CN110730860B

CN110730860B - Vibration suppression method and vibration suppression device for supercharger capable of being driven by motor

Info

Publication number: CN110730860B
Application number: CN201880018334.8A
Authority: CN
Inventors: 吉田正; 坂本武藏; 佐佐木领士; 小野嘉久; 西村英高; 辻刚志
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Marine Machinery and Equipment Co Ltd
Priority date: 2018-05-17
Filing date: 2018-05-17
Publication date: 2021-06-11
Anticipated expiration: 2038-05-17
Also published as: WO2019220591A1; KR102252548B1; KR20190132398A; CN110730860A

Abstract

A vibration suppressing method of a supercharger according to the present invention is a method of suppressing shaft vibration of a supercharger that can be driven by a motor, the method including: a specific vibration state determination step of determining whether or not a specific vibration state in which the magnitude of shaft vibration of a rotor shaft of a supercharger exceeds a predetermined magnitude or is likely to exceed the predetermined magnitude is established; an excitation state determination step of determining whether or not the motor is in an excitation state in which an excitation voltage is applied to the motor; and a vibration suppression execution step of applying an excitation voltage to the motor when the specific vibration state is determined by the specific vibration state determination step and when the excitation state is determined not to be the excitation state by the excitation state determination step.

Description

Vibration suppression method and vibration suppression device for supercharger capable of being driven by motor

Technical Field

The present invention relates to vibration suppression of a supercharger provided with a motor.

Background

Conventionally, a supercharger is known which compresses a gas such as air to increase the density thereof and pressurizes the compressed gas as a combustion gas into a combustion chamber of an engine (internal combustion engine). The supercharger is constituted by a rotor shaft (rotating shaft), and a turbine and a compressor disposed at both ends of the rotor shaft. Energy of exhaust gas discharged from a combustion chamber of the internal combustion engine to an exhaust passage is converted into rotational energy by a turbine to drive a compressor, thereby compressing gas such as air and delivering the compressed gas to the combustion chamber as combustion gas. By providing a supercharger on the engine, the same engine output can be obtained using less fuel, and thus the engine output can be improved and the fuel consumption can be reduced. On the other hand, since the turbine is driven by the energy of the exhaust gas, the effect of the supercharger is low during low-load operation of the engine in which the flow rate of the exhaust gas is small. For example, in a ship, a deceleration operation may be performed to reduce the fuel consumption (fuel cost), but the engine is under a low load during the deceleration operation, and therefore the flow rate of exhaust gas is small, and the capacity of the supercharger is significantly insufficient.

Therefore, an electric-assisted supercharger having a motor (electric motor) capable of rotating a rotor shaft without being affected by exhaust gas has been developed (for example, patent document 1). In an engine provided with an electrically-assisted supercharger, the rotation of a rotor shaft is increased by a motor during low-load operation, thereby compensating for the shortage of the supercharger. On the other hand, at the time of engine high load operation, the energy of the exhaust gas becomes sufficient, and thus the motor is stopped. As a type of electric-assisted supercharger, there is also known a hybrid supercharger that performs supercharging in the same manner as an electric-assisted supercharger and recovers surplus energy of exhaust gas as electric power during the high-load engine operation.

As a structure of the above-described electric-assisted supercharger, a motor suspension structure is known in which a small-sized motor is attached to a shaft extension portion that extends a compressor-side end portion of a rotor shaft (see patent document 1). In the motor suspension structure, the weight of the small motor can be sufficiently borne by the usual two bearings for supporting the rotor shaft. Therefore, a special bearing for supporting the motor is not required. However, in the electrically-assisted supercharger, since a heavy object (motor) is present at the tip of the rotor shaft located outside the bearing, shaft vibration is likely to occur, and noise generated by the shaft vibration may become a problem. For example, patent document 2 discloses a method of reducing noise and vibration of an electric supercharger (super charger), and discloses countermeasures such as mounting an elastic member between housing cases of the supercharger, the motor, and the inverter, and mounting a sound absorbing member in a duct. Since the main cause of vibration noise is propagation of shaft vibration of the rotor shaft to the housing or the like, in patent document 2, the propagation of vibration is cut off by an elastic material, and thus vibration noise can be reduced.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open No. 2015-158161

Patent document 2: japanese patent application laid-open No. 2010-174680

Non-patent document

Non-patent document 1: baishikayi and other 3 people, electric power-assisted energy saving effect of turbocharger for marine diesel engine, [ online ], 3 months 2015, 11 months 2016 and 28 days search 2016, Internet (URL: http:// www.mhi.co.jp/technology/review/pdf/e521/e521036.pdf)

Disclosure of Invention

In an electric booster having a motor suspension structure as disclosed in patent document 1, a large vibration is generated when a dangerous speed is passed. The present inventors have made intensive studies to find out that: in particular, when the motor is not operated (non-operating) such as when the rotation of the rotor shaft is not intensified by the motor or when the power is not generated by the motor, a large vibration is generated at a dangerous speed (see fig. 3A and 3B described later).

In view of the above circumstances, an object of at least one embodiment of the present invention is to provide a vibration suppression method for a supercharger, which can suppress shaft vibration of a rotor shaft generated when a motor is not operating.

(1) A vibration suppression method for a supercharger according to at least one embodiment of the present invention is a vibration suppression method for a supercharger that suppresses shaft vibration of a supercharger that can be driven by a motor, the vibration suppression method including the steps of:

a specific vibration state determination step of determining whether or not a specific vibration state in which the magnitude of shaft vibration of the rotor shaft of the supercharger exceeds a predetermined magnitude or is likely to exceed a predetermined magnitude is obtained;

an excitation state determination step of determining whether or not the motor is in an excitation state in which an excitation voltage is applied to the motor; and

and a vibration suppression execution step of applying the excitation voltage to the motor when the specific vibration state is determined by the specific vibration state determination step and when the excitation state is determined not to be the excitation state by the excitation state determination step.

In general, when the motor is operated (during operation) such as when the rotation of the rotor shaft is increased by the motor or when the motor generates power, the motor is in an excited state in which the motor is excited. When the motor is in an excited state, a voltage for excitation (excitation voltage) is applied to a stator (coil) included in the motor, and a current flows through the stator, so that a magnetic force is generated from the stator. The present inventors have also found that by attracting the motor rotor toward the stator by the magnetic force (attraction force) from the stator of the motor in an excited state, the relative movement of the motor rotor with respect to the stator can be suppressed, and the level of shaft vibration of the rotor shaft attached to the motor rotor can be reduced.

According to the configuration of the above (1), when it is determined that the motor is not in the excited state and the vibration of the rotor shaft is in the specific vibration state which is a state in which the vibration needs to be suppressed, the excitation voltage is applied to the motor. By thus setting the motor to the excited state, the relative movement of the motor rotor with respect to the stator can be suppressed by the magnetic force (attraction force) from the stator generated in the excited state, and the shaft vibration of the rotor shaft connected to and rotating with the motor rotor can be reduced.

(2) In the constitution of the above (1),

the specific vibration state judging step includes:

a vibration acquisition step of acquiring a vibration detection value of shaft vibration of the rotor shaft; and

a vibration determination step of determining that the magnitude of the shaft vibration of the rotor shaft exceeds the specific vibration state of a predetermined magnitude when the vibration detection value obtained in the vibration acquisition step is larger than a predetermined vibration threshold value.

According to the configuration of the above (2), it is possible to determine whether or not the magnitude of the shaft vibration of the rotor shaft exceeds a predetermined magnitude (determine whether or not the rotor shaft is in a specific vibration state) based on the vibration detection value F obtained by directly detecting the shaft vibration of the rotor shaft.

(3) In the constitution of the above (1),

the specific vibration state judging step includes:

an actual turbine rotational speed acquisition step of acquiring an actual turbine rotational speed of the rotor shaft; and

the critical speed region is determined by determining that the magnitude of shaft vibration of the rotor shaft is likely to exceed the specific vibration state of a predetermined magnitude when the actual turbine rotational speed obtained in the actual turbine rotational speed obtaining step enters the critical speed region of the rotor shaft.

According to the configuration of the above (3), it is possible to determine whether or not the magnitude of the shaft vibration of the rotor shaft is likely to exceed a predetermined magnitude (determine whether or not the rotor shaft is in a specific vibration state) based on the rotation speed of the rotor shaft (actual turbine rotation speed).

(4) In the constitution of (3) above,

further comprising a dangerous velocity zone correction step of correcting a range of the dangerous velocity zone,

the dangerous speed area correcting step includes:

a bearing temperature acquisition step of acquiring a bearing temperature of a bearing of the rotor shaft; and

and a correction execution step of correcting the range of the dangerous speed region according to the bearing temperature obtained in the bearing temperature obtaining step.

According to the configuration of the above (4), the dangerous speed region D is corrected based on the bearing temperature obtained based on, for example, the oil temperature of the lubricating oil of the bearing, the metal temperature of the bearing, or the like. Thus, when the specific vibration state is determined based on the actual turbine rotational speed and the possibility of the magnitude of the shaft vibration exceeding the predetermined magnitude, the specific vibration state can be determined based on the actual turbine rotational speed V with higher accuracy in consideration of the actual operation condition of the supercharger.

(5) In the constitution of the above (1),

the specific vibration state judging step includes:

a bearing temperature determination step of determining that the magnitude of the shaft vibration of the rotor shaft is likely to exceed the specific vibration state of a predetermined magnitude when the bearing temperature obtained in the bearing temperature obtaining step is higher than a predetermined bearing temperature threshold value.

According to the configuration of (5), it is possible to determine whether or not the magnitude of the shaft vibration of the rotor shaft is likely to exceed a predetermined magnitude (determine whether or not the rotor shaft is in a specific vibration state) based on the bearing temperature of the bearing that supports the rotor shaft.

(6) Several embodiments are the constitution of (1) to (5) above,

the motor is mounted to a compressor-side end of the supercharger.

