JP2010270718A - Vane pump and refrigerant circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vane pump allowing vanes to be projected to an inner peripheral wall of a cylinder when starting, and a refrigerant circuit utilizing the vane pump. <P>SOLUTION: The vane pump 1 is rotatably provided with a rotor 12 having a plurality of vane grooves 12a radially formed in the cylinder 11 of elliptic cylinder shape. Vanes 13 movable in the radial direction of the rotor are provided in the respective vane grooves 12a, and communicating passages 14c are provided from a discharge port 11a to vane groove bottom parts 12b. A normally closed bypass passage 15 is provided between the discharge port 11a and an intake port 11b, and a driving motor 16 for the rotor 12 is provided. An on-off valve 15a and a check valve 15b are provided for opening the bypass passage 15 after driving of the rotor 12 is started, and closing the bypass passage 15 when the pressure of the discharge port 11a becomes higher than the pressure of the intake port 11b. A refrigerant circuit includes the vane pump 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vane pump having a bypass structure and a refrigerant circuit using the same.

  Generally, a vane-type pump configured by rotatably providing a rotor having a plurality of radially formed vane grooves in an elliptical cylinder and providing each vane groove with a vane movable in the radial direction of the rotor. It has been known. In this vane type pump, the lubricant supplied to the bottom of the vane groove is pressurized with the discharge pressure of the refrigerant gas, so that the vane jumps out when the compressor is started.

  However, when pressurizing the lubricating oil supplied to the bottom of the vane groove with the discharge pressure of the refrigerant gas, there is a concern that if the discharge pressure is not increased, the ability of the vane to jump out becomes worse.

  Therefore, conventionally, in this vane type pump, a configuration is known in which high-pressure refrigerant that does not depend on the discharge pressure is supplied to the bottom of the vane groove in order to project the vane to the inner peripheral wall of the cylinder at the time of startup.

  For example, in Patent Document 1, the refrigerant flowing into the gap between the vane and the bottom of the vane groove generated when the vane jumps out in the radial direction of the rotor at the time of startup is compressed by the return of the vane to the bottom of the vane groove and becomes high pressure. Therefore, it is disclosed that the vane is extended by adopting a configuration in which the high-pressure refrigerant is guided to the bottom of another vane groove.

Japanese Patent No. 4095869

  However, in the case of the vane type pump described in Patent Document 1, it is assumed that the vane jumps out in the radial direction of the rotor even when the vane is not sufficiently partitioned within the cylinder at the time of starting, and the amount of vane popping out is insufficient May not be possible.

  The present invention has been made in view of such circumstances, and a vane pump capable of projecting a vane to a cylinder inner peripheral wall at the time of startup without relying on a refrigerant flowing between the vane and the bottom of the vane groove, and this It aims at providing the refrigerant circuit using the.

  The vane type pump of the present invention for solving the above-mentioned problems is provided with an elliptic cylinder, and a rotor having a plurality of radially formed vane grooves is rotatably provided in each of the vane grooves. In the vane type pump provided with a vane movable in the radial direction of the rotor and provided with a communication path from the discharge port to the bottom of the vane groove, a normally closed bypass path is provided between the discharge port and the suction port, and the rotor And a pressure adjusting means for closing the bypass path when the pressure of the discharge port becomes higher than the pressure of the suction port.

  In the vane type pump, an expander that rotates due to the expansion of the discharged gas refrigerant is provided as a drive means on the drive shaft of the rotor.

  In the vane type pump, an electric motor is provided as a driving means on the drive shaft of the rotor. In the vane type pump, the drive shaft of the rotor and the output shaft of the electric motor are connected by a magnetic coupling.

  Moreover, the refrigerant circuit of this invention for solving the said subject is equipped with the said vane type pump as a 2nd compressor.

  As described above, according to the present invention, when the vane pump is started, the phenomenon that the discharge pressure becomes lower than the suction port pressure due to insufficient pumping of the vane causes the pressure loss of the pump itself. Arise. At this time, by temporarily bypassing the discharge port and the suction port by the pressure adjusting means of the bypass path, the suction port pressure before receiving the pressure loss works on the discharge port, and through this discharge port to the bottom of the vane groove. Also, the suction pressure works and the vane can be projected onto the inner wall of the cylinder.

