Dynamic Shaft Sealing Structure of Electric Powder Stirring and Crushing Machine

Abstract

The present invention discloses a dynamic shaft sealing structure for an electric powder blender, comprising a fly-cutter shaft, a flange seat, a cavity seat, a housing lining, a dust cover, an airtight sealing passage formed between the fly-cutter shaft and the cavity seat, and between the cavity seat and the dust cover, and further comprising at least one air compression chamber and an air inlet, wherein the air inlet provides air for the air compression chamber, the air compression chamber is connected to the airtight sealing passage, and air compression blades are provided in the air compression chamber for providing compressed air for sealing. The present invention does not require an external pressure air source, thereby solving the problem of powder leakage caused by air interruption or insufficient air pressure when an external air source is used as an air seal in the prior art, and avoids the problems of accelerated wear of parts in the dynamic shaft device, short service life, poor maintenance and repairability, product contamination, and high cost of use caused by powder leakage.

Description

Technical Field

[0001] This technology relates to a dynamic shaft sealing structure of an electric powder blender Background Art

[0002] The driving shaft of an electric powder blender is often referred to as the "flying knife shaft." Because the flying knife shaft rotates during operation, even at high speeds, a poorly sealed shaft can cause powder to overflow, reducing production and polluting the environment. Therefore, sealing is crucial. Three basic sealing methods have been used for the driving shaft of electric powder blenders: airtight seals, airbag seals, and mechanical seals.

[0003] The air seal is to set up an air seal channel in the dynamic shaft seal structure and connect it to an external pressure gas source, and pass a certain pressure of sealing gas into it. The pressure of the sealing gas must be greater than the pressure in the stirring chamber, so as to achieve air sealing. Commonly used air seal structures are shown in Figure 1 The mixing equipment comprises: flange seat I, cutter shaft II, chamber seat III, and dust cover IV. Chamber seat III is mounted on flange seat I. Chamber seat III has an air inlet, which is connected to an external pressure gas source via a switch. A radial gap e is formed between cutter shaft II and the inner hole of chamber seat III, and a radial gap f is formed between dust cover IV and chamber seat III. These gaps e and f form a continuous airtight seal. Before the mixing equipment is operated, turn on the compressed air switch on the equipment and introduce a sealed gas at a certain pressure into the air inlet on chamber seat III. The sealed gas pressure must be greater than the pressure within the mixing chamber to achieve an airtight seal.

[0004] This type of dynamic shaft sealing structure that relies on an external pressure gas source for sealing generally has the following problems:

[0005] 1. If the gas source is impure or there are metal foreign objects generated when tightening the threads of the gas pipe joint, the sealed gas will be brought into the equipment and contaminate the powder material in the equipment.

[0006] 2. If the sealing gas is suddenly cut off or the air pressure is insufficient, the powder will leak into the dynamic shaft sealing device, thereby causing the parts in the dynamic shaft device to wear faster and reducing the service life of the parts.

[0007] Airbag sealing structure: the principle of this sealing structure is that the inner hole of the airbag and the outer circle of the dynamic shaft at the sealing point are interference fit or converted into end face sealing. This sealing structure has very high requirements on the wear resistance of the airbag material, otherwise the airbag needs to be replaced frequently.

[0008] Due to the structural principle of mechanical seals, friction and wear will occur during operation, causing metal chips to fall into the equipment and contaminate the powder material inside the equipment.

[0009] In order to solve the above problems, an electric powder blender has a dynamic shaft sealing structure. Summary of the Invention

[0010] The object of the present invention is to provide a dynamic shaft sealing structure for an electric powder blender which has good sealing performance, long service life, low cost and no pollution to the blended product.

[0011] The dynamic shaft sealing structure of the electric powder grinder provided by the present invention includes a flying knife shaft, a flange seat, a cavity seat, a box lining, a dust cover, and an air-sealing channel formed between the flying knife shaft and the cavity seat and between the cavity seat and the dust cover. It is characterized in that it also includes at least one air compression chamber and an air inlet, the air inlet provides air to the air compression chamber, the air compression chamber is connected to the air-sealing channel, and air compression blades are provided in the air compression chamber for providing compressed air for sealing.

[0012] A clearance fit is employed between the cutter shaft and the cavity seat, and between the cavity seat and the dust cover, to form an airtight passage. The air compression blades are spiral blades. The air compression chamber is disposed between the cavity seat and the flange seat, formed by the cavity formed by the flange seat and the cavity seat. The air compression chamber is disposed within the dust cover. The air inlet is disposed on the flange seat. Alternatively, the air inlet may be disposed on the cavity seat.

