JP2009013828A - Gas compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas compressor that inhibits the increase of frictional force between vane tip and inner circumferential surface of cylinder, even if the amount of an oil content that returns to a gas compressor reduces. <P>SOLUTION: Oil content passages 58c, 58f, 58h that communicate with a tip 58a of protruding from a burial side end 58b are formed in a vane 58 protruding from an outer circumferential surface 50a of a rotor 50, as well as there is arranged a ball valve consisting of a ball 58d and a spring 58e in the oil content passages 58f, that is displaced between an open position that permits the passage of the oil content passages 58c, 58f, 58h and a close position that blocks it. The ball valve is positioned at a close position when a resultant force (resultant pressure) F of a pressure Pv of refrigerating machine oil R in a vane back pressure chamber 59 acting on the burial side end 58b and a centrifugal force C acting on the ball valve 58d is less than a predetermined threshold value, and positioned at an open position when the resultant force F is equal to or greater than the predetermined threshold value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas compressor, and more particularly to an improvement in lubrication at a vane tip in a vane rotary type compressor body.

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

  Here, a vane rotary type compressor is known as a typical type of a general compressor. This vane rotary type compressor has a configuration in which a compressor main body is accommodated in a housing.

  The compressor main body includes a substantially cylindrical rotor that rotates integrally with the rotating shaft, a cylinder that surrounds the outer periphery of the rotor (the cylindrical peripheral surface), and a cross-sectional contour of the inner peripheral surface that is substantially elliptical; A plate-like vane that is embedded in the vane groove formed on the inner surface of the rotor and has a variable protrusion amount from the outer peripheral surface of the rotor so that the tip on the protruding side follows the inner peripheral surface of the cylinder, and at least the rotor and the vane. And two side blocks each having a boss formed on the outer surface of the bearing that covers both ends of the rotor and supports the rotating shaft that protrudes on both sides from the rotor. It is configured to protrude from the outer peripheral surface of the rotor by the pressure of the oil supplied to the vane back pressure space facing the buried side end and the centrifugal force acting on the vane according to the rotation of the rotor.

Then, the rotation of the rotor is performed by the mutually opposing surfaces of the two vanes in the rotational direction of the rotor, the inner peripheral surface of the cylinder, the outer peripheral surface of the rotor, and the end surfaces of both side blocks (the inner end surfaces on the side facing the rotor). Accordingly, a plurality of compression chambers whose volumes change are defined, and the gas confined in the compression chambers is compressed by this volume change (Patent Document 1).
JP-A-2005-337115

  By the way, since the tip of the vane and the inner peripheral surface of the cylinder slide relative to each other, a frictional force acts between them, and this frictional force becomes a resistance force that rotationally drives the gas compressor. Therefore, when the frictional force increases, the power consumption increases and the driving efficiency is reduced.

  Further, the increase in the frictional force increases the temperature of the gas in the compression chamber, leading to a decrease in volumetric efficiency.

  The gas compressor bears a part of the air conditioning system described above. When excess oil is discharged from the gas compressor together with the compressed gas to the air conditioning system (directly a condenser), the operating efficiency of the system is increased. Therefore, various measures are taken to suppress the amount of oil discharged from the gas compressor.

  On the other hand, if the amount of oil discharged from the gas compressor is excessively reduced, the amount of oil returning from the air conditioning system (directly the evaporator) to the gas compressor is reduced. This reduction in the amount of returned oil causes a reduction in the amount of oil sucked into the compression chamber and increases the frictional force between the tip of the vane and the inner peripheral surface of the cylinder, resulting in the operation of the gas compressor. The efficiency and volumetric efficiency are reduced.

  In particular, as the rotational speed of the compressor body increases, the lubrication state between the tip of the vane and the inner peripheral surface of the cylinder becomes more severe, which tends to increase the frictional force.

  The present invention has been made in view of the above circumstances, and even if the amount of oil returned to the gas compressor is reduced, an increase in frictional force between the tip of the vane and the inner peripheral surface of the cylinder can be suppressed. An object is to provide a gas compressor.

  In the gas compressor according to the present invention, when the rotation speed of the compressor main body increases, oil is supplied from the tip of the vane itself, thereby improving the lubrication state between the tip of the vane and the inner peripheral surface of the cylinder. It is something to keep.

