Sealing device for output shaft of rolling mill speed reducer

Abstract

The invention relates to the technical field of speed reducers, in particular to a sealing device for an output shaft of a rolling mill speed reducer. According to the sealing device for the output shaft of the rolling mill speed reducer, a rolling mill bearing sealing device is arranged on a vertically-arranged shaft body in a sleeving mode, and the rolling mill bearing sealing device comprises a movable ring, a static ring and a lubricating oil automatic circulating mechanism; the movable ring is lower than the static ring, and an oil groove is formed between the movable ring and the static ring; the automatic lubricating oil circulation mechanism comprises an automatic oil suction and discharge mechanism and a backflow mechanism, the automatic oil suction and discharge mechanism comprises an oil discharge channel arranged on the static ring and an oil suction and discharge structure, the oil discharge channel comprises an oil inlet and discharge cavity and an oil discharge cavity, and the oil inlet and discharge cavity comprises a first vertical cavity, a transverse cavity and a second vertical cavity. The lubricating oil automatic circulation mechanism does not need external power, completes oil discharge work by means of self structural design, and is good in oil discharge effect.

Description

Technical Field

[0001] The present invention relates to the technical field of reducers, and in particular to a sealing device for an output shaft of a rolling mill reducer. Background Art

[0002] In large rolling mill reducers, if the reducer is mounted horizontally but the output shaft is at the bottom and vertical (i.e., perpendicular to the ground), the output shaft's mechanical seal structure (including the stationary and rotating rings) must resist the tendency of lubricating oil to leak downward due to gravity. In particular, under high-temperature conditions, the viscosity of the lubricating oil decreases, increasing its fluidity and making it more likely to flow along the output shaft under the influence of gravity and penetrate the sealing gap between the rotating and stationary rings. At high speeds, the centrifugal force generated by the rotating output shaft can easily cause the lubricating oil to be thrown into the sealing gap between the rotating and stationary rings, thereby disrupting the oil film balance on the sealing surface of the seal structure and increasing the possibility of lubricating oil entering the sealing gap.

[0003] During normal operation of a rolling mill reducer, the lubricating oil forms a thin film on the output shaft, providing both lubrication and sealing. However, because the output shaft is oriented vertically downward, the lubricating oil tends to flow downward under the influence of gravity. This tendency is more pronounced when the equipment is operating at high temperatures or high speeds. Initially, the lubricating oil flows downward along the circumference of the output shaft and gradually accumulates in the oil groove between the rotating and stationary rings. As the lubricating oil continues to flow into the oil groove, the oil pressure within the groove gradually increases. When the oil pressure exceeds the limit of the sealing structure, the lubricating oil begins to seep out through the tiny gap between the rotating and stationary rings. Once the lubricating oil begins to seep out, the oil film balance on the sealing surface is disrupted, and the leakage rate gradually increases. The leaked lubricating oil continues to flow downward under the influence of gravity, forming a noticeable oil stain. Summary of the Invention

[0004] (1) The problem to be solved by the present invention is that when the output shaft of the reducer is perpendicular to the ground, the mechanical seal structure of the output shaft is prone to lubricating oil leakage.

[0005] (2) Technical solution

[0006] A sealing device for an output shaft of a rolling mill reducer, wherein the rolling mill bearing sealing device is sleeved on a vertically arranged shaft body, and comprises a dynamic ring, a static ring, and an automatic lubricating oil circulation mechanism; the dynamic ring is lower than the static ring, and an oil groove is formed between the dynamic ring and the static ring;

[0007] The lubricating oil automatic circulation mechanism includes an automatic oil suction and discharge mechanism and a reflux mechanism. The automatic oil suction and discharge mechanism includes an oil discharge channel and an oil suction and discharge structure provided on the static ring. The oil discharge channel includes an oil inlet and discharge chamber and an oil discharge chamber. The oil inlet and discharge chamber includes a first vertical chamber, a horizontal chamber, and a second vertical chamber.

[0008] The first vertical cavity and the second vertical cavity are vertically arranged on the static ring, the two ends of the transverse cavity are respectively connected to the top ends of the first vertical cavity and the second vertical cavity, the ends of the first vertical cavity and the second vertical cavity away from the transverse cavity are connected to the oil groove, one end of the oil drain cavity is connected to the transverse cavity, and the other end is connected to the reflux mechanism, and the end of the reflux mechanism away from the oil drain cavity is connected to the bearing chamber;

[0009] The oil suction and discharge structure includes a third spring, an oil discharge ball core, a first piston structure, a second piston structure, and a plurality of stepped protrusions; the first piston structure and the second piston structure are respectively installed in the first vertical cavity and the second vertical cavity, the third spring is vertically installed in the oil discharge cavity, the oil discharge ball core is fixed to the bottom end of the third spring, and the stepped protrusion is provided on the inner bottom wall of the oil tank;

[0010] The first piston structure and the second piston structure cooperate with the step protrusion to change the pressure in the oil inlet and discharge chamber; when the rolling mill bearing sealing device is in the oil suction state, the oil in the oil groove flows into the oil inlet and discharge chamber from the oil inlet of the first piston structure; when the rolling mill bearing sealing device is in the oil discharge state, under the action of pressure, the oil in the oil inlet and discharge chamber pushes open the oil discharge ball core, enters the oil discharge chamber, and flows back into the bearing chamber through the reflux mechanism.

[0011] According to one embodiment of the present invention, the bottom surface of the static ring has an annular protrusion coaxial with the static ring, the top of the dynamic ring is provided with an annular groove, the annular protrusion extends into the annular groove, the first vertical cavity, the transverse cavity and the second vertical cavity are arranged in the annular protrusion; the oil drainage chamber includes a connected flow channel chamber and an oil outlet chamber, the flow channel chamber is vertically arranged on the static ring, the bottom end of the flow channel chamber is connected to the transverse cavity, one end of the oil outlet chamber is connected to the top of the flow channel chamber, and the other end is connected to the reflux mechanism, the top of the third spring is fixed on the inner wall of the flow channel chamber, and the oil drainage ball core acts on the connection between the flow channel chamber and the transverse cavity, and is used to control the on and off of the connection.

