JP2005344658A - Electric gas compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve various problems resulting from the compression of a liquid in an electric gas compressor. <P>SOLUTION: This electric gas compressor 10 comprises an electric motor 16 disposed in an intake chamber 15 formed in communication with the intake port 11 of a housing 12 and cooled by a refrigerant flow flowing from the intake port 11 into the intake chamber 15, a gas compression mechanism 17 disposed in the housing 12 and operated by the electric motor 16, a refrigerant guide passage 30 guiding a refrigerant flowing in the intake chamber 15 to the compression mechanism 17 to compress the refrigerant in the compression mechanism, and a lubricating oil guide passage 31 having one end opened to the bottom part of the intake chamber 15 to supply a lubricating oil separated from the refrigerant in the intake chamber 15 and accumulated at the bottom part of the intake chamber to the compression mechanism 17 through the refrigerant guide passage 30 and the other end opening to the refrigerant guide passage 30. The lubricating oil at the bottom part of the intake chamber 15 is entrained to the compression mechanism 17 via. the lubricating oil guide passage 31 by a refrigerant flow flowing through the refrigerant guide passage 30 toward the compression mechanism 17. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric gas compressor in which an electric motor as a drive source is incorporated in a housing, and more particularly to an electric gas compressor suitable for incorporation as a refrigerant compressor in a refrigerator or an air conditioner.

  In this type of conventional electric gas compressor, an electric motor is disposed in a suction chamber that communicates with a suction port of the housing in order to cool an electric motor that is a driving source by using a refrigerant flow flowing in the housing. (For example, refer to Patent Document 1).

  When the gas compression mechanism is operated by the operation of the electric motor, the refrigerant is sucked into the gas compression mechanism through the suction port of the housing and is compressed by the gas compression mechanism, and the refrigerant is condensed from the discharge port formed in the housing. It is pumped to the vessel.

  The electric motor is suitably cooled by the refrigerant flow flowing from the suction port to the gas compressor through the suction chamber in which the electric motor is disposed. However, the lubricating oil contained in the refrigerant is separated in the suction chamber, May accumulate. When such a refrigerant from which the lubricating oil is separated is sent to the compression mechanism, a shortage of lubricating oil occurs in the operating portion of the compression mechanism, making it difficult to smoothly operate the compression mechanism.

  Therefore, in Patent Document 1, it has been proposed to provide a refrigerant-containing opening of a refrigerant guide passage for guiding refrigerant from the suction chamber to the compression mechanism at the bottom of the suction chamber in order to prevent the separated lubricating oil from accumulating in the suction chamber. .

According to this, the refrigerant flowing in the suction chamber communicating with the suction port is supplied to the compression mechanism together with the lubricating oil accumulated in the bottom portion of the suction chamber from the refrigerant guide passage opened to the bottom portion of the suction chamber. Lack of lubricating oil can be resolved.
JP 2004-36455 A (page 4-6, FIG. 3)

  However, since the lubricating oil and refrigerant in the suction chamber are guided to the compression mechanism through a common refrigerant guide passage extending from the bottom of the suction chamber to the compression mechanism, they are separated into the bottom of the suction chamber when the operation of the gas compressor is stopped. If the lubricating oil or the liquefied refrigerant accumulates, only the liquid such as the lubricating oil or the liquefied refrigerant may be supplied to the compression mechanism at the time of restart.

  When such a gas-free liquid is supplied to the compression mechanism, liquid compression occurs in the compression mechanism, and a large load is applied to the operation part of the compression mechanism, and this operation part is damaged or an excessive load is applied to the electric motor. Cause abnormal noise and vibration.

  Accordingly, an object of the present invention is to eliminate various problems caused by liquid compression caused by supplying a liquid that does not contain gas as described above to a compression mechanism.

