Sealing structure for shaft of semi-direct-drive speed reducer of vertical mill
By adopting a double seal design of maze oil-swinging structure and skeleton oil seal on the shaft of the vertical grinding semi-direct drive reducer, the existing sealing structure is easily leaked and has insufficient durability, achieving better sealing effect and longer service life.
Patent Information
- Application Number
- CN202422071255.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-08-26
AI Technical Summary
The sealing structure of the existing vertical grinding semi-direct drive reducer shaft has oil leakage problems and is insufficient durability, especially the nitride sleeve-double oil seal and single oil seal-laze cover structures are prone to wear and poor sealing effect after long-term operation.
A sealing structure including an input shaft, a support and an end cover is adopted. A maze oil-swinging structure is set between the input shaft and the end cover, a skeleton oil seal is set up, and grease is sent to the top of the skeleton oil seal through an oil inlet sleeve to form an oil film to reduce friction, thereby achieving a better sealing effect.
Through the combination of the driving shaft and the static ring and the double sealing structure of the skeleton oil seal, the oil leakage problem is effectively avoided, the service life is extended, and the sealing effect is improved, achieving higher durability and longer service life.
Smart Images
Figure CN223004401U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of semi-direct drive reducer shafts, and in particular to a sealing structure for a vertical mill semi-direct drive reducer shaft. Background Technique
[0002] Vertical mills are widely used in mining machinery production industries such as coal, cement, and chemical engineering. As a key component of vertical mills, reducers have an important impact on the comprehensive performance of vertical mills. With the development of science and technology, in order to promote the development of vertical mills towards the direction of light weight, high power, low vibration, and high reliability, the research and development of semi-direct drive vertical mill reducers is of great significance for promoting the optimization and improvement of the vertical mill gearbox structure.
[0003] The working environment of vertical mill reducers is harsh with a large amount of dust, and high requirements are imposed on sealing. At the same time, the problem of oil leakage has always troubled production, so it is very important to select a reasonable sealing structure. The commonly used sealing structures at present are mainly contact type and non-contact type. The contact type sealing structure is usually a nitrided sleeve - double oil seal or single oil seal - labyrinth cover structure, and the non-contact type is usually an oil slinger - labyrinth cover structure.
[0004] However, the nitrided sleeve - double oil seal existing in the current market is prone to severe wear during operation, resulting in a short service life of the oil seal and poor sealing effect; the nitrided oil seal sleeve of the single oil seal - labyrinth cover structure will have wear after long-term operation; while the processing accuracy requirements of the oil slinger - labyrinth cover structure are very high and the required cost is relatively high. Content of the Utility Model
[0005] The technical problem to be solved by the utility model is to provide a sealing structure for a vertical mill semi-direct drive reducer shaft that can avoid oil leakage problems and has good durability.
[0006] In order to solve the above technical problems, the sealing structure for a vertical mill semi-direct drive reducer shaft provided by the utility model adopts the following technical scheme:
[0007] A sealing structure for a vertical mill semi-direct drive reducer shaft includes an input shaft, a support and an end cover sleeved on the input shaft. The end cover is fixedly arranged on one end face of the support close to the oil inlet side. The end cover and the input shaft are in clearance fit, and a labyrinth oil slinging structure is arranged at the clearance fit between the end cover and the input shaft; a skeleton oil seal is arranged on the support, the skeleton oil seal is sleeved and fitted on the input shaft, an oil inlet sleeve is fixed on the support, the oil inlet sleeve penetrates through the support and is communicated with the clearance between the input shaft and the support, and the oil outlet end of the oil inlet sleeve is located between the skeleton oil seal and the end cover.