It is the schematic which shows the whole structure of the vane type pump which has a bypass structure concerning this invention. It is a disassembled perspective view which shows the principal part structure of the vane type pump which concerns on this invention. It is a top view which shows the rotor part stored in the cylinder of the vane type pump which concerns on this invention. FIG. 4 is a sectional view taken along line IV-IV of the cylinder block shown in FIG. (A) And (b) is the schematic which shows other embodiment of the vane type pump which concerns on this invention. It is sectional drawing explaining the drive connection state of the vane type pump which concerns on this invention. It is sectional drawing which shows other embodiment of FIG. It is a refrigerant circuit diagram which uses the vane type pump which concerns on this invention shown in FIG. It is a Mollier diagram of the refrigerant circuit shown in FIG. (A) is the schematic of the air conditioning apparatus using the vane type pump shown in FIG. 7, (b) is the schematic of the air conditioning apparatus using the vane type pump shown in FIG.

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

  1 to 4 schematically show the overall configuration of a vane type pump 1 according to the present invention.

  That is, the vane pump 1 includes an elliptic cylinder 11 and a rotor 12 having a plurality of vane grooves 12a formed radially in the cylinder 11 so as to be rotatable. In the rotor 12 provided with a vane 13 movable in the radial direction and provided with a communication path 14c from the discharge port 11a to the vane groove bottom 12b, an on-off valve 15a and a reverse valve are provided between the discharge port 11a and the suction port 11b. A bypass path 15 having a stop valve 15b is provided, a drive motor 16 for the rotor 12 is provided, the bypass path 15 opens after the start of driving of the rotor 12, and the bypass path is opened when the pressure of the discharge port 11a becomes higher than the pressure of the suction port 11b. 15 closes.

  The cylinder 11 has an inner peripheral surface formed in an elliptical cylinder shape, and two discharge ports 11a and two suction ports 11b are alternately provided on the inner peripheral wall surface. The discharge ports 11a and the suction ports 11b are provided at positions facing each other. The discharge port 11a can discharge the compressed refrigerant to the outside through a discharge path 14a provided in the cylinder 11 and the side block 14. The suction port 11 b is also configured to be able to suck the refrigerant into the cylinder 11 through the suction passage 14 b provided in the cylinder 11 and the side block 14. The side block 14 of the cylinder 11 corresponding to the bottom surface of the cylinder 11 is provided with a back pressure supply port 14d formed in an arc groove shape. As shown in FIG. 4, the back pressure supply port 14d communicates with the discharge path 14a through a communication path 14c.

  The rotor 12 is formed in a columnar shape that can be mounted in the cylinder 11, and a rotation shaft attachment hole 12 d is provided at the center of the rotor 12 to which the rotation shaft 12 c is attached. The rotor 12 is mounted in the cylinder 11. Slit-like vane grooves 12 a are formed radially on the outer peripheral surface of the rotor 12. A vane 13 is mounted in each vane groove 12a so as to be able to appear and disappear in the radial direction of the rotor 12.

  The vane 13 is movable forward and backward from the outer peripheral surface of the rotor 12 toward the inner peripheral surface of the cylinder 11 by a centrifugal force generated by the rotation of the rotor 12 and a vane back pressure acting on the vane groove bottom portion 12b. A space formed by the peripheral surface and the outer peripheral surface of the rotor 12 is partitioned into a plurality of compression chambers 110. At this time, the vane back pressure acting on the vane groove bottom portion 12b is supplied from the discharge passage 14a of the cylinder 11 and the side block 14 from the back pressure supply port 14d through the communication path 14c. The vane back pressure is applied only within a certain angle range where the distance between the inner peripheral surface of the cylinder 11 and the outer peripheral surface of the rotor 12 is away. Accordingly, the back pressure supply port 14d is formed in an arc shape that falls within the range of the constant angle described above, communicates with the vane groove bottom 12b within the range of the constant angle, and applies the vane back pressure to the vane groove bottom 12b. Thus, the vane 13 can be protruded from the vane groove 12 a of the rotor 12.

