Cooling tower fan speed reducer

Abstract

The utility model discloses a speed reducer of a cooling tower fan. The speed reducer comprises a box body, an input shaft, an intermediate shaft and an output shaft, the input shaft and the middle shaft are horizontally arranged, and the middle shaft is located below the input shaft. The output shaft is vertically arranged and extends out of the top of the box body to output power; the input shaft and the intermediate shaft are subjected to speed reduction transmission through a first-stage speed reduction gear pair, and the intermediate shaft and the output shaft are subjected to speed reduction transmission through a second-stage bevel gear pair; the highest liquid level of lubricating oil in the speed reducer is located below the mounting hole position of the input shaft, so that the contact area of the input shaft and the gear box is completely separated from the oil soaking environment, and the path that the lubricating oil leaks outwards through the shaft-box body gap is physically blocked.

Description

Technical Field

[0001] This utility model relates to the field of industrial cooling equipment, specifically to a cooling tower fan speed reducer. Background Technology

[0002] Oil leakage is a long-standing technical problem in traditional industrial cooling tower fan reducers, seriously affecting equipment reliability, maintenance costs, and environmental safety. Existing reducers mostly use skeleton oil seals or single-layer rubber seals, which lack sufficient wear resistance and high-temperature resistance. Under high-speed operation, the contact surface between the oil seal and the input shaft is prone to rubber aging and hardening due to frictional heat, leading to cracking of the sealing lip and leakage of lubricating oil. Furthermore, poor tolerance control between the input shaft and the seal exacerbates seal wear, increasing the probability of oil leakage. On the other hand, when the input shaft rotates at high speed, lubricating oil splashes outwards due to centrifugal force. Traditional static sealing structures cannot adapt to dynamic pressure changes, causing the oil film at the sealing interface to rupture and resulting in leakage.

[0003] In existing technologies, improper oil level design in the cooling tower fan reducer also exacerbates the risk of leakage. For example... Figure 7 The diagram shows a common existing speed reducer structure, with the input shaft horizontally positioned and the intermediate and output shafts vertically arranged. The input shaft first transmits power to the intermediate shaft via a primary bevel gear pair, and then to the output shaft via a secondary spur gear pair. To ensure gear lubrication, the input shaft needs to be partially or completely immersed in a lubricating oil sump. The interface between the input shaft and the gearbox housing is in constant contact with the oil, and lubricating oil slowly seeps out through the shaft-housing gap, resulting in continuous oil leakage. When the oil level is too high, the high-speed rotating gears agitate the oil, generating foam and further increasing the air pressure inside the gearbox, forcing lubricating oil to overflow from weak sealing points. Existing designs rely on splash lubrication to ensure gear meshing surface lubrication, but the high oil level requirement conflicts with the input shaft sealing requirements, making it difficult to balance lubrication effectiveness and leak prevention. Current speed reducer manufacturers generally alleviate oil leakage by "optimizing sealing materials" or "adding auxiliary sealant," but these methods do not address the root cause of the problem in the structural design.

[0004] Therefore, a completely new reducer structure design is needed to completely block the leakage path of lubricating oil from the input shaft area while ensuring lubrication performance. Utility Model Content

[0005] In view of this, the purpose of this utility model is to develop a cooling tower fan reducer that eliminates the risk of oil leakage by installing the input shaft above the lubricating oil level and combining it with a sealing ring and oil circuit return design.

[0006] The cooling tower fan reducer of this utility model includes a housing, an input shaft, an intermediate shaft, and an output shaft; the input shaft and the intermediate shaft are arranged horizontally, with the intermediate shaft located below the input shaft; the output shaft is arranged vertically and extends from the top of the housing to output power; the input shaft and the intermediate shaft are driven by a single-stage reduction gear pair, and the intermediate shaft and the output shaft are driven by a two-stage bevel gear pair; the highest level of lubricating oil in the reducer is located below the mounting hole on the input shaft.

[0007] Preferably, the input shaft and the motor shaft are connected by a flexible coupling.