  The present invention relates to an electric motor that is disposed in a suction chamber formed in a housing in communication with a suction port of the housing, and that is cooled by a refrigerant flow flowing from the suction port into the suction chamber, and is disposed in the housing. A gas compression mechanism that is operated by the driving force of the electric motor, a refrigerant guide path that guides the refrigerant flowing into the suction chamber to the compression mechanism to be compressed by the compression mechanism, and a refrigerant that is separated from the refrigerant in the suction chamber. A lubricating oil guide passage having one end opened to the bottom of the suction chamber and the other end opened to the refrigerant guide passage so as to supply the lubricating oil accumulated at the bottom of the suction chamber to the compression mechanism through the refrigerant guide passage. The lubricating oil at the bottom of the suction chamber can be taken to the compression mechanism through the lubricating oil guide passage by the refrigerant flow flowing through the refrigerant guide path toward the compression mechanism. To.

  In the gas compressor according to the present invention, a liquid such as lubricating oil that accumulates at the bottom of the suction chamber is guided to the refrigerant guide passage through a lubricating oil guide passage that opens at one end to the bottom of the suction chamber. On the other hand, the refrigerant gas containing the gas in the suction chamber flows to the gas compression mechanism through the refrigerant guide path opened at the other end of the lubricant guide path without passing through the lubricant guide path. The refrigerant gas flow flowing through the refrigerant guide path to the gas compression mechanism entrains a liquid such as lubricating oil guided through the lubricant guide path from the other end of the lubricant guide path to the compression mechanism.

  As a result, even if lubricating oil or liquefied refrigerant accumulates at the bottom of the suction chamber, only these liquids are not supplied to the gas compressing mechanism, and the cooling gas contains appropriate lubricating oil in the gas compressing mechanism. Supplied. Accordingly, it is possible to solve various problems caused by lack of lubricating oil in the gas compression mechanism and liquid compression.

  When the compression mechanism has a pair of suction ports that are opposed to each other in the radial direction, the refrigerant guide path includes an arc-shaped first connection path portion that extends in the circumferential direction of the compression mechanism so as to communicate the suction ports. The connecting passage portion can be constituted by a linear second connecting passage portion that connects to the suction chamber, and the lubricant guide passage that opens to the suction chamber serves as the refrigerant in the first connecting passage portion. It can be connected to a guide passage. Further, the second connecting path portion can be connected to the first connecting path portion at a position higher than a portion of the first connecting path portion to which the lubricant guide passage is connected.

  The present invention can be applied to a so-called horizontal electric gas compressor in which the electric motor and the gas compression mechanism are arranged with their axes aligned.

  According to the present invention, liquid compression of the gas compression mechanism at the time of restart can be prevented, and insufficient supply of lubricating oil to the compression mechanism can be reliably prevented. Large load, damage to the operating part due to this excessive load or excessive load on the electric motor can be prevented, durability deterioration due to these can be prevented, and abnormal noise and vibration due to liquid compression can be prevented.

  The present invention will be described in detail below with reference to illustrated embodiments.

  The gas compressor according to the present invention is applied to, for example, an air conditioner mounted on an automobile and is used for a cooling cycle together with conventionally well-known condensers, expansion valves, evaporators, and the like that are components of the air conditioner. The refrigerant circulation path is configured.

  In the example shown in FIG. 1, the gas compressor 10 according to the present invention includes a cylindrical front housing member 12 a having an open end formed with a suction port 11 connected to the evaporator (not shown), and both ends open. A cylindrical intermediate housing member 12b and a cylindrical rear housing member 12c having an open end formed with a discharge port 13 connected to the condenser (not shown) are assembled in a cylindrical shape as a whole. The three-part housing 12 is provided.

  A partition wall 14 is formed in the intermediate housing member 12b to partition the housing 12 in the axial direction. The partition wall 14 defines a suction chamber 15 communicating with the suction port 11 on the front housing member 12 a side of the partition wall 14 in the housing 12, and an electric motor 16 is disposed in the suction chamber 15. Further, a gas compression mechanism 17 is arranged on the rear housing member 12 c side of the partition wall 14 in the housing 12, and a high pressure chamber 18 communicating with the discharge port 13 is defined.