[0012] According to one embodiment of the present invention, the first piston structure includes a first spring and an oil inlet piston, the top end of the first spring is fixed to the inner top wall of the first vertical cavity, the length of the first spring is smaller than the length of the first vertical cavity, the oil inlet piston is fixed to the bottom end of the first spring, and an oil inlet hole is provided on the oil inlet piston.

[0013] According to one embodiment of the present invention, the second piston structure includes a second spring and a movable piston, the top end of the second spring is fixed to the inner top wall of the second vertical cavity, the movable piston is fixed to the bottom end of the second spring, and the length of the second spring is smaller than the length of the second vertical cavity.

[0014] According to one embodiment of the present invention, the step protrusion is in the shape of an isosceles trapezoid, which includes a first inclined surface, a top surface and a second inclined surface connected in sequence; the direction from the first inclined surface to the second inclined surface is the length direction of the step protrusion, and the width direction of the step protrusion is the same as the radial direction of the dynamic ring.

[0015] According to one embodiment of the present invention, when the first piston structure and the second piston structure are respectively staggered with the step protrusion, under the action of the first spring, the top end of the oil inlet piston is located in the first vertical cavity, and the bottom end thereof acts on the inner bottom wall of the annular groove, and the oil inlet hole on the oil inlet piston extends out of the first vertical cavity; under the action of the second spring, the top end of the movable piston is located in the second vertical cavity, and the bottom end thereof acts on the inner bottom wall of the annular groove.

[0016] According to one embodiment of the present invention, the sum of the length of the first spring in a natural state and the length of the oil inlet piston is greater than the distance between the top surface of the step protrusion and the inner top wall of the first vertical cavity; the sum of the length of the second spring in a natural state and the length of the moving piston is greater than the distance between the top surface of the step protrusion and the inner top wall of the second vertical cavity.

[0017] According to one embodiment of the present invention, a plurality of step protrusions are evenly arranged around the axis of the moving ring.

[0018] According to one embodiment of the present invention, the reflux mechanism includes a reflux pipe, one end of which is connected to an end of the oil outlet cavity away from the flow channel cavity, and the other end of which is connected to the bearing chamber.

[0019] According to one embodiment of the present invention, the bottom opening of the flow channel cavity and the transverse cavity are connected through a cylindrical cavity, the diameter of the oil-draining ball core is larger than the diameter of the cylindrical cavity, and the diameter of the oil-draining ball core is smaller than the diameter of the flow channel cavity.

[0020] The present invention has the following beneficial effects: The automatic lubricating oil circulation mechanism of this embodiment requires no external power and relies on its own structural design to complete the oil drainage work. The oil drainage effect is good, with 1-2 ml of oil discharged at a time. Moreover, a small amount of oil is always retained in the oil tank, which can provide a certain sealing effect to prevent the intrusion of external dust and water. The discharged lubricating oil can be returned to the bearing chamber of the reducer through the return pipe. When the output shaft is in continuous operation, there is no need to add lubricating oil separately, thus achieving recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A schematic diagram of a sealing device for a rolling mill reducer output shaft according to an embodiment of the present invention;

[0023] Figure 2 A top view of a sealing device for a rolling mill reducer output shaft provided by an embodiment of the present invention;

[0024] Figure 3 The embodiment of the present invention provides Figure 2 Cross-sectional view of AA;

[0025] Figure 4 The embodiment of the present invention provides Figure 2 Cross-sectional view of the middle BB;

[0026] Figure 5 A top view of the sealing device for the output shaft of a rolling mill reducer provided in an embodiment of the present invention, with the oil suction and discharge structure removed;

[0027] Figure 6 The embodiment of the present invention provides Figure 5 Cross-sectional view of CC;

[0028] Figure 7 A schematic diagram of a first state of a sealing device for an output shaft of a rolling mill reducer provided by an embodiment of the present invention;

[0029] Figure 8 A schematic diagram of a second state of a sealing device for an output shaft of a rolling mill reducer provided by an embodiment of the present invention;

[0030] Figure 9 A schematic diagram of a third state of the sealing device for the output shaft of a rolling mill reducer provided by an embodiment of the present invention;

[0031] Figure 10 A schematic diagram of a fourth state of the sealing device for the output shaft of a rolling mill reducer provided by an embodiment of the present invention;

[0032] Figure 11 A schematic diagram of a fifth state of the sealing device for the output shaft of a rolling mill reducer provided by an embodiment of the present invention;

[0033] Figure 12 This is a schematic diagram of the sixth state of the sealing device for the output shaft of a rolling mill reducer provided by an embodiment of the present invention.

[0034] Icons: 1. Shaft; 2. Bearing; 3. Moving ring; 301. Annular groove; 4. Static ring; 401. Oil drain channel; 402. Temperature measurement channel; 403. Purge channel; 404. Pressure measurement channel; 405. Annular protrusion; 406. First vertical cavity; 407. Horizontal cavity; 408. Second vertical cavity; 409. Flow channel cavity; 410. Oil outlet cavity; 5. Labyrinth channel; 6. Micro-protrusion structure; 7. Skeleton oil seal; 8. Sealing ring; 9. Oil suction and discharge structure; 10. Oil drain joint; 11. Compressed air purge nozzle; 12. First spring; 13. Oil inlet piston; 14. Second spring; 15. Moving piston; 16. Third spring; 17. Oil drain ball core; 18. Step protrusion; 181. First inclined surface; 182. Top surface; 183. Second inclined surface. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] like Figures 1-12 As shown, one embodiment of the present invention provides a sealing device for the output shaft of a rolling mill reducer. The rolling mill bearing sealing device is sleeved on a vertically arranged shaft body 1. The rolling mill bearing sealing device includes a dynamic ring 3, a static ring 4, and an automatic lubricating oil circulation mechanism. The dynamic ring 3 is lower than the static ring 4, and an oil groove is formed between the dynamic ring 3 and the static ring 4.

