CN206769963U - The centering torsion pass of multistage high speed turbine machine is locked mechanism - Google Patents

Abstract

A centering transmission torque locking combination mechanism of a multi-stage high-speed steam turbine, comprising a rotating shaft and several stages of impellers installed on the rotating shaft, the several stages of impellers are connected with the rotating shaft to drive the rotating shaft to rotate, the The impellers of each stage are connected in transmission through the meshing of end teeth, and the two ends of the impellers of several stages are respectively provided with lock nuts to apply a pre-tightening force to the impellers of each stage. The centering transmission torsion locking combined mechanism of the utility model has the advantages of high efficiency, stable transmission of axial force and torsion force, compact structure, simple assembly, strong ability to adapt to working conditions, and the like.

Description

Centering Torsion Transmission and Locking Combination Mechanism of Multi-stage High-speed Steam Turbine

technical field

The invention relates to the field of multi-stage high-speed steam turbines, in particular to a centering transmission torque locking combination mechanism of multi-stage high-speed steam turbines.

Background technique

In traditional multi-stage high-speed steam turbines, pin keys are used to realize the connection between the shaft and the impeller disc, which plays the role of torque transmission. The fastening form between the impeller disc and the shaft is also mostly realized by the interference fit of the pin key. The multi-stage high-speed steam turbine uses pin-key structure in many places, which will fail due to plastic deformation of the material during long-term operation, and the pin-key structure should not be used at high speed.

Contents of the invention

In view of this, the present invention proposes a centering torque transmission and locking combination mechanism of a multi-stage high-speed steam turbine that can effectively realize torque transmission and has a stable structure.

The present invention proposes a centering torque transmission and locking combination mechanism for a multi-stage high-speed steam turbine, which includes a rotating shaft and several stages of impellers installed on the rotating shaft, and the several stages of impellers are connected to the rotating shaft to drive the rotating shaft to rotate , the impellers of each stage are connected by transmission through the meshing of end teeth, and the two ends of the impellers of several stages are respectively provided with lock nuts to apply a pre-tightening force to the impellers of each stage.

In one embodiment, the impeller includes a disc and blades mounted on the disc, the disc has a central through hole for the shaft to pass through, and the several stages of impellers include primary impellers located at both ends and the final stage impeller and at least one intermediate stage impeller between the primary impeller and the final stage impeller, the disc of the primary impeller is provided with end teeth on the side facing the final stage impeller, and the final stage impeller The side of the disc facing the primary impeller is provided with end teeth, and both sides of the at least one intermediate stage impeller are provided with end teeth.

In one embodiment, the mating surfaces of the primary impeller and the final impeller and the rotating shaft adopt an interference fit.

In one embodiment, at least one stage of the intermediate stage impellers is in transmission connection with the shaft gear.

In one embodiment, impeller splines are provided on the wall surface of the central through hole of the at least one intermediate stage impeller, and the rotating shaft is provided on the outer wall surface of the at least one intermediate stage impeller for Shaft splines meshing with said impeller spline gears.

In one embodiment, the impellers are arranged in four stages, including a first-stage impeller, a second-stage impeller, a third-stage impeller, and a fourth-stage impeller, the first-stage impeller serves as the primary impeller, and the first-stage impeller serves as the primary impeller. The four-stage impeller is used as the last-stage impeller, and the impeller splines are arranged on the second-stage impeller.

In one embodiment, an interference fit is used between the first-stage impeller and the fourth-stage impeller and the rotating shaft for torque transmission.

In one embodiment, the interference fit between the first-stage impeller and the fourth-stage impeller and the rotating shaft is 0.08 mm, and the axial interference length is 15 mm.

In one embodiment, the thread direction of the locking nut is set to be opposite to the rotation direction of the impeller.

In one embodiment, there is a clearance fit between at least one of the intermediate stage impellers and the rotating shaft.

