JP2018123805A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately control flow rate of lubricant passing an orifice even when cooling operation and heating operation are switched.SOLUTION: A compressor includes: a compression mechanism compressing working fluid; an oil separator separating lubricant from the working fluid compressed by the compression mechanism; an orifice OL which is disposed in a flow path L4 of the lubricant separated by the oil separator; and a flow rate variable mechanism 260 which performs phase change in accordance with the temperature of the lubricant and varies flow rate of the lubricant passing the orifice OL. The flow rate variable mechanism 260 is composed of a phase change material positioned on an upstream side of the orifice OL and, by changing a distance to an upstream side opening of the orifice OL in accordance with temperature, changes a flow path area of the lubricant on the upstream side of the orifice OL. Then, by changing the flow path area of the lubricant, flow rate of lubricant passing the orifice OL is suitably varied, and the flow rate is appropriately controlled.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a compressor that compresses a working fluid such as a refrigerant.

  In the compressor, when the mist of lubricating oil is mixed into the gaseous refrigerant (gas refrigerant) compressed by the compression mechanism, it may be introduced into a condenser or the like of the refrigerant circuit and the efficiency may be reduced. For this reason, as described in JP-A-2005-240646 (Patent Document 1), the compressor is provided with an oil separator that separates the lubricating oil from the gaseous refrigerant compressed by the compression mechanism. The lubricating oil separated by the oil separator is used, for example, to press the orbiting scroll against the fixed scroll in a scroll compressor or to lubricate the sliding portion of the compression mechanism. In this case, in order to control the supply amount of the lubricating oil from the oil separator, an orifice (throttle) that restricts the flow rate of the lubricating oil is provided in the flow path of the lubricating oil.

Japanese Patent Laid-Open No. 2005-240646

  By the way, when using a compressor in air-conditioning equipment, the temperature of the lubricating oil becomes high and the viscosity becomes low because the temperature of the gas refrigerant sucked into the compressor is high during the cooling operation. Moreover, since the temperature of the gaseous refrigerant sucked into the compressor is low during the heating operation, the temperature of the lubricating oil is also lowered and the viscosity thereof is increased.

  For this reason, if the orifice diameter is set so as to suit the cooling operation, the flow rate of the lubricating oil passing through the orifice becomes too small during the heating operation, and for example, there is a risk that the lubrication of the sliding portion of the compression mechanism will be insufficient. is there. In addition, if the orifice diameter is set so as to suit the heating operation, the flow rate of the lubricating oil passing through the orifice becomes excessive during the cooling operation, which exceeds the lubricating oil separation capability of the oil separator, and gas flows into the lubricating oil flow path. There is a possibility that internal leakage or the like may occur due to the mixture of refrigerant.

  Then, an object of this invention is to provide the compressor which can control appropriately the flow volume of the lubricating oil which passes an orifice, even if it switches cooling operation and heating operation.

  For this reason, the compressor is disposed in a compression mechanism for compressing the working fluid, an oil separator for separating the lubricating oil from the working fluid compressed by the compression mechanism, and a flow path for the lubricating oil separated by the oil separator. An orifice and a flow rate variable mechanism that changes phase according to the temperature of the lubricating oil and makes the flow rate of the lubricating oil that passes through the orifice variable.

  According to the present invention, the flow rate of the lubricating oil passing through the orifice can be appropriately controlled even when the cooling operation and the heating operation are switched.

It is sectional drawing which shows an example of a scroll compressor. It is explanatory drawing of the separation method of the lubricating oil by an oil separator. It is a block diagram explaining the flow of a gaseous refrigerant. It is a longitudinal section explaining a 1st embodiment of a flow variable mechanism. It is a longitudinal cross-sectional view explaining 2nd Embodiment of a flow variable mechanism. It is a longitudinal section explaining a 3rd embodiment of a flow variable mechanism. It is a longitudinal section explaining a 4th embodiment of a flow variable mechanism. It is a longitudinal section explaining a 5th embodiment of a flow variable mechanism.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows an example of a scroll compressor. A scroll compressor is an example of a compressor.

  The scroll compressor 100 includes a scroll unit 120, a housing 140 having a gas refrigerant suction chamber H1 and a discharge chamber H2, an electric motor 160 that drives the scroll unit 120, and an inverter 180 that controls the electric motor 160. ing. The scroll unit 120 may be driven by, for example, engine output instead of the electric motor 160. Further, the inverter 180 may not be incorporated in the scroll compressor 100.