[0037] The automatic lubricating oil circulation mechanism includes an automatic oil suction and discharge mechanism and a reflux mechanism. The automatic oil suction and discharge mechanism includes an oil discharge channel 401 and an oil suction and discharge structure 9 provided on the stationary ring 4. The oil discharge channel 401 includes an oil inlet and discharge chamber and an oil discharge chamber. The oil inlet and discharge chamber includes a first vertical chamber 406, a horizontal chamber 407, and a second vertical chamber 408.

[0038] The first vertical cavity 406 and the second vertical cavity 408 are vertically arranged on the stationary ring 4. The two ends of the transverse cavity 407 are respectively connected to the top of the first vertical cavity 406 and the second vertical cavity 408. The ends of the first vertical cavity 406 and the second vertical cavity 408 away from the transverse cavity 407 are connected to the oil groove. One end of the oil drain cavity is connected to the transverse cavity 407, and the other end is connected to the reflux mechanism. The end of the reflux mechanism away from the oil drain cavity is connected to the bearing chamber.

[0039] The oil suction and discharge structure 9 includes a third spring 16, an oil discharge ball core 17, a first piston structure, a second piston structure, and a plurality of stepped protrusions 18. The first piston structure and the second piston structure are respectively installed in the first vertical cavity 406 and the second vertical cavity 408. The third spring 16 is vertically installed in the oil discharge cavity. The oil discharge ball core 17 is fixed to the bottom end of the third spring 16. The stepped protrusion 18 is provided on the inner bottom wall of the oil tank.

[0040] The first piston structure and the second piston structure cooperate with the step protrusion 18 to change the pressure in the oil inlet and discharge chamber; when the rolling mill bearing sealing device is in the oil suction state, the oil in the oil tank flows into the oil inlet and discharge chamber from the oil inlet of the first piston structure; when the rolling mill bearing sealing device is in the oil discharge state, under the action of pressure, the oil in the oil inlet and discharge chamber pushes open the oil discharge ball core 17 and enters the oil discharge chamber and flows back to the bearing room through the reflux mechanism.

[0041] It should be noted that in large rolling mill reducers, when the output shaft is installed vertically downward, the fundamental cause of leakage in the mechanical seal (dynamic ring 3 and static ring 4 combination) at its bottom is the combined effect of the continuous downward flow of lubricating oil under the action of gravity and the destruction of the dynamic balance of the seal end face. Specific factors include:

[0042] Gravity drive: The shaft 1 is vertically downward, and the lubricating oil naturally tends to flow downward along the surface of the shaft 1 under the action of gravity. The sealing gap of the mechanical seal structure is located below the bearing 2, becoming a natural gathering point for the lubricating oil to flow downward.

[0043] Reduced lubricant viscosity: Under high-temperature conditions, the mill's operating environment is high, and the reducer's internal operating temperature is also high. This high temperature significantly reduces the viscosity of the lubricant (making it thinner), enhancing its fluidity, making it easier to flow along the output shaft and penetrate the sealing gap between the dynamic ring 3 and the static ring 4. High-speed conditions also cause the lubricant to exhibit a temporary decrease in viscosity (shear thinning), making it easier to flow. Furthermore, low-viscosity lubricants are more likely to penetrate tiny gaps and capillary channels.

[0044] Changes in the seal face state: Mechanical seals rely on maintaining an extremely thin film of lubricant between the end faces of the dynamic ring 3 and the static ring 4 to achieve sealing (prevent dry friction) and reduce leakage. Ideally, this film is dynamically stable. However, when installed at the bottom with the shaft 1 pointing downward, gravity continuously pulls the lubricant toward the seal face. As the lubricant continues to flow into the seal gap, the oil pressure within the gap gradually increases. When the oil pressure exceeds the limit of the seal structure, the lubricant begins to seep out through the tiny gap between the dynamic ring 3 and the static ring 4.

[0045] Different from this, in this embodiment, Figure 1As shown, a sealing gap (hereinafter referred to as the oil groove) is formed between the dynamic ring 3 and the stationary ring 4. The lower surface of the stationary ring 4 has an annular protrusion 405 coaxially arranged therewith, while the stationary ring 4 also has an annular groove 301. The gap formed between the inner wall of the annular groove 301 and the annular protrusion 405 constitutes part of the oil groove. The height of the annular protrusion 405 is less than the depth of the annular groove 301. When the dynamic ring 3 and the stationary ring 4 are assembled, the annular protrusion 405 on the stationary ring 4 extends into the annular groove 301 of the dynamic ring 3, and the bottom surface of the annular protrusion 405 is higher than the inner bottom wall of the annular groove 301.

[0046] like Figure 3 、 Figure 4 and Figure 6 As shown, the above-mentioned oil discharge channel 401 includes an oil inlet and outlet chamber and an oil discharge chamber, wherein the oil inlet and outlet chamber includes a first vertical chamber 406, a transverse chamber 407 and a second vertical chamber 408; the first vertical chamber 406 and the second vertical chamber 408 are vertically arranged in the annular protrusion 405 of the static ring 4, and the bottom end openings of the first vertical chamber 406 and the second vertical chamber 408 are both connected to the oil groove, the lengths of the first vertical chamber 406 and the second vertical chamber 408 are the same, and the two ends of the transverse chamber 407 are respectively connected to the top of the first vertical chamber 406 and the second vertical chamber 408.

[0047] Further, such as Figure 6 As shown, the oil drain chamber includes a connected flow channel chamber 409 and an oil outlet chamber 410, wherein the flow channel chamber 409 is vertically arranged on the static ring 4, the flow channel chamber 409 is higher than the transverse chamber 407, the cross-section of the flow channel chamber 409 is circular, and the bottom opening of the flow channel chamber 409 and the transverse chamber 407 are connected through a cylindrical chamber. The cylindrical chamber and the flow channel chamber 409 are coaxially arranged, and the diameter of the cylindrical chamber is smaller than the diameter of the flow channel chamber 409. One end of the oil outlet chamber 410 is connected to the top of the flow channel chamber 409, and the other end thereof extends to the outer circumference of the static ring 4. One end of the above-mentioned reflux mechanism is connected to the opening formed by the oil outlet chamber 410 on the outer circumference of the static ring 4, and the other end thereof is connected to the bearing chamber of the reducer.

