bottom stirring seal mechanism

Abstract

The utility model discloses a bottom stirring sealing mechanism, including tank bottom wall, tank bottom wall is equipped with first through -hole, be equipped with the shaft sleeve in first through -hole, and the shaft sleeve is sealed and fixedly connected with tank bottom wall, and the shaft sleeve rotation is provided with the stirring shaft in, the top of stirring shaft is equipped with the rotary seat for installing the stirring vane, and the bottom of rotary seat is equipped with the first ring part of the sleeve in the outside of shaft sleeve, and the first ring part is vertically floating and is provided with the first sealing washer between the shaft sleeve. Through setting first sealing washer between first ring part and shaft sleeve, and first sealing washer floating, first sealing washer can float up and down along the axial direction of shaft sleeve in the stirring process, axial floating allows first sealing washer to have slight yielding action under the axial pressure or friction effect from sand, can release or push away the sand grain that squeezes into narrow gap, and slow down the wear and tear of first sealing washer and shaft sleeve / first ring part, and the continuous slight axial floating is helpful to destroy the deposition and agglomerate that sand forms at the edge dead angle of first sealing washer.

Description

Technical Field

[0001] This utility model relates to the field of sealing technology, and in particular to a bottom stirring sealing mechanism. Background Technology

[0002] The molding sand for sand mold 3D printers is made by mixing quartz sand and binder. During the printing process, a mixing tank is needed to mix the quartz sand and binder. In order to achieve continuous printing, the top of the mixing tank is set to be open to facilitate the addition of quartz sand. This requires the mixing shaft to extend from the bottom of the mixing tank wall, and a shaft hole sealing mechanism is set between the mixing shaft and the tank wall. The shaft hole sealing mechanism of existing mixing equipment is generally located at the top of the mixing tank to block the small amount of splashed molding sand, but it is not suitable for the bottom of the mixing tank that needs to be in continuous contact with molding sand. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a bottom stirring and sealing mechanism.

[0004] According to an embodiment of the present invention, a bottom stirring and sealing mechanism includes a tank bottom wall, the tank bottom wall having a first through hole, a bushing being provided in the first through hole, the bushing being sealed and fixedly connected to the tank bottom wall, and a stirring shaft being rotatably arranged inside the bushing; the top end of the stirring shaft having a rotating seat for mounting stirring blades, the bottom of the rotating seat having a first ring portion fitted around the outside of the bushing, and a first sealing ring being vertically floating between the first ring portion and the bushing.

[0005] The bottom stirring and sealing mechanism according to the embodiment of this utility model has at least the following technical effects: by setting the first sealing ring between the first ring and the bushing, and the first sealing ring floating, the position where the first sealing ring contacts the molding sand is the bottom surface of the first sealing ring. The force applied by the molding sand to the first sealing ring is upward, and the weight of the first sealing ring itself is downward, so that the first sealing ring can float up and down along the axial direction of the bushing during the stirring process; the axial floating allows the first sealing ring to have a slight yielding action under the axial pressure or friction from the molding sand, which can release or push away the sand particles squeezed into the narrow gap, avoid the sand particles being stuck and continuously ground, and slow down the wear of the first sealing ring and the bushing / first ring; moreover, the continuous slight axial floating helps to break the deposits and agglomerates formed by the molding sand at the edge dead corner of the first sealing ring, and avoid the first sealing ring getting stuck or its rotation being blocked.

[0006] According to some embodiments of the present invention, a first gap is provided between the first ring portion and the bottom wall of the tank, and the vertical dimension of the first gap is smaller than the vertical dimension of the first sealing ring.

[0007] According to some embodiments of the present invention, a second ring portion is provided on the upper side of the first sealing ring, the second ring portion is fixedly connected to the first ring portion, and the second ring portion is rotatably connected to the bushing.

[0008] According to some embodiments of the present invention, a limiting snap ring is provided on the lower side of the first sealing ring, and the limiting snap ring is detachably connected to the first ring portion or the bushing.

[0009] According to some embodiments of the present invention, a second sealing ring is provided between the bushing and the stirring shaft.

[0010] According to some embodiments of the present invention, the number of the second sealing rings is two, and the two second sealing rings are stacked.