  The scroll unit 120 includes a fixed scroll 122 and a turning scroll 124 that are meshed with each other. The fixed scroll 122 includes a disc-shaped bottom plate 122A and an involute-shaped (spiral shape) wrap 122B standing from one surface of the bottom plate 122A. Similar to the fixed scroll 122, the orbiting scroll 124 includes a disc-shaped bottom plate 124A and an involute-shaped wrap 124B standing from one surface of the bottom plate 124A.

  The fixed scroll 122 and the orbiting scroll 124 are arranged so as to mesh the wraps 122B and 124B. Specifically, the front end portion of the wrap 122B of the fixed scroll 122 is in contact with one surface of the bottom plate 124A of the orbiting scroll 124, and the front end portion of the wrap 124B of the orbiting scroll 124 is in contact with one surface of the bottom plate 122A of the fixed scroll 122. Is arranged. A tip seal (not shown) is attached to the tip of the wraps 122B and 124B.

  Further, the fixed scroll 122 and the orbiting scroll 124 are arranged such that the side walls of the wraps 122B and 124B are in partial contact with each other in a state where the circumferential angles of the wraps 122B and 124B are shifted from each other. Therefore, a crescent-shaped sealed space that functions as the compression chamber H3 is formed between the wrap 122B of the fixed scroll 122 and the wrap 124B of the orbiting scroll 124.

  The orbiting scroll 124 is disposed so as to be able to revolve around the axis of the fixed scroll 122 via a crank mechanism 240 described later in a state in which the rotation is prevented. Therefore, the scroll unit 120 moves the compression chamber H3 defined by the wrap 122B of the fixed scroll 122 and the wrap 124B of the orbiting scroll 124 to the center, and gradually reduces the volume thereof. As a result, the scroll unit 120 compresses the gaseous refrigerant sucked into the compression chamber H3 from the outer ends of the wraps 122B and 124B.

  The housing 140 includes a front housing 142 that houses the electric motor 160 and the inverter 180, a center housing 144 that houses the scroll unit 120, a rear housing 146, and an inverter cover 148. The front housing 142, the center housing 144, the rear housing 146, and the inverter cover 148 are integrally fastened by, for example, a fastener (not shown) including a bolt and a washer, so that the housing of the scroll compressor 100 is obtained. 140 is configured.

  The front housing 142 includes a substantially cylindrical peripheral wall portion 142A and a partition wall portion 142B. The internal space of the front housing 142 is partitioned into a space for housing the electric motor 160 and a space for housing the inverter 180 by the partition wall 142B. The opening on one end side of the peripheral wall portion 142 </ b> A is closed by the inverter cover 148. Further, the opening on the other end side of the peripheral wall portion 142 </ b> A is closed by the center housing 144. The partition wall 142B has a substantially cylindrical support 142B1 that rotatably supports one end of a drive shaft 166, which will be described later, at the center in the radial direction, and protrudes toward the other end of the peripheral wall 142A. Has been.

  Further, a gas refrigerant suction chamber H <b> 1 is defined by the peripheral wall 142 </ b> A and the partition wall 142 </ b> B of the front housing 142 and the center housing 144. Low-pressure and low-temperature gaseous refrigerant is sucked into the suction chamber H1 through a suction port P1 formed in the peripheral wall 142A. In the suction chamber H1, gas refrigerant flows around the electric motor 160 so that the electric motor 160 can be cooled, and the space on one side of the electric motor 160 communicates with the space on the other side. A suction chamber H1 is formed. An appropriate amount of lubricating oil is stored in the suction chamber H1 in order to lubricate sliding portions such as the drive shaft 166 that is rotationally driven. For this reason, in the suction chamber H1, the gaseous refrigerant flows as a mixed fluid with the lubricating oil.

  The center housing 144 has a substantially bottomed cylindrical shape that is open on the side opposite to the fastening side with the front housing 142, and can accommodate the scroll unit 120 therein. The center housing 144 has a cylindrical portion 144A and a bottom wall portion 144B on one end side thereof. The scroll unit 120 is accommodated in a space defined by the cylindrical portion 144A and the bottom wall portion 144B. A fitting portion 144A1 into which the fixed scroll 122 is fitted is formed on the other end side of the cylindrical portion 144A. Therefore, the opening of the center housing 144 is closed by the fixed scroll 122. Further, the bottom wall portion 144 </ b> B is formed so that a central portion in the radial direction bulges toward the electric motor 160. A through hole for allowing the other end portion of the drive shaft 166 to penetrate is formed in the radial center portion of the bulging portion 144B1 of the bottom wall portion 144B. And the fitting part which the bearing 200 which supports the other end part of the drive shaft 166 freely rotatably is formed in the scroll unit 120 side of the bulging part 144B1.