According to the configuration of the above (6), the electric-powered auxiliary supercharger has a suspension structure. In the suspension structure, since a weight (motor) is present at the leading end of the rotor shaft located outside the bearing, shaft vibration is easily caused, and shaft vibration of the electric-assisted supercharger having the suspension structure can be effectively suppressed.

(7) In the constitution of (6) above,

the motor includes a stator disposed around the rotor shaft,

the stator has a plurality of stator elements arranged in series along the rotor shaft,

the vibration suppression executing step is configured to: the excitation voltage is applied to a target stator element that is configured by one or more of the plurality of stator elements, the one or more being determined for each vibration mode of the rotor shaft.

According to the configuration of the above (7), the stator of the motor is constituted by a plurality of stator elements arranged in the axial direction of the rotor shaft. Here, the magnitude of the amplitude of the vibration of the rotor shaft and the position of the vibration are different depending on the primary, secondary, tertiary, and other vibration modes. Therefore, the structure is as follows: when vibration suppression is performed, the excitation voltage is not applied to all the stator elements, but is applied only to a limited number of stator elements (target stator elements) by limiting the number of stator elements to at least a part of the plurality of stator elements or to stator elements located at a part where the amplitude of each vibration mode is large, depending on the magnitude of vibration. This can suppress power consumption as compared with applying an excitation voltage to all the stator elements, and can suppress vibration of the rotor shaft while suppressing power consumption.

(8) Several embodiments are the constitution of (1) to (7) above,

further comprising a vibration suppression execution prohibition step of prohibiting execution of the vibration suppression execution step,

the vibration suppression execution prohibition step includes:

a device temperature acquisition step of acquiring a device temperature of a device including at least one of the motor and an inverter that drives the motor; and

and an execution prohibition step of prohibiting execution of the vibration suppression execution step when the device temperature is equal to or higher than a predetermined device temperature threshold value.

According to the configuration of the above (8), when the device temperature is excessively high, execution of vibration suppression is prohibited. This can prevent the temperature of the device from further rising due to the vibration suppression, and can protect the device.

(9) In the constitution of the above (8),

further comprising a notifying step of notifying execution of the vibration suppression execution prohibiting step.

According to the configuration of (9) above, it is possible to notify the operator, the outside of the external system, or the like that the vibration suppression execution step cannot be executed. In other words, it is possible to notify the outside that vibration (noise) of the supercharger that can be driven by the motor cannot be suppressed.

(10) A vibration suppression device for a supercharger according to at least one embodiment of the present invention is a vibration suppression device for a supercharger that suppresses shaft vibration of the supercharger that can be driven by a motor, the vibration suppression device including:

a specific vibration state determination unit configured to determine whether or not a specific vibration state in which the magnitude of shaft vibration of the rotor shaft of the supercharger exceeds a predetermined magnitude or is likely to exceed the predetermined magnitude is obtained;

an excitation state determination unit configured to determine whether or not the motor is in an excitation state in which an excitation voltage is applied to the motor; and

and a vibration suppression execution unit configured to apply the excitation voltage to the motor when the specific vibration state determination unit determines that the specific vibration state is the specific vibration state and when the excitation state determination unit determines that the excitation state is not the excitation state.

According to the configuration of the above item (10), the same effects as those of the above item (1) can be obtained.

(11) In the constitution of the above (10),

the specific vibration state determination unit includes:

a vibration detection value acquisition unit that acquires a vibration detection value of shaft vibration of the rotor shaft; and

and a vibration determination unit configured to determine that the magnitude of the shaft vibration of the rotor shaft exceeds the specific vibration state of a predetermined magnitude when the vibration detection value obtained by the vibration detection value obtaining unit is greater than a predetermined vibration threshold value.

According to the configuration of the above (11), the same effects as those of the above (2) can be obtained.

(12) In the constitution of the above (10),

the specific vibration state determination unit includes:

an actual turbine rotational speed acquisition unit that acquires an actual turbine rotational speed of the rotor shaft; and

and a critical speed region passage determination unit configured to determine that the magnitude of shaft vibration of the rotor shaft is likely to exceed the specific vibration state of a predetermined magnitude when the actual turbine rotational speed obtained by the actual turbine rotational speed obtaining unit enters a critical speed region of the rotor shaft.

According to the configuration of the above item (12), the same effects as those of the above item (3) can be obtained.

(13) In the constitution of the above (12),

further comprises a dangerous velocity zone correction unit for correcting the range of the dangerous velocity zone,

the dangerous speed area correction unit includes:

a bearing temperature acquisition unit that acquires a bearing temperature of a bearing of the rotor shaft; and

and a correction execution unit that corrects the range of the dangerous speed region based on the bearing temperature obtained by the bearing temperature obtaining unit.

According to the configuration of the above item (13), the same effects as those of the above item (4) can be obtained.

(14) In the constitution of the above (10),

the specific vibration state determination unit includes:

and a bearing temperature determination unit configured to determine that the magnitude of the shaft vibration of the rotor shaft is likely to exceed the specific vibration state of a predetermined magnitude when the bearing temperature obtained by the bearing temperature obtaining unit is higher than a predetermined bearing temperature threshold value.

According to the configuration of the above item (14), the same effects as those of the above item (5) can be obtained.

(15) Several embodiments are the constitution of (10) to (14) above,

the motor is mounted to a compressor-side end of the supercharger.

According to the configuration of the above item (15), the same effects as those of the above item (6) can be obtained.

(16) In the constitution of (15) above,

the motor includes a stator disposed around the rotor shaft,

the vibration suppression executing unit is configured to: the excitation voltage is applied to a target stator element that is configured by one or more of the plurality of stator elements, the one or more being determined for each vibration mode of the rotor shaft.

According to the configuration of the above item (16), the same effects as those of the above item (7) can be obtained.

(17) In the constitution of the above (16),

the subject stator element includes a stator element of an end of the plurality of stator elements closest to the compressor side of the supercharger.

According to the configuration of the above (17), the stator element closest to the compressor-side end of the supercharger is configured to be included in the target stator element regardless of the type (number) of the vibration mode. Here, the present inventors have noted that: the compressor-side end of the supercharger tends to have the largest amplitude in any vibration mode. In this way, by including the stator element closest to the compressor-side end of the supercharger in the subject stator element regardless of the type (number) of vibration modes, vibration of the rotor shaft can be suppressed more effectively.

(18) Several embodiments are the constitution of (10) to (17) above,

further comprises a vibration suppression execution prohibition portion that prohibits execution of the vibration suppression execution portion,

the vibration suppression execution prohibition unit includes:

a device temperature acquisition unit that acquires a device temperature of a device including at least one of the motor and an inverter that drives the motor; and

and an execution prohibition unit that prohibits execution of the vibration suppression execution unit when the device temperature is equal to or higher than a predetermined device temperature threshold value.

According to the configuration of the above (18), the same effects as those of the above (8) can be obtained.

(19) In the constitution of the above (18),

the vibration suppression control device further includes a notification unit configured to notify execution of the vibration suppression execution prohibition unit.

According to the configuration of the above (19), the same effects as those of the above (9) can be obtained.

(20) A supercharger according to at least one embodiment of the present invention is a supercharger that can be driven by a motor, the supercharger including:

a rotor shaft;

a turbine wheel driven by exhaust gas discharged from an engine;

a compressor wheel coupled to the turbine wheel via the rotor shaft;

the motor, can utilize the electric power to exert the rotary force to the said rotor shaft; and

the vibration suppression device for a supercharger according to any one of (10) to (19) above.

According to the configuration of the above item (20), the same effects as those of the items (10) to (19) can be achieved.

(effect of the invention)

According to at least one embodiment of the present invention, a vibration suppression method for a supercharger capable of suppressing shaft vibration of a rotor shaft generated when a motor is not operating can be provided.

Drawings

Fig. 1 is a diagram showing a vibration suppression device for a supercharger and a main part of an electric-assisted supercharger according to an embodiment of the present invention.

Fig. 2 is an enlarged view of a peripheral portion of the motor shown in fig. 1.

Fig. 3A is a diagram for explaining a timing of supercharging with the electrically-assisted supercharger according to the embodiment of the present invention, and shows a relationship between an engine load and a scavenging pressure.

Fig. 3B is a diagram for explaining a timing of supercharging with the electrically-assisted supercharger according to the embodiment of the present invention, and shows a relationship between an engine load and a scavenging pressure.

Fig. 4 is a diagram for explaining an effect of reducing the shaft vibration level by exciting the motor of the electric-assisted supercharger according to the embodiment of the present invention.

Fig. 5 is a flowchart illustrating a vibration suppression method for a supercharger according to an embodiment of the present invention.

Fig. 6 is a diagram showing a configuration of a vibration suppression device for a supercharger that monitors vibration to determine a specific vibration state according to an embodiment of the present invention.

Fig. 7 is a flowchart showing details of a specific vibration state determination step in the vibration suppression method for a supercharger according to an embodiment of the present invention, and determines whether or not the specific vibration state is achieved by monitoring shaft vibration.

Fig. 8 is a diagram showing a configuration of a vibration suppression device for a supercharger according to an embodiment of the present invention for determining a specific vibration state from an actual turbine rotation speed of a rotor shaft.

Fig. 9 is a diagram for explaining a vibration mode of shaft vibration of the rotor shaft according to the embodiment of the present invention.

Fig. 10 is a flowchart showing details of a specific vibration state determination step in the vibration suppression method for a supercharger according to the embodiment of the present invention, and determines the specific vibration state from the actual turbine rotation speed of the rotor shaft.

Fig. 11 is a diagram showing a configuration of a vibration suppression device for a supercharger for determining a specific vibration state from a bearing temperature according to an embodiment of the present invention.

Fig. 12 is a flowchart showing details of a specific vibration state determination step in the vibration suppression method for a supercharger according to the embodiment of the present invention, and determines whether or not the specific vibration state is present based on the bearing temperature.

Fig. 13 is a diagram showing a configuration of a vibration suppression device for a supercharger including a dangerous velocity range correction unit according to an embodiment of the present invention.

Fig. 14 is a flowchart showing a dangerous velocity region correction procedure according to an embodiment of the present invention.

