JP3744526B2 - Rotary compressor - Google Patents

Description

  The present invention relates to a rotary compressor, and in particular, a compression in which an annular piston is disposed inside an annular cylinder chamber of a cylinder, and the cylinder and the annular piston relatively rotate eccentrically. The present invention relates to a rotary compressor having a mechanism.

  Conventionally, this type of rotary compressor is configured to compress a refrigerant by a change in volume of a cylinder chamber when an annular piston performs an eccentric rotational motion inside the annular cylinder chamber (for example, Patent Documents). 1). As shown in FIG. 3 and FIG. 4 (IV-IV cross-sectional view of FIG. 3: hatching omitted), in this compressor (100), a compression mechanism (120) and a compression mechanism (120) are placed in a sealed casing (110). An electric motor (not shown) for driving the mechanism (120) is accommodated.

  The compression mechanism (120) includes a cylinder (121) having an annular cylinder chamber (C1, C2) and an annular piston (122) disposed in the cylinder chamber (C1, C2). The cylinder (121) includes an outer cylinder (124) and an inner cylinder (125) arranged concentrically with each other, and the cylinder chambers (C1, C2) between the outer cylinder (124) and the inner cylinder (125). ) Is formed.

  The cylinder (121) is fixed to the casing (110). The annular piston (122) is connected to the eccentric part (133a) of the drive shaft (133) connected to the electric motor via a circular piston base (160), and is connected to the center of the drive shaft (133). It is configured to perform an eccentric rotational motion.

  In the annular piston (122), one point on the outer peripheral surface is substantially in contact with the inner peripheral surface of the outer cylinder (124). A state in which there is no problem of refrigerant leakage in the gap), and at the same time, one point on the inner peripheral surface is substantially in contact with the outer peripheral surface of the inner cylinder (125) at a position 180 degrees out of phase with it. It is configured to make an eccentric rotational movement while maintaining the above. As a result, an outer cylinder chamber (C1) is formed outside the annular piston (122), and an inner cylinder chamber (C2) is formed inside.

  An outer blade (123A) is disposed outside the annular piston (122), and an inner blade (123B) is disposed on an extension line of the outer blade (123A) on the inner side. The outer blade (123A) is urged toward the radially inner side of the annular piston (122), and the inner peripheral end is in pressure contact with the outer peripheral surface of the annular piston (122). The inner blade (123B) is biased toward the radially outer side of the annular piston (122), and the outer peripheral end is in pressure contact with the inner peripheral surface of the annular piston (122).

  The outer blade (123A) divides the outer cylinder chamber (C1) into two, and the inner blade (123B) divides the inner cylinder chamber (C2) into two. Specifically, the outer blade (123A) divides the outer cylinder chamber (C1) into a low pressure chamber (C1-Lp) and a high pressure chamber (C1-Hp), and the inner blade (123B) separates the inner cylinder chamber (C2). It is divided into a low pressure chamber (C2-Lp) and a high pressure chamber (C2-Hp). The outer cylinder (124) has a suction port (141) communicating with the outer cylinder chamber (C1) from a suction pipe (114) provided in the casing (110) in the vicinity of the outer blade (123A). The annular piston (122) is formed with a through hole (143) in the vicinity of the suction port (141), and the through hole (143) allows low pressures in the outer cylinder chamber (C1) and the inner cylinder chamber (C2). The chambers (C1-Lp, C2-Lp) communicate with each other. Further, the compression mechanism (120) has a discharge port (C1 and C2) for communicating the high pressure chambers (C1-Hp, C2-Hp) of the cylinder chambers (C1, C2) with the high pressure space (S) in the casing (110) ( (Not shown) is provided.

  In this example, the Oldham mechanism (161) is provided as the rotation prevention mechanism in order to allow only the eccentric rotational movement (revolution) while preventing the rotation of the annular piston (122).

  In this compression mechanism (120), when the annular piston (122) rotates eccentrically with the rotation of the drive shaft (133), the volume of each of the outer cylinder chamber (C1) and the inner cylinder chamber (C2) is increased. Enlargement and reduction are repeated alternately. When the volume of each cylinder chamber (C1, C2) is increased, a suction stroke is performed in which refrigerant is sucked into the cylinder chamber (C1, C2) from the suction port (141). Has a compression process for compressing the refrigerant in each cylinder chamber (C1, C2), and discharges the refrigerant from each cylinder chamber (C1, C2) to the high-pressure space (S) in the casing (110) through the discharge port. A discharge stroke is performed. The high-pressure refrigerant discharged into the high-pressure space (S) of the casing (110) flows out to the condenser of the refrigerant circuit via the discharge pipe (115) provided in the casing (110).

On the other hand, as shown in FIG. 5, Patent Document 1 also discloses an example in which the configuration of FIG. 4 is partially changed. In this compression mechanism (120), the annular piston (122) is cut at one point to form a C shape, and a single blade (123) crosses the cut point and the inner peripheral surface and the inner side of the outer cylinder (124). It is in contact with the outer peripheral surface of the cylinder (125). The inner peripheral surface of the outer cylinder (124) is formed such that a portion where the blade (123) contacts has the same radius of curvature as the outer peripheral surface of the inner cylinder (125). An Oldham mechanism (not shown) is provided so that the annular piston (122) rotates eccentrically (revolves) around the inner cylinder (125) but does not rotate. The refrigerant suction stroke, compression stroke, and discharge stroke are performed by the eccentric rotational movement of the annular piston (122), which is the same as in the examples of FIGS.
JP-A-6-288358

However, since the compressor (100) is a so-called high-pressure dome type compressor in which the space in the casing (110) becomes high pressure, the capacity of the motor is insufficient for the commercialization of a large-capacity compressor. There was a problem that the performance decreased. The reason is that if the outer diameter of the motor is D and the axial length is L, the output of the motor is proportional to D ² × L, and the surface area of the motor is approximately proportional to D × L, so the output is increased. This is because the heat transfer area (surface area) decreases with respect to the heat generation amount that increases in proportion to the output, resulting in insufficient cooling.

