Electric compressor

Abstract

[Problem] To provide an electric compressor in which condensed water does not readily drop onto a power source connector. [Solution] An electric compressor 1 comprises: a rotary shaft 10 that extends in a horizontal direction; an electric motor 20 that rotates the rotary shaft 10; a compression mechanism 30 that is driven by the rotary shaft 10; a housing 50 that accommodates the electric motor 20 and the compression mechanism 30 while accommodating the rotary shaft 10 in a rotatable manner; and a cover member 60 that covers the periphery of the housing 50. A refrigerant suction port 52B is formed in an upper part of the housing 50, and a power source connector 42 is attached to a lower part of the housing 50 positioned directly below the suction port 52B. On an outer peripheral surface of the cover member 60, a protruding part 67 is formed as one example of a drain passage for guiding condensed water, which flows down from the suction port 52B or a suction pipe connected thereto, to the lower part of the cover member 60 so as to avoid the power source connector 42.

Description

Electric compressor

[0001] The present invention relates to an electric compressor that compresses a refrigerant with an electric motor.

[0002] In order to reduce the noise generated by an electric compressor, a technique has been proposed in which the periphery of the electric compressor is covered with a cover member such as a sound-insulating material, as described in Japanese Patent Laid-Open No. 2015-224824 (Patent Document 1).

[0003] JP 2015-224824 A

[0004] Some electric compressors have an upper intake port for refrigerant intake and a lower power connector located directly below the intake port. In this case, if condensation builds up on the intake port or the intake piping connected to it, the condensation may flow down the outer periphery of the cover or through the minute gap between the housing and the cover, potentially dripping onto the power connector from the bottom of the cover. If the condensation drips onto the power connector and penetrates the connector, it can corrode the connector terminals or cause a short circuit.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electric compressor in which condensed water is less likely to drip onto the power connector.

[0006] The electric compressor includes a horizontally extending rotating shaft, an electric motor that rotates the rotating shaft, a compression mechanism driven by the rotating shaft, a housing that rotatably accommodates the rotating shaft and houses the electric motor and the compression mechanism, and a cover member that covers the periphery of the housing. The housing has an upper portion formed with a refrigerant suction port, and a power connector attached to a lower portion of the housing directly below the suction port. The cover member has a drain passage that guides condensation water that flows down from the suction port or the suction piping connected to it to the lower portion of the cover member, avoiding the power connector.

[0007] According to the present invention, it is possible to make it difficult for condensed water to drip onto the power connector of an electric compressor.

[0008] Fig. 1 is a longitudinal sectional view showing an overview of an electric compressor to which the present invention can be applied; Fig. 2 is a perspective view showing an example of the appearance of an electric compressor with a cover member removed; Fig. 3 is a perspective view showing an example of the appearance of a cover member; Fig. 4 is a perspective view showing an example of an electric compressor with a cover member attached; Fig. 5 is a plan view showing an example of a cover member having a two-part structure; Fig. 6 is an explanatory diagram of the action and effect of a convex portion formed on the outer peripheral surface of the cover member; Fig. 7 is an explanatory diagram of the action and effect of a concave portion formed on the inner peripheral surface of the cover member;

[0009] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an example of a horizontally mounted electric compressor 1 to which the present invention can be applied. Note that the electric compressor 1 described below is merely an example and should not be construed as being limited to this configuration. Therefore, it should be noted that the present invention can be applied to a variety of electric compressors known to those skilled in the art.

[0010] The electric compressor 1 has a rotating shaft 10 extending horizontally (forward and backward), an electric motor 20 that rotates the rotating shaft 10, a compression mechanism 30 driven by the rotating shaft 10, an inverter 40 that drives and controls the electric motor 20, a housing 50 that supports the rotating shaft 10 so that it can rotate freely and accommodates the rotating shaft 10, the electric motor 20, the compression mechanism 30 and the inverter 40, and a cover member 60 that covers the periphery of the housing 50.

