JP2015206329A - scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll compressor having high efficiency and high reliability by keeping a back pressure proper.SOLUTION: A scroll compressor comprises: a compression mechanism part comprising a fixed scroll with a fixed side wrap formed on a fixed side plate member, and an orbiting side scroll with an orbiting side wrap formed on an orbiting side plate member, in which the fixed side wrap and the orbiting side wrap are meshed with each other to form compression chambers; an electric motor for driving the compression mechanism part via a crankshaft; a back pressure chamber provided on a back face side of the orbiting scroll member and kept at a pressure between the pressure of a discharge space, in which refrigerant is discharged from the compression mechanism part, and the pressure in a suction chamber of the compression mechanism part; a back pressure chamber fluid outflow path provided in the fixed scroll and providing communication between the compression chamber or the suction chamber and the back pressure chamber; a back pressure control space communicating with the back pressure chamber fluid outflow path; a back pressure chamber communication passage providing communication between the back pressure control space and the back pressure chamber; and a back pressure control means provided in the back pressure control space, opening and closing a valve element by a differential pressure. The back pressure chamber fluid outflow path is arranged on a bottom face side of the back pressure control space.

Description

  The present invention relates to improvement in efficiency and reliability of refrigerant compressors for refrigeration and air conditioning, air and other electric scroll compressors.

  In the scroll compressor, a force that pulls the scrolls apart from each other is exerted by the compression action of the fixed scroll and the orbiting scroll. Therefore, the orbiting scroll is discharged to the opposite side of the orbiting scroll so as not to be separated from the fixed scroll. A back pressure chamber that is an intermediate pressure between the pressure and the suction pressure is provided, and the orbiting scroll is pressed against the fixed scroll by the back pressure that is the pressure of the back pressure chamber. As a result, it is possible to improve the performance by reducing leakage of the wrap portion of the orbiting scroll and the fixed scroll. And this back pressure is adjusted by the back pressure control which is a pressure difference control valve provided in the communicating path which connects a back pressure chamber and a suction chamber.

  A scroll compressor using such a back pressure control valve is disclosed in Japanese Patent Application Laid-Open No. 11-247786 (Patent Document 1). In the scroll compressor of Patent Document 1, a back pressure control valve including a valve body and a differential pressure valve spring that presses the valve body is provided in a communication path that connects the back pressure chamber and the suction chamber, and the back pressure is sucked into the suction chamber pressure. Is adjusted to be higher by a certain value. And back pressure is always applied to the valve body of the back pressure control valve immediately after starting, and this back pressure rises with the discharge pressure from the start of the compressor start, and when the difference between the back pressure and the suction pressure exceeds a certain value The back pressure control valve will open. In the scroll of Patent Document 1, a plurality of back pressure control valves are provided, and the back pressure is abnormal when there is a large amount of oil or gas flowing through the back pressure control valve at the time of start-up or when the operating state changes suddenly. I try to prevent it from rising.

Japanese Patent Laid-Open No. 11-247786

  In the scroll compressor described in Patent Document 1 including a back pressure control space in which a valve body is opened and closed by a differential pressure, a gas flowing from the back pressure control space into a back pressure fluid outflow passage that connects the suction chamber and the compression chamber, and Since the oil passes through the gap between the valve body that opens and closes by the differential pressure and the wall surface of the back pressure control space, passage resistance is generated due to the passage reduction, and it becomes difficult to flow into the back pressure chamber fluid outflow passage. Therefore, the back pressure fluctuates from a desired pressure, and an appropriate orbiting scroll push-up force cannot be secured, causing problems such as a reduction in efficiency.

  Therefore, an object of the present invention is to provide a highly efficient and highly reliable compressor that keeps the back pressure appropriately stable.

  In order to solve the above-mentioned problems, the present invention includes: a fixed scroll in which a fixed side wrap is formed on a fixed side plate-like member, and a turning side scroll in which a turning side wrap is formed on a turning side plate-like member, A compression mechanism portion that forms a compression chamber by meshing the side wrap and the orbiting side wrap, an electric motor that drives the compression mechanism portion via a crankshaft, and a rear surface side of the orbiting scroll member; A back pressure chamber maintained at a pressure between the pressure of the discharge space from which the refrigerant is discharged from the mechanism and the pressure of the suction chamber of the compression mechanism; and the compression chamber or the suction provided in the fixed scroll A back pressure chamber fluid outflow passage communicating with the back pressure chamber, a back pressure control space communicating with the back pressure chamber fluid outflow passage, and a back pressure communicating between the back pressure control space and the back pressure chamber. Room communication passage and back pressure control space Vignetting, comprising a back pressure control means for opening and closing the valve body by pressure difference, and is characterized by "placing the back pressure chamber fluid outflow path on the bottom side of the back pressure control space.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide a highly efficient and reliable compressor by keeping back pressure appropriately stable. Other configurations, operations, and effects of the present invention will be described in detail in the following examples.

