A combined seal for high line speed gearboxes

Abstract

A combined seal for high-speed gearboxes relates to a shaft sealing structure. This invention addresses the problem that existing contact and non-contact seals are insufficient for the shaft sealing performance of high-speed gearboxes, failing to provide reliable sealing. The invention includes an oil drain nozzle, a lock nut, an oil slinger ring, a graphite sealing ring, a graphite sealing ring mounting base, an adjusting ring, an oil baffle ring, and a bearing end cover. The bearing end cover is fitted onto the outside of the rotating shaft and fixed to the gearbox bushing. The lock nut is threaded to the rotating shaft and positioned on the outside of the bearing end cover. The oil slinger ring, graphite sealing ring mounting base, adjusting ring, and oil baffle ring are sequentially arranged from the outside to the inside between the bearing end cover and the outer wall of the rotating shaft. A graphite sealing ring is embedded in the graphite sealing ring mounting base. The oil drain nozzle is inserted into the outer end of the bearing end cover. This invention is used for gearbox shaft sealing.

Description

Technical Field

[0001] This invention relates to shaft sealing structures, and more specifically to a combined seal for a high linear velocity gearbox. Background Technology

[0002] Gearboxes are widely used industrial equipment. During operation, lubricating oil from gears and bearings splashes and mists inside the gearbox. To prevent oil leakage, a suitable sealing structure is needed for the rotating shaft system. An inadequate sealing structure can lead to leakage at the shaft seal, causing environmental pollution and oil waste. Common sealing methods include contact and non-contact seals. Contact seals often use lip seals, with a permissible linear speed of approximately 15 m / s. However, contact seals are unsuitable for rotating shafts exceeding this speed limit. Contact seals are generally designed for a limited lifespan and require regular maintenance and replacement. Non-contact seals typically have a gap between rotating and stationary parts, preventing contact during operation. Therefore, under normal operating conditions, non-contact seals have an unlimited lifespan. As the gearbox rotation speed gradually increases, the flange on the gear shaft causes a gradual increase in negative pressure outside the shaft seal. When a certain critical speed is reached, oil begins to be drawn from the gearbox through the shaft seal, at which point leakage begins. Therefore, different shaft seal designs have different effects at different speeds. Generally, in order to achieve a better sealing effect, non-contact seal designs often do not use a single structure, but require a combination of seals. Summary of the Invention

[0003] In order to solve the problem that the sealing effect of existing contact seals and non-contact seals is difficult to meet the requirements of shaft sealing in high linear speed gearboxes and to provide reliable sealing performance, this invention proposes a combined seal for high linear speed gearboxes.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0005] A combined seal for a high linear speed gearbox includes an oil drain nozzle, a lock nut, an oil slinger ring, a graphite sealing ring, a graphite sealing ring mounting base, an adjusting ring, an oil baffle ring, and a bearing end cover. The bearing end cover is fitted onto the outside of the rotating shaft and fixedly connected to the gearbox bushing. The lock nut is threaded to the rotating shaft and is located on the outside of the bearing end cover. The oil slinger ring, graphite sealing ring mounting base, adjusting ring, and oil baffle ring are arranged sequentially from the outside to the inside between the bearing end cover and the outer wall of the rotating shaft. A graphite sealing ring is embedded in the graphite sealing ring mounting base, and the oil drain nozzle is inserted into the outer end of the bearing end cover.

[0006] Furthermore, the bearing end cover includes an outer end cover, a stepped end cover, a small-diameter sleeve, a large-diameter sleeve, an inner sleeve, and an outer positioning disc. The outer end cover is disposed on the outside of the stepped end cover. The outer end of the small-diameter sleeve is perpendicularly fixed to the outer edge of the outer end cover. The inner end of the small-diameter sleeve is perpendicularly fixed to the outer end face of the stepped end cover. The outer end of the large-diameter sleeve is perpendicularly fixed to the outer edge of the stepped end cover. The inner sleeve is disposed on the inside of the large-diameter sleeve. The outer end of the inner sleeve is perpendicularly fixed to the inner edge of the stepped end cover. A central hole is provided in the middle of the outer end face of the outer end cover. A Babbitt alloy sleeve is fixedly attached to the inner circumferential sidewall of the central hole. The outer positioning disc is fitted and fixedly attached to the outer sidewall of the large-diameter sleeve.

