阅读说明：本技术 离心式旋转机械的叶轮及离心式旋转机械 (Impeller of centrifugal rotary machine and centrifugal rotary machine ) 是由 本田浩范 岩切健一郎 于 2017-10-11 设计创作，主要内容包括：本发明的一些实施方式的离心式旋转机械的叶轮具备：轮毂,其具有位于轴向的一端部的小径部、以及位于所述轴向的另一端部且直径比所述小径部大的大径部；叶片,其具有位于所述小径部的轴向位置的第一边缘以及位于所述大径部的轴向位置的第二边缘,且设置在所述轮毂的外周面,所述叶轮的经过所述第一边缘的末梢的、轴向位置处的第一半径方向截面中的50％以上的叶高度范围的至少一部分,相对于半径方向向所述叶轮的旋转方向的下游侧倾斜。(An impeller of a centrifugal rotary machine according to some embodiments of the present invention includes: a hub having a small diameter portion located at one end in an axial direction and a large diameter portion located at the other end in the axial direction and having a diameter larger than the small diameter portion; and a blade that has a first edge located at an axial position of the small diameter portion and a second edge located at an axial position of the large diameter portion, and that is provided on an outer peripheral surface of the hub, wherein at least a part of a blade height range of 50% or more in a first radial direction cross section of the impeller passing through a tip of the first edge at the axial position is inclined to a downstream side in a rotation direction of the impeller with respect to a radial direction.)

1. An impeller of a centrifugal rotary machine, comprising:

A hub having a small diameter portion located at one end in an axial direction and a large diameter portion located at the other end in the axial direction and having a diameter larger than the small diameter portion;

A blade having a first edge located at an axial position of the small diameter portion and a second edge located at an axial position of the large diameter portion, and provided on an outer peripheral surface of the hub,

The impeller is inclined to the downstream side in the rotation direction of the impeller with respect to the radial direction, at least a part of a range of a blade height of 50% or more in a first radial direction cross section at an axial position passing through a tip of the first edge.

2. The impeller of a centrifugal rotary machine according to claim 1,

On a first reference line connecting midpoints in the thickness direction of the first radial cross section,

When a first hub-side reference point located at a radial position of a hub surface of the hub and a first tip-side reference point located at a radial position of the tip are defined,

The first tip side reference point is located on a downstream side of the rotation direction with respect to the first hub side reference point.

3. The impeller of a centrifugal rotary machine according to claim 2,

the first reference line includes a curved portion having a center of curvature on a downstream side in the rotation direction in the first radial direction cross section.

4. The impeller of a centrifugal rotary machine according to claim 2 or 3,

The first reference line includes a straight line portion.

5. The impeller of a centrifugal rotary machine according to any one of claims 2 to 4,

A phase angle difference Δ θ between the first tip-side reference point and the first hub-side reference point₁Is more than 20 degrees.

6. The impeller of a centrifugal rotary machine according to any one of claims 2 to 5,

The first reference line is an angle θ between a first tangent line to each point on the first reference line and a radial line passing through each point₁When the angle is defined as the angle theta₁When the first tangent line extending radially outward from each point is positive when the first tangent line is located downstream in the rotational direction with respect to the radial line,

Theta is described₁The maximum value of (2) is 20 degrees or more.

7. The impeller of a centrifugal rotary machine according to any one of claims 1 to 6,

The impeller is inclined to the upstream side in the rotation direction of the impeller with respect to the radial direction, in at least a part of a range of a blade height of 50% or more in a second radial direction cross section at an axial position passing through the tip of the second edge.

8. the impeller of a centrifugal rotary machine according to claim 7,

On a second reference line connecting midpoints in the thickness direction of the second radial cross section,

When a second hub-side reference point located at a radial position of the hub surface of the hub and a second tip-side reference point located at a radial position of the tip are defined,

The second tip-side reference point is located on an upstream side in the rotation direction with respect to the second hub-side reference point.

9. The impeller of a centrifugal rotary machine according to claim 8,

The second reference line includes a curved portion having a center of curvature on an upstream side in the rotation direction in the second radial direction cross section.

10. The impeller of a centrifugal rotary machine according to claim 8 or 9,

The second reference line includes a straight line portion.

