JP2005048654A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacity controllable compressor 10 preventive of operating efficiency degradation. <P>SOLUTION: The compressor 10 comprises a compression mechanism 31 and an expansion mechanism 32 both provided in a casing 11. Its capacity is controlled by introducing part of discharge gas from the compression mechanism 31 into the expansion mechanism 32 while recovering power. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a compressor, and more particularly to a compressor having a capacity control mechanism.

  Conventionally, for example, a scroll compressor or a rotary compressor has been used as a compressor for compressing a refrigerant in a refrigeration cycle. Among these, the scroll compressor is provided with a compression mechanism having a fixed scroll and a movable scroll in which spiral wraps that mesh with each other are provided in a casing. The fixed scroll is fixed to the casing, and the movable scroll is connected to the eccentric portion of the drive shaft. And this scroll compressor changes the volume of the compression chamber formed between both lap | wraps by the operation | movement in which a movable scroll revolves without rotating with respect to a fixed scroll, and compresses the refrigerant | coolant introduced into the inside. It is configured as follows. Refrigerant is sucked into the spiral compression chamber from the outer peripheral edge, and when the volume of the compression chamber decreases toward the center, the refrigerant is compressed and discharged from the center of the compression chamber.

By the way, in order to make the operating capacity of the compressor variable, a compressor having a so-called low-pressure bypass type capacity control mechanism has been proposed (for example, see Patent Document 1). The capacity control mechanism of Patent Document 1 is applied to a scroll compressor. Specifically, in this low-pressure bypass type capacity control mechanism, a bypass valve for bypassing a part of the gas being compressed to the low-pressure side is provided on the fixed scroll. When the load is full, the bypass valve is closed to compress the entire amount of refrigerant sucked into the compression chamber. On the other hand, during capacity control, the bypass valve is opened and a part of the gas being compressed is compressed. The amount of discharge gas can be reduced by returning the pressure to the low pressure side.
JP 2001-165073 A

  However, in the low pressure bypass type compression mechanism, the bypass gas is compressed halfway, so that there is a problem that the compression power is wasted and the operation efficiency is lowered.

  The present invention has been made in view of such problems, and an object thereof is to prevent a reduction in operating efficiency in a compressor capable of capacity control.

  In the present invention, an expansion mechanism is provided in the casing of the compressor together with the compression mechanism, and a part of the discharge gas from the compression mechanism is introduced into the expansion mechanism to control the capacity while recovering power.

  1st invention presupposes the compressor provided with the drive mechanism (16,20) which drives a compression mechanism (31) (131) and this compression mechanism (31) (131) in a casing (11) It is said. The compressor according to the present invention includes expansion mechanisms (32) and (132) in the casing (11), and output side members (54) and (113) of the expansion mechanisms (32) and (132) are compressed. Connected to the input side members (53) and (113) of the mechanisms (31) and (131), and further introduces part of the discharge gas of the compression mechanisms (31) and (131) into the expansion mechanisms (32) and (132). A bypass passage (96) is provided, and the bypass passage (96) is provided with a flow rate adjusting mechanism (97).

  In the first invention, a part of the high-pressure discharge gas discharged from the compression mechanism (31) (131) is introduced into the expansion mechanism (32) (132) through the bypass passage (96). The capacity of the compressor is controlled by adjusting the flow rate of the discharge gas by the flow rate adjusting mechanism (97) in the bypass passage (96). On the other hand, high-pressure discharge gas flows into the expansion mechanisms (32) and (132), and the discharge gas expands. As a result, part of the energy of the refrigerant becomes the output of the output side members (54) and (113) of the expansion mechanisms (32) and (132), and this output is the input side member (53 of the compression mechanisms (31) and (131)). ) (113). Therefore, the power of the drive mechanisms (16, 20) that drive the compression mechanisms (31) (131) can be suppressed, and an efficient operation is possible.

  According to a second aspect of the present invention, in the compressor according to the first aspect, the discharge ports (74) and (142) and the suction ports (73) and (141) communicating with the compression mechanisms (31) and (131), and the expansion mechanism (32) (132) An inflow port (75) (143) and an outflow port (76) (144) communicating with the discharge port (96) are connected to the discharge port (74) (142). It is characterized by being branched from 94) and connected to the inflow ports (75) and (143).

  In the second invention, when the discharge gas discharged from the compression mechanism (31) (131) flows through the discharge pipe (94), a part of the discharge gas branches into the bypass passage (96), and the expansion mechanism (32) Introduced in (132). Therefore, by adjusting the flow rate adjustment mechanism (97) of the bypass passage (96), the capacity of the compression mechanisms (31) and (131) can be controlled, and power can be recovered in the expansion mechanisms (32) and (132). COP (coefficient of performance) is improved. And it is only necessary to change the piping system of the machine in which the compression mechanism (31) (131) and the expansion mechanism (32) (132) are integrated. There are also merits such as sharing.

