Compressor

A rotor that gives rotational power to a compressor part that compresses refrigerant has a rotor core in which through-holes through which the refrigerant passes are formed, the through-holes having a cross section with a plurality of forks in a direction away from a rotation axis, a first end plate that covers a first end surface where one end of both end portions of the through-holes of the rotor core closer to the compressor part is formed, and an upper rotor end plate that covers a lower rotor end surface where the other end of the plurality of holes of the rotor core is formed. The first end plate has a first opening portion that causes the through-holes to communicate with an internal space. The upper rotor end plate has an upper opening portion that causes the through-holes to communicate with the internal space. The upper rotor end plate has projection portions that cover tip end portions, which are divided to respective forks, of the through-holes.

CROSS REFERENCE TO PRIOR APPLICATION

This application is a National Stage Patent Application of PCT International Patent Application No. PCT/JP2019/016406 (filed on Apr. 17, 2019) under 35 U.S.C. § 371, which claims priority to Japanese Patent Application No. 2018-087268 (filed on Apr. 27, 2018), which are all hereby incorporated by reference in their entirety.

FIELD

The technique of the present disclosure relates to a compressor.

BACKGROUND

A sealed compressor in which a compressor part and a motor part are housed inside a sealed container is known. The motor part (electric motor part) includes a stator and a rotor. The stator generates a rotating magnetic field to rotate the rotor. The compressor part compresses refrigerant as the rotor is rotated. The rotor is formed with a plurality of through-holes through which the refrigerant compressed by the compressor part passes. Refrigerator oil that lubricates the compressor part is stored in the sealed container, passes through the plurality of through-holes together with the refrigerant compressed by the compressor part, and is discharged together with the refrigerant to a subsequent-stage device. Such a compressor can prevent the refrigerator oil stored in the sealed container from being decreased by suppressing that the refrigerator oil passes through the plurality of through-holes, and thereby appropriately lubricate the compressor part.

As a technique of such a compressor, there is a technique in the related art in which a gas flow path that is formed to penetrate a rotor core and extends in an axial direction of a rotation axis is provided, a projection portion that projects to the gas flow path is provided to a boundary plate and an end plate of the rotor core, and thereby the refrigerator oil is separated from the refrigerant. Further, a compressor has been proposed which has a rotor in which refrigerant flow holes are formed and end plates provided on both end sides of the rotor in the axial direction and in which an opening portion of the end plate as formed to expose a region of an end surface of the rotor core closer to the rotation axis than the refrigerant flow holes (refer to Patent Literatures 1 and 2).

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

However, such a compressor has a problem that the efficiency of the system is reduced when the refrigerator oil passes through the plurality of through-holes and projects to the subsequent-stage device together with the refrigerant. On the other hand, the inventors of the present application have recognized the problem that if the projection portion is simply provided to the end plate, a flow path resistance of the refrigerant flow passage is increased so that a flow rate of the refrigerant is decreased, and the efficiency of a refrigeration cycle apparatus provided with the compressor is reduced, as in Patent Literature 1.

The disclosed technique has been made in view of the above circumstances, and an object thereof is to provide a compressor that reduces an oil discharge amount while suppressing a flow path resistance when a refrigerant passes through a through-hole formed in a rotor.

Solution to Problem

A compressor disclosed in this application, according to an aspect, includes: a rotor; a stator that rotates the rotor around a rotation axis; a compressor part that compresses refrigerant by rotation of the rotor; and a sealed container that forms an internal space in which the rotor, the stator, and the compressor part are housed, wherein the rotor has a rotor core in which a plurality of holes through which the refrigerant passes are formed, a first end plate that covers a first end surface where one end of both end portions of the plurality of holes of the rotor core closer to the compressor part is formed, and a second end plate that covers a second end surface where the other end of the plurality of holes of the rotor core is formed, the first end plate has a first opening portion that causes the plurality of holes to communicate with the internal space, the second end plate has a second opening portion that causes the plurality of holes to communicate with the internal space, and a plurality of projection portions that cover a region of the other end of the hole distant from the rotation axis are formed.

Advantageous Effects of Invention

The disclosed compressor can reduce the oil discharge amount while suppressing the flow path resistance.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a compressor according to an embodiment disclosed in the present application will be described with reference to the drawings. Note that, the technique of the present disclosure is not limited to the following description. Further, in the following description, the same constituents will be given the same reference numerals and the duplicated description omitted.

Embodiment

FIG.1is a vertical sectional view illustrating a compressor1of a first embodiment. As illustrated inFIG.1, the compressor1includes a container2, a shaft3, a compressor part5, and a motor part6. The container2forms a sealed internal space7. The internal space7is formed in a substantially columnar shape. The compressor1is formed such that the axis of the cylinder of the internal space7is parallel to a vertical direction when the container2is placed vertically on a horizontal plane. In the container2, an oil sump8is formed in a lower portion of the internal space7. Refrigerator oil for lubricating the compressor part5is stored in the oil sump8. A suction pipe11and a discharge pipe12are connected to the container2. The shaft3is formed in a rod shape, and is disposed in the internal space7of the container2such that one end thereof is disposed in the oil sump8. The shaft3is supported by the container2so as to be rotatable around a rotation axis that is parallel to the axis of the cylinder formed by the internal space7. The refrigerator oil stored in the oil sump8is supplied to the compressor part5by the rotation of the shaft3.

