JP2008042956A - Electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the cooling capacity of an inverter 20 in an electric compressor 100. <P>SOLUTION: In the electric compressor 100, a slot cover section 16 is formed to cover each slot 14a and a stator coil 15 from one end side in the axial direction and thereby the slot cover section 16 can suppress inflow of refrigerant into each slot 14a from the motor housing 11. Consequently, a sufficient quantity of refrigerant flowing between the outer surface of the stator coil 15 and the inner surface of the motor housing 11 can be ensured and the cooling capacity of an inverter 20 can be enhanced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric compressor that electrically drives a compressor.

  As shown in FIG. 10, a conventional electric compressor includes a motor housing 1, a rotating shaft 2, a rotor 3, a stator core 4, a stator coil 5, an inverter device 6, and a compressor 7 (see Patent Document 1). FIG. 10 schematically illustrates the configuration shown in Patent Document 1.

  In this configuration, the rotating shaft 2 rotates in the motor housing 1 and transmits a driving force to the compressor 7. The rotor 3 is fixed by the rotating shaft 2 and is rotated by a rotating magnetic field generated from the stator core 4. The stator core 4 includes a plurality of slots (voids) 4 a that are arranged radially outward with respect to the rotor 3 and arranged in the rotational direction, and a plurality of protrusions 4 b that respectively protrude toward the rotor 3.

The stator coil 5 is wound around each of the plurality of protrusions so as to pass through the slot, and generates a rotating magnetic field from the stator core 4 by energization. The inverter device 6 is disposed on the outer surface of the motor housing 1. A refrigerant is allowed to flow between the inner peripheral surface of the motor housing 1 and the outer peripheral surface of the stator core 5 as indicated by arrows, and the refrigerant cools the inverter device 6 via the motor housing 1.
JP 2003-324900 A

  However, in the above-described prior art, the stator coil 5 is wound around the plurality of protrusions of the stator core 4 so as to pass through the slot, but the slot is not sealed by the stator coil 5. A gap is formed in the slot.

  Therefore, when a refrigerant is flowed into the motor housing 1 to cool the inverter device, the refrigerant flows not only between the inner peripheral surface of the motor housing 1 and the outer peripheral surface of the stator core but also in the gap in the slot 4a. For this reason, since the amount of refrigerant flowing between the inner peripheral surface of the motor housing 1 and the outer peripheral surface of the stator core is limited, the cooling capacity of the inverter device (that is, the drive electric circuit) is limited.

  An object of the present invention is to provide an electric compressor capable of improving the cooling capacity of an electric circuit for driving in view of the above points.

  In order to achieve the above object, in the present invention, a motor housing, a compressor, a rotating shaft, a rotor, a stator core having a plurality of slots and a plurality of protrusions, a stator coil, an electric circuit for driving, In the electric compressor configured to flow a refrigerant through the motor housing and cool the driving electric circuit via the motor housing, the refrigerant is prevented from passing through the plurality of slots. A first feature is that a refrigerant passage suppression member is provided.

  Accordingly, since the refrigerant is prevented from passing through the plurality of slots, a sufficient amount of the refrigerant can flow between the motor housing and the stator core, so that the cooling capacity of the driving electric circuit can be improved. become.

  Moreover, this invention makes it 2nd characteristic that the refrigerant | coolant passage suppression member is formed so that the axial direction one end side of several slots may be covered, respectively. Specifically, the axial direction one end side as the installation position of the refrigerant passage suppressing member may be the refrigerant flow upstream side of the plurality of slots.

  Moreover, it is good also considering the axial direction one end side as an installation position of a refrigerant | coolant passage suppression member as a refrigerant | coolant flow downstream among several slots. In this case, although it becomes difficult for the refrigerant to pass through the plurality of slots, the refrigerant flows into the slots from the upstream side of the refrigerant flow. For this reason, even if heat is generated from the stator core and the stator coil, the stator core and the stator coil can be cooled by the refrigerant in the slot.

  Specifically, as the refrigerant passage suppression member, a member formed in an annular shape so as to cover each of the plurality of slots may be used, or as the refrigerant passage suppression member, each of the plurality of slots is filled. Thus, the refrigerant may be prevented from passing through the plurality of slots.

  In addition, the code | symbol in the bracket | parenthesis of each means described in a claim and this column shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
FIG. 1 shows a first embodiment of an electric compressor according to the present invention. 1 shows the inside of the electric compressor, FIG. 2 shows a cross-sectional view taken along the line AA in FIG. 1, and FIG. 3 shows a cross-sectional view taken along the line BB in FIG.

