Bidirectional tripping barring gear of steam turbine

Abstract

The utility model discloses a turbine two-way tripping turning gear, which relates to the technical field of turbine turning and comprises a turbine bearing box, the turbine two-way tripping turning gear is mounted on an upper cover of the turbine bearing box, and a shifting fork is rotatably connected to the upper portion of a shell of the turbine two-way tripping turning gear and used for shifting a small spiral gear. The barring motor drives the barring shaft through a chain; the turning gear is connected to the rotor and meshed with the small spiral gear. The belleville spring is fixed on the right side of the small spiral gear; the first inductive switch is positioned on the side of the fork; the output end of the oil cylinder is rotationally connected with the barring shaft through a thrust bearing; and the electromagnetic valve is electrically connected with the first inductive switch. On the basis of spiral gear connection, the meshing gear of the turning gear can be automatically disengaged when a unit rotates forwards and reversely, and damage to the turning gear and the rotor due to reverse rotation of the unit is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbine turning gear devices, and more specifically, to a steam turbine bidirectional tripping turning gear device. Background Art

[0002] The turbine cranking device is mainly divided into two categories according to the power source: electric cranking device and hydraulic cranking device. Among them, the electric cranking device is further divided into the following categories according to the structural characteristics: 1) electric cranking device with a screw shaft; 2) electric cranking device with an oscillating gear; 3) electric cranking device with a sprocket-worm gear. The hydraulic cranking device is a pulse cranking device. The cranking device must be completely stopped before the turbine unit is started. The start-up is not allowed during use. The electric cranking device is a continuous cranking device. The turbine unit can be started after the cranking device is stopped and disengaged, and the turbine unit can also be started by start-up in the cranking state.

[0003] The above-mentioned electric cranking device structure is such that when the turbine starts and the speed of the rotor in the cranking and normal operation rotation directions of the unit is higher than the cranking speed, the passive gear on the originally meshed rotor becomes the active gear, and the active gear driven by the motor is changed to the passive gear, that is, the cranking gear drives the meshing gear to rotate, the force received by the gear changes direction, and the cranking gear driven by the motor moves to the disengaged position along the cranking axis and exits the meshing position, thereby realizing automatic tripping in the positive overspeed direction.

[0004] However, during its use, when the driven equipment (such as a centrifugal compressor, etc.) fails due to equipment or pipeline components, and the driven machine rotor reverses during the cranking process due to problems such as gas backflow, which drives the turbine rotor to reverse, the above-mentioned cranking devices cannot achieve reverse release, which can easily cause damage to the cranking device or the rotor crank wheel. Utility Model Content

[0005] In order to overcome the above-mentioned defects of the prior art, the utility model provides a steam turbine bidirectional tripping turning gear device.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A steam turbine bidirectional tripping turning gear device, comprising a steam turbine bearing housing, wherein the steam turbine bidirectional tripping turning gear device is mounted on an upper cover of the steam turbine bearing housing; the steam turbine is provided with a rotor, and further comprises a shift fork, a turning gear shaft, a turning gear, a small helical gear, a disc spring, a turning motor, an oil cylinder, a sprocket, a thrust bearing, a first induction switch, and an electromagnetic valve;

[0008] The shift fork is rotatably connected to the upper portion of the housing of the steam turbine bidirectional tripping winch device, and is used to shift the small helical gear;

[0009] The turning motor is fixed to the upper part of the housing, and the output end of the turning motor is connected to the sprocket, and the sprocket drives the turning shaft through a chain;

[0010] The small helical gear is fixed to the turning shaft;

[0011] The turning gear is connected to the rotor, and the turning gear and the small helical gear are meshed with each other;

[0012] The disc spring is fixed to the right side of the small helical gear;

[0013] The first induction switch is located on the side of the shift fork, close to the small helical gear, and is used to control the solenoid valve;

[0014] The output end of the oil cylinder is rotatably connected to the turning shaft via the thrust bearing;

[0015] The solenoid valve is electrically connected to the first induction switch and is used to control the unloading of the oil cylinder that supports the axial force of the turning shaft.

[0016] As a further preferred embodiment of the present invention, the oil cylinder is replenished with oil through an oil inlet and the oil is returned through an oil return line connected to the oil cylinder, so as to be used for the circulation of the hydraulic oil.

[0017] As a further preference of the present invention, a flow limiting orifice is provided in the oil circuit between the oil inlet and the oil cylinder. The flow limiting orifice can reduce the pressure of the fluid by throttling, thereby reducing the impact of the fluid on the pipeline and equipment and extending the service life of the equipment.

[0018] As a further preferred embodiment of the present invention, a second induction switch for displaying the position of the cylinder piston is provided between the oil cylinder and the thrust bearing, so as to facilitate detection of the piston position.

