Vibration / noise reduction device, electric compressor incorporating the vibration / noise reduction device, and vibration / noise reduction method

Abstract

Vibration / noise reduction device (100) for reducing vibration or noise of an electric compressor, the electric compressor (1, 1A) comprising: a rotating shaft (2); a compressor wheel (4) arranged on the rotary shaft (2); an electric motor (10) for applying a rotational force to the rotary shaft (2), the electric motor (10) comprising: a rotor (12) fixed to the rotating shaft (2); and a stator (14) arranged around the rotor (12) for applying the rotational force to the rotor (12) by an electromagnetic force, the vibration / noise reduction device (100) comprising: a detector (150) for detecting a frequency associated with a vibration of the stator (14); and a signal generator (102) for generating a vibration signal having a frequency of a predetermined integral multiple of an electrical angular frequency obtained from the frequency detected by the detector (150) and having a signal wave that dampens the vibration of the stator (14), and a vibrator (104, 104a, 104b) configured to vibrate the electric compressor based on the vibration signal generated by the signal generator (102); wherein the electric compressor further comprises: a motor housing (18) for accommodating the electric motor (10); and an inverter (50) for controlling an electrical frequency of an alternating current supplied to the stator (14), and wherein the inverter (50) is housed in an inverter housing space (26, 26A) formed within the motor housing (18), wherein the electric compressor (1, 1A) further includes a cover member (28) for covering an opening of the inverter housing space (26, 26A), and wherein the vibrator (104, 104a, 104b) is arranged on the cover element (28).

Description

TECHNICAL FIELDThe present disclosure relates to a vibration / noise reduction device, an electric compressor including the vibration / noise reduction device, and a vibration / noise reduction method.BACKGROUNDIt is desirable to reduce vibration / noise caused during operation of an electric compressor. The vibration / noise includes not only a vibration / noise caused by the rotation of a compressor wheel but also a vibration / noise caused by the vibration of a stator of an electric motor.According to the findings of the present inventors, it is apparent that, in the vibration / noise caused in the electric compressor / noise, the vibration / noise generated by the vibration of the stator of the electric motor is more dominant. Thus, in order to reduce the vibration / noise of the electric compressor, it is effective to reduce the vibration / noise generated by the vibration of the stator of the electric motor.In this regard, Patent Document 1 discloses a technique for reducing vibration / noise of the electric motor by installing a damping member between a stator disposed around a rotor of the electric motor and a housing for accommodating the stator to reduce vibration / noise of the electric motor in an electric motor used as a drive source for vehicle drive.List of Citer ListsPatent LiteraturePatent Document 1: JP 2006-166 554 A;Patent Document 2: EP 2 505 840 A2;Patent Document 3; EP 2 733 359 A1.Patent Document 2 is the closest prior art. Although this document discloses the feature "inverter", it does not disclose any details of the structural construction of the inverter and how it is accommodated in the housing.SUMMARYTechnical ProblemHowever, when the damping member is installed between the housing and the stator of the electric motor as in Patent Document 1 to reduce the vibration of the stator, it is difficult to transfer the heat generated from the stator to the housing, which may hinder the promotion of cooling (heat exchange) of the stator. As a result, the heat can be transmitted to a bearing and the like having low heat resistance.The present invention has been made in view of the above, and an object of the present invention is to provide a vibration / noise reduction device for reducing vibration / noise of an electric compressor without impairing coolability of a stator, an electric compressor including the vibration / noise reduction device, and a vibration / noise reduction method.Solution of the ProblemThe object is achieved by the features of claim 1, namely, by the features of the following configuration (1): A vibration / noise reduction device according to at least one embodiment of the present invention is a vibration / noise reduction device for reducing a vibration or a noise of an electric compressor, the electric compressor including a rotation shaft, a compressor wheel disposed on the rotation shaft, an electric motor for applying a rotational force to the rotation shaft, the electric motor including a rotor fixed to the rotation shaft, and a stator disposed around the rotor for applying the rotational force to the rotor by an electromagnetic force, the vibration / noise reduction device including a detector for detecting a frequency related to a vibration of the stator, and a signal generator for generating a vibration signal, having a frequency of a predetermined integral multiple of an electrical angular frequency obtained from the frequency detected by the detector and having a signal wave attenuating vibration of the stator and a vibrator configured to vibrate the electric compressor based on the vibration signal generated by the signal generator; wherein the electric compressor further includes: a motor housing for accommodating the electric motor; and an inverter for controlling an electrical frequency of an alternating current supplied to the stator, and wherein the inverter is accommodated in an inverter housing space formed inside the motor housing, wherein the electric compressor further includes a lid member for covering an opening of the inverter housing space, and wherein the vibrator (104, 104a, 104b) is disposed on the lid member.The object is also achieved by the features of claim 2, namely, by the features of the following configuration (2): a vibration / noise reduction device for reducing vibration or noise of an electric compressor, the electric compressor including a rotation shaft; a compressor wheel disposed on the rotation shaft; an electric motor for applying a rotational force to the rotation shaft, the electric motor including: a rotor fixed to the rotation shaft; and a stator disposed around the rotor for applying the rotational force to the rotor by an electromagnetic force, the vibration / noise reduction device comprising: a detector for detecting a frequency related to vibration of the stator; A signal generator for generating a vibration signal having a frequency of a predetermined integral multiple of an electrical angular frequency obtained from the frequency detected by the detector and having a signal wave attenuating vibration of the stator, and a vibrator configured to vibrate the electric compressor based on the vibration signal generated by the signal generator; wherein the electric compressor further includes: a motor housing for accommodating the electric motor; and an inverter for controlling an electrical frequency of an alternating current supplied to the stator, and wherein the inverter is accommodated in an inverter housing space formed inside the motor housing, and wherein the vibrator is disposed in the inverter housing space.The object is also achieved by the features of claim 3, namely, by the features of the following configuration (3): a vibration / noise reduction device for reducing vibration or noise of an electric compressor, the electric compressor including: a rotation shaft; a compressor wheel disposed on the rotation shaft; an electric motor for applying a rotational force to the rotation shaft, the electric motor including: a rotor fixed to the rotation shaft; and a stator disposed around the rotor for applying the rotational force to the rotor by an electromagnetic force, the vibration / noise reduction device including: a detector for detecting a frequency related to vibration of the stator; and a signal generator for generating a vibration signal having a frequency of a predetermined integral multiple of an electrical angular frequency obtained from the frequency detected by the detector and having a signal wave attenuating vibration of the stator, and a vibrator configured to vibrate the electric compressor based on the vibration signal generated by the signal generator; wherein the electric compressor further includes: a motor housing for accommodating the electric motor, an inverter for controlling an electrical frequency of an alternating current supplied to the stator; and an inverter case having an inverter housing space inside for accommodating the inverter, and the inverter case being coupled to the motor case via an elastic member, wherein the electric compressor further includes a lid member for covering an opening of the inverter housing space, and wherein the vibrator is