  An annular thrust plate 210 is disposed between the bottom wall portion 144 </ b> B of the center housing 144 and the bottom plate 124 </ b> A of the orbiting scroll 124. The outer peripheral portion of the bottom wall portion 144 </ b> B receives a thrust force from the orbiting scroll 124 via the thrust plate 210. Sealing members (not shown) are embedded in the bottom wall portion 144B and the portions of the bottom plate 124A that are in contact with the thrust plate 210, respectively.

  Further, a back pressure chamber H4 is formed between the end surface of the bottom plate 124A on the electric motor 160 side and the bottom wall portion 144B, that is, between the end surface of the orbiting scroll 124 opposite to the fixed scroll 122 and the center housing 144. Has been. A gas refrigerant (specifically, a mixed fluid of a gas refrigerant and lubricating oil) is introduced into the center housing 144 from the suction chamber H1 to the space H5 near the outer ends of the wraps 122B and 124B of the scroll unit 120. A refrigerant introduction passage L1 is formed. Since the refrigerant introduction passage L1 communicates the space H5 and the suction chamber H1, the pressure of the space H5 is equal to the pressure of the suction chamber H1 (suction pressure Ps).

  The rear housing 146 is fastened to a fitting portion 144A1 side end portion of the cylindrical portion 144A of the center housing 144 by a fastener. Accordingly, the bottom plate 122A of the fixed scroll 122 is fixed by being sandwiched between the fitting portion 144A1 and the rear housing 146. Further, the rear housing 146 has a substantially bottomed cylindrical shape with an opening on the fastening side (one end side) with the center housing 144, and has a cylindrical portion 146A and a bottom wall portion 146B on the other end side.

  A gas refrigerant discharge chamber H <b> 2 is defined by the cylindrical portion 146 </ b> A and the bottom wall portion 146 </ b> B of the rear housing 146 and the bottom plate 122 </ b> A of the fixed scroll 122. A compressed refrigerant discharge passage (discharge hole) L2 is formed at the center of the bottom plate 122A, and the discharge passage L2 restricts the flow from the discharge chamber H2 to the scroll unit 120, for example, a check valve comprising a reed valve. A valve 220 is attached. Compressed refrigerant compressed in the compression chamber H3 of the scroll unit 120 is discharged into the discharge chamber H2 through the discharge passage L2 and the check valve 220.

  In the rear housing 146, an oil separator 230 for separating the lubricating oil from the gaseous refrigerant in the discharge chamber H2 is disposed. Specifically, the rear end portion of the rear housing 146, that is, the end portion on the side opposite to the center housing 144, has a gas-liquid separation chamber having a circular cross section extending from the outer peripheral wall to the inside. 230A is formed. A stepped inner cylinder 230B having a circular cross section is inserted into the gas-liquid separation chamber 230A so as to be concentric with the gas-liquid separation chamber 230A. The base end portion of the inner cylinder 230B is locked to the step portion 230A1 of the gas-liquid separation chamber 230A, and the distal end portion extends to a position spaced apart from the innermost portion of the gas-liquid separation chamber 230A by a predetermined interval. Here, at least the space of the gas-liquid separation chamber 230A in which the inner cylinder 230B is disposed functions as a separation portion that separates the lubricating oil from the gas refrigerant, and is substantially cylindrical in shape at the innermost portion of the gas-liquid separation chamber 230A. This space functions as a reservoir for temporarily storing the lubricating oil separated by the oil separator 230.

  The opening of the gas-liquid separation chamber 230A in the rear housing 146 is closed by a bolt (not shown) that can press the inner cylinder 230B. The bolt is formed with a through-hole penetrating from the end surface of the head portion to the tip end portion of the shaft portion. A discharge port P2 for connecting piping is formed at the head of the bolt in order to guide the gaseous refrigerant from which the lubricating oil is separated by the oil separator 230 to a condenser (not shown). The gas-liquid separation chamber 230A communicates with the discharge chamber H2 via an introduction port 146C extending in the tangential direction of the inner peripheral surface thereof.