The compressor part5is disposed in the lower portion of the internal space7, and is disposed above the oil sump8. The compressor1further includes an upper muffler cover14and a lower muffler cover15. The upper muffler cover14is disposed above the compressor part5in the internal space7. The upper muffler cover14forms an upper muffler chamber16therein. The lower muffler cover15is disposed below the compressor part5in the internal space7, and is disposed above the oil sump8. The lower muffler cover15forms a lower muffler chamber17therein. The lower muffler chamber17communicates with the upper muffler chamber16via a communication passage (not illustrated) formed in the compressor part5. A compressed refrigerant discharge hole18is formed between the upper muffler cover14and the shaft3, and the upper muffler chamber16communicates with the internal space7via the compressed refrigerant discharge hole18.

The compressor part5is a so-called rotary type compressor, which compresses the refrigerant supplied from the suction pipe11by the rotation of the shaft3, and supplies the compressed refrigerant to the upper muffler chamber16and the lower muffler chamber17. The refrigerant is compatible with refrigerator oil.

The motor part6is disposed above the compressor part5in the internal space7. The motor part6includes a rotor21and a stator22. The rotor21is fixed to the shaft3. The stator22is formed in a substantially cylindrical shape, is disposed so as to surround the rotor21, and is fixed to the container2. The stator22includes windings26. The stator22generates a rotating magnetic field to rotate the rotor21when a single-phase or three-phase voltage is appropriately applied to the windings26.

FIG.2is a sectional view illustrating the rotor21of the compressor1of the first embodiment. As illustrated inFIG.2, the rotor21includes a rotor core31, a lower rotor end plate32, and an upper rotor end plate33. The rotor core31is formed in a substantially columnar shape, and is formed by stacking a plurality of steel plates formed of a soft magnetic material such as a silicon steel plate. The rotor core31is fixed to the shaft3such that the axis of the cylinder formed by the rotor core31overlaps the rotation axis of the shaft3. Further, the rotor core31has a lower rotor end surface3-1, an upper rotor end surface35, and a plurality of through-holes36-1to36-6.

The lower rotor end surface34is formed at a portion corresponding to one bottom surface of the cylinder formed by the rotor core31, and is formed at a portion of the rotor core31facing the compressor part5. The upper rotor end surface35is formed at a portion corresponding to the other bottom surface of the cylinder formed by the rotor core31, and is formed on a side of the rotor core31opposite to the side where the lower rotor end surface34is formed. The plurality of through-holes36-1to36-6are formed parallel to the rotation axis of the shaft3, and are arranged around the shaft3at equal intervals. The plurality of through-holes36-1to36-6are formed so as to penetrate the lower rotor end surface34and the upper rotor end surface35.

The lower rotor end plate32is formed in a substantially disc shape. The lower rotor end plate32is fixed to the rotor core31to be in close contact with the lower rotor end surface34so as to cover the lower rotor end surface34of the rotor core31. The upper rotor end plate33is formed in a substantially disc shape. The upper rotor end plate33is fixed to the rotor core31to be in close contact with the upper rotor end surface35so as to cover the upper rotor end surface35of the rotor core31.

The rotor21further includes permanent magnets37-1to37-6and a balancer (not illustrated). The permanent magnets37-1to37-6and the balancer are fixed to the rotor core31by the lower rotor end plate32and the upper rotor end plate33being fixed to the rotor core31. The permanent magnets37-1to37-6are provided so that the rotor21is rotated by the rotating magnetic field generated by the stator22. The balancer provided so that the rotor21is rotated around the rotation axis, that is, the center of gravity of the rotor21overlaps the rotation axis of the shaft3.

FIG.3Ais a bottom view illustrating the rotor21of the compressor1of the first embodiment, andFIG.3Bis a top view illustrating the rotor21of the compressor1of the first embodiment. InFIGS.3A and3B, members covered by the lower rotor end plate32and the upper rotor end surface35are illustrated by broken lines in a see-through manner for easily understanding.

The permanent magnets37-1to37-6included in the rotor21have a V-shape, as illustrated inFIGS.3A and3B. Further, the permanent magnets37-1to37-6are disposed such that a projection direction of the bent portion of the V-shape is directed to the center of the rotor21, that is, toward the rotation axis. The permanent magnets37-1to37-6are arranged around the shaft3at equal intervals of 60° mechanical angle in a circumferential direction. The permanent magnets37-1to37-6are arranged such that ends of the adjacent permanent magnets are adjacent to each other, and are disposed to form a star shape when viewed as a whole of the permanent magnets. By disposing the permanent magnets in a star shape (V-shape), larger permanent magnets37-1to37-6can be disposed in the rotor21and a stronger magnetic force can be secured as compared with a case where the permanent magnets are disposed in a plate shape instead of a V-shape.

Opening portions of the plurality of through-holes36-1to36-6provided in the rotor21have a V-shape. In other words, the opening portions of the plurality of through-holes36-1to36-6have a biforked shape. Further, the through-holes36-1to36-6are disposed such that a projection direction of the bent portion of the V-shape is directed to the center of the rotor21, that is, toward the rotation axis.

