A supercharger low inertia turbine impeller and optimization method

Abstract

The present invention discloses a low-inertia turbine impeller for a supercharger, comprising a turbine hub; a plurality of turbine blades are distributed on the upper surface of the turbine hub; the plurality of turbine blades are distributed at equal intervals along the circumferential direction; the wheel disc at the bottom of the turbine hub comprises a plurality of new outer edge portions of the turbine wheel disc and a plurality of corrected inner edge portions of the turbine wheel disc; each new outer edge portion of the turbine wheel disc is respectively located directly below the outer end of the root of a turbine blade; a corrected inner edge portion of the turbine wheel disc is respectively arranged between any two adjacent new outer edge portions of the turbine wheel disc; each corrected inner edge portion of the turbine wheel disc is respectively located in the blade gap between two adjacent turbine blades; a plurality of new outer edge portions of the turbine wheel disc and a plurality of corrected inner edge portions of the turbine wheel disc are distributed along the circumferential direction on the edges of the wheel disc. The present invention also discloses an optimization method for a turbine impeller. The present invention can effectively reduce the weight of the turbine hub, reduce the inertia of the turbine impeller, and significantly improve its acceleration responsiveness.

Description

Technical Field

[0001] The present invention relates to the technical field of turbochargers, and in particular to a turbocharger low-inertia turbine impeller and an optimization method thereof. Background Art

[0002] Turbocharging technology uses the engine's high-temperature exhaust gas to drive the turbine impeller in the turbocharger to rotate, which in turn drives the compressor impeller to rotate. The compressor impeller then compresses the air flowing in from the outside and then charges the compressed air into the engine.

[0003] Among them, the turbine impeller, which is in direct contact with the high-temperature exhaust gas, is the core driving part of the turbocharger power source. The high-temperature exhaust gas flow works on the blades on the turbine impeller, causing the turbine impeller to change from low speed to high speed.

[0004] Currently, existing small turbochargers have poor turbine impeller acceleration performance and cannot fully meet the needs of users.

[0005] The acceleration performance of the turbine impeller is closely related to the inertia of the turbine impeller. The greater the inertia of the turbine impeller, the worse the acceleration performance of the turbine impeller; the smaller the inertia of the turbine impeller, the better the acceleration performance of the turbine impeller. The greater the weight of the turbine impeller, the greater its inertia. Therefore, the acceleration performance of the turbine impeller is mainly affected by the weight of the turbine impeller. If you want to effectively improve the acceleration performance of the turbine impeller, you need to further reduce the weight of the turbine impeller, thereby reducing the inertia of the turbine impeller.

[0006] However, there is currently no technology that can effectively reduce the inertia of the turbine impeller in the turbocharger. Summary of the invention

[0007] The purpose of the present invention is to provide a low-inertia turbine impeller for a supercharger and an optimization method thereof in view of the technical defects existing in the prior art.

[0008] To this end, the present invention provides a low-inertia turbine impeller for a supercharger, comprising a turbine hub;

[0009] A plurality of turbine blades are distributed around the outer sides of the upper surface of the turbine hub;

[0010] A plurality of turbine blades are equally spaced and distributed along the circumferential direction with the vertical central axis of the turbine hub as the center;

[0011] The wheel disc at the bottom of the turbine hub includes a plurality of spaced-apart new outer edge portions of the turbine wheel disc and a plurality of spaced-apart modified inner edge portions of the turbine wheel disc;

[0012] The new outer edge of each turbine wheel disc is located directly below the outer end of the root of a turbine blade;

[0013] Between any two adjacent turbine wheel disc new outer edge portions, there is respectively provided a concave turbine wheel disc modified inner edge portion;

[0014] The modified inner edge portion of each turbine wheel disc is respectively located in the blade gap between two adjacent turbine blades;

[0015] A plurality of new outer edge portions of turbine wheel discs and a plurality of modified inner edge portions of turbine wheel discs are circumferentially distributed around the edges of the wheel discs, with the vertical central axis of the turbine hub as the center.

[0016] In addition, the present invention also provides a method for optimizing a low-inertia turbine impeller of a supercharger as described above, comprising the following steps:

[0017] The first step is to build a three-dimensional model of the existing traditional turbine impeller;

[0018] The conventional turbine impeller comprises a turbine hub; a plurality of turbine blades are distributed around the upper surface of the turbine hub; the edges around the wheel disc at the bottom of the turbine hub are the original outer edge of the turbine wheel disc distributed in a circular shape;

[0019] The second step is to construct a modified inner edge of the turbine wheel and a new outer edge of the turbine wheel;

[0020] The third step is to correct the original outer edge of the turbine disk in the three-dimensional model of the traditional turbine impeller according to the corrected inner edge of the turbine disk and the new outer edge of the turbine disk constructed in the third step, so as to obtain a three-dimensional model of the turbine impeller having the corrected inner edge of the turbine disk and the new outer edge of the turbine disk.