  That is, the gas compressor according to the present invention has a substantially cylindrical rotor that rotates about the axis integrally with the rotary shaft, and a cross-sectional contour of the inner peripheral surface that surrounds the outer peripheral surface of the rotor. And a plate that is embedded in a vane groove formed in the rotor, and whose protrusion amount from the outer peripheral surface of the rotor is variable so that a tip on the protruding side follows the inner peripheral surface of the cylinder. And at least the rotor and two side blocks that cover the vane from both end surfaces of the rotor, and the vane has a vane back pressure that faces an embedded side end of the vane in the vane groove. It protrudes from the outer peripheral surface of the rotor by the pressure of the oil component supplied to the space and the centrifugal force acting on the vane according to the rotation of the rotor. Protrusion An oil passage that communicates with the tip of the oil passage, and a ball valve that is displaced between an open position that allows passage of the oil passage and a closed position that blocks passage of the oil passage is disposed in the oil passage. When the resultant force (the resultant pressure) between the oil pressure and the centrifugal force is less than a predetermined threshold value, the oil is located at the closed position, and when the resultant force is greater than or equal to a predetermined threshold value, the oil is located at the open position. It is characterized by that.

  According to the gas compressor according to the present invention configured as described above, the resultant force of the oil pressure supplied to the vane back pressure space and the centrifugal force acting on the vane according to the rotation of the rotor is greater than or equal to a predetermined threshold value. When the ball valve is in the open position, the end of the vane on the embedded side and the end of the protruding side communicate with each other through the oil passage, and as a result, the vane back that applies the protruding pressure to the embedded end of the vane. Even if the oil content of the pressure space is supplied directly to the tip of the vane protruding side through the oil passage, and the amount of oil returning from the air conditioning system to the gas compressor is reduced, the tip of the vane and the inner peripheral surface of the cylinder The lubricating state between the two can be kept good, and an increase in frictional force between them can be suppressed.

  As a result, it is possible to prevent the temperature of the compressed gas from rising excessively, to prevent a decrease in volumetric efficiency and to prevent a decrease in operating efficiency.

  On the other hand, when the resultant force of the oil pressure supplied to the vane back pressure space and the centrifugal force acting on the vane according to the rotation of the rotor is less than a predetermined threshold, the ball valve is positioned at the closed position, Since the oil content in the vane back pressure space that exerts the projecting pressure on the buried side end of the air does not escape to the oil passage, the projecting pressure that acts on the buried side end of the vane does not decrease, and the vane immediately after the start of rotation It is possible to prevent the protrusion from becoming insufficient.

  In the gas compressor according to the present invention, it is preferable that the ball valve includes a ball that moves in the oil passage and a spring that biases the ball to the closed position.

  According to the gas compressor having such a preferable configuration, the setting of switching the opening and closing of the oil passage according to the resultant force of the pressure of the oil supplied to the vane back pressure space and the centrifugal force acting on the vane according to the rotation of the rotor. The pressure can be easily adjusted by the mass of the ball (which affects the applied centrifugal force), the elastic force of the spring (adjusted by the elastic coefficient), and the initial biasing force (adjusted by the amount of elastic displacement applied initially). .

  According to the gas compressor concerning the present invention, even if the amount of oil returning to the gas compressor decreases, an increase in the frictional force between the tip of the vane and the inner peripheral surface of the cylinder can be suppressed.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the gas compressor of the invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing a vane rotary compressor 100 which is an embodiment of a gas compressor according to the present invention, and FIG. 2 is a view showing a cross section taken along line AA 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 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 liquefies the compressed refrigerant gas G 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 compressor 100 is attached to the compressor body 60 housed in the housing 10 including the case 11 and the front head 12 and the front head 12, and transmits a driving force from a driving source (not shown) to the compressor body. A transmission mechanism 80.

  Here, the transmission mechanism 80 is energized to the pulley 81 that is rotatably supported by the radial ball bearing 14 and is rotated by driving a circulation belt (not shown) wound around the outer periphery thereof, the electromagnet 82, and the electromagnet 82. And an electromagnetic clutch that includes an armature 83 that is sucked by the pulley 81 and transmits the rotation of the pulley 81 to the rotation shaft 51 described later, and that connects and disconnects transmission of the rotation of the pulley 81 to the compressor body 60. is there.

