Shaft seal mechanism

Abstract

The present invention relates to a shaft seal mechanism, which is located on the equipment body and includes a valve plate, a shaft, a shaft sleeve with a flange at one end, and a sealing packing; the sealing packing is filled in the annular gap between the shaft and the shaft sleeve and is pressed at both ends; a through hole is provided on the equipment body corresponding to the position of the shaft sleeve, and the end of the shaft sleeve without the flange passes through the through hole and protrudes out of the inner wall of the equipment body; a notch corresponding to the outer dimension of the part of the shaft sleeve protruding out of the inner wall of the equipment body is provided at the corresponding position on the valve plate. The present invention can be widely applied to the shaft seal parts in many occasions such as mechanical equipment or valves, effectively preventing problems such as water ingress at the shaft seal part, resulting in scaling, caking, and jamming of the shaft, thereby ensuring safe production, saving maintenance costs, and reducing production costs.

Description

Technical Field

[0001] The present invention relates to a shaft seal, and more particularly to a shaft seal mechanism that can prevent water from entering the shaft seal portion. Background Art

[0002] The shaft seal portion of a pipeline or flue for a gaseous medium is often located at or near the junction of hot and cold walls. Due to the presence of hot and cold walls, condensation often occurs at the shaft seal portion, and the water formed by condensation will flow into the shaft seal portion; sometimes, external substances including rainwater, etc. will also enter through the poorly sealed parts on the pipeline or flue and then flow into the shaft seal portion. When the medium is a sulfur-containing gas, its penetration power is extremely strong and often penetrates into the shaft seal, and then reacts chemically with the water entering the shaft seal to form extremely hard lumps. For example, after water reacts with sulfur-containing flue gas, it scales and cakes, locking the shaft and making it very difficult to rotate the shaft. Such examples are common, and the most typical one is the multi-blade baffle at the inlet and outlet of a blower. If the temperature of the medium is very high, the shaft seal portion is extremely prone to condensation, and the same problems will occur after condensation. In addition, the medium produced after the dew reacts with the sulfur content in the flue gas is highly corrosive and harmful to the equipment. These situations will undoubtedly pose potential safety hazards. Therefore, this has become an urgent problem to be solved in this field.

[0003] Taking the multi-blade baffle as an example, its commonly used shaft seal mechanism is as Figure 1 shown. This shaft seal mechanism is located on the equipment body 1 of the multi-blade baffle, and includes a valve plate 2, a shaft 4 connected to the valve plate 1, and a shaft sleeve 3 connected to the equipment body 1. As can be seen from the figure, the inner wall of the shaft sleeve 3 is flush with the inner wall of the equipment body 1. When condensation occurs inside or water enters the pipeline, the water will flow into the inside of the shaft sleeve 3. The dust in the medium in the pipeline or flue will also penetrate into the shaft seal, and the two react chemically to form extremely hard lumps, causing the shaft to be locked. Especially for the several shaft seals below the multi-blade baffle, it is extremely easy to let water in. Obviously, this technical problem and the series of problems caused by it have become a worldwide problem in the industry. Summary of the Invention

[0004] In view of the above problems existing in the prior art, the present invention aims to disclose a shaft seal mechanism to solve the problem of water entering the shaft seal portion and a series of problems and hazards brought about by the water entering the shaft seal portion.

[0005] The technical solution of the present invention is realized as follows:

[0006] A shaft seal mechanism is located on the equipment body and includes a valve plate, a shaft, a shaft sleeve with a flange at one end, and a sealing packing; the sealing packing is filled in the annular gap between the shaft and the shaft sleeve and is pressed at both ends; specifically, a flange gland and a limiting structure can be used to press at both ends respectively. The limiting structure, such as a limiting ring, is fixed inside the non-flanged end of the shaft sleeve to press the sealing packing from this end. The outer ring of the limiting ring fits against the inner wall of the shaft sleeve, and its inner ring has a clearance fit with the shaft.

[0007] A through hole is provided on the equipment body corresponding to the position of the shaft sleeve, and the non-flanged end of the shaft sleeve passes through the through hole and protrudes out of the inner wall of the equipment body; a notch corresponding to the outer dimension of the part of the shaft sleeve protruding out of the inner wall of the equipment body is correspondingly opened on the valve plate. The outer peripheral surface of the shaft sleeve is a cylindrical surface, and the inner peripheral surface is adapted to the outer peripheral surface of the shaft.

[0008] Furthermore, the shaft seal mechanism further includes a waterproof cover, which is coaxial with the shaft sleeve and is fixed to the valve plate in the equipment body near the shaft sleeve.