[0019] Technical effects and advantages of the utility model:

[0020] The purpose of the utility model is to provide a two-way tripping cranking device for a steam turbine to solve the problem that the meshing gears of the cranking device cannot be automatically disengaged when the turbine rotor is reversed. On the basis of the helical gear connection, an oil cylinder and matching electronic components are added, which can not only meet the requirements of automatically tripping and exiting the cranking when the steam turbine is directly started under normal cranking state, but also achieve the purpose of automatically disengaging and exiting the cranking when a reverse failure occurs in the unit shaft system under the cranking state, so that the meshing gears of the cranking device can be automatically disengaged when the unit is rotating forward and reverse, thereby avoiding damage to the cranking device and the rotor due to the reversal of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The utility model is a structural schematic diagram of a steam turbine bidirectional tripping turning gear device.

[0022] Figure 2 The utility model is a schematic diagram of the engagement state of a steam turbine bidirectional tripping winch device.

[0023] Figure 3 The utility model is a schematic diagram of a steam turbine bidirectional tripping winch device in a forward tripping state.

[0024] Figure 4 The utility model is a schematic diagram of a reverse tripping state of a steam turbine bidirectional tripping winch device.

[0025] Figure 5 for Figure 1 Cross-sectional view at AA.

[0026] The accompanying drawings are marked as follows: 1. shift fork; 2. turning shaft; 3. first induction switch; 4. turning gear; 5. small helical gear; 6. disc spring; 7. turning motor; 8. second induction switch; 9. oil cylinder; 10. sprocket; 11. thrust bearing; 12. solenoid valve; 13. oil return line; 14. oil inlet; 15. flow limiting orifice. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] See attached Figure 1-4As shown, a steam turbine bidirectional tripping turning gear device includes a steam turbine bearing box, the steam turbine bidirectional tripping turning gear device is installed on the upper cover of the steam turbine bearing box, and the steam turbine is provided with a rotor, characterized in that it also includes a shift fork 1, a turning shaft 2, a turning gear 4, a small helical gear 5, a disc spring 6, a turning motor 7, an oil cylinder 9, a sprocket 10, a thrust bearing 11, a first induction switch 3 and a solenoid valve 12; the shift fork 1 is rotatably connected to the upper part of the housing of the steam turbine bidirectional tripping turning gear device, for shifting the small helical gear 5; the turning motor 7 is fixed to the upper part of the housing, and its output end is connected to the sprocket 10, which drives the turning shaft 2 through a chain; the small helical gear 5 is fixed to the turning shaft 2; the turning gear 4 is fixedly connected to The rotor, the winch gear 4 and the small helical gear 5 are meshed with each other; the disc spring 6 is fixed to the right side of the small helical gear 5; the first induction switch 3 is located on the side of the fork 1, and the solenoid valve 12 is electrically connected to the first induction switch 3, which is used to control the unloading of the cylinder 9 that supports the axial force of the winch shaft 2 close to the small helical gear 5, and is used to control the solenoid valve 12; the output end of the cylinder 9 is rotationally connected to the winch shaft 2 through the thrust bearing 11, and the cylinder 9 is replenished with oil through the oil inlet 14, and returned to the oil through the return oil line 13 connected to the cylinder 9 for the circulation of hydraulic oil. A second induction switch 8 for displaying the piston position of the cylinder 9 is provided between the cylinder 9 and the thrust bearing 11 to facilitate the detection of the piston position.

[0029] like Figure 1 As shown, in the embodiment of the present invention, a flow limiting orifice 15 is provided in the oil circuit between the oil inlet 14 and the oil cylinder 9. The flow limiting orifice 15 can reduce the pressure of the fluid through the throttling effect, slow down the oil inlet speed, and thus slow down the filling speed of the oil in the oil cylinder, thereby avoiding the problem that the oil cylinder cannot be quickly drained during reverse tripping due to excessive cylinder flow, thereby reducing the tripping response speed; the safety of reverse tripping is improved by the flow limiting orifice, and the impact of the fluid on the pipeline and equipment is reduced by reducing the oil inlet speed, thereby extending the service life of the equipment.

[0030] During the operation of the present invention, during normal cranking, the axial force generated by the cranking is balanced with the pressure of the oil cylinder 9, and the oil pressure before and after the flow-limiting orifice 15 is basically the same. When the turbine rotor reverses and reverse trips during the cranking process, the oil inlet 14 is provided with the flow-limiting orifice 15, and the aperture of the oil return path 13 is much larger than the aperture of the flow-limiting orifice 15. Therefore, at the moment of reverse tripping, the oil inlet pressure at the oil inlet 14 is low, the flow rate is small, and the flow rate is slow, so the oil in the oil cylinder 9 can be quickly drained, thereby achieving rapid tripping.

