JP2012154338A - Gas compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the excessive lowering of an oil circulation rate at high-speed rotation, in a gas compressor.SOLUTION: A cyclone block 70 (oil separator) has a substantially-cylindrical space 75 (oil component separation space) into which a compression refrigerant gas G(compressed gas) is introduced and which separates refrigerator oil R (oil component), a pressure bypass passage 77 which communicates to a second passage 71a and communicatively continues to a discharge chamber 21 low in pressure than the substantially-cylindrical space 75 is formed at a body member 71, a leaf spring 79 (pressure valve) which opens and closes the pressure bypass passage 77 according to the internal pressure of the second passage 71a in which the pressure bypass passage 77 is formed is arranged at the pressure bypass passage 77, and at a high-speed operation, the refrigerant gas G which is insufficient in the separation of the refrigerator oil R is discharged from the pressure bypass passage 77.

Description

  The present invention relates to a gas compressor, and more particularly to an improvement in an oil separator that centrifuges oil from compressed gas discharged from a compressor body.

  Conventionally, a gas compressor (compressor) for compressing a gas such as a refrigerant gas and circulating the gas in the air conditioning system is used in an air conditioning system (hereinafter referred to as an air conditioning system).

  Here, a general compressor includes a compressor main body that compresses and discharges gas, and an oil separator that separates oil such as refrigeration oil from the compressed refrigerant gas discharged from the compressor main body. It has become.

  As an oil separator, for example, a main body member having a substantially cylindrical space whose lower end surface is closed by an end wall in which a drainage passage is formed, and a main body that is substantially coaxial with the substantially cylindrical space of the main body member A substantially cylindrical space (oil separation space) defined by the inner peripheral surface of the main body member and the outer peripheral surface of the inner cylindrical member, having a substantially cylindrical inner cylindrical member disposed inside the member Is known in which refrigeration oil is centrifuged by passing compressed refrigerant gas while swirling (Patent Document 1).

  Here, the inner cylinder member and the main body member are separate parts, and the inner cylinder member is fixed to the main body member by press-fitting or caulking into the main body member, and is configured integrally as an entire oil separator.

JP 2007-327340 A

  By the way, although the number of rotations of the compressor body changes according to the desired output of the air conditioning system, the flow rate in the oil separation space of the oil separator becomes very fast at high speed rotation, and the oil separation performance by centrifugal separation Is better than during normal operation.

  On the other hand, the improvement in oil separation performance will reduce the amount of refrigeration oil discharged from the gas compressor to the air conditioning system together with the refrigerant gas (decrease in OCR (Oil Content Rate)), but air conditioning When the outflow amount of the refrigeration oil to the system (condenser) decreases, the refrigeration oil returned to the gas compressor together with the refrigerant gas from the air conditioning system (evaporator) also decreases. Then, the amount of refrigerating machine oil mixed in the refrigerant gas sucked into the compression chamber is reduced, the refrigerating machine oil introduced into the compression chamber together with the refrigerant gas is reduced, and the reduction of the refrigerating machine oil acting as a cooling medium is reduced. The temperature of the refrigerant gas discharged from the compression chamber increases, resulting in a decrease in volumetric efficiency.

  Therefore, it is required to prevent an excessive decrease in OCR during high-speed rotation.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the gas compressor which can prevent the excessive fall of an oil circulation rate at the time of high speed rotation.

  In the gas compressor according to the present invention, a pressure valve is provided in a compressed gas passage for allowing compressed gas to pass from the compressor body to the oil separator, and the compressed gas passage or the oil separation space is provided by high-speed rotation of the gas compressor. When the internal pressure rises, the pressure valve is opened, and compressed gas with insufficient oil separation is discharged from the gas compressor to the system via the pressure bypass passage, resulting in excessive reduction in oil circulation rate (OCR). Is to prevent.

  That is, the gas compressor according to the present invention includes a compressor body that compresses a supplied gas into a high-pressure compressed gas, and a single oil separator that separates oil from the compressed gas discharged from the compressor body. A compressed gas passage through which the compressed gas passes from the compressor main body to the oil separator, and the oil separator includes a main body portion that forms a substantially cylindrical space with one end closed, and a substantially circular shape. A substantially cylindrical inner cylinder portion provided along the axial direction of the columnar space, and compressing the substantially cylindrical space defined by the inner surface of the main body portion and the outer surface of the inner cylinder portion. There is an oil separation space in which gas is introduced to separate the oil component, and a pressure bypass passage communicating from the compressed gas passage to a space whose pressure is relatively lower than the internal pressure of the oil separation space is provided in the main body portion. The pressure bypass passage is formed with the pressure Said bypass passage is formed in accordance with the internal pressure of the compressed gas passage, characterized in that the pressure valve for opening and closing the pressure bypass passage.

