Turbine instrument cable leading-out sealing structure

Abstract

The utility model relates to the technical field of steam turbines, and particularly discloses a steam turbine instrument cable leading-out sealing structure which comprises a leading-out pipe arranged on a machine body, a cable is arranged in the leading-out pipe in a penetrating mode, the two ends of the leading-out pipe are provided with a front end sealing assembly and a tail end sealing assembly respectively, and the front end sealing assembly and the tail end sealing assembly can block a gap between the cable and the leading-out pipe. A sealing cavity is formed in the outlet pipe and located between the front end sealing assembly and the tail end sealing assembly. According to the utility model, the front end sealing assembly and the tail end sealing assembly are used for sealing the two ends of the part, located at the outlet pipe, of the cable to form internal and external dual sealing, the tightening sealing element is arranged in the front end sealing assembly located on the outer side and used for fixing the cable, and the elastic sealing element is used for performing primary sealing on the cable; second sealing is carried out through cooperation of the positioning sealing piece and the oil seal which are located on the inner side, and the sealing effect on cable gaps is greatly enhanced through double sealing; and a tightening sealing piece and the like are adopted, so that leakage caused by gaps due to displacement of the cable is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbines, in particular to a sealing structure for steam turbine instrument cables. Background Art

[0002] During the daily operation of the steam turbine, inspectors are required to use temperature and vibration measuring instruments to check the measuring points of the equipment. The instrument cables for measuring shaft temperature and vibration of the steam turbine need to pass through the body for wiring measurement, and there is oil inside the body. Therefore, a sealing component is required to seal the cable leading out of the steam turbine. The sealing component must ensure that it can both lead out the cable and seal to prevent oil leakage.

[0003] The existing sealing structure is composed of a nut, several sealing rings and a rubber sleeve. When the nut is tightened, the rubber sleeve and the sealing ring are squeezed so that the two are sealed in the gap between the cable and the steam turbine, thereby achieving the purpose of sealing.

[0004] However, the existing sealing structure has the problem of poor sealing effect. At the same time, when the cable is repeatedly used, it is easy to shift and form gaps, causing oil leakage. Utility Model Content

[0005] In view of the deficiencies in the prior art, the utility model provides a steam turbine instrument cable lead-out sealing structure, which solves the problems of poor sealing effect of the existing steam turbine instrument cable sealing structure and oil leakage caused by gaps when the cable is repeatedly used.

[0006] In order to solve the above technical problems, the utility model is implemented through the following technical solutions: a steam turbine instrument cable lead-out sealing structure, comprising a lead-out pipe arranged on a machine body, the lead-out pipe is used to pass the cable, and also comprises: a front end sealing component and a rear end sealing component; the front end sealing component (3) and the rear end sealing component (4) are respectively arranged at the two ends of the lead-out pipe to seal the gap between the cable and the lead-out pipe, and a sealed chamber is formed in the lead-out pipe and between the front end sealing component and the rear end sealing component.

[0007] Preferably, the lead-out pipe includes a connecting section a and a connecting section b, the front end sealing assembly is arranged on the connecting section a, and the tail end sealing assembly is arranged on the connecting section b; the axis of the connecting section a and the axis of the connecting section b are in a vertical or coaxial relationship.

[0008] Preferably, the front end sealing assembly comprises: a buckle cap, a tightening seal and an elastic seal, and the cable passes through the buckle cap, the tightening seal and the elastic seal in sequence;

[0009] The buckle cap is fixed on the outlet pipe through a nut;

[0010] A tightening seal is arranged inside the buckle cap;

[0011] The elastic sealing member is fitted onto the tightening sealing member and the lead-out pipe.

[0012] Preferably, the tightening seal comprises a first sealing ring and a clamping joint abutting against the bottom surface of the first sealing ring.

[0013] Preferably, the clamping connector is a connector plastic claw made of metal, which is deformed when squeezed and its claw part is tightened inwardly and fixed on the cable.

[0014] Preferably, the elastic sealing member comprises a second sealing ring and a third sealing ring, and an elastic member is abutted and connected between the second sealing ring and the third sealing ring.

