JP4635819B2 - Rotary compressor - Google Patents

Description

  The present invention relates to a rotary compressor, and in particular, an annular piston that divides the cylinder chamber into an outer cylinder chamber and an inner cylinder chamber is disposed inside an annular cylinder chamber of a cylinder, and the outer cylinder chamber and the inner cylinder chamber are arranged inside. The present invention relates to a rotary compressor having a compression mechanism that includes a blade that divides a cylinder chamber into a high-pressure chamber and a low-pressure chamber, and is configured so that the cylinder and the annular piston relatively rotate eccentrically.

  Conventionally, as this type of rotary compressor, there is a compressor configured to compress a refrigerant by a change in volume of the cylinder chamber when the annular piston performs an eccentric rotational motion inside the annular cylinder chamber (for example, Patent Document 1). As shown in FIGS. 16 and 17 (XVII-XVII cross-sectional view of FIG. 15: hatching omitted), in this compressor (100), a compression mechanism (120) and a compression mechanism (120) are placed in a hermetic 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 part (124) and an inner cylinder part (125) arranged concentrically with each other, and the cylinder chamber is interposed between the outer cylinder part (124) and the inner cylinder part (125). (C1, C2) 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 part (124). At the same time, one point on the inner peripheral surface is substantially on the outer peripheral surface of the inner cylinder part (125) at a position that is 180 ° out of phase with that. It is configured to perform an eccentric rotational movement while maintaining a contact state. 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) partitions the outer cylinder chamber (C1) into a high pressure chamber (C1-Hp) and a low pressure chamber (C1-Lp), and the inner blade (123B) is the inner cylinder chamber (C2). Is divided into a high pressure chamber (C2-Hp) and a low pressure chamber (C2-Lp). The outer cylinder portion (124) has a suction port (141) communicating with the outer cylinder chamber (C1) from the 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).

  In the compressor, since the blades (123A, 123B) and the annular piston (122) are in line contact with each other, the load received by the contact portion when the annular piston (122) performs eccentric rotational movement during operation is large. There was a risk that the contact portion would be worn or seized. Further, since the members are in line contact with each other in this way, there is also a drawback that the sealability of the contact portion is low. Therefore, in the above configuration, the refrigerant flows from the high pressure chamber (C1-Hp, C2-Hp) to the low pressure chamber (C1-Lp, C2-Lp) in each of the outer cylinder chamber (C1) and the inner cylinder chamber (C2). Leakage may reduce the compression efficiency.

  Therefore, the applicant of the present application has proposed a compressor (200) having a structure as shown in FIGS. 18 and 19 and has already filed an application (Japanese Patent Application No. 2004-152688). FIG. 18 shows a vertical cross-sectional structure of the compressor (200), and FIGS. 19 (A) to 19 (D) show cross-sectional structures of the compression mechanism (220). In this compression mechanism (220), the annular piston (221) is formed in a C-shape with a part of the ring cut off, and the blade (223) is provided in the annular cylinder chamber (C1, C2) of the cylinder (221). ) Extending from the inner wall surface to the outer wall surface of the annular piston (222) through the parting portion of the annular piston (222). The annular piston (222) and the blade (223) are connected to the swing bush (227). ) So that it can swing freely.

  An outer cylinder chamber (C1) is formed outside the annular piston (222), and an inner cylinder chamber (C2) is formed inside. The outer cylinder chamber (C1) and the inner cylinder chamber (C2) The blade (223) is divided into a high pressure chamber (C1-Hp, C2-Hp) and a low pressure chamber (C1-Lp, C2-Lp). The cylinder (221) has discharge ports (245, 246) communicating with the high pressure chambers (C1-Hp, C2-Hp) of the outer cylinder chamber (C1) and the inner cylinder chamber (C2), respectively, and the outer cylinder chamber (C1 ) And a low-pressure chamber (C1-Lp, C2-Lp) in the inner cylinder chamber (C2).

