JP2016017427A - Turbocharger thrust reaction force application device, turbocharger including same, and turbocharger thrust reaction force application method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power loss due to a thrust load for pressing a turbine shaft toward a compressor disc wheel by the pressure of exhaust gas flowing into a turbine disc wheel, reduce the size of a thrust bearing, and improve turbocharger performance.SOLUTION: In a turbocharger 1 that includes a turbine disc wheel 17 driven by exhaust gas, a turbine shaft 3 having one end portion to which the turbine disc wheel 17 is connected, and a compressor disc wheel 18 connected to the other end portion of the turbine shaft 3, a thrust reaction force application device 24 comprises: an excitation shaft 28 whose one end portion is connected to the other end portion of the turbine shaft 3; an excitation coil 32 provided to surround a circumferential surface of the excitation shaft 28; and a repulsive elastic body 34 provided on the other end portion of the excitation shaft 28 and generating a magnetic force repelling the magnetic force emitted from the excitation shaft 28.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thrust reaction force applying device for a supercharger, a supercharger provided with the same, and a method for applying a thrust reaction force of a supercharger.

  In a supercharger that is driven by exhaust gas from an internal combustion engine and supercharges intake air, a strong thrust load is generated to press the turbine shaft toward the compressor wheel due to the pressure of the exhaust gas flowing into the turbine wheel. For this reason, the turbine shaft is rotatably supported by a pair of radial bearings, and movement in the axial direction is restricted by the thrust bearing.

  However, since the strong thrust load applied to the turbine shaft is received by the thrust bearing in this way, the rotational resistance in the thrust bearing is increased and power loss is generated. In particular, during low-load operation, the ratio of power loss due to rotational resistance in the thrust bearing increases, so this loss reduction is required.

  In order to solve this problem, for example, in the following Patent Document 1, in a turbocharger, a surface on the air inlet side of a compressor impeller hub, an air inlet side surface of a compressor impeller, and an inlet of a compressor impeller An airtight space defined by a cup-shaped retainer that rectifies air and a seal member that seals between the compressor impeller and the cup-shaped retainer is formed, and a compressor (compressor impeller) is formed in the airtight space. A technique is disclosed in which a part of compressed compressed air is extracted and introduced.

  Thus, by introducing compressed air into the airtight space provided on the air inlet side surface of the hub of the compressor impeller, it is possible to generate a reverse thrust reaction force that cancels the thrust load due to the pressure of the exhaust gas, As a result, power loss in the thrust bearing can be reduced.

  Patent Document 2 below discloses a thrust magnetic bearing capable of displacing the axial position of a rotating shaft by a magnetic force separately from a pair of radial bearings that support the rotating shaft (turbine shaft) in a gas turbomachine. The provided technology is disclosed. The thrust magnetic bearing is provided inside a casing on which a rotating shaft is pivotally supported.

  In this gas turbomachine, for example, when the rotating shaft thermally expands and the axial position of the impeller in the casing is displaced, the magnetic attractive force in the thrust magnetic bearing is controlled, and the axial position of the impeller is corrected. . For this reason, the impeller can continue to rotate at an ideal position (highly efficient position) in the casing, thereby preventing a reduction in efficiency of the gas turbomachine.

Japanese Patent No. 3073348 JP-A-6-50334

  In the turbocharger of Patent Document 1, a part of the air compressed by the compressor is extracted and supplied to the airtight space in order to generate a thrust reaction force in the reverse direction that cancels the thrust load due to the pressure of the exhaust gas. However, there is a problem that the power loss in the thrust bearing can be avoided while the efficiency of the compressor is lowered.

  Further, in the gas turbomachine of Patent Document 2, since the thrust magnetic bearing for displacing the axial position of the rotating shaft is provided inside the casing on which the rotating shaft is supported, the temperature of the thrust magnetic bearing has increased. In this case, there is a problem that the performance and reliability of the thrust magnetic bearing are lowered due to a decrease in magnetic force.

  The present invention can reduce the power loss due to the thrust load that presses the turbine shaft toward the compressor wheel by the pressure of the exhaust gas flowing into the turbine wheel, thereby reducing the size of the thrust bearing and improving the supercharger performance. It is an object of the present invention to provide a thrust reaction force applying device for a supercharger, a supercharger provided with the same, and a method for applying a thrust reaction force of a supercharger.

