Front bearing box for supporting flexible plate of steam turbine

Abstract

The utility model discloses a steam turbine flexible plate supporting front bearing box, and particularly relates to the technical field of steam turbine expansion, the steam turbine flexible plate supporting front bearing box comprises a bearing box body, a cylinder is arranged on one side of the bearing box body and located above a public base, a cylinder cat claw is installed on a bearing box supporting transverse plate through a cat claw bolt and a cat claw cushion block, and the cylinder cat claw is used for supporting the cylinder; a transverse flexible plate arranged in the axial direction of the bearing box body is fixed between the bearing box body and the cylinder, and the two ends of the transverse flexible plate are fixed to the lower half of the cylinder and the lower half of the bearing box body respectively; the multiple supporting flexible plates are arranged in parallel, the supporting flexible plates are vertical trapezoidal plates perpendicular to the axial direction, the supporting flexible plates and the transverse flexible plates are of a welding structure and do not slide relative to each other, and therefore deviation in the left-right side direction and the vertical direction cannot be generated, and the possible jamming phenomenon of a traditional guide key sliding pin structure of a steam turbine is avoided; periodic maintenance and lubricant addition are not needed, the maintenance cost is reduced, and the safety and reliability of stable operation of a unit are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbine expansion, and more specifically, the utility model relates to a flexible plate supported front bearing box of a steam turbine. Background Art

[0002] As an important component of a steam turbine unit, the bearing box not only bears the axial and radial forces generated during the operation of the unit, but is also an important part of the steam turbine unit's sliding key system, used to support the cylinder and the rotor and ensure the correct positions of the cylinder and the rotor before and after operation.

[0003] Most of the steam turbine support structures are sliding key systems, which need to be regularly injected with lubricating oil for maintenance and repair, and individual steam turbine sliding key devices sometimes get stuck, bringing certain potential hazards to the safe operation of the steam turbine. Summary of the Utility Model

[0004] In order to overcome the above-mentioned defects of the prior art, the utility model provides a flexible plate supported front bearing box of a steam turbine.

[0005] To achieve the above purpose, the utility model provides the following technical solution: a flexible plate supported front bearing box of a steam turbine, including a bearing box body, with a cylinder on one side, located above a common base, and further including a support cross plate, a support flexible plate, a bearing box support bottom plate, and a cylinder cat paw;

[0006] The cylinder cat paw is installed on the bearing box support cross plate through cat paw bolts and cat paw pads, and a certain gap is reserved between the cat paw bolts and the cylinder cat paw. The cylinder cat paw is used to support the cylinder and does not transfer the expansion force of the unit.

[0007] A transverse flexible plate is fixed between the bearing box body and the cylinder along the axial direction of the bearing box body. Both ends of the transverse flexible plate are respectively fixed to the lower half of the cylinder and the lower half of the bearing box body. The lower half of the cylinder and the lower half of the bearing box body are connected through the transverse flexible plate to transfer the axial force generated by the expansion and cooling of the unit;

[0008] There are multiple support flexible plates, which are arranged in parallel. The support flexible plate is a vertical trapezoidal plate perpendicular to the axial direction. Its upper end is fixed with a support cross plate, and the support cross plate is fixedly connected to the bearing box body. Its lower end is fixed to the bearing box support bottom plate and is located above the common base. The transverse flexible plate penetrates through the support flexible plate and is welded to it. The multiple support flexible plates are parallel to each other and perpendicular to the axial direction of the bearing box body, so as to ensure the alignment during the thermal expansion process, ensure that the length direction of the flexible plate is perpendicular to the axis line of the cylinder, and ensure that the direction of its flexible deformation is consistent with the cylinder and the axis direction, playing a guiding role.

[0009] As a further preference of the present utility model, the clearance between the cat's paw bolt and the cylinder cat's paw is 0.10 - 0.15 mm. An appropriate clearance can prevent thermal stress and accompanying vibration caused by uneven expansion.

[0010] As a further preference of the present utility model, a safety block is installed between the bearing box body and the lower half of the cylinder. The safety block is fixed to the lower half of the cylinder and faces the support cross plate. There is a clearance of 1 - 1.5 mm between the safety block and the support cross plate. The safety block is used to continue to push the cylinder after the lateral flexible plate fails, avoiding damage to the cylinder cat's paw due to shear force.

[0011] As a further preference of the present utility model, an expansion meter bracket is fixed above the support bottom plate, and an expansion meter is installed at the upper end of the expansion meter bracket, which is used to monitor the expansion of the steam turbine unit and avoid excessive expansion due to too high temperature.

