Shutdown sealing device of centrifugal pump

Abstract

A shutdown sealing device of a centrifugal pump comprises a pump cover (7), a pump shaft (1) penetrates through the pump cover, a disc body (4) is connected to the upper portion of the pump cover in a sealed mode, an electromagnet composed of a magnet yoke (5), a coil (6) and an annular plate (9) is fixedly connected to the disc body, a spring (3) is arranged between the annular plate and the disc body, a sealing plate (12) is connected to the annular plate, a shaft sleeve (14) is arranged on the right side of the sealing plate, and the pump shaft is fixedly sleeved with the shaft sleeve. The left end of the shaft sleeve is provided with a flange (13). When the pump shaft rotates, the electromagnet is attracted, the sealing plate does not make contact with the flange, when the pump shaft stops, the electromagnet is released, the sealing plate is tightly attached to the flange, and shutdown sealing is achieved. The centrifugal pump has the advantages that sealing can be reliably achieved when the centrifugal pump is shut down, and a sealing piece is not abraded when the centrifugal pump works; parts of the shutdown sealing device are basically installed on the pump cover, the load of the pump shaft is reduced, no movable part similar to a traction block is arranged on the pump shaft, unbalanced force cannot be generated on the pump shaft, and the service life of the pump shaft is prolonged.

Description

Technical Field

[0001] The utility model relates to a shutdown sealing device for a centrifugal pump. Background Art

[0002] A centrifugal pump using dynamic sealing has no sealing element between the pump shaft and the pump cover. When the pump shaft rotates, the auxiliary impeller can generate reverse pressure to prevent liquid leakage. When the centrifugal pump is stopped, the auxiliary impeller does not generate reverse pressure, and the liquid in the pump body will leak out of the gap between the pump shaft and the pump cover. This requires the provision of a shutdown sealing device. As shown in the prior art, patent No. CN 118110689 A, the shutdown seal is located on the rear side of the pump cover and includes a static ring that is sleeved on the shaft sleeve and installed on the pump cover, a dynamic ring that is sleeved on the shaft sleeve and located behind the static ring, and a traction block. The dynamic ring adopts a metal bellows structure and one end away from the static ring is fixed on the shaft sleeve, and the other end is free. The traction blocks are respectively connected to both ends of the dynamic ring. When stopped, the sealing surfaces of the dynamic ring and the static ring are tightly attached. During operation, the centrifugal force generated by the traction block pulls the free end of the dynamic ring away from the static ring.

[0003] The above-mentioned moving ring, traction block, and other components are all installed on the pump shaft and rotate with the pump shaft, which increases the load on the pump shaft. Among them, the traction block is movably installed on the pump shaft. When the pump shaft rotates, an unbalanced force will be generated, the movable parts will vibrate, and the parts are prone to fatigue; at the same time, the unbalanced force will also damage the pump shaft. Utility Model Content

[0004] In response to the above problems, the utility model proposes a shutdown sealing device for a centrifugal pump. The shutdown sealing device has no components similar to traction blocks, no unbalanced force is generated, the shutdown sealing device is not easily damaged, and has no adverse effects on the pump shaft; when the centrifugal pump is shut down, the seal between the pump shaft and the pump cover can be reliably achieved; when the centrifugal pump is working, the sealing component is not worn.

[0005] The technical solution of the present utility model is a shutdown sealing device for a centrifugal pump, which includes a pump cover 7, a pump shaft 1 passing through the pump cover and entering the pump body, and is characterized in that a disc body 4 is sealed and connected on the right end surface of the pump cover, the disc body is sleeved on the pump shaft, a sleeve body 8 is extended to the right at the edge of the disc body, a sleeve 2 is extended to the right at the inner circle of the disc body, an annular yoke 5 is fixedly inserted on the inner wall of the sleeve body 8, the annular surface of the yoke is provided with a recess, a coil 6 is installed in the recess, a ring plate 9 is provided on the right side of the yoke, a sliding sleeve 15 is extended to the left at the inner circle of the ring plate, the sliding sleeve is sleeved on the outer circle of the sleeve, a sealing ring 17 is provided between the sliding sleeve and the sleeve 2, a spring 3 is sleeved on the outer circle of the sliding sleeve, an annular sealing plate 12 is fixedly connected to the right end surface of the ring plate, an axial gap is left between the sealing plate and the right end of the sleeve 2, a shaft sleeve 14 is provided on the right side of the sealing plate, the shaft sleeve is fixedly sleeved on the pump shaft, a sealing ring 16 is provided between the shaft sleeve and the pump shaft, and the left end of the shaft sleeve has a flange 13.

[0006] The beneficial effects of the utility model are that the centrifugal pump can be reliably sealed when it is shut down, and the seals are free of wear when the centrifugal pump is working; the components of the shutdown sealing device are basically installed on the pump cover, which reduces the load on the pump shaft, and there are no movable parts such as traction blocks on the pump shaft, so no unbalanced force is generated on the pump shaft, the shutdown sealing device is not easily damaged, and there is no adverse effect on the pump shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a structural diagram of the present utility model.

