JP2024091916A - Scroll Compressor - Google Patents

Abstract

To provide a highly efficient scroll compressor that can control force to press a revolving scroll to a stationary scroll.SOLUTION: A scroll compressor is provided with: a pressure introduction groove 55 at a thrust surface of a stationary scroll 11; and a communication groove 56a at a lap surface of a revolving scroll end plate 12a, where mutual grooves overlap at a certain crank angle and are communicated to another space to adjust internal pressure of the grooves, thereby optimizing back pressure applied to a revolving scroll 12. Accordingly, the scroll compressor can reduce unnecessary mechanical loss and has high efficiency.SELECTED DRAWING: Figure 4

Description

The present invention relates to scroll compressors, particularly for use in refrigeration equipment such as air conditioners, water heaters, and refrigerators.

Patent Document 1 discloses a scroll compressor used in air conditioners and the like. This scroll compressor provides a back pressure area on the opposite wrap surface of the orbiting scroll end plate, and by pressing the orbiting scroll against the fixed scroll, it reduces leakage loss and improves theoretical efficiency and heating/cooling capacity. In other words, grooves and spaces that always maintain suction pressure are provided on the fixed scroll side that slides against the wrap surface of the orbiting scroll end plate, and the orbiting scroll is pressed against the fixed scroll using the differential pressure with the back pressure, making the behavior more stable.

Japanese Patent No. 4892238

This disclosure provides a scroll compressor that further improves efficiency by making it possible to control the force pressing the orbiting scroll against the fixed scroll.

The scroll compressor disclosed herein has a first compression chamber formed on the outer wall side of the orbiting spiral wrap, a second compression chamber formed on the inner wall side of the orbiting spiral wrap, and a back pressure area formed on the opposite wrap surface of the orbiting scroll end plate to press the orbiting scroll against the fixed scroll. In this scroll compressor, a pressure introduction groove is provided on the sliding surface of the fixed scroll, and a communication groove is provided on the wrap surface of the orbiting spiral scroll end plate, and the grooves communicate with each other at certain crank angles.

The scroll compressor disclosed herein is able to adjust the force pressing the orbiting scroll against the fixed scroll in accordance with the strength of the pushing back force of the orbiting scroll, reducing unnecessary mechanical loss and making the scroll compressor highly efficient.

FIG. 1 is a vertical cross-sectional view of a scroll compressor according to a first embodiment of the present invention; FIG. 3 is an enlarged cross-sectional view showing a compression mechanism of the scroll compressor; FIG. 13 shows the change in volume of the compression chamber caused by the orbital motion of the scroll compressor. FIG. 13 shows the change in volume of the compression chamber caused by the orbital motion of the scroll compressor. FIG. 13 shows the change in volume of the compression chamber caused by the orbital motion of the scroll compressor. FIG. 13 shows the change in volume of the compression chamber caused by the orbital motion of the scroll compressor. FIG. 2 is a plan view showing the meshing surfaces of the fixed scroll and the orbiting scroll of the scroll compressor. FIG. 13 is a diagram showing an example of how the pressure introduction groove and the communication groove are communicated with each other in accordance with the orbital motion of the scroll compressor. FIG. 13 is a diagram showing an example of how the pressure introduction groove and the communication groove are communicated with each other in accordance with the orbital motion of the scroll compressor. FIG. 13 is a diagram showing an example of how the pressure introduction groove and the communication groove are communicated with each other in accordance with the orbital motion of the scroll compressor. FIG. 13 is a diagram showing an example of how the pressure introduction groove and the communication groove are communicated with each other in accordance with the orbital motion of the scroll compressor.

(Knowledge and other information that forms the basis of this disclosure)
At the time when the inventors came up with the present disclosure, scroll compressors use a pressure difference with the back pressure to press the orbiting scroll against the fixed scroll, thereby making the behavior more stable. However, the inventors discovered that there was a problem in that the pressure in the compression chamber acting in a direction to separate the orbiting scroll from the fixed scroll fluctuates during one rotation of the crankshaft, resulting in more pressing than necessary at certain crank angles. In order to solve this problem, the inventors came to form the subject of the present disclosure.

Therefore, this disclosure provides a scroll compressor with improved efficiency by varying the back pressure applied to the end plate according to the strength of the force acting in the direction that pulls the orbiting scroll away from the fixed scroll.

Below, the embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to make it easier for those skilled in the art to understand.

The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 5D.

[1-1. Configuration]
1 to 5D, the scroll compressor is configured by arranging a compression mechanism 10 for compressing a refrigerant and an electric mechanism 20 for driving the compression mechanism 10 in a sealed container 1.