  The bypass path 15 is provided so as to communicate between the discharge path 14a and the suction path 14b. The bypass path 15 is provided with an on-off valve 15a and a check valve 15b in series.

  The on-off valve 15a is normally set in a state in which the bypass path 15 is closed.

  The check valve 15b flows in the bypass path 15 from the suction path 14b side to the discharge path 14a side, but is provided in a direction not to flow in the bypass path 15 from the discharge path 14a side to the suction path 14b side.

  The total pressure loss of the on-off valve 15a and the check valve 15b with the on-off valve 15a open is smaller than the pressure loss when passing through the cylinder 11 from the suction passage 14b to the discharge passage 14a. Is set.

  Either the on-off valve 15a or the check valve 15b may be provided on the upstream side or the downstream side of the flow.

  The on-off valve 15a is normally closed, but is opened when the vane pump 1 is started. That is, when the vane pump 1 is started, the vane 13 is not sufficiently projected, causing the pressure loss of the vane pump 1 itself, so that the pressure at the discharge port 11a becomes lower than the pressure at the suction port 11b. Occurs. At this time, by opening the on-off valve 15a of the bypass path 15 and temporarily bypassing the discharge path 14a and the suction path 14b, the pressure of the suction port 11b before receiving pressure loss acts on the discharge port 11a. The suction pressure acts also on the vane groove bottom portion 12b through the discharge port 11a, and the vane 13 can be projected on the inner peripheral wall of the cylinder 11.

  When the vane 13 can project to the inner peripheral wall of the cylinder 11, the vane pump 1 starts to start normally, and the pressure on the discharge passage 14a side with the discharge port 11a is changed to the suction passage with the suction port 11b. Since the pressure becomes higher than the pressure on the 14b side, the on-off valve 15a is closed at the timing when the pressure on the discharge path 14a side becomes higher than the pressure on the suction path 14b side. This timing may be automatically closed after a lapse of a predetermined time from the start, or may be manually closed by an operator while looking at the operation state after the start, or the discharge of the vane pump 1 Pressure sensors (not shown) may be provided in the passage 14a and the suction passage 14b, respectively, and the pressure change may be detected and automatically closed. Further, the pressure sensor (not shown) in this case is not specifically provided, but may be provided on the further upstream side of the suction passage 14b of the vane pump 1 or the further downstream side of the discharge passage 14a. A pressure sensor (not shown) may be used.

  Even if the timing for closing the on-off valve 15a is delayed, the bypass passage 15 is provided with a check valve 15b in addition to the on-off valve 15a, and therefore, from the discharge passage 14a side to the suction passage 14b side through the bypass passage 15. It is possible to prevent the refrigerant from flowing backward.

  In the present embodiment, the bypass path 15 is provided with the opening / closing valve 15a and the check valve 15b, but the timing for closing the opening / closing valve 15a is measured by a pressure sensor (not shown) or the like. As shown in FIG. 5A, the check valve 15b may be omitted and only the on-off valve 15a may be configured.

  Moreover, as shown in FIG.5 (b), it is good also as a structure which left the check valve 15b and abbreviate | omitted the on-off valve 15a. In this case, when the pressure on the suction path 14b side is high, the pressure communicates with the discharge path 14a side from the bypass path 15 via the check valve 15b, and the pressure becomes equal, but the pressure on the discharge path 14a side becomes high. In this case, since the check valve 15b works, there is no back flow toward the suction path 14b. Further, when the pressure on the discharge passage 14a side becomes high, the check valve 15b does not function due to the high pressure on the discharge passage 14a side. Therefore, even if there is no on-off valve 15a, the suction passage 14b side passes through the bypass passage 15. The refrigerant can be prevented from flowing to the discharge path 14 a side, and the refrigerant from the suction path 14 b side can be reliably flowed to the vane type pump 1.

  Furthermore, in the present embodiment, the bypass passage 15 and the on-off valve 15a and / or the check valve 15b provided in the bypass passage 15 are provided with a discharge passage 14a and a suction passage that extend outside the cylinder 11 and the cylinder block 14, respectively. 14b, it may be configured so as to be housed in the cylinder 11 or the cylinder block 14.

