JP2016084707A - Turbocharger and turbo rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the mechanical loss of an entire rotor and improve the efficiency of a vehicle turbocharger 1 while accelerating increasing the pressure ratio of the vehicle turbocharger 1.SOLUTION: A turbocharger is configured so that a plurality of guide grooves 51 serving as a plurality of guide passages guiding exhaust gas from radially outward to radially inward is formed equidistantly in a back surface 39b of a turbine disc 39 along the circumferential direction, and each guide groove 51 is configured so that a radially inward end 51i thereof is located on a reverse rotation direction side (a side in the opposite direction to the rotation direction of a turbine impeller 37) with respect to a radially outward end 51o, and the abovementioned configuration enables the guide grooves 51 to function as a reverse swirl flow generation part generating a swirl flow in the reverse rotation direction relative to the turbine impeller 37 on the back surface 39b of the turbine disc 39.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a supercharger such as a vehicle supercharger that supercharges air supplied to the engine side using pressure energy of exhaust gas from an engine.

  2. Description of the Related Art In recent years, various developments have been made on superchargers such as a vehicle supercharger, and a general configuration of a supercharger will be briefly described as follows (see Patent Document 1).

  The supercharger includes a supercharger housing, and a rotor shaft is rotatably provided in the supercharger housing. A compressor impeller that compresses air using centrifugal force is integrally provided at one axial end of the rotor shaft. The compressor impeller includes a compressor disk having a hub surface (outer peripheral surface) extending radially outward from one axial direction and a rear surface facing the other axial direction, and a circumferential direction ( A plurality of compressor blades integrally provided at intervals in the circumferential direction of the hub surface. Further, a turbine impeller that generates a rotational force (rotational torque) in the forward rotation direction by using the pressure energy of the exhaust gas is provided at the other axial end portion of the rotor shaft. The turbine impeller includes a turbine disk having a hub surface extending radially outward from the other side in the axial direction and a back surface facing the one side in the axial direction, and a hub surface of the turbine disk in a circumferential direction (a circumferential direction of the hub surface). And a plurality of turbine blades integrally provided at intervals.

  During the operation of the turbocharger, the axial thrust force (positive thrust force) acts on the back surface of the compressor disk due to the pressure on the outlet side of the compressor impeller (directly downstream in the main flow direction of air). Also, the pressure on the other side in the axial direction on the hub surface of the compressor disk is smaller than the pressure on the outlet side of the compressor impeller, and the pressure in the compressor impeller (mainstream flowing from the inlet side to the outlet side of the compressor impeller) Thrust force (thrust force in the reverse direction) will work. On the other hand, a thrust force in the reverse direction acts on the rear surface of the turbine disk by the pressure on the inlet side of the turbine impeller (directly upstream in the main flow direction of the exhaust gas). Also, the thrust force in the positive direction acts on the hub surface of the turbine disk due to the pressure of the main flow in the turbine impeller (the main flow flowing from the inlet side to the outlet side of the turbine impeller), which is smaller than the pressure on the inlet side of the turbine impeller. become. Here, due to the characteristics of the turbocharger, the forward thrust force acting on the back surface of the compressor disk and the hub surface of the turbine disk is greater than the reverse thrust force acting on the hub surface of the compressor disk and the back surface of the turbine disk. It is getting bigger. That is, during operation of the turbocharger, the entire rotor including the compressor impeller and the turbine impeller is applied to the compressor disk hub surface and the turbine disk rear surface from the thrust force acting on the back surface of the compressor disk and the hub surface of the turbine disk. The thrust force in the positive direction of the difference obtained by subtracting the working thrust force will work.

JP 2011-231780 A

  By the way, with a request for a higher pressure ratio of a vehicle supercharger, the compressor impeller tends to increase in diameter. On the other hand, when the diameter of the compressor impeller is increased, the positive thrust force acting on the back surface of the compressor disk is increased, and the positive thrust force acting on the entire rotor including the compressor impeller and the turbine impeller is increased. As a result, the mechanical loss of the entire rotor is increased, and the efficiency of the supercharger is reduced. In other words, there is a problem that it is difficult to improve the efficiency of the supercharger by reducing the mechanical loss of the entire rotor while promoting the higher pressure ratio of the supercharger.

  Therefore, an object of the present invention is to provide a new supercharger that can solve the above-described problems, and a turbo rotating machine that has technical characteristics common to the new supercharger.

  The supercharger of the present invention comprises a compressor impeller provided with a compressor disk and a turbine impeller provided with a turbine disk, and at least reversely rotates in the direction of rotation of the turbine impeller on the back side of the turbine disk. A reverse swirl flow generating unit that generates a swirl flow in a direction (a direction opposite to the rotation direction of the turbine impeller) is formed, or the rotation direction of the compressor impeller (the compressor) on the back side of the compressor disk A swirling flow generating section that generates a swirling flow in the same direction as the impeller rotation direction is formed.

