Mechanical seal for engineering plastic centrifugal pump

Abstract

The utility model discloses a mechanical seal for an engineering plastic centrifugal pump, which belongs to the technical field of mechanical seals and comprises a static ring component and a moving ring component, the static ring component comprises a static ring, a static ring seat and a pressing ring, the static ring seat comprises a seat ring and a lining, the seat ring comprises a metal framework ring and an outer ring body, and the lining is arranged on the outer ring body. And a first groove for accommodating the metal framework ring is formed in the lining. The seat ring comprises the metal framework ring and the outer ring body, the deformation of the seat ring is small when the seat ring is subjected to pressure and high temperature, the assembly precision cannot be affected by deformation, and the service life of the mechanical seal is prolonged; the metal framework ring can support the lining to reduce the influence of deformation on the mounting precision, the lining is made of a corrosion-resistant plastic material, and the whole mechanical seal is suitable for corrosion-resistant, high-temperature and high-pressure occasions; and the transmission seat and the adjusting nut are arranged, the adjusting nut is used for uniformly jacking the movable ring seat to a proper position, the assembly precision is ensured, the movable ring is uniformly stressed, and the service life of the mechanical seal is ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to mechanical seal technical field, concretely relates to a mechanical seal for engineering plastic centrifugal pump. BACKGROUND

[0002] The mechanical seal for pump is an important part for ensuring that the liquid in the pump chamber does not leak to the outside during the operation of the water pump, and the centrifugal pump includes a main shaft, a bearing, a bearing box, a bearing end cover, a seal and a pump shell impeller, and the mechanical seal mainly prevents the leakage of the transported liquid. The sealing form of the centrifugal pump mainly includes mechanical seal, oil seal power seal and packing seal, and the service life of the mechanical seal is the longest and can also adapt to various complex and harsh working conditions. In order to maximize the service life of the mechanical seal, it is necessary to improve the installation accuracy of the seal and the stability of each part during the later use, so as to ensure that the seal always operates in ideal conditions and guarantees the service life. In order to improve the corrosion resistance, the static ring seat of the existing mechanical seal is made of plastic material, and the static ring seat made of plastic material is prone to deformation under high pressure and high temperature, which cannot guarantee the installation accuracy and affects the service life of the mechanical seal. When adjusting the compression amount of the dynamic ring, some mechanical seals use a crowbar to pry to the appropriate position and then lock the positioning bolt, and this method cannot guarantee that the compression amount and pressure around the seal are uniform. CONTENT OF THE UTILITY MODEL

[0003] The technical problem solved by the utility model lies in providing a mechanical seal for engineering plastic centrifugal pump, which improves the installation accuracy of the static ring and the service life of the seal.

[0004] Technical scheme: in order to solve the above technical problem, the utility model adopts the following technical scheme:

[0005] A kind of mechanical seal for engineering plastic centrifugal pump, including static ring assembly and dynamic ring assembly, the static ring assembly includes static ring, static ring seat for supporting the static ring and pressure ring for being pressed on the static ring seat, the static ring seat includes seat ring and inner lining integrally connected with the seat ring, the seat ring includes metal framework ring and outer ring body connected with the metal framework ring, first recess for accommodating the metal framework ring is arranged on the inner lining.

[0006] Further, the metal framework ring is provided with a first through hole, and the first recess is provided with a first connecting column penetrating through the first through hole, and the first connecting column is integrally connected with the inner lining.

[0007] Further, the static ring is provided with a first protruding block, a first sealing ring is arranged between the first protruding block and the inner lining, and a second sealing ring is arranged between the first protruding block and the pressure ring.

[0008] Further, the first through holes are arranged in a ring array on the metal skeleton ring.

[0009] Further, the dynamic ring assembly comprises a dynamic ring, a dynamic ring seat for supporting the dynamic ring, a transmission seat sleeved on a transmission shaft, and an adjusting nut in threaded connection with the transmission seat, the adjusting nut being used for abutting against the dynamic ring seat.

[0010] Further, the dynamic ring seat is provided with a plurality of second accommodating grooves, and springs are arranged in the second accommodating grooves, and the dynamic ring is pressed on the static ring under the elastic force of the springs.

