Valve shaft sealing device

Abstract

A shaft sleeve is fixedly installed on a valve body through a bolt, an O-shaped sealing ring is installed between the shaft sleeve and a valve shaft, an oil box is fixedly installed on the valve body through a bolt, an O-shaped sealing ring is installed between the oil box and the valve shaft, the outer portion of the shaft sleeve is integrally contained in the oil box, a grease nipple is installed on the oil box, and the oil box is filled with grease. The shaft sleeve and the O-shaped sealing ring installed on the shaft sleeve can completely meet the sealing requirement of the valve under the normal working condition. Meanwhile, second effective sealing is formed by the butter, and medium leakage caused by shaking of the valve shaft or abrasion of the O-shaped sealing ring of the shaft sleeve can be completely prevented; and an O-shaped sealing ring is also arranged between the oil box and the valve shaft, so that grease can be prevented from flowing out, and third effective sealing is formed. In addition, the grease in the grease box has a good lubricating effect on the shaft sleeve and the O-shaped sealing ring, and the service life of the shaft sleeve and the O-shaped sealing ring can be greatly prolonged.

Description

Technical Field

[0001] This invention patent relates to a valve shaft sealing device, especially a sealing device for rotary valves that can prevent medium leakage. Background Art

[0002] In existing pipe network systems, traditional valves for controlling fluid media include butterfly valves, ball valves, cock valves, and hemisphere valves. These traditional valves have a common feature that their valve plates or valve cores are fixedly connected to the valve shaft and rotate around the valve shaft centerline during opening and closing operations. Currently, the commonly used sealing device at the connection between the valve shaft and the valve body is to set a stuffing box on the valve body, fill asbestos packing or flexible graphite packing in the stuffing box, and then tighten the bolts of the stuffing gland to compress the packing to achieve the sealing purpose. The advantage of this sealing device is the low cost of the packing, but the disadvantage is that the sealing effect is not ideal, and phenomena such as running, leaking, dripping, and oozing often occur, resulting in a large amount of maintenance work. The reason for the unsatisfactory sealing effect of this sealing device is that after the packing is compressed, its sealing position is relatively fixed, but the valve shaft vibrates due to the fluctuation of the fluid medium, and the shaft is pushed to one side by the unidirectional force of the fluid medium, resulting in a gap between the valve shaft and the packing, and at this time, medium leakage will occur at the valve shaft end of the valve body. Currently, the phenomena of running, leaking, dripping, and oozing caused by the failure of the valve shaft seal have always been difficult problems that the valve industry has not been able to solve. Summary of the Invention

[0003] The purpose of this invention patent is to provide a valve shaft sealing device that can not only meet the sealing requirements at the connection between the valve body and the valve shaft, effectively prevent external leakage, but also solve the technical problems of easy failure of the packing in the traditional valve shaft sealing device, short service life, and large maintenance workload.

[0004] The technical solution of this invention patent: This valve sealing device is composed of a shaft sleeve, an "O" - shaped sealing ring, grease, an oil box, a grease nipple, bolts, etc.; the shaft sleeve is fixedly installed on the valve body with bolts, an "O" - shaped sealing ring is installed between the shaft sleeve and the valve shaft, the oil box is fixedly installed on the valve body with bolts, an "O" - shaped sealing ring is installed between the oil box and the valve shaft, the outside of the shaft sleeve is integrally contained within the oil box, a grease nipple is installed on the oil box, and the oil box is filled with grease.