  Here, in the description of the specification of the present application regarding the supercharger, “provided” means that it is indirectly provided via another member in addition to being directly provided, and formation. It is meant to include what has been done. In addition, “one axial end portion” refers to one axial end portion, and “axial other end portion” refers to the other axial end portion. “Axial direction one side” means one side in the axial direction, “Axial direction other side” means the other side in the axial direction, and “Axial direction” unless otherwise specified, The axial direction of the compressor impeller or turbine impeller. Further, “radially outer” means the radially outer side, “radially inner” means the radially inner side, and “radial direction” means the compressor unless otherwise specified. It refers to the radial direction of the impeller or turbine impeller.

  According to the turbocharger of the present invention, the exhaust gas flows from the inlet side of the turbine impeller (immediately upstream in the mainstream direction of the exhaust gas) to the outlet side (immediately downstream in the mainstream direction of the exhaust gas). The turbine impeller uses the pressure energy of the exhaust gas to generate a rotational force in the forward rotation direction, and rotates the compressor impeller in the forward rotation direction integrally with the turbine impeller. Thereby, the air supplied to the engine can be supercharged by compressing air using the centrifugal force by the compressor impeller.

  During the operation of the turbocharger, the thrust force on the one side in the axial direction (the thrust force in the positive direction) is exerted on the back surface of the compressor disk due to the pressure on the outlet side of the compressor impeller (directly downstream in the main air flow direction). ) Will work. Also, the pressure on the hub surface of the compressor disk is smaller than the pressure on the outlet side of the compressor impeller, due to the pressure of the main flow in the compressor impeller (the main flow flowing from the inlet side to the outlet side of the compressor impeller). A thrust force on the other side in the axial direction (thrust force in the reverse direction) is applied. On the other hand, a thrust force in the reverse direction acts on the rear surface of the turbine disk due to the pressure on the inlet side of the turbine impeller. Further, the pressure of the main flow in the turbine impeller (the main flow flowing from the inlet side to the outlet side of the turbine impeller), which is smaller than the pressure on the inlet side of the turbine impeller, is positively applied to the hub surface of the turbine disk. Thrust force will work. Here, the forward thrust force acting on the rear surface of the compressor disk and the hub surface of the turbine disk is in the reverse direction acting on the hub surface of the compressor disk and the rear surface of the turbine disk due to the characteristics of the turbocharger. It is larger than the thrust force of. That is, during the operation of the supercharger, the entire rotor including the compressor impeller and the turbine impeller has a hub surface of the compressor disk from a thrust force acting on the back surface of the compressor disk and the hub surface of the turbine disk. In addition, a positive thrust force that is a difference obtained by subtracting the thrust force acting on the back surface of the turbine disk acts.

  When the reverse swirl flow generation unit is formed, during the operation of the supercharger, a swirl flow in the reverse rotation direction is generated on the back side of the turbine disk, and the flow on the back side of the turbine disk is generated. The circumferential component of the absolute velocity vector can be reduced. Thereby, the centrifugal force due to the flow on the back side of the turbine disk is reduced, and the radial pressure difference on the back side of the turbine disk that balances with the centrifugal force, in other words, the radial direction on the back side of the turbine disk. And the thrust force in the reverse direction acting on the rear surface of the turbine disk can be increased.

  When the swirl flow generating portion is formed, during the operation of the supercharger, a swirl flow in the rotation direction of the compressor impeller is generated on the back side of the compressor disk, and the compressor disk The circumferential component of the absolute velocity vector of the flow on the back side can be increased. This increases the centrifugal force due to the flow on the back side of the compressor disk and balances the centrifugal force with the radial pressure difference on the back side of the compressor disk, in other words, the back side of the compressor disk. The pressure gradient in the radial direction can be increased, and the thrust force in the positive direction acting on the back surface of the compressor disk can be reduced.

  The turbo rotating machine of the present invention is a turbo rotating machine including an impeller provided with a disk, and a reverse swirl flow generating unit that generates a swirl flow in a direction opposite to the rotation direction of the impeller on the back side of the disk, or A swirling flow generating portion that generates a swirling flow in the same direction as the rotation direction of the impeller is formed on the back side of the disk.

  Here, in the description of the specification of the present application concerning the turbo rotating machine, the “turbo rotating machine” means a centrifugal compressor that compresses a fluid using centrifugal force, and a rotating force that uses pressure energy of the fluid. It is meant to include a radial turbine that generates The term “centrifugal compressor” includes a centrifugal compressor used for a supercharger, an industrial machine, or a gas turbine. The “radial turbine” means a radial turbine used for a supercharger or a gas turbine. Etc. In addition, “fluid” is meant to include gas such as air or exhaust gas. The “impeller” is intended to include a compressor impeller used for a centrifugal compressor and a turbine impeller used for a radial turbine. Further, “disk” means a compressor disk in a compressor impeller and a turbine disk in a turbine impeller, and “blade” means a compressor blade in a compressor impeller and a turbine blade in a turbine impeller. It is.

