JP5748723B2 - Hermetic rotary compressor and refrigeration cycle apparatus - Google Patents

Description

  The present invention relates to a hermetic rotary compressor that is used, for example, for refrigerant compression in air-conditioning / cooling equipment, and a refrigeration cycle apparatus that uses this hermetic rotary compressor.

  2. Description of the Related Art Conventionally, a hermetic rotary compressor used in a refrigeration cycle has a configuration in which an electric motor part and a compression mechanism part are housed in a hermetic container and both are connected by a rotating shaft. Lubricating oil is stored at the bottom of the hermetic container. The lubricating oil is pumped up by an oil supply mechanism provided at the lower end of the rotating shaft and supplied to the compression mechanism. The oil supply mechanism has a structure in which pump blades twisted in a spiral shape are fitted into an oil supply hole provided in the shaft core of the rotating shaft, and the lubricating oil is sucked and rotated by the centrifugal pump action generated by the rotation of the rotating shaft. Oil is supplied to the compression chamber of the compression mechanism and the sliding parts of the bearings via the oil supply holes in the shaft.

  In this type of hermetic rotary compressor, a pump blade having a twist angle of 90 ° has been conventionally used. However, in recent years, in order to increase the amount of oil supplied to the sliding portion of the compression mechanism portion, it has been proposed to increase the twist angle to 180 °. When the twist angle is increased in this way, the contact area with the peripheral wall surface of the oil supply hole of the pump blade is increased as compared with the case where the twist angle is small. For this reason, the pump blades are less likely to fall out of the oil supply holes and the retainability is ensured. On the other hand, there is a problem that the rigidity of the pump blades themselves increases and the assembly workability deteriorates.

  Therefore, various improvements have been made to the shape of the pump blade from the viewpoint of improving workability when inserting the pump blade into the oil supply hole and securing the holding force for holding the pump blade in the oil supply hole. The following patent documents 1 to 3 have been proposed.

  Patent Documents 1 and 2 disclose a technique in which a widened portion having a width larger than the inner diameter of the oil supply hole is formed in a part of the pump blade to improve the holding force of the pump blade in the oil supply hole.

  In Patent Document 3, the pump blade is formed by twisting a strip-shaped metal plate 180 ° in a spiral shape, and the end of the pump blade opposite to the tip in the direction of insertion into the oil supply hole is divided into two forks. A configuration is disclosed in which a pair of locking claws are formed, each locking claw is bent in opposite directions, and each locking claw is elastically pressed against each of the opposite positions of the peripheral wall surface of the oil supply hole. ing. According to this configuration, the pair of locking claws are pressed against each other in the opposite direction inside the oil supply hole, and the pump blade can be firmly held so as not to come out of the oil supply hole.

Japanese Utility Model Publication No. 6-049791 (summary, FIG. 1) Japanese Patent Laying-Open No. 2011-032934 (page 8, FIG. 3) Japanese Unexamined Patent Publication No. 2000-186669 (page 4, FIG. 3)

  In the hermetic rotary compressors of Patent Documents 1 and 2, since the pump blades are supported only by the widened portion, the overall holding force is weak, and there is a possibility that they will come off during operation in the hermetic rotary compressor operation. There was a problem of low long-term reliability. Further, there is a problem in that the widened portion is tensioned and deformed during insertion.

  In the hermetic rotary compressor of Patent Document 3, the corners that press the peripheral wall surface of the oil supply hole in each locking piece are at right angles. For this reason, during the punching process for forming the locking piece, a burr is generated in the direction perpendicular to the insertion direction from the end of the locking piece. There was a problem in that it was caught on the wall surface and the insertion property was hard.

  The present invention has been made to solve the above-described problems, and provides a hermetic rotary compressor and refrigeration cycle apparatus capable of improving the insertion performance of pump blades during assembly and ensuring the holding power of the pump blades. For the purpose.