  The electric compressor 100 shown in FIG. 1 constitutes a refrigeration cycle device for a vehicle air conditioner together with a condenser, a decompressor, and an evaporator. The electric compressor 100 includes a motor unit 10, an inverter device 20, and a compressor unit 30. The motor unit 10 rotationally drives the compressor unit 30 via the rotary shaft 12.

  Specifically, the motor unit 10 includes a motor housing 11, a rotating shaft 12, a rotor 13, a stator core 14, a stator coil 15, and a slot cover unit 16.

  The motor housing 11 is made of a metal such as iron having high heat conductivity, and is formed in a substantially cylindrical shape. A refrigerant suction port 11 a is provided on one end side in the axial direction Z of the motor housing 11. On the other end side in the axial direction Z of the motor housing 11, a refrigerant discharge port 11b is provided.

  The rotating shaft 12 is disposed in the motor housing 11 and is rotatably supported by bearings 12a and 12b. The rotating shaft 12 transmits the rotational driving force received from the rotor 13 to the compressor unit 30. The bearing 12 a is supported by the motor housing 11 via the support portion 120. The bearing 12 b is supported by the bottom wall of the motor housing 11.

  The rotor 13 is made of a permanent magnet, is formed in a cylindrical shape, and is fixed to the rotating shaft 12. The rotor 13 rotates together with the rotating shaft 12 based on the rotating magnetic field generated from the stator core 14.

  As shown in FIG. 2, the stator core 14 is disposed radially outward with respect to the rotor 13 (rotating shaft 12) and is formed in an annular shape in the motor housing 11. The stator core 14 is made of a magnetic material and is supported from the inner peripheral surface of the motor housing 11.

  The stator core 14 has slots (gap) 14a arranged in the rotation direction of the rotor 13 and a plurality of protrusions 14b that protrude toward the rotor 13 between two adjacent slots 14a of the slots 14a. . Here, each slot 14a is formed so as to penetrate in the axial direction and open to the rotor 13 side. FIG. 2 shows an example in which twelve protrusions 14b and twelve slots 14a are provided.

  The stator coil 15 is wound around the projections 14b of the stator core 14 so as to pass through the slots 14a.

  As shown in FIG. 3, the slot cover portion (refrigerant passage suppressing member) 16 is formed in a donut shape (annular shape), and is disposed on one end side in the axial direction of the stator core 14 (upstream side of the refrigerant flow described later). The slot cover portion 16 is formed so as to cover each slot 14a and the stator coil 15 from one end side in the axial direction, and the slot cover portion 16 prevents the refrigerant from flowing into each slot 14a, as will be described later. is doing.

  The slot cover portion 16 is made of a resin material (specifically, PBT: polybutylene terephthalate) that has a high electrical insulating property and has little deterioration with respect to the refrigerant. The slot cover portion 16 is fixed to the stator core 14 and the stator coil 15 with, for example, an adhesive.

  Here, the slot cover portion 16 has a notch portion 160 a, and the notch portion 160 a is provided to allow the electric wire 150 to pass therethrough. The electric wire 150 connects between the stator coil 15 and the inverter device 20. The notch 160a is arranged at a position offset by 90 degrees in the clockwise direction from the position on the inverter device 20 side (position a in FIG. 3), and the electric wire 160 is connected to the inverter device from the notch 160a (penetrating portion). After being arranged along the slot cover portion 16 up to the position a on the 20 side, it is extended to the inverter device 20.

  The compressor unit 30 is a scroll type compressor, and is rotated by a rotational driving force from the rotating shaft 12 of the motor unit 10 to suck, compress, and discharge the refrigerant. The inverter device 20 is made of a semiconductor element or the like, and constitutes an electric circuit for driving that drives the motor unit 10. The inverter device 20 is disposed on the outer surface of the motor housing 11.

  Next, the operation of the electric compressor 100 of the present embodiment will be described.

  First, the inverter device 20 is powered on, and a drive current is supplied to the stator coil 15 of the motor unit 10. Along with this, a rotating magnetic field is generated from the stator core 14, and thus a rotational force is generated on the rotor 13. Then, the rotor 13 rotates with the rotating shaft 12. Therefore, the compressor unit 30 is swung by the rotational driving force from the rotary shaft 12 to suck, compress, and discharge the refrigerant.

  Here, the refrigerant from the evaporator side flows into the refrigerant inlet 11 a side of the motor housing 11, but the slot cover portion 16 prevents the refrigerant from flowing into each slot 14 a of the stator core 14.

  Therefore, the refrigerant flows in the axial direction as shown by the arrow in FIG. That is, the refrigerant flows through the refrigerant flow path (R in FIG. 1) between the inner surface of the motor housing 11 and the outer surface of the stator core 14 and flows to the compressor unit 30 side, and then the refrigerant is compressed by the compressor unit 30 and discharged from the refrigerant. It is discharged from the outlet 11b to the condenser side.

