A main shaft sealing structure for an axial mixer

Abstract

A main shaft sealing structure for a shaft-type mixer, comprising a main shaft, a sealing ring, a flange, and a side plate of the feed box; an annular flange is provided on the main shaft, and reverse arc corners are used for transition between the two end faces of the annular flange and the side wall of the main shaft, and one end face of the annular flange is flush with the inner wall of the side plate of the feed box; the sealing ring is sleeved on the annular flange of the main shaft, one end face thereof is flush with the inner wall of the side plate of the feed box, and a circular ring sleeve edge is provided on the outer wall of the other end; the flange is sleeved on the sealing ring and is installed on the outer wall of the side plate of the feed box, and is provided with a plurality of connection through holes, a first flange boss, a second flange boss, a sealing ring installation groove, and a plurality of first threaded blind holes; through holes are opened on the side plate of the feed box, and a flange installation groove and a plurality of second threaded blind holes are opened on its outer wall. The present invention changes the connection structure between the side wall of the main shaft and the side plate of the feed box from a traditional 90° angle to an arc transition, transfers the position of the rotation gap of the main shaft, is convenient for cleaning and sanitation, and improves the flatness of the inner wall of the side plate of the feed box.

Description

Technical Field

[0001] The present invention belongs to the technical field of shaft mixers, and particularly relates to a main shaft sealing structure for a shaft mixer. Background Art

[0002] Shaft mixers include spiral ribbon mixers, paddle mixers, etc. Their most obvious structure is to have at least one main shaft passing horizontally through the mixing tank of the mixer, and several stirring spiral ribbons or paddles are welded on the main shaft. When the equipment is running, the main shaft drives the spiral ribbons or paddles to rotate, and stirs and mixes various materials in the mixing tank.

[0003] Since the main shaft needs to rotate, there must be a certain gap between it and the side plate of the tank. If the gap is too large, it will inevitably cause the materials to flow into the gap during mixing, which will, in the lightest case, block the gap and increase the stirring resistance, and in the worst case, directly lock the stirring shaft and damage the motor. Therefore, manufacturers of shaft mixers will focus on making a sealing structure for this rotating gap between the main shaft and the tank.

[0004] Generally speaking, the main shaft sealing structures of each manufacturer at present are mainly the following several types:

[0005] (1) Sealing block type: Refer to Figure 1 , a large hole is opened on the side plate 1 of the tank, and an annular sealing block 2 with an outer circle in transitional fit with the large hole and an inner circle in clearance fit with the main shaft is embedded. The sealing block 2 is generally made of polytetrafluoroethylene, and its installation plane is flush with the inner wall of the side plate 1 of the tank (some manufacturers slightly arch inward), and a pressing plate 3 is installed from the outside of the tank to press the sealing block 2 on the side plate 1 of the tank, and finally the main shaft 4 is sleeved. The main shaft sealing structures of different manufacturers' sealing block types will be different, but the principle is basically the same.

[0006] (2) Air sealing type: Refer to Figure 2 , a large hole is opened on the side plate 1 of the tank, and a hollow sealing seat cylinder 2 is installed from the outside of the tank, with its outer circle in transitional fit with the large hole and its inner circle in clearance fit with the main shaft, and its installation plane is flush with the inner wall of the side plate 1 of the tank; the main shaft 3 is inserted, and a soft sealing strip such as a sealing packing 4 is filled in the sealing seat cylinder 2, and the sealing packing 4 is pressed by a pressing plate 5. When the main shaft 3 is working, compressed air is introduced into the sealing cavity 7 through the compressed air inlet 6. Since there is a relatively large gap between the sealing seat cylinder 2 and the main shaft 3, the compressed air will decompress and spray out here, thereby preventing the materials from blocking here. The main shaft sealing structures of different manufacturers' air sealing types will be different, but the principle is basically the same.

[0007] Whether using the main shaft sealing structure of the sealing block type or the air sealing type can effectively prevent the materials from locking the main shaft, but these main shaft sealing structures all have two problems:

[0008] (1)The junction between the inner wall of the bin side plate and the side wall of the main shaft is at 90°. This annular area cannot be cleaned thoroughly during sanitation, which is a sanitation dead corner.