[0021] It can be seen from the technical solution provided by the present invention that, compared with the prior art, the present invention provides a low-inertia turbine impeller of a supercharger and an optimization method, which are scientifically designed and can solve the limitation of poor turbine acceleration performance of small superchargers. The present invention arranges multiple turbine wheel disc correction inner edge portions on the turbine hub. The turbine wheel disc correction inner edge portions serve as structural features that can correct weight reduction. On the basis of not damaging the strength of the turbine, the weight of the turbine hub can be effectively reduced, the inertia of the turbine impeller can be effectively reduced, and a low-inertia turbine impeller can be obtained, so that the acceleration responsiveness of the turbine impeller is significantly improved, which has great practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1a It is a schematic diagram of the three-dimensional structure of a conventional supercharger turbine impeller;

[0023] Figure 1b A top view of a conventional supercharger turbine wheel;

[0024] Figure 2aA schematic diagram of the three-dimensional structure of a low-inertia turbine impeller for a supercharger provided by the present invention;

[0025] Figure 2b A top view of a low-inertia turbine impeller for a supercharger provided by the present invention;

[0026] Figure 3a A schematic diagram of the three-dimensional structure of a low-inertia turbine impeller for a supercharger provided by the present invention when marking various structural parameters;

[0027] Figure 3b for Figure 3a An enlarged view of section A shown in;

[0028] Figure 3c A bottom view of an integral wheel disc of a low-inertia turbine impeller for a supercharger provided by the present invention;

[0029] Figure 3d A cross-sectional view of the connection position between any turbine blade and the wheel disc in an integral wheel disc of a low-inertia turbine impeller of a supercharger provided by the present invention;

[0030] In the figure, 1 is a turbine blade, 2 is an original outer edge of a turbine wheel disc, 3 is a turbine hub; 4 is a modified inner edge of a turbine wheel disc (i.e., a modified region of a turbine wheel disc); 5 is a new outer edge of a turbine wheel disc;

[0031] 301 is the symmetry centerline of the turbine blade, 31 is the blade suction surface, and 32 is the blade pressure surface;

[0032] 341 is the starting point of the first modified root, and 342 is the starting point of the second modified root;

[0033] 351 is a first corrected straight line segment, and 352 is a second corrected straight line segment;

[0034] 361 is a first corrected arc segment, and 362 is a second corrected arc segment;

[0035] 371 is the arc portion connecting the suction surface blade root and the wheel disc;

[0036] 372 is the arc portion connecting the root of the pressure surface blade and the wheel disc;

[0037] 7 is the arc segment of the corrected inner radius;

[0038] t is the root thickness of the turbine blade;

[0039] T_s is the first blade root modified thickness close to the blade suction surface 31 (i.e., the thickness from the first modified root starting point 341 to the symmetry centerline 301 of the turbine blade);

[0040] T_p is the modified thickness of the second blade root close to the blade pressure surface 32 (i.e., the thickness from the second modified root starting point 342 to the symmetry centerline 301 of the turbine blade);

[0041] R_s is the radius of the modified circular arc close to the blade suction surface 31 (i.e., the radius of the first modified circular arc segment 361);

[0042] R_p is the radius of the modified arc close to the blade pressure surface 32 (i.e., the radius of the second modified arc segment 362);

[0043] θ_s is the angle between the correction line segment close to the blade suction surface 31 (i.e., the first correction straight line segment 351) and the symmetry centerline 301 of the turbine blade;

[0044] θ_p is the angle between the correction line segment close to the blade pressure surface 32 (i.e., the second correction straight line segment 352) and the symmetry centerline 301 of the turbine blade;

[0045] R_n is the inner radius of the channel correction arc (i.e. the inner radius of the turbine wheel correction inner edge);

[0046] R_w is the outer edge radius of the channel wheel (i.e. the outer edge radius of the new outer edge portion 5 of the turbine wheel, i.e. the radius of the original outer edge portion 2 of the turbine wheel). DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and implementation modes.

[0048] See also Figures 1a to 3d As shown, the present invention provides a low-inertia turbine impeller for a supercharger, which is used to reduce the rotational inertia of the turbine impeller, and specifically includes a turbine hub 3;

[0049] A plurality of turbine blades 1 are distributed around the outer sides of the upper surface of the turbine hub 3;

[0050] A plurality of turbine blades 1 are equally spaced and distributed along the circumferential direction with the vertical central axis of the turbine hub 3 as the center;

[0051] The wheel disc 30 at the bottom of the turbine hub 3 includes a plurality of spaced-apart turbine wheel disc new outer edge portions 5 and a plurality of spaced-apart turbine wheel disc modified inner edge portions 4;

[0052] Each turbine wheel disc novel outer edge portion 5 is located directly below the outer end of the root (i.e., bottom) of a turbine blade 1;

[0053] Between any two adjacent turbine wheel disc new outer edge portions 5, there is respectively provided a concave turbine wheel disc modified inner edge portion 4 (i.e., serving as a turbine wheel disc hub modified structure);

[0054] The modified inner edge portion 4 of each turbine wheel disc is respectively located in the blade gap 100 between two adjacent turbine blades 1;

[0055] A plurality of new turbine wheel outer edge portions 5 and a plurality of modified turbine wheel inner edge portions 4 are circumferentially distributed around the edges of the wheel 30 with the vertical central axis of the turbine hub 3 as the center.