[0048] like Figure 4 As shown, the oil-draining ball core 17 acts on the top opening of the cylindrical cavity, and the third spring 16 is vertically disposed within the flow channel cavity 409. The bottom end of the third spring 16 is connected to the oil-draining ball core 17, and the top end of the third spring 16 is fixed to the inner wall of the flow channel cavity 409. It should be noted that the diameter of the oil-draining ball core 17 is larger than the diameter of the cylindrical cavity to block the cylindrical cavity; the diameter of the oil-draining ball core 17 is smaller than the diameter of the flow channel cavity 409 to enable the oil-draining ball core 17 to move along the flow channel cavity 409 under the pull of the third spring 16.

[0049] In this embodiment, if Figure 4As shown, the first piston structure includes a first spring 12 and an oil inlet piston 13. The top end of the first spring 12 is fixed to the inner top wall of the first vertical cavity 406. The length of the first spring 12 is less than that of the first vertical cavity 406. The oil inlet piston 13 is fixed to the bottom end of the first spring 12 and is provided with an oil inlet hole. The second piston structure includes a second spring 14 and a movable piston 15. The top end of the second spring 14 is fixed to the inner top wall of the second vertical cavity 408, and the movable piston 15 is fixed to the bottom end of the second spring 14. It should be noted that the first vertical cavity 406 and the second vertical cavity 408 are the same length, the first spring 12 and the second spring 14 have the same specifications, and the oil inlet piston 13 and the movable piston 15 are the same length.

[0050] Furthermore, a plurality of step protrusions 18 are evenly arranged on the inner bottom wall of the annular groove 301 of the moving ring 3 around the axis of the moving ring 3. The step protrusions 18 are in the shape of an isosceles trapezoid, such as Figure 10 As shown, it includes a first inclined surface 181, a top surface 182 and a second inclined surface 183 connected in sequence. It should be noted that Figure 2 This is a top view of the sealing device for the output shaft of the rolling mill reducer. Figure 4 for Figure 2 The cross-sectional view of BB, from Figure 4 It can be seen that along the radial direction of the dynamic ring 3, the cross-section of the step protrusion 18 is an isosceles trapezoid. In other words, the direction from the first inclined surface 181 to the second inclined surface 183 is the length direction of the step protrusion 18, and the width direction of the step protrusion 18 is the same as the radial direction of the dynamic ring 3.

[0051] In this embodiment, if Figure 7 As shown, the sum of the lengths of the first spring 12 in its natural state and the oil inlet piston 13 is greater than the distance between the top surface 182 of the stepped protrusion 18 and the inner top wall of the first vertical cavity 406. The sum of the lengths of the second spring 14 in its natural state and the movable piston 15 is greater than the distance between the top surface 182 of the stepped protrusion 18 and the inner top wall of the second vertical cavity 408. Therefore, when the stepped protrusion 18 is offset from the two pistons, the oil inlet piston 13 and the movable piston 15, respectively, are pressed against the inner bottom wall of the annular groove 301 by the action of the first spring 12 and the second spring 14. At this point, the first spring 12 and the second spring 14 are at their maximum length.

[0052] The following details the oil suction and discharge process of the sealing device for the output shaft of the rolling mill reducer:

[0053] The initial state of the oil absorption process is as follows Figure 10As shown, at this time, the first spring 12 and the second spring 14 are compressed, the oil inlet piston 13 and the movable piston 15 simultaneously act on the top surface 182 of the first stepped protrusion 18, and the oil inlet hole of the oil inlet piston 13 extends into the first vertical cavity 406. Because the cylindrical cavity between the flow channel cavity 409 and the transverse cavity 407 is blocked by the oil discharge ball core 17, the oil inlet hole of the oil inlet piston 13 extends into the first vertical cavity 406, and the second vertical cavity 408 is blocked by the movable piston 15. Therefore, a sealed cavity is formed between the first vertical cavity 406, the transverse cavity 407, and the second vertical cavity 408, and the pressure within the cavity is stable.

[0054] As the shaft 1 drives the moving ring 3 to rotate in the first direction, the step protrusion 18 further rotates to Figure 11 In the position shown, the oil inlet piston 13 acts on the second inclined surface 183 of the first stepped protrusion 18 and moves along the second inclined surface 183. During this process, the first spring 12 gradually extends, the height of the oil inlet piston 13 gradually decreases, the portion of the oil inlet piston 13 extending into the first vertical cavity 406 gradually decreases, and the oil inlet hole on the oil inlet piston 13 gradually opens. As a result, the volume of the sealed cavity formed between the first vertical cavity 406, the transverse cavity 407, and the second vertical cavity 408 increases, and the pressure in the sealed cavity decreases, forming a negative pressure. Under the action of the negative pressure, the lubricating oil in the gap between the lower surface of the annular protrusion 405 and the inner bottom wall of the annular groove 301 is sucked into the oil inlet hole of the oil inlet piston 13, and then flows from the oil inlet hole into the sealed cavity between the first vertical cavity 406, the transverse cavity 407, and the second vertical cavity 408.

[0055] As the shaft body 1 continues to drive the dynamic ring 3 to rotate in the first direction, the oil inlet piston 13 leaves the second inclined surface 183 of the stepped protrusion 18, thereby acting on the inner bottom wall of the annular groove 301, and the movable piston 15 leaves the top surface 182 of the stepped protrusion 18 and moves downward along the second inclined surface 183 of the stepped protrusion 18 until the movable piston 15 leaves the second inclined surface 183 of the stepped protrusion 18 and acts on the inner bottom wall of the annular groove 301. During this process, because the volume of the sealed cavity formed between the first vertical cavity 406, the transverse cavity 407, and the second vertical cavity 408 is constantly increasing, the lubricating oil in the oil tank is continuously sucked into the sealed cavity.

[0056] The above process is the oil absorption process.

[0057] When the oil inlet piston 13 and the moving piston 15 act on the inner bottom wall of the annular groove 301 at the same time, the following is achieved: Figure 7 In the state shown, the volume of the sealed cavity formed between the first vertical cavity 406, the transverse cavity 407 and the second vertical cavity 408 remains unchanged, and the oil inlet and outlet cavities are connected to the oil tank through the oil inlet holes on the oil inlet piston 13. Therefore, the pressure inside and outside the oil inlet and outlet cavities is in a balanced state.