  According to the gas compressor according to the present invention configured as above, when the pressure of the compressed gas discharged from the compressor body to the oil separator is increased by the high speed rotation of the compressor body, the compressed gas passes. The internal pressure of the compressed gas passage from the compressor body to the oil separator increases.

  When the internal pressure of the compressed gas passage increases, a pressure valve that opens and closes according to the internal pressure of the compressed gas passage opens a pressure bypass passage that communicates the compressed gas passage with a space having a relatively lower pressure than these spaces. As a result, the compressed gas passage communicates with a relatively low-pressure space without passing through the oil separation space, and the compressed gas in the compressed gas passage does not undergo oil separation in the oil separation space, and is bypassed by pressure. Escape to a relatively low pressure space through the passage.

  Therefore, the compressed gas that has escaped to the relatively low pressure space contains more oil than the original compressed gas after sufficient oil separation in the oil separation space, and contains more oil than before. The compressed gas is discharged from the space having a relatively low pressure to the outside (air conditioning system) of the gas compression chamber, whereby the OCR increases and an excessive decrease in the OCR during high-speed operation can be prevented.

  The relatively low pressure space is a space (discharge chamber) from which the compressed refrigerant gas is discharged after the refrigeration oil is centrifuged in the oil separation space, and the space from the oil separation space that leads to the discharge chamber. Since the space is wider than the passage, the pressure difference when the compressed gas is discharged from the inside of the oil separator (inside the oil separation space) to the outside of the oil separator (discharge chamber) becomes very large. Therefore, it is easy to set a pressure threshold value for opening and closing the pressure valve.

  Since the pressure valve opens the pressure bypass passage and the pressure in the oil separation space is lowered, the required strength of the member that defines the oil separation space can be set lower than that in the past.

  The gas compressor according to the present invention can prevent an excessive decrease in the oil circulation rate during high-speed rotation.

It is a longitudinal section showing a vane rotary type compressor which is one embodiment of a gas compressor concerning the present invention. (A) is an enlarged view showing details of the cyclone block in FIG. 1, (b) is a cross-sectional view taken along line AA in (a) and shows a state in which the pressure bypass passage is closed, (c) is It is sectional drawing along the AA in (a), and is a figure which shows the state which the pressure bypass channel opened.

  Hereinafter, an embodiment according to the gas compressor of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing a vane rotary compressor 100 as an embodiment of a gas compressor according to the present invention, and FIG. 2 is an enlarged view and a sectional view showing details of a cyclone block 70 in FIG.

  The illustrated compressor 100 is configured, for example, as a part of an air conditioning system (hereinafter simply referred to as an air conditioning system) that performs cooling using the heat of vaporization of a cooling medium, and condensing that is another component of the air conditioning system. Along with a condenser, an expansion valve, an evaporator, and the like (all not shown), they are provided on a cooling medium circulation path.

  The compressor 100 compresses the refrigerant gas G (gas, compressed gas) as a gaseous cooling medium taken from the evaporator of the air conditioning system, and supplies the compressed refrigerant gas G to the condenser of the air conditioning system. . The condenser heat-exchanges the compressed refrigerant gas G with ambient air and the like to dissipate heat from the refrigerant gas G and liquefy it, and sends it to the expansion valve as a high-pressure liquid refrigerant.

  The high-pressure liquid refrigerant is reduced in pressure by the expansion valve and sent to the evaporator. The low-pressure liquid refrigerant absorbs heat from ambient air and vaporizes in the evaporator, and cools the air around the evaporator by heat exchange with the heat of vaporization.

  The vaporized low-pressure refrigerant gas G returns to the compressor 100 and is compressed, and the above steps are repeated thereafter.

  The compressor 100 houses a compressor main body 60 and a single cyclone block 70 that is a centrifugal oil separator in the housing 10.

  The housing 10 includes a case 11 having a cylindrical pair with one end closed and the other end opened, and a front head 12 covering the other open end of the case 11. The front head 12 is attached to the case 11. In the assembled state, a space for accommodating the compressor main body 60 and the cyclone block 70 (oil separator) is defined in the housing 10.

