JP7267087B2 - Air conditioning compressor - Google Patents

Description

The present invention relates to air-conditioning compressors.

For example, rotary compressors and scroll compressors are known as devices used for compressing refrigerant in air conditioners. A rotary compressor includes a shaft, a motor that drives the shaft to rotate, a piston rotor attached to an eccentric portion of the shaft, a cylinder that has a cylinder chamber that houses the piston rotor, and is arranged on both sides in the axial direction of the cylinder chamber. An upper bearing and a lower bearing, blades projecting toward the cylinder chamber, a housing that accommodates these, a centrifugal pump that circulates lubricating oil stored in the housing and supplies it to the upper bearing and the lower bearing, etc. and a lubricating oil supply device.

Japanese Unexamined Patent Application Publication No. 2012-137008

A motor has a rotor that rotates together with a shaft, and a cylindrical stator that covers the rotor from the outer peripheral side and generates a magnetic field by electric power supplied from the outside. The rotor is rotationally driven by magnetic forces generated by the stator. It is known that when a rotary compressor is continuously operated, the motor generates heat due to its own internal resistance or the like. Increased heat generation can affect motor performance. Therefore, there is an increasing demand for a technology capable of efficiently cooling the motor.

SUMMARY OF THE INVENTION An object of the present invention is to provide an air-conditioning compressor with improved performance by cooling the motor more efficiently.

An air-conditioning compressor according to one aspect of the present invention includes a shaft extending along an axis extending in a vertical direction , a motor that rotationally drives the shaft, a compression section that compresses a refrigerant as the shaft rotates, and the a housing that accommodates the shaft, the motor, and the compression section; and a lubrication oil supply section that pumps up lubrication oil stored in the housing and supplies the lubrication oil to the compression section, wherein the motor is integrated with the shaft. and a stator that covers the rotor from the outer peripheral side, and an oil flow path through which the lubricating oil flows is formed inside the shaft, and both ends of the shaft in the axial direction is formed with an injection hole that communicates with the oil flow path to inject the lubricating oil toward the outer peripheral side of the stator, and the dimension of the stator in the axial direction is larger than the dimension of the rotor, The injection holes inject lubricating oil toward the stator by extending only in a direction gradually separating from the rotor as it goes from the radially inner side to the outer side with respect to the axis.

According to the above configuration, the injection holes for injecting the lubricating oil toward the outer periphery toward the stator are formed at both end portions of the shaft. Here, the temperature of the motor during operation may reach approximately 100° C. to 150° C. , for example. On the other hand, the lubricating oil temperature remains lower than the motor temperature. Therefore, the motor can be actively cooled by the lubricating oil injected from the injection holes. By the way, in cooling the motor, it is conceivable to employ a configuration in which lubricating oil is supplied to both the rotor and the stator. The rotor rotates at high speed together with the shaft. When lubricating oil is sprayed from the outside onto a rotating rotor, the lubricating oil scatters around. As a result, for example, a large amount of lubricating oil is mixed with the flow of refrigerant, and the oil is released out of the housing of the air conditioning compressor and accumulates in the heat exchanger, which may reduce the thermal efficiency of the entire cycle. However, according to the above configuration, lubricating oil is positively supplied to the stator instead of the rotor. Therefore, it is possible to reduce the possibility that performance will be affected by the lubricating oil being supplied to the rotor as described above.
Furthermore, according to the above configuration, the dimension of the stator in the axial direction is larger than the dimension of the rotor. That is, the stator covers the end of the rotor in the axial direction from the outer peripheral side and the axial direction. In such a configuration, the injection holes extend in a direction gradually separating from the rotor (that is, toward the end of the stator) from the radially inner side to the outer side. Therefore, the lubricating oil supplied from the injection holes is injected in a direction away from the rotor and positively contacts the ends of the stator. This further reduces the possibility of contact of the lubricating oil with the rotor, and allows the stator to be cooled more positively.

In the air-conditioning compressor, among the injection holes, the injection hole on the side farther from the lubricating oil supply portion in the axial direction is more likely than the injection hole on the side close to the lubricating oil supply portion. The pore size may be large.

Here, the air-conditioning compressor is generally arranged and operated in such a posture that the lubricating oil supply portion is positioned downward, that is, the axis is oriented in the vertical direction. Therefore, the lubricating oil supplied from the injection hole drips downward after coming into contact with the stator. According to the above configuration, the injection hole on the side away from the lubricating oil supply section has a larger opening diameter than the injection hole on the side close to the lubricating oil supply section. Therefore, the lubricating oil supplied from the upper injection hole spreads evenly over the entire stator in the course of dripping downward after coming into contact with the stator. This allows the stator to be cooled more efficiently.

