JP2013155640A - Variable stator vane mechanism of turbo machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable stator vane mechanism of a turbo mechanism which is capable of reducing pressure loss while reducing fluid leakage.SOLUTION: In a variable stator vane mechanism for a turbo machine which has: a plurality of nozzle vanes; and a plurality of wing axes respectively fixed to a plurality of the nozzle vanes and pivotally supported by shaft holes freely rotatable; and allows the nozzle vanes to change the angle in a flow passage accompanied by a rotation of the wing axes. The nozzle vane 50 is provided with: a first surface 50a and a second surface 50b which has a front and back relationship to each other; a side surface 50c, 50d which extend in the opposed direction of the first surface and the second surface and provided with the wing axes 51 having axis center shifted from the center in the opposed direction to the first surface side and a collar part 52 projected from the end part of the side surface of the first surface side and covering the shaft hole of a flow passage forming wall part. The collar part 52 is positioned in the upstream side of the flow direction of a fluid when the nozzle vane is closed in the maximum and the flow passage surface area between the adjacent nozzle vanes becomes the minimum.

Description

  The present invention relates to a variable stationary blade mechanism that variably controls a flow rate of a fluid in a turbo machine such as a supercharger, a gas turbine, a steam turbine, or a compressor.

  2. Description of the Related Art Conventionally, a variable stationary blade mechanism for changing the flow rate of a fluid has been widely adopted in turbo machines in which a fluid flows in a flow path including a supercharger. In such a variable vane mechanism, for example, as shown in Patent Document 1, a blade axis is fixed to each of a plurality of nozzle vanes arranged in an annular arrangement in a flow path, and the blade axis is formed on a flow path wall surface. The shaft hole is rotatably supported. And if a nozzle vane changes an angle in a flow path with rotation of a blade axis | shaft, the flow area of a flow path will change and the flow volume of the fluid which distribute | circulates a flow path will be controlled.

  In the above variable stationary blade mechanism, if the shaft hole for supporting the blade shaft is exposed on the flow wall surface, a part of the fluid flowing between the adjacent nozzle vanes leaks from the shaft hole. Occurs. Therefore, when the thickness of the nozzle vane is smaller than the diameter of the blade shaft and the shaft hole cannot be completely blocked by the side surface of the nozzle vane (the fixed surface of the blade shaft), in other words, a part of the shaft hole flows. When exposed to the road, etc., it is common to reduce the leakage from the shaft hole by providing a flange on the side surface of the nozzle vane and closing the shaft hole with the flange facing the shaft hole. It has become.

JP 2010-127093 A

  However, when the nozzle vane is provided with the flange as described above, the flange protrudes into the flow path from the first surface or the second surface of the nozzle vane that guides the fluid. Pressure loss may occur. Such pressure loss is considered to increase particularly as the nozzle vane approaches the fully closed state, in other words, as the flow path area decreases.

  Therefore, an object of the present invention is to provide a variable stationary blade mechanism for a turbomachine that can reduce pressure loss while reducing fluid leakage.

  In order to solve the above problems, a variable stationary blade mechanism of a turbomachine according to the present invention includes a plurality of nozzle vanes arranged annularly in a flow path through which fluid flows, and fixed to each of the plurality of nozzle vanes, A plurality of blade shafts rotatably supported by shaft holes provided in a flow channel forming wall section that divides the flow channel, and the nozzle vane is angled in the flow channel as the blade shaft rotates. The variable vane mechanism of a turbomachine that is variable, wherein the nozzle vane extends in a direction opposite to the first surface and the second surface, and the first surface and the second surface, which are in front and back relation to each other. , A side surface on which the blade axis is provided by shifting the axis from the center in the facing direction to either the first surface side or the second surface side, and the first surface side and the second surface side Raised from the end of the side surface on the side where the axis of the blade axis is located A flange that covers the shaft hole of the flow path forming wall, and the flange is closed when the nozzle vane is closed to the maximum and the flow area between adjacent nozzle vanes is minimized. It is located upstream of the fluid flow direction.

  According to the present invention, it is possible to reduce pressure loss while reducing fluid leakage.

It is a schematic sectional drawing of a supercharger. It is a rear view of a support ring. It is a figure which shows the state by which the drive ring was supported by the support ring. It is a figure explaining the structure of a nozzle vane and a blade axis | shaft. It is a figure explaining the variable flow path formed with a nozzle vane.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  The variable stator vane mechanism of the present invention can be widely applied to a mechanical device generally called a turbomachine. In this embodiment, the variable stationary blade mechanism is applied to the engine by the energy of exhaust gas discharged from the engine. A variable stationary blade mechanism applied to a supercharger that supercharges supplied air will be described. Here, first, the configuration of the supercharger will be described, and then the variable stationary blade mechanism will be specifically described.

