JP2009041546A - Rotary compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary compressor capable of reducing difference of loads acting on an upper and a lower surface of a rolling piston and reducing sliding loss caused by having the rolling piston pressed to a low load side. <P>SOLUTION: A low stage side bearing load adjusting part 44 is hollowly provided in an annular shape on an inner circumference of an upper end surface of a low stage side bearing 34 so as to open to an outer circumference of a shaft part 5, and a high stage side bearing load adjusting part 45 is hollowly provided in an annular shape on an inner circumference of a lower end surface of a high stage side bearing 35 so as to open to the outer circumference of the shaft part 5. An opening diameter at the end surfaces of the low stage side and the high stage side bearing load adjusting part 44, 45 are substantially consistent with a diameter of an insertion hole 31a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotary compressor in which a compression mechanism is housed in a hermetic shell.

  Conventionally, a rotary compressor used in a vapor compression refrigeration cycle or a heat pump cycle compresses in a cylinder by contacting a cylinder whose end opening is closed, a roller rotating in the cylinder by a drive shaft, and the roller. A low-pressure side and high-pressure side rotary compression element comprising vanes that form a space, these rotary compression elements are housed in a sealed container, carbon dioxide refrigerant is sucked in, compressed by the rotary compression element, and discharged The low pressure side and high pressure side rotary compression elements are partitioned by a plate middle, and the ends of the low pressure side and high pressure side rotary compression elements are closed by bearings.

  Here, since the center hole of the plate middle passes the eccentric part of the drive shaft, the inner diameter is larger than the diameter of the eccentric part. The inner diameter of the bearing is the outer diameter of the drive shaft and is smaller than the inner diameter of the center hole of the plate middle. Therefore, in order to ensure the sealing performance on the plate middle side of the rotary compression element, the minimum overlap width between the roller of the rotary compression element and the plate middle is set to 1/3 or more of the axial thickness of the cylinder (for example, Patent Documents). 1). Alternatively, in order to ensure the seal width on the plate middle side, the outer peripheral shape of the roller and the inner peripheral shape of the cylinder are tapered so that the outer diameter of the roller and the inner diameter of the cylinder gradually increase toward the plate middle side ( For example, see Patent Document 2).

JP 2002-371982 A Japanese Utility Model Publication No. 5-47472

In the thing of patent document 1, 2, since the circumference | surroundings of a drive shaft are connected with the inside of an airtight container, the internal diameter side of a roller is the same pressure as the inside of an airtight container. The range of pressures acting on the upper and lower surfaces of the roller differs depending on the dimensional difference between the inner diameter of the bearing and the inner diameter of the center hole of the plate middle, and the loads acting on the upper and lower surfaces of the roller are different. Therefore, the roller is pressed to the low load side, and a sliding loss occurs, resulting in performance degradation.
Furthermore, in the thing of patent document 2, in addition to the outer peripheral shape of a roller and the inner peripheral shape of a cylinder, it is necessary to process the front-end | tip part of a vane in a taper shape, and high processing accuracy is requested | required and workability deteriorates. There is also a problem of doing.

  The present invention has been made to solve the above-described problems, and the end face opening diameter of the bearing is made substantially equal to the inner diameter of the insertion hole of the intermediate plate without requiring high processing accuracy, so that the upper and lower surfaces of the rolling piston are It is an object of the present invention to obtain a rotary compressor that can reduce the difference in load acting on the cylinder and reduce the sliding loss caused by the rolling piston being pressed to the low load side.

  The rotary compressor according to the present invention includes a hermetic shell, a low-stage compression mechanism unit and a high-stage compression mechanism unit housed in the hermetic shell, and a low-stage compression mechanism unit housed in the hermetic shell. And a motor that drives the high-stage compression mechanism, and compresses the low-pressure refrigerant to an intermediate pressure by the low-stage compression mechanism, and then compresses it to a high pressure by the high-stage compression mechanism. The low-stage compression mechanism section and the high-stage compression mechanism section include a low-stage cylinder and a high-stage cylinder that are arranged to face each other with an intermediate plate interposed therebetween, and the intermediate plate with the low-stage cylinder interposed therebetween. A low-stage bearing disposed opposite the high-stage cylinder, a high-stage bearing disposed opposed to the intermediate plate across the high-stage cylinder, and connected to the motor and spaced apart in the axial direction. The formed low-stage eccentric part and high-stage eccentric part are accommodated in the low-stage cylinder and the high-stage cylinder, respectively, and are pivotally supported by the low-stage bearing and the high-stage bearing. The drive shaft and the low-stage eccentric part and the high-stage eccentric part are fitted in an externally fitted state, and can be eccentrically rotated in the low-stage cylinder and the high-stage cylinder. Low stage side rolling piston and high stage side rolling Comprising piston and the low-stage vanes and the high-stage vane constituting the compression space in contact with the respective outer peripheral surfaces of the low-stage rolling piston and the high-stage rolling piston, a. The drive shaft insertion hole formed in the intermediate plate is formed to have a diameter through which at least one of the low-stage eccentric portion and the high-stage eccentric portion can be inserted, and the low-stage bearing load adjustment And the high stage side bearing load adjusting part are respectively provided in an annular shape so as to open the outer peripheral surface of the drive shaft on the inner periphery of the end surface facing the intermediate plate of the low stage side bearing and the high stage side bearing. The opening diameters of the low-stage bearing load adjustment section and the high-stage bearing load adjustment section at the end surfaces of the low-stage bearing and the high-stage bearing facing the intermediate plate are substantially equal to the diameter of the insertion hole. Match.

