JP7413753B2 - electric compressor - Google Patents

Description

The present invention relates to an electric compressor.

Patent Document 1 discloses a conventional electric compressor. This electric compressor includes a compression mechanism, a motor mechanism, an inverter, a motor housing, and an inverter case.

The compression mechanism compresses the refrigerant as a fluid. A motor mechanism drives the compression mechanism. The inverter controls the drive of the motor mechanism. The motor housing has a cylindrical shape with a bottom and houses a motor mechanism therein. The inverter case houses the inverter therein and is joined to the end of the motor housing.

The motor housing includes a first housing that is fastened to the compression mechanism, and a second housing that is fastened to the first housing and the inverter case. The second housing has a motor peripheral wall and a motor bottom wall. The motor peripheral wall has a cylindrical shape extending in the axial direction, and houses the motor mechanism therein together with the first housing. The motor bottom wall has a disc shape extending radially inward from the motor peripheral wall at one end in the axial direction of the motor peripheral wall, and faces the inverter case in the axial direction. An opening is formed in the bottom wall of the motor, and a plurality of terminals serving as conductive members for connecting the motor mechanism and the inverter are inserted into the opening.

The inverter case includes an inverter box that comes into contact with one end of the second housing, and an inverter cover that is fastened to the inverter box. The inverter box has a box peripheral wall and an inverter bottom wall. The box peripheral wall has a cylindrical shape extending in the axial direction and surrounds the inverter. The inverter bottom wall extends in a radially inward direction of the box peripheral wall on the motor housing side of the box peripheral wall, faces the motor bottom wall, and comes into contact with the motor bottom wall and the motor peripheral wall. The inverter cover has a cover peripheral wall and an inverter top wall. The cover peripheral wall has a cylindrical shape and abuts against the box peripheral wall. The inverter upper wall has a disc shape extending in the radial direction, is connected to the cover peripheral wall, and faces the inverter.

In this electric compressor, external power is supplied to an inverter in an inverter case, and the power is supplied to a motor mechanism via a terminal to operate the motor mechanism. This causes the compression mechanism to operate, and the air conditioner of the vehicle to operate.

Korean Published Patent No. 10-2018-0120129

However, the conventional electric compressor described above does not disclose a sealing member that seals between the motor housing and the inverter case. Therefore, in this electric compressor, there is a risk that external moisture may come into contact with the terminals, causing deterioration of the terminals or short circuit between phases.

Therefore, an annular first end face extending in a direction perpendicular to the axial direction is formed on the motor peripheral wall and the motor bottom wall, and an annular first end face extending in the direction perpendicular to the axial direction is formed on the box peripheral wall of the inverter case and the inverter bottom wall. It is conceivable to form a second end face of the first end face, and provide an annular sealing member between the first end face and the second end face.

However, even with the electric compressor configured in this manner, the above-mentioned concerns remain when used in an environment where a relatively large amount of water, salt water, etc. are present. In particular, when the motor housing and the inverter case are axially fastened using multiple fasteners, if a suitable sealing performance is pursued, there is a risk that the sealing member will be crushed excessively in the axial direction by the fastening force of the fasteners. . For this reason, the durability of the seal member is impaired.

Therefore, for example, it is conceivable to configure the seal member to be sandwiched between the motor housing and the inverter case in the radial direction of the motor housing. However, in this case, when assembling the inverter case to the motor housing, the seal member may move in the axial direction of the motor housing, that is, in the direction in which the inverter case and motor housing are fastened, and the seal member may be deformed accordingly. By doing so, there is a concern that durability and sealing performance may be impaired.

The present invention has been made in view of the above-mentioned conventional situation, and even under severe conditions, the deterioration of the conductive member that electrically connects the inverter and the motor mechanism and short circuits between phases can be prevented with higher durability. The problem to be solved is to provide an electric compressor that can more reliably prevent the above problems.

The electric compressor of the present invention includes a compression mechanism that compresses fluid;
a motor mechanism that drives the compression mechanism;
an inverter that controls the drive of the motor mechanism;
a bottomed cylindrical motor housing that houses the motor mechanism therein;
an inverter case that accommodates the inverter therein and is joined to a bottom end of the motor housing;
a fastener that fastens the motor housing and the inverter case in an axial direction of the motor housing;
comprising a conductive member that electrically connects the inverter and the motor mechanism,
The inverter case has a case peripheral wall that has a cylindrical shape and surrounds the inverter and the end portion,
The end portion extends in the radial direction of the motor housing and has an end surface on which the conductive member is provided, and a peripheral surface connected to the end surface and extending in the axial direction,
An annular sealing member is provided between the peripheral surface and the case peripheral wall,
An accommodation groove for accommodating the seal member is recessed in the circumferential surface,
The sealing member is radially sandwiched between the peripheral surface and the case peripheral wall to seal a space in which the conductive member is arranged;
The inverter case has an inverter bottom wall extending in the radial direction and connected to the case peripheral wall and facing the end surface in the axial direction,
The case peripheral wall has a first peripheral wall surrounding the inverter, and a second peripheral wall surrounding the end portion and sandwiching the sealing member between the peripheral surface and the peripheral wall,
The second peripheral wall is located on the opposite side of the first peripheral wall in the axial direction with the inverter bottom wall in between ,
The inverter bottom wall, the first circumferential wall, and the second circumferential wall are integral .