[0015] Preferably, the second sealing ring comprises a cylinder having a hollow cavity inside for the cable to pass through, wherein an upper sealing section, a first sealing cavity and a lower sealing section are sequentially arranged in the hollow cavity from top to bottom, and the first sealing cavity is arranged around the circumference of the cylinder.

[0016] Preferably, the elastic member is a top-to-top wave spring or a strong spring.

[0017] Preferably, the tail end sealing assembly comprises a guide sleeve, an oil seal and a positioning seal which are sequentially stacked and screwed; a second sealing cavity is left between the inner side of the oil seal and the cable.

[0018] Preferably, the positioning seal comprises: a positioning sleeve and a rubber sleeve;

[0019] A positioning sleeve, fixed on the outlet pipe;

[0020] The rubber sleeve is arranged inside the positioning sleeve and wraps the cable.

[0021] The utility model has the following beneficial effects:

[0022] By using a steam turbine instrument cable lead-out sealing structure provided by the utility model, a front-end sealing component and a rear-end sealing component are used to seal the two ends of the cable located at the lead-out pipe part, so as to form an internal and external double seal, a tightening seal is arranged in the front-end sealing component located on the outside to fix the cable, an elastic seal performs a first seal on the cable, and a positioning seal and an oil seal located on the inside cooperate to perform a second seal, and the double seal greatly enhances the sealing effect on the cable gap; the tightening seal can lock and fix the cable, and the elastic part arranged in the elastic seal can squeeze the second sealing ring and the third sealing ring to reduce the possibility of their displacement, so that both have the effect of avoiding leakage caused by gaps due to cable displacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is a structural schematic diagram of the connection state of the sealing structure of the utility model connected to the machine body;

[0024] Figure 2 It is a structural schematic diagram of the second connection state of the sealing structure of the utility model connected to the machine body;

[0025] Figure 3 This is a diagram showing the state of use of the cable of the utility model when it is introduced into the sealing structure;

[0026] Figure 4 This is a schematic diagram of the structure of the tail end sealing assembly of the utility model;

[0027] Figure 5 This is an exploded view of the front end sealing component structure of the utility model;

[0028] Figure 6 It is a three-dimensional partial cross-sectional view of the second sealing ring of the utility model.

[0029] Description of reference numerals:

[0030] 1 body;

[0031] 2. Lead-out pipe;

[0032] 3 front end sealing assembly, 31 buckle cap, 32 first sealing ring, 33 clamping joint, 34 second sealing ring, 34a upper sealing section, 34b first sealing cavity, 34c lower sealing section, 35 elastic member, 36 third sealing ring;

[0033] 4 tail end sealing assembly, 41 guide sleeve, 42 oil seal, 43 second sealing chamber, 44 positioning sleeve, 45 rubber sleeve;

[0034] 5 cables. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. As long as the effect of the utility model can be exerted, various changes can be made to the implementation scheme.

[0036] By those skilled in the art, the components in this case are connected in sequence. The specific connection and operation sequence should refer to the following working principle. The detailed connection means are well-known technologies in the art. The following mainly introduces the working principle and process.

[0037] Reference Figure 1-6 A steam turbine instrument cable lead-out sealing structure and its installation method according to this implementation scheme are described.

[0038] The utility model discloses a steam turbine instrument cable lead-out sealing structure comprising: a lead-out pipe 2, a front end sealing component 3 and a rear end sealing component 4.

[0039] The outlet pipe 2 is provided on the machine body 1, and a cable 5 is passed through the outlet pipe 2. The front end sealing component 3 and the rear end sealing component 4 are respectively provided at the two ends of the outlet pipe 2 to seal the gap between the cable 5 and the outlet pipe 2, and a sealed chamber is formed in the outlet pipe 2 between the front end sealing component 3 and the rear end sealing component 4. When the cable 5 is led out from the outlet pipe 2, it passes through the front end sealing component 3 and the rear end sealing component 4 respectively. During the passing process, the outer wall surface of the cable 5 is tightly attached to the front end sealing component 3 and the rear end sealing component 4, forming a seal at the gap when the cable 5 passes through the machine body 1, thereby preventing oil leakage inside the machine body 1.