[0009] (2)Since a large hole is opened on the bin side plate, no matter how it is processed later, when looking from the inside of the bin, this place will still look like a patched scar, with obvious appearance differences, affecting the overall aesthetics of the bin. Summary of the Invention

[0010] The present invention aims at the above problems and provides a main shaft sealing structure for an axial mixer.

[0011] The object of the present invention can be achieved by the following technical solutions: A main shaft sealing structure for an axial mixer, comprising a main shaft, a sealing ring, a flange, and a bin side plate;

[0012] The main shaft passes through the bin side plate, and a circumferentially outwardly convex annular flange is provided at the corresponding position of the main shaft on the bin side plate. Reverse arc angles are used for transition between the two end faces of the annular flange and the side wall of the main shaft. The end face of the annular flange facing the inside of the bin is flush with the inner wall of the bin side plate;

[0013] The sealing ring is sleeved on the annular flange of the main shaft. The end face of the sealing ring facing the inside of the bin is flush with the inner wall of the bin side plate. The outer wall of the other end of the sealing ring facing the outside of the bin is provided with a circumferentially outwardly convex circular ring edge;

[0014] The flange is sleeved on the sealing ring and installed on the outer wall of the bin side plate. A plurality of connection through holes are evenly distributed along the circumference on the flange. A first flange boss is concentrically provided on the end face of the flange facing the inside of the bin, and a second flange boss is concentrically provided on the end face of the flange facing the outside of the bin. The inner hole of the flange penetrates through the first flange boss and the second flange boss. A sealing ring installation groove matching with the circular ring edge of the sealing ring is concentrically opened on the end face of the second flange boss, and a plurality of first threaded blind holes are evenly distributed along the circumference on the end face of the second flange boss;

[0015] A through hole for the main shaft to pass through and matching with the outer wall of the sealing ring is opened on the bin side plate. A flange installation groove concentric with the through hole and matching with the first flange boss of the flange is opened on the outer wall of the bin side plate. A plurality of second threaded blind holes are evenly distributed along the circumference on the periphery of the flange installation groove on the outer wall of the bin side plate, and the plurality of second threaded blind holes correspond to the plurality of connection through holes of the flange.

[0016] Further, the length of the annular flange of the main shaft is greater than the thickness of the bin side plate.

[0017] Further, the inner wall of the sealing ring is in clearance fit with the side wall of the annular flange of the main shaft.

[0018] Furthermore, the outer wall of the sealing ring is in transitional fit with the through hole of the side plate of the material box.

[0019] Furthermore, the length of the sealing ring is greater than the length of the annular flange of the main shaft.

[0020] Furthermore, the first flange boss of the flange is in clearance fit with the flange mounting groove of the side plate of the material box, and the height of the first flange boss is slightly less than the depth of the flange mounting groove.

[0021] Furthermore, the diameter of the first flange boss of the flange is greater than the diameter of the second flange boss.

[0022] Furthermore, the diameter of the sealing ring mounting groove of the flange is greater than the diameter of the inner hole.

[0023] Furthermore, a gas sealing assembly is further included. The gas sealing assembly is sleeved on the main shaft and installed on the second flange boss of the flange; or, a cover plate is further included. The cover plate presses the sealing ring and is installed on the second flange boss of the flange.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) By designing an annular flange with a locally increased diameter on the main shaft and chamfering the two end faces of the annular flange and the side wall of the main shaft in a reverse arc shape, the connection structure between the side wall of the main shaft and the side plate of the material box is changed from the traditional 90° angle to an arc transition, thereby shifting the position of the rotation gap of the main shaft, which is convenient for cleaning and sanitation;

[0026] (2) By machining a flange mounting groove on the outer wall of the side plate of the material box, the through-hole area of the side plate of the material box is minimized to the greatest extent, so that the flatness of the inner wall plane of the side plate of the material box is retained to the greatest extent. With the main shaft with an arc transition, the transition of the entire main shaft sealing structure at the inner wall of the side plate of the material box appears very smooth, improving the flatness of the inner wall of the side plate of the material box;

[0027] (3) A gas sealing assembly can be installed at the outer docking joint of the flange to assist the sealing ring in sealing, or a cover plate can be directly installed to directly press the sealing ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of a sealing block type main shaft sealing structure in the prior art.