  On the other hand, it is possible to cool the motor with a low-pressure gas by placing the motor in a low-pressure space. However, if the motor is simply placed in the low-pressure space, the gas refrigerant is directly discharged from the compressor (100) to the outside of the compressor (100). Therefore, oil droplets contained in the discharge gas are discharged without being separated. In addition, there is a problem that the efficiency of the heat exchanger decreases due to an increase in the amount of oil circulation in the refrigerant circuit, and that it is necessary to provide a separate oil separator to avoid an increase in the amount of oil circulation. It was.

  The present invention has been made in view of such a problem, and an object of the present invention is to arrange an annular piston inside an annular cylinder chamber of a cylinder, and to relatively connect the cylinder and the annular piston. In a rotary compressor having a compression mechanism configured to perform eccentric rotational motion and further having a compression mechanism in which the cylinder chamber is partitioned by a blade into a high pressure chamber and a low pressure chamber, the cooling effect of the motor does not deteriorate even when the capacity is increased. Moreover, the amount of oil circulating in the refrigerant circuit should not be increased.

  In the present invention, the electric motor (30) is disposed in the low pressure space (S1) to cool the electric motor (30), and the discharge side of the compression mechanism (20) and the discharge pipe (15) of the casing (10) A high pressure space (S2) is provided between them to perform oil separation.

Specifically, the first invention comprises an outer cylinder (24), an inner cylinder (25), and an end plate (26) connected to the end of the outer cylinder (24) and the inner cylinder (25) . Cylinder (21) with cylinder chamber (C1, C2), and eccentric with respect to cylinder (21) and stored in cylinder chamber (C1, C2). Cylinder chamber (C1, C2) is connected to outer cylinder chamber (C1) An annular piston (22) that is divided into an inner cylinder chamber (C2) and the cylinder chamber (C1, C2). Each cylinder chamber (C1, C2) is placed in a high-pressure chamber (C1-Hp, C2-Hp) And a blade (23) partitioned into a low-pressure chamber (C1-Lp, C2-Lp), and a compression mechanism (20) in which the cylinder (21) and the annular piston (22) move relatively eccentrically. And a motor (30) for driving the compression mechanism (20), and a casing (10) for housing the compression mechanism (20) and the electric motor (30). It is based on the premise formula compressor.

In this rotary compressor, two spaces are formed in the casing (10) , one is a low pressure space (S1) communicating with the suction side of the compression mechanism (20), and the other is a compression mechanism (20 ) In the high pressure space (S2) (49) communicating with the discharge side, the motor (30) is disposed in the low pressure space (S1), the end plate (26) of the cylinder (21) and the annular piston (22) It is equipped with a compliance mechanism (29a, 29b, 36a, 36b) that reduces the axial clearance between the end surfaces of the two and the compliance mechanism (29a, 29b, 36a, 36b) is the pressure in the high-pressure space (S2) (49) Thus, the axial gap between the end plate (26) of the cylinder (21) and the end face of the annular piston (22) is reduced .

In the first invention, the suction gas flows into the low pressure space (S1) in the casing (10) and is then sucked into the compression mechanism (20). The gas sucked into the compression mechanism (20) is compressed by the compression mechanism (20) to become high pressure, flows out into the high-pressure space (S2) in the casing (10), and is then discharged from the casing (10). . In the present invention, since the electric motor (30) is disposed in the low pressure space (S1), the suction gas flows around the electric motor (30). In addition, because the compliance mechanism (29a, 29b, 36a, 36b) is provided, the pressure between the end plate (26) of the cylinder (21) and the end face of the annular piston (22) is caused by the pressure in the high-pressure space (S2) (49). The effect of reducing the axial gap of the is produced.

The second invention is a rotary compressor having the same configuration as that of the first invention. In the casing (10), two spaces are formed in the casing (10) with the compression mechanism (20) sandwiched between them. A low pressure space (S1) located below (20) and communicating with the suction side of the compression mechanism (20), and the other is located above the compression mechanism (20) and discharged from the compression mechanism (20) A high pressure space (S2) communicating with the side, wherein the electric motor (30) is disposed in the low pressure space (S1), and between the end plate (26) of the cylinder (21) and the end face of the annular piston (22) A compliance mechanism (29a, 29b, 36a, 36b) that reduces the axial clearance is provided, and this compliance mechanism (29a, 29b, 36a, 36b) is operated by the end plate (26) of the cylinder (21) by the pressure of the high-pressure space (S2). ) And the end face of the annular piston (22). It is a sign.

In the second aspect of the invention, the suction gas flows into the low pressure space (S1) defined in the casing (10) with the compression mechanism (20) interposed therebetween , and is then sucked into the compression mechanism (20) to increase the pressure. Become. The high-pressure gas flows out into the high-pressure space (S2) formed on the opposite side of the low-pressure space (S1) across the compression mechanism (20), and is then discharged from the discharge pipe (15).

Specifically, the suction gas is sucked into the compression mechanism (20) through the low pressure space (S1) below the compression mechanism (20). Therefore, even if a liquid back occurs due to a change in operating conditions in the refrigerant circuit, the liquid refrigerant can be prevented from being sucked into the compression mechanism (20). The high pressure gas is discharged from the casing (10) after filling the high pressure space (S2) above the compression mechanism (20).

According to a third invention, in the rotary compressor according to the first or second invention, a lower housing (17) in contact with the end plate (26) is provided below the end plate (26) of the cylinder (21), A discharge space (49) communicating with the high pressure space (S2) is provided above the compression mechanism (20), and the compliance mechanism (29a, 29b, 36a, 36b) is an annular piston ( 22) The piston-side high-pressure introduction passage (36a) formed so as to penetrate from the upper end surface to the lower end surface and the end plate (26) of the cylinder (21) are formed so as to penetrate from the upper end surface to the lower end surface. Cylinder side high pressure introduction passage (36b) communicating with the side high pressure introduction passage (36a), and an inner seal ring provided in the lower housing (17) so as to be located radially inward of the cylinder side high pressure introduction passage (36b) (29a) and the cylinder side high pressure introduction passage (36b) It is characterized in that it is constituted by an outer seal ring provided in the lower housing (17) so as to be located outwardly (29 b).

