Cutting head sealing mechanism of cantilever type longitudinal shaft heading machine

Abstract

The invention provides a cutting head sealing mechanism of a cantilever type longitudinal shaft heading machine. Two stages of sealing devices in different forms are used for sealing invasion of two objects in different forms, such as coal, rock mass, powder and water. Wherein the first-stage sealing structure is based on the body structure of the cutting arm or the cutting head, a protruding structure is designed to reduce a large gap between the tail of the cutting head and the cutting arm to the minimum, so that the objects can be prevented from entering the gap, and meanwhile, a labyrinth seal is arranged to isolate a part of dust; the secondary seal mainly adopts a contact type mechanical seal, and the structure consists of a moving ring, a static ring, a sealing ring, a mounting connecting seat and a supplementary buffer mechanism. The movable ring is fixed with the cross section and rotates along with the cross section, the static ring is in contact with the movable ring under the action of the spring to realize sealing, the other side of the spring is provided with the mounting connecting seat, the mounting connecting seat is fixed with the cutting wall, a gap between the mounting connecting seat and the static ring is sealed by the sealing ring, and finally, isolated sealing of fine dust, water and other substances is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of large-scale rotating equipment sealing, and in particular to a cantilever type longitudinal axis roadheader cutting head sealing mechanism. Background Art

[0002] The cantilever roadheader is the most important equipment used for excavating coal and rock roadways and tunnels. It has strong versatility and a wide operating range. It is effective in reducing labor intensity, improving efficiency, and shortening project cycles. It has been widely used in major engineering projects such as mining, water conservancy construction, tunnel transportation, urban subways, industry, agriculture, and civil construction.

[0003] A large gap exists between the tail end of the cutting head and the cutting arm of a cantilevered longitudinal roadheader. During the roadheader's sweeping operation, cut coal and rock pass through this gap and into the front end of the cutting arm. From there, they pass through the front maze and into the floating oil seal, damaging it. While the cutting head provides lubrication, existing technology can easily allow coal dust and particles to enter the oil cup inside the shear pin, reducing its service life and hindering oil filling. Furthermore, the sealing packing material expands when exposed to water, potentially tightening the steel sleeve and the cantilever barrel, causing the cutting head to malfunction.

[0004] Therefore, it is of great significance to develop a sealing mechanism for the cutting head of a cantilever longitudinal axis roadheader. Summary of the Invention

[0005] The purpose of the present invention is to provide a cantilever type longitudinal axis roadheader cutting head sealing mechanism to solve the problems existing in the prior art.

[0006] The technical solution employed to achieve the objectives of the present invention is as follows: a cantilevered longitudinal-axis tunnel boring machine cutting head sealing mechanism, wherein the cutting head is in the shape of a hollow truncated cone. Cutting teeth are spirally distributed on the outer surface of the cutting head. A main shaft extends through the cutting arm. The main shaft and the cutting arm extend into the inner cavity of the cutting head. One end of the main shaft is connected to the cutting head, and the other end is connected to the drive motor. A rearward open cavity is formed between the tail end of the cutting head and the cutting arm. The sealing mechanism comprises a primary sealing unit, a mounting connector, and a secondary sealing unit, arranged sequentially from the head end to the tail end.

[0007] The mounting connector is housed in the open cavity at the rear end. The mounting connector comprises a circular ring body, an annular flange I extending from the outside of the ring body, and an annular flange II extending from the inside. A gap exists between annular flange I and the inner wall of the cutting head. An annular mounting cavity is defined between annular flanges I and II. The circular ring body is sleeved onto the cutting arm. Annular flanges I and II face the head end. Annular flange II is fixedly connected to the cutting arm.

[0008] The first-level sealing unit uses a non-contact labyrinth seal. The non-contact labyrinth seal includes a static labyrinth and a heavy-load sealing ring. The heavy-load sealing ring is mounted on the cutting arm and blocks the tail end opening of the rear end open cavity. The heavy-load sealing ring is fixedly connected to the tail end face of the cutting head. A concave annular groove is provided on the head end face of the heavy-load sealing ring. The head end of the static labyrinth is fixedly connected to the annular body, and a convex annular groove is provided at the tail end. The tail end of the static labyrinth cooperates with the head end of the heavy-load sealing ring to form a labyrinth sealing gap.