  According to a third aspect of the present invention, in the compressor according to the first or second aspect, the compression mechanism (31) and the expansion mechanism (32) are scroll mechanisms, and the first flat plate portion (51), the first movable side wrap (53 ), The second flat plate portion (52), and the second movable side wrap (54) are sequentially stacked and integrated, and the first fixed side meshing with the first movable side wrap (53). A fixed scroll (40) having a wrap (42) and a second fixed wrap (47) meshing with the second movable wrap (54), the first fixed wrap (42) and the first movable wrap A compression mechanism (31) is configured by (53), and an expansion mechanism (32) is configured by the second fixed side wrap (47) and the second movable side wrap (54).

  In this third invention, a compression mechanism (31) comprising a first fixed side wrap (42) and a first movable side wrap (53), a second fixed side wrap (47) and a second movable side wrap (54). In the scroll compressor in which the expansion mechanism (32) composed of the two is arranged in two stages, by introducing a part of the discharge gas from the compression mechanism (31) into the expansion mechanism (32), the capacity control can be performed efficiently.

  According to a fourth aspect of the present invention, in the compressor according to the first or second aspect, the compression mechanism (31) and the expansion mechanism (32) are scroll mechanisms, and are provided upright on one surface of the flat plate portion (55). A movable scroll (50) having a first movable side wrap (53) and a second movable side wrap (54) erected on the other surface of the flat plate portion (55), and a first movable side wrap (53) A fixed scroll (40) having a first fixed-side wrap (42) meshing with the second fixed-side wrap (47) meshing with the second movable-side wrap (54), and a first fixed-side wrap (42) And the first movable side wrap (53) constitutes a compression mechanism (31), and the second fixed side wrap (47) and the second movable side wrap (54) constitute an expansion mechanism (31). It is said.

  In the fourth aspect of the invention, in the scroll compressor having the compression mechanism (31) and the expansion mechanism (32) disposed on both sides of the flat plate portion (55) of the movable scroll (50), the compression mechanism (31) By introducing a part of the discharge gas from the expansion mechanism (32), capacity control can be performed efficiently.

  According to a fifth invention, in the compressor according to the first or second invention, the compression mechanism (131) and the expansion mechanism (132) are a multi-vane type rotary mechanism, and a cylinder chamber (112) having a non-circular cross section, A piston (113) that rotates in the cylinder chamber (112); and a plurality of vanes (114) that are attached to the piston (113) and press-contact with the inner surface of the cylinder chamber (112). In the compression chamber (121) between the cylinder chamber (112) and the piston (113), the cylinder chamber (112), the piston (113), and the vane (114) constitute a compression mechanism (131). ) Between the cylinder chamber (122), the piston (113), and the vane (114) constitutes an expansion mechanism (132).

  According to the fifth aspect of the present invention, in the multi-vane rotary compressor, a part of the discharge gas from the compression mechanism (31) is introduced into the expansion mechanism (32), so that the capacity control can be performed efficiently.

  According to the first aspect of the invention, the output side members (54) and (113) of the expansion mechanisms (32) and (132) are connected to the input side members (53) and (113) of the compression mechanisms (31) and (131). In addition, since the flow rate adjusting mechanism (97) is provided in the bypass passage (96) for introducing a part of the discharge gas of the compression mechanism (31) (131) into the expansion mechanism (32) (132), the bypass passage (96 ), The capacity of the compressor can be controlled. Further, by introducing a high-pressure discharge gas into the expansion mechanisms (32) and (132) and expanding the gas, a part of the energy of the gas expansion is supplied to the input side members (53) and (113) of the compression mechanisms (31) and (131). ) Can be transmitted. Thereby, since the compression power of the drive mechanism (16, 20) can be suppressed, it is possible to prevent the operation efficiency from being lowered.

  In addition, as a compressor for controlling the capacity of a compressor, an inverter that drives an electric motor at a variable speed is generally known, but as long as the capacity is controlled using a bypass passage (96) as in the present invention. Since an inverter is not required, power loss due to the inverter does not occur, and the cost is low.

  According to the second aspect of the invention, the bypass passage (96) branches from the discharge pipe (94) connected to the discharge ports (74) and (142) and is connected to the inflow ports (75) and (143). With a simple configuration, the capacity of the compression mechanisms (31) and (131) can be controlled, and power can be recovered in the expansion mechanisms (32) and (132), thereby improving the COP (coefficient of performance) of the refrigeration cycle. And it is only necessary to change the piping system of the machine in which the compression mechanism (31) (131) and the expansion mechanism (32) (132) are integrated. There are also merits such as sharing.

  According to the third aspect of the invention, since the scroll type compression mechanism (31) and the expansion mechanism (32) are arranged in two stages, it is possible to prevent the compressor from becoming large.

  According to the fourth aspect of the invention, the first movable side wrap (53) erected on one surface of the flat plate portion (55) and the second movable erected on the other surface of the flat plate portion (55). Since the double-tooth type movable scroll (50) having the side wrap (54) is used, the number of parts can be reduced and the cost can be reduced.

  According to the fifth aspect, the piston (113) rotating in the cylinder chamber (112) serves as both the output side member of the expansion mechanism (132) and the input side member of the compression mechanism (132). Can be simplified, and the cost of the apparatus can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The compressors of the embodiments described below are all connected to the refrigerant circuit (90) of the refrigeration apparatus.

