CN219012705U

CN219012705U - Impeller axial force balancing structure of magnetic suspension expansion machine

Info

Publication number: CN219012705U
Application number: CN202223259885.6U
Authority: CN
Inventors: 黄振华; 胡思宁; 林英哲; 吴立华; 董继勇
Original assignee: Nanjing Cigu Technology Co Ltd
Current assignee: Nanjing Cigu Technology Co Ltd
Priority date: 2022-12-06
Filing date: 2022-12-06
Publication date: 2023-05-12
Anticipated expiration: 2032-12-06

Abstract

The utility model discloses an impeller axial force balancing structure of a magnetic suspension expansion machine, which comprises an impeller and a sealing shaft, wherein the sealing shaft is sleeved at the end part of a rotor of the magnetic suspension expansion machine, one end of the sealing shaft is fixedly connected with the impeller, torque applied by the rotor is transmitted, and the other end of the sealing shaft is abutted on a shaft shoulder of the rotor and is flatly attached to the shaft shoulder of the rotor; the sealing shaft adopts a step shaft structure with gradually reduced diameter, one end with smaller diameter faces to one side where the rotor is located, and the magnetic suspension expander is correspondingly provided with sealing teeth which are in clearance fit with steps on the sealing shaft at the sealing shaft; the sealing shaft can reduce the contact area of wind pressure, reduce the axial pressure, and can form a labyrinth air seal structure by matching with the sealing teeth, so that the expansion gas is prevented from entering the magnetic suspension expander body.

Description

Impeller axial force balancing structure of magnetic suspension expansion machine

Technical Field

The utility model relates to the technical field of expanders, in particular to an impeller axial force balancing structure of a magnetic suspension expander.

Background

The expander mainly utilizes high-temperature and high-pressure gas from the evaporator to carry out adiabatic expansion in the expander to push the impeller to rotate, and consumes internal energy and pressure potential energy of the gas, so that heat energy of a heat source is converted into mechanical energy for driving a generator rotor, and pressure difference between an inlet and an outlet of the impeller acts on the impeller to generate larger axial tension.

The impeller axial force increases the bearing load, increases bearing loss, and increases the failure rate. Since magnetic suspension bearings are more sensitive to load than mechanical bearings, measures need to be taken to reduce the axial load of the bearings. Meanwhile, since the rotor speed of the magnetic levitation expander is far higher than that of a general expander, the compression axial dimension is required to increase the natural frequency of the rotor. The traditional force balance structure is characterized in that a balance disc is added through the main shaft, so that the axial force generated by the action of air pressure on the main shaft is balanced, the length of the main shaft is increased, and the rigidity of the main shaft is reduced.

Disclosure of Invention

The technical purpose is that: aiming at the defects that the axial force generated by air pressure is balanced by adopting a balance disc in the existing expander, the length of a main shaft is increased, and the rigidity of the main shaft is reduced, the utility model discloses an axial force balancing structure of an impeller of a magnetic suspension expander, which can reduce the axial length of a rotor and reduce the axial force.

The technical scheme is as follows: in order to achieve the technical purpose, the utility model adopts the following technical scheme:

the axial force balancing structure of the impeller of the magnetic suspension expansion machine comprises an impeller and a sealing shaft, wherein the sealing shaft is sleeved at the end part of a rotor of the magnetic suspension expansion machine, one end of the sealing shaft is fixedly connected with the impeller, torque applied by the rotor is transmitted, the other end of the sealing shaft is abutted on a shaft shoulder of the rotor, and the sealing shaft is flatly attached to the shaft shoulder of the rotor; the sealing shaft adopts a stepped shaft structure with gradually reduced diameter, one end with smaller diameter faces to one side where the rotor is located, and the magnetic suspension expansion machine is correspondingly provided with sealing teeth which are in clearance fit with steps on the sealing shaft.

Preferably, the seal shaft of the present utility model is cast integrally with the impeller and then machined.

Preferably, the sealing shaft of the utility model is provided with a flat bore and the end of the rotor is provided with a torque transmission section matching the shape of the flat bore.

Preferably, the impeller of the present utility model is fixedly connected to the rotor by means of concentric threaded studs.

Preferably, the tail part of the impeller of the utility model corresponds to the nozzle of the magnetic suspension expander in the circumferential direction, and the expansion air flow is sprayed by the nozzle to push the impeller to rotate.

The beneficial effects are that: the axial force balancing structure of the impeller of the magnetic suspension expansion machine has the following beneficial effects:

1. according to the utility model, the sealing shaft is added on the impeller, and adopts a stepped shaft structure, so that the contact area of wind pressure is reduced, and the axial pressure is reduced.

2. The sealing shaft is sleeved on the rotor, the length of the main shaft of the rotor is not required to be increased, the rigidity of the main shaft can be improved, and the natural frequency can be improved.