  In order to solve the above problems, a thrust reaction force applying device for a supercharger according to a first aspect of the present invention includes a turbine impeller driven by exhaust gas, and a turbine shaft having the turbine impeller connected to one end. And a compressor impeller connected to the other end of the turbine shaft, and a thrust reaction force imparting device for a turbocharger, wherein one end is connected to the other end of the turbine shaft An excitation coil provided so as to surround a peripheral surface of the excitation shaft, a repulsive magnetic body provided on the other end portion side of the excitation shaft, and generating a magnetic force repelling the magnetic force generated by the excitation shaft; .

  According to the thrust reaction force imparting device for a turbocharger having the above-described configuration, the excitation shaft is excited by supplying current to the excitation coil, and the magnetic force (magnetic flux) of the excitation shaft and the magnetic force (magnetic flux) of the repulsive magnetic material. A repulsive force is generated between them. Since the repulsive magnetic body is fixed on the casing side, a thrust reaction force is generated by the repulsive force. The thrust reaction force causes the excitation shaft and the turbine shaft to move in the direction opposite to the flow direction of the exhaust gas in the exhaust gas passage. That is, it is pressed to the turbine impeller side.

  For this reason, the thrust load that presses the turbine shaft toward the compressor wheel due to the pressure of the exhaust gas flowing into the turbine wheel and the thrust reaction force generated in the thrust reaction force imparting device cancel each other, and the thrust load applied to the turbine shaft is It is reduced. Therefore, an increase in rotational resistance in the thrust bearing provided on the turbine shaft can be prevented, power loss can be reduced, the thrust bearing can be downsized and the supercharger performance can be enhanced.

  In addition, the thrust reaction force imparting device of the supercharger uses the air compressed by the compressor as described in Patent Document 1 to introduce the thrust reaction force by introducing the compressed air to the inlet side of the compressor impeller. Unlike what is generated, the thrust reaction force is generated by the magnetic force, so that the efficiency of the compressor is not reduced.

  Furthermore, in this thrust reaction force imparting device of the supercharger, the excitation coil is provided so as to surround the excitation shaft provided coaxially at the end of the turbine shaft on the compressor impeller side. Located in the intake passage. For this reason, even when the excitation coil and the excitation shaft are accompanied by heat generation, since it is easy to be cooled by the intake air flowing at high speed in the intake passage, the temperature rise is suppressed and the magnetic force does not decrease. The durability and reliability can be improved.

  The turbocharger thrust reaction force imparting device coaxially connects a short excitation shaft to a turbine shaft, an excitation coil surrounding the excitation shaft, a repulsive magnetic body that repels the excitation shaft, and an excitation Since it has a simple configuration that only includes a power supply unit that supplies current to the coil, it can be easily installed and can be easily added (remodeled) to an existing supercharger.

  In the thrust reaction force imparting device for a turbocharger having the above-described configuration, a holding member that accommodates the excitation shaft, the excitation coil, and the repulsive magnetic body is further provided, and the compressor blade among the axial ends of the holding member It is preferable that the end portion on the side opposite to the vehicle side has an aerodynamically smooth shape.

According to this configuration, since the thrust reaction force applying device of the supercharger is housed inside the aerodynamically smooth holding member provided on the upstream side of the compressor wheel, the thrust reaction force applying device is It is possible to prevent a decrease in supercharger performance by avoiding resistance to intake air.
In addition, since the holding member in which the exciting coil that generates heat is accommodated is positioned immediately upstream of the compressor wheel, the exciting coil can be effectively cooled by the intake air.

  In the turbocharger thrust reaction force imparting device having the above-described configuration, control for controlling the current introduced from the power supply unit to the excitation coil or the voltage to be applied according to the operating conditions such as the rotational speed of the supercharger and the exhaust gas pressure. It is preferable to further have a part.

  According to the said structure, the thrust reaction force output by the thrust reaction force provision apparatus of a supercharger can be suitably adjusted according to the driving | running state of a supercharger. For this reason, even if the operating state of the turbocharger changes, the thrust reaction force is increased or decreased following the thrust load applied to the turbine shaft. Therefore, the thrust bearing is always reduced to reduce the size of the thrust bearing and The machine performance can be improved.