Embodiment 1 of the Invention
The first embodiment relates to a scroll compressor (10).

  As shown in FIG. 1, the scroll compressor (10) includes a casing (11) formed in a vertically long and cylindrical closed container shape. Inside the casing (11), a main body mechanism (30), an electric motor (16), and a lower bearing (19) are arranged in order from top to bottom. Further, a drive shaft (20) extending vertically is provided as a rotation shaft inside the casing (11). The electric motor (16) and the drive shaft (20) constitute a drive mechanism (16, 20) that drives a compression mechanism (31) described later.

  The inside of the casing (11) is partitioned up and down by the housing (33) of the main body mechanism (30). In the casing (11), the space above the housing (33) is the low pressure chamber (12), and the space below it is the high pressure chamber (13).

  An electric motor (16) and a lower bearing (19) are accommodated in the high pressure chamber (13). The electric motor (16) includes a stator (17) and a rotor (18). The stator (17) is fixed to the body of the casing (11). On the other hand, the rotor (18) is fixed to the central portion of the drive shaft (20) in the vertical direction. The lower bearing (19) is fixed to the body of the casing (11). The lower bearing (19) rotatably supports the lower end portion of the drive shaft (20).

  The casing (11) is provided with a tubular discharge port (74). One end of the discharge port (74) opens into a space above the electric motor (16) in the high pressure chamber (13).

  The housing (33) of the main body mechanism (30) is formed with a main bearing (34) penetrating vertically. The drive shaft (20) is inserted through the main bearing (34) and is rotatably supported by the main bearing (34). In the drive shaft (20), an upper end portion protruding from the upper portion of the housing (33) constitutes an eccentric portion (21). The eccentric part (21) is eccentric with respect to the central axis of the drive shaft (20).

  A balance weight (25) is attached to the drive shaft (20) between the housing (33) and the stator (17). The drive shaft (20) has an oil supply passage (not shown). The refrigerating machine oil accumulated at the bottom of the housing (33) is sucked up from the lower end of the drive shaft (20) by the action of the oil pump (26) provided at the lower end of the drive shaft, and supplied to each part through the oil supply passage. . Further, a discharge passage (22) is formed in the drive shaft (20). The discharge passage (22) will be described later.

  As shown in FIG. 2, the low pressure chamber (12) accommodates the fixed scroll (40) and the movable scroll (50) of the main body mechanism (30). In the main body mechanism (30), a compression mechanism (31) and an expansion mechanism (32) are formed. An Oldham ring (39) is housed in the low pressure chamber (12).

  The fixed scroll (40) includes a first fixed side member (41) and a second fixed side member (46). The first fixed side member (41) and the second fixed side member (46) constituting the fixed scroll (40) are fixed to the housing (33).

  As shown in FIG. 3, the first fixed side member (41) includes a first fixed side wrap (42) and a first outer peripheral portion (43). FIG. 3 shows only the first fixed member (41) in the AA cross section of FIG.

  The first fixed side wrap (42) is formed in a spiral wall shape having a constant height. On the other hand, the first outer peripheral portion (43) is formed in a thick ring shape surrounding the first fixed side wrap (42) and is formed integrally with the first fixed side wrap (42). That is, in the first fixed side member (41), the first fixed side wrap (42) protrudes from the inner peripheral surface of the first outer peripheral portion (43). The first outer peripheral portion (43) has three insertion holes (44) and three bolt holes (45). The first fixed side member (41) is fastened and fixed to the housing (33) by a bolt passed through the bolt hole (45).

  One end of a tubular suction port (73) is inserted into the first fixed side member (41) (see FIG. 2). The suction port (73) is provided through the upper end of the casing (11). A suction check valve (35) is provided below the suction port (73) of the first fixed side member (41). The suction check valve (35) includes a valve body (36) and a coil spring (37). The valve body (36) is formed in a cap shape and is installed so as to close the lower end of the suction port (73). The valve body (36) is pressed against the lower end of the suction port (73) by the coil spring (37).

  As shown in FIG. 2, the second fixed side member (46) includes a second fixed side wrap (47), a second outer peripheral portion (48), and a third flat plate portion (49). The entire shape of the second fixed side member (46) is a disk having a smaller thickness and a smaller diameter than the first fixed side member (41). The third flat plate portion (49) is formed in a disc shape and is disposed on the upper portion of the second fixed side member (46). The second outer peripheral portion (48) is formed integrally with the third flat plate portion (49) and extends downward from the third flat plate portion (49). The shape of the second outer peripheral portion (48) is a ring shape with a wall thickness equal to that of the third flat plate portion (49).

  In the second fixed side member (46), the second fixed side wrap (47) is disposed inside the second outer peripheral portion (48) and is formed integrally with the third flat plate portion (49). The second fixed side wrap (47) is formed in a spiral wall shape lower than the first fixed side wrap (42), and extends downward from the lower surface of the third flat plate portion (49). Further, the spiral direction of the second fixed side wrap (47) is opposite to the spiral direction of the first fixed side wrap (42). That is, the first fixed-side wrap (42) is formed in a right-handed spiral wall shape (see FIG. 3), whereas the second fixed-side wrap (47) is formed in a left-handed spiral wall shape. Yes.