[0011] Further, the dynamic ring assembly further comprises a compression round nut, and the compression round nut is used for limiting the axial movement of the transmission seat.

[0012] Beneficial effects: compared with the prior art, the utility model has the following advantages:

[0013] 1, the static ring assembly includes a compression ring and a static ring seat, the static ring seat includes a seat ring, the seat ring includes a metal skeleton ring and an outer ring body, the seat ring has small deformation amount when subjected to pressure and high temperature, and the assembly precision is not affected due to deformation, and the service life of the mechanical seal is improved;

[0014] 2, the inner liner of the static ring seat is integrally connected with the seat ring, the metal skeleton ring can support the inner liner, and the influence of the deformation amount on the installation precision is reduced;

[0015] 3, the inner liner is made of corrosion-resistant plastic material, the inner liner wraps the metal skeleton ring, a sealing ring is arranged between the static ring, the inner liner and the compression ring, the conveyed medium can only contact the corrosion-resistant materials such as the static ring, the inner liner and the dynamic ring, and does not contact other metal parts, and the whole mechanical seal is suitable for corrosion-resistant, high-temperature and high-pressure occasions;

[0016] 4, the transmission seat and the adjusting nut are arranged, the adjusting nut is used for uniformly pressing the dynamic ring seat to a suitable position, the assembly precision is ensured, the dynamic ring is uniformly stressed, and the service life of the mechanical seal is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of the external structure of the mechanical seal of the embodiment of the utility model;

[0018] Figure 2 is a schematic diagram of the cross-sectional structure of the mechanical seal of the embodiment;

[0019] Figure 3 is a schematic diagram of the cross-sectional structure of the mechanical seal in the use state of the embodiment;

[0020] Figure 4 is a schematic diagram of the static ring structure of the embodiment;

[0021] Figure 5is an embodiment of a structure schematic diagram of a compression ring;

[0022] Figure 6 is an embodiment of a structure schematic diagram of a seat ring;

[0023] Figure 7 is an embodiment of a structure schematic diagram of another angle of a seat ring;

[0024] Figure 8 is an embodiment of a structure schematic diagram of a cross section of a seat ring;

[0025] Figure 9 is an embodiment of a structure schematic diagram of an inner liner;

[0026] Figure 10 is an embodiment of a structure schematic diagram of another angle of an inner liner;

[0027] Figure 11 is an embodiment of a structure schematic diagram of a dynamic ring;

[0028] Figure 12 is an embodiment of a structure schematic diagram of a dynamic ring seat;

[0029] Figure 13 is an embodiment of a structure schematic diagram of a spring;

[0030] Figure 14 is an embodiment of a structure schematic diagram of a transmission seat;

[0031] Figure 15 is an embodiment of a structure schematic diagram of an adjusting nut;

[0032] Figure 16 is an embodiment of a structure schematic diagram of a compression round nut; DETAILED DESCRIPTION

[0033] The utility model will be further illustrated in combination with specific embodiments, and the embodiments are implemented on the premise of the technical scheme of the utility model, and it should be understood that the embodiments are only used for illustrating the utility model and are not used for limiting the scope of the utility model.

[0034] As shown in Figure 1 and Figure 3 , a mechanical seal for an engineering plastic centrifugal pump comprises a static ring assembly and a dynamic ring assembly, the static ring assembly comprises a static ring 1, a compression ring 2 and a static ring seat, the static ring 1 is a circular ring, the static ring seat is used for supporting the static ring 1, the static ring seat comprises a seat ring 3 and an inner liner 4, a circle of bolt holes is arranged on the corresponding positions of the seat ring 3 and the compression ring 2, a bolt is arranged through the bolt hole, the seat ring 3 and the compression ring 2 are connected on the pump shell through the bolt, the compression ring 2 is pressed on the static ring seat, the static ring 1 is supported by the static ring seat, and a transmission shaft passes through the middle of the static ring 1, so that the static ring 1 is in a static state relative to the transmission shaft.