[0007] Furthermore, the inner end of the oil baffle ring is provided with an inner disc, which is fitted onto the rotating shaft. The outer side of the oil baffle ring is fitted onto the inner sleeve. The outer side wall of the outer end of the oil baffle ring is provided with a flange along the circumferential direction. The inner side wall of the outer side of the oil baffle ring that mates with the inner sleeve is provided with an inner ring spiral groove.

[0008] Furthermore, the spiral direction of the inner ring spiral groove is opposite to the rotation direction of the rotating shaft.

[0009] Furthermore, the inner annular spiral groove has a trapezoidal shape.

[0010] Furthermore, the oil slinger ring is fitted onto the rotating shaft, and a set of first toothed sealing rings are evenly distributed on the outer side of the outer wall of the oil slinger ring. The inner circumferential side wall of the Babbitt alloy sleeve mates with the outer circumferential side wall of the first toothed sealing ring. A set of second toothed sealing rings is provided in the middle of the outer wall of the oil slinger ring. The second toothed sealing rings are located between the inner end face of the outer end cover and the outer end face of the stepped end cover. The inner end of the outer wall of the oil slinger ring is provided with a step along the circumferential direction. The step is located on the inner side of the stepped end cover.

[0011] Furthermore, each end of the outer wall of the graphite sealing ring mounting base is provided with a mounting ring groove, and each mounting ring groove contains a graphite sealing ring.

[0012] Furthermore, the outer circumferential sidewall of the graphite sealing ring and the inner circumferential sidewall of the inner sleeve are interference-fitted.

[0013] Furthermore, the inner circumferential sidewall of the graphite sealing ring is clearance-fitted with the bottom of the mounting ring groove.

[0014] Furthermore, the inner end face of the oil slinger ring and the outer end face of the adjusting ring are respectively clearance-fitted with the outer end face of the adjacent graphite sealing ring.

[0015] The beneficial effects of this invention compared to the prior art are:

[0016] This invention uses an oil-retaining ring as the first sealing structure, which can throw some lubricating oil onto the shaft seal end cover and flow back into the housing. The oil-retaining ring is designed as a trapezoidal internal thread reverse thread sealing structure. At high speeds, this thread can provide positive pressure gas into the cavity, preventing lubricating oil from flowing into the trapezoidal thread. The higher the rotational speed, the higher the pressure supplied into the cavity, and the better the sealing effect. The second seal is a contact seal using a graphite sealing ring structure, which contacts and engages with the shaft seal end cover to prevent further leakage of lubricating oil. During operation, the graphite sealing ring remains stationary, and when it wears, the mating parts remain intact. The third seal is an oil-throwing seal. The oil-throwing ring has grates that throw leaked lubricating oil into the cavity of the shaft seal end cover, and then collect it back into the housing through the oil drain nozzle. Therefore, this combined sealing method is not constrained by the linear velocity of the shaft system. Through multiple seals, a very good sealing effect can be achieved, providing reliable sealing performance under high temperature, high pressure, and high speed conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 This is an airflow diagram of the combined seal in this invention, where the direction of the arrows indicates the direction of gas flow;

[0019] Figure 3 This is a schematic diagram of the structure of the oil baffle ring 8 in this invention;

[0020] Figure 4 This is a schematic diagram of the bearing end cap 9 in this invention;

[0021] Figure 5 This is a schematic diagram of the structure of the oil-slinging ring 4 in this invention. Detailed Implementation

[0022] Specific implementation method one: Combining Figures 1 to 5 This embodiment describes a combined seal for a high linear velocity gearbox, comprising an oil drain nozzle 1, a locking nut 3, an oil slinger ring 4, a graphite sealing ring 5, a graphite sealing ring mounting base 6, an adjusting ring 7, an oil baffle ring 8, and a bearing end cover 9. The bearing end cover 9 is fitted onto the outside of the rotating shaft 2 and fixedly connected to the housing bushing 10. The locking nut 3 is threaded to the rotating shaft 2 and is located on the outside of the bearing end cover 9. The oil slinger ring 4, the graphite sealing ring mounting base 6, the adjusting ring 7, and the oil baffle ring 8 are arranged sequentially from the outside to the inside between the bearing end cover 9 and the outer wall of the rotating shaft 2. The graphite sealing ring 5 is embedded in the graphite sealing ring mounting base 6, and the oil drain nozzle 1 is inserted into the outer end of the bearing end cover 9.