According to the present invention, the low-stage side and high-stage side bearing load adjustment portions are respectively annularly formed so as to open the outer peripheral surface of the drive shaft to the inner periphery of the end surface facing the intermediate plate of the low-stage side and high-stage side bearings. It is recessed. Furthermore, the opening diameters at the end surfaces of the low-stage side and high-stage side bearing load adjusters facing the intermediate plate of the low-stage side and high-stage side bearings substantially coincide with the diameter of the insertion hole. Therefore, the load applied to the upper and lower surfaces of the low-stage side and high-stage side rolling pistons is neutralized, and the sliding loss due to the low-stage side and high-stage side rolling pistons being pressed against the low-load side can be reduced. .
In addition, there is no need to machine the inner peripheral surface shape of the low-stage side and high-stage side cylinders and the outer peripheral surface shape of the low-stage side and high-stage side rolling pistons into a tapered shape, reducing the sliding loss with a simple structure. it can.

Embodiment 1 FIG.
FIG. 1 is a longitudinal sectional view showing a configuration of a two-stage rotary compressor according to Embodiment 1 of the present invention, and FIG. 2 explains a configuration of a compression mechanism section in the two-stage rotary compressor according to Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view illustrating the configuration of the low-stage compression mechanism in the two-stage rotary compressor according to Embodiment 1 of the present invention, and FIG. 4 is related to Embodiment 1 of the present invention. It is a cross-sectional view explaining the structure of the high stage side compression mechanism part in a two-stage rotary compressor.

  1 to 4, the two-stage rotary compressor includes a vertical hermetic shell 1. The motor 2 is disposed above the sealed shell 1, and the compression mechanism 3 is disposed below the motor 2. The motor 2 and the compression mechanism unit 3 are interlocked and connected via a drive shaft 4. The drive shaft 4 includes a shaft portion 5 having a single diameter, and a low-stage eccentric portion 6 and a high-stage eccentric portion 7 that are formed apart from each other in the axial direction of the shaft portion 5.

  The motor 2 includes a stator 12 formed in a ring shape and a rotor 13 supported so as to be able to rotate inside the stator 12. One end portion of the shaft portion 5 is fixed to the axial center position of the rotor 13.

  The compression mechanism unit 3 includes an intermediate plate 31 having a thickness equivalent to the axial distance between the low-stage side eccentric part 6 and the high-stage side eccentric part 7 and having an insertion hole 31a, and an intermediate plate A low-stage cylinder 32 and a high-stage cylinder 33 that are mounted concentrically facing each other across 31, a low-stage bearing 34 that closes a lower-end opening of the low-stage cylinder 32, and an upper end of the high-stage cylinder 33 A high-stage bearing 35 that closes the opening, a low-stage-side rolling piston 36 disposed in a low-stage-side space composed of a low-stage-side cylinder 32, a low-stage-side bearing 34, and an intermediate plate 31; The high-stage side rolling piston 37 disposed in the high-stage side space composed of the side cylinder 33, the high-stage side bearing 35 and the intermediate plate 31 and the outer peripheral surface of the low-stage side rolling piston 36 are in contact with each other. The side space is compressed with the lower stage suction chamber 42a and the lower stage side compression. A low-stage vane 38 that is partitioned into 42 b, a low-stage spring 39 that urges the low-stage vane 38 against the outer peripheral surface of the low-stage rolling piston 36, and an outer peripheral surface of the high-stage rolling piston 37. The high-stage vane 40 that partitions the high-stage space into the high-stage suction chamber 43a and the high-stage compression chamber 43b, and presses the high-stage vane 40 against the outer peripheral surface of the high-stage rolling piston 37. And a high-stage spring 41 that urges in this manner.

  The shaft portion 5 of the drive shaft 4 passes through the axial center positions of the low-stage cylinder 32, the intermediate plate 31, and the high-stage cylinder 33, and is freely rotatable by the low-stage bearing 34 and the high-stage bearing 35. It is supported by. At this time, the low-stage eccentric part 6 is accommodated in the low-stage cylinder 32, and the high-stage eccentric part 7 is accommodated in the high-stage cylinder 33. The low-stage side rolling piston 36 is fitted on the low-stage side eccentric part 6 in an externally fitted state, and the high-stage side rolling piston 37 is fitted on the high-stage side eccentric part 7 in an externally fitted state. By rotating 4, eccentric rotation is performed.

  Here, in the low-stage compression mechanism, the low-stage bearing 34 and the intermediate plate 31 are arranged to face each other with the low-stage cylinder 32 interposed therebetween, and the low-stage side rolling piston 36 is arranged in the low-stage side eccentric part 6. The low-stage side vane 38 is disposed so as to be in contact with the outer peripheral surface of the low-stage side rolling piston 36. The high-stage compression mechanism is configured such that the high-stage bearing 35 and the intermediate plate 31 are opposed to each other with the high-stage cylinder 33 interposed therebetween, and the high-stage rolling piston 37 is disposed on the high-stage eccentric part 7. The high-stage side vane 40 is disposed so as to be eccentrically rotatable by being mounted, and the high-stage vane 40 is disposed so as to contact the outer peripheral surface of the high-stage side rolling piston 37.

  A suction pipe 8 for sucking refrigerant gas is connected to the low-stage side suction chamber 42 a, and a discharge pipe 9 for discharging compressed refrigerant gas is provided at the upper part of the hermetic shell 1. The communication pipe 10 is provided so as to communicate the low-stage compression chamber 42b and the high-stage suction chamber 43a. Further, the high-stage compression chamber 43 b communicates with the hermetic shell 1, and high-pressure refrigerant gas compressed by the high-stage compression mechanism is discharged into the hermetic shell 1. An accumulator 11 is connected to the suction pipe 8.