Moreover, the supercharger which concerns on the 2nd aspect of this invention was provided with the thrust reaction force provision apparatus of the supercharger which concerns on the said 1st aspect.
According to this turbocharger, the repulsive magnetic material repels against the thrust load that presses the turbine shaft toward the compressor wheel by the pressure of the exhaust gas flowing into the turbine wheel and the excitation shaft excited by the excitation coil. This cancels out the thrust reaction force that presses the turbine shaft toward the turbine wheel side.
For this reason, the thrust load applied to the turbine shaft is reduced or eliminated, thereby preventing an increase in rotational resistance in the thrust bearing provided on the turbine shaft, reducing power loss and reducing the size of the thrust bearing and supercharging. The machine performance can be improved.

  In addition, a method for applying a thrust reaction force of a supercharger according to the third aspect of the present invention includes a turbine impeller driven by exhaust gas, a turbine shaft connected to one end of the turbine impeller, and a turbine shaft A thrust reaction force applying method for a supercharger including a compressor impeller connected to the other end side, wherein the excitation shaft has one end connected to the other end of the turbine shaft, and the excitation shaft. An excitation coil provided so as to surround the peripheral surface of the excitation shaft, a repulsive magnetic body that is provided on the other end side of the excitation shaft and generates a magnetic force repelling the magnetic force generated by the excitation shaft, and the supercharger A supercharger operation information detector for detecting operation information and a control unit are provided, and the control unit determines a thrust load acting on the turbine shaft based on input information from the supercharger operation information detector. Thrust reaction force of the magnitude to cancel To control the current or voltage applied to introduce into the excitation coil.

  According to the thrust reaction force imparting method of the turbocharger having the above configuration, the operation state of the turbocharger is appropriately adjusted by adjusting the thrust reaction force output by the thrust reaction force imparting device according to the operation state of the turbocharger. Even if there is a change, the thrust reaction force can be increased or decreased following the thrust load applied to the turbine shaft, the load on the thrust bearing can be constantly reduced, the thrust bearing can be downsized, and the supercharger performance can be improved.

  As described above, according to the thrust reaction force applying device for a supercharger according to the present invention, the turbocharger equipped with the same, and the thrust reaction force applying method for the supercharger, the pressure of the exhaust gas flowing into the turbine impeller As a result, it is possible to reduce power loss due to the thrust load that presses the turbine shaft toward the compressor wheel, to reduce the size of the thrust bearing and to improve the supercharger performance.

It is a longitudinal cross-sectional view which shows an example of the supercharger to which the thrust reaction force provision apparatus which concerns on this invention was applied.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to FIG.
FIG. 1 is a longitudinal sectional view showing an example of a supercharger to which a thrust reaction force applying device according to the present invention is applied.

  The supercharger 1 is equipped with, for example, a large marine diesel engine (internal combustion engine) (not shown) for supercharging intake air, except that a thrust reaction force applying device 24 described later is equipped. It has a general configuration.

  In other words, the supercharger 1 includes a casing 2 that forms the entire outer shell. The casing 2 is positioned at the center, and a bearing base 5 that supports the turbine shaft 3. The exhaust gas passage constituting member 7 connected to the side and constituting the exhaust turbine 6 and the intake passage constituting member 9 connected to the other side of the bearing base 5 and constituting the compressor 8 (compressor) are provided. . An intake silencer 11 is connected to the external opening side of the intake passage constituting member 9.

  The turbine shaft 3 is horizontally supported inside the bearing stand 5 and is supported by a pair of radial bearings 13 and 14 and one thrust bearing 15 so as to be rotatable and not movable in the axial direction. ing. A turbine rotor 20 is configured by coaxially providing a turbine impeller 17 at one end of the turbine shaft 3 and a compressor impeller 18 at the other end. The turbine impeller 17 is an axial turbine that rotates inside the exhaust turbine 6, and the compressor impeller 18 is a centrifugal turbine that rotates inside the compressor 8.

  The exhaust gas passage constituting member 7 forms an exhaust gas passage 7A along the axial direction of the turbine shaft 3, and a turbine impeller 17 protrudes inside the exhaust gas passage 7A. An intake passage 9A is formed by the intake passage constituting member 9, and a compressor impeller 18 is accommodated therein. The compressor impeller 18 has a shape in which a hub 18a that forms the center of the compressor impeller 18 becomes thicker from the intake upstream side toward the downstream side (bearing stand 5 side), and a large number of fins (blades) 18b project from the outer peripheral surface thereof. Has been.