  Therefore, the gaseous refrigerant compressed by the scroll unit 120 is introduced from the introduction port 146C to the oil separator 230 via the discharge chamber H2. As shown in FIG. 2, the gas refrigerant introduced into the oil separator 230 moves downward while swirling in an annular space formed by the inner peripheral surface of the gas-liquid separation chamber 230A and the outer peripheral surface of the inner cylinder 230B. And flow. At this time, the mist of the lubricating oil contained in the gas refrigerant receives a centrifugal force generated when the gas refrigerant swirls and moves outward. When the lubricant mist moves outward, it adheres to the inner peripheral surface of the gas-liquid separation chamber 230A and is dropped onto the bottom using gravity. Then, the lubricating oil separated by the oil separator 230 is guided to a pressure supply passage L3 described later. On the other hand, the gaseous refrigerant from which the lubricating oil has been separated enters the internal space from the tip of the inner cylinder 230B, and is discharged from a discharge port P2 formed in the head of the bolt using the pressure.

  In FIG. 1, the flow of the gaseous refrigerant before or after mixing the lubricating oil is indicated by a hatched arrow, and the flow of the gaseous refrigerant (mixed fluid) mixed with the lubricating oil is indicated by a black arrow. The flow of lubricating oil separated from the refrigerant is indicated by white arrows.

  The electric motor 160 is composed of, for example, a three-phase AC motor, and includes a rotor 162 and a stator core unit 164 disposed on the radially outer side of the rotor 162. For example, a direct current from an on-vehicle battery (not shown) is converted into an alternating current by the inverter 180 and supplied to the electric motor 160.

  The rotor 162 is rotatably supported on the radially inner side of the stator core unit 164 through a drive shaft 166 that is press-fitted into a shaft hole formed at the center in the radial direction. One end portion of the drive shaft 166 is rotatably supported by the support portion 142B1 of the front housing 142. The other end of the drive shaft 166 passes through a through hole formed in the center housing 144 and is rotatably supported by the bearing 200. When a magnetic field is generated in the stator core unit 164 by power feeding from the inverter 180, a rotational force acts on the rotor 162, and the drive shaft 166 is rotationally driven. The other end of the drive shaft 166 is connected to the orbiting scroll 124 via the crank mechanism 240.

  The crank mechanism 240 is attached in an eccentric state to a substantially cylindrical boss portion 240A that protrudes from the end surface on the back pressure chamber H4 side of the bottom plate 124A of the orbiting scroll 124 and a crank 240B that is provided at the other end portion of the drive shaft 166. And an eccentric bush 240C. The eccentric bush 240C is rotatably supported by the boss portion 240A. Note that a balancer weight 240 </ b> D is attached to the other end portion of the drive shaft 166 to resist centrifugal force during the operation of the orbiting scroll 124. Therefore, the orbiting scroll 124 can revolve around the axis of the fixed scroll 122 via the crank mechanism 240 in a state where the rotation of the orbiting scroll 124 is suppressed. Here, the scroll unit 120, the drive shaft 166, and the crank mechanism 240 are cited as examples of the compression mechanism.

  FIG. 3 is a block diagram for explaining the flow of refrigerant and lubricating oil in the scroll compressor 100.

  As shown in FIGS. 1 and 3, the low-pressure / low-temperature gas refrigerant from the evaporator is introduced into the suction chamber H1 through the suction port P1, and then the outer end of the scroll unit 120 through the refrigerant introduction passage L1. To the space H5 near the section. The gaseous refrigerant in the space H5 is taken into the compression chamber H3 of the scroll unit 120 and compressed. The compressed refrigerant compressed in the compression chamber H3 is discharged to the discharge chamber H2 through the discharge passage L2 and the check valve 220, and is then guided from the discharge chamber H2 to the oil separator 230 through the introduction port 146C. The gaseous refrigerant from which the lubricating oil is separated by the oil separator 230 is discharged to the condenser through the discharge port P2. In this way, the scroll unit 120 that compresses the gaseous refrigerant flowing in through the suction chamber H1 in the compression chamber H3 and discharges the compressed refrigerant through the discharge chamber H2 is configured.

  Here, as shown in FIG. 1, a back pressure control valve 250 for adjusting the pressure of the back pressure chamber H4 is further incorporated in the rear end portion of the rear housing 146.

  The back pressure control valve 250 operates according to the suction pressure Ps of the suction chamber H1 and the discharge pressure Pd of the discharge chamber H2, and the back pressure Pm of the back pressure chamber H4 is a target back pressure according to the suction pressure Ps and the discharge pressure Pd. This is a known mechanical (autonomous) flow control valve that automatically adjusts the valve opening so as to approach Pc.

