Electric compressor

This electric compressor (10) has: an accommodating case (15) that accommodates an inverter device (19) and includes an accommodating section body (31), a substrate support section (32) protruding from a bottom surface (31a) of the accommodating section body (31), and a cover member (34) that closes an opening in the accommodating section body (31); and an antivibration member (17) that is positioned between one surface (51a) of a head part (51) of a bolt (16) fastened to the substrate support section (32) and an inner surface (34a) of the cover member (34), and that is bonded to the one surface (51a) of the head part (51) and the inner surface (34a) of the cover member (34).

TECHNICAL FIELD

The present invention relates to an electric compressor.

BACKGROUND ART

In the related art, as a compressor for an air conditioner mounted in vehicles such as electric vehicles or hybrid vehicles, an electric compressor in which an inverter device is integrally built-in has been used.

The electric compressor having such a configuration includes an accommodation casing (inverter box) made of metal that is disposed at an outer periphery of a housing in which an electric motor and a compressor (for example, a scroll compressor) are built-in.

The inverter device that converts DC power supplied from a high-voltage power supply unit, into three-phase AC power to supply the three-way AC power to the electric motor is built-in inside the accommodation casing.

The accommodation casing includes an accommodation portion body having an opening into which the inverter device is inserted, and a cover member that is fixed to close the opening of the accommodation portion body.

The cover member is fixed to the accommodation portion body with bolts or the like to close the opening of the accommodation portion body.

Since a part of the accommodation portion body is in direct contact with or in contact with the cover member via fastening bolts, the accommodation portion body and the cover member are in metal contact with each other.

In the case of such a structure where the accommodation portion body and the cover member are in metal contact with each other, when vibration is generated by the compressor or the like, the vibration is transmitted to the cover member via the accommodation portion body, and the cover member vibrates and generates noise, which is a problem.

As a technique intended to solve such a problem, there is an electric compressor disclosed in PTL 1.

PTL 1 discloses an electric compressor including an accommodation portion body which has an opening and inside which an inverter device is accommodated and installed; a cover member that covers the opening; and a gasket that is interposed between the accommodation portion body and the cover member to seal a gap between the accommodation portion body and the cover member. The gasket includes a flat metal core material and a foamed elastic body provided to cover both surfaces of the core material, and has concavities and convexities of a predetermined shape provided by embossing. The accommodation portion body and the cover member are fastened with bolts, and the concavities and convexities imparted to the gasket are disposed to be closer to an inside of the accommodation portion body than the bolts.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

However, in the electric compressor disclosed in PTL 1, since the accommodation portion body and the cover member are configured to be fastened with the bolts via the gasket, when the cover member is displaced in a direction away from the accommodation portion body and the gasket is separated from the gasket or the accommodation portion body, it is difficult for the gasket to isolate vibration of the cover member, and noise caused by vibration of the cover member cannot be reduced, which is a concern.

Therefore, an object of the present invention is to provide an electric compressor capable of reducing noise caused by vibration of a cover member.

Solution to Problem

In order to solve the above problem, according to a first aspect of the present invention, there is provided an electric compressor including: a housing that accommodates a compressor and an electric motor that drives the compressor; an inverter device including a circuit substrate on which an electronic component is mounted; an accommodation casing including an accommodation portion body provided on a side surface of the housing to accommodate the inverter device, a substrate support portion that protrudes to an inside of the accommodation portion body to support one surface of the circuit substrate, and a cover member fixed to the accommodation portion body to close an opening of the accommodation portion body; a bolt which is fastened to the substrate support portion to restrict a position of the circuit substrate with respect to the substrate support portion, and in which one surface of a head facing an inner surface of the cover member is flat; and a first vibration isolation member that is disposed between the one surface of the head and the inner surface of the cover member and that is bonded to the one surface of the head and to the inner surface of the cover member.

According to the present invention, since the first vibration isolation member is provided that is disposed between the one surface (flat surface) of the head of the bolt and the inner surface of the cover member and that is bonded to the one surface of the head and to the inner surface of the cover member, when the cover member is displaced in a direction away from the head of the bolt, a state where the first vibration isolation member is connected to the head and to the cover member can be maintained.

Accordingly, the state where the first vibration isolation member is connected to the head and to the cover member can be maintained without depending on displacement directions of the cover member (in this case, a direction where the cover member is separated from the head of the bolt and a direction where the cover member approaches the head of the bolt). Accordingly, when the cover member vibrates, the vibration of the cover member can be suppressed by the first vibration isolation member, so that noise caused by the vibration of the cover member can be reduced.

In the electric compressor according to the first aspect of the present invention, the head may be provided with a screw hole, and a gasket disposed on an outer surface of the cover member, and a screw screwed into the screw hole via the gasket may be provided.

According to the present invention, since the gasket having a vibration isolation function that is disposed on the outer surface of the cover member, and the screw that is screwed into the screw hole provided in the head via the gasket are provided, when the cover member is displaced in the direction away from the head of the bolt, the state where the first vibration isolation member is connected to the head and to the cover member can be maintained without bonding the first vibration isolation member to the one surface of the head and to the inner surface of the cover member.

Accordingly, the state where the first vibration isolation member is connected to the head and to the cover member can be maintained without depending on displacement directions of the cover member (in this case, a direction where the cover member is separated from the head of the bolt and a direction where the cover member approaches the head of the bolt). Therefore, when the cover member vibrates, the vibration of the cover member can be suppressed by the first vibration isolation member, so that noise caused by the vibration of the cover member can be reduced.

In the electric compressor according to the first aspect of the present invention, the gasket may be made of rubber.

