Mechanical seal type drilling box

Abstract

The present invention discloses a mechanical seal type drilling box, comprising a box body and a rotating shaft connected by a bearing, and a shell sleeved on the outer side of the rotating shaft, wherein the shell is fixedly connected to the box body, a water inlet is provided on the shell, a water inlet cavity is provided on the inner side of the shell facing the rotating shaft, and a mechanical seal mechanism is provided in the water inlet cavity. The mechanical seal mechanism comprises a sealing static ring and a sealing dynamic ring which forms an end face seal with the sealing static ring, and a water through hole corresponding to the radial water hole of the rotating shaft is provided on the sealing dynamic ring. The sealing dynamic ring has a spring compensation function. It also comprises a core shaft arranged inside the rotating shaft, and the outside of the core shaft comprises a threaded section connected to the rotating shaft and a reduced diameter section connected to the radial water hole. A one-way valve is provided at the end of the reduced diameter section of the core shaft. The present invention modifies the traditional sealing ring type seal into an end face mechanical seal through the improved setting of the mechanical seal mechanism, and realizes the separate installation of the bearing and the sealing mechanism, so that the sealing effect is good, the wear resistance is high, the service life is long, and the maintenance is convenient, and the maintenance cost is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic anchor rod and cable drilling vehicles for coal mines, in particular to a mechanically sealed drilling box. Background Art

[0002] At present, most of the anchor bolt and cable drilling vehicles commonly used in China use wet drill boxes, which are designed to have a maximum speed of 500RPM and a maximum water pressure of 20bar. That is, when drilling, a hollow drill rod is installed in the drill box. High-pressure water needs to pass through the drill box into the tail of the high-speed rotating drill rod, and finally the front end of the borehole is flushed with high-pressure water to achieve the purpose of slag removal and dust removal during the drilling process.

[0003] Due to the frequent use of the drilling rig, the drilling box works for more than 10 hours a day. Damage to the sealing ring in the drilling box or wear of the sealing ring on the shaft will cause water leakage, resulting in insufficient water pressure and water volume when the drilling rig is drilling, affecting the normal use of the drilling rig. According to market research, there are 1,200 drilling boxes in stock in China for two-arm coal mine anchor cable drilling rigs (excluding four-arm and six-arm anchor drilling rigs). Based on the maximum service life of each drilling box of 60 days, about 7,200 drilling boxes need to be repaired and replaced each year. At the same time, there are the following problems during the replacement process: (1) If the leakage is caused by the wear of the sealing ring, then the sealing ring needs to be replaced when repairing the drilling box. To replace the sealing ring, the rotating shaft, motor, bearing, end cover and other parts need to be disassembled. There are many disassembled parts and the maintenance time is long; (2) If the leakage is caused by the wear of the sealing ring on the rotating shaft and grooves, the rotating shaft needs to be replaced, which greatly increases the maintenance cost and maintenance time.

[0004] It can be seen that the existing drill box of the drill vehicle still has inconveniences and defects in structure, method and use, and it is urgent to further improve. How to create a new mechanical seal drill box, which adopts a new mechanical seal structure, achieves good sealing effect, wear resistance, low maintenance cost and long service life, has become a goal that the industry needs to improve. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a mechanical seal drill box which adopts a new mechanical seal structure to achieve good sealing effect, wear resistance, low maintenance cost and long service life, thereby overcoming the shortcomings of existing drill boxes.

[0006] In order to solve the above technical problems, the present invention provides a mechanically sealed drill box, comprising a box body and a rotating shaft rotatably arranged on the axial direction of the box body through a bearing, and also comprising a shell sleeved on the outside of the rotating shaft, the shell being arranged on the side of the rotating shaft connected to the drill rod, and the shell being fixedly connected to the end of the box body, a water inlet being arranged on the shell, a water inlet cavity being opened on the shell toward the inner side of the rotating shaft, and a mechanical sealing mechanism being arranged in the water inlet cavity;

[0007] The mechanical sealing mechanism includes a sealing static ring and a sealing dynamic ring forming an end face seal therewith, the sealing static ring is fixedly connected to the inner wall of the water inlet cavity, the sealing dynamic ring is fixedly connected to the rotating shaft, and a water hole is opened on the sealing dynamic ring, the water hole corresponds to the radial water hole on the rotating shaft, and is used to transmit the high-pressure water entering the water inlet cavity from the water inlet into the interior of the rotating shaft.

