阅读说明：本技术 一种流线隧道式压气机轮 (Streamline tunnel type compressor wheel ) 是由 黄若 郭文杰 于 2020-07-31 设计创作，主要内容包括：本发明公开了一种流线隧道式压气机轮,包括压气机轮,所述压气机轮为一种闭式压气机轮,通常由多达几十个流道组成,各流道中心线为三维曲线,三维曲线的方程可根据“流线隧道式旋转流体机械流道设计与成形方法”提供的方法构造,即构造为柱面埃尔米特曲线向中心线所在环曲面做柱面投影所得的投影曲线,其方程即为柱面埃尔米特曲线与中心线所在环曲面的组合。本发明应用三次埃尔米特曲线的流道中心线成形方法可准确控制流道构造角,且曲线的曲率平缓过渡,可保证流道内较小的流动损失；阶梯式迷宫密封结构充分利用了流线孔道式压气机轮外侧圆锥面,且具有很好的密封效果,大大降低了间隙泄漏损失。(The invention discloses a streamline tunnel type compressor wheel, which comprises a compressor wheel, wherein the compressor wheel is a closed type compressor wheel and generally consists of dozens of flow passages, the center line of each flow passage is a three-dimensional curve, the equation of the three-dimensional curve can be constructed according to the method provided by the design and forming method of the streamline tunnel type rotary fluid machinery flow passage, namely the equation is a projection curve obtained by performing cylindrical projection on a cylindrical surface from a cylindrical Hermite curve to a ring surface where the center line is located, and the equation is the combination of the cylindrical Hermite curve and the ring surface where the center line is located. The method for forming the center line of the flow channel by applying the cubic Hermite curve can accurately control the construction angle of the flow channel, the curvature of the curve is in smooth transition, and small flow loss in the flow channel can be ensured; the stepped labyrinth seal structure fully utilizes the outer side conical surface of the streamline tunnel type compressor wheel, has good sealing effect and greatly reduces the gap leakage loss.)

1. The utility model provides a streamline tunnel formula compressor wheel which characterized in that, includes the compressor wheel, the compressor wheel is a closed compressor wheel, usually comprises by as many as several tens runners, and each runner central line is the three-dimensional curve.

2. The streamlined tunnel compressor wheel of claim 1,

the equation of the three-dimensional curve can be constructed according to a method provided by a flow passage design and forming method of a streamline tunnel type rotating fluid machine, namely a projection curve obtained by performing cylindrical projection on a cylindrical surface Hermite curve to a ring curved surface where a central line is located is constructed, and the equation is the combination of the cylindrical surface Hermite curve and the ring curved surface where the central line is located.

3. The streamlined tunnel compressor wheel of claim 1,

the normal cross section of each part of the flow channel is a circle or an ellipse, when the cross section is an ellipse, the projection of the long axis to the xy plane is vertical to the point radius line, and the ratio of the long axis to the short axis of the cross section ellipse is kept unchanged; the area of the inlet and the outlet of the flow channel is obtained according to the flow characteristics and the speed conditions of the rotary machine, and the area of the cross section is uniformly changed along the center line of the flow channel, so that the complete flow channel is formed.

4. The streamlined tunnel compressor wheel of claim 1,

the runners can be divided into a plurality of groups, the inlet and the outlet of the runners among the groups can be distributed on different radiuses, and the runners are uniformly distributed in the circumferential direction and are symmetrical about the center of the axis of the rotor.

5. The streamlined tunnel compressor wheel of claim 1,

the compressor wheel material comprises but is not limited to lightweight metals such as aluminum alloy and titanium alloy, plastics and other composite materials, and the manufacturing process adopts 3D printing and injection molding manufacturing technologies.

6. The streamlined tunnel compressor wheel of claim 1,

the outer surface of the compressor wheel can be provided with a comb structure, and a stepped sealing structure is formed by the comb structure and a designed casing.

7. The streamlined tunnel compressor wheel of claim 2,

the cylindrical surface Hermite curve is obtained by bending a plane Hermite curve into a cylindrical surface, the radius of the cylindrical surface is the radius of the inlet of the runner, and the axis is the axis (z axis) of the compressor wheel.

8. The streamlined tunnel compressor wheel of claim 2,

and the annular curved surface where the central line is located is a curved surface obtained by rotating the central meridian of the flow channel around the axis of the compressor for one circle.

Technical Field

The invention relates to a design and a forming method of a compressor wheel, in particular to a streamline tunnel type compressor wheel.