[0005] This valve shaft sealing device meets the sealing requirements through the reasonable combination of an "O" - ring seal and grease. When the valve shaft is in a static state, the "O" - ring set on the shaft sleeve can meet the sealing requirements. When opening and closing the valve, due to the fluctuating impact of the pressure medium, it will cause the valve shaft to shake and be squeezed against the side. At this time, because the "O" - ring has good elasticity, it can always ensure the sealing effect between the shaft sleeve and the valve shaft. If the valve is opened and closed frequently for a long time, causing wear of the "O" - ring and affecting its sealing effect, since the oil box is filled with grease, the grease forms a tight oil seal on the entire shaft sleeve. In this way, the grease in the oil box forms a second effective seal to prevent the leakage of the pressure medium. Finally, an "O" - ring is also installed between the oil box and the valve shaft, which not only prevents the outflow of grease but also is the third effective seal to prevent the leakage of the pressure medium. At the same time, the grease in the oil box also has a good lubricating effect on the oil sleeve and the "O" - ring, so it can greatly extend the service life of the shaft sleeve and the "O" - ring. Therefore, this valve shaft sealing device completely solves the technical problems of the traditional packing seal of the sealing device, such as easy failure, short service life, and large maintenance workload. Brief Description of the Drawings

[0006] Figure 1 It is a schematic diagram of the structural principle of this invention patent.

[0007] 1. Valve body; 2. "O" - ring seal; 3. "O" - ring seal; 4. Valve shaft; 5. Shaft sleeve; 6. Bolt; 7. Grease nipple; 8. Grease; 9. "O" - ring seal; 10. Oil box; 11. Bolt Detailed Description of the Invention

[0008] Figure 1 This is an embodiment of the valve shaft sealing device. The shaft sleeve 5 of this valve shaft sealing device is fixedly installed on the valve body 1 with bolts 6. An "O" - ring seal 2 and an "O" - ring seal 3 are installed between the shaft sleeve 5 and the valve shaft 4. The oil box 10 is fixedly installed on the valve body 1 with bolts 11. An "O" - ring seal 9 is installed between the oil box 10 and the valve shaft 4. A grease nipple 7 is installed on the oil box 10, and the inner cavity of the oil box 10 is filled with grease 8.

[0009] When the valve is in normal working condition, the valve shaft 4 has no jitter phenomenon. The shaft sleeve 5, "O" - ring seal 2 and "O" - ring seal 3 of this valve shaft sealing device can form a reliable seal at the connection between the valve body 1 and the valve shaft 4; when the pressure medium inside the valve fluctuates, it will cause the jitter and side extrusion of the valve shaft 4, resulting in a larger unilateral gap and affecting the sealing effect. At this time, due to the good elasticity of the "O" - ring seal 2 and "O" - ring seal 3, the gap can be basically compensated, and the sealing effect can still be ensured; when the "O" - ring seal 2, "O" - ring seal 3 and shaft sleeve 5, etc. lose their sealing function due to rupture, wear, aging, etc., the butter 8 filled in the inner cavity of the oil box 10 forms an oil seal around the shaft sleeve 5, which can completely prevent the pressurized medium in the valve body from leaking out; in addition, an "O" - ring seal 9 is also installed between the oil box 10 and the valve shaft 4, which can not only prevent the butter 8 in the inner cavity of the oil box 10 from flowing out, but also further prevent the pressurized medium in the valve body from leaking out. Therefore, this valve shaft sealing device forms triple - effective seals between the valve body 1 and the valve shaft 4. At the same time, the butter 8 filled in the inner cavity of the oil box 10 has a good lubricating effect on the shaft sleeve 5, "O" - ring seal 2 and "O" - ring seal 9, so it can greatly extend their service life and ensure that the valve shaft sealing device can still maintain a good sealing effect after long - term use.

Claims

1. A valve shaft sealing device, which is composed of a shaft sleeve, an "O" - shaped sealing ring, grease, an oil box, a grease nipple, bolts, etc., and is characterized in that: The shaft sleeve is fixedly installed on the valve body with bolts, and an "O" - shaped sealing ring is installed between the shaft sleeve and the valve shaft. The oil box is fixedly installed on the valve body with bolts, and an "O" - shaped sealing ring is installed between the oil box and the valve shaft. The oil box is filled with grease.

2. The valve shaft sealing device according to claim 1, wherein: The outside of the shaft sleeve is completely contained within the oil box.

3. The valve shaft sealing device according to claim 1, characterized in that: A grease nipple is installed on the oil box.

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