  The case 11 has a cylindrical body that is open at one end, and the front head 12 is assembled so as to cover the opened part of the case 11. The front head 12 is formed with a suction port 12a through which a low-pressure refrigerant gas G is drawn from the evaporator. On the other hand, the case 11 is a condenser for receiving the high-pressure Pd refrigerant gas G compressed by the compressor body. A discharge port 11a is formed to discharge the liquid.

  The compressor main body 60 accommodated in the housing 10 includes a rotary shaft 51 that is driven to rotate about an axis by a transmission mechanism 80, a columnar rotor 50 that rotates integrally with the rotary shaft 51, and a rotor. The outer peripheral surface 50a of the outer peripheral surface 50a surrounding the outer periphery 50a, the inner peripheral surface 49a has a substantially oval cross-sectional outline, both ends open cylinder 40, and five vane grooves formed in the rotor 50 at equal angular intervals around the axis 56, five plate-like vanes 58 that are respectively embedded in the inner surface 56a of the rotor 50 so that the protruding end 58a can follow the inner peripheral surface 49a of the cylinder 40. 50, the vane 58, and the cylinder 40 are respectively provided with two side blocks (front side block 30 and rear side block 20) that respectively cover the both end surfaces from the outside.

  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 is compressed and discharged.

  One of the portions of the rotating 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 penetrating portion is pivotally supported by the front head 12, and the portion extending outward is connected to the armature 83. Similarly, 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 compressor main body 60 is supported by the front head 12 supporting the rotating shaft 51 and the outer peripheral portions of the side blocks 20 and 30 being held on the inner peripheral surfaces of the case 11 and the front head 12 by O-rings or the like. It is held at a predetermined position in the housing 10.

  Further, the discharge chamber 21 is formed by the rear side block 20 and the case 11 in a state where the compressor main body 60 is accommodated in the case 11, while the suction chamber 34 is formed by the front side block 30 and the front head 12. The discharge chamber 21 communicates with the discharge port 11a, and the suction chamber 34 communicates with the suction port 12a.

  The suction chamber 34 and the discharge chamber 21 are hermetically isolated by the above-described O-ring or the like. The rear side block 20 is assembled with a cyclone block 70 having a metal mesh 78 for separating the refrigerating machine oil R from the refrigerant gas G. The cyclone block 70 is arranged in the discharge chamber 21.

  A short columnar axial back pressure space 79 is defined between the outer surface of the rear side block 20 and the outer surface of the cyclone block 70 by assembling the rear side block 20 and the cyclone block 70.

  Here, the rear side block 20 is formed with an intermediate pressure oil passage 28 that connects a later-described salai groove 25 and a shaft back pressure space 79.

  In the lower part of the discharge chamber 21, the sliding portion of the compressor 100 is lubricated, cooled, and cleaned, and the vane 58 is protruded toward the inner peripheral surface 49a of the cylinder 40, and the tip 58a is protruded toward the inner peripheral surface 49a. A refrigerating machine oil R for applying a back pressure (protruding pressure) to the vane 58 is stored so as to urge the vane 58 to abut.

  As shown in FIG. 2, the rotor 50 is formed with five slit-like vane grooves 56 in which the above-described vanes 58 are embedded radially and at equal angular intervals around the rotation center of the rotor 50. Each of the vanes 58 into which the vane 58 is inserted is a centrifugal force C generated by the rotation of the rotor 50 and the refrigerating machine oil R supplied to the vane back pressure space 59 facing the buried side end 58b of the vane 58 in the vane groove 56. In response to the resultant force (combined pressure) F with the hydraulic pressure (back pressure) Pv, the protrusion 58 protrudes toward the inner peripheral surface 49a of the cylinder 40, and the tip 58a on the protruding side of the vane 58 contacts the inner peripheral surface 49a of the cylinder 40. The tip 58a follows the inner peripheral surface 49a as the rotating shaft 51 is rotated.

  As a result, each compression chamber 48 defined by the cylinder 40, the rotor 50, the two vanes 58 and 58 that are arranged in the rotational direction of the rotating shaft 51, the front side block 30, and the rear side block 20 is The change in volume is repeated according to the rotation of the rotor 50, and the refrigerant gas G is sucked from the suction chamber 34 during a period when the volume increases, and the compressed refrigerant high pressure is compressed during the period when the volume decreases. The refrigerant gas G is discharged into the discharge chamber 21 through the cyclone block 70.

