JP2003083251A - Hermetic motor-driven compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that when using a DC blushless electric motor containing a permanent magnet in a rotor, the thinner the stator becomes, the thinner a stator iron core is, and further when using a concentrated winding method for directly winding a stator winding on a magnetic tooth, a width of a slot is widened, and deformation of the stator due to welding heat of the stator iron core becomes larger so that a desired electric motor performance cannot be obtained. SOLUTION: In this hermetic motor-driven compressor, the electric motor comprises the stator composed of the stator iron core made by laminating a plurality of layers of stator steel plates, and the stator winding directly wound on the magnetic tooth through an insulating material, passing through slots of both sides of the magnetic tooth in the concentrated winding method; and the rotor rotationally supported around a crank shaft inside the stator. The stator iron core is made by welding the laminated stator steel plates to each other at a position on an approximately central line of the magnetic pole tooth in a surrounding wall.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically-sealed electric compressor in which an electric motor and a compression element driven by the electric motor are housed in a hermetic container and the refrigerant is compressed by the operation of the compression element.

[0002]

2. Description of the Related Art In a hermetic electric compressor in which an electric motor and a reciprocating compression element driven by the electric motor are housed in an airtight container, and the refrigerant is compressed by the operation of the compression element, the electric motor is a stator steel plate. A stator composed of a plurality of laminated stator cores and stator windings wound through the slots of the stator core, and a stator rotatably supported inside the stator about a rotation axis. And a rotor configured as described in Japanese Patent Application Laid-Open No. 08-10
Known as No. 5385.

In this case, the stator 6a is formed by laminating a plurality of stator steel plates, and caulking at a plurality of locations while the plurality of laminated stator steel plates are tightened by a tightening device, whereby a predetermined stator is formed. 6a is completed. However, in this type of hermetic electric compressor, the crankshaft 4 rotating with the rotor 5 is provided on the upper surface of the stator 6a.
A structural frame body 3A (also referred to as a bearing frame body) that rotatably supports the structural frame body 3A is attached by bolts.
A compression element 3 including a cylinder and a piston is arranged above it.

In this structure, when the structural frame body 3A is attached by the bolts penetrating the stator 6a at four locations which are substantially evenly arranged with respect to the stator 6a, the rigidity of the stator 6a is increased, so Low frequency noise due to vibration can be reduced. However, due to downsizing of the electric compressor, material saving, and the like, the structural frame body 3A cannot be attached to the stator 6a at four locations, and there are cases where there are two attachment locations. In that case, the stator 6a can be obtained only by the caulking.
The rigidity is not obtained, and electromagnetic vibration causes low-frequency noise of about 500 Hz. Therefore, there is a technique for reducing this low frequency noise by increasing the rigidity of the stator 6a by welding the outer peripheral portion of the stator 6a in the stacking thickness direction of the stator steel plate after the crimping step.

[0005]

In this case, when the welded portion corresponds to each slot, the heat generated during the welding causes the two side portions of the tip of the magnetic pole teeth of the stator 6a located on both sides of the inner opening of the slot. It transforms inward. In particular, in a DC brushless electric motor in which a permanent magnet is housed in the rotor 5, when the magnetic pole teeth of the stator 6a are formed at 40 ° or 60 ° intervals and the size of the stator 6a is formed efficiently and economically, a slot is used. When the distance between the inner wall of the stator and the outer surface of the stator 6a is narrowed and the welded portions correspond to the respective slots, both sides of the tip of the magnetic pole teeth of the stator 6a are stretched inward by about 20 μm to 30 μm due to heat generated by welding. It transforms to put out. Due to this deformation, the air gap between the rotor 5 and the stator 6a is narrowed at this portion, and the deviation of the magnetic flux is generated, which deteriorates the performance of the motor. Further, when this deformation is large, the rotor 5 and the rotor 5 are fixed during high-speed rotation. There is concern about contact with the child 6a.

Further, in the case of a DC brushless electric motor in which a permanent magnet is housed in the rotor, the thickness of the stator core is reduced as the thickness of the rotor can be reduced. When the concentrated winding method is used to wind directly around the teeth, the width of the slot becomes wider than in distributed winding,
There is a problem that the above-mentioned deformation of the magnetic pole teeth of the stator due to welding heat becomes large and the desired motor performance cannot be obtained.