In the above air-conditioning compressor, the motor further includes balance weights provided at both ends of the rotor in the axial direction and at a portion of the rotor in the circumferential direction with respect to the axis, and the injection holes are arranged in the circumferential direction. may be formed at a position different from the balance weight.

According to the above configuration, the injection holes are formed at positions different from the balance weights in the circumferential direction. Therefore, the lubricating oil is not blocked by the balance weight, and the lubricating oil can be sprayed to the stator more smoothly than in a configuration in which the injection holes overlap the balance weight in the circumferential direction.

According to the present invention, it is possible to provide an air conditioning compressor with improved performance by cooling the motor more efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows the structure of the air-conditioning compressor (rotary compressor) which concerns on 1st embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a principal part expanded sectional view of the compressor for air conditioning which concerns on 1st embodiment of this invention. FIG. 4 is an enlarged cross-sectional view of a main portion of an air-conditioning compressor according to a second embodiment of the present invention;

[First embodiment]
An embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. As shown in FIG. 1, a rotary compressor 100 as an air-conditioning compressor according to this embodiment includes an accumulator 24, suction pipes 26A and 26B, and a compressor body 10. As shown in FIG. The compressor body 10 includes a crankshaft 16 (shaft) extending along the axis O, a motor 18 that rotates the crankshaft 16, a compression section 10A that compresses refrigerant as the crankshaft 16 rotates, and the crankshaft 16. , a motor 18, a housing 11 covering the compression section 10A, and a centrifugal pump P (lubricating oil supply section) for pumping up the lubricating oil stored in the housing 11 and supplying it to the compressing section 10A.

The compression section 10A includes piston rotors 13A and 13B (first piston rotor 13A and second piston rotor 13B) that revolve (rotate) at positions eccentric from the axis O as the crankshaft 16 rotates, and these first piston rotors. It has cylinders 12A and 12B forming compression chambers C in which 13A and second piston rotor 13B are accommodated, respectively, and upper bearing 17A and lower bearing 17B that rotatably support crankshaft 16 .

The compression section 10A is a so-called two-cylinder type rotary compressor in which annular cylinders 12A and 12B are provided in two upper and lower stages in a cylindrical housing 11 . The housing 11 surrounds the cylinders 12A and 12B to form a discharge space V through which the compressed refrigerant is discharged. A cylindrical first piston rotor 13A and a second piston rotor 13B each having an outer shape smaller than the inside of the cylinder inner wall surface are arranged inside the cylinders 12A and 12B. The first piston rotor 13A and the second piston rotor 13B are inserted and fixed to the crankshafts 14A and 14B (the first crankshaft 14A and the second crankshaft 14B) of the crankshaft 16, respectively.

The first piston rotor 13A of the cylinder 12A on the upper side and the second piston rotor 13B on the lower side are provided so that their phases are different from each other by 180°. That is, the first piston rotor 13A is eccentric in the direction opposite to the eccentric direction of the second piston rotor 13B. A disc-shaped partition plate 15 is provided between the upper and lower cylinders 12A and 12B. A space R in the cylinder 12A on the upper side and a space R on the lower side are partitioned from each other by the partition plate 15 to form compression chambers C1 and C2, respectively.

Cylinders 12A and 12B are fixed to housing 11 by upper bearing 17A and lower bearing 17B. More specifically, the upper bearing 17A has a disc shape fixed to the upper portion of the compression portion 10A, and its outer peripheral surface is fixed to the inner peripheral surface of the housing 11. As shown in FIG. The lower bearing 17B has a disc shape fixed to the lower portion of the compression portion 10A, and its outer peripheral surface is fixed to the inner peripheral surface of the housing 11. As shown in FIG. The upper bearing 17A covers the upper cylinder 12A from above (one side in the direction of the axis O). The lower bearing 17B covers the lower cylinder 12B from below (the other side in the direction of the axis O). That is, the upper bearing 17A together with the cylinder 12A and the partition plate 15 forms the compression chamber C1, and the lower bearing 17B together with the cylinder 12B and the partition plate 15 forms the compression chamber C2. Note that the rotary compressor 100 may have one cylinder instead of two cylinders. In the case of a single-cylinder engine, without providing the partition plate 15, both sides of the cylinder in the direction of the axis O are covered by an upper bearing 17A and a lower bearing 17B, respectively.