  As shown in FIGS. 1 and 3, the scroll compressor 100 includes a pressure supply passage L3 and a pressure release passage L4 in addition to the refrigerant introduction passage L1 and the discharge passage L2.

  The back pressure control valve 250 is disposed in the middle of the pressure supply passage L3 so as to constitute a part of the pressure supply passage L3. Accordingly, the lubricating oil separated by the oil separator 230 is supplied to the back pressure chamber H4 via the pressure supply passage L3 while being appropriately decompressed by the back pressure control valve 250. That is, by adjusting the opening of the pressure supply passage L3 connected to the inlet side (upstream side) of the back pressure chamber H4 with the back pressure control valve 250, the flow rate of the lubricating oil flowing into the back pressure chamber H4 is increased or decreased. Then, the back pressure Pm is adjusted.

  The pressure release passage L4 communicates the back pressure chamber H4 and the suction chamber H1. An orifice OL is arranged in the middle of the pressure release passage L4. The pressure release passage L4 in which the orifice OL is disposed is formed so as to penetrate the drive shaft 166 and extend along the central axis of the drive shaft 166. For example, the orifice OL is disposed at the end of the drive shaft 166 on the suction chamber H1 side. The lubricating oil in the back pressure chamber H4 is returned to the suction chamber H1 while the flow rate is limited by the orifice OL. At this time, the lubricating oil is supplied to the sliding portion between the drive shaft 166 and the support portion 142B1 of the front housing 142, and is used for the lubrication.

  Then, the orbiting scroll 124 is pressed toward the fixed scroll 122 by the back pressure Pm in the back pressure chamber H4. During the compression operation of the scroll unit 120, the resultant force of the back pressure Pm acting on the back pressure chamber H4 side end surface of the bottom plate 124A of the orbiting scroll 124 is smaller than the compression reaction force acting on the compression chamber H3 side end surface of the bottom plate 124A. When the back pressure is insufficient, a gap is generated between the tip of the wrap 124B of the orbiting scroll 124 and the bottom plate 122A of the fixed scroll 122, and the bottom plate 124A of the orbiting scroll 124 and the tip of the wrap 122B of the fixed scroll 122 There may be a gap between them, which may reduce the volumetric efficiency of the compressor. For this reason, the back pressure Pm is adjusted by the back pressure control valve 250 so that the resultant force is greater than the compression reaction force.

  On the other hand, when the resultant force due to the back pressure Pm in the back pressure chamber H4 is too higher than the compression reaction force, that is, when the back pressure is excessive, the frictional force between the fixed scroll 122 and the orbiting scroll 124 becomes large. The machine efficiency is reduced. For this reason, when the back pressure Pm exceeds the target back pressure Pc, the back pressure control valve 250 reduces the back pressure Pm so as to approach the target back pressure Pc so that the back pressure does not become excessive.

  When the scroll compressor 100 is used in an air conditioner, the temperature of the gas refrigerant sucked into the scroll compressor 100 is high during the cooling operation, and the temperature of the gas refrigerant sucked into the scroll compressor 100 is high during the heating operation. Low. For this reason, when the cooling operation and the heating operation are switched, since the temperature of the lubricating oil is different, the problem described in “Problems to be solved by the invention” occurs.

  Therefore, the scroll compressor 100 is provided with a flow rate variable mechanism that makes the flow rate of the lubricating oil passing through the orifice OL variable by a volume change material whose volume changes according to the temperature of the lubricating oil. The variable flow rate mechanism has an operating characteristic that decreases the flow rate of the lubricating oil passing through the orifice OL when the temperature of the lubricating oil increases, and increases the flow rate of the lubricating oil passing through the orifice OL when the temperature of the lubricating oil decreases. . Here, as the volume change material, the temperature of the lubricating oil during heating operation is about 30 to 40 ° C., and the temperature of the lubricating oil during cooling operation is about 50 to 60 ° C. A material having a characteristic that the volume greatly changes at 60 ° C. is used.