  The drive motor 16 is drivingly connected to the rotary shaft 12 c of the rotor 12. This drive connection may be a direct connection between the rotation shaft 12 c of the rotor 12 and the drive shaft 16 a of the drive motor 16, or between the rotation shaft 12 c of the rotor 12 and the drive shaft 16 a of the drive motor 16. A belt drive or a chain drive may be used, or a gear may be engaged to drive. The drive means may be driven by an engine other than the drive motor 16, but it is preferable to use the drive motor 16 because it is possible to easily control the rotational speed arbitrarily.

  Moreover, as drive connection, as shown in FIG. 6, you may drive a magnet coupling. In this magnet coupling drive, the drive motor 16 has a cylindrical outer mug 16b fixed to the tip of the drive shaft 16a. A plurality of permanent magnets 16c are provided on the inner peripheral surface of the outer mug 16b. On the other hand, the rotating shaft 12c of the rotor 12 protruding from the side block 17 of the cylinder 11 is provided with a cylindrical rotor 16e having a magnet 16d on the outer peripheral surface. The rotor 16e is sealed in the canister 16f. The canister 16f is inserted into the outer mug 16b in a non-contact state, and is set so that the magnet 16d of the rotor 16e and the permanent magnet 16c of the outer mug 16b face each other in this state.

  According to this magnet coupling drive, the sealing performance of the rotary shaft 12c of the vane pump 1 can be improved.

  Further, as shown in FIG. 7, the expander 10 that is rotated by the compressed refrigerant is configured coaxially with the rotating shaft 12c of the vane pump 1, and the drive motor 16 drives the vane pump 1 to this expander. 10 may assist. In the vane type composite pump 1a with the drive assist function, the cylinder 10a constituting the expander 10 is provided between the cylinder 11 of the vane type pump 1 and the cylinder block 18 on the other surface side through the cylinder block 18. The cylinder block 19 is fixed together with the cylinder 11 and the cylinder block 17 of the vane pump 1. In this state, the expander 10 is configured such that when the vane pump 1 rotates in the direction in which the refrigerant is compressed, the rotor 10b and the vane 10c function by rotating in the direction in which the refrigerant is expanded. In FIG. 7, the same members as those in FIG.

  According to the vane type composite pump 1a with the drive assist function, the expander 10 is rotated by the high-pressure refrigerant compressed by the vane type pump 1, and the rotational energy of the expander 10 is used for driving the vane type pump 1. The driving can be completed by itself, and the driving force by the driving motor 16 can be reduced.

  Next, the refrigerant circuit 2 using the vane type composite pump 1a with a drive assist function will be described.

  FIG. 8 shows an example in which the portion of the vane type pump 1 of the vane type composite pump 1a is used as the auxiliary compressor 21 of the refrigerant circuit 2 using the carbon dioxide refrigerant, and the portion of the expander 10 is used as the expander 22. Is shown.

  The refrigerant gas compressed from the low pressure to the medium pressure by the main compressor 23 during cooling is radiated and cooled by the first outdoor radiator 26 via the oil separator 24 and the four-way valve 25.

  The cooled refrigerant gas is compressed from medium pressure to high pressure by the auxiliary compressor 21.

  The refrigerant gas compressed to a high pressure by the auxiliary compressor 21 is radiated and cooled by the second outdoor radiator 27 and then decompressed and expanded by the expander 22 to become a low pressure, and is heated from the block circuit 28 through the receiver 29. It evaporates and vaporizes in the exchanger 30, flows to the main compressor 23, and thereafter circulates in the same manner.

  The Mollier diagram at this time is as shown in FIG. In FIG. 9, the horizontal axis indicates enthalpy and the vertical axis indicates pressure. The refrigerant compressed from the point a of the low pressure Pl to the point b of the medium pressure Pm by the main compressor 23 is radiated to the point c by the first outdoor radiator 26 and then the point c of the medium pressure Pm by the auxiliary compressor 21. To d of high pressure Ph. Then, after the heat is radiated to the point e by the second outdoor radiator 27, the refrigerant that is decompressed and expanded to the point f of the low pressure Pl by the expander 22 and heated by the heat exchanger 30 returns to the point a.