[0008] As a further improvement, the mechanical sealing mechanism comprises two static sealing rings and a dynamic sealing ring arranged between the two static sealing rings, and the dynamic sealing ring is a dynamic sealing ring with a spring compensation function.

[0009] As a further improvement, the mating end faces of the sealing static ring and the sealing dynamic ring are both made of high-hardness alloy material.

[0010] As a further improvement, an end cover is fixed between the shell and the box body.

[0011] As a further improvement, the inner ring of the end cover is arranged to be a step-like structure close to the shell side, the step-like structure and the inner wall of the shell form the water inlet cavity, and a sealing static ring is fixedly connected to the step-like structure.

[0012] As a further improvement, a static ring sealing ring is provided between the sealing static ring and the inner wall of the water inlet cavity.

[0013] As a further improvement, two dynamic ring sealing rings are provided between the sealing dynamic ring and the rotating shaft, and the two dynamic ring sealing rings are respectively arranged on both sides of the water through hole.

[0014] A further improvement includes a core shaft arranged inside the rotating shaft for installing a hollow drill rod, the outside of the core shaft includes a threaded section movably connected to the inner wall of the rotating shaft, and a reduced diameter section connected to the radial water hole of the rotating shaft, the reduced diameter section is located on the tail end side of the hollow drill rod, so that the high-pressure water in the water inlet cavity passes through the radial water hole of the rotating shaft, flows along the reduced diameter section of the core shaft to the tail of the hollow drill rod, and then flows from the tail of the hollow drill rod to the front end of the hollow drill rod.

[0015] As a further improvement, a one-way valve is also provided at the end of the reduced diameter section of the core shaft.

[0016] As a further improvement, the opening pressure of the one-way valve is 0.5-1 Bar.

[0017] After adopting such a design, the present invention has at least the following advantages:

[0018] 1. The present invention arranges a mechanical seal mechanism between the housing and the rotating shaft, and opens a water hole on the sealing dynamic ring that is connected to the radial water hole of the rotating shaft, that is, arranges the mechanical seal mechanism on the high-pressure water transmission channel, modifies the traditional sealing ring seal into an end face mechanical seal, and realizes zero wear of the rotating shaft and the sealing dynamic ring, has good sealing effect, is wear-resistant, and greatly improves the service life of the drill box.

[0019] 2. The present invention arranges the bearing supporting the rotating shaft inside the box body, and arranges the mechanical sealing mechanism inside the shell, that is, the bearing and the sealing mechanism are installed separately. In this way, if the water leakage is caused by the wear of the sealing mechanism, it is only necessary to replace the sealing mechanism assembly, and there is no need to disassemble the rotating shaft, bearing and other parts as a whole, which greatly saves maintenance time and maintenance costs, and is simple and convenient.

[0020] 3. By setting two static sealing rings and a dynamic sealing ring with spring compensation function, and combining the auxiliary sealing effect of the static ring sealing ring and the dynamic ring sealing ring, and making the fitting end faces of the static sealing ring and the dynamic sealing ring both made of high-hardness alloy material, it can further ensure the close fitting of the joint surfaces of the dynamic and static rings, and greatly improve the wear resistance, thereby ensuring good sealing effect and service life.

[0021] 4. By arranging a core shaft inside the rotating shaft, the traditional rotating shaft is arranged into a split structure, so that after the drill rod and the core shaft are worn, the core shaft can be replaced separately without replacing the rotating shaft as a whole, thus saving costs.

[0022] 5. A one-way valve is also arranged at the tail of the core shaft. Since a certain water pressure is required to open the one-way valve, it is ensured that after the external high-pressure water source is cut off, a certain amount of water is still stored in the channel between the water inlet of the shell and the one-way valve, thereby solving the problem that the mechanical sealing mechanism cannot operate under waterless conditions. The mechanical sealing mechanism of the present invention has significant improvements in wear resistance and adaptability compared with the traditional sealing ring sealing method. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0024] Figure 1 It is a schematic structural cross-sectional view of the mechanical seal drilling box of the present invention.