FIG. 4 shows a first embodiment of a flow rate variable mechanism that changes volume by phase change.
The flow rate variable mechanism 260 according to the first embodiment is a pressure release passage L4 located on the upstream side of the orifice OL, specifically, on the upstream side of the orifice OL, and is positioned opposite to the opening on the upstream side of the orifice OL. It is arranged. The flow variable mechanism 260 is made of, for example, a cylindrical phase change material, and an end face (opposing end face) facing the opening on the upstream side of the orifice OL is fixed to be extendable and contractable in the axial direction. On the other hand, the end surface on the opposite side is fixed integrally to the pressure relief passage L4 by, for example, a member in which a plurality of lubricating oil flow paths are formed on a metal disk. Here, as an example of the phase change material, for example, a paraffin, a saturated fatty acid, a hardened oil (triglyceride), a higher alcohol, or an ester can be used which becomes a solid phase below the melting point and becomes a liquid phase above the melting point ( The same applies below). The flow rate variable mechanism 260 is disposed at a position facing the opening on the downstream side of the orifice OL, specifically, the pressure release passage L4 located on the downstream side of the orifice OL. You can also.

  According to the flow rate variable mechanism 260, when the temperature of the lubricating oil is lower than the melting point (lubricating oil temperature: low), the temperature of the phase change material is also lower than the melting point. The volume becomes smaller. For this reason, the distance between the opening on the upstream side of the orifice OL and the facing end surface of the phase change material is increased, and the flow path area on the upstream side of the orifice OL is increased. Further, in a state where the temperature of the lubricating oil is equal to or higher than the melting point (lubricating oil temperature: high), the temperature of the phase change material is equal to or higher than the melting point, so that the phase change material becomes a liquid phase and its volume increases. For this reason, the distance between the opening on the upstream side of the orifice OL and the facing end surface of the phase change material is reduced, and the flow path area on the upstream side of the orifice OL is reduced. That is, the flow rate variable mechanism 260 changes the flow rate of the lubricating oil passing through the orifice OL by changing the flow passage area upstream of the orifice OL in accordance with the temperature of the lubricating oil.

  Accordingly, during the cooling operation, since the temperature of the lubricating oil is high, the flow area on the upstream side of the orifice OL is reduced, and the flow rate of the lubricating oil passing through the orifice OL is reduced. Further, during the heating operation, since the temperature of the lubricating oil is low, the flow area on the upstream side of the orifice OL is increased, and the flow rate of the lubricating oil passing through the orifice OL is increased. For this reason, even if switching between the cooling operation and the heating operation, a change in the flow rate of the lubricating oil passing through the orifice OL is reduced, and for example, occurrence of insufficient lubrication, internal leakage, and the like can be suppressed.

FIG. 5 shows a second embodiment of the variable flow rate mechanism that changes volume by phase change.
The variable flow mechanism 270 according to the second embodiment is made of a cylindrical phase change material and is incorporated in the orifice OL. Specifically, the cylindrical phase change material has an outer diameter slightly larger than the inner diameter of the pressure release passage L4, and press-fits into the pressure release passage L4 to form the orifice OL. In addition, a region defined by the cylindrical inner peripheral surface, that is, a central portion of the transverse section of the orifice OL serves as a lubricating oil flow path. Here, since the phase change material undergoes a phase change between the solid phase and the liquid phase and changes in volume, the phase change follows the change in volume on the lubricating oil flow path side, that is, on the cylindrical inner peripheral surface. A stretchable film 272 is attached to prevent material leakage.

  According to such a variable flow rate mechanism 270, in a state where the temperature of the lubricating oil is lower than the melting point (lubricating oil temperature: low), the temperature of the phase change material is also lower than the melting point. The volume becomes smaller. At this time, since the cylindrical phase change material is press-fitted into the pressure release passage L4, the cylindrical inner peripheral surface extends radially outward, and the flow area of the lubricating oil in the orifice OL increases. Further, in a state where the temperature of the lubricating oil is equal to or higher than the melting point (lubricating oil temperature: high), the temperature of the phase change material is equal to or higher than the melting point, so that the phase change material becomes a liquid phase and its volume increases. At this time, since the cylindrical phase change material is press-fitted into the pressure release passage L4, the cylindrical inner peripheral surface is contracted radially inward, and the flow path area of the lubricating oil in the orifice OL is reduced. In other words, the flow rate variable mechanism 270 changes the flow rate of the lubricating oil passing through the orifice OL by changing the flow passage area of the lubricating oil in the orifice OL according to the temperature of the lubricating oil.

  Accordingly, during cooling operation, since the temperature of the lubricating oil is high, the flow path area in the orifice OL is reduced, and the flow rate of the lubricating oil passing through the orifice OL is reduced. Further, during the heating operation, since the temperature of the lubricating oil is low, the flow passage area in the orifice OL is increased, and the flow rate of the lubricating oil passing through the orifice OL is increased. For this reason, even if switching between the cooling operation and the heating operation, a change in the flow rate of the lubricating oil passing through the orifice OL is reduced, and for example, occurrence of insufficient lubrication, internal leakage, and the like can be suppressed.