[0009] The secondary sealing unit uses a contact-type mechanical seal. The contact-type mechanical seal includes a dynamic ring, a sealing ring, a static ring, and a supplementary buffer mechanism. The dynamic ring and the static ring are both mounted on the cutting arm. An annular flange III and an annular flange IV are provided on the tail end face of the dynamic ring. The annular flange III abuts against the inner wall of the cutting head and is fixedly connected to the inner wall of the cutting head. The static ring is arranged between the dynamic ring and the mounting connection seat. An annular flange V and an annular flange VI are provided on the head end face of the static ring, and an annular flange VII is provided on the tail end face. The end faces of the annular flange V and the annular flange VI abut against the end face of the dynamic ring. The side wall of the annular flange VI is in close contact with the side wall of the annular flange IV. The annular flange VII is accommodated in the annular mounting cavity. A sealing ring is provided between the annular flange VII and the annular flange I.

[0010] The supplementary buffer mechanism is arranged in the annular mounting cavity. The supplementary buffer mechanism includes a plurality of springs arranged at intervals along the annular direction. One end of the spring is fixedly connected to the annular body, and the other end is fixedly connected to the stationary ring.

[0011] Furthermore, the material of the dynamic ring is tungsten carbide hard alloy.

[0012] Furthermore, the material of the stationary ring is carbon graphite material impregnated with resin.

[0013] The technical effects of the present invention are unquestionable:

[0014] Because actual operations often involve intrusion in the form of coal, rock, and powder and water, two different attachment structures were designed based on the cutting head structure of the roadheader to achieve different effects. For large, heavy objects like coal and rock, a protruding structure, based on the cutting arm or the main structure of the cutting head, minimizes the large gap between the tail of the cutting head and the cutting arm, thereby preventing such objects from entering the gap. Because this protruding structure is located near the direct working area, it requires a certain degree of rigidity to avoid damage. Furthermore, a labyrinth seal, part of the gap seal, is installed behind this structure to isolate some dust. A secondary seal further seals against fine dust, water, and other substances. This primary seal utilizes a contact-type mechanical seal consisting of a rotating ring, a stationary ring, a sealing ring, a mounting adapter, and a supplementary buffer mechanism consisting of six springs. The rotating ring is fixed to the crosshead and rotates with it. The stationary ring, acting under the action of a spring, contacts the rotating ring to achieve a seal. On the other side of the spring is the mounting adapter, which is fixed to the cutting wall. The gap between the mounting adapter and the stationary ring is sealed by a sealing ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a half-section diagram of the cutting head;

[0016] Figure 2 Schematic diagram of the sealing structure.

[0017] In the figure: nozzle 1, cutting head 2, cutting teeth 3, cutting arm 4, dynamic ring 5, sealing ring 6, static ring 7, compensation buffer mechanism 8, mounting connection seat 9, dynamic labyrinth teeth 10, static labyrinth teeth 11. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the following examples, but it should not be understood that the scope of the present invention is limited to the following examples. Without departing from the above technical ideas of the present invention, various substitutions and modifications can be made according to common technical knowledge and customary means in the art, and all should be included in the scope of protection of the present invention.

[0019] Example 1:

[0020] See also Figure 1 and Figure 2 This embodiment provides a cantilevered longitudinal axis tunnel boring machine cutting head sealing mechanism, wherein the cutting head 2 is in the shape of a hollow frustum. Cutting teeth 3 are spirally distributed on the outer surface of the cutting head 2. The main shaft passes through the cutting arm 4. The main shaft and the cutting arm 4 extend into the inner cavity of the cutting head 2. One end of the main shaft is connected to the cutting head 2, and the other end is connected to the drive motor. A rear end open cavity is formed between the tail end of the cutting head 2 and the cutting arm 4. The sealing mechanism includes a primary sealing unit, a mounting connection seat 9 and a secondary sealing unit arranged in sequence from the head end to the tail end.