[0025] Among them, 1. core shaft, 2. rotating shaft, 3. sealing static ring, 4. one-way valve, 5. bearing, 6. casing, 7. end cover, 8. shell, 9. sealing dynamic ring, 10. static ring sealing ring, 11. dynamic ring sealing ring, 12. water inlet cavity, 13. water hole, 14. radial water hole, 15. reduced diameter section, 16. threaded section. DETAILED DESCRIPTION

[0026] Refer to the attached Figure 1 As shown, the mechanically sealed drill box of this embodiment includes a box body 6 and a rotating shaft 2 rotatably arranged in the axial direction of the box body 6 through a bearing 5, and a shell 8 sleeved on the outside of the rotating shaft 2. The shell 8 is arranged on the side of the rotating shaft 2 connected to the drill rod, and the shell 8 is fixedly connected to the end of the box body 6 by bolts.

[0027] The housing 8 is provided with a water inlet, and the housing 8 is provided with a water inlet cavity 12 on the inner side facing the rotating shaft 2 . A mechanical sealing mechanism is provided in the water inlet cavity 12 .

[0028] In this embodiment, the mechanical seal mechanism includes two static seal rings 3 and a dynamic seal ring 9 disposed therein, and the two end faces of the dynamic seal ring 9 are tightly fitted with the two static seal rings 3 to achieve end face sealing. The static seal ring 3 is fixedly connected to the inner wall of the water inlet cavity 12, and a static ring seal 10 is also provided on the fixed connection surface, so that the static seal ring 3 is stationary relative to the housing 8, and the seal between the two is good.

[0029] In this embodiment, the sealing dynamic ring 9 is fixedly connected to the rotating shaft 2, and the sealing dynamic ring 9 rotates at high speed with the rotating shaft 2, achieving zero wear between the rotating shaft and the sealing dynamic ring. The mechanical seal structure modifies the traditional sealing ring seal into an end face mechanical seal, which has good sealing effect and wear resistance, and can greatly increase the service life of the drill box.

[0030] In a preferred embodiment, the sealing dynamic ring 9 adopts a sealing dynamic ring with a spring compensation function, which can play a good compensation role and ensure that the sealing function of the sealing mechanism is not affected after slight wear between the sealing static ring 3 and the sealing dynamic ring 9.

[0031] A water hole 13 is provided on the sealing dynamic ring 9, and the water hole 13 corresponds to the radial water hole 14 on the rotating shaft 2. The high-pressure water entering from the water inlet on the shell 8 enters the interior of the rotating shaft 2 through the water inlet cavity 12, the water hole 13, and the radial water hole 14.

[0032] In order to further ensure the sealing, two dynamic ring sealing rings 11 are also provided between the sealing dynamic ring 9 and the rotating shaft 2. The two dynamic ring sealing rings 11 are respectively arranged on both sides of the water through hole 13 to achieve a better water sealing effect.

[0033] In order to further improve the wear resistance of the mechanical seal mechanism, the mating end faces of the sealing static ring 3 and the sealing dynamic ring 9 of this embodiment are both made of high-hardness alloy material, which enhances the wear resistance and prolongs the service life.

[0034] Refer to the attached Figure 1 As shown, an end cover 7 is also fixed between the shell 8 and the box body 6. The inner ring of the end cover 7 is arranged in a step-like structure near the shell side, and the step-like structure and the inner wall of the shell form the water inlet cavity 12. One of the two sealing static rings 9 is fixedly connected to the step-like structure, and a static ring sealing ring 10 is also arranged between the sealing static ring 9 and the inner wall of the end cover 7 to ensure the seal between the sealing static ring and the end cover.

[0035] A more preferred embodiment is that the mechanical seal drill box of this embodiment further includes a core shaft 1 for installing a hollow drill rod, which is arranged inside the rotating shaft 2. The outside of the core shaft 1 includes a threaded section 16 movably connected to the inner wall of the rotating shaft 2, and a reduced diameter section 15 connected to the radial water hole 14 of the rotating shaft. The reduced diameter section 15 is located at the end side of the tail of the hollow drill rod. After the high-pressure water in the water inlet cavity 12 passes through the radial water hole 14 of the rotating shaft 2, it flows along the reduced diameter section 15 of the core shaft 1 to the tail of the hollow drill rod, and then flows from the tail of the hollow drill rod to the front end of the hollow drill rod, so that the high-pressure water flushes the front end of the drill hole, and achieves the purpose of slag removal and dust removal during drilling.