  A hermetic rotary compressor according to the present invention includes an electric motor unit, a compression mechanism unit that compresses refrigerant, a rotary shaft that extends in a vertical direction that transmits the rotational force of the electric motor unit to the compression mechanism unit, and an axis of the rotary shaft The pump blade is inserted into the lower side of the oil supply hole formed in the suction hole and sucks the lubricating oil from the lower end of the oil supply hole. Of the pair of end faces in the width direction of the distal end portion on the insertion side of the pump blade, one end face on the opposite side to the side on which the pump blade is curved and convex is inside as it goes to the tip. The pair of end faces are provided with chamfers at the corners on the distal end side of the other end face.

  ADVANTAGE OF THE INVENTION According to this invention, the hermetic rotary compressor which can improve the insertion property of a pump blade | blade at the time of an assembly, and ensuring the retention strength of a pump blade | wing can be obtained.

It is the figure which represented typically the longitudinal cross-section of the sealed rotary compressor which concerns on Embodiment 1 of this invention. It is a perspective view of the pump blade | wing of FIG. It is shape explanatory drawing of the pump blade | wing of FIG. It is the figure which showed the mode at the time of inserting the pump blade | wing of FIG. 1 in an oil supply hole. It is the figure which showed the pump blade | wing of "270 degree twist" which is a comparative example. It is a figure which shows the state by which the pump blade | wing of FIG. 1 was inserted in the oil supply hole. It is a figure which shows the result of having changed the angle (beta) of the pump blade of FIG. 1, and having measured the indentation load. It is a figure which shows the result of having changed the angle (beta) of the pump blade of FIG. It is the figure which showed the relationship between the minimum diameter min-maximum diameter max of an oil supply hole by a hole diameter tolerance, and indentation load. It is the figure which showed the relationship between the minimum diameter min-maximum diameter max of the oil supply hole by hole diameter tolerance, and a removal load. It is a figure which shows the refrigerant circuit of the refrigerating-cycle apparatus which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram schematically showing a longitudinal section of a hermetic rotary compressor according to Embodiment 1 of the present invention.
The hermetic rotary compressor 1 includes an electric motor unit 2 and a compression mechanism unit 3 that compresses a refrigerant in a hermetic container 1 a, and has a configuration in which both are connected by a rotating shaft 4. The rotating shaft 4 is disposed so as to extend in the vertical direction in the sealed container 1a, and a rotor 2b (described later) of the motor unit 2 is connected to the upper side of the rotating shaft 4, and the compression mechanism unit 3 is provided on the lower side. It has been. A pump blade 20 is provided at the lower end of the rotating shaft 4. The pump blade 20 sucks the lubricating oil in the oil reservoir 5 provided at the lower portion of the sealed container 1 a by the centrifugal pump action generated by the rotation of the rotating shaft 4, and passes through the oil supply hole 16 provided in the rotating shaft 4. Oil is supplied to the compression chamber of the compression mechanism 3 and sliding parts such as bearings (slide bearings).

  A suction muffler 6 for separating the refrigerant from the refrigerant circuit (not shown) into liquid refrigerant and gas refrigerant and allowing only the gas refrigerant to flow into the hermetic rotary compressor 1 is provided outside the sealed container 1a. Yes. The suction muffler 6 is connected to the compression mechanism 3 in the sealed container 1a by a suction pipe 7. Further, a discharge pipe 8 for discharging the compressed refrigerant is provided on the upper surface of the sealed container 1a.

  The electric motor unit 2 includes a stator 2a and a rotor 2b, and a rotating shaft 4 is fitted into the rotor 2b. The rotation of the rotor 2b is transmitted to the compression mechanism unit 3 through the rotating shaft 4. A disc-shaped oil separation plate 9 having an outer diameter smaller than the outer diameter of the rotor 2b is held at the upper end of the rotating shaft 4, and rotates together with the rotor 2b.

  The compression mechanism 3 is a so-called rotary compression mechanism including a cylinder 11, a rolling piston 12, a vane (not shown), and the like. A substantially cylindrical through-hole is formed in the vertical direction at substantially the center of the cylinder 11, and the through-hole is closed by the upper bearing 13 and the lower bearing 14 to form a cylinder chamber 15. A rolling piston 12 is disposed in the cylinder chamber 15, and the rolling piston 12 is rotatably inserted into an eccentric portion of the rotating shaft 4 and revolves in the cylinder chamber 15 by the rotation of the rotating shaft 4.