  The front head 12 is formed with a suction port 12a for taking in the low-pressure refrigerant gas G supplied from the evaporator, and the case 11 condenses the high-pressure refrigerant gas G compressed by the compressor body 60. A discharge port 11a for discharging to the container is formed.

  The compressor main body 60 includes a rotary shaft 51 that is driven to rotate about an axis, a columnar rotor 50 that rotates integrally with the rotary shaft 51, and a cross-sectional contour that is substantially elliptical so as to surround the outer periphery of the rotor 50. The cylinder 40 having the inner peripheral surface 49 and both ends open, and the outer periphery of the rotor 50 are embedded so as to protrude outward, and the tip of the protruding side is the contour shape of the inner peripheral surface 49 of the cylinder 40 The amount of protrusion is variable so as to follow, and the five plate-like vanes 58 embedded in the rotor 50 at equiangular intervals around the rotation shaft 51, and the open end surfaces from the outside of the open end surfaces on both sides of the cylinder 40, respectively. The front side block 30 and the rear side block 20 are fixed so as to cover them.

  The volume of each compression chamber 48 defined by the two side blocks 20, 30, the rotor 50, the cylinder 40, and the two vanes 58, 58 that precede and follow the rotation direction of the rotation shaft 51 is By repeating the increase / decrease according to the rotation, the refrigerant gas G sucked into each compression chamber 48 through the front side block 30 is compressed and discharged through the rear side block 20.

  One of the portions of the rotary shaft 51 protruding from both end surfaces of the rotor 50 is pivotally supported by the bearing portion 32 of the front side block 30 and extends outward through the front head 12. The driving force transmitting unit 80 is connected to external power (not shown).

  The other side of the protruding portion of the rotating shaft 51 is pivotally supported by the bearing portion 22 of the rear side block 20.

  The discharge chamber 21 defined by the case 11, the compressor main body 60, and the cyclone block 70 is a space from which the refrigerant gas G is discharged from the compressor main body 60 through the cyclone block 70. The discharge port 11a described above is The discharge chamber 21 is communicated.

  Refrigerating machine oil R separated from the refrigerant gas G by the cyclone block 70 is stored at the bottom of the discharge chamber 21, and the refrigerating machine oil R is used for back pressure for causing the vane 58 to protrude and lubricating oil for the compression chamber 48. For example, the oil is supplied into the compressor body 60 through an oil guide passage formed in the rear side block 20 or the like.

  The cyclone block 70 is assembled to the rear side block 20 of the compressor main body 60 and separates the refrigerating machine oil R (oil content) from the high-pressure refrigerant gas G discharged from the compression chamber 48 through the rear side block 20. As shown in detail in FIG. 2, a main body member 71 (main body portion) in which a substantially cylindrical space 71d having a closed lower end is formed, and a substantially cylindrical cylinder having a smaller diameter than the substantially cylindrical space 71d of the main body member 71. And an inner cylinder member 72 (inner cylinder part) having a cylindrical inner cylinder part 72 a, and an inner cylinder member inside the substantially columnar space 71 d along the axial direction of the substantially columnar space 71 d of the main body member 71. In a state where the inner cylinder portion 72 a of 72 is disposed, the substantially cylindrical as an oil separation space for separating the refrigerating machine oil R from the refrigerant gas G by the inner surface of the main body member 71 and the outer surface of the inner cylinder portion 72 a of the inner cylinder member 72. Space 75 It has been made.

  Here, a discharge hole 71 c for discharging the refrigerating machine oil R separated from the refrigerant gas G to the bottom of the discharge chamber 21 by the cyclone block 70 is formed at the lower end of the main body member 71.

  The high-pressure refrigerant gas G discharged from the compression chamber 48 is, as shown in FIG. 2, the first passage 25 formed in the rear side block 20, and the second passage 71a and the third passage 71b formed in the cyclone block 70. And is discharged into a substantially cylindrical space 75 defined by the inner surface of the main body member 71 of the cyclone block 70 and the outer surface of the inner cylinder portion 72a of the inner cylinder member 72. The

  The high-pressure refrigerant gas G discharged into the substantially cylindrical space 75 descends while spirally swirling in the substantially cylindrical space 75 by the airflow at the time of being discharged, and the centrifugal force acting while turning The refrigerating machine oil R mixed in the high-pressure refrigerant gas G is separated by force, and the separated refrigerating machine oil R flows down to the bottom of the substantially cylindrical space 71d of the main body member 71 and is discharged from the discharge hole 71c to the discharge chamber. It is dripped at 21.

