JP5984444B2 - Rotary compressor - Google Patents

Description

  The present invention relates to a rotary compressor used in a refrigeration apparatus, and more particularly to a multi-cylinder type rotary compressor including a plurality of sets of cylinders and piston rotors.

  A rotary compressor used in a refrigeration apparatus includes a cylinder having a cylindrical inner wall surface in a hermetically sealed housing, and a piston rotor provided eccentrically with respect to the center of the cylinder. Then, the refrigerant is supplied from the suction port to the compression chamber formed between the cylinder and the piston rotor, the volume of the compression chamber is reduced by the rotation of the piston rotor, and the refrigerant is compressed and discharged from the discharge port. Among such compressors, there is a multi-cylinder type that includes a plurality of sets of cylinders and piston rotors. In a multi-cylinder type compressor, a plurality of sets of cylinders and piston rotors are arranged in a housing along the axial direction of the housing, and each set of piston rotors is fixed to a single shaft. .

  One example will be described with reference to FIG. As shown in FIG. 11, the rotary compressor includes a cylinder 2A, 2B having a cylindrical inner wall surface in a hermetically sealed housing 1, and a piston rotor provided eccentrically with respect to the centers of the cylinders 2A, 2B, respectively. 3A, 3B. Each piston rotor 3A, 3B is provided in the eccentric part 4A, 4B of the shaft 4 provided along the central axis of the cylinders 2A, 2B. The shaft 4 is rotatably provided around its axis via bearings 5A and 5B fixed to the cylinders 2A and 2B. The shaft 4 is provided with a rotor 6 </ b> A constituting a motor 6 for rotating the shaft 4. A stator 6B fixed to the inner peripheral surface of the housing 1 is disposed on the outer peripheral side of the rotor 6A. When the stator 6B is energized, the shaft 4 is rotationally driven, and the piston rotors 3A and 3B are connected to the cylinders 2A and 2B. Turn inside. Then, the refrigerant is sucked into the compression chamber formed between the cylinders 2A and 2B and the piston rotors 3A and 3B, and the compression chamber volume is reduced by the rotation of the piston rotors 3A and 3B, and the refrigerant is compressed and discharged.

Japanese Utility Model Publication No. 61-197288

In the above rotary compressor, if the displacement is large, the deflection (deformation) of the shaft 4 occurring between the bearings 5A and 5B increases. In particular, in a rotary compressor including two piston rotors 3A and 3B, as shown in FIG. 12, the small-diameter connecting portion 4C between the eccentric portions 4A and 4B bends so that there is an inflection point. Such deformation of the shaft 4 may increase a refrigerant leakage gap between the cylinders 2A and 2B and the piston rotors 3A and 3B. In FIG. 12, the degree of deformation is exaggerated.
On the other hand, patent document 1 has proposed providing the bearing 7 which supports a connection part (4C) in FIG. In Patent Document 1, a partition plate 8 and a bearing 7 provided between the piston rotors 3A and 3B are integrally provided. However, the partition plate 8 that is normally formed integrally is divided as shown in FIG. When the partition plate 8 is in contact with the piston rotors 3 </ b> A and 3 </ b> B and is required to be airtight, when the partition plate 8 is divided as in Patent Document 1, there is a possibility that a refrigerant leakage gap is generated in the divided portion. Note that Patent Document 1 divides the partition plate 8 because otherwise the bearing 7 formed integrally in a ring shape cannot be inserted between the connecting portion 4C and the partition plate 8.
The present invention has been made based on such a problem, and provides a rotary compressor having a shaft support structure that does not cause a refrigerant leakage gap while providing a bearing that supports a coupling portion of the shaft. The purpose is to provide.

The rotary compressor according to the present invention, which has been made for this purpose, is supplied with a refrigerant therein, and independently includes a first cylinder and a second cylinder, a partition plate that partitions the first cylinder and the second cylinder, and a drive A shaft that is driven to rotate around its central axis by a source, and is provided eccentrically in a direction perpendicular to the central axis of the shaft, the shaft passing through the first cylinder, the partition plate, and the second cylinder. And a first piston rotor and a second piston rotor that are driven to rotate eccentrically with respect to the centers of the first cylinder and the second cylinder inside the cylinder.
In the rotary compressor according to the present invention, the shaft includes a first eccentric portion where the first piston rotor is held and a second eccentric portion where the second piston rotor is held. A shaft through-hole that penetrates is provided, and is supported around the shaft between the first eccentric portion and the second eccentric portion and inside the shaft through-hole of the partition plate, and has a central angle of 180 degrees or less. and providing a multiple split bearing you.

