WO2022105208A1

WO2022105208A1 - Compressor having oblique thrust structure, and rotor system

Info

Publication number: WO2022105208A1
Application number: PCT/CN2021/099962
Authority: WO
Inventors: 靳普
Original assignee: 至玥腾风科技集团有限公司
Priority date: 2020-11-18
Filing date: 2021-06-15
Publication date: 2022-05-27
Also published as: CN112503002A

Abstract

A compressor having an oblique thrust structure, and a rotor system. The compressor having an oblique thrust structure comprises a rotating shaft (1); an impeller (2) and a motor (4) are sleeved on the rotating shaft (1); a stator (3) covers the impeller (2); air holes (301) arranged in a circle or in multiple circles are uniformly formed on the part of the stator (3) directly opposite to the impeller (2); air entering from here can be decomposed into axial and radial airflows; the radial airflow enables the impeller (2) to be suspended in the stator (3) and rotate stably; the axial airflow pushes the impeller (2) backwards; the stator (3) has the functions of a radial bearing and a thrust bearing while acting as an air bearing.

Description

A compressor and rotor system with oblique thrust structure

technical field

The invention relates to a compressor and a rotor system with an oblique thrust structure whose stator is also used as an air bearing, and belongs to the technical field of compressors.

Background technique

Industrial gas turbines mainly include three components: compressor, combustion chamber and turbine. The compressor is a component that uses high-speed rotating blades to work on the gas (mostly air) to increase the gas pressure. It compresses the air into high-temperature and high-pressure air, and then supplies fuel to the combustion chamber for combustion, and the generated high-temperature and high-pressure gas expands in the turbine. acting.

At present, compressors generally use bearing sets composed of multiple radial bearings and thrust bearings, which often require a long enough shaft for installation. The problem is that the axial size of the compressor increases. If this type of compressor is used in In equipment such as micro gas turbine generator sets, the space occupied by the equipment will increase, and the overall weight will be increased, which is not conducive to integrated design; and the processing and assembly errors caused by the arrangement of multiple bearings will increase, making processing and assembly difficult. .

In addition, most of the impellers used in current compressors are semi-open impellers, and there is still room for improvement in how to obtain smaller friction loss and flow resistance, higher efficiency, lightness and high strength.

SUMMARY OF THE INVENTION

In view of the above-mentioned prior art, the present invention provides a compressor with an oblique thrust structure, and the stator is also used as an air bearing, which can reduce or even replace the original radial bearing and thrust bearing. The present invention also provides a rotor system.

The present invention is achieved through the following technical solutions:

A compressor with an oblique thrust structure includes a rotating shaft, an impeller and a motor are sleeved on the rotating shaft, and a stator is arranged on the outer cover of the impeller, wherein one or more circles of air holes are evenly opened on the part of the stator facing the impeller blades. It can be decomposed into axial and radial airflow. The radial airflow will make the impeller suspended in the stator and rotate stably. The axial airflow will push the impeller backward. The stator is used as an air bearing and plays the role of radial bearing and thrust bearing.

Further, one side or/and both sides of the motor is provided with a radial bearing sleeved on the rotating shaft, or no radial bearing is provided. When there are two radial bearings, it is equivalent to a total of three radial bearing supports, the overall vibration is small, and the operation is stable. When there is no radial bearing or only one of them is included, the length of the rotating shaft is shortened, it is easy to ensure the coaxiality of the parts on the shaft, the processing is easier, the integration is high, and the reliability of the whole machine is high.

Further, the radial bearing is an air bearing.

Further, a thrust bearing may or may not be provided on the rotating shaft, which is determined according to the calculation result of the axial force. If the axial force is too large and difficult to offset, a thrust bearing needs to be provided.