[0021] The mounting connection seat 9 is accommodated in the rear end open cavity. The mounting connection seat 9 includes a circular ring body 901, an annular flange I 902 extending from the outside of the circular ring body, and an annular flange II 903 extending from the inside. There is a gap between the annular flange I 902 and the inner wall of the cutting head 2. An annular mounting cavity 904 is sandwiched between the annular flange I 902 and the annular flange II 903. The circular ring body 901 is sleeved on the cutting arm 4. The annular flange I 902 and the annular flange II 903 face the head end. The annular flange II 903 is fixedly connected to the cutting arm 4.

[0022] The first-level sealing unit uses a non-contact labyrinth seal. The non-contact labyrinth seal includes a static labyrinth part 11 and a high-load sealing ring 10. The high-load sealing ring 10 is mounted on the cutting arm 4 and blocks the tail end opening of the rear end open cavity. The high-load sealing ring 10 is fixedly connected to the tail end face of the cutting head 2. A concave annular groove is provided on the head end face of the high-load sealing ring 10. The head end of the static labyrinth part 11 is fixedly connected to the annular body 901, and a convex annular groove is provided at the tail end. The tail end of the static labyrinth part 11 cooperates with the head end of the high-load sealing ring 10 to form a labyrinth sealing gap.

[0023] The secondary sealing unit uses a contact-type mechanical seal. The contact-type mechanical seal includes a dynamic ring 5, a sealing ring 6, a static ring 7, and a supplementary buffer mechanism 8. The dynamic ring 5 and the static ring 7 are both mounted on the cutting arm 4. The tail end face of the dynamic ring 5 is provided with an annular flange III 501 and an annular flange IV 502. The annular flange III 501 abuts against the inner wall of the cutting head 2 and is fixedly connected to the inner wall of the cutting head 2. The static ring 7 is arranged between the dynamic ring 5 and the mounting connection seat 9. The head end face of the static ring 7 is provided with an annular flange V 701 and an annular flange VI 702, and the tail end face is provided with an annular flange VII 703. The end faces of the annular flange V 701 and the annular flange VI 702 abut against the end face of the dynamic ring 5. The side wall of the annular flange VI 702 is in close contact with the side wall of the annular flange IV 502. The annular flange VII 703 is accommodated in the annular mounting cavity 904. A sealing ring 6 is provided between the annular flange VII 703 and the annular flange I 902.

[0024] The supplementary buffer mechanism 8 is arranged in the annular mounting cavity 904. The supplementary buffer mechanism 8 includes a plurality of springs arranged at intervals along the annular direction. One end of the spring is fixedly connected to the annular body 901, and the other end is fixedly connected to the static ring 7. The static ring 7 is axially floatingly arranged by the supplementary buffer mechanism 8. The supplementary buffer mechanism 8 pushes the static ring 7 to continuously fit the dynamic ring 5 to maintain the contact of the sealing surface. During the operation of the equipment, if the cutting arm 4 vibrates, the floating characteristics of the static ring 7 can absorb part of the impact to avoid damage to the sealing surface due to hard contact.

[0025] This embodiment provides a sealing mechanism for the cutting head of a cantilevered longitudinal roadheader. This mechanism can isolate two different types of objects, such as coal, rock blocks, powder, and water, from the outside of the cutting head of a cantilevered longitudinal roadheader through a two-stage seal. Based on the existing structure of the cutting head of the roadheader, the two-stage sealing structure is attached to the cutting head through screws, welding, or other fixing methods.

[0026] Example 2:

[0027] This embodiment shares the same principles as Example 1, except that the secondary seal requires the friction pair to be made of materials with high thermal conductivity, high-temperature resistance, and a low coefficient of friction. Therefore, this design utilizes tungsten carbide for the dynamic ring 5 and resin-impregnated carbon graphite for the static ring 7. Both materials exhibit excellent wear and thermal properties, ensuring a long service life. Furthermore, the inherent lubricity of the resin-impregnated carbon graphite, combined with the precision grinding of the mating surfaces, ensures an extremely low coefficient of friction.