In such a manner, when the gasket made of rubber is used, vibration of the cover member can be suppressed by using the first vibration isolation member and the gasket, so that the effect of reducing noise caused by the vibration of the cover member can be further enhanced.

In the electric compressor according to the first aspect of the present invention, the gasket may have a surging frequency equal to or higher than a frequency of a primary eigenvalue of the cover member.

In such a manner, since the gasket is used that has a surging frequency equal to or higher than the frequency of the primary eigenvalue of the cover member, the effect of reducing noise caused by vibration of the cover member can be enhanced.

In the electric compressor according to the first aspect of the present invention, the head may be provided with a screw hole, and a screw may be provided that penetrates through the cover member and through the first vibration isolation member from outside the cover member to be screwed into the screw hole.

In such a manner, since the screw is provided that penetrates through the cover member and through the first vibration isolation member from outside the cover member to be screwed into the screw hole provided in the head of the bolt, the displacement of the cover member in the direction away from the head of the bolt can be restricted, and the strength of connection between the inner surface of the cover member and the first vibration isolation member can be increased.

Accordingly, the effect of suppressing vibration of the cover member can be enhanced, so that the effect of reducing noise caused by the vibration of the cover member can be enhanced.

According to a second aspect of the present invention, there is provided an electric compressor including: a housing that accommodates a compressor and an electric motor that drives the compressor; an inverter device including a circuit substrate on which an electronic component is mounted; an accommodation casing including an accommodation portion body provided on a side surface of the housing to accommodate the inverter device, a substrate support portion that protrudes to an inside of the accommodation portion body to support one surface of the circuit substrate, and a cover member fixed to the accommodation portion body to close an opening of the accommodation portion body; a bolt which is fastened to the substrate support portion to restrict a position of the circuit substrate with respect to the substrate support portion, and in which one surface of a head facing an inner surface of the cover member is flat; and a second vibration isolation member that is disposed between the one surface of the head and the inner surface of the cover member and that has a surging frequency equal to or higher than a frequency of a primary eigenvalue of the cover member.

In such a manner, since the second vibration isolation member is provided that is disposed between the one surface of the head of the bolt and the inner surface of the cover member and that has a surging frequency equal to or higher than the frequency of the primary eigenvalue of the cover member, noise caused by vibration of the cover member can be reduced without bonding the second vibration isolation member to the one surface of the head of the bolt and to the inner surface of the cover member.

In the electric compressor according to the second aspect of the present invention, the head may be provided with a screw hole, and a screw may be provided that penetrates through the cover member and through the second vibration isolation member from outside the cover member to be screwed into the screw hole.

In such a manner, since the screw is provided that penetrates through the cover member and through the second vibration isolation member from outside the cover member to be screwed into the screw hole provided in the head of the bolt, the displacement of the cover member in the direction away from the head of the bolt can be restricted, and the strength of connection between the inner surface of the cover member and the second vibration isolation member can be increased.

Accordingly, the effect of suppressing vibration of the cover member can be enhanced, so that the effect of reducing noise caused by the vibration of the cover member can be enhanced.

The electric compressor according to the second aspect of the present invention may further include a gasket disposed on an outer surface of the cover member, and the screw may be screwed into the screw hole via the gasket.

In such a manner, since the gasket disposed on the outer surface of the cover member is provided and the screw is screwed into the screw hole via the gasket, when the gasket is made of metal, the loosening of the screw can be prevented.

In the electric compressor according to the second aspect of the present invention, the gasket may be made of rubber.

In such a manner, when the gasket made of rubber is used, vibration of the cover member can be suppressed by using the second vibration isolation member and the gasket, so that the effect of reducing noise caused by the vibration of the cover member can be further enhanced.

According to a third aspect of the present invention, there is provided an electric compressor including: a housing that accommodates a compressor and an electric motor that drives the compressor; an inverter device including a circuit substrate on which an electronic component is mounted; and an accommodation casing including an accommodation portion body provided on a side surface of the housing to accommodate the inverter device, a substrate support portion that protrudes to an inside of the accommodation portion body to support one surface of the circuit substrate, and a cover member fixed to the accommodation portion body to close an opening of the accommodation portion body. The cover member includes a through-hole at a portion facing the substrate support portion. A grommet having a vibration isolation property that includes a ring-shaped groove accommodating the cover member located around the through-hole and that is mounted in the through-hole, and a screw that penetrates through the grommet from outside the cover member to be screwed to the substrate support portion are provided.

According to the present invention, since the grommet having a vibration isolation property that includes the ring-shaped groove accommodating the cover member located around the through-hole provided in the cover member and that is mounted in the through-hole, and the screw that penetrates through the grommet from outside the cover member to be screwed to the substrate support portion are provided, when the cover member is displaced in the direction away from the head of the bolt, a state where the grommet is connected to the other surface of the circuit substrate and to the cover member can be maintained. Therefore, noise caused by vibration of the cover member can be reduced.

In addition, since a part of the grommet is disposed not only between the circuit substrate and the cover member but also on an outer side of the cover member, the effect of reducing noise caused by vibration of the cover member can be further enhanced.

In the electric compressor according to the third aspect of the present invention, the grommet may be bonded to the other surface of the circuit substrate and to the cover member.

According to the present invention, since the grommet is bonded to the other surface of the circuit substrate and to the cover member, when the cover member is displaced in the direction away from the circuit substrate, the state where the grommet is connected to the other surface of the circuit substrate and to the cover member can be maintained.

Accordingly, vibration of the cover member can be suppressed by the grommet, so that noise caused by the vibration of the cover member can be reduced.

