WO2017061014A1

WO2017061014A1 - Rotary compressor

Info

Publication number: WO2017061014A1
Application number: PCT/JP2015/078662
Authority: WO
Inventors: 友宏井柳; 高橋　真一; 瀬畑　崇史; 直隆服部
Original assignee: 三菱電機株式会社
Priority date: 2015-10-08
Filing date: 2015-10-08
Publication date: 2017-04-13
Also published as: CN206268076U; JPWO2017061014A1; CN107035690A

Abstract

A rotary compressor is provided with an electric motor section and a compression mechanism section which is driven by the electric motor section, the electric motor section and the compression mechanism section being accommodated within a closed container. The compression mechanism section is provided with: a crankshaft which is rotationally driven by the electric motor section; a cylinder provided with a cylinder chamber; a rolling piston fitted over the eccentric shaft section of the crankshaft and eccentrically rotating within the cylinder chamber; a plate-shaped vane having a front end pressed against the rolling piston and dividing the cylinder chamber into an intake chamber and a compression chamber; and a vane groove formed in the cylinder and accommodating the vane so that the vane can slide in a reciprocating manner. A passage is formed in the intake chamber-side side surface of the vane, the passage introducing a refrigerant compressed by the compression mechanism section, into the intake side of the vane.

Description

Rotary compressor

This invention relates to a rotary compressor, and more particularly to an improvement in followability of a vane to a rolling piston.

The rotary compressor is arranged in the cylinder so that the rolling piston fitted to the eccentric shaft portion of the crankshaft rotates eccentrically in a line contact state with the inner wall surface of the central space portion in the cylinder. The cylinder has a vane groove extending in the radial direction, and the vane is provided in the vane groove. The vane reciprocates in the vane groove following the eccentric rotational motion of the rolling piston, and partitions the space formed in the gap between the cylinder and the rolling piston into a compression chamber and a suction chamber. ing.

In such a case, when the rolling piston rotates eccentrically (revolves), a series of suction steps and compression steps that sequentially shift from the step of sucking the refrigerant gas to the step of compressing are repeated continuously. The compressed gas is discharged from the compression chamber into the sealed container, and then sent from the discharge pipe to the refrigeration circuit.

In the compression process of the rotary compressor, as the crankshaft rotates, the vane reciprocates in the vane groove between the bottom dead center that has moved forward (the rolling piston side) and the top dead center that has moved backward. To do. From the phase 0 ° to the phase 180 ° of the eccentric shaft portion of the crankshaft, the pressing load generated from the differential pressure inside and outside the compression chamber acts on the vane from the back pressure chamber located behind the vane, and the vane moves to the bottom dead center. And move. At a phase of 180 ° or more, the vane receives a load from the rolling piston and moves to the top dead center as the crankshaft rotates (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-166495

In a rotary compressor, if the sliding resistance between the vane and the vane groove increases while the vane moves from top dead center to bottom dead center (before the crankshaft phase reaches 180 °), the vane rolls. Does not follow the piston. In this case, there arises a problem that noise occurs when the vane and the rolling piston are separated from each other and contacted again. Further, since the vane does not follow the rolling piston and a gap is generated between the vane and the rolling piston, there arises a problem that the refrigerant leaks from the high pressure side to the low pressure side and the performance is deteriorated.

The present invention has been made to solve the above-described problems, and is a compression capable of reducing the sliding resistance between the vane and the vane groove and improving the followability of the vane to the rolling piston. The aim is to get a chance.

A rotary compressor according to the present invention includes an electric motor unit and a compression mechanism unit driven by the electric motor unit in a sealed container, and the compression mechanism unit includes a crankshaft that is rotationally driven by the electric motor unit, and a cylinder chamber. A cylinder, a rolling piston that is fitted to the eccentric shaft portion of the crankshaft and rotates eccentrically in the cylinder chamber, and a plate-shaped vane that is pressed by the rolling piston and that partitions the cylinder chamber into a suction chamber and a compression chamber; A vane groove formed in the cylinder and configured to reciprocally slide the vane is provided, and a passage for drawing the refrigerant compressed by the compression mechanism portion to the suction side of the vane is provided on a side surface of the vane on the suction chamber side. Is.

According to this invention, since the passage for drawing the refrigerant compressed by the compression mechanism portion to the suction side of the vane is provided on the side surface of the vane on the suction chamber side, the discharge pressure acts on the side surface of the vane on the suction chamber side, The difference in pressure load between the suction side and the discharge side of the vane can be reduced. For this reason, the slidability between the vane and the vane groove can be improved, and as a result, the followability of the vane to the rolling piston can be improved.