  FIG. 1 is a schematic sectional view of the supercharger 1. In the following description, the arrow F direction shown in the figure is the front side of the supercharger 1, and the arrow R direction is the rear side of the supercharger 1. As shown in FIG. 1, the supercharger 1 is connected to a bearing housing 2, a turbine housing 4 connected to the front side of the bearing housing 2 by a fastening bolt 3, and a fastening bolt 5 to the rear side of the bearing housing 2. And a compressor housing 6.

  The bearing housing 2 is formed with a bearing hole 2a penetrating in the front-rear direction of the supercharger 1, and a turbine shaft 7 is rotatably supported by the bearing hole 2a via a bearing. A turbine impeller 8 is integrally connected to a front end portion of the turbine shaft 7, and the turbine impeller 8 is rotatably accommodated in the turbine housing 4. A compressor impeller 9 is integrally connected to the rear end portion of the turbine shaft 7, and the compressor impeller 9 is rotatably accommodated in the compressor housing 6.

  The compressor housing 6 is formed with an air inlet 10 that opens to the rear side of the supercharger 1 and is connected to an air cleaner (not shown). Further, in a state where the bearing housing 2 and the compressor housing 6 are connected by the fastening bolt 5, a diffuser flow path 11 that compresses and pressurizes air is formed by the facing surfaces of both the housings 2 and 6. The diffuser passage 11 is formed in an annular shape from the radially inner side to the outer side of the turbine shaft 7 (compressor impeller 9), and communicates with the intake port 10 via the compressor impeller 9 on the radially inner side. ing.

  Further, the compressor housing 6 is provided with an annular compressor scroll passage 12 positioned on the radially outer side of the turbine shaft 7 (compressor impeller 9) with respect to the diffuser passage 11. The compressor scroll passage 12 communicates with an intake port of an engine (not shown) and also communicates with the diffuser passage 11. Therefore, when the compressor impeller 9 rotates, fluid is sucked into the compressor housing 6 from the intake port 10, and the sucked fluid is boosted in the diffuser flow path 11 and the compressor scroll flow path 12 to be sucked into the engine intake port. Will be led to.

  The turbine housing 4 is formed with a discharge port 13 that opens to the front side of the supercharger 1 and is connected to an exhaust gas purification device (not shown). Further, in a state where the bearing housing 2 and the turbine housing 4 are connected by the fastening bolt 3, a gap 14 is formed between the facing surfaces of both the housings 2 and 4. The gap 14 is a portion in which a variable flow path x in which a later-described nozzle vane 50 is arranged to flow a fluid is formed, and is formed in an annular shape from the radially inner side to the outer side of the turbine shaft 7 (turbine impeller 8). ing.

  Further, the turbine housing 4 is provided with an annular turbine scroll flow path 15 located on the radially outer side of the turbine shaft 7 (turbine impeller 8) with respect to the gap 14. The turbine scroll passage 15 communicates with a gas inlet (not shown) through which exhaust gas discharged from the engine is guided, and also communicates with the gap 14. Therefore, the exhaust gas led from the gas inlet to the turbine scroll passage 15 is led to the discharge port 13 via the variable passage x and the turbine impeller 8, and the turbine impeller 8 is rotated in the flow process. Become. Then, the rotational force of the turbine impeller 8 is transmitted to the compressor impeller 9 via the turbine shaft 7, and the fluid is boosted by the rotational force of the compressor impeller 9 as described above, and the intake port of the engine Will be led to.

  At this time, if the flow rate of the exhaust gas guided to the turbine housing 4 changes, the rotation amounts of the turbine impeller 8 and the compressor impeller 9 change, and the pressurized fluid cannot be stably guided to the engine intake port. End up. Accordingly, a variable stationary blade mechanism 20 is provided in the gap 14 of the turbine housing 4 to change the flow rate of the exhaust gas guided to the turbine impeller 8 according to the flow rate of the exhaust gas. When the engine speed is low and the flow rate of the exhaust gas is small, the variable stationary blade mechanism 20 increases the flow rate of the exhaust gas guided to the turbine impeller 8 by reducing the opening of the variable flow path x and reducing the flow rate. The turbine impeller 8 can be rotated even at a flow rate. Below, the structure of the variable stationary blade mechanism 20 is demonstrated.