[0029] Figure 1 The component numbers in the figure are as follows:

[0030] 1 Side plate of the material box

[0031] 2 Sealing block

[0032] 3 Pressure plate

[0033] 4 main shafts.

[0034] Figure 2 It is a schematic diagram of the airtight main shaft seal structure in the prior art.

[0035] Figure 2 The component numbers in it are as follows:

[0036] 1 side plate of the material box

[0037] 2 seal seat cylinder

[0038] 3 main shaft

[0039] 4 packing

[0040] 5 pressure plate

[0041] 6 compressed air inlet

[0042] 7 sealing cavity.

[0043] Figure 3 It is a schematic diagram of the structure of the present invention.

[0044] Figure 4 It is a schematic diagram of the structure of the main shaft in the present invention.

[0045] Figure 5 It is a schematic diagram of the structure of the sealing ring in the present invention.

[0046] Figure 6 It is a schematic diagram of the structure of the flange in the present invention.

[0047] Figure 7 is Figure 6 the right view of.

[0048] Figure 8 It is a schematic diagram of the structure of the side plate of the material box in the present invention.

[0049] Figure 9 It is a schematic diagram of the outer wall of the side plate of the material box in the present invention.

[0050] Figure 10 It is a schematic diagram of the structure of the shaft mixer applying the present invention.

[0051] Figures 3 - 10 The component numbers in it are as follows:

[0052] 1 main shaft

[0053] 101 annular flange

[0054] 102 reverse arc angle

[0055] 2 sealing ring

[0056] 201 Ring Sleeve Edge

[0057] 3 Flange

[0058] 301 Connecting Through Hole

[0059] 302 First Flange Boss

[0060] 303 Second Flange Boss

[0061] 304 Inner Hole

[0062] 305 Sealing Ring Installation Groove

[0063] 306 First Threaded Blind Hole

[0064] 4 Hopper Side Plate

[0065] 401 Through Hole

[0066] 402 Flange Installation Groove

[0067] 403 Second Threaded Blind Hole

[0068] 5 Gas Sealing Assembly. Detailed Implementation Manner

[0069] The following will describe in detail the specific implementation manner of the present invention with reference to the accompanying drawings, so that those skilled in the art can more clearly understand how to practice the present invention. Although the present invention is described in conjunction with its preferred specific embodiments, these embodiments are only illustrative and do not limit the scope of the present invention.

[0070] See Figure 3 , a main shaft sealing structure for a shaft-type mixer, including a main shaft 1, a sealing ring 2, a flange 3, and a hopper side plate 4.

[0071] See Figure 3 and Figure 4 , the main shaft 1 passes through the hopper side plate 4, and a circumferentially outwardly convex annular flange 101 is provided at the corresponding position of the main shaft 1 on the hopper side plate 4. Reverse arc corners 102 are used for transition between both end faces of the annular flange 101 and the side wall of the main shaft 1. One end face of the annular flange 101 facing the inside of the hopper is flush with the inner wall of the hopper side plate 4, and the length of the annular flange 101 is greater than the thickness of the hopper side plate 4. By increasing the local diameter of the main shaft 1 (referring to the annular flange 101) and then chamfering the reverse arc corners 102 between both end faces of the annular flange 101 and the side wall of the main shaft 1, the connection structure between the side wall of the main shaft 1 and the hopper side plate 4 is changed from the traditional 90° angle to an arc transition, thereby shifting the rotation gap position of the main shaft 1 and facilitating cleaning and sanitation.

[0072] See Figure 3 and Figure 5, the sealing ring 2 is sleeved on the annular flange 101 of the main shaft 1. The inner wall of the sealing ring 2 is in clearance fit with the side wall of the annular flange 101. One end face of the sealing ring 2 facing the inside of the material box is flush with one end face of the annular flange 101 and the inner wall of the side plate 4 of the material box. The outer wall of the other end of the sealing ring 2 facing the outside of the material box is provided with a circumferentially outwardly protruding circular ring edge 201. The length of the sealing ring 2 is greater than the length of the annular flange 101. The sealing ring 2 can be made of a food-grade plastic material with good lubricity such as polytetrafluoroethylene.