  The cylinder 11 is provided with a plate-like vane (not shown) that reciprocates in a groove provided in the cylinder 11 with its tip abutting against a rolling piston 12 that revolves. The inside of the chamber 15 is divided into a suction chamber and a compression chamber. When the refrigerant is sucked into the suction chamber from the suction pipe 7 and the rolling piston 12 revolves in the cylinder chamber 15 as the rotating shaft 4 rotates, the area of the suction chamber gradually increases with the revolving motion. When the refrigerant is sucked and the maximum area is reduced, the suction chamber becomes a compression chamber and compresses the gas refrigerant inside.

Next, the operation of the hermetic rotary compressor 1 will be described.
The refrigerant in the refrigerant circuit constituting the refrigeration cycle passes through the suction muffler 6 and is sucked from the suction pipe 7 into the compression mechanism portion 3 in the sealed container 1a. The low-pressure refrigerant gas sucked into the compression mechanism unit 3 is compressed as described above, and is discharged into the sealed container 1a through a discharge port (not shown) provided in the upper bearing 13, and is discharged from the discharge pipe 8. It is discharged to the refrigerant circuit outside the sealed container 1a.

Next, the oil supply mechanism including the pump blade 20 which is a characteristic part of the present embodiment will be described.
The rotary shaft 4 is provided with an oil supply hole 16 extending in the vertical direction at the shaft center. The oil supply hole 16 is formed with a plurality of lateral holes 17 penetrating in the radial direction. Lubricating oil in the oil supply hole 16 is supplied to the compression chamber of the compression mechanism unit 3 and sliding parts such as bearings. The pump blade 20 is inserted into the lower side of the oil supply hole 16.

FIG. 2 is a perspective view of the pump blade of FIG. FIG. 3 is an explanatory view of the shape of the pump blade of FIG. 1, (a) is a completed drawing, and (b) is a development view.
The pump blade 20 has a shape in which a strip-shaped metal plate is spirally twisted as a whole and curved as shown by a dotted line in FIG. The metal plate used as the pump blade 20 is formed to have a width substantially the same as the diameter of the oil supply hole 16.

  Of the pair of end faces in the width direction of the insertion-side distal end portion 21 that becomes the distal end when the pump blade 20 is fitted into the oil supply hole 16 of the rotating shaft 4, the pump blade 20 is opposite to the side on which the pump blade 20 is curved and convex. The end face (one end face) is an inclined portion 23 that inclines at an angle (inclination angle) β toward the front end. In the first embodiment, the inclined portion 23 is provided at 1/3 on the tip side of the entire length L of the pump blade 20. The inclined portion 23 is formed by punching at the same time when a strip-shaped metal plate to be the pump blade 20 is formed from the base material. Further, chamfers 24 and 25 are provided at the corners of the insertion-side distal end portion 21. In addition, from the viewpoint of improving insertability, the chamfer 24 at the corner opposite to the inclined portion 23 is necessary, but the chamfer 25 at the corner on the inclined portion 23 side may be omitted.

  Moreover, the back of the pump blade 20 is formed in a bifurcated shape, each of which is bent in the opposite direction, and serves as a trigger portion 22 that serves as a trigger for sucking up the lubricating oil.

  By the way, conventionally, when the motor unit is a constant speed motor, the operating frequency is 50 to 60 rps, and the lubricating oil is sucked up by pump blades having a twist angle of 90 °. However, in recent years, since the motor has been switched to the inverter specification, the operating range of the hermetic rotary compressor has been changed from low speed (15 rps) to high speed (130 rps). Reduced compared to using a motor.

  In the first embodiment, the twist angle of the pump blade 20 is set to 270 °, and the oil is supplied to the compression mechanism unit 3 as described above by increasing the twist angle as compared with the conventional 90 ° and 180 °. The amount can be increased. And if the amount of oil supply increases, since the sealing effect by lubricating oil will raise, the sealing performance of the compression mechanism part 3 will improve, and since lubricity will improve, the performance of a hermetic rotary compressor will also improve.