  The shaft portion 5 of the drive shaft 4 is pivotally supported by the low-stage side bearing 34 and the high-stage side bearing 35 and is inserted through the compression mechanism portion 3. The insertion hole 31 a formed in the intermediate plate 31 has an inner diameter through which the low-stage eccentric portion 6 and the high-stage eccentric portion 7 can be inserted, and supports the shaft portion 5 on the low-stage side. It is larger than the inner diameter of the bearing 34 and the high stage side bearing 35.

  A low-stage bearing load adjusting portion 44 is annularly recessed in the inner periphery of the upper end surface (the surface facing the intermediate plate 31) of the low-stage bearing 34 so as to open the outer peripheral surface of the shaft portion 5. Yes. Similarly, the high-stage bearing load adjusting portion 45 is annularly recessed so as to open the outer peripheral surface of the shaft portion 5 on the inner periphery of the lower end surface (the surface facing the intermediate plate 31) of the high-stage bearing 35. It is installed. The bottom surfaces of the low stage side bearing load adjustment unit 44 and the high stage side bearing load adjustment unit 45 are flat surfaces. The inner peripheral surfaces of the low stage side bearing load adjustment unit 44 and the high stage side bearing load adjustment unit 45 are formed in a tapered shape in which the inner diameter gradually decreases in the direction away from the intermediate plate 31. That is, the low stage side bearing load adjustment part 44 and the high stage side bearing load adjustment part 45 are formed in a truncated conical concave shape. And the opening diameter in the upper end surface of the low stage side bearing 34 of the low stage side bearing load adjustment part 44 and the opening diameter in the lower end face of the high stage side bearing 35 of the high stage side bearing load adjustment part 45 are the insertion holes 31a. It almost matches the inner diameter.

Next, the operation of the two-stage rotary compressor configured as described above will be described.
When electric power is supplied to the motor 2 and the motor 2 is driven, the drive shaft 4 supported by the low stage side bearing 34 and the high stage side bearing 35 is rotationally driven. Then, the low-stage side rolling piston 36 and the high-stage side rolling piston 37 rotate eccentrically in the low-stage side cylinder 32 and the high-stage side cylinder 33. At this time, the upper and lower surfaces of the low stage side rolling piston 36 and the high stage side rolling piston 37 are sealed with lubricating oil.
The low-pressure refrigerant is introduced into the low-stage side suction chamber 42a through the accumulator 11 and the suction pipe 8, is compressed by the low-stage side compression mechanism, and is increased to an intermediate pressure. The refrigerant whose pressure has been increased to the intermediate pressure is introduced from the low-stage compression chamber 42b into the high-stage suction chamber 43a through the communication pipe 10, is compressed by the high-stage compression mechanism, and is increased to a high pressure. The refrigerant whose pressure has been increased to a high pressure is discharged from the high-stage compression chamber 43 b into the sealed shell 1 and discharged from the discharge pipe 9.

Next, effects of the first embodiment will be described.
First, the operation of a comparative example in which the low stage side bearing load adjustment unit 44 and the high stage side bearing load adjustment unit 45 are omitted will be described with reference to FIGS. 5 and 6. FIG. 5 is a longitudinal sectional view for explaining the operation of the compression mechanism in a two-stage rotary compressor as a comparative example, and FIG. 6 is a high-stage compression for explaining the operation of the compression mechanism in a two-stage rotary compressor as a comparative example. It is a cross-sectional view around the mechanism.

  The high-pressure refrigerant compressed by the high-stage compression mechanism is discharged into the sealed shell 1, and the inside of the sealed shell 1 is at a high pressure. Since the periphery of the drive shaft 4 communicates with the inside of the sealed shell 1, the inner diameter sides of the low-stage side rolling piston 36 and the high-stage side rolling piston 37 have the same high pressure as that in the sealed shell 1.

  On the surface of the high-stage side rolling piston 37 facing the high-stage side bearing 35, the high pressure is within the range of the bearing inner diameter 52 of the high-stage side bearing 35. On the other hand, on the surface of the high stage side rolling piston 37 facing the intermediate plate 31, the inside diameter range 53 of the insertion hole 31 a formed in the intermediate plate 31 is high. As shown in FIG. 6, the high pressure is directly applied to the range A of the surface of the high stage side rolling piston 37 facing the intermediate plate 31.

  The outer diameter side of the high-stage side rolling piston 37 continuously changes from an intermediate pressure to a high pressure during the compression process. Moreover, the part of the surface facing the high stage side bearing 35 of the high stage side rolling piston 37 facing the range A is a part of the seal part. Therefore, the pressure on the outer diameter side of the high-stage side rolling piston 37 and the inner diameter side of the high-stage side rolling piston 37 are arranged on the surface portion of the high-stage side rolling piston 37 facing the range A facing the high-stage side bearing 35. The average pressure of the high pressure is applied.

  For this reason, the pressure applied to the range A of the surface facing the intermediate plate 31 of the high-stage rolling piston 37 is applied to the portion of the surface facing the high-stage bearing 35 of the high-stage rolling piston 37 facing the range A. Higher than pressure. Thereby, as shown in FIG. 5, the high stage side rolling piston 37 is pressed against the high stage side bearing 35.

  Also in the low-stage compression mechanism, the inner diameter dimension of the insertion hole 31a of the intermediate plate 31 is larger than the bearing inner diameter dimension of the low-stage bearing 32. Therefore, the high pressure is directly applied to a predetermined range of the surface of the low stage rolling piston 36 facing the intermediate plate 31. On the other hand, an average of the pressure on the outer diameter side of the low-stage side rolling piston 36 and the high pressure on the inner diameter side of the low-stage side rolling piston 36 is formed on the surface portion of the low-stage side rolling piston 36 facing the low-stage side bearing 34. Is under pressure. Therefore, the pressure applied to the surface facing the intermediate plate 31 of the low-stage side rolling piston 36 is higher than the pressure applied to the surface facing the low-stage side bearing 34 of the low-stage side rolling piston 36, as shown in FIG. Thus, the low stage side rolling piston 36 is pressed against the low stage side bearing 34.