In addition, since a part of the grommet is disposed not only between the circuit substrate and the cover member but also on the outer side of the cover member, the effect of reducing noise caused by vibration of the cover member can be further enhanced.

In the electric compressor according to the third aspect of the present invention, the grommet may have a surging frequency equal to or higher than a frequency of a primary eigenvalue of the cover member.

In such a manner, since the grommet is used that has a surging frequency equal to or higher than the frequency of the primary eigenvalue of the cover member, the effect of reducing noise caused by vibration of the cover member can be enhanced without bonding the grommet to the circuit substrate and to the cover member.

In the electric compressor according to the first to third aspects of the present invention, the compressor may include a fixed scroll and a movable scroll each having a spiral shape, a plurality of compression chambers that are formed between the fixed scroll and the movable scroll to compress a refrigerant by means of a movement of the movable scroll, and a discharge port that discharges the compressed refrigerant. When an average value of a length S1(mm) of an inner curved line of the fixed scroll in a stage where the compressor discharges the refrigerant from the discharge port, the fixed scroll partitioning a compression chamber formed on an innermost side among the plurality of compression chambers, and of a length S2(mm) of an outer curved line of the movable scroll that partitions the compression chamber formed on the innermost side is an average value SAV(mm), an eigenvalue E (kHz) of the cover member may satisfy the following equation (1):
E≥V/SAV(1)

here, in the equation (1), V (m/s) is a sound speed of the refrigerant.

In such a manner, since the eigenvalue E of the cover member is set to satisfy the equation (1), when vibration of the compressor is transmitted to the accommodation portion body, the vibration of the cover member can be suppressed by the first or second vibration isolation member. Accordingly, noise caused by the vibration of the cover member can be reduced.

According to a fourth aspect of the present invention, there is provided an electric compressor including: a housing that accommodates a compressor and an electric motor that drives the compressor; an inverter device including a circuit substrate on which an electronic component is mounted; an accommodation casing including an accommodation portion body provided on a side surface of the housing to accommodate the inverter device, a substrate support portion that protrudes to an inside of the accommodation portion body to support one surface of the circuit substrate, and a cover member fixed to the accommodation portion body to close an opening of the accommodation portion body; and a third vibration isolation member that is in contact with an inner surface of the cover member. The compressor includes a fixed scroll and a movable scroll each having a spiral shape, a plurality of compression chambers that are formed between the fixed scroll and the movable scroll to compress a refrigerant by means of a movement of the movable scroll, and a discharge port that discharges the compressed refrigerant. When an average value of a length S1(mm) of an inner curved line of the fixed scroll in a stage where the compressor discharges the refrigerant from the discharge port, the fixed scroll partitioning a compression chamber formed on an innermost side among the plurality of compression chambers, and of a length S2(mm) of an outer curved line of the movable scroll that partitions the compression chamber formed on the innermost side is an average value SAV(mm), an eigenvalue E (kHz) of the cover member satisfies the following equation (2):
E≥V/SAV(2)

here, in the equation (2), V (m/s) is a sound speed of the refrigerant.

Fluid sound in a cylinder of the scroll compressor is generated by a relationship between a representative length of the compression chambers and the sound speed. The representative length is a length equivalent to a length of an innermost circumference of the scroll compression chamber. Therefore, the eigenvalue E (kHz) of the cover member may be equal to or more than an eigenvalue of the fluid sound in the cylinder.

Since the eigenvalue of the cover member is set to satisfy the equation (2), with the simple configuration, vibration of the cover member can be suppressed by using the third vibration isolation member. Accordingly, noise caused by the vibration of the cover member can be reduced.

The inner curved line of the fixed scroll may be referred to as a ventral side curved line. In addition, the outer curved line of the movable scroll may be referred to as a dorsal side curved line.

Advantageous Effects of Invention

According to the present invention, noise caused by vibration of the cover member can be reduced.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments to which the present invention is applied will be described in detail with reference to the drawings. The drawings to be used in the following description are for describing configurations of the embodiments of the present invention, and the size, thickness, dimension and the like of each portion illustrated may be different from a dimensional relationship of an actual electric compressor.

First Embodiment

FIG.1is a side view illustrating a schematic configuration of an electric compressor according to a first embodiment of the present invention.FIG.1illustrates an inverter-integrated electric compressor to be used in a vehicle air conditioner, as one example of an electric compressor10.

FIG.2is a side view of the electric compressor illustrated inFIG.1as viewed from A. InFIG.2, the same components as those of the structure illustrated inFIG.1are denoted by the same reference signs.

FIG.3is a cross-sectional view of an accommodation casing illustrated inFIG.2that accommodates an inverter device illustrated inFIG.1, taken along line B1-B2. InFIG.3, the same components as those of the structure illustrated inFIGS.1and2are denoted by the same reference signs.

Referring toFIGS.1to3, the electric compressor of the first embodiment includes a housing11, an electric motor12, a compressor13, a motor shaft14, an accommodation casing15, a bolt16, a vibration isolation member17, a first adhesive layer18A, a second adhesive layer18B, and an inverter device19.

The housing11includes a first housing portion21and a second housing portion22. The first housing portion21includes a housing main body24that accommodates the electric motor12, and a refrigerant suction port25provided in the housing main body24.

The refrigerant suction port25introduces the refrigerant gas (refrigerant) of low temperature and low pressure into the housing main body24from outside the housing11. The refrigerant gas of low temperature and low pressure introduced into the housing main body24flows around the electric motor12, flows into the second housing portion22, and then is suctioned into and compressed by the compressor13.