That is, in each of the permanent magnet37-1and the through-hole36-1, the projection direction of the bent portion of the V-shape is directed toward the rotation axis of the rotor21. Then, the permanent magnet37-1and the through-hole36-1are disposed such that the permanent magnet37-1and the through-hole36-1are parallel to a direction in which the rotation axis extends, that is, the axial direction of the rotation axis, and the permanent magnet37-1and the through-hole36-1overlap in a radial direction toward the outer periphery. In each of the permanent magnet37-2and the through-hole36-2, the projection direction of the bent portion of the V-shape is directed toward the rotation axis of the rotor21. Then, the permanent magnet37-2and the through-hole36-2are disposed such that the permanent magnet37-2and the through-hole36-2are parallel to the axial direction of the rotation axis, and the permanent magnet37-2and the through-hole36-2overlap in the radial direction toward the outer periphery. In each of the permanent magnet37-3and the through-hole36-3, the projection direction of the bent portion of the V-shape is directed toward the rotation axis of the rotor21. Then, the permanent magnet37-3and the through-hole36-3are disposed such that the permanent magnet37-3and the through-hole36-3are parallel to the axial direction of the rotation axis, and the permanent magnet37-3and the through-hole36-3overlap in the radial direction toward the outer periphery. In each of the permanent magnet37-4and the through-hole36-4, the projection direction of the bent portion of the V-shape is directed toward the rotation axis of the rotor21. Then, the permanent magnet37-4and the through-hole36-4are disposed such that the permanent magnet37-4and the through-hole36-4are parallel to the axial direction of the rotation axis, and the permanent magnet37-4and the through-hole36-4overlap in the radial direction toward the outer periphery. In each of the permanent magnet37-5and the through-hole36-5, the projection direction of the bent portion of the V-shape is directed toward the rotation axis of the rotor21. Then, the permanent magnet37-5and the through-hole36-5are disposed such that the permanent magnet37-5and the through-hole36-5are parallel to the axial direction of the rotation axis, and the permanent magnet37-5and the through-hole36-5overlap in the radial direction toward the outer periphery. In each of the permanent magnet37-6and the through-hole36-6, the projection direction of the bent portion of the V-shape is directed toward the rotation axis of the rotor21. Then, the permanent magnet37-6and the through-hole36-6are disposed such that the permanent magnet37-6and the through-hole36-6are parallel to the axial direction of the rotation axis, and the permanent magnet37-6and the through-hole36-6overlap in the radial direction toward the outer periphery.

In the lower rotor end plate32, a lower opening portion41is formed, as illustrated inFIG.3A. The lower opening portion41is formed in a circular shape. The shaft3penetrates the lower opening portion41when the rotor21is fixed to the shaft3. The lower opening portion41allows all of the lower ends of the plurality of through-holes36-1to36-6on the lower rotor end surface34side to be open to the internal space7, and causes each of the plurality of through-holes36-1to36-6to communicate with the internal space7.

The lower rotor end surface34includes a plurality of lower inner peripheral side adjacent regions42-1to42-6. The plurality of lower inner peripheral side adjacent regions42-1to42-6are disposed on the inner peripheral side of the plurality of through-holes36-1to36-6, and are adjacent to the plurality of through-holes36-1to36-6, respectively.

That is, the lower inner peripheral side adjacent region42-1is disposed on the inner peripheral side of the through-hole36-1and is adjacent to the through-hole36-1. The lower inner peripheral side adjacent region42-2is disposed on the inner peripheral side of the through-hole36-2and is adjacent to the through-hole36-2. The lower inner peripheral side adjacent region42-3is disposed on the inner peripheral side of the through-hole36-3and is adjacent to the through hole36-3. The lower inner peripheral side adjacent region42-4is disposed on the inner peripheral side of the through-hole36-4and is adjacent to the through-hole36-4. The lower inner peripheral side adjacent region42-5is disposed on the inner peripheral side of the through-hole36-5and is adjacent to the through-hole36-5. The lower inner peripheral side adjacent region42-6is disposed on the inner peripheral side of the through-hole36-6and is adjacent to the through-hole36-6. The lower opening portion41exposes all of the plurality of lower inner peripheral side adjacent regions42-1to42-6to the internal space7.

Since the lower opening portion41is formed of one hole, the lower rotor end plate32can be more easily manufactured as compared with a structure in which the lower opening portion is formed of a plurality of holes. Since the lower rotor end plate32can be easily manufactured, such a compressor1can be easily manufactured as a whole.

Furthermore, the lower rotor end plate32covers all regions adjacent to the plurality of through-holes36-1to36-6, other than the region of the lower rotor end surface34exposed to the internal space7by the lower opening portion41. For example, the lower rotor end plate32covers the permanent magnets37-1to37-6to prevent the permanent magnets37-1to37-6from coming off the rotor21.

In the upper rotor end plate33, an upper opening portion43is formed, as illustrated inFIG.3B. The upper opening portion43is formed in a circular shape. The upper opening portion43exposes an upper end of the shaft3to the internal space7when the rotor21is fixed to the shaft3.