1 is an overall schematic cross-sectional view of a rotary compressor according to Embodiment 1 of the present invention. It is detail drawing of the principal part of the rotary compressor which concerns on Embodiment 1 of this invention. It is a perspective view of the vane of the rotary compressor which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the force produced in the vane side in the comparative example of a rotary compressor. It is a schematic diagram which shows the force which arises on the vane side of the rotary compressor which concerns on Embodiment 1 of this invention. It is a graph which shows the relationship between the phase of the crankshaft and vane side load of the rotary compressor which concerns on Embodiment 1 of this invention compared with a comparative example. It is a perspective view which shows the modification 1 of the notch of the vane of the rotary compressor which concerns on Embodiment 1 of this invention. It is a perspective view which shows the modification 2 of the channel | path of the vane of the rotary compressor which concerns on Embodiment 1 of this invention.

Embodiment 1 FIG.
1 is an overall schematic cross-sectional view of a rotary compressor according to Embodiment 1 of the present invention. FIG. 2 is a detailed view of a main part of the rotary compressor according to Embodiment 1 of the present invention. FIG. 3 is a perspective view of the vane of the rotary compressor according to the first embodiment of the present invention.
A rotary compressor according to Embodiment 1 of the present invention houses an electric motor unit 3 and a compression mechanism unit 4 driven by the electric motor unit 3 in a sealed container 1 as shown in FIG. In addition, refrigerating machine oil (not shown) is stored at the bottom of the sealed container 1. The refrigerating machine oil mainly lubricates the sliding part of the compression mechanism part 4. A suction pipe 9 communicating with the accumulator 2 is connected to the sealed container 1, and the refrigerant is taken into the sealed container 1 from the accumulator 2. Moreover, the discharge pipe 1a is connected to the upper part of the airtight container 1, and the compressed refrigerant | coolant is discharged | emitted.

The electric motor unit 3 includes a stator 31 fixed to the hermetic container 1 and a rotor 32 fixed to the crankshaft 10, and is supplied with electric power from the outside through an airtight terminal (not shown) and driven. The electric motor unit 3 and the compression mechanism unit 4 are connected via a crankshaft 10. An oil supply passage is formed in the axial center of the crankshaft 10, and a pump (not shown) is provided in the oil supply passage so that the refrigerating machine oil stored at the bottom of the sealed container 1 can be used as the crankshaft. Oil is supplied to the sliding portion of the compression mechanism portion 4 through an oil supply passage in the cylinder 10.

As shown in FIGS. 1 and 2, the compression mechanism unit 4 includes a cylinder 7, an upper bearing 5 and a lower bearing 8 that are two bearings, a crankshaft 10, a rolling piston 11, a discharge muffler 6, and a vane 12. And.

This will be described in further detail. The outer periphery of the cylinder 7 is formed in a circle in plan view, and a circular through hole 71a is formed through substantially the center in a vertical direction in plan view. Openings at both ends in the axial direction of the through hole 71 a are closed by the upper bearing 5 and the lower bearing 8, and a cylindrical cylinder chamber 71 is formed in the cylinder 7. The cylinder 7 has a predetermined axial height in side view.

As shown in FIG. 2, the cylinder 7 is provided with a vane groove 7a that communicates with the cylinder chamber 71 and extends in the radial direction so as to penetrate in the axial direction (direction perpendicular to the paper surface of FIG. 2). A plate-like vane 12 is accommodated in the vane groove 7a so as to be slidable back and forth. In the cylinder 7, a back pressure chamber 7 b that guides discharge pressure to the rear end portion 12 a of the vane 12 is provided on the rear side (back side) of the vane groove 7 a.

The back pressure chamber 7b is a substantially circular space in plan view that communicates with the vane groove 7a, and communicates with the internal space of the sealed container 1 to form a pressure space equivalent to that in the sealed container 1. As will be described later, during the operation of the rotary compressor, since the internal space of the sealed container 1 becomes the discharge pressure, the back pressure chamber 7b also becomes the discharge pressure.