  As shown in FIG. 1, the variable stationary blade mechanism 20 includes a shroud ring 21 provided on the turbine housing 4 side and a nozzle ring 22 provided on the bearing housing 2 side so as to face the shroud ring 21. . The shroud ring 21 and the nozzle ring 22 form a flow path forming wall portion that defines a flow path through which the exhaust gas flows, and the exhaust gas is guided between the shroud ring 21 and the nozzle ring 22. The shroud ring 21 has a thin plate ring-shaped main body 21a and a protruding portion 21b protruding from the inner peripheral edge of the main body 21a toward the discharge port 13, and the main body 21a has a thickness direction (turbine shaft). 7 are formed at equal intervals in the circumferential direction.

  Further, the nozzle ring 22 includes a thin plate ring-shaped main body 22a having the same diameter as the main body 21a of the shroud ring 21, and is opposed to the shroud ring 21 while maintaining a predetermined distance. In the nozzle ring 22, a plurality of connection pins 24 (three in the present embodiment, only one shown in FIG. 1) are rotatably inserted near the outer periphery of the main body 22 a, and the shroud is connected by the connection pins 24. The spacing between the ring 21 and the ring 21 is kept constant.

  A plurality of shaft holes 25 penetrating in the thickness direction (the axial direction of the turbine shaft 7) are formed in the main body 22 a of the nozzle ring 22 at equal intervals in the circumferential direction, and the shaft formed in the shroud ring 21. The hole 23 and the shaft hole 25 formed in the nozzle ring 22 are disposed to face each other. One end of the connecting pin 24 protrudes to the rear side of the nozzle ring 22, and the support ring 30 is fixed to the rear side of the nozzle ring 22 by caulking the protruding portion.

  FIG. 2 is a rear view of the support ring 30. As shown in FIGS. 1 and 2, the support ring 30 is formed of a cylindrical member and has a cross-sectional shape obtained by bending a thin plate-like member. The support ring 30 includes an annular flange portion 31, a cylindrical portion 32 erected on the front side from the inner peripheral edge of the flange portion 31, a flat surface portion 33 that is bent radially inward from a front end portion of the cylindrical portion 32, The fastening bolt 3 is fastened in a state where the flange portion 31 is sandwiched between opposing surfaces of the bearing housing 2 and the turbine housing 4 so that the bearing housing 2 and the turbine housing 4 are held in the turbine housing 4.

  The flat portion 33 is provided with three insertion holes 33a through which one end of the connection pin 24 can be inserted at equal intervals in the circumferential direction, and the connection pin 24 is inserted into the insertion hole 33a and caulked. As a result, the support ring 30, the shroud ring 21 and the nozzle ring 22 are integrated.

  In addition, the flat portion 33 is provided with a plurality of concave portions 34 cut out radially outward from the inner peripheral end thereof, and a support piece 35 is provided in the concave portion 34. ing. The support piece 35 includes a support portion 35a that bends rearward from the flat portion 33, and a drop-off prevention portion that is bent outward from the support portion 35a in the radial direction and is spaced apart from the flat portion 33 by a predetermined distance. 35b. As shown in FIG. 3, the drive ring 40 is rotatably supported by the support piece 35.

  FIG. 3 is a view showing a state in which the drive ring 40 is supported by the support ring 30. As shown in this figure, the drive ring 40 is constituted by an annular thin plate member, and the inner peripheral edge thereof is rotatably supported by the support piece 35 of the support ring 30. The drive ring 40 is formed with a plurality of engagement recesses 41 that are notched radially outward from the inner peripheral end thereof, and the engagement recess 41 has a transmission link 42. One end is engaged. One end of the drive ring 40 on the inner peripheral side is formed with one second engagement recess 43 having the same shape as the engagement recess 41, and the transmission link is connected to the second engagement recess 43. One end of a drive transmission link 44 having the same shape as 42 is engaged.

  A fitting hole 42 a is formed on the other end side of the transmission link 42, and a fitting hole 44 a is formed on the other end side of the driving transmission link 44. As shown in FIG. 1, the blade hole 51 fixed to the nozzle vane 50 is fixed in the fitting hole 42 a, and the fitting hole 44 a of the drive transmission link 44 is fixed to the fitting hole 42 a. One end of the drive shaft 45 is fitted. The drive shaft 45 extends to the rear side of the drive ring 40, and a drive lever 46 that is driven by an actuator such as a cylinder (not shown) is integrally connected to the other end.