  According to the turbo rotating machine of the present invention, when the turbo rotating machine is a radial turbine, the fluid taken in the housing flows from the inlet side to the outlet side of the impeller, thereby utilizing the pressure energy of the fluid. Thus, a rotational force can be generated to rotate the impeller around its axis (axis of the impeller). The fluid that has flowed to the outlet side of the impeller is discharged to the outside of the housing.

  When the turbo rotating machine is a centrifugal compressor, the fluid taken into the housing can be compressed by rotating the impeller around its axis (axis of the impeller). The compressed fluid (compressed fluid) is discharged to the outside of the housing.

  Here, when the reverse swirl flow generation unit is formed, during the operation of the turbo rotating machine, a swirl flow in a direction opposite to the rotation direction of the impeller is generated on the back side of the disk, and the disk The circumferential component of the absolute velocity vector of the flow on the back side of the can be reduced. Thereby, the centrifugal force due to the flow on the back side of the disc is reduced, and the radial pressure difference on the back side of the disc that balances the centrifugal force, in other words, the radial pressure gradient on the back side of the disc. And the thrust force acting on the back surface of the disk can be increased.

  In addition, when the swirl flow generation unit is formed, during the operation of the turbo rotating machine, a swirl flow in the rotation direction of the impeller is generated on the back side of the disk, and the flow on the back side of the disk is generated. The circumferential component of the absolute velocity vector can be increased. Thereby, the centrifugal force due to the flow on the back side of the disk is increased, and the radial pressure difference on the back side of the disk that balances the centrifugal force, in other words, the radial pressure gradient on the back side of the disk. And the thrust force acting on the back surface of the disk can be reduced.

  That is, the thrust force acting on the back surface of the disk can be adjusted by the reverse swirl flow generation unit or the swirl flow generation unit.

  According to the turbocharger of the present invention, during the operation of the turbocharger, the reverse thrust force acting on the rear surface of the turbine disk is increased, or the forward thrust force acting on the rear surface of the compressor disk is decreased. Therefore, even if the diameter of the compressor impeller is increased, the positive thrust force acting on the entire rotor including the compressor impeller and the turbine impeller can be reduced. Accordingly, it is possible to improve the efficiency of the supercharger by reducing the mechanical loss of the entire rotor while promoting the increase in the pressure ratio of the supercharger.

  According to the turbo rotating machine of the present invention, since the thrust force acting on the back surface of the disk can be adjusted by the reverse swirling flow generating unit or the swirling flow generating unit, the degree of freedom in designing the turbo rotating machine can be increased. .

FIG. 1 is an enlarged view of an arrow I in FIG. FIG. 2 (a) is a front sectional view of a part of the turbine impeller according to the first embodiment of the present invention, and FIG. 2 (b) is a part of the rear surface of the turbine disk according to the first embodiment of the present invention. It is a figure which shows the velocity triangle of the flow in the back side of a turbine disk. FIG. 3A is a front sectional view of a part of a turbine impeller according to another aspect of the first embodiment of the present invention, and FIG. 3B is a turbine disk according to another aspect of the first embodiment of the present invention. It is a figure which shows the velocity triangle of the flow in a part of back surface of this, and the back surface side of a turbine disk. FIG. 4A is a diagram showing the relationship between the pressure on the back side of the turbine disk and the radial position, and FIG. 4B shows the flow velocity triangle on the back side of the turbine disk in the case of the comparative example. FIG. FIG. 1 is an enlarged view of the arrow V in FIG. FIG. 6 is a front sectional view of the vehicle supercharger according to the embodiment of the present invention. FIG. 7 is a view showing the periphery of the compressor impeller according to the second embodiment of the present invention, and is a view corresponding to an enlarged view of an arrow V in FIG. FIG. 8A is a diagram showing a part of the back surface of the compressor disk and the flow velocity triangle on the back surface side of the compressor disk according to the second embodiment of the present invention, and FIG. It is a front sectional view of a part of a compressor impeller according to a second embodiment. FIG. 9A is a diagram showing a part of the back surface of the compressor disk according to another aspect of the second embodiment of the present invention and a flow velocity triangle on the back surface side of the compressor disk, and FIG. It is a front sectional view of a part of a compressor impeller according to another aspect of the second embodiment of the present invention. FIG. 10A is a diagram showing the relationship between the pressure on the back side of the compressor disk and the radial position, and FIG. 10B is the flow velocity on the back side of the compressor disk in the case of the comparative example. It is a figure which shows a triangle.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in the drawings, “L” is the left direction, “R” is the right direction, “AD” is the axial direction, “BD” is the radial direction, “BDi” is the radially inner side, “BDo” "Is radially outward, and" RD "is the forward rotation direction.

(First embodiment of the present invention)
As shown in FIG. 6, the vehicle supercharger 1 according to the embodiment (first embodiment) of the present invention is supplied to the engine using the pressure energy of the exhaust gas from the engine (not shown). The air is supercharged (compressed). And the specific structure of the supercharger 1 for vehicles is as follows.

