Floating seal structure of a reduction gearbox

Abstract

The utility model provides a kind of reduction gearbox floating sealing structure, comprising: output flange and along transverse through installation in the output shaft of output flange center, the output flange is sealed with output shaft butt joint place by sealing end cap assembly, the sealing end cap assembly includes end cap, the end cap covers on output flange, and it is locked by gland pressure on output flange front side and by first fixed bolt, output shaft is along transverse through the central hole of the end cap, the gap of output shaft and end cap central hole is fixedly installed with stationary felt, gasket is installed in the rear end of output shaft and end cap assembly, clamping spring is installed in the rear side of gasket, the end cap is integrally injection moulded with polyurethane. This reduction gearbox floating sealing structure design is ingenious, can greatly improve sealing effect.

Description

Technical Field

[0001] This utility model relates to the field of sealing structure technology, specifically to a floating sealing structure for a gearbox. Background Technology

[0002] Powdered materials such as cement, fly ash, and mineral powder used in concrete mixing plants are generally transported by screw conveyors. Multiple screw conveyors are used to transport different materials from silos to weighing hoppers for metering, and then into the mixer. When the screw conveyor is working, the motor drives the screw shaft to rotate in a specified direction through the gearbox, transporting the dry powdered material from a low position to a high position.

[0003] To facilitate manufacturing, packaging, and transportation, screw conveyors exceeding a certain length (5 meters) adopt a segmented structure, meaning the outer tube and screw shaft are manufactured separately and then assembled on-site. Currently, the basic structure of a screw conveyor mainly consists of a motor, gearbox, inlet, screw shaft, outer tube, intermediate hanger shaft, outlet, and tail bearing. The screw shaft is connected to the gearbox, intermediate hanger shaft, or tail bearing via splined sleeves at both ends. The gearbox output flange connects to the outer tube, and the output shaft connects to the screw shaft. The two ends of the screw shaft are connected by splines, forming a simply supported beam structure. Due to its own weight, it will bend to some extent. When the screw conveyor is working, the rotation of the screw shaft will generate a certain eccentric torque, which acts directly on the output shaft of the gearbox. The gearbox output shaft is a cantilever beam structure. When the eccentric torque of the screw shaft is large, the cantilever end of the output shaft will bend to some extent, rotating eccentrically with the screw shaft. This will accelerate the wear of the seals in the sealing end cover assembly, leading to seal failure and dust leakage.

[0004] The existing gearbox output shaft sealing structure of the screw conveyor has the following defects: (1) The screw shaft bends under its own gravity, and the centrifugal torque generated during rotation is transmitted to the gearbox output shaft. (2) The gearbox output shaft rotates eccentrically with the screw shaft under the action of centrifugal torque, while the sealing end cover assembly is fixed in position, resulting in gaps in the sealing end cover assembly. Powdered materials can easily enter the interior of the sealing end cover assembly from the gap. (3) Once powdered materials enter the interior of the sealing end cover assembly, they will accelerate the wear of the output shaft, cause the sealing structure to fail prematurely, and lead to dust leakage faults in the screw conveyor, reducing its service life. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention proposes a floating sealing structure for a gearbox, which can significantly improve the sealing effect.

[0006] To achieve the above technical solution, this utility model provides a gearbox floating sealing structure, including: an output flange and an output shaft installed transversely through the center of the output flange. The connection between the output flange and the output shaft is sealed by a sealing end cover assembly. The sealing end cover assembly includes an end cover, which covers the output flange and is pressed against the front side of the output flange by a pressure cap and locked by a first fixing bolt. The output shaft passes transversely through the center hole of the end cover. A stationary felt is fixedly installed in the gap between the output shaft and the center hole of the end cover. A gasket is installed at the rear end of the assembly of the output shaft and the end cover, and a retaining spring is installed on the rear side of the gasket. The end cover is integrally injection molded with polyurethane.