[0056] In the present invention, in a specific implementation, the shape of the outer edge of the novel outer edge portion 5 of the turbine wheel disc is an arc shape;

[0057] The outer edges of the novel outer edge portions 5 of the plurality of turbine wheel disks are located on the same circle, the center of which is located on the vertical central axis of the turbine hub 3 .

[0058] It should be noted that see Figure 1a and Figure 1b The existing traditional turbine impeller includes a turbine hub 3; a plurality of turbine blades 1 are distributed around the upper surface of the turbine hub 3; and the edges around the wheel disc 30 at the bottom of the turbine hub 3 are the original outer edge portion 2 of the turbine wheel disc distributed in a circular shape.

[0059] It should be noted that, in the present invention, the turbine wheel disc modified inner edge portion 4, as a turbine wheel disc hub modified structure, is a concave inner edge structure. Figure 2a The grid line area in the figure indicates a recessed area of ​​a modified inner edge portion 4 of a turbine wheel relative to an original outer edge portion 2 of the turbine wheel.

[0060] In the present invention, in a specific implementation, each turbine blade 1 has a blade suction surface 31 and a blade pressure surface 32 on both sides of the blade surface;

[0061] Each turbine wheel disc modified inner edge portion 4 includes a modified inner edge radius arc segment 7, an edge portion close to the blade suction surface and an edge portion close to the blade pressure surface;

[0062] The edge of the blade suction surface and the edge of the blade pressure surface are respectively connected to the two ends of the modified inner edge radius arc segment 7;

[0063] It should be noted that the blade pressure side is the surface of the turbine blade facing the high-temperature combustion gas entering the turbine, and the blade surface pressure is under a large positive pressure; the blade suction side is the other side of the turbine blade pressure side, and the blade surface pressure is smaller than the blade pressure side pressure.

[0064] For the edge portion close to the suction surface of the blade, it includes a first modified root starting point 341, a first modified straight line segment 351 and a first modified arc segment 361 close to the suction surface 31 of the adjacent turbine blade 1;

[0065] The first correction root starting point 341 is used as the starting point of the first correction straight line segment 351, which is located on the new outer edge portion 5 of the turbine wheel, and the other end of the first correction straight line segment 351 is connected to the first correction arc segment 361;

[0066] The other end of the first corrected arc segment 361 is connected to one end of the corrected inner radius arc segment 7;

[0067] For the edge portion close to the blade pressure surface, it includes a second modified root starting point 342 close to the blade pressure surface 32 of the adjacent turbine blade 1, a second modified straight line segment 352 and a second modified arc segment 362;

[0068] The second correction root starting point 342 is used as the starting point of the second correction straight line segment 352, which is located on the new outer edge portion 5 of the turbine wheel, and the other end of the second correction straight line segment 352 is connected to one end of the second correction arc segment 362;

[0069] The other end of the second corrected arc segment 362 is connected to the other end of the corrected inner edge radius arc segment 7 .

[0070] In the present invention, in a specific implementation, the thickness of the novel outer edge portion 5 of the turbine wheel disc is equal to the sum of the modified root thickness T_s and T_p of each turbine blade 1;

[0071] T_s is the first blade root modified thickness close to the blade suction surface 31 (i.e., the thickness from the first modified root starting point 341 to the symmetry centerline 301 of the turbine blade);

[0072] T_p is the second blade root modified thickness close to the blade pressure surface 32 (ie, the thickness from the second modified root starting point 342 to the symmetry centerline 301 of the turbine blade).

[0073] For specific implementation, see Figure 3d As shown, between the suction surface 31 of the blade and the top surface of the wheel disc 30, there is provided an arc portion 371 connecting the suction surface blade root and the wheel disc;

[0074] A pressure surface blade root and wheel disc connecting arc portion 372 is provided between the blade pressure surface 32 and the top surface of the wheel disc 30 .

[0075] That is to say, for the present invention, a modified transition arc structure is designed at the connection between the pressure surface, suction surface and hub of the turbine blade (i.e. the arc portion 371 connecting the suction surface blade root and the impeller, and the arc portion 372 connecting the pressure surface blade root and the impeller).

[0076] It should be noted that in the present invention, Figure 3a The middle blade connecting arcs 371 and 372 are simplified and are not shown in the figure.

[0077] For the present invention, Figure 3d , a cross-sectional view of a blade is shown, which includes a blade suction surface 31, a blade root and an arc portion 371 connecting the wheel disc 30, and a blade pressure surface 32, a blade root and an arc portion 372 connecting the wheel disc 30; Figure 3d The specific location of the cross section is Figure 3c Marked in.