[0023] The combined seal consists of a reverse thread seal, a contact seal, and an oil-slinging seal. This type of combined seal is not constrained by the linear velocity of the shaft system. Through multiple seals, it can achieve a very good sealing effect and provide reliable sealing performance under high temperature, high pressure, and high speed conditions.

[0024] The oil baffle ring 8 is installed on the rotating shaft 2, close to the bearing. When the bearing lubricating oil splashes onto the oil baffle ring 8, it is thrown away from the shaft seal by the high-speed rotation of the rotating shaft 2.

[0025] Adjusting ring 7, graphite ring mounting base 6, and oil slinger ring 4 are mounted on rotating shaft 2 and fixed by locking nut 3 at shaft end. Adjusting ring 7 is close to oil baffle ring 8 and is used to adjust the axial contact position between graphite sealing ring 5 and shaft seal end cover 9. Graphite ring mounting base 6 is used to install graphite sealing ring 5. Oil slinger ring 4 is used to seal lubricating oil that leaks through graphite sealing ring 5.

[0026] The shaft seal end cover 9 is a complex structural part with four mating surfaces. The first mating surface A is the outer circumferential side wall of the large-diameter sleeve 9-4, which serves as a stop and is installed on the housing bushing 10 with the outer positioning disc 9-6. The second mating surface B is the outer circumferential side wall of the inner sleeve 9-5, which is in clearance fit with the oil baffle ring 8. The third mating surface C is the inner circumferential side wall of the inner sleeve 9-5, which is in contact fit with the graphite sealing ring 5. The fourth mating surface D is the inner circumferential side wall of the Babbitt alloy sleeve 9-8, which is in clearance fit with the oil slinger ring 4. An inclined surface is provided between the lower part of the outer end of the small-diameter sleeve 9-3 and the lower part of the outer end cover 9-1. The oil drain nozzle 1 is installed on the inclined surface to drain the lubricating oil that leaks through the graphite sealing ring 5.

[0027] The graphite sealing ring 5 is installed on the graphite ring mounting base 6. Its outer circle is in contact with the bearing end cover 9, and its inner hole and end face are in clearance fit with the graphite ring mounting base 6.

[0028] Specific Implementation Method Two: Combining Figures 1 to 5This embodiment describes a bearing end cover 9 comprising an outer end cover 9-1, a stepped end cover 9-2, a small-diameter sleeve 9-3, a large-diameter sleeve 9-4, an inner sleeve 9-5, and an outer positioning disc 9-6. The outer end cover 9-1 is disposed outside the stepped end cover 9-2. The outer end of the small-diameter sleeve 9-3 is perpendicularly fixed to the outer edge of the outer end cover 9-1, and the inner end of the small-diameter sleeve 9-3 is perpendicularly fixed to the outer end face of the stepped end cover 9-2. The outer end of the large-diameter sleeve 9-4 is perpendicularly fixed to the outer edge of the stepped end cap 9-2. The inner sleeve 9-5 is disposed inside the large-diameter sleeve 9-4, and its outer end is perpendicularly fixed to the inner edge of the stepped end cap 9-2. A central hole 9-7 is provided in the middle of the outer end face of the outer end cap 9-1. A Babbitt alloy sleeve 9-8 is fixed to the inner circumferential side wall of the central hole 9-7. The outer positioning disc 9-6 is fitted and fixed to the outer side wall of the large-diameter sleeve 9-4. Other components and connection methods are the same as in specific embodiment one.

[0029] The shaft seal end cover 9 is an integral structure with two oil return chambers and four mating surfaces. A Babbitt alloy sleeve 9-8 is hung on the inner hole that mates with the first grate sealing ring 4-1 of the oil slinger ring 4. When the shaft system is misaligned, the first grate sealing ring 4-1 of the oil slinger ring 4 can be embedded into the Babbitt alloy sleeve 9-8, thereby protecting the shaft seal end cover 9 and the oil slinger ring 4 from damage.