[0008] Preferably, the flexible coupling includes two corresponding outer metal flanges that are keyed to the input shaft and the motor shaft; the two metal flanges have a number of pin holes evenly distributed along the circumference, and flexible pins are installed in the pin holes.

[0009] Preferably, the housing is provided with a flange structure for direct connection with the motor housing.

[0010] Preferably, the input shaft axis is positioned 45-87mm above the lubricating oil level.

[0011] Preferably, the input shaft is integrally formed with a high-speed gear, and the intermediate shaft is fixedly mounted with a driven gear; the driven gear meshes with the high-speed gear to form the first-stage reduction gear pair.

[0012] Preferably, the output shaft is welded and fixed with a bevel gear mounting seat, and a bevel gear disc is fixedly mounted on the bevel gear mounting seat by fasteners; a bevel gear is integrally formed at one end of the intermediate shaft; the bevel gear and the bevel gear disc mesh with each other to form the secondary bevel gear pair.

[0013] Preferably, one side of the housing has an integrally formed gear cavity for accommodating a primary reduction gear pair, and the opening side of the gear cavity is closed by a high-speed housing cover.

[0014] Preferably, the housing is directly connected to the motor housing via a motor connector; one end of the motor connector is fixedly connected to the outside of the high-speed housing cover, and the other end forms a flange structure for direct connection with the motor housing.

[0015] Preferably, the gear cavity sidewall of the housing and the high-speed housing cover respectively form an input shaft mounting hole and an intermediate shaft mounting hole; the input shaft mounting hole supports the rotation of the input shaft through a bearing; a bearing seat is installed in the intermediate shaft mounting hole, and a bearing is installed in the bearing seat to support the rotation of the intermediate shaft.

[0016] Preferably, a cover and a large bearing seat are installed at the openings at the top and bottom of the housing, respectively. The cover has a bearing hole and a bearing is installed inside. The output shaft is supported by the cover and the large bearing seat through the bearing.

[0017] The beneficial effects of this invention are as follows: By arranging the intermediate shaft parallel to the input shaft below it, and transmitting power between the input shaft and the intermediate shaft via a primary reduction gear pair, and between the intermediate shaft and the vertically positioned output shaft via a secondary bevel gear pair, this arrangement lowers the required lubricating oil level for both the primary and secondary reduction gear pairs below the installation position of the input shaft. This completely isolates the contact area between the input shaft and the gearbox from the oil immersion environment, physically blocking the path of lubricating oil leakage through the shaft-box gap. The depth of the lubricating oil sump is designed according to the gear meshing requirements, covering only below the gear meshing surface to ensure effective lubrication by preventing oil from contacting the input shaft. A double seal is used at the junction of the input shaft and the gearbox; even if a small amount of oil mist rises, it can be blocked by the inner seal. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0019] Figure 1 This is a schematic diagram of the working process of this utility model;

[0020] Figure 2 This is a schematic diagram of the reducer structure of this utility model;

[0021] Figure 3 This is a schematic diagram of the structure of the box body of this utility model;

[0022] Figure 4 This is a schematic diagram of the structure of the box lid of this utility model;

[0023] Figure 5 This is a schematic diagram of the structure of the high-speed box cover of this utility model;

[0024] Figure 6 This is a schematic diagram of the structure of the motor connector of this utility model;

[0025] Figure 7 This is a structural diagram of a gearbox in the prior art.

[0026] Attached reference numerals: Oil pipe assembly-1, housing-2, housing cover-3, lower oil seal cover-4, output shaft-5, upper oil seal cover-6, high-speed gear shaft-7, high-speed oil seal cover-8, blind cover-9, bevel gear shaft-10, outer bearing housing-11, inner bearing housing-12, driven gear-13, high-speed housing cover-14, large bearing housing-15, spacer-16, motor housing-17, motor connector-18, inner bearing washer-19, outer bearing washer-20. Detailed Implementation