The second housing portion22includes a housing main body27that accommodates the compressor13, and a discharge portion28that is provided in the housing main body27to discharge the refrigerant gas. The housing main body27is fastened and fixed to the housing main body24using a plurality of bolts (not illustrated). Accordingly, the first housing portion21and the second housing portion22are integrally configured.

The housing11is configured such that the refrigerant in the first housing portion21is movable into the second housing portion22. The discharge portion28includes a discharge port28A that extends to a central portion of the compressor13to discharge the compressed refrigerant gas. The discharge port28A forms a part of the compressor13.

The discharge portion28having the above configuration discharges the refrigerant of high temperature and high pressure compressed and generated by the compressor13, to the outside of the housing11.

The housing11having the above configuration functions as a pressure resistant container. For example, die cast aluminum can be used as a material of the housing11.

The electric motor12is connected to one end of the motor shaft14. The electric motor12drives the compressor13via the motor shaft14.

FIG.4is a cross-sectional view illustrating an internal structure of the compressor illustrated inFIG.1.FIG.4illustrates a scroll compressor as one example of the compressor13. The compressor13illustrated inFIG.4schematically illustrates a state where the refrigerant gas of high temperature and high pressure is discharged from the discharge port28A.

In addition,FIG.4illustrates a state where a position angle θ of a movable scroll42with respect to the position of a fixed scroll41is 230°. The position angle θ is an angle indicating the position of the movable scroll42with respect to a back side winding end of the fixed scroll41.

Further,FIG.4illustrates a compression chamber that is formed at a position closest to the discharge port28A among a plurality of compression chambers44in a refrigerant gas discharge stage, as a compression chamber44A. InFIG.4, the same components as those of the structure illustrated inFIGS.1to3are denoted by the same reference signs.

Referring toFIGS.1and4, the compressor13is a scroll compressor and is connected to the other end of the motor shaft14.

The compressor13includes the fixed scroll41having a spiral shape; the movable scroll42each having a spiral shape; the plurality of compression chambers44that are formed between the fixed scroll41and the movable scroll42to compress the refrigerant gas by means of movement of the movable scroll42(including the compression chamber44A); and the discharge port28A that faces a central portion of the fixed scroll41to discharge the compressed refrigerant gas.

The compressor13compresses the refrigerant gas of low temperature and low pressure in a direction toward a center of the compressor13using the plurality of compression chambers44that are changed in shape by movement of the movable scroll42, thereby generating the refrigerant gas of high temperature and high pressure.

Then, the refrigerant gas of high temperature and high pressure is guided to the discharge port28A disposed at the center of the compressor13(center of the fixed scroll41), and is supplied to the outside of the electric compressor10via the discharge port28A.

The accommodation casing15is a metal casing, and includes an accommodation portion body31, a substrate support portion32, a cover member34, and a plurality of screws35.

The accommodation portion body31is provided on a side surface of the first housing portion21(side surface of the housing11). The accommodation portion body31has an opening31A. The accommodation portion body31accommodates the inverter device19.

The substrate support portion32is provided on a bottom surface31aof the accommodation portion body31. The substrate support portion32protrudes in a direction orthogonal to the bottom surface31aof the accommodation portion body31. Namely, the substrate support portion32protrudes to an inside of the accommodation portion body31. A tip surface32aof the substrate support portion32is a flat surface. The tip surface32aof the substrate support portion32supports one surface55aof a circuit substrate55to be described later that forms the inverter device19.

The substrate support portion32has a screw hole32A to which the bolt16is fastened. The screw hole32A is exposed from the tip surface32a, and extends in the direction orthogonal to the bottom surface31a.

The cover member34is a plate-shaped member, and is disposed on the accommodation portion body31to close the opening31A. The cover member34has an inner surface34adisposed on an accommodation portion body31side, and an outer surface34bdisposed on a side opposite the inner surface34a. In addition, the cover member34has a plurality of screw holes (not illustrated) in an outer peripheral portion of the cover member34.

Shanks of the plurality of screws35are screwed into the screw holes formed in the cover member34and to an edge portion of the accommodation portion body31that faces the screw holes of the cover member34. Accordingly, the cover member34is fixed to the accommodation portion body31.

Referring toFIG.3, the bolt16includes a head51and a shank52that is male threaded. The head51has one surface51aand the other surface51bon which the shank52is provided. The one surface51ais a flat surface and has a circular shape. The other surface51bis a flat surface disposed on a side opposite the one surface51a.

The shank52of the bolt16is fastened to the screw hole32A provided in the substrate support portion32in a state where the shank52is inserted into a through-hole55A formed in the circuit substrate55. Accordingly, the circuit substrate55is fixed to the substrate support portion32with the bolt16.

The vibration isolation member17is provided between the one surface51aof the head51and the inner surface34aof the cover member34. The vibration isolation member17is a member that suppresses vibration of the cover member34when vibration generated from the compressor13is transmitted to the cover member34. For example, a vibration isolation rubber (vibration isolation member made of rubber) can be used as the vibration isolation member17.

When a vibration isolation rubber is used as the vibration isolation member17, a thickness of the vibration isolation member17can be set within, for example, a range of 2 mm to 20 mm.

The vibration isolation member17has one surface17afacing the one surface51aof the head51, and the other surface17bfacing the inner surface34aof the cover member34. The one surface17aand the other surface17bare flat surfaces. The other surface17bis a surface disposed on a side opposite the one surface17a.

The one surface17aof the vibration isolation member17is bonded to the one surface51aof the head51via the first adhesive layer18A. The other surface17bof the vibration isolation member17is bonded to the inner surface34aof the cover member34via the second adhesive layer18B.

For example, vulcanizing adhesive agents, moisture-curing adhesive agents, or the like can be used as the first and second adhesive layers18A and18B.