[0078] In specific implementation, the first corrected root starting point 341, the first corrected straight line segment 351 and the first corrected arc segment 361 near the edge of the suction surface of the blade are respectively symmetrically distributed with the second corrected root starting point 342, the second corrected straight line segment 352 and the second corrected arc segment 362 near the edge of the pressure surface of the blade, with the corrected inner edge radius arc segment 7 as the center.

[0079] In a specific implementation, the first corrected root starting point 341, the first corrected straight line segment 351 and the first corrected arc segment 361 of the blade suction surface 31 close to the adjacent turbine blade 1 are respectively evenly distributed along the circumference of the wheel disc 30 with the second corrected root starting point 342, the second corrected straight line segment 352 and the second corrected arc segment 362 of the blade pressure surface 32 close to the adjacent turbine blade 1.

[0080] It should be noted that, for the present invention, the blade suction surface 31 is the convex surface of the blade surface of the turbine blade 1 , and the blade pressure surface 32 is the concave surface of the blade surface of the turbine blade 1 .

[0081] It should be noted that, compared with the existing turbine impeller with an integral disc mechanism, the low-inertia turbine impeller provided by the present invention is based on a turbine hub (i.e., an integral turbine disc), and a turbine disc modified inner edge portion is respectively provided between every two adjacent impeller channels of the turbine hub. The turbine disc modified inner edge portion serves as a structural feature that can correct for weight reduction. It can effectively reduce the weight of the turbine hub without damaging the strength of the turbine, effectively reduce the inertia of the turbine impeller, obtain a low-inertia turbine impeller, and significantly improve the acceleration responsiveness of the turbine impeller.

[0082] In the present invention, in a specific implementation, each turbine wheel disc modified inner edge portion 4 (i.e., turbine wheel disc hub modified inner edge structure) has an inner edge radius R_n and an outer edge radius R_w of the turbine wheel disc new outer edge portion 5 (i.e., the outer edge radius of the original circular wheel disc 30, i.e., the radius of the original outer edge portion 2 of the turbine wheel disc), which have a proportional relationship as follows:

[0083] R_n / R_w=0.84~0.86;

[0084] Among them, the inner edge radius R_n of the corrected inner edge portion 4 of the turbine wheel disc is the vertical distance between the inner edge middle point of the corrected inner edge portion 4 of the turbine wheel disc (specifically, the middle point of the corrected inner edge radius arc segment 7) and the vertical center axis of the turbine hub 3 (that is, the center of the circle is located on the vertical center axis of the turbine hub 3), that is, the inner edge radius of the corrected inner edge radius arc segment 7 (the inner edge radius of the channel correction arc). R_w is the outer edge radius of the channel wheel disc.

[0085] It should be noted that, regarding the determination of the ratio of R_n and R_w, several design limitations are taken into consideration. A small ratio will lead to a reduction in inertia, but a too small ratio will weaken the strength of the wheel. At the same time, the correction part of the wheel will be enlarged, and the lack of this part will also lead to discontinuity of the airflow channel and increased airflow efficiency loss. A large ratio will not significantly reduce the inertia. Therefore, the choice of the value here takes into account strength, efficiency, inertia and other aspects, and is set within the range of 0.84 to 0.86.

[0086] It should be noted that, for the present invention, for the turbine impeller modified inner edge portion 4 (i.e., the turbine impeller hub modified inner edge structure), the parameters close to the blade suction surface are represented by the symbol (_s), and the parameters close to the blade pressure surface are represented by the symbol (_p).

[0087] In the present invention, in a specific implementation, the first blade root corrected thickness T_s (i.e., the thickness from the first corrected root starting point 341 to the symmetry center line 301 of the turbine blade) close to the blade suction surface 31 has a numerical value equal to the sum of 1 / 2 of the root thickness t of the turbine blade 1 and a preset first constant. For example, its value is generally T_s=t / 2+(1.5~3mm).

[0088] It should be noted that the value set by the preset first constant (for example, 1.5 to 3 mm) is an increased value to ensure the reliable connection between the suction surface of the blade root and the disk, to ensure that a transition arc portion of the root suction surface (i.e., the arc portion 371 connecting the suction surface blade root and the disk) can be formed to improve the blade connection strength; at the same time, this value is related to the size of the turbine. The larger the turbine, the larger the range. The upper limit of the preset first constant of 3 mm corresponds to a turbine with a disk radius R_w≦70 mm. If the turbine is further increased, the upper limit of the preset first constant will increase accordingly.

[0089] It should be noted that the root thickness t of each turbine blade 1 is equal.

[0090] In the present invention, in a specific implementation, the second blade root corrected thickness T_p close to the blade pressure surface 32 (i.e., the thickness from the second corrected root starting point 342 to the symmetry center line 301 of the turbine blade) is equal to the sum of 1 / 2 of the root thickness t of the turbine blade 1 and a preset second constant. For example, its value is generally T_p=t / 2+(1~2.5mm).