[0008] By adopting the above technical solution, a combination of a moving shaft and a stationary ring is formed between the input shaft and the end cover. When oil seeps to the labyrinth oil slinging structure, a cavity is formed between the high-speed rotating input shaft and the labyrinth oil slinging structure. The negative pressure and centrifugal force formed by the high-speed rotation eject the infiltrated oil, thus achieving the first seal. Moreover, there is no direct contact and no metal friction between the input shaft and the end cover, which extends the service life of the input shaft and the end cover. The skeleton oil seal between the input shaft and the support forms the second seal against oil leakage. And grease is sent above the skeleton oil seal through the oil inlet sleeve. When the grease reaches the skeleton oil seal, with the rotation of the input shaft, an oil film is formed at the joint surface. By using the distance between the friction pairs and the surface tension of the grease oil film, the continuous friction between the input shaft and the skeleton oil seal can be reduced or eliminated, forming a good planar seal, thus achieving a better sealing effect and being more durable with a longer service life.
[0009] Optionally, the number of the skeleton oil seals is set to two, and the two skeleton oil seals are arranged at intervals in the vertical direction; one end of the support away from the end cover extends inward to obtain a fixing ring. The upper skeleton oil seal abuts against the end cover, and the lower skeleton oil seal abuts against the fixing ring. The oil outlet end of the oil inlet sleeve is clamped between the two skeleton oil seals.
[0010] By adopting the above technical solution, the two skeleton oil seals can form two seals, further improving the sealing effect. At the same time, the upper skeleton oil seal can also prevent particles such as water or dust from entering the rotating structure of the input shaft and causing damage; the upper skeleton oil seal can also prevent the lubricating grease input by the oil inlet sleeve from being sucked in by the negative pressure at the labyrinth oil slinging structure, resulting in the situation that it is difficult for the lubricating grease to form an oil film between the two skeleton oil seals and the input shaft. And the two skeleton oil seals limit the movement space of the lubricating grease, enabling the lubricating grease to more stably form an oil film at the joint surface between the two skeleton seals and the input shaft. And through the clamping and fixing of the two skeleton oil seals by the end cover, the fixing ring and the oil outlet end of the oil inlet sleeve, the two skeleton oil seals can be stably fixed on the support.
[0011] Optionally, the input shaft is provided with a boss, the support is sleeved on the boss, and a clearance fit is provided between the end cover and the upper end surface of the boss. A labyrinth oil slinging structure is provided at the clearance fit between the end cover and the upper end surface of the boss.
[0012] By adopting the above technical solution, through the setting of the boss, the labyrinth oil slinging structure between the end cover and the input shaft changes from the vertical direction to the horizontal direction, and the path of oil infiltration is extended, so that the oil entering the labyrinth oil slinging structure is relatively reduced, thus more effectively realizing oil slinging and preventing oil leakage.
[0013] Optionally, the clearance between the end cover and the boss is 1 - 2 mm.
[0014] By adopting the above technical solution, by controlling the gap between 1 - 2 mm, it is possible to ensure that there is no direct contact and no metal friction between the boss of the input shaft and the end cover, while there is a certain space between the boss of the input shaft and the end cover to form negative pressure and centrifugal force during high-speed rotation, so as to effectively throw out the infiltrated oil.
[0015] Optionally, the surface finish of the input shaft is 1 - 4 μm, and the fit tolerance grade is H11.
[0016] By adopting the above technical solution, when processing the input shaft to reach the above surface finish and fit tolerance grade, the friction coefficient between the input shaft and the skeleton oil seal can be reduced, thereby reducing the wear and heat generation between the input shaft and the lip of the skeleton oil seal during the rotation of the input shaft, and improving the service life of the input shaft and the skeleton oil seal.
[0017] Optionally, the surface finish of the boss of the input shaft is 1 - 4 μm, and the fit tolerance grade is H11.
[0018] Optionally, the end cover is placed on the end face of the support near the oil inlet side, and the end cover is fixedly connected to the support by a plurality of circumferentially distributed bolts.
[0019] By adopting the above technical solution, the end cover is fixedly connected to the support by bolts, which can ensure the tightness between the end cover and the support, thus avoiding the situation that small oil droplets and oil mist penetrate through the end cover and the support; and it can better fix and support the weight of the end cover to ensure its static state.
[0020] Optionally, both the support and the input shaft are provided with an oil collecting box, the oil collecting box is located on the side of the support far from the oil inlet side, and the oil collecting box is used to collect the oil mist leaking from between the support and the input shaft.