[0007] In the above technical solution, when the screw conveyor is working, the output shaft of the gearbox drives the screw shaft to rotate synchronously. All resistance (axial and radial) generated by the rotation of the screw shaft is borne by the output bearing. The output shaft is a cantilever beam structure. When the radial force exceeds the bearing capacity of the output shaft, the cantilever part of the output shaft will bend to a certain extent, causing the cantilever part to rotate eccentrically. Since the cantilever end of the output shaft is in contact with the sealing end cover assembly, the radial force generated is borne by the sealing end cover assembly. According to the sealing structure of the gearbox output shaft, the output shaft only contacts the felt inside the sealing end cover assembly. The output shaft rotates while the felt remains stationary. The radial force generated by the eccentric rotation of the output shaft acts directly on the felt. The felt has a certain elasticity, and after being subjected to force, it will eventually transmit this radial force outward to the end cover, causing the end cover to bear the radial force. Because the end cap is made of polyurethane through one-piece injection molding, the polyurethane end cap has a certain degree of elasticity. When it is subjected to force, it will deform in the direction of the force. When the output shaft rotates eccentrically, the sealing end cap assembly will swing synchronously in the direction of the radial force, so that its internal sealing structure is always in an ideal state, that is, the output shaft and the felt are in close contact, and the circumferential gap is always kept uniform, thus achieving an ideal sealing effect.

[0008] Preferably, the output flange is fixed to the front housing by a second fixing bolt, and the front housing and the rear housing are locked together by a third fixing bolt.

[0009] Preferably, a front bearing mounting position is provided in the front housing, and the front bearing is installed in the front bearing mounting position. A rear bearing mounting position is provided in the rear housing, and the rear bearing is installed in the rear bearing mounting position. The rear end of the output shaft is assembled in the front bearing and the rear bearing to ensure stable rotation of the output shaft.

[0010] The beneficial effects of the floating sealing structure for a gearbox provided by this utility model are as follows: Through the structural design of the sealing end cover assembly, the end cover is integrally injection molded with polyurethane and assembled with felt, gaskets, and retaining springs. This ensures that the output shaft only contacts the felt inside the sealing end cover assembly. The output shaft rotates while the felt remains stationary. The radial force generated by the eccentric rotation of the output shaft acts directly on the felt. The felt, possessing a certain elasticity, transmits this radial force outward to the end cover, allowing the end cover to bear the radial force. Because the end cover is integrally injection molded with polyurethane, the polyurethane material has a certain elasticity and deforms along the direction of force. When the output shaft rotates eccentrically, the sealing end cover assembly swings synchronously along the radial force direction, ensuring that its internal sealing structure remains in an ideal state—that is, the output shaft and felt are in close contact, and the circumferential gap remains uniform, achieving an ideal sealing effect. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the assembly structure of this utility model.

[0012] Figure 2 This is a schematic diagram of the structural assembly of the sealing end cap assembly in this utility model.

[0013] In the diagram: 1. Output shaft; 2. Sealing end cover assembly; 21. End cover; 22. Felt; 23. Gasket; 24. Pressure cap; 25. Snap ring; 3. First fixing bolt; 4. Front bearing; 5. Rear bearing; 6. Output flange; 7. Second fixing bolt; 8. Front housing; 9. Rear housing; 10. Third fixing bolt. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0015] Example: A floating seal structure for a gearbox.

[0016] Reference Figures 1 to 2As shown, a gearbox floating seal structure includes: an output flange 6 and an output shaft 1 that is transversely mounted through the center of the output flange 6. The output flange 6 is fixed to a front housing 8 by a second fixing bolt 7. The front housing 8 and a rear housing 9 are locked together by a third fixing bolt 10. A front bearing mounting position is provided inside the front housing 8, and a front bearing 4 is installed in the front bearing mounting position. A rear bearing mounting position is provided inside the rear housing 9, and a rear bearing 5 is installed in the rear bearing mounting position. The rear end of the output shaft 1 is assembled in the front bearing 4 and the rear bearing 5 to ensure stable rotation of the output shaft 1. The connection between the output flange 6 and the output shaft 1 is achieved through... The sealing end cap assembly 2 is sealed. The sealing end cap assembly 2 includes an end cap 21, which covers the output flange 6 and is pressed against the front side of the output flange 6 by a pressure cap 24 and locked by a first fixing bolt 3. The output shaft 1 passes through the center hole of the end cap 21 in a transverse direction. A stationary felt 22 is fixedly installed in the gap between the output shaft 1 and the center hole of the end cap 21. A gasket 23 is installed at the rear end of the assembly of the output shaft 1 and the end cap 21. A retaining ring 25 is installed on the rear side of the gasket 23. By installing the retaining ring 25, the axial movement of the output shaft 1 during high-speed rotation can be reduced. The end cap 21 is integrally injection molded with polyurethane.

