Air seal and oil seal integrated sealing structure of high-speed shaft

Abstract

The utility model provides an air seal and oil seal integrated sealing structure of a high-speed shaft, which belongs to the field of mechanical equipment and comprises a box body, a shaft, a radial bearing and a composite bearing are respectively arranged in the box body, the radial bearing is arranged at the right end of the shaft, the composite bearing is arranged in the middle of the shaft, the radial bearing and the composite bearing support the shaft, and an impeller is arranged at the left end of the shaft. An air sealing ring is arranged on the shaft close to one end of the impeller, and an integrated sealing section is arranged between the impeller and the composite bearing. The high-speed centrifugal fan is compact in structure, the air seal is of a stepped sealing structure, the sealing effect is greatly improved, and the efficiency of the high-speed centrifugal fan is improved; in the sealing structure assembling process, the impeller does not need to be disassembled, and the dynamic balance precision is not damaged.

Description

Technical Field

[0001] The utility model relates to the field of mechanical equipment, in particular to an integrated air seal and oil seal structure for a high-speed shaft. Background Art

[0002] The sealing performance of the gearbox of the current conventional single-stage high-speed centrifugal fan has always been a concern. Due to structural limitations, the center of gravity of the high-speed rotor of a high-speed centrifugal fan is usually located outside the two bearing fulcrums. The radial clearance between the commonly used sliding bearings and the shaft is generally around 0.1 to 0.15 mm. This causes the high-speed rotor of the fan to be affected by gravity when it is stationary, and the rotor may contact the sealing teeth. At the moment of starting and stopping, the high-speed shaft and the sealing teeth rub against each other. Since the sealing teeth are generally made of aluminum alloy, they are easily damaged, resulting in poor sealing effect, reduced fan efficiency, or oil leakage.

[0003] There are two types of high-speed shaft sealing structures for fans at present. One is a gearbox structure with upper and lower splits, such as the cantilever high-speed turbine vacuum pump and its vacuuming method disclosed in application number 200710071245.3. This sealing structure has the disadvantages of poor sealing effect and easy wear. At the same time, its sealing structure requires a longer axial dimension, which causes the rotor rigidity to weaken, further aggravating the wear of the sealing teeth. The other is a barrel-mounted gearbox structure, such as a high-speed shaft sealing structure disclosed in application number 201410332495.8. This sealing structure relies on a wave spring to compress the seal, and during the operation of the rotor, the air seal rotates with the shaft, resulting in greater wear. In addition, during the assembly process, the impeller needs to be removed before the air seal structure can be assembled. For high-speed rotors, it is generally required to be assembled after the overall dynamic balancing is completed. This disassembly will also cause the dynamic balancing accuracy to deteriorate, thereby affecting the operating stability. Therefore, a high-speed shaft air seal and oil seal integrated sealing structure is required. Utility Model Content

[0004] The utility model aims to provide an integrated air seal and oil seal structure for a high-speed shaft, so as to solve the technical problem that the existing high-speed shaft seal structure has poor sealing effect. The utility model has good sealing effect, compact structure, easy installation, and does not affect the dynamic balance accuracy.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0006] The invention discloses an integrated air seal and oil seal structure for a high-speed shaft, comprising a housing, wherein a shaft, a radial bearing and a composite bearing are arranged inside the housing, the radial bearing is arranged at the right end of the shaft, the composite bearing is arranged in the middle of the shaft, the radial bearing and the composite bearing support the shaft, an impeller is arranged at the left end of the shaft, an air seal ring is arranged on the shaft near one end of the impeller, and an integrated sealing section is arranged between the impeller and the composite bearing.

[0007] Further, the impeller is connected to the shaft, the left side of the impeller is fixed by a locking nut, and the locking nut is connected to the left end of the shaft.

[0008] Furthermore, the composite bearing is fixed to the housing by means of fixing screws, and the composite bearing is connected to one end of the integrated sealing section by means of connecting screws.

[0009] Furthermore, the left end of the integrated sealing section is arranged on the outside of the air sealing ring, and a gap is arranged between the integrated sealing section and the air sealing ring. The outside of the air sealing ring is provided with sealing teeth, which are stepped.

[0010] Furthermore, the integrated sealing section includes an air sealing section and an oil sealing section. The air sealing section is arranged on the outside of the air sealing ring. The air sealing section is connected to the oil sealing section. A sealing section hollow part is arranged between the air sealing section and the oil sealing section. A box body air vent is arranged on the box body above the sealing section hollow part. The interior of the air sealing section is stepped.

[0011] Furthermore, the oil seal section includes a sealing tooth and an oil baffle plate mounting groove. The sealing tooth is connected to the air seal section. The oil baffle plate mounting groove is arranged at the right end of the sealing tooth. An oil return hole is arranged on one side of the oil baffle plate mounting groove. The oil return hole is connected to the oil return hole of the box body. An oil baffle plate is arranged in the oil baffle plate mounting groove.

[0012] The utility model has the following beneficial effects due to the adoption of the above technical solution:

[0013] 1. The utility model has a compact structure, and the air seal adopts a stepped sealing structure, which greatly improves the sealing effect and the efficiency of the high-speed centrifugal fan; during the assembly of the sealing structure, there is no need to disassemble the impeller and the dynamic balance accuracy is not damaged.