  On the exhaust turbine 6 side, the turbine impeller 17 is driven and rotated by exhaust gas of a high-temperature, high-pressure marine diesel engine flowing in the flow direction G in the exhaust gas passage 7A. As a result, the turbine shaft 3 and the compressor impeller 18 rotate together, and on the compressor 8 side, the compressor impeller 18 sucks outside air from the center of the intake passage 9A, compresses it, and discharges it in the centrifugal direction. At this time, a high-speed intake air flow A is generated in the intake passage 9A. The discharged compressed air is supercharged from a discharge port (not shown) to a large marine diesel engine. Note that, in the intake silencer 11, intake noise generated by driving the compressor 8 is silenced.

  Since the exhaust turbine 6 is an axial turbine, the energy of the exhaust gas flowing through the exhaust gas passage 7A can be efficiently recovered. However, the pressure of the exhaust gas flowing into the turbine impeller 17 causes the turbine shaft 3 to flow in the exhaust gas flow direction G, that is, the compressor. A strong thrust load W is generated to be pressed toward the impeller 18 side (bearing base 5 side). Although this thrust load W is received by the thrust bearing 15, it leads to a power loss due to an increase in rotational resistance in the thrust bearing 15, resulting in a decrease in supercharger performance.

  In order to avoid such deterioration of the supercharger performance due to the thrust load W, the supercharger 1 is equipped with a thrust reaction force applying device 24. The thrust reaction force applying device 24 is configured as follows.

  First, the holding member 25 is disposed on the upstream side of the compressor wheel 18 in the intake passage 9 </ b> A and on a coaxial extension line with respect to the turbine shaft 3. The holding member 25 has a substantially cylindrical shape, and the outer diameter thereof is substantially equal to the outer diameter of the tip end portion of the hub 18 a of the compressor impeller 18. Further, the shape of the end portion of the holding member 25 on the intake upstream side is an aerodynamically smooth shape (for example, streamlined or hemispherical).

  The holding member 25 is located concentrically at the center of a connection cylinder portion 11 a for connecting to the intake passage constituting member 9 provided in the intake silencer 11, for example, and the casing 2 is interposed via the intake silencer 11. It is fixed on the side. Specifically, the inner peripheral surface of the connection cylinder portion 11a and the outer peripheral surface of the holding member 25 are connected by a plurality of (preferably three or more) support plates 26 arranged at equiangular intervals. The concentric position is maintained. Note that the cross-sectional shape of the support plate 26 does not obstruct the air flow in the connecting cylinder portion 11a, and is thin and rigid (for example, a cross-section with a rounded corner or an airfoil cross-section). preferable.

  On the other hand, an excitation shaft 28 formed in a columnar shape by a magnetic material such as steel is coaxially connected to the tip of the turbine shaft 3 on the compressor impeller 18 side. Specifically, the hub 18 a of the compressor wheel 18 is fixed by a lock nut 29 near the tip of the turbine shaft 3, and the exciting shaft 28 is disposed at the most distal portion of the turbine shaft 3 protruding from the lock nut 29. A male screw portion 28a protruding from the rear end face is screwed. The vicinity of the screwing portion is covered with a separate cover member 30. The excitation shaft 28 is accommodated in the holding member 25, and the outer peripheral surface of the cover member 30 is formed so as to smoothly follow the outer peripheral surface of the hub 18a and the outer peripheral surface of the holding member 25.

  An excitation coil 32 is fixed inside the holding member 25 so as to surround the excitation shaft 28. The excitation coil 32 excites the excitation shaft 28 by being supplied with DC power from a power supply unit 36 outside the supercharger 1. The inner peripheral surface of the excitation coil 32 and the outer peripheral surface of the excitation shaft 28 are close to each other up to several millimeters so as not to contact each other, and the excitation shaft 28 can rotate while receiving the excitation force from the excitation coil 32.