  Therefore, when the drive lever 46 is driven by the actuator, as shown in FIGS. 1 and 3, the drive shaft 45 rotates, and the drive transmission link 44 swings around the drive shaft 45, and this drive transmission is performed. As the link 44 swings, the drive ring 40 rotates. When the drive ring 40 is rotated in this manner, the transmission link 42 is swung by the rotation of the drive ring 40, and the blade shaft 51 is rotated along with the swing of the transmission link 42. When the blade shaft 51 rotates, the nozzle vane 50 swings about the blade shaft 51, and the area of the variable flow path x is varied.

  4A and 4B are views for explaining the structure of the nozzle vane 50 and the blade shaft 51. FIG. 4A is a perspective view and FIG. 4B is a plan view. As shown in this figure, the nozzle vane 50 includes a first surface 50a and a second surface 50b that are in a front-back relationship with each other, and a side surface 50c that extends in the opposing direction of the first surface 50a and the second surface 50b. 50d. In the present embodiment, in a state where the nozzle vane 50 is located in the gap 14, the first surface 50a is located on the turbine scroll flow path 15 side, and the second surface 50b is located on the turbine impeller 8 side (FIG. 1). reference). At this time, the side surface 50 c faces the main body 21 a of the shroud ring 21, and the side surface 50 d faces the main body 22 a of the nozzle ring 22.

  Each of the side surfaces 50c and 50d is provided with a blade axis 51 so that its axis is orthogonal to the side surfaces 50c and 50d. At this time, as shown in FIG. 4B, the axial center z of the blade shaft 51 is first from the center c in the opposing direction of the first surface 50a and the second surface 50b (the thickness direction of the nozzle vane 50). Is shifted to the surface 50a side. The blade shaft 51 thus provided is rotatably supported by a shaft hole 23 formed in the shroud ring 21 and a shaft hole 25 formed in the nozzle ring 22 (see FIG. 1).

  Here, as shown in FIG. 4B, the blade shaft 51 protrudes from the end of the side surfaces 50c and 50d on the first surface 50a side. Therefore, when the blade shaft 51 is pivotally supported by the shaft holes 23 and 25, the shaft holes 23 and 25 are exposed in the flow path through which the exhaust gas flows. As described above, if the shaft holes 23 and 25 remain exposed in the flow path, a part of the exhaust gas flows into the shaft holes 23 and 25 and leaks, resulting in a pressure loss. Therefore, the nozzle vane 50 is provided with a flange 52 that protrudes from the end of the side surfaces 50c and 50d on the first surface 50a side, and the shaft holes 23 and 25 are covered by the flange 52. .

  As described above, the nozzle vane 50 of the present embodiment extends in the opposing direction of the first surface 50a and the second surface 50b, and the first surface 50a and the second surface 50b, which are in a front-back relationship with each other, Sides 50c and 50d on which the blade axis 51 is provided by shifting the axis z on the first surface 50a side, and the first surface 50a side on which the axis z of the blade shaft 51 is located. And a flange 52 that covers the shaft holes 23 and 25. Since the flange 52 is provided only on the first surface 50a side, when the nozzle vane 50 is closed to the maximum and the flow area between the adjacent nozzle vanes 50 becomes the smallest, the turbine scroll flow is reduced. It is located on the path 15 side, that is, on the upstream side in the exhaust gas flow direction.

  5A and 5B are diagrams for explaining the variable flow path x formed by the nozzle vane 50. FIG. 5A shows a conventional nozzle vane 100, and FIG. 5B shows the nozzle vane 50 of the present embodiment. . In addition, the conventional nozzle vane 100 is the same as the nozzle vane 50 of this embodiment, and the 1st surface 100a and the 2nd surface 100b which are front-back relation, and the side surface extended in the opposing direction of these 1st surfaces 100a and 100b 100c, 100d, and the shape thereof is the same as the nozzle vane 50 of the present embodiment. However, in the nozzle vane 100, the axis of the blade shaft 101 provided on the side surfaces 100c and 100d is located in the center in the opposing direction of the first surfaces 100a and 100b, and the first surface 100a side and the second surface The collar portion 102 is provided on both sides of the 100b side.

