JP2015140660A - Motor compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor compressor capable of reducing an oil content, that is, oil rate of refrigerant discharged from a hermetic vessel.SOLUTION: A motor compressor according to the present invention comprises: a compressor mechanism compressing refrigerant; an electric motor driving the compressor mechanism to rotate; and a rotary shaft transmitting a turning force of the electric motor to the compressor mechanism, the electric motor including a stator and a rotor arranged inside of the stator and rotatable about the rotary shaft, the stator including an iron core, a coil wound around the iron core, an insulator isolating an end face of the iron core from the coil in an axial direction of the rotary shaft, and an insulator cover disposed on an end of the insulator opposite to the iron core and having an opening formed in a central portion thereof, and a projected portion by projecting an air gap formed between an inner circumference of the stator and an outer circumference of the stator in the axial direction of the rotary shaft being entirely superimposed on a projected portion by projecting the insulator cover in the axial direction of the rotary shaft.

Description

  The present invention relates to an electric compressor used for a refrigeration air conditioner or the like.

  In the compressor described in Patent Document 1, an electric motor and a compression mechanism that is rotationally driven by the electric motor are provided in a hermetic container, and the stator of the electric motor has an insulator that insulates the iron core from the winding, and the outside of the insulator The guide portion is configured to be higher than the inner guide portion. The space between the stator and the rotor is used as the forward path for the refrigerant discharged from the compression mechanism and the refrigerator oil, and the space between the stator and the sealed container is used as the return path for the refrigerator oil, thereby compressing the refrigerator oil. Return to the oil sump at the bottom of the machine to prevent the oil from running out.

JP 2008-121487 A

  However, when the refrigeration oil lifted up from the space between the rotor and stator to the upper part of the motor does not return to the lower part of the compressor from the space between the stator and the sealed container, but is discharged from the discharge pipe to the outside of the compressor There is. If the refrigerating machine oil is discharged outside the compressor, it will cause a decrease in reliability due to the lack of oil level, a hindrance to heat exchange in the refrigeration cycle, and a pressure loss due to a decrease in refrigerant gas fluidity. Become.

  An object of this invention is to provide the electric compressor which reduced the oil content rate in the refrigerant | coolant discharged from an airtight container, ie, an oil rate.

  An electric compressor of the present invention includes a compression mechanism unit that compresses a refrigerant, an electric motor that rotationally drives the compression mechanism unit, and a rotary shaft that transmits the rotational force of the electric motor unit to the compression mechanism unit, and the electric motor is fixed And a rotor that is disposed inside the stator and is rotatable around a rotation axis. The stator includes an iron core, a winding wound around the iron core, and an iron core in the axial direction of the rotation axis. An insulator that insulates the end face and the winding; and an insulating cover that is disposed at an end opposite to the iron core of the insulator and has an opening at the center, and is formed between the stator inner periphery and the rotor outer periphery. The projection unit that projects the air gap in the axial direction of the rotation axis is configured to overlap with the projection unit that projects the insulation cover in the axial direction of the rotation axis.

  According to the electric compressor of the present invention, the oil content in the refrigerant discharged from the sealed container can be reduced.

Electric motor unit longitudinal cross-sectional view of the vertical rotary compressor of Example 1 Sectional drawing in the electric motor upper part of the vertical rotary compressor of Example 1. FIG. 1 is a longitudinal sectional view showing the overall configuration of a vertical rotary compressor of Embodiment 1. FIG. Sectional view at the top of the motor of a conventional vertical rotary compressor Electric motor part longitudinal cross-sectional view of the vertical rotary compressor of Example 2 Sectional drawing in the motor upper part of the vertical rotary compressor of Example 2. FIG. The conceptual diagram which shows the flow of the refrigeration oil in the motor part longitudinal cross-sectional view of the vertical rotary compressor of Example 2. FIG. Insulated cover convex part of Example 2 Insulated cover convex part of Example 2 Vertical sectional view showing the overall configuration of the vertical scroll compressor

  The electric compressor of the present embodiment includes a compression mechanism portion that compresses the refrigerant, an electric motor that rotationally drives the compression mechanism portion, and a rotating shaft that transmits the rotational force of the electric motor portion to the compression mechanism portion. A stator, a rotor disposed inside the stator and rotatable about a rotation axis, the stator including an iron core, a winding wound around the iron core, and an iron core in an axial direction of the rotation axis And an insulator cover that is disposed at an end opposite to the iron core of the insulator and has an opening at the center, and is formed between the inner periphery of the stator and the outer periphery of the rotor Since the projection unit that projects the air gap that is projected in the axial direction of the rotation axis overlaps with the projection unit that projects the insulation cover in the axial direction of the rotation axis, the refrigerant that passes through the air gap collides with the insulation cover. The oil is easily separated Result, it is possible to reduce the oil content in the refrigerant discharged from the sealed container.