An accumulator 24 is fixed to the housing 11 via a stay 25 in the compressor main body 10 to separate the refrigerant from gas and liquid prior to supply to the compressor main body 10 . Suction pipes 26A and 26B are provided between the accumulator 24 and the compressor main body 10 to allow the compressor main body 10 to suck the refrigerant in the accumulator 24 . One ends of the suction pipes 26A, 26B are connected to the lower portion of the accumulator 24, and the other ends communicate with suction ports 23A, 23B formed in the cylinders 12A, 12B through openings 22A, 22B, respectively. One end of the crankshaft 16 is integrally provided with a rotor 19A of a motor 18 for driving the crankshaft 16 to rotate. A cylindrical stator 19B centered on the axis O is fixed to the inner peripheral surface of the housing 11 so as to face the outer peripheral portion of the rotor 19A. The rotor 19A is rotationally driven around the axis O by receiving the force of the magnetic field generated by the stator 19B.

The dimension of the stator 19B in the direction of the axis O is larger than the dimension of the rotor 19A. Therefore, the upper end of the stator 19B is positioned above (on one side in the direction of the axis O) the upper end of the rotor 19A. Further, the upper end of the stator 19B is located below the lower end of the rotor 19A (the other side in the direction of the axis O). That is, both ends of the rotor 19A are covered with the stator 19B from the outer peripheral side. In addition, balance weights W for maintaining inertial force during rotation are provided at both ends of the rotor 19A. Specifically, the balance weight W is provided only on a part of the rotor 19A in the circumferential direction. Further, the positions of the balance weights W are different between the upper end side and the lower end side of the rotor 19A.

The centrifugal pump P is provided on the other side of the crankshaft 16 in the direction of the axis O (bottom side in the vertical direction). The centrifugal pump P pumps up the lubricant stored in the housing 11 along the crankshaft 16 as the crankshaft 16 rotates. The pumped lubricating oil is used to lubricate the upper bearing 17A and the lower bearing 17B and to cool the motor 18 (described later). As long as the lubricating oil can be pumped up, it is also possible to use a structure other than the centrifugal pump P as the lubricating oil supply unit. Note that the amount of heat generated by the motor 18 in the rotary compressor 100 according to the present embodiment remains at a level that can be sufficiently cooled by the amount of lubricating oil that can be pumped up by the centrifugal pump P. That is, there is no need to separately provide a supply device or the like outside the air-conditioning compressor in place of the centrifugal pump P in order to secure the head.

Next, referring to FIG. 2, the configuration around the upper bearing 17A will be described. As shown in FIG. 2, the upper bearing 17A includes a disk-shaped disk portion 171 centered on the axis O, and a cylindrical cylindrical portion 172 integrally provided with the disk portion 171 and centered on the axis O. ,have. The disk portion 171 covers the cylinder 12A from one side (upper side) in the direction of the axis O. As shown in FIG. That is, the disk portion 171 forms an inner surface on one side (upper side) in the direction of the axis O in the compression chamber C1. The tubular portion 172 is open in the direction of the axis O, and the crankshaft 16 is inserted through the inside thereof. That is, the cylindrical portion 172 supports the crankshaft 16 so as to be rotatable around the axis O. As shown in FIG.

Furthermore, a muffler M is attached to the disc portion 171 . The muffler M is provided to reduce the flow velocity of the high-pressure refrigerant discharged from the compression chamber C and diffuse it over a wide range within the housing 11 . Specifically, the muffler M has a cup shape that covers the disk portion 171 from one side in the axis O direction. That is, the muffler M is formed so as to extend from the outer peripheral edge of the disc portion 171 toward one side in the direction of the axis O and gradually decrease in radial dimension in a cross-sectional view including the axis O. Thus, a muffler space Vm is formed between the muffler M and the disk portion 171, through which the high-pressure refrigerant discharged from the compression chamber C flows.

The center portion of the muffler M is formed with an opening Mh through which the cylindrical portion 172 is inserted. The opening Mh has a diameter dimension larger than the outer diameter dimension of the tubular portion 172 . That is, an annular gap g centered on the axis O is formed between the edge of the opening Mh and the outer peripheral surface of the tubular portion 172 . The high-pressure refrigerant discharged from the compression chamber C flows toward one side (upper side) in the direction of the axis O through the gap g.

Next, the structure of the crankshaft 16 will be described. As shown in FIG. 2, inside the crankshaft 16, an oil flow path Fo is formed through which part of the lubricating oil pumped up by the centrifugal pump P flows. The oil flow path Fo extends vertically along the axis O. As shown in FIG. A centrifugal pump P is communicated with the lower end of the oil flow path Fo. The upper end of the oil flow path Fo is closed by a lid member L provided on the upper end surface of the crankshaft 16 .