The upper rotor end plate33covers each of tip end portions36-11to36-62divided in a biforked manner of the V-shape of the upper ends of the plurality of through-holes36-1to36-6on the upper rotor end surface35side. Here, the tip end portion divided in a biforked manner represents both end portions of the V-shape formed by the hole. In the following, the tip end portion divided in a biforked manner may be simply referred to as a “biforked tip end portion”. A portion where the upper rotor end plate33covers the biforked tip end portions36-11to36-62is called a projection portion. That is, the upper rotor end plate33includes a plurality of projection portions44-1to44-6and45-1to45-6.

In the present embodiment, as illustrated inFIG.3B, the upper rotor end plate33covers a region from a position, which connects a concave-side apex of a bent part of the V-shape of the upper ends of the through-holes36-1to36-6to a point between a projection-side apex of the bent part and the biforked tip end portion, to the biforked tip end portion. The upper opening portion43allows a part of the upper ends of the plurality of through-holes36-1to36-6on the upper rotor end surface35side, which includes the bent part of the V-shape, to be open to the internal space7, respectively, and causes each of the through-holes36-1to36-6to communicate with the internal space7. The upper opening portion43further exposes all of the plurality of upper inner peripheral side adjacent regions46-1to46-6to the internal space7.

The plurality of projection portions44-1to44-6and45-1to45-6cover the biforked tip end portions of the upper ends of the plurality of through-holes36-1to36-6, respectively. That is, the projection portion44-1covers the tip end portion36-11on the left side of the biforked portion of the opening formed by the upper end of the through-hole36-1when the upper rotor end surface35is viewed from the axial direction of the rotation axis. The projection portion44-2covers the tip end portion36-21on the left side of the biforked portion of the opening formed by the upper end of the through-hole36-2when the upper rotor end surface35is viewed from the axial direction of the rotation axis. The projection portion44-3covers the tip end portion36-31on the left side of the biforked portion of the opening formed by the upper end of the through-hole36-3when the upper rotor end surface35is viewed from the axial direction of the rotation axis. The projection portion44-4covers the tip end portion36-41on the left side of the biforked portion of the opening formed by the upper end of the through-hole36-4when the upper rotor end surface35is viewed from the axial direction of the rotation axis. The projection portion44-5covers the tip end portion36-51on the left side of the biforked portion of the opening formed by the upper end of the through-hole36-5when the upper rotor end surface35is viewed from the axial direction of the rotation axis. The projection portion44-6covers the tip end portion36-61on the left side of the biforked portion of the opening formed by the upper end of the through-hole36-6when the upper surface rotor end surface35is viewed from the axial direction of the rotation axis.

Further, the projection portion45-1covers the tip end portion36-12on the right side of the biforked portion of the opening formed by the upper end of the through-hole36-1when the upper rotor end surface35is viewed from the axial direction of the rotation axis. The projection portion45-2covers the tip end portion36-22on the right side of the biforked portion of the opening formed by the upper end of the through-hole36-2when the upper rotor end surface35is viewed from the axial direction of the rotation axis. The projection portion45-3covers the tip end portion36-32on the right side of the biforked portion of the opening formed by the upper end of the through-hole36-3when the upper rotor end surface35is viewed from the axial direction of the rotation axis. The projection portion45-4covers the tip end portion36-42on the right side of the biforked portion of the opening formed by the upper end of the through-hole36-4when the upper rotor end surface35is viewed from the axial direction of the rotation axis. The projection portion45-5covers the tip end portion36-52on the right side of the biforked portion of the opening formed by the upper end of the through-hole36-5when the upper rotor end surface35is viewed from the axial direction of the rotation axis. The projection portion45-6covers the tip end portion36-62on the right side of the biforked portion of the opening formed by the upper end of the through-hole36-6when the upper rotor end surface35is viewed from the axial direction of the rotation axis.

Operation of Compressor1

The compressor1is provided in a refrigeration cycle apparatus (not illustrated), and is used for compressing the refrigerant and circulating the refrigerant in the refrigeration cycle apparatus. The motor part6of the compressor1generates a rotating magnetic field when a single-phase or three-phase voltage is applied to the windings26of the stator22. The rotor21is rotated by the rotating magnetic field generated by the stator22, and accordingly, the shaft3is rotated.

When the shaft3is rotated, the compressor part5suctions a low-pressure refrigerant gas through the suction pipe11, compresses the suctioned low-pressure refrigerant gas to generate a high-pressure refrigerant gas, and supplies the high-pressure refrigerant gas to the upper muffler chamber16and the lower muffler chamber17. The lower muffler cover15reduces pressure pulsations of the high-pressure refrigerant gas supplied to the lower muffler chamber17, and supplies the high-pressure refrigerant gas with the reduced pressure pulsations to the upper muffler chamber16. The upper muffler cover14reduces pressure pulsations of the high-pressure refrigerant gas supplied to the upper muffler chamber16, and supplies the high-pressure refrigerant gas with the reduced pressure pulsations to a space between the compressor part5and the motor part6in the internal space7through the compressed refrigerant discharge hole18. The high-pressure refrigerant gas supplied to the space between the compressor part5and the motor part6in the internal space7passes through the plurality of through-holes36-1to36-6to be supplied to a space above the motor part6in the internal space7. The refrigerant supplied to the space above the motor part6in the internal space7is discharged to the subsequent-stage device of the refrigeration cycle apparatus through the discharge pipe12.