Further, the structure of the impeller includes a rear cover, a blade, a sleeve body and a front cover, wherein the rear cover is arranged at the tail end of the sleeve body, and an integrated through hole is arranged in the center of the rear cover and the sleeve body for sleeve and sleeve. It is fixed on the rotating shaft; the blades are arranged around the sleeve body and rotate in the same direction, one end of the blade is connected with the outer wall of the sleeve, and the other end is connected with the end face of the rear cover; the front cover is set on the blade, and the front cover is in the shape of a circular cone; The air inlet surface is a curved surface with a smooth transition along the contour of the ridge line of the blade, and the back air surface is provided with a groove that matches the end of the blade, and the end of the blade corresponding to each groove is embedded in the groove for a tight fit connection; the blade, the rear cover A flow channel is formed between the front cover and the front cover; the air outlet is spaced by the blades between the tail of the front cover and the rear cover, and the gas flows out from the air outlet through the flow channel from the front of the blade.

Further, the rear cover, the blade and the sleeve body are integrally formed.

Further, the outer edge of the blade protrudes from the end face of the rear cover in the axial direction.

Further, the blade includes a longer main blade and a shorter splitter blade, and the main blade and the splitter blade are arranged at intervals in sequence. The front cover grooves are divided into main blade grooves and splitter blade grooves, which are respectively set at the ends of the main blades and the splitter blades.

Further, the leading edge of the front cover protrudes from the leading edge of the blade, or is flatter than the leading edge of the blade, or is shorter than the leading edge of the blade.

Further, the front cover is made of carbon fiber composite material. The specific preparation method is:

Step A, the carbon fiber of the set volume is put into the oil bed, and the carbon fiber is infiltrated with the liquid binder in the oil bed;

Step B, extracting the fully infiltrated carbon fiber, and extruding it to remove excess glue;

Step C, winding the carbon fiber after extruding the excess glue to form a sponge-like carbon fiber covered with the glue and having a three-dimensional structure;

Step D, vacuumizing the sponge-like carbon fiber covered with adhesive and having a three-dimensional structure, so that the gas in the three-dimensional structure of the carbon fiber is extracted;

Step E, injecting the liquid steel base material into the carbon fiber three-dimensional structure through a micro-syringe, and performing micro-vibration on the carbon fiber three-dimensional structure during the injection process, to obtain a composite material of the steel base material and the carbon fiber covered with adhesive;

In step F, the steel-based material and the composite material covered with the adhesive carbon fiber are put into a mold for pressure cooling and molding to obtain a formed steel-based carbon fiber composite front cover connected by chemical bonds.

A rotor system includes the compressor of the above structure.

The compressor of the present invention is provided with an oblique thrust structure, and the stator is used as an air bearing and plays the role of a radial bearing and a thrust bearing at the same time (gas is introduced into the gap between the stator and the impeller from the air hole, so that the gap is evenly formed. The stable air film makes the impeller rotate stably in the stator, thus playing the role of air bearing), which can reduce or even replace the original radial bearing and thrust bearing. When the stator is also used as a thrust bearing, if other radial bearings are installed on the rotating shaft, it is equivalent to having multiple radial bearings to support, the overall vibration is small, and the operation is stable. If there are no other radial bearings or only a small amount of radial bearings on the rotating shaft, the length of the rotating shaft can be shortened, it is easy to ensure the coaxiality of the parts on the shaft, the processing is easier, the integration is high, and the reliability of the whole machine is high.

The compressor with the oblique thrust structure of the present invention uses the stator as an air bearing, which can reduce or even replace the original radial bearing and thrust bearing. On the basis of ensuring stable operation, the number of radial bearings and thrust bearings can be reduced, thereby shortening the length of the rotating shaft, reducing the weight, and reducing the space occupied, which is conducive to integrated design and reduces the difficulty of processing and assembly. When the same number of radial bearings are set, the operation is more stable.