  Embodiments of the present invention will be described below with reference to the drawings. First, a compressor according to a first embodiment of the present invention will be described with reference to FIGS.

  1 is a longitudinal section of the rotary compressor, FIG. 2 is a sectional view of the upper part of the electric motor, FIG. 3 is a longitudinal sectional view of the rotary compressor, and FIG. 4 is a sectional view of the upper part of the electric motor in the conventional rotary compressor. As shown in FIG. 1C, the rotary compressor of the present embodiment includes an airtight container 1 that includes an electric element (electric motor) and a compression mechanism connected to the electric element by a rotating shaft (crankshaft) 5. To do. The sealed container 1 includes a cylindrical body 1A, a lid body 1B, and a bottom body 1C. The lid body 1B and the bottom body 1C are fitted to the cylindrical body 1A, and the fitting portion is welded to seal the inside. The electric element includes a stator 3 fixed to the cylindrical body 1A by shrink fitting or the like, and a rotor 4 fixed to the rotary shaft 5 by press fitting or the like. The compression mechanism section includes the main bearing 6, the rotating shaft 5, the auxiliary bearing 10, the cylinder 7, the roller 11, and the vane 13 as main elements.

  The rotary shaft 5 has a main bearing insertion portion 5B that is inserted into the main bearing 6 on one side, and a sub bearing insertion portion 5C that is inserted into the sub bearing 10 on the other side. Furthermore, the rotating shaft 5 is formed integrally with the eccentric portion 5A between the main bearing insertion portion 5B and the sub-bearing insertion portion 5C. A roller 11 is rotatably fitted in the eccentric portion 5 </ b> A of the rotating shaft 5. A vane 13 is fitted into the cylinder 7 so as to contact the outer periphery of the roller 11.

  By inserting the main bearing insertion portion 5B and the auxiliary bearing insertion portion 5C into the main bearing 6 and the auxiliary bearing 10, respectively, the rotary shaft 5 is rotatably arranged. The cylinder 7 is fastened to the main bearing 6 by main bearing fastening bolts 15. Further, the sub bearing 10 is fastened to the cylinder 7 by the sub bearing tightening bolt 16. The outer periphery of the main bearing 6 is fixed to the cylindrical body 1 </ b> A by welding or the like, so that the compression mechanism is fixed in the sealed container 1. A required amount of refrigerating machine oil is enclosed in the sealed container 1.

  An insulator 3B for insulating the iron core 3A and the coil 3E is disposed on the iron core 3A of the stator 3. Further, an insulator cover 3C for housing the wire connection portion of the coil 3E and preventing jumping out is disposed at the end of the insulator 3B opposite to the iron core 3A. The insulation cover 3C has an opening at the center.

  The accumulator 2 is disposed in front of the suction port 30 of the compression mechanism unit. The accumulator 2 is fixed to the sealed container 1 by welding with a plate-like member 24 coupled to the sealed container 1.

  The refrigerant sucked into the cylinder 7 via the accumulator 2 is compressed from the suction pressure to the discharge pressure in the compression element. Thereafter, the compressed refrigerant is discharged into the hermetic container 1 and then discharged from a discharge pipe 17 installed in the lid 1B to a refrigeration cycle such as an air conditioner.

  Generally, in order to separate the refrigerant and the refrigerating machine oil, the oil is dropped by reducing the flow rate of the refrigerant. In addition, the refrigerant and the refrigerating machine oil can be separated by causing the oil to collide with the inner wall or the like of the cylindrical body 1A by the centrifugal force generated by the swirling flow generated by the rotor 4 and dropping it. Further, since the refrigeration oil is easily discharged together with the refrigerant by being misted, the stirring of the refrigerant and the refrigeration oil is reduced by making the balance weight 4A of the rotor 4 into an annular shape.