FIG. 3 is an overall structure of the scroll compressor according to the first embodiment. These are the detailed structures of the back pressure control means in the scroll compressor of 1st Embodiment, and are the states which the valve body opened most. Is the fixed scroll detailed structure of the first embodiment. These are the detailed structures of the back pressure control means in the scroll compressor of 1st Embodiment, and are the states which the valve body opened most. These are the detailed structures of the back pressure control means in the scroll compressor of 2nd Embodiment, and are the states which the valve body opened most. These are the detailed structures of the back pressure control means in the scroll compressor of 3rd Embodiment, and are the states which the valve body opened most. These are the detailed structures of the back pressure control means in the scroll compressor of 4th Embodiment, and are the states which the valve body opened most.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a scroll compressor according to a first embodiment for carrying out the present invention. First, the overall structure of the scroll compressor will be described. In the scroll compressor 1, a compression mechanism formed by a fixed scroll 20 and a turning scroll 19 and a drive unit 3 are housed in a sealed container 21. The fixed scroll 20 is formed by forming a fixed-side wrap on a fixed-side plate member, and the orbiting scroll 19 is formed by forming an orbiting-side wrap on the orbiting-side plate member, and these wraps are engaged with each other to compress the compression chamber 2. Is formed.

  The drive unit 3 includes a motor 10 including a stator 8 fixed to the hermetic container 21 and a rotor 9 that rotates on the inner peripheral side of the stator 8, and a crankshaft 11 that rotationally drives the rotor 9 as basic elements. Configured as The frame 12 is fixed to the sealed container 21 and fixes the fixed scroll 19, the sub-frame 13 is fixed to the lower part of the sealed container 21, and the sub-bearing housing 16 is fixed to the sub-frame 13.

  The electric motor 10 that drives the compression mechanism is driven by an electric input from an inverter (not shown) via the electric terminal 17 and applies a rotating action to the crankshaft 11. The crankshaft 11 includes a central main shaft portion 11a, a lower auxiliary shaft portion 11b, and an upper eccentric pin portion 11c. The shaft support portion 14 disposed on the frame 12 and the shaft support portion 15 disposed on the auxiliary bearing housing 16 are shaft support portions that rotatably engage the main shaft portion 11 a and the sub shaft portion 11 b of the crankshaft 11. Configure.

  Further, lubricating oil for lubricating the shaft support portions 14 and 15 is stored in the oil sump 18 at the bottom of the sealed container 21, and the subframe 13 engaged with the frame 12 and the subbearing housing 16 is fixed to the sealed container 21. The As the orbiting scroll 19 orbits as the crankshaft 11 rotates, a suction chamber and a compression chamber 2 are formed between the orbiting scroll 19 and the fixed scroll 20, and a compression operation is performed by reducing the volume of the compression chamber 2. Is done. The working fluid (refrigerant) is sucked into the compression chamber 2 from the suction pipe 6, is discharged from the discharge port 4 to the discharge space 5 in the sealed container 21 through the compression process, and is further discharged from the discharge pipe 7 to the outside of the sealed container 21. .

  In this embodiment, an intermediate pressure between the pressure in the discharge space 5 and the pressure in the suction chamber (hereinafter referred to as back pressure) is used as a space on the back side of the orbiting scroll 19 (hereinafter referred to as back pressure chamber 100). It is acting. By pressing the orbiting scroll 19 against the fixed scroll 20 by the back pressure chamber 100, the function of maintaining the hermeticity of the compression chamber 2 is achieved. Further, in order to keep the pressure in the back pressure chamber 100 properly, the back pressure control means 106 is provided in the fixed scroll 20. Thereby, the energy loss by the refrigerant | coolant leak at the time of compression operation can be reduced, and favorable reliability can be ensured regarding the pressing sliding of the turning scroll 19.

  Next, the configuration of the back pressure control unit 101 will be described with reference to FIG. FIG. 2 shows the back pressure control means 101 shown in FIG. 1 in detail. The back pressure control means 101 includes a seal member 103 in the back pressure control space 102, a spring 104 attached to the seal member 103, a valve body 105 for closing the flow path, and a valve seat serving as a receiving portion of the valve body 105. Part 106.

  The back pressure control means 101 is provided between the back pressure chamber fluid outflow passage 107 and the back pressure chamber communication passage 113. The back pressure chamber fluid outflow passage 107 opens into the suction groove 108 of the fixed scroll 20 and serves to communicate the back pressure control space 102 and the suction groove 108.