The sealed container 1 is composed of a body 1a formed in a cylindrical shape extending in the vertical direction, a lower lid 1b that closes the lower opening of the body 1a, and an upper lid 1c that closes the upper opening of the body 1a. The sealed container 1 is provided with a refrigerant suction pipe 2 that introduces refrigerant to the compression mechanism 10, and a refrigerant discharge pipe 3 that discharges the refrigerant compressed by the compression mechanism 10 out of the sealed container 1.

The compression mechanism 10 has a fixed scroll 11, a rotating scroll 12, and a rotating shaft 13 that drives the rotating scroll 12 to rotate.

The electric mechanism 20 comprises a stator 21 fixed to the sealed container 1 and a rotor 22 arranged inside the stator 21. The rotor 22 is fixed to the rotating shaft 13, and an eccentric shaft 13a that is eccentric with respect to the rotating shaft 13 is formed at the upper end of the rotating shaft 13. The eccentric shaft 13a has an oil reservoir formed by a recess that opens to the upper surface of the eccentric shaft 13a.

Below the fixed scroll 11 and the orbiting scroll 12, a main bearing 30 is provided to support the fixed scroll 11 and the orbiting scroll 12.

The main bearing 30 is formed with a bearing portion 31 that supports the rotating shaft 13 and a boss housing portion 32. The main bearing 30 is fixed to the sealed container 1 by welding or shrink fitting.

The fixed scroll 11 comprises a disk-shaped fixed scroll end plate 11a, a spiral-shaped fixed spiral wrap 11b standing on the fixed scroll end plate 11a, and an outer peripheral wall portion 11c standing to surround the periphery of the fixed spiral wrap 11b, and a discharge port 14 is formed approximately at the center of the fixed scroll end plate 11a.

The orbiting scroll 12 comprises a disk-shaped orbiting scroll end plate 12a, an orbiting spiral wrap 12b erected on the wrap side end surface of the orbiting scroll end plate 12a, and a cylindrical boss portion 12c formed on the opposite wrap side end surface of the orbiting scroll end plate 12a.

The fixed spiral wrap 11b of the fixed scroll 11 and the orbiting spiral wrap 12b of the orbiting scroll 12 are meshed with each other, and multiple compression chambers 15 are formed between the fixed spiral wrap 11b and the orbiting spiral wrap 12b.

The boss portion 12c is formed approximately in the center of the orbiting scroll end plate 12a and is housed in the boss housing portion 32 when inserted into the eccentric shaft 13a.

The fixed scroll 11 is fixed to the main bearing 30 by using a plurality of bolts (not shown) at the outer peripheral wall portion 11c. On the other hand, the movement of the orbiting scroll 12 is restricted with respect to the fixed scroll 11 via a rotation restraining member 17 such as an Oldham ring. The rotation restraining member 17 that restrains the rotation of the orbiting scroll 12 is provided between the fixed scroll 11 and the main bearing 30. As a result, the orbiting scroll 12 orbits with respect to the fixed scroll 11 without rotating on its own axis as the eccentric shaft 13a of the rotating shaft 13 rotates by crank rotation.

An oil reservoir 4 for storing lubricating oil is formed at the bottom of the sealed container 1, and the lower end 13b of the rotating shaft 13 is supported by a secondary bearing 18 located at the bottom of the sealed container 1.

A volumetric oil pump 5 is provided at the lower end of the rotating shaft 13. The oil pump 5 is positioned so that its suction port is located inside the oil reservoir 4. The oil pump 5 is driven by the rotating shaft 13 and reliably draws up the lubricating oil in the oil reservoir 4, which is provided at the bottom of the sealed container 1, regardless of pressure conditions or operating speed, eliminating the worry of running out of oil.

The rotating shaft 13 is formed with a rotating shaft oil supply hole 13c that runs from the lower end 13b of the rotating shaft 13 to the eccentric shaft 13a. The lubricating oil pumped up by the oil pump 5 is supplied to the bearing of the auxiliary bearing 18, the bearing portion 31, and the boss portion 12c through the rotating shaft oil supply hole 13c formed in the rotating shaft 13.

The refrigerant sucked from the refrigerant suction pipe 2 is led to the compression chamber 15 from the suction port 15a. The compression chamber 15 moves from the outer periphery toward the center while reducing its volume, and the refrigerant that reaches a predetermined pressure in the compression chamber 15 is discharged from the discharge port 14 provided in the center of the fixed scroll 11 to the discharge chamber 6. The discharge port 14 is provided with a discharge reed valve (not shown). The refrigerant that reaches a predetermined pressure in the compression chamber 15 pushes open the discharge reed valve and is discharged into the discharge chamber 6. The refrigerant discharged into the discharge chamber 6 is led to the upper part of the sealed container 1 and discharged from the refrigerant discharge pipe 3.