[0012] As a further preference of the present utility model, the bearing box support bottom plate is fixed on the common base through the bottom plate bolts, and the common base is fixed on the foundation through the bottom plate bolts. There are adjustment shims between the bearing box support bottom plate and the common base. The adjustment shims are fixed to the common base through the bottom plate bolts, which are used to adjust and fix the support flexible plate, and adjust the center height of the bearing box body to be consistent with the center height of the cylinder.

[0013] As a further preference of the present utility model, an oil inlet flange and an oil return flange are provided below the bearing box body, which are used for oil inlet and oil return inside the bearing box body.

[0014] Technical effects and advantages of the utility model:

[0015] The structure of the front bearing box supported by the flexible plate of the steam turbine described in the present utility model is reasonably designed. The support flexible plate and the lateral flexible plate are of welded structure without relative sliding, so there will be no offset in the left - right direction and the vertical direction, thus avoiding the jamming phenomenon that may occur in the traditional guiding key and sliding pin structure of the steam turbine, eliminating the need for regular maintenance and lubricant addition, reducing the maintenance cost, and improving the safety and reliability of the stable operation of the unit. Description of the drawings

[0016] Figure 1 It is a schematic structural view of a front bearing box supported by a flexible plate of a steam turbine of the present utility model.

[0017] Figure 2 It is a top view of a front bearing box supported by a flexible plate of a steam turbine of the present utility model.

[0018] Figure 3 It is a side view of a front bearing box supported by a flexible plate of a steam turbine of the present utility model.

[0019] Figure 4 This is a cross-sectional view of the cylinder cat's paw of the front bearing box supported by a flexible plate in a steam turbine of the present utility model.

[0020] The reference numerals are: 1, cat's paw bolt; 2, cylinder cat's paw; 3, cat's paw spacer block; 4, safety block; 5, cylinder; 6, transverse flexible plate; 7, oil inlet flange; 8, bearing box support bottom plate; 9, bearing box body; 10, support cross plate; 11, oil return flange; 12, expansion meter bracket; 13, support flexible plate; 14, bottom plate bolt; 15, adjusting gasket; 16, common base. Specific embodiments

[0021] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0022] Refer to the attached Figures 1-4 As shown, a steam turbine flexible plate-supported front bearing box includes a bearing box body 9, with a cylinder 5 provided on one side thereof, above the common base 16, and also includes a support cross plate 10, a support flexible plate 13, a bearing box support bottom plate 8, and a cylinder cat's paw 2;

[0023] The cylinder cat's paw 2 is installed on the bearing box support cross plate 10 through the cat's paw bolt 1 and the cat's paw spacer block 3, and a certain gap is reserved between the cat's paw bolt 1 and the cylinder cat's paw 2. The gap between the cat's paw bolt 1 and the cylinder cat's paw 2 is 0.10 - 0.15 mm. An appropriate gap can prevent thermal stress and accompanying vibrations caused by uneven expansion. The cylinder cat's paw 2 is used to support the cylinder 5 and does not transmit the expansion force of the unit.

[0024] A transverse flexible plate 6 is fixed between the bearing box body 9 and the cylinder 5 along the axial direction of the bearing box body 9. Both ends of the transverse flexible plate 6 are respectively fixed to the lower half of the cylinder 5 and the lower half of the bearing box body 9. The lower half of the cylinder 5 and the lower half of the bearing box body 9 are connected through the transverse flexible plate 6 to transmit the axial force generated by the expansion and cooling of the unit;

[0025] There are multiple support flexible plates 13, which are arranged in parallel. The support flexible plates 13 are vertical trapezoidal plates perpendicular to the axial direction. A support cross plate 10 is fixed to the upper end thereof. The support cross plate 10 is fixedly connected to the bearing box body 9. The lower end thereof is fixed to the bearing box support bottom plate 8 and is located above the common base 16. The transverse flexible plate 6 penetrates through the support flexible plates 13 and is welded to them. The multiple support flexible plates 13 are parallel to each other and perpendicular to the axial direction of the bearing box body 9, so as to ensure the centering during the thermal expansion process. By ensuring that the length direction of the support flexible plates 13 is perpendicular to the axis line of the cylinder 5, it is ensured that the direction of the flexible deformation is consistent with the cylinder 5 and the axis direction, playing a guiding role and preventing displacement in the length direction of the support flexible plates 13.

[0026] As Figure 3 shown, in the embodiment of the present invention, a safety block 4 is installed between the bearing box body 9 and the lower half of the cylinder 5. The safety block 4 is fixed to the lower half of the cylinder 5 and faces the support cross plate 10. There is a gap of 1 - 1.5 mm between the safety block 4 and the support cross plate 10. During the expansion of the cylinder 5 during the operation of the present invention, the bearing box body 9 is pushed to move in the axial direction through the transverse flexible plate 6. When the transverse flexible plate 6 fails, the safety block 4 can continue to push the bearing box forward to transmit the expansion. The safety block 4 is used to continue to push the cylinder 5 after the transverse flexible plate 6 fails, avoiding damage to the cylinder cat's paw 2 caused by shear force.