  The thickness of the low stage side rolling piston 36 and the high stage side rolling piston 37 is, for example, about 10 to 20 μm thinner than the thickness of the low stage side cylinder 32 and the high stage side cylinder 33. Therefore, the low-stage side rolling piston 36 and the high-stage side rolling piston 37 are pressed against the low-stage side bearing 34 and the high-stage side bearing 35, respectively, so that a gap between the low-stage side rolling piston 36 and the intermediate plate 31 is obtained. And the clearance gap between the high stage side rolling piston 37 and the intermediate | middle plate 31 expands. As a result, as indicated by arrows in FIG. 5, the amount of refrigerant leakage from the high-stage compression mechanism section to the low-stage compression mechanism section increases. Further, the low-stage side rolling piston 36 and the high-stage side rolling piston 37 are pressed against the low-stage side bearing 34 and the high-stage side bearing 35, respectively, so that the sliding loss increases and the performance is deteriorated.

In this Embodiment 1, the opening diameter in the lower end surface of the high stage side bearing 35 of the high stage side bearing load adjustment part 45 is substantially corresponded with the internal diameter of the penetration hole 31a. Therefore, in FIG. 6, a high pressure is also applied to the portion of the surface of the high-stage rolling piston 37 facing the range A that faces the high-stage bearing 35. Accordingly, the pressure applied to the range A of the surface facing the intermediate plate 31 of the high-stage rolling piston 37 and the portion of the surface facing the high-stage bearing 35 of the high-stage rolling piston 37 facing the range A are applied. The pressure becomes equal. Therefore, as shown in FIG. 7, equivalent pressure is applied to the upper and lower surfaces of the high-stage rolling piston 37, and the vertical load applied to the high-stage rolling piston 37 can be neutralized.
The opening diameter at the upper end surface of the low stage side bearing 34 of the low stage side bearing load adjusting portion 44 substantially matches the inner diameter of the insertion hole 31a. Accordingly, similarly, the upper and lower loads applied to the lower stage side rolling piston 36 can be neutralized.

When the low stage side bearing load adjusting part 44 and the high stage side bearing load adjusting part 45 are omitted, the low stage side rolling piston 36 and the high stage side rolling piston 37 are respectively connected to the low stage side bearing 34 and the high stage side bearing 35. The load that is pressed against the surface is large depending on operating conditions. For example, in a CO ₂ two-stage rotary compressor with an exclusion volume of 4.5 cc used for a heat pump water heater having an oil supply capacity of 6 kW, when the pressing load on the low stage side and the pressing load on the high stage side are combined, 300 to 400 N become. By adopting the configuration of the first embodiment, the upper and lower loads applied to the low-stage side rolling piston 36 and the high-stage side rolling piston 37 can be neutralized, so that this pressing load can be reduced and the sliding loss can be reduced. be able to.

  At this time, the load applied from the low stage side bearing 34 and the high stage side bearing 35 side to the low stage side rolling piston 36 and the high stage side rolling piston 37 is from the high pressure intermediate plate 31 side to the low stage side rolling piston 36 and the high stage side rolling piston 36. It is preferable to adjust the load to the step side rolling piston 37 to ± 5% or less. To adjust in this way, the opening diameter at the upper end surface of the low stage side bearing 34 of the low stage side bearing load adjustment unit 44 and the opening at the lower end surface of the high stage side bearing 35 of the high stage side bearing load adjustment unit 45. The diameter is preferably suppressed to ± 0.1 mm or less with respect to the inner diameter of the insertion hole 31a of the intermediate plate 31.

  Further, by adopting the configuration of the first embodiment, the loads applied to the upper and lower surfaces of the low-stage side rolling piston 36 and the high-stage side rolling piston 37 can be neutralized, so the low-stage side rolling piston 36 and the high-stage side piston No force is generated to press the rolling piston 37 against the low-stage bearing 34 side and the high-stage bearing 35 side. Therefore, the gap between the low stage side rolling piston 36 and the intermediate plate 31 and the gap between the low stage side rolling piston 36 and the low stage side bearing 34 are substantially equal. Similarly, the gap between the high stage side rolling piston 37 and the intermediate plate 31 and the gap between the high stage side rolling piston 37 and the high stage side bearing 35 are substantially equal. Thereby, the amount of refrigerant leakage from the high-stage compression mechanism section to the low-stage compression mechanism section is reduced. The amount of refrigerant leakage is proportional to the third power of the gap. Since the gaps are averaged by adopting the configuration of the first embodiment, the gaps between the low stage side rolling piston 36 and the high stage side rolling piston 37 and the intermediate plate 31 are compared as shown in FIG. About half of the example. Therefore, the rotary compressor according to the first embodiment can suppress the leakage amount of the refrigerant from the high stage side compression mechanism part to the low stage side compression mechanism part to about 1/8 of the comparative example.

In the first embodiment, the lower end surface of the high stage side bearing 35 is countersunk, and then the peripheral surface is chamfered to form the truncated conical concave high stage side bearing load adjusting unit 45. However, the concave shape of the high stage side bearing load adjustment portion is not limited to the truncated cone shape, and the opening diameter only needs to substantially match the inner diameter of the insertion hole 31a of the intermediate plate 31.
For example, as shown in FIG. 8 (a), the lower end surface of the high stage side bearing 35 may be countersunk to form the high stage side bearing load adjusting portion 45a in a cylindrical concave shape. Further, as shown in FIG. 8B, the taper angle may be increased, the flat bottom surface may be eliminated, and the high stage side bearing load adjusting portion 45b may be formed in a concave shape having only a tapered surface. Note that the low-stage bearing load adjusting portion may also be formed in a cylindrical concave shape or a concave shape having only a tapered surface.