disposed on the lid member.Finally, the object is achieved by the features of claim 4, namely, by the features of the following configuration (4): a vibration / noise reduction device for reducing vibration or noise of an electric compressor, the electric compressor including: a rotation shaft; a compressor wheel disposed on the rotation shaft; an electric motor for applying a rotational force to the rotation shaft, the electric motor including: a rotor fixed to the rotation shaft; and a stator disposed around the rotor for applying the rotational force to the rotor by an electromagnetic force, the vibration / noise reduction device including: a detector for detecting a frequency related to vibration of the stator; and a signal generator for generating a vibration signal having a frequency of a predetermined integral multiple of an electrical angular frequency obtained from the frequency detected by the detector and having a signal wave attenuating the vibration of the stator, and a vibrator configured to vibrate the electric compressor based on the vibration signal generated by the signal generator; wherein the electric compressor further includes: a motor housing for accommodating the electric motor, an inverter for controlling an electrical frequency of an alternating current supplied to the stator; and an inverter housing having an inverter housing space inside for accommodating the inverter, and wherein the inverter housing is coupled to the motor housing via an elastic member, and wherein the vibrator is disposed in the inverter housing space.With the above configuration (1), the electric compressor is applied with the vibration based on the vibration signal that is the predetermined integral multiple of the electrical angular frequency obtained from the frequency related to the vibration of the stator and has the signal wave that attenuates the vibration of the stator. In this way, it is possible to cancel the vibration / noise of the electric compressor resulting from the vibration of the stator by the vibration based on the vibration signal, and reduce the vibration / noise of the electric compressor. Therefore, it is no longer necessary to arrange a damping member for suppressing the vibration of the stator of the electric motor between the stator and the housing as before, or it is possible to reduce the thickness of the damping member to increase the capacity of the heat generated by the stator that is transmitted to the housing. Accordingly, it is possible to reduce the vibration / noise of the electric compressor without impairing the coolability of the stator.In the above configurations (1) and (2), the electric compressor further includes a motor housing for accommodating the electric motor and an inverter for regulating an electric frequency of an alternating current supplied to the stator, and the inverter is accommodated in an inverter housing space formed inside the motor housing.With the above configurations (1) and (2), in the structure where the electric motor and the inverter are housed inside the motor housing, it is possible to reduce the vibration / noise of the electric compressor.In the above configurations (3) and (4), the electric compressor includes a motor housing for accommodating the electric motor, an inverter for controlling an electric frequency of an alternating current supplied to the stator, and an inverter housing having an inverter housing space inside for accommodating the inverter, and the inverter housing is coupled to the motor housing via an elastic member.With the above configurations (3) and (4), even in the structure where the motor housing for accommodating the electric motor and the inverter housing for accommodating the inverter are coupled via the elastic member (so-called edge-cut structure), it is possible to reduce the vibration / noise of the electric compressor.In the above configurations (1) and (3), the electric compressor further includes a lid member for covering an opening of the inverter housing space, and the vibrator is disposed on the lid member.In general, the cover member of the electric compressor has a relatively small thickness as compared with the other members constituting the electric compressor, and causes a large vibration / noise. With the above configurations (1) and (3), since the vibrator is disposed on the lid member that causes the large vibration / noise, it is possible to effectively reduce the vibration / noise of the electric compressor based on the principle described in the above configuration (1).(5) In some embodiments, in any of the above configurations (1) and (3), the vibrator is disposed in the inverter housing space. In addition, in the configurations (2) and (4), the vibrator is always disposed in the inverter housing space.Thereby, it is possible to protect the vibrator from external water, dirt and the like. In addition, since the vibrator is disposed in the inverter housing space, a space where the vibrator is disposed outside the electric compressor is no longer required.(6) In some embodiments, in any of the above configurations (2) to (5), the signal generator is disposed in the inverter housing space in which the inverter is accommodated.With the above configuration (6), it is possible to protect the signal generator from external water, dirt, and the like. Moreover, it is possible to simplify the wiring between the signal generator and the vibrator when the vibrator is disposed in the inverter housing space.(7) In some embodiments, in any one of the above configurations (1) to (6), the detector is configured to detect the frequency related to the vibration of the stator based on the electrical frequency of the alternating current supplied to the stator.According to the findings of the present inventors, it is seen that the stator of the electric motor vibrates at a frequency corresponding to the electric frequency of the alternating current supplied to the stator. With the above configuration (7), since the frequency related to the vibration of the stator is detected based on the electrical frequency of the alternating current supplied to the stator, it is possible to detect the frequency related to the vibration of the stator even before the vibration / noise generated by the vibration of the stator is actually caused. Thus, it is possible to reduce the vibration / noise of the electric compressor more quickly than a case where the vibration / noise resulting from the vibration of the stator is detected by using a vibration sensor or a noise sensor.(8) In some embodiments, in the above configuration (7), the detector includes a frequency measuring instrument for measuring the electrical frequency of the alternating current supplied to the stator.With the above configuration (8), since the electric compressor is vibrated based on the vibration signal generated from the electric frequency of the alternating current supplied to the stator, it is possible to reduce the vibration / noise of the electric compressor arising from the vibration of the stator.(9) In some embodiments, in the above configuration (7), the detector includes a target value detection instrument for detecting a target value with respect to the electric frequency of the alternating current supplied to the inverter.With the above configuration (9) that detects the target value regarding the electric frequency of the alternating current input to the inverter, it is possible to detect the frequency related to the vibration of the stator even before the alternating current is generated in accordance with the target value in the inverter. Therefore, it is possible to quickly detect the frequency related to the vibration of the stator, as compared with the above configuration (8).(10) In some embodiments, in any one of the above configurations (1) to (9), the detector includes a vibration sensor configured to detect a frequency of vibration of the electric compressor.With the above configuration (10), it is possible to reduce the vibration / noise of the electric compressor because the frequency of the vibration of the electric compressor is detected and the detected vibration of the electric compressor is canceled based on the principle described in the above configuration (1).(11) In some embodiments, in any of the above configurations (1) to (10), the detector includes a noise sensor configured to detect a frequency of the noise caused by the electric compressor.With the above configuration (11), it is possible to reduce the vibration / noise of the electric compressor because the frequency of the noise caused by the electric compressor is detected and the detected noise of the electric compressor is canceled based on the principle described in the above configuration (1).(12) In some embodiments, in any one of the above configurations (1) to (11), the vibration signal includes a signal wave having an opposite phase to vibration of the stator.With the above configuration (12), it is possible to cancel the vibration / noise of the electric compressor arising from the vibration of the stator by the vibration based on the vibration signal, and reduce the vibration / noise of the electric compressor.