[0014] 2. A hollow seal section is provided between the gas seal section and the oil seal section of the utility model, which ensures that high-pressure gas will not enter the gear box, causing the cavity pressure to increase and affecting the sealing performance; on the other hand, it ensures that the oil and gas on the gear box side will not enter the impeller area and pollute the transported gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the high-speed shaft sealing structure of the utility model;

[0016] Figure 2 It is a structural schematic diagram of the integrated sealing section of the utility model.

[0017] In the attached drawings, 1-locking nut, 2-shaft, 3-impeller, 4-air seal ring, 5-oil baffle plate, 6-housing, 6-1-housing oil return hole, 6-2-housing air vent hole, 7-connecting screw, 8-fixing screw, 9-radial bearing, 10-composite bearing, 11-integrated sealing section, 11-1-air seal section, 11-2-oil seal section, 11-3-oil baffle plate mounting groove, 11-4-oil return hole, 11-5-hollow part of the sealing section. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are only for the purpose of enabling readers to have a thorough understanding of one or more aspects of the utility model, and these aspects of the utility model can be realized even without these specific details.

[0019] like Figure 1 As shown, an integrated air seal and oil seal structure for a high-speed shaft includes a housing 6, wherein a shaft 2, a radial bearing 9 and a composite bearing 10 are arranged inside the housing 6, wherein the radial bearing 9 is arranged at the right end of the shaft 2, and the composite bearing 10 is arranged in the middle of the shaft 2, wherein the radial bearing 9 and the composite bearing 10 support the shaft 2, wherein an impeller 3 is arranged at the left end of the shaft 2, and an air seal ring 4 is arranged on the shaft 2 near one end of the impeller 3, and an integrated seal section 11 is arranged between the impeller 3 and the composite bearing 10. The utility model has a compact structure, and the air seal adopts a stepped seal structure, which greatly improves the sealing effect and the efficiency of the high-speed centrifugal fan; during the assembly of the seal structure, the impeller 3 does not need to be disassembled, and the dynamic balance accuracy is not damaged.

[0020] In the embodiment of the utility model, the impeller 3 is connected to the shaft 2, and the left side of the impeller 3 is fixed by the locking nut 1, and the locking nut 1 is connected to the left end of the shaft 2. The locking nut 1 is threadedly connected to the shaft 2 to ensure that the impeller 3 is fixed to the shaft 2.

[0021] In the embodiment of the utility model, the composite bearing 10 is fixed to the housing 6 by means of fixing screws 8, and the composite bearing 10 is connected to one end of the integrated sealing section 11 by means of connecting screws 7. The left end of the integrated sealing section 11 is arranged on the outside of the gas sealing ring 4, and a gap is arranged between the integrated sealing section 11 and the gas sealing ring 4, and sealing teeth are arranged on the outside of the gas sealing ring 4, and the height of the sealing teeth gradually decreases from the left end to the right end, and the sealing teeth are in a stepped shape.

[0022] like Figure 2As shown, the integrated sealing section 11 includes an air sealing section 11-1 and an oil sealing section 11-2. The air sealing section 11-1 is arranged outside the air sealing ring 4. The interior of the air sealing section 11-1 is stepped. The air sealing section 11-1 cooperates with the air sealing ring 4 to form a stepped sealing structure. The sealing structure is made of aluminum material, which greatly improves the air sealing effect and the efficiency of the high-speed centrifugal fan. The air sealing section 11-1 is connected to the oil sealing section 11-2. A sealing section hollow 11-5 is arranged between the air sealing section 11-1 and the oil sealing section 11-2. A box body venting hole 6-2 is arranged on the box body 6 above the sealing section hollow 11-5. The sealing section hollow 11-5 is used to release a small amount of gas leaked from the air sealing section 11-1 into the atmosphere. When the high-speed centrifugal fan is running, the high-pressure gas in the volute will leak out from the gap between the impeller 3 and the box 6. The stepped sealing structure formed by the gas seal section 11-1 and the gas seal ring 4 greatly reduces the pressure of the gas flowing through, thereby controlling the leakage of the gas through this gap. The sealing effect is 5-15% higher than that of ordinary straight seals. The small amount of leaked gas is discharged to the outside atmosphere through the hollow part 11-5 of the sealing section and the air vent 6-2 of the box.

[0023] In the embodiment of the utility model, the oil seal section 11-2 includes a sealing tooth and an oil baffle plate installation groove 11-3, the sealing tooth is connected to the gas seal section 11-1, the oil baffle plate installation groove 11-3 is arranged at the right end of the sealing tooth, an oil return hole 11-4 is arranged on one side of the oil baffle plate installation groove 11-3, the oil return hole 11-4 is connected to the oil return hole 6-1 of the housing, and an oil baffle plate 5 is arranged in the oil baffle plate installation groove 11-3. The oil baffle plate installation groove 11-3 is used to fix the oil baffle plate 5. After the lubricating oil flows out from the gap of the composite bearing 10, it first passes through the oil baffle plate 5, and most of the lubricating oil flows into the oil tank from the oil return hole 11-4 of the sealing section and the oil return hole 6-1 of the housing; the remaining small amount of lubricating oil passes through the sealing tooth of the oil seal section 11-2, so that the lubricating oil flowing through is greatly reduced in pressure, thereby controlling the leakage of the lubricating oil.