To sum up, the present invention proposes a centering torque transmission and locking combination mechanism for multi-stage high-speed steam turbines. The impellers of the mechanism are connected by end teeth, so that the central axis of the steam turbine can be automatically aligned at high speed. , The torque is evenly distributed to each tooth, avoiding centering failure caused by concentrated torque transmission. The pressure surface of the end tooth is pressed by the lock nut, so that the end tooth can achieve effective torque, and avoid the phenomenon of plastic deformation failure of the traditional multi-stage steam turbine pin key using interference fit torsion transmission under high-speed operation. Through this combination mechanism, the function of transmitting axial force between the wheel disc and the shaft can be realized, avoiding the appearance of various alternating cyclic stresses in one mechanism, making the function distribution of the mechanism more reasonable, and the service life longer. Compared with the transmission axial force of the traditional steam turbine The force mechanism is simpler and more reliable, and the assembly is relatively simple. In addition, in some embodiments, the present invention adopts an interference fit between the two ends of the multi-stage impeller disc and the shaft, and a clearance fit between the intermediate stage impeller and the shaft, so that the torque transmission point between the shaft and the disc It is greatly reduced, and the effective torque transmission between the shaft and the impeller can be realized only by relying on the two ends. In addition, in some embodiments, at least one wheel is connected to the shaft through an auxiliary torsion transmission structure (eg, spline) to assist torsion transmission and prevent slippage, so as to adapt to work under any working conditions. The centering torque transmission and locking combination mechanism of the present invention has the advantages of high efficiency, stable transmission of axial force and torsion force, compact structure, simple assembly, strong ability to adapt to working conditions, and the like.

Description of drawings

Fig. 1 is a structural diagram of a steam turbine rotor where the centering torque transmission and locking combination mechanism of the present invention is located.

Fig. 2 is a schematic diagram of the centering torque transmission and locking combination mechanism of the present invention.

Fig. 3 is a structural schematic diagram of the interference fit surface of the impeller of the present invention.

Fig. 4 is a structural schematic diagram of the end teeth connection between adjacent two-stage impellers in the present invention.

Fig. 5 is a schematic structural view of the impeller spline of the present invention.

Fig. 6 is a schematic structural view of the rotating shaft of the present invention.

detailed description

Before describing the embodiments in detail, it should be understood that the present invention is not limited to the detailed structures or arrangements of elements described herein below or in the accompanying drawings. The present invention can be an embodiment implemented in other ways. Also, it should be understood that the phraseology and terminology used herein are for descriptive purposes only and should not be interpreted as limiting. The terms "including", "comprising", "having" and similar expressions used herein are meant to include the items listed thereafter, their equivalents and other additional items. In particular, when "a certain element" is described, the present invention does not limit the number of the element to one, but may also include a plurality.

As shown in Figures 1-3, the centering torque transmission and locking combination mechanism 10 of a multi-stage high-speed steam turbine according to an embodiment of the present invention includes a rotating shaft 12 and several stages of impellers installed on the rotating shaft 12, such as four-stage impellers, several stages The impeller is in transmission connection with the rotating shaft 12 so that the impeller rotates and then drives the rotating shaft 12 to rotate. The impellers of each stage are connected by transmission through end tooth engagement 121 , and at the same time, lock nuts 14 are respectively provided at both ends of the impellers of several stages to apply a pre-tightening force to the impellers of each stage.

Each impeller includes a disc and blades mounted on the disc, and the disc has a central through hole for the rotating shaft 12 to pass through. The several stages of impellers include a primary impeller and a final stage impeller at both ends and at least one intermediate stage impeller between the primary impeller and the final stage impeller. Teeth, the disc of the final stage impeller is provided with end teeth on the side facing the primary impeller, and both sides of the at least one intermediate stage impeller are provided with end teeth.

In the illustrated embodiment, the impellers are arranged in four stages, and the four-stage impellers include a first-stage impeller 16 , a second-stage impeller 18 , a third-stage impeller 20 and a fourth-stage impeller 22 arranged in sequence along the shaft 12 axially. . The size of the four-stage impeller increases step by step along the axial direction of the rotating shaft 12 . The disc of the first-stage impeller 16 is provided with end teeth on the side towards the fourth-stage impeller 22 , the disc of the fourth-stage impeller is provided with end teeth on the side towards the first-stage impeller 16 , and the second-stage impeller 18 The discs of the third-stage impeller 20 and the third-stage impeller 20 are provided with end teeth on both sides, and the fourth-stage impellers are connected together through end-tooth gear meshing. The use of end-tooth connection can make the steam turbine automatically align with the central axis at high speed, thus effectively solving the problems of unstable centering and torsion transmission of multi-stage high-speed steam turbines.