  The vehicle supercharger 1 includes a supercharger housing 3. The supercharger housing 3 includes a bearing housing 5 (center housing) and a compressor housing (on the right side of the bearing housing 5). A first side housing) 7 and a turbine housing (second side housing) 9 provided on the left side of the bearing housing 5 are provided. The compressor housing 7 includes a compressor housing body 11 having a shroud 11 s inside, and an annular seal provided on the right side of the compressor housing body 11 and integrally connected to the left side portion of the bearing housing 5. It consists of a plate 13. Further, the turbine housing 9 has a shroud 9s inside.

  A plurality of radial bearings 15 and a plurality of thrust bearings 17 are provided in the bearing housing 5. Further, the plurality of bearings 15 and 17 are provided with a rotor shaft (turbine shaft) 19 extending in the left-right direction so as to be rotatable. In other words, the rotor shaft 19 is provided in the bearing housing 5 with the plurality of bearings 15. , 17 are rotatably provided.

  As shown in FIGS. 5 and 6, a compressor impeller 21 that compresses air using centrifugal force is integrally and concentrically with the rotor shaft 19 at one axial end portion (right end portion) of the rotor shaft 19. The compressor impeller 21 is rotatably accommodated in the compressor housing 7. The compressor impeller 21 includes a compressor disk 23 that is integrally connected to one end of the rotor shaft 19 in the axial direction. A hub surface (outer peripheral surface) 23h of the compressor disk 23 has one axial direction. The rear surface 23b of the compressor disk 23 faces the other side (left side) in the axial direction, extending from the side (right side) to the radially outer side (the radially outer side of the compressor impeller 21). Further, a plurality of compressor blades 25 are formed on the hub surface 23h of the compressor disk 23 at equal intervals (integrally formed) in the circumferential direction (the circumferential direction of the hub surface 23h). Another compressor blade 27 having a cord length shorter than that of the compressor blade 25 is formed (integrated) between the adjacent compressor blades 25 in 23h. In other words, two types of compressor blades 25 and 27 having different cord lengths are alternately formed on the hub surface 23h of the compressor disk 23 at intervals in the circumferential direction. Further, the tip end (tip edge) 25 t of each compressor blade 25 and the tip end 27 t of each compressor blade 27 extend along the shroud 11 s of the compressor housing body 11. Instead of the two types of compressor blades 25 and 27 having different cord lengths, one type of compressor blade (not shown) having the same cord length may be used.

  An air intake port 29 for taking air into the compressor housing 7 is formed on the compressor housing 7 on the upstream side of the compressor impeller 21 (upstream side in the main air flow direction). 29 can be connected to an air cleaner (not shown) for purifying air. In addition, an annular diffuser flow path 31 that pressurizes the compressed air is formed on the downstream side of the compressor impeller 21 in the compressor housing 7 (downstream side in the main air flow direction). Further, a spiral compressor scroll passage 33 is formed in the compressor housing 7, and the compressor scroll passage 33 communicates with the diffuser passage 31. An air discharge port 35 for discharging the compressed air to the outside of the compressor housing 7 is formed at an appropriate position of the compressor housing 7, and the air discharge port 35 has a compressor scroll flow path. 33 and can be connected to an intake manifold (not shown) of the engine.

  The compressor housing 7 and the compressor impeller 23 constitute a centrifugal compressor used in the vehicle supercharger 1.

  As shown in FIGS. 1 and 6, at the other axial end (left end) of the rotor shaft 19, a turbine impeller that generates rotational force (rotational torque) in the positive rotational direction using the pressure energy of the exhaust gas. 37 is formed concentrically with the rotor shaft 19 (integrally formed), and the turbine impeller 37 is rotatably accommodated in the turbine housing 9. The turbine impeller 37 includes a turbine disk 39 formed at the other axial end of the rotor shaft 19, and the hub surface 39 h of the turbine disk 39 is radially outward from the other axial side (left side). The turbine impeller 37 extends outward (in the radial direction), and the rear surface 39b of the turbine disk 39 faces one side (right side) in the axial direction. Further, a plurality of turbine blades 41 are formed on the hub surface 39h of the turbine disk 39 at equal intervals (integral formation) in the circumferential direction (circumferential direction of the hub surface 39h), and the tip end (tip) of each turbine blade 41 is formed. The edge 41t extends along the shroud 9s of the turbine housing 9.

  An exhaust inlet 43 for taking exhaust gas into the turbine housing 9 is formed at an appropriate position of the turbine housing 9, and the exhaust inlet 43 can be connected to an engine exhaust manifold (not shown). is there. A spiral turbine scroll passage 45 is formed on the upstream side of the turbine impeller 37 inside the turbine housing 9 (upstream side in the main flow direction of the exhaust gas). It communicates with the intake 43. Further, an exhaust exhaust port 47 for exhaust gas exhaust is formed on the downstream side of the turbine impeller 37 in the turbine housing 9 (downstream side in the main flow direction of the exhaust gas). The exhaust exhaust port 47 is connected to the turbine housing 9. It can be connected to an exhaust gas purification device (not shown) via a pipe (not shown).