[0091] It should be noted that the value set by the preset second constant (for example, 1 to 2.5 mm) is an increased value to ensure the reliable connection between the pressure surface of the blade root and the disk, to ensure that a transition arc portion of the root pressure surface (i.e., the arc portion 372 connecting the pressure surface blade root and the disk) can be formed to improve the blade connection strength; at the same time, this value is related to the size of the turbine. The larger the turbine, the larger the range. The upper limit of the preset second constant of 3 mm corresponds to a turbine with a disk radius R_w≦70 mm. If the turbine is further increased, the upper limit of the preset second constant will increase accordingly.

[0092] In the present invention, in a specific implementation, the correction arc radius R_s close to the blade suction surface 31 (i.e., the radius of the first correction arc segment 361 ) is R_s=(0.8-0.9)*(R_w-R_n);

[0093] It should be noted that, in the present invention, the size setting of the modified arc radius R_s close to the blade suction surface 31 (ie, the radius of the first modified arc segment 361 ) is to ensure a smooth connection transition between R_w and R_n and avoid stress concentration at sharp corners.

[0094] In the present invention, in a specific implementation, the correction arc radius (i.e., the radius of the second correction arc segment 362) R_p close to the blade pressure surface 32 has a value of R_n=(0.8-0.9)*(R_w-R_n);

[0095] It should be noted that, in the present invention, the size setting of the modified arc radius R_p close to the blade pressure surface 32 (ie, the radius of the second modified arc segment 362) is to ensure a smooth connection transition between R_w and R_n and avoid stress concentration at sharp corners.

[0096] In the present invention, in a specific implementation, the angle θ_s between the correction line segment (ie, the first correction straight line segment 351 ) close to the blade suction surface 31 and the symmetry centerline 301 of the turbine blade is θ_s=10 to 25 degrees.

[0097] It should be noted that the angle θ_s between the correction line segment close to the suction surface 31 of the blade (i.e., the first correction straight line segment 351) and the symmetry centerline 301 of the turbine blade, as the design of the correction edge inclination angle, gradually increases the thickness from the outer R_w to R_n according to the correction of the blade root to meet the hub strength requirements.

[0098] In the present invention, in a specific implementation, the angle θ_p between the correction line segment close to the blade pressure surface 32 (i.e., the second correction straight line segment 352) and the symmetry center line 301 of the turbine blade is θ_p=5-20 degrees;

[0099] It should be noted that the angle θ_p between the correction line segment close to the blade pressure surface 32 (i.e., the second correction straight line segment 352) and the symmetry centerline 301 of the turbine blade, as the design of the correction edge inclination angle, gradually increases the thickness from the outer R_w to R_n according to the blade root correction to meet the hub strength requirements.

[0100] It should be noted that, based on the above scheme, in the present invention, T_s, T_p and θ_s, θ_p jointly solve the connection design strength between the root of the turbine blade 1 and the wheel disc 30. As the value increases, the connection contact surface between the root of the turbine blade 1 and the wheel disc 30 increases, which can improve the connection strength of the root of the turbine blade, and at the same time, can meet the establishment of the arc transition structure at the connection between the root of the turbine blade 1 and the wheel disc 30 (i.e., the arc portion 371 connecting the suction surface blade root and the wheel disc, and the arc portion 372 connecting the pressure surface blade root and the wheel disc);

[0101] For the present invention, R_n and R_w are key parameters for solving the problem of wheel weight reduction. The size of R_n directly reflects the amount of wheel weight reduction. Within a preset reasonable range (e.g., R_n / R_w=0.84-0.86), the smaller R_n is, the lighter the turbine weight is, and the smaller the turbine rotational inertia is.

[0102] Based on the technical solution provided by the present invention, compared with the prior art, the present invention adopts the modified structure of the turbine wheel hub (i.e., the modified inner edge portion 4 of the turbine wheel), and finally forms a low-inertia turbine impeller structure, which reduces the weight of the turbine hub while ensuring the stable installation of the turbine blades. After inspection, the turbine using the structure of the present invention reduces the weight by 3-6%, and the acceleration performance of the turbine impeller is greatly improved.

[0103] In the present invention, in a specific implementation, the lower outer side of each turbine blade 1 has a blade inlet edge portion 101;

[0104] The inner end of the blade inlet edge portion 101 is fixedly connected to the outer side of the upper surface of the turbine hub 3;

[0105] The top of each turbine blade 1 has a blade outlet edge portion 102;

[0106] The inner end of the blade outlet edge portion 102 is fixedly connected to the outer side of the upper surface of the turbine hub 3 .

[0107] In a specific implementation, the shape of the blade outlet edge portion 102 is a curve shape that conforms to a Bezier spline curve.

[0108] In specific implementation, the blade inlet edge 101 gradually tilts upward from the inside to the outside (ie, the closer to the vertical center axis of the turbine hub 1, the lower the height), and the turbine inlet is in the form of a mixed flow design.

[0109] It should be noted that, for the present invention, based on the inclined design of the blade inlet edge 101, the axial airflow velocity component of the high-temperature exhaust gas discharged by the engine entering the turbine is increased, which is beneficial for the turbine to obtain a larger intake flow rate, further enhancing the flow capacity of the turbine, thereby enhancing the working ability of the exhaust gas and improving the turbine efficiency.