  In the illustrated example, the electric motor 16 is a well-known multiphase brushless DC motor. The electric motor 16 includes a rotary shaft 20 that is rotatably supported by a bearing 19 formed on the front housing member 12a so as to coincide with the axis of the housing 12, a rotor 16a that is fixed to the rotary shaft, and surrounding the rotor. And a stator 16b fixed to the front housing member 12a. As is well known in the art, the electric motor 16 includes a permanent magnet (not shown) embedded in the rotor 16a and a field generated by a multiphase pulse current supplied to the stator winding 16c of the stator 16b. Due to the magnetic interaction, the rotating shaft 20 rotates in one direction. An electrical connector 21 is provided on the front housing member 12a for supplying power to the stator winding.

  The rotary shaft 20 extends through the partition wall member 14 along the axis of the housing 12 and extends to the gas compression mechanism 17.

  The gas compression mechanism 17 is, for example, a conventionally well-known vane rotary type gas compressor. The vane rotary type gas compression mechanism 17 includes a cylinder member 22 that is open at both ends that defines an elliptical shape, and both side blocks 23a and 23b that are configured by a front side block 23a and a rear side block 23b that close both ends of the cylinder member. A cylinder chamber 17a having an elliptical cross-sectional shape as shown in FIG.

  In the cylinder chamber 17a, as shown in FIG. 2, a rotor 17b fixed to the rotary shaft 20 is disposed so as to be rotatable integrally with the rotary shaft 20. The rotor 17b is formed with a vane groove 17c for accommodating the vane 17d so as to be able to advance and retreat. The vane 17d in each vane groove 17c is, as is well known, from the oil storage recess 24 to the back pressure chamber 17e. Is pressed toward the peripheral wall of the cylinder chamber 17a.

  When the rotor 17b rotates integrally with the rotation of the rotating shaft 20, the vane 17d of the rotor slides on the peripheral wall of the cylinder chamber 17a. As the vane 17d slides, the volumes of the plurality of pressurizing chambers 17g partitioned by the vanes 17d increase or decrease, as is well known. As the volume of the pressurizing chamber 17g increases or decreases, the gas compression mechanism 17 sucks the refrigerant gas from the suction chamber 15 through a suction port 25 (see FIG. 3) described later, and is compressed in the pressurization chamber 17g. Is discharged into a high-pressure chamber 18 (see FIG. 1) partitioned in the rear housing member 12c through a discharge port 27 provided with a check valve 26.

  Referring to FIG. 1 again, in the high pressure chamber 18 communicating with the discharge port 13, a discharge port 28 for discharging the refrigerant gas guided from the discharge port 27 to the high pressure chamber 18 is opened and discharged from the discharge port 28. An oil separator 29 for separating the oil in the refrigerant gas is disposed.

  In the illustrated example, the gas compression mechanism 17 that compresses the refrigerant gas is supported by the partition wall 14 by a front side block 23a. In relation to the front side block 23a and the front side block, as shown in FIGS. 1, 3 and 4, a refrigerant guide path 30 for guiding the refrigerant gas in the suction chamber 15 to the cylinder chamber 17a, A lubricating oil guide passage 31 is formed.

  In the front side block 23a, as shown in FIG. 3, the suction port 25 that passes through the front side block 23a in the thickness direction and opens to the side of the cylinder chamber 17a is opposed to the radial direction of the cylinder chamber 17a. Is formed. Further, on the surface of the front side block 23 a that faces the partition wall 14, an arc-shaped concave groove 30 a that extends along the circumferential direction outside the rotating shaft 20 and reaches both suction ports 25 at both ends is formed. . The concave groove 30a forms a first connection path portion 30a for the refrigerant guide path 30 between the groove 30a and the partition wall by closing the open surface of the groove with the partition wall 14. As shown in FIG. 4, the first connection path portion 30 a opens to the side wall in the suction chamber 15 through a second connection path portion 30 b formed of a through hole formed in the partition wall 14 in the plate thickness direction. The height position at which the second connection path portion 30 b opens into the suction chamber 15 is set to be higher than the oil level of the lubricating oil accumulated in the suction chamber 15.