[0030] Specific implementation method three: Combining Figures 1 to 5 In this embodiment, the inner end of the oil baffle ring 8 is provided with an inner disc 8-1, which is fitted onto the rotating shaft 2. The outer side of the oil baffle ring 8 is fitted onto an inner sleeve 9-5. A flange 8-2 is provided along the circumferential direction on the outer side wall of the outer end of the oil baffle ring 8. An inner annular spiral groove 8-3 is provided on the inner side wall of the outer side of the oil baffle ring 8 that mates with the inner sleeve 9-5. Other components and connection methods are the same as in specific embodiment two.

[0031] The oil baffle ring 8 has an outer ring with a stepped flange 8-2 and an inner ring with a trapezoidal thread structure 8-3, which has both the radial oil throwing function of the end face step and the sealing function of the reverse thread.

[0032] Specific implementation method four: Combination Figures 1 to 5 In this embodiment, the spiral direction of the inner annular spiral groove 8-3 is opposite to the rotation direction of the rotating shaft 2. Other components and connections are the same as in specific embodiment three.

[0033] The helical direction of the inner ring trapezoidal thread is opposite to the rotation direction of the shaft system, which provides a better sealing effect at high speeds.

[0034] Specific Implementation Method Five: Combining Figures 1 to 5In this embodiment, the inner annular spiral groove 8-3 is trapezoidal in shape. Other components and connection methods are the same as in specific embodiment four.

[0035] The wide grooves of the trapezoidal thread can hold more air and lubricating oil, resulting in better sealing at high speeds.

[0036] Specific Implementation Method Six: Combination Figures 1 to 5 In this embodiment, the oil slinger ring 4 is mounted on the rotating shaft 2. A set of first toothed sealing rings 4-1 are evenly distributed on the outer side of the outer wall of the oil slinger ring 4. The inner circumferential sidewall of the Babbitt alloy sleeve 9-8 mates with the outer circumferential sidewall of the first toothed sealing rings 4-1. A set of second toothed sealing rings 4-2 is provided in the middle of the outer wall of the oil slinger ring 4. The second toothed sealing rings 4-2 are positioned between the inner end face of the outer end cover 9-1 and the outer end face of the stepped end cover 9-2. A step 4-3 is provided along the circumferential direction on the inner end of the outer wall of the oil slinger ring 4, and the step 4-3 is located inside the stepped end cover 9-2. Other components and connection methods are the same as in specific embodiment two.

[0037] There are multiple first-tooth sealing rings 4-1, with a total width slightly smaller than the length of the Babbitt alloy sleeve 9-8. There is one second-tooth sealing ring 4-2.

[0038] The oil slinger ring 4 has a structure with grates on its outer diameter and two grates. The second grate sealing ring 4-2 is radially aligned with the inner cavity of the shaft seal end cover 9. The grates help to throw out the axially moving lubricating oil radially and collect it in the cavity. The oil flows back to the housing through the oil drain nozzle 1. The first grate sealing ring 4-1 is fitted with the hole of the shaft seal end cover 9 with a clearance to reduce the leakage of lubricating oil.

[0039] Specific implementation method seven: Combination Figures 1 to 5 In this embodiment, each end of the outer wall of the graphite sealing ring mounting base 6 is provided with a mounting ring groove 6-1, and each mounting ring groove 6-1 contains a graphite sealing ring 5. Other components and connection methods are the same as in specific embodiment two.

[0040] Specific implementation method eight: Combination Figures 1 to 5 In this embodiment, the outer circumferential sidewall of the graphite sealing ring 5 and the inner circumferential sidewall of the inner sleeve 9-5 are interference-fitted. Other components and connection methods are the same as in specific embodiment seven.

[0041] The graphite sealing ring 5 is interference-fitted into the inner hole of the shaft seal end cover 9. During operation, the graphite sealing ring 5 does not rotate with the shaft system. The graphite sealing ring mounting base 6 has a T-shaped structure, with one graphite sealing ring 5 installed at each end. The graphite sealing ring 5 is radially clearance-fitted with the graphite sealing ring mounting base 6, and the graphite sealing ring 5 is axially clearance-fitted with the oil slinger ring 4 and the adjusting ring 7, respectively.

