotates synchronously with the roller connecting sleeve, the end cover is coaxially fixed to the front end of the planetary carrier, and presses the roller connecting sleeve axially backward, and axial static seals are provided between the radial inner sealing assembly and the roller connecting sleeve, between the radial outer sealing assembly and the pressure cover, and between the pressure cover and the bearing seat.

14. The rocker arm cutting head for a coal mining machine according to claim 13, characterized in that: The axial dimensions of the outer cylindrical surface of the inner sealing ring are equal to those of the inner cylindrical surface of the outer sealing ring, or the former is larger than the latter.

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