  One end of a tubular outflow port (76) is inserted into the second fixed side member (46). The outflow port (76) is provided through the upper end of the casing (11). Further, the third flat plate portion (49) of the second fixed side member (46) has an inflow port (66) formed at the center thereof. The inflow port (66) is formed so as to penetrate the third flat plate portion (49). One end of a tubular inflow port (75) is inserted into the inflow port (66). The inflow port (75) is provided through the upper end of the casing (11).

  The movable scroll (50) includes a first flat plate portion (51), a first movable side wrap (53), a second flat plate portion (52), and a second movable side wrap (54), which are sequentially stacked. And a strut member (61) for integration. The first movable wrap (53) is formed integrally with the first flat plate portion (51). On the other hand, the second movable side wrap (54) is formed integrally with the second flat plate portion (52). In the movable scroll (50), three support members (61) are erected on the upper surface of the first flat plate portion (51) integrated with the first movable side wrap (53), and integrated with the second movable side wrap (54). The second flat plate portion (52) is placed on the support member (61). In the movable scroll (50), the stacked first flat plate portion (51), support member (61), and second flat plate portion (52) are fastened by bolts (62).

  The first flat plate portion (51) and the first movable side wrap (53) will be described with reference to FIGS. FIG. 4 shows only the movable scroll (50) in the AA cross section of FIG. FIG. 5 shows the first fixed-side member (41) and the movable scroll (50) in the AA cross section of FIG.

  As shown in FIG. 4, the first flat plate portion (51) is formed in a substantially circular flat plate shape. The front surface (upper surface in FIG. 2) of the first flat plate portion (51) is in sliding contact with the lower end surface of the first fixed side wrap (42). The first flat plate portion (51) is formed with three portions bulging in the radial direction, and one column member (61) is erected on each of the portions. The column member (61) is a slightly thick and tubular member, and is formed separately from the first flat plate portion (51).

  The first movable side wrap (53) is formed in a spiral wall shape having a constant height, and is erected on the front surface side (upper surface side in FIG. 2) of the first flat surface portion. The first movable side wrap (53) is engaged with the first fixed side wrap (42) of the first fixed side member (41) (see FIG. 5). The side surface of the first movable side wrap (53) is in sliding contact with the side surface of the first fixed side wrap (42).

  As shown in FIG. 2, the 2nd flat plate part (52) is formed in the flat plate shape of substantially the same shape as the 1st flat plate part (51). The rear surface (the lower surface in FIG. 2) of the second flat plate portion (52) is in sliding contact with the upper end surface of the first fixed side wrap (42), and the front surface (the upper surface in FIG. 2) is the second fixed side wrap (47). ) Is in sliding contact with the lower end surface.

  A second movable side wrap (54) is erected on the front surface side (the upper surface side in FIG. 2) of the second flat plate portion (52). The spiral direction of the second movable side wrap (54) is opposite to the spiral direction of the first movable side wrap (53). That is, the first movable side wrap (53) is formed in a right-handed spiral wall shape (see FIG. 4), whereas the second movable side wrap (54) is formed in a left-handed spiral wall shape. Yes.

  In the main body mechanism (30), a compression chamber (71) is formed by the first fixed side wrap (42), the first movable side wrap (53), the first flat plate portion (51), and the second flat plate portion (52). Has been. And the fixed scroll (40) provided with the 1st flat plate part (51) of the movable scroll (50), the 2nd flat plate part (52), the 1st movable side wrap (53), and the 1st fixed side wrap (42). The first fixed side member (41) forms a compression mechanism (31).

  Further, in the main body mechanism (30), the second fixed side wrap (47), the second movable side wrap (54), the second flat plate portion (52), and the third flat plate portion (49) are used to expand the expansion chamber (72). Is formed. And, the fixed scroll (40) including the second flat plate portion (52) and the second movable side wrap (54) of the movable scroll (50), and the third flat plate portion (49) and the second fixed side wrap (47). The second fixed side member (46) forms an expansion mechanism (32).

  In the above configuration, the first movable side wrap (53) is an input side member of the compression mechanism (31), and the second movable side wrap (54) is an output side member of the expansion mechanism (32). . The output side member (second movable side wrap) (54) of the expansion mechanism (32) is connected to the input side member (first movable side wrap) (53) of the compression mechanism (31). The second movable side wrap (54) and the first movable side wrap (53) may be directly connected, or may be connected via a connecting member therebetween.

  The first flat plate portion (51) of the movable scroll (50) has a discharge port (63) formed at the center thereof. The discharge port (63) passes through the first flat plate portion (51). The first flat plate portion (51) is formed with a bearing portion (64). The bearing portion (64) is formed in a substantially cylindrical shape, and protrudes from the back surface side (the lower surface side in FIG. 2) of the first flat plate portion (51). Furthermore, a bowl-shaped flange part (65) is formed at the lower end part of the bearing part (64).

  A seal ring (38) is provided between the lower surface of the flange portion (65) of the bearing portion (64) and the housing (33). Inside the seal ring (38), high-pressure refrigerating machine oil is supplied through an oil supply passage of the drive shaft (20). When high-pressure refrigerating machine oil is fed into the seal ring (38), hydraulic pressure acts on the bottom surface of the flange (65), and the movable scroll (50) is pushed upward.