[0058] Oil discharge process Figure 8 、 Figure 9 and Figure 10 The process proceeds in the following order: As the shaft 1 continues to drive the rotating ring 3 to rotate in the first direction, the oil inlet piston 13 acts on the first inclined surface 181 of the next stepped protrusion 18. The portion of the oil inlet piston 13 that extends into the first vertical cavity 406 gradually increases, and the oil inlet hole of the oil inlet piston 13 gradually closes until the oil inlet piston 13 leaves the first inclined surface 181 of the stepped protrusion 18 and acts on the top surface 182 of the stepped protrusion 18. At this point, the oil inlet hole in the oil inlet piston 13 fully extends into the first vertical cavity 406, completely blocking the first vertical cavity 406. At this point, the sealed cavity formed between the first vertical cavity 406, the transverse cavity 407, and the second vertical cavity 408 is in a completely sealed state.

[0059] As the shaft 1 continues to drive the rotating ring 3 to rotate in the first direction, the movable piston 15 moves diagonally upward along the first inclined surface 181 of the stepped protrusion 18, the second spring 14 is gradually compressed, and the portion of the movable piston 15 extending into the second vertical cavity 408 gradually increases. During this process, the volume of the sealed cavity is rapidly compressed, causing the lubricating oil in the sealed cavity to push off the oil discharge ball core 17, causing the oil discharge ball core 17 to detach from the cylindrical cavity. The lubricating oil then flows from the sealed cavity into the flow channel cavity 409, passes through the oil outlet cavity 410 and the return mechanism, and finally flows into the bearing chamber.

[0060] As the shaft 1 continues to drive the dynamic ring 3 to rotate in the first direction, the movable piston 15 disengages from the first inclined surface 181 of the step protrusion 18 and enters the top surface 182 of the step protrusion 18. At this time, the oil inlet piston 13 and the movable piston 15 both act on the top surface 182 of the step protrusion 18. The oil inlet hole of the oil inlet piston 13 extends into the first vertical cavity 406, and the second vertical cavity 408 is blocked by the movable piston 15. The oil discharge ball core 17 is tightly attached to the cylindrical cavity at the connection between the transverse cavity 407 and the flow channel cavity 409 under the action of the third spring 16, thereby blocking the cylindrical cavity. Therefore, a sealed cavity is formed again between the first vertical cavity 406, the transverse cavity 407 and the second vertical cavity 408, and the pressure in the cavity is stable. That is, it returns to the state of the oil discharge ball core 17. Figure 10 The status shown.

[0061] In this embodiment, the reflux mechanism includes a reflux pipe, such as Figure 1 As shown, an oil drain joint 10 is sealed and installed on the outer peripheral surface of the static ring 4, at the outlet of the oil outlet cavity 410. One end of the return pipe is connected to the oil drain joint 10, and the other end is connected to the bearing chamber of the reducer.

[0062] The automatic lubricating oil circulation mechanism in this embodiment requires no external power source and relies on its own structural design to complete the oil drainage task. The mechanism achieves excellent oil drainage, discharging 1-2 ml of oil at a time. A small amount of oil is always retained in the oil tank, providing a seal to prevent the intrusion of dust and water. The discharged lubricating oil can flow back into the bearing chamber of the reducer through a return pipe. Even when the output shaft is in continuous operation, there is no need to refill the lubricating oil separately, thus achieving recycling.

[0063] In this embodiment, there is no specific limit on the number of stepped protrusions 18 and they can be appropriately set based on the specific conditions of the reducer on site. Of course, the number of stepped protrusions 18 should not be too large. If there are too many, the oil drainage efficiency per unit time will be too high, and the amount of lubricating oil in the sealing gap between the dynamic ring 3 and the static ring 4 will be too small, which is not conducive to the sealing between the dynamic ring 3 and the static ring 4. In this embodiment, preferably, three stepped protrusions 18 are provided, and the three stepped protrusions 18 are evenly arranged on the inner bottom wall of the annular groove 301 around the axis of the dynamic ring 3.

[0064] It's important to note that because the output shaft is located below the reducer, the oil level and pressure inside the reducer are relatively high. Under the influence of gravity and oil pressure, the lubricating oil easily flows along the output shaft and penetrates the sealing gap between the dynamic ring 3 and the static ring 4. However, traditional mechanical seal structures fail to fully account for the extremely strong gravity oil drainage effect when the output shaft is installed vertically, making it difficult to achieve effective sealing.

[0065] In this embodiment, the output shaft of the rolling mill reducer is sealed with a sealing device such as Figure 1 As shown, when the dynamic ring 3 and the static ring 4 cooperate with each other, the above-mentioned oil groove is formed between the dynamic ring 3 and the static ring 4. The oil groove includes a labyrinth channel 5, an oil suction channel and a sealing channel that are connected in sequence, wherein the channel formed between the annular groove 301 and the annular protrusion 405 is the oil suction channel.

[0066] The labyrinth channel 5 has multiple bending paths and is located outside the oil suction channel. The end of the labyrinth channel 5 away from the oil suction channel is connected to the external environment, and the end of the sealing channel away from the oil suction channel is connected to the space inside the dynamic ring 3.

[0067] In this embodiment, the outermost labyrinth channel 5 has multiple winding paths. Due to its special labyrinth structure, it can prevent large external dust particles from entering the sealing gap between the dynamic ring 3 and the static ring 4. In addition, water or oil needs to undergo multiple direction changes and throttling when passing through, which greatly increases the resistance to water or oil leakage, thereby effectively improving the sealing performance and avoiding the leakage of lubricating oil to the greatest extent. It is especially suitable for sealing under harsh working conditions such as high speed, high pressure, and high temperature.

[0068] In some embodiments, as Figure 1 As shown, a micro-protrusion structure 6 is provided on the inner wall of the sealing channel.