  FIG. 3 shows the fixed scroll 20. As shown in FIG. 3, the suction groove 108 is formed on the surface side of the fixed scroll 20 that contacts the orbiting scroll 19, and communicates the suction chamber 109 and the compression chamber 2. The back pressure control space 102 communicates with the back pressure chamber fluid outflow passage 107 and communicates with the back pressure chamber 100 through the back pressure chamber communication passage 113.

  A configuration in which the valve body 105 opens in the back pressure control means 102 provided in the back pressure control space 102 and opening and closing the valve body 105 by differential pressure will be described. When the compressor is stopped, the valve body 105 is pressed against the valve seat portion 106 by the spring load of the spring 104. In the compressor operating state, the pressure in the suction groove 108 communicating with the suction chamber 109 decreases, and the back pressure chamber 100 in which the upper pressure P1 of the valve body 105 is lower than the valve body 105 through the back pressure chamber fluid outflow passage 107. Lower than the pressure Pb. When the load acting on the valve body 105 is larger than the spring load of the spring 104 due to the pressure difference between the pressure P2 and the pressure P1, the valve body 105 is opened. Gas and oil flowing out from the back pressure chamber 100 to the back pressure control space 102 pass through a gap 111 between the valve body 105 and the side surface 110 of the back pressure control space, so that the gas and oil from the back pressure chamber 100 are sucked into the suction groove 108. The back pressure control is performed to maintain the pressure Pb of the back pressure chamber 100 at a predetermined pressure.

  FIG. 4 shows the positional relationship between the back pressure chamber fluid outflow passage 107 and the valve body 105 existing in the back pressure control space 102 in the first embodiment. When the valve body 105 is in the most open state due to the differential pressure, the back pressure chamber fluid outflow passage 107 is disposed on the bottom surface 112 of the back pressure control space 102. Even when the valve body 105 is closed, the communication portion of the back pressure chamber fluid outflow passage 107 to the back pressure control space 102 is located below the valve body 105. That is, by disposing the back pressure chamber fluid outflow passage 107 on the bottom surface side in the back pressure control space 102, the passage resistance generated by the passage reduction from the back pressure control space 102 to the back pressure chamber fluid outflow passage 107 is reduced. Therefore, the gas and oil can easily flow into the back pressure chamber fluid outflow passage 107, and the gas and oil can flow smoothly.

  The back pressure chamber fluid outflow passage 107 is more than the state in which the valve element 105 is most opened so that the opening to the back pressure control space 102 of the back pressure chamber fluid outflow passage 107 has an area equivalent to the passage sectional area S0. By configuring so as to open downward, the gas and oil that have flowed out of the back pressure chamber 100 into the back pressure control space 102 can be prevented from passing through the gap 111 between the valve body 105 and the side surface 110 of the back pressure control space.

  More specifically, the back pressure chamber fluid outflow passage 107 is configured to open an area equivalent to the passage cross-sectional area S0 of the back pressure chamber fluid outflow passage 107 below the state in which the valve body 105 is most opened. To do. Therefore, it is possible to prevent the problem of an increase in the back pressure Pb, which is the orbiting scroll pushing force, thereby maintaining the pushing force of the orbiting scroll 19 against the fixed scroll 20 properly, and reducing the sliding loss due to the excessive orbiting scroll pushing force. It is possible to suppress the reliability of the sliding of the orbiting scroll 19. Therefore, a scroll compressor suitable for realizing high reliability and high energy efficiency can be realized.

  FIG. 5 shows a positional relationship between the back pressure chamber fluid outflow passage 107 and the valve body 105 existing in the back pressure control space 102 in the second embodiment. When the back pressure chamber fluid outflow passage 107 is arranged on the side surface 110 of the back pressure control space and the valve body 105 is in the most open state as in the first embodiment, the back pressure chamber fluid outflow is located below the valve body 105. An effect of ensuring an appropriate back pressure Pb can be obtained by configuring the passage 107 so as to open an area equivalent to the passage sectional area S0.

  According to the present embodiment, it can be easily configured by adjusting the angle of the back pressure chamber fluid outflow passage 107.

  FIG. 6 shows the positional relationship between the back pressure chamber fluid outflow passage 107 and the valve body 105 existing in the back pressure control space 102 in the third embodiment. When the back pressure chamber fluid outflow passage 107 is arranged across the side surface 110 of the back pressure control space and the bottom surface 112 of the back pressure control space, and the valve body 105 is in the most open state as in the first embodiment, the valve body An effect of ensuring an appropriate back pressure Pb can be obtained by opening an area equivalent to the passage cross-sectional area S0 of the back pressure chamber fluid outflow passage 107 below 105.