  The eccentric part (21) of the drive shaft (20) is inserted into the bearing part (64) of the first flat plate part (51). The inlet end of the discharge passage (22) is opened at the upper end surface of the eccentric part (21). The discharge passage (22) has a slightly larger diameter near the inlet end, and a cylindrical seal (23) and a coil spring (24) are installed therein. The cylindrical seal (23) is formed in a tubular shape whose inner diameter is slightly larger than the diameter of the discharge port (63), and is pressed against the back surface of the first flat plate portion (51) by the coil spring (24). Further, the outlet end of the discharge passage (22) opens between the stator (17) and the lower bearing (19) on the side surface of the drive shaft (20) (see FIG. 1).

  An Oldham ring (39) is interposed between the first flat plate portion (51) and the housing (33). Although not shown, the Oldham ring (39) includes a pair of keys that engage with the first flat plate portion (51) and a pair of keys that engage with the housing (33). The Oldham ring (39) constitutes a rotation prevention mechanism for the movable scroll (50).

  As shown in FIG. 6, the scroll compressor (10) of this embodiment is provided in the refrigerant circuit (90) of the refrigeration apparatus. In the refrigerant circuit (90), the refrigerant circulates to perform a vapor compression refrigeration cycle.

  In the refrigerant circuit (90), the scroll compressor (10) has a discharge port (74) connected to one end of a condenser (91) via a discharge pipe (94). The other end of the condenser (91) is connected to one end of an evaporator (93) via an expansion valve (92), and the other end of the evaporator (91) is connected to a suction port (73) via a suction pipe (95). )It is connected to the.

  The refrigerant circuit (90) is provided with a bypass passage (96) for introducing a part of the discharge gas of the compression mechanism (31) into the expansion mechanism (32). The bypass passage (96) is a passage branched from the discharge pipe (95) connected to the discharge port (74) and connected to the inflow port (75). The bypass passage (96) is provided with an electric valve (97) as a flow rate adjusting mechanism. The inflow port (75) is connected to the suction pipe (95) through the outflow pipe (98).

-Driving action-
In the scroll compressor (10), the rotational power generated by the electric motor (16) is transmitted to the movable scroll (50) by the drive shaft (20). The movable scroll (50) engaged with the eccentric portion (21) of the drive shaft (20) is guided by the Oldham ring (39) and performs only the revolving motion without rotating.

  Along with the revolving motion of the movable scroll (50), the low-pressure refrigerant evaporated by the evaporator (93) is sucked into the suction port (73). This low-pressure refrigerant pushes down the valve body (36) of the suction check valve (35) and flows into the compression chamber (71). As the first movable side wrap (53) of the movable scroll (50) moves, the volume of the compression chamber (71) decreases, and the refrigerant in the compression chamber (71) is compressed. The compressed refrigerant flows from the compression chamber (71) to the discharge passage (22) through the discharge port (63). Thereafter, the high-pressure refrigerant flows into the high-pressure chamber (13) from the discharge passage (22), and is sent out from the casing (11) through the discharge port (74).

  A part of the high-pressure refrigerant discharged from the discharge port (74) branches to the bypass passage (96), while the rest is sent to the condenser (91) to be condensed. The refrigerant condensed in the condenser (91) is depressurized when passing through the expansion valve (92) and is evaporated in the evaporator (93). The evaporated refrigerant is sucked into the compression mechanism (31) from the suction port (73).

  On the other hand, the flow rate of a part of the refrigerant discharged from the discharge port (74) is adjusted by the motor-operated valve (97) of the bypass passage (96), and flows into the expansion mechanism (32) from the inflow port (75). In the expansion mechanism, the second movable side wrap (54) moves when the refrigerant expands, and the volume of the expansion chamber (72) increases as the second movable side wrap (54) moves. That is, a part of the internal energy of the refrigerant introduced into the expansion chamber (72) of the expansion mechanism (32) is converted into power for moving the second movable side wrap (54). The movable scroll (50) is driven by both the driving force generated by the electric motor (16) and the power recovered from the refrigerant by the expansion mechanism (32).

  In the first embodiment, the capacity control of the compressor (10) can be performed by adjusting the valve opening degree of the electric valve (97). For example, when the amount of compressed refrigerant gas is set to 100 and 10 of them is turned to the expansion mechanism (32) to recover the power, the power consumption required for the compression is reduced to about 90. Moreover, since 90 refrigerant | coolants flow into an evaporator at that time, it can also prevent that a capability falls significantly.

-Effect of Embodiment 1-
According to the first embodiment, since the bypass valve (96) for introducing a part of the discharge gas of the compression mechanism (31) to the expansion mechanism (32) is provided with the motor operated valve (97) as the flow rate adjusting mechanism, The capacity of the compressor can be controlled steplessly by adjusting the flow rate of the discharge gas flowing through the passage (96).