[0042] Specific Implementation Method Nine: Combining Figures 1 to 5 In this embodiment, the inner circumferential sidewall of the graphite sealing ring 5 is clearance-fitted with the bottom of the mounting ring groove 6-1. Other components and connection methods are the same as in specific embodiment eight.

[0043] Specific Implementation Method Ten: Combining Figures 1 to 5 In this embodiment, the inner end face of the oil slinger ring 4 and the outer end face of the adjusting ring 7 are respectively clearance-fitted with the outer end face of the adjacent graphite sealing ring 5. Other components and connection methods are the same as in specific embodiment nine.

[0044] Working principle

[0045] like Figure 1 As shown, the combined seal used in this invention consists of three sealing forms: reverse thread seal, contact seal, and oil-throwing seal. When the shaft rotates, the lubricating oil first passes through the oil baffle ring 8, throwing most of the lubricating oil into the inner cavity of the bearing end cover 9, and then flows back into the housing through the oil return port of the housing bushing 10. A portion of the lubricating oil falls back into the axial gap formed by the oil baffle ring 8 and the bearing end cover 9. At this time, the reverse thread of the inner hole of the oil baffle ring 8 plays a sealing role, drawing in external air and blowing it into the axial gap formed with the bearing end cover 9 to prevent lubricating oil from flowing in. If the amount of lubricating oil is too much and passes through the first seal, the second contact seal begins to play a sealing role. The contact seal uses two graphite sealing rings 5 ​​as contact sealing elements, installed in the graphite ring mounting seat 6. Their outer diameter is interference-fitted with the bearing end cover 9, and their inner diameter is clearance-fitted with the graphite ring mounting seat 6. After the combined seal is installed, the graphite sealing rings 5 ​​are stationary, and the end faces of the graphite sealing rings 5 ​​are in contact with the graphite ring mounting seat 6 and the adjusting ring 7, respectively. During high-speed rotation, the graphite ring mounting base 6 and adjusting ring 7 will rub against the end face of the graphite sealing ring 5. When the graphite sealing ring 5 wears, the mating parts will remain intact. After the contact sealing by the graphite sealing ring 5, the leakage of lubricating oil will become very small or even non-existent. At this time, the lubricating oil is thrown into the inner cavity of the bearing end cover 9 by the oil slinger ring 4 and flows back to the housing through the oil drain nozzle 1.

[0046] like Figure 2 As shown, the reverse thread design is on the rotating component 8 (oil retainer ring) rather than the stationary component 9 (bearing end cap). The purpose is to leverage the high-speed rotation of the oil retainer ring to provide a better seal for the reverse thread. Under the action of the reverse thread, whether the contents of the thread are lubricating oil or air, they will be pushed out along the thread direction. Therefore, in the combined seal, the airflow is from the outside air to the inside of the housing, and the reverse thread acts as a suction force to the inside of the housing. The trapezoidal reverse thread design provides more air intake and has a better sealing effect than the triangular reverse thread design.

[0047] like Figure 3As shown, the helical direction of the trapezoidal thread is opposite to the rotation direction of the rotating shaft, and the inner hole is clearance-fitted with the rotating shaft, rotating in the same direction; a flange 8-2 is designed on the thread end face to guide the oil to enter the bearing end cover cavity in the direction of oil throwing, so as to reduce the oil ingress in the axial gap formed by the oil retainer ring 8 and the bearing end cover 9.