  On the other hand, the refrigerant gas G after the refrigerating machine oil R is separated rebounds and rises at the bottom of the substantially cylindrical space 71d of the main body member 71, and passes through the inner space 72c of the inner cylinder portion 72a of the inner cylinder member 72. Then, the liquid is discharged into the discharge chamber 21 from the opening at the upper end.

  Thus, the substantially cylindrical space 75 defined by the inner surface of the main body member 71 and the outer surface of the inner cylinder portion 72a of the inner cylinder member 72 is a space (oil separation space) that separates the refrigerating machine oil R from the refrigerant gas G. It has become.

  As shown in FIG. 2, the main body member 71 communicates with the second passage 71 a of the main body member 71 and the discharge chamber 21, which is a space whose pressure is relatively lower than the internal pressure of the substantially cylindrical space 75. A passage 77 is formed, and a leaf spring valve 79 (pressure valve) that opens and closes the pressure bypass passage 77 according to the internal pressure of the compressed gas passage is fixed to the main body member 71 by a fastening member 78. ing.

  When the internal pressure of the compressed gas passage is lower than a predetermined pressure, the leaf spring valve 79 is not deformed as shown in FIG. The refrigerant gas G discharged from the compression chamber 48 is guided to the substantially cylindrical space 75 in the cyclone block 70.

  On the other hand, when the internal pressure of the compressed gas passage is higher than a predetermined pressure, the leaf spring valve 79 receives the pressure of the pressure bypass passage 77 and elastically deforms toward the discharge chamber 21 as shown in FIG. Thus, the pressure bypass passage 77 is opened, and the refrigerant gas G discharged from the compression chamber 48 passes to the discharge chamber 21 via the pressure bypass passage 77 without passing through the substantially cylindrical space 75 in the cyclone block 70. Direct discharge.

  At this time, since the high-pressure refrigerant gas G discharged into the discharge chamber 21 does not descend while spirally turning in the substantially cylindrical space 75, the refrigerating machine oil R is not sufficiently centrifuged. More refrigerant oil R is mixed than refrigerant gas G in a normal operation state (operation state other than high-speed operation).

  Therefore, the amount of the refrigerating machine oil R taken out to the air conditioning system (condenser) outside the compressor 100 through the discharge port 11a is larger than that in the normal operation state, and avoids low OCR (oil circulation rate) at high speed operation. can do.

  In other words, the compressor generally has a higher refrigerant gas flow rate in the substantially cylindrical space of the cyclone block than in normal operation during high-speed rotation, and the oil separation performance by centrifugal separation in the substantially cylindrical space is higher than in normal operation. improves.

  On the other hand, by improving the oil separation performance, the amount of refrigerating machine oil discharged from the compressor to the air conditioning system (condenser) together with the refrigerant gas is reduced (low OCR), but refrigeration to the air conditioning system (condenser) is reduced. When the outflow amount of machine oil decreases, the amount of refrigerating machine oil returned to the compressor together with the refrigerant gas from the air conditioning system (evaporator) also decreases.

  Then, the amount of the refrigerating machine oil mixed in the refrigerant gas sucked into the compression chamber is reduced, the refrigerating machine oil introduced into the compression chamber together with the refrigerant gas is reduced, and the reduction of the refrigerating machine oil as the cooling medium reduces the compression chamber oil. As a result, the temperature of the refrigerant gas discharged from the chamber increases, resulting in a decrease in volumetric efficiency.

  However, in the compressor 100 of the present embodiment, the leaf spring valve 79 opens the pressure bypass passage 77 based on the internal pressure of the substantially cylindrical space 75 that is increased by high-speed operation during high-speed rotation. The passage 71a communicates with the discharge chamber 21 having a relatively low pressure through the pressure bypass passage 77, and the high-pressure refrigerant gas G passing through the first passage 25 and the second passage 71a does not pass through the substantially cylindrical space 75. It escapes to the discharge chamber 21 through the pressure bypass passage 77.

  Therefore, the refrigerant gas G that has escaped to the discharge chamber 21 via the pressure bypass passage 77 is supplied with the refrigerating machine oil R more than the original compressed refrigerant gas G after the refrigerating machine oil R is sufficiently separated in the substantially cylindrical space 75. The compressed refrigerant gas G containing more refrigeration oil R than before is discharged through the discharge chamber 21 to the outside of the compressor 100 (air conditioning system), thereby increasing the OCR and during high-speed operation. An excessive decrease in OCR can be prevented.