  An annular heat shield plate 49 that shields heat from the turbine impeller 37 side is provided on the left side surface of the bearing housing 5, and an outer edge portion 49 o of the heat shield plate 49 is formed by the bearing housing 5 and the turbine housing 9. It is pinched.

  The turbine housing 9 and the turbine impeller 37 constitute a radial turbine used in the vehicle supercharger 1.

  Then, the characteristic part of 1st Embodiment of this invention is demonstrated.

  As shown in FIGS. 1 and 2 (a) and 2 (b), a plurality of guide grooves 51 as a plurality of guide passages for guiding the exhaust gas from the radially outer side to the radially inner side are formed on the rear surface 39b of the turbine disk 39. It is formed at equal intervals along the circumferential direction (the circumferential direction of the back surface 39b). Further, each guide groove 51 is configured such that the radially inner end (outlet end) 51i is positioned on the side opposite to the radially outer end (inlet end) 51o in the reverse rotational direction (the direction opposite to the rotational direction of the turbine impeller 37). Has been. Furthermore, the amount of depression of each guide groove 51 gradually decreases from the front side of the radial inner end 51i to the radial inner end 51i. With the above-described configuration, the plurality of guide grooves 51 generate a reverse swirl flow generation unit that generates a swirl flow in the reverse rotation direction relative to the turbine impeller 37 (rotating turbine impeller 37) on the back surface 39b side of the turbine disk 39. It has the function as. In other words, a plurality of guide grooves 51 as reverse swirl flow generating portions are formed on the back surface 39b of the turbine disk 39. The number of guide grooves 51 and the radial position of the inner end 51i in the radial direction of the guide groove 51 can be changed as appropriate.

  Here, instead of forming the plurality of guide grooves 51 on the back surface 39b of the turbine disk 39, a plurality of protrusion rows (not shown) projecting to one side in the axial direction on the back surface 39b of the turbine disk 39 along the circumferential direction. A plurality of guide passages (not shown) that are formed at equal intervals and guide the exhaust gas from the radially outer side to the radially inner side may be formed between the adjacent protrusion rows. In this case, each guide passage is configured such that the radially inner end is positioned on the side opposite to the rotational direction of the turbine impeller 37 relative to the radially outer end.

  Instead of forming a plurality of guide grooves 51 and the like on the rear surface 39b of the turbine disk 39, exhaust gas is guided to the turbine disk 39 from the radially outer side to the radially inner side as shown in FIGS. The guide holes 53 as a plurality of guide passages may be formed through (formed through). In this case, the radially outer end (inlet end) 53o of each guide hole 53 is opened to the maximum diameter portion 39g side of the turbine disk 39, and the radially inner end (outlet end) 53i of each guide hole 53 is opened. Is opened on the rear surface 39 b side of the turbine disk 39. Each guide hole 53 is configured such that the radially inner end 53i is positioned on the side opposite to the rotational direction of the turbine impeller 37 relative to the radially outer end 53o.

  Then, the effect | action and effect of 1st Embodiment of this invention are demonstrated.

  As shown in FIG. 6, the exhaust gas taken into the turbine housing 9 from the exhaust inlet 43 passes through the turbine scroll passage 45 and exits from the inlet side of the turbine impeller 37 (immediately upstream in the main flow direction of the exhaust gas). Circulates to the side (immediately downstream in the mainstream direction of exhaust gas). Then, a rotational force (rotational torque) in the forward rotation direction is generated by the turbine impeller 37 using the pressure energy of the exhaust gas, and the rotor shaft 19 and the compressor impeller 21 are integrated with the turbine impeller 37 in the forward rotation direction. Can be rotated. As a result, the air taken into the compressor housing 7 from the air intake port 29 is compressed by the compressor impeller 21 and discharged from the air discharge port 35 via the diffuser flow path 31 and the compressor scroll flow path 33. The air supplied to the engine can be supercharged. The exhaust gas flowing to the outlet side of the turbine impeller 37 is discharged from the exhaust discharge port 47 to the outside of the turbine housing 9 (normal operation of the vehicle supercharger 1).