(13) An electric compressor according to at least one embodiment of the present invention includes a rotating shaft, a compressor wheel disposed on the rotating shaft, an electric motor for applying a rotational force to the rotating shaft, the electric motor having a rotor fixed to the rotating shaft, and a stator disposed around the rotor for applying the rotational force to the rotor by an electromagnetic force, and the vibration / noise reduction device according to any one of the above configurations (1) to (12).With the above configuration (13), it is possible to provide the electric compressor in which the vibration / noise is reduced based on the principle described in the above configuration (1).(14) A vibration / noise reduction method according to at least one embodiment of the present invention is a vibration / noise reduction method for reducing vibration or noise of an electric compressor, the electric compressor including a rotating shaft, a compressor wheel disposed on the rotating shaft, an electric motor for applying a rotational force to the rotating shaft, the electric motor including a rotor fixed to the rotating shaft, and a stator disposed around the rotor for applying the rotational force to the rotor by an electromagnetic force, wherein the vibration / noise reduction method includes a step of detecting a frequency related to vibration of the stator, a step of generating a vibration signal having a frequency of a predetermined integral multiple of an electrical angular frequency obtained from the frequency, and a signal wave, which attenuates vibration of the stator, and includes a step of vibrating the electric compressor based on the vibration signal.With the above method (14), the electric compressor is applied with the vibration based on the vibration signal that is the predetermined integral multiple of the electrical angular frequency obtained from the frequency related to the vibration of the stator and has the signal wave that attenuates the vibration of the stator. In this way, it is possible to cancel the vibration / noise resulting from the vibration of the stator by the vibration based on the vibration signal, and reduce the vibration / noise of the electric compressor. Therefore, it is no longer necessary to arrange a damping member for suppressing the vibration of the stator of the electric motor between the stator and the housing as before, or it is possible to reduce the thickness of the damping member to increase the capacity of the heat generated by the stator that is transmitted to the housing. Accordingly, it is possible to reduce the vibration / noise of the electric compressor without impairing the coolability of the stator.(15) In some embodiments, in the above method (14), the step of detecting the frequency includes detecting the frequency based on an electrical frequency of an alternating current supplied to the stator.According to the findings of the present inventors, it is seen that the stator of the electric motor vibrates at a frequency corresponding to the electric frequency of the alternating current supplied to the stator. With the above method (15), since the frequency related to the vibration of the stator is detected based on the electric frequency of the alternating current supplied to the stator, it is possible to detect the frequency related to the vibration of the stator even before the vibration / noise caused by the vibration of the stator is caused. Therefore, it is possible to reduce the vibration / noise of the electric compressor more quickly than a case where the vibration / noise generated by the vibration of the stator is detected with a vibration sensor or a noise sensor.Advantageous EffectsAccording to some embodiments of the present invention, it is possible to reduce vibration / noise of an electric compressor without impairing coolability of a stator.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a schematic configuration view of an electric compressor according to an embodiment of the present invention. FIG. 2 is a schematic configuration view of an electric compressor according to another embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line A-A of the electric motor in FIGS. 1 and 2. FIG. 4 is a block diagram showing the configuration of a vibration / noise reduction device according to an embodiment of the present invention. FIG. 5 is a diagram for describing a flow in which a signal generator generates a vibration signal according to an embodiment of the present invention. FIG. 6 is a diagram for describing the vibration signal generated by the signal generator according to an embodiment of the present invention. FIG. 7 shows analysis diagrams obtained by performing electromagnetic field response analysis of the electric compressor according to an embodiment of the present invention. FIG. 8A is a functional block diagram for describing a flow in which vibration / noise of the electric compressor is reduced by using a frequency measurement instrument according to an embodiment of the present invention. FIG. 8B is a functional block diagram for describing a flow in which vibration / noise of the electric compressor is reduced by using a target value detection instrument according to an embodiment of the present invention. FIG. 8C is a functional block diagram for describing a flow in which vibration / noise of the electric compressor is reduced by using a vibration sensor according to an embodiment of the present invention. FIG. 8D is a functional block diagram for describing a flow in which vibration / noise of the electric compressor is reduced by using a noise sensor according to an embodiment of the present invention. FIG. 9 is a flowchart of a vibration / noise reduction method according to an embodiment of the present invention.DETAILED DESCRIPTIONEmbodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, the scope of the present invention is not limited to the following embodiments. It is intended that dimensions, materials, shapes, relative positions, and the like of components described in the embodiments be understood as illustrative only and not intended to limit the scope of the present invention.< Configuration of Electric Compressor>FIG. 1 is a schematic configuration view of an electric compressor according to an embodiment of the present invention. FIG. 2 is a schematic configuration view of an electric compressor according to another embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line A-A of the electric motor shown in FIGS. 1 and 2. FIG. 4 is a block diagram showing the configuration of a vibration / noise reduction device according to an embodiment of the present invention. FIG. 5 is a functional block diagram showing a flow in which a signal generator generates a vibration signal according to an embodiment of the present invention. FIG. 6 is a diagram for describing the vibration signal generated by the signal generator according to an embodiment of the present invention.As shown in FIGS. 1 and 2, an electric compressor 1, 1A includes a rotary shaft 2, a compressor wheel 4 disposed on the rotary shaft 2, and an electric motor 10 for applying a rotational force to the rotary shaft 2.The rotary shaft 2 is rotatably supported by a bearing 3 and has an end at which the compressor wheel 4 is disposed. The rotary shaft 2 is inserted through a bore 4a formed in the compressor wheel 4 and is fixed to the compressor wheel 4 by a nut 22. At another end of the rotating shaft 2, a pre-compression applying member 24 is disposed to prevent the rotating shaft 2 from swinging.The compressor wheel 4 is accommodated in a compressor housing 20. The compressor wheel 4 is configured to rotate with the rotary shaft 2 when the electric motor 10 applies the rotational force to the rotary shaft 2, and to compress air.The configuration of the electric motor 10 will be described with reference to FIG. 3. As illustrated in FIG. 3, the electric motor 10 includes a rotor 12 fixed to the rotary shaft 2, and stators 14 arranged separately from each other around the rotor 12 to apply the rotational force to the rotor 12 by an electromagnetic force. In the embodiment shown, the electric motor 10 is designed as a four-pole motor. The stators 14 are each wound around with a stator coil 16. By passing an alternating current through the stator coil 16, a voltage (excitation voltage) is applied to the stator 14 and generates a magnetic field. The rotor 12 is, for example, a permanent magnet, and is configured to rotate by the magnetic field generated by the stator 14.With reference to FIGS. 1 and 2, the configuration of the electric compressor 1, 1A will be described. As shown in FIGS. 1 and 2, the electric compressor 1, 1A may further include a motor housing 18 in which a motor housing space 17 for accommodating the electric motor 10 is