[0011] The housing 50 includes a cylindrical center housing 51, a cylindrical front housing 52 with a bottom and an opening joined to the front end (left end in FIG. 1 ) of the center housing 51, a cylindrical rear housing 53 with a bottom and an opening joined to the rear end (right end in FIG. 1 ) of the center housing 51, a rectangular inverter housing 54 with a bottom and an opening joined to the front end of the front housing 52, and an inverter cover 55 that closes the opening end of the inverter housing 54. Here, the inverter housing 54 is integrated with the front housing 52, but may also be completely separate from the front housing 52. The center housing 51, the front housing 52, and the rear housing 53 are not limited to having a cylindrical cross section and may have any cross section, such as a square or polygonal cross section.

[0012] The electric motor 20 includes a cylindrical stator 21 disposed on the inner peripheral surface of the front end of the center housing 51, and a cylindrical rotor 22 rotatably disposed inside the stator 21. The compression mechanism 30 is a well-known compression mechanism such as a scroll compression mechanism, and is disposed on the rear end of the center housing 51.

[0013] The rotating shaft 10 has an intermediate portion that passes through a through-hole located at the center of the rotor 22 and is integrated with the rotor 22. The front end of the rotating shaft 10 is rotatably supported by a bearing 52A formed on the bottom wall of the front housing 52. The rear end of the rotating shaft 10 is connected to a drive unit (not shown) of the compression mechanism 30. Therefore, when a drive current is supplied to the stator 21 of the electric motor 20, the rotor 22 and the rotating shaft 10 integrated therewith rotate, thereby operating the compression mechanism 30. The rotating shaft 10 may be rotatably supported by another bearing (not shown).

[0014] A suction port 52B for drawing refrigerant from the low-pressure side of an external refrigerant circuit is formed at a predetermined location of the front housing 52, specifically at an upper portion forward of the electric motor 20. Furthermore, a discharge port 53A for discharging high-pressure refrigerant discharged from the compression mechanism 30 to the high-pressure side of the external refrigerant circuit is formed at a predetermined location of the rear housing 53, specifically at an upper portion near the bottom wall of the rear housing 53. It should be understood that the term "upper portion" is not limited to the uppermost portion of the front housing 52 or the rear housing 53, but may also refer to the vicinity thereof.

[0015] The refrigerant drawn into the interior of the front housing 52 through the suction port 52B passes through the gap between the stator 21 and the rotor 22 to cool the electric motor 20, and is then introduced into the compression chamber through a refrigerant inlet (not shown) of the compression mechanism 30. The refrigerant introduced into the compression chamber is compressed into a high-pressure refrigerant, and is discharged into the interior of the rear housing 53 through a refrigerant outlet (not shown) of the compression mechanism 30. The refrigerant is then returned to the high-pressure side of the external refrigerant circuit through a discharge port 53A of the rear housing 53.

[0016] The inverter housing 54 is integrated with the front housing 52 in front of the front housing 52, sharing a bottom wall with the front housing 52. The inverter housing 54 is disposed such that its upper portion is located above the front housing 52 and its lower portion is located below the front housing 52. The lower portion of the inverter housing 54 protrudes from the front housing 52 by a greater amount than the upper portion.

[0017] An inverter 40 for driving and controlling the electric motor 20 is disposed inside the inverter housing 54. The inverter 40 is configured to supply a drive current to the stator 21 of the electric motor 20 via a power supply line 41 that extends through the bottom wall shared by the front housing 52 and the inverter housing 54. The inverter 40 is also configured to be able to receive a DC current from an external DC power source via a power connector 42 that is disposed in the lower part of the inverter housing 54, specifically in a position directly below the suction port 52B of the front housing 52. It should be understood that "directly below" herein is not limited to being directly below the suction port 52B, but may also refer to the vicinity thereof.

[0018] The cover member 60 is made of, for example, a resin having sound insulation properties, and is configured to cover at least the outer peripheral surface of the housing 50 excluding the suction port 52B, the discharge port 53A, and the power connector 42 of the electric compressor 1. Therefore, the cover member 60 is configured to have an inner surface that conforms to the outer surface of the housing 50 of the electric compressor 1.

[0019] FIG. 2 shows an example of the appearance of the electric compressor 1 with the cover member 60 removed. The housing 50 of the electric compressor 1 has, for example, multiple bosses BS and brackets BK for mounting to a vehicle, as well as multiple ribs for ensuring strength. In the example shown in FIG. 2 , one boss BS is formed on the top of the center housing 51 and a pair of bosses BS are formed on the top of the inverter housing 54. However, the number and positions of the bosses BS can be changed depending on, for example, the size of the electric compressor 1. Also, in the example shown in FIG. 2 , two brackets BK are attached to the inverter housing 54. However, the number and positions of the brackets BK can be changed depending on, for example, the size of the electric compressor 1. Therefore, the inner circumferential surface of the cover member 60 is formed to conform to the outer circumferential surface of the housing 50, which has such a complex shape.