  Further, if the depth d1 of the high stage side bearing load adjusting portion 45a is very small, for example, about 10 μm or more and 20 μm or less (10 to 20 μm), in addition to the function of neutralizing the load, it functions as a seal, Leakage can be further reduced. The surface roughness of the high stage side bearing 35 in contact with the high stage side rolling piston 37 is, for example, about Rz1, but the surface roughness of the inner surface of the high stage side bearing load adjusting portion 45a may be, for example, about Rz10. Similarly, if the depth d2 of the high stage side bearing load adjustment portion 45b is also small, for example, about 10 to 20 μm, in addition to the function of neutralizing the load, it functions as a seal and further reduces refrigerant leakage. Can do. Furthermore, if the depth of the high stage side bearing load adjusting portion 45 is also very small, for example, about 10 to 20 μm, it functions as a seal in addition to the function of neutralizing the load, and refrigerant leakage can be further reduced.

  In the first embodiment, the inside of the sealed shell 1 is described as having a high pressure. However, even when the inside of the sealed shell 1 is at a low pressure or an intermediate pressure, the insertion hole 31a of the intermediate plate 31 is not provided. By providing a low-stage bearing load adjustment section and a high-stage bearing load adjustment section with an opening diameter that approximately matches the inner diameter, the load can be neutralized. The amount of refrigerant leakage to the part can be reduced, and the performance can be improved.

  In the first embodiment, the insertion hole 31a is formed to have an inner diameter through which the low-stage eccentric portion 6 and the high-stage eccentric portion 7 can be inserted. It is not necessary that both the stage-side eccentric part 6 and the high-stage side eccentric part 7 can be inserted, and it is sufficient that at least one of the low-stage side eccentric part 6 and the high-stage side eccentric part 7 can be inserted. . For example, if the diameter of the high-stage eccentric part 7 <the inner diameter of the insertion hole 31 a <the diameter of the low-stage eccentric part 6, the high stage of the shaft part 5 of the drive shaft 4 is inserted into the insertion hole 31 a of the intermediate plate 31. What is necessary is just to insert from the edge part by the side eccentric part 7 side, and to arrange | position the intermediate | middle plate 31 between the high stage side eccentric part 7 and the low stage side eccentric part 6. FIG. If the diameter of the high-stage eccentric part 7> the inner diameter of the insertion hole 31 a> the diameter of the low-stage eccentric part 6, the low stage of the shaft part 5 of the drive shaft 4 is inserted into the insertion hole 31 a of the intermediate plate 31. What is necessary is just to insert from the edge part by the side eccentric part 6 side, and to arrange | position the intermediate | middle plate 31 between the high stage side eccentric part 7 and the low stage side eccentric part 6. FIG.

Embodiment 2. FIG.
FIG. 9 is a longitudinal sectional view illustrating the configuration of the compression mechanism portion in the two-stage rotary compressor according to the second embodiment of the present invention, and FIG. 10 is a high stage in the two-stage rotary compressor according to the second embodiment of the present invention. It is a cross-sectional view explaining operation | movement of a side compression mechanism part.
In FIG. 9, the low-stage side rolling piston 36 has a tapered low-stage side rolling piston load adjusting part 46 formed by chamfering the inner peripheral edge on the side facing the low-stage side bearing 34. Similarly, the high-stage side rolling piston 37 is chamfered at the inner peripheral edge on the side facing the high-stage side bearing 35 to form a tapered high-stage side rolling piston load adjusting part 47. Other configurations are the same as those in the first embodiment.

  In the second embodiment, the load applied to the high-stage rolling piston 37 from above and below is neutralized by providing the high-stage bearing load adjusting portion 45. And the area | region of the upper-lower surface of the high stage side rolling piston 37 outside the range of the internal-diameter dimension 53 of the insertion hole 31a of the intermediate | middle plate 31 becomes a sealing surface. A pressure obtained by averaging the pressure on the outer diameter side of the high-stage rolling piston 37 and the pressure (high pressure) on the inner diameter side of the high-stage rolling piston 37 is applied to the seal surface. Here, since the high stage side rolling piston load adjusting portion 47 is formed, as shown in FIG. 10, the high pressure is directly applied to the range B of the surface of the high stage side rolling piston 37 facing the high stage side bearing 35. Take it. As a result, a load that presses the high-stage rolling piston 37 against the intermediate plate 31 is generated, and the gap between the high-stage rolling piston 37 and the intermediate plate 31 is reduced.

Similarly, since the low stage side rolling piston load adjusting portion 46 is formed, a load for pressing the low stage side rolling piston 36 against the intermediate plate 31 is generated, and the low stage side rolling piston 36 and the intermediate plate 31 are placed between each other. The gap becomes smaller.
Thereby, the leakage amount of the refrigerant | coolant from a high stage compression mechanism part to a low stage compression mechanism part can be reduced, and performance can be improved.