  Here, the pump blade 20 has a twist structure from the twist start portion S (see FIG. 3) to the twist end portion E through the twist central portion M, and from the viewpoint of efficient oil supply to the sliding portion, It is desirable that the positional relationship with the lateral hole 17 is the following positional relationship. That is, the curved surface portion C1 between the twist center portion M and the twist end portion E and the curved surface portion C2 opposite to the curved surface portion C1 with the twist center portion M as the center are formed as shown in FIG. It is desirable that the positions are opposed to each other. However, when the twisted shape is 270 ° or more for the purpose of increasing the amount of oil supply, the positional relationship is broken, and the sucked-up lubricating oil cannot be efficiently supplied. Further, when the twist angle is increased by 270 ° or more, the rigidity of the pump blade itself is increased, and the insertability of the pump blade 20 into the oil supply hole 16 is lowered.

  Therefore, in the first embodiment, the twist angle is set to 270 °, and the performance as a hermetic rotary compressor is improved by contributing to an increase in the suction amount at low speeds. It is possible to achieve both ease of insertion into 16 and difficulty of removal. Hereinafter, this point will be described.

  FIG. 4 is a view showing a state when the pump blade of FIG. 1 is inserted into the oil supply hole. FIG. 4A shows the case of the pump blade of FIG. 1, and FIG. 4B shows the case of the pump blade without the inclined portion 23 as a comparative example. FIG. 5 shows a pump blade 20A of a comparative example, which is the same as the pump blade of FIG. 1 except that the inclined portion 23 is not provided, and has a curved shape with a twist angle of 270 °.

  First, a comparative example (hereinafter referred to as “270 ° twist”) in FIG. 4B will be described. Similarly to the pump blade 20, the pump blade 20 </ b> A of “270 ° twist” is also curved. Therefore, when the pump blade 20A is inserted into the oil supply hole 16 in the direction of the arrow, the pump blade 20A is pushed into the oil supply hole 16 while resisting the spring force due to the curve, and is indicated by ● as shown in FIG. It gets caught at 2 points. The pump blade 20A has a twist angle of 270 ° and has higher rigidity than that of 90 ° or 180 °. For this reason, it is difficult to push the pump blade 20A caught at two points into the oil supply hole 16, and it is difficult to insert the pump blade 20A.

  On the other hand, since the pump blade 20 of the first embodiment has the inclined portion 23 at the insertion-side distal end portion 21, the contact resistance with the peripheral wall surface of the oil supply hole 16 at the time of inserting the distal end is suppressed, and it is easy to the back It becomes possible to assemble, and the assembly insertability is improved.

6 is a view showing a state in which the pump blade of FIG. 1 is inserted into the oil supply hole. FIG. 6 shows a state in which the pump blade is rotated by 90 ° about the central axis of the oil supply hole 16 from FIG. This is shown in (b). 6A and 6B, the left side is a sectional view and the right side is a side view.
Since the pump blade 20 is curved in the direction of the dotted line in FIG. 6 before insertion, when the pump blade 20 is mounted in the linear oil supply hole 16, the three points indicated by ● in FIG. Supported by The black circles in FIG. 2 indicate the same three points as in FIG. Therefore, the pump blade 20 can maintain the same holding force in the oil supply hole 16 as the “270 ° twist” pump blade 20A without the inclined portion 23.

  Further, in the pump blade 20 of the first embodiment, the angle β of the inclined portion 23 is set to 0 ° <β ≦ 2 °. By setting it as this range, the following effects can be obtained as compared with the pump blade 20A of “270 ° twist” without the inclined portion 23. That is, the indentation load generated when the pump blade 20 is assembled to the oil supply hole 16 is reduced, and the removal load that is an index of the holding force of the pump blade 20 in the oil supply hole 16 is maintained. This point will be described below based on experimental results.