Fig. 15 is a view showing a motor having a plurality of stator elements according to an embodiment of the present invention.

Fig. 16 is a diagram showing a configuration of a vibration suppression device for a supercharger including a vibration suppression execution prohibition unit and a notification unit according to an embodiment of the present invention.

Fig. 17 is a flowchart showing a vibration suppression execution prohibition step according to an embodiment of the present invention.

Fig. 18 is a flowchart showing a vibration suppression execution procedure according to an embodiment of the present invention, and is executed together with fig. 17.

Detailed Description

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

For example, the terms "in a certain direction", "along a certain direction", "parallel", "orthogonal", "central", "concentric" or "coaxial" and the like indicate relative or absolute arrangements, and indicate not only such arrangements in a strict sense but also a state in which relative displacements are caused by an angle or a distance to the extent that a tolerance or the like can be obtained to achieve the same function.

For example, expressions such as "identical", "equal", and "homogeneous" indicate that objects are in the same state, and indicate not only a state of being exactly the same but also a state of being different in tolerance or degree of being able to achieve the same function.

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

On the other hand, expressions such as "provided", "including", or "having" a certain constituent element are not exclusive expressions which exclude the presence of other constituent elements.

Fig. 1 is a diagram showing a vibration suppression device 6 for a supercharger and a main part of an electric-assisted supercharger 1 according to an embodiment of the present invention. Fig. 2 is an enlarged view of a peripheral portion of the motor 3 shown in fig. 1. Fig. 3A and 3B are diagrams for explaining a sequence of supercharging by the electrically-assisted supercharger 1 according to the embodiment of the present invention, and show a relationship between an engine load and a scavenging pressure. Fig. 4 is a diagram for explaining an effect of reducing the shaft vibration level by exciting the motor 3 of the electric-assisted supercharger 1 according to the embodiment of the present invention.

Hereinafter, a case will be described where shaft vibration of the electric-assisted supercharger 1 is suppressed by the supercharger vibration suppression device 6 (hereinafter, simply referred to as the vibration suppression device 6) and the supercharger vibration suppression method (hereinafter, simply referred to as the vibration suppression method), but the electric-assisted supercharger 1 may be a hybrid supercharger that can perform supercharging in the same manner as the electric-assisted supercharger 1 as described below. The hybrid supercharger can perform supercharging in the same manner as the electric-assisted supercharger 1, and when the engine is operated in a high-load operation region in which sufficient exhaust energy can be obtained, the remaining energy of the exhaust gas is recovered as electric power.

The electric-assisted supercharger 1 is a supercharger (turbocharger) configured as follows: the turbine wheel 2T provided in the exhaust passage of the engine is rotated by the exhaust gas, and the compressor wheel 2C coupled to the turbine wheel 2T via the rotor shaft 15 is rotated, thereby compressing the gas such as air in the scavenging passage flowing toward the combustion chamber of the engine. The electrically-assisted supercharger 1 includes a motor 3 (electric motor) capable of applying a rotational force to the rotor shaft 15 by electric power. The motor 3 is constituted: when the energy of the exhaust gas for driving the turbine wheel 2T is insufficient, for example, when the engine is operated in a low load operation region, the rotation of the rotor shaft 15 can be enhanced by applying a rotational force to the rotor shaft 15 using electric power.

In the following description, a case where the electric-assisted supercharger 1 is provided in a two-stroke diesel engine of a one-way scavenging system as a propulsion mechanism of a large ship will be described with reference to fig. 1 to 18. In addition, the hybrid supercharger and the electric-assisted supercharger 1 are referred to as a supercharger 1 as appropriate. In a two-stroke diesel engine of a one-way scavenging system, when a piston pushed downward by combustion and explosion of fuel descends below a scavenging port that opens at a lower portion of a cylinder, scavenging air (scavenging gas) flows into the cylinder. At this time, the exhaust valve at the upper portion of the cylinder is opened, whereby the exhaust gas and the combustion gas are exchanged, and the piston is raised again to compress the combustion gas. Therefore, the supercharger 1 described below is used.

As shown in fig. 1, the supercharger 1 is configured by integrally fastening an exhaust gas inlet housing 1, an exhaust gas outlet housing 12, a bearing housing 13, and an air guide housing 14 on the compressor side by bolts (not shown). The rotor shaft 15 is rotatably supported by a thrust bearing 17T and

radial bearings

17a and 17b provided in the bearing housing 13, and has a turbine wheel 2T constituting a turbine (turbine portion) at one end and a compressor wheel 2C constituting a compressor (compressor portion) at the other end. The turbine wheel 2T has a plurality of blades 2Ta on the outer peripheral portion, the blades 2Ta of the turbine wheel 2T are disposed between an exhaust gas introduction passage 22 and an exhaust gas discharge passage 23, the exhaust gas introduction passage 22 is provided in the exhaust gas inlet casing 11 for introducing exhaust gas into the turbine wheel 2T, and the exhaust gas discharge passage 23 is provided in the exhaust gas outlet casing 12 for guiding the exhaust gas having passed through the turbine wheel 2T to the outside. On the other hand, the compressor wheel 2C has a plurality of blades 2Ca on the outer peripheral portion, the blades 2Ca of the compressor wheel 2C are disposed between an intake air introduction passage 24 and a scroll chamber 25, the intake air introduction passage 24 is provided in the air guide casing 14 that is a part of the supercharger housing, air is introduced into the compressor wheel 2C, and combustion gas compressed by the compressor wheel 2C flows into the scroll chamber 25. The volute chamber 25 is connected to the downstream side of a scavenging passage, not shown, and the combustion gas that has passed through the volute chamber 25 flows toward the combustion chamber of the engine.

The supercharger 1 of the embodiment shown in fig. 1 to 4 includes a muffler 26 on the upstream side of the intake air introduction passage 24. The muffler 26 is provided on the upstream side of the inlet portion of the intake air introduction passage 24, has a muffler function of absorbing noise generated by intake air, and is supported by the air guide casing 14 via an intermediate member 27. The same applies to the embodiments shown in fig. 6 to 18 described later.

As shown in fig. 1 to 2 and fig. 6, 8, 11, and 15 described later, the motor 3 of the supercharger 1 includes a motor rotor 31, a stator 32, and a housing 33. The motor 3 is attached to a shaft extension portion 15e that extends the compressor-side end of the rotor shaft, and the motor 3 has a motor suspension structure without a dedicated bearing. That is, the motor 3 is supported by the thrust bearing 17t and the

radial bearings

17a and 17b that support the rotor shaft 15 (see fig. 1).

In the embodiment shown in fig. 1 to 2 (the same applies to fig. 6, 8, 11, and 15 described later), the motor rotor 31 is a cylindrical member having a permanent magnet on its outer peripheral surface, and is attached to the rotor shaft 15 by fastening a flange 15f provided on a shaft extension 15e at an end of the rotor shaft 15 and a flange 31f provided at an end (base end) of the motor rotor 31 to each other by a plurality of bolts and nuts 34. The stator 32 is housed in a cylindrical housing 33 so as to surround the outer periphery of the motor rotor 31 in a state separated from the motor rotor 31. In other words, the motor rotor 31 is disposed in the hollow portion formed inside the stator 32 in a state of not contacting the stator 32. Further, the housing 33 is supported by the air guide case 14 via a support member 35, and an end cover 37 is fixedly attached to a front end portion thereof by a bolt 38.

The motor 3 of the supercharger 1 is, for example, a three-phase ac motor, and is driven by a motor control device (for example, an inverter 4) that controls the motor 3. The motor control device is configured to be capable of independently performing the following operations: an operation of applying an excitation voltage to the motor 3 to set the motor 3 in an excited state, and an operation of rotating the motor rotor 31 by rotating the direction of a magnetic field generated by the excitation voltage. That is, the motor 3 is brought into a state in which a rotational force is applied to the motor rotor 31 (motor operating state) by applying the excitation voltage and rotating the direction of the magnetic field of the stator 32 generated by the application of the excitation voltage. On the other hand, when the excitation voltage is applied only to the motor 3 and the direction of the magnetic field of the stator 32 generated by the application of the excitation voltage is not rotated, the state (excitation restricted state) in which the motor rotor 31 is attracted only by the magnetic force from the stator 32 is maintained without applying the rotational force to the motor rotor 31.

In the embodiment shown in fig. 1 to 2 (the same applies to fig. 6, 8, 11, and 16 described later), the motor control device is the inverter 4 that can rotate the motor rotor 31 at the target rotational speed by controlling the voltage (excitation voltage) and frequency applied to the stator 32. More specifically, the inverter 4 periodically switches the three phases of the stator 32 through which the current flows by periodically switching elements (for example, six transistors) such as a plurality of transistors provided in the inverter 4. Accordingly, since the direction of the magnetic field of the stator 32 is sequentially switched to rotate in one direction, the rotating magnetic field attracts the magnet (permanent magnet) on the motor rotor 31 side, thereby rotating the motor rotor 31. That is, the inverter 4 applies an excitation voltage to the motor 3 and switches the direction of the current flowing through the stator 32 (winding) so as to generate the rotating magnetic field, thereby enabling the motor 3 to be in a motor operating state. On the other hand, the inverter 4 can set the motor 3 in the excitation restricted state by applying an excitation voltage having a frequency of zero to the stator 32, for example.

The motor 3 of the supercharger 1 having the above-described configuration is configured to be started and closed according to the operating state of the engine. The motor 3 is started to be in the motor operating state, and the application of the excitation voltage is stopped by turning off the motor 3 (motor non-operating state). The sequence of turning on and off the motor 3 will be described with reference to fig. 3A and 3B. Fig. 3A and 3B show a case where the supercharger 1 generates the scavenging pressure shown in fig. 3B as the engine load (%) changes as illustrated in fig. 3A. In other embodiments, an electric auxiliary blower may be attached to the compressor outlet of the supercharger to generate the scavenging pressure by turning on and off the auxiliary blower, or the scavenging pressure from the auxiliary blower may be generated by the auxiliary blower before time t1 or after time t5 described later. The assist blower is composed of a centrifugal impeller and an induction motor that operate at a constant rotational speed, and is automatically started and stopped (started/stopped) in accordance with a change in the scavenging pressure of the engine. In addition, the auxiliary blower is not essential, and in other embodiments, the engine may not include the auxiliary blower.