  In the illustrated example, a cylinder (221) composed of an outer cylinder part (224) and an inner cylinder part (225) is connected to the eccentric part (233a) of the drive shaft (233) to be a movable side (swing side), An annular piston (222) is formed integrally with a housing (216) fixed to the casing (210) to form a fixed side. The cylinder (221) swings in the order of FIGS. 19A to 19D with respect to the fixed annular piston (222).

According to this configuration, the blade (223) and the swing bush (227) are in surface contact, and the annular piston (222) and the swing bush (227) are also in surface contact. The sealing failure is improved, and a reduction in compression efficiency due to refrigerant leakage can be prevented.
JP-A-6-288358

  By the way, in the compressor shown in FIGS. 18 and 19, the compression torque of the outer cylinder chamber (C1) peaks near the top dead center shown in FIG. The compression torque reaches a peak near the bottom dead center shown in FIG.

  Here, since there is a volume difference between the outer cylinder chamber (C1) and the inner cylinder chamber (C2), there is also a difference in the peak value of the compression torque. Therefore, as the transition of the compression torque in the entire compression mechanism, the peak value of the outer cylinder chamber (C1) and the peak value of the inner cylinder chamber (C2) appear every time the drive shaft rotates 180 °. As a result, the pulsation of the compression torque occurs, which causes the compressor vibration and noise.

  The present invention has been made in view of such a point, and an object thereof is to arrange an annular piston that divides the cylinder chamber into an outer cylinder chamber and an inner cylinder chamber inside an annular cylinder chamber of the cylinder. And a rotary type having a compression mechanism configured to relatively eccentrically rotate the cylinder and the annular piston provided with a blade that divides the outer cylinder chamber and the inner cylinder chamber into a high pressure chamber and a low pressure chamber. In the compressor, the pulsation of the compression torque can be reduced.

The present invention includes a cylinder (21) having an annular cylinder chamber (C1, C2) and a cylinder chamber (C1, C2) that is eccentric with respect to the cylinder (21) and stored in the cylinder chamber (C1, C2). An annular piston (22) that is divided into an outer cylinder chamber (C1) and an inner cylinder chamber (C2), and the cylinder chambers (C1, C2) are arranged in the cylinder chambers (C1, C2). Hp, C2-Hp) and a blade (23) partitioned into a low pressure chamber (C1-Lp, C2-Lp). The cylinder (21) and the annular piston (22) are relatively eccentrically rotating. A compression mechanism (20), a drive mechanism (30) for driving the compression mechanism (20), and a casing (10) for housing the compression mechanism (20), and the compression mechanism (20) A rotary type equipped with an outer discharge port (45) that discharges gas from the cylinder chamber (C1) and an inner discharge port (46) that discharges gas from the inner cylinder chamber (C2) A compressor is assumed.

In this rotary compressor, the cylinder (21) is fixed to the casing (10), while the annular piston (22) is connected to the drive mechanism (30), and the annular piston (22) is a part of the ring. The blade (23) is inserted through the part of the annular piston (22) from the inner peripheral wall surface to the outer peripheral wall surface of the annular cylinder chamber (C1, C2). An oscillating bush (27) provided on the cylinder (21) so as to extend and movably couples the annular piston (22) to the blade (23) at a portion where the annular piston (22) is divided. It has.

In the present invention , a method is adopted in which the cylinder (21) is a fixed side and the annular piston (22) is a movable side, and the compressor of Japanese Patent Application No. 2004-152688 whose structure is shown in FIGS. This is the opposite of the system in which the annular piston (22) is the fixed side and the cylinder (21) is the movable side. Here, the former (configuration of the present invention) is referred to as a movable bush method, and the latter (configuration of FIGS. 18 and 19) is referred to as a fixed bush method. Occurrence of pulsation of compression torque in these movable bush method and fixed bush method. The principle will be described.

  FIG. 6 is a view showing the operating state of the fixed bush type compression mechanism (20). The cylinder (21) is displaced in the clockwise direction in the figure at intervals of 45 ° from FIG. 6 (A) to FIG. 6 (H). It shows how it is. FIG. 3 is a view showing an operating state of the movable bush type compression mechanism (20), and the annular piston (22) is rotated clockwise at 45 ° intervals from FIG. 3 (A) to FIG. 3 (H). It shows a state of displacement.