  Next, the relationship between the rolling piston load adjusting portion and the gap will be described by taking the high-stage compression mechanism portion as an example. FIG. 11 is a view for explaining the relationship between the high-stage side rolling piston and the clearance in the two-stage rotary compressor according to Embodiment 2 of the present invention. In FIG. 11, h0 is a gap between the high stage side bearing 35 and the intermediate plate 31, h1 is a thickness of the high stage side rolling piston 37, t1 is a gap between the high stage side rolling piston 37 and the intermediate plate 31, t2 is a gap between the high-stage side rolling piston 37 and the high-stage side bearing 35, and c is a width of the high-stage side rolling piston load adjusting unit 47. FIG. 12 is a characteristic diagram of leakage loss and compressor efficiency in the two-stage rotary compressor according to the second embodiment of the present invention. FIG. 12 (a) shows the relationship between the gap t1 and the leakage loss. 12 (b) shows the relationship between the width c of the rolling piston load adjusting portion and the compressor efficiency.

The thickness difference between the high-stage side cylinder 33 and the high-stage side rolling piston 37 is 2ε (= h0−h1). And in the state where the load applied to the high-stage side rolling piston 37 from above and below is neutral, t1 = t2 = ε.
Here, when the width c of the high stage side rolling piston load adjusting portion 47 is increased, the area of the high pressure applied from the high stage side bearing 35 side to the high stage side rolling piston 37 increases. And the load which presses the high stage side rolling piston 37 against the intermediate | middle plate 31 increases, the clearance t1 becomes small, and the clearance t2 becomes large by that.

Here, the leakage amount of the refrigerant is proportional to the cube of the gap. Therefore, the refrigerant leakage from the upper and lower surfaces of the high-stage side rolling piston 37 is minimized when the upper and lower gaps are averaged (t1 = t2 = ε). However, since the refrigerant leakage directly from the high-stage compression mechanism to the low-stage compression mechanism is a loss, the gap t1 is an optimum value smaller than ε as shown in FIG. Leakage loss is minimized.
Further, as shown in FIG. 12B, when the width c of the high-stage side rolling piston load adjustment unit 47 is increased, the compressor efficiency increases, and when the width c reaches an optimum value, the compressor is increased. Efficiency is maximum. The time when the compressor efficiency reaches the maximum value is when the gap t1 becomes the optimum value. When the width c becomes larger than the optimum value, the gap t1 becomes smaller than the optimum value. When the gap t1 becomes small, the sliding loss due to the pressing load increases, and the compressor efficiency decreases.

  The pressure in the low-stage compression mechanism is lower than the pressure in the high-stage compression mechanism. The differential pressure between the outer diameter side and the inner diameter side of the low stage side rolling piston 36 is larger than the differential pressure between the outer diameter side and the inner diameter side of the high stage side rolling piston 37. Therefore, the optimum value of the width c of the low-stage side rolling piston load adjusting unit 46 is smaller than the optimum value of the width c of the high-stage side rolling piston load adjusting unit 47. When an equal load is applied to the low-stage side rolling piston 36 and the high-stage side rolling piston 37, the optimum value of the width c of the low-stage side rolling piston load adjustment unit 46 is the high-stage side rolling piston load adjustment unit. It becomes about 1/3 of the optimum value of the width c of 47.

For example, in a CO ₂ two-stage rotary compressor with a displacement volume of 4.5 cc used for a heat pump water heater equivalent to a hot water supply capacity of 6 kW, the optimum dimension of the width c of the low-stage side rolling piston load adjustment unit 46 is 0.3 to The optimum dimension of the width c of the high-stage side rolling piston load adjustment portion 47 is 1.0 to 1.5 mm. Further, since the differential pressure between the outer diameter side and the inner diameter side of the low stage side rolling piston 36 is large, the low stage side rolling piston 36 is applied to the low stage side rolling piston 36 with a slight difference in the width c of the low stage side rolling piston load adjusting portion 46. The load changes greatly. For this reason, when forming the low stage side rolling piston load adjustment part 46, severer processing precision is required compared with the case where the high stage side rolling piston load adjustment part 47 is formed.

  Here, although the low stage side rolling piston load adjustment part 46 and the high stage side rolling piston load adjustment part 47 are provided, the low stage side rolling piston load adjustment part 46 and the high stage side rolling piston load adjustment part 47 are provided. Even if any one is formed, the effect of suppressing the direct refrigerant leakage from the high-stage compression mechanism to the low-stage compression mechanism can be obtained. In this case, it is preferable to provide only the high-stage side rolling piston load adjustment unit 47 from the viewpoint of processing accuracy.

  In the second embodiment, the high-stage side rolling piston load adjusting portion 47 is chamfered by chamfering the inner peripheral edge portion (upper surface) of the high-stage side rolling piston 37 facing the high-stage side bearing 35. Although formed, the shape of the high-stage side rolling piston load adjusting portion 47 is not limited to the tapered shape. For example, as shown in FIG. 13A, the upper surface of the high-stage rolling piston 37 may be countersunk to form the high-stage rolling piston load adjusting portion 47a in a cylindrical concave shape. . Further, as shown in FIG. 13B, the upper surface of the high-stage side rolling piston 37 is countersunk, and the peripheral surface is chamfered so that the high-stage side rolling piston load adjusting portion 47a is truncated. You may form in conical concave shape. The low-stage rolling piston load adjustment portion may also be formed in a cylindrical concave shape or a truncated conical concave shape.

  Further, if the depth d3 of the high-stage side rolling piston load adjusting portion 47a is very small, for example, about 10 to 20 μm, in addition to the function of neutralizing the load, it functions as a seal and further reduces refrigerant leakage. Can do. The surface roughness of the upper and lower surfaces of the high stage side rolling piston 37 is, for example, about Rz1, but the surface roughness of the inner surface of the high stage side rolling piston load adjustment portion 47a may be, for example, about Rz10. Similarly, if the depth d4 of the high-stage side rolling piston load adjusting portion 47b is also small, for example, about 10 to 20 μm, in addition to the function of neutralizing the load, it functions as a seal and further reduces refrigerant leakage. be able to. Furthermore, if the depth of the high-stage side rolling piston load adjusting portion 47 is also small, for example, about 10 to 20 μm, in addition to the function of neutralizing the load, it also functions as a seal, and refrigerant leakage can be further reduced. .