[0013] In order to further improve the sealing effect, there are two air compression chambers to form two-stage air compression, wherein the first-stage air compression chamber is arranged between the cavity seat and the flange seat, and is formed by the cavity formed by the flange seat and the cavity seat; the second-stage air compression chamber is arranged in the dust cover.

[0014] In order to prevent powder from accumulating at the compressed air outlet of the dust cover, the lining of the box is designed to be a slope facing the compressed air outlet of the dust cover.

[0015] In order to prevent the dust cover 7 from rubbing against the powder material during operation to generate metal chips that contaminate the powder material, and to increase the service life of the dust cover 7 and reduce the maintenance frequency, the outer layer of the sealing cover is designed with a wear-resistant non-metallic protective sleeve.

[0016] The air compression blade is of an external type, comprising an external blade and a first mounting seat, wherein the external blade is mounted on the periphery of the first mounting seat. Alternatively, the air compression blade is of an internal type, comprising an internal blade and a second mounting seat, wherein the second mounting seat has an inner ring and an outer ring, and the internal blade is mounted between the inner ring and the outer ring.

[0017] The air compression blades used in the first stage air compression are of external type, and the air compression blades used in the second stage air compression are of internal type.

[0018] The electric powder blender's dynamic shaft sealing structure, provided with an air compression chamber, compresses air entering the air compression chamber via air compression blades, achieving a pressure greater than that within the blending chamber. The compressed air then enters the blender's housing through an airtight seal channel, thereby sealing the blender's dynamic shaft. The present invention eliminates the need for an external pressure air source, thereby resolving the prior art issue of using an external air source as an air seal, which can lead to powder leakage due to air interruption or insufficient air pressure. This avoids issues such as accelerated wear of components within the dynamic shaft device, shortened service life, poor maintenance, product contamination, and high operating costs caused by powder leakage, thereby indirectly improving production efficiency and reducing operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the prior art.

[0020] Figure 2 It is a structural schematic diagram of the present invention.

[0021] Figure 3 yes Figure 2 Enlarged view of part A.

[0022] Figure 4 Schematic diagram of the structure of external air compression blades.

[0023] Figure 5 It is a structural diagram of a built-in air compression blade.

[0024] Figure 6 It is a structural diagram of the box lining.

[0025] Figure 7 It is a schematic diagram of the structure of the dust cover.

[0026] Figure 2-Figure 7 The reference numerals are as follows:

[0027] Motor 1, flange seat 2, coupling 3, bearing 4, primary air compression chamber 5, secondary air compression chamber 6, external air compression blades 7, internal air compression blades 8, flying knife shaft 9, dust cover 10, locking nut 11, flying knife 12, positioning sleeve 13, box liner 14, cavity seat 15, air inlet 16, ramp 17, wear-resistant non-metallic protective cover 18. DETAILED DESCRIPTION

[0028] See also Figure 2-Figure 7 It can be seen that the present invention has a flange seat 2, a primary air compression chamber 5, a secondary air compression chamber 6, an external air compression blade 7, an internal air compression blade 8, a knife shaft 9, a dust cover 10, a box lining 14, a cavity seat 15, an air inlet 16, a slope 17, and a wear-resistant non-metallic protective cover 18.

[0029] The flange seat 2, the cavity seat 15, and the dust cover 10 are sequentially installed on the fly cutter shaft 9. The fly cutter shaft 9 and the cavity seat 15 are clearance-fitted with a radial gap e1. An axial gap e2 is provided between the end of the cavity seat 15 and the dust cover 10. The radial gap e1 is connected to the axial gap e2 to form an airtight passage.

[0030] The flange seat 2 is connected to the cavity seat 15, and a primary air compression chamber 5 is provided between them. The primary air compression chamber is connected to the external air. The connection method can be to provide an air inlet 16 on the flange seat 2 or the cavity seat 15 to allow air to enter the primary air compression chamber 5. The primary air compression chamber has an external air compression blade 7, which has an external blade 71 and a first mounting seat 72. The external blade 71 is installed on the periphery of the first mounting seat 72 using a spiral blade. The external air compression blade is installed on the fly cutter shaft 9. When the fly cutter shaft rotates, the external air compression blade 71 rotates accordingly, thereby performing a primary compression on the air. A vent cap needs to be installed at the air inlet 16 to replenish air in time, purify the air, and prevent compressed air from overflowing.