Specifically describing fig. 3A and 3B, at time t1, the engine starts operating and is in an idle state before time t 2. Then, from time t2, the engine load starts to increase due to the start of the ship sailing or the like, and the engine load increases in a stepwise manner beyond time t3 (see fig. 3A).

The period from time t2 to time t3 is also a period during which the engine is operated in a low load state. Therefore, as shown by the thick solid line in fig. 3B, during the period from time t2 to time t3, the motor 3 of the supercharger 1 is started, and the motor 3 applies a rotational force to the rotor shaft 15, thereby enhancing the rotation of the rotor shaft 15 driven by the exhaust gas. Then, during the period from time T3 to time T4, the engine is operated in a high load state, and the motor 3 of the supercharger 1 is turned off because the exhaust gas has sufficient energy to drive the turbine wheel 2T. In the case where the supercharger 1 is a hybrid supercharger, the motor 3 may be used as a generator to recover the surplus energy of the exhaust gas using the motor 3 during the period from the time t3 to the time t 4.

After time t3, the peak of the engine load is between time t3 and time t4 as shown in fig. 3A, and after the peak is crossed, the engine is stopped at time t6 after time t4 and time t5 have elapsed. At time t4 after the peak of the engine load is crossed, the operating state of the engine returns to the low load state again, and thus the motor 3 of the supercharger 1 is started. The motor 3 of the supercharger 1 remains activated until it is determined at time t5 that boost is not required, and the motor 3 of the supercharger 1 is turned off.

As described above, in the embodiment shown in fig. 3A and 3B, the supercharger 1 compresses air or the like while turning on or off the motor 3 in accordance with the load of the engine, however, when the rotor shaft 15 of the supercharger 1 rotates, shaft vibration may be generated in the rotor shaft 15 due to, for example, unbalance of the rotor shaft 15 itself or vibration of the bearing 17 (the thrust bearing 17t or the radial bearings 17a, 17B) of the rotor shaft 15. At this time, the present inventors have noticed that shaft vibration becomes more pronounced when the motor 3 of the supercharger 1 is turned off. When the motor 3 is started, the motor 3 is in an excited state and the rotation of the rotor shaft 15 is increased by the motor 3, whereas when the motor 3 is turned off, the motor 3 is not in an excited state and the rotor shaft 15 is rotated only by the drive of the exhaust gas. The inventors have thus found that, as shown in fig. 4, when shaft vibration occurs in the rotor shaft 15 of the supercharger 1, the vibration level of the shaft vibration can be reduced by exciting the motor 3. As illustrated in fig. 4, when the rotor shaft 15 generates shaft vibration, the vibration level decreases at and after time tx when the excitation voltage is turned on at time tx.

That is, the present inventors have found that by attracting the motor rotor 31 toward the stator 32 by the magnetic force (attraction force) from the stator 32 of the motor 3 in the excited state, the relative movement of the motor rotor 31 with respect to the stator 32 can be suppressed, and the shaft vibration level of the rotor shaft 15 attached to the motor rotor 31 can be reduced. In particular, by setting the motor 3 to the excitation restricting state instead of the motor operating state, the shaft vibration level of the rotor shaft 15 can be reduced without affecting the scavenging pressure because the motor 3 does not enhance the rotation of the rotor shaft 15.

The vibration suppression device 6 is configured to: shaft vibration during engine operation (including a period from when the engine load after the engine start is greater than 0% to when the engine stops including an idling state) of the electrically-assisted supercharger 1 in which the motor 3 is attached to the compressor-side end portion of the rotor shaft 15 as described above is suppressed according to the above-described principle. In the illustration of fig. 3A and 3B, in the time period between the time t0 and the time t2, between the time t3 and the time t4, and between the time t5 and the time t6, that is, the vibration suppression executable region, the motor 3 of the supercharger 1 is not in the motor operation state, so that there is a possibility that shaft vibration of the rotor shaft 15 is generated. Therefore, the vibration suppression device 6 is configured to: the state corresponding to the vibration suppression executable region is determined, and the motor 3 is brought into an excited state as necessary. In the embodiment in which an auxiliary blower, not shown, is mounted on the engine, shaft vibration may occur due to the auxiliary blower in the activated state, and in this case, the motor 3 in the non-excited state may be excited to reduce the shaft vibration level of the rotor shaft 15.

Specifically, as shown in fig. 1 (the same applies to fig. 6, 8, 11, 13, and 16 described later), the vibration suppression device 6 includes a specific vibration state determination unit 61, an excitation state determination unit 64, and a vibration suppression execution unit 65. The vibration suppression device 6 is constituted by, for example, a computer, and includes a CPU (processor) not shown, and a memory M (storage device) such as a ROM or a RAM. The functional units of the vibration suppression device 6 are realized by the CPU operating (e.g., calculating data) in accordance with a command of a program loaded on the main storage device. In the embodiment shown in fig. 1, the vibration suppression device 6 is mounted as one functional unit of the inverter 4, but in some other embodiments, it may be an independent device communicably connected to, for example, a motor control device as the inverter 4.

Hereinafter, each functional unit included in the vibration suppression device 6 will be described.

The specific vibration state determination unit 61 determines whether or not the magnitude of the shaft vibration of the rotor shaft 15 of the supercharger 1 exceeds a predetermined magnitude, or whether or not there is a possibility that the magnitude of the shaft vibration exceeds a predetermined magnitude. For example, as will be described later, the determination of the specific vibration state, which is a state in which the vibration of the rotor shaft is to be suppressed, may be performed based on the vibration detection value F of the shaft vibration actually measured (see fig. 6 to 7), may be performed based on the actual turbine rotation speed V of the rotor shaft 15 of the supercharger 1 (see fig. 8 to 10), or may be performed based on the bearing temperature Bt of the bearing 17 of the supercharger 1 (see fig. 11 to 12).

The excitation state determination unit 64 determines whether or not the motor 3 of the supercharger 1 is in an excitation state in which an excitation voltage is applied. For example, whether the motor 3 is started or not may be determined based on information on the motor control device side obtained by communication with a control unit of the motor control device (the inverter 4 or the like), or by acquiring information in a memory of the motor control device. In this case, when the motor 3 is started, it is determined that the motor 3 is in the excited state. Alternatively, the determination may be made based on the same logic as that for the activation and deactivation of the supercharger 1, and for example, the engine operating state such as the engine load or the engine speed as shown in fig. 3A and 3B may be confirmed to determine whether or not the engine is in the operating state in which the supercharger 1 is activated or deactivated. In this case, when the engine is in an operating state in which the supercharger 1 is started, it is determined that the motor 3 is in an excited state. The voltage of the motor 3 may be actually detected, and when the excitation voltage is detected, it may be determined that the motor 3 is in the excited state.

The vibration suppression execution unit 65 applies an excitation voltage to the motor 3 when the specific vibration state determination unit 61 determines that the vibration state is the specific vibration state and when the excitation state determination unit 64 determines that the vibration state is the non-excitation state. As shown in fig. 4, by applying an excitation voltage to the motor 3, the shaft vibration level can be reduced.

Next, a vibration suppression method (vibration suppression method of a supercharger) including the above configuration will be described with reference to fig. 5. Fig. 5 is a flowchart illustrating a vibration suppression method for a supercharger according to an embodiment of the present invention.

As shown in fig. 5, the vibration suppression method according to at least one embodiment of the present invention is a method for suppressing shaft vibration during engine operation of an electric-assisted supercharger 1 having a motor 3 attached to a compressor-side end of a rotor shaft 15, and includes a specific vibration state determination step (S51), an excitation state determination step (S52), and vibration suppression execution steps (S53 to S54). Furthermore, the vibration suppression method may also be performed by the above-described vibration suppression device 6. Alternatively, the operation may be performed manually, for example, by determining a specific vibration state by monitoring the operating state of the supercharger 1 by an operator, and performing an operation (such as pressing a switch) of applying an excitation voltage to the motor 3 when it is determined that the specific vibration state is achieved. The vibration suppressing method is explained based on the flow of fig. 5.

In step S51 of fig. 5, a specific vibration state determination step is performed. The specific vibration state determination step (S51) is a step of determining whether or not the magnitude of the shaft vibration of the rotor shaft 15 of the supercharger 1 exceeds a predetermined magnitude, or whether or not there is a possibility that the magnitude of the shaft vibration exceeds a predetermined magnitude. This step (S51) corresponds to the processing executed by the specific vibration state determination unit 61, and is not described in detail since it has already been described.

In the next step S52, an excitation state determination step is executed. The excitation state determination step (S52) is a step of determining whether or not the motor 3 of the supercharger 1 is in an excitation state in which an excitation voltage is applied. This step (S52) corresponds to the processing performed by the excitation state determination unit 64, and is not described in detail since it has already been described.

Then, in the next steps S53 to S54, a vibration suppression execution step is executed. The vibration suppression execution steps (S53 to S54) are executed when the specific vibration state determination unit 61 determines that the vibration state is the specific vibration state and when the excitation state determination unit 64 determines that the vibration state is the non-excitation state, the excitation voltage is applied to the motor 3. More specifically, when it is determined in step S53 that the rotor shaft 15 is in the specific vibration state and the motor 3 is in the non-excited state that is the non-excited state, the excitation voltage is applied to the motor 3 in step S54. Namely, vibration suppression is performed. On the contrary, when it is determined in step S53 that the vibration state is not specified or the motor 3 is already in the excited state, the vibration suppression in step S54 is not executed, and the flow of fig. 5 is ended.