[0017] In this embodiment, when the screw conveyor is working, the output shaft 1 of the gearbox drives the screw shaft to rotate synchronously. All resistance (axial and radial) generated by the rotation of the screw shaft is borne by the output bearing. The output shaft 1 is a cantilever beam structure. When the radial force exceeds the bearing capacity of the output shaft 1, the cantilever part of the output shaft 1 will bend to a certain extent, causing the cantilever part to rotate eccentrically. Since the cantilever end of the output shaft 1 is in contact with the sealing end cover assembly 2, the radial force generated is borne by the sealing end cover assembly 2. According to the sealing structure of the gearbox output shaft, the output shaft 1 only contacts the felt 22 inside the sealing end cover assembly 2. The output shaft 1 rotates while the felt 22 remains stationary. The radial force generated by the eccentric rotation of the output shaft 1 acts directly on the felt 22. The felt 22 has a certain elasticity, and after being subjected to force, it will eventually transmit this radial force outward to the end cover 21, causing the end cover 21 to bear the radial force. Since the end cap 21 is made of polyurethane integral injection molding, the polyurethane end cap 21 has a certain elasticity. When it is subjected to force, it will deform in a certain direction of force. When the output shaft 1 rotates eccentrically, the sealing end cap assembly 2 will swing synchronously in the radial force direction, so that its internal sealing structure is always in an ideal state, that is, the output shaft 1 and the felt 22 are in close contact, and the circumferential gap is always kept uniform, so as to achieve an ideal sealing effect.

[0018] In this embodiment, the end cap 21 is made of PU and molded using injection molding, resulting in fewer processes, stable quality, and low cost. The elastic properties of the PU material in the end cap 21 are utilized to achieve a floating seal. This improves the sealing reliability of the screw conveyor, enhances product quality, and reduces the ash leakage failure rate by approximately 70%.

[0019] The above description is only a preferred embodiment of the present utility model. However, the present utility model should not be limited to the content disclosed in the embodiment and the accompanying drawings. Therefore, any equivalent or modified embodiments made without departing from the spirit disclosed in the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A gearbox floating seal structure, comprising an output flange and an output shaft transversely mounted at the center of the output flange, characterized in that: The connection between the output flange and the output shaft is sealed by a sealing end cap assembly. The sealing end cap assembly includes an end cap that covers the output flange, is pressed against the front side of the output flange by a pressure cap, and is locked by a first fixing bolt. The output shaft passes through the center hole of the end cap laterally. A stationary felt is fixedly installed in the gap between the output shaft and the center hole of the end cap. A gasket is installed at the rear end of the assembly point between the output shaft and the end cap, and a retaining spring is installed on the rear side of the gasket. The end cap is integrally injection molded with polyurethane.

2. The gearbox floating seal structure as described in claim 1, characterized in that: The output flange is fixed to the front housing by the second fixing bolt, and the front housing and the rear housing are locked together by the third fixing bolt.

3. The gearbox floating seal structure as described in claim 2, characterized in that: The front housing has a front bearing mounting position, and the front bearing is installed in the front bearing mounting position. The rear housing has a rear bearing mounting position, and the rear bearing is installed in the rear bearing mounting position. The rear end of the output shaft is assembled in the front bearing and the rear bearing.

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