[0035] As shown in Figure 1 , Figure 2, Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown, the seat ring 3 includes a metal frame ring 31 and an outer ring body 32. The metal frame ring 31 is made of HT200 cast iron, carbon steel, or stainless steel. The outer ring body 32 is made of the same material as the metal frame ring 31 and is integrally connected to the metal frame ring 31. The metal frame ring 31 is annular, and the outer ring body 32 forms a larger annular shape around the metal frame ring 31. The metal frame ring 31 has multiple first through holes 311, which are arranged in a ring array on the metal frame ring 31. The inner liner 4 is integrally connected to the seat ring 3. The inner liner 4 is generally annular. A first groove 41 is provided on the outer circumferential side surface of the inner liner 4. The first groove 41 is annular and is used to accommodate the metal skeleton ring 31. A plurality of first connecting posts 42 are provided in the first groove 41. The first connecting posts 42 correspond one-to-one with the first through holes 311 and the first connecting posts 42 penetrate the corresponding first through holes 311. The first connecting posts 42 are integrally connected to the inner liner 4. In this embodiment, the inner liner 4 is made of plastic material and is integrally formed with the seat ring 3 by injection molding or pressure injection process. During manufacturing, the metal skeleton ring 31 is placed in a mold, and then molten plastic raw material is injected into the mold. After cooling and forming, the raw material in the mold forms the inner liner 4. Part of the raw material is located in the first through hole 311 to form the first connecting posts 42, thereby integrally connecting with the metal skeleton ring 31. Due to the large amount of thermal expansion and contraction deformation of plastic parts, in order to prevent deformation of parts during use, the stationary ring seat in this embodiment includes a seat ring 3, which includes a metal skeleton ring 31. This ensures the installation dimensions of each component and prevents deformation from affecting assembly accuracy and sealing service life. A first protruding block 11 is provided on the outer circumference of the stationary ring 1. A first sealing ring 12 is provided between the lower side of the first protruding block 11 and the inner liner 4, and a second sealing ring 13 is provided between the upper side of the first protruding block 11 and the pressure ring 2. The first sealing ring 12 and the second sealing ring 13 play an auxiliary sealing role.

[0036] like Figure 1 , Figure 2 , Figure 3 , Figure 11 , Figure 12 , Figure 13 , Figure 14 , Figure 15 and Figure 16As shown, the moving ring assembly includes a moving ring 5, a moving ring seat 6, a transmission seat 7, an adjusting nut 71 and a compression round nut 8. The moving ring 5 is also annular in whole. The lower end surface of the moving ring 5 is pressed against the upper end surface of the static ring 1. The moving ring seat 6 is used to support the moving ring 5. The moving ring seat 6 is provided with a first accommodating groove. A part of the upper end of the moving ring 5 is located in the first accommodating groove. The first accommodating groove is provided with a plurality of second accommodating grooves 61. The second accommodating grooves 61 are provided with springs 62. The moving ring 5 is pressed against the static ring 1 under the elastic force of the springs 62. A moving ring washer is arranged between the upper end surface of the moving ring 5 and the spring 62. The moving ring washer is used to balance and press against the spring 62. The first accommodating groove is provided with a check ring 63. The upper end of the moving ring 5 is provided with a groove corresponding to the check ring 63. The check ring 63 is partially located in the groove of the moving ring 5. The check ring 63 can limit the radial movement of the moving ring 5, thereby ensuring the stability of the moving ring 5. The transmission seat 7 is used to be sleeved on the transmission shaft. The moving ring seat 6 is partially sleeved on the transmission seat 7. The transmission seat 7 is provided with external threads. The adjusting nut 71 is provided with internal threads corresponding to the external threads. The adjusting nut 71 is threadedly connected with the transmission seat 7, so as to be able to move up and down. The adjusting nut 71 is used to be tightly pressed against the moving ring seat 6. When the adjusting nut 71 is tightened, the adjusting nut 71 pushes the moving ring seat 6 to move in the direction of the static ring 1, so as to adjust the moving ring seat 6 to a suitable position. Since the nut uniformly pushes, the moving ring seat 6 is uniformly stressed and the installation precision is improved. The stress of the moving ring 5 is uniformly distributed, thereby ensuring the service life of the seal.