formed. In the embodiments shown in FIGS. 1 and 2, the motor housing 18 accommodates the electric motor 10 in the motor housing space 17 so as to be in contact with an outer circumferential surface of the stator 14 of the electric motor 10. In addition, the motor housing 18 is connected to the compressor housing 20 described above on a side opposite to an inverter housing space 26 to be described later. Further, in the motor housing 18, a cooling passage 15 through which a cooling medium such as cooling water flows may be formed.In addition, the electric compressor 1, 1A includes an inverter 50 connected to the stator coil 16 to regulate an electric frequency of the alternating current supplied to the stator 14 (the current flowing through the stator coil 16). The inverter 50 receives a command value (armature current command value) regarding an electric frequency of an alternating current output from an ECU 40 installed outside the electric compressor 1, 1A, and converts a direct current into an alternating current based on the received armature current command value. The armature current command value may be determined based on an armature current command value map (not shown) preset in the ECU 40 when the electric compressor 1, 1A is disposed in a vehicle, for example. The armature current command value map is a map in which the armature current command value is associated with a request torque, and when the request torque is input to the map, the armature current command value corresponding thereto is output. The armature current command value may include a command value relating to a current value of the alternating current in addition to the command value relating to the electric frequency of the alternating current.In the embodiment shown in FIG. 1, the inverter 50 is accommodated in the inverter housing space 26 formed inside the motor housing 18. The inverter housing space 26 is formed inside the motor housing 18 as another space different from the motor housing space 17. That is, in the embodiment shown in FIG. 1, unlike the embodiment shown in FIG. 2, the motor housing space 17 for accommodating the electric motor 10 and the inverter housing space 26 for accommodating the inverter 50 are formed separately from each other within the same housing (motor housing 18).On the other hand, in the embodiment shown in FIG. 2, the inverter 50 is accommodated in an inverter housing space 26A formed inside an inverter housing 32. The inverter housing 32 is coupled to the motor housing 18 to be positioned opposite to the compressor housing 20 opposite to the motor housing 18. The inverter case 32 is coupled to the motor case 18 via an elastic member 30 formed of an elastic material such as a synthetic resin. That is, in the embodiment shown in FIG. 2, unlike the embodiment shown in FIG. 1, the housing (motor housing 18) in which the motor housing space 17 for accommodating the electric motor 10 is formed and the housing (inverter housing 32) in which the inverter housing space 26A for accommodating the inverter 50 is formed are configured separately from each other. With the configuration of the electric compressor 1A shown in FIG. 2, since the inverter housing 32 is coupled to the motor housing 18 via the elastic member 30, the vibration of the stator 14 is less transmitted to a cover member 28 to be described later.Meanwhile, according to the findings of the present inventors, it is seen that, as a / a vibration / noise caused in the electric compressor 1, 1A, a vibration / a noise resulting from the vibration of the stator 14 is dominant. The vibration of the stator 14 is caused by a periodic change in the magnetic attractive force associated with the rotation of the rotor 12. In addition, when the stator coil 16 is energized, Joule heat is generated in the stator 14. When the stator 14 is heated, heat is dissipated to the environment, which may adversely affect the bearing 3 and the inverter 50. Therefore, it is necessary to cool the stator 14. Next, a vibration / noise reduction device 100 for reducing the vibration / noise of the electric compressor 1, 1A without impairing the coolability of the stator 14 will be described.As illustrated in FIG. 4, the vibration / noise reduction device according to an embodiment of the present invention includes a detector 150, a signal generator 102, and a vibrator 104.The detector 150 detects a frequency related to the vibration of the stator 14. the "frequency related to the vibration of the stator" includes not only a frequency of the vibration itself of the stator 14 but also frequencies other than the vibration of the stator 14 (such as the electric frequency of the alternating current supplied to the stator 14, a frequency of the vibration in the electric compressor 1, 1A, and a frequency of the noise caused by the electric compressor 1, 1A, which will be described later) capable of deriving the frequency of the vibration itself of the stator 14.The signal generator 102 generates a vibration signal having a frequency of a predetermined integral multiple of an electrical angular frequency ω obtained by executing a predetermined process on the frequency detected by the detector 150, and a signal wave attenuating the vibration of the stator 14. Here, the "electrical angular frequency ω" is a frequency of vibration itself of the stator 14 caused by the periodic change in the magnetic attractive force in association with the rotation of the rotor 12. The vibration signal will be described later.Next, the flow in which the signal generator 102 generates the vibration signal will be described with reference to FIG. 5. As shown in FIG. 5, the vibration signal generator 102 detects the frequency related to the vibration of the stator 14 detected by the detector 150. Then, the signal generator 102 calculates a vibration force F acting on the electric compressor 1, 1A using: where F is the vibration force, G is a magnitude of a gain, α is a vibration order of a damping object, ω is the electrical angular frequency, and t is a time component. G is a parameter corresponding to the magnitude of the vibration force in the vibration signal. It may be configured such that G obtains a value of a gain preset to cancel vibration / noise caused in a possible operation state, or a value of a gain optimum for canceling vibration / noise changing according to an actual operation state is constantly calculated, and G obtains the calculated value. α is a predetermined integral value that can be calculated by performing eigenvalue analysis or the like for the electric compressor 1, 1A.Next, the vibration signal generated by the signal generator 102 will be described with reference to FIG. 6. In FIG. 6, the abscissa indicates time, and the ordinate indicates magnitude of amplitude. A signal wave W 1, which is indicated by a solid line, is a wave having a frequency of a predetermined integral multiple of the electrical angular frequency ω, and a signal wave W 2, which is indicated by a dotted line, is a wave having a phase opposite to the signal wave W 1. In addition, a signal wave W 3 indicated by a single-dotted chain line is a wave having a phase shifted by a phase difference Δ relative to the signal wave W 2.As shown in FIG. 6, the signal generator 102 generates a vibration signal having the frequency of the predetermined integral multiple of the electrical angular frequency ω and the signal wave (W 2, W 3) that suppresses the vibration of the stator 14. The signal wave W 2 is the wave having the opposite phase to the vibration of the stator 14, and the signal wave W 3 is the wave having the phase shifted by the phase difference Δ relative to the signal wave W 2. It is only necessary that the phase difference Δ falls within a range in which an effect of reducing the vibration / noise of the electric compressor 1, 1A is obtained, and more specifically, within a range (phase adjustment range) of -π / 4<Δ<π / 4 when the electric compressor 1, 1A is vibrated by the vibrator 104 which will be described later.The vibrator 104 is configured to vibrate the electric compressor 1, 1A based on the vibration signal generated by the signal generator 102. A device to be used as the vibrator 104 is not particularly limited as long as the device can periodically vibrate the electric compressor 1, 1A. For example, it is possible to use a damping device for generating a periodic vibration by an electromagnetic force or a damping device for generating a periodic vibration by a piezoelectric element.In view of the above, with the configuration of the vibration / noise reduction device 100 according to an embodiment of the present invention, the electric compressor 1, 1A is applied with the vibration based on the vibration signal that is the predetermined integral multiple of the electrical angular frequency ω obtained from the frequency related to the vibration of the stator 14 and has the signal wave that suppresses the vibration of the stator 14. Thus, it is possible to cancel the vibration / noise resulting from the vibration of the stator 14 by the vibration based on the vibration signal, and reduce the vibration / noise of the electric compressor 1, 1A. Therefore, it is no longer necessary to arrange the damping member for suppressing the vibration of the stator 14 of the electric motor 10 between the stator 14 and the motor housing 18 as before, or it is possible to reduce the thickness of the damping member to increase the capacity of the heat generated by the stator 14 that is transmitted to the motor housing 18. Accordingly, it is possible to reduce the vibration / noise of the electric compressor 1, 1A without impairing the coolability of the stator 14.Moreover, in the configuration of the electric compressor 1, 1A shown in FIGS. 1 and 2, since the electric compressor 1, 1A includes the vibration / noise reduction device 100, it is possible to provide the electric compressor 1, 1A with reduced vibration / noise.Further, with the configuration of the electric compressor 1 shown in FIG. 1, it is possible to reduce the vibration / noise of the electric compressor 1 even in the structure in which the electric motor 10 and the inverter 50 are accommodated inside the motor housing 18. Further, in the configuration of the electric compressor 1A shown in FIG. 2, it is possible to reduce the vibration / noise of the electric compressor 1A, even in the structure in which the motor housing 18 for accommodating the electric motor 10 and the inverter housing 32 for accommodating the inverter 50 are coupled via the elastic member 30 (so-called edge cut structure).In some embodiments, as shown in FIGS. 1 and 2, the electric compressor 1, 1A further includes a lid member 28 for covering an opening of the inverter housing space 26, 26A. Then, the vibrator 104 includes a first vibrator 104a disposed on the lid member 28.The lid member 28 has a planar shape and is configured to have a small thickness (axial length of the rotary shaft 2 in the embodiments shown in FIGS. 1 and 2, respectively) so that the overall dimension of the electric compressor 1, 1A is small. The lid member 28 covers the opening of the inverter housing space 26, 26A, and thus the inverter housing space 26, 26A is a closed space.FIG. 7 shows analysis diagrams obtained by performing electromagnetic field response analysis of the electric compressor according to an embodiment of the present invention. FIG. 7 shows the analysis diagrams in which the vibration orders are second-order, fourth-order, sixth-order, and eighth-order rotations, respectively. Moreover, FIG. 7 illustrates the shift caused by the vibration of the stator 14 in the electric compressor 1, 1A by shading, and the shift caused by the vibration of the stator 14 increases the darker a color is.As a result of analyzing a vibration mode of the electric compressor 1, as shown in FIG. 7, among the vibrations transmitted from the stator 14 and caused in the lid member 28, a vibration component of the fourth-order rotation is larger than the vibration components of the other vibration modes. Therefore, when the first vibrator 104 ais disposed on the lid member 28 and has the fourth-order rotation vibration mode as a damping object, it is possible to effectively reduce the vibration / noise of the lid member 28. Moreover, among the vibrations transmitted from the stator 14 and caused in the compressor housing 20, a vibration component of the second-order rotation is larger than the vibration components of the other vibration modes. Therefore, when a second vibrator 104 bis disposed on the compressor housing 20 having the vibration mode of the second-order rotation as a damping object, it is possible to effectively reduce the vibration / noise of the compressor housing 20. Specifically, the lid member 28 has a relatively small thickness as compared with the other members constituting the electric compressor 1, 1A, and thus is a main source in which vibration / noise is caused in the electric compressor 1, 1A.With such a configuration, since the first vibrator 104 ais disposed on the lid member 28 that causes the large vibration / noise, the vibration based on the vibration signal is directly applied to the lid member 28, whereby it is possible to effectively reduce the vibration / noise of the electric compressor 1, 1A.Moreover, when the vibrator 104 is disposed on the member such as the above-described lid member 28 or the compressor housing 20, it is preferably disposed at a position of the large displacement member. It is possible to confirm which kind of displacement occurs at each position of the electric compressor 1, 1A by a method such as the electromagnetic field response analysis, the hammer impact measurement, or the eigenvalue analysis.Moreover, it is preferable that the eigenvalue analysis is performed on the electric compressor 1, 1A and the vibrator 104 is disposed at a position of an antinode (maximum displacement position) of the vibration in the vibration mode of the damping object. The position of the antinode of the vibration in the vibration mode of the damping object is a portion that is most affected by the vibration of the stator 14, and is, for example, an antinode 28 a(a darkest color portion) of the lid member 28 when the fourth-order vibration mode illustrated in FIG. 7 is the damping object. With such a configuration, it is possible to more effectively reduce the vibration / noise of the electric compressor 1, 1A.In some embodiments, as shown in FIGS. 1 and 2, the first vibrator 104 ais disposed in the inverter housing space 26, 26A. With such a configuration, it is possible to protect the first vibrator 104 afrom external water, dirt, and the like. Moreover, a space in which the first vibrator 104 ais disposed outside the electric compressor 1, 1A is no longer required.In some embodiments, as in FIGS. 1 and 2, the signal generator 102 is disposed in the inverter housing space 26, 26A. With such a configuration, it is possible to protect the signal generator 102 from external water, dirt, and the like. Moreover, it is possible to simplify the wiring between the signal generator 102 and the first vibrator 104 a.In some embodiments, the detector 150 is configured to detect the frequency related to the vibration of the stator 14 based on the electrical frequency of the alternating current supplied to the stator 14.In general, it is known that a synchronous speed (a rotation speed at which the stator 14 rotates the rotor 12) when the alternating current is supplied to the stator 14 is obtained by using: where Ns is a rotation speed (rotation speed / min), f is the electric frequency (Hz) of the alternating current supplied to the stator 14, and P is the number of poles of the stator 14. As described above, the vibration of the stator 14 is caused by the periodic change in the magnetic attractive force associated with the rotation of the rotor 12. Thus, when the detector 150 detects the electric frequency of the alternating current, the rotational speed Ns of the rotor 12 is calculated from the electric frequency of the alternating current. Then, it is possible to calculate the electrical angular frequency ω from the rotational speed Ns of the rotor 12 using: which is modified by substituting the electrical angular frequency ω / 2π into the electrical frequency f of the alternating current in Equation (2).According to the findings of the present inventors, it is seen that the stator 14 of the electric motor 10 vibrates at a frequency corresponding to the electric frequency of the alternating current supplied to the stator 14. Thus, with the configuration in which the detector 150 detects the frequency related to the vibration of the stator 14 based on the electric frequency of the alternating current supplied to the stator 14, the detector 150 can detect the frequency related to the vibration of the stator 14 even before the vibration / noise generated by the vibration of the stator 14 is actually caused. Thereby, it is possible to reduce the vibration / noise of the electric compressor 1, 1A more quickly than a case where the vibration / noise generated by the vibration of the stator 14 is detected using a vibration sensor 156 or a noise sensor 158 described later.Next, a description will be given of a procedure in which the vibration / noise of the electric compressor is reduced with reference to FIGS. 8A to 8D. FIG. 8A is a functional block diagram for describing a flow in which vibration / noise of the electric compressor is reduced by using a frequency measurement instrument according to an embodiment of the present invention. FIG. 8B is a functional block diagram for describing a flow in which vibration / noise of the electric compressor is reduced by using a target value detection instrument according to an embodiment of the present invention. FIG. 8C is a functional block diagram for describing a flow in which the vibration / noise of the electric compressor is reduced by using the vibration sensor according to an embodiment of the present