  The rotary compressor of the present invention does not divide the partition plate, but divides the bearing that supports the shaft between the first eccentric portion and the second eccentric portion, so that the partition plate is around the shaft. It became possible to mount a bearing inside the shaft through hole. Therefore, according to the rotary compressor of the present invention, it is possible to prevent deformation of the connecting portion of the shaft while preventing leakage of the refrigerant from the partition plate.

In the present invention, it described the configuration for supporting the shaft by split bearings.
Form of this, a plurality, typically by two split bearing, which supports the entire circumference of the shaft, since this embodiment supports the entire circumference of the shaft, carry out the deformation prevention of the shaft more reliably There are advantages that can be made .

In the present invention described above , the split bearing is preferably formed with a notch that avoids interference with the first eccentric portion or the second eccentric portion. As shown in an embodiment described later, when two split bearings having a central angle of about 180 degrees are provided, the split bearing cannot be mounted at a predetermined position if it interferes with the first eccentric part or the second eccentric part. Because .

In the present invention described above, the total thickness of the plurality of split bearings is preferably smaller than the distance between the first eccentric portion and the second eccentric portion. Although it shows in detail in the column of the embodiment, in the first embodiment, a plurality, typically two split bearings, are stacked between the first eccentric portion and the second eccentric portion in the same direction and stacked. This is necessary.
In this case, the thicknesses of the plurality of bearings may be the same or different. In the latter case, it is preferable to provide a thickest split bearing corresponding to the direction in which the maximum load is applied to the shaft. In accordance with the magnitude of the load to be applied, the split bearing having the larger thickness and the greater load resistance is arranged.

  According to the rotary compressor of the present invention, it is possible to prevent deformation of the connecting portion of the shaft while preventing leakage of the refrigerant from the partition plate.

It is sectional drawing which shows the structure of the rotary compressor in this Embodiment. It is a figure which shows the cylinder and piston rotor in this Embodiment, and is sectional drawing in the surface orthogonal to the axis line of a compressor. It is a perspective view which extracts and shows the shaft in this Embodiment, a bearing, and a piston rotor. It is a top view which shows the shaft in this Embodiment, a bearing, and a piston rotor from an axial direction. It is a figure which shows the assembly | attachment procedure of a shaft, a bearing, and a piston rotor. FIG. 6 is a diagram illustrating a procedure for assembling the shaft, the bearing, and the piston rotor, following FIG. 5. It is a figure which shows the modification of this embodiment. It is a figure which shows the other modification of this embodiment. It is a figure which shows the position which provides the bearing in the example of FIG. It is a figure which shows the other modification of this embodiment. It is sectional drawing which shows an example of the conventional rotary compressor. It is a figure which shows a mode that the shaft in the conventional rotary compressor is bent. It is a top view which shows the partition plate currently disclosed by patent document 1. FIG.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
As shown in FIG. 1, a compressor 10 is a so-called two-stage type in which disk-shaped cylinders 20A and 20B are provided in two upper and lower stages in a cylindrical hermetic housing 11 having a central axis in the vertical direction. This is a cylinder type rotary compressor. Cylindrical cylinder inner wall surfaces 20S each having an axial line in the vertical direction are formed at the central portions of the cylinders 20A and 20B.

Piston rotors 21A and 21B having an outer diameter smaller than the inner diameter of the cylinder inner wall surface 20S are arranged inside the cylinders 20A and 20B. Each of the piston rotors 21 </ b> A and 21 </ b> B is inserted and fixed to eccentric portions 23 </ b> A and 23 </ b> B of the shaft 23 along the center axis of the housing 11. The eccentric portions 23A and 23B each have a cylindrical shape, but are formed so that the shaft center is shifted from the shaft 23. Thus, spaces R each having a crescent-shaped cross section are formed between the cylinder inner wall surfaces 20S of the cylinders 20A and 20B and the outer peripheral surfaces of the piston rotors 21A and 21B.
Here, the eccentric portion 23A and the eccentric portion 23B of the shaft 23 are provided so that their phases are different from each other by 180 degrees, and the upper-stage piston rotor 21A and the lower-stage piston rotor 21B have their phases Differ from each other by 180 degrees.