In such a manner, since the vibration isolation member17is provided that is disposed between the one surface51a(flat surface) of the head51of the bolt16and the inner surface34aof the cover member34and that is bonded to the one surface51aof the head51and to the inner surface34aof the cover member34, even when the cover member34is displaced in a direction away from the head51of the bolt16, a state where the vibration isolation member17is connected to the head51and to the cover member34can be maintained.

Accordingly, the state where the vibration isolation member17is connected to the head51and to the cover member34can be maintained without depending on displacement directions of the cover member34(in this case, a direction where the cover member34is separated from the head51of the bolt16and a direction where the cover member34approaches the head51of the bolt16).

Therefore, when the cover member34vibrates, the vibration of the cover member34can be suppressed by the vibration isolation member17, so that noise caused by the vibration of the cover member34can be reduced.

A shape of the vibration isolation member17can be, for example, a circular columnar shape having a diameter equal to a diameter of the one surface51aof the head51having a circular shape. In this case, shapes of the one surface17aand the other surface17bof the vibration isolation member17are a circular shape.

InFIG.3, the case where the vibration isolation member17is bonded to the one surface51aof the head51and to the inner surface34aof the cover member34using the first and second adhesive layers18A and18B has been described as an example; however, for example, when the vibration isolation member17itself is a material having a tackiness property and an adhesive property, the vibration isolation member17may be bonded to the one surface51aof the head51and to the inner surface34aof the cover member34without using the first and second adhesive layers18A and18B.

The inverter device19is accommodated in the accommodation casing15. The inverter device19includes high-voltage components (not illustrated), a power substrate (not illustrated), a CPU substrate58including an electronic component57and the circuit substrate55, and an inverter module (not illustrated).

For example, components such as a smoothing capacitor, a normal mode coil, and a common mode coil provided in a high-voltage power supply line (not illustrated) can be used as the high-voltage components (not illustrated).

A structure formed of, for example, a circuit substrate, a plurality of power semiconductor switching elements (IGBTs) mounted on the circuit substrate, and a power control circuit that operates the power semiconductor switching elements can be used as the power substrate (not illustrated).

The circuit substrate55includes a substrate body (not illustrated) and a circuit pattern (not illustrated) formed on the substrate body. The circuit substrate55is fixed to the tip surface32aof the substrate support portion32.

The circuit substrate55has the one surface55athat is in contact with the tip surface32aof the substrate support portion32; the other surface55bfacing the inner surface34aof the cover member34; and the through-hole55A into which the shank52of the bolt16is inserted.

The electronic component57is mounted on the other surface55bof the circuit substrate55. For example, an element such as a CPU that operates at a low voltage can be used as the electronic component57.

FIG.5is a view schematically illustrating the discharge port and the compression chamber that is formed at the position closest to the discharge port among the plurality of compression chambers in the state (refrigerant gas discharge state) illustrated inFIG.4. InFIG.5, the same components as those of the structure illustrated inFIG.4are denoted by the same reference signs.

Here, an exemplary eigenvalue E of the cover member34will be described with reference toFIGS.1,4, and5.

Referring toFIG.5, an average value SAV(mm) of a length S1(mm) of an inner curved line CL1of the fixed scroll41that partitions the compression chamber44A formed on an innermost side among the plurality of compression chambers44in a stage where the compressor13discharges the refrigerant gas (refrigerant) from the discharge port28A (state illustrated inFIG.4), and of a length S2(mm) of an outer curved line CL2of the movable scroll42that partitions the compression chamber44A formed on the innermost side is calculated by the following equation (3). The average value SAV(representative length) is a value corresponding to a length of a center curved line CL3illustrated inFIG.5.
SAV=(S1+S2)/2  (3)

Then, the eigenvalue E (kHz) of the cover member34may be set to satisfy the following equation (4).
E≥V/SAV(4)

However, in the equation (4), V (m/s) is a sound speed of the refrigerant gas (refrigerant).

In such a manner, since the eigenvalue E of the cover member34is set to satisfy the equation (4), when vibration of the compressor13is transmitted to the accommodation portion body31, the vibration of the cover member34can be suppressed by the vibration isolation member17, so that noise caused by the vibration of the cover member34can be reduced.

In addition, since the cover member34having the eigenvalue E satisfying the equation (4), and the vibration isolation member17bonded to the one surface51aof the head51and to the inner surface34aof the cover member34are provided, the effect of suppressing vibration of the cover member34can be enhanced, so that noise caused by the vibration of the cover member34can be further reduced.

Here, a specific example of the eigenvalue E (kHz) of the cover member34will be described.

When R-134a that is a fluorine-based refrigerant is used as the refrigerant gas (refrigerant), a sound speed V of the refrigerant is approximately 150 m/s to 180 m/s.

In a case where a 33 cc scroll compressor is used as the compressor13for a vehicle air conditioner, when the length S1is 79.97 mm and the length S2is 103.09 mm, the average value SAVof these two lengths is 91.53 mm.

Therefore, in the case of the above-described conditions, when the eigenvalue E of the cover member34is 1.97 kHz or more, vibration of the cover member34can be suppressed, and noise caused by the vibration of the cover member34can be reduced.

According to the electric compressor10of the first embodiment, since the vibration isolation member17is provided that is disposed between the one surface51a(flat surface) of the head51of the bolt16and the inner surface34aof the cover member34and that is bonded to the one surface51aof the head51and to the inner surface34aof the cover member34, when the cover member34is displaced in the direction away from the head51of the bolt16, the state where the vibration isolation member17is connected to the head51and to the cover member34can be maintained.