[0009] Specifically, the waterproof cover is in the shape of an umbrella, and the radius of the cover surface or a dimension equivalent to the radius of the cover surface is larger than the radius of the non-flanged end of the shaft sleeve.

[0010] Furthermore, the shaft seal mechanism further includes a positive pressure ventilation structure, which is arranged in the annular gap between the shaft and the shaft sleeve between the sealing packing and the non-flanged end of the shaft sleeve and includes a ventilation cavity and an air inlet hole. The ventilation cavity is formed by separating two limiting structures sleeved in the annular gap by a certain distance along the axial direction. The air inlet hole is located on the shaft sleeve wall corresponding to the ventilation cavity and is externally connected to an air inlet pipe. The limiting structure can be a limiting ring; the outer rings of the limiting rings respectively fit against the inner wall of the shaft sleeve, and their inner rings respectively have a clearance fit with the shaft.

[0011] Preferably, the positive pressure ventilation structure further includes a floating ring. The floating ring and the sealing packing are respectively located on both sides of the ventilation cavity and are respectively limited and fixed by the limiting structure; the floating ring is limited and fixed by another limiting ring on the side close to the non-flanged end of the shaft sleeve; the outer diameter of the floating ring is smaller than the inner diameter of the shaft sleeve, and its inner diameter is larger than the outer diameter of the shaft.

[0012] The setting of the positive pressure ventilation structure aims to use the positive pressure ventilation effect to prevent dust from entering the shaft seal part, thereby preventing water formed due to condensation from entering the shaft seal and caking with dust to lock the shaft. Specifically, reference can be made to Chinese Patent Application for Invention CN110762215A.

[0013] Specifically, the equipment body is a multi-blade baffle or a single-shaft baffle, a double-shaft baffle, or a multi-shaft baffle, and the shaft seal mechanism is arranged at the shaft seal part of the lower half of the equipment body.

[0014] The shaft seal mechanism can be applied to various shaft seals with non-horizontal shafts and shaft sleeves. For example, the equipment body can be a single-shaft baffle, a double-shaft baffle, or a multi-vane baffle. For a multi-vane baffle, the shaft seal mechanism is particularly applicable to the shaft seal part at the lower half of the multi-vane baffle.

[0015] Compared with the prior art, the technical solution of the present invention has significant progress:

[0016] The shaft seal mechanism of the present invention has a simple structure. One end of the shaft sleeve without a flange passes through the through hole on the equipment body and extends out of the inner wall of the equipment body, which avoids water flowing into the shaft seal and further avoids problems such as scaling, caking, and shaft jamming at the shaft seal part.

[0017] Considering the problems that condensation may occur on the valve plate and the shaft or external water may enter the interior, an umbrella-shaped waterproof cover is provided to prevent water from flowing into the shaft seal and avoid the above-mentioned problems.

[0018] The present invention also utilizes the function of positive pressure ventilation to effectively prevent problems such as dust impurities in flue gas from entering the shaft seal and condensation.

[0019] The present invention can be widely applied to the shaft seal parts of many occasions such as mechanical equipment or valves to prevent problems such as scaling, caking, and shaft jamming caused by water entering the shaft seal part, thus ensuring safe production, saving maintenance costs, and reducing production costs. Brief Description of the Drawings

[0020] Figure 1 is a schematic diagram of the shaft seal structure of the prior art;

[0021] Figure 2 is a schematic diagram of the structure of the multi-vane baffle in Embodiment 1 of the present invention;

[0022] Figure 3 is a schematic diagram of the structure of the single-shaft baffle in Embodiment 2 of the present invention;

[0023] Figure 4 is a schematic diagram of the positive pressure ventilation structure that can be adopted in the embodiment of the present invention;

[0024] Figure 5 is Figure 4 the sectional view taken along the line A-A of

[0025] In the figures, 1. equipment body; 2. valve plate; 3. shaft sleeve; 4. shaft; 5. flange gland; 6. umbrella-shaped waterproof cover; 7. packing; 8, 11, 13. limit ring; 9. ventilation cavity; 10. intake pipe; 12. floating ring. Detailed Description of the Embodiments

[0026] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described herein are only some of the embodiments of the present invention, rather than all embodiments. All other implementation manners obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope protected by the present invention.

[0027] The following embodiments do not limit the content of the invention recorded in the claims in any way; and all the contents of the structures shown in the following embodiments are not limited to those necessary for the solution of the invention recorded in the claims.