In the electric compressor of the present invention, the annular seal member is provided between the end of the motor housing and the case circumferential wall of the inverter case, more specifically, between the housing groove formed on the circumferential surface of the end and the case circumferential wall. and the inner circumferential surface of the

Here, in this electric compressor, the fastener fastens the motor housing and the inverter case in the axial direction of the motor housing, but the seal member is located between the housing groove and the case peripheral wall, that is, around the end. and the inner peripheral surface of the case peripheral wall. The sealing member is radially sandwiched between the housing groove and the inner peripheral surface of the inverter peripheral wall. Therefore, the seal member is not crushed in the axial direction by the fastening force of the fastener.

Here, in this electric compressor, the housing groove accommodates the seal member. Therefore, when the motor housing and the inverter case are fastened together in the axial direction using a fastener, even if the seal member tries to move in the axial direction while being accommodated in the accommodation groove, the seal member will move in the accommodation groove. By coming into contact with the inner surface, movement in the axial direction is restricted. As a result, in this electric compressor, the seal member is prevented from moving in the axial direction when the inverter case is assembled to the motor housing, and the seal member seals between the end and the case peripheral wall at a suitable position. Can be stopped. Further, in this electric compressor, unnecessary deformation of the seal member due to movement in the axial direction is also suppressed, so that the durability and sealing performance of the seal member are not easily impaired.

In this way, even when this electric compressor is used in an environment where there is a relatively large amount of water or salt water, it is difficult for external moisture to come into contact with the conductive members, leading to deterioration of the conductive members or short circuit between phases. It is more reliably prevented from occurring.

Therefore, in the electric compressor of the present invention, even under severe conditions, deterioration of the conductive member and interphase short circuit can be more reliably prevented with higher durability.

It is preferable that the sealing member has a plurality of annular protrusions on the outer circumferential surface and the inner circumferential surface. In this case, since the sealing member contacts the end portion and the case peripheral wall at each convex portion, even if moisture from the outside gets over the first convexity from the outside of the sealing member, it will not reach the second convexity from the outside. Entry is prevented in the area, and higher sealing performance can be achieved.

On the other hand, since the sealing member does not come into contact with the housing groove or the inner circumferential surface of the case circumferential wall outside of each convex portion, the outer circumferential surface and the inner circumferential surface of the sealing member are in surface contact with the containing groove and the inner circumferential surface of the case circumferential wall, respectively. The contact area between the housing groove and the case circumferential wall and the sealing member is reduced compared to a configuration in which the housing groove and the case peripheral wall are in contact with each other. Therefore, when the motor housing and the inverter case are fastened together in the axial direction, the sealing member deforms while moving in the axial direction, and some of the protrusions may become separated from the housing groove or the case peripheral wall. There is a concern that it may not make sufficient contact with the housing groove or the case peripheral wall. However, in this electric compressor, since the axial movement of the seal member is restricted by the housing groove, deformation of the seal member is less likely to occur. Therefore, it is possible to highly reliably prevent a portion of each convex portion from separating from the housing groove or the case circumferential wall or from not sufficiently abutting the convex portion.

Further, it is also preferable that the seal member has a rectangular cross section in the radial direction. In this case, the sealing member can come into surface contact with the housing groove and the case peripheral wall on the outer peripheral surface and the inner peripheral surface, respectively. Thereby, the sealing member can exhibit higher sealing performance.

Preferably, the second peripheral wall covers the entire housing groove. In this case, the sealing member within the housing groove is less likely to be deteriorated by ultraviolet rays and can exhibit higher durability. Moreover, since the entire housing groove is covered by the second peripheral wall, it becomes difficult for moisture outside the electric compressor to reach the sealing member, so that the sealing member can exhibit higher sealing performance.

The inverter case has an inverter bottom wall that extends in the radial direction, connects to the case peripheral wall, and faces the end surface in the axial direction. Further, the case peripheral wall includes a first peripheral wall that surrounds the inverter, and a second peripheral wall that surrounds the end portion and holds the seal member between the peripheral surface and the first peripheral wall. The second peripheral wall is located on the opposite side of the first peripheral wall in the axial direction with the inverter bottom wall in between .

Therefore , due to the shape formed by the first peripheral wall, the second peripheral wall, and the inverter bottom wall, the inverter case exhibits sufficient rigidity that will not deform even when a high fastening force is applied. As a result, in this electric compressor, the sealing member exhibits suitable sealing performance with excellent durability. The inverter case also exhibits excellent durability.

It is preferable that the peripheral surface and the second peripheral wall have a cylindrical shape, and that the seal member and the housing groove have an annular shape. In this case, by arranging the electric compressor so that the axial direction is horizontal, moisture that has entered the gap between the end and the second peripheral wall on the outside of the sealing member from the outside can be easily discharged to the outside by its own weight. It can prevent deterioration of the seal member, motor housing, and inverter case, and exhibit higher durability.

It is preferable that the first circumferential wall and the second circumferential wall have a cylindrical shape having the same diameter and the same axis. In this case, the first peripheral wall and the second peripheral wall have a structure as one continuous peripheral wall, and can easily exhibit strength even if the inverter case is made thinner to reduce weight.