According to a fourth invention, in the rotary compressor according to any one of the first to third inventions, an oil return passage (37) communicating from the high pressure space (S2) to the low pressure space (S1) is provided. It is a feature.

  In the fourth aspect of the invention, the lubricating oil contained in the discharge gas discharged from the compression mechanism (20) into the high pressure space (S2) is separated from the discharge gas in the high pressure space (S2), and then the oil return passage ( 37) to return to the low pressure space (S1) below the compression mechanism (20).

  According to a fifth invention, in the rotary compressor according to any one of the first to fourth inventions, the blade (23) is provided integrally with the cylinder (21), and the annular piston (22) and the blade (23 ) Are movably connected to each other, and the connecting member (27) includes a first sliding surface (P1) for the annular piston (22) and a second sliding for the blade (23). It has a surface (P1).

  In the fifth invention, when the compression mechanism (20) is driven, the cylinder (21) and the annular piston (22) relatively eccentrically rotate. During the eccentric rotational movement, the annular piston (22) and the blade (23) relatively swing at a predetermined swing center and relatively advance and retreat in the surface direction of the blade (23). Gas is sucked into the cylinder chamber (C1, C2) when the volume of the cylinder chamber (C1, C2) is expanded, and the gas is compressed when the volume of the cylinder chamber (C1, C2) is reduced. The

  3 and 4, the blades (123A, 123B) and the annular piston (122) are in line contact, and in the configuration shown in FIG. 5, the blade (123) and the cylinder (124 , 125) are in line contact with each other, and the load received by the contact portion when the annular piston (122) rotates eccentrically during operation is large, and the contact portion may be worn or seized. It was.

  Moreover, in the structure of FIGS. 3-5, since members are carrying out line contact in this way, the sealing performance of a contact part is low, and in each of an outer cylinder chamber (C1) and an inner cylinder chamber (C2), There was also a risk that the compression efficiency would decrease due to the refrigerant leaking from the high pressure chamber (C1-Hp, C2-Hp) to the low pressure chamber (C1-Lp, C2-Lp).

  However, in the present invention, when the blade (23) and the annular piston (22) operate through the connecting member (27) (relative swinging operation and advancing and retracting operation), the connecting member (27) Since the sliding surfaces (P1, P2) are substantially in surface contact with both the annular piston (22) and the blade (23), the load acting on the contact portion is reduced, and the contact portion is worn and seized. Is less likely to occur. In addition, since the members make surface contact with each other on the sliding surfaces (P1, P2) in this way, gas leakage from the contact point is prevented as compared with the structure having a line contact as in Patent Document 1. it can.

  According to a sixth aspect of the present invention, in the rotary compressor of the fifth aspect, the annular piston (22) is formed in a C-shape with a part of the annular ring divided, and the blade (23) is an annular cylinder chamber ( C1, C2) is configured to extend from the inner peripheral wall surface to the outer peripheral wall surface of the annular piston (22) through the dividing portion, and the connecting member (27) includes the blade (23). The rocking bush (27) has a blade groove (28) that is held so as to be able to advance and retreat, and an arcuate outer peripheral surface that is held by the annular piston (22) so as to be able to swing freely.

  In the sixth aspect of the invention, when the compression mechanism (20) is driven, the blade (23) advances and retreats while being in surface contact with the blade groove (28) of the swing bush (27), and the swing bush (27) is annular. It swings while making surface contact with the part of the piston (22). By doing so, the connecting member (27) can be surely brought into contact with the annular piston (22) and the blade (23) surface-to-face, and gas leakage from the contact location can be reliably prevented.

  According to the first aspect of the invention, the low pressure space (S1) communicating with the suction side of the compression mechanism (20) and the high pressure space (S2) communicating with the discharge side of the compression mechanism (20) in the casing (10). ) And the electric motor (30) is arranged in the low-pressure space (S1), so that the suction gas to the compression mechanism (30) flows around the electric motor (30), and the electric motor (30 ) Can be cooled efficiently.

Moreover, since the high-pressure space (S2) communicating with the discharge side of the compression mechanism (20) is provided in the casing, discharge gas such as refrigerant is discharged from the compression mechanism (20) through the high-pressure space (S2). It becomes a structure. Therefore, even if the discharged gas contains a large amount of lubricating oil immediately after being discharged from the compression mechanism (20), the lubricating oil is separated in the high-pressure space (S2). For this reason, since the discharge gas discharged from the compressor (1) is separated from the lubricating oil, the amount of circulating oil in the refrigerant circuit can be reduced, and the shortage of oil in the compressor (1) can be eliminated. . In addition, an oil separator is not required to solve the oil shortage of the compressor (1). In addition, because the compliance mechanism (29a, 29b, 36a, 36b) is provided, the pressure between the end plate (26) of the cylinder (21) and the end face of the annular piston (22) is caused by the pressure in the high-pressure space (S2) (49). The axial gap can be reduced.

  According to the second aspect of the present invention, two spaces are formed in the casing (10) with the compression mechanism (20) sandwiched therebetween, one being the low pressure space (S1) and the other being the high pressure space (S2). The low pressure space (S1) and the high pressure space (S2) can be provided with a simple configuration. Therefore, the structure of the compressor (1) is not complicated, and an increase in size can be prevented.

Further , since the low pressure space (S1) is formed below the compression mechanism (20) and the high pressure space (S2) is formed above the compression mechanism (20), the liquid back is caused by a change in operating conditions in the refrigerant circuit. Even when it occurs, liquid compression can be prevented because the liquid refrigerant is not sucked into the compression mechanism (20). For this reason, since the compressor itself has an accumulator function, it is not necessary to provide an accumulator in the refrigerant circuit.

  According to the fourth aspect of the invention, since the oil return passage (37) communicating from the high pressure space (S2) to the low pressure space (S1) is provided, the oil is discharged from the compression mechanism (20) to the high pressure space (S2). The lubricating oil contained in the discharge gas is separated from the discharge gas in the high-pressure space (S2), and then returns to the low-pressure space (S1) below the compression mechanism (20) through the oil return passage (37). Lubricating oil may be supplied from the low pressure space (S1) to the sliding portion of the compression mechanism (20).