[0110] In the present invention, in a specific implementation, the inner edge of the turbine blade 1 connected to the turbine hub 3 is the hub curved edge portion 103;

[0111] On the turbine blade 1, the outer edge away from the turbine hub 1 and not connected to the turbine hub 1 is the wheel cover curved edge portion 104;

[0112] The shapes of the wheel hub curved edge portion 103 and the wheel cover curved edge portion 104 both conform to the shapes of Bezier spline curves; specifically, they conform to the shapes of high-order (eg, third-order and above) Bezier spline curves.

[0113] In order to obtain a supercharger low-inertia turbine impeller provided by the present invention, the present invention also provides a method for optimizing a supercharger low-inertia turbine impeller, comprising the following steps:

[0114] The first step is to build a three-dimensional model of the existing traditional turbine impeller;

[0115] It should be noted that, in the first step, a three-dimensional model of a conventional turbine impeller without a modified hub can be designed by using a computer in a conventional manner, such as Figure 1a and Figure 1b As shown; for example, the conventional design method of a conventional turbine impeller can be: first, according to the requirements of aerodynamic performance, the control curves of the turbine wheel cover and the wheel hub are designed, and the wheel hub and the wheel cover curved surface are formed by rotation to meet the turbine strength requirements, and then according to the aerodynamic performance of the turbine, the corresponding turbine blades are designed, the turbine blades are connected to the turbine hub curved surface, and the blade root and the wheel hub curved surface are transitioned through an arc, and finally the overall structure of the turbine is formed. Of course, other existing conventional design methods can also be used, which will not be repeated here.

[0116] See also Figure 1a and Figure 1bThe existing traditional turbine impeller includes a turbine hub 3; a plurality of turbine blades 1 are distributed around the upper surface of the turbine hub 3; and the edges around the wheel disc 30 at the bottom of the turbine hub 3 are the original outer edge portion 2 of the turbine wheel disc distributed in a circular shape.

[0117] The second step is to construct the modified inner edge 4 of the turbine wheel and the new outer edge 5 of the turbine wheel;

[0118] In the second step, the turbine disk correction structure (ie, the turbine disk correction inner edge portion 4) is constructed according to the determined hub correction parameters (ie, the structural parameters of the turbine disk correction inner edge portion 4).

[0119] In the second step, in the specific implementation, the hub correction parameters, i.e., the structural parameters of the corrected inner edge portion 4 of the turbine wheel disc, are determined as follows (here is an example when the original outer edge portion 2 of the turbine wheel disc in the first step has a diameter of 48 mm):

[0120] The first blade root modified thickness T_s close to the blade suction surface 31 is t / 2+2 mm;

[0121] The second blade root modified thickness T_p close to the blade pressure surface 32 is t / 2+1.5 mm;

[0122] The radius of the modified circular arc close to the blade suction surface 31 (i.e., the radius of the first modified circular arc segment 361 ) R_s=3 mm;

[0123] The radius of the modified circular arc close to the blade pressure surface 32 (ie, the radius of the second modified circular arc segment 362 ) R_p=3 mm;

[0124] The angle θ_s between the correction line segment close to the blade suction surface 31 (i.e., the first correction straight line segment 351 ) and the symmetry centerline 301 of the turbine blade is 20 degrees;

[0125] The angle θ_p between the correction line segment close to the blade pressure surface 32 (i.e., the second correction straight line segment 352) and the symmetry center line 301 of the turbine blade is 15 degrees;

[0126] The inner edge radius R_n of each turbine wheel disc modified inner edge portion 4 (i.e., the turbine wheel disc hub modified inner edge structure) is 20.5 mm;

[0127] The outer edge radius of the new outer edge portion 5 of the turbine wheel (i.e., the outer edge radius of the original circular turbine wheel, which is equal to the radius of the original outer edge portion 2 of the turbine wheel in the three-dimensional model of the traditional turbine impeller) R_w=24 mm;

[0128] In the second step, the thickness of the new outer edge 5 of the turbine wheel is equal to the sum of the modified root thickness T_p+T_s of each turbine blade 1, see Figure 3a to Figure 3c shown.

[0129] In the third step, the original outer edge portion 2 of the turbine impeller in the three-dimensional model of the traditional turbine impeller is corrected according to the corrected inner edge portion 4 of the turbine impeller and the new outer edge portion 5 of the turbine impeller constructed in the third step, so as to obtain a three-dimensional model of the turbine impeller having the corrected inner edge portion 4 of the turbine impeller and the new outer edge portion 5 of the turbine impeller.

[0130] In the third step, in specific implementation, according to Figure 3a to Figure 3c The correction structure shown (specifically, the turbine wheel disc correction inner edge portion 4) corrects the wheel disc 30 at the bottom of the turbine hub 3, and determines the hub correction structure parameters such as the correction root starting point (including the first correction root starting point 341 and the second correction root starting point 342), the correction straight line segment (including the first correction straight line segment 351 and the second correction straight line segment 352), the correction arc segment (including the first correction arc segment 361 and the second correction arc segment 362) and the correction inner edge radius arc segment 7.