11. The impeller of a centrifugal rotary machine according to any one of claims 8 to 10,

A phase angle difference Δ θ between the second tip-side reference point and the second hub-side reference point₂Is more than 20 degrees.

12. The impeller of a centrifugal rotary machine according to any one of claims 8 to 11,

The second reference line is an angle θ between a second tangent line to each point on the second reference line and a radial line passing through each point₂when the angle is defined as the angle theta₂When the sign of (b) is positive when the second tangent line directed radially outward from the respective points is located on the upstream side in the rotational direction with respect to the radial line,

Theta is described₂The maximum value is more than 30 degrees.

13. A centrifugal rotary machine is characterized by comprising:

the impeller of any one of claims 1 to 12;

A casing provided so as to cover the impeller.

14. The centrifugal rotary machine of claim 13,

The impeller includes:

A leading edge as the first edge;

A trailing edge as the second edge;

The centrifugal rotary machine is a centrifugal compressor.

Technical Field

The present disclosure relates to an impeller of a centrifugal rotary machine and a centrifugal rotary machine provided with the impeller.

Background

In an impeller of a centrifugal rotary machine such as a turbocharger and a turbine, centrifugal stress generated at a blade surface and a blade end tends to increase as the rotation speed increases. Methods of increasing impeller strength by adjusting blade thickness or increasing fillet diameter for this stress increase may result in a reduction in throat area or performance.

patent document 1 describes a method of attaching a ring to a blade end portion (a portion that deforms greatly when a high centrifugal stress is applied) of a rotor blade to improve strength and reduce deformation due to the centrifugal stress. However, since the structure of this method is complicated, there is a problem in that the cost required for manufacturing and assembling increases.

Disclosure of Invention

drawings

FIG. 1 is a side view of an embodiment of an impeller.

FIG. 2 is a front view of an embodiment of an impeller.

Fig. 3 is a front view showing a blade shape of an impeller according to an embodiment.

Fig. 4 is a side sectional view of a centrifugal rotary machine according to an embodiment.

Fig. 5 is a front view showing a blade shape of an impeller according to an embodiment.

Fig. 6 is a front view showing a blade shape of an impeller according to an embodiment.

Fig. 7 is a front view showing a blade shape of an impeller according to an embodiment.

Fig. 8 is a front view showing a blade shape of an impeller according to an embodiment.

Fig. 9 is a front view showing a blade shape of an impeller according to an embodiment.

Fig. 10 is a side view of a conventional impeller.

Fig. 11 is a front view of a conventional impeller.

Detailed Description

Hereinafter, some embodiments of the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described as the embodiments and shown in the drawings are not intended to limit the scope of the present invention, and are merely illustrative examples.

For example, a term indicating a relative or absolute arrangement such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "central", "concentric", or "coaxial" means not only such an arrangement strictly, but also a state in which the arrangement is relatively displaced by an angle or a distance to the extent of a tolerance or a function equivalent thereto.

For example, a term indicating that things such as "same", "equal", and "uniform" are equal means not only a state of being strictly equal but also a state of being different in tolerance or degree of obtaining the same function.

For example, the expression "a shape such as a square shape or a cylindrical shape" means not only a shape such as a square shape or a cylindrical shape in a strict geometrical sense but also a shape including a concave and convex portion, a chamfered portion, and the like within a range in which the same effect can be obtained.

On the other hand, the expression "provided with", "having", "provided with", "including" or "containing" one constituent element is not an exclusive expression excluding the presence of other constituent elements.

Fig. 10 and 11 show an impeller of a conventional centrifugal compressor.

In fig. 10 and 11, an impeller 100 of a conventional centrifugal compressor includes a hub portion 102 and a plurality of blades 104 provided on an outer peripheral surface of the hub portion 102. The hub portion 102 has a small diameter portion 106 located at one end in the axial direction a and a large diameter portion 108 located at the other end in the axial direction a and having a larger diameter than the small diameter portion 106. The vanes 104 have a leading edge 110 at an axial position of the small diameter portion 106 and a trailing edge 112 at an axial position of the large diameter portion 108. In the drawing, b represents the rotation direction of the impeller 100.

As shown in fig. 11, the leading edge 110 and the trailing edge 112 are inclined radially to the downstream side in the rotational direction.