FIG. 7 is a diagram showing the results of measuring the indentation load by changing the angle β of the pump blade of FIG. 1 variously. In FIG. 7, the horizontal axis indicates the angle β, and the vertical axis indicates the indentation load in a non-dimensional manner. FIG. 7 shows the case of the pump blade 20 of the present embodiment and the case of the pump blade 20A of “270 ° twist” shown in FIG.
As shown in FIG. 7, by making the angle β larger than 0 °, the indentation load can be reduced more than “270 ° twist”. As the angle β is increased, the indentation load can be reduced. However, if the angle β is increased too much, the unloading load becomes smaller and the removal becomes easier. Therefore, the upper limit value of the angle β is determined from the relationship with the drop load.

FIG. 8 is a diagram showing the results of measuring the removal load by changing the angle β of the pump blade in FIG. 1 variously. The horizontal axis in FIG. 8 indicates the angle β, and the vertical axis indicates the drop load in a non-dimensional manner. In FIG. 8, the solid line indicates the case of the pump blade 20 of the present embodiment, and the dotted line indicates the case of the pump blade having a curved shape with a twist angle of 90 °.
As shown in FIG. 8, when the angle β is set to 2 ° or less, the removal load can be made larger than “90 ° twist”. That is, it is possible to obtain a removal load that is higher than or substantially equivalent to “90 ° twist” that is easy to come off.

  From the above, it is preferable that the angle β is 0 ° <β ≦ 2 °.

Next, the hole diameter tolerance of the oil supply hole 16, the indentation load, and the removal load will be described.
FIG. 9 shows the relationship between the minimum diameter min to the maximum diameter max of the oil supply hole 16 due to the hole diameter tolerance and the indentation load for “this embodiment”, “270 ° twist”, and “90 ° twist”. FIG. FIG. 10 shows the relationship between the minimum diameter min to the maximum diameter max of the oil supply hole 16 due to the hole diameter tolerance and the removal load for each of “this embodiment”, “270 ° twist”, and “90 ° twist”. FIG. 9 and 10, the indentation load and the removal load are shown in a non-dimensional manner.

  As shown in FIG. 9, the indentation load of “the present embodiment” is lower than the “270 ° twist” in the whole range of the hole diameter of the oil supply hole 16 from min to max, and the insertion property is improved. I understand that. It should be noted that “this embodiment” has a larger indentation load and lower insertability than “90 ° twist”, but the difference is slight. From the viewpoint of increasing the amount of oil supply, as described above. The twist angle is preferably 270 °. Further, when the shape of the present embodiment is provided with the inclined portion 23, the insertability can be improved as compared with the “270 ° twist” without the inclined portion 23.

  Further, as shown in FIG. 10, the unloading load of “the present embodiment” is slightly lower than the “270 ° twist” in the whole range of the hole diameters of the oil supply holes 16 from min to max. It can be seen that it is higher than or substantially equivalent to “degree of twist”, and the retaining property is also secured.

  As described above, according to the first embodiment, the inclined portion 23 is provided at the insertion-side distal end portion 21 of the pump blade 20 having a shape obtained by spirally twisting a strip-shaped metal plate, and is opposite to the inclined portion 23. Since the chamfer 24 is provided at the tip corner portion on the side, the contact resistance at the time of insertion is suppressed, and the assembly insertion property can be improved. Further, by making the pump blade 20 curved and using the repulsive force of the warping of the leaf spring, it is possible to hold three points in the oil supply hole 16 of the rotating shaft 4, and hold the pump blade 20 in the oil supply hole 16. Power can also be secured.

  Moreover, when forming the metal plate used as the pump blade 20 by punching from the base material, even if burrs remain in the inclined portion 23, the insertion-side distal end portion 21 is narrowed by providing the inclined portion 23. For this reason, when the pump blade 20 is inserted into the oil supply hole 16, the burr is not caught by the oil supply hole 16, which contributes to improvement in insertability.

  In addition, by setting the angle β to 0 ° <β ≦ 2 °, it is possible to achieve both improved insertability and difficulty in removal compared to a pump blade having the same twist angle and no inclined portion 23.