FIG. 6 shows a third embodiment of a variable flow rate mechanism that changes volume by phase change.
The variable flow rate mechanism 280 according to the third embodiment is made of a cylindrical phase change material and is incorporated in the orifice OL. Specifically, the columnar phase change material is disposed in a central portion of the pressure release passage L4 so as to be expandable and contractable in the radial direction by a known method, thereby forming the orifice OL. A region located outside the outer peripheral surface of the columnar shape, that is, an annular region located between the outer peripheral surface and the inner peripheral surface of the pressure release passage L4 is a lubricating oil flow path. Here, since the phase change material undergoes a phase change between the solid phase and the liquid phase and changes in volume, it follows the volume change on the lubricating oil flow path side, that is, on the outer peripheral surface of the cylindrical phase change member. A stretchable film 282 is attached to prevent leakage of the phase change material.

  According to such a variable flow rate mechanism 280, in a state where the temperature of the lubricating oil is lower than the melting point (lubricating oil temperature: low), the temperature of the phase change material is also lower than the melting point. The volume becomes smaller. At this time, the cylindrical phase change material shrinks inward in the radius, and the flow area of the lubricating oil in the orifice OL increases. Further, in a state where the temperature of the lubricating oil is equal to or higher than the melting point (lubricating oil temperature: high), the temperature of the phase change material is equal to or higher than the melting point, so that the phase change material becomes a gas phase and its volume increases. At this time, the cylindrical phase change material spreads outward in the radius, and the flow area of the lubricating oil in the orifice OL is reduced. In other words, the flow rate variable mechanism 280 changes the flow rate of the lubricating oil passing through the orifice OL by changing the flow passage area of the lubricating oil in the orifice OL according to the temperature of the lubricating oil.

  In addition, since the effect by the flow volume variable mechanism 280 is the same as the effect by the flow volume variable mechanism 270 which concerns on 2nd Embodiment, in order to eliminate duplication description, the description is abbreviate | omitted. If necessary, refer to the description of the flow rate variable mechanism 270 according to the second embodiment.

FIG. 7 shows a fourth embodiment of a variable flow rate mechanism that changes in volume by thermal expansion.
The flow rate variable mechanism 290 according to the fourth embodiment is made of a cylindrical thermal expansion material having a thermal expansion coefficient larger than that of the drive shaft 166 that forms the pressure release passage L4, for example, a cylindrical resin, and is disposed inside the orifice OL. Incorporated. Specifically, the cylindrical thermal expansion material has an outer diameter slightly larger than the inner diameter of the pressure release passage L4, and press-fits into the pressure release passage L4 to form the orifice OL. In addition, a region defined by the cylindrical inner peripheral surface, that is, a central portion of the transverse section of the orifice OL serves as a lubricating oil flow path.

  According to the variable flow rate mechanism 290, when the temperature of the lubricating oil is low, the thermal expansion coefficient of the thermal expansion material is larger than the thermal expansion coefficient of the drive shaft 166, and the cylindrical thermal expansion material flows into the pressure release passage L4. Since it is press-fitted, the inner peripheral surface of the cylindrical shape extends radially outward, and the flow path area of the lubricating oil in the orifice OL increases. Further, in the state where the temperature of the lubricating oil is high, the above limitation is imposed, so that the cylindrical inner peripheral surface contracts radially inward, and the lubricating oil passage area in the orifice OL is reduced. In other words, the flow rate variable mechanism 290 changes the flow rate of the lubricating oil passing through the orifice OL by changing the flow passage area of the lubricating oil in the orifice OL according to the temperature of the lubricating oil.

  In addition, since the effect by the flow volume variable mechanism 290 is the same as the effect by the flow volume variable mechanism 270 which concerns on 2nd Embodiment, in order to eliminate duplication description, the description is abbreviate | omitted. If necessary, refer to the description of the flow rate variable mechanism 270 according to the second embodiment.