[0028] Hereinafter, the present invention will be further described in detail in conjunction with the accompanying drawings and embodiments.

[0029] Embodiment 1

[0030] A shaft seal mechanism for a multi-blade baffle is located in the lower half of the multi-blade baffle equipment body 1, as Figure 2 shown, and includes a valve plate 2, a shaft 4, a shaft sleeve 3 with a flange at one end, and a sealing packing 7; the sealing packing 7 is filled in the annular gap between the shaft 4 and the shaft sleeve 3, and both ends are respectively pressed by a flange gland 5 and a limit ring 8, and the limit ring 8 is fixed inside the non-flanged end of the shaft sleeve 3; its outer ring fits against the inner wall of the shaft sleeve, and its inner ring has a clearance fit with the shaft.

[0031] A through hole is provided on the equipment body 1 corresponding to the position of the shaft sleeve 3, and the non-flanged end of the shaft sleeve 3 passes through the through hole and protrudes from the inner wall of the equipment body 1; a notch corresponding to the outer dimension of the part of the shaft sleeve 3 protruding from the inner wall of the equipment body 1 is correspondingly provided on the valve plate 2: the outer peripheral surface of the shaft sleeve is a cylindrical surface, and the inner peripheral surface is adapted to the outer peripheral surface of the shaft.

[0032] Since the shaft sleeve 3 protrudes from the inner wall of the equipment body 1, it effectively prevents water formed by condensation due to the existence of cold and hot walls or water that may enter from the outside from flowing into the inside of the shaft seal, thereby avoiding the problem that the water flowing into the shaft seal reacts chemically with the sulfur-containing dust in the shaft seal and caking occurs, resulting in the shaft being locked.

[0033] At the same time, the shaft seal mechanism further includes an umbrella-shaped waterproof cover 6, which is coaxial with the shaft sleeve 3, and the radius of the cover surface or the effective cover surface size equivalent to the radius of the cover surface (such as when the cover surface is a non-standard circle) is greater than the radius of the non-flanged end of the shaft sleeve 3, and is fixed at a position on the valve plate 2 in the multi-blade baffle 1 close to the shaft sleeve 3.

[0034] The waterproof cover 6 is provided to shield the shaft cover to prevent water formed by condensation of the valve plate 2 and the shaft 4 from flowing into the shaft seal.

[0035] Example 2

[0036] A shaft seal mechanism for a single-axis baffle is located in the lower half of the single-axis baffle equipment body 1, as Figure 3 shown, and includes a valve plate 2, a shaft 4, a shaft sleeve 3 with a flange at one end, and a sealing packing 7; the sealing packing 7 is filled in the annular gap between the shaft 4 and the shaft sleeve 3, and both ends are respectively pressed by a flange gland 5 and a limit ring 8, and the limit ring 8 is fixed inside the end of the shaft sleeve 3 without a flange; the dimensions and fits of the limit ring 8 with the shaft 4 and the shaft sleeve 3 are the same as those in Embodiment 1.

[0037] A through hole is provided on the equipment body 1 corresponding to the position of the shaft sleeve 3, and the end of the shaft sleeve 3 without a flange passes through the through hole and protrudes out of the inner wall of the single-axis baffle 1; a notch corresponding to the outer dimension of the part of the shaft sleeve 3 protruding out of the inner wall of the equipment body 1 is correspondingly opened on the valve plate 2.

[0038] Similar to Embodiment 1, the shaft seal mechanism may also include an umbrella-shaped waterproof cover 6, etc., to better prevent water, impurities, etc. from entering the shaft seal and causing problems such as scaling, caking, and even the phenomenon of shaft seizure.

[0039] For the above embodiments of the shaft seal mechanism, a positive pressure ventilation structure may further be included, such as Figure 4 and Figure 5 shown, which may be arranged in the annular gap between the shaft 4 and the shaft sleeve 3 between the sealing packing 7 and the end of the shaft sleeve 3 without a flange, and includes a ventilation cavity 9 and an air inlet hole. The ventilation cavity 9 is formed by two limit rings 8, 11 sleeved in the annular gap and separated by a certain distance along the axial direction. The other side of the limit ring 8 is the sealing packing, and the other end of the limit ring 11 may be located at the end of the shaft sleeve 3 without a flange; the air inlet hole is located on the wall of the shaft sleeve 3 corresponding to the ventilation cavity 9 and is externally connected to an air inlet pipe 10.