  First, during low-speed operation where torque pulsation is particularly problematic, the discharge valve (47, 48) opens quickly because the compression ratio is small, and the discharge pressure is maximized at that time. In the fixed bushing system, the discharge valve (47) in the outer cylinder chamber (C1) opens at the timing of 0 ° in FIG. 6 (A), and the discharge valve (48) in the inner cylinder chamber (C2) approximately in FIG. ) At 180 ° timing. In the movable bush system, the discharge valve (47) in the outer cylinder chamber (C1) opens at about 180 ° in FIG. 3 (E), and the discharge valve (48) in the inner cylinder chamber (C2) is substantially in FIG. Open at 0 ° timing of (A).

  Assuming that the opening timing of the discharge valve (47) in the fixed bush type outer cylinder chamber (C1) is exactly as shown in FIG. 6 (A), the drive shaft (33) is at a minute angle Δt before and after that. A change in volume when rotated by θ will be discussed with reference to FIG. As shown in FIG. 7, when the rotation angle changes in order of (A) 0 ° −θ, (B) 0 °, and (C) 0 ° + θ, the seal point on the outer wall (outer cylinder part (21a)) side Are point A1, point A2, and point A3, and seal points on the inner wall (annular piston body (22b)) side are point B1, point B2, and point B3. At this time, when the movement distance of the outer wall (the arc length from the point A1 to the point A2 and the arc length from the point A2 to the point A3) is expressed in angle, it increases by θ corresponding to the swing angle of the cylinder (21). Therefore, θ + α. On the other hand, if the movement distance of the inner wall (the arc length from the point B1 to the point B2 and the arc length from the point B2 to the point B3) is expressed in angle, the swing angle of the cylinder (21) has no effect, It becomes.

  On the other hand, assuming that the opening timing of the discharge valve (47) is exactly the time of FIG. 3 (E) for the movable bush type outer cylinder chamber (C1), the drive shaft (33) is at Δt time before and after that. A change in volume when rotated by a minute angle θ will be discussed with reference to FIG. As shown in FIG. 8, when the rotation angle changes in order of (A) 180 ° −θ, (B) 180 °, and (C) 180 ° + θ, the seal point on the outer wall (outer cylinder part (21a)) side. Are point A1, point A2, and point A3, and seal points on the inner wall (annular piston body (22b)) side are point B1, point B2, and point B3. At this time, if the moving distance of the outer wall (the arc length from the point A1 to the point A2 and the arc length from the point A2 to the point A3) is expressed by an angle, the swing angle of the cylinder (21) does not affect and is θ. . On the other hand, the movement distance of the inner wall (the arc length from the point B1 to the point B2 and the arc length from the point B2 to the point B3) is expressed by an angle, which is reduced by the swing angle of the cylinder (21). θ−α.

  From the above, in the fixed bush system, the seal point on the outer wall side moves faster by the swing angle α before and after the state shown in FIG. 6A, so that the volume of the compression chamber (high pressure chamber) changes ( In contrast, in the movable bush system, the seal point on the inner wall side moves slower by the swing angle α before and after the state shown in FIG. 3E. It can be seen that the compression torque decreases as the volume of the compression chamber changes (becomes smaller).

  Next, with respect to the inner cylinder chamber (C2) of the fixed bush system, it is assumed that the opening timing of the discharge valve (48) is just at the time of FIG. Next, a change in volume when rotated by a minute angle θ will be discussed with reference to FIG. As shown in FIG. 9, the seal on the outer wall (annular piston body (22b)) side when the rotation angle changes in order of (A) 180 ° −θ, (B) 180 °, and (C) 180 ° + θ. The points are point A1, point A2, and point A3, and the seal points on the inner wall (inner cylinder part (21b)) side are point B1, point B2, and point B3. At this time, if the moving distance of the outer wall (the arc length from the point A1 to the point A2 and the arc length from the point A2 to the point A3) is expressed by an angle, the swing angle of the cylinder (21) does not affect and is θ. . On the other hand, when the movement distance of the inner wall (the arc length from the point B1 to the point B2 and the arc length from the point B2 to the point B3) is expressed as an angle, it corresponds to the swing angle of the cylinder (21) with respect to θ. Since it becomes smaller, θ−α.