According to the above configuration, when it is determined that the motor 3 is not in the non-excited state and that the vibration of the rotor shaft 15 is in a specific vibration state, which is a state in which vibration needs to be suppressed, the excitation voltage is applied to the motor 3. By thus bringing the motor 3 into the excited state, the relative movement of the motor rotor 31 with respect to the stator 32 can be suppressed by the attractive force (magnetic force) from the stator 32 (coil) generated in the excited state, and the shaft vibration of the rotor shaft 15 connected to and rotating together with the motor rotor 31 can be reduced.

Next, several embodiments relating to the above-described method for determining the specific vibration state will be described with reference to fig. 6 to 18.

Fig. 6 to 7 are diagrams illustrating an embodiment of monitoring a vibration detection value F obtained by actually measuring vibration. Fig. 6 is a diagram showing the configuration of the vibration suppression device 6 for a supercharger that determines a specific vibration state by monitoring vibration according to an embodiment of the present invention. Fig. 7 is a flowchart showing details of the specific vibration state determination step (step S51 in fig. 5) in the vibration suppression method for a supercharger according to the embodiment of the present invention, and determines whether or not the specific vibration state is achieved by monitoring the shaft vibration.

Fig. 8 to 10 are diagrams illustrating an embodiment in which a specific vibration state is determined from the rotation speed of the rotor shaft 15 (actual turbine rotation speed V). Fig. 8 is a diagram showing the configuration of the vibration suppression device 6 for a supercharger according to an embodiment of the present invention, which determines a specific vibration state from the actual turbine rotation speed V of the rotor shaft 15. Fig. 9 is a diagram for explaining a vibration mode of shaft vibration of the rotor shaft 15 according to the embodiment of the present invention. Fig. 10 is a flowchart showing details of the specific vibration state determination step (step S51 in fig. 5) in the vibration suppression method for a supercharger according to the embodiment of the present invention, and the specific vibration state is determined from the actual turbine rotation speed V of the rotor shaft 15.

Fig. 11 to 12 are diagrams illustrating an embodiment in which a specific vibration state is determined from the bearing temperature Bt of the bearing 17 that supports the rotor shaft 15 of the supercharger 1. Fig. 11 is a diagram showing the configuration of the vibration suppression device 6 for a supercharger for determining a specific vibration state from the bearing temperature Bt according to the embodiment of the present invention. Fig. 12 is a flowchart showing details of the specific vibration state determination step (step S51 in fig. 5) in the vibration suppression method for a supercharger according to the embodiment of the present invention, and determines whether or not the specific vibration state is present based on the bearing temperature Bt.

Fig. 13 is a diagram showing the configuration of the vibration suppression device 6 for a supercharger including the dangerous velocity range correction unit 63d according to the embodiment of the present invention. Fig. 14 is a flowchart showing a dangerous velocity region correction procedure according to an embodiment of the present invention. Fig. 15 is a diagram showing a motor 3 having a plurality of stator elements according to an embodiment of the present invention. Fig. 16 is a diagram showing the configuration of the vibration suppression device 6 for a supercharger including the vibration suppression execution prohibition unit 66 and the notification unit 67 according to the embodiment of the present invention. Fig. 17 is a flowchart showing a vibration suppression execution prohibition step according to an embodiment of the present invention. Fig. 18 is a flowchart showing a vibration suppression execution procedure according to an embodiment of the present invention, and is executed together with fig. 17.

In some embodiments, as shown in fig. 6, the specific vibration state determination unit 61 includes a vibration detection value acquisition unit 62a and a vibration determination unit 63a, wherein the vibration detection value acquisition unit 62a acquires a vibration detection value F of shaft vibration of the rotor shaft 15 of the supercharger 1, and the vibration determination unit 63a determines that the magnitude of the shaft vibration of the rotor shaft 15 exceeds a specific vibration state of a predetermined magnitude when the vibration detection value F acquired by the vibration detection value acquisition unit 62a is greater than a predetermined vibration threshold value Tf. As shown in fig. 6, the supercharger 1 includes a vibration detection unit 71 capable of detecting shaft vibration. The vibration detection unit 71 is connected to the vibration detection value acquisition unit 62a, and the vibration detection value F detected by the vibration detection unit 71 is input to the vibration detection value acquisition unit 62 a. Thus, the vibration detection value acquisition unit 62a can obtain the vibration detection value F of the rotor shaft 15. The vibration detection unit 71 may be, for example, a pickup capable of converting vibration or speed into a current corresponding to the magnitude thereof.

In the embodiment shown in fig. 6, the vibration detection unit 71 is provided on the bearing housing 13, and detects a bearing housing speed Fs (mm/s) as a vibration detection value F. Then, the vibration determination unit 63a determines that the vibration state is a specific vibration state when the bearing seat speed Fs is greater than a vibration threshold Tf (Tf < Fs), which is a predetermined bearing seat speed. However, the present invention is not limited to this, and all physical quantities detectable as shaft vibration may be detected by the vibration detection unit 71. For example, in some other embodiments, the vibration detection unit 71 may detect the magnitude of the shaft vibration (vibration level Fi (μ)) as the vibration detection value F, and determine that the vibration state is the specific vibration state when the vibration level Fi is greater than a vibration threshold Tf (Tf < Fi), which is a predetermined vibration level.

A vibration suppression method corresponding to the above-described embodiment (see fig. 6) will be described with reference to fig. 7. Fig. 7 corresponds to a specific method of the specific vibration state determination step of S51 in fig. 5. In some embodiments, as shown in fig. 7, the specific vibration state determination step (S51 in fig. 5) includes a vibration acquisition step (S71) of acquiring a vibration detection value F of shaft vibration of the rotor shaft 15, and a vibration determination step (S72 to S73) of determining that the magnitude of the shaft vibration of the rotor shaft 15 exceeds a specific vibration state of a predetermined magnitude when the vibration detection value F acquired in the vibration acquisition step (S71) is greater than a predetermined vibration threshold value Tf. To explain according to the flow of fig. 7, in step 71, a vibration detection value F of the rotor shaft 15 is acquired by acquisition from the vibration detection unit 71 or the like. For example, as described above, the bearing housing speed Fs or the vibration level Fi may be detected by the vibration detection unit 71. When it is determined in step S72 that the vibration detection value F is larger than the vibration threshold value Tf (Tf < F) after comparing the vibration detection value F with the vibration threshold value Tf, it is determined in step S73 that a vibration state is specified. On the contrary, when it is determined in step S72 that the vibration detection value F is equal to or less than the vibration threshold value Tf (Tf ≧ F), step S73 is not executed, and the flow of fig. 7 ends. In addition, the end of the flow of fig. 7 is the same as the end of step S51 of fig. 5 described above, and thus step S52 of fig. 5 and the subsequent steps are continuously executed as the vibration suppressing method.

According to the above configuration, as shown in fig. 6 to 7, it is possible to determine whether or not the magnitude of the shaft vibration of the rotor shaft 15 exceeds a predetermined magnitude (determine whether or not the rotor shaft is in a specific vibration state) based on the vibration detection value F obtained by directly detecting the shaft vibration of the rotor shaft 15.

In other embodiments, as shown in fig. 8 (the same applies to fig. 13 described later), the specific vibration state determination unit 61 includes an actual turbine rotation speed acquisition unit 62b that acquires the actual turbine rotation speed V of the rotor shaft 15 of the supercharger 1, and a dangerous speed region passage determination unit 63b that determines that there is a possibility that the magnitude of the shaft vibration of the rotor shaft 15 exceeds a specific vibration state of a predetermined magnitude when the actual turbine rotation speed V acquired by the actual turbine rotation speed acquisition unit 62b enters a dangerous speed region D of the rotor shaft 15. As shown in fig. 8, the supercharger 1 includes an actual turbine rotational speed detection means 72 capable of detecting an actual turbine rotational speed V that is a rotational speed (rotational speed) of the rotor shaft 15 during operation. The actual turbine rotational speed detecting means 72 is connected to the actual turbine rotational speed acquiring unit 62b, and the actual turbine rotational speed V detected by the actual turbine rotational speed detecting means 72 is input to the actual turbine rotational speed acquiring unit 62 b. Thereby, the actual turbine rotational speed acquisition unit 62b can acquire the actual turbine rotational speed V. The actual turbine rotational speed detection means 72 may be a rotational speed sensor. In the embodiment shown in fig. 8, the actual turbine rotational speed detection means 72 is provided by being supported by the air guide casing 14 of the supercharger 1 in a state of facing the shroud-side edge portion of the blade 2Ca of the compressor impeller 2C.

The critical speed region D of the rotor shaft 15 is a speed region in which the rotor shaft 15 may be damaged by deflection or the like during rotation, and when the rotation speed of the rotor shaft 15 enters the critical speed region D, shaft vibration increases. Therefore, when the rotation speed of the rotor shaft 15 enters the critical speed region D, the critical speed region passage determination unit 63b determines that the magnitude of the shaft vibration of the rotor shaft 15 may exceed a predetermined magnitude, and determines that the vibration state is a specific vibration state. In more detail, as shown in fig. 9, the dangerous speed region D is generally plural, and is arranged like the first dangerous speed region D1, the second dangerous speed region D2, the third dangerous speed region D3, and the fourth dangerous speed regions D4, … … as the rotation speed of the rotor shaft 15 is increased from low to high. The nth dangerous velocity region Dn (n is 1, 2, 3, 4, … …) as each dangerous velocity region D is defined by a lower limit Dd and an upper limit Du, respectively. When the rotational speed of the rotor shaft 15 enters the first dangerous speed region D1, the primary vibration mode shown in fig. 9 (a) occurs. Similarly, when the rotation speed of the rotor shaft 15 enters the second dangerous speed region D2, the third dangerous speed region D3, and the fourth dangerous speed region D4, a secondary vibration mode shown in fig. 9 (b), a tertiary vibration mode shown in fig. 9 (c), and a quaternary vibration mode shown in fig. 9 (D) occur, respectively. The upper limit value Du of the nth dangerous velocity region Dn is smaller than the lower limit value Dd of the (n + 1) th dangerous velocity region Dn + 1.