One end of the first-stage impeller 16 away from the fourth-stage impeller 22 and one end of the fourth-stage impeller 22 away from the first-stage impeller 16 are respectively provided with a locking nut 14, such as a self-locking nut, and the locking nut 14 exerts a force on the corresponding impeller. The pre-tightening force makes the end teeth of the impellers at all levels tightly combined, and when the steam turbine is running, the torque is evenly distributed to each tooth to avoid centering failure caused by concentrated torque transmission, so that the end teeth can achieve effective torque. The pre-tightening force exerted by the locking nut 14 on the impeller can be determined according to the pre-tightening force required for the meshing of the end teeth, so as to apply an appropriate moment to the locking nut 14 . The locking nut 14 of the present invention can solve the functions of locking both ends of the end teeth and sharing a small part of the torque transmitted to the rotating shaft 12 .

In this embodiment, in order to further enhance the locking function of the lock nut 14, the thread direction of the lock nut 14 is set to be opposite to the rotation direction of the impeller. The advantage of such setting is that during high-speed rotation, the lock nut 14 will not loosen, which ensures that the end teeth of the impellers at all levels can effectively transmit torque and prevent fretting damage.

The cooperation form between the rotating shaft and the impeller disc of the present invention is designed to reduce the torsion transmission points between the rotating shaft and the disc. Specifically, the mating surfaces of the primary impeller and the final impeller and the rotating shaft adopt an interference fit, which can solve the problem of multi-stage high-speed steam turbines transmitting torque to the rotating shaft in order to output shaft work. The at least one intermediate-stage impeller is matched with the rotating shaft in clearance fit. Through the interference fit between the two ends of the impeller disc and the rotating shaft, the position points for torque transmission between the rotating shaft and the disc are greatly reduced, and the effective torque transmission between the rotating shaft and the impeller can be realized only by relying on the two ends.

As shown in FIG. 4 , interference fits 161 and 221 are respectively used between the first-stage impeller 16 and the fourth-stage impeller 22 and the shaft 12 . The interference fit has a fit amount of 0.08 mm and an axial interference length of 15 mm. This interference can satisfy the transmission torque on the steam turbine shaft to output 100KW power. Of course, in other embodiments, other interference settings can also be set.

In order to adapt to the normal operation of the steam turbine under high rotational speed and any working condition, some embodiments of the present invention are also equipped with an auxiliary torque transmission mechanism. Specifically, at least one stage of the intermediate stage impellers and the rotating shaft conduct torque transmission through an auxiliary torque transmission mechanism 181 . In this embodiment, the auxiliary torsion transmission mechanism is a spline to assist torsion transmission. In this way, even when the working conditions of the combined mechanism change drastically, the problem of slipping and instability can be prevented, and it can work under any working conditions to realize effective torque transmission between the impeller and the rotating shaft. However, in other embodiments, other forms of auxiliary torque transmission mechanisms may also be used.

Please refer to Fig. 5 and Fig. 6 simultaneously, the impeller spline 26 is provided on the wall surface of the central through hole 24 of the second-stage impeller 18, and the rotating shaft 12 is provided on its outer wall at the position of the second-stage impeller 18 for connecting with the impeller. The rotating shaft spline 28 that spline 26 gear meshes, to assist torsion transmission. In the specific implementation, the specific parameters of the spline: the modulus is 2, the number of teeth is 22, the pressure angle is 37.50, the spline fit length is 20mm, and the tooth height is 4.6mm. It should be understood that the above parameters are just a specific setting and may be modified according to actual conditions.

It should be understood that the above-mentioned setting of the splines on the second-stage impeller 18 is mainly due to the consideration that the bending moment acting on the support points at both ends is relatively small and the balance is better during operation. But the present invention is not limited thereto. In other embodiments, according to the actual design requirements of the steam turbine, the splines can also be arranged on the third-stage impeller 20, or the splines can be arranged on the second-stage impeller 18 and the third-stage impeller 18 at the same time. Stage impeller 20.