  On the other hand, for the movable bush type inner cylinder chamber (C2), assuming that the opening timing of the discharge valve (48) is exactly the time of FIG. A change in volume when rotated by a minute angle θ will be discussed with reference to FIG. As shown in FIG. 10, when the rotation angle changes in order of (A) 0 ° −θ, (B) 0 °, and (C) 0 ° + θ, the seal on the outer wall (annular piston body (22b)) side is sealed. The points are point A1, point A2, and point A3, and the seal points on the inner wall (inner cylinder part (21b)) side are point B1, point B2, and point B3. At this time, when the movement distance of the outer wall (the arc length from the point A1 to the point A2 and the arc length from the point A2 to the point A3) is expressed in angle, it increases by θ corresponding to the swing angle of the cylinder (21). Therefore, θ + α. On the other hand, if the movement distance of the inner wall (the arc length from the point B1 to the point B2 and the arc length from the point B2 to the point B3) is expressed in angle, the swing angle of the cylinder (21) has no effect, It becomes.

  From the above, in the fixed bushing system, the volume of the compression chamber changes (becomes smaller) before and after the state shown in FIG. 6E, because the seal point on the inner wall side moves slower by the swing angle α. In contrast, in the movable bush method, the seal point on the outer wall side moves faster by the swing angle α before and after the state shown in FIG. The volume changes (becomes smaller) faster and the compression torque increases.

  The graphs of FIGS. 11 and 12 show the volume change in the fixed bush system. Actually, the diagram showing the volume change rate of the outer cylinder chamber (C1) (outer compression chamber) and the inner cylinder chamber (C2) (inner compression chamber) is 180 degrees out of phase. In order to make it easier to compare the volume change rates of the outer cylinder chamber (C1) and the inner cylinder chamber (C2), the diagrams are shown in a phased state. As shown in FIGS. 11 and 12, the outer cylinder chamber (C1) has a larger volume change rate gradient around 180 ° than the inner cylinder chamber (C2), indicating that the volume change is fast.

  Therefore, in the fixed bush method, the compression torque of the outer cylinder chamber (C1) with a large cylinder volume increases, whereas the compression torque of the inner cylinder chamber (C2) with a small cylinder volume decreases, so torque pulsation (maximum The difference between the torque and the minimum torque is increased.

  On the other hand, the graphs of FIGS. 13 and 14 show the volume change in the movable bush system. In this case as well, the diagram showing the volume change rate of the outer cylinder chamber (C1) (outer compression chamber) and the inner cylinder chamber (C2) (inner compression chamber) is actually out of phase by 180 °. In this figure, in order to make it easier to compare the volume change rates of the outer cylinder chamber (C1) and the inner cylinder chamber (C2), they are shown in a state where the phases of the diagrams are matched. As shown in FIGS. 13 and 14, the outer cylinder chamber (C1) has a smaller volume change rate gradient around 180 ° than the inner cylinder chamber (C2), indicating that the volume change is slow.

  Therefore, in the movable bush method, the compression torque of the outer cylinder chamber (C1) with a large cylinder volume is reduced, while the compression torque of the inner cylinder chamber (C2) with a small cylinder volume is increased, so that the torque pulsation is small. Become.

  An example in which the torque pulsations of the fixed bush type and the movable bush type are compared is shown in the graph of FIG. In the movable bush system with small torque pulsation, the maximum torque is reduced while the minimum torque is increased compared to the fixed bush system. In the example shown in the figure, the fluctuation range (the magnitude of torque pulsation) of the compression torque of the fixed bush type is a value represented by B, whereas the fluctuation range of the compression torque of the movable bush type is smaller than B. The value is A.

In the present invention, the drive mechanism (30) includes an electric motor (30) and a drive shaft (33) connected to the electric motor (30), and is housed in a casing (10), and the drive shaft ( 33) includes an eccentric portion (33a) eccentric from the center of rotation, and the annular piston (22) is coupled to the eccentric portion (33a) .