In the electric compressor of the present invention, even under severe conditions, deterioration of the conductive member and phase-to-phase short circuit can be more reliably prevented with higher durability.

FIG. 1 is a longitudinal sectional view of an electric compressor according to an embodiment . FIG. 2 is an enlarged sectional view of the main parts of the electric compressor of the embodiment . FIG. 3 is an enlarged cross-sectional view of the main parts of the electric compressor of Reference Example 1 . FIG. 4 is an enlarged sectional view of the main parts of the electric compressor of Reference Example 2 .

Embodiments embodying the present invention will be described below with reference to the drawings.

( Example )
As shown in FIG. 1, the electric compressor of the embodiment includes a scroll-type compression mechanism 10, a motor mechanism 12, an inverter 14, and a housing 16. The housing 16 includes a front housing 1, a motor housing 3, and an inverter case 4.

In the following description, the front housing 1 side located on the left side of the paper in FIG. 1 is defined as the front side of the electric compressor, and the inverter case 4 side located on the right side of the paper in FIG. 1 is defined as the rear side of the electric compressor. Furthermore, the upper side of the paper in FIG. 1 is defined as the upper side of the electric compressor, and the lower side of the paper in FIG. 1 is defined as the lower side of the electric compressor. The longitudinal direction corresponds to the "axial direction" in the present invention, and the vertical direction corresponds to the "radial direction" in the present invention. The front-rear direction and up-down direction shown in each figure after FIG. 2 are all shown corresponding to FIG. 1. Note that the front-rear direction in the embodiment is an example. The longitudinal direction of the electric compressor is changed as appropriate depending on the vehicle in which it is mounted.

As shown in FIG. 1, the front housing 1 and the motor housing 3 are butted against each other and fastened to each other by a plurality of bolts 9. The motor housing 3 has a motor peripheral wall 3d extending in a cylindrical shape from front to back, and a motor bottom wall 3a having a disk shape at the rear end of the motor peripheral wall 3d, and has a bottomed cylindrical shape with an opening on the front housing 1 side. doing. A shaft support member 11 is provided within the motor housing 3, and a fixed scroll 13 is provided in front of the shaft support member 11. The front housing 1 and the motor housing 3 house the fixed scroll 13 and the shaft support member 11 in a state where they are in contact with each other.

The motor bottom wall 3a has a front surface 30a facing the front side and a rear surface 30b facing the rear side. The rear surface 30b is an example of an "end surface" in the present invention. The rear surface 30b is located at the rear end of the motor housing 3, including the motor bottom wall 3a. On the other hand, at the center of the inner surface of the front surface 30a, a cylindrical shaft support 3b is provided to protrude forward. On the other hand, the shaft support member 11 includes a cylindrical main body portion 11a and a flange portion 11b projecting outward from the opening edge at the front end of the main body portion 11a. A shaft hole 11c is formed through the center of the main body portion 11a. The flange portion 11b is fixed to the inner peripheral surface of the motor housing 3. On the front side of the flange portion 11b, a rotation prevention pin 17a that restricts the rotation of the movable scroll 15, which will be described later, and allows only revolution is provided to protrude forward.

A rotating shaft 19 extending in the front-rear direction is inserted into the shaft hole 11c. Each end of the rotating shaft 19 is rotatably supported by the shaft support member 11 and the shaft support 3b via radial bearings 21 and 23. A sealing material 25 is provided behind the radial bearing 23, and the sealing material 25 seals between the shaft support member 11 and the rotating shaft 19.

A cylindrical eccentric pin 19a is formed at the front end of the rotating shaft 19 so as to protrude from the axis O extending in the axial direction of the rotating shaft 19. A bush 27 is fitted and supported by the eccentric pin 19a. A balance weight 27a that extends outward in a fan shape is integrally formed approximately half the circumference of the outer peripheral surface of the bush 27.

The fixed scroll 13 includes a disk-shaped fixed substrate 13a extending in the radial direction, a shell 13b extending rearward in a cylindrical shape on the outer peripheral side of the fixed substrate 13a, and a shell 13b extending rearward from the fixed substrate 13a inside the shell 13b. and a fixed spiral wall 13c extending in a spiral shape.

On the other hand, the movable scroll 15 is provided between the bush 27 and the fixed scroll 13 via a radial bearing 29. The movable scroll 15 includes a movable base plate 15a having a disk shape extending in the radial direction, and a movable spiral wall 15b spirally extending forward from the movable base plate 15a. The movable spiral wall 15b is engaged with the fixed spiral wall 13c.

A rotation prevention hole 17b is recessed in the rear surface of the movable substrate 15a and receives the tip of the rotation prevention pin 17a in a loosely fitted state. A cylindrical ring 17c is loosely fitted into the rotation prevention hole 17b. As the rotation prevention pin 17a slides and rolls on the inner peripheral surface of the ring 17c, the movable scroll 15 is restricted from rotating and can only revolve around the axis O. The compression chamber 31 is defined by the fixed substrate 13a, the fixed spiral wall 13c, the movable substrate 15a, and the movable spiral wall 15b.