[0131] It should be noted that see Figure 2a As shown, Figure 2a To construct the three-dimensional model of the turbine impeller of the present invention, the grid lines in the figure are the wheel disc correction area (i.e., the weight reduction area of ​​the bottom wheel disc 30 of the turbine hub 3, which is also the omitted area);

[0132] After testing, it was found that, for the present invention, the overall weight of the turbine can be reduced by 4% through the low inertia structure modification of the turbine hub 3, and the improvement effect is obvious.

[0133] It can be seen from the technical solution provided by the present invention that, compared with the prior art, the overall design performance of the turbine impeller is greatly improved through the structure of the present invention.

[0134] In summary, compared with the prior art, the low-inertia turbine impeller and optimization method for a supercharger provided by the present invention are scientifically designed and can solve the limitation of poor turbine acceleration performance of a small supercharger. The present invention arranges a plurality of turbine wheel disc correction inner edge portions on the turbine hub. The turbine wheel disc correction inner edge portions serve as structural features that can correct weight reduction. The weight of the turbine hub can be effectively reduced without damaging the strength of the turbine, and the inertia of the turbine impeller can be effectively reduced to obtain a low-inertia turbine impeller, so that the acceleration responsiveness of the turbine impeller is significantly improved, which has great practical significance.

[0135] It should be noted that, in the present invention, by adding a corresponding structure with T_s and T_p to the connection between the root of the turbine blade 1 and the hub (specifically, the disk 30 at the bottom of the turbine hub 3), the connection position between the hub and the root of the blade satisfies T_s+T_p>t, thereby forming a structure in which the root of the blade is connected to the wing plate, thereby increasing the strength of the impeller root. At the same time, an inclined angle structure with θ_s and θ_p is designed, and the connection arc transition structure (i.e., the suction side blade root and the disk connecting arc portion 371, and the pressure side blade root and the disk connecting arc portion 372) is satisfied. Through the combined effect of these structural designs, weight reduction is achieved without damaging the hub strength.

[0136] It should also be noted that if a simple non-wing plate connection is used at the root of the blade, a non-circular transition connection is used between the root of the blade and the hub, a non-circular connection is used between the wheels R_n and R_w, and rectangular, semicircular and other modified structures are used, they cannot meet the turbine strength design requirements well.

[0137] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A low inertia turbine impeller for a supercharger, characterized in that: comprising a turbine hub (3); A plurality of turbine blades (1) are distributed around the outer sides of the upper surface of the turbine hub (3); A plurality of turbine blades (1) are distributed at equal intervals along the circumferential direction with the vertical central axis of the turbine hub (3) as the center; A wheel disc (30) at the bottom of a turbine hub (3) comprises a plurality of spaced-apart new turbine wheel disc outer edge portions (5) and a plurality of spaced-apart modified turbine wheel disc inner edge portions (4); Each turbine wheel disc novel outer edge portion (5) is located directly below the outer end of the root of a turbine blade (1); A concave turbine wheel disc modified inner edge portion (4) is respectively provided between any two adjacent turbine wheel disc new outer edge portions (5); The modified inner edge portion (4) of each turbine wheel is respectively located in a blade gap (100) between two adjacent turbine blades (1); A plurality of new turbine wheel disc outer edge portions (5) and a plurality of modified turbine wheel disc inner edge portions (4), centered on the vertical central axis of the turbine hub (3), and distributed circumferentially around the edges of the wheel disc (30); Each turbine blade (1) has a blade suction surface (31) and a blade pressure surface (32) on both sides of the blade surface; Each turbine wheel disc modified inner edge portion (4) comprises a modified inner edge radius arc segment (7), an edge portion close to the blade suction surface, and an edge portion close to the blade pressure surface; The edge portion close to the suction surface of the blade and the edge portion close to the pressure surface of the blade are respectively connected to the two ends of the modified inner edge radius arc segment (7); For the edge portion close to the suction surface of the blade, it includes a first corrected root starting point (341), a first corrected straight line segment (351) and a first corrected circular arc segment (361) close to the suction surface (31) of the adjacent turbine blade (1); The first correction root starting point (341) is used as the starting point of the first correction straight line segment (351), which is located on the new outer edge portion (5) of the turbine wheel, and the other end of the first correction straight line segment (351) is connected to one end of the first correction circular arc segment (361); The other end of the first corrected arc segment (361) is connected to one end of the corrected inner edge radius arc segment (7); For the edge portion close to the blade pressure surface, it includes a second corrected root starting point (342) close to the blade pressure surface (32) of the adjacent turbine blade (1), a second corrected straight line segment (352) and a second corrected circular arc segment (362); The second correction root starting point (342) is used as the starting point of the second correction straight line segment (352), which is located on the new outer edge portion (5) of the turbine wheel, and the other end of the second correction straight line segment (352) is connected to one end of the second correction circular arc segment (362); The other end of the second corrected arc segment (362) is connected to the other end of the corrected inner edge radius arc segment (7); A circular arc portion (371) connecting the suction surface blade root and the wheel disc is provided between the blade suction surface (31) and the top surface of the wheel disc (30); A circular arc portion (372) connecting the root of the blade on the pressure surface and the wheel disc is provided between the blade pressure surface (32) and the top surface of the wheel disc (30); The inner radius R_n of each turbine wheel disc modified inner edge portion (4) and the outer radius R_w of the turbine wheel disc new outer edge portion (5) have a proportional relationship as follows: R_n / R_w=0.84~0.86; The thickness of the novel outer edge portion (5) of the turbine wheel disc is equal to the sum of the modified root thickness T_s and T_p of each turbine blade (1); Wherein: a first corrected root corrected thickness T_s close to the blade suction surface (31) has a value equal to the sum of 1 / 2 of the root thickness t of the turbine blade 1 and a preset first constant; Wherein: the second corrected root corrected thickness T_p close to the blade pressure surface (32) has a value equal to the sum of 1 / 2 of the root thickness t of the turbine blade 1 and a preset second constant; The radius R_s of the first corrected arc segment (361) is R_s=(0.8~0.9)*(R_w-R_n); The radius R_p of the second corrected arc segment (362) is R_n=(0.8-0.9)*(R_w-R_n); An angle θ_s between the first corrected straight line segment (351) and the symmetric center line (301) of the turbine blade has a value of 10 to 25 degrees; The angle θ_p between the second corrected straight line segment (352) and the symmetric center line (301) of the turbine blade has a value of 5 to 20 degrees.