[0040] The outlet pipe 2 includes a connecting section a and a connecting section b, a front end sealing assembly 3 is arranged on the connecting section a, and a rear end sealing assembly 4 is arranged on the connecting section b; the connecting section b is connected to the body 1, or is integrally formed with the body 1.

[0041] The axis of the connecting section a and the axis of the connecting section b are in a perpendicular or coaxial relationship. Figure 1 As shown, the connection section a and the connection section b are in a vertical relationship, that is, the outlet of the lead-out pipe 2 is bent to one side to change the lead-out direction of the cable 5. Figure 2 As shown, the connection section a is arranged on the connection section b to form a coaxial relationship, that is, the outlet pipe 2 is a straight pipe. Furthermore, the connection section a and the connection section b can also be connected in an inclined relationship, and the formation method of the outlet pipe 2 can be selected according to the actual use scenario. In this embodiment, it is only necessary to pay attention to that the front end sealing component 3 and the rear end sealing component 4 are arranged at the two ends of the outlet pipe 2.

[0042] During installation, all parts of the front-end sealing component 3 and the rear-end sealing component 4 are pre-set on the cable 5, and the rear-end sealing component 4 is installed first, and then the elastic seal of the front-end sealing component 3 is installed. High-pressure gas can be filled into the sealing chamber, and then the sealing chamber is blocked by the elastic seal. After the high-pressure gas is filled into the sealing chamber, the gas will press against the front-end sealing component 3 and the rear-end sealing component 4, thereby improving the sealing effect of the front-end sealing component 3 and the rear-end sealing component. Accordingly, in order to simplify the operation process during installation, the step of filling with high-pressure gas can also be eliminated.

[0043] In one embodiment, the front end sealing assembly 3 includes a buckle cap 31, a tightening seal and an elastic seal. The cable 5 passes through the buckle cap 31, the tightening seal and the elastic seal in sequence.

[0044] The buckle cap 31 is fixed to the outlet pipe 2 through a nut, and the tightening seal and the elastic seal are pressed together and fixed in the outlet pipe 2; the tightening seal is arranged in the buckle cap 31; the elastic seal is pressed against the tightening seal and the outlet pipe 2.

[0045] The tightening seal comprises a first sealing ring 32 and a clamping joint 33 abutting against the bottom surface of the first sealing ring 32. The clamping joint is a joint plastic claw, preferably made of metal, which deforms when squeezed, and its claw part tightens inward and clamps on the cable 5, thereby locking and fixing the cable 5 to prevent the cable 5 from shifting due to dragging and causing leakage in the gap.

[0046] The elastic seal comprises a second sealing ring 34 and a third sealing ring 36, and an elastic member 35 is abutted and connected between the second sealing ring 34 and the third sealing ring 36. The elastic member 35 is a top-to-top wave spring or a strong spring. When the buckle 31 is installed, its pressure compresses the elastic member 35 to deform it, and the elastic restoring force of the elastic member 35 squeezes the second sealing ring 34 and the third sealing ring 36, so that the second sealing ring 34 and the third sealing ring 36 are continuously fixed by the thrust, reducing the possibility of their displacement, thereby avoiding leakage caused by gaps due to the displacement of the cable 5, and ensuring the sealing effect of the elastic seal.

[0047] The second sealing ring 34 includes a cylinder, and the inside of the cylinder has a hollow cavity for the cable 5 to pass through. The upper sealing section 34a, the first sealing cavity 34b and the lower sealing section 34c are arranged in sequence from top to bottom in the hollow cavity, and the first sealing cavity 34b is arranged around the circumference of the cylinder. It should be explained in detail that the bottom part of the clamping joint 33 is located at the upper sealing section 34a, and is tightened by the second sealing ring 34 to deform the clamping joint 33, so that its claws are tightened inwardly and fixed on the cable 5, thereby locking and fixing the cable 5.

[0048] The lower sealing section 34c is tightly fitted on the cable 5. The first sealing cavity 34b is filled with solid sealing grease to prevent leakage of oil and gas.