  As shown in FIG. 5, during the operation of the vehicle supercharger 1, the pressure on the outlet side of the compressor impeller 21 (directly downstream in the main air flow direction) causes the rear surface 23 b of the compressor disk 23 to be on one side in the axial direction. The thrust force (thrust force in the positive direction) CF1 works. Further, the hub surface 23h of the compressor disk 23 is caused by the mainstream pressure (mainstream flowing from the inlet side to the outlet side of the compressor impeller 21) in the compressor impeller 21, which is lower than the pressure on the outlet side of the compressor impeller 21. A thrust force on the other side in the axial direction (a thrust force in the reverse direction) CF2 is applied to this. On the other hand, as shown in FIG. 1, the thrust force TF1 in the reverse direction acts on the rear surface 39b of the turbine disk 39 due to the pressure on the inlet side of the turbine impeller 37 (immediately upstream in the main flow direction of the exhaust gas). Further, the pressure of the main flow in the turbine impeller 37 (the main flow flowing from the inlet side to the outlet side of the turbine impeller 37), which is lower than the pressure on the inlet side of the turbine impeller 37, is positively applied to the hub surface 39h of the turbine disk 39. The thrust force TF2 will work. Here, due to the characteristics of the supercharger 1 for the vehicle, the positive thrust force (CF1 + TF2) acting on the rear surface 23b of the compressor disk 23 and the hub surface 39h of the turbine disk 39 is the hub surface 23h of the compressor disk 23 and the aforementioned The thrust force in the reverse direction (CF2 + TF1) acting on the rear surface of the turbine disk is larger. In other words, during the operation of the vehicle supercharger 1, the entire rotor including the compressor impeller 21 and the turbine impeller 37 is subjected to the thrust force acting on the rear surface 23 b of the compressor disk 23 and the hub surface 39 h of the turbine disk 39. Thus, a positive thrust force (CF1 + TF2-CF2-TF1) of the difference obtained by subtracting the thrust force acting on the hub surface 23h of 23 and the rear surface 39b of the turbine disk 39 is applied.

  As shown in FIGS. 2A and 2B to FIGS. 4A and 4B, a plurality of guide grooves 51 as reverse swirl flow generating portions are formed on the rear surface 39b of the turbine disk 39, so that the vehicle During operation of the turbocharger 1, a swirl flow in the reverse rotation direction relative to the turbine impeller 37 is generated on the rear surface 39 b side of the turbine disk 39. As a result, the circumferential component Vu of the absolute velocity vector V of the flow on the rear surface 39b side of the turbine disk 39 can be reduced as compared with the case where the plurality of guide grooves 51 and the like are not formed (in the case of the comparative example). .

  Here, since the exhaust gas (an example of fluid) on the back surface 39b side of the turbine disk 39 is rotating, the exhaust gas has a centrifugal force based on the radial position and flow velocity of the back surface 39b of the turbine disk 39. Working radially outward. On the other hand, since the exhaust gas stays in the region of the rear surface 39b of the turbine disk 39 and keeps rotating, it is considered that the exhaust gas has a pressure having a component that balances with the centrifugal force directed outward in the radial direction. When attention is paid to the minute region in the radial direction, this pressure is generated by the pressure difference between the both ends in the radial direction of the exhaust gas in the minute region. Accordingly, considering the entire area of the rear surface 39b of the turbine disk 39, the exhaust gas on the rear surface 39b of the turbine disk 39 has a pressure gradient with respect to the radial position. Since the circumferential component Vu of the absolute velocity vector V of the flow on the rear surface 39b side of the turbine disk 37 is reduced by the guide groove 51 and the like, each centrifugal force at each radial position on the rear surface 39b of the turbine disk 37 is also reduced. Therefore, the above-mentioned pressure difference corresponding to each centrifugal force is also reduced. As a result, the pressure gradient of the exhaust gas with respect to the radial position of the rear surface 39b of the turbine disk 39 is relaxed.

  That is, during operation of the vehicle supercharger 1, the radial force on the back surface 39b side of the turbine disk 39 for reducing the centrifugal force due to the flow on the back surface 39b side of the turbine disk 39 and generating a pressure balanced with the centrifugal force. In other words, the pressure gradient in the radial direction on the rear surface 39b side of the turbine disk 39 can be reduced. Here, the fact that the pressure gradient with respect to the radial position of the rear surface 39b of the turbine disk 39 is relaxed means that the pressure is less likely to decrease on the rear surface 39b of the turbine disk 39. Therefore, as shown in FIG. 4A, the pressure on the rear surface 39b side of the turbine disk 39 rises with respect to the radial position as compared with the case where the guide groove 51 or the like is not provided. Here, the pressure is a scalar quantity and acts in multiple directions. Therefore, by providing the guide groove 51 and the like, the pressure at the rear surface 39b of the turbine disk 39 is increased, so that the exhaust gas on the rear surface 39b of the turbine disk 39 pushes the turbine disk 39, in other words, the rear surface of the turbine disk 39. The thrust force TF1 in the reverse direction acting on 39b can be increased.

  2B, FIG. 3B, and FIG. 4B, in the velocity triangle of the flow on the rear surface 39b side of the turbine disk 39, U is a circumferential velocity vector, and W is a relative velocity vector. It is.

  Therefore, according to the first embodiment of the present invention, the thrust force TF1 in the reverse direction acting on the rear surface 39b of the turbine disk 39 can be increased during the operation of the vehicle turbocharger 1, so that the compressor impeller 21 is increased in diameter. However, the positive thrust force (CF1 + TF2-CF2-TF1) acting on the entire rotor including the compressor impeller 21 and the turbine impeller 37 can be reduced. Therefore, it is possible to improve the efficiency of the vehicle supercharger 1 by reducing the mechanical loss of the entire rotor while promoting an increase in the pressure ratio of the vehicle supercharger 1.