invention. FIG. 8D is a functional block diagram for describing a flow in which vibration / noise of the electric compressor is reduced by using the noise sensor according to an embodiment of the present invention. FIGS. 8A to 8D exemplarily show a case where the vibration / noise of the lid member 28 of the electric compressor 1, 1A is reduced.In some embodiments, the detector 150 is a frequency measurement instrument 152 for measuring the electrical frequency of the alternating current supplied to the stator 14. In the embodiments shown in FIGS. 1 and 2, the frequency measuring instrument 152 is disposed near the output of the inverter 50, and measures the electric frequency of the alternating current immediately after it is converted into the alternating current by the inverter 50.As illustrated in FIG. 8A, the inverter 50 detects an armature current command value output from the ECU 40, converts a direct current supplied from a battery (not illustrated) into an alternating current, and supplies the converted alternating current to the stator 14. The vibration of the stator 14 is transmitted to the surroundings (e.g., the cover member 28) of the stator 14.The frequency measuring instrument 152 measures the electrical frequency of the alternating current supplied to the stator 14. The signal generator 102 generates the vibration signal based on the electrical angular frequency ω obtained by performing a predetermined process (such as Fourier transform) on a measurement value of the electrical frequency of the alternating current measured by the frequency measurement instrument 152. The first vibrator 104a vibrates the lid member 28 based on the vibration signal generated from the signal generator 102.In such a configuration, the frequency measurement instrument 152 detects the frequency associated with the vibration of the stator 14 based on the electrical frequency of the alternating current supplied to the stator 14. Thus, it is possible to detect the frequency related to the vibration of the stator 14 even before the vibration / noise generated by the vibration of the stator 14 is actually caused (feedforward control). Further, since the lid member 28 (electric compressor 1, 1A) is vibrated based on the vibration signal generated from the measurement value of the electric frequency of the alternating current supplied to the stator 14, it is possible to reduce the vibration / noise of the electric compressor 1, 1A generated by the vibration of the stator 14.In some embodiments, the detector 150 is a target value detection instrument 154 disposed in the inverter 50 to detect a target value (armature current target value) with respect to the electrical frequency of the alternating current supplied to the inverter 50.As shown in FIG. 8B, the target value detection instrument 154 detects the armature current target value output from the ECU 40, and calculates the frequency of the alternating current from the armature current target value. The signal generator 102 generates the vibration signal based on the electrical angular frequency ω obtained by executing the predetermined process (equation (2)) on the electrical frequency of the alternating current calculated by the target value detection instrument 154. The first vibrator 104a vibrates the lid member 28 based on the vibration signal generated from the signal generator 102. The flow until the vibration of the stator 14 is transmitted to the lid member 28 by the armature current command value output from the ECU 40 is common to the flow shown in FIG. 8A, so a description thereof will be omitted.In such a configuration, the target value detection instrument 154 detects the frequency related to the vibration of the stator 14 based on the electrical frequency of the alternating current supplied to the stator 14. Thus, it is possible to detect the frequency related to the vibration of the stator 14 even before the vibration / noise caused by the vibration of the stator 14 is actually caused (feedforward control). Moreover, by detecting the armature current command value output from the ECU 40, it is possible to detect the frequency related to the vibration of the stator 14 even before the alternating current is generated in accordance with the armature current command value in the inverter 50. Therefore, it is possible to quickly detect the frequency associated with the vibration of the stator 14 as compared with the case where the frequency measurement instrument 152 is used.In some embodiments, the detector 150 is the vibration sensor 156 configured to detect the frequency of vibration of the electric compressor 1, 1A. In the embodiments shown in FIGS. 1 and 2, the vibration sensor 156 includes a first vibration sensor 156 adisposed so as to be in contact with the lid member 28 in the inverter housing space 26, 26A. The first vibration sensor 156 amay be disposed adjacent to the first vibrator 104 ato detect the vibration of the lid member 28 vibrated by the first vibrator 104 a.As shown in FIG. 8C, the signal generator 102 generates the vibration signal on the basis of the electrical angular frequency ω obtained by executing the predetermined process such as Fourier transform on the frequency of vibration of the lid member 28 detected by the first vibration sensor 156 a. The first vibrator 104a vibrates the lid member 28 based on the vibration signal generated from the signal generator 102. The flow until the vibration of the stator 14 is transmitted to the lid member 28 by the armature current command value output from the ECU 40 is common to the flow shown in FIG. 8A, so a description thereof will be omitted.With such a configuration, since the first vibrator 104 a vibrates the lid member 28 to cancel the vibration of the lid member 28 detected by the first vibration sensor 156 a, it is possible to reduce the vibration / noise of the electric compressor 1, 1A (feedback control).In some embodiments, the detector 150 is the noise sensor 158 configured to detect the frequency of the noise caused by the electric compressor 1, 1A. In the embodiments shown in FIGS. 1 and 2, respectively, the noise sensor 158 includes a first noise sensor 158 adisposed on the lid member 28 in the inverter housing space 26, 26A.As shown in FIG. 8D, the signal generator 102 generates the vibration signal on the basis of the electrical angular frequency ω obtained by executing the predetermined process such as Fourier transform on the frequency of the sound of the lid member 28 detected by the first sound sensor 158 a. The first vibrator 104a vibrates the lid member 28 based on the vibration signal generated from the signal generator 102. The flow until the vibration of the stator 14 is transmitted to the lid member 28 by the armature current command value output from the ECU 40 is common to the flow shown in FIG. 8A, so a description thereof will be omitted.With such a configuration, since the first vibrator 104 amends the lid member 28 to vibrate to cancel the sound of the lid member 28 detected by the first sound sensor 158 a, it is possible to reduce the vibration / sound of the electric compressor 1, 1A (feedback control).In some embodiments, as shown in FIGS. 1 and 2, the vibrator 104 includes the second vibrator 104 bdisposed on the compressor housing 20. In the embodiments shown in FIGS. 1 and 2, respectively, the second vibrator 104 bis disposed outside the electric compressor 1, 1A. With such a configuration, it is possible to directly apply the vibration to the compressor housing 20 based on the vibration signal and reduce the vibration / noise of the electric compressor 1, 1A.In some embodiments, as shown in FIGS. 1 and 2, the vibration sensor 156 includes a second vibration sensor 156 bdisposed outside the electric compressor 1, 1A and disposed to be in contact with the compressor housing 20. In such a configuration, the vibration signal for canceling the vibration of the compressor housing 20 is generated by the signal generator 102, and the vibration based on the vibration signal is applied to the compressor housing 20 by the vibrator 104 (second vibrator 104 b). Thereby, it is possible to reduce the vibration / noise of the electric compressor 1, 1A. The second vibration sensor 156 bmay be disposed adjacent to the second vibrator 104 bto detect the vibration of the compressor housing 20 vibrated by the second vibrator 104 b.In some embodiments, as shown in FIGS. 1 and 2, the noise sensor 158 includes a second noise sensor 158 bdisposed outside the electric compressor 1, 1A and disposed near the lid member 28 so as to be able to detect the noise caused by the lid member 28. Moreover, the noise sensor 158 includes a third noise sensor 158c disposed outside the electric compressor 1, 1A and disposed near the compressor housing 20 to be able to detect the noise caused by the compressor housing.In the configuration in which the noise sensor 158 includes the second noise sensor 158 b, the vibration signal for canceling the noise of the lid member 28 is