A vibration suppression method corresponding to the above-described embodiment (see fig. 8) will be described with reference to fig. 10. Fig. 10 corresponds to a specific method of the specific vibration state determination step of S51 in fig. 5. In some embodiments, as shown in fig. 10, the specific vibration state determination step (S51 in fig. 5) includes an actual turbine rotational speed acquisition step (S101) of acquiring the actual turbine rotational speed V of the rotor shaft 15 of the supercharger 1, and a dangerous speed region passage determination step (S102 to S103) of determining that there is a possibility that the magnitude of the shaft vibration of the rotor shaft 15 exceeds a specific vibration state of a predetermined magnitude when the actual turbine rotational speed V acquired in the actual turbine rotational speed acquisition step (S101) enters the dangerous speed region D of the rotor shaft 15. To explain according to the flow of fig. 10, in step S101, the actual turbine rotational speed V of the rotor shaft 15 is acquired by acquisition from the actual turbine rotational speed detection means 72 or the like. When it is determined that the actual turbine rotational speed V enters the dangerous speed region D (Dd ≦ V ≦ Du) after comparing the actual turbine rotational speed V with the dangerous speed region D in step S102, it is determined as the specific vibration state in step S103. On the other hand, if it is determined in step S102 that the actual turbine rotational speed V does not enter the dangerous speed region D (Dd > V, Du < V), step S103 is not executed, and the flow of fig. 10 ends.

In the determination of whether or not the actual turbine rotational speed V enters the dangerous speed region D in step S102, if it is determined that the actual turbine rotational speed V does not enter any of all the dangerous speed regions D (nth dangerous speed region Dn), it is determined that the actual turbine rotational speed V does not enter the dangerous speed region D. Since the end of the flow of fig. 10 is the same as the end of step S51 of fig. 5, step S52 and subsequent steps of fig. 5 are continuously executed as the vibration suppressing method.

According to the above configuration, as shown in fig. 8 to 10, it is possible to determine whether or not the magnitude of the shaft vibration of the rotor shaft 15 is likely to exceed a predetermined magnitude, based on the rotation speed of the rotor shaft (actual turbine rotation speed V) (determine whether or not the rotor shaft is in a specific vibration state).

In some other embodiments, as shown in fig. 11, the specific vibration state determination unit 61 includes a bearing temperature acquisition unit 62c and a bearing temperature determination unit 63c, wherein the bearing temperature acquisition unit 62c acquires a bearing temperature Bt of the bearing 17 of the rotor shaft 15, and the bearing temperature determination unit 63c determines that there is a possibility that the magnitude of the shaft vibration of the rotor shaft 15 exceeds a specific vibration state of a predetermined magnitude when the bearing temperature Bt acquired by the bearing temperature acquisition unit 62c is higher than a predetermined bearing temperature threshold Tb. As shown in fig. 11, the rotor shaft 15 of the supercharger 1 is supported by bearings 17(17t, 17a, 17b), and the temperature (bearing temperature Bt) tends to increase due to friction heat or the like as the shaft vibration of the rotor shaft 15 increases. In particular, in the critical speed region D, the temperature of the metal forming the bearing 17 (metal temperature) or the temperature of the lubricating oil increases as a result of the rotor shaft 15 greatly oscillating in the bearing 17 and the oil film thickness of the lubricating oil becoming thin. By utilizing this phenomenon, the bearing temperature determination unit 63c is configured to determine whether or not the rotor shaft 15 is in a specific vibration state based on the bearing temperature Bt. Therefore, the supercharger 1 includes a bearing temperature detection unit 73 (e.g., a thermometer) capable of detecting the bearing temperature Bt. The bearing temperature detection unit 73 is connected to the bearing temperature acquisition unit 62c, and the bearing temperature Bt detected by the bearing temperature detection unit 73 is input to the bearing temperature acquisition unit 62 c. Thereby, the bearing temperature acquisition unit 62c can acquire the bearing temperature Bt.

In the embodiment shown in fig. 11, the bearing temperature detection means 73 is provided in the radial bearing 17a on the compressor side, which tends to vibrate more greatly than the radial bearing 17b on the turbine side (see fig. 9). Also, the bearing temperature detection unit 73 detects the metal temperature of the radial bearing 17a as the bearing temperature Bt. However, the present invention is not limited to this, and in other embodiments, the bearing temperature detection means 73 may be provided on the radial bearing 17b on the turbine side or may be provided on the thrust bearing 17 t. Alternatively, the bearing temperature detection means 73 may be provided on at least one of the bearings 17(17a, 17b, 17 t). In some other embodiments, the bearing temperature detection unit 73 may be configured to detect the oil temperature of the lubricating oil supplied to the bearing 17 as the bearing temperature Bt.

A vibration suppression method corresponding to the above-described embodiment (see fig. 11) will be described with reference to fig. 12. Fig. 12 corresponds to a specific method of the specific vibration state determination step of S51 in fig. 5. In some embodiments, as shown in fig. 12, the specific vibration state determination step (S51 in fig. 5) includes a bearing temperature acquisition step (S121) of acquiring a bearing temperature Bt of the bearing 17 of the rotor shaft 15, and a bearing temperature determination step (S122 to S123) of determining that there is a possibility that the magnitude of the shaft vibration of the rotor shaft 15 exceeds a specific vibration state of a predetermined magnitude when the bearing temperature Bt acquired in the bearing temperature acquisition step (S121) is higher than a predetermined bearing temperature threshold Tb. To explain according to the flow of fig. 12, in step S121, the bearing temperature Bt is acquired by acquisition from the bearing temperature detection unit 73 or the like. For example, as described above, the metal temperature of the bearing 17 or the oil temperature of the lubricating oil may be detected by the bearing temperature detection unit 73. When it is determined in step S122 that bearing temperature Bt is higher than bearing temperature threshold Tb (Tb < Bt) after bearing temperature Bt is compared with bearing temperature threshold Tb, it is determined in step S123 that the vibration state is specified. On the other hand, when it is determined in step S122 that the bearing temperature Bt is equal to or lower than the bearing temperature threshold Tb (Tb ≧ Bt), step S123 is not executed, and the flow of FIG. 12 is ended. The end of the flow of fig. 12 is the same as the end of step S51 of fig. 5, and thus step S52 and subsequent steps of fig. 5 are continuously executed as a vibration suppressing method.

According to the above configuration, it is possible to determine whether or not the magnitude of the shaft vibration of the rotor shaft 15 is likely to exceed a predetermined magnitude (determine whether or not the rotor shaft 15 is in a specific vibration state) based on the bearing temperature Bt of the bearing 17 that supports the rotor shaft 15.

In some other embodiments, the critical speed region D of the embodiment (see fig. 8 to 10) in which the specific vibration state is determined from the actual turbine rotational speed V may be corrected based on the bearing temperature Bt of the bearing 17. Specifically, as shown in fig. 13, the vibration suppression device 6 further includes a dangerous velocity range correction unit 63D that corrects the range of the dangerous velocity range D. The critical speed range correction unit 63D includes a bearing temperature acquisition unit 62c and a correction execution unit 63e, wherein the bearing temperature acquisition unit 62c acquires a bearing temperature Bt of the bearing of the rotor shaft 15, and the correction execution unit 63e corrects the range of the critical speed range D based on the bearing temperature Bt acquired by the bearing temperature acquisition unit 62 c. As described above, the bearing temperature acquisition unit 62c acquires the bearing temperature Bt from the bearing temperature detection unit 73.

The critical speed range correction unit 63d has information (bearing reference temperature information Rt) of the bearing temperature Bt with respect to the reference of the actual turbine rotational speed V, and can calculate the bearing reference temperature Bs from the actual turbine rotational speed V based on the bearing reference temperature information Rt. Further, since it is suggested that the shaft vibration may be larger than expected (standard) when the bearing temperature Bt is higher than the bearing standard temperature Bs (Bt > Bs), the region of the critical speed region d (dn) is expanded by at least one of making the upper limit value Du of the critical speed region d (dn) larger or making the lower limit value Dd smaller depending on the magnitude of the difference (Bt-Bs). Thus, even if the actual turbine rotational speed V is the same, it is more easily determined that the actual turbine rotational speed V has entered the dangerous speed region D, and it is possible to avoid a situation in which vibration suppression is not performed even though the actual shaft vibration is larger than expected, depending on the operating situation. On the other hand, when the bearing temperature Bt is lower than the bearing reference temperature Bs (Bt < Bs), it is suggested that the shaft vibration may be smaller than expected, and therefore, the region of the critical speed region d (dn) is narrowed by at least one of making the upper limit value Du of the critical speed region d (dn) smaller or making the lower limit value Dd larger according to the magnitude of the difference (Bs-Bt) or the like. Thus, even if the actual turbine rotational speed V is the same, it is more difficult to determine that the actual turbine rotational speed V has entered the dangerous speed region D, and it is possible to avoid a situation in which vibration suppression is performed even if the actual shaft vibration is smaller than expected, depending on the operating situation. In the case of correcting the dangerous speed regions D (Dn), some of the plurality of dangerous speed regions D (nth dangerous speed regions Dn) may be corrected, for example, the dangerous speed region D closest to the actual turbine rotational speed V, or the dangerous speed regions D located before and after the actual turbine rotational speed V, or all of the dangerous speed regions D may be corrected.

The embodiment shown in fig. 13 is configured such that: the actual turbine rotational speed acquisition unit 62b and the bearing temperature acquisition unit 62c are connected to the correction execution unit 63e, respectively, and the actual turbine rotational speed V and the bearing temperature Bt are input from the respective functional units to the correction execution unit 63 e. Upon receiving these inputs, the correction execution section 63e obtains the bearing standard temperature Bs corresponding to the actual turbine rotational speed V using the bearing standard temperature information Rt in the memory M. Then, the detected bearing temperature Bt is compared with the bearing reference temperature Bs, and whether the detected bearing temperature Bt is higher or lower than the bearing reference temperature Bs is determined, and the range of the critical speed region D is corrected as described above according to the degree of the difference. Specifically, the dangerous velocity range correcting unit 63d may directly correct the dangerous velocity range d (dn) stored in the memory M included in the vibration suppressing apparatus 6. Note that the specific vibration state determination unit 61 shown in fig. 13 is not described since it has already been described.