  As shown in FIGS. 3 and 4, the lubricating oil guide passage 31 communicates with the first connection path portion 30a at the lower center portion of the first connection path portion 30a of the refrigerant guide path 30, and is directed downward in the figure. A first passage portion 31a formed in the front side block 23a to be extended and a second passage portion 31b opened from the communication passage portion to the bottom of the suction chamber 15 through the partition wall 14 of the intermediate housing member 12b. Prepare.

  The refrigerant guide path 30 composed of the first connection path portion 30a and the second connection path portion 30b does not open to the bottom of the suction chamber 15, and as described above, the lubricant oil that accumulates in the suction chamber 15 Since it is set to be higher than the surface, as long as the rotary shaft 20 is operated in the lateral orientation as shown in FIG. 1, the lubricating oil accumulates in the suction chamber 15. However, the lubricating oil is not sucked into the refrigerant guide path 30 from the second connection path portion 30 b of the refrigerant guide path 30.

  Instead of connecting the lubricating oil guide passage 31 to the first connection path portion at the center lower portion of the first connection path portion 30a, the middle portion between the both ends of the first connection path portion 30a is replaced with the first guide path portion 30a. It is possible to communicate with one connecting portion.

  In the gas compressor 10 according to the present invention, when the gas compression mechanism 17 is activated by the activation of the electric motor 16, the refrigerant gas containing lubricating oil is sucked into the suction chamber 15 from the suction port 11, and this refrigerant gas is electrically driven. The motor 16 is guided to the gas compression mechanism 17 through the refrigerant guide path 30 while being cooled. A part of the lubricating oil in the refrigerant gas flowing in the suction chamber 15 is accumulated at the bottom of the suction chamber 15 due to condensation. As described above, the lubricating oil accumulated at the bottom of the suction chamber 15 is second in the refrigerant guide path 30. It does not go to the connecting path portion 30b. However, when the pressure at the portion where the lubricating oil guide passage 31 in the refrigerant guide passage 30 opens due to an increase in the flow of the refrigerant gas flowing through the refrigerant guide passage 30, the lubricating oil at the bottom of the suction chamber 15 is lubricated by the so-called Venturi effect. The oil is sucked through the oil guide passage 31 toward the first connecting passage portion 30a.

  As a result, the lubricating oil in the suction chamber 15 is sequentially sucked into the first connecting passage portion 30a through the lubricating oil guide passage 31, and is mixed with the refrigerant gas passing through the first connecting passage portion 30a. The refrigerant gas properly entrains each cylinder port 17a to the cylinder chamber 17a.

  Since the lubricating oil sucked into the cylinder chamber 17a together with the refrigerant gas is appropriately mixed with the refrigerant gas, the compression of the refrigerant gas in the pressurizing chamber 17g causes liquid compression without causing liquid compression. Lubricate the sliding part properly.

  As described above, the lubricating oil in the refrigerant gas discharged from the gas compression mechanism 17 is separated by the oil separator 29 and held in the high-pressure chamber 18. A part of the lubricating oil in the high-pressure chamber 18 is supplied to the oil storage recess 24 and used as the back pressure of the vane 17d as is well known.

  In the gas compressor 10 according to the present invention, as described above, the lubricating oil accumulated at the bottom of the suction chamber 15 is supplied from the lubricating oil guide passage 31 by using the venturi effect caused by the refrigerant flow flowing through the refrigerant guide passage 30. Since it is supplied to the gas compression mechanism 17 through the first connection path portion 30a of the guide path 30, only the lubricating oil in the suction chamber 15 is not sucked into the gas compression mechanism 17, thereby Liquid compression can be prevented.