According to the present invention , in the rotary compressor configured to include the drive mechanism (30), the annular piston (22) connected to the eccentric portion (33a) of the drive shaft (33) is disposed in the cylinder chamber (C1, C2). Eccentric rotation motion. Also in this configuration, the pulsation of the compression torque can be reduced as compared with the fixed bush method because the movable bush method in which the cylinder (21) is fixed and the annular piston (22) is movable is employed.

In the present invention, the annular piston (22) is fitted to the eccentric part (33a) of the drive shaft (33), and the bearing part (22a) is concentric with the bearing part (22a) on the outer peripheral side of the bearing part (22a). An annular piston main body (22b) positioned above, a piston side end plate (22c) that connects the bearing (22a) and the annular piston main body (22b) at one end in the axial direction of the compression mechanism (20). The cylinder (21) includes an inner cylinder part (21b) concentric with the drive shaft (33) between the bearing part (22a) and the annular piston body part (22b), and an annular piston body part (22b ) On the outer peripheral side of the inner cylinder part (21b) concentrically with the inner cylinder part (21b), the inner cylinder part (21b) and the outer cylinder part (21a) in the axial direction of the compression mechanism (20). Cylinder end plate (21c) connected at the end side, cylinder side end plate (21c), piston side end plate (22c) and inner side An outer cylinder chamber (C1) is formed between the cylinder part (21b) and the annular piston body part (22b). The cylinder side end plate (21c), the piston side end plate (22c), the inner cylinder part (21b), and the annular piston An inner cylinder chamber (C2) is formed between the main body (22b) .

In the present invention , the annular piston main body (22b) is positioned on the outer periphery of the bearing portion (22a) fitted to the eccentric portion (33a) of the drive shaft (33), and the annular piston main body (22b) is connected to the cylinder (21 ) Between the outer cylinder part (21a) and the inner cylinder part (21b). Then, when the volume of the outer cylinder chamber (C1) and the volume of the inner cylinder chamber (C2) are changed, gas is sucked, compressed, and discharged in the compression mechanism (20). When the gas is compressed, a lateral load is generated in the cylinder chamber (C1, C2) due to the reaction force of the gas. At that time, for example, when the axial position of the bearing portion (22a) and the annular piston body portion (22b) is shifted, the annular piston (by the lateral load accompanying the compression of gas in the cylinder chamber (C1, C2)) Although force (overturning moment) is generated to incline 22), in the present invention, since the annular piston main body portion (22b) is positioned around the bearing portion (22a), occurrence of the overturning moment can be suppressed.

Further, according to the present invention, the casing (10) flows out of the suction pipe (14) communicating with the suction side of the compression mechanism (20) and the high-pressure gas discharged from the compression mechanism (20) into the casing (10). The discharge pipe (15) is provided, and is formed between the cylinder end plate (21c), the piston end plate (22c), the bearing portion (22a) of the annular piston (22), and the inner cylinder portion (21b). The space is a high-pressure space.

In this invention , the inside of the casing (10) is a high-pressure space, and the lubricating oil that lubricates the sliding portions of the compression mechanism (20) and the bearing portion (22a) also has a high pressure. When high-pressure lubricating oil is supplied to the bearing (22a) of the annular piston (22), the cylinder end plate (21c), the piston end plate (22c), the bearing portion (22a) of the annular piston (22) and the inner cylinder portion ( 21b), the lubricating oil flows more and more into the low pressure space. However, in the present invention, since the space is a high pressure space, the lubricating oil enters the space. It is possible to suppress the inflow.