As shown in the enlarged cross-sectional view of the main part of the scroll compressor in this embodiment, the boss accommodating section 32 is a high-pressure region A, and the outer periphery of the orbiting scroll 12 where the rotation restraining member 17 is arranged is an intermediate-pressure region B, and the orbiting scroll 12 is pressed against the fixed scroll 11. The configuration will be described below.

The eccentric shaft 13a is inserted into the boss portion 12c via a swivel bearing 13d so that it can be rotated. An oil groove 13e is formed on the outer circumferential surface of the eccentric shaft 13a.

A ring-shaped seal member 33 is provided on the thrust surface of the main bearing 30, which receives the thrust force of the orbiting scroll end plate 12a. The seal member 33 is disposed on the outer periphery of the boss housing portion 32.

The sealed container 1 is filled with the same high-pressure refrigerant as the refrigerant discharged into the discharge chamber 6, and the rotating shaft oil supply hole 13c opens to the upper end of the eccentric shaft 13a, so the inside of the boss portion 12c becomes a high-pressure region A equivalent to the discharged refrigerant.

The lubricating oil introduced into the boss portion 12c through the rotating shaft oil supply hole 13c is supplied to the orbiting bearing 13d and the boss accommodating portion 32 by the oil groove 13e formed on the outer circumferential surface of the eccentric shaft 13a. The boss accommodating portion 32 is provided with the seal member 33 on its outer periphery, so that the boss accommodating portion 32 becomes a high-pressure region A.

The orbiting scroll end plate 12a is provided with a first oil inlet hole 51 formed toward the inside of the boss portion 12c, a first oil outlet hole 52 opening to the outer periphery of the wrap side end face, and a first end plate oil communication passage 53 connecting the first oil inlet hole 51 and the first oil outlet hole 52.

The orbiting scroll end plate 12a is provided with a second oil inlet hole 61 that opens into the intermediate pressure region B of the outer periphery of the orbiting scroll 12, a second oil outlet hole 62 that opens into the compression chamber 15, and a second end plate oil communication passage 63 that connects the second oil inlet hole 61 and the second oil outlet hole 62. The second oil inlet hole 61 is formed on the upper surface of the orbiting scroll end plate 12a.

In this way, by forming a second oil outlet hole 62 in the orbiting scroll 12 that intermittently connects the intermediate pressure region B to the compression chamber 15, the intermediate pressure of the compression chamber 15 can be introduced into the intermediate pressure region B, and the orbiting scroll 12 can be pressed against the fixed scroll 11 with the minimum necessary load even under various operating conditions. This reduces friction loss in the compressor while preventing the orbiting scroll 12 from moving away from the fixed scroll 11, thereby improving the airtightness of the compression chamber 15.

Figure 3 shows the change in volume of the compression chamber due to the orbiting motion of the scroll compressor, with the orbiting scroll 12 meshed with the fixed scroll 11, as viewed from the back of the orbiting scroll 12. Figure 3B shows the state after 90 degrees of rotation from Figure 3A, Figure 3C shows the state after a further 90 degrees of rotation from Figure 3B, and Figure 3D shows the state after a further 90 degrees of rotation from Figure 3C.

The fixed scroll 11 and the orbiting scroll 12 form a compression chamber 15, with a first compression chamber 15A formed on the outer wall side of the orbiting spiral wrap 12b and a second compression chamber 15B formed on the inner wall side of the orbiting spiral wrap 12b.

Then, with the fixed scroll 11 and the orbiting scroll 12 meshed together, the outer peripheral end 11be of the fixed spiral wrap 11b is extended to the same extent as the outer peripheral end 12be of the orbiting spiral wrap 12b, so that the position where the refrigerant is trapped in the first compression chamber 15A and the position where the refrigerant is trapped in the second compression chamber 15B are shifted by approximately 180 degrees. Furthermore, the suction volume of the first compression chamber 15A is configured to be larger than the suction volume of the second compression chamber 15B.

Furthermore, in the scroll compressor of this embodiment, as shown in the diagram of the meshing surfaces of the fixed scroll 11 and the orbiting scroll 12 in Figure 4, two pressure introduction grooves 55 are provided on the thrust surface 54a of the fixed scroll 11, and two communication grooves 56a that communicate with the suction space and one hole 56b that communicates with the space of the intermediate pressure region B as necessary are provided on the thrust surface 54b of the orbiting scroll, so that at a certain crank angle, the grooves communicate with each other and the compression chamber 15, the suction port 15a, or the space of the intermediate pressure region B.