Furthermore, with the rotor 19A as a reference, injection holes Fj communicating with the oil flow path Fo are formed at both ends of the crankshaft 16 in the direction of the axis O. As shown in FIG. In this embodiment, the injection holes Fj extend radially outward from the oil flow path Fo and are formed in plurality at intervals in the circumferential direction. The lubricating oil injected radially outward from the injection holes Fj is sprayed against the stator 19B of the motor 18 from the inner peripheral side. In the following description, the injection hole Fj positioned on one side (upper side) in the direction of the axis O is called a first injection hole F1, and the injection hole Fj positioned on the other side (lower side) in the direction of the axis O is called a second injection hole F2. call. The opening diameter of the first injection hole F1 is larger than the opening diameter of the second injection hole F2. Further, these injection holes Fj are formed at circumferential positions different from those of the balance weight W described above. That is, the injection holes Fj are formed at circumferential positions that do not overlap with the balance weight W. As shown in FIG.

Next, operation of the rotary compressor 100 according to this embodiment will be described. When operating the rotary compressor 100, the motor 18 is first driven by an external power supply. The crankshaft 16 rotates about the axis O as the motor 18 is driven. As the crankshaft 16 rotates, the first crankshaft 14A and the second crankshaft 14B turn around the central axis (axis O) of the crankshaft 16 . Following this turning, the first piston rotor 13A and the second piston rotor 13B rotate eccentrically within the compression chambers C1 and C2. The eccentric rotation of the first piston rotor 13A and the second piston rotor 13B changes the volumes of the compression chambers C1 and C2, compressing the refrigerant taken into the compression chambers C1 and C2. The compressed refrigerant is taken out through the muffler space Vm and the discharge space V inside the housing 11 .

Here, it is known that when the rotary compressor 100 is continuously operated, the motor 18 generates heat due to its own internal resistance or the like. Increased heat generation may affect the performance of the motor 18 . Therefore, there is an increasing demand for a technology capable of cooling the motor 18 efficiently.

Therefore, in the present embodiment, a configuration is adopted in which the motor 18 (stator 19B) is cooled by spraying part of the lubricating oil onto the motor 18 (stator 19B) through the oil passage Fo and the injection holes Fj. According to the above configuration, the injection holes Fj for injecting the lubricating oil to the outer peripheral side toward the stator 19B are formed at both end portions of the crankshaft 16 . Here, the temperature of the motor 18 during operation may reach approximately 200 to 300° C., for example. On the other hand, the lubricating oil temperature remains lower than the motor 18 temperature. Therefore, the motor 18 can be actively cooled by the lubricating oil injected from the injection holes Fj.

By the way, in cooling the motor 18, it is conceivable to employ a configuration in which lubricating oil is supplied to both the rotor 19A and the stator 19B. However, the rotor 19A rotates together with the crankshaft 16 at high speed. When the lubricating oil is sprayed from the outside onto the rotating rotor 19A, the lubricating oil scatters around. As a result, for example, a large amount of lubricating oil is mixed in the flow of refrigerant, which may reduce the efficiency of the rotary compressor 100 . On the other hand, according to the above configuration, lubricating oil is positively supplied to the stator 19B instead of the rotor 19A. Therefore, it is possible to reduce the possibility that the performance is affected by the lubricating oil being supplied to the rotor 19A as described above. As a result, the motor 18 can be operated more stably, and the performance of the rotary compressor 100 can be further improved.

Here, the rotary compressor 100 is generally arranged and operated in such a posture that the centrifugal pump P is positioned downward, that is, the axis O is along the vertical direction. Therefore, the lubricating oil supplied from the injection hole Fj drips downward after coming into contact with the stator 19B. According to the above configuration, the injection hole Fj (first injection hole F1) on the side farther from the centrifugal pump P is opened more than the injection hole Fj (second injection hole F2) on the side close to the centrifugal pump P. Large pore size. Therefore, the lubricating oil supplied from the first injection holes F1 on the upper side spreads evenly over the entire stator 19B while dropping downward after coming into contact with the stator 19B. Thereby, the stator 19B can be cooled more efficiently.

Furthermore, according to the above configuration, the injection hole Fj is formed at a different position from the balance weight W in the circumferential direction. Therefore, compared to a configuration in which the injection holes Fj overlap the balance weight W in the circumferential direction, the flow of the lubricant is not hindered by the balance weight W, and the lubricant is more smoothly sprayed onto the stator 19B. be able to.