Further, a repulsive magnetic body 34 is accommodated in the holding member 25. The repulsive magnetic body 34 is, for example, a disk-shaped permanent magnet, and is fixed to the holding member 25 so that one surface thereof faces the end surface of the excitation shaft 28 on the upstream side of the intake air with a slight gap (about several millimeters). It is arranged so that one surface of the repulsive magnetic body 34 and the end surface of the excitation shaft 28 on the intake upstream side do not come into contact with each other. That is, the repulsive magnetic body 34 is also fixed to the casing 2 side via the holding member 25.
As the repulsive magnetic body 34, for example, a material having a strong magnetic force such as an iron-neodymium-based material permanent magnet or a samarium-cobalt-based magnet is preferable.

  The repulsive magnetic body 34 generates a magnetic force repelling the axial magnetic force generated by the excitation shaft 28 excited by the excitation coil 32. This repulsive force generates a thrust reaction force T that presses the excitation shaft 28 and the turbine shaft 3 in the direction opposite to the flow direction G of the exhaust gas in the exhaust gas passage 7A. In the present embodiment, a permanent magnet is used as the repulsive magnet 34, but it may be replaced with an electromagnet.

The supercharger 1 is provided with a supercharger operation information detector 39. The supercharger operation information detector 39 acquires rotational speed information from a not-shown speed meter provided on the turbine shaft 3 and detection information from a pressure gauge provided at an exhaust gas passage portion to obtain information on the supercharger 1. This is to judge the driving situation.
Further, the supercharger 1 is introduced into the excitation coil 32 from the power supply unit 36 in accordance with the operation status such as the rotational speed of the supercharger 1 and the exhaust gas pressure input from the supercharger operation information detector 39. A control unit 38 that controls the current or the voltage to be applied is provided.

  In the supercharger 1 equipped with the thrust reaction force applying device 24 configured as described above, when the turbine rotor 20 (the turbine shaft 3) is rotated by the energy of the exhaust gas flowing in the exhaust gas passage 7A, the thrust reaction is performed. When a current is supplied to the exciting coil 32 from the power supply unit 36 of the force applying device 24, the exciting shaft 28 is excited, the axial magnetic force (magnetic flux) generated by the exciting shaft 28, and the axial direction generated by the repulsive magnetic body 34. Repulsion occurs between the magnetic force (magnetic flux). Since the repulsive magnetic body 34 is fixed to the casing 2 via the holding member 25, a thrust reaction force T is generated by the repulsive force, and the thrust reaction force T causes the excitation shaft 28 and the turbine shaft 3 to be exhausted. The exhaust gas is pressed in the direction opposite to the flow direction G of the exhaust gas in the passage 7A, that is, toward the turbine impeller 17 side (bearing base 5 side).

  For this reason, the thrust load W that presses the turbine shaft 3 toward the compressor wheel 18 by the pressure of the exhaust gas flowing into the turbine wheel 17 is reduced or offset by the thrust reaction force T generated in the thrust reaction force applying device 24. The thrust load W applied to the turbine shaft 3 is reduced or eliminated. Therefore, an increase in rotational resistance in the thrust bearing 15 provided on the turbine shaft 3 is prevented, and power loss is reduced. As a result, the thrust bearing 15 can be reduced in size and the performance of the supercharger 1 can be improved. .

  Moreover, the thrust reaction force applying device 24 is different from the conventional device that extracts the air compressed by the compressor 8 and introduces the compressed air to the inlet side of the compressor wheel 18 to generate the thrust reaction force. Since the thrust reaction force T is generated by the magnetic force, the performance of the compressor 8 is not deteriorated.

Further, the thrust reaction force applying device 24 is provided so that the excitation coil 32 surrounds the excitation shaft 28 provided coaxially at the end of the turbine shaft 3 on the compressor impeller 18 side. The coil 32 is located in the intake passage 9A.
For this reason, even if heat is generated in the exciting coil 32 due to Joule heat or magnetic flux density fluctuation, it becomes easy to be cooled by the intake air flow A flowing at high speed in the intake passage 9A, and the temperature of the exciting coil 32 rises and the magnetic force decreases. There is nothing. Thereby, the reliability of the thrust reaction force applying device 24 can be improved.