  According to the present invention, the cylinder chamber (C1, C2) is partitioned into an outer cylinder chamber (C1) and an inner cylinder chamber (C2) inside an annular cylinder chamber (C1, C2) of the cylinder (21). An annular piston (22) is arranged, and the outer cylinder chamber (C1) and inner cylinder chamber (C2) are divided into a high pressure chamber (C1-Hp, C2-Hp) and a low pressure chamber (C1-Lp, C2-Lp). The compression mechanism (20) includes a blade (23) for partitioning, and is configured so that the cylinder (21) and the annular piston (22) are relatively eccentrically rotated. In a rotary compressor provided with an outer discharge port (45) for discharging gas from the outer cylinder chamber (C1) and an inner discharge port (46) for discharging gas from the inner cylinder chamber (C2), a blade (23 ) To connect the annular piston (22) so as to be able to swing at the split portion of the annular piston (22). A movable bushing system is employed in which a cylinder (21) is provided on the fixed side and an annular piston (22) is provided on the movable side.

  In the fixed bush method, the compression torque of the outer cylinder chamber (C1) having a large cylinder (21) volume is increased, whereas the compression torque of the inner cylinder chamber (C2) having a small cylinder (21) volume is decreased. Therefore, the torque pulsation increases, but in the movable bush system of the present invention, the compression torque of the outer cylinder chamber (C1) having a large cylinder (21) volume is reduced, whereas the inner cylinder having a small cylinder (21) volume is used. Since the compression torque of the chamber (C2) increases, torque pulsation can be reduced.

  Also, for example, when considering a method that does not use the swing bush (27) between the annular piston (22) and the blade (23), the annular piston (22) can be made thinner in this method, so the outer cylinder chamber and the inner cylinder Even if the cylinder (21) is fixed, it can be designed to suppress torque pulsation by reducing the volume difference between the chambers. However, when the swing bush (27) is used, the annular piston (22) becomes thicker and the outer cylinder Since the volume difference between the chamber and the inner cylinder chamber becomes large, it is extremely effective to use the movable bush system of the present invention for suppressing torque pulsation.

Further , according to the present invention , in the rotary compressor configured to incorporate the drive mechanism (30), the annular piston (22) connected to the eccentric portion (33a) of the drive shaft (33) is provided in the cylinder chamber (C1 , C2) within the eccentric rotational movement. That is, also in this invention, the pulsation of the compression torque can be reduced as compared with the fixed bush method because the movable bush method in which the cylinder (21) is fixed and the annular piston (22) is movable is adopted.

Further , according to the present invention, when the axial positions of the bearing portion (22a) and the annular piston body portion (22b) are shifted, the lateral load accompanying the compression of the gas in the cylinder chamber (C1, C2). This causes a force (overturning moment) to tilt the annular piston (22), while the annular piston body (22b) is positioned around the bearing (22a). It is possible to prevent the occurrence of a rollover moment due to the gas compression reaction force (lateral load) in C1, C2).

In addition, when the high-pressure lubricating oil in the casing (10) is supplied to the bearing portion (22a) of the annular piston (22), the cylinder end plate (21c), the piston end plate (22c), and the bearing portion of the annular piston (22) When the space formed between (22a) and the inner cylinder part (21b) is a low-pressure space, the lubricating oil flows more and more into the low-pressure space, resulting in poor lubrication at other sliding locations. Although there is a possibility, according to this invention , since the said space is made into the high voltage | pressure space, it can suppress that lubricating oil flows in into the space rapidly. Therefore, poor lubrication at other sliding locations can be prevented.

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

-Embodiment (movable bush system)-
FIG. 1 is a longitudinal sectional view of a rotary compressor (1) according to this embodiment, FIG. 2 is a transverse sectional view of a compression mechanism (20), and FIG. 3 is an operation state diagram of the compression mechanism (30). As shown in FIG. 1, this compressor (1) is housed in a casing (10) in which a compression mechanism (eccentric rotary piston mechanism) (20) and an electric motor (drive mechanism) (30) are housed. It is structured into a mold. 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). ing.

  The compression mechanism (20) is configured between a front head (16) and a rear head (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 FIGS. As shown in Fig. 2, the cylinder chambers (C1, C2) are divided into a high pressure chamber (compression chamber) (C1-Hp, C2-Hp) as the first chamber and a low pressure chamber (suction chamber) (C1-Lp, C2) as the second chamber. -Lp) and a blade (23) partitioned into two. In this embodiment, the front head (16) constitutes a cylinder (21). In this embodiment, the cylinder (21) having the cylinder chambers (C1, C2) is the fixed side, the annular piston (22) is the movable side, and the annular piston (22) is eccentric with respect to the cylinder (21). It is configured to rotate. In the following description, a method in which the annular piston (22) is movable as in this embodiment is referred to as a movable bush method, and conversely, as shown in FIGS. 18 and 19 (Japanese Patent Application No. 2004-152688). The method that becomes the fixed side is called a fixed bush method.