  According to the fifth aspect of the present invention, when the compression mechanism (20) is operated, the connecting member (27) is substantially slid on the sliding surfaces (P1, P2) with respect to the annular piston (22) and the blade (23). Therefore, the load per unit area acting on the contact portion can be reduced as compared with the structure in which line contact is made as in Patent Document 1. Therefore, when the blade (23) and the annular piston (22) slide through the connecting member (27) during operation, the contact portion is less likely to be worn or seized. The connecting member (27) is in surface contact with the annular piston (22) and the blade (23) at the sliding surfaces (P1, P2), so that the high pressure chamber (C1-Hp, C2-Hp) and the low pressure chamber are Gas leakage between (C1-Lp, C2-Lp) can also be prevented.

  According to the sixth aspect of the present invention, the connecting member (27) is held by the blade groove (28) for holding the blade (23) so as to be able to advance and retreat, and the annular piston (22) so as to be swingable at the dividing position. The rocking bush (27) with an arcuate outer peripheral surface can be used to reliably prevent gas leakage, wear and seizure during operation, and a complicated connection structure. Can also be prevented. For this reason, the enlargement of a mechanism and the increase in cost can also be prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the rotary compressor (1) includes a casing (10) in which a compression mechanism (20) and an electric motor (drive mechanism) (30) are housed, and is configured as a completely sealed type. Yes. The compressor (1) is used, for example, in the refrigerant circuit of the air conditioner to compress the refrigerant sucked from the evaporator and discharge it to the condenser.

  The casing (10) includes a cylindrical body (11), an upper end panel (12) fixed to the upper end of the body (11), and a lower end panel fixed to the lower end of the body (11). (13). The body (11) is provided with a suction pipe (14) that passes through the body (11), and the upper end panel (12) is provided with a discharge pipe (15) that passes through the end panel (12). It has been.

  The compression mechanism (20) is configured between an upper housing (16) and a lower housing (17) fixed to the casing (10). The compression mechanism (20) includes a cylinder (21) having an annular cylinder chamber (C1, C2), an annular piston (22) disposed in the cylinder chamber (C1, C2), and as shown in FIG. The blade (23) that divides the cylinder chamber (C1, C2) into a high pressure chamber (compression chamber) (C1-Hp, C2-Hp) and a low pressure chamber (suction chamber) (C1-Lp, C2-Lp) Have. The cylinder (21) and the annular piston (22) are configured to relatively rotate eccentrically. In this embodiment, the cylinder (21) having the cylinder chambers (C1, C2) is the movable side, and the annular piston (22) disposed in the cylinder chamber (C1, C2) is the fixed side.

  The electric motor (30) includes a stator (31) and a rotor (32). The stator (31) is disposed below the compression mechanism (20), and is fixed to the body (11) of the casing (10). A drive shaft (33) is connected to the rotor (32), and the drive shaft (33) is configured to rotate together with the rotor (32). The drive shaft (33) penetrates the cylinder chamber (C1, C2) in the vertical direction. The lower end portion of the drive shaft (33) is supported by the bearing member (19).

  The drive shaft (33) is provided with an oil supply passage (not shown) extending in the axial direction inside the drive shaft (33). An oil supply pump (volumetric pump) (34) is provided at the lower end of the drive shaft (33). The oil supply path extends upward from the oil supply pump (34) to the compression mechanism (20). With this configuration, the lubricating oil stored at the bottom of the casing (10) is supplied to the sliding portion of the compression mechanism (20) through the oil supply passage by the oil supply pump (34).

  The drive shaft (33) is formed with an eccentric portion (33a) at a portion located in the cylinder chamber (C1, C2). The eccentric part (33a) is formed to have a larger diameter than the upper and lower parts of the eccentric part (33a), and is eccentric from the axis of the drive shaft (33) by a predetermined amount.

  The cylinder (21) includes an outer cylinder (24) and an inner cylinder (25). The outer cylinder (24) and the inner cylinder (25) are integrated by connecting the lower end portions thereof with the end plate (26). The inner cylinder (25) is slidably fitted in the eccentric part (33a) of the drive shaft (33).

  The annular piston (22) is formed integrally with the upper housing (16). The upper housing (16) and the lower housing (17) are formed with bearing portions (16a, 17a) for supporting the drive shaft (33), respectively. Thus, in the compressor (1) of the present embodiment, the drive shaft (33) penetrates the cylinder chamber (C1, C2) in the vertical direction, and both axial portions of the eccentric portion (33a) are bearing portions. It has a through shaft structure that is held by the casing (10) via (16a, 17a).

  The compression mechanism (20) includes an oscillating bush (27) as a connecting member for movably connecting the annular piston (22) and the blade (23) to each other. The annular piston (22) is formed in a C shape in which a part of the annular ring is divided. The blade (23) is located on the radial line of the cylinder chamber (C1, C2), from the inner peripheral wall surface (the outer peripheral surface of the inner cylinder (25)) of the cylinder chamber (C1, C2) to the outer peripheral wall surface (outer side). The cylinder (24) is configured so as to extend through the part where the annular piston (22) is divided, and is fixed to the outer cylinder (24) and the inner cylinder (25). The swinging bush (27) connects the annular piston (22) and the blade (23) at a parting point of the annular piston (22). The blade (23) may be formed integrally with the outer cylinder (24) and the inner cylinder (25) as shown in FIG. 2, or separate members may be integrated with both cylinders (24, 25). It may be formed.

  The inner peripheral surface of the outer cylinder (24) and the outer peripheral surface of the inner cylinder (25) are cylindrical surfaces arranged on the same center, and the cylinder chambers (C1, C2) are formed therebetween. The annular piston (22) has an outer peripheral surface having a smaller diameter than the inner peripheral surface of the outer cylinder (24) and an inner peripheral surface having a larger diameter than the outer peripheral surface of the inner cylinder (25). Thus, an outer cylinder chamber (C1) is formed between the outer peripheral surface of the annular piston (22) and the inner peripheral surface of the outer cylinder (24), and the inner peripheral surface of the annular piston (22) and the inner cylinder (25 ) Is formed between the inner cylinder chamber (C2).