  A disc-shaped partition plate 24 is provided between the upper and lower cylinders 20A and 20B. The partition plate 24 partitions the space R in the upper cylinder 20A and the space R in the lower cylinder 20B into the compression chamber R1 and the compression chamber R2 without communicating with each other. The partition plate 24 is formed with a shaft hole 24a penetrating the front and back at the center portion, and the shaft 23 penetrates the shaft hole 24a. When the partition plate 24 is assembled at a predetermined position, the partition plate 24 is coaxially disposed with the shaft 23, but is eccentric with the eccentric portions 23A and 23B. That is, when viewed from the axial direction, the partition plate 24 and the eccentric portions 23A and 23B partially interfere with each other. This causes the difficulty of inserting the bearing 50 into the shaft hole 24a of the partition plate 24 of the shaft 23 as will be described in detail later.

  As shown in FIG. 2, the upper and lower cylinders 20A and 20B are provided with blades 25 that divide the compression chambers R1 and R2 into two, respectively. In each of the cylinders 20A and 20B, the blade 25 is held in an insertion groove 26 formed to extend in the radial direction of the cylinders 20A and 20B so as to be able to advance and retract in a direction approaching and separating from the piston rotors 21A and 21B. Has been. The rear end portion 25a of the blade 25 is pressed by the coil spring 28, and the front end portion 25b is always pressed against the piston rotors 21A and 21B.

  As shown in FIG. 1, the shaft 23 is supported by upper and lower main bearings 29A and 29B fixed to upper and lower cylinders 20A and 20B by bolts 29 so as to be rotatable around its axis. Thus, when the shaft 23 rotates, the upper and lower piston rotors 21A and 21B roll eccentrically in the cylinders 20A and 20B. At this time, since the blade 25 is pressed by the coil spring 28, the tip portion 25b advances and retreats following the movement of the piston rotors 21A and 21B, and is always pressed against the piston rotors 21A and 21B.

  The shaft 23 includes eccentric portions 23A and 23B into which the piston rotors 21A and 21B are fitted. As described above, the eccentric portions 23A and 23B are formed so that the phases thereof are different from each other by 180 degrees, and the two are connected by the connecting portion 23C therebetween. A bearing 50 is provided around the connecting portion 23 </ b> C and inside the shaft hole 24 a of the partition plate 24. Since the bearing 50 is provided between the connecting portion 23C and the partition plate 24 without a gap, the bearing 50 plays a role of preventing deformation of the connecting portion 23C when the shaft 23 rotates.

  The shaft 23 extends upward from the main bearing 29 </ b> A, and a rotor 37 of a motor 36 for rotating the shaft 23 is integrally provided at the protruding portion. A stator 38 is fixed to the inner peripheral surface of the housing 11 so as to face the outer peripheral portion of the rotor 37.

As shown in FIGS. 3 and 4, the bearing 50 has a form in which a ring-shaped member is halved, and includes two split bearings 50 </ b> A and 50 </ b> B. As shown in FIG. 4, the split bearings 50A and 50B have arc-shaped inner edges 51A and 51B and outer edges 52A and 52B, each having a central angle of 180 degrees. In the present invention, the split bearing having a central angle of 180 degrees or less refers to a central angle as a single unit, and is not a central angle when a plurality of bearings are combined.
The split bearings 50A and 50B are mounted around a connecting portion 23C of the shaft 23 in a ring shape by making the inner edges 51A and 51B face each other, at a predetermined position between the eccentric portion 23A and the eccentric portion 23B. The Then, the connecting portion 23C is supported by the inner edges 51A and 51B, and the outer edges 52A and 52B are supported by the partition plate 24, thereby forming a bearing structure that supports the connecting portion 23C.