FIG.4is an enlarged sectional view illustrating the vicinity of the biforked tip end portion or the opening formed by the lower end of the through-hole36-1. The high-pressure refrigerant gas flowing out from the compressed refrigerant discharge hole18rises along the shaft3, advances obliquely from the shaft3side toward the outer peripheral side as illustrated inFIG.4, and enters the inside of the through-hole36-1. The lower rotor end plate32exposes the plurality of lower inner peripheral side adjacent regions42-1to42-6to the internal space7to be less likely to interfere with the high-pressure refrigerant gas that obliquely enters the inside of the through-hole36-1from the shaft3side. Therefore, the motor part6of the compressor1can reduce the resistance received when the high-pressure refrigerant gas enters the inside of the through-hole36-1from the lower portion of the motor part6in the internal space7, and reduce the pressure loss when the high-pressure refrigerant gas enters the inside of the through-hole36-1. In the compressor1, since the plurality of lower inner peripheral side adjacent regions42-1to42-6are exposed, the length of the flow path connecting the lower portion and the upper portion of the motor part6via the plurality of through-holes36-1to36-6can be shortened by the thickness of the lower rotor end plate32. In the compressor1, since the length of the flow path is short, the flow path resistance of the high-pressure refrigerant gas passing through the flow path can be reduced, and the pressure loss when the high-pressure refrigerant gas passes through the flow path can be reduced. In the compressor1, since the pressure loss when the high-pressure refrigerant gas passes through the flow path is reduced, a decrease in pressure of the refrigerant discharged to the subsequent-stage device can be suppressed, and the refrigerant can be compressed with high efficiency.

FIG.5is an enlarged sectional view illustrating the vicinity of the biforked tip end portion of the opening formed by the upper end of the through-hole36-1. When the high-pressure refrigerant gas passes through the through-hole36-1, the high-pressure refrigerant gas collides with the projection portion44-1as illustrated inFIG.5, and flows obliquely from the upper end opening portion of the through-hole36-1toward the rotation axis of the shaft3. The upper rotor end plate33exposes the upper inner peripheral side adjacent region46-1to the internal space7to be less likely to interfere with the high-pressure refrigerant gas that flows obliquely from the upper end opening portion of the through-hole36-1toward the rotation axis of the shaft3. Therefore, the motor part6can reduce the resistance received when the high-pressure refrigerant gas flows obliquely from the upper end opening portion of the through-hole36-1toward the rotation axis of the shaft3, and reduce the pressure loss when the high-pressure refrigerant gas flows out from the through-hole36-1. In the motor part6, since the upper inner peripheral side adjacent region46-1is exposed to the internal space7, the length of the flow path connecting the lower portion and the upper portion of the motor part6via the through-hole36-1can further be shortened by the thickness of the upper rotor end plate33. In the motor part6, since the length of the flow path is short, the flow path resistance of the high-pressure refrigerant gas passing through the flow path can be reduced, and the pressure loss when the high-pressure refrigerant gas passes through the flow path can be reduced. Regarding the through-holes36-2to36-6, as with the through-hole36-1, the pressure loss when the high-pressure refrigerant gas passes through the flow path connecting the lower portion and the upper portion of the motor part6can be reduced. In the compressor1, since the pressure loss when the high-pressure refrigerant gas passes through the flow path is reduced, a decrease in pressure of the refrigerant discharged to the subsequent-stage device can be suppressed, and the refrigerant can be compressed with high efficiency.

The refrigerator oil stored in the oil sump8is supplied to the compressor part5by the rotation of the shaft3to be used as lubricating oil that reduces friction acting between mechanical elements constituting the compressor part5. The refrigerator oil is mixed with the high-pressure refrigerant gas when the compressor part5compresses the low-pressure refrigerant gas to generate the high-pressure refrigerant gas, and is supplied to a space between the motor part6and the compressor part5in the internal space7. Further, the refrigerator oil is further discharged to the space between the motor part6and the compressor part5in the internal space7by the rotation of the shaft3, and is mixed with the high-pressure refrigerant gas. A part of the refrigerator oil supplied to the space between the motor part6and the compressor part5in the internal space7passes through the plurality of through-holes36-1to36-6together with the high-pressure refrigerant gas to be supplied to the space above the motor part6in the internal space7. The refrigerant supplied to the space above the motor part6in the internal space7is discharged together with the high-pressure refrigerant gas to the subsequent-stage device of the refrigeration cycle apparatus through the discharge pipe12.