[0020] 3 shows an example of the appearance of the cover member 60. The cover member 60 includes a first cover member 61 having a cylindrical shape with a bottom that covers the center housing 51, the front housing 52, and the rear housing 53, and a second cover member 62 having a rectangular cylindrical shape with a bottom that covers the inverter housing 54 and the inverter cover 55.

[0021] The first cover member 61 is formed with at least a first notch 63 for accessing the discharge port 53A formed in the rear housing 53, and a second notch 64 for avoiding interference with bosses BS formed in the center housing 51. The second cover member 62 is formed with at least a third notch 65 for accessing the power connector 42 attached to the inverter housing 54 and for avoiding interference with the bracket BK. The first cover member 61 and the second cover member 62 are further formed with a fourth notch 66 for avoiding interference with a pair of bosses BS formed on the upper part of the inverter housing 54 and for accessing the suction port 52B formed in the front housing 52.

[0022] Therefore, when the cover member 60 is attached around the housing 50, as shown in FIG. 4 , the first notch 63, the second notch 64, the third notch 65, and the fourth notch 66 expose the power connector 42, the suction port 52B, the discharge port 53A, the three bosses BS, and the two brackets BK to the outside. Therefore, even when the cover member 60 is attached around the housing 50, the electric compressor 1 can be mounted to a vehicle using the three bosses BS and the two brackets BK. Furthermore, even when the cover member 60 is attached around the housing 50, an intake pipe (not shown) can be connected to the suction port 52B, and an exhaust pipe (not shown) can be connected to the exhaust port 53A. Furthermore, even when the cover member 60 is attached around the housing 50, a harness can be connected to the power connector 42. Furthermore, with the cover member 60 attached around the housing 50, the suction pipe and discharge pipe can be removed from the suction port 52B and discharge port 53A, the harness can be removed from the power connector 42, and the electric compressor 1 can be removed from the vehicle.

[0023] To facilitate attachment of the cover member 60 to the housing 50, it is desirable to configure the cover member 60 so that it is divided into two parts by a vertical plane extending along the central axis of the rotating shaft 10, that is, divided into left and right halves, as shown in Fig. 5. In this case, the two halves of the cover member 60 are connected by a hinge 69, and the cover member 60 is completed by folding the two halves of the cover member 60. In addition, the first notch 63, the second notch 64, the third notch 65, and the fourth notch 66 of the cover member 60 are formed by folding the two halves of the cover member 60. Note that the hinge 69 may be cut off, if necessary, after the cover member 60 is attached to the housing 50.

[0024] In the electric compressor 1, when the temperature of the suction port 52B or the suction piping connected thereto drops below the atmospheric dew point, water vapor in the atmosphere may turn into droplets, resulting in condensation water adhering to the suction port 52B or the suction piping. As the condensation water adhering to the suction port 52B or the suction piping grows, it flows downward due to gravity, and the condensation water flows downward along at least one of the outer peripheral surface of the cover member 60 and the minute gap between the housing 50 and the cover member 60. If the condensation water drips from the bottom of the cover member 60 onto the power connector 42 located directly below the suction port 52B, the condensation water may enter the power connector 42 through a gap between the power connector 42 and the harness connected thereto, potentially causing, for example, terminal corrosion or a short circuit.

[0025] Therefore, a drain passage is formed in the cover member 60 to guide condensation water flowing down from the suction port 52B or the suction piping connected thereto to the lower part of the cover member 60, avoiding the power connector 42. The drain passage can be composed of a pair of protrusions 67 formed on the outer peripheral surface of the cover member 60, as shown in Figures 3 and 4, and a pair of recesses 68 formed on the inner peripheral surface of the cover member 60, as shown in Figure 5.

[0026] 3 and 4, each of the protrusions 67 formed on the outer peripheral surface of the cover member 60 is formed to extend obliquely downward from the transitional portion to the second cover member 62 in the upper half of the first cover member 61 to a position that avoids the power connector 42. Here, in the illustrated example, the protrusions 67 are further bent downward midway, but the protrusions 67 may also extend linearly.