Inside the motor housing 3, a motor chamber 3c is formed behind the shaft support member 11. The motor chamber 3c also serves as a suction chamber. A stator 33 is provided in the motor chamber 3c and fixed to the inner peripheral surface of the motor peripheral wall 3d. A rotor 35 fixed to the rotating shaft 19 is provided inside the stator 33 . When the rotor 35 and rotating shaft 19 rotate together by energizing the stator 33, the driving force is transmitted to the movable scroll 15 via the eccentric pin 19a and the bush 27, causing the movable scroll 15 to revolve.

A suction port 3e that communicates the outside with the motor chamber 3c is provided through the motor peripheral wall 3d. The suction port 3e is connected to an evaporator (not shown) via piping. The evaporator is connected to the expansion valve and the condenser by piping. The low-pressure, low-temperature refrigerant in the evaporator is introduced into the motor chamber 3c from the suction port 3e, and is supplied to the compression chamber 31 through a suction passage (not shown) formed in the shaft support member 11.

A discharge chamber 37 is formed between the fixed substrate 13a and the front housing 1. A discharge port 13d is formed to penetrate through the center of the fixed substrate 13a, and the discharge port 13d communicates the compression chamber 31 and the discharge chamber 37. The fixed substrate 13a is provided with a discharge valve 39 for opening and closing the discharge port 13d in the discharge chamber 37, and a retainer 41 for regulating the opening degree of the discharge valve 39.

A discharge port 1a is provided through the front housing 1 to communicate the discharge chamber 37 with the outside. The discharge port 1a is connected to a condenser (not shown) via piping. The refrigerant introduced into the discharge chamber 37 is discharged to the condenser through the discharge port 1a.

The motor chamber 3c, rotating shaft 19, bush 27, radial bearing 29, movable scroll 15, fixed scroll 13, discharge chamber 37, discharge valve 39, retainer 41, etc. constitute a compression mechanism 10 that compresses refrigerant. The compression mechanism 10 may also include an oil separator (not shown) provided in the discharge chamber 37. The rotor 35, stator 33, and rotating shaft 19 constitute a motor mechanism 12 that drives the compression mechanism 10. The front housing 1, the motor housing 3, the compression mechanism 10, the motor mechanism 12, and the bolts 9 constitute a compressor main body 20.

The inverter case 4 includes an inverter box 5 and an inverter cover 7. The inverter box 5 has a first peripheral wall 5a, an inverter bottom wall 5b, and a second peripheral wall 5c. The first peripheral wall 5a has a cylindrical shape extending rearward in the direction of the axis O. The inverter bottom wall 5b has a disk shape extending in the radially inward direction of the first peripheral wall 5a on the motor peripheral wall 3d side of the first peripheral wall 5a. The inverter bottom wall 5b is in contact with the rear surface 30b while facing the rear surface 30b of the motor bottom wall 3a. The second peripheral wall 5c has a cylindrical shape that extends forward in the axial direction from the inverter bottom wall 5b, that is, on the opposite side to the first peripheral wall 5a. In this way, the first peripheral wall 5a, the inverter bottom wall 5b, and the second peripheral wall 5c are integrated.

The inverter cover 7 has a cover peripheral wall 7a and an inverter top wall 7b. The cover peripheral wall 7a has a cylindrical shape having the same diameter and the same axis as the first peripheral wall 5a, and is in contact with the first peripheral wall 5a via a gasket (not shown). The first circumferential wall 5a, the second circumferential wall 5c, and the cover circumferential wall 7a constitute a "case circumferential wall" in the present invention. The inverter upper wall 7b has a disc shape that extends radially inward from the cover peripheral wall 7a while being connected to the cover peripheral wall 7a. The cover peripheral wall 7a faces the inverter 14, more specifically, the substrate 14a of the inverter 14 in the front-rear direction.

The inverter 14 is integrated with an inverter holder 45 made of resin. The inverter 14 includes a substrate 14a provided on the inverter cover 7 side of the inverter holder 45, and a switching element 14b, a coil 14c, a connector 14d, etc. connected to the substrate 14a and provided on the inverter box 5 side. Further, the inverter 14 is connected to an external power source through an opening (not shown) formed in the inverter box 5 and the inverter cover 7. The inverter holder 45 is held within the first peripheral wall 5a of the inverter box 5.

An opening 3f communicating with the motor chamber 3c is formed in the rear surface 30b of the motor bottom wall 3a, and an opening 5d communicating with the opening 3f is formed in the inverter bottom wall 5b. Three terminals 49 as conductive members are inserted through the openings 3f and 5d via an insulator 47. Each terminal 49 is connected to the coil of the stator 33 and the connector 14d.

As shown in FIG. 2, the end portion 50 located at the rear end of the motor housing 3 is formed to have a smaller diameter than the other portions. The outer circumferential surface of the end portion 50 is a first circumferential surface 51 having a cylindrical shape extending in the axial direction. The first peripheral surface 51 is an example of a "surrounding surface" in the present invention. That is, the end portion 50 has the motor bottom wall 3a including the rear surface 30a, and the first circumferential surface 51. Further, the first circumferential surface 51 also serves as the outer circumferential surface of the motor bottom wall 3a. The first circumferential surface 51 is connected to the rear end of the motor circumferential wall 3d.