  On the other hand, although the inverter device 20 generates heat with the operation, the refrigerant in the refrigerant flow path can cool the inverter device 20 through the motor housing 11.

  According to the present embodiment described above, the slot cover portion 16 is formed so as to cover each slot 14a and the stator coil 15 from one end in the axial direction, so that the slot cover portion 16 flows into the motor housing 11. It is possible to suppress the refrigerant that has flowed into the slots 14a. Therefore, it is possible to secure a sufficient amount of refrigerant flowing between the outer surface of the stator coil 15 and the inner surface of the motor housing 11. Therefore, it is possible to improve the cooling capacity for cooling the inverter device (drive electric circuit) 30.

  In the present embodiment, the cutout portion 160a of the slot cover portion 16 is disposed at a position that is offset by 90 degrees in the rotational direction from the position on the inverter device 20 side (position a in FIG. 3). From the portion 160a to the position a on the inverter device 20 side, the slot cover portion 16 is disposed. Therefore, in the present embodiment, an extra length of the electric wire 160 is used as compared with the case where the notch 160a is arranged at the position on the inverter device 20 side (position a in FIG. 3).

  Here, in the assembly process of the electric wire 160 and the like, there is a possibility that the electric wire 160 is accidentally pulled to cause problems such as disconnection. However, as described above, by using the extra length of the electric wire 160, the electric wire 160 Even if the wire is pulled, problems such as disconnection are less likely to occur.

  In general, one end side in the axial direction of the stator coil 15 (and the other end side in the axial direction) needs to be bundled and tied with a string or the like so that the winding state of the stator coil 15 cannot be unwound. In this case, since the slot cover portion 16 is fixed to the stator core 14 and the stator coil 15 with an adhesive or the like, the winding state of the stator coil 15 becomes difficult to be unwound, so that it is not necessary to bind and bind with a string or the like.

(Second Embodiment)
In the above-described embodiment, the example in which the slot cover portion 16 is arranged on the refrigerant flow upstream side of the stator core 14 has been described. Instead, in the second embodiment, as shown in FIGS. 4 and 5, The slot cover portion 16 is arranged on the downstream side of the refrigerant flow of the stator core 14. 4 shows the inside of the electric compressor, and FIG. 5 shows a cross-sectional view taken along the line CC in FIG. Since the slot cover part 16 of this embodiment is the same as the slot cover part 16 of the above-mentioned embodiment, detailed description is abbreviate | omitted.

  In the present embodiment, since the slot cover portion 16 is disposed on the downstream side of the refrigerant flow of the stator core 14, it is difficult for the refrigerant to pass through each slot 14a, but the refrigerant flows into the slot 14a from the upstream of the refrigerant flow. Become. For this reason, even if heat is generated from the stator core 14 and the stator coil 15, the stator core 14 and the stator coil 15 can be cooled by the refrigerant in the slot 14a.

(Third embodiment)
In the first and second embodiments described above, the example has been described in which the slot cover portion 16 is formed so as to cover each slot 14a of the stator core 14 so that the refrigerant does not easily flow into each slot 14a. Instead, in the third embodiment, as shown in FIGS. 6 and 7, a resin is embedded in each slot 14a and a refrigerant inflow stop 16a as a refrigerant passage restraining member is inserted in each slot 14a (FIG. 7, FIG. 7). A hatched portion in FIG. 6 is formed to make it difficult for the refrigerant to flow. FIG. 6 shows the inside of the electric compressor, and FIG. 7 shows a DD cross-sectional view in FIG.

  As the refrigerant inflow stopper 16a of the present embodiment, a thermosetting resin is used, and a resin having high electrical insulation and small deterioration with respect to the refrigerant, such as electrical insulation, is preferable. A thermosetting resin is used.

  Here, when molding the refrigerant inflow stopper 16a, the stator coil 15 is wound around the stator core 14, and then a thermosetting resin is embedded in each slot 14a. Thereafter, the embedded resin is heated and cured together with the stator core 14 and the stator coil 15. Thereby, the refrigerant inflow stop 16a is molded.

(Experimental example)
Next, the experimental results of the cooling performance of the inverter device 20 of the first and third embodiments will be described with reference to FIGS.

  In this experiment, as shown in FIG. 8, temperature sensors 100 a, 100 b, 100 c, and 100 d are attached to the contact surface 200 with which the inverter device 20 contacts in the motor housing 11, and the temperature of the contact surface 200 of the motor housing 11 is adjusted. To detect. On the contact surface 200, the temperature sensors 100a, 100b, 100c, and 100d are arranged in this order from the upstream side to the downstream side in the refrigerant flow direction.