[0021] Optionally, the oil collecting box has an annular structure and is arranged concentrically with the input shaft, the oil collecting box is provided with an upper opening, the vertical projection of the opening contour of the oil collecting box partially coincides with the lower end faces of the input shaft and the support, the oil collecting box and the support are in static seal, and the oil collecting box and the input shaft are in rotary dynamic seal.
[0022] By adopting the above technical solution, the oil collecting box forms a closed-loop seal with the input shaft and the support. The oil collecting box simultaneously forms a rotary dynamic seal with the input shaft and a static seal with the support. The above structure can effectively prevent the oil mist from leaking out through the shaft gap, damaging the lower electromechanical equipment or polluting the environment.
[0023] Optionally, an oil return pipe is connected to the bottom of the oil collecting box.
[0024] By adopting the above technical solution, the oil collected in the oil collecting box is pumped out of the speed reducer through the oil return pipe, which can be recycled, thus saving costs.
[0025] In summary, the utility model includes at least one of the following beneficial technical effects:
[0026] 1. A combination of a moving shaft and a static ring is formed between the input shaft and the end cover. When oil seeps to the labyrinth oil throwing structure, a cavity is formed between the high-speed rotating input shaft and the labyrinth oil throwing structure. The negative pressure and centrifugal force formed by the high-speed rotation throw out the infiltrated oil, thus realizing the first seal. Moreover, there is no direct contact and no metal friction between the input shaft and the end cover, which prolongs the service life of the input shaft and the end cover.
[0027] 2. The skeleton oil seal between the input shaft and the support forms the second seal against oil leakage. And the grease is sent above the skeleton oil seal through the grease inlet sleeve. When the grease reaches the skeleton oil seal, with the rotation of the input shaft, the grease forms an oil film at the joint surface. By using the distance between the friction pairs and the surface tension of the grease oil film, the continuous friction between the input shaft and the skeleton oil seal can be reduced or eliminated, forming a good planar seal, thus achieving a better sealing effect and being more durable with a longer service life.
[0028] 3. The oil collecting box forms a closed-loop seal with the input shaft and the support. The oil collecting box forms a rotary dynamic seal with the input shaft and a static seal with the support at the same time. The above structure can effectively prevent oil mist from seeping out between the shaft gaps, damaging the mechanical and electrical equipment below or polluting the environment. Description of the Drawings
[0029] Figure 1 is a schematic structural diagram of a shaft sealing structure of a vertical mill semi-direct drive speed reducer of the utility model.
[0030] Figure 2 is Figure 1 an enlarged structural schematic diagram of part A in
[0031] Description of the reference numerals: 1. Input shaft; 11. Boss; 2. End cover; 3. Grease inlet sleeve; 4. Support; 5. Skeleton oil seal; 6. Oil collecting box; 7. Oil return pipe; 8. Embedded groove. Detailed Description of the Invention
[0032] The following further describes the utility model in detail Figure 1 with reference to the attached drawings.
[0033] An embodiment of the utility model discloses a shaft sealing structure of a vertical mill semi-direct drive speed reducer. Refer to Figure 1, the seal structure for the shaft of a vertical mill semi-direct drive speed reducer includes an input shaft 1 and a support 4. A boss 11 is integrally formed at the lower end of the input shaft 1, and the boss 11 is arranged around the central axis of the input shaft 1. The support 4 is in a circular ring shape, and the support 4 is sleeved on the boss 11.
[0034] Refer to Figure 1 , an end cover 2 is sleeved on the input shaft 1. The end cover 2 is simultaneously placed on the end face of the support 4 close to the oil inlet side. The end cover 2 is fixedly connected to the support 4 through a plurality of bolts distributed circumferentially. The end cover 2 is fixedly connected to the support 4 through bolts, which can ensure the tightness between the end cover 2 and the support 4, thus avoiding the situation where small oil droplets and oil mist seep through between the end cover 2 and the support 4; and it can better fix and support the weight of the end cover 2 to ensure its stationary state.