  The thrust reaction force applying device 24 coaxially connects a short excitation shaft 28 to the turbine shaft 3, an excitation coil 32 that surrounds the excitation shaft 28, and a power supply unit 36 that supplies current to the excitation coil 32. In addition, since it has a simple configuration that merely provides a repulsive magnetic body 34 that repels against the excitation shaft 28, it can be easily installed and can be easily added to the existing supercharger (version upgrade). It is. By additionally attaching the thrust reaction force applying device 24 to the existing supercharger, the performance of the supercharger can be improved, and the load on the thrust bearing can be constantly reduced to reduce the size of the thrust bearing. In addition, the life of the thrust bearing can be extended and maintainability can be improved.

The holding member 25 in which the excitation shaft 28, the excitation coil 32, and the repulsive magnetic body 34 are accommodated is located in the intake passage 9 </ b> A on the intake upstream side of the compressor impeller 18 and on a coaxial extension line with respect to the turbine shaft 3. In this way, the cylinder 2 is fixed to the casing 2 side, has a cylindrical shape with an outer diameter substantially equal to the outer diameter of the tip end of the hub 18a of the compressor wheel 18, and the end shape on the upstream side of the intake air is aerodynamically Smooth shape.
For this reason, the thrust reaction force applying device 24 can be housed in the smooth contour of the outer diameter of the tip end of the hub 18a of the compressor impeller 18 as viewed in the axial direction of the turbine shaft 3, thereby the thrust reaction force applying device. It is possible to prevent the supercharger performance from being lowered by avoiding the fact that 24 becomes a resistance to intake air.

  Moreover, since the axial direction of the holding member 25 in which the exciting coil 32 that generates heat is accommodated is along the passage direction of the intake passage 9A and directly upstream of the compressor wheel 18, excitation is performed by the intake air flow A. The coil 32 can be effectively cooled. For example, the exciting coil 32 may be cooled more effectively by further forming heat radiating fins or the like along the air flow direction of the intake air flow A on the outer peripheral surface of the holding member 25 to increase the surface area thereof.

  Further, since the repulsive magnetic body 34 is provided on the holding member 25 so as to face the end surface of the excitation shaft 28 on the upstream side of the intake air, the repulsive magnetic body 34 has the excitation shaft 28 in the axial direction of the turbine shaft 3. And it fits inside the outer contour of the exciting coil 32. Thereby, the thrust reaction force application device 24 can be made compact.

  Further, the control unit 38 controls the exciting coil 32 from the power source unit 36 according to the operation status estimated from the detection information (rotational speed, exhaust gas pressure, etc.) of the supercharger operation information detector 39 provided in the supercharger 1. Therefore, the thrust reaction force T output by the thrust reaction force applying device 24 can be appropriately adjusted according to the operating state of the supercharger 1. For this reason, the thrust reaction force T having a magnitude that can cancel the thrust load W applied to the turbine shaft 3 as much as possible is output, and the thrust load W is controlled so as not to exceed the thrust load W. The power loss due to the increase in rotational resistance in the thrust bearing 15 can be reduced and the supercharger performance can be improved.

Further, by appropriately adjusting the thrust reaction force T output from the thrust reaction force applying device 24 in accordance with the operation state of the supercharger 1, even if the operation state of the supercharger 1 changes, the turbine shaft 3 Control is performed to increase or decrease the thrust reaction force T so as to follow a change in the applied thrust load W, so that the load of the thrust bearing 15 is always within a predetermined reaction force. Thereby, when the thrust bearing 15 is reduced in size, the reliability of the thrust bearing 15 can be maintained.
Here, the predetermined reaction force of the thrust bearing 15 is, for example, the design reaction force generated in the thrust bearing 15 by using the thrust reaction force applying device 24 in the operation of the supercharger 1 (in the operation state where the operation is maximized). Reaction force).

  As described above, according to the thrust reaction force applying device 24 and the thrust reaction force applying method according to the present embodiment, the exhaust gas flowing into the turbine impeller 17 with a simple and reliable configuration with respect to the thrust bearing 15. The power loss due to the thrust load W that presses the turbine shaft 3 toward the compressor impeller 18 due to the pressure of can be reduced, and the turbocharger performance can be improved.

In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the summary, it can add a change suitably.
For example, in the said embodiment, although the example which applied the thrust reaction force provision apparatus 24 which concerns on this invention to the supercharger 1 with which a marine large sized diesel engine is equipped is not restricted, it is not restricted to the supercharger of a marine engine, The present invention can be widely applied to other types of turbochargers for engines, as well as axial turbines of other types and applications such as gas turbines and jet engines.