[0027] like Figure 1 , 2As shown, this embodiment of a cooling tower fan reducer includes a housing 2, an input shaft, an intermediate shaft, and an output shaft 5. The input shaft and intermediate shaft are horizontally arranged, with the intermediate shaft located below the input shaft. The output shaft 5 is vertically arranged and extends from the top of the housing 2 to output power. The input shaft and intermediate shaft are driven by a primary reduction gear pair, and the intermediate shaft and output shaft 5 are driven by a secondary bevel gear pair. The highest lubricating oil level in the reducer is located below the mounting hole of the input shaft. This arrangement lowers the required lubricating oil level for the primary and secondary reduction gear pairs to below the mounting position of the reducer input shaft, completely isolating the contact area between the input shaft and the gearbox from the oil immersion environment, and physically blocking the path of lubricating oil leakage through the shaft-housing 2 gap. The depth of the lubricating oil sump is designed according to the gear meshing requirements, only covering below the gear meshing surface, ensuring the gear splash lubrication effect while preventing oil from contacting the input shaft. In this embodiment, an oil pipe assembly 1 is provided on the side wall of the housing 2, and the user can judge the lubricating oil level through the observation window in the oil pipe assembly 1.

[0028] In this embodiment, the input shaft and the motor shaft are connected by a flexible coupling, and the motor is mounted on a motor mount 17. The flexible coupling includes two corresponding outer metal flanges keyed to the input shaft and the motor shaft; each of the two metal flanges has a plurality of pin holes evenly distributed circumferentially, with elastic pins installed in the pin holes. The flexible coupling, through the deformation capability of its elastic pins (such as polyurethane, rubber, etc.), reduces the instantaneous impact force generated when the rotor accelerates from rest to its rated speed during motor startup. The flexible coupling absorbs impact energy through the compression or shear deformation of the elastic element, significantly reducing the peak torque transmitted to the reducer gear system and greatly improving gear life.

[0029] In this embodiment, the housing 2 is provided with a flange structure for direct connection to the motor housing. In this embodiment, the housing 2 is directly connected to the motor housing via a motor connector 18; one end of the motor connector 18 is fixedly connected to the outside of the high-speed housing cover 14, and the other end forms a flange structure for direct connection to the motor housing. Traditionally, the reducer and motor are connected via a drive shaft, which has a complex structure, requires an additional support, and increases potential failure points (such as shaft breakage or keyway damage). This embodiment eliminates the intermediate transmission components, improving transmission efficiency.

[0030] In this embodiment, the input shaft axis is positioned 45-87mm above the lubricating oil surface. The oil level is designed so that the gear meshing surface is submerged below the oil, ensuring effective splash lubrication while preventing excessive oil agitation that could lead to temperature rise.

[0031] In this embodiment, the input shaft is a high-speed gear shaft 7, which is integrally formed with a high-speed gear, and a driven gear 13 is fixedly installed on the intermediate shaft; the driven gear 13 meshes with the high-speed gear to form the first-stage reduction gear pair.

[0032] In this embodiment, the output shaft 5 is welded and fixed with a bevel gear mounting seat, and the bevel gear mounting seat has several connecting holes distributed along the circumference. A bevel gear disk is fixedly installed by fasteners. The intermediate shaft is a bevel gear shaft 10, one end of which is integrally formed with a bevel gear. The bevel gear and the bevel gear disk mesh with each other to form the secondary bevel gear pair.

[0033] In this embodiment, one side of the housing 2 is integrally formed with a gear cavity for accommodating the first-stage reduction gear pair, and the opening side of the gear cavity is closed by a high-speed housing cover 14. The sidewall of the gear cavity of the housing 2 and the high-speed housing cover 14 respectively form an input shaft mounting hole and an intermediate shaft mounting hole; the input shaft mounting hole is supported by two opposing tapered roller bearings for rotation; a high-speed oil seal cover 8 is provided at the input shaft mounting hole of the high-speed housing cover 14 for sealing; a bearing housing (including an inner bearing housing 12 and an outer bearing housing 11) is installed in the intermediate shaft mounting hole. A pair of cylindrical roller bearings are installed in the inner bearing housing 12, and a spacer 16 is provided between the cylindrical roller bearings and the bevel gear for positioning; a pair of tapered roller bearings are installed in the outer bearing housing 11 to support the rotation of the intermediate shaft, and the bearing housing hole of the outer bearing housing 11 is closed by a cap 9. The gear cavity concentrates the first-stage reduction gear pair on one side of the housing 2, reducing axial space occupation and reducing the overall volume compared to the traditional split design.