When the refrigerator oil passes through the plurality of through-holes36-1to36-6together with the high-pressure refrigerant gas, the refrigerator oil collides with the plurality of projection portions44-1to44-6and45-1to45-6to be separated from the refrigerant in the plurality of through-holes36-1to36-6. The refrigerator oil separated from the refrigerant in the plurality of through-holes36-1to36-6is moved to the outer peripheral side of the plurality of through-holes36-1to36-6by the centrifugal force due to the rotation of the rotor21, and is collected on the outer peripheral side of the plurality of through-holes36-1to36-6. Here, since the through-holes36-1to36-6have a V-shape that is separated toward the outer periphery, the refrigerator oil is collected in both of the biforked tip end portions36-11to36-62of the V-shape. A part of the refrigerator oil collected in the tip end portions36-11to36-62of the V-shape of the plurality of through-holes36-1to36-6is supplied to the space between the motor part6and the compressor part5in the internal space7since all of the lower ends of the plurality of through-holes36-1to36-6are open. In addition, the plurality of projection portions44-1to44-6and45-1to45-6suppress that the refrigerator oil collected in the biforked tip end portions36-11to36-62of the V-shaped opening formed by the upper end of the plurality of through-holes36-1to36-6is supplied to the space above the motor part6in the internal space7since the upper end of the plurality of through-holes36-1to36-6covers the biforked tip end portions36-11to36-62of the V-shaped opening formed by the upper end of the plurality of through-holes36-1to36-6. In the compressor1, since it is suppressed that the refrigerator oil is supplied to the space above the motor part6in the internal space7, the oil discharge amount of the refrigerator oil discharged together with the refrigerant to the subsequent-stage device through the discharge pipe12is reduced. In the compressor1, since the oil discharge amount of the refrigerator oil discharged to the subsequent-stage device is reduced, the refrigerator oil stored inside the container2can be prevented from being decreased. In the compressor1, since the refrigerator oil stored inside the container2is prevented from being decreased, the lubricating oil can be appropriately supplied to the compressor part5, and the compressor part5can be appropriately lubricated. Further, in the compressor1, since the oil discharge amount is decreased, the refrigerator oil that does not contribute to heat exchange is less likely to be supplied to a heat exchanger of the refrigeration cycle apparatus, and the heat exchange efficiency of the heat exchanger of the refrigeration cycle can be improved.

Effects of Compressor1of First Embodiment

The compressor1of the first embodiment includes the rotor21, the stator22that rotates the rotor21around the rotation axis, the compressor part5that compresses refrigerant by the rotation of the rotor21, and the container2that forms the internal space7in which the rotor21, the stator22, and the compressor part5are housed. The rotor21includes the rotor core31in which the plurality of through-holes36-1to36-6through which the refrigerant passes are formed, the through-holes36-1to36-6having a V-shaped cross section of which the bent portion projects toward the rotation axis, the lower rotor end plate32(first end plate) that covers the lower rotor end surface34(first end surface) where one end of the both end portions of the through-holes36-1to36-6of the rotor core31closer to the compressor part5is formed, and the upper rotor end plate33(second end plate) that covers the upper rotor end surface35(second end surface) where the other end of the through-holes36-1to36-6of the rotor core31is formed. The lower rotor end plate32has the lower opening portion41(first opening portion) that causes the through holes36-1to36-6to communicate with the internal space7. The upper rotor end plate33has the upper opening portion43(second opening portion) that causes the through holes36-1to36-6to communicate with the internal space7. The upper opening portion43exposes the region closer to the rotation axis than the through-holes36-1to36-6to the internal space7, and has the projection portions44-1to44-6and45-1to45-6that cover the biforked tip end portions36-11to36-62of the V-shape of the other end.

In such a compressor1, since the plurality of upper inner peripheral side adjacent regions43-1to43-6are exposed to the internal space7, the length of the flow path connecting the lower portion and the upper portion of the motor part6via the plurality of through-holes36-1to36-6can be shortened by the thickness of the upper rotor end plate33. Therefore, in the compressor1, since the plurality of upper inner peripheral side adjacent regions43-1to43-6are exposed to the internal space7, the flow path resistance of the high-pressure refrigerant gas passing through the flow path can be reduced, and the pressure loss when the high-pressure refrigerant gas passes through the motor part6can be reduced. In the compressor1, since the pressure loss when the high-pressure refrigerant gas passes through the motor part6is reduced, the refrigerant can be compressed with high efficiency. In the compressor1, since the refrigerant is compressed with high efficiency, the efficiency of the refrigeration cycle provided with the compressor1can be improved.

Further, the upper rotor end plate33of the compressor1of the first embodiment has the plurality of projection portions44-1to44-6and45-1to45-6that respectively cover the biforked tip end portions36-11to36-62of the V-shape separated toward the outer periphery of the upper end of the plurality of through-holes36-1to36-6on the upper rotor end surface35side. When the refrigerator oil passes through the plurality of through-holes36-1to36-6in a state of being mixed with the refrigerant, the refrigerator oil collides with the plurality of projection portions44-1to44-6and45-1to45-6to be separated from the refrigerant in the plurality of through-holes36-1to36-6. The refrigerator oil separated from the refrigerant in the plurality of through-holes36-1to36-6is moved to the outer peripheral side of the plurality of through-holes36-1to36-6by the centrifugal force due to the rotation of the rotor21, and is collected in the biforked tip end portions36-11to36-62of the V-shape of the upper end of the plurality of through-holes36-1to36-6. In such a compressor1, since the plurality of projection portions44-1to44-6and45-1to45-6are formed, it is suppressed that the refrigerator oil collected in the biforked tip end portions36-11to36-62of the V-shape of the plurality of through-holes36-1to36-6flows out to a portion above the motor part6in the internal space7. Therefore, the compressor1can reduce the amount of refrigerator oil supplied to a portion above the motor part6in the internal space7, and reduce the oil discharge amount of the refrigerator oil discharged together with the refrigerant to the subsequent-stage device. In the compressor1, even in a case where the plurality of projection portions44-1to44-6and45-1to45-6are formed, since the plurality of upper inner peripheral side adjacent regions43-1to43-6of the upper rotor end surface35are exposed to the internal space7, an increase in pressure loss when the high-pressure refrigerant gas passes through the motor part6can be suppressed.