Further, a vane spring 13 is disposed in the back pressure chamber 7b. The vane 12 has a function of partitioning the cylinder chamber 71 into the suction chamber 7c and the discharge chamber 7d by the tip 12d of the vane 12 being pressed toward the outer peripheral surface of the rolling piston 11 by the biasing force of the vane spring 13. During the operation of the rotary compressor, the vane 12 follows and is pressed against the rolling piston 11 by a pressing load (back pressure) generated from the differential pressure inside and outside the compression chamber. Therefore, the vane spring 13 is mainly used to press the vane 12 against the rolling piston 11 when the compressor is started (when there is no difference in pressure between the internal space of the sealed container 1 and the cylinder chamber 71). used.

Also, the cylinder 7 is provided with a suction port 7e through which the refrigerant sucked from the suction pipe 9 passes through the cylinder chamber 71 from the outer peripheral surface of the cylinder 7.

Further, the cylinder 7 is provided with a discharge port 7f in which the vicinity of the edge of the circle forming the cylinder chamber 71 which is a circular space is cut out.

The rolling piston 11 is configured in a ring shape, and the inner periphery of the rolling piston 11 is slidably fitted to the outer periphery of the eccentric shaft portion 10a of the crankshaft 10. As the crankshaft 10 rotates, the rolling piston 11 rotates eccentrically in the cylinder chamber 71.

2 and 3, the vane 12 has a flat rectangular shape (the thickness in the circumferential direction is smaller than the length in the radial direction and the axial direction), and is formed on the side surface 12c of the vane 12 on the suction chamber side. Is formed with a notch 12b serving as a passage for drawing the compressed refrigerant to the intake side of the vane 12. Thus, the notch 12b is formed in the vane 12, and thus the vane 12 has an asymmetric shape.

A space 14 formed between the notch 12b and the vane groove 7a communicates with the back pressure chamber 7b, and the space 14 communicates with the back pressure chamber 7b. The refrigerant having the discharge pressure is supplied to the space 14. That is, the space 14 communicates with the back pressure chamber 7b, so that the compressed refrigerant is drawn into the space 14 via the back pressure chamber 7b, that is, drawn into the suction side of the vane 12. Note that oil is also drawn into the intake side of the vane 12 together with the refrigerant.

The upper bearing 5 is slidably fitted to the main shaft portion 10b of the crankshaft 10, and closes the vane groove 7a of the cylinder 7 and one end face (the motor portion 3 side) of the through hole 71a. The upper bearing 5 is formed in an inverted T shape in a side view.

Further, the upper bearing 5 is provided with a discharge hole 5a at the same position as the discharge port 7f of the cylinder 7 in plan view, and a discharge valve 5b is attached to the discharge hole 5a.

The discharge valve 5b receives the pressure in the cylinder chamber 71 and the pressure in the sealed container 1, and when the pressure in the cylinder chamber 71 is lower than the pressure in the sealed container 1, the discharge valve 5b is pressed against the discharge port 7f to close the discharge hole 5a. To do. Further, the discharge valve 5b is pushed upward by the pressure in the cylinder chamber 71 when the pressure in the cylinder chamber 71 becomes higher than the pressure in the sealed container 1, and opens the discharge hole 5a to remove the compressed refrigerant. Lead outside the cylinder chamber 71.

Further, a discharge muffler 6 is attached to the upper bearing 5 on the upper side, and a muffler space is formed by the discharge muffler 6 and the upper bearing 5.

The high-temperature and high-pressure refrigerant gas discharged from the discharge hole 5 a of the upper bearing 5 once enters the muffler space, and then is discharged into the sealed container 1 from the discharge hole 6 a of the discharge muffler 6.

The lower bearing 8 is slidably fitted to the countershaft portion 10c of the crankshaft 10, and closes the vane groove 7a of the cylinder 7 and the other end surface (the refrigerator oil side) of the through hole 71a. The lower bearing 8 is formed in a T shape in a side view.

Next, the operation of the rotary compressor according to the first embodiment of the present invention will be described.
In the rotary compressor according to Embodiment 1 of the present invention, the refrigerant of the accumulator 2 is introduced into the suction chamber 7c through the suction pipe 9 and the suction port 7e, and then the motor unit 3 is driven to drive the crankshaft. 10 is rotated eccentrically. Thereby, the refrigerant in the cylinder chamber 71 is compressed. The refrigerant compressed in the cylinder chamber 71 is discharged into the muffler space from the discharge hole 5 a of the upper bearing 5 and then discharged into the sealed container 1 through the discharge hole 6 a of the discharge muffler 6. The discharged refrigerant passes through the gap of the electric motor unit 3 and is then discharged from the discharge pipe 1a.