The pressure introduction groove 55 provided in the fixed scroll 11 is always set within the range in which the orbiting scroll end plate 12a moves, and can only communicate with other spaces via the communication groove 56a. In other words, the pressure introduction groove 55 is not directly connected to the compression chamber 15. However, it is configured to communicate with the compression chamber 15 when the pressure introduction groove 55 and the communication groove 56a reach suction pressure.

[1-2. Operation]
The operation and function of the scroll compressor constructed as above will now be described.

As shown in Figures 5A to 5D, the scroll compressor of the above configuration can control the pressure inside the pressure introduction groove 55 to a predetermined pressure for each crank angle by connecting and disconnecting the pressure introduction groove 55 provided on the thrust surface 54a of the fixed scroll 11 and the communication groove 56a that communicates with the suction space provided on the thrust surface 54b of the orbiting scroll. For example, in Figure 5A, the two pressure introduction grooves 55 and the two communication grooves 56a are connected to each other, and in Figure 5B, the two pressure introduction grooves 55 and one of the two communication grooves 56a are connected to each other. In Figure 5C, both the two pressure introduction grooves 55 and the two communication grooves 56a are not connected to each other, and one of the pressure introduction grooves 55 is connected to the hole 56b, and in Figure 5D, the two pressure introduction grooves 55 and one of the two communication grooves 56a are connected to each other.

Therefore, when the pressing force of the orbiting scroll 12 becomes weak at a certain crank angle, the pressure introduction groove 55 can be connected to a space with a lower pressure than the intermediate pressure region B to supplement the pressing force and suppress overturning.

On the other hand, if the pressing force of the orbiting scroll 12 against the fixed scroll 11 at a certain crank angle is greater than necessary, the pressing force can be weakened by connecting the pressure introduction groove 55 to the space in the intermediate pressure region B, thereby reducing friction loss.

[1-3. Effects, etc.]
As described above, the scroll compressor in this embodiment includes the compression mechanism unit 10 that compresses a refrigerant, the electric mechanism unit 20 that drives the compression mechanism unit 10, and the sealed container 1 that houses the compression mechanism unit 10 and the electric mechanism unit 20. The compression mechanism unit 10 has a fixed scroll 11, an orbiting scroll 12, and a rotating shaft 13 that drives the orbiting scroll 12 to orbit. The fixed scroll 11 includes a disk-shaped fixed scroll end plate 11a and a fixed spiral wrap 11b erected on the fixed scroll end plate 11a. The orbiting scroll 12 includes a disk-shaped orbiting scroll end plate 12a and an orbiting spiral wrap 12b erected on the wrap side end surface of the orbiting scroll end plate 12a. The fixed spiral wrap 11b and the orbiting scroll end plate 12a are arranged in a circular shape. The fixed scroll 11 and the orbiting spiral wrap 12b are meshed with each other to form a plurality of compression chambers 15 between the fixed scroll 11b and the orbiting spiral wrap 12b, and the compression chambers 15 are formed such that a first compression chamber 15A is formed on the outer wall side of the orbiting spiral wrap 12b and a second compression chamber 15B is formed on the inner wall side of the orbiting spiral wrap 12b, and the orbiting scroll is pressed against the fixed scroll 11 by back pressure formed on the opposite wrap surface side of the orbiting scroll end plate 12a, and a pressure introduction groove 55 is provided on the sliding surface of the fixed scroll 11, and a communicating groove 56a is provided on the wrap surface of the orbiting scroll end plate 12a, so that the grooves overlap at a certain crank angle and communicate with a space of a different pressure.

According to this configuration, by controlling the pressure in the pressure introduction groove 55 and the timing at which that pressure is reached, it is possible to adjust the force pressing the orbiting scroll 12 against the fixed scroll 11 in accordance with the strength of the pushing back force of the orbiting scroll 12, thereby reducing frictional resistance and making the scroll compressor highly efficient.

In addition, this scroll compressor is configured so that the pressure introduction groove 55 provided in the fixed scroll 11 is not directly connected to the compression chamber 15 on the back surface of the orbiting scroll. With this configuration, when the pressure introduction groove 55 and the communication groove 56a do not overlap, there is no effect on the compression process, so re-expansion loss of the refrigerant is suppressed, making it a highly efficient scroll compressor.