In view of the above problems, the present invention is particularly equipped with a concentrated winding type stator winding which is directly wound around a magnetic pole tooth of a stator core through an insulating material through slots on both sides of the magnetic pole tooth. (EN) Provided is an electric compressor that reduces the distortion in the stator that requires the above-mentioned welding in the stator configuration and reduces the deformation of the air gap between the rotor and the stator core due to this distortion.

[0008]

According to the present invention, in order to solve the above problems, an electric motor and a compression element driven by the electric motor are housed in a closed container, and the refrigerant is compressed by the operation of the compression element. In the hermetic electric compressor, the electric motor is directly wound through a stator core formed by laminating a plurality of annular stator steel plates and magnetic pole teeth of this stator core through slots on both sides of the magnetic pole teeth via an insulating material. The stator is composed of a concentrated winding type stator winding, and a rotor that is rotatably supported inside the stator so as to be rotatable about a crankshaft. A hermetic electric compressor in which the laminated stator steel plates are welded to each other in a portion located substantially on the center line of the magnetic pole teeth.

Thus, in particular, in a stator having a concentrated winding type stator winding in which the slot width in which the stator winding is accommodated is large, in order to obtain the rigidity of the stator core with the structure of the electric compressor. When the welding is adopted as described above, the heat distribution by the welding becomes good, the distortion due to the welding heat at the tips of the magnetic pole teeth is small, and the rigidity of the stator core can be increased by the welding.

Further, in the above, the crankshaft is rotatably provided on a bearing portion of a structural frame body which is bolted on the stator core at two points, and the compression element is provided on the structural frame body. The hermetically sealed electric compressor is characterized in that the electric motor is a DC brushless electric motor in which magnetic pole teeth of the stator core are formed at intervals of 40 ° or 60 °, and permanent magnets are housed in the rotor. .

Thus, in order to reduce the size and material of the electric compressor and to save energy, which is suitable for inverter control, a DC brushless motor in which a permanent magnet is housed in the rotor and the stator winding is a concentrated winding type is provided. When adopted, when the magnetic pole teeth are formed at 40 ° or 60 ° intervals to form a 4-pole or 6-pole structure, the deformation of the magnetic pole teeth due to heat during welding, which is adopted to increase the rigidity of the stator core, is reduced. It is possible.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described. Each drawing shows an embodiment of the present invention, FIG. 1 is a structural explanatory view by a cross section of an electric motor of a hermetic electric compressor according to the present invention, and FIG. 2 is a vertical cross section of a hermetic electric compressor according to the present invention. 3 is an explanatory view of the compression element portion of the hermetic electric compressor according to the present invention as seen from above.

The hermetic electric compressor of the present invention will be described with reference to the drawings. FIG. 1 shows a vertical hermetic electric compressor. Reference numeral 1 denotes a hermetic electric compressor, which houses a hermetic container 20, an electric motor 2 and a compression element 3 driven by the electric motor 2 in the hermetic container 20. Closed container 20
Is a device in which the electric motor 2 and the compression element 3 are housed in a two-divided product in advance, and the joint between the two is sealed by high-frequency welding or the like.

The electric motor 2 is composed of a stator 4 and a rotor 5 centering on a crankshaft 6 inside the stator 4. The rotor 5 has a configuration in which permanent magnets 21 are housed in a plurality of laminated electromagnetic steel plates to form four magnetic poles, and a crankshaft 6 is fitted as a rotating shaft. The crankshaft 6 is rotatably supported by a bearing portion 23 of a structural frame body 13 attached to the stator 4 by bolts 8. The stator 4 includes a stator core 40 and a stator winding 41,
The stator core 40 is configured by laminating a plurality of annular stator steel plates. On the stator core 40, a stator winding of a concentrated winding type is directly wound around six magnetic pole teeth 42 formed at 60 ° intervals through an insulating material through six slots 43 on both sides of the magnetic pole teeth 42. The wire 41 is attached to form the stator 4. With such a configuration, the stator winding 4
1 gives a rotating magnetic field to the rotor 5 and DC with 4 poles and 6 slots
Refrigerant hermetic electric compressor 1 that uses a brushless electric motor
Is formed.