  Thus, when carbon dioxide is used as a refrigerant, the heat radiation area can be lengthened by the two-stage compression by the main compressor 23 and the auxiliary compressor 21 to increase the operation efficiency. In addition, since the pressure is increased by the main compressor 23, the heat is radiated, and then the pressure is increased again by the auxiliary compressor 21, so that the differential pressure before and after the pressure increase applied to each of the main compressor 23 and the auxiliary compressor 21 can be alleviated. Compared with the case, sliding loss can be reduced and durability can be improved.

  In addition, a part of the energy required for driving the auxiliary compressor 21 can be assisted by the energy generated by rotation when the refrigerant expands in the expander 22, and thus is required for driving the auxiliary compressor 21. Energy can be reduced and energy saving of the refrigerant circuit 2 can be achieved.

  As described above, when the vane type composite pump 1a is used in the refrigerant circuit 2, the auxiliary compressor 21 and the expander 22 are provided at adjacent positions, so that the refrigerant capable of handling the pipes is provided. Circuit 2 must be configured. Therefore, when using this vane type | mold composite pump 1a, as shown to Fig.10 (a), the refrigerant circuit 2 is integrated in the chiller type air conditioning apparatus 3. As shown in FIG. The air conditioner 3 is configured to exchange heat between a heat medium circulating between the indoor unit 31 and the heat exchanger 30 and a refrigerant circulating in the refrigerant circuit 2. Since both the outdoor unit 33 and the heat exchanger 32 can be provided outdoors, the piping can be routed even if the above-described vane type composite pump 1a is used.

  In the refrigerant circuit 2 described above, the vane-type composite pump 1a in which the vane-type pump 1 and the expander 10 are provided adjacent to each other is used, so that a chiller-type cooling / heating device 3 is configured. However, if the normal vane type pump 1 shown in FIG. 6 is used, instead of such a chiller method, a direct expansion method in which the expander 22 is housed in the indoor unit 31 as shown in FIG. The air-conditioning apparatus 3a may be configured.

  It can be used for air conditioners.

DESCRIPTION OF SYMBOLS 1 Vane type pump 11 Cylinder 11a Discharge port 11b Suction port 12 Rotor 12a Vane groove 12b Vane groove bottom part 12c Rotating shaft 13 Vane 14a Discharge path 14b Suction path 15 Bypass path 15a On-off valve (pressure control means)
15b Check valve (pressure adjusting means)
16 Drive motor (drive means)
16a Drive shaft 16b Outer mug (magnetic coupling)
16c Permanent magnet (magnetic coupling)
16d magnet (magnetic coupling)
16e Rotor (magnetic coupling)
16f canister (magnetic coupling)
2 Refrigerant circuit 21 Auxiliary compressor (secondary compressor)
22 Expander

Claims (5)

An elliptic cylindrical cylinder is provided, a rotor having a plurality of radially formed vane grooves is rotatably provided in the cylinder, and vanes that are movable in the rotor radial direction are provided in the vane grooves. In a vane type pump provided with a communication path to the bottom of the vane groove,
A bypass path that is normally closed is provided between the discharge port and the suction port, the rotor drive means is provided, the bypass route opens after the start of the rotor drive, and the bypass is bypassed when the pressure at the discharge port becomes higher than the pressure at the suction port A vane type pump characterized in that pressure regulating means for closing the path is provided.   2. The vane type pump according to claim 1, wherein an expander that rotates by expansion of the discharge gas refrigerant is provided as a drive means on the drive shaft of the rotor.   2. The vane type pump according to claim 1, wherein an electric motor is provided as a driving means on the drive shaft of the rotor.   4. The vane type pump according to claim 3, wherein a drive shaft of the rotor and an output shaft of the electric motor are connected by a magnetic coupling.   A refrigerant circuit comprising the vane pump according to any one of claims 1 to 4 as a second compressor.

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