Accordingly, when vibration of the compressor13is transmitted to the accommodation portion body31, the vibration isolation member17is capable of suppressing vibration of the cover member34without depending on the displacement directions of the cover member34(in this case, the direction where the cover member34is separated from the head51of the bolt16and the direction where the cover member34approaches the head51of the bolt16), so that noise caused by the vibration of the cover member34can be reduced.

In the electric compressor10of the first embodiment, the case where the inner surface34aof the cover member34and the one surface51aof the head51are bonded to the vibration isolation member17using the first and second adhesive layers18A and18B has been described as an example; however, for example, when a vibration isolation member having a surging frequency equal to or higher than a frequency of a primary eigenvalue of the cover member34(equal to or higher than a frequency that has to be damped) is used as the vibration isolation member17, a vibration isolation member having a surging frequency equal to or higher than the frequency of the primary eigenvalue of the cover member34(equal to or higher than a frequency that has to be damped) may be used as the vibration isolation member without bonding the inner surface34aof the cover member34and the one surface51aof the head51to the vibration isolation member17.

In such a manner, since the vibration isolation member17is provided that is disposed between the one surface51aof the head51of the bolt16and the inner surface34aof the cover member34and that has a surging frequency equal to or higher than the frequency of the primary eigenvalue of the cover member34, the vibration isolation member17is capable of fully following a displacement of the cover member34even without bonding the one surface51aof the head51of the bolt16and the inner surface34aof the cover member34to the vibration isolation member17, so that noise caused by vibration of the cover member34can be reduced.

In addition, when the first and second adhesive layers18A and18B are not used, an initial crushing amount (initial displacement) may be set to be larger than a vibration displacement at the frequency that has to be damped. Accordingly, noise caused by vibration of the cover member34can be further reduced by using the vibration isolation member17.

When the first and second adhesive layers18A and18B are used, a vibration isolation member may be used that has a surging frequency equal to or higher than the frequency (equal to or higher than the frequency that has to be damped) of the primary eigenvalue of the cover member34.

Second Embodiment

FIG.6is a side view illustrating a schematic configuration of an electric compressor according to a second embodiment of the present invention. InFIG.6, the same components as those of the structure illustrated inFIG.1are denoted by the same reference signs.

FIG.7is a cross-sectional view of an accommodation casing illustrated inFIG.6taken along line C1-C2. InFIG.7, the same components as those of the structure illustrated inFIG.3described in the first embodiment are denoted by the same reference signs.

Referring toFIGS.6and7, an electric compressor65of the second embodiment has the same configuration as that of the electric compressor10except that a bolt66is provided instead of the bolt16forming the electric compressor10of the first embodiment and except that the electric compressor65includes a through-hole34A provided in the cover member34and a screw68.

The bolt66has the same configuration as that of the bolt16except that the head51has a screw hole51A. The bolt66is fastened to the screw hole32A of the substrate support portion32in a state where the bolt66is inserted into the through-hole55A provided in the circuit substrate55.

The screw hole51A is exposed from the one surface51aof the head51, and extends in a direction from the one surface51atoward the shank52. A depth of the screw hole51A is smaller than a thickness of the head51.

The through-hole34A is formed to penetrate through a portion of the cover member34that faces the screw hole51A.

The screw68includes a head69and a shank71integrated with the head69. The screw68is screwed into the screw hole51A provided in the head51in a state where the shank71is inserted into the through-hole34A from outside the cover member34. In this state, the shank71of the screw68penetrates through the first adhesive layer18A, through the vibration isolation member17, and through the second adhesive layer18B.

According to the electric compressor65of the second embodiment, in addition to the vibration isolation member17, the first adhesive layer18A, and the second adhesive layer18B, the screw68is provided that penetrates through the cover member34and through the vibration isolation member17from outside the cover member34to be screwed into the screw hole51A provided in the head51of the bolt66, so that the displacement of the cover member34in the direction away from the head51can be restricted, and the strength of connection between the inner surface34aof the cover member34and the vibration isolation member17can be increased.

Accordingly, the effect of suppressing vibration of the cover member34can be enhanced, so that the effect of reducing noise caused by the vibration of the cover member34can be enhanced.

In addition, the eigenvalue E of the cover member34forming the electric compressor65of the second embodiment may be set to satisfy the equation (4) described in the first embodiment.

In the electric compressor65of the second embodiment, the case where the inner surface34aof the cover member34and the one surface51aof the head51are bonded to the vibration isolation member17using the first and second adhesive layers18A and18B has been described as an example; however, for example, a vibration isolation member having a surging frequency equal to or higher than the frequency of the primary eigenvalue of the cover member34(equal to or higher than a frequency that has to be damped) may be used as the vibration isolation member17without bonding the inner surface34aof the cover member34and the one surface51aof the head51to the vibration isolation member17.

In such a manner, since the vibration isolation member17is provided that is disposed between the one surface51aof the head51of the bolt16and the inner surface34aof the cover member34and that has a surging frequency equal to or higher than the frequency of the primary eigenvalue of the cover member34, the vibration isolation member17is capable of fully following a displacement of the cover member34even without bonding the one surface51aof the head51of the bolt16and the inner surface34aof the cover member34to the vibration isolation member17, so that noise caused by vibration of the cover member34can be reduced.

In addition, when the first and second adhesive layers18A and18B are not used, an initial crushing amount (initial displacement) may be set to be larger than a vibration displacement at the frequency that has to be damped. Accordingly, noise caused by vibration of the cover member34can be further reduced by using the vibration isolation member17.

When the first and second adhesive layers18A and18B are used, a vibration isolation member may be used that has a surging frequency equal to or higher than the frequency (equal to or higher than the frequency that has to be damped) of the primary eigenvalue of the cover member34.