[0048] like Figure 4 As shown, the bearing end cover 9 consists of an end cover body and a Babbitt alloy sleeve 9-8. The function of the Babbitt alloy sleeve 9-8 is that when the shaft system is misaligned, the first grate seal ring 4-1 of the oil slinger ring 4 will rub against the bearing end cover 9, and the first grate seal ring 4-1 will embed into the Babbitt alloy sleeve 9-8, thereby protecting the first grate seal ring 4-1 and the bearing end cover 9 from damage. The bearing end cover 9 has four mating surfaces. Surface A is connected to the housing bushing 10 through a stop. Surface B is clearance-fitted with the inner ring spiral groove 8-3 of the oil baffle ring 8. Surface C is interference-fitted with the graphite sealing ring 5. Surface D is clearance-fitted with the first grate sealing ring 4-1 of the oil slinger ring 4. It forms two cavities. Cavity E is formed between the inner circumferential side wall of the large diameter sleeve 9-4, the inner end face of the stepped end cover 9-2, and the outer circumferential side wall of the inner sleeve 9-5. Cavity E is used to collect the lubricating oil thrown out by the oil baffle ring 8. Cavity F is formed between the inner end face of the outer end cover 9-1, the inner circumferential side wall of the small diameter sleeve 9-3, and the outer end face of the stepped end cover 9-2. Cavity F is used to collect the lubricating oil thrown out by the second grate sealing ring 4-2 of the oil slinger ring 4. The inner end of the oil drain nozzle 1 is connected to cavity F.

[0049] like Figure 5 As shown, a step 4-3 is designed on the right side of the oil slinger ring 4, and its end face is clearance-fitted with the graphite sealing ring 5. Grate teeth are designed on the left side and the middle part. The second grate tooth sealing ring 4-2 is separated from the first grate tooth sealing ring 4-1. The function of the second grate tooth sealing ring 4-2 is to throw the lubricating oil into the cavity F of the shaft seal end cover 9. The first grate tooth sealing ring 4-1 is clearance-fitted with the Babbitt alloy sleeve 9-8 on the D surface of the bearing end cover 9. The multiple grates reduce the leakage of lubricating oil.

[0050] This invention provides a combined seal for high linear speed gearboxes, consisting of three sealing methods: a reverse thread seal, a contact seal, and an oil slinger seal. The reverse thread seal employs a trapezoidal internal thread structure, installed on the rotating shaft, and pushes air and lubricating oil back into the gearbox through high-speed rotation. The contact seal uses a graphite sealing ring, which, compared to a lip seal, significantly increases the linear speed of the shaft operation, and ensures that the mating parts remain intact even when the graphite sealing ring wears. The oil slinger seal utilizes the grates on the oil slinger ring to convert the axial movement of lubricating oil into radial movement, which is then collected by the oil return chamber of the bearing end cover and returned to the gearbox through the oil drain nozzle.

[0051] When the shaft system rotates at high speed, the first seal, through the flange 8-2 of the oil retainer ring 8, throws most of the lubricating oil into the inner cavity of the bearing end cover 9, and flows back into the housing through the oil return port of the housing bushing 10. A portion of the lubricating oil falls back into the axial gap formed by the oil retainer ring 8 and the bearing end cover 9, while the reverse thread of the inner hole of the oil retainer ring 8 acts as a seal at this time. When the lubricating oil enters the second seal, the contact seal begins to function. The graphite sealing ring 5 is interference-fitted in the shaft seal end cover 9 and remains stationary. The graphite ring mounting seat 6 and the adjusting ring 7 will rub against the end face of the graphite sealing ring 5. When the graphite sealing ring 5 wears, the mating parts can still remain intact. When the lubricating oil enters the third seal, the oil slinger seal begins to function, relying on the grates of the oil slinger ring 4 to throw the oil into the inner cavity of the bearing end cover 9, and flows back into the housing through the oil drain nozzle 1.

[0052] This type of combined sealing is not constrained by the linear velocity of the shaft system. Through multiple seals, it can achieve a good sealing effect and provide reliable sealing performance under high temperature, high pressure, and high speed conditions.