Next, the pressure during refrigerant compression will be described. During the compression of the refrigerant, the inside of the cylinder chamber 71 is divided into a suction chamber 7c and a discharge chamber 7d by the vane 12. When the notch 12b is not provided in the vane 12, a load is applied to the vane 12 due to a differential pressure between the pressure in the suction chamber 7c and the pressure in the discharge chamber 7d, and sliding resistance is generated between the vane groove 7a.

However, in the rotary compressor according to the first embodiment, the vane 12 is provided with the notch 12b so that the discharge pressure acts on the side surface 12c of the vane 12 on the suction chamber side. For this reason, it is possible to reduce the difference in pressure load between the suction side and the discharge side generated on both side surfaces of the vane 12, and to reduce the sliding resistance of the vane 12. Therefore, the followability of the vane 12 to the rolling piston 11 is improved. As a result, the vane 12 and the rolling piston 11 are not separated from each other, noise is suppressed, and refrigerant leakage from the high pressure side to the low pressure side can be reduced.

FIG. 4 is a schematic diagram showing the force generated on the vane side in the comparative example of the rotary compressor. FIG. 5 is a schematic diagram showing the force generated on the vane side of the rotary compressor according to Embodiment 1 of the present invention. That is, FIG. 4 shows a distribution of vane side loads during operation of the compressor when a vane having no notch 12b is used. On the other hand, FIG. 5 shows a distribution of vane side loads during operation of the compressor when the vane 12 of the first embodiment in which the notch 12b is formed is used. 4 and 5, Pd is discharge pressure, Ps is suction pressure, Pm is pressure during compression, F1 and f1 are distributed loads caused by Pd, F2 is distributed loads caused by Pd to Pm, and f2 is caused by Pd to Ps. A distributed load, F3 is a distributed load caused by Pm, and f3 is a distributed load caused by Ps.

As is apparent from FIGS. 4 and 5, when the vane 12 has the notch 12b, the distribution load f2 (distribution load in the range indicated by A in FIG. 5) generated by Pd to Ps is increased by the notch 12b. . Therefore, the value (ΣF−Σf) obtained by subtracting Σf, which is the total value (f1 + f2 + f3) of the distributed load f, from ΣF, which is the total value (F1 + F2 + F3) of the distributed load F, is reduced as compared with the configuration in which the notch 12b is not provided. ing. For this reason, the sliding resistance between the vane 12 and the vane groove 7 a is reduced, the followability of the vane 12 to the rolling piston 11 is improved, and the vane 12 is not separated from the rolling piston 11. As a result, no noise is generated, and no refrigerant leaks from the high pressure side to the low pressure side, so that the performance can be maintained.

FIG. 6 is a graph showing the relationship between the phase of the crankshaft and the vane side load of the rotary compressor according to Embodiment 1 of the present invention in comparison with the comparative example. Further, in FIG. 6, a shows the relationship between the phase of the crankshaft 10 and the vane side load when a has the notch 12b and b does not have the notch 12b. In FIG. 6, the horizontal axis represents the crank phase [deg], and the vertical axis represents the load [N]. The condition used for the calculation is that the refrigerant is a CO ₂ refrigerant. The operating conditions are a discharge pressure of 8.3 MPa, a suction pressure of 4.7 MPa, and a rotation speed of 40 rps, which are actually used when the rotary compressor is applied to a water heater. As can be seen from FIG. 6, when the notch 12b is provided, the vane side load is reduced when the crankshaft 10 is in any angular position as compared with the case where the notch 12b is not provided. .

As described above, according to the first embodiment, the notch 12 b for drawing the compressed refrigerant to the suction side of the vane 12 is provided on the side surface 12 c of the vane 12 on the suction chamber 7 c side. For this reason, the discharge pressure acts on the side surface 12c of the vane on the suction chamber 7c side, and the difference in pressure load between the suction side and the discharge side of the vane 12 can be reduced. Therefore, the sliding resistance between the vane 12 and the vane groove 7a can be reduced. As a result, the followability of the vane 12 to the rolling piston 11 can be improved.

Here, in forming the notch 12b, by providing the notch 12b on the vane 12 itself, for example, the following effects can be obtained as compared with the case where the notch is provided on the vane groove side. The vane groove is a portion that is generally a narrow gap of about 2 mm to 5 mm and is difficult to process. For this reason, it is difficult to remove burrs, burrs, and the like that are generated when notches are formed in the vane grooves during polishing of the vane grooves. Therefore, in the structure in which the notch is provided on the vane groove side, the frictional resistance increases due to the remaining material that cannot be removed.