FIG. 8 shows a fifth embodiment of the variable flow rate mechanism that changes in volume by thermal expansion.
The flow rate variable mechanism 300 according to the fifth embodiment is made of a cylindrical thermal expansion material having a thermal expansion coefficient larger than that of the drive shaft 166 that forms the pressure release passage L4, for example, a cylindrical resin, and is disposed inside the orifice OL. Incorporated. Specifically, the cylindrical thermal expansion material is disposed in the center portion of the pressure release passage L4 so as to be expandable and contractable in the radial direction by a known method, thereby forming the orifice OL. A region located outside the outer peripheral surface of the columnar shape, that is, an annular region located between the outer peripheral surface and the inner peripheral surface of the pressure release passage L4 is a lubricating oil flow path.

  According to the variable flow rate mechanism 300, when the temperature of the lubricating oil is low, the thermal expansion coefficient of the thermal expansion material is larger than the thermal expansion coefficient of the drive shaft 166. And the flow area of the lubricating oil in the orifice OL increases. Further, when the temperature of the lubricating oil is high, the cylindrical thermal expansion material spreads outward in the radius, and the flow area of the lubricating oil in the orifice OL becomes small. That is, the flow rate variable mechanism 300 changes the flow rate of the lubricating oil passing through the orifice OL by changing the flow passage area of the lubricating oil in the orifice OL according to the temperature of the lubricating oil.

  In addition, since the effect by the flow volume variable mechanism 300 is the same as the effect by the flow volume variable mechanism 280 which concerns on 3rd Embodiment, in order to eliminate duplication description, the description is abbreviate | omitted. If necessary, refer to the description of the flow rate variable mechanism 280 according to the third embodiment.

Here, a specific effect when a phase change material is used in the flow rate variable mechanism will be described.
When the phase change material undergoes a phase change from a solid phase to a liquid phase, for example, the volume increases by about 5 to 10%, although there are some differences depending on the material. Further, the phase change material undergoes a volume change corresponding to a temperature change even when a solid phase and a liquid phase coexist. On the other hand, for example, in the case of aluminum, when the temperature is changed by 1 ° C., the volume of the thermal expansion material is changed by about 0.002%. It changes so much.

  When the cooling operation and the heating operation are switched, for example, assuming that the temperature change of the lubricating oil is 20 to 30 ° C., the volume change of the thermal expansion material is about 0.06% for aluminum and about 0.06% for resin. About 3%. Therefore, since the phase change material has a volume change characteristic of 10 times or more compared with the thermal expansion material, the variable width of the flow rate of the lubricating oil passing through the orifice can be increased.

  In the embodiment described above, the compressor is assumed to be a scroll compressor, but it may be a reciprocating compressor, a swash plate compressor, a rotary piston compressor, a slide vane compressor, or the like. Further, the oil separator is not limited to the centrifugal separation type, and may be a method of separating the lubricating oil from the gaseous refrigerant through a labyrinth passage, for example.

100 scroll compressor (compressor)
120 Scroll unit (compression mechanism)
166 Drive shaft (compression mechanism)
230 Oil separator 240 Crank mechanism (compression mechanism)
260 Flow variable mechanism 270 Flow variable mechanism 272 Film 280 Flow variable mechanism 282 Film L4 Pressure release passage (lubricant flow passage)
OL orifice

Claims (7)

A compression mechanism for compressing the working fluid;
An oil separator that separates lubricating oil from the working fluid compressed by the compression mechanism;
An orifice disposed in a flow path of lubricating oil separated by the oil separator;
A flow rate variable mechanism that changes the phase according to the temperature of the lubricating oil and makes the flow rate of the lubricating oil passing through the orifice variable,
Equipped with a compressor. The flow rate variable mechanism decreases the flow rate of the lubricating oil passing through the orifice when the temperature of the lubricating oil increases, and increases the flow rate of the lubricating oil passing through the orifice when the temperature of the lubricating oil decreases.
The compressor according to claim 1. The flow rate variable mechanism is disposed on the upstream side or downstream side of the orifice, and the flow area on the upstream side or downstream side of the orifice is variable.
The compressor according to claim 1 or 2. The flow rate variable mechanism is incorporated in the orifice, and the flow area of the lubricating oil in the orifice is variable.
The compressor according to claim 1 or 2. The flow rate variable mechanism is made of a cylindrical phase change material, and a region partitioned by an inner peripheral surface thereof is a lubricating oil flow path.
The compressor according to claim 4. The flow rate variable mechanism is made of a cylindrical phase change material, and the region located outside the outer peripheral surface is a flow path for the lubricating oil.
The compressor according to claim 4. A film having stretchability is attached to the flow path side of the lubricating oil of the flow rate variable mechanism,
The compressor according to claim 5 or 6.