JPH03265714A - Thrust gas bearing device - Google Patents

Abstract

PURPOSE:To keep bearing clearance in a stable condition to ensure a stable high-speed rotation, and improve reliability and safety by interposing elastic rings between first, second brackets and respective thrust resting plates respectively. CONSTITUTION:A first bracket 15, a bracket isolating cylinder body 16, a second bracket 17 are provided between a case body 1 and a casing 14. Further, a thrust rotating disc 19 is journalled to a rotor shaft 8, and thrust-resting plates 20a, 20b are provided on opposite sides of the thrust rotating disc 19 through a thrust isolating plate 23 between the first, second brackets 15, 17. In a part of the thrust isolating plate 23, an air inlet port 23a is drilled to be connected to the outer periphery of the thrust rotating disc 19. The first, second brackets 15, 17 have, peripheral grooves 15a, 17a respectively on their side opposite to the thrust resting plates 20a, 20b, while the grooves 15a, 17a have elastic rings 24a, 24b respectively. Thus, even when a non-parallel state occurs in bearing clearance, stable conditions can be kept to prevent the generation of vibration.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is applicable to, for example, a rotor shaft that supports ultra-high-speed rotation of a turbine, a near compressor (air compressor), a turbo machine, etc. in a power generation plant. The present invention relates to a dynamic pressure type thrust gas bearing device, and particularly relates to a self-aligning device for this thrust gas bearing device.

(Prior Art) Recently, a Cropol generator has been proposed for power generation plants, which is equipped with a turbine and an air compressor at both ends of the rotor shaft of the generator.

This Cropol generator rotates at extremely high speed, so
The rotor shaft, which is integral with the rotor, is supported by a dynamic pressure type thrust gas bearing device.

This type of dynamic pressure type thrust gas bearing device that has already been proposed is constructed as shown in FIG.

That is, in FIG. 5, a stator 3 constituting one side of a generator 2 such as a Cropol generator is provided within a cylindrical case body 1. Each of the bearing seat plates 4 having a cylindrical shape is provided at both ends of the bearing seat 1 .

Each bearing seat plate 4 is provided with a plurality of (one in the figure) pivot supports 5 facing toward the axis from three sides, and each ball portion 5a of each pivot support 5 has a , each butt member 6 is provided to support a rotor shaft 8 that is integral with a rotor 7 that constitutes the other part of the generator 2. Furthermore, a bearing clearance (gas film) 9 is formed between each of the butt members 6 and the rotor shaft 8, and this rotor shaft 8 is supported by each of the butt members 6 through the gas film 9. ing.

In this way, the rotor shaft 8 is supported by the pivot supports 5 provided from three sides toward the axial center via the butt members 6 and the bearing clearance 9, which are connected to the radial gas bearing device 10. being called.

On the other hand, the case body 1 near the one bearing seat plate 4
A turbine case 11 is provided through an isolation cylinder 12, and a turbine (turbine blade) 13 is disposed at one end of the rotor shaft 8 located inside the turbine case 11.
is attached to the shaft.

On the other hand, the case body 1 near the other bearing seat plate 4
, the casing 14 is connected to the first bracket 15 and the air supply port 1.
6a through a bracket isolation cylinder 16 and a second bracket 17, and this casing 14
A compressor (compressor rotor) 18 is pivotally attached to the other end of the rotor shaft 8 located inside.

Further, one thrust rotating disk is mounted on the rotor shaft 8 on which the bracket isolation cylinder 16 is located, and each thrust stationary plate is provided between the first bracket 15 and the second bracket 17. 20a120b is provided facing the thrust rotating disk 19. Further, the thrust rotating disk 19 and each thrust stationary plate 20a, 20
Each bearing clearance 21 is formed between the rotor shaft 8 and each thrust stationary plate 20a.
, 20b via respective bearing clearance lances 21, and these are called a thrust gas bearing device 22.

Therefore, when the rotor shaft 8 rotates at an extremely high speed, the thrust gas bearing device 22 described above forms compressed air from the air supply port 16a between the one thrust rotating disk and each thrust stationary plate 20a, 20b. The rotor shaft 8 is supported as a thrust gas bearing by being forcibly supplied to each bearing clearance lance 21.

(Problems to be Solved by the Invention) However, in the thrust gas bearing device described above, each bearing clearance 21 is very small, and furthermore, due to processing errors of each component, the thrust rotating disk 19 and each thrust stationary plate 20a120b An unparallel state occurs in each bearing clearance 21 between the two bearings. In particular, when the thrust stationary plates 20a and 20b are installed at an angle, even if the amount of inclination is as small as several tens of micrometers, the allowable clearance (about 50μ) of the thrust gas bearing device is extremely large. Since the amount is small, it is predicted that the thrust rotating disk 19 and each of the thrust stationary plates 20a and 20b may come into contact and be damaged.