(Second embodiment of the present invention)
The supercharger 1 for a vehicle uses a compressor impeller 55 according to the second embodiment of the present invention shown in FIG. 7 instead of the compressor impeller 21 (see FIG. 2) according to the first embodiment of the present invention. In this case, the plurality of guide grooves 51 and the like (see FIGS. 2A and 3A) as the reverse swirl flow generation unit may be omitted. The compressor impeller 55 has the same configuration as that of the compressor impeller 21, and only the configuration of the compressor impeller 55 that is different from the compressor impeller 21 will be described. Of the plurality of components in the compressor impeller 55, those corresponding to the components in the compressor impeller 21 are denoted by the same reference numerals in the drawings.

  As shown in FIGS. 7 and 8A and 8B, the back surface 23b of the compressor disk 23 has a plurality of guide grooves 57 as a plurality of guide passages for guiding air from the radially outer side to the radially inner side. It is formed at equal intervals along the circumferential direction (the circumferential direction of the back surface 23b). Each guide groove 57 is configured such that the radially inner end (outlet end) 57i is located on the positive rotation direction side (the rotation direction side of the compressor impeller 21) with respect to the radial outer end (inlet end) 57o. ing. Furthermore, the amount of depression of each guide groove 57 gradually decreases from the front side of the radial inner end 57i to the radial inner end 57i. With the above-described configuration, the plurality of guide grooves 57 are arranged in the positive rotation direction relative to the compressor impeller 21 (the rotating compressor impeller 21) on the back surface 23b side of the compressor disk 23 (the rotation direction of the compressor impeller 21). And a function as a swirl flow generation unit that generates a swirl flow in the same direction as the above. In other words, a plurality of guide grooves 57 serving as a swirl flow generating portion are formed on the back surface 23 b of the compressor disk 23. The number of guide grooves 57 and the radial position of the inner end 57i in the radial direction of the guide groove 57 can be changed as appropriate.

  Here, instead of forming a plurality of guide grooves 57 on the back surface 23b of the compressor disk 23, a plurality of projection rows (not shown) projecting to the other side in the axial direction on the back surface 23b of the compressor disk 23 in the circumferential direction. A plurality of guide passages (not shown) may be formed between the adjacent protrusion rows so as to guide the air from the radially outer side to the radially inner side. In this case, each guide passage is configured such that the radially inner end is positioned closer to the forward rotation direction than the radially outer end.

  Instead of forming a plurality of guide grooves 57 and the like on the back surface 23b of the compressor disk 23, air is guided to the compressor disk 23 from the radially outer side to the radially inner side as shown in FIGS. A plurality of guide holes 59 as guide passages may be formed. In this case, the radially outer end (inlet end) 59o of each guide hole 59 is open to the maximum diameter portion 23g side of the compressor disk 23, and the radially inner end (outlet end) of each guide hole 59. 59 i is opened on the back surface 23 b side of the compressor disk 23. Each guide hole 59 is configured such that the radially inner end 59i is positioned on the forward rotation direction side of the radially outer end 59o.

  Then, the effect | action and effect of 2nd Embodiment of this invention are demonstrated.

  As shown in FIGS. 8 (a), 10 (b) to 10 (a), 10 (b), during operation of the vehicle supercharger 1, a plurality of guide grooves as a swirl flow generating portion are formed on the back surface 23b of the compressor disk 23. 57 or the like is formed, a swirl flow in the positive rotation direction relative to the compressor impeller 21 is generated on the back surface 23b side of the compressor disk 23, and the plurality of guide grooves 51 and the like are not formed. Compared to the case (in the case of the comparative example), the circumferential component Vu of the absolute velocity vector V of the flow on the back surface 23b side of the compressor disk 23 can be increased. Thus, based on the same principle as in the first embodiment of the present invention, during operation of the vehicle supercharger 1, the centrifugal force due to the flow on the back surface 23b side of the compressor disk 23 is increased, and the centrifugal force and The pressure difference in the radial direction on the back surface 23b side of the compressor disk 23 to be balanced, in other words, the radial pressure gradient on the back surface 23b side of the compressor disk 23 can be increased. As a result, the positive thrust force CF1 acting on the back surface 23b of the compressor disk 23 can be reduced. 8 (a), 9 (a), and 10 (b), in the flow velocity triangle on the back surface 39b side of the compressor disk 23, U is a circumferential velocity vector, and W is a relative velocity. Is a vector.

  Therefore, according to 2nd Embodiment of this invention, there exists an effect similar to 1st Embodiment of this invention.

  In addition, this invention is not restricted to description of the above-mentioned embodiment, It can implement in a various aspect as follows. That is, the technical idea applied to the turbine impeller 37 according to the first embodiment of the present invention is applied to a radial turbine (not shown) used in a gas turbine (not shown), and a turbine disk (not shown) in the radial turbine is applied. ) The thrust force acting on the back surface may be adjusted. Further, the technical idea applied to the compressor impeller 55 according to the second embodiment of the present invention is applied to a centrifugal compressor (not shown) used in an industrial machine (not shown) or a gas turbine (not shown), You may adjust the thrust force which acts on the back surface of the compressor disk (illustration omitted) in the centrifugal compressor.