To sum up, the present invention proposes a centering torque transmission and locking combination mechanism for multi-stage high-speed steam turbines. The impellers of the mechanism are connected by end teeth, so that the central axis of the steam turbine can be automatically aligned at high speed. , The torque is evenly distributed to each tooth, avoiding centering failure caused by concentrated torque transmission. The pressure surface of the end tooth is pressed by the lock nut, so that the end tooth can achieve effective torque, and avoid the phenomenon of plastic deformation failure of the traditional multi-stage steam turbine pin key using interference fit torsion transmission under high-speed operation. Through this combination mechanism, the function of transmitting axial force between the wheel disc and the shaft can be realized, avoiding the appearance of various alternating cyclic stresses in one mechanism, making the function distribution of the mechanism more reasonable, and the service life longer. Compared with the transmission axial force of the traditional steam turbine The force mechanism is simpler and more reliable, and the assembly is relatively simple. In addition, the invention adopts interference fit between the two ends of the multi-stage impeller disc and the shaft, so that the position points for torque transmission between the shaft and the disc are greatly reduced, and the effective torque transmission between the shaft and the impeller can be realized only by relying on the two ends. . In addition, in some embodiments, at least one wheel is connected to the shaft through an auxiliary torsion transmission structure (eg, spline) to assist torsion transmission and prevent slippage, so as to adapt to work under any working conditions. The centering torque transmission and locking combination mechanism of the present invention has the advantages of high efficiency, stable transmission of axial force and torsion force, compact structure, simple assembly, strong ability to adapt to working conditions, and the like.

The concepts described herein may be implemented in other forms without departing from their spirit and characteristics. The particular embodiments disclosed are to be considered as illustrative rather than restrictive. Accordingly, the scope of the invention is to be determined by the appended claims rather than by these preceding descriptions. Any change within the literal meaning of the claims and within the range of equivalency shall belong to the scope of these claims.

Claims (10)

1. A centering transmission torque locking combined mechanism of a multi-stage high-speed steam turbine, comprising a rotating shaft and several stages of impellers mounted on the rotating shaft, the several stages of impellers are connected to the rotating shaft to drive the rotating shaft to rotate, It is characterized in that the impellers of each stage are connected by transmission through the meshing of end teeth, and the two ends of the impellers of several stages are respectively provided with lock nuts to apply a pre-tightening force to the impellers of each stage. 2. The centering torque transmission and locking combined mechanism of a multi-stage high-speed steam turbine according to claim 1, wherein the impeller comprises a disc and blades mounted on the disc, and the disc has a The central through hole through which the rotating shaft passes, the several stages of impellers include primary impellers and final stage impellers located at both ends and at least one intermediate stage impeller between the primary impellers and final stage impellers, the wheels of the primary impellers The disc is provided with end teeth on the side facing the final stage impeller, the disc of the final stage impeller is provided with end teeth on the side facing the primary impeller, and both sides of the at least one intermediate stage impeller are provided with Has terminal teeth. 3. The centering torque transmission and locking combined mechanism of a multi-stage high-speed steam turbine as claimed in claim 2, wherein the mating surfaces of the primary impeller and the final impeller and the rotating shaft adopt an interference fit . 4. The centering torque transmission and locking combined mechanism of multi-stage high-speed steam turbine according to claim 2, characterized in that, at least one stage of the intermediate-stage impellers is in transmission connection with the shaft gear. 5. The centering torque transmission and locking combined mechanism of a multi-stage high-speed steam turbine as claimed in claim 4, wherein an impeller spline is arranged on the wall surface of the central through hole of the at least one intermediate stage impeller, and said The rotating shaft is provided with rotating shaft splines on the outer wall surface of the at least one intermediate stage impeller for meshing with the spline gear of the impeller. 6. The centering torque transmission and locking combined mechanism of a multi-stage high-speed steam turbine according to claim 5, wherein the impellers are arranged in four stages, including a first-stage impeller, a second-stage impeller, and a third-stage impeller and a fourth-stage impeller, the first-stage impeller serves as the primary impeller, the fourth-stage impeller serves as the final-stage impeller, and the impeller splines are arranged on the second-stage impeller. 7. The centering torque transmission and locking combined mechanism of a multi-stage high-speed steam turbine according to claim 6, characterized in that, an interference fit is used between the first-stage impeller and the fourth-stage impeller and the rotating shaft to carry out Pass the twist. 8. The centering torque transmission and locking combined mechanism of a multi-stage high-speed steam turbine according to claim 7, characterized in that the amount of interference fit between the first-stage impeller and the fourth-stage impeller and the rotating shaft is is 0.08mm, and the axial interference length is 15mm. 9. The centering torque transmission and locking combined mechanism of a multi-stage high-speed steam turbine according to claim 1, characterized in that, the thread direction of the lock nut is set to be opposite to the rotation direction of the impeller. 10. The centering torque transmission and locking combined mechanism of multi-stage high-speed steam turbine according to claim 3, characterized in that at least one of the intermediate-stage impellers and the rotating shaft is a clearance fit.