  On the other hand, the refrigerating machine oil R separated from the refrigerant gas G by the peripheral wall 71 and the metal net 78 of the cyclone block 70 is dropped onto the bottom of the discharge chamber 21 and is stored at the bottom as described above.

  The rear side block 20 of the compressor main body 60 is formed with a high-pressure oil guide passage 23 that is stored at the bottom of the discharge chamber 21 and guides the refrigerating machine oil R of high pressure Pd to the bearing portion 22. A small gap (throttle portion) between the refrigeration oil R having a high pressure Pd is squeezed to an intermediate pressure Pv that is lower than the pressure in the discharge chamber 21, and the rotor 50 in the shaft back pressure space 79 and the rear side block 20 It supplies to the Sarai groove 25 formed in the opposing surface.

  The salai groove 25 communicates with a vane back pressure chamber 59 (vane back pressure space) disposed in the rotor 50 and supplies a refrigerating machine oil R having an intermediate pressure Pv as the back pressure of the vane 58.

  On the other hand, the refrigerating machine oil R having the intermediate pressure Pv supplied to the shaft back pressure space 79 is also guided to the Sarai groove 25 through the intermediate pressure guide oil passage 28 and supplied to the vane back pressure chamber 59.

  Further, a through hole 46 connected to the high pressure oil guide passage 23 of the rear side block 20 is provided at the bottom of the cylinder 40, and the opening on the front side block 30 side of the through hole 46 and the bearing portion are provided in the front side block 30. A high-pressure oil guide path 33 that communicates with the rotary shaft 32 is formed, and the refrigerating machine oil R passes through a minute gap between the bearing portion 32 and the rotary shaft 51 and is a recess formed on the inner end surface of the front side block 30. It is guided to a certain Saray groove 35.

  The salai groove 35 of the front side block 30 also communicates with the vane back pressure chamber 59 formed in the rotor 50, similarly to the saray groove 25 of the rear side block 20, and a minute gap between the bearing portion 32 and the rotary shaft 51. Refrigerating machine oil R that has been squeezed to an intermediate pressure Pv by (throttle part) is supplied.

  As a result, the back pressure supplied to the vane back pressure chamber 59 of the rotor 50 through the Sarai grooves 25 and 35 acts on the embedded side end portion 58b of the vane 58, and causes the vane 58 to move to the inner peripheral surface 49a of the cylinder 40. Protrusively toward.

  Here, as shown in the enlarged views of FIGS. 3 and 4, the vane 58 is formed with oil content passages 58 c, 58 f, 58 h communicating from the embedded side end portion 58 b to the projecting side tip 58 a, and refrigeration oil. A ball valve (58d, 58e) in which R is displaced between an open position (FIG. 4) allowing passage of the oil passages 58c, 58f and 58h and a closed position (FIG. 3) blocking passage is arranged in the oil passage 58f. It is installed.

  The ball valve is composed of a ball (steel ball) 58d that moves in the oil passage 58f and a spring 58e that urges the ball 58d to the closed position, and the refrigerating machine oil R acting on the vane back pressure chamber 59. When the resultant force F of the pressure Pv and the centrifugal force C is less than a predetermined threshold value, the ball 58d is located at a closed position that closes between the oil passages 58c and 58f (FIG. 3), and the resultant force F is equal to or greater than the predetermined threshold value. Is set so that the ball 58d is located at the open position that allows the oil passages 58c and 58f to communicate with each other (FIG. 4).

  Such a predetermined threshold value is determined by experiment or experience so that the frictional force between the inner peripheral surface 49a of the cylinder 40 and the tip 58a on the protruding side of the vane 50 does not increase excessively. It is a value defined in advance.

  Then, the set pressure for switching when the ball 58d changes from the open position to the closed position, or from the closed position to the open position, corresponding to the predetermined threshold value, affects the mass of the ball 58d (the centrifugal force C that acts). ) And the elastic force (adjusted by the elastic coefficient) and the initial biasing force (adjusted by the initial elastic displacement) of the spring 58e.

  3 and 4, one end of the spring 58e is in contact with the ball 58d, and the other end is in contact with a retaining member 58g that prevents the ball 58d and the spring 58e from dropping out of the oil passage 58f.