The structural frame 13 has a fan shape for downsizing and material saving of the electric compressor, and is attached to the stator 4 by the bolts 8 at two places, and the compression element 3 is attached and arranged thereon. is doing. The compression element 3 is composed of a cylinder 9 and a piston 10 which reciprocates therein, and a slider 11 rotatably fitted to an eccentric shaft 12 of a crankshaft 6.
Due to the configuration in which is slidably fitted with the base of the piston 10, the crankshaft 6 rotates with the rotation of the rotor 5, and the piston 10 reciprocates via the slider 11 to compress the refrigerant in the cylinder 9. The compressed refrigerant is passed through the discharge pipe connected to the discharge valve unit 14 to close the sealed container 20.
Circulate to the outside refrigeration cycle.

The stator core 40 is formed by laminating a plurality of substantially quadrilateral stator steel plates having straight vertical sides 44 and straight horizontal sides 45 orthogonal to each other and having substantially the same vertical dimension P and horizontal dimension Q. Then, the plurality of laminated stator steel plates are caulked at the fixing portion 49 in a state where the stator steel plates are fastened with the bolts passed through the bolt holes 46. Since the structure frame 13 is attached to the stator 4 at two points by the bolts 8, the rigidity of the stator core 40 cannot be obtained with the caulking as it is, and when the electric motor 2 rotates, low frequency noise due to electromagnetic vibration is generated. Occurs. Therefore, in the present invention, in order to effectively reduce this low frequency noise, the laminated stator steel plates are welded at appropriate places. This is the weld 48.

In the hermetic electric compressor 1 employing the DC brushless motor of the present invention, the stator 4 of the DC brushless motor 2 is formed in the stator core 40 at intervals of 40 °.
9 on both sides of the magnetic pole tooth 42 through an insulating material
The concentrated winding type stator winding 41 wound directly through the individual slots 43 may be attached. Therefore, it is possible to use four poles and nine slots or six poles and nine slots.

As described above, in the case of the DC brushless motor and the stator winding 41 is of the concentrated winding type, the distance L between the inner wall of the slot 43 and the outer surface of the stator core 40 is short, and the number of distributed windings is two. The distance is about half that of a pole induction motor. Therefore, when welding is performed on the outer surface of the stator core 40 at this portion, the amount of strain and deformation at the tips of the magnetic pole teeth 42 increases due to the heat.

In view of such a point, the present invention forms the welded portion 48 for welding the stator steel plates to each other on the outer surface of the stator core 40 located substantially on the center line S of the magnetic pole teeth 42. The welded portion 48 is a portion in which the laminated stator steel plates are linearly welded in the laminating direction by a method such as argon welding or electric arc welding. Therefore, welding is performed at a portion where the linear distance from the welded portion 48 to the tip of the magnetic pole tooth 42 is long, and the heat is well dispersed by the welding, whereby the distortion of the tip of the magnetic pole tooth 42 due to the welding heat is small. Moreover, it is possible to obtain the stator core 40 whose rigidity is increased by welding. The vertical dimension P and the horizontal dimension Q of the stator steel plate
Is not limited to the above.

Further, a DC having a permanent magnet housed in the rotor 5
In the case of a brushless electric motor, the thickness of the stator core becomes thinner as the rotor 5 becomes thinner, and the stator winding 41 is directly wound around the magnetic pole teeth 42. In such a case, the width of the slot becomes wider, and the deformation of the stator due to welding heat increases, which may result in failure to obtain desired electric motor performance.
Since the laminated stator steel plates are welded to each other at the portion of the magnetic pole teeth 42 located substantially on the center line S, the welded portion 4
8 is welded at a portion where the linear distance from the tip of the magnetic pole tooth 42 is long, and the deformation of the air gap 33 between the rotor 5 and the stator core 40 due to the distortion of the tip of the magnetic pole tooth 42 due to this welding is extremely small. Become.