As shown in fig. 10, it is known that when the impeller 100 rotates, a large centrifugal stress is generated around a mid-height position a1 of the blade 104.

As a result of analysis by the present inventors, the deformation of the blade 104 due to the centrifugal force becomes large on the leading edge side and the trailing edge side, and on the leading edge side, the deformation is made in a direction in which the inclination is gentle in the circumferential direction of the blade 104 (the direction of arrow X toward the downstream side in the rotation direction b), and on the trailing edge side, the deformation is made in the upward and downward direction (the direction of arrow Y from the leading edge side toward the trailing edge side) in general. As a result, the tensile stress and the bending moment M are generated in the tip-side region center portion a2 of the blade chord 114 of the blade 104.

In centrifugal rotary machines, straight blades (blades having leading edges extending straight in the radial direction) have been the mainstream in the past, but in recent years, three-dimensional machining has been possible. Therefore, in the course of the study of the three-dimensional blade, the present inventors designed a three-dimensional shape in which the leading edge is raised upward in the rotational direction with respect to the radial direction, but as described above, it is known that tensile stress acts on the tip-side region central portion a2 of the rotor blade tip.

fig. 1 to 3 show an impeller 10 of a centrifugal rotary machine according to an embodiment. Fig. 1 is a side view of the impeller 10, fig. 2 is a front view of the impeller 10, and fig. 3 is a first radial direction cross section S described later₁is a front view of the shape of the blades 14 of the impeller 10.

In fig. 1 and 2, the impeller 10 includes a hub portion 12 and a plurality of blades 14 provided on an outer peripheral surface of the hub portion 12. The hub portion 12 has a small diameter portion 16 located at one end in the axial direction a and a large diameter portion 18 located at the other end in the axial direction a and having a larger diameter than the small diameter portion 16. The vane 14 has a first edge 20 at an axial position of the small diameter portion 16 and a second edge 22 at an axial position of the large diameter portion 18.

As shown in FIG. 3, a first radial cross-section S of the impeller 10 at an axial location past the tip 26 of the first rim 20₁At least a part of the range of the blade height of 50% or more is inclined to the downstream side in the rotation direction b of the impeller 10 with respect to the radial direction c.

according to the above structure, as shown in FIG. 2, the first radial direction cross section S is formed₁At least a part of the blade height range of 50% or more of (b) is inclined to the downstream side in the rotation direction b with respect to the radial direction c, and therefore, even when the second edge 22 on the hub large diameter portion side is inclined to the upstream side in the rotation direction with respect to the radial direction c, the first edge side and the second edge side can be deformed in a direction in which the tensile stress is not relatively increased. Specifically, the first edge and the second edge are displaced in a direction in which the edges are relatively laterally close to each other or in a direction in which a compressive stress is generated in the distal region center portion a 2. This can reduce the tensile stress and the bending moment M generated in the distal region center portion a2 between the first edge 20 and the second edge 22.

In one embodiment, in fig. 1 and 2, a rotation shaft 28 is provided at the center of the hub portion 12, and the rotation shaft 28 rotates in the arrow b direction about the rotation center O.

As shown in fig. 4, a centrifugal rotary machine 50 according to one embodiment includes the impeller 10 having the above-described configuration and a casing 52 provided so as to cover the impeller 10.

According to the above structure, the vane 14 can be deformed in a direction in which the first edge 20 side and the second edge 22 side relatively do not increase the tensile stress by the centrifugal force applied to the vane 14 when the impeller 10 rotates. This reduces the tensile stress and the bending moment M generated in the distal region center portion a2 between the first edge 20 and the second edge 22.

In one embodiment, the centrifugal rotary machine 50 is a centrifugal compressor, wherein the impeller 10 includes blades 14 having a leading edge as a first edge 20 and a trailing edge as a second edge 22. By the rotation of the impeller 10, the gas G to be compressed passes through the flow path 56 formed between the blades from the inlet passage 54, is compressed, and is discharged to the discharge passage 58.

According to this embodiment, when the impeller 10 rotates, the tensile stress and the bending moment M generated in the tip-side region center portion a2 between the leading edge and the trailing edge can be reduced.