  The refrigerant compressed by the compression mechanism section passes through the space 23 composed of the cylindrical body 1 </ b> A and the stator 3 and the space 22 composed of the stator 3 and the rotor 4. A space 22 composed of the stator 3 and the rotor 4 is generally referred to as an air gap 22. The refrigerant and refrigerating machine oil that have passed through the air gap 22 are blown up near the center in the radial direction. Although the discharge pipe 17 is often arranged near the center in the radial direction for the purpose of reducing the oil rate, the refrigeration oil that has passed through the air gap 22 is easily discharged from the discharge pipe 17. On the other hand, in the space 23 composed of the cylindrical body 1A and the stator 3, the refrigerating machine oil is dripped by adhering to the inner wall of the cylindrical body 1A and thus is easily separated. Further, the space formed by the insulator inner wall 3F, the coil 3E, the insulator outer wall 3G, and the insulator cover 3C (insulator inner space) has a low flow velocity, and the refrigerating machine oil easily adheres to the coil 3E and the insulator outer wall 3G and drops. That is, by guiding the refrigerant and the refrigerating machine oil passing through the air gap 22 to the insulator internal space, the separation and dropping of the refrigerating machine oil can be promoted, and the discharge of the refrigerating machine oil from the discharge pipe 17 can be suppressed.

  That is, in the compressor, the refrigerating machine oil that has passed through the air gap 22 is discharged from the discharge pipe 17 and tends to increase the oil rate. Therefore, in the electric compressor of the present embodiment, as shown in FIG. 1, the inner diameter of the insulation cover 3 </ b> C is formed smaller than the outer diameter of the rotor 4 (that is, between the stator inner periphery and the rotor outer periphery). The projection part which projected the formed air gap to the axial direction of a rotating shaft overlaps with the projection part which projected the insulation cover to the axial direction of the rotating shaft. That is, as shown in FIG. 2, the insulation cover 3C is disposed above the air gap 22, and the air gap 22 becomes invisible by the insulation cover 3C when viewed from above. By configuring in this way, the refrigerant and the refrigerating machine oil that have passed through the air gap 22 collide with the insulation cover 3C before flowing out into the space above the electric motor, so that the refrigerating machine oil drops and easily falls. Furthermore, since refrigeration oil is guide | induced to the insulator internal space of the rotor 4 upper part and the cylinder 1A inner-diameter direction, refrigeration oil becomes easy to fall more. Therefore, the refrigeration oil discharged from the discharge pipe 17 to the outside of the compressor, that is, the oil rate can be reduced.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In the electric compressor of the present embodiment, as shown in FIGS. 5 and 6, a convex shape portion 3 </ b> D (insulation cover convex portion) directed toward the iron core side (downward on the paper surface in FIG. 5) is provided in the vicinity of the inner periphery of the insulation cover 3 </ b> C. Provide. That is, the insulation cover 3 </ b> C has a convex shape portion 3 </ b> D that is convex toward the iron core side in the axial direction on the inner side of the inner periphery of the stator.

  The flow path of the refrigerating machine oil in the present embodiment is indicated by arrows in FIG. Refrigerating machine oil that has passed through the air gap 22 and collided with the insulation cover 3 </ b> C is prevented from being taken out toward the compressor center.

  For example, the convex portion 3D can be configured by a cylindrical portion parallel to the rotation axis. Specifically, the insulation cover 3 </ b> C has an insulation cover vertical portion (the cylindrical portion, not shown) directed toward the iron core side in the axial direction of the rotation shaft (downward in FIG. 5) inside the outer periphery of the rotor. The convex portion 3D is formed by the vertical portion of the insulation cover. By means of the insulation cover 3C including the insulation cover vertical portion, it is possible to suppress the refrigerating machine oil that has passed through the air gap 22 and collided with the insulation cover 3C from being taken out toward the compressor center.

  Moreover, convex-shaped part 3D can also be comprised using an inclination part. Specifically, the insulation cover 3 </ b> C has an insulation cover inclined portion that is inclined toward the iron core side in the axial direction of the rotation shaft toward the center at a position where the air gap 22 is projected in the axial direction of the rotation shaft. A convex portion 3D is formed by the insul cover inclined portion. As with the case where the insulation cover vertical part is formed, the insulation cover 3C including the insulation cover inclined part suppresses the refrigerating machine oil that has passed through the air gap 22 and collided with the insulation cover 3C from being taken out to the compressor center side. can do. In particular, since the convex portion 3D is configured by the inclined portion, the refrigerating machine oil can be guided more smoothly in the insulator internal space and the cylindrical body 1A direction. Further, it is possible to suppress the generation of pressure loss and noise caused by a sudden change in the flow direction.

  Here, the insulation cover inclined portion may be formed of a curved surface, or may be combined with surfaces having different slope angles and curvatures. For example, as shown in FIG. 9, the closer to the center side, the smaller the angle formed with the rotation axis. By comprising in this way, since a refrigerant | coolant and refrigerating machine oil can be guide | induced to an insulator internal space more smoothly, refrigerating machine oil can be isolate | separated more effectively.