[0011] According to some embodiments of the present invention, the inner wall of the bushing is provided with a retaining ring, and the second sealing ring is disposed on the upper side of the retaining ring.

[0012] According to some embodiments of the present invention, the stirring shaft has a first shaft segment and a second shaft segment disposed below the first shaft segment. The diameter of the first shaft segment is smaller than the diameter of the second shaft segment. A bearing assembly is connected between the first shaft segment and the bushing, and the bearing assembly abuts against the retaining ring and the second shaft segment.

[0013] According to some embodiments of the present invention, the bearing assembly includes a first bearing, a sleeve abutting against the lower side of the first bearing, and a second bearing abutting against the lower side of the sleeve.

[0014] According to some embodiments of the present invention, a first retaining ring is provided on the upper side of the first bearing, and the first retaining ring is detachably connected to the first shaft segment; a second retaining ring is provided on the lower side of the second bearing, and the second retaining ring is detachably connected to the bushing.

[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0017] Figure 1 This is a schematic diagram of the bottom stirring and sealing mechanism according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the bottom stirring and sealing mechanism of another embodiment of the present invention;

[0019] In the attached image:

[0020] 100-Bottom wall of tank; 200-Sleeve; 210-Retaining ring; 300-Agitator shaft; 400-Rotating seat; 410-First ring; 411-First gap; 420-Second ring; 500-Agitator blade; 611-First sealing ring; 612-Second sealing ring; 621-First snap ring; 622-Second snap ring; 623-Limiting snap ring; 631-First bearing; 632-Second bearing; 640-Sleeve. Detailed Implementation

[0021] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0022] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number, while "above," "below," "within," etc., are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0023] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0024] The following is for reference. Figure 1 and Figure 2 This invention describes the bottom stirring and sealing mechanism of an embodiment of the present invention.

[0025] The bottom stirring and sealing mechanism of this utility model embodiment includes a tank bottom wall 100, which is the bottom wall of the stirring tank. The tank bottom wall 100 is provided with a first through hole, and a bushing 200 is provided in the first through hole. The bushing 200 is vertically arranged and can be installed on the tank bottom wall 100 by welding or a suitable gas method to achieve a sealed and fixed connection between the bushing 200 and the tank bottom wall 100, so that the molding sand in the stirring tank will not leak from the gap between the first through hole and the bushing 200. A stirring shaft 300 is rotatably arranged in the bushing 200. The stirring shaft 300 is vertically arranged, and the lower end of the stirring shaft 300 is connected to an electric motor. The stirring shaft 300 is equipped with a rotating seat 400 at its top end for mounting the stirring blades 500. The stirring shaft 300 and the rotating seat 400 can be connected by threads, bolts, or other suitable means, so that the rotating seat 400 can be rotated by starting the control motor, thereby stirring the molding sand in the mixing tank. The bottom of the rotating seat 400 is provided with a first ring 410 that is sleeved on the outside of the bushing 200. The first ring 410 and the rotating seat 400 can be an integral component. A first sealing ring 611 is vertically floating between the first ring 410 and the bushing 200.

[0026] It is understandable that quartz sand, one of the raw materials for molding sand, is an extremely hard abrasive. If the position of the first sealing ring 611 is fixed, the quartz sand will be squeezed into the narrow gap between the stationary first sealing ring 611 and the bushing 200 / first ring 410 during the mixing process, forming a continuous grinding band and accelerating the wear of the first sealing ring 611 and the bushing 200 / first ring 410. Moreover, the molding sand contains binder, which will deposit and harden at the dead corners of the fixed edge of the first sealing ring 611, causing the first sealing ring 611 to jam or be obstructed from rotating.

[0027] This invention, by placing a first sealing ring 611 between the first ring portion 410 and the bushing 200, and by having the first sealing ring 611 float, with the contact point between the first sealing ring 611 and the molding sand being the bottom surface of the first sealing ring 611, and the force exerted by the molding sand on the first sealing ring 611 being upward, while the weight of the first sealing ring 611 itself is downward, allows the first sealing ring 611 to float up and down along the axial direction of the bushing 200 during the stirring process. The axial floating allows the first sealing ring 611 to have a slight yielding action under the axial pressure or friction from the molding sand, which can release or push away sand particles squeezed into narrow gaps, preventing sand particles from being stuck and continuously grinding, and slowing down the wear of the first sealing ring 611 and the bushing 200 / first ring portion 410. Moreover, the continuous slight axial floating helps to break up the deposits and agglomerates formed by the molding sand in the dead corners of the edge of the first sealing ring 611, preventing the first sealing ring 611 from getting stuck or its rotation from being obstructed.