Claims

1. A cantilever-type longitudinal-axis roadheader cutting head sealing mechanism, wherein the cutting head (2) is in the shape of a hollow truncated cone; the cutting teeth (3) are spirally distributed on the outer surface of the cutting head (2); the main shaft passes through the cutting arm (4); the main shaft and the cutting arm (4) extend into the inner cavity of the cutting head (2); one end of the main shaft is connected to the cutting head (2), and the other end is connected to the drive motor; a rear end open cavity is formed between the tail end of the cutting head (2) and the cutting arm (4); and the characteristics are: The sealing mechanism comprises a primary sealing unit, a mounting connection seat (9) and a secondary sealing unit arranged in sequence from the head end to the tail end; The mounting connection seat (9) is accommodated in the rear end open cavity; the mounting connection seat (9) includes a circular ring body (901), and an annular flange I (902) extending from the outer side of the circular ring body and an annular flange II (903) extending from the inner side; there is a gap between the annular flange I (902) and the inner wall of the cutting head (2); an annular mounting cavity (904) is sandwiched between the annular flange I (902) and the annular flange II (903); the circular ring body (901) is sleeved on the cutting arm (4); the annular flange I (902) and the annular flange II (903) face the head end; the annular flange II (903) is fixedly connected to the cutting arm (4); The first-level sealing unit uses a non-contact labyrinth seal; the non-contact labyrinth seal includes a static labyrinth (11) and a heavy-load sealing ring (10); the heavy-load sealing ring (10) is sleeved on the cutting arm (4) and blocks the tail end opening of the rear end open cavity; the heavy-load sealing ring (10) is fixedly connected to the tail end face of the cutting head (2); a concave annular groove is provided on the head end face of the heavy-load sealing ring (10); the head end of the static labyrinth (11) is fixedly connected to the annular body (901), and a convex annular groove is provided on the tail end; the tail end of the static labyrinth (11) cooperates with the head end of the heavy-load sealing ring (10) to form a labyrinth sealing gap; The secondary sealing unit is a contact type mechanical seal; the contact type mechanical seal comprises a dynamic ring (5), a sealing ring (6), a static ring (7) and a supplementary buffer mechanism (8); the dynamic ring (5) and the static ring (7) are both sleeved on the cutting arm (4); an annular flange III (501) and an annular flange IV (502) are provided on the tail end face of the dynamic ring (5); the annular flange III (501) abuts against the inner wall of the cutting head (2) and is fixedly connected to the inner wall of the cutting head (2); the static ring (7) is arranged between the dynamic ring (5) and the mounting connection seat (9) ; The front end face of the static ring (7) is provided with an annular flange V (701) and an annular flange VI (702), and the rear end face is provided with an annular flange VII (703); the end faces of the annular flange V (701) and the annular flange VI (702) are pressed against the end face of the dynamic ring (5); the side wall of the annular flange VI (702) is in close contact with the side wall of the annular flange IV (502); the annular flange VII (703) is accommodated in the annular mounting cavity (904); a sealing ring (6) is provided between the annular flange VII (703) and the annular flange I (902); The supplementary buffer mechanism (8) is arranged in the annular mounting cavity (904); the supplementary buffer mechanism (8) comprises a plurality of springs arranged at intervals along the annular direction; one end of the spring is fixedly connected to the annular body (901), and the other end is fixedly connected to the stationary ring (7).

2. The cantilevered longitudinal axis roadheader cutting head sealing mechanism according to claim 1, characterized in that: The material of the moving ring (5) is tungsten carbide hard alloy material.

3. The cantilevered longitudinal axis roadheader cutting head sealing mechanism according to claim 1, characterized in that: The material of the stationary ring (7) is a carbon graphite material impregnated with resin.

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