  In a state where the bearing 50 is mounted at the predetermined position described above, the partition plate 24 and the eccentric portion 23A interfere with each other, and the partition plate 24 and the eccentric portion 23B interfere with each other as can be understood from FIG. This suggests that even if the bearing 50 bearing 50 is divided into two split bearings 50A and 50B, it is not easy to mount them in a predetermined position. That is, if the shaft 23 and the partition plate 24 are coaxially arranged, a sufficient opening for inserting the split bearings 50 </ b> A and 50 </ b> B is not secured between the shaft 23 and the partition plate 24. Therefore, in order to secure this gap, in the present embodiment, the split bearings 50A and 50B are mounted at predetermined positions in the following procedure.

<FIGS. 5A to 5E>
First, as shown in FIG. 5A, the two split bearings 50A and 50B are stacked in the same direction. This suppresses the opening area of the insertion opening 53 provided between the shaft 23 and the partition plate 24 by setting the area in plan view to one split bearing 50A, 50B.
On the other hand, as shown in FIGS. 5B and 5C, the shaft 23 and the partition plate 24 are eccentric from each other so that the amount of eccentricity is maximized. At this time, when viewed in the axial direction, the partition plate 24 is placed between the eccentric portion 23A and the eccentric portion 23B. Then, an insertion opening 53 for inserting the two split bearings 50A and 50B is secured between the shaft 23 and the partition plate 24. The insertion opening 53 has an opening area for receiving one split bearing 50A, 50B.

Next, the split bearings 50 </ b> A and 50 </ b> B are inserted into the insertion slot 53 while being stacked.
Although the insertion opening 53 has a margin in the radial direction, for the next procedure, as shown in FIGS. 5D and 5E, by moving the relative position of the partition plate 24 with respect to the shaft 23, The partition plate 24 is arranged coaxially with the shaft 23. By doing so, a space is formed on the side opposite to the side where the split bearings 50A and 50B are inserted, with the central axis of the shaft 23 interposed therebetween. This space is formed to move one of the split bearings 50A and 50B (the split bearing 50A in this example).

Here, the split bearings 50A and 50B are provided with notches 43A and 43B at both ends of the inner edges 51A and 51B. As is clear from FIG. 4B, if the notches 43A and 43B are not provided, the split bearings 50A and 50B interfere with the eccentric portions 23A and 23B, and the split bearings 50A and 50B are inserted into the insertion opening 53. It is because it becomes impossible to insert in.
As described above, when the split bearings 50A and 50B are divided into two and the center angle is 180 degrees, it is necessary to provide notches for avoiding interference between the eccentric portions 23A and 23B.

<See FIGS. 6A to 6C>
Next, as shown in FIG. 6A, of the split bearings 50A and 50B, the split bearing 50A located on the front side of the insertion opening 53 is directed toward the previously formed space, and the central axis of the shaft 23 Rotate and move around 180 degrees. Then, since the split bearing 50A and the split bearing 50B are eliminated from each other, by moving the split bearing 50A and the split bearing 50B relatively in the axial direction, as shown in FIGS. 6B and 6C, A bearing 50 surrounding the periphery of the connecting portion 23C is formed. Normally, the bearing 50 is abutted against the eccentric portion 23B by pushing the split bearing 50A in the axial direction. However, the axial position of the bearing 50 is arbitrary, and the bearing 50 may be abutted against the eccentric portion 23A, or the bearing 50 may be disposed so as to provide a gap with both the eccentric portions 23A and 24B. May be.

Here, in order to overlap the split bearings 50A and 50B and insert them into the insertion slot 53, and then rotate the split bearing 50A (or 50B), the thickness when the two split bearings 50A and 50B are overlapped (total) It is necessary to satisfy the following relationship between the thickness) and the distance between the eccentric portion 23A and the eccentric portion 24B.
That is, as shown also in FIG. 7, when the thickness of each of the split bearings 50A and 50B is TA and TB, the total thickness is T (= TA + TB), and the distance between the eccentric portion 23A and the eccentric portion 24B is L. Satisfying the formula (1). Otherwise, the overlapped split bearings 50A and 50B cannot be inserted between the eccentric portion 23A and the eccentric portion 24A.
T (= TA + TB) <L (1)