  In the above embodiment, the excitation shaft 28 is connected to the turbine shaft 3 so as to rotate integrally with the turbine shaft 3, but the end of the turbine shaft 3 itself is extended to integrally form the excitation shaft. May be. Further, the excitation shaft is not rotated, a thrust bearing having a small rotational resistance is interposed between the excitation shaft and the turbine shaft 3, and the repulsive force applied to the excitation shaft is transmitted to the turbine shaft 3 via the thrust bearing. Is also possible.

  Further, in the hybrid turbine apparatus configured to assist the rotation of the turbine shaft 3 by providing an auxiliary motor at the end of the turbine shaft 3 on the compressor impeller 18 side, the auxiliary motor is adjacent to the auxiliary motor. The excitation shaft 28, the excitation coil 32, and the repulsive magnetic body 34 may be provided in a built-in form.

DESCRIPTION OF SYMBOLS 1 Supercharger 2 Casing 3 Turbine shaft 5 Bearing stand 6 Exhaust turbine 7A Exhaust gas passage 8 Compressor 9A Intake passage 13, 14 Radial bearing 15 Thrust bearing 17 Turbine wheel 18 Compressor wheel 18a Compressor wheel hub 20 Turbine rotor 24 Thrust Reaction force applying device 25 Holding member 28 Excitation shaft 32 Excitation coil 34 Repulsive magnet 36 Power supply unit 38 Control unit 39 Supercharger operation information detector G Flow direction T of exhaust gas Thrust reaction force W Thrust load

Further, turbocharger according to the second aspect of the present invention, Ru Tei includes a thrust reaction force applying device of the turbocharger according to the first aspect.
According to this turbocharger, the repulsive magnetic material repels against the thrust load that presses the turbine shaft toward the compressor wheel by the pressure of the exhaust gas flowing into the turbine wheel and the excitation shaft excited by the excitation coil. This cancels out the thrust reaction force that presses the turbine shaft toward the turbine wheel side.
For this reason, the thrust load applied to the turbine shaft is reduced or eliminated, thereby preventing an increase in rotational resistance in the thrust bearing provided on the turbine shaft, reducing power loss and reducing the size of the thrust bearing and supercharging. The machine performance can be improved.

Claims (5)

A turbine impeller driven by exhaust gas;
A turbine shaft having the turbine impeller connected to one end;
A compressor impeller connected to the other end side of the turbine shaft, and a thrust reaction force imparting device for a supercharger,
An excitation shaft having one end connected to the other end of the turbine shaft;
An excitation coil provided so as to surround the peripheral surface of the excitation shaft;
A repulsive magnetic body that is provided on the other end side of the excitation shaft and generates a magnetic force repelling the magnetic force generated by the excitation shaft;
A thrust reaction force imparting device for a turbocharger. A holding member that accommodates the excitation shaft, the excitation coil, and the repulsive magnetic body,
A thrust reaction force imparting device for a supercharger, wherein an end portion of the holding member in the axial direction opposite to the compressor wheel side is aerodynamically smooth.   The supercharging according to claim 1 or 2, further comprising a control unit that controls a current to be introduced from the power supply unit to the exciting coil or a voltage to be applied in accordance with operating conditions such as a rotation speed of the supercharger and exhaust gas pressure. Thrust reaction force imparting device.   The supercharger provided with the thrust reaction force provision apparatus of the supercharger in any one of Claim 1 to 3. A turbine impeller driven by exhaust gas;
A turbine shaft having the turbine impeller connected to one end;
A compressor wheel connected to the other end of the turbine shaft;
A thrust reaction force imparting method for a turbocharger including:
An excitation shaft having one end connected to the other end of the turbine shaft;
An excitation coil provided so as to surround the peripheral surface of the excitation shaft;
A repulsive magnetic body that is provided on the other end side of the excitation shaft and generates a magnetic force repelling the magnetic force generated by the excitation shaft;
A supercharger operation information detector for detecting operation information of the supercharger;
A control unit;
Provided,
The control unit, based on the input information from the supercharger operation information detector, current to be introduced into the exciting coil so as to generate a thrust reaction force that cancels the thrust load acting on the turbine shaft or A method for applying a thrust reaction force of a supercharger, wherein the applied voltage is controlled.

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