On the other hand, when the radial gas bearing devices 10 are assembled eccentrically for some reason, the radial gas bearing devices 10 self-align and align with the rotor shaft 8.
tilts and rotates. At this time, the thrust rotating disk 1
Reference numeral 9 denotes each thrust stationary plate 20a, 2 installed horizontally.
0b, and due to this, each bearing clearance (gas film) 21 becomes non-parallel, and the one thrust rotating disk and each thrust stationary plate 20a, 20b become unparallel to each other. It is also expected that there will be damage due to contact.

The present invention has been made in view of the above-mentioned circumstances, and the bearing clearance (gas film) between the thrust rotating disk and each thrust stationary plate automatically establishes a parallel state. The purpose of the present invention is to provide a thrust gas bearing device that maintains the rotor shaft in a stable state, prevents vibration of the rotor shaft, ensures stable ultra-high-speed rotation of the rotor shaft, and improves reliability and safety. shall be.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a rotor shaft supported by a pair of radial gas bearings, a thrust rotating disk mounted on one end of the rotor shaft,
A first bracket and a second bracket are provided near the thrust rotating disk via a bracket isolation cylinder, and each thrust stationary plate is provided on both brackets facing the thrust rotating disk via the thrust separating plate. , an air supply port is bored in the thrust separator so as to communicate with the outer periphery of the thrust rotating disk, and elastic rings are interposed between the first and second brackets and each of the thrust stationary plates. It is equipped.

(Function) The present invention creates an unparallel state in the bearing clearance (gas film) by interposing each elastic ring between the first bracket and the second bracket and each of the thrust stationary plates. Even if the rotor shaft is deformed, each elastic ring automatically aligns and corrects the deformation, keeping the bearing clearance in a parallel and stable state, preventing the occurrence of vibration of the rotor shaft, and ensuring a stable and ultra-high speed rotor shaft. This is designed to ensure rotation and improve reliability and safety.

(Example) Hereinafter, the present invention will be described with reference to an illustrated embodiment.

Note that the present invention will be described with the same reference numerals assigned to the same constituent members as those of the conventional example described above.

In FIGS. 1 to 4, reference numeral 1 denotes a cylindrical case body, and inside this case body 1, for example,
A stator 3 constituting one side of a generator 2 such as a Cropol generator is provided, and cylindrical bearing seat plates 4 are provided at both ends of the case body 1. . Each bearing seat plate 4 is provided with a plurality of (one in the figure) pivot supports 5 facing toward the axis from three sides, and each ball portion 5a of each pivot support 5 has a , each butt member 6 is provided to support a rotor shaft 8 that is integral with a rotor 7 that constitutes the other part of the generator 2. Further, a bearing clearance (gas film) 9 is formed between each of the butt members 6 and the rotor shaft 8, and this rotor shaft 8 is supported by each of the butt members 6 via the bearing clearance 9. ing.

In this way, the rotor shaft 8 is supported by the pivot supports 5 provided from three sides toward the axial center via the butt members 6 and the bearing clearance 9, which are connected to the radial gas bearing device 10. being called.

On the other hand, the case body 1 near the one bearing seat plate 4
A turbine case 11 is provided through an isolation cylinder 12, and a turbine (turbine blade) 13 is disposed at one end of the rotor shaft 8 located inside the turbine case 11.
is attached to the shaft.

On the other hand, the case body 1 near the other bearing seat plate 4
, the casing 14 is connected to the first bracket 15 and the air supply port 1.
6a through a bracket isolation cylinder 16 and a second bracket 17, and this casing 14
A compressor (compressor rotor) 18 is pivotally attached to the other end of the rotor shaft 8 located inside.

Further, one thrust rotating disk is mounted on the rotor shaft 8 on which the bracket isolation cylinder 16 is located, and each thrust stationary plate is provided between the first bracket 15 and the second bracket 17. 20a120b is thrust separator 2
It is provided facing the thrust rotating disk 19 via 3. Further, an air supply hole 23a is formed in a part of the thrust separating plate 23 so as to communicate with the outer periphery of the thrust rotating disk, and this air supply hole 23a communicates with the air supply port 16a. . Furthermore, bearing clearances 21 are formed between the thrust rotating disk 19 and the thrust stationary plates 20a, 20b, and the rotor shaft 8 is connected to the thrust stationary plates 20a, 20b.
b through bearing clearance lances 21, and these are called a thrust gas bearing device 22.