  When the flow rate of the exhaust gas discharged from the engine is small, the interval between the adjacent nozzle vanes 50 and 100 is reduced to narrow the variable flow path x, and the flow rate of the exhaust gas is improved and guided to the turbine impeller 8. At this time, in the conventional nozzle vane 100 shown in FIG. 5A, the flange portion 102 is located downstream of the narrowed variable flow path x formed between the adjacent nozzle vanes 100. Therefore, a part of the exhaust gas with increased flow velocity collides with the flange portion 102 to cause a pressure loss, and in particular, a flow path forming wall portion that forms a flow path (the main body 21a of the shroud ring 21 and the main body of the nozzle ring 22). In the vicinity of both opposing surfaces 22a, the flow velocity drop in the portion surrounded by the broken line in FIG.

  On the other hand, according to the nozzle vane 50 of the present embodiment, when the variable flow path x is throttled, as shown in FIG. 5B, the flow of the exhaust gas flows on the downstream side of the variable flow path x. There is no hindrance and no pressure loss occurs. Thus, the exhaust gas is guided to the turbine impeller 8 while maintaining a desired flow rate, and the turbine efficiency can be improved as compared with the conventional case.

  In the present embodiment, the case where the axis of the blade shaft 51 is shifted on the first surface 50a side and the flange 52 is raised only on the first surface 50a side has been described. The axial center position and the position where the flange portion 52 is provided may be on the second surface 50b side. However, in this case, when the nozzle vane 50 is closed to the maximum and the flow path area between the adjacent nozzle vanes 50 becomes the smallest, the second surface 50b needs to be positioned upstream in the fluid flow direction. is there. In any case, the side surfaces 50c and 50d are shifted from the center in the opposing direction of the first surface 50a and the second surface 50b to either the first surface 50a side or the second surface 50b side. It is only necessary that the blade shaft 51 is provided at the position. The flange 52 is raised from the end of the side surface 50c, 50d on the side where the axis of the blade shaft 51 is located, and the flange 52 is closed to the maximum at the nozzle vane 50 so that the flow path area is minimized. At the upstream side in the fluid flow direction.

  In the present embodiment, the blade shaft 51 is provided on both the side surfaces 50c and 50d, and the nozzle vane 50 is so-called both-end supported. However, the blade shaft 51 is disposed only on one of the side surfaces 50c and 50d. A so-called cantilever structure may be provided.

  Further, the configuration of the variable stationary blade mechanism 20 in this embodiment is merely an example, and the specific structure for changing the nozzle vane 50 is not limited to the above structure. In the present embodiment, the case where the variable stationary blade mechanism 20 is provided in the turbine housing 4 and the flow passage area through which the exhaust gas flows is variable has been described. However, the variable stationary blade mechanism 20 is provided in the compressor housing 6. It is good as well. However, in this case, the compressor impeller 9 side is the upstream side in the fluid flow direction, and the compressor scroll flow path 12 side is the downstream side in the fluid flow direction. Therefore, in this case, when the nozzle vane 50 is closed to the maximum and the flow path area between the adjacent nozzle vanes 50 becomes the smallest, the blade shaft 51 is located upstream in the fluid flow direction, that is, on the compressor impeller 9 side. The shaft center and the collar portion 52 are located.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  INDUSTRIAL APPLICABILITY The present invention can be used for a variable stationary blade mechanism that variably controls the flow rate of fluid in turbomachines such as a supercharger, a gas turbine, a steam turbine, and a compressor.

DESCRIPTION OF SYMBOLS 1 ... Supercharger 20 ... Variable stator blade mechanism 23, 25 ... Shaft hole 50 ... Nozzle vane 50a ... 1st surface 50b ... 2nd surface 50c, 50d ... Side surface 51 ... Blade axis | shaft 52 ... ridge part x ... Variable flow path

Claims (1)

A plurality of nozzle vanes arranged in an annular arrangement in a flow path through which fluid flows, and fixed to each of the plurality of nozzle vanes, and freely rotatable in a shaft hole provided in a flow path forming wall section that divides the flow path A variable stationary blade mechanism of a turbomachine having a plurality of blade shafts that are pivotally supported, wherein the nozzle vane varies an angle in the flow path as the blade shaft rotates;
The nozzle vane is
A first surface and a second surface that are in reverse relation to each other;
The blade axis extends in the opposing direction of the first surface and the second surface, and the blade axis is shifted from the center of the opposing direction to either the first surface side or the second surface side. Side,
A ridge that protrudes from an end of the side surface on the side where the axial center of the blade axis is located among the first surface side and the second surface side, and covers the shaft hole of the flow path forming wall portion; With
The buttocks
A variable stator vane mechanism for a turbomachine, wherein the variable vane mechanism is located upstream in the fluid flow direction when the nozzle vane is closed to the maximum and the flow path area between adjacent nozzle vanes becomes the smallest.

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