[0035] Refer to Figure 1 , the upper end face of the end cover 2 and the boss 11 are in clearance fit. A labyrinth oil throwing structure is arranged at the clearance fit between the end cover 2 and the boss 11. The labyrinth oil throwing structure is a number of annular sealing teeth arranged in sequence on the upper end faces of the end cover 2 and the boss 11. The annular sealing teeth on the upper end faces of the end cover 2 and the boss 11 are staggered and inserted, and the annular sealing teeth on the upper end faces of the end cover 2 and the boss 11 are in clearance fit. The clearance between the annular sealing teeth on the upper end faces of the end cover 2 and the boss 11 is also 1 mm.
[0036] A series of throttling gaps and expansion cavities are formed between the annular sealing teeth of the labyrinth oil throwing structure. When the sealed medium passes through the gaps of the tortuous labyrinth, a throttling effect is generated to achieve the purpose of leakage prevention. And a combination of a moving shaft and a static ring is formed between the input shaft 1 and the end cover 2. When oil seeps to the labyrinth oil throwing structure, a cavity is formed between the high-speed rotating input shaft 1 and the labyrinth oil throwing structure. The negative pressure and centrifugal force formed by the high-speed rotation will throw out the infiltrated oil, thus realizing the first-stage seal. And there is no direct contact and no metal friction between the input shaft 1 and the end cover 2, which prolongs the service life of the input shaft 1 and the end cover 2.
[0037] Through the setting of the boss 11, the labyrinth oil throwing structure between the end cover 2 and the input shaft 1 changes from the vertical direction to the horizontal direction, and the path of oil infiltration is extended, so that the oil entering the labyrinth oil throwing structure is relatively reduced, thus more effectively realizing oil throwing and anti-seepage. By controlling the clearance to 1 mm, while there is no direct contact and no metal friction between the input shaft 1 and the end cover 2, there is also a certain space between the input shaft 1 and the end cover 2 to form a negative pressure and centrifugal force during high-speed rotation to effectively throw out the infiltrated oil.
[0038] Refer to Figure 1, To further improve the sealing effect, the support 4 is provided with two skeleton oil seals 5. The skeleton oil seals 5 are of the standard AS type, with the lip facing upwards. The skeleton oil seals 5 are made of nitrile rubber as the raw material and have a rigid wire inside. Both of the two skeleton oil seals 5 are sleeved on the input shaft 1, and the lips of the two skeleton oil seals 5 are attached to the outer circular surface of the boss 11. The two skeleton oil seals 5 are arranged at intervals in the vertical direction. One end of the support 4 away from the end cover 2 extends inwards to obtain a fixing ring. The upper skeleton oil seal 5 abuts against the end cover 2, and the lower skeleton oil seal 5 abuts against the fixing ring. The oil outlet end of the oil inlet sleeve 3 is clamped between the two skeleton oil seals 5. By clamping and fixing the two skeleton oil seals 5 through the end cover 2, the fixing ring and the oil outlet end of the oil inlet sleeve 3, the two skeleton oil seals 5 can be stably fixed to the support 4.
[0039] The above-mentioned skeleton oil seals 5 have the advantages of good oil resistance, a heat resistance of up to 100 °C, high tensile strength, high fracture ductility, and small swelling in water, etc.; and the skeleton oil seals 5 have a rigid wire inside, which plays a good supporting role for the rubber. When the input shaft 1 rotates, the skeleton oil seals 5 have instant followability, forming a 360° rotary dynamic seal to achieve a better sealing effect. At the same time, the two skeleton oil seals 5 can form two seals to further improve the sealing effect, and the upper skeleton oil seal 5 can also prevent water, dust and other particulate matters from entering the rotating structure of the input shaft 1 and causing damage.