From equation (1), TA and TB may be equal or different, and FIG. 7 shows different examples.
When TA and TB are equal, the load resistance of each of the split bearings 50A and 50B can be made equal. However, usually, the load applied to the shaft 23 differs depending on the direction, and as shown in FIG. 12, the maximum deflection occurs in a specific direction. Therefore, the load resistance of the split bearing 50A or 50B provided in the region corresponding to this direction is reduced. Just make it bigger. Therefore, for example, when TA> TB, it is effective to arrange the split bearing 50A at a position corresponding to the direction of the load that causes the maximum deformation. According to the study by the present inventors, depending on the specifications of the compressor 10 including the shaft 23, the deformation in the direction different from the direction in which the maximum deformation occurs may be very small. As shown in FIG. 8, only one split bearing 50C can be provided corresponding to the direction A in which the maximum deformation occurs.

The direction in which the maximum deformation occurs depends on the positions in the cylinders 20A and 20B as described below. When the position of the blade 25 provided in the cylinders 20A and 20B is set to 0 degree, as shown in FIG. 9, it occurs at a position near 90 degrees around the suction ports 30A and 30B (hereinafter referred to as a reference position). Therefore, when only one split bearing 50C is provided, as shown in FIG. 9, it is recommended that it be provided in a range of ± 90 degrees, preferably ± 45 degrees with respect to the reference position.
The center angle of the split bearing 50C in this case is set within a range of 180 degrees or less.

  Openings 12A and 12B are formed on the side of the housing 11 at positions facing the outer peripheral surfaces of the cylinders 20A and 20B. Cylindrical sleeves 13A and 13B are inserted into the openings 12A and 12B and fixed by brazing. The other ends of the sleeves 13 </ b> A and 13 </ b> B protrude outside the housing 11. The cylinders 20A and 20B are formed with suction ports 30A and 30B that communicate with the openings 12A and 12B up to a predetermined position on the cylinder inner wall surface 20S. Then, the distal ends of cylindrical pipes 17A and 17B are inserted into the suction ports 30A and 30B through the sleeves 13A and 13B. The rear ends of the pipes 17A and 17B are located at substantially the same position as the other ends of the sleeves 13A and 13B protruding to the outside of the housing 11.

An accumulator 14 for gas-liquid separation of refrigerant before being supplied to the compressor 10 is fixed to the housing 11 via a stay 15 outside the housing 11.
The accumulator 14 is provided with suction pipes 16A and 16B for letting the compressor 10 suck the refrigerant in the accumulator 14. The distal ends of the suction pipes 16A and 16B are inserted into the pipes 17A and 17B. The entire circumferences of the leading ends of the suction pipes 16A and 16B, the rear ends of the pipes 17A and 17B, and the other ends of the sleeves 13A and 13B are fixed by brazing.

In such a compressor 10, the refrigerant is taken into the accumulator 14 from the suction port 14a of the accumulator 14, the refrigerant is gas-liquid separated in the accumulator 14, and the gas phase is drawn from the suction pipes 16A and 16B to the pipe 17A, 17B and the suction ports 30A, 30B of the cylinders 20A, 20B are supplied to the compression chambers R1, R2, which are the internal spaces of the cylinder inner wall surfaces 20S of the cylinders 20A, 20B.
Then, due to the eccentric rolling of the piston rotors 21A and 21B, the volumes of the compression chambers R1 and R2 are gradually reduced and the refrigerant is compressed. Discharge holes (not shown) for discharging the refrigerant are formed at predetermined positions of the cylinders 20A and 20B, and reed valves (not shown) are provided in the discharge holes. Thereby, when the pressure of the compressed refrigerant increases, the reed valve is pushed open, and the refrigerant is discharged to the outside of the cylinders 20A and 20B. The discharged refrigerant passes through upper and lower muffler chambers 41 and is discharged from an outlet 42 provided in the upper part of the housing 11 to an external pipe (not shown).

  According to the compressor 10 having the above configuration, since the connecting portion 23C of the shaft 23 is supported by the bearing 50, the deformation of the connecting portion 23C can be prevented or suppressed. Further, since the partition plate 24 that holds the bearing 50 from the periphery is formed of an integral plate member that does not have a dividing surface, there is no possibility that the refrigerant leaks from the dividing surface.