The first embodiment of the present invention has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present invention. For example, in the above-described first embodiment, the rotary compressor 100 has been described as an example of the air-conditioning compressor. However, the example of the air-conditioning compressor is not limited to the rotary compressor 100, and it is also possible to apply the configuration according to the above embodiment to a scroll compressor as another example. Even in this case, effects similar to those described above can be obtained.

[Second embodiment]
Next, a second embodiment of the invention will be described with reference to FIG. In addition, the same code|symbol is attached|subjected about the structure similar to said 1st embodiment, and detailed description is abbreviate|omitted. As shown in FIG. 3, in this embodiment, the configuration of the injection holes Fj' is different from that in the first embodiment. In this embodiment, the injection hole Fj' extends in a direction inclined with respect to the radial direction. More specifically, the injection hole Fj' extends in a direction gradually separating from the rotor 19A as it goes from the radially inner side to the outer side. More specifically, the first injection hole F1' on the upper side extends from the lower side to the upper side (from the other side to the one side in the direction of the axis O) as it goes from the inner side to the outer side in the radial direction. The lower second injection hole F2' extends from the upper side to the lower side (from one side to the other side in the direction of the axis O) as it goes from the radially inner side to the outer side. Also in this embodiment, the opening diameter of the first injection hole F1' is larger than the opening diameter of the second injection hole F2'.

Here, in the above first embodiment and this embodiment, the dimension of the stator 19B in the direction of the axis O is larger than the dimension of the rotor 19A. That is, the stator 19B covers the end of the rotor 19A in the direction of the axis O from the outer peripheral side. In such a configuration, the injection holes Fj according to the present embodiment extend in a direction gradually separating from the rotor 19A (that is, in a direction toward the end of the stator 19B) from radially inside to outside.

According to this configuration, the lubricating oil supplied from the injection hole Fj' is injected in a direction away from the rotor 19A and positively contacts the end of the stator 19B. As a result, the possibility of the lubricant coming into contact with the rotor 19A is further reduced, and the stator 19B can be cooled more positively. As a result, the motor 18 can be operated more stably, and the performance of the rotary compressor 100 can be further improved.

The second embodiment of the present invention has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present invention. For example, in the above-described second embodiment, the rotary compressor 100 has been described as an example of the air-conditioning compressor. However, the example of the air-conditioning compressor is not limited to the rotary compressor 100, and it is also possible to apply the configuration according to the above embodiment to a scroll compressor as another example. Even in this case, effects similar to those described above can be obtained.

DESCRIPTION OF SYMBOLS 100... Rotary compressor 10... Compressor main body 10A... Compression part 11... Housing 12A, 12B... Cylinder 13A... First piston rotor 13B... Second piston rotor 14A. First crankshaft 14B Second crankshaft 16 Crankshaft 17A Upper bearing 171 Disk part 172 Cylindrical part 17B Lower bearing 18 Motor 19A... Rotor 19B... Stator 22A, 22B... Openings 23A, 23B... Suction port 24... Accumulator 25... Stays 26A, 26B... Suction pipes C, C1, C2... Compression chambers F1, F1' First injection holes F2, F2' Second injection holes Fj, Fj' Injection hole Fo Oil passage g Gap L Lid member Mh Opening P Centrifugal pump V Discharge space Vm Muffler space W Balance weight

Claims (3)

a shaft extending along a vertically extending axis;
a motor that rotationally drives the shaft;
a compression section that compresses the refrigerant as the shaft rotates;
a housing that accommodates the shaft, the motor, and the compression section;
a lubricating oil supply section for pumping up lubricating oil stored in the housing and supplying it to the compression section;
with
The motor is
a rotor provided integrally with the shaft;
a stator that covers the rotor from the outer peripheral side;
has
An oil passage through which the lubricating oil flows is formed inside the shaft,
Injection holes for injecting the lubricating oil to the outer peripheral side toward the stator by communicating with the oil flow path are formed at both ends of the shaft in the axial direction ,
the dimensions of the stator in the axial direction are greater than the dimensions of the rotor,
The injection holes inject lubricating oil toward the stator by extending only in a direction gradually separating from the rotor as it goes from the radially inner side to the outer side with respect to the axis.
Air conditioning compressor. 2. Among the injection holes, the injection hole on the side away from the lubricating oil supply portion in the axial direction has a larger opening diameter than the injection hole on the side close to the lubricating oil supply portion. The air conditioning compressor according to . The motor further has balance weights provided at both ends of the rotor in the axial direction and at a part in the circumferential direction with respect to the axis,
3. The air-conditioning compressor according to claim 1 , wherein said injection hole is formed at a position different from said balance weight in the circumferential direction.

Images