generated by the signal generator 102, and the vibration based on the vibration signal is applied to the lid member 28 by the vibrator 104 (first vibrator 104 a). In this way, it is possible to reduce the vibration / noise of the electric compressor 1, 1A. In addition, in such a configuration that the noise sensor 158 includes the third noise sensor 158 c, the vibration signal for canceling the noise of the compressor housing 20 is generated by the signal generator 102, and the vibration based on the vibration signal is applied to the compressor housing 20 by the vibrator 104 (second vibrator 104 b). Thereby, it is possible to reduce the vibration / noise of the electric compressor 1, 1A.In the embodiments shown in FIGS. 1 and 2, respectively, the electric compressor 1, 1A includes the four detectors 150 (frequency measuring instrument 152, target value detecting instrument 154, vibration sensor 156, noise sensor 158). However, the present invention is not limited to such an embodiment, and the electric compressor 1, 1A may be configured to include only the frequency measurement instrument 152, or may be configured to include the target value detection instrument 154 and the vibration sensor 156, for example. Further, although the description has been given taking the case where the electric motor 10 has four poles as an example, the present invention is not limited to such an embodiment, and, for example, the electric motor 10 may have two poles or six poles.Moreover, an elastic member (not illustrated) may be disposed between the electric motor 10 and the motor housing 18 (that is, the stator 14 and the motor housing 18 may not be directly in contact). In this case, it is possible to reduce a thickness relative to the elastic member (damping member) disposed in the conventional electric compressor 1, 1A. Accordingly, it is possible to increase the capacity of the heat generated by the stator 14 to transfer it to the motor housing 18 and reduce the vibration / noise of the electric compressor 1, 1A without impairing the coolability of the stator 14.< / Noise Reduction Method>Next, a vibration / noise reduction method according to an embodiment of the present invention will be described with reference to FIG. 9. FIG. 9 is a flowchart of the vibration / noise reduction method according to an embodiment of the present invention.As shown in FIG. 9, the vibration / noise reduction method according to an embodiment of the present invention includes a step (detection step S 1) of detecting the frequency related to the vibration of the stator 14, a step (signal generation step S 2) of generating the vibration signal having the frequency of the predetermined integral multiple of the electrical angular frequency ω obtained from the frequency and having the signal wave attenuating the vibration of the stator 14, and a step (vibration step S 3) of vibrating the electric compressor 1, 1A based on the vibration signal.In such a vibration / noise reduction method, the electric compressor 1, 1A is applied with the vibration on the basis of the vibration signal that is the predetermined integral multiple of the electrical angular frequency ω obtained from the frequency related to the vibration of the stator 14 and has the signal wave that suppresses the vibration of the stator 14. Thus, it is possible to cancel the vibration / noise resulting from the vibration of the stator 14 by the vibration based on the vibration signal, and reduce the vibration / noise of the electric compressor 1, 1A. Therefore, it is no longer necessary to arrange the damping member between the stator 14 and the motor housing 18 for suppressing the vibration of the stator 14 of the electric motor 10 as before, or it is possible to reduce the thickness of the damping member to increase the capacity of the heat generated by the stator 14 that is transmitted to the motor housing 18. Accordingly, it is possible to reduce the vibration / noise of the electric compressor 1, 1A without impairing the coolability of the stator 14.In some embodiments, the detecting step S 1 includes detecting the frequency related to the vibration of the stator 14 based on the electrical frequency of the alternating current supplied to the stator 14.In such a vibration / noise reduction method, since the frequency related to the vibration of the stator 14 is detected based on the electric frequency of the alternating current supplied to the stator 14, it is possible to perform so-called feedforward control and detect the frequency related to the vibration of the stator 14 even before the vibration / noise resulting from the vibration of the stator 14 is caused.In some embodiments, the detection step S 1 includes detecting the frequency related to the vibration of the stator 14, by detecting the frequency of the vibration of the electric compressor 1, 1A, or by detecting the frequency of the noise caused by the electric compressor 1, 1A.In such a vibration / noise reduction method, the frequency related to the vibration of the stator 14 is detected from the frequency of the vibration or the frequency of the noise of the electric compressor 1, 1A, whereby it is possible to reduce the vibration / noise actually caused of the electric compressor 1, 1A.In some embodiments, the magnitude of the vibration (vibration force F) (the magnitude of the above-described gain G) applied to the electric compressor 1, 1A may be adjusted in accordance with the magnitude of the vibration of the stator 14 predicted from a current value of the alternating current supplied to the stator 14. Thereby, it is possible to determine the magnitude of the vibration force F capable of canceling the vibration of the electric compressor 1, 1A in accordance with an operating state of the electric compressor 1, 1A in the forward direction. The current value of the alternating current supplied to the stator 14 may be detected from the armature current command value output from the ECU 40 or a current value of the alternating current converted by the inverter 50.In some embodiments, the magnitude of the vibration (vibration force F) (the magnitude of the above-described gain G) applied to the electric compressor 1, 1A may be adjusted by inputting a target vibration value preset to be capable of canceling the vibration / noise caused by the electric compressor 1, 1A in a possible operation state to the signal generator 102, and detecting a difference between the target vibration value and the vibration of the electric compressor 1, 1A measured by the vibration sensor 156. Also, the magnitude of the vibration (vibration force F) (the magnitude of the above-described gain G) applied to the electric compressor 1, 1A can be adjusted by inputting a target sound value preset to be capable of canceling the vibration / sound caused by the electric compressor 1, 1A in the possible operation state to the signal generator 102 and detecting a difference between the target sound value and the sound of the electric compressor 1, 1A measured by the sound sensor 158. In this way, it is possible to decide feedback, depending on a change in the operating state of the electric compressor 1, 1A, the magnitude of the vibrating force F suitable for canceling the vibration / noise of the electric compressor 1, 1A.The vibration / noise reduction device, the electric compressor including the vibration / noise reduction device, and the vibration / noise reduction method according to an embodiment of the present invention have been described above. However, the present invention is not limited to the above-described embodiment, and various modifications may be made within a range without departing from the subject matter of the present invention.Reference Character List1, 1A electric compressor 2 rotary shaft 3 bearing 4 compressor wheel 10 electric motor 12 rotor 14 stator 15 cooling passage 16 stator coil 17 motor housing space 18 motor housing 20 compressor housing 22 nut 24 pre-compression application member 26, 26A inverter housing space 28 lid member 30 elastic member 32 inverter housing 50 inverter 100 vibration / noise reduction device 102 signal generator 104 vibrator 150 detector 152 frequency measurement instrument 154 target value detection instrument 156 vibration sensor 158 noise sensor S 1 detection step S 2 signal generation step S 3 vibration step

Claims