Electric power is supplied to the stator winding 41 from the outside of the sealed container 20 through a sealed terminal (not shown). Lubricating oil is stored in the bottom portion of the closed container 20, and the lubricating oil flows into the container 15 and enters the crankshaft 6
Is sucked from the suction hole 16 at the lower end of the crankshaft 6, passes through the oil supply passage 17 in the crankshaft 6, and ascends the spiral groove 18 from the communication hole 21 to lubricate the bearing portion 23 of the structural frame body 13 with the crankshaft 6. Through the passage 22 in the eccentric shaft 12, the eccentric shaft 1
2. Lubricate the sliding parts of the slider 11, the piston 10, and the cylinder 9. Reference numeral 19 is an elastic support device that supports the electric motor 2 and the compression element 3 in the closed container 20 so as to be swingable by a coil spring.

As described above, the hermetic electric compressor for refrigerant, which adopts the 4-pole or 9-pole DC brushless electric motor in which the permanent magnet is housed in the rotor, is applied to the air conditioner and other cooling equipments. This is suitable for performing energy saving operation by controlling the rotation speed of the electric motor 2 by inverter control.

Further, in order to prevent the welded portion of the stator core from protruding from the outer peripheral surface of the stator core, a groove deeper than the welding thickness is formed in the stator core in advance, and welding is performed in this groove. No processing is required.

The present invention is not limited to the above-mentioned embodiment, and various modifications can be considered without departing from the technical scope of the present invention, and include various embodiments related thereto.

[0025]

According to the first aspect of the present invention, in a stator having a concentrated winding type stator winding in which the slot width in which the stator winding is accommodated is large, the stator core is associated with the structure of the electric compressor. When welding is used to obtain the rigidity of the stator, the heat distribution by the welding becomes good, the distortion due to the welding heat at the tips of the magnetic pole teeth is small, and the rigidity of the stator core can be increased by the welding.

According to the second aspect of the present invention, in order to reduce the size and material of the electric compressor and save energy, which is suitable for inverter control, a permanent magnet is housed in the rotor and a stator winding is concentrated. In the case of adopting the DC brushless motor described above, when the magnetic pole teeth are formed at intervals of 40 ° or 60 °, the deformation of the magnetic pole teeth due to heat at the time of welding adopted to increase the rigidity of the stator core can be reduced. .

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration explanatory diagram of an electric motor of a hermetic electric compressor according to the present invention.

FIG. 2 is a structural explanatory view of a vertical cross section of the hermetic electric compressor according to the present invention.

FIG. 3 is an explanatory view of the compression element portion of the hermetic electric compressor according to the present invention as viewed from above.

[Explanation of symbols]

1 ·· Hermetic electric compressor 2 ... Electric motor 3 ... Compression element 4 ... Stator 5 ... Rotor 6 ... Crankshaft 9 ... Cylinder 10 ... Piston 11 ... Slider 12 ... Eccentric shaft 13 ... Bearing frame 20 ··· Closed container 40 ... Stator core 41 ... Stator winding 42 ... 43 ... Slots 48 ... Welding part

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsuichi Idei             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Katsuyuki Takeda             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. F-term (reference) 3H003 AA02 AB05 AC03 CA01 CB01                       CE02 CE03 CF05 CF06                 5H002 AA07 AA08 AB01 AB06 AC02                       AE07                 5H615 AA01 BB01 BB07 BB14 PP01                       PP06 PP10 SS09 SS16

Claims (2)

[Claims] 1. A hermetic electric compressor in which an electric motor and a compression element driven by the electric motor are housed in a hermetic container, and a refrigerant is compressed by the operation of the compression element,
The electric motor includes a stator core in which a plurality of stator steel plates are laminated, and a stator winding of a concentrated winding type that is directly wound around the magnetic pole teeth of the stator core through an insulating material through slots on both sides of the magnetic pole teeth. And a rotor rotatably supported inside the stator so as to be rotatable about a crankshaft, the stator core being located on a substantially central line of the magnetic pole teeth of a peripheral wall of the stator core. A hermetic electric compressor characterized in that the laminated stator steel plates are welded to each other at a portion located at the position. 2. The crankshaft according to claim 1, wherein the crankshaft is rotatably provided on a bearing portion of a structural frame body fixed to the stator core at two points by bolts, and the compression element is provided on the structural frame body. The electric motor is a DC brushless electric motor arranged above, in which magnetic pole teeth of the stator core are formed at intervals of 40 ° or 60 °, and permanent magnets are housed in the rotor. Machine.