Third Embodiment

FIG.8is a side view illustrating a schematic configuration of an electric compressor according to a third embodiment of the present invention. InFIG.8, the same components as those of the structure illustrated inFIG.6are denoted by the same reference signs.

FIG.9is a cross-sectional view of an accommodation casing illustrated inFIG.8taken along line D1-D2. InFIG.9, the same components as those of the structure illustrated inFIG.7described in the second embodiment are denoted by the same reference signs.

Referring toFIGS.8and9, an electric compressor75of the third embodiment has the same configuration as that of the electric compressor65except that a gasket78is further provided to the configuration of the electric compressor65of the second embodiment.

The gasket78has a hole (not illustrated) through which the shank71of the screw68is capable of passing. The gasket78is disposed on the outer surface34bof the cover member34such that the hole faces the through-hole34A provided in the cover member34.

For example, a gasket of which a surface is coated with rubber can be used as the gasket78.

The screw68is screwed into the screw hole51A via the gasket78, the cover member34, the first adhesive layer18A, the vibration isolation member17, and the second adhesive layer18B.

According to the electric compressor75of the third embodiment, since the gasket78disposed on the outer surface34bof the cover member34is provided and the screw68is screwed into the screw hole51A via the gasket78, when the gasket78is made of metal, the loosening of the screw68can be prevented. In addition, when the gasket78is made of rubber, vibration of the cover member can be suppressed by using the vibration isolation member17and the gasket78, so that the effect of reducing noise caused by the vibration of the cover member34can be further enhanced.

The eigenvalue E of the cover member34forming the electric compressor75of the third embodiment may also be set to satisfy the equation (4) described in the first embodiment.

FIG.10is a cross-sectional view of a principal section of an electric compressor according to a modification example of the third embodiment of the present invention. InFIG.10, the same components as those of the structure illustrated inFIG.7described in the third embodiment are denoted by the same reference signs.

Referring toFIG.10, an electric compressor85of a modification example of the third embodiment has the same configuration as that of the electric compressor75except that the first and second adhesive layers18A and18B are eliminated from the configuration of the electric compressor75of the third embodiment and a gasket having a vibration isolation function is used as the gasket78. For example, a gasket of which a surface is coated with rubber can be used as the gasket78.

Namely, in the electric compressor85, in a state where the cover member34is stationary, the inner surface34aof the cover member34and the one surface51aof the head51are in contact with the vibration isolation member17, and the outer surface34bof the cover member34and the gasket78are in contact with each other.

Therefore, when the cover member34vibrates and the cover member34is displaced from a stationary position in a direction where the cover member34approaches the head69, even if the vibration isolation member17is separated from the inner surface34aof the cover member34, vibration of the cover member34can be suppressed by the gasket78since the gasket78abuts on the head69and on the outer surface34bof the cover member34.

On the other hand, when the cover member34vibrates and the cover member34is displaced from the stationary position in a direction away from the head69(direction toward the circuit substrate55), even if the gasket78is separated from the outer surface34bof the cover member34, vibration of the cover member34can be suppressed by the vibration isolation member17since the vibration isolation member17abuts on the one surface51aof the head51and on the inner surface34aof the cover member34.

Namely, according to the electric compressor85of the modification example of the third embodiment, vibration of the cover member34can be suppressed by the simplified configuration without using the first and second adhesive layers18A and18B (in other words, without bonding the vibration isolation member17to the head51of the bolt66and to the inner surface34aof the cover member34).

The eigenvalue E of the cover member34forming the electric compressor85of the modification example of the third embodiment may also be set to satisfy the equation (4) described in the first embodiment.

For example, a gasket having a surging frequency equal to or higher than the frequency of the primary eigenvalue of the cover member34(equal to or higher than a frequency that has to be damped) may be used as the gasket78forming the electric compressor75or85described above. Noise caused by vibration of the cover member34can be reduced by using the gasket78having such a configuration.

Fourth Embodiment

FIG.11is a side view illustrating a schematic configuration of an electric compressor according to a fourth embodiment of the present invention. InFIG.11, the same components as those of the structure illustrated inFIG.3are denoted by the same reference signs.

FIG.12is a cross-sectional view of an accommodation casing illustrated inFIG.11taken along line F1-F2. InFIG.12, the same components as those of the structure illustrated inFIG.3described in the first embodiment are denoted by the same reference signs.

Referring toFIGS.11and12, an electric compressor90of the fourth embodiment has the same configuration as that of the electric compressor10except that a grommet91having a vibration isolation property and a screw92are provided instead of the bolt16and the vibration isolation member17forming the electric compressor10of the first embodiment and except that the cover member34has a through-hole34B in which the grommet91is disposed.

The through-hole34B is provided to penetrate through a portion of the cover member34that faces the substrate support portion32. A diameter of the through-hole34B is sized such that the cover member34which partitions a periphery of the through-hole34B can be accommodated in a ring-shaped groove to be described provided in the grommet91.

The grommet91has a screw through-hole91A penetrating through a center of the grommet91, and a ring-shaped groove91B. The ring-shaped groove91B is formed by cutting out a part of a side wall of the grommet91in a ring shape.

A portion of the cover member34that is inserted into the ring-shaped groove91B is bonded to the grommet that partitions the ring-shaped groove91B, by the first adhesive layer18A.

In addition, an end surface of two end surfaces of the grommet91which faces the other surface55bof the circuit substrate55is bonded to the other surface55bof the circuit substrate55by the second adhesive layer18B.

For example, a grommet made of rubber can be used as the grommet91.