In this way, the refrigerator oil in the plurality of through-holes36-1to36-6is easily discharged to the internal space7on the compressor part5side from the lower opening portion41of the rotor21along the side surfaces of the through-holes36-1to36-6. As a result, the refrigerator oil guided to the internal space7on the discharge pipe12side of the rotor21is decreased. Note that, this effect does not depend on the type of refrigerant gas.

Further, in the compressor1of the first embodiment, the plurality of lower inner peripheral side adjacent regions42-1to42-6of the lower rotor end surface34are exposed to the internal space7. In such a compressor, since the plurality of lower inner peripheral side adjacent regions42-1to42-6are exposed to the internal space7, the length of the flow path connecting the lower portion and the upper portion of the motor part6via the plurality of through-holes36-1to36-6can be shortened by the thickness of the lower rotor end plate32. Therefore, in the compressor1, the flow path resistance of the high-pressure refrigerant gas passing through the flow path can be reduced, and the pressure loss when the high-pressure refrigerant gas passes through the flow path can be further reduced. In the compressor1, since the pressure loss when the high-pressure refrigerant gas passes through the flow path is further reduced, the high-pressure refrigerant gas can be discharged with higher efficiency, and the efficiency of the refrigeration cycle provided with the compressor1can be further improved.

Further, since a structure in which the region closer to the shaft3than the through-holes36-1to36-6is exposed to the internal space7is adopted for the lower side, the refrigerator oil falling down along the side surfaces of the through-holes36-1to36-6can be more efficiently discharged to the internal space7on the compressor part5side from the lower opening portion41.

Further, the upper rotor end plate33and the lower rotor end plate32of the compressor1respectively have one upper opening portion43and one lower opening portion41. Since the each of the upper opening portion43and the lower opening portion41is formed of one hole, the manufacturing can be easily performed. Since the upper rotor end plate33and the lower rotor end plate32can be easily manufactured, such a compressor1can be easily manufactured as a whole.

Compressor of First Comparative Example

FIG.6Ais a bottom view illustrating a rotor of a compressor of a first comparative example, andFIG.6Bis a top view illustrating the rotor of the compressor of the first comparative example. The compressor of the first comparative example has through-holes71-1to71-6in a rotor70as illustrated inFIG.6A. The through-holes71-1to71-6have a shape close to an ellipse. Then, a lower rotor end plate72is fixed to a rotor core to be in close contact with a lower rotor end surface so as to cover the lower rotor end surface of the rotor core. Then, the lower rotor end plate72has a lower central hole73and a plurality of lower opening portions74-1to74-6. The lower central hole73is formed in the center of the lower rotor end plate72.

The plurality of lower opening portions74-1to74-6are formed around the lower central hole73. The plurality of lower opening portions74-1to74-6are formed in the same shape as the cross section where the plurality of through-holes71-1to71-6intersect the plane orthogonal to the rotation axis of the shaft3. The plurality of lower opening portions74-1to74-6allow each of the lower ends of the plurality of through-holes71-1to71-6to be open to the internal space7, and causes each of the plurality of through-holes71-1to71-6to communicate with the internal space7. The lower rotor end plate72further covers all the regions of the lower rotor end surface which are adjacent to the plurality of through-holes71-1to71-6.

Further, as illustrated inFIG.6B, an upper rotor end plate75of the compressor of the first comparative example is fixed to the rotor core to be in close contact with an upper rotor end surface so as to cover the upper rotor end surface of the rotor core. Then, the upper rotor end plate75has an upper central hole76and a plurality of upper opening portions77-1to77-6. The upper central hole76is formed in the center of the upper rotor end plate75.

The plurality of upper opening portions77-1to77-6are formed around the upper central hole76. The plurality of upper opening portions77-1to77-6are formed in the same shape as the cross section where the plurality of through-holes71-1to71-6intersect the plane orthogonal to the rotation axis of the shaft3. The plurality of upper opening portions77-1to77-6allow each of the upper ends of the plurality of through-holes71-1to71-6to be open to the internal space7, and causes each of the plurality of through-holes71-1to71-6to communicate with the internal space7. The upper rotor end plate75further covers all the regions of the upper rotor end surface which are adjacent to the plurality of through-holes71-1to71-6. Then, the compressor of the first comparative example has the same configuration of the compressor1of the first embodiment except for the configuration of the rotor70illustrated inFIG.6.

FIG.7is a bar graph illustrating an oil discharge amount of the compressor of the first embodiment and an oil discharge amount of the compressor of the first comparative example under a high rotation condition in a case where a heating operation is performed using R32 as the refrigerant. The oil discharge amount indicates the concentration of the refrigerator oil contained in the refrigerant discharged through the discharge pipe12. The height of a bar81in the bar graph ofFIG.7indicates the oil discharge amount of the compressor1of the first embodiment. The height of a bar82indicates the oil discharge amount of the compressor of the first comparative example.