[0040] Refer to Figure 1 , To avoid the situation of excessive friction coefficient between the skeleton oil seal 5 and the boss 11 of the input shaft 1, which accelerates the wear and heat generation of the lip support between the input shaft 1 and the skeleton oil seal 5, the surface finish of the boss 11 of the input shaft 1 is 2 μm, and the fit tolerance grade is H11. Processing the boss 11 of the input shaft 1 to reach the above surface finish and fit tolerance grade can reduce the friction coefficient between the boss 11 of the input shaft 1 and the skeleton oil seal 5, thereby reducing the wear and heat generation between the boss 11 of the input shaft 1 and the lip of the skeleton oil seal 5 during the rotation of the input shaft 1, and improving the service life of the input shaft 1 and the skeleton oil seal 5.
[0041] Refer to Figure 1 , To further reduce the friction coefficient between the skeleton oil seal 5 and the boss 11 of the input shaft 1, the support 4 is fixed with an oil inlet sleeve 3. The oil inlet sleeve 3 penetrates the support 4 and is connected to the gap between the input shaft 1 and the support 4. The communication port of the oil inlet sleeve 3 is located between the two skeleton oil seals 5.
[0042] The grease is sent above the skeleton oil seal 5 through the oil inlet sleeve 3. When the grease reaches the skeleton oil seal 5, with the rotation of the input shaft 1, an oil film is formed at the joint surface. By using the distance between the friction pairs and the surface tension of the grease oil film, the continuous friction between the input shaft 1 and the skeleton oil seal 5 can be reduced or eliminated, forming a good planar seal, thus achieving a better sealing effect, being more durable, and having a longer service life. The communication port of the oil inlet sleeve 3 is located between the two skeleton oil seals 5. The upper skeleton oil seal 5 can prevent the grease oil input by the oil inlet sleeve 3 from being sucked in by the negative pressure at the labyrinth oil throwing structure, which may cause the grease oil to be difficult to form an oil film between the two skeleton oil seals 5 and the input shaft 1. Moreover, the two skeleton oil seals 5 restrict the movement space of the grease, enabling the grease to more stably form an oil film at the joint surface between the two skeleton seals and the input shaft 1.
[0043] Refer to Figure 1 , both the support 4 and the input shaft 1 are provided with an oil collecting box 6. The oil collecting box 6 is in an annular structure. The oil collecting box 6 is arranged concentrically with the input shaft 1. The oil collecting box 6 is provided with an upper opening, and the vertical projection of the opening contour of the oil collecting box 6 partially coincides with the lower end surfaces of the input shaft 1 and the support 4. The oil collecting box 6 is fixedly installed on other components in the speed reducer. Embedding grooves 8 are respectively opened on the lower end surfaces of the input shaft 1 and the support 4. The two side opening edges of the oil collecting box 6 are respectively inserted into the embedding grooves 8 of the input shaft 1 and the support 4 to form a static seal between the oil collecting box 6 and the support 4 and a rotary dynamic seal between the oil collecting box 6 and the input shaft 1. A return oil pipe 7 is communicated and arranged at the bottom of the oil collecting box 6.
[0044] The oil collecting box 6 forms a closed-loop seal with the input shaft 1 and the support 4. The oil collecting box 6 simultaneously forms a rotary dynamic seal with the input shaft 1 and a static seal with the support 4. The above structure can effectively prevent oil mist from seeping out between the shaft gaps, damaging the electromechanical equipment below or causing environmental pollution. Through the return oil pipe 7, the oil collected in the oil collecting box 6 is pumped out of the speed reducer and can be recycled, thus saving costs.
[0045] The implementation principle of the shaft sealing structure of the vertical mill semi-direct drive speed reducer in the embodiment of the present utility model is as follows: A combination of a moving shaft and a static ring is formed between the input shaft 1 and the end cover 2. When oil seeps to the labyrinth oil throwing structure, a cavity is formed between the high-speed rotating input shaft 1 and the labyrinth oil throwing structure. The negative pressure and centrifugal force formed by the high-speed rotation throw out the infiltrated oil, thus achieving the first-stage seal, and there is no direct contact and no metal friction between the input shaft 1 and the end cover 2. The two skeleton oil seals 5 form the second-stage seal against oil leakage. And through the oil inlet sleeve 3, the grease is sent above the skeleton oil seal 5. When the grease reaches the skeleton oil seal 5, it can reduce or eliminate the continuous friction between the input shaft 1 and the skeleton oil seal 5, form a good planar seal, thus achieving a better sealing effect, being more durable, and having a longer service life.