In the compressor of the present invention, the impeller used can be a closed impeller provided with a front cover, the front cover is in the shape of a truncated truncated ring, the air inlet surface is a curved surface with a smooth transition along the contour of the blade ridge line, and the back air surface is provided with a blade end corresponding to the The matching groove has small friction loss, small flow resistance and high efficiency during operation; the front cover and the blade are tightly engaged during operation, and the gas flows out from the air outlet through the flow channel at the front of the blade, and the gas leakage is very small. The front cover is made of carbon fiber composite material. The impeller is light in overall weight and has high strength. The blade (metal material) will expand when rotating, while the front cover does not expand. Therefore, with the increase of rotation speed and time, the blade and the front cover will not expand. The occlusion between the grooves of the blades will become tighter and tighter, and the air intake of the air holes will also be applied to the front cover to further prevent the separation of the blades and the grooves of the front cover, which is suitable for high-speed rotation conditions. The provision of splitter vanes can not only reduce the blockage of the inlet air flow, but also improve the slip coefficient of the impeller outlet, which not only improves the efficiency of the impeller, but also improves the overall efficiency of the compressor due to the improved flow field at the impeller outlet. The front cover is made of carbon fiber composite material. Through the addition of steel matrix, carbon fiber and adhesive, the formed composite material far exceeds the upper limit of the modulus of conventional steel matrix materials, and the stiffness is greatly increased. The tensile strength, breaking force, and shear strength have also been greatly improved, and their properties are much higher than those of ordinary steel; at the same time, production costs, process thresholds, batch processes and versatility are all controlled within the metal material system. It generally benefits industries that require high-performance materials.

Various terms and phrases used herein have their ordinary meanings as known to those skilled in the art. If the terms and phrases mentioned are inconsistent with the known meanings, the meanings expressed in the present invention shall prevail.

Description of drawings

Figure 1: Schematic diagram of the oblique thrust structure in which the stator of the present invention doubles as an air bearing.

Figure 2: Schematic diagram of the structure of radial bearings sleeved on the rotating shaft on both sides of the motor.

Figure 3: A schematic diagram of the structure of a radial bearing sleeved on the rotating shaft on one side of the motor.

Figure 4: Schematic diagram of the structure without radial bearings on both sides of the motor.

Figure 5: Schematic diagram of the structure of the impeller.

Figure 6: Schematic diagram of the structure of the rear cover, the blade and the sleeve body.

FIG. 7 : Front view of FIG. 6 .

FIG. 8 : Side view of FIG. 6 .

FIG. 9 : Sectional view at position A-A in FIG. 8 .

Figure 10: The fabrication flow chart of the front cover.

Among them, 1-shaft, 2-impeller, 201-back cover, 202-blades, 203-body, 204-front cover, 205-runner, 206-air outlet, 3-static, 301-air hole, 4-motor .

Detailed ways

The present invention will be further described below in conjunction with the examples. However, the scope of the present invention is not limited to the following examples. It will be understood by those skilled in the art that various changes and modifications can be made in the present invention without departing from the spirit and scope of the inventions.

Example 1

A compressor includes a rotating shaft 1, an impeller 2 and a motor 4 are sleeved on the rotating shaft 1, and a stator 3 is arranged on the outer cover of the impeller 2. As shown in FIG. 1, the part of the stator 3 facing the front cover 204 is evenly opened one or more circles Air hole 301, where the air intake can be decomposed into axial and radial air flow, the radial air flow will make the impeller suspended in the stator 3 and rotate stably, the axial air flow will push the impeller backward, and the stator 3 will be used as an air bearing at the same time. To the role of radial bearings and thrust bearings.

Both sides of the motor are provided with radial bearings sleeved on the rotating shaft (Fig. 2), or one side is provided with radial bearings sleeved on the rotating shaft (Fig. 3), or no radial bearings are provided (Fig. 4). When there are two radial bearings, it is equivalent to a total of three radial bearing supports, the overall vibration is small, and the operation is stable. When there is no radial bearing or only one of them is included, the length of the rotating shaft is shortened (in Figures 2 to 4, the length of the shaft is shortened in turn), it is easy to ensure the coaxiality of the parts on the shaft, the processing is easier, the integration is high, and the whole machine is reliable. Sex is high.