Embodiment 3 FIG.
FIG. 14 is a longitudinal sectional view for explaining the structure of the compression mechanism in the single-stage rotary compressor according to Embodiment 3 of the present invention.

In FIG. 14, the drive shaft 20 includes a first shaft portion 21 and a second shaft portion 22 that is coaxially connected to the first shaft portion 21 via the eccentric portion 23 and has a smaller diameter than the first shaft portion 21. I have.
The compression mechanism 24 includes a cylinder 25, a secondary bearing 27 as a second bearing that closes the lower end opening of the cylinder 25, a main bearing 26 as a first bearing that closes the upper end opening of the cylinder 25, And a rolling piston 28 disposed in a space formed by the bearing 27 and the main bearing 26. Although not shown, a vane that abuts on the outer peripheral surface of the rolling piston 28 and partitions the space into a suction chamber and a compression chamber, and a spring that biases the vane to press against the outer peripheral surface of the rolling piston 28; It has.

  In the drive shaft 20, the first shaft portion 21 is pivotally supported by the main bearing 26, the second shaft portion 22 is pivotally supported by the auxiliary bearing 27, and the compression mechanism portion 24 is inserted. The eccentric part 23 is accommodated in the cylinder 25. The rolling piston 28 is fitted to the eccentric portion 23 in an externally fitted state, and is eccentrically rotated by the rotation of the drive shaft 20. A bearing load adjusting portion 29 is annularly recessed in the inner periphery of the upper end surface (the surface facing the rolling piston 28) of the auxiliary bearing 27 so as to open the outer peripheral surface of the second shaft portion 22. The bottom surface of the bearing load adjusting unit 29 is a flat surface. The inner peripheral surface of the bearing load adjusting portion 29 is formed in a tapered shape whose inner diameter gradually decreases in a direction away from the rolling piston 28. That is, the bearing load adjusting portion 29 is formed in a truncated conical concave shape. The opening diameter at the upper end surface of the bearing load adjusting portion 29 substantially matches the bearing inner diameter of the main bearing 26.

The compression mechanism portion 24 configured as described above is disposed in the hermetic shell 1. A motor (not shown) for driving the compression mechanism unit 24 is disposed above the compression mechanism unit 24 in the compression mechanism unit 24.
When the motor is driven, the drive shaft 20 pivotally supported by the main bearing 26 and the sub bearing 27 is rotationally driven. Then, the rolling piston 28 rotates eccentrically within the cylinder 25. At this time, the upper and lower surfaces of the rolling piston 28 are sealed with lubricating oil. The low-pressure refrigerant is introduced into the suction chamber via a suction pipe (not shown), compressed by the compression mechanism 24, and pressurized. The refrigerant whose pressure has been increased by the compression mechanism 24 is discharged from the compression chamber into the sealed shell 1.

At this time, since the bearing inner diameter of the main bearing 26 is larger than the bearing inner diameter of the sub bearing 27, the load applied to the rolling piston 28 from the main bearing 26 side becomes larger than the load applied to the rolling piston 28 from the sub bearing 27 side. Therefore, the rolling piston 28 is pressed against the auxiliary bearing 27 side, and the sliding loss increases.
In the third embodiment, the bearing load adjusting portion 29 is formed on the inner peripheral side of the upper end surface of the sub-bearing 27 so that the opening diameter at the upper end surface thereof substantially matches the bearing inner diameter of the main bearing 26. Therefore, as shown in FIG. 14, since the load applied to the upper and lower surfaces of the rolling piston 28 is neutralized, an increase in sliding loss due to the rolling piston 28 being pressed against the auxiliary bearing 27 is suppressed, Performance can be improved.

In the third embodiment, the case where the inner diameter of the main bearing 26 is larger than the inner diameter of the auxiliary bearing 27 is described. However, the inner diameter of the main bearing 26 is larger than the inner diameter of the auxiliary bearing 27. If it is small, the bearing load adjusting portion may be formed on the main bearing 26.
Further, the bearing load adjusting portion 29 is not limited to the truncated conical concave shape, but may be a cylindrical concave shape or a concave shape having only a tapered surface.
Similarly to the first embodiment, the opening diameter of the bearing load adjustment unit 29 is preferably adjusted to ± 0.1 mm or less with respect to the bearing inner diameter of the main bearing 26, and the depth of the bearing load adjustment unit 29 is adjusted. Moreover, it is preferable to adjust to 10 to 20 μm.