A housing groove 71 is formed in the first circumferential surface 51 . The accommodation groove 71 is recessed in the first circumferential surface 51 so as to move away from the second circumferential wall 5c in the radial direction. Moreover, the accommodation groove 71 is formed in an annular shape that goes around the first circumferential surface 51 in the circumferential direction. The housing groove 71 has a bottom surface 71a and side surfaces 71b. The bottom surface 71a has a planar shape and faces the second peripheral wall 5c in the radial direction. The side surface 71a extends in the radial direction and is connected to the bottom surface 71a and the first circumferential surface 51. On the other hand, the second circumferential wall 5c has a cylindrical second circumferential surface 53 that extends forward in the axial direction and faces the first circumferential surface 51 and the accommodation groove 71. The first circumferential wall 5a and the second circumferential wall 5c have the same diameter and coaxial cylindrical shape, and their respective outer circumferential surfaces are continuously connected. Further, the first circumferential wall 5a, the second circumferential wall 5c, the cover circumferential wall 7a, and the motor circumferential wall 3d have the same diameter and are coaxial.

A rubber seal member 55 is provided between the motor housing 3 and the inverter case 4 and is sandwiched in the radial direction by the housing groove 71 and the second peripheral wall 5c, and further by the end portion 50 and the second peripheral wall 5c. . The seal member 55 seals the space in which the terminal 49 is placed. More specifically, the seal member 55 has an annular shape. The sealing member 55 has a plurality of annular protrusions 55a formed on the inner circumferential surface facing the housing groove 71 and the outer circumferential surface facing the second peripheral surface 53. Moreover, the seal member 55 is provided between the accommodation groove 71 and the second circumferential surface 53, that is, between the first circumferential surface 51 and the second circumferential surface 53, while being accommodated in the accommodation groove 71. . At this time, although the seal member 55 is entirely accommodated in the accommodation groove 71 in the axial direction, a portion of the outer circumferential side including the outer circumferential surface protrudes outside the accommodation groove 71 . In other words, the housing groove 71 is formed to a depth that can accommodate approximately half of the seal member 55 in the radial direction. The seal member 55 is radially sandwiched between the bottom surface 71a and the second circumferential wall 5c in the housing groove 71, so that the entire seal member 55 is covered from the outer circumferential side by the second circumferential wall 5c. Thereby, the seal member 55 is entirely hidden from the outside of the electric compressor by the second peripheral wall 5c.

A plurality of bolt holes 7c, 45a, 5e, and 3g are formed in the inverter top wall 7b of the inverter cover 7, the inverter holder 45, the inverter bottom wall 5b of the inverter box 5, and the motor peripheral wall 3d, respectively. Each bolt 43 is inserted into each bolt hole 7c, 45a, 5e, and screwed into the bolt hole 3g. That is, each bolt 43 is fastened to one end of the motor housing 3 while passing through the inverter case 4 .

The electric compressor configured as described above constitutes a refrigeration circuit of a vehicle air conditioner together with an evaporator, an expansion valve, and a condenser. This electric compressor operates as follows. That is, when the driver of the vehicle performs an operation on the vehicle air conditioner, the inverter 14 controls the motor mechanism 12 to rotate the rotor 35 and the rotating shaft 19. Then, the eccentric pin 19a is rotated around the axis O. At this time, the rotation prevention pin 17a slides and rolls along the inner peripheral surface of the ring 17c, so that the movable scroll 15 is prevented from rotating and is only allowed to revolve around the axis O. Then, as the movable scroll 15 revolves, the compression chamber 31 is moved from the outer peripheral side of the fixed scroll 13 and the movable scroll 15 to the center side while decreasing the volume. Therefore, the refrigerant supplied from the evaporator to the motor chamber 3c through the suction port 3e is sucked into the compression chamber 31 and compressed. The refrigerant compressed to the discharge pressure is discharged from the discharge port 13d into the discharge chamber 37, and then discharged to the condenser via the discharge port 1a. In this way, air conditioning of the vehicle air conditioner is performed.

At this time, in this electric compressor, the annular seal member 55 is arranged between the bottom surface 71a of the housing groove 71 and the second circumferential surface 53 of the second circumferential wall 5c of the inverter box 5, and between the end portion 50 and the second circumferential wall. 5c is sealed.

Here, in this electric compressor, the plurality of bolts 43 fasten the motor housing 3 and the inverter case 4 in the axial direction, but the seal member 55 is located between the housing groove 71 and the second peripheral wall 5c, that is, , located between the first circumferential surface 51 of the end portion 50 and the second circumferential surface 53 of the second circumferential wall 5c. The first circumferential surface 51 on which the accommodation groove 71 is formed has a cylindrical shape extending in the axial direction, and the second circumferential surface 53 also has a cylindrical shape extending in the axial direction. For this reason, the seal member 55 is not crushed in the axial direction by the fastening force. Further, in this electric compressor, a seal member 55 is accommodated in an accommodation groove 71 formed in the end portion 50 of the motor housing 3, more specifically, in the first circumferential surface 51 of the end portion 50. Therefore, when assembling the motor housing 3 and the inverter box 5 in the axial direction, or when fastening the motor housing 3 and the inverter case 4 in the axial direction using a plurality of bolts 43, this electric compressor When the seal member 55 tries to move in the axial direction, the seal member 55 comes into contact with the accommodation groove 71, more specifically, the side surface 71b of the accommodation groove 71. In this way, in this electric compressor, the seal member 55 is restricted from moving beyond the accommodation groove 71 in the axial direction. Thereby, the seal member 55 is difficult to shift in the axial direction with respect to the first circumferential surface 51 and the second circumferential surface 53, and it is possible to seal between the end portion 50 and the second circumferential wall 5c at a suitable position. It becomes.