[0069] The function of the micro-protrusion structure 6 is to increase the contact area: the micro-protrusion structure 6 formed by electroplating or spraying can increase the microscopic contact area of ​​the sealing contact surface, thereby improving the sealing effect. These micro-protrusions form a series of tiny contact points on the contact surface, making the sealing surface fit more tightly at the microscopic level and reducing leakage paths.

[0070] Improved lubrication conditions: The micro-protrusion structure 6 can also improve the lubrication conditions of the sealing contact surface. The lubricating medium can form a tiny lubricating film between the micro-protrusions, reducing friction and wear between the sealing surfaces, and also helping to reduce the temperature of the sealing contact surface.

[0071] In some embodiments, a skeleton oil seal 7 is further provided on the inner wall of the sealing channel. The skeleton oil seal 7 is a skeleton dustproof oil seal. Under the action of a self-tightening coil spring, the sealing lip of the skeleton dustproof oil seal forms a close contact with the inner wall of the sealing channel to achieve a sealing effect.

[0072] In some embodiments, two skeleton oil seals 7 are provided. The two skeleton oil seals 7 are arranged along the axis of the dynamic ring 3 and close to the inner side of the dynamic ring 3 and the static ring 4. A sealed cavity is formed between the two skeleton oil seals 7. The two skeleton oil seals 7 are provided to prevent oil contamination inside the reducer from intruding into the sealed channel, thereby preventing the oil contamination from entering the oil tank.

[0073] In some embodiments, a lubricant, such as graphite or grease, is added into the sealing cavity between the two skeleton oil seals 7 to ensure the lubrication effect of the skeleton oil seals 7 .

[0074] It can be seen that the sealing device for the output shaft of the rolling mill reducer in this embodiment greatly improves the sealing performance through the synergistic effect of multiple sealing structures, has stronger adaptability and higher durability, and ensures the service life of the sealing device.

[0075] It should be noted that during long-term continuous operation of a large reducer, if the skeleton oil seal 7 is functioning properly, it can prevent the lubricating oil from entering the oil tank. However, if the skeleton oil seal 7 is severely worn, it will no longer be able to prevent the lubricating oil from entering the oil tank. Moreover, due to various production reasons, the machine is generally not shut down to replace the seal structure, which will only cause the oil leakage to persist until the next round of overhaul.

[0076] In this embodiment, once the skeleton oil seal 7 is severely worn and a large amount of lubricating oil enters the oil tank, the lubricating oil automatic circulation mechanism can automatically complete the oil drainage work.

[0077] It can be seen that in this embodiment, the synergistic effect of multiple sealing structures greatly improves the sealing performance of the sealing device and reduces the occurrence of oil leakage. Once the skeleton oil seal 7 fails, the lubricating oil penetrates into the sealing gap between the dynamic ring 3 and the static ring 4 under the action of gravity and oil pressure. At this time, the automatic lubricating oil circulation mechanism automatically completes the oil drainage work, thereby avoiding the occurrence of oil leakage.

[0078] Furthermore, the end surface of the rotating ring 3 facing the stationary ring 4 is provided with a plurality of annular labyrinth grooves. The labyrinth grooves are coaxially arranged with the rotating ring 3, and the diameters of the labyrinth grooves decrease in a radial direction of the rotating ring 3. That is, the diameters of the labyrinth grooves decrease from the outside to the inside of the rotating ring 3. The end surface of the stationary ring 4 facing the rotating ring 3 is provided with a plurality of labyrinth protrusions corresponding one-to-one with the labyrinth grooves. The width of the labyrinth protrusions is smaller than that of the corresponding labyrinth grooves. The labyrinth channel 5 is formed between the labyrinth grooves and the labyrinth protrusions.

[0079] In this embodiment, the micro-protrusion structure 6 formed by electroplating can be formed by electroplating on the side of the sealing channel located on the dynamic ring 3, or can be formed by electroplating on the side of the sealing channel located on the static ring 4, or, electroplating can be performed on both the side of the sealing channel located on the dynamic ring 3 and the side of the static ring 4 at the same time.

[0080] Furthermore, it should be noted that skeleton-type dustproof oil seals have a metal skeleton, which provides additional strength and rigidity, enabling them to adapt to different operating environments and conditions, including high and low temperatures and high pressures, and have excellent heat, cold, and pressure resistance. Furthermore, due to their structural design and material selection, skeleton-type dustproof oil seals are able to maintain good sealing performance over a long period of time, reducing the frequency of replacement and maintenance.

[0081] In this embodiment, a sealing ring 8 is provided on the inner wall of the dynamic ring 3. This sealing ring 8 is made of polytetrafluoroethylene (PTFE). PTFE is virtually insoluble in all solvents and is resistant to acids, alkalis, and various organic solvents. It can operate for extended periods at temperatures between -180°C and 260°C, exhibiting excellent heat and cold resistance. Therefore, this sealing ring 8 maintains stable performance in high-temperature and oily environments.

[0082] It can be seen that in this embodiment, sealing is achieved by cooperating with multiple sealing structures, and the synergistic effect of the multiple sealing structures greatly improves the sealing performance.

[0083] It should be noted that the metal surfaces of the dynamic ring 3 and the static ring 4 are prone to rust in a humid environment, and contaminants adhering to the dynamic ring 3 and the static ring 4 will accelerate the wear of the sealing surfaces.

[0084] In order to solve this technical problem, in this embodiment, the metal surfaces of the dynamic ring 3 and the static ring 4 are first subjected to surface hardening treatment (such as nitriding or chrome plating), and the thickness of the hardened layer is 0.05-0.1mm. Then, a special wear-resistant and corrosion-resistant coating (such as a ceramic coating or a nano coating) is evenly sprayed on the surface of the dynamic ring 3 and the static ring 4, and the coating thickness is 0.1-0.3mm. Finally, a fluorosilicone nano coating is sprayed on the outermost layer with a contact angle of >150° to prevent water and oil from adhering. In this way, the durability of the seal in dusty and oily environments can be significantly improved, and the sealing failure caused by surface wear can be reduced. The anti-pollution ability of the seal is improved, and it is suitable for high-dust and high-humidity environments.