[0036] As a further improvement, a one-way valve 4 is further provided at the end of the reduced diameter section 15 of the mandrel 1. The opening pressure of the one-way valve 4 is 0.5-1 Bar. The function of the one-way valve is that, since a certain water pressure is required to open the one-way valve, it is ensured that a certain amount of water is still stored in the channel between the water inlet of the housing 8 and the one-way valve 4 after the external high-pressure water source is cut off, thereby solving the problem that the mechanical sealing mechanism cannot operate under waterless conditions.

[0037] The present invention modifies the traditional sealing ring type seal into an end face mechanical seal by arranging a mechanical sealing mechanism between the shell and the rotating shaft. The improved sealing method has significant improvements in both wear resistance and adaptability compared with the traditional sealing method, has good sealing effect and wear resistance, and greatly improves the service life of the drill box.

[0038] Furthermore, by arranging the bearings supporting the rotating shaft inside the box body and the mechanical sealing mechanism inside the shell body, the bearings and the sealing mechanism are installed separately. If the leakage is caused by the wear of the sealing mechanism, only the sealing mechanism assembly needs to be replaced, and there is no need to disassemble the rotating shaft, bearings and other parts as a whole, which greatly saves maintenance time and maintenance costs. The method is simple and convenient, and is conducive to promotion.

[0039] Furthermore, by arranging the rotating shaft into a split structure, the drill rod is directly connected to the core shaft. After the core shaft is worn, it can be replaced separately without causing the entire rotating shaft to be scrapped, thereby greatly saving costs.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Those skilled in the art may make some simple modifications, equivalent changes or modifications using the technical contents disclosed above, which all fall within the protection scope of the present invention.

Claims

1. A mechanically sealed drill box, comprising a box body and a rotating shaft rotatably arranged in the axial direction of the box body through a bearing, characterized in that: It also includes a shell sleeved on the outside of the rotating shaft, the shell is arranged on the side of the rotating shaft connected to the drill rod, and the shell is fixedly connected to the end of the box body, a water inlet is arranged on the shell, and a water inlet cavity is opened on the inner side of the shell toward the rotating shaft, and a mechanical sealing mechanism is arranged in the water inlet cavity; The mechanical sealing mechanism comprises a sealing static ring and a sealing dynamic ring which forms an end face seal therewith, wherein the sealing static ring is fixedly connected to the inner wall of the water inlet cavity, the sealing dynamic ring is fixedly connected to the rotating shaft, and a water through hole is provided on the sealing dynamic ring, wherein the water through hole corresponds to the radial water hole on the rotating shaft and is used to transmit the high-pressure water which enters the water inlet cavity from the water inlet into the interior of the rotating shaft; It also includes a core shaft arranged inside the rotating shaft for installing a hollow drill rod, the outside of the core shaft includes a threaded section movably connected to the inner wall of the rotating shaft, and a reduced diameter section connected to the radial water hole of the rotating shaft, the reduced diameter section is located at the end side of the tail of the hollow drill rod, so that the high-pressure water in the water inlet cavity flows to the tail of the hollow drill rod along the reduced diameter section of the core shaft after passing through the radial water hole of the rotating shaft, and then flows from the tail of the hollow drill rod to the front end of the hollow drill rod; A one-way valve is also provided at the end of the reduced diameter section of the core shaft.

2. The mechanical seal drill box according to claim 1, characterized in that: The mechanical sealing mechanism comprises two static sealing rings and a dynamic sealing ring arranged between the two static sealing rings, and the dynamic sealing ring is a dynamic sealing ring with a spring compensation function.

3. The mechanical seal drill box according to claim 2, characterized in that: The mating end faces of the sealing static ring and the sealing dynamic ring are both made of high-hardness alloy material.

4. The mechanical seal drill box according to claim 3, characterized in that: An end cover is also fixed between the shell and the box body.

5. The mechanical seal drill box according to claim 4, characterized in that: The inner ring of the end cover is arranged in a step-like structure close to the shell side, and the step-like structure and the inner wall of the shell form the water inlet cavity. A sealing static ring is fixedly connected to the step-like structure.

6. The mechanical seal drill box according to claim 5, characterized in that: A static ring sealing ring is provided between the sealing static ring and the inner wall of the water inlet cavity.

7. The mechanical seal drill box according to claim 6, characterized in that: Two dynamic ring sealing rings are arranged between the sealing dynamic ring and the rotating shaft, and the two dynamic ring sealing rings are respectively arranged on both sides of the water through hole.

8. The mechanical seal drill box according to claim 1, characterized in that: The opening pressure of the one-way valve is 0.5-1 Bar.

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