Furthermore, in this electric compressor, since the first peripheral wall 5a and the second peripheral wall 5c extend in opposite directions from the inverter bottom wall 5b between them, a high fastening force is applied to the inverter case 4. It also exhibits sufficient rigidity to prevent deformation.

In particular, in this electric compressor, since the first circumferential wall 5a and the second circumferential wall 5c are cylindrical with the same diameter, they have a structure as one continuous circumferential wall, and the inverter case 4 is designed to be lightweight. Easily exhibits strength even when made thin. Therefore, the inverter case 4 exhibits excellent durability.

In addition, since the seal member 55 has a plurality of annular convex portions 55a on the outer circumferential surface and the inner circumferential surface, the seal member 55 is attached to the bottom surface 71a of the housing groove 71 and the second circumferential surface 53 of the second circumferential wall 5c. A plurality of strips abut against each other. Therefore, even if moisture from the outside overcomes the first protrusion 55a from the outside in the sealing member 55, the second protrusion 55a from the outside prevents moisture from entering, and higher sealing performance can be achieved. . Therefore, the seal member 55 exhibits suitable sealing performance with excellent durability.

Therefore, even when this electric compressor is used in an environment where there is a relatively large amount of water or salt water, it is difficult for external moisture to come into contact with the terminal 49, causing deterioration of the terminal 49 or short circuit. It is more reliably prevented from occurring. Here, the seal member 55 does not come into contact with the bottom surface 71a and the second circumferential surface 53 except for each convex portion 55a. In other words, the seal member 55 only makes point contact with the bottom surface 71a and the second circumferential surface 53 through each convex portion 55a. Therefore, the contact area between the bottom surface 71a and the second circumferential surface 53 and the seal member 55 is reduced. However, as described above, in this electric compressor, the accommodation groove 71 restricts the movement of the seal member 55 in the axial direction. Thereby, even if the contact area between the bottom surface 71a and the second circumferential surface 53 and the seal member 55 is small, the seal member 55 is unlikely to be deformed due to movement in the axial direction. Therefore, in this electric compressor, each convex portion is It is possible to highly reliably prevent a part of 55a from separating from the second circumferential surface 53 of the bottom surface 71a or from not sufficiently abutting the second circumferential surface 53 of the bottom surface 71a.

Therefore, in this electric compressor, deterioration and short circuit of the terminal 49 can be more reliably prevented with higher durability even under severe conditions.

Further, in this electric compressor, the first circumferential surface 51 and the second circumferential surface 53 are cylindrical, and the seal member 55 and the housing groove 71 are annular. Therefore, by arranging the electric compressor so that the axial direction is horizontal, moisture that has entered the first circumferential surface 51 and the second circumferential surface 53 on the outside of the seal member 55 from the outside is discharged to the outside by its own weight. This prevents deterioration of the seal member 55, motor housing 3, and inverter case 4, thereby achieving higher durability.

Further, in this electric compressor, the motor housing 3 and the inverter case 4 are fastened together, so that the second peripheral wall 5c covers the entire housing groove 71 from the outer peripheral side. Thereby, the second circumferential wall 5c also covers the entirety of the seal member 55 accommodated in the accommodation groove 71 from the outer circumferential side. As a result, in this electric compressor, the seal member 55 is less likely to deteriorate due to ultraviolet rays, and the seal member 55 exhibits higher durability. Further, since the housing groove 71 and the sealing member 55 are entirely covered by the second peripheral wall 5c in this way, it becomes difficult for moisture outside the electric compressor to reach the sealing member 55. In particular, since the sealing member 55 contacts the bottom surface 71a and the second circumferential surface 53 in a plurality of strips, even if moisture from the outside reaches the sealing member 55, and the first strip from the outside in the sealing member 55 Even if you get over the section, the second section from the outside will prevent you from entering. Therefore, the seal member 55 can exhibit higher sealing performance.

Furthermore, in this electric compressor, the inverter bottom wall 5b is in contact with the rear surface 30b of the motor bottom wall 3a of the motor housing 3, which has a motor chamber 3c that also serves as a suction chamber, so that the inverter 14 can be easily cooled. ing. In particular, when it is desired to cool the switching element 14b and the coil 14c, it is also possible to bring them into contact with the inverter bottom wall 5b.

Further, in this electric compressor, unlike an electric compressor in which a cup-shaped member is joined to the end surface of the motor housing 3 to form an inverter housing chamber, the inverter case 4 is a housing container completely independent of the motor housing 3. It is configured as. Therefore, even if the inverter 14 including the filter element is increased in size, the housing space can be easily increased in size. On the contrary, the weight of the inverter case 4 and the inverter 14 increases, and a high fastening force is required, but the sealing member 55 does not deteriorate.