  Further, since the second movable side wrap (54) which is the output side member of the expansion mechanism (32) is connected to the first movable side wrap (53) which is the input side member of the compression mechanism (31), By introducing a high-pressure discharge gas into the mechanism (32) and expanding it, a part of the energy of the gas expansion is directly transmitted to the first movable side wrap (53) which is an input side member of the compression mechanism (31). It becomes possible. Therefore, the compression power of the electric motor (16) can be suppressed, and high-efficiency operation is possible.

  Further, in the first embodiment, since the scroll type compression mechanism (31) and the expansion mechanism (32) are arranged in two stages, it is possible to prevent the compressor from becoming large. Further, a single-stage compressor without an expansion mechanism (32) (specifically, there is no second movable side wrap (54), second fixed side member (46), inflow port (75), and outflow port (76)). The second flat plate part (52) with the second movable side wrap (54), and by adding the second fixed side member (46), the inflow port (75) and the outflow port (76) to this structure It can be easily shared.

  Further, since the bypass passage (96) has a simple configuration in which the bypass passage (96) is branched from the discharge pipe (94) connected to the discharge port (74) and connected to the inflow port (75), an increase in cost can be suppressed.

  Furthermore, since it is only necessary to change the piping system of the compression / expansion integrated machine that can increase the COP of the refrigeration cycle, there is a merit such as common use of parts without processing internal parts as in the conventional example.

  In addition, as a compressor for controlling the capacity of a compressor, an inverter that drives an electric motor at a variable speed is generally known, but as long as the capacity is controlled using a bypass passage (96) as in the present invention. Since an inverter is not required, power loss due to the inverter does not occur, and the cost is low.

  Furthermore, in the above-described conventional low-pressure bypass capacity control mechanism, it is difficult to adjust the capacity steplessly unless a plurality of bypass valves are provided, but in this embodiment, stepless adjustment can be easily performed. It becomes. In addition, when a large number of bypass valves are provided, dead volumes are created in each of them, so that the efficiency is reduced due to compression loss. However, in this embodiment, such a problem does not occur. In addition, since the conventional structure cannot be compressed without a discharge check valve to control to a low capacity (about 10 to 30% of the total load), noise and vibration problems are likely to occur. A check valve is not required, and no noise or vibration occurs.

<< Embodiment 2 of the Invention >>
A second embodiment of the present invention will be described. The second embodiment also relates to the scroll compressor (10), but the structure of the main body mechanism (30) is different from that of the first embodiment.

  The main body mechanism (30) is a movable scroll (50) configured as a so-called double-toothed type. As shown in FIG. 7, the movable scroll (50) includes one flat plate portion (55), a first movable side wrap (53) formed on the lower surface of the flat plate portion (55), and a flat plate portion ( 55) and a second movable side wrap (54) formed on the upper surface. A bearing portion (64) is formed on the lower surface of the flat plate portion (55) of the movable scroll (50), and an eccentric portion (21) of the drive shaft (20) is inserted into the bearing portion (64).

  The fixed scroll (40) is fixed to the upper surface of the first fixed side member (41) and the first fixed side member (41) fixed to the casing (11) at a position below the movable scroll (50). And a second fixed side member (46). The first fixed side member (41) is formed with a first fixed side wrap (42) that meshes with the first movable side wrap (53), and the second fixed side member (46) has the second movable side wrap (42). A second fixed side wrap (47) is formed in which the side wrap (54) meshes. A compression chamber (71) of the compression mechanism (31) is formed by the first fixed side member (41) and the movable scroll (50), and is expanded by the second fixed side member (46) and the movable scroll (50). An expansion chamber (72) of the mechanism (32) is formed.

  An Oldham ring (39) for preventing rotation of the movable scroll (50) is mounted between the second fixed side member (46) and the movable scroll (50). The first fixed side member (41) has a main bearing (34), and the drive shaft (20) is rotatably supported by the main bearing (34).

  In the casing (11), a partition plate (85) is fixed immediately above the main body mechanism (30). The upper end portion (86) of the second fixed side member (46) is inserted into the partition plate (85) and an O-ring (87) is attached to the partition plate (85). The space is sealed. An O-ring (88) is also mounted on the outer peripheral surface of the second fixed side member (46), and the space above and below is sealed by the O-ring (88).

  The casing (11) has a suction port (73) communicating with the compression chamber (71) through the first fixed side member (41) and a first discharge port (63) from the compression chamber (71). A discharge port (74) for discharging the refrigerant flowing into the space below the first fixed side member (41) is provided. The casing (11) is provided with an inflow port (75) for introducing the refrigerant into the expansion mechanism (31) and an outflow port (76) for extracting the refrigerant from the expansion mechanism.

  Since other configurations are substantially the same as those of the above-described embodiment, description thereof is omitted here. Note that the same reference numerals as those in the first embodiment indicate the same components as those in the first embodiment.

  The refrigerant circuit using the scroll compressor (10) is not shown, but the discharge port (74) is the same as that shown in FIG. 6 in the first embodiment, but the condenser, the expansion valve, and the evaporator. To the suction port (73). A bypass passage branched from the discharge pipe is connected to the inflow port (75), and the outflow port (76) is connected to the suction pipe.