[0053] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A combined seal for a high linear velocity gearbox, characterized in that: It includes an oil drain nozzle (1), a locking nut (3), an oil slinger ring (4), a graphite sealing ring (5), a graphite sealing ring mounting base (6), an adjusting ring (7), an oil baffle ring (8), and a bearing end cover (9). The bearing end cover (9) is fitted on the outside of the rotating shaft (2) and fixed to the housing bushing (10). The locking nut (3) is threaded to the rotating shaft (2) and is located on the outside of the bearing end cover (9). The oil slinger ring (4), the graphite sealing ring mounting base (6), the adjusting ring (7), and the oil baffle ring (8) are arranged from the outside to the inside between the bearing end cover (9) and the outer wall of the rotating shaft (2). The graphite sealing ring mounting base (6) is fitted with a graphite sealing ring (5). The oil drain nozzle (1) is inserted into the outer end of the bearing end cover (9). The bearing end cover (9) includes an outer end cover (9-1), a stepped end cover (9-2), a small-diameter sleeve (9-3), a large-diameter sleeve (9-4), an inner sleeve (9-5), and an outer positioning disc (9-6). The outer end cover (9-1) is located outside the stepped end cover (9-2). The outer end of the small-diameter sleeve (9-3) is perpendicularly fixed to the outer edge of the outer end cover (9-1). The inner end of the small-diameter sleeve (9-3) is perpendicularly fixed to the outer end face of the stepped end cover (9-2). The large-diameter sleeve (9-1) is located outside the stepped end cover (9-2). 4) The outer end is perpendicularly fixed to the outer edge of the stepped end cap (9-2). The inner sleeve (9-5) is set inside the large diameter sleeve (9-4). The outer end of the inner sleeve (9-5) is perpendicularly fixed to the inner edge of the stepped end cap (9-2). The outer end cap (9-1) has a central hole (9-7) in the middle of its outer end face. A Babbitt alloy sleeve (9-8) is fixed to the inner circumferential side wall of the central hole (9-7). The outer positioning disc (9-6) is fitted and fixed to the outer side wall of the large diameter sleeve (9-4).

2. The combined seal for a high linear velocity gearbox according to claim 1, characterized in that: The inner end of the oil baffle ring (8) is provided with an inner disc (8-1), which is fitted on the rotating shaft (2). The outer side of the oil baffle ring (8) is fitted on the inner sleeve (9-5). The outer side wall of the outer end of the oil baffle ring (8) is provided with a flange (8-2) along the circumferential direction. The inner side wall of the outer side of the oil baffle ring (8) that cooperates with the inner sleeve (9-5) is provided with an inner ring spiral groove (8-3).

3. The combined seal for a high linear velocity gearbox according to claim 2, characterized in that: The spiral direction of the inner ring spiral groove (8-3) is opposite to the rotation direction of the rotating shaft (2).

4. The combined seal for a high linear velocity gearbox according to claim 3, characterized in that: The inner ring spiral groove (8-3) has a trapezoidal shape.

5. A combined seal for a high linear velocity gearbox according to claim 1, characterized in that: The oil slinger ring (4) is fitted on the rotating shaft (2). A set of first toothed sealing rings (4-1) are evenly distributed on the outer side of the outer wall of the oil slinger ring (4). The inner circumferential side wall of the Babbitt alloy sleeve (9-8) is matched with the outer circumferential side wall of the first toothed sealing ring (4-1). A set of second toothed sealing rings (4-2) is provided in the middle of the outer wall of the oil slinger ring (4). The second toothed sealing rings (4-2) are located between the inner end face of the outer end cover (9-1) and the outer end face of the stepped end cover (9-2). The inner end of the outer wall of the oil slinger ring (4) is provided with a step (4-3) along the circumferential direction. The step (4-3) is located on the inner side of the stepped end cover (9-2).

6. The combined seal for a high linear velocity gearbox according to claim 1, characterized in that: The graphite sealing ring mounting base (6) has a mounting ring groove (6-1) at each end of its outer side wall, and a graphite sealing ring (5) is provided in each mounting ring groove (6-1).

7. A combined seal for a high linear velocity gearbox according to claim 6, characterized in that: The outer circumferential sidewall of the graphite sealing ring (5) and the inner circumferential sidewall of the inner sleeve (9-5) are interference-fitted.

8. A combined seal for a high linear velocity gearbox according to claim 7, characterized in that: The inner circumferential sidewall of the graphite sealing ring (5) is fitted with a clearance between it and the bottom of the mounting ring groove (6-1).

9. A combined seal for a high linear velocity gearbox according to claim 8, characterized in that: The inner end face of the oil slinger ring (4) and the outer end face of the adjusting ring (7) are respectively fitted with the outer end face of the adjacent graphite sealing ring (5) with a clearance.

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