( Reference example 1 )
As shown in FIG. 3, the electric compressor of Reference Example 1 includes an inverter case 8 and a seal member 56 in place of the inverter case 4 and seal member 55 in the electric compressor of the example . Here, in the electric compressor of the example , the inverter case 4 is constituted by two members, the inverter box 5 and the inverter cover 7, whereas in the electric compressor of the reference example 1 , the inverter case 4 is constituted by one member. An inverter case 8 is configured.

Inverter case 8 has a case peripheral wall 8a and a case bottom wall 8b. The case peripheral wall 8a is formed in a cylindrical shape extending in the axial direction. More specifically, the case circumferential wall 8a is formed into a cylindrical shape having the same diameter and the same axis as the motor circumferential wall 3d of the motor housing 3. That is, the case peripheral wall 8a has a larger diameter than the end portion 50 of the motor housing 3. Further, a third circumferential surface 81 facing the first circumferential surface 51 of the end portion 50 and the housing groove 71 is formed on the case circumferential wall 8a.

The case bottom wall 8b has a disc shape that extends radially inward from the case peripheral wall 8a while being connected to the case peripheral wall 8a. Further, a plurality of bolt holes 8c are formed in the case bottom wall 8b. Here, the inverter case 8 is not provided with the inverter bottom wall 5b. Therefore, the inverter case 8 has a bottomed cylindrical shape, that is, a cup shape, by the case peripheral wall 8a and the case bottom wall 8b.

Also in this electric compressor, the inverter case 8 accommodates the inverter 14 and the inverter holder 45 therein, and is joined to the end portion 50 of the motor housing 3 by a plurality of bolts 43. Thereby, in the inverter case 8, the case peripheral wall 8a surrounds the inverter 14 and the inverter holder 45, and also surrounds the end portion 50. Further, the case bottom wall 8b faces the board 14a of the inverter 14 in the front-back direction. Here, since the inverter case 8 is not provided with the inverter bottom wall 5b, the inverter holder 45 is held on the rear surface 30b of the motor bottom wall 3a of the motor housing 3.

Like the seal member 55, the seal member 56 is made of rubber and has an annular shape. Here, unlike the seal member 55, the seal member 56 does not have a convex portion 55a formed therein. Thereby, the seal member 56 has a rectangular cross section in the radial direction. More specifically, the radial cross section of the seal member 56 has a rectangular shape in which the axial sides are longer than the radial sides.

The seal member 56 is housed in the housing groove 71 and is provided between the bottom surface 71a of the housing groove 71 and the third circumferential surface 81, that is, between the first circumferential surface 51 and the third circumferential surface 81. There is. At this time, the seal member 56 is also entirely accommodated in the accommodation groove 71 in the axial direction, but a portion of the outer circumferential side including the outer circumferential surface protrudes outside the accommodation groove 71. The seal member 56 is radially sandwiched between the bottom surface 71a and the case peripheral wall 8a within the housing groove 71, thereby sealing the space in which the terminal 49 is disposed. Further, the seal member 56 is entirely covered from the outer peripheral side by the case peripheral wall 8a. Thereby, the seal member 56 is entirely hidden from the outside of the electric compressor by the case peripheral wall 8a. The other configurations of this electric compressor are the same as those of the electric compressor of the embodiment , and the same configurations are given the same reference numerals and detailed explanations regarding the configurations will be omitted.

In this electric compressor, since the radial cross section of the seal member 56 is rectangular, the outer circumferential surface of the seal member 56 is in surface contact with the third circumferential surface 81, and the inner circumferential surface of the seal member 56 is in surface contact with the bottom surface. 71a. Thereby, a large contact area between the third circumferential surface 81 and the bottom surface 71a and the seal member 56 is ensured. In particular, the radial cross section of the seal member 56 has a rectangular shape in which the axial sides are longer than the radial sides. Therefore, in this electric compressor, the contact area between the third circumferential surface 81 and the bottom surface 71a and the seal member 56 is larger than in the case where the seal member 56 has a cubic cross section in the radial direction. Therefore, in this electric compressor, the sealing member 56 can suitably seal between the bottom surface 71a and the third circumferential surface 81, and further between the end portion 50 and the case circumferential wall 8a. ing. Further, unlike the seal member 55, there is no need to provide the convex portion 55a on the seal member 56, so the configuration of the seal member 56 is simplified compared to the seal member 55. Therefore, in this electric compressor, formation of the seal member 56 is also easy.

In this electric compressor, the inverter case 8 is constituted by one member, and has a bottomed cylindrical shape with a case peripheral wall 8a and a case bottom wall 8b. Therefore, in this electric compressor, the manufacturing cost is reduced by reducing the number of parts compared to the electric compressor of the embodiment . Other functions of this electric compressor are similar to those of the electric compressor of the embodiment .

(Reference example 2 )
In the electric compressor of Reference Example 2 , as shown in FIG. 4, a cylindrical tube portion 3j is formed at the rear end of the motor bottom wall 3a of the motor housing 3, and a cylindrical tube portion 3j is formed at the rear end in the axial direction as the inner peripheral surface of the tube portion 3j. A first circumferential surface 61 is formed in a cylindrical shape that extends. The cylindrical portion 3j is connected to the motor peripheral wall 3d. On the other hand, the inverter box 5 is formed with a first circumferential wall 5g having a small diameter and a first circumferential wall 5h having a large diameter continuous with the first circumferential wall 5g, and does not have a second circumferential wall 5c as in the embodiment . A second circumferential surface 62 facing the first circumferential surface 61 is formed as an outer circumferential surface of the first circumferential wall 5g. A seal member 55 is provided between the first circumferential surface 61 and the second circumferential surface 62. Here, in this electric compressor, the accommodation groove 71 for accommodating the seal member 55 is not formed on the first circumferential surface 61 or the second circumferential surface 62. The other configurations of this electric compressor are similar to the electric compressor of the embodiment .