  The electric motor (30) includes a stator (31) and a rotor (32). The stator (31) is disposed above 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 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 (34) is provided at the lower end of the drive shaft (33). The oil supply passage extends upward from the oil supply pump (34). 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 annular piston (22) is a member integrally formed of a lightweight aluminum material for vibration reduction, and a bearing portion (slidably fitted to the eccentric portion (33a) of the drive shaft (33)). 22a), the annular piston main body (22b) positioned concentrically with the bearing (22a) on the outer peripheral side of the bearing (22a), the bearing (22a) and the annular piston main body (22b). And a piston side end plate (22c) connected on the lower end side (one end side in the axial direction of the compression mechanism (20)), and the annular piston body (22b) has a C-shaped shape in which a part of the ring is divided. Is formed.

  The cylinder (21) includes an inner cylinder portion (21b) concentric with the drive shaft (33) between the bearing portion (22a) and the annular piston body portion (22b), and an annular piston body portion (22b). The outer cylinder part (21a), the inner cylinder part (21b) and the outer cylinder part (21a), which are located concentrically with the inner cylinder part (21b) on the outer peripheral side of the And a cylinder side end plate (21c) connected at the other end in the axial direction.

  The front head (16) and the rear head (17) are respectively formed with bearing portions (16a, 17a) for supporting the drive shaft (33). 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 oscillatingly connecting the annular piston (22) to the blade (23) at a parting position of the annular piston (22). ing. 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 portion (21b)) of the cylinder chamber (C1, C2) to the outer peripheral wall surface ( It is configured to extend through the part where the annular piston (22) is split to the inner peripheral surface of the outer cylinder (21a), and is fixed to the outer cylinder (21a) and the inner cylinder (21b) Yes. The blade (23) may be formed integrally with the outer cylinder part (21a) and the inner cylinder part (21b), or another member may be attached to both cylinder parts (21a, 21b). The example shown in FIG. 2 is an example in which another member is fixed to both cylinder parts (21a, 21b).

  The inner peripheral surface of the outer cylinder portion (21a) and the outer peripheral surface of the inner cylinder portion (21b) 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 portion (21a) and an inner peripheral surface having a larger diameter than the outer peripheral surface of the inner cylinder portion (21b). As a result, 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 portion (21a), and the inner peripheral surface and the inner cylinder portion of the annular piston (22). An inner cylinder chamber (C2) is formed between the outer peripheral surface of (21b).

  Specifically, an outer cylinder chamber (C1) is formed between the cylinder side end plate (21c), the piston side end plate (22c), the outer cylinder portion (21a), and the annular piston main body portion (22b). An inner cylinder chamber (C2) is formed between (21c), the piston side end plate (22c), the inner cylinder part (21b), and the annular piston main body part (22b). In addition, between the cylinder side end plate (21c), piston side end plate (22c), bearing part (22a) of the annular piston (22) and inner cylinder part (21b), the inner peripheral side of the inner cylinder part (21b) Thus, an operation space (25) for allowing the eccentric rotation operation of the bearing portion (22a) is formed. This operation space (25) is configured to be a high-pressure space in the present embodiment.