[0028] In some embodiments of this utility model, reference is made to Figure 2A limiting snap ring 623 is provided on the lower side of the first sealing ring 611. The limiting snap ring 623 is detachably connected to the first ring portion 410 or the bushing 200. Taking the limiting snap ring 623 being provided in the bushing 200 as an example, the outer wall of the bushing 200 is provided with a limiting groove that matches the limiting snap ring 623. The limiting snap ring 623 is engaged in the limiting groove to limit the lower limit position of the first sealing ring 611, thereby preventing the first sealing ring 611 from moving downwards beyond the first ring portion 410 and causing the seal to fail.

[0029] In some embodiments of this utility model, reference is made to Figure 1 A first gap 411 is provided between the first ring portion 410 and the bottom wall 100 of the tank. The vertical dimension of the first gap 411 is smaller than the vertical dimension of the first sealing ring 611. In this way, there is no need to provide a limiting spring 623. The bottom wall 100 of the tank can prevent the first sealing ring 611 from moving downward beyond the first ring portion 410. At the same time, it also avoids the problem of stress concentration at the contact point between the limiting spring 623 and the first sealing ring 611, which would accelerate the wear of the first sealing ring 611.

[0030] In some embodiments of this utility model, a second ring portion 420 is provided on the upper side of the first sealing ring 611. The second ring portion 420 is fixedly connected to the first ring portion 410 and rotatably connected to the bushing 200. The first ring portion 410, the second ring portion 420, and the rotating seat 400 are integral components, and the second ring portion 420 is clearance-fitted with the bushing 200. This reduces the radial floating of the rotating seat 400 relative to the bushing 200, reduces the radial compression deformation of the first sealing ring 611, and improves the sealing effect of the first sealing ring 611.

[0031] In some embodiments of this utility model, a second sealing ring 612 is provided between the bushing 200 and the stirring shaft 300. The second sealing ring 612 is located at the top of the bushing 200. It can be understood that, since the first sealing ring 611 floats axially, a small amount of sand particles embedded between the first sealing ring 611 and the bushing 200 / first ring portion 410 may be pushed above the first sealing ring 611 and then move between the stirring shaft 300 and the bushing 200, which may adversely affect the rotation of the stirring shaft 300. In this embodiment, by providing the second sealing ring 612, this part of the sand particles is prevented from moving between the stirring shaft 300 and the bushing 200, so that the stirring shaft 300 can rotate smoothly.

[0032] In some embodiments of this utility model, there are two second sealing rings 612, which are stacked. This allows for a secondary seal between the stirring shaft 300 and the bushing 200, further preventing sand particles from entering between the stirring shaft 300 and the bushing 200.

[0033] In some embodiments of this utility model, a retaining ring 210 is provided on the inner wall of the bushing 200, and a second sealing ring 612 is disposed on the upper side of the retaining ring 210. The retaining ring 210 and the bushing 200 can be an integral component. The retaining ring 210 can restrict the lower limit position of the second sealing ring 612, so that the second sealing ring 612 is kept at the top of the bushing 200, preventing the second sealing ring 612 from moving down and contacting the bearing assembly, causing wear.

[0034] In some embodiments of this utility model, the stirring shaft 300 has a first shaft segment and a second shaft segment disposed below the first shaft segment. The diameter of the first shaft segment is smaller than the diameter of the second shaft segment. A bearing assembly is connected between the first shaft segment and the bushing 200, and the bearing assembly abuts against the retaining ring 210 and the second shaft segment. By providing the bearing assembly, the relative rotation between the stirring shaft 300 and the bushing 200 is stable and smooth; the bearing assembly abutting against the retaining ring 210 and the second shaft segment can prevent axial displacement of the bearing assembly and improve stability.