In particular, the first bracket 15 and the second bracket 17
At positions facing each other, each circumferential groove 15 a % 17
a is formed, and each circumferential groove 15 a s 17
As shown in FIGS. 2 and 3, each elastic ring 24a, 24b has an O-ring-shaped slit a.
is provided. Further, the elastic rings 24a, 24b are interposed between the thrust rotating disk and the thrust stationary plates 20a, 20b so as to support them, respectively.

Therefore, when the rotor shaft 8 rotates at an extremely high speed, the thrust gas bearing device 22 described above forms compressed air from the air supply port 16a between the thrust rotating disk 19 and each thrust stationary plate 20a, 20b. The rotor shaft 8 is supported as a thrust gas bearing by being forcibly supplied to the bearing clearance lance 21.

On the other hand, if a non-parallel state occurs in each of the bearing clearance lances 21, a large bearing pressure is generated in the minimum thickness portion of each of the bearing clearance lances 21, and the thrust stationary plates 2
Transmit moment force to 0a and 20b. Then, this moment force is applied to each of the O-ring shaped elastic rings 24a, 2.
4b, each of the elastic rings 24a, 24b is deformed largely at the location where the load is large, and is automatically corrected and aligned so that the bearing clearances 21 of the thrust bearings are always parallel to each other.

That is, since each of the elastic rings 20a and 20b deforms and automatically aligns and corrects the alignment, each bearing clearance 21 is held in a parallel and stable state, preventing the occurrence of vibration of the rotor shaft 8, and the rotor This ensures stable ultra-high speed rotation of the shaft 8 to improve reliability and safety.

Next, another embodiment of the present invention shown in FIG. 4 has the same structure as the embodiment described above, in which each elastic ring 20a, 20b is replaced with a coil spring 24.

Although the present invention is applied to a claw pole generator and one embodiment has been described, the design may be changed to be used in a normal turbine, etc., without changing the gist of the present invention. You are free to do what you want.

〔Effect of the invention〕

As described above, according to the present invention, a rotor shaft is supported by a pair of radial gas bearings, a thrust rotating disk is mounted on one end of the rotor shaft, and a bracket separator is provided near the thrust rotating disk. a first bracket and a second bracket are provided through the brackets, each thrust stationary plate is provided on both brackets facing the thrust rotating disk via a thrust separator, and an air supply port is provided on the thrust separator plate so that the The holes are formed so as to communicate with the outer periphery of the rotating disk, and each elastic ring is interposed between the first bracket, the second bracket, and each of the thrust stationary plates. Even if such a condition occurs, each elastic ring deforms and automatically aligns to correct the situation, and also maintains the bearing clearance in a parallel and stable state to prevent the occurrence of vibration of the rotor shaft, It is possible to improve reliability and safety by ensuring stable ultra-high speed rotation of the shaft, and furthermore, the present invention eliminates the need to increase the processing precision of each bearing component, and can be manufactured and provided at low cost. death,
Since the elastic ring uses a metal material, it has excellent effects such as sufficient resistance to high temperature environments.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a Cropol generator equipped with a thrust gas bearing device of the present invention, Fig. 2 is a plan view of an elastic ring incorporated in the present invention, and Fig. 3 is a chain line A in Fig. 2. -A
4 is a diagram showing another embodiment of the present invention, and FIG. 5 is a sectional diagram of a Cropol generator equipped with an already proposed thrust gas bearing device. 2... Generator, 7... Rotor, 8... Rotor shaft,
DESCRIPTION OF SYMBOLS 10... Radial gas bearing, 15... First bracket, 16... Bracket isolation cylinder, 17... Second bracket, 18... Compressor, one... Thrust rotating disk, 20a , 20b... Thrust stationary plate,
21... Bearing clearance, 22... Thrust gas bearing, 23... Thrust separator, 24a, 24b...
・Elastic ring.

Claims (1)

[Claims] A rotor shaft is supported by a pair of radial gas bearings, a thrust rotating disk is mounted on one end of the rotor shaft, and a bracket is provided on the case body near the thrust rotating disk via a bracket isolation cylindrical body. a first bracket and a second bracket; each thrust stationary plate provided on both brackets facing the thrust rotating disk via a thrust separator; and an outer periphery of the thrust rotating disk on the thrust separator; an air supply port bored to communicate with the first
A thrust gas bearing device comprising elastic ring bodies interposed between a bracket, a second bracket, and each of the thrust stationary plates.