In one embodiment, as shown in FIG. 3, the cross section S is taken in the first radial direction₁A first reference line L connecting the midpoints in the leaf thickness direction₁in the above, a point located in the radial direction of the hub surface of the hub portion 12 is set as the first hub-side reference point Ph₁The point located at the radial position of the tip 26 is set as a first tip-side reference point Pt₁First tip side fiducial point Pt₁relative to the first hub side reference point Ph₁Is located on the downstream side in the rotation direction b of the impeller 10.

According to this embodiment, since the first tip side reference point Pt₁Relative to the first hub side reference point Ph₁The first edge 20 and the second edge 22 can be deformed in the above-described direction so as to be opposed to each other without increasing the tensile stress, because the deformation is located on the downstream side in the impeller rotation direction. This reduces the tensile stress and the bending moment M generated in the distal region center portion a2 between the first edge 20 and the second edge 22.

In one embodiment, as shown in FIG. 3, the first reference line L₁Includes a bent portion 30, the bent portion 30 having a first radial cross section S₁Middle ratio first reference line L₁A position further downstream in the impeller rotation direction b has a center of curvature C₁。

according to this embodiment, the center of curvature C of the curved portion 30 is due to₁Located on the downstream side in the impeller rotation direction, the first edge 20 side and the second edge 22 side can be deformed in directions that are relatively free from an increase in tensile stress. Thereby, can be reduced inTensile stress and bending moment M are generated between the first edge 20 and the second edge 22 at the distal-side region center portion a 2.

In one embodiment, as shown in FIG. 3, the first reference line L₁Including straight portions 32.

According to this embodiment, the first reference line L is passed₁The linear portion 32 allows the blade 14 to have a simple shape in its outer shape, and facilitates the production of the blade 14.

FIGS. 5 and 6 show a first radial cross-section S₁The shape of the blade 14 of each embodiment.

In one embodiment, as shown in FIG. 5, the first tip side fiducial point Pt₁And a first hub side reference point Ph₁phase angle difference Δ θ between₁Is more than 20 degrees.

According to this embodiment, the first radial direction cross section S is formed₁At least the tip side of the rotor is inclined toward the downstream side in the rotation direction of the impeller, and the phase angle difference Δ θ is secured₁And the first edge side and the second edge side can be deformed in a direction relatively without increasing the tensile stress. This reduces the tensile stress and the bending moment M generated in the distal region center portion a2 between the first edge 20 and the second edge 22. In addition, even when the degree of curvature of the three-dimensional leaf is large, the satisfaction in strength can be improved.

In one embodiment, as shown in FIG. 6, with respect to the first reference line L₁In other words, an angle θ between a first tangent line 34 to each point on the first reference line and a radial line 36 passing through each point on the first reference line₁In the case where the angle is defined as the angle θ₁Is positive when a first tangent line 34 extending radially outward from each of the points is located downstream of a radial line 36 in the impeller rotation direction b, the reference symbol θ is set₁the maximum value of (2) is 20 degrees or more.

According to this embodiment, since θ₁Is 20 degrees or more, the first edge 20 side can be reliably prevented from increasing laterally relative to the second edge 22 side when the impeller 10 rotatesThe direction of the applied tensile stress is deformed. This can reliably reduce the tensile stress and the bending moment M.

FIGS. 7 to 9 show a second radial cross section S to be described later₂The shape of the blade 14 in each embodiment.

in one embodiment, as shown in fig. 7, a second radial cross-section S of the impeller 10 at an axial position past the tip 38 of the second rim 22₂At least a part of the range of the blade height of 50% or more (see fig. 1) is inclined to the upstream side in the impeller rotation direction b with respect to the radial direction.

According to this embodiment, when the impeller 10 rotates, the first edge 20 side and the second edge 22 side can be deformed in a direction in which the tensile stress is not relatively increased. That is, the first edge and the second edge are displaced in a direction in which they relatively approach each other laterally or in a direction in which a compressive stress is generated in the distal region center portion a 2.

this reduces the tensile stress and the bending moment M generated in the distal region center portion a2 between the first edge 20 and the second edge 22.

in one embodiment, as shown in FIG. 7, the second radial cross section S is₂A second reference line L connecting the midpoints in the leaf thickness direction₂in the above, a point located in the radial direction of the hub surface of the hub portion 12 is set as the second hub-side reference point Ph₂The point located at the radial position of the tip 38 is set as a second tip-side reference point Pt₂Second tip side fiducial point Pt₂Relative to the second hub side reference point Ph₂Located on the upstream side in the impeller rotation direction b.