3. The sealing teeth which are in clearance fit with the stepped structure of the sealing shaft are arranged outside the sealing shaft, so that a labyrinth air seal structure can be formed, and the expansion gas is prevented from entering the inside of the magnetic suspension expander body.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.

FIG. 1 is a cross-sectional view of the present utility model taken along the axial direction of a rotor;

FIG. 2 is a block diagram of the end face of the seal shaft of the present utility model;

FIG. 3 is a block diagram of the impeller and seal shaft of the present utility model;

wherein, 1-impeller, 2-sealed axle, 3-magnetic suspension expander, 4-rotor, 5-seal tooth, 6-flat hole, 7-stud, 8-nozzle.

Detailed Description

The present utility model will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the utility model are shown, but in which the utility model is not so limited.

1-3 show an impeller axial force balance structure of a magnetic suspension expansion machine, which is disclosed by the utility model, and comprises an impeller 1 and a sealing shaft 2, wherein the sealing shaft 2 is sleeved at the end part of a rotor 4 of the magnetic suspension expansion machine 3, one end of the sealing shaft 2 is fixedly connected with the impeller 1, torque applied by the rotor 4 is transmitted, and the other end of the sealing shaft is abutted against the shaft shoulder of the rotor 4 and is flatly attached to the shaft shoulder of the rotor 4; the sealing shaft 2 adopts a stepped shaft structure with gradually reduced diameter, one end with smaller diameter faces to one side where the rotor 4 is located, and the magnetic suspension expander 3 is correspondingly provided with sealing teeth 5 which are in clearance fit with steps on the sealing shaft at the sealing shaft 2. Preferably, the seal shaft 2 of the present utility model is cast integrally with the impeller 1 and then formed, so that the overall structural strength can be increased.

Meanwhile, the sealing shaft 2 is provided with a flat hole 6, the end part of the rotor 4 is provided with a torque transmission section matched with the shape of the flat hole 6, and the impeller 1 is fixedly connected with the rotor 4 through a stud bolt 7 which is concentrically penetrated; the torque of the rotor is transmitted by the sealing shaft 2, the torque transmission-free hole is directly machined into the impeller 1, the torque is increased while the rotating speed is increased, and the structure can meet the requirement of a high-rotating-speed motor.

When the impeller 1 is assembled with a magnetic suspension expander, the tail of the impeller 1 corresponds to a nozzle of the magnetic suspension expander 3 in the circumferential direction, and the impeller 1 is driven to rotate by jetting expansion air flow through the nozzle 8.

When the magnetic suspension expansion machine is used, in a system where the magnetic suspension expansion machine is positioned, the expansion air flow reaches the impeller 1 through the nozzle, the impeller rotates under the drive of the expansion air flow, the stepped shaft structure with gradually reduced diameter reduces the axial force of the air acting on the impeller, and meanwhile, the labyrinth sealing structure formed between the sealing teeth and the sealing shaft can also prevent the air from entering the interior of the expansion machine, form a vortex space and reduce the pressure difference and the flow velocity.

The foregoing is only a preferred embodiment of the utility model, it being noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present utility model, and such modifications and adaptations are intended to be comprehended within the scope of the utility model.

Claims

1. The axial force balancing structure of the impeller of the magnetic suspension expansion machine is characterized by comprising an impeller (1) and a sealing shaft (2), wherein the sealing shaft (2) is sleeved at the end part of a rotor (4) of the magnetic suspension expansion machine (3), one end of the sealing shaft (2) is fixedly connected with the impeller (1), torque applied by the rotor (4) is transmitted, and the other end of the sealing shaft is abutted to the shaft shoulder of the rotor (4) and is flatly attached to the shaft shoulder of the rotor (4); the sealing shaft (2) adopts a stepped shaft structure with gradually reduced diameter, one end with smaller diameter faces one side where the rotor (4) is located, and the magnetic suspension expander (3) is correspondingly provided with sealing teeth (5) which are in clearance fit with steps on the sealing shaft at the sealing shaft (2).

2. A magnetic levitation expander impeller axial force balance structure according to claim 1, characterized in that the sealing shaft (2) is cast and reworked integrally with the impeller (1).

3. A magnetic levitation expander impeller axial force balance structure according to claim 1 or 2, characterized in that the sealing shaft (2) is provided with a flat hole (6) and that the end of the rotor (4) is provided with a torque transmission section matching the shape of the flat hole (6).

4. A magnetic levitation expander impeller axial force balance structure according to claim 3, characterized in that the impeller (1) is fixedly connected with the rotor (4) by means of concentric threaded studs (7).

5. The axial force balancing structure of the impeller of the magnetic suspension expander according to claim 1, wherein the tail of the impeller (1) corresponds to the nozzle of the magnetic suspension expander (3) in the circumferential direction, and the impeller (1) is driven to rotate by jetting the expansion air flow through the nozzle (8).