  In addition, the annular piston (22) and the cylinder (21) are in a state in which the outer peripheral surface of the annular piston (22) and the inner peripheral surface of the outer cylinder (24) are substantially in contact at one point (strictly, a clearance in the micron order) In the state where refrigerant leakage in the gap is not a problem), the inner peripheral surface of the annular piston (22) and the outer peripheral surface of the inner cylinder (25) It comes to substantially touch at one point.

  The swing bush (27) includes a discharge side bush (27A) located on the high pressure chamber (C1-Hp, C2-Hp) side with respect to the blade (23), and a low pressure chamber (C1 -Lp, C2-Lp) and suction side bush (27B). The discharge-side bush (27A) and the suction-side bush (27B) are both substantially semicircular in cross section and formed in the same shape, and are arranged so that the flat surfaces face each other. And the space between the opposing surfaces of both bushes (27A, 27B) constitutes a blade groove (28).

  The blade (23) is inserted into the blade groove (28), and the flat surface (second sliding surface (P2): see FIG. 2 (C)) of the swing bush (27A, 27B) is substantially the same as the blade (23). Surface contact, and the arc-shaped outer peripheral surface (first sliding surface (P1)) is substantially in surface contact with the annular piston (22). The swing bushes (27A, 27B) are configured such that the blade (23) advances and retreats in the blade groove (28) in the surface direction with the blade (23) sandwiched between the blade grooves (28). . At the same time, the swing bushes (27A, 27B) are configured to swing integrally with the blade (23) with respect to the annular piston (22). Therefore, the swing bush (27) is configured such that the blade (23) and the annular piston (22) can swing relatively with the center point of the swing bush (27) as the swing center, and the blade (23) is configured to be movable back and forth in the surface direction of the blade (23) with respect to the annular piston (22).

  In this embodiment, an example in which both bushes (27A, 27B) are separated from each other has been described. However, both bushes (27A, 27B) may be integrated with each other.

  In the above configuration, when the drive shaft (33) rotates, the outer cylinder (24) and the inner cylinder (25) move the blade (23) while the blade (23) advances and retreats in the blade groove (28). Oscillates with the center point as the oscillation center. By this swinging operation, the contact point between the annular piston (22) and the cylinder (21) is moved sequentially from FIG. 2 (A) to (D). At this time, the outer cylinder (24) and the inner cylinder (25) revolve around the rotation center of the drive shaft (33), but do not rotate.

  The lower housing (17) is formed with a suction port (41) opened to a space (low pressure space (S1)) below the compression mechanism (20). The upper housing (16) includes a suction space (42) communicating with the suction port (41), a low pressure chamber (C1-Lp) and an inner cylinder chamber of the outer cylinder chamber (C1) from the suction space (42). A suction passage (42a) communicating with the low pressure chamber (C2-Lp) of (C2) is formed. The outer cylinder (24) has a through hole (43) that communicates the suction space (42) and the low pressure chamber (C1-Lp) of the outer cylinder chamber (C1). The annular piston (22) A through hole (44) is formed to communicate the low pressure chamber (C1-Lp) of the outer cylinder chamber (C1) and the low pressure chamber (C2-Lp) of the inner cylinder chamber (C2).

  Discharge ports (45, 46) are formed in the upper housing (16). Each of these discharge ports (45, 46) penetrates the upper housing (16) in the axial direction thereof. The lower end of the discharge port (45) opens to the high pressure chamber (C1-Hp) of the outer cylinder chamber (C1), and the lower end of the discharge port (46) is the high pressure chamber (C2-Hp) of the inner cylinder chamber (C2). ). On the other hand, the upper ends of these discharge ports (45, 46) communicate with the discharge space (49) via discharge valves (reed valves) (47, 48) that open and close the discharge ports (45, 46). .

  The discharge space (49) is formed between the upper housing (16) and the cover plate (18). The discharge space (49) is a space that is continuous in the circumferential direction above the compression mechanism (20), and is a high-pressure space (above the cover plate (18) through the opening (18a) of the cover plate (18). S2). The discharge pipe (15) has a lower end opened to the high-pressure space (S2).

  The annular piston (22) is formed with a piston-side high-pressure introduction passage (36a) that penetrates from the upper end surface to the lower end surface, and the end plate (26) of the cylinder (21) penetrates from the upper end surface to the lower end surface. A cylinder side high pressure introduction passage (36b) is formed. The piston side high pressure introduction passage (36a) and the cylinder side high pressure introduction passage (36b) communicate with each other even during operation of the compression mechanism (20) by making the lower end of the piston side high pressure introduction passage (36a) larger in diameter. The high pressure in the discharge space (49) is introduced to the contact surface between the lower housing (17) and the end plate (26).

  The lower housing (17) includes an inner seal ring (29a) located radially inward of the cylinder side high pressure introduction passage (36b) and an outer seal located radially outward of the cylinder side high pressure introduction passage (36b). A ring (29b) is provided. These seal rings (29a, 29b) are loaded in the annular grooves (17b, 17c) of the lower housing (17). This constitutes a compliance mechanism that reduces the axial gap that can occur between the cylinder (21) and the annular piston (22) using the pressure between the seal rings (29a, 29b).

  On the other hand, an oil return pipe (oil return passage) (37) is provided through the upper housing (16) and the lower housing (17) vertically. The oil return pipe (37) is constituted by a capillary tube. The discharge gas discharged from the compression mechanism (20) contains lubricating oil. This lubricating oil is separated from the refrigerant in the high-pressure space (S1) and collected on the upper surface of the upper housing (16). Then, due to the differential pressure between the high pressure space (S2) and the low pressure space (S1), the lubricating oil returns to the bottom of the casing (10) through the oil return pipe (37).

-Driving action-
Next, the operation of the compressor (1) will be described.