[0034] In this embodiment, a cover 3 and a large bearing seat 15 are respectively installed at the openings at the top and bottom of the housing 2. The cover 3 has bearing holes and a tapered roller bearing and a cylindrical roller bearing are installed inside. The two bearings are separated by an inner bearing washer 19 and an outer bearing washer 20. An upper oil seal cover 6 and a lower oil seal cover 4 are respectively provided at both ends of the bearing holes of the cover 3 for sealing. The output shaft 5 is supported by the cover 3 and the large bearing seat 15 by bearings.

[0035] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model are included within the protection scope of the present utility model.

Claims

1. A cooling tower fan reducer, characterized in that: It includes a housing, an input shaft, an intermediate shaft, and an output shaft; the input shaft and the intermediate shaft are horizontally arranged, with the intermediate shaft located below the input shaft; the output shaft is vertically arranged and extends from the top of the housing to output power; the input shaft and the intermediate shaft are driven by a single-stage reduction gear pair, and the intermediate shaft and the output shaft are driven by a two-stage bevel gear pair; the highest level of lubricating oil in the reducer is located below the mounting hole on the input shaft.

2. The cooling tower fan reducer according to claim 1, characterized in that: The input shaft and the motor shaft are connected by a flexible coupling.

3. The cooling tower fan reducer according to claim 2, characterized in that: The flexible coupling includes two corresponding outer metal flanges that are keyed to the input shaft and the motor shaft; the two metal flanges have a number of pin holes evenly distributed along the circumference, and flexible pins are installed in the pin holes.

4. The cooling tower fan reducer according to claim 3, characterized in that: The enclosure is equipped with a flange structure for direct connection to the motor housing.

5. The cooling tower fan reducer according to claim 1, characterized in that: The input shaft is integrally formed with a high-speed gear, and the intermediate shaft is fixedly mounted with a driven gear; the driven gear meshes with the high-speed gear to form the first-stage reduction gear pair.

6. The cooling tower fan reducer according to claim 1, characterized in that: The output shaft is welded and fixed with a bevel gear mounting seat, and a bevel gear disc is fixedly mounted on the bevel gear mounting seat by fasteners; a bevel gear is integrally formed at one end of the intermediate shaft; the bevel gear and the bevel gear disc mesh with each other to form the secondary bevel gear pair.

7. The cooling tower fan reducer according to claim 5, characterized in that: One side of the housing has an integrally formed gear cavity for accommodating a primary reduction gear pair, and the opening side of the gear cavity is closed by a high-speed housing cover.

8. The cooling tower fan reducer according to claim 4, characterized in that: The enclosure is directly connected to the motor housing via a motor connector; one end of the motor connector is fixedly connected to the outside of the high-speed enclosure cover, and the other end forms a flange structure for direct connection with the motor housing.

9. The cooling tower fan reducer according to claim 7, characterized in that: The gear cavity sidewall of the housing and the high-speed housing cover respectively form an input shaft mounting hole and an intermediate shaft mounting hole; the input shaft mounting hole supports the rotation of the input shaft through a bearing; a bearing seat is installed in the intermediate shaft mounting hole, and a bearing is installed in the bearing seat to support the rotation of the intermediate shaft.

10. The cooling tower fan reducer according to claim 1, characterized in that: The top and bottom openings of the housing are respectively equipped with a housing cover and a large bearing seat. The housing cover has a bearing hole inside and a bearing is installed therein. The output shaft is supported by the housing cover and the large bearing seat through the bearing.

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