  In the second embodiment, a first movable side wrap (53) erected on one surface of the flat plate portion (55) and a second movable lap erected on the other surface of the flat plate portion (55). Therefore, the number of parts can be reduced and the cost can be reduced. In addition, the thrust load acts above and below the flat plate part (55) of the movable scroll (50), but since the direction of the action is opposite, there is less thrust bearing loss than a scroll compressor with a movable wrap on only one side. High efficiency.

  Further, the compression power can be reduced by introducing a part of the discharge gas of the compression mechanism (31) into the expansion mechanism (32) and recovering the power by the expansion mechanism (32). Further, the capacity of the compression mechanism (31) can be controlled steplessly by adjusting the flow rate of the discharge gas introduced into the expansion mechanism (32).

<< Embodiment 3 of the Invention >>
Next, a third embodiment of the present invention will be described. Embodiment 3 relates to a refrigeration apparatus using a multi-vane rotary compressor.

  FIG. 8 is a configuration diagram of the refrigerant circuit (90) in this refrigeration apparatus, and shows a schematic configuration of the main body mechanism (110) for the rotary compressor (100). The main body mechanism (110) of the rotary compressor (100) is housed in a casing (not shown). The main body mechanism (110) includes a cylinder (111) having a non-circular cylinder chamber (112), a piston (113) rotating in the cylinder chamber (112), and a cylinder mounted on the piston (113). A plurality of vanes (114) in pressure contact with the inner peripheral surface of the chamber (112). A front head and a rear head (not shown) are attached to the cylinder (111) so as to close the cylinder chamber (112).

  The cylinder chamber (112) is substantially elliptical in cross section perpendicular to the axis, and the piston (113) is circular in section perpendicular to the axis. A plurality of vanes (114) are attached to the piston (113), and each vane (114) is configured to be in pressure contact with the inner peripheral surface of the cylinder chamber (112).

  A compression chamber (121) and an expansion chamber (122) having a smaller volume are formed between the cylinder chamber (112) and the piston (113). In the compression chamber (121), the cylinder chamber (112), the piston (113), and the vane (114) constitute a compression mechanism (131). In the expansion chamber (122), the cylinder chamber (112) The expansion mechanism (132) is configured by the piston (113) and the vane (114). In this configuration, the piston (113) is an input side member of the compression mechanism (131) and an output side member of the expansion mechanism (132).

  The cylinder (111) is provided with a suction port (141) and a discharge port (142) communicating with the compression chamber (121), and an inflow port (143) and an outflow port (144) communicating with the expansion chamber (122). ing. The discharge port (142) is provided with a discharge valve (145), while the outflow port (144) is not provided with a valve.

  Also in the refrigerant circuit (90) of this embodiment, the discharge port (142) is connected to one end of the condenser (91) via the discharge pipe (94). The other end of the condenser (91) is connected to one end of the evaporator (93) via the expansion valve (92), and the other end of the evaporator (93) is connected to the suction port (141) via the suction pipe (95). It is connected to the. The bypass passage (96) branched from the discharge pipe (94) is connected to the inflow port (143) via the motorized valve (97) which is a flow rate adjusting mechanism, and the outflow port (144) is connected to the outflow pipe (98). To the suction pipe (95).

  In Embodiment 3, when the piston (113) rotates, the volume of the space defined between the two adjacent vanes (114), the cylinder (111), and the piston (113) in the compression chamber (121) increases. As a result, the refrigerant is sucked from the evaporator (93), and when the piston (113) further rotates, the above-mentioned volume is reduced and the refrigerant is compressed. The refrigerant is discharged from the compression chamber (121) by opening the discharge valve (145) when the pressure in the compression chamber (121) reaches a predetermined pressure. A part of this refrigerant flows through the bypass passage (96), while the rest flows into the condenser (91) to be condensed. The condensed refrigerant is depressurized in the expansion valve (92), then evaporated in the evaporator (93), sucked into the compression chamber (121) through the suction pipe (95), and compressed again.

  The refrigerant flowing through the bypass passage (96) is adjusted in flow rate by the motor operated valve (97) and flows into the expansion chamber (122) from the inflow port (143). This refrigerant expands in the expansion chamber (122), then flows out through the outflow port (144), merges with the refrigerant from the evaporator (93), and is sucked into the compression chamber (121). In the expansion chamber, a part of the energy when the refrigerant expands is recovered as power for rotating the piston (113).

  In the third embodiment, since the piston (113) rotating in the cylinder chamber (112) serves as both the output side member of the expansion mechanism (131) and the input side member of the compression mechanism (112), the structure is simple. Yes, the cost of the apparatus can be reduced.

  Similarly to the above embodiments, a part of the discharge gas of the compression mechanism (131) is introduced into the expansion mechanism (132), and the power is recovered by the expansion mechanism (132), so that the compression power can be reduced. Further, the capacity of the compression mechanism (131) can be continuously controlled by adjusting the flow rate of the discharge gas introduced into the expansion mechanism (132).

<< Other Embodiments >>
The present invention may be configured as follows with respect to the above embodiment.

  For example, in Embodiment 1, the bypass passage (94) branched from the discharge pipe (94) is connected to the inflow port (75) of the expansion mechanism (32), but the bypass passage (94) is connected to the compression mechanism. A part of the refrigerant discharged from the discharge port (63) of (31) may be a passage through the casing (11) of the compressor (10) to the inlet (66) of the expansion mechanism (32). .