According to this embodiment, the second blade end side reference point Pt due to the second edge 22₂Relative to the second hub side reference point Ph₂Since the second edge 22 is located on the upstream side in the rotational direction, the second edge can be displaced toward the upstream side in the rotational direction when the impeller rotates. This can reduce the tensile stress and the bending moment M generated in the distal region center portion a2 between the first edge 20 and the second edge 22.

In one embodiment, as shown in FIG. 7, secondReference line L₂Comprises a curved portion 40, the curved portion 40 having a cross section S in the second radial direction₂has a center of curvature C on the upstream side in the impeller rotation direction b₂。

according to this embodiment, the center of curvature C due to the curved portion 40₂Since the second edge 22 is located on the upstream side in the impeller rotation direction, the second edge can be displaced toward the upstream side in the rotation direction when the impeller rotates. This can reduce the tensile stress and the bending moment M generated in the distal region center portion a2 between the first edge 20 and the second edge 22.

in one embodiment, as shown in FIG. 7, the second reference line L₂Including straight portions 42.

According to this embodiment, the second reference line L is passed₂The blade 14 can be formed in a simple shape by including the straight portion 42, and the manufacturing is easy.

In one embodiment, as shown in FIG. 8, the second tip side fiducial point Pt₂And a second hub side reference point Ph₂phase angle difference Δ θ between₂Is more than 20 degrees.

According to this embodiment, the second radial cross section S is formed₂At least the tip side of the rotor is inclined toward the upstream side in the rotating direction of the impeller, and a phase angle difference Delta theta of 20 degrees or more is ensured₂However, when the impeller rotates, the first edge 20 side and the second edge 22 side can be deformed in a direction in which the tensile stress is not relatively increased. This reduces the tensile stress and the bending moment M generated in the distal region center portion a2 between the first edge 20 and the second edge 22. In addition, even when the degree of curvature of the three-dimensional leaf is large, the satisfaction in strength can be improved.

In one embodiment, as shown in FIG. 9, with respect to the second reference line L₂An angle θ between a second tangent 44 to each point P on the second reference line and a radial line 36 passing through each point P₂In the case where the angle is defined as the angle θ₂A second tangent 44 extending radially outward from each point P is located upstream of the radial line 36 in the impeller rotation directionWhen the time is positive, the configuration is θ₂The maximum value of (2) is 30 degrees or more.

According to this embodiment, the angle θ₂Is 30 degrees or more, the second edge 22 side can be reliably deformed in a direction not increasing the tensile stress with respect to the first edge 20 side when the impeller rotates. This can reliably reduce the tensile stress and the bending moment M.

In one embodiment, when Δ θ₁And Δ θ₂To the same extent, the effect of reducing the tensile stress and the bending moment M generated in the distal region center portion a2 between the first edge 20 and the second edge 22 can be maximized.

industrial applicability

According to some embodiments, it is possible to reduce tensile stress and bending moment generated on the blade tip side of the blade of the impeller of a centrifugal rotary machine such as an automobile, a turbocharger of a ship, a gas turbine, a steam turbine, or the like.

Description of the reference numerals

10. 100 impeller

12. 102 hub part

14. 104 blade

16. 106 small diameter part

18. 108 large diameter part

20 first edge

22 second edge

24. 114 blade chord

26. 38 tip

28 rotating shaft

30. 40 bending part

32. 42 straight line part

34 first tangent line

36 radial direction line

44 second tangent line

50 centrifugal rotary machine

52 casing

54 into the channel

56 flow path

58 discharge passage

110 leading edge

112 trailing edge

Central part of distal region of A2

L₁First datum line

L₂Second datum line

m bending moment

Ph₁First hub side reference point

Ph₂Second hub side reference point

Pt₁First tip-side fiducial point

Pt₂Second tip-side fiducial point

S₁Cross section in the first radial direction

S₂Second radial cross section

a axial direction

b direction of rotation

c radial direction

Δθ₁、Δθ₂phase angle difference