[0085] To prevent external dust from entering the labyrinth passage 5 and clogging it, a purge mechanism is provided. The purge mechanism includes a compressor, pretreatment equipment, an air storage tank, a compressed air purge nozzle 11, and a purge channel 403 located within the static ring 4. One end of the purge channel 403 is connected to the labyrinth passage 5, and the other end is connected to the external environment. The compressed air purge nozzle 11 is sealably mounted on the end of the purge channel 403 away from the labyrinth passage 5. The compressor, pretreatment equipment, and air storage tank are connected in sequence by pipes, and the air storage tank and the compressed air purge nozzle 11 are connected by an outlet pipe, on which a pressure valve and an on-off valve are mounted.

[0086] In this way, the compressor compresses the outside air into high-pressure gas, which is then transported to the pre-treatment equipment. The pre-treatment equipment filters, cools, dries, and degreases the compressed air to remove impurities and moisture, preventing them from entering between the dynamic ring 3 and the static ring 4. The pre-treated compressed air is then transported to the air storage tank for storage. The compressed air in the air storage tank is then transported to the compressed air purge nozzle 11 through the air outlet pipe and ejected from the compressed air purge nozzle 11.

[0087] Such regular blowing can blow out some of the dust in the maze channel 5 and avoid dust blockage. It should be noted that the outermost side of the maze channel 5 is usually more prone to clogging, so the end of the purge channel 403 needs to be close to the outlet end of the maze channel 5 and blow the dust from the inside out. In addition, in this embodiment, there is no specific restriction on the number of purge channels 403 and compressed air purge nozzles 11, and they can be reasonably selected according to actual conditions. For example, six purge channels 403 are set, and the six purge channels 403 are evenly arranged around the axis of the static ring 4. A compressed air purge nozzle 11 is installed at the air inlet of each purge channel 403, and these six compressed air purge nozzles 11 are supplied with air from the same air tank.

[0088] In addition, the purge angle of the purge channel 403 can be reasonably set, for example, by blowing obliquely outward, which can achieve a better purge effect.

[0089] In this embodiment, a temperature detection mechanism is installed on the static ring 4, and the temperature detection mechanism includes a temperature measurement channel 402, a temperature sensor, a microprocessor, a wireless transmitter and a power module. The temperature measurement channel 402 is arranged in the static ring 4 and one end of the temperature measurement channel 402 is connected to the external environment. The temperature detection joint is sealed and installed at one end of the temperature measurement channel 402, and the temperature sensor is installed in the temperature measurement channel 402.

[0090] The temperature sensor converts temperature changes into electrical signals. The signal processing circuit amplifies, filters, and performs analog-to-digital conversion (A / D conversion) on the weak electrical signals output by the temperature sensor to facilitate subsequent wireless transmission. The microprocessor receives the digital signals from the signal processing circuit, further processes and encodes them, and prepares them for transmission to the wireless transmitter. The wireless transmitter uses a variety of communication protocols, such as Wi-Fi, Bluetooth, Zigbee, LoRa, and cellular networks, to transmit the data in the form of wireless signals to the control center or controller. The power module is used to power various electrical components.

[0091] When bearing 2 is severely worn or has poor lubrication, the shaft 1 rotates rapidly, causing the bearing 2 to heat up rapidly. Since both the rotating ring 3 and the stationary ring 4 are metal parts, their temperatures will also rise rapidly. The stationary ring 4, in particular, heats up faster due to its direct contact with bearing 2, typically reaching 60°C-80°C in just a few minutes. Furthermore, if the bearing temperature exceeds 60°C, an alarm will sound, and if it exceeds 90°C, the mill will shut down.

[0092] In this application, the temperature of the static ring 4 is measured by a temperature detection mechanism. When the measured temperature value exceeds the threshold, it means that the current bearing 2 is severely worn or the lubrication effect is poor. At this time, lubricating oil should be added to the bearing chamber in time or the machine should be shut down in time.

[0093] Furthermore, a pressure detection mechanism is installed on the static ring 4, which includes a pressure detection connector, a pressure measuring channel 404, a pressure sensor, a microprocessor, a wireless transmitter, and a power supply module, wherein the first end of the pressure measuring channel 404 is connected to the sealing channel, and the second end thereof is connected to the external environment, the pressure detection connector is sealed and installed at the second end of the pressure measuring channel 404, and the pressure sensor is connected to the pressure detection connector through line communication.

[0094] It should be noted that operating pressure significantly impacts sealing performance. Excessive pressure within the oil groove between the dynamic ring 3 and the static ring 4 can damage the internal micro-protrusion structure 6 and the skeleton oil seal 7, leading to leakage. Conversely, excessively low pressure can result in a loose seal and an inability to effectively prevent media leakage. Therefore, in this embodiment, a pressure sensor monitors changes in internal pressure to determine whether the seal is operating properly.

[0095] In this application, the pressure sensor converts the pressure change between the dynamic ring 3 and the static ring 4 into an electrical signal, the signal processing circuit amplifies, filters and A / D converts the electrical signal, the microprocessor receives the digital signal, encodes and packages it, and the wireless transmitter sends the encoded data through a wireless signal.

[0096] The power management module provides stable power for the entire system. The control center or controller receives wireless signals, decodes and processes data to achieve monitoring and control.

[0097] In this way, the pressure change between the dynamic ring 3 and the static ring 4 can be detected in real time, so that it can be judged whether the current seal is in a normal working state based on the measured pressure value.

[0098] Optionally, the pressure sensor is a MEMS pressure sensor (accuracy ±0.1% FS), and the temperature sensor is an optical fiber temperature sensor (temperature measurement range -50°C to 300°C).