In addition, as a forming method of the vane groove, forming using a broach blade or a cutter is generally used, but since the vane groove has an asymmetric shape by providing a notch, processing at the time of processing is performed. Resistance becomes uneven. Therefore, it is difficult to perform machining with high accuracy, and the tool life is shortened. The above problem is particularly noticeable when a large notch is formed.

Currently, the amount of eccentricity of rotary compressors has been expanded for higher performance. As the amount of eccentricity increases, the vane moves greatly into the vane groove, and the amount of movement of the vane increases. For this reason, if the vane groove is not provided with a large notch, when the vane moves to the bottom dead center side, the vane is positioned in front of the notch and the vane suction side surface does not face the notch. Can be. In the first embodiment, the vane spring is located in the back pressure chamber and the vane spring does not come out of the back pressure chamber. However, depending on the model, the vane spring may move when the vane moves to the bottom dead center side. There is also a model in which the end of the vane side enters the vane groove. In such a model, the vane is positioned in front of the notch (rolling piston side), and the side surface on the suction side of the vane may not face the notch. In such a state, the UP amount of f2 shown in FIG. 5 decreases, and a sufficient effect cannot be achieved.

In contrast, in the first embodiment, since the vanes themselves are provided with the notches 12b, the discharge pressure is applied to the suction side surface 12c of the vane 12 even when the vane 12 has moved to the bottom dead center. And f2 does not decrease.

The shape of the notch 12b is not limited to a triangular shape in plan view as shown in FIG. 2, and can be modified as follows, for example.

FIG. 7 is a perspective view showing Modification 1 of the vane notch 12b of the rotary compressor according to Embodiment 1 of the present invention.
In FIG. 7, the notch 12b has a rectangular shape in plan view. Even with this configuration, the same effect as the notch 12b described above can be obtained.

In the above description, the passage of the present invention for drawing the compressed refrigerant to the suction side of the vane 12 has been described with reference to a notch. However, the present invention is not limited to the notch and is shown in FIG. It is good also as a groove | channel.

FIG. 8 is a perspective view showing a second modification of the vane passage of the rotary compressor according to the first embodiment of the present invention.
In FIG. 8, a groove 12e is provided on the side surface 12c of the vane 12 on the suction chamber side. Even in this configuration, the same effect as that obtained when the notch 12b described above is provided can be obtained. Note that the number of grooves 12e is not limited to two as shown in FIG. 8, but may be one or more. Further, the size of the groove 12e can be freely set.

1 closed container, 1a discharge pipe, 2 accumulator, 3 motor section, 4 compression mechanism section, 5 upper bearing, 5a discharge hole, 5b discharge valve, 6 discharge muffler, 6a discharge hole, 7 cylinder, 7a vane groove, 7b back Pressure chamber, 7c suction chamber, 7d discharge chamber, 7e suction port, 7f discharge port, 8 lower bearing, 9 suction pipe, 10 crankshaft, 10a eccentric shaft, 10b main shaft, 10c countershaft, 11 rolling piston, 12 Vane, 12a rear end, 12b notch, 12c side, 12d front end, 12e groove, 13 vane spring, 14 space, 31 stator, 32 rotor, 71 cylinder chamber, 71a through hole.

Claims

An electric motor part and a compression mechanism part driven by the electric motor part in a sealed container;
The compression mechanism is
A crankshaft that is rotationally driven by the motor section;
A cylinder with a cylinder chamber;
A rolling piston fitted into the eccentric shaft portion of the crankshaft and rotating eccentrically in the cylinder chamber;
A plate-like vane whose front end is pressed by the rolling piston and partitions the cylinder chamber into a suction chamber and a compression chamber;
A vane groove formed in the cylinder and reciprocally slidably receiving the vane;
A rotary compressor, wherein a passage for drawing the refrigerant compressed by the compression mechanism portion to the suction side of the vane is provided on a side surface of the vane on the suction chamber side.
2. The rotary compression according to claim 1, wherein the cylinder further includes a back pressure chamber that is provided on a rear end side of the vane so as to communicate with the vane groove and the passage and guides a compressed refrigerant to the rear end of the vane. Machine.
The rotary compressor according to claim 1, wherein the passage is a notch or a groove.