The radial bearing is an air bearing.

The rotating shaft may or may not be provided with a thrust bearing, which is determined according to the calculation result of the axial force. If the axial force is too large and difficult to offset, a thrust bearing needs to be provided.

The specific structure of the impeller 2 is: including a rear cover 201 , blades 202 , a sleeve body 203 and a front cover 204 , as shown in FIGS. 5 to 9 , wherein the rear cover 201 is arranged at the rear end of the sleeve body 203 , and the rear cover 201 A through hole integrated with the center of the sleeve body 203 is used to sleeve and fix on the rotating shaft 1; the blade 202 is arranged around the sleeve body 203 and rotates in the same direction, one end of the blade 202 is connected to the outer wall of the sleeve body 203, and the other end is connected to the back cover The front cover 204 is covered on the blade 202, and the front cover 204 is in the shape of a truncated cone; the air inlet surface of the front cover 204 is a curved surface that smoothly transitions along the contour of the ridge line of the blade 202, and the back air surface is provided with the end of the blade 202. There are grooves that match each other, and the ends of the blades 202 corresponding to the grooves are embedded in the grooves for tight fitting connection; a flow channel 205 is formed between the blades 202 , the rear cover 201 and the front cover 204 ; The air outlets 206 are spaced apart by the blades 202, and the gas flows out from the air outlets 206 from the front of the blades 202 through the flow channel 205.

The rear cover 201 , the blades 202 and the sleeve body 203 are integrally formed, as shown in FIGS. 6 to 9 .

The outer edge of the blade 202 protrudes from the end surface of the rear cover 201 in the axial direction.

The blade 202 includes a longer main blade and a shorter splitter blade, and the main blade and the splitter blade are arranged in sequence at intervals. The grooves of the front cover 204 are divided into main blade grooves and splitter blade grooves, which are respectively provided at the ends of the main blade and the splitter blade.

The leading edge of the front cover 204 protrudes from the leading edge of the blade 202 , or is flatter than the leading edge of the blade 202 , or shorter than the leading edge of the blade 202 .

The front cover 204 is made of carbon fiber composite material, and the specific preparation method is (as shown in the flowchart in FIG. 10 ):

A rotor system is applied to the compressor of the above structure.

The above-mentioned compressor is equipped with an oblique thrust structure, and the stator is used as an air bearing and plays the role of a radial bearing and a thrust bearing at the same time (gas is introduced into the gap between the stator and the impeller from the air hole, so that a uniform and stable air is formed in the gap. air film, so that the impeller rotates stably in the stator, so as to play the role of air bearing), which can reduce or even replace the original radial bearing and thrust bearing. When the stator is also used as a thrust bearing, if other radial bearings are installed on the rotating shaft, it is equivalent to having multiple radial bearings for support, the overall vibration is small, and the operation is stable. If there are no other radial bearings or only a small amount of radial bearings on the rotating shaft, the length of the rotating shaft can be shortened, it is easy to ensure the coaxiality of the parts on the shaft, the processing is easier, the integration is high, and the reliability of the whole machine is high.

The impeller of the above-mentioned compressor is provided with a detachable front cover, the front cover is in the shape of a truncated cone, the air inlet surface is a curved surface with a smooth transition along the contour of the blade ridge line, and the back air surface is provided with a groove that matches the end of the blade. The friction loss is small, the flow resistance is small, and the efficiency is high; when working, the front cover and the blade are tightly engaged, and the gas flows out from the air outlet from the front of the blade through the flow channel, and the gas leakage is very small. The front cover is made of carbon fiber composite material. The impeller is light in overall weight and has high strength. The blade (metal material) will expand when rotating, while the front cover does not expand. Therefore, with the increase of rotation speed and time, the blade and the front cover will not expand. The occlusion between the grooves of the blades will become tighter and tighter, and the air intake of the air holes will also be applied to the front cover, which can better prevent the separation of the blades and the grooves of the front cover, and is suitable for high-speed rotation conditions. The provision of splitter vanes can not only reduce the blockage of the inlet air flow, but also improve the slip coefficient of the impeller outlet, which not only improves the efficiency of the impeller, but also improves the overall efficiency of the compressor due to the improved flow field at the impeller outlet.