[0073] See Figure 3 , Figure 6 and Figure 7 , the flange 3 is sleeved on the sealing ring 2 and installed on the outer wall of the side plate 4 of the material box. A plurality of connecting through holes 301 are circumferentially and evenly arranged on the flange 3. The connecting through holes 301 are used to connect with the side plate 4 of the material box. A circular first flange boss 302 is concentrically provided on one end face of the flange 3 facing the inside of the material box. A circular second flange boss 303 is concentrically provided on the other end face of the flange 3 facing the outside of the material box. The inner hole 304 of the flange 3 penetrates through the first flange boss 302 and the second flange boss 303. Among them, the diameter of the first flange boss 302 is greater than the diameter of the second flange boss 303, and the height of the first flange boss 302 is less than the thickness of the side plate 4 of the material box; a circular sealing ring mounting groove 305 is concentrically opened on the end face of the second flange boss 303. The diameter of the sealing ring mounting groove 305 is greater than the diameter of the inner hole 304 of the flange 3. The sealing ring mounting groove 305 is matched with the circular ring edge 201 of the sealing ring 2. The sealing ring mounting groove 305 is also used for concentricity alignment when installing the air sealing component 5. The diameter of the second flange boss 303 matches the air sealing component 5. A plurality of first threaded blind holes 306 are circumferentially and evenly arranged on the end face of the second flange boss 303. The first threaded blind holes 306 are used to connect with the air sealing component 5.

[0074] See Figure 3 , Figure 8 and Figure 9 , a through hole 401 for the main shaft 1 to pass through is opened on the side plate 4 of the material box. The through hole 401 is in transitional fit with the outer wall of the sealing ring 2. A circular flange mounting groove 402 concentric with the through hole 401 is opened on the outer wall of the side plate 4 of the material box. The flange mounting groove 402 is in clearance fit with the first flange boss 302 of the flange 3, and the depth of the flange mounting groove 402 is slightly greater than the height of the first flange boss 302. The flange mounting groove 402 is used for concentricity alignment when installing the flange 3. A plurality of second threaded blind holes 403 are circumferentially and evenly arranged on the periphery of the flange mounting groove 402 on the outer wall of the side plate 4 of the material box. The plurality of second threaded blind holes 403 correspond to the plurality of connecting through holes 301 of the flange 3. The second threaded blind holes 403 are used to connect with the flange 3.

[0075] SeeFigure 3 A gas seal assembly 5 is also sleeved on the main shaft 1. The gas seal assembly 5 is installed on the second flange boss 303 of the flange 3. The gas seal assembly 5 assists the sealing ring 2 in sealing. The gas seal assembly 5 is made according to actual requirements and can adopt existing technologies, so its structure will not be described here. The gas seal assembly 5 can also be replaced with a cover plate, which directly presses the sealing ring 2, and the cover plate is installed on the second flange boss 303 of the flange 3.

[0076] During assembly, the following steps can be adopted: The main shaft 1 passes through the through hole 401 of the side plate 4 of the material box. First, the sealing ring 2 and the flange 3 are simply assembled. The flange 3 is sleeved on the sealing ring 2, so that the circular ring sleeve edge 201 of the sealing ring 2 is installed in the sealing ring installation groove 305 of the flange 3. Then, the sealing ring 2 and the flange 3 are sleeved on the main shaft 1 together from the outside of the material box, so that the sealing ring 2 is sleeved on the annular flange 101 of the main shaft 1, and the first flange boss 302 of the flange 3 is inserted into the flange installation groove 402 of the side plate 4 of the material box. Then, the positions of the sealing ring 2 and the flange 3 are adjusted so that the end face of the sealing ring 2 facing the inside of the material box is flush with one end face of the annular flange 101 of the main shaft 1 and the inner wall of the side plate 4 of the material box, and the plurality of through holes 401 of the flange 3 are aligned with the plurality of second threaded blind holes 403 of the side plate 4 of the material box. Finally, the flange 3 and the side plate 4 of the material box are connected by a plurality of screws, and thus the assembly of the main shaft sealing structure is completed. In addition, the assembly steps of the gas seal assembly 5 are as follows: After the above steps, the gas seal assembly 5 is sleeved on the main shaft 1 from the outside of the material box, and the gas seal assembly 5 is installed on the second flange boss 303 of the flange 3 by a plurality of screws.