  The retaining member 58g is formed by press-fitting the ball 58d and the spring 58e into the oil passage 58f after the ball 58d and the spring 58e are disposed, and the oil passage 58f and the tip 58a of the vane 58 are disposed at the center thereof. An oil content passage 58h is formed for communicating the.

  According to the compressor 100 according to the present embodiment configured as described above, the centrifugal force C (acting on the ball 58d according to the pressure Pv of the refrigerating machine oil R supplied to the vane back pressure chamber 59 and the rotation of the rotor 50 is achieved. When the resultant force F between the centrifugal force acting on the vane 58 and a predetermined correspondence) is equal to or greater than a predetermined threshold value, the ball valve (58d, 58e) is positioned in the open position, so that the embedded side end of the vane 58 As a result, the refrigerating machine oil R in the vane back pressure chamber 59 that exerts a projecting pressure on the embedded side end 58b of the vane 58 is communicated with the tip 58a of the projecting side through the oil content passages 58c, 58f, and 58h. , 58f and 58h, the vane 58 is supplied directly to the projecting side tip 58a, so that even if the amount of the refrigerating machine oil R returning from the air conditioning system to the compressor 100 is reduced, the vane The lubrication between the inner peripheral surface 49a of the eighth tip 58a and the cylinder 40 can be kept good, both 58a, an increase in the frictional force between 49a can be suppressed.

  As a result, the temperature of the compressed refrigerant gas G can be prevented from rising excessively, and the volumetric efficiency can be prevented from decreasing.

  On the other hand, when the resultant force F of the pressure Pv of the refrigerating machine oil R supplied to the vane back pressure chamber 59 and the centrifugal force C acting on the ball 58d according to the rotation of the rotor 50 is less than a predetermined threshold, the ball valve (58d , 58e) is located in the closed position, so that the refrigerating machine oil R in the vane back pressure chamber 59 that exerts a protruding pressure on the embedded side end 58b of the vane 58 does not escape to the oil passages 58f, 58h. The protrusion pressure acting on the side end portion 58b does not decrease, and it is possible to prevent the vane 58 from becoming insufficiently protruded immediately after the rotation of the compressor body 60 starts.

It is a longitudinal section showing a vane rotary type compressor which is one embodiment of a gas compressor concerning the present invention. It is a figure which shows the cross section along the AA in FIG. It is a figure which shows the expanded sectional view of a vane, and is a figure which shows the mode in the state in which the resultant force of a centrifugal force and a vane back pressure is less than predetermined value. It is a figure which shows the expanded sectional view of a vane, and is a figure which shows the mode in the state in which the resultant force of a centrifugal force and a vane back pressure is more than predetermined value.

Explanation of symbols

40 Cylinder 49a Inner peripheral surface 50 Rotor 56 Vane groove 58 Vane 58a Buried side end 58b Protruding end 58c, 58f, 58h Oil passage 58d Ball 58e Spring 58g Retaining member 59 Vane back pressure chamber (vane back pressure space)
Pv Compressor oil pressure (Vane back pressure chamber oil pressure)
C Centrifugal force acting on the ball R Refrigerating machine oil (oil content)
100 compressor (gas compressor)

Claims (2)

A substantially columnar rotor that rotates about the axis integrally with the rotary shaft, a cylinder that surrounds the outer periphery of the rotor and that has an inner peripheral surface that is substantially elliptical, and a vane formed on the rotor A plate-like vane embedded in the groove and having a protruding amount from the outer peripheral surface of the rotor variable so that a protruding tip follows the inner peripheral surface of the cylinder, and at least the rotor and the vane And two side blocks that cover the rotor from both end face sides, and the vane has a pressure of oil supplied to a vane back pressure space facing an embedded side end portion of the vane in the vane groove and the rotor. Projecting from the outer peripheral surface of the rotor by centrifugal force acting on the vane according to the rotation of
The vane is formed with an oil passage that communicates from the embedded side end to the tip of the protruding side,
A ball valve that is displaced between an open position that allows passage of the oil passage and a closed position that blocks passage is disposed in the oil passage,
The ball valve is located in the closed position when the resultant force of the oil pressure and the centrifugal force is less than a predetermined threshold, and is located in the open position when the resultant force is greater than or equal to a predetermined threshold. A gas compressor characterized by that.   The gas compressor according to claim 1, wherein the ball valve includes a ball that moves in the oil passage and a spring that biases the ball to the closed position.

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