A vibration suppression method corresponding to the above-described embodiment (see fig. 13) will be described with reference to fig. 14. In several embodiments, as shown in fig. 14, the vibration suppression method further includes a dangerous velocity region correction step (S140) of correcting the range of the dangerous velocity region D. Further, the critical speed region correction step includes a bearing temperature acquisition step (S141) of acquiring the bearing temperature Bt of the bearing 17 of the rotor shaft 15, and a correction execution step (S142 to S147) of correcting the range of the critical speed region D based on the bearing temperature Bt acquired in the bearing temperature acquisition step (S141). To explain according to the flow of fig. 14, in step S141, the bearing temperature Bt is acquired by acquisition from the bearing temperature detection unit 73 or the like. In step S142, the actual turbine rotational speed V is acquired by acquisition from the actual turbine rotational speed detection unit 72 or the like. In step S143, a bearing reference temperature Bs corresponding to the obtained actual turbine rotational speed V is calculated by referring to the above-described bearing reference temperature information Rt and the like.

Then, when the bearing temperature Bt is higher than the bearing reference temperature Bs (Bt > Bs) as a result of comparing the bearing temperature Bt with the bearing reference temperature Bs in step S144, the range of the critical speed region d (dn) is corrected to expand the region based on the difference (Bt-Bs) and the like as described above in step S145. On the contrary, when the bearing temperature Bt is not higher than the bearing standard temperature Bs (Bt ≦ Bs) in step S144, the process proceeds to the next step S146 without executing step S145. When the bearing temperature Bt is lower than the bearing reference temperature Bs (Bt < Bs) as a result of comparing the bearing temperature Bt with the bearing reference temperature Bs in step S146, the range of the critical speed region d (dn) is corrected to be narrowed in accordance with the difference (Bs-Bt) or the like as described above in step S147. On the other hand, when the bearing temperature Bt is not lower than the bearing reference temperature Bs (Bt ≧ Bs) in step S146, step S147 is not executed, and the flow of FIG. 14 is terminated.

According to the above configuration, the critical speed region D is corrected based on the bearing temperature Bt obtained based on the oil temperature of the lubricating oil of the bearing 17, the metal temperature of the bearing, or the like, for example. Thus, when the specific vibration state is determined based on the actual turbine rotational speed V and the possibility of the magnitude of the shaft vibration exceeding the predetermined magnitude, the specific vibration state can be determined based on the actual turbine rotational speed V with higher accuracy in consideration of the actual operation of the supercharger 1.

Other configurations of the vibration suppression device 6 and the vibration suppression method will be described below.

In several embodiments, as described above, the motor 3 has the stator 32 disposed so as to surround the rotor shaft 15. As shown in fig. 15, the stator 32 includes a plurality of stator elements (three elements 32a to 32c in fig. 15) arranged in series along the rotor shaft 15. The vibration suppression execution unit 65 provided in the vibration suppression device 6 or the vibration suppression execution step (S54 in fig. 5) in the vibration suppression method may be configured to: the excitation voltage is applied to the target stator element, which is formed of one or more stator elements determined for each vibration mode of the rotor shaft 15 among the plurality of stator elements. That is, the stator 32 of the motor 3 is configured to be able to apply an excitation voltage to each of the plurality of stator elements independently. In the embodiment shown in fig. 15, the stator 32 of the motor 3 is divided into three stator elements (32a to 32c) in the axial direction of the rotor shaft 15. However, the number of stator elements constituting the stator 32 is not limited to this, and may be two or more.

The vibration suppression device 6 includes target stator element information for associating each of a plurality of vibration modes (see fig. 9) generated in the rotor shaft 15 with one or more stator elements selected from the plurality of stator elements. In other words, the target stator element information is information in which each of a plurality of vibration modes, in other words, each of a plurality of risk velocity regions D (nth risk velocity region Dn) is associated with one or more stator elements. When vibration suppression is to be performed, the vibration suppression execution unit 65 determines a vibration pattern from a comparison between the actual turbine rotational speed V and the dangerous speed region d (dn), for example, and determines one or more target stator elements to which an excitation voltage should be applied from the determined vibration pattern by referring to the target stator element information. When the target stator element is not all the stator elements, power consumption can be suppressed as compared with applying the excitation voltage to all the stator elements.

For example, in some embodiments, the target stator element may be determined by focusing on the amplitude of the vibration mode of the rotor shaft 15. Since the larger the amplitude of the shaft vibration is, the more strongly the motor rotor 31 needs to be attracted toward the stator 32, the more stator elements can be set as the target stator elements.

In other embodiments, the stator element may be defined in each vibration mode as a stator element close to a position where the amplitude is larger, so as to determine the stator element as the target stator element in each vibration mode. Specifically, when the rotor shaft 15 (the motor 3 and the rotor shaft 15) is assumed to vibrate as shown in fig. 9, for example, in the primary vibration mode shown in (a) of fig. 9, the shaft vibration of the rotor shaft 15 is large at all positions, and therefore, all the stator elements are set as the target stator elements, and in the secondary to fourth vibration modes shown in (b) to (d) of fig. 9, for example, the first stator element 32a and the second stator element 32b may be set as the target stator elements. In this case, in the embodiment shown in fig. 15, in the case of the secondary to quaternary vibration modes, the excitation voltage is not applied to the third stator element 32c, and therefore the power consumption is suppressed accordingly.

According to the above configuration, the stator 32 of the motor 3 is configured by a plurality of stator elements (three

elements

32a, 32b, and 32c in fig. 15) arranged in the axial direction of the rotor shaft 15. Here, the magnitude of the amplitude of the vibration of the rotor shaft 15 and the position of the vibration are different depending on the primary, secondary, tertiary, and other vibration modes. Therefore, the structure is as follows: when vibration suppression is performed, the excitation voltage is not applied to all the stator elements, but is applied only to a limited number of stator elements (target stator elements) by limiting the number of stator elements to at least a part of the plurality of stator elements or to stator elements located in a part where the amplitude of each vibration mode is large, depending on the magnitude of vibration. This can suppress power consumption as compared with applying an excitation voltage to all the stator elements, and can suppress vibration of the rotor shaft 15 while suppressing power consumption.

In the embodiment described with reference to fig. 15, in some other embodiments, the target stator element corresponding to each vibration mode may include the stator element closest to the compressor-side end of the supercharger 1 among the plurality of stator elements. In the embodiment shown in fig. 15, the first stator element 32a is conformed.

According to the above configuration, the stator element (the first stator element 32a in fig. 15) closest to the compressor-side end of the supercharger 1 is configured to be included in the target stator element regardless of the type of the vibration mode (the number of times n). Here, the present inventors have noted that: the end of the supercharger 1 on the compressor side tends to have the maximum amplitude in any vibration mode. In this way, by including the stator element closest to the compressor-side end of the supercharger 1 in the subject stator element regardless of the kind (number) of vibration modes, the vibration of the rotor shaft 15 can be suppressed more effectively.

In some embodiments, as shown in fig. 16, in each of the above embodiments, the vibration suppression device 6 may further include a vibration suppression execution prohibition unit 66 that prohibits execution of the vibration suppression execution unit 65. The vibration suppression execution prohibition unit 66 includes a device temperature acquisition unit 66a and a prohibition execution unit 66b, wherein the device temperature acquisition unit 66a acquires a device temperature Et of a device including at least one of the motor 3 of the supercharger 1 and the inverter 4 that drives the motor 3, and the prohibition execution unit 66b prohibits the execution of the vibration suppression execution unit 65 when the device temperature is equal to or higher than a predetermined device temperature threshold Te. The device temperature acquisition unit 66a is configured to: is connected to an apparatus temperature detecting unit 74 capable of detecting the apparatus temperature Et, and receives an input of the apparatus temperature Et from the apparatus temperature detecting unit 74. For example, the inhibition execution unit 66b may be configured to be able to update the execution permission flag f indicating permission or prohibition of execution of vibration suppression stored in the memory M of the vibration suppression device 6, thereby permitting or prohibiting the vibration suppression execution unit 65 from applying the excitation voltage to the motor 3 (executing vibration suppression). In this case, the vibration suppression executing unit 65 is configured to: the execution permission flag f in the memory M is checked, and whether or not execution of vibration suppression is permitted is determined based on information of the execution permission flag f (see fig. 18 described later).

A vibration suppression method corresponding to the above-described embodiment (see fig. 16) will be described with reference to fig. 17. In several embodiments, as shown in fig. 17, the vibration suppression method may further include vibration suppression execution prohibition steps (S171 to S173) that prohibit execution of the vibration suppression execution step (step S54 of fig. 5). Specifically, the vibration suppression execution prohibition step (S171 to S173) includes a device temperature acquisition step (S171) of acquiring a device temperature Et of a device including at least one of the motor 3 of the supercharger 1 and the inverter 4 that drives the motor 3, and a prohibition execution step (S172 to S173) of prohibiting execution of the vibration suppression execution step (S54 of fig. 5) when the device temperature is equal to or higher than a predetermined device temperature threshold Te. To explain according to the flow of fig. 17, in step S171, the apparatus temperature Et is acquired by acquiring from the apparatus temperature detecting unit 74 or the like. Then, when the result of comparison of the apparatus temperature Et with the apparatus temperature threshold Te in step S172 is that the apparatus temperature Et is higher than the apparatus temperature threshold Te (Et > Te), the execution permission flag f described above is updated to be prohibited, for example, in step S173, so that the execution of the vibration suppression execution step is prohibited (S54 of fig. 5). On the other hand, when the apparatus temperature Et is not higher than the apparatus temperature threshold Te (Et. ltoreq. Te) in step S172, step S173 is not executed, and the flow of FIG. 17 is ended. Further, in the embodiment shown in fig. 17, when no in step S172 (Et ≦ Te), the execution permission flag f described above is set to permit, for example, in step S174, so that execution of vibration suppression is permitted, and then the flow of fig. 17 is ended.