[0077] Figure 10 An axial mixer applying the main shaft sealing structure is shown. Looking at the side plate 4 of the material box from the inside of the material box, on the inner wall of the side plate 4 of the material box, there is a small through hole 401 and a plane without threaded blind holes around it. Through the main shaft sealing structure, the area of the through hole 401 is minimized, the consistency of the inner wall plane of the side plate 4 of the material box is retained, and the aesthetic degree is improved.

[0078] It should be noted that for the present invention that has been fully described, there can also be various transformation and modification implementation schemes, and it is not limited to the specific embodiments of the above implementation manners. The above embodiments are only used as the description of the present invention, rather than the limitation of the present invention. In short, the protection scope of the present invention should include those transformations, substitutions and modifications that are obvious to those of ordinary skill in the art.

Claims

1. A main shaft sealing structure for a shaft mixer, characterized in that, it includes a main shaft, a sealing ring, a flange, and a side plate of the material box; the main shaft penetrates through the side plate of the material box, and a circumferentially outwardly convex annular flange is provided at the corresponding position of the main shaft on the side plate of the material box. Reverse arc corners are used for transition between the two end faces of the annular flange and the side wall of the main shaft, and the end face of the annular flange facing the inside of the material box is flush with the inner wall of the side plate of the material box; the sealing ring is sleeved on the annular flange of the main shaft, the end face of the sealing ring facing the inside of the material box is flush with the inner wall of the side plate of the material box, and a circumferentially outwardly convex circular ring sleeve edge is provided on the outer wall of the other end of the sealing ring facing the outside of the material box; the flange is sleeved on the sealing ring and installed on the outer wall of the side plate of the material box. A plurality of connecting through holes are evenly distributed along the circumference on the flange. A first flange boss is concentrically provided on the end face of the flange facing the inside of the material box, and a second flange boss is concentrically provided on the end face of the other end of the flange facing the outside of the material box. The inner hole of the flange penetrates through the first flange boss and the second flange boss. A sealing ring installation groove matching with the circular ring sleeve edge of the sealing ring is concentrically opened on the end face of the second flange boss, and a plurality of first threaded blind holes are evenly distributed along the circumference on the end face of the second flange boss; a through hole for the main shaft to pass through and matching with the outer wall of the sealing ring is opened on the side plate of the material box. A flange installation groove concentric with the through hole and matching with the first flange boss of the flange is opened on the outer wall of the side plate of the material box. A plurality of second threaded blind holes are evenly distributed along the circumference on the periphery of the flange installation groove on the outer wall of the side plate of the material box, and the plurality of second threaded blind holes correspond to the plurality of connecting through holes of the flange; the length of the annular flange of the main shaft is greater than the thickness of the side plate of the material box; the inner wall of the sealing ring is in clearance fit with the side wall of the annular flange of the main shaft.

2. The main shaft sealing structure for a shaft mixer according to claim 1, characterized in that, the outer wall of the sealing ring is in transitional fit with the through hole of the side plate of the material box.

3. The main shaft sealing structure for a shaft mixer according to claim 1, characterized in that, the length of the sealing ring is greater than the length of the annular flange of the main shaft.

4. The main shaft sealing structure for a shaft mixer according to claim 1, characterized in that, the first flange boss of the flange is in clearance fit with the flange installation groove of the side plate of the material box, and the height of the first flange boss is slightly less than the depth of the flange installation groove.

5. The main shaft sealing structure for a shaft mixer according to claim 1, characterized in that, the diameter of the first flange boss of the flange is greater than the diameter of the second flange boss.

6. The main shaft sealing structure for a shaft mixer according to claim 1, characterized in that, the diameter of the sealing ring installation groove of the flange is greater than the diameter of the inner hole.

7. The main shaft sealing structure for a shaft mixer according to any one of claims 1 to 6, characterized in that, it further includes a gas sealing assembly. The gas sealing assembly is sleeved on the main shaft and installed on the second flange boss of the flange.

8. The main shaft sealing structure for a shaft mixer according to any one of claims 1 to 6, characterized in that, It further includes a cover plate which presses against the sealing ring and is installed on the second flange boss of the flange.

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