2. The low inertia turbine impeller for a supercharger according to claim 1, characterized in that: The shape of the outer edge of the novel outer edge portion (5) of the turbine wheel disc is an arc shape; The outer edges of the novel outer edge portions (5) of the plurality of turbine wheel discs are located on the same circle, the center of which is located on the vertical central axis of the turbine hub (3).

3. The low inertia turbine impeller for a supercharger according to claim 1, characterized in that: A first corrected root starting point (341), a first corrected straight line segment (351) and a first corrected circular arc segment (361) near the edge of the blade suction surface are respectively symmetrically distributed with a second corrected root starting point (342), a second corrected straight line segment (352) and a second corrected circular arc segment (362) near the edge of the blade pressure surface, with the corrected inner edge radius circular arc segment (7) as the center.

4. The low-inertia turbine impeller for a supercharger according to claim 1, characterized in that: A first corrected root starting point (341), a first corrected straight line segment (351) and a first corrected circular arc segment (361) of a blade suction surface (31) close to an adjacent turbine blade (1) are respectively evenly distributed along the circumference of the wheel disc (30) with a second corrected root starting point (342), a second corrected straight line segment (352) and a second corrected circular arc segment (362) of a blade pressure surface (32) close to an adjacent turbine blade (1).

5. A method for optimizing a supercharger low inertia turbine impeller according to any one of claims 1 to 4, characterized in that: The following steps are involved: The first step is to build a three-dimensional model of the turbine impeller; A turbine impeller comprises a turbine hub (3); a plurality of turbine blades (1) are distributed around the upper surface of the turbine hub (3); and the edges around the wheel disc (30) at the bottom of the turbine hub (3) are original outer edge portions (2) of the turbine wheel disc distributed in a circular shape. The second step is to construct a modified inner edge portion (4) of the turbine wheel and a new outer edge portion (5) of the turbine wheel; The third step is to modify the original outer edge portion (2) of the turbine impeller in the three-dimensional model of the turbine impeller according to the modified inner edge portion (4) of the turbine impeller and the new outer edge portion (5) of the turbine impeller constructed in the third step, so as to obtain a three-dimensional model of the turbine impeller having the modified inner edge portion (4) of the turbine impeller and the new outer edge portion (5) of the turbine impeller; When the original outer edge portion (2) of the turbine wheel disc in the first step has a diameter of 48 mm, in the second step, the structural parameters of the inner edge portion (4) of the turbine wheel disc are modified as follows: The first corrected root corrected thickness T_s=t / 2+2mm close to the blade suction surface (31); The second modified root modified thickness T_p = t / 2 + 1.5 mm close to the blade pressure surface (32); The radius of the first corrected circular arc segment (361) close to the blade suction surface (31) is R_s = 3 mm; The radius R_p of the second modified arc segment (362) close to the blade pressure surface (32) is 3 mm; An angle θ_s between the first corrected straight line segment (351) close to the blade suction surface (31) and the symmetry center line (301) of the turbine blade is 20 degrees; An angle θ_p between the second corrected straight line segment (352) close to the blade pressure surface (32) and the symmetry center line (301) of the turbine blade is 15 degrees; The inner edge radius R_n of the corrected inner edge portion (4) of each turbine wheel is 20.5 mm; The outer edge radius R_w of the new outer edge portion (5) of the turbine impeller is 24 mm.

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