  Further, even if the cyclone block 70 of the compressor 100 according to the present embodiment has a liquid compression in the compression chamber 48, before the internal pressure of the substantially cylindrical space 75 becomes an unexpectedly high pressure, that is, When a predetermined pressure lower than the abnormal high pressure is reached, the pressure bypass passage 77 is opened, and the state where the internal pressure of the substantially cylindrical space 75 exceeds the predetermined pressure is prevented from continuing for a long period of time. And can prevent the cyclone block 70 from being unexpectedly damaged.

  Therefore, it is also possible to set the required strength of the members (the main body member 71 and the inner cylinder member 72) that define the substantially cylindrical space 75 of the cyclone block 70 to be lower than the conventional one.

  When the high-speed operation is shifted to the middle / low-speed operation or the liquid compression state is canceled, the internal pressure of the substantially cylindrical space 75 is lowered to a predetermined pressure lower than the predetermined pressure, thereby deforming the deformed leaf spring. The valve 79 comes into contact with the outer surface of the main body member 71 by a restoring force (elastic force), and the pressure bypass passage 77 is closed.

  As a result, the cyclone block 70 returns to the original state shown in FIG. 2B (the state at the time of normal operation or stop), and the refrigerant gas G passing through the first passage 25 and the second passage 71a is changed. Guided to the substantially cylindrical space 75, spirally swivels and descends in the substantially cylindrical space 75, the refrigeration oil R is separated by centrifugation, and the refrigeration oil R drops into the discharge chamber 21 from the discharge hole 71c, The refrigerant gas G is discharged into the discharge chamber 21 through the inner space 72 c of the inner cylinder portion 72.

  In addition, the oil separator of this embodiment in which both the main body member 71 and the inner cylinder member 72 are not constituent elements of the pressure valve at the same time (the oil separator in which only the main body member 71 is a constituent element of the pressure valve; In the case of the compressor 100 of the above-described embodiment, the main body member 71 and the inner cylinder member 72 do not need to be separate components.

  That is, the oil separator has a main body portion (a portion corresponding to the main body member 71 in the illustrated embodiment) that forms a substantially cylindrical space with one end closed, and an axial direction of the substantially cylindrical space. And a substantially cylindrical inner cylinder portion (a portion corresponding to the inner cylinder portion 72a of the inner cylinder member 72 in the illustrated embodiment), which are integrally formed, and an inner surface of the main body portion The substantially cylindrical space defined by the outer surface of the inner cylinder portion may be an oil separation space (a portion corresponding to the substantially cylindrical space 75 in the illustrated embodiment), and is discharged to the main body portion or the inner cylinder portion. A pressure bypass passage communicating with the chamber may be formed, and a pressure valve for opening and closing the pressure bypass passage may be provided in the main body portion or the inner cylinder portion where the pressure bypass passage is formed.

20 Rear side block (part of compressor body)
60 Compressor body 70 Cyclone block (oil separator)
71 body member 72 inner cylinder member 75 substantially cylindrical space (oil separation space)
77 Pressure bypass passage 79 Leaf spring valve (pressure valve)
100 compressor (gas compressor)
G Refrigerant gas (gas, compressed gas)
R Refrigerating machine oil (oil content)

Claims (2)

A compressor body that compresses the supplied gas into a high-pressure compressed gas; a single oil separator that separates oil from the compressed gas discharged from the compressor body; and the compressed gas from the compressor body. A compressed gas passage that passes to the oil separator,
The oil separator has a main body part that forms a substantially cylindrical space with one end closed, and a substantially cylindrical inner cylinder part that is provided along the axial direction of the substantially cylindrical space, A substantially cylindrical space defined by the inner surface of the main body and the outer surface of the inner cylinder as an oil separation space into which the compressed gas is introduced and the oil is separated;
A pressure bypass passage communicating from the compressed gas passage to a space whose pressure is relatively lower than the internal pressure of the oil separation space is formed in the main body portion,
The gas compressor according to claim 1, wherein the pressure bypass passage is provided with a pressure valve that opens and closes the pressure bypass passage according to an internal pressure of the compressed gas passage in which the pressure bypass passage is formed.   The pressure valve opens the pressure bypass passage when the internal pressure is equal to or higher than a predetermined pressure, and closes the pressure bypass passage when the internal pressure is less than a predetermined pressure. The gas compressor according to claim 1, wherein the gas compressor is set.