[0046] The above are all the preferred embodiments of the present utility model, and the protection scope of the present utility model is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present utility model shall be covered within the protection scope of the present utility model.
Claims
1. A sealing structure for a semi-direct drive reducer shaft of a vertical mill, characterized in that: The invention comprises an input shaft (1), a support (4) sleeved on the input shaft (1), and an end cover (2); the end cover (2) is fixedly arranged on an end surface of the support (4) close to the oil supply side; the end cover (2) and the input shaft (1) are clearance-matched; a labyrinth oil-slinging structure is arranged at the clearance-matching position between the end cover (2) and the input shaft (1); the support (4) is provided with a skeleton oil seal (5); the skeleton oil seal (5) is sleeved and fitted on the input shaft (1); the support (4) is fixed with an oil inlet sleeve (3); the oil inlet sleeve (3) passes through the support (4) and is connected to the gap between the input shaft (1) and the support (4); the oil outlet end of the oil inlet sleeve (3) is located between the skeleton oil seal (5) and the end cover (2).
2. A sealing structure for a shaft of a semi-direct drive reducer of a vertical mill according to claim 1, characterized in that: The number of the skeleton oil seals (5) is set to two, and the two skeleton oil seals (5) are arranged at intervals in the vertical direction; the end of the support (4) away from the end cover (2) extends inward to obtain a fixing ring, the upper skeleton oil seal (5) abuts against the end cover (2), and the lower skeleton oil seal (5) abuts against the fixing ring, and the oil outlet end of the oil inlet sleeve (3) is clamped between the two skeleton oil seals (5).
3. A sealing structure for a shaft of a semi-direct drive reducer of a vertical mill according to any one of claims 1 or 2, characterized in that: The input shaft (1) is provided with a boss (11), the support (4) is sleeved on the boss (11), the end cover (2) and the upper end surface of the boss (11) are both clearance-fitted, and a labyrinth oil-swinging structure is provided at the clearance-fitting position between the end cover (2) and the upper end surface of the boss (11).
4. A sealing structure for a shaft of a semi-direct drive reducer of a vertical mill according to claim 3, characterized in that: The gap between the end cover (2) and the boss (11) is 1-2 mm.
5. A sealing structure for a shaft of a semi-direct drive reducer of a vertical mill according to any one of claims 1 or 2, characterized in that: The surface finish of the boss (11) of the input shaft (1) is 1-4 μm, and the matching tolerance grade is H11.
6. A sealing structure for a shaft of a semi-direct drive reducer of a vertical mill according to any one of claims 1 or 2, characterized in that: The end cover (2) is placed on an end surface of the support (4) close to the oil supply side, and the end cover (2) is fixedly connected to the support (4) by a plurality of circumferentially distributed bolts.
7. A sealing structure for a shaft of a semi-direct drive reducer of a vertical mill according to any one of claims 1 or 2, characterized in that: The support (4) and the input shaft (1) are both provided with an oil collecting box (6), the oil collecting box (6) being located on a side of the support (4) away from the oil supply side, and the oil collecting box (6) being used to collect oil mist seeping from between the support (4) and the input shaft (1).
8. The sealing structure for the shaft of a semi-direct drive reducer of a vertical mill according to claim 7, characterized in that: The oil collecting box (6) is annular in structure and is arranged coaxially with the input shaft (1). The oil collecting box (6) is provided with an opening, and the vertical projection of the opening contour of the oil collecting box (6) partially overlaps with the lower end surfaces of the input shaft (1) and the support (4). A static seal is formed between the oil collecting box (6) and the support (4), and a rotating dynamic seal is formed between the oil collecting box (6) and the input shaft (1).
9. The sealing structure for the shaft of a semi-direct drive reducer of a vertical mill according to claim 7, characterized in that: The bottom of the oil collecting box (6) is connected to an oil return pipe (7).