It is a longitudinal cross-sectional view which shows the structure of the two-stage rotary compressor which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view explaining the structure of the compression mechanism part in the two-stage rotary compressor which concerns on Embodiment 1 of this invention. It is a cross-sectional view explaining the structure of the low stage side compression mechanism part in the two stage rotary compressor which concerns on Embodiment 1 of this invention. It is a cross-sectional view explaining the structure of the high stage side compression mechanism part in the two stage rotary compressor which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view explaining operation | movement of the compression mechanism part in the two-stage rotary compressor as a comparative example. It is a cross-sectional view around the high-stage compression mechanism for explaining the operation of the compression mechanism in a two-stage rotary compressor as a comparative example. It is a longitudinal cross-sectional view explaining operation | movement of the compression mechanism part in the two-stage rotary compressor which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the embodiment of the high stage side bearing applied to the compression mechanism part in the two-stage rotary compressor which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view explaining the structure of the compression mechanism part in the two-stage rotary compressor which concerns on Embodiment 2 of this invention. It is a cross-sectional view explaining the operation | movement of the high stage compression mechanism part in the two stage rotary compressor which concerns on Embodiment 2 of this invention. It is a figure explaining the relationship between the high stage side rolling piston and clearance gap in the two-stage rotary compressor which concerns on Embodiment 2 of this invention. FIG. 6 is a characteristic diagram of leakage loss and compressor efficiency in a two-stage rotary compressor according to Embodiment 2 of the present invention. It is a longitudinal cross-sectional view which shows the embodiment of the high stage side rolling piston applied to the compression mechanism part in the two-stage rotary compressor which concerns on Embodiment 2 of this invention. It is a longitudinal cross-sectional view explaining the structure of the compression mechanism part in the single stage rotary compressor which concerns on Embodiment 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Sealing shell, 2 Motor, 3 Compression mechanism part, 4 Drive shaft, 5 shaft part, 6 Low stage side eccentric part, 7 High stage side eccentric part, 20 Drive shaft, 21 1st shaft part, 22 2nd axis , 23 Eccentric part, 24 Compression mechanism part, 25 Cylinder, 26 Main bearing (first bearing), 27 Sub bearing (second bearing), 28 Rolling piston, 29 Bearing load adjusting part, 31 Intermediate plate, 31a Insertion hole , 32 Low stage side cylinder, 33 High stage side cylinder, 34 Low stage side bearing, 35 High stage side bearing, 36 Low stage side rolling piston, 37 High stage side rolling piston, 38 Low stage side vane, 40 High stage side vane , 44 Low stage side bearing load adjustment part, 45, 45a, 45b High stage side bearing load adjustment part, 46 Low stage side rolling piston load adjustment part, 47, 47a, 47b High stage side rolling piston load adjustment part

Claims (6)

A sealed shell, a low-stage compression mechanism section and a high-stage compression mechanism section housed in the sealed shell, and a low-stage compression mechanism section and the high-stage compression mechanism section housed in the sealed shell A rotary compressor that compresses the low-pressure refrigerant to an intermediate pressure by the low-stage compression mechanism and then compresses the low-pressure refrigerant to a high pressure by the high-stage compression mechanism,
The low-stage compression mechanism and the high-stage compression mechanism are
A low-stage cylinder and a high-stage cylinder disposed opposite to each other with an intermediate plate interposed therebetween;
A low-stage bearing disposed opposite to the intermediate plate with the low-stage cylinder interposed therebetween;
A high-stage bearing disposed opposite to the intermediate plate with the high-stage cylinder interposed therebetween;
The low-stage eccentric part and the high-stage eccentric part connected to the motor and spaced apart in the axial direction are accommodated in the low-stage cylinder and the high-stage cylinder, respectively. A drive shaft pivotally supported by the stage side bearing and the high stage side bearing;
The low-stage eccentric part and the high-stage eccentric part are fitted in an externally fitted state, and are arranged in the low-stage cylinder and the high-stage cylinder so as to be eccentrically rotatable. A stage side rolling piston and a high stage side rolling piston;
A low-stage vane and a high-stage vane that form a compression space in contact with the outer peripheral surfaces of the low-stage side rolling piston and the high-stage side rolling piston,
The insertion hole of the drive shaft formed in the intermediate plate is formed with a diameter through which at least one of the low-stage side eccentric part and the high-stage side eccentric part can be inserted,
The low stage side bearing load adjustment unit and the high stage side bearing load adjustment unit open the outer peripheral surface of the drive shaft to the inner periphery of the end surface facing the intermediate plate of the low stage side bearing and the high stage side bearing. Each ring is recessed,
The opening diameters of the low-stage bearing load adjusting section and the high-stage bearing load adjusting section at the end surfaces of the low-stage bearing and the high-stage bearing facing the intermediate plate are substantially equal to the diameter of the insertion hole. A rotary compressor characterized by the fact that   The rotary compressor according to claim 1, wherein the low stage side bearing load adjustment part and the high stage side bearing load adjustment part have a sealing function.   3. The rotary compressor according to claim 1, wherein the inside of the hermetic shell is at a high pressure.   A rolling piston load adjustment portion is formed in an annular recess by removing an inner peripheral edge portion on the opposite side of the intermediate plate of at least one of the high-stage side rolling piston and the low-stage side rolling piston. The rotary compressor according to claim 3.   The rotary compressor according to claim 4, wherein the rolling piston load adjusting unit has a sealing function. A hermetic shell, a compression mechanism housed in the hermetic shell, a motor housed in the hermetic shell and driving the compression mechanism, and a driving force of the motor coupled to the motor A rotary compressor that compresses the low-pressure refrigerant with the compression mechanism unit,
The drive shaft includes an eccentric portion, a first shaft portion, and a second shaft portion that is coaxially connected to the first shaft portion via the eccentric portion and has a smaller diameter than the first shaft portion. ,
The compression mechanism is
A first bearing that pivotally supports the first shaft portion;
A cylinder disposed opposite to the first bearing and accommodating the eccentric portion;
A second bearing disposed opposite to the first bearing across the cylinder and supporting the second shaft portion;
A rolling piston fitted to the eccentric part in an externally fitted state and arranged to be eccentrically rotatable in the cylinder;
A vane that abuts on the outer peripheral surface of the rolling piston to form a compression space, and
A bearing load adjusting portion is annularly recessed to open an outer peripheral surface of the second shaft portion on an inner periphery of an end surface facing the cylinder of the second bearing;
The rotary compressor according to claim 1, wherein an opening diameter of an end face of the bearing load adjusting portion facing the cylinder is substantially equal to an inner diameter of the first bearing.

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