  The scope of rights encompassed by the present invention is not limited to these embodiments.

  1: Supercharger for vehicle (supercharger), 3: Supercharger housing, 5: Bearing housing, 7: Compressor housing, 9: Turbine housing, 11: Compressor housing body, 13: Seal plate, 19: Rotor shaft, 21: Compressor impeller, 23: Compressor disk, 23b: Back surface, 23g: Maximum diameter portion, 23h: Hub surface, 25: Compressor blade, 27: Compressor blade, 37: Turbine impeller, 39: Turbine Disc, 39b: Back surface, 39g: Maximum diameter portion, 39h: Hub surface, 41: Turbine blade, 51: Guide groove, 51i: Radial inner end, 51o: Radial outer end, 53: Guide hole, 53i: Radial direction Inner end, 53o: radially outer end, 55: compressor impeller, 57: guide groove, 57i, radially inner end, 57o: radially outer end, 59: guide hole, 59i: half Inward end, 59o: radially outer end

Claims (10)

A compressor impeller with a compressor disk;
A turbine impeller provided with a turbine disk,
At least a reverse swirl flow generating portion that generates a swirl flow in the direction opposite to the rotation direction of the turbine impeller is formed on the back side of the turbine disk, or the compressor impeller is formed on the back side of the compressor disk. The supercharger in which the swirl flow production | generation part which produces | generates the swirl flow of the rotation direction of is formed.   The reverse swirl generator is a plurality of guide passages formed on the rear surface of the turbine disk at intervals along the circumferential direction thereof, and guides exhaust gas from the radially outer side to the radially inner side. The supercharger according to claim 1, wherein the inner end in the radial direction is positioned closer to the rotation direction opposite to the rotation direction of the turbine impeller than the outer end in the radial direction.   The reverse swirl generating unit is a plurality of guide passages that are formed through the turbine disk at intervals along the circumferential direction thereof and guide exhaust gas from the radially outer side to the radially inner side. A radially outer end is opened to the maximum diameter portion side of the turbine disk, a radially inner end of each guide passage is opened to a rear side of the turbine disk, and each guide passage has a radially inner end at the radially outer end. The supercharger according to claim 1, wherein the supercharger is configured to be positioned closer to a rotation direction opposite to a rotation direction of the turbine impeller.   The swirl generator is a plurality of guide passages formed on the back surface of the compressor disk at intervals along the circumferential direction thereof, and guides air from the radially outer side to the radially inner side. The supercharger according to claim 1, wherein the radially inner end is configured to be located on the forward rotation direction side with respect to the radially outer end.   The swirl generator is a plurality of guide passages that are formed through the compressor disk at intervals along the circumferential direction and guide air from the radially outer side to the radially inner side. The outer end in the direction is opened to the maximum diameter portion side of the compressor disk, the inner end in the radial direction of each guide passage is opened to the back side of the compressor disk, and the inner end in the radial direction of each guide passage is radially outward. The supercharger according to claim 1, wherein the supercharger is configured to be positioned on a rotational direction side from an end. A turbo rotating machine having an impeller with a disk,
A reverse swirl flow generating unit that generates a swirl flow in the direction opposite to the rotation direction of the impeller on the back side of the disk, or a swirl flow that generates a swirl flow in the same direction as the rotation direction of the impeller on the back side of the disk. A turbo rotating machine in which a generator is formed.   The reverse swirl generator is a plurality of guide passages formed on the back surface of the disk at intervals along the circumferential direction thereof, and guides the fluid from the radially outer side to the radial inner side. The turbo rotating machine according to claim 6, wherein a radially inner end is configured to be positioned on a side opposite to a rotational direction of the impeller with respect to a radial direction outer end than a radially outer end.   The reverse swirl generating unit is a plurality of guide passages that are formed through the disk at intervals along the circumferential direction and guide the fluid from the radially outer side to the radially inner side. The outer end is opened to the maximum diameter portion side of the disk, the radially inner end of each guide passage is opened to the back side of the disk, and each guide passage has a radially inner end that is closer to the impeller than the radially outer end. The turbo rotating machine according to claim 6, wherein the turbo rotating machine is configured to be located on a side opposite to a rotation direction of the first rotation direction.   The swivel generator is a plurality of guide passages formed on the back surface of the disk at intervals along the circumferential direction thereof, and guides the fluid from the radially outer side to the radially inner side. The turbo rotating machine according to claim 6, wherein an inner end in the direction is configured to be positioned closer to a rotation direction side of the impeller than an outer end in the radial direction.   The swirl generator is a plurality of guide passages that are formed through the disk at intervals along the circumferential direction and guide the fluid from the radially outer side to the radially inner side. The end is opened to the maximum diameter portion side of the disk, the radially inner end of each guide passage is opened to the back side of the disk, and each guide passage has a radially inner end that is closer to the impeller than the radially outer end. The turbo rotating machine according to claim 6, wherein the turbo rotating machine is configured to be positioned on a rotational direction side.

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