  In order for the lubricating oil in the suction chamber 15 to be entrained, it is necessary to suck up the lubricating oil in the suction chamber 15 via the lubricating oil guide passage 31. The refrigerant used is R134a, the volume of the gas compressor 10 is 25 cc / rev, the volume efficiency is 80%, the cross-sectional area of the refrigerant guide path 30 is 25 square mm, and as shown in FIG. Lubricating in the refrigerant guide path 30 is a case where a flow is caused to flow toward the two inlets 25 and the temperature at the time of stoppage is a uniform temperature of 30 degrees and the starting rotational speed of the gas compressor 10 is 1000 rpm. The refrigerant flow velocity at the portion where the oil guide passage 31 is opened is 6.7 m / s, the gas compression mechanism 17 is saturated, and the refrigerant density is 37.5 kg / cubic meter. ) Is 834 Pa. Since the density of the lubricating oil is about 1 kg / cubic meter, the lubricating oil can be sucked up to a height of about 85 mm through the lubricating oil guide passage 31.

  As described above, the lubricating oil can be sucked up through the lubricating oil guide passage 31 due to the height difference between the lubricating oil guide passage 31 and the minimum dynamic pressure generation condition (low temperature and low speed), and the sucked lubricating oil can be taken to the cylinder chamber 17a. The cross-sectional area of the refrigerant guide path 30 is determined so that the flow velocity is generated.

  According to the gas compressor 10 according to the present invention, as described above, only the lubricating oil in the suction chamber 15 is not sucked into the gas compression mechanism 17 and liquid compression can be prevented. An increase in load on the gas compressor 10 can be prevented, damage to the operating unit due to an increase in load and an excessive load on the electric motor can be prevented, and the reliability of the operation of the gas compressor 10 can be improved. In addition, it is possible to prevent the generation of abnormal noise and vibration at the time of startup due to liquid compression.

  As described above, an example of the vane rotary type gas compression mechanism has been shown as the gas compression mechanism 17, but a scroll type and other compression mechanisms can be adopted as the gas compression mechanism. As the electric motor 16, various electric motors can be adopted in addition to the above-described multiphase brushless DC motor.

It is a longitudinal cross-sectional view of the gas compressor which concerns on this invention. It is sectional drawing obtained along line II-II shown in FIG. FIG. 3 is a cross-sectional view taken along line III-III shown in FIG. FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG.

Explanation of symbols

10 Gas compressor 11 Suction port 12 (12a, 12b, 12c) Housing (front housing member, intermediate housing member, rear housing member)
14 Partition 15 Suction chamber 16 Electric motor 17 Gas compression mechanism 20 Rotating shaft 25 Suction port 30 (30a, 30b) Refrigerant guide path (first connection path part, second connection path part)
31 (31a, 31b) Lubricating oil guide passage (first passage portion, second passage portion)

Claims (3)

  An electric motor disposed in a suction chamber formed in the housing in communication with the suction port of the housing and receiving cooling by a refrigerant flow flowing from the suction port into the suction chamber; and the electric motor disposed in the housing A gas compression mechanism that is actuated by the driving force, a refrigerant guide path that guides the refrigerant flowing into the suction chamber to the compression mechanism to be compressed by the compression mechanism, and the suction chamber separated from the refrigerant in the suction chamber A lubricating oil guide passage having one end opened to the bottom of the suction chamber and the other end opened to the refrigerant guide passage so as to supply the lubricating oil accumulated in the bottom of the room to the compression mechanism through the refrigerant guide passage, The electric motor characterized in that the lubricating oil flowing through the refrigerant guide path toward the compression mechanism allows the lubricating oil at the bottom of the suction chamber to be taken to the compression mechanism through the lubricating oil guide path. Body compressor.   The compression mechanism has a pair of suction ports that are opposed to each other in the radial direction, and the refrigerant guide path includes an arc-shaped first connection path portion that extends in a circumferential direction of the compression mechanism so as to communicate the suction ports. A linear second connecting passage portion connecting the connecting passage portion to the suction chamber, the lubricating oil guide passage being connected to the refrigerant guide passage at the first connecting passage portion, 2. The electric gas compressor according to claim 1, wherein the second connecting path portion is connected to the first connecting path portion at a position higher than a portion of the first connecting path portion to which the lubricant guide passage is connected.   3. The electric gas compressor according to claim 1, wherein the electric motor and the gas compression mechanism are a horizontal electric gas compressor in which axes are aligned with each other.

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