A vibration / noise reduction device (100) for reducing vibration or noise of an electric compressor, the electric compressor (1, 1A) including: a rotation shaft (2); a compressor wheel (4) disposed on the rotation shaft (2); an electric motor (10) for applying a rotational force to the rotation shaft (2), the electric motor (10) including: a rotor (12) fixed to the rotation shaft (2); and a stator (14) disposed around the rotor (12) for applying the rotational force to the rotor (12) by an electromagnetic force, the vibration / noise reduction device (100) comprising: a detector (150) for detecting a frequency related to vibration of the stator (14); and a signal generator (102) for generating a vibration signal having a frequency of a predetermined integral multiple of an electrical angular frequency obtained from the frequency detected by the detector (150) and having a signal wave attenuating the vibration of the stator (14), and a vibrator (104, 104a, 104b) configured to vibrate the electric compressor based on the vibration signal generated by the signal generator (102); wherein the electric compressor further includes: a motor housing (18) for housing the electric motor (10); and an inverter (50) for controlling an electric frequency of an alternating current supplied to the stator (14), and wherein the inverter (50) is accommodated in an inverter housing space (26, 26A) formed inside the motor housing (18), wherein the electric compressor (1, 1A) further includes a lid member (28) for covering an opening of the inverter housing space (26, 26A), and wherein the vibrator (104, 104a, 104b) is disposed on the lid member (28).A vibration / noise reduction device (100) for reducing vibration or noise of an electric compressor (1, 1A), the electric compressor (1, 1A) including: a rotation shaft (2); a compressor wheel (4) disposed on the rotation shaft (2); an electric motor (10) for applying a rotational force to the rotation shaft (2), the electric motor (10) including: a rotor (12) fixed to the rotation shaft (2); and a stator (14) disposed around the rotor (12) for applying the rotational force to the rotor (12) by an electromagnetic force, the vibration / noise reduction device (100) comprising: a detector (150) for detecting a frequency related to vibration of the stator (14); and a signal generator (102) for generating a vibration signal having a frequency of a predetermined integral multiple of an electrical angular frequency obtained from the frequency detected by the detector (150) and having a signal wave attenuating the vibration of the stator (14), and a vibrator (104, 104a, 104b) configured to vibrate the electric compressor (1, 1A) based on the vibration signal generated by the signal generator (102); wherein the electric compressor (1, 1A) further includes: a motor housing (18) for housing the electric motor (10); and an inverter (50) for controlling an electric frequency of an alternating current supplied to the stator (14), and wherein the inverter (50) is accommodated in an inverter housing space (26, 26A) formed inside the motor housing (18), and wherein the vibrator (104, 104a, 104b) is disposed in the inverter housing space (26, 26A).A vibration / noise reduction device (100) for reducing vibration or noise of an electric compressor, the electric compressor (1, 1A) including: a rotation shaft (2); a compressor wheel (4) disposed on the rotation shaft (2); an electric motor (10) for applying a rotational force to the rotation shaft (2), the electric motor (10) including: a rotor (12) fixed to the rotation shaft (2); and a stator (14) disposed around the rotor (12) for applying the rotational force to the rotor (12) by an electromagnetic force, the vibration / noise reduction device (100) comprising: a detector (150) for detecting a frequency related to vibration of the stator (14); and a signal generator (102) for generating a vibration signal having a frequency of a predetermined integral multiple of an electrical angular frequency obtained from the frequency detected by the detector (150) and having a signal wave attenuating the vibration of the stator (14), and a vibrator (104, 104a, 104b) configured to vibrate the electric compressor (1, 1A) based on the vibration signal generated by the signal generator (102); wherein the electric compressor (1, 1A) further includes: a motor housing (18) for housing the electric motor (10), an inverter (50) for controlling an electrical frequency of an alternating current supplied to the stator (14); and an inverter case (32) having an inverter case space (26, 26A) inside for accommodating the inverter (50), and the inverter case (32) being coupled to the motor case (18) via an elastic member (30), wherein the electric compressor (1, 1A) further includes a lid member (28) for covering an opening of the inverter case space (26, 26A), and wherein the vibrator (104, 104a, 104b) is disposed on the lid member (28).A vibration / noise reduction device (100) for reducing vibration or noise of an electric compressor (1, 1A), the electric compressor (1, 1A) including: a rotation shaft (2); a compressor wheel (4) disposed on the rotation shaft (2); an electric motor (10) for applying a rotational force to the rotation shaft (2), the electric motor (10) including: a rotor (12) fixed to the rotation shaft (2); and a stator (14) disposed around the rotor (12) for applying the rotational force to the rotor (12) by an electromagnetic force, the vibration / noise reduction device (100) comprising: a detector (150) for detecting a frequency related to vibration of the stator (14); and a signal generator (102) for generating a vibration signal having a frequency of a predetermined integral multiple of an electrical angular frequency obtained from the frequency detected by the detector (150) and having a signal wave attenuating the vibration of the stator (14), and a vibrator (104, 104a, 104b) configured to vibrate the electric compressor based on the vibration signal generated by the signal generator (102); wherein the electric compressor (1, 1A) further includes: a motor housing (18) for housing the electric motor (10), an inverter (50) for controlling an electrical frequency of an alternating current supplied to the stator (14); and an inverter case (32) having an inverter case space (26, 26A) inside for accommodating the inverter (50), and the inverter case (32) being coupled to the motor case (18) via an elastic member (30), and the vibrator (104, 104a, 104b) being disposed in the inverter case space (26, 26A).The vibration / noise reduction device (100) according to claim 1 or 3, wherein the vibrator (104, 104a, 104b) is disposed in the inverter housing space (26, 26A).The vibration / noise reduction device (100) according to any one of claims 1 to 5, wherein the signal generator (102) is disposed in the inverter housing space (26, 26A) in which the inverter (50) is accommodated.The vibration / noise reduction device (100) according to any one of claims 1 to 6, wherein the detector (150) is configured to detect the frequency associated with the vibration of the stator (14) based on the electrical frequency of the alternating current supplied to the stator.The vibration / noise reduction device (100) according to claim 7, wherein the detector (150) includes a frequency measurement instrument (152) for measuring the electrical frequency of the alternating current supplied to the stator (14).The vibration / noise reduction device (100) according to claim 7, wherein the detector (150) includes a target value detection instrument (154) for detecting a target value relating to the electric frequency of the alternating current input to the inverter (50).The vibration / noise reduction device (100) according to any one of claims 1 to 9, wherein the detector (150) includes a vibration sensor (156, 156a, 156b) configured to detect a frequency of vibration of the electric compressor (1, 1A).The vibration / noise reduction device (100) according to any one of claims 1 to 10, wherein the detector (150) includes a noise sensor (158, 158a-c) configured to detect a frequency of a noise caused by the electric compressor (1, 1A).The vibration / noise reduction device (100) according to any one of claims 1 to 11, wherein the vibration signal includes a signal wave having a phase opposite to vibration of the stator (14).An electric compressor (1, 1A) comprising: a rotary shaft (2); a compressor wheel (4) disposed on the rotary shaft (2); an electric motor (10) for applying a rotational force to the rotary shaft (2), the electric motor (10) including: a rotor (12) fixed to the rotary shaft (2); and a stator (14) disposed around the rotor (12) for applying the rotational force to the rotor (12) by an electromagnetic force; and the vibration / noise reduction device (100) according to any one of claims 1 to 12.A vibration / noise reduction method for reducing vibration or noise of an electric compressor according to claim 13, the vibration / noise reduction method comprising: a step of detecting a frequency related to vibration of the stator (14); a step of generating a vibration signal having a frequency of a predetermined integral multiple of an electric angular frequency obtained from the frequency and having a signal wave attenuating vibration of the stator (14); and a step of vibrating the electric compressor (1, 1A) based on the vibration signal.The vibration / noise reduction method according to claim 14, wherein the step of detecting the frequency includes detecting the frequency based on an electric frequency of an alternating current supplied to the stator (14).

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