  According to the present embodiment, it can be easily configured by adjusting the angle of the back pressure chamber fluid outflow passage 107.

  7 shows the positional relationship between the back pressure chamber fluid outflow passage 107 and the valve body 105 existing in the back pressure control space 102 in the fourth embodiment. When the back pressure chamber fluid outflow passage 107 is disposed on the side surface 110 of the back pressure control space and the valve body 105 is in the most opened state, the passage cross-sectional area of the back pressure chamber fluid outflow passage 107 is located below the valve body 105. By opening approximately 1/2 of S0 and by opening approximately 1/2 of the passage cross-sectional area S0 of the back pressure chamber fluid outflow passage 107 above the valve body 105, the valve body 105 is opened from below and above. Since it becomes easy to flow gas and oil into the back pressure chamber fluid outflow passage 107, an effect of securing an appropriate back pressure Pb is obtained.

  According to the present embodiment, it can be easily configured by adjusting the angle of the back pressure chamber fluid outflow passage 107.

In the above embodiment, the outlet position to the compression chamber 2 in the back pressure chamber fluid outflow passage 107 is opposed to the flat plate portions of the fixed scroll 20 and the orbiting scroll 19 rather than the inlet position from the back pressure control space 102. It is arranged on the position side. Then, since the back pressure chamber fluid outflow passage 107 is disposed on the bottom surface 112 side of the back pressure control space, the length of the back pressure chamber fluid outflow passage 107 can be shortened, and the pressure loss can be reduced accordingly. Is possible.

DESCRIPTION OF SYMBOLS 1 ... Scroll compressor, 2 ... Compression chamber, 3 ... Drive part, 4 ... Discharge port, 5 ... Discharge space, 6 ... Suction pipe, 8 ... Discharge pipe, 8 ... Stator, 9 ... Rotor, 10 ... Electric motor, DESCRIPTION OF SYMBOLS 11 ... Crankshaft, 12 ... Frame, 13 ... Subframe, 14, 15 ... Shaft support, 16 ... Subbearing housing, 17 ... Electrical terminal, 18 ... Oil sump, 19 ... Orbiting scroll, 20 ... Fixed scroll, 21 ... 101: Back pressure chamber, 101 ... Back pressure control means, 102 ... Back pressure control space, 103 ... Seal member, 104 ... Spring, 105 ... Valve body, 106 ... Valve seat, 107 ... Back pressure chamber fluid outflow 108, fixed suction groove, 109 ... suction chamber, 110 ... side surface of back pressure control space, 111 ... gap, 112 ... bottom surface of back pressure control space, 113 ... back pressure chamber communication passage, P1 ... upper pressure of valve body , Pb ... back pressure chamber pressure.

Claims (5)

A fixed scroll in which a fixed side wrap is formed on the fixed side plate member;
A turning-side scroll formed on a turning-side plate-like member, and a compression mechanism part that forms a compression chamber by meshing the fixed-side wrap and the turning-side wrap;
An electric motor that drives the compression mechanism through a crankshaft;
A back pressure chamber that is provided on the back side of the orbiting scroll member and is maintained at a pressure between the pressure of the discharge space from which the refrigerant is discharged from the compression mechanism and the pressure of the suction chamber of the compression mechanism;
A back pressure chamber fluid outflow passage which is provided in the fixed scroll and communicates the compression chamber or the suction chamber and the back pressure chamber;
A back pressure control space communicating with the back pressure chamber fluid outflow passage;
A back pressure chamber communication passage communicating the back pressure control space and the back pressure chamber;
Back pressure control means provided in the back pressure control space and opening and closing the valve body by differential pressure,
A scroll compressor characterized in that the back pressure chamber fluid outflow passage is disposed on the bottom side of the back pressure control space. The scroll compressor according to claim 1.
The scroll compressor according to claim 1, wherein the back pressure chamber fluid outflow passage is configured to be opened downward from a state in which the valve body is most opened. The scroll compressor according to claim 1.
A scroll compressor characterized in that the back pressure chamber fluid outflow passage is arranged on a side surface side of the back pressure control space. The scroll compressor according to claim 1.
A scroll compressor characterized in that the back pressure chamber fluid outflow passage is disposed on an outer peripheral portion of the valve seat across a side surface and a bottom surface of the back pressure control space. The scroll compressor according to claim 1.
The back pressure chamber fluid outflow passage is disposed on a side surface of the back pressure control space, and the back pressure chamber fluid outflow passage is located under the valve body in a state where the valve body is most opened. A scroll compressor characterized in that an area of approximately ½ of the passage cross-sectional area of the outflow passage is opened, and the remaining area of approximately ½ is opened above the valve body.