This indicates that the oil discharge amount of the compressor1of the first embodiment is smaller than that of the compressor of the first comparative example when the shaft3is rotated under the high rotation condition during the heating operation. Specifically, the oil discharge amount of the compressor1of the first embodiment is about 50% smaller than the oil discharge amount of the compressor of the first comparative example.

The compressor1of the first embodiment has the lower rotor end plate32and the upper rotor end plate33. That is, the upper rotor end plate33of the compressor1of the first embodiment has the plurality of projection portions44-1to44-6and45-1to45-6that cover the biforked tip end portions36-11to36-62of the openings formed by the upper ends of the plurality of through-holes36-1to36-6. On the other hand, the upper rotor end plate75of the compressor of the first comparative example does not have a plurality of projection portions, and allows the through-holes71-1to71-6to be open to the internal space7in a state of covering the entire vicinity of the plurality of through-holes71-1to71-6. Therefore, the bar81of the bar graph indicates that the oil discharge amount of the compressor1is reduced since the biforked tip end portions36-11to36-62of the openings formed by the upper ends of the plurality of through-holes36-1to36-6are covered, and indicates that the amount of the refrigerator oil passing from the lower portion to the upper portion of the motor part6through the plurality of through-holes36-1to36-6is reduced.

In short, the bar81and the bar82in the bar graph indicate that the oil discharge amount of the compressor1of the first embodiment is smaller than the oil discharge amount of the compressor of the first comparative example under the high rotation condition during the heating operation. That is, the bar81of the bar graph indicates that the oil discharge amount of the compressor1is reduced since the biforked tip end portions36-11to36-62of the openings formed by the upper ends of the plurality of through-holes36-1to36-6are covered, and indicates that the amount of the refrigerator oil passing from the lower portion to the upper portion of the motor part6through the plurality of through-holes36-1to36-6is reduced.

FIG.8is a bar graph illustrating an oil discharge amount of the compressor of the first embodiment and an oil discharge amount of the compressor of the first comparative example under the high rotation condition in a case where a heating operation is performed using R410A as the refrigerant. The oil discharge amount indicates the concentration of the refrigerator oil contained in the refrigerant discharged through the discharge pipe12. The height of a bar83in the bar graph ofFIG.7indicates the oil discharge amount of the compressor1of the first embodiment. The height of a bar84indicates the oil discharge amount of the compressor of the first comparative example.

This indicates that the oil discharge amount of the compressor1of the first embodiment is smaller than that of the compressor of the first comparative example when the shaft3is rotated under the high rotation condition during the heating operation. Specifically, the oil discharge amount of the compressor1of the first embodiment is about 60% smaller than the oil discharge amount of the compressor of the first comparative example.

The compressor1of the first embodiment has the lower rotor end plate32and the upper rotor end plate33. That is, the upper rotor end plate33of the compressor1of the first embodiment has the plurality of projection portions44-1to44-6and45-1to45-6that cover the biforked tip end portions36-11to36-62of the openings formed by the upper ends of the plurality of through-holes36-1to36-6. On the other hand, the upper rotor end plate75of the compressor of the first comparative example does not have a plurality of projection portions, and allows the through-holes71-1to71-6to be open to the internal space7in a state of covering the entire vicinity of the plurality of through-holes71-1to71-6. Therefore, the bar81of the bar graph indicates that the oil discharge amount of the compressor1is reduced since the biforked tip end portions36-11to36-62of the openings formed by the upper ends of the plurality of through-holes36-1to36-6are covered, and indicates that the amount of the refrigerator oil passing from the lower portion to the upper portion of the motor part6through the plurality of through-holes36-1to36-6is reduced.

In short, the bar81and the bar82in the bar graph indicate that the oil discharge amount of the compressor1of the first embodiment as smaller than the oil discharge amount of the compressor of the first comparative example under the high rotation condition during the heating operation. That is, the bar81of the bar graph indicates that the oil discharge amount of the compressor is reduced since the biforked tip end portions36-11to36-62of the openings formed by the upper ends of the plurality of through-holes36-1to36-6are covered, and indicates that the amount of the refrigerator oil passing from the lower portion to the upper portion of the motor part6through the plurality of through-holes36-1to36-6is reduced. In this way, the oil discharge amount can be reduced even in a case where either R32 or R410A is used as the refrigerant. That is, the compressor1according to the first embodiment can reduce the oil discharge amount without depending on the type of refrigerant.

Here, in the embodiment described above, the case where the plurality of through-holes36-1to36-6have a V-shape that is divided in a biforked manner has been described, but the number of forks is not particularly limited. In that case, as long as the tip end portions divided in respective forks are covered with the projection portion of the upper rotor end plate33, it is suppressed that the refrigerator oil flows out to the portion above the motor part6in the internal space7by the projection portion. Further, the shape of the through-hole is not limited to the V-shape. For example, a part of the outer periphery of the through-hole formed in a circular shape may project to the outer diameter side to have a plurality of tip end portions. Further, the through-hole need not have the tip end portion in a direction toward the outer periphery. In this case, for example, the through-hole may be formed in a circular shape, and the projection portion may be formed in a manner that a part of the opening portion of the rotor end plate extends toward the shaft side.

REFERENCE SIGNS LIST