A thickness of the grommet91in an extending direction of the screw through-hole91A is set to be larger than a distance from the other surface55bof the circuit substrate55to the outer surface34bof the cover member34. Accordingly, the grommets91are disposed on both an inner surface34aside and an outer surface34bside of the cover member34.

The screw92has the same configuration as that of the screw68except that the screw92includes a shank95having a length longer than that of the shank71of the screw68described with reference toFIG.7. The length of the shank95is set to such a length that the shank95can be screwed into the screw hole32A provided in the substrate support portion32.

The screw92having the above configuration is screwed into the screw hole32A in a state where the shank95is inserted into the through-hole34B from outside the cover member34. Accordingly, the shank95penetrates through the grommet91and through the second adhesive layer18B.

According to the electric compressor90of the fourth embodiment, the configuration is such that the grommet91having a vibration isolation property that includes the ring-shaped groove91B accommodating a portion of the cover member34located around the through-hole34B and that is mounted in the through-hole34B, and the screw92that penetrates through the grommet91from outside the cover member34to be screwed to the substrate support portion32are provided, and the grommet91is bonded to the other surface55bof the circuit substrate55and to the cover member34. Therefore, when the cover member34is displaced in the direction away from the circuit substrate55, a state where the grommet91is connected to the other surface55bof the circuit substrate55and to the cover member can be maintained.

For this reason, vibration of the cover member34can be suppressed by the grommet91, so that noise caused by the vibration of the cover member34can be reduced.

In addition, since a part of the grommet91is disposed not only between the circuit substrate55and the cover member34but also on an outer side (outer surface34b) of the cover member34, the effect of reducing noise caused by vibration of the cover member34can be further enhanced.

The eigenvalue E of the cover member34forming the electric compressor90of the fourth embodiment may also be set to satisfy the equation (4) described in the first embodiment.

FIG.13is a cross-sectional view of a principal section of an electric compressor according to a modification example of the fourth embodiment of the present invention. InFIG.13, the same components as those of the structure illustrated inFIG.12described in the fourth embodiment are denoted by the same reference signs.

Referring toFIG.13, an electric compressor100of a modification example of the fourth embodiment has the same configuration as that of the electric compressor90except that the first and second adhesive layers18A and18B are eliminated from the configuration of the electric compressor90of the fourth embodiment.

In the electric compressor100, a part of the grommet91is disposed on both the inner surface34aand the outer surface34bof the cover member34, and the inner surface34aand the outer surface34bof the cover member34are in contact with the grommet91in a state where the cover member34is stationary.

In the electric compressor100, when the cover member34vibrates and the cover member34is displaced from a stationary position in the direction away from the circuit substrate55, even if the grommet91is separated from the inner surface34aof the cover member34, a part of the grommet91disposed on the outer side of the cover member34abuts on the outer surface34bof the cover member34and on the head69of the screw92, so that vibration of the cover member34can be suppressed by the grommet91disposed on the outer side of the cover member34.

On the other hand, when the cover member34vibrates and the cover member34is displaced from the stationary position in the direction toward the circuit substrate55, even if the grommet91is separated from the outer surface34bof the cover member34, a part of the grommet91abuts on the inner surface34aof the cover member34and on the other surface55bof the circuit substrate55, so that vibration of the cover member34can be suppressed by the grommet91disposed on an inner side of the cover member34.

Namely, according to the electric compressor100of the modification example of the fourth embodiment, vibration of the cover member34can be suppressed by the simplified configuration without using the first and second adhesive layers18A and18B.

The eigenvalue E of the cover member34forming the electric compressor100of the modification example of the fourth embodiment may also be set to satisfy the equation (4) described in the first embodiment.

For example, a grommet having a surging frequency equal to or higher than the frequency of the primary eigenvalue of the cover member34(equal to or higher than a frequency that has to be damped) may be used as the grommet91forming the electric compressor90or100described above. Noise caused by vibration of the cover member34can be reduced by using the grommet91having such a configuration.

Fifth Embodiment

FIG.14is a cross-sectional view of a principal section of an electric compressor according to a fifth embodiment of the present invention. InFIG.14, the same components as those of the structure illustrated inFIG.3described in the first embodiment are denoted by the same reference signs.

Referring toFIG.14, an electric compressor110of the fifth embodiment has the same configuration as that of the electric compressor10except that the first and second adhesive layers18A and18B are eliminated from the configuration of the electric compressor10of the first embodiment and except that the eigenvalue E of the cover member34is set to satisfy the equation (4) described in the first embodiment.

In the electric compressor110of the fifth embodiment having such a configuration, since vibration of the cover member34can be suppressed without bonding the vibration isolation member17to the inner surface34aof the cover member34and to the one surface51aof the head51using the first and second adhesive layers18A and18B, noise caused by the vibration of the cover member34can be reduced by the simple configuration.

In addition, the cover member34having the eigenvalue E satisfying the equation (4) is applicable to an electric compressor (specifically, an electric compressor in which the first and second adhesive layers18A and18B illustrated inFIG.3are not provided at both ends of the vibration isolation member17) other than the structure illustrated inFIG.14.

For example, a vibration isolation member having a surging frequency equal to or higher than the frequency of the primary eigenvalue of the cover member34(equal to or higher than a frequency that has to be damped) may be used as the vibration isolation member17forming the electric compressor110described above. Noise caused by vibration of the cover member34can be reduced by using the vibration isolation member17having such a configuration.

The exemplary embodiments of the present invention have been described in detail above; however, the present invention is not limited to such specific embodiments, and various modifications and changes can be made without departing from the concept of the present invention described in the claims.

REFERENCE SIGNS LIST