[0024] In order to facilitate installation, the integrated sealing section 11 is designed as an upper and lower split structure. After the rotor (including the shaft 2, the gas seal ring 4, the impeller 3, and the locking nut 1) is dynamically balanced, it can be easily installed without disassembling the impeller 3, ensuring that the dynamic balance accuracy of the rotor is not damaged.

[0025] The utility model has a compact structure, and can realize the overall assembly and disassembly of the high-speed rotor of the fan in the cylinder-mounted box, which is convenient for ensuring the rotation accuracy of the rotor at high speed; during the assembly of the sealing structure, there is no need to disassemble the impeller, and the dynamic balancing accuracy of the rotor is not damaged; the integrated structural design has a compact axial dimension, which improves the rigidity of the rotor and runs more smoothly; the gas seal adopts a stepped sealing structure, which greatly improves the gas sealing effect and improves the efficiency of the high-speed centrifugal fan; a sealing section hollow part is provided between the gas seal section and the oil seal section, which on the one hand ensures that high-pressure gas will not enter the gear box, causing the cavity pressure to increase and affecting the sealing performance; on the other hand ensures that the oil and gas on the gear box side will not enter the impeller area and pollute the transported gas.

[0026] How it works

[0027] When the high-speed centrifugal fan is running, the high-pressure gas in the volute will leak out from the gap between the impeller 3 and the box body 6. The stepped sealing structure formed by the gas seal section 11-1 and the gas seal ring 4 greatly reduces the pressure of the gas flowing through, thereby controlling the leakage of the gas through this gap; the small amount of gas leaked out is discharged to the outside atmosphere through the hollow part 11-5 of the sealing section and the air release hole 6-2 of the box body;

[0028] After the lubricating oil flows out from the gap of the composite bearing 10, it first passes through the oil baffle 5, and most of the lubricating oil flows into the oil tank from the oil return hole 11-4 of the sealing section and the oil return hole 6-1 of the box body; the remaining small amount of lubricating oil passes through the sealing teeth of the oil seal section 11-2, which greatly reduces the pressure of the lubricating oil flowing through, thereby controlling the leakage of the lubricating oil.

[0029] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An integrated air seal and oil seal structure for a high-speed shaft, characterized in that: The invention comprises a housing (6), wherein a shaft (2), a radial bearing (9) and a composite bearing (10) are respectively arranged inside the housing (6), the radial bearing (9) is arranged at the right end of the shaft (2), the composite bearing (10) is arranged at the middle of the shaft (2), the radial bearing (9) and the composite bearing (10) support the shaft (2), an impeller (3) is arranged at the left end of the shaft (2), an air seal ring (4) is arranged on the shaft (2) near one end of the impeller (3), and an integrated seal section (11) is arranged between the impeller (3) and the composite bearing (10); The left end of the integrated sealing section (11) is arranged on the outside of the air sealing ring (4), and a gap is arranged between the integrated sealing section (11) and the air sealing ring (4). The outside of the air sealing ring (4) is provided with sealing teeth, which are in a stepped shape.

2. The integrated air seal and oil seal structure for a high-speed shaft according to claim 1, characterized in that: The impeller (3) is connected to the shaft (2), the left side of the impeller (3) is fixed by a locking nut (1), and the locking nut (1) is connected to the left end of the shaft (2).

3. The integrated air seal and oil seal structure for a high-speed shaft according to claim 1, characterized in that: The composite bearing (10) is fixed to the housing (6) via a fixing screw (8), and the composite bearing (10) is connected to one end of the integrated sealing section (11) via a connecting screw (7).

4. The integrated air seal and oil seal structure for a high-speed shaft according to claim 1, characterized in that: The integrated sealing section (11) comprises an air sealing section (11-1) and an oil sealing section (11-2); the air sealing section (11-1) is arranged outside an air sealing ring (4); the air sealing section (11-1) is connected to the oil sealing section (11-2); a sealing section hollow portion (11-5) is arranged between the air sealing section (11-1) and the oil sealing section (11-2); a box body air release hole (6-2) is arranged on the box body (6) above the sealing section hollow portion (11-5); and the interior of the air sealing section (11-1) is stepped.

5. The integrated air seal and oil seal structure for a high-speed shaft according to claim 4, characterized in that: The oil seal section (11-2) comprises a sealing tooth and an oil baffle plate mounting groove (11-3); the sealing tooth is connected to the gas seal section (11-1); the oil baffle plate mounting groove (11-3) is arranged at the right end of the sealing tooth; an oil return hole (11-4) is arranged on one side of the oil baffle plate mounting groove (11-3); the oil return hole (11-4) is connected to the box body oil return hole (6-1); and an oil baffle plate (5) is arranged in the oil baffle plate mounting groove (11-3).

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