  FIG. 9 is a graph in which the horizontal axis represents the temperature sensor and the vertical axis represents the measured temperature in this experiment. (A) shows the case of the prior art (when the slot cover portion 16 is not used), (b) shows the case of the first embodiment (when the slot cover portion 16 is used), and (c) shows the first case. The case of 3 embodiment (refrigerant inflow stop 16a) is shown.

  As can be seen from FIG. 9, the temperature of the cases (b) and (c) is lower than that of (a), and the cooling performance of the inverter device 20 is improved by the cover portion 16 and the refrigerant inflow stop 16a. You can see that In particular, in the case of (c), it can be seen that the cooling performance of the inverter device 20 is high.

(Other embodiments)
In the above-described embodiment, the stator core 14 is formed such that each slot 14a is open to the rotor 13 side. However, the present invention is not limited thereto, and the stator core 14 is configured so that each slot 14a is closed. You may use what was formed.

  In the above-described embodiment, the example in which the electric compressor 100 is applied to a refrigeration cycle apparatus for a vehicle air conditioner has been described. However, the invention is not limited thereto, and the electric compressor 100 may be applied to a refrigeration cycle apparatus of an installation type vehicle air conditioner. Or you may apply to the refrigerating cycle apparatus of a hot-water supply machine.

It is a schematic diagram which shows the structure of 1st Embodiment of the electric compressor of this invention. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is a schematic diagram which shows the structure of 2nd Embodiment of the electric compressor of this invention. It is CC sectional drawing in FIG. It is a schematic diagram which shows the structure of 3rd Embodiment of the electric compressor of this invention. It is DD sectional drawing in FIG. It is a figure which shows the electric compressor used in experiment. It is a graph which shows an experimental measurement value. It is a figure which shows the structure of the electric compressor of a prior art.

Explanation of symbols

12 ... Rotating shaft, 11 ... Motor housing, 13 ... Rotor,
14 ... Stator core, 15 ... Stator coil, 16 ... Slot cover part,
DESCRIPTION OF SYMBOLS 10 ... Motor part, 20 ... Compressor part, 30 ... Inverter apparatus,
100: Electric compressor.

Claims (8)

A motor housing;
A compressor for compressing the refrigerant;
A rotating shaft that is rotatably supported in the motor housing and transmits a driving force to the compressor;
A rotor housed in the motor housing and supported by a rotating shaft;
A plurality of slots which are arranged in the motor housing in the outer diameter direction of the rotor and arranged in the rotation direction of the rotor, and two adjacent slots among the plurality of slots are respectively directed to the rotor. A stator core having a plurality of protruding portions projecting
A stator coil wound around each of the plurality of protrusions of the stator core so as to pass through the slot;
An electric circuit for driving that is disposed outside the motor housing and causes a driving current to flow through the stator coil to generate a rotating magnetic field from the stator core. In the electric compressor configured to cool the electric circuit for driving via
An electric compressor comprising: a refrigerant passage restraining member that restrains the refrigerant from passing through the plurality of slots. Each of the plurality of slots is formed so as to penetrate in the axial direction of the rotation shaft,
The electric compressor according to claim 1, wherein the refrigerant passage suppressing member is formed so as to cover one end side in the axial direction of the plurality of slots. The refrigerant flows in the axial direction in the motor housing,
The electric compressor according to claim 2, wherein the one end side in the axial direction is an upstream side of a refrigerant flow among the plurality of slots. The electric compressor according to claim 2, wherein the one end side in the axial direction is a refrigerant flow downstream side of the plurality of slots. The electric compressor according to any one of claims 1 to 4, wherein the refrigerant passage suppressing member is formed in an annular shape so as to cover the plurality of slots. The stator coil and the driving electric circuit are connected by an electric wire,
The electric compressor according to claim 5, wherein the refrigerant passage suppressing member is provided with a penetrating portion through which the electric wire penetrates into and out of the slot. The electric circuit for driving is disposed radially outward with respect to the refrigerant passage suppressing member,
The penetrating portion is arranged with a certain angle (θ) offset with respect to the position on the driving electric circuit side,
The electric wire is arranged so as to be along the refrigerant passage suppressing member from the penetrating portion to a position on the driving electric circuit side, and then extends to the electric circuit for driving. 6. The electric compressor according to 6. 2. The refrigerant passage suppression member is formed so as to fill each of the plurality of slots and suppresses the passage of the refrigerant through the plurality of slots. The electric compressor described in 1.

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