[0008] Figure symbols: 1- pump shaft, 2- sleeve, 3- spring, 4- disc, 5- yoke, 6- coil, 7- pump cover, 8- sleeve, 9- plate, 10- cylinder, 11- press sleeve, 12- sealing plate, 13- flange, 14- shaft sleeve, 15- sliding sleeve, 16- sealing ring, 17- sealing ring, 18- stopper. DETAILED DESCRIPTION

[0009] A shutdown sealing device for a centrifugal pump includes a pump cover 7, a pump shaft 1 passing through the pump cover and entering the pump body, wherein a disc 4 is sealed and connected on the right end face of the pump cover, the disc is fixed to the pump cover by screws, a hole in the center of the disc is sleeved on the pump shaft, a sleeve 8 extends to the right from the edge of the disc, a sleeve 2 extends to the right from the inner circle of the disc, an annular yoke 5 is fixedly inserted on the inner wall of the sleeve 8, and the fixing method is to have an interference fit between the outer circle of the yoke and the inner wall of the sleeve, or to fix the yoke to the disc by screws; a recess is provided on the annular surface of the yoke, a coil 6 is installed in the recess, and a ring plate 9 is provided on the right side of the yoke, and the ring plate is made of metal The ring plate is made of a magnetic conductive material, and a sliding sleeve 15 extends to the left from the inner circle of the ring plate. The sliding sleeve 15 is fitted on the outer circle of the sleeve 2. A sealing ring 17 is provided between the sliding sleeve and the sleeve 2. A spring 3 is provided on the outer circle of the sliding sleeve. The outer circle of the ring plate is larger than or equal to the outer circle of the magnetic yoke. An annular sealing plate 12 is fixedly connected to the right end face of the ring plate. The inner circle of the sealing plate is slightly larger than the outer circle of the pump shaft. The sealing plate is made of rubber material. An axial gap is left between the sealing plate and the right end of the sleeve 2. A shaft sleeve 14 is provided on the right side of the sealing plate. The shaft sleeve is fixedly mounted on the pump shaft. A sealing ring 16 is provided between the shaft sleeve and the pump shaft. The left end of the shaft sleeve has a flange 13.

[0010] The yoke, coil and ring plate form an electromagnet. When the electromagnet is attracted, the sealing plate has no contact with the flange of the shaft sleeve; when the electromagnet is released, the sealing plate is in close contact with the flange of the shaft sleeve under the action of the spring.

[0011] The sealing ring 16 is used to prevent the liquid in the pump body from leaking along the shaft sleeve. The sealing ring has no wear when the pump shaft rotates or stops.

[0012] The sealing ring is used to prevent the liquid in the pump body from leaking along the sleeve. It should be noted that the relative movement between the sleeve and the sleeve only occurs at the moment of shutdown and startup. The friction time of the sealing ring is very short and will not affect the service life of the sealing ring.

[0013] The principle of shutdown sealing is that the yoke, coil and ring plate form an electromagnet. When the centrifugal pump motor is energized, the electromagnet is also energized, the yoke attracts the ring plate, and the sealing plate is out of contact with the flange of the shaft sleeve. When the pump shaft rotates, there is no friction between the sealing plate and the flange; when the centrifugal pump is shut down, the electromagnet is de-energized, and the spring pushes the ring plate toward the shaft sleeve, so that the sealing plate and the flange of the shaft sleeve are tightly attached to achieve shutdown sealing.

[0014] In order to facilitate the positioning of the disc on the pump cover, a stopper 18 is provided on the pump cover, and the disc is located in the stopper, and the inner circle of the stopper matches the outer circle of the disc.

[0015] The sealing plate can be fixed to the ring plate with screws or a press sleeve. Specifically, a cylinder 10 extends rightward from the edge of the ring plate. The outer diameter of the sealing plate is slightly smaller than the inner diameter of the cylinder. The sealing plate is located within the cylinder, and a press sleeve 11 extends into the cylinder to abut against the sealing plate. The flange of the press sleeve is connected to the cylinder with screws. Tightening the screws presses the sealing plate against the ring plate. This avoids punching holes in the sealing plate and also facilitates installation.

Claims

1. A shutdown sealing device for a centrifugal pump, comprising a pump cover (7), a pump shaft (1) passing through the pump cover and entering the pump body, wherein: A disc body (4) is sealed and connected on the right end surface of the pump cover. The disc body is sleeved on the pump shaft. A sleeve body (8) extends to the right at the edge of the disc body. A sleeve (2) extends to the right at the inner circle of the disc body. An annular magnetic yoke (5) is fixedly inserted on the inner wall of the sleeve body (8). The annular surface of the magnetic yoke is provided with a recess, and a coil (6) is installed in the recess. A ring plate (9) is provided on the right side of the magnetic yoke. A sliding sleeve (15) extends to the left from the inner circle of the ring plate. The sliding sleeve is sleeved on the outer circle of the sleeve (2). A sealing ring (17) is provided between the sliding sleeve and the sleeve (2). A spring (3) is sleeved on the outer circle of the sliding sleeve. An annular sealing plate (12) is fixedly connected to the right end surface of the ring plate. The inner circle of the sealing plate is larger than the outer circle of the pump shaft. An axial gap is left between the sealing plate and the right end of the sleeve (2). A shaft sleeve (14) is provided on the right side of the sealing plate. The shaft sleeve is fixedly sleeved on the pump shaft. A sealing ring (16) is provided between the shaft sleeve and the pump shaft. The left end of the shaft sleeve has a flange (13).

2. The shutdown sealing device of a centrifugal pump according to claim 1, characterized in that: A stopper (18) is provided on the pump cover, the disc body is located in the stopper, and the inner circle of the stopper matches the outer circle of the disc body.

3. The shutdown sealing device of a centrifugal pump according to claim 1, characterized in that: A cylinder (10) extends to the right at the edge of the ring plate. The outer circle of the sealing plate is smaller than the inner circle of the cylinder. The sealing plate is located in the cylinder. The pressing sleeve (11) extends into the cylinder and abuts against the sealing plate. The flange of the pressing sleeve is connected to the cylinder by screws.

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