  As described above, as shown in FIG. 8 as an example, the angle formed between the tangent at the inner peripheral side end of the insulation cover 3C and the rotation axis is 0 ° ≦ θ <90 ° (θ = 0 °: the insulation cover vertical portion) , 0 ° <θ <90 °: Insulating cover inclined portion), the convex portion 3D can be configured.

  In addition, an insulator inner wall 3F and an insulation cover projection 3H that are paired with each other can be provided on the inner periphery of the insulation 3B and the insulation cover 3C. By providing the insulator inner wall 3F and the insulation cover projection 3H, the coil 3E and the connection portion are accommodated, the space with the balance weight 4A is partitioned, the flow velocity in the insulator internal space is lowered, and the refrigerating machine oil is easily dropped. Can do.

  In each of the above embodiments, a sealed vertical rotary compressor has been described as an example. However, the present invention is not limited to this, and can be applied to, for example, a non-sealed rotary compressor, a scroll compressor, and the like. For example, in the scroll compressor, as shown in FIG. 10, the refrigerating machine oil ejected from the lower part of the compressor through the air gap 22 can be separated, and the refrigerating machine oil discharged from the discharge pipe 17 can be reduced.

DESCRIPTION OF SYMBOLS 1 ... Airtight container, 1A ... Cylindrical body, 1B ... Cover body, 1C ... Bottom body, 2 ... Accumulator, 3 ... Stator, 3A ... Iron core, 3B ... Insulator, 3C ... Insulation cover, 3D ... Convex-shaped part, 3E ... Coil, 3F ... Insulator inner wall, 3G ... Insulator outer wall, 3H ... Insulation cover projection, 4 ... Rotor, 4A ... Balance weight, 5 ... Rotating shaft, 5A ... Eccentric part, 5B ... Main bearing insertion part, 5C ... Sub-bearing insertion , 6 ... main bearing, 7 ... cylinder, 10 ... secondary bearing, 11 ... roller, 13 ... vane, 15 ... main bearing clamping bolt, 16 ... secondary bearing clamping bolt, 17 ... discharge pipe, 22 ... air gap, 23: Space consisting of a cylinder and a stator, 24 ... Plate member

Claims (6)

A compression mechanism for compressing the refrigerant;
An electric motor that rotationally drives the compression mechanism,
A rotating shaft that transmits the rotational force of the electric motor section to the compression mechanism section;
With
The electric motor includes a stator, and a rotor disposed inside the stator and rotatable around the rotation axis,
The stator includes an iron core, a winding wound around the iron core, an insulator that insulates the end face of the iron core in the axial direction of the rotating shaft and the winding, and the insulator on the side opposite to the iron core. An insulation cover disposed at the end,
The projection unit that projects an air gap formed between the inner periphery of the stator and the outer periphery of the rotor in the axial direction of the rotation shaft overlaps with the projection unit that projects the insulation cover in the axial direction of the rotation shaft. An electric compressor configured as described above. A compression mechanism for compressing the refrigerant;
An electric motor that rotationally drives the compression mechanism,
A rotating shaft that transmits the rotational force of the electric motor section to the compression mechanism section;
With
The electric motor includes a stator, and a rotor disposed inside the stator and rotatable around the rotation axis,
The stator includes an iron core, a winding wound around the iron core, an insulator that insulates the end face of the iron core in the axial direction of the rotating shaft and the winding, and the insulator on the side opposite to the iron core. An insulation cover disposed at the end,
The electric cover is configured such that the insulating cover has an opening at a central portion thereof, and an inner diameter of the insulating cover is positioned inside an outer diameter of the rotor.   3. The electric compressor according to claim 1, wherein the insulation cover includes an insulation cover convex portion that is convex toward the iron core side in the axial direction of the rotation shaft, on the inner side of the inner periphery of the stator.   4. The insulation cover according to claim 3, wherein the insulation cover has an insulation cover vertical portion that is directed to the iron core side in parallel with the axial direction of the rotation shaft inside the outer periphery of the rotor. An electric compressor in which convex portions are formed.   4. The insulation cover according to claim 3, wherein the insulation cover has an insulation cover inclined portion that is inclined toward the iron core in the axial direction of the rotary shaft toward the center at a position where the air gap is projected in the axial direction of the rotary shaft. An electric compressor in which an insulation cover convex part is formed by the insulation cover inclined part.   6. The electric compressor according to claim 5, wherein the angle of the insulating cover inclined portion and the axis of the rotating shaft is smaller as it is closer to the center.