[0031] like Figure 2As shown, during the working process of the embodiment of the utility model, the turbine bidirectional tripping cranking device is driven by the cranking motor 7 through the sprocket 10 and the chain to drive the cranking shaft 2 and the small helical gear 5 to rotate, and the small helical gear 5 and the cranking gear 4 are engaged with each other to drive the rotor shaft system to achieve cranking, wherein the cranking gear 4;

[0032] like Figure 3 As shown, during the operation of the embodiment of the present invention, the steam turbine is normally started in the cranking state. When the speed of the steam turbine rotor exceeds the cranking speed, the relationship between the driving wheel and the driven wheel changes, the force direction of the gears changes, and the small helical gear 5 automatically springs to the left and disengages from the rotor, achieving positive tripping.

[0033] like Figure 4 and Figure 5 As shown, during the operation of the embodiment of the present invention, when the rotor reverses due to a fault during the cranking process, the oil cylinder 9 balances the axial force generated by the cranking shaft 2 during the cranking through the thrust bearing 11 on the piston. The axial force on the cranking shaft 2 increases, and the disc spring 6 on the right side of the small helical gear 5 continues to be compressed. The signal of the first induction switch 3 on the side of the shift fork 1 changes, and the control solenoid valve 12 quickly unloads the oil pressure of the oil cylinder 9 that supports the axial force. Under the push of the cranking gear 4, the small helical gear 5, the cranking shaft 2 and the piston of the oil cylinder 9 spring open to the right, disengaging the two meshing gears and realizing reverse tripping.

[0034] During the operation of the embodiment of the present invention, after the generator set rotor stops completely, the cranking shaft 2 and the small helical gear 5 are restored to the forward disengaged position to prepare for the next cranking.

[0035] The working process of the present invention is as follows: when the turbine is started by impulse, and the speed of the turbine rotor exceeds the turning speed, the relationship between the master and slave gears driving the unit turning changes, resulting in a change in the force direction of the gears. The small helical gear 5 is pushed to the left by the turning gear 4 until it is completely disengaged and realizes positive tripping. The turning motor 7 and the oil pipeline are turned off to complete the turning. When in the turning state, due to the reverse rotation of the faulty rotor, the turbine rotor is reversed, and the turning small helical gear 5 moves to the right. The force on the butterfly spring increases until the spring compression increases, triggering the position sensing switch signal change on the side of the shift fork 1, and then triggering the solenoid valve 12 to open, so that the oil cylinder 9 supporting the axial force quickly unloads the pressure oil. Under the push of the turning gear 4, the small helical gear 5, the turning shaft 2 and the piston of the oil cylinder 9 bounce to the right, disengaging the two meshing gears and realizing reverse tripping. The turning motor 7 is turned off. After the unit rotor stops completely, the turning shaft 2 and the small helical gear 5 are restored to the normal disengaged position to prepare for the next turning.

[0036] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A steam turbine bidirectional tripping turning gear device, comprising a steam turbine bearing housing, wherein the steam turbine bidirectional tripping turning gear device is mounted on an upper cover of the steam turbine bearing housing, wherein a rotor is disposed within the steam turbine bearing housing, and wherein: It also includes a shift fork, a crankshaft, a crank gear, a small helical gear, a disc spring, a crank motor, an oil cylinder, a sprocket, a thrust bearing, a first induction switch and a solenoid valve; The shift fork is rotatably connected to the upper portion of the housing of the steam turbine bidirectional tripping winch device, and is used to shift the small helical gear; The turning motor is fixed to the upper part of the housing, and the output end of the turning motor is connected to the sprocket, and the sprocket drives the turning shaft through a chain; The small helical gear is fixed to the turning shaft; The turning gear is connected to the rotor, and the turning gear and the small helical gear are meshed with each other; The disc spring is fixed to the right side of the small helical gear; The first induction switch is located on the side of the shift fork, close to the small helical gear, and is used to control the solenoid valve; The output end of the oil cylinder is rotatably connected to the turning shaft via the thrust bearing; The solenoid valve is electrically connected to the first induction switch and is used to control the unloading of the oil cylinder that supports the axial force of the turning shaft.

2. The steam turbine bidirectional tripping turning device according to claim 1, characterized in that: The oil cylinder is replenished with oil through the oil inlet and is returned to the oil cylinder through the oil return path connected to the oil cylinder.

3. The steam turbine bidirectional tripping turning gear device according to claim 2, characterized in that: A flow limiting orifice is provided in the oil circuit between the oil inlet and the oil cylinder.

4. The steam turbine bidirectional tripping turning gear device according to claim 1, characterized in that: A second induction switch for displaying the position of the oil cylinder piston is provided between the oil cylinder and the thrust bearing.

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