In addition, in each of the above configurations, the scroll compressor is configured to communicate with the compression chamber 15 at a timing when the pressure introduction groove 55 and the communication groove 56a become suction pressure. According to this configuration, the difference between the pressure in the pressure introduction groove 55 and the pressure on the back surface of the orbiting scroll 12 becomes large, and the force pressing the orbiting scroll 12 against the fixed scroll 11 can be increased, so that the behavior of the orbiting scroll 12 can be stabilized. In addition, since the pressure in the pressure introduction groove 55 is lower than that of the first compression chamber 15A, a flow of lubricating oil can be formed from the first compression chamber 15A toward the pressure introduction groove 55 on the thrust surface therebetween. Therefore, it is possible to prevent the lubricating oil from entering the compression chamber from the medium pressure space in an unnecessary large amount, and as a result, the amount of oil discharge can be reduced, resulting in a highly efficient refrigeration system. Furthermore, according to this configuration, even if the lubricating oil in the intermediate pressure space accumulates at the bottom due to gravity and no lubricating oil is present at the upper part of the intermediate pressure space in a horizontal scroll compressor or the like, it is possible to supply lubricating oil to the thrust surface from the compression chamber side, thereby making it possible to provide a highly reliable scroll compressor.

The present invention has been described above using the above embodiment, but since the above embodiment is intended to illustrate the technology in this disclosure, various modifications, substitutions, additions, omissions, etc. can be made within the scope of the claims or their equivalents.

The scroll compressor described in the above embodiment can use R32, carbon dioxide, or a refrigerant with a carbon-carbon double bond.

The scroll compressor disclosed herein is highly efficient and is useful in various refrigeration cycle devices such as hot water heating systems, air conditioners, water heaters, and freezers.

REFERENCE SIGNS LIST 1 sealed container 2 refrigerant suction pipe 3 refrigerant discharge pipe 4 oil storage section 5 oil pump 6 discharge chamber 10 compression mechanism section 11 fixed scroll 11a fixed scroll end plate 11b fixed spiral wrap 12 orbiting scroll 12a orbiting scroll end plate 12b orbiting spiral wrap 13 rotating shaft 13a eccentric shaft 13b lower end 13c rotating shaft oil supply hole 13d orbiting bearing 13e oil groove 14 discharge port 15 compression chamber 15a suction port 15A first compression chamber 15B second compression chamber 17 rotation restraining member 18 auxiliary bearing 20 electric mechanism section 21 stator 22 rotor 30 main bearing 31 bearing section 32 boss accommodating section 51 first oil inlet hole 52 first oil outlet hole 53 First end plate oil communication passage 54, 54a, 54b Thrust surface 55 Pressure introduction groove 56a Communication groove 56b Hole 61 Second oil introduction hole 62 Second oil discharge hole 63 Second end plate oil communication passage A High pressure region B Intermediate pressure region

Claims (3)

The compressor includes a compression mechanism that compresses a refrigerant, an electric mechanism that drives the compression mechanism, and a sealed container that houses the compression mechanism and the electric mechanism,
The compression mechanism includes a fixed scroll, a rotating scroll, and a rotation shaft that drives the rotating scroll to rotate.
The fixed scroll includes a disk-shaped fixed scroll end plate and a fixed spiral wrap provided upright on the fixed scroll end plate,
The orbiting scroll includes a disk-shaped orbiting scroll end plate and an orbiting spiral wrap provided on a wrap side end surface of the orbiting scroll end plate,
the fixed spiral wrap and the orbiting spiral wrap are intermeshed with each other to form a plurality of compression chambers between the fixed spiral wrap and the orbiting spiral wrap;
The compression chamber includes a first compression chamber formed on an outer wall side of the orbiting spiral wrap, and a second compression chamber formed on an inner wall side of the orbiting spiral wrap,
A scroll compressor in which the orbiting scroll is pressed against the fixed scroll by a back pressure formed on an opposite wrap surface side of the orbiting scroll end plate,
A scroll compressor in which a pressure introduction groove is provided on the thrust surface of the fixed scroll and a communicating groove is provided on the wrap surface of the end plate of the orbiting spiral scroll, the grooves overlap at a certain crank angle and communicate with a space of a different pressure, and the pressure in the grooves is adjusted by controlling the timing at which the grooves overlap and the communicating space, thereby optimizing the force applied to the orbiting scroll. The scroll compressor according to claim 1, characterized in that the pressure introduction groove provided in the fixed scroll is always set within the range in which the orbiting scroll end plate moves, and cannot communicate with other spaces except through the communication groove. 3. The scroll compressor according to claim 1, wherein said pressure introducing groove and said communication groove are configured to communicate with said compression chamber at a timing when said pressure reaches a suction pressure.