In the present embodiment, the vibration suppression execution step of S54 in fig. 5 is replaced with the flow shown in fig. 18. To explain the flow of fig. 18, in step S181, it is determined whether or not execution of vibration suppression is possible by checking the execution permission flag f in the memory M set (updated) in the vibration suppression execution prohibition step (fig. 17), for example. Then, when it is determined in step S182 that the vibration suppression is permitted to be performed, the vibration suppression is performed in step S183. That is, an excitation voltage is applied to the motor 3. On the other hand, if it is determined in step S182 that the execution of the vibration suppression is prohibited, step S183 is not executed, and the flow of fig. 18 (fig. 5) is ended.

According to the above configuration, when the apparatus temperature Et is excessively high, execution of vibration suppression is prohibited. This can prevent the temperature of the device from further rising due to the vibration suppression, and can protect the device.

In some embodiments, as shown in fig. 16, the vibration suppression device 6 may further include a notification unit 67 that notifies the execution of the vibration suppression execution prohibition unit 66. The notification unit 67 is connected to a display, a sound, a light, or other notification device, and outputs information to the notification device to perform notification. At this time, the vibration detection value F, the actual turbine rotation speed V, the bearing temperature Bt, the transition of the equipment temperature Et, and the like may be notified together. Likewise, as shown in fig. 18, the vibration suppression method may further include a notification step of notifying execution of the vibration suppression execution prohibition step (S184). In the embodiment shown in fig. 18, when it is determined in step S182 of fig. 18 that execution of vibration suppression is prohibited, the notification step (S184) is executed until the end of the flow of fig. 18.

In the embodiment shown in fig. 16, the vibration suppression device 6 includes the vibration suppression execution prohibition unit 66 and the notification unit 67, and in the embodiments shown in fig. 17 to 18, the vibration suppression method includes the vibration suppression execution prohibition steps (S171 to S173) and the notification step (S184), but the notification unit 67 and the notification step (S184) are not essential, and the notification unit 67 and the notification step (S184) may be omitted in other embodiments. Further, the dangerous velocity range correcting unit 63d and the dangerous velocity range correcting step may be provided.

With the above configuration, the operator, the external system, and the like can be notified that the vibration suppression execution step (S54 in fig. 5) cannot be executed. In other words, it is possible to notify the outside that the vibration (noise) of the electric-assisted supercharger 1 cannot be suppressed.

The electric-assisted supercharger 1 having the motor mount structure according to the embodiment of the present invention is described above by taking a marine two-stroke diesel engine as an example. The present invention is not limited to the above embodiments, and includes a mode in which the above embodiments are modified or a mode in which these modes are appropriately combined.

For example, in some other embodiments, the electric-powered auxiliary supercharger 1 may be provided in a four-stroke diesel engine for a ship. In some other embodiments, the electrically-assisted supercharger 1 may be provided in an engine other than a marine engine, such as a vehicle.

In addition, the present invention can be applied to an electric-assisted supercharger 1 having no motor suspension structure. In this case, for example, the electric-assisted supercharger 1 may be located between the two

radial bearings

17a and 17b, and the position of the motor 3 may be located between the two

radial bearings

17a and 17b, as shown in each of fig. 1, 2, 6, 8, 11, and 15.

Description of the reference numerals

1: pressure booster

11: waste gas inlet shell

12: waste gas outlet shell

13: bearing seat

14: air guide shell

15: rotor shaft

15 e: shaft extension

15 f: flange

17: bearing assembly

17 a: radial bearing (compressor side)

17 b: radial bearing (turbine side)

17 t: thrust bearing

2C: compressor impeller

2 Ca: blade

2T: turbine wheel

2 Ta: blade

22: exhaust gas introduction passage

23: exhaust gas discharge passage

24: intake air introduction passage

25: vortex chamber

26: silencer with improved structure

27: intermediate member

3: motor with a stator having a stator core

31: motor rotor

31 f: flange

32: stator

32 a: first stator element

32 b: second stator element

32c, the ratio of: third stator element

33: outer casing

34: bolt and nut

35: support member

37: end cap

38: bolt

4: inverter with a voltage regulator

6: vibration suppressing device

61: specific vibration state determination unit

62 a: vibration detection value acquisition unit

62 b: actual turbine rotation speed acquisition unit

62c, the ratio of: bearing temperature acquisition unit

63 a: vibration determination unit

63 b: dangerous speed region passing judgment unit

63 c: bearing temperature determination unit

63 d: dangerous speed area correction unit

63 e: correction execution unit

64: excitation state determination unit

65: vibration suppression executing part

66: vibration suppression execution prohibition unit

66 a: device temperature acquisition unit

66 b: execution prohibition unit

67: notification part

M: memory device

71: vibration detecting unit

72: actual turbine rotation speed detection unit

73: bearing temperature detection unit

74: equipment temperature detection unit

F: detection value of vibration

Tf: threshold value of vibration

Fi: vibration level

Fs: bearing block speed

V: actual turbine rotational speed

D: region of danger velocity

And Dd: lower limit value

Du: upper limit value

Dn: n-th region of critical velocity

D1: first region of risk velocity

D2: second region of risk velocity

D3: third region of risk velocity

D4: fourth region of risk velocity

Bt: bearing temperature

Tb: bearing temperature threshold

Rt: bearing standard temperature information

Bs: bearing standard temperature

Et: temperature of the apparatus

Te: device temperature threshold

f: execution propriety flag

Claims

1. A vibration suppressing method of a supercharger for suppressing shaft vibration of a supercharger drivable with a motor, characterized by comprising the steps of:

a vibration suppression execution step of applying the excitation voltage to the motor when the specific vibration state is determined by the specific vibration state determination step and when the excitation state is determined not to be the excitation state by the excitation state determination step,

the specific vibration state judging step includes:

a critical speed region passing determination step of determining that the magnitude of shaft vibration of the rotor shaft is likely to exceed the specific vibration state of a prescribed magnitude when the actual turbine rotation speed obtained in the actual turbine rotation speed obtaining step enters a critical speed region of the rotor shaft,

the vibration suppressing method further includes a dangerous velocity region correcting step of correcting a range of the dangerous velocity region,

the dangerous speed area correcting step includes:

2. A vibration suppressing method of a supercharger for suppressing shaft vibration of a supercharger drivable with a motor, characterized by comprising the steps of:

the specific vibration state judging step includes:

3. A vibration suppressing method of a supercharger for suppressing shaft vibration of a supercharger drivable with a motor, characterized by comprising the steps of:

the motor includes a stator disposed around the rotor shaft,

4. A vibration suppressing method of a supercharger for suppressing shaft vibration of a supercharger drivable with a motor, characterized by comprising the steps of:

an excitation state determination step of determining whether or not the motor is in an excitation state in which an excitation voltage is applied to the motor;

a vibration suppression execution step of applying the excitation voltage to the motor when the specific vibration state is determined by the specific vibration state determination step and when the excitation state is determined not to be the excitation state by the excitation state determination step; and

a vibration suppression execution prohibition step of prohibiting execution of the vibration suppression execution step,

the vibration suppression execution prohibition step includes:

5. The vibration suppressing method of a supercharger according to any one of claims 1 to 4,

the specific vibration state judging step includes:

6. The vibration suppressing method of a supercharger according to claim 4,

7. The vibration suppressing method of a supercharger according to any one of claims 1 to 4,

the motor is mounted to a compressor-side end of the supercharger.

8. A vibration suppression device for a supercharger for suppressing shaft vibration of the supercharger that can be driven by a motor, the vibration suppression device comprising:

a vibration suppression execution unit configured to apply the excitation voltage to the motor when the specific vibration state determination unit determines that the specific vibration state is present and when the excitation state determination unit determines that the excitation state is not present,

the specific vibration state determination unit includes:

a critical speed region passage determination unit that determines that the magnitude of shaft vibration of the rotor shaft is likely to exceed the specific vibration state of a predetermined magnitude when the actual turbine rotational speed obtained by the actual turbine rotational speed obtaining unit enters a critical speed region of the rotor shaft;

the vibration suppression device further includes a dangerous velocity range correction unit that corrects a range of the dangerous velocity range,

the dangerous speed area correction unit includes:

9. A vibration suppression device for a supercharger for suppressing shaft vibration of the supercharger that can be driven by a motor, the vibration suppression device comprising:

the specific vibration state determination unit includes:

10. A vibration suppression device for a supercharger for suppressing shaft vibration of the supercharger that can be driven by a motor, the vibration suppression device comprising:

the motor includes a stator disposed around the rotor shaft,

11. A vibration suppression device for a supercharger for suppressing shaft vibration of the supercharger that can be driven by a motor, the vibration suppression device comprising:

an excitation state determination unit configured to determine whether or not the motor is in an excitation state in which an excitation voltage is applied to the motor;

a vibration suppression execution unit configured to apply the excitation voltage to the motor when the specific vibration state determination unit determines that the specific vibration state is the specific vibration state and when the excitation state determination unit determines that the excitation state is not the excitation state; and

a vibration suppression execution prohibition portion that prohibits execution of the vibration suppression execution portion,

the vibration suppression execution prohibition unit includes:

12. The vibration suppressing device of a supercharger according to any one of claims 8 to 11,

the specific vibration state determination unit includes:

13. The vibration suppressing device of a supercharger of claim 10,

the subject stator element includes a stator element of an end of the plurality of stator elements closest to a compressor side of the supercharger.

14. The vibration suppressing device of a supercharger of claim 11,

further comprising a notifying section that notifies execution of the vibration suppression execution prohibiting section.

15. The vibration suppressing device of a supercharger according to any one of claims 8 to 11,

the motor is mounted to a compressor-side end of the supercharger.

16. A supercharger which can be driven by a motor, the supercharger comprising:

a rotor shaft;

a turbine wheel driven by exhaust gas discharged from an engine;

a compressor wheel coupled to the turbine wheel via the rotor shaft;

a vibration suppressing device of a supercharger as claimed in any one of claims 8 to 15.