[0099] In the description of the present invention, it should be noted that the terms "upper" and "lower" and other terms indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0100] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or they can refer to connections between the internal parts of two components. A person of ordinary skill in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A sealing device for the output shaft of a rolling mill reducer, characterized in that: The rolling mill bearing sealing device is sleeved on a vertically arranged shaft (1), and comprises a dynamic ring (3), a static ring (4), and an automatic lubricating oil circulation mechanism; the dynamic ring (3) is lower than the static ring (4), and an oil groove is formed between the dynamic ring (3) and the static ring (4); The lubricating oil automatic circulation mechanism includes an automatic oil suction and discharge mechanism and a reflux mechanism. The automatic oil suction and discharge mechanism includes an oil discharge channel (401) and an oil suction and discharge structure provided on a stationary ring (4). The oil discharge channel (401) includes an oil inlet and discharge chamber and an oil discharge chamber. The oil inlet and discharge chamber includes a first vertical chamber (406), a horizontal chamber (407) and a second vertical chamber (408). The first vertical cavity (406) and the second vertical cavity (408) are vertically arranged on the static ring (4); the two ends of the transverse cavity (407) are respectively connected to the top ends of the first vertical cavity (406) and the second vertical cavity (408); the ends of the first vertical cavity (406) and the second vertical cavity (408) away from the transverse cavity (407) are connected to the oil groove; one end of the oil drain cavity is connected to the transverse cavity (407), and the other end is connected to the reflux mechanism; the end of the reflux mechanism away from the oil drain cavity is connected to the bearing chamber; The oil suction and discharge structure comprises a third spring (16), an oil discharge ball core (17), a first piston structure, a second piston structure and a plurality of step protrusions (18); the first piston structure and the second piston structure are respectively installed in the first vertical cavity (406) and the second vertical cavity (408); the third spring (16) is vertically installed in the oil discharge cavity; the oil discharge ball core (17) is fixed to the bottom end of the third spring (16); and the step protrusion (18) is provided on the inner bottom wall of the oil groove; The first piston structure and the second piston structure cooperate with the step protrusion (18) to change the pressure in the oil inlet and outlet chamber; when the rolling mill bearing sealing device is in the oil suction state, the oil in the oil tank flows into the oil inlet and outlet chamber from the oil inlet of the first piston structure; when the rolling mill bearing sealing device is in the oil discharge state, under the action of pressure, the oil in the oil inlet and outlet chamber pushes open the oil discharge ball core (17) into the oil discharge chamber and flows back into the bearing chamber through the reflux mechanism.

2. The sealing device for the output shaft of a rolling mill reducer according to claim 1, characterized in that: The bottom surface of the static ring (4) has an annular protrusion (405) coaxial therewith, the top of the dynamic ring (3) is provided with an annular groove (301), the annular protrusion (405) extends into the annular groove (301), the first vertical cavity (406), the horizontal cavity (407) and the second vertical cavity (408) are arranged in the annular protrusion (405); the oil discharge cavity includes a flow channel cavity (409) and an oil outlet cavity (410) connected to each other, the flow channel cavity (409) is vertically arranged It is placed on the static ring (4), the bottom end of the flow channel cavity (409) is connected to the transverse cavity (407), one end of the oil outlet cavity (410) is connected to the top end of the flow channel cavity (409), and the other end is connected to the return mechanism, the top end of the third spring (16) is fixed on the inner wall of the flow channel cavity (409), and the oil discharge ball core (17) acts on the connection between the flow channel cavity (409) and the transverse cavity (407), and is used to control the on-off of the connection.

3. The sealing device for the output shaft of a rolling mill reducer according to claim 2, characterized in that: The first piston structure includes a first spring (12) and an oil inlet piston (13), the top end of the first spring (12) is fixed to the inner top wall of the first vertical cavity (406), the length of the first spring (12) is smaller than the length of the first vertical cavity (406), the oil inlet piston (13) is fixed to the bottom end of the first spring (12), and an oil inlet hole is provided on the oil inlet piston (13).

4. A sealing device for a rolling mill reducer output shaft according to claim 3, characterized in that: The second piston structure includes a second spring (14) and a movable piston (15), the top end of the second spring (14) is fixed to the inner top wall of the second vertical cavity (408), and the movable piston (15) is fixed to the bottom end of the second spring (14), and the length of the second spring (14) is less than the length of the second vertical cavity (408).

5. The sealing device for the output shaft of a rolling mill reducer according to claim 4, characterized in that: The step protrusion (18) is in the shape of an isosceles trapezoid, comprising a first inclined surface (181), a top surface (182), and a second inclined surface (183) connected in sequence; the direction from the first inclined surface (181) to the second inclined surface (183) is the length direction of the step protrusion (18), and the width direction of the step protrusion (18) is the same as the radial direction of the dynamic ring (3).

6. The sealing device for the output shaft of a rolling mill reducer according to claim 5, characterized in that: When the first piston structure and the second piston structure are respectively offset from the step protrusion (18), under the action of the first spring (12), the top end of the oil inlet piston (13) is located in the first vertical cavity (406), and its bottom end acts on the inner bottom wall of the annular groove (301), and the oil inlet hole on the oil inlet piston (13) extends out of the first vertical cavity (406); under the action of the second spring (14), the top end of the movable piston (15) is located in the second vertical cavity (408), and its bottom end acts on the inner bottom wall of the annular groove (301).

7. The sealing device for the output shaft of a rolling mill reducer according to claim 6, characterized in that: The sum of the length of the first spring (12) in its natural state and the length of the oil inlet piston (13) is greater than the distance between the top surface (182) of the step protrusion (18) and the inner top wall of the first vertical cavity (406); the sum of the length of the second spring (14) in its natural state and the length of the moving piston (15) is greater than the distance between the top surface (182) of the step protrusion (18) and the inner top wall of the second vertical cavity (408).

8. The sealing device for the output shaft of a rolling mill reducer according to claim 1, characterized in that: A plurality of step protrusions (18) are evenly arranged around the axis of the moving ring (3).

9. The sealing device for the output shaft of a rolling mill reducer according to claim 2, characterized in that: The reflux mechanism comprises a reflux pipe, one end of which is connected to an end of the oil outlet cavity (410) away from the flow channel cavity (409), and the other end of which is connected to the bearing chamber.

10. The sealing device for the output shaft of a rolling mill reducer according to claim 2, characterized in that: The bottom opening of the flow channel cavity (409) and the transverse cavity (407) are connected via a cylindrical cavity, the diameter of the oil-draining ball core (17) is larger than the diameter of the cylindrical cavity, and the diameter of the oil-draining ball core (17) is smaller than the diameter of the flow channel cavity (409).

Images