The present invention also introduces a part of refrigerant discharged from the compression mechanism (31) (131) into the expansion mechanism (32) (132) to enable power recovery and capacity control. Mechanism (31) (131) and expansion mechanism
The types (32) and (132) are not limited to the scroll type or multi-vane type rotary type, and other types may be adopted.

  As described above, the present invention is useful for a compressor that performs capacity control.

It is a schematic sectional drawing which shows the structure of the scroll compressor in Embodiment 1. It is an expanded sectional view which shows the principal part of the scroll compressor of FIG. It is sectional drawing which shows the 1st fixed side member of a fixed scroll. It is sectional drawing which shows a movable scroll. It is a top view which shows a 1st fixed side member and a movable scroll. It is a block diagram of the refrigerant circuit using the scroll compressor of FIG. It is a fragmentary sectional view of the scroll compressor of Embodiment 2. FIG. 6 is a configuration diagram of a refrigerant circuit of a third embodiment.

Explanation of symbols

(10) Scroll compressor
(11) Casing
(16) Electric motor (drive mechanism)
(20) Drive shaft (drive mechanism)
(31) Compression mechanism
(32) Expansion mechanism
(40) Fixed scroll
(42) First fixed side wrap
(47) Second fixed wrap
(50) Moveable scroll
(51) First flat plate
(52) Second flat plate
(53) First movable side wrap (input side member)
(54) Second movable side wrap (output side member)
(55) Flat plate
(73) Suction port
(74) Discharge port
(75) Inflow port
(76) Outflow port
(94) Discharge piping
(96) Bypass passage
(97) Flow rate adjustment mechanism
(100) Rotary compressor
(112) Cylinder chamber
(113) Piston (input side member, output side member)
(114) Vane
(121) Compression chamber
(122) Expansion chamber
(131) Compression mechanism
(132) Expansion mechanism
(142) Discharge port
(141) Suction port
(143) Inflow port
(144) Outflow port

Claims (5)

A compressor provided with a compression mechanism (31) (131) and a drive mechanism (16, 20) for driving the compression mechanism (31) (131) in the casing (11),
The casing (11) includes an expansion mechanism (32) (132), and the output side members (54) (113) of the expansion mechanism (32) (132) are input to the compression mechanism (31) (131). Connected to the side member (53) (113),
A bypass passage (96) for introducing a part of the discharge gas of the compression mechanism (31) (131) into the expansion mechanism (32) (132) is provided, and a flow rate adjusting mechanism (97) is provided in the bypass passage (96). A compressor characterized by being provided. The compressor according to claim 1,
Discharge ports (74) (142) and suction ports (73) (141) communicating with the compression mechanisms (31) (131), and inflow ports (75) (143) communicating with the expansion mechanisms (32) (132) Outflow ports (76) (144) are provided,
The bypass passage (96) is branched from the discharge pipe (94) connected to the discharge port (74) (142) and connected to the inflow port (75) (143). . The compressor according to claim 1 or 2,
The compression mechanism (31) and the expansion mechanism (32) are scroll mechanisms,
A movable scroll (50) in which a first flat plate portion (51), a first movable side wrap (53), a second flat plate portion (52), and a second movable side wrap (54) are sequentially stacked and integrated; A fixed scroll (40) having a first fixed side wrap (42) meshing with the first movable side wrap (53) and a second fixed side wrap (47) meshing with the second movable side wrap (54); ,
The first fixed side wrap (42) and the first movable side wrap (53) constitute a compression mechanism (31),
The compressor characterized in that an expansion mechanism (32) is constituted by the second fixed side wrap (47) and the second movable side wrap (54). The compressor according to claim 1 or 2,
The compression mechanism (31) and the expansion mechanism (32) are scroll mechanisms,
A movable having a first movable side wrap (53) erected on one surface of the flat plate portion (55) and a second movable wrap (54) erected on the other surface of the flat plate portion (55). A fixed scroll having a scroll (50), a first fixed side wrap (42) meshing with the first movable side wrap (53), and a second fixed side wrap (47) meshing with the second movable side wrap (54) (40)
The first fixed side wrap (42) and the first movable side wrap (53) constitute a compression mechanism (31),
A compressor characterized in that an expansion mechanism (31) is constituted by the second fixed side wrap (47) and the second movable side wrap (54). The compressor according to claim 1 or 2,
The compression mechanism (131) and the expansion mechanism (132) are multi-vane type rotary mechanisms,
A non-circular cylinder chamber (112), a piston (113) that rotates in the cylinder chamber (112), and a plurality of vanes that are attached to the piston (113) and press-contact with the inner surface of the cylinder chamber (112) ( 114)
In the compression chamber (121) between the cylinder chamber (112) and the piston (113), the cylinder chamber (112), the piston (113), and the vane (114) constitute a compression mechanism (131),
In the expansion chamber (122) between the cylinder chamber (112) and the piston (113), the cylinder chamber (112), the piston (113), and the vane (114) constitute an expansion mechanism (132). Compressor.

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