[0027] As shown in Figure 5, each recess 68 formed on the inner peripheral surface of the cover member 60 extends diagonally downward from the lower end of the fourth cutout 66, which provides access to the suction port 52B, to a position that avoids the power connector 42. The tip (lower end) of each recess 68 extends to the lowest part of the first cover member 61, where a drain port 68A that communicates with the outside of the cover member 60 is formed. Therefore, when the cover member 60 is attached to the housing 50, the outer peripheral surface of the housing 50 and the inner peripheral surfaces of the recesses 68 of the cover member 60 form a drain passage having a substantially semicircular cross section.

[0028] Next, the action and effect of the convex portion 67 and the concave portion 68 formed on the cover member 60 will be described. As shown in Figure 6, when condensed water CW adheres to and grows on the suction port 52B of the electric compressor 1 or the suction piping SC connected thereto, the condensed water begins to flow downward due to gravity. The condensed water that flows downward then drips between the periphery of the suction port 52B and the inner periphery of the fourth notch portion 66, and some of the condensed water flows downward along the outer circumferential surface of the cover member 60, while the rest flows downward through the minute gap between the housing 50 and the cover member 60.

[0029] Condensed water that flows downward along the outer peripheral surface of the cover member 60 is received by a protrusion 67 formed on the cover member 60, as shown by the dashed line in Figure 6, and is guided along the protrusion 67 to a position that avoids the power connector 42. The condensed water then drips from the tip of the protrusion 67 onto the harness HN connected to the power connector 42. The harness HN is usually covered with a water-resistant material, so dripping of condensed water onto it does not cause any problems (the same applies below).

[0030] 7, the condensed water that flows downward through the small gap between the housing 50 and the cover member 60 is received by a recess 68 formed in the cover member 60 and guided along the recess 68 to a position away from the power connector 42. The condensed water is then discharged from a drain port 68A formed at the tip of the recess 68 and drips onto the harness HN connected to the power connector 42.

[0031] Therefore, even if condensation water adheres to and grows on the suction port 52B or the suction piping SC connected thereto, the condensation water is prevented from dripping onto the power connector 42. Furthermore, by preventing condensation water from dripping onto the power connector 42, the condensation water is prevented from entering the interior between the power connector 42 and the harness HN, thereby preventing terminal corrosion and short circuits.

[0032] Furthermore, a person skilled in the art will easily understand that new embodiments can be created by omitting parts of the technical ideas of the various above-mentioned embodiments, combining parts of them appropriately, or replacing parts of them with well-known technology, provided that the desired effects are achieved.

[0033] For example, the electric compressor 1 may not have the inverter 40, the inverter housing 54, and the inverter cover 55. In this case, the electric compressor 1 may be configured so that the drive current for the electric motor 20 is supplied from an externally disposed inverter via the power connector 42.

[0034] 1...electric compressor, 10...rotating shaft, 20...electric motor, 30...compression mechanism, 40...inverter, 42...power connector, 50...housing, 52B...suction port, 60...cover member, 67...convex portion (drain passage), 68...concave portion (drain passage), CW...condensed water, SC...suction pipe

Claims

1. An electric compressor having a rotating shaft extending horizontally, an electric motor which rotates the rotating shaft, a compression mechanism driven by the rotating shaft, a housing which rotatably supports the rotating shaft and contains the electric motor and the compression mechanism, and a cover member which covers the periphery of the housing, wherein a refrigerant suction port is formed in an upper part of the housing and a power connector is attached to a lower part of the housing located directly below the suction port, wherein the cover member is formed with a drain passage which guides condensation water flowing down from the suction port or an suction piping connected thereto to the lower part of the cover member avoiding the power connector.

2. The electric compressor according to claim 1, wherein the drain passage comprises at least one of a protrusion extending obliquely on the outer circumferential surface of the cover member and a recess extending obliquely on the inner circumferential surface of the cover member.

3. The electric compressor according to claim 1, wherein the cover member is configured to be divided into two by a vertical plane extending along the central axis of the rotating shaft.

4. The electric compressor according to claim 1, further comprising an inverter for controlling the driving of said electric motor, said inverter being disposed on the electric motor side of said housing.

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