  When the electric motor (30) is started, the rotation of the rotor (32) is transmitted to the outer cylinder (24) and the inner cylinder (25) of the compression mechanism (20) via the drive shaft (33). Then, the blade (23) reciprocates (advances and retreats) between the swing bushes (27A, 27B), and the blade (23) and the swing bushes (27A, 27B) are integrated into an annular shape. Oscillates with respect to the piston (22). At that time, the oscillating bushes (27A, 27B) substantially make surface contact with the annular piston (22) and the blade (23) at the sliding surfaces (P1, P2). Then, the outer cylinder (24) and the inner cylinder (25) revolve while swinging with respect to the annular piston (22), and the compression mechanism (20) performs a predetermined compression operation.

  Specifically, in the outer cylinder chamber (C1), the volume of the low pressure chamber (C1-Lp) is almost minimum in the state of FIG. 2 (D), from which the drive shaft (33) rotates clockwise in the figure. When the volume of the low pressure chamber (C1-Lp) increases as the state changes to the state shown in FIGS. 2 (A), 2 (B), and 2 (C), the refrigerant is introduced into the suction pipe (14 ), And is sucked into the low pressure chamber (C1-Lp) through the low pressure space (S1) and the suction port (41). Specifically, the refrigerant partially passes from the suction port (41) and the suction space (42) through the suction passage (42a), and the other part passes through the through hole (43) to the low pressure chamber (C1- Lp).

  When the drive shaft (33) makes one revolution and enters the state of FIG. 2 (D) again, the suction of the refrigerant into the low pressure chamber (C1-Lp) is completed. The low-pressure chamber (C1-Lp) is now a high-pressure chamber (C1-Hp) in which the refrigerant is compressed, and a new low-pressure chamber (C1-Lp) is formed across the blade (23). When the drive shaft (33) further rotates, the suction of the refrigerant is repeated in the low pressure chamber (C1-Lp), while the volume of the high pressure chamber (C1-Hp) is reduced, and the refrigerant in the high pressure chamber (C1-Hp) Is compressed. When the pressure in the high-pressure chamber (C1-Hp) reaches a set value and the differential pressure from the discharge space (49) reaches the set value, the high-pressure refrigerant in the high-pressure chamber (C1-Hp) opens the discharge valve (47). The high-pressure refrigerant flows out from the discharge space (49) to the high-pressure space (S2).

  In the inner cylinder chamber (C2), the volume of the low pressure chamber (C2-Lp) is almost the minimum in the state of FIG. 2 (B), from which the drive shaft (33) rotates clockwise in FIG. C), when the volume of the low pressure chamber (C2-Lp) increases with the change to the state of FIG. 2 (D), FIG. 2 (A), the refrigerant is taken into the suction pipe (14), the low pressure space. The air is sucked into the low pressure chamber (C2-Lp) through (S1) and the suction port (41). Specifically, the refrigerant partially passes from the suction port (41) and the suction space (42) through the suction passage (42a), and the other part is the through hole (43), the low pressure chamber ( C1-Lp) and the through-hole (44) are sucked into the low pressure chamber (C2-Lp) of the inner cylinder chamber (C2).

  When the drive shaft (33) makes one revolution and enters the state of FIG. 2 (B) again, the suction of the refrigerant into the low pressure chamber (C2-Lp) is completed. The low-pressure chamber (C2-Lp) is now a high-pressure chamber (C2-Hp) in which the refrigerant is compressed, and a new low-pressure chamber (C2-Lp) is formed across the blade (23). When the drive shaft (33) further rotates, the suction of the refrigerant is repeated in the low pressure chamber (C2-Lp), while the volume of the high pressure chamber (C2-Hp) decreases, and the refrigerant in the high pressure chamber (C2-Hp) Is compressed. When the pressure in the high pressure chamber (C2-Hp) reaches a preset value and the differential pressure from the discharge space (49) reaches the set value, the high pressure refrigerant in the high pressure chamber (C2-Hp) opens the discharge valve (48). The high-pressure refrigerant flows out from the discharge space (49) to the high-pressure space (S2).

  The high-pressure refrigerant compressed in the outer cylinder chamber (C1) and the inner cylinder chamber (C2) and flowing into the high-pressure space (S2) in this way is discharged from the discharge pipe (15) and is condensed and expanded in the refrigerant circuit. , And after evaporating stroke, it is sucked into the compressor (1) again. The lubricating oil contained in the refrigerant discharged from the compression mechanism (20) is separated from the refrigerant in the high-pressure space (S2), dropped through the oil return pipe (37) to the low-pressure space (S1), and the casing. Return to the oil sump at the bottom of (10).

-Effect of the embodiment-
In this embodiment, since the lower side of the compression mechanism (20) is a low pressure space (S1) and the electric motor (30) is disposed in the low pressure space (S1), the electric motor (30) is efficiently cooled by the low pressure gas. it can. Therefore, even when the capacity of the compressor (1) is increased, the reduction in the capacity of the electric motor (30) can be suppressed, so that the operation efficiency is improved.

  Also, since the discharge gas from the compression mechanism (30) flows into the high-pressure space (S2) and is discharged from the discharge pipe (15), the lubricating oil contained in the discharge gas is separated in the high-pressure space (S2). it can. The lubricating oil returns to the oil sump in the casing (10) through the oil return pipe (37). Therefore, it is possible to prevent the amount of oil circulating in the refrigerant circuit from increasing, and conversely, it is possible to prevent a shortage of lubricating oil inside the compressor (1). In addition, a dedicated oil separator is not required to prevent the lack of lubricating oil in the compressor (1).

  Furthermore, two spaces are formed in the casing (10) with the compression mechanism (20) sandwiched between them, one being the low pressure space (S1) and the other being the high pressure space (S2). (S1) and high-pressure space (S2) can be provided. Therefore, the structure of the compressor (1) is not complicated, and an increase in size can be prevented.

  Further, since the low pressure space (S1) is formed below the compression mechanism (20) and the high pressure space (S2) is formed above the compression mechanism (20), the liquid back is caused by a change in operating conditions in the refrigerant circuit. Even when it occurs, liquid compression can be prevented because the liquid refrigerant is not sucked into the compression mechanism (20).