[0037] As shown in Figure 2 and Figure 3 , the mechanical seal of the embodiment is sleeved outside the transmission shaft in use. The shaft sleeve 91 is sleeved on the transmission shaft. The impeller pad 92 is arranged at the lower end of the shaft sleeve 91. The shaft sleeve 91 presses the impeller pad 92 against the impeller 95. The lower end of the transmission shaft is connected with the impeller 95. The impeller 95 is located in the pump shell. The static ring assembly is sleeved outside the shaft sleeve 91. The retainer 3 and the compression ring 2 are connected with the rear clamping plate 94 by bolts. The rear clamping plate 94 is located above the pump cover 93. The retainer 3 and the compression ring 2 limit the static ring 1 to a predetermined position. The moving ring 5 is sleeved outside the shaft sleeve 91. The third sealing ring 51 is arranged between the moving ring 5 and the shaft sleeve 91, which is used for auxiliary sealing. The transmission seat 7 is sleeved outside the transmission shaft. The transmission shaft drives the transmission seat 7 to rotate, thereby driving the moving ring seat 6 and the moving ring 5 to rotate. The moving ring seat 6 is adjusted to a suitable position by pushing the moving ring seat 6 through the adjusting nut 71. At this time, the lower end surface of the moving ring 5 is pressed against the static ring 1 to form a seal.

[0038] The static ring 1 and the dynamic ring 5 are commonly made of pressureless silicon carbide SSic, hard alloy or filled graphite, and in the embodiment, pressureless silicon carbide SSic is selected; the shaft sleeve 91 is commonly made of pressureless silicon carbide SSic, corrosion-resistant alloy and the like, and in the embodiment, pressureless silicon carbide SSic is selected; corresponding materials can also be selected according to needs; the inner liner 4 is commonly made of the same material as the flow part, such as ultra-high molecular weight polyethylene UHMWPE or PVDF-c modified material, F46, PFA and the like, and in the embodiment, the inner liner 4 is made of ultra-high molecular weight polyethylene, so as to ensure that the sealing part is not corroded or worn by the medium.

[0039] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. A mechanical seal for an engineered plastic centrifugal pump, characterized by, The application relates to a static ring assembly and a dynamic ring assembly, the static ring assembly comprising a static ring (1), a static ring seat for supporting the static ring (1), and a pressing ring (2) for pressing on the static ring seat, the static ring seat comprising a seat ring (3) and an inner lining (4) integrally connected with the seat ring (3), the seat ring (3) comprising a metal framework ring (31) and an outer ring body (32) connected with the metal framework ring (31), and the inner lining (4) being provided with a first recess (41) for accommodating the metal framework ring (31).

2. Mechanical seal for an engineering plastic centrifugal pump according to claim 1, characterized in that The metal framework ring (31) is provided with a first through hole (311), and the first recess (41) is provided with a first connecting column (42) penetrating through the first through hole (311), and the first connecting column (42) is integrally connected with the inner lining (4).

3. Mechanical seal for an engineering plastic centrifugal pump according to claim 2, characterized in that The static ring (1) is provided with a first protruding block (11), a first sealing ring (12) is arranged between the first protruding block (11) and the inner lining (4), and a second sealing ring (13) is arranged between the first protruding block (11) and the pressing ring (2).

4. The mechanical seal for an engineered plastic centrifugal pump of claim 2, wherein, The first through hole (311) is provided with a plurality of first through holes (311) which are arranged in a ring array on the metal framework ring (31).

5. The mechanical seal for an engineered plastic centrifugal pump of claim 1, wherein, The dynamic ring assembly comprises a dynamic ring (5), a dynamic ring seat (6) for supporting the dynamic ring (5), a transmission seat (7) sleeved on a transmission shaft, and an adjusting nut (71) threadedly connected with the transmission seat (7), and the adjusting nut (71) is used for abutting against the dynamic ring seat (6).

6. Mechanical seal for an engineering plastic centrifugal pump according to claim 5, characterized in that The dynamic ring seat (6) is provided with a plurality of second accommodating grooves (61), and the second accommodating grooves (61) are provided with springs (62), and the dynamic ring (5) is pressed on the static ring (1) under the elastic force of the springs (62).

7. The mechanical seal for an engineered plastic centrifugal pump of claim 5, wherein, The dynamic ring assembly further comprises a pressing round nut (8) for limiting the axial movement of the transmission seat (7).

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