The front cover is made of carbon fiber composite material. Through the addition of steel matrix, carbon fiber and adhesive, the formed composite material far exceeds the upper limit of the modulus of conventional steel matrix materials, and the stiffness is greatly increased. The tensile strength, breaking force, and shear strength have also been greatly improved, and their properties are much higher than those of ordinary steel; at the same time, production costs, process thresholds, batch processes, and versatility are all controlled within the metal material system. It generally benefits industries that require high-performance materials.

Example 2

A compressor, comprising a rotating shaft 1, an impeller 2 and a motor 4 are sleeved on the rotating shaft 1, a stator 3 is arranged on the outer cover of the impeller 2, and one or more circles of air holes 301 are evenly opened on the part of the stator 3 that is facing the blades of the impeller 2, and the air holes 301 are opened at this place. After the air, it can be decomposed into axial and radial airflow. The radial airflow will make the impeller suspended in the stator 3 and rotate stably. The axial airflow will push the impeller backward. The role of bearings.

A rotor system is applied to the compressor of the above structure.

The foregoing examples are provided to those skilled in the art to fully disclose and describe how to make and use the claimed embodiments, and are not intended to limit the scope of the disclosure herein. Modifications obvious to those skilled in the art are intended to be within the scope of the appended claims.

Claims

A compressor includes a rotating shaft, an impeller and a motor are sleeved on the rotating shaft, and a stator is arranged on the outer cover of the impeller.
The compressor according to claim 1, wherein a radial bearing sleeved on the rotating shaft is arranged on one side or/and both sides of the motor, or no radial bearing is arranged.
The compressor of claim 2, wherein the radial bearing is an air bearing.
The compressor according to claim 1, wherein a thrust bearing may or may not be provided on the rotating shaft.
The compressor according to claim 1, wherein the specific structure of the impeller includes: a back cover, a blade, a casing body and a front cover, wherein the back cover is arranged at the rear end of the casing body, and the back cover is connected to the casing An integrated through hole is arranged in the center of the body for being sleeved and fixed on the rotating shaft; the blades are arranged around the sleeve body and rotate in the same direction, one end of the blade is connected with the outer wall of the sleeve, and the other end is connected with the end face of the rear cover; On the blade, the front cover is in the shape of a truncated cone; the intake surface of the front cover is a curved surface that smoothly transitions along the contour of the ridge line of the blade, and the back air surface is provided with grooves that match the ends of the blades, and each groove corresponds to the end of the blade. It is embedded in the groove and connected tightly; a flow channel is formed between the blades, the rear cover and the front cover; the air outlet is separated by the blades between the tail of the front cover and the rear cover, and the gas flows out from the outlet through the flow channel from the front of the blade .
The compressor according to claim 5, characterized in that: the rear cover, the vane and the sleeve are integrally formed; or/and: the outer edge of the vane protrudes from the end face of the rear cover in the axial direction.
The compressor according to claim 5, wherein: the blades comprise longer main blades and shorter splitter blades, the main blades and the splitter blades are arranged at intervals in sequence; the front cover grooves are divided into main blade grooves and the splitter vane grooves, which are respectively set at the ends of the main vane and the splitter vane.
The compressor according to claim 5, wherein the leading edge of the front cover protrudes from the leading edge of the blade, or is parallel to the leading edge of the blade, or is shorter than the leading edge of the blade.
The compressor of claim 5, wherein the front cover is made of carbon fiber composite material.
A rotor system is characterized by comprising the compressor described in claims 1-9.