[0031] The dust cover 10 is mounted on one end of the cavity seat 15 and has an axial gap e2 with its end face. The inner cavity of the dust cover 10 serves as a secondary air compression chamber 6. In the secondary air compression chamber, there is a built-in air compression blade 8, which has a built-in blade 81 and a second mounting seat 82. The second mounting seat 82 has an inner ring and an outer ring. The built-in blade 81 is a spiral blade mounted between the inner ring and the outer ring. The built-in air compression blade is mounted on the fly cutter shaft 9. When the fly cutter shaft rotates, the built-in air compression blade 8 rotates accordingly, thereby performing secondary compression on the air. The outer layer of the dust cover 10 adopts a wear-resistant non-metallic protective cover 18 to prevent the dust cover 10 from rubbing against the powder material during operation to generate metal debris that contaminates the powder material, and to increase the service life of the dust cover 10 and reduce the frequency of maintenance.

[0032] The box lining 12 is designed with a slope 17 with an angle C between 0 and 90 degrees. The slope faces the compressed air outlet of the dust cover 10, so that powder materials are not easily accumulated there.

[0033] The compressed air enters the box through the air-sealed channel to seal the cutter shaft very well.

[0034] When installing the dynamic shaft sealing structure of the electric powder blender of the present invention, the bearing 4 and the external air compression blade 7 are first installed into the fly cutter shaft 9, one end of the coupling 3 is connected to the fly cutter shaft 9, and the other end is connected to the shaft extension of the motor 1 to form an assembly; then the formed assembly is installed into the flange seat 2, the flange seat 2 is bolted to the cavity seat 15, and the built-in air compression blade 8 is installed into the dust cover 10 to form a dust cover assembly; finally, the dust cover assembly, the positioning sleeve 13, and the fly cutter 12 are sequentially installed into the fly cutter shaft 9 and locked with the locking nut 11, thereby forming the dynamic shaft sealing structure of the blender.

[0035] During operation, motor 1 is started, and air enters the primary air compression chamber 5 through air inlet 16. External air compression blades 7 rotate with the cutter shaft 12, compressing and pressurizing the air entering the primary air compression chamber 5. The air then passes through the airtight passage formed by the radial gap e1 between the cutter shaft 12 and the chamber seat 15, and the axial gap e2 between the dust cover 10 and the chamber seat 15. Internal air compression blades 8 further compress and pressurize the compressed air. This second stage of pressurization directly enters the equipment chamber, sealing the pulverizer's dynamic shaft. For maintenance, remove the locknut 11, cutter 12, dust cover 10, flange seat 2, and finally the components of the motor 1 and cutter shaft 6.

[0036] The above example uses two air compression chambers, but of course one or more can also be used. Multiple groups of air compression blades are used in each air compression chamber, and each group has a mounting seat and several spiral blades mounted on the mounting seat. The number of air compression chambers and the number of groups of air compression blades can be determined according to actual needs within the scope of knowledge of those skilled in the art, so as to minimize costs while meeting the desired effect.

Claims

1. A sealing structure for a dynamic shaft of an electric powder blender, comprising a fly cutter shaft (9), a flange seat (2), a cavity seat (15), a box lining (14), and a dust cover (10), characterized in that It also includes a primary air compression chamber (5), a secondary air compression chamber (6), external air compression blades (7) and internal air compression blades (8); The flange seat (2), the cavity seat (15), and the dust cover (10) are sequentially mounted on the fly cutter shaft (9); the fly cutter shaft (9) and the cavity seat (15) are clearance-fitted and have a radial gap; an axial gap is present between the end of the cavity seat (15) and the dust cover (10); the radial gap and the axial gap are connected to form an airtight passage; The first-stage air compression chamber (5) is arranged between the cavity seat and the flange seat, and is formed by a cavity formed by the flange seat (2) and the cavity seat (15); the second-stage air compression chamber (6) is arranged in the dust cover (10); An external air compression blade (7) is provided in the first-stage air compression chamber. The blade is a spiral blade and is mounted on the knife shaft (9). When the knife shaft rotates, the external air compression blade rotates accordingly, thereby performing first-stage compression on the air. The secondary air compression chamber includes a built-in air compression blade (8) which is a spiral blade and is mounted on the fly cutter shaft (9). When the fly cutter shaft rotates, the built-in air compression blade (8) rotates accordingly, thereby performing secondary compression on the air. An air inlet (16) is provided on the flange seat (2) or the cavity seat (15), and a vent cap is installed at the air inlet (16).

2. The dynamic shaft sealing structure of the electric powder pulverizer according to claim 1 is characterized in that The box inner lining (14) is designed as a slope (17) at a position facing the compressed air outlet of the dust cover.

3. The dynamic shaft sealing structure of the electric powder pulverizer according to claim 1 is characterized in that The outer layer of the dust cover is a wear-resistant sheath (18).

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