  In this embodiment, a swinging bush (27) is provided as a connecting member for connecting the annular piston (22) and the blade (23), and the swinging bush (27) is provided with the annular piston (22) and the blade (23 ) With the sliding surfaces (P1, P2), the ring piston (22) and blade (23) are worn during operation in the case of line contact. Such a problem can be prevented while the contact portion may be burned out.

  In addition, since the swing bush (27) is provided in this way so that the swing bush (27) is in surface contact with the annular piston (22) and the blade (23), the sealing performance of the contact portion is also improved. Are better. Therefore, in each of the outer cylinder chamber (C1) and the inner cylinder chamber (C2), refrigerant leaks from the high pressure chamber (C1-Hp, C2-Hp) to the low pressure chamber (C1-Lp, C2-Lp), resulting in compression efficiency. Can also be prevented.

  Furthermore, according to the compressor (1) of this embodiment, the phase difference between the torque fluctuation accompanying the compression operation in the outer cylinder chamber (C1) and the torque fluctuation accompanying the compression operation in the inner cylinder chamber (C2) is 180 °. As a result, the amplitude of the total torque curve is smaller than that of a one-cylinder compressor. If this amplitude is large, vibration and noise of the compressor (1) become a problem. In this embodiment, such a problem can also be prevented. In addition, since the structure is low in noise, no soundproofing material is required, and the cost can be reduced.

  Further, for example, in a conventional two-cylinder type compressor (for example, see Japanese Patent Application Laid-Open No. 2000-161276) in which compression mechanisms are stacked in two stages, the configuration becomes complicated and the cost increases. In the machine (1), the two cylinder chambers (C1, C2) provided in one compression mechanism (20) can provide the same capacity as the above-mentioned two-cylinder machine, and the structure can be simplified and the cost can be reduced. It is done.

  Furthermore, according to the structure of this embodiment, when a liquid back is generated from the evaporator of the refrigerant circuit to the compressor (1) due to a change in operating conditions, the refrigerant is once introduced into the low-pressure space (S1). Here, the liquid and the gas are separated, and only the gas can be sucked into the cylinder chamber (C1, C2). Therefore, since the compressor (1) can be provided with an accumulator function, it is not necessary to provide an accumulator as a component of the refrigerant circuit.

  Even if liquid refrigerant is introduced into the cylinder chamber (C1, C2), if the high pressure in the high pressure chamber (C1-Hp, C2-Hp) of the cylinder chamber (C1, C2) rises abnormally, the seal ring The cylinder (21) is displaced downward by deforming (29). By doing so, the liquid refrigerant can be leaked from the high pressure chamber (C1-Hp, C2-Hp) to the low pressure chamber (C1-Lp, C2-Lp), thereby preventing liquid compression. As a result, there is little risk of failure of the compression mechanism (20), and reliability is improved.

  Further, according to this embodiment, since the blade (23) is provided integrally with the cylinder (21) and is held by the cylinder (21) at both ends thereof, abnormal concentration on the blade (23) during operation is achieved. It is difficult for load and stress concentration to occur. For this reason, a sliding part is hard to be damaged and the reliability of a mechanism can be improved also from the point.

  3 to 5, the Oldham mechanism is used as a rotation preventing mechanism for rotating the annular piston (22) only eccentrically without rotating. Connecting the annular piston (22) and the blade (23) via the bush (27) itself is a rotation prevention mechanism for the annular piston, and a dedicated rotation prevention mechanism is not required. It becomes possible.

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

  In each of the above-described embodiments, the annular piston (22) has a C-shaped shape in which a part of the annular ring is divided, and the blade (23) is inserted through the divided portion, and the annular piston (22), the blade (23), Are connected via a swinging bush (27), but the swinging bush (27) is not necessarily provided.

That is, in the present invention, the cylinder (21), the annular piston (22) disposed in the cylinder chamber (C1, C2) of the cylinder (21), and the cylinder chamber (C1, C2) are connected to the high pressure chamber (C1 -Hp, C2-Hp) and blade (23) partitioned into low-pressure chambers (C1-Lp, C2-Lp), and the cylinder (21) and the annular piston (22) are relatively eccentrically rotated. In the rotary compressor provided with the compression mechanism (20) for performing the operation, the low pressure space (S1) communicating with the suction side of the compression mechanism (20) in the casing (10), and the discharge side of the compression mechanism (20) A high-pressure space (S2) that communicates with the motor, and the electric motor (30) is placed in the low-pressure space (S1) and the pressure in the high-pressure space (S2) (49) that communicates with the discharge side of the compression mechanism (20) As long as the compliance mechanism (29a, 29b, 36a, 36b) is configured by use, other specific structures may be appropriately changed.

  For example, in each of the above embodiments, the blade (23) is arranged so as to be positioned on the radial line of the cylinder chamber (C1, C2). However, the blade (23) has a diameter of the cylinder chamber (C1, C2). The arrangement may be slightly inclined with respect to the direction line segment.

  In the above embodiment, the cylinder (21) having the cylinder chambers (C1, C2) is set to the movable side, and the annular piston (22) disposed in the cylinder chamber (C1, C2) is set to the fixed side. The cylinder (21) may be on the fixed side and the annular piston (22) may be on the movable side.

  As described above, in the present invention, the annular piston (22) is disposed inside the annular cylinder chamber (C1, C2) of the cylinder (21), and the cylinder (21) and the annular piston (22) Are configured to relatively eccentrically rotate, and the cylinder chambers (C1, C2) are blades (23), and a high pressure chamber (C1-Hp, C2-Hp) and a low pressure chamber (C1-Lp, C2- It is useful for a rotary compressor having a compression mechanism (20) partitioned into Lp).

It is a longitudinal section of a rotary compressor concerning an embodiment of the present invention. It is a cross-sectional view showing the operation of the compression mechanism. It is a partial longitudinal cross-sectional view of the rotary compressor which concerns on a prior art. It is IV-IV sectional drawing of FIG. It is sectional drawing which shows the modification of FIG.