[0035] In some embodiments of this utility model, the bearing assembly includes a first bearing 631, a sleeve 640 abutting against the lower side of the first bearing 631, and a second bearing 632 abutting against the lower side of the sleeve 640. This results in a larger vertical dimension of the bearing assembly, which is beneficial for improving the coaxiality between the stirring shaft 300 and the bushing 200, thereby improving the stability of the stirring shaft 300's rotation. The sleeve 640 prevents axial displacement of the first bearing 631 and the second bearing 632, further enhancing stability. The number of first bearings 631 can be two, stacked vertically between the sleeve 640 and the retaining ring 210. Similarly, the number of second bearings 632 can be two, stacked vertically between the sleeve 640 and the second shaft segment.

[0036] In some embodiments of this utility model, a first retaining ring 621 is provided on the upper side of the first bearing 631. The first retaining ring 621 is detachably connected to the first shaft segment. The outer wall of the first shaft segment is provided with a first retaining groove, and the first retaining ring 621 is engaged in the first retaining groove. A second retaining ring 622 is provided on the lower side of the second bearing 632. The second retaining ring 622 is detachably connected to the bushing 200. The inner wall of the bushing 200 is provided with a second retaining groove, and the second retaining ring 622 is engaged in the second retaining groove. It can be understood that the bearing has an inner ring and an outer ring. In this embodiment, by providing the first retaining ring 621 and the second retaining ring 622, the retaining ring 210 and the first retaining ring 621 respectively abut against the outer ring and the inner ring of the first bearing 631, and the second retaining ring 622 and the second shaft segment respectively abut against the outer ring and the inner ring of the second bearing 632, which is beneficial to improving the stability of the first bearing 631 and the second bearing 632.

[0037] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A bottom stirring and sealing mechanism, characterized in that: The device includes a bottom wall of a tank, a first through hole, a bushing inside the first through hole, the bushing being sealed and fixedly connected to the bottom wall of the tank, and a stirring shaft being rotatably mounted inside the bushing; the top end of the stirring shaft is provided with a rotating seat for mounting stirring blades, and the bottom of the rotating seat is provided with a first ring portion fitted around the outside of the bushing, and a first sealing ring is vertically floating between the first ring portion and the bushing.

2. The bottom stirring and sealing mechanism according to claim 1, characterized in that: A first gap is provided between the first ring portion and the bottom wall of the tank, and the vertical dimension of the first gap is smaller than the vertical dimension of the first sealing ring.

3. The bottom stirring and sealing mechanism according to claim 1, characterized in that: The upper side of the first sealing ring is provided with a second ring portion, which is fixedly connected to the first ring portion and rotatably connected to the bushing.

4. The bottom stirring and sealing mechanism according to claim 1, characterized in that: A limiting snap ring is provided on the lower side of the first sealing ring, and the limiting snap ring is detachably connected to the first ring or the bushing.

5. The bottom stirring and sealing mechanism according to claim 1, characterized in that: A second sealing ring is provided between the bushing and the stirring shaft.

6. The bottom stirring and sealing mechanism according to claim 5, characterized in that: The number of the second sealing rings is two, and the two second sealing rings are stacked.

7. The bottom stirring and sealing mechanism according to claim 5, characterized in that: The inner wall of the bushing is provided with a retaining ring, and the second sealing ring is located on the upper side of the retaining ring.

8. The bottom stirring and sealing mechanism according to claim 7, characterized in that: The stirring shaft has a first shaft section and a second shaft section located below the first shaft section. The diameter of the first shaft section is smaller than the diameter of the second shaft section. A bearing assembly is connected between the first shaft section and the bushing, and the bearing assembly abuts against the retaining ring and the second shaft section.

9. The bottom stirring and sealing mechanism according to claim 8, characterized in that: The bearing assembly includes a first bearing, a sleeve abutting against the lower side of the first bearing, and a second bearing abutting against the lower side of the sleeve.

10. The bottom stirring and sealing mechanism according to claim 9, characterized in that: The first bearing has a first retaining ring on its upper side, which is detachably connected to the first shaft segment; the second bearing has a second retaining ring on its lower side, which is detachably connected to the bushing.

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