  Also, by setting the twist angle to 270 °, the amount of oil supply can be increased compared to the case where the twist angle is set to 90 ° or 180 °, and the sealing performance and lubricity are improved to improve the compressor performance. Can do. Particularly, the effect of increasing the suction amount when the hermetic rotary compressor is operated at a low speed is very effective in improving the compressor performance.

  As described above, the stability of the oil supply to the compression mechanism 3, the improvement of the sealing performance of the closed type rotary compression mechanism by the sealing effect of the lubricating oil, and the wear of the sliding part such as the rotating shaft 4 and the bearing and the shaft by the lubricating effect. The hermetic rotary compressor 1 that can reduce galling can be obtained.

Embodiment 2. FIG.
The second embodiment relates to a refrigeration cycle apparatus including the hermetic rotary compressor 1 of the first embodiment.

FIG. 11 is a diagram showing a refrigerant circuit of the refrigeration cycle apparatus according to Embodiment 2 of the present invention.
This refrigeration cycle apparatus includes a hermetic rotary compressor 1, a condenser 101, a decompression apparatus 102, and an evaporator 103, and includes a refrigerant circuit configured by sequentially connecting them through a refrigerant pipe. By using the hermetic rotary compressor of the first embodiment in the refrigeration cycle apparatus configured as described above, a refrigeration cycle apparatus capable of improving the operation efficiency can be obtained. The refrigerant circuit mentioned here is an example, and the hermetic rotary compressor of the present invention can be applied to various refrigerant circuits.

  In the above description, the pump blade according to the present invention is applied to a so-called one-cylinder rotary compressor. However, the present invention is not limited to this and is applied to a two-cylinder rotary compressor or a scroll compressor. Also good.

  DESCRIPTION OF SYMBOLS 1 Sealing type rotary compressor, 1a Sealed container, 2 Motor part, 2a Stator, 2b Rotor, 3 Compression mechanism part, 4 Rotating shaft, 5 Oil reservoir part, 6 Suction muffler, 7 Suction pipe, 8 Discharge pipe, 9 Oil separation Plate, 11 Cylinder, 12 Rolling piston, 13 Upper bearing, 14 Lower bearing, 15 Cylinder chamber, 16 Oil supply hole, 17 Side hole, 20 Pump blade, 20A Pump blade, 21 Insertion-side tip, 22 Trigger, 23 Inclination 24 chamfering, 25 chamfering, 101 condenser, 102 decompression device, 103 evaporator, C1 curved surface portion, C2 curved surface portion, E twist end portion, M twist central portion, S twist start portion.

Claims (6)

An electric motor section;
A compression mechanism for compressing the refrigerant;
A rotating shaft extending in the vertical direction for transmitting the rotational force of the electric motor unit to the compression mechanism unit;
A pump blade for oil supply, which is fitted and inserted into a lower side of an oil supply hole formed in the shaft center of the rotary shaft, and sucks lubricating oil from a lower end of the oil supply hole;
The pump blade has a shape in which a strip-shaped plate material is spirally twisted and curved as a whole, and the pump blade is curved among a pair of end faces in the width direction of the distal end portion on the insertion side of the pump blade. One end surface opposite to the convex side is an inclined portion that is inclined inwardly toward the tip, and a chamfer is provided at a corner on the tip of the other end surface of the pair of end surfaces. A hermetic rotary compressor characterized in that   2. The hermetic rotary compressor according to claim 1, wherein an inclination angle of the inclined portion is greater than 0 ° and 2 ° or less. 3. The hermetic rotary compressor according to claim 1, wherein the inclined portion is provided in 1/3 of the entire length of the pump blade on the tip side. The hermetic rotary compressor according to any one of claims 1 to 3, wherein a twist angle of the pump blade is 270 °. The pump blade has a curved surface portion up and down around a twisted central portion, and both the vertical center portion of the one curved surface portion and the vertical center portion of the other curved surface portion are the oil supply holes. 5. The hermetic rotary compressor according to claim 4, wherein the closed rotary compressor is disposed in the oil supply hole so as to face two lateral holes penetrating the rotary shaft in a radial direction. A refrigeration cycle apparatus comprising the hermetic rotary compressor according to any one of claims 1 to 5 .

Images