Background

The compressor is a part used for pressurizing inlet air in machinery such as a gas turbine, a turbocharger and the like, and the performance of the compressor determines the inlet air density, so that the fuel economy and the harmful gas emission are influenced. The optimization direction of the gas compressor is mainly light weight, miniaturization, high strength, easy processing, low cost, high efficiency and long service life, but the optimization direction is mainly limited by the following aspects; in the aspect of blade strength, in order to improve the pneumatic performance, the rotating speed and the light weight requirement, the thinner the blade of the traditional open type compressor impeller is, the better the blade is, the thinnest part of the blade of the conventional automotive turbocharger compressor is only 0.5-0.7 mm, but the strength of the material limits the further improvement of the rotating speed, and the high-strength titanium-aluminum alloy and the like are adopted, so that the weight is increased, and the cost is greatly increased; structurally, blade tip clearance leakage loss exists in the existing mainstream open type compressor impeller, and the efficiency and the service life of the compressor are influenced; in the manufacturing process, the overspeed pre-overload treatment and the dynamic balance precision control of the impeller are two major difficulties in the processing of the impeller of the gas compressor; when the impeller is subjected to overspeed pre-overload treatment, the plastic deformation of the inner hole of the impeller is not large, and the overspeed tool and the inner hole are positioned without failure; in order to ensure the dynamic balance precision of the impeller, all machining process benchmarks of the impeller are required to be uniform, and the traditional processes of turning and milling the impeller use different datum surfaces in different procedures, so that the precision is poor;

the novel streamline tunnel type compressor wheel is an effective way for solving the problems, is used as a closed rotary machine, has higher strength and smaller leakage loss, and has the advantages of large streamline design optimization space, adaptation to higher rotating speed and the like, so that the efficiency of the compressor can be further improved, the power density can be improved, the size can be reduced, the higher structural strength is also beneficial to widening the material selection range, for example, high-strength engineering plastics can be selected, and the weight and the cost can be reduced; with the progress of scientific technology, the additive manufacturing technology is mature, and the novel compressor wheel can be produced in large batch by applying advanced manufacturing technologies such as three-dimensional printing, injection molding and the like;

at present, few researches on the flow line tunnel type compressor wheel are not deep, and especially, researches on the design and the forming method of the flow line tunnel type compressor wheel are lacked.

Disclosure of Invention

In order to solve the technical problems, the invention provides the following technical scheme:

the invention provides a streamline tunnel type compressor wheel which comprises a compressor wheel, wherein the compressor wheel is a closed compressor wheel and generally consists of dozens of flow channels, and the center line of each flow channel is a three-dimensional curve.

Preferably, the equation of the three-dimensional curve can be constructed according to a method provided by a flow passage design and forming method of a streamline tunnel type rotating fluid machine, namely, the equation is a projection curve obtained by performing cylindrical projection on a cylindrical surface Hermite curve to a toroidal surface where a center line is located, and the equation is the combination of the cylindrical surface Hermite curve and the toroidal surface where the center line is located.

Preferably, each normal section of the flow channel is a circle or an ellipse, when the normal section is an ellipse, the projection of the long axis to the xy plane is vertical to the point radius line, and the ratio of the long axis to the short axis of the ellipse of the section is kept unchanged; the area of the inlet and the outlet of the flow channel is obtained according to the flow characteristics and the speed conditions of the rotary machine, and the area of the cross section is uniformly changed along the center line of the flow channel, so that the complete flow channel is formed.

Preferably, the runners can be divided into a plurality of groups, the inlet and outlet of the runners among the groups can be distributed on different radiuses, and the runners are circumferentially and uniformly distributed and are centrosymmetric about the axis of the rotor.

Preferably, the compressor wheel material comprises lightweight metals such as aluminum alloy and titanium alloy, plastics and other composite materials, and the manufacturing process adopts 3D printing and injection molding manufacturing technologies.

Preferably, the outer surface of the compressor wheel can be provided with a grate structure, and a stepped sealing structure is formed by the grate structure and the designed casing.

Preferably, the cylindrical surface hermitian curve is obtained by bending a plane hermitian curve into a cylindrical surface, the radius of the cylindrical surface is the radius of the inlet of the runner, and the axis is the axis (z axis) of the compressor wheel.

Preferably, the annular curved surface where the center line is located is a curved surface obtained by rotating the flow channel center meridian around the axis of the compressor for one circle.

The invention has the beneficial effects

The compressor wheel adopts a streamline tunnel type structure, and gas in a flow channel flows at a high Reynolds number, so that the hydraulic resistance is low, the efficiency of the supercharger is improved, and compared with a blade type structure, the compressor wheel has higher strength and is not easy to damage when being subjected to grinding particles, welding particles, gravel and the like; the flow channel center line forming method applying the cubic Hermite curve can accurately control the flow channel structure angle, the curvature of the curve is in smooth transition, and smaller flow loss in the flow channel can be ensured; the stepped labyrinth seal structure fully utilizes the outer side conical surface of the streamline tunnel type compressor wheel, has good sealing effect and greatly reduces the gap leakage loss.

Drawings

Fig. 1 is a meridian plane schematic view of a single-runner flow-passage flow-line tunnel type centrifugal compressor wheel.

FIG. 2 is a schematic view of a complete flow channel and a normal cross section of the flow channel.

Fig. 3 is a schematic view of a centrifugal compressor wheel with three sets of runners.

In the figure: 1. a flow channel center meridian; 2. a comb structure; 3. the actual flow channel center line; 4. a normal section of the flow channel; 5. and (4) completing the flow channel.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.