[0049] In one embodiment, the tail end sealing assembly 4 includes a guide sleeve 41 , an oil seal 42 and a positioning seal which are stacked in sequence; a second sealing cavity 43 is left between the inner side of the oil seal 42 and the cable 5 .

[0050] The positioning seal comprises a positioning sleeve 44 and a rubber sleeve 45. The positioning sleeve 44 is fixed on the lead-out pipe 2; the rubber sleeve 45 is arranged inside the positioning sleeve 44 and wraps the cable 5.

[0051] The second sealing cavity 43 inside the oil seal 42 is filled with solid sealing grease to prevent leakage of oil and gas. The positioning sleeve 44 fixes the rubber sleeve 45, the oil seal 42 and the guide sleeve 41. The rubber sleeve 45 fits tightly on the cable 5, and at the same time limits and fixes the oil seal 42 and the solid sealing grease in the second sealing cavity 43.

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A steam turbine instrument cable lead-out sealing structure, comprising a lead-out pipe (2) arranged on a turbine body, wherein the lead-out pipe (2) is used for passing cables, and is characterized in that: It also includes: a front end sealing component (3) and a rear end sealing component (4); The front end sealing component (3) and the rear end sealing component (4) are respectively arranged at the two ends of the lead-out tube (2) to seal the gap between the cable and the lead-out tube (2); a sealed chamber is formed in the lead-out tube (2) between the front end sealing component (3) and the rear end sealing component (4).

2. A steam turbine instrument cable lead-out sealing structure according to claim 1, characterized in that: The outlet pipe (2) comprises a connecting section a and a connecting section b, the front end sealing component (3) is arranged on the connecting section a, and the rear end sealing component (4) is arranged on the connecting section b; The axis of the connecting section a and the axis of the connecting section b are in a vertical or coaxial relationship.

3. A steam turbine instrument cable lead-out sealing structure according to claim 1 or 2, characterized in that: The front end sealing assembly (3) comprises: a buckle cap (31), a tightening seal and an elastic seal, and the cable passes through the buckle cap (31), the tightening seal and the elastic seal in sequence; The buckle cap (31) is fixed on the outlet pipe (2) via a nut; The tightening seal is arranged in the buckle (31); The elastic sealing member abuts against the tightening sealing member and the lead-out pipe (2).

4. A steam turbine instrument cable lead-out sealing structure according to claim 3, characterized in that: The tightening seal comprises a first sealing ring (32) and a clamping joint (33) abutting against the bottom surface of the first sealing ring (32).

5. A steam turbine instrument cable lead-out sealing structure according to claim 4, characterized in that: The clamping connector (33) is a connector plastic claw made of a metal piece, which deforms when squeezed and its claw portion tightens inwards and is fixed on the cable.

6. A steam turbine instrument cable lead-out sealing structure according to claim 3, characterized in that: The elastic sealing member comprises a second sealing ring (34) and a third sealing ring (36), and an elastic member (35) is abutted and connected between the second sealing ring (34) and the third sealing ring (36).

7. A steam turbine instrument cable lead-out sealing structure according to claim 6, characterized in that: The second sealing ring (34) comprises a cylinder having a hollow cavity inside the cylinder for the cable to pass through, wherein an upper sealing section (34a), a first sealing cavity (34b) and a lower sealing section (34c) are arranged in sequence from top to bottom in the hollow cavity, and the first sealing cavity (34b) is arranged around the circumference of the cylinder.

8. A steam turbine instrument cable lead-out sealing structure according to claim 6, characterized in that: The elastic member (35) is a top-to-top wave spring or a strong spring.

9. A steam turbine instrument cable lead-out sealing structure according to claim 1 or 2, characterized in that: The tail end sealing assembly (4) comprises a guide sleeve (41), an oil seal (42) and a positioning seal which are stacked in sequence; A second sealing cavity (43) is left between the inner side surface of the oil seal (42) and the cable (5).

10. A steam turbine instrument cable lead-out sealing structure according to claim 9, characterized in that: The positioning seal comprises: a positioning sleeve (44) and a rubber sleeve (45); The positioning sleeve (44) is fixed on the outlet pipe (2); The rubber sleeve (45) is arranged inside the positioning sleeve (44) and wraps the cable.

Images