  Further, in the present embodiment, the split bearings 50A and 50B are divided, and notches 43A and 43B are provided in order to avoid interference with the eccentric portions 24A and 24B when inserted into the insertion gap 53, and the total thickness is further increased. T was made smaller than the interval L between the eccentric portion 24A and the eccentric portion 24B. By doing so, the bearing 50 can be mounted around the coupling portion 23 </ b> C and inside the shaft hole 24 a of the partition plate 24.

  In the present invention, it is not essential to provide the bearing 50 over the entire circumference of the connecting portion 23C, and as shown in FIGS. 8 and 9, the bearing is provided only in a part of the connecting portion 23C. Is included. In this case, the split bearing 50C can set the center angle within a range of 180 degrees or less. That is, instead of providing the notches 43A and 43B provided by the split bearings 50A and 50B, the center angle is set to, for example, about 170 degrees, thereby avoiding interference with the eccentric portions 24A and 24B when inserted into the insertion slot 53. be able to. Such adjustment of the center angle is also effective when the bearing 50 is constituted by two split bearings 50A and 50B.

Although the present invention has been described above with respect to the configuration of the compressor 10, the configuration of each part can be appropriately changed within a range not departing from the gist of the present invention.
For example, the compressor 10 has been exemplified by two cylinders including two sets of cylinders 20A and 20B and piston rotors 21A and 21B, but the present invention can also be applied to a compressor having three or more cylinders.
Further, as shown in FIG. 10, by providing oil supply passages H to the split bearings 50A and 50B, oil supply to the eccentric portion 23A of the shaft 23 located above the split bearings 50A and 50B and the main bearing 29A is performed. Can be secured.
Furthermore, although the example of the two split bearings 50A and 50B has been shown, the present invention can be implemented as, for example, three split bearings having a central angle of 60 degrees.

DESCRIPTION OF SYMBOLS 10 Compressor 11 Housing 12A Opening part 13A Sleeve 14 Accumulator 14a Suction port 15 Stay 16A Suction pipe 17A Pipe 20A, 20B Cylinder 20S Cylinder inner wall surface 21A, 21B Piston rotor 23 Shaft 23A, 23B Eccentric part 23C Connection part 24 Partition plate 24a Shaft Hole 25 Blade 25a Rear end portion 25b Front end portion 26 Insertion groove 28 Coil spring 29 Bolts 29A, 29B Main bearing 30A Suction port 36 Motor 37 Rotor 38 Stator 41 Muffler chamber 42 Discharge port 50 Bearings 50A, 50B, 50C Split bearing 51A, 51B Inner edge 52A, 52B Outer edge 53 Insertion opening R Space R1, R2 Compression chamber

Claims (5)

A refrigerant is supplied therein, and each of the first and second cylinders is independent;
A partition plate that partitions the first cylinder and the second cylinder;
A shaft that is driven to rotate around its central axis by a drive source and passes through the first cylinder, the partition plate, and the second cylinder;
Each shaft is eccentrically provided in a direction orthogonal to the central axis of the shaft, and is driven to rotate eccentrically with respect to the centers of the first cylinder and the second cylinder inside the first cylinder and the second cylinder. A first piston rotor and a second piston rotor;
With
The shaft includes a first eccentric portion that holds the first piston rotor, and a second eccentric portion that holds the second piston rotor,
The partition plate includes a shaft through hole through which the shaft passes,
A periphery of said shaft between said second eccentric portion and said first eccentric portion, the interior of the shaft through hole of the partition plate, said shaft supporting, that have a central angle of 180 degrees or less providing multiple split bearing,
A rotary compressor characterized by that. By providing a plurality of the divided bearings, the entire periphery of the shaft is supported.
The rotary compressor according to claim 1. The split bearing is formed with a notch that avoids interference with the first eccentric part or the second eccentric part,
The rotary compressor according to claim 1 or 2. A total thickness of the plurality of bearings is smaller than a distance between the first eccentric portion and the second eccentric portion;
The rotary compressor according to claim 2 or 3. The thickness of the plurality of bearings is different,
Corresponding to the direction in which the maximum load is applied to the shaft, the thickest split bearing is provided.
The rotary compressor according to claim 4.

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