Explanation of symbols

(1) Compressor (10) Casing (14) Suction pipe (15) Discharge pipe (16) Upper housing (16a) Bearing part (17) Lower housing (17a) Bearing part (19) Bearing member (20) Compression mechanism ( 21) Cylinder (22) Ring piston (23) Blade (24) Outer cylinder (25) Inner cylinder (26) End plate (27) Connecting member (oscillating bush)
(28) Blade groove (30) Electric motor (33) Drive shaft (33a) Eccentric part (C1) Cylinder chamber (outer cylinder chamber)
(C2) Cylinder chamber (inner cylinder chamber)
(C1-Hp) High pressure chamber (compression chamber)
(C2-Hp) High pressure chamber (compression chamber)
(C1-Lp) Low pressure chamber (suction chamber)
(C2-Lp) Low pressure chamber (suction chamber)
(P1) First sliding surface (P2) Second sliding surface (S1) Low pressure space (S2) High pressure space

Claims (6)

A cylinder having an annular cylinder chamber (C1, C2) with an outer cylinder (24), an inner cylinder (25), and an end plate (26) connected to the end of the outer cylinder (24) and the inner cylinder (25) (21) and is eccentric to the cylinder (21) and stored in the cylinder chamber (C1, C2), and the cylinder chamber (C1, C2) is divided into an outer cylinder chamber (C1) and an inner cylinder chamber (C2). An annular piston (22) and the cylinder chambers (C1, C2) are arranged, and each cylinder chamber (C1, C2) is divided into a high pressure chamber (C1-Hp, C2-Hp) and a low pressure chamber (C1-Lp, C2- A compression mechanism (20) having a blade (23) partitioned into Lp), wherein the cylinder (21) and the annular piston (22) relatively rotate eccentrically,
An electric motor (30) for driving the compression mechanism (20);
A rotary compressor comprising the compression mechanism (20) and a casing (10) for housing the electric motor (30),
Two spaces are formed in the casing (10) , one is a low pressure space (S1) communicating with the suction side of the compression mechanism (20), and the other is a high pressure communicating with the discharge side of the compression mechanism (20). Space (S2) (49),
The electric motor (30) is disposed in the low-pressure space (S1) ;
A compliance mechanism (29a, 29b, 36a, 36b) for reducing the axial clearance between the end plate (26) of the cylinder (21) and the end face of the annular piston (22);
The compliance mechanism (29a, 29b, 36a, 36b) reduces the axial clearance between the end plate (26) of the cylinder (21) and the end face of the annular piston (22) by the pressure in the high-pressure space (S2) (49) It is comprised so that it may do, The rotary compressor characterized by the above-mentioned . A cylinder having an annular cylinder chamber (C1, C2) with an outer cylinder (24), an inner cylinder (25), and an end plate (26) connected to the end of the outer cylinder (24) and the inner cylinder (25) (21) and is eccentric to the cylinder (21) and stored in the cylinder chamber (C1, C2), and the cylinder chamber (C1, C2) is divided into an outer cylinder chamber (C1) and an inner cylinder chamber (C2). An annular piston (22) and the cylinder chambers (C1, C2) are arranged, and each cylinder chamber (C1, C2) is divided into a high pressure chamber (C1-Hp, C2-Hp) and a low pressure chamber (C1-Lp, C2- A compression mechanism (20) having a blade (23) partitioned into Lp), wherein the cylinder (21) and the annular piston (22) relatively rotate eccentrically,
An electric motor (30) for driving the compression mechanism (20);
A rotary compressor comprising the compression mechanism (20) and a casing (10) for housing the electric motor (30),
In the casing (10), two spaces are formed with the compression mechanism (20) interposed therebetween, and one of the spaces is located below the compression mechanism (20) and communicates with the suction side of the compression mechanism (20). (S1), and the other is a high-pressure space (S2) located above the compression mechanism (20) and communicating with the discharge side of the compression mechanism (20),
The electric motor (30) is disposed in the low-pressure space (S1);
A compliance mechanism (29a, 29b, 36a, 36b) for reducing the axial clearance between the end plate (26) of the cylinder (21) and the end face of the annular piston (22);
The compliance mechanism (29a, 29b, 36a, 36b) reduces the axial clearance between the end plate (26) of the cylinder (21) and the end face of the annular piston (22) by the pressure of the high pressure space (S2). A rotary compressor characterized in that it is configured . The rotary compressor according to claim 1 or 2 ,
A lower housing (17) in contact with the end plate (26) is provided below the end plate (26) of the cylinder (21), while a discharge space (S2) communicating with the high pressure space (S2) is provided above the compression mechanism (20). 49)
The compliance mechanism (29a, 29b, 36a, 36b) includes a piston-side high-pressure introduction passage (36a) formed so as to penetrate from the upper end surface to the lower end surface of the annular piston (22) communicating with the discharge space (49), A cylinder-side high-pressure introduction passage (36b) that is formed so as to penetrate the end plate (26) of the cylinder (21) from the upper end surface to the lower-end surface and communicates with the piston-side high-pressure introduction passage (36a); 36b) is located radially inward of the lower housing (17), and the lower housing (29a) is positioned radially outward of the cylinder side high pressure introduction passage (36b). A rotary compressor characterized by comprising an outer seal ring (29b) provided in 17) . The rotary compressor according to any one of claims 1 to 3 ,
A rotary compressor comprising an oil return passage (37) communicating from a high pressure space (S2) to a low pressure space (S1). The rotary compressor according to any one of claims 1 to 4,
The blade (23) is provided integrally with the cylinder (21),
A connecting member (27) for movably connecting the annular piston (22) and the blade (23) to each other;
The connecting member (27) includes a first sliding surface (P1) for the annular piston (22) and a second sliding surface (P1) for the blade (23). Machine. The rotary compressor according to claim 5,
The annular piston (22) is formed in a C shape in which a part of the annular ring is divided,
The blade (23) is configured to extend from the inner peripheral wall surface to the outer peripheral wall surface of the annular cylinder chamber (C1, C2) through the dividing portion of the annular piston (22),
The connecting member (27) includes a blade groove (28) that holds the blade (23) so as to be able to advance and retreat, and an arcuate outer peripheral surface that is held by the annular piston (22) so as to be swingable at a parting position. A rotary compressor characterized by a dynamic bush (27).

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