  In addition, the annular piston (22) and the cylinder (21) are in a state where the outer peripheral surface of the annular piston (22) and the inner peripheral surface of the outer cylinder part (21a) are substantially in contact with each other (strictly in the order of microns). In a state where there is a gap but leakage of the refrigerant in the gap does not become a problem), the inner peripheral surface of the annular piston (22) and the outer peripheral surface of the inner cylinder part (21b) at a position that is 180 ° out of phase with the contact point Are substantially touching 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), the flat surface of the swing bush (27A, 27B) is substantially in surface contact with the blade (23), and the swing bush (27A, 27B) has an arcuate shape. The outer peripheral surface is substantially in surface contact with the annular piston (22). The swing bushes (27A, 27B) are configured to advance and retreat in the surface direction of the blade (23) with the blade (23) sandwiched between the blade grooves (28). The swing bushes (27A, 27B) are configured such that the annular piston (22) swings with respect to the blade (23). Therefore, the swing bush (27) is configured such that the annular piston (22) can swing with respect to the blade (23) with the center point of the swing bush (27) as the swing center, and the annular piston ( 22) is configured to be able to advance and retract in the surface direction of the blade (23) with respect to the blade (23).

  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 annular piston (22) swings the center point of the swing bush (27) while the swing bush (27) advances and retreats along the blade (23). Swings as the center of movement. By this swinging operation, the contact point between the annular piston (22) and the cylinder (21) moves in order from FIG. 3 (A) to FIG. 3 (H). FIG. 3 is a view showing an operating state of the movable bush type compression mechanism (20), and the annular piston (22) is rotated clockwise at 45 ° intervals from FIG. 3 (A) to FIG. 3 (H). It shows a state of moving to. At this time, the annular piston (22) revolves around the drive shaft (33) but does not rotate.

  The front head (16) is formed so that a suction port (41) to which the suction pipe (14) is connected communicates with the low pressure chamber (C1-Lp) of the outer cylinder chamber (C1). The annular piston (22) has a through hole (44) that communicates 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). Is formed.

  The front head (16) has an outer discharge port (45) and an inner discharge port (46). Each of these discharge ports (45, 46) penetrates the cylinder side end plate (21c) of the front head (16) in the axial direction thereof. The lower end of the outer discharge port (45) is opened to face the high pressure chamber (C1-Hp) of the outer cylinder chamber (C1), and the lower end of the inner discharge port (46) is the high pressure chamber (C2) of the inner cylinder chamber (C2). -Hp). 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 front head (16) and the cover member (18). The cover member (18) discharges the discharge gas from the compression mechanism (20) into the discharge space (49) once, and then discharges the discharge opening between the cover member (18) and the bearing portion (16a) ( A muffler mechanism for obtaining a silencing function by flowing out into the high-pressure space (19) in the casing (10) through 18a) is constructed.

  On the other hand, the piston side end plate (22c) is provided with a seal ring (29). The seal ring (29) is loaded in the annular groove (22d) of the piston side end plate (22c) and is in pressure contact with the rear head (17). The axial clearance between the upper end surface of the annular piston main body (22b) and the lower surface of the cylinder side end plate (21c), and the lower end surfaces of the outer cylinder portion (21a) and the inner cylinder portion (21b) and the piston side end plate The compliance mechanism which reduces the axial clearance between the upper surface of (22c) is configured.

-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 annular piston (22) of the compression mechanism (20) via the drive shaft (33). Then, the swing bush (27A, 27B) reciprocates (advances and retracts) along the blade (23), and the annular piston (22) and the swing bush (27A, 27B) are integrated into the blade. Oscillate with respect to (23). At that time, the swing bushes (27A, 27B) substantially make surface contact with the annular piston (22) and the blade (23). Then, the annular piston (22) revolves while swinging with respect to the outer cylinder part (21a) and the inner cylinder part (21b), 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. 3B, and from here 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. 3C to 3A, the refrigerant flows into the suction pipe (14) and the suction port (41). ) Through the low pressure chamber (C1-Lp).

  When the drive shaft (33) makes one revolution and returns to the state of FIG. 3 (B), 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) through the discharge opening (18a) to the high-pressure space (19) in the casing (10).

  In the inner cylinder chamber (C2), the volume of the low-pressure chamber (C2-Lp) is almost minimum in the state of FIG. 3 (F), and from here the drive shaft (33) rotates clockwise in FIG. When the volume of the low pressure chamber (C2-Lp) increases with the change to the state of G) to FIG. 3 (E), the refrigerant passes through the suction pipe (14), the suction port (41), and the penetration. It is sucked into the low pressure chamber (C2-Lp) of the inner cylinder