[0027] As Figure 1 shown, in the embodiment of the present invention, an expansion meter bracket 12 is fixed above the support bottom plate. An expansion meter is installed at the upper end of the expansion meter bracket 12, which is used to monitor the expansion of the steam turbine unit and avoid excessive expansion due to too high temperature. The expansion meter is a conventional structure and will not be elaborated here.

[0028] As Figure 1 shown, in the embodiment of the present invention, the bearing box support bottom plate 8 is fixed to the common base 16 through a bottom plate bolt 14. The common base 16 is fixed to the foundation through a bottom plate bolt 14. There is an adjustment gasket 15 between the bearing box support bottom plate 8 and the common base 16. The adjustment gasket 15 is fixed to the common base 16 through a bottom plate bolt 14 and is used to adjust and fix the support flexible plates 13, and the center height of the bearing box body 9 is adjusted to be consistent with the center height of the cylinder 5 through the adjustment gasket 15.

[0029] As Figure 1 shown, in the embodiment of the present invention, an oil inlet flange 7 and an oil return flange 11 are provided below the bearing box body 9, which are used for the oil inlet and oil return inside the bearing box body 9. The oil circuit is provided for the lubrication of the bearing box body 9.

[0030] During the operation of the utility model, the exhaust position at the rear end of the steam turbine is the expansion dead point. When the unit expands due to heat, the cylinder 5 generates an axial thrust forward on the front bearing housing body 9 and the support cross plate 10 supporting the upper part of the support flexible plate 13 through the lateral flexible plate 6. The bearing housing support bottom plate 8 at the lower end of the support flexible plate 13 is fixed to the common base 16. Therefore, a bending moment is generated on the support flexible plate 13, forcing it to deform. This deformation needs to be determined through calculation within the elastic deformation range. When the unit cools down, the support flexible plate 13 returns to the state before thermal expansion again, realizing reciprocating operation.

[0031] The above are only the preferred embodiments of the utility model and are not used to limit the utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A steam turbine flexible plate supported front bearing box, comprising a bearing box body, one side of which is provided with a cylinder, located above a common base, characterized in that: Also includes a supporting cross plate, a supporting flexible plate, a bearing housing supporting bottom plate and a cylinder cat's claw; The cylinder cat claw is installed on the bearing box supporting cross plate through the cat claw bolt and the cat claw pad, and a certain gap is reserved between the cat claw bolt and the cylinder cat claw, and the cylinder cat claw is used to support the cylinder; A transverse flexible plate is fixed between the bearing box body and the cylinder and is arranged along the axial direction of the bearing box body. Two ends of the transverse flexible plate are respectively fixed to the lower half of the cylinder and the lower half of the bearing box body. The lower half of the cylinder and the lower half of the bearing box body are connected through the transverse flexible plate to transmit the axial force generated by the expansion and cooling of the unit. There are multiple supporting flexible plates, which are arranged in parallel. The supporting flexible plates are vertical trapezoidal plates perpendicular to the axial direction, with a supporting cross plate fixed on the upper end. The supporting cross plate is fixedly connected to the bearing box body, and its lower end is fixed to the bearing box supporting bottom plate and is located above the common base. The cross flexible plate passes through the supporting flexible plate and is welded to it.

2. A steam turbine flexible plate support front bearing box according to claim 1, characterized in that: The clearance between the cat's claw bolt and the cylinder cat's claw is 0.10-0.15 mm.

3. The front bearing box supported by a flexible plate of a steam turbine according to claim 1, characterized in that: A safety block is installed between the bearing box body and the lower half of the cylinder. The safety block is fixed to the lower half of the cylinder and faces the supporting cross plate. There is a 1-1.5mm gap between the safety block and the supporting cross plate.

4. The front bearing box supported by a flexible plate of a steam turbine according to claim 1, characterized in that: An expansion meter bracket is fixed above the supporting bottom plate, and an expansion meter is installed on the upper end of the expansion meter bracket.

5. The front bearing box supported by a flexible plate of a steam turbine according to claim 1, characterized in that: The bearing box support base plate is fixed to the common base through base plate bolts, and the common base is fixed to the foundation through base plate bolts; an adjustment gasket is arranged between the bearing box support base plate and the common base; the adjustment gasket is fixed to the common base through base plate bolts.

6. The front bearing box supported by a flexible plate of a steam turbine according to claim 1, characterized in that: An oil inlet flange and an oil return flange are arranged below the bearing box body and are communicated with the bearing box body.

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