In this electric compressor, since the inverter box 5 does not have a second peripheral wall, there is a concern about the strength. Further, in this electric compressor, since it is necessary to form the cylindrical portion 3j in the motor housing 3, manufacturing of the motor housing 3 becomes complicated and manufacturing cost increases. Furthermore, in this electric compressor, since the housing groove 71 is not formed in the first circumferential surface 61 or the second circumferential surface 62, it is difficult to assemble the motor housing 3 and the inverter box 5 in the axial direction, Therefore, when the motor housing 3 and the inverter case 4 are fastened together in the axial direction, the seal member 55 is easily moved in the axial direction. This makes it difficult for the seal member 55 to seal between the first circumferential surface 61 and the second circumferential surface 62 at a suitable position.

Although the present invention has been described above based on examples , it goes without saying that the present invention is not limited to the above-mentioned examples , and can be applied with appropriate modifications without departing from the spirit thereof.

For example, in the above embodiment , the compression mechanism 10 is a scroll type, but in the electric compressor of the present invention, it is also possible to employ other types of compression mechanisms such as a swash plate type and a vane type.

Further, an electric compressor may be formed by appropriately combining the configuration of the embodiment and the configuration of Reference Example 1 .

INDUSTRIAL APPLICATION This invention can be utilized for air conditioners, such as a vehicle.

3...Motor housing 3a...Motor bottom wall 4...Inverter case (5...Inverter box, 7...Inverter cover)
5a...first peripheral wall (case peripheral wall)
5b...Inverter bottom wall 5c...Second peripheral wall (case peripheral wall)
7a...Cover peripheral wall (case peripheral wall)
8... Inverter case 8a... Case peripheral wall 10... Compression mechanism 12... Motor mechanism 14... Inverter 30b... Rear surface (end surface)
43... Fastener (bolt)
49...Conductive member (terminal)
50... End portion 51... First circumferential surface (circumferential surface)
55... Seal member 55a... Convex portion 56... Seal member 71... Accommodation groove

Claims (6)

a compression mechanism that compresses fluid;
a motor mechanism that drives the compression mechanism;
an inverter that controls the drive of the motor mechanism;
a bottomed cylindrical motor housing that houses the motor mechanism therein;
an inverter case that accommodates the inverter therein and is joined to a bottom end of the motor housing;
a fastener that fastens the motor housing and the inverter case in an axial direction of the motor housing;
comprising a conductive member that electrically connects the inverter and the motor mechanism,
The inverter case has a case peripheral wall that has a cylindrical shape and surrounds the inverter and the end portion,
The end portion extends in the radial direction of the motor housing and has an end surface on which the conductive member is provided, and a peripheral surface connected to the end surface and extending in the axial direction,
An annular sealing member is provided between the peripheral surface and the case peripheral wall,
An accommodation groove for accommodating the seal member is recessed in the circumferential surface,
The sealing member is radially sandwiched between the peripheral surface and the case peripheral wall to seal a space in which the conductive member is arranged;
The inverter case has an inverter bottom wall extending in the radial direction and connected to the case peripheral wall and facing the end surface in the axial direction,
The case peripheral wall has a first peripheral wall surrounding the inverter, and a second peripheral wall surrounding the end portion and sandwiching the sealing member between the peripheral surface and the peripheral wall,
The second peripheral wall is located on the opposite side of the first peripheral wall in the axial direction with the inverter bottom wall in between ,
An electric compressor , wherein the inverter bottom wall, the first circumferential wall, and the second circumferential wall are integral . The peripheral surface and the second peripheral wall are cylindrical,
The electric compressor according to claim 1, wherein the seal member and the housing groove are annular. The first peripheral wall and the second peripheral wall are cylindrical with the same diameter and coaxial ,
the end portion has a smaller diameter than other portions of the motor housing;
The outer circumferential surface of the end portion is the circumferential surface,
The electric compressor according to claim 2 , wherein the other portion has the same diameter and coaxiality as the first circumferential wall and the second circumferential wall . The electric compressor according to any one of claims 1 to 3, wherein the sealing member has a plurality of annular protrusions on an outer circumferential surface and an inner circumferential surface. The electric compressor according to any one of claims 1 to 3, wherein the seal member has a rectangular cross section in the radial direction. The second peripheral wall covers the entire housing groove ,
The inverter case includes an inverter box having the inverter bottom wall, the first peripheral wall, and the second peripheral wall;
a cylindrical cover peripheral wall having the same diameter and coaxiality as the first peripheral wall; and a disk-shaped inverter upper wall extending radially inward from the cover peripheral wall while being connected to the cover peripheral wall; The electric compressor according to any one of claims 1 to 5, further comprising an inverter cover fastened to the inverter box in the direction of the inverter cover .

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