[0040] Using the positive pressure ventilation structure, the shaft seal mechanism passes a dry gas medium, such as air, nitrogen, etc., into the ventilation cavity 9 through the air inlet pipe 10 connected to the air inlet hole. The pressure of the gas medium passed into the ventilation cavity 9 is greater than the pressure inside the equipment body 1, avoiding the possible formation of scaling, caking of impurities such as dust and sulfur content after entering the shaft seal, and avoiding the condensation of the shaft seal part, and further avoiding the phenomenon of shaft seizure, ensuring safe production.

[0041] Preferably, the positive pressure ventilation structure may further include a floating ring 12. The floating ring 12 and the sealing packing 7 are respectively located on both sides of the ventilation cavity 9, and are respectively limited and fixed by limit rings 8 and 11. The floating ring 12 is limited and fixed on the side close to the flange-free end of the sleeve 3 by a limit ring 13. Similar to the limit ring 8, the outer rings of the limit rings 11 and 13 also respectively fit against the inner wall of the sleeve, and their inner rings are also respectively in clearance fit with the shaft. The outer diameter of the floating ring 12 is smaller than the inner diameter of the sleeve 3, and the inner diameter is larger than the outer diameter of the shaft 4. On the inner ring wall of the floating ring 12, there are three conical bosses 121 facing the center of the ring. Looking from the axial direction of the floating ring 12, all the bosses 121 are of the same height and are evenly distributed along the inner wall of the floating ring. The diameter of the circle where the most prominent points of all the bosses 121 facing the center of the floating ring 12, that is, the cone tips, are located is close to the outer diameter of the shaft 4, and a sliding fit is formed between the two. In this way, the floating ring 12 can float radially to keep the ventilation gaps unchanged under the action of positive pressure ventilation, ensure the uniformity of positive pressure ventilation, and further ensure the purging effect of the ventilation process on the shaft seal part. At the same time, the requirement for the machining accuracy of the shaft can be reduced, especially the requirement for the coaxiality of the shaft, thereby reducing the production cost and improving the market competitiveness of the product. Thus, the problem of jamming of the limit rings and the like often occurring between the shaft and the sleeve is solved.

[0042] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A shaft seal mechanism is located on the equipment body and includes a valve plate, a shaft, a shaft sleeve with a flange at one end, and a sealing packing; the sealing packing is filled in the annular gap between the shaft and the shaft sleeve and is pressed at both ends; the characteristic is that: Corresponding to the lower part of the equipment body Half A through hole is provided at the position of the shaft sleeve corresponding to the shaft seal part of the lower part of the equipment body, and the end of the shaft sleeve without a flange passes through the through hole and protrudes out of the inner wall of the equipment body; a notch corresponding to the outer dimension of the part of the shaft sleeve protruding out of the inner wall of the equipment body is correspondingly formed on the valve plate; The shaft seal mechanism further includes a waterproof cover; The waterproof cover is coaxial with the shaft sleeve and is fixed on the valve plate in the equipment body near the shaft sleeve, and the radius of its cover surface is greater than the radius of the non-flange end of the shaft sleeve.

2. The shaft seal mechanism according to claim 1, wherein: The waterproof cover is in an umbrella shape.

3. The shaft seal mechanism according to claim 1 or 2, wherein: It further includes a positive pressure ventilation structure, which is arranged in the annular gap between the shaft and the shaft sleeve between the sealing packing and the non-flange end of the shaft sleeve, and includes a ventilation cavity and an air inlet hole. The ventilation cavity is formed by two limiting structures sleeved in the annular gap being separated by a certain distance along the axial direction, and the air inlet hole is located on the shaft sleeve wall corresponding to the ventilation cavity and is externally connected to an air inlet pipe.

4. The shaft seal mechanism according to claim 3, wherein: The positive pressure ventilation structure further includes a floating ring. The floating ring and the sealing packing are respectively located on both sides of the ventilation cavity and are respectively limited and fixed by the limiting structures; the floating ring is limited and fixed by another limiting ring on the side close to the non-flange end of the shaft sleeve; the outer diameter of the floating ring is smaller than the inner diameter of the shaft sleeve, and its inner diameter is larger than the outer diameter of the shaft.

5. The shaft seal mechanism according to any one of claims 1, 2, and 4, wherein: The equipment body is a multi-blade baffle, a single-shaft baffle, a double-shaft baffle, or a multi-shaft baffle.

6. The shaft seal mechanism according to claim 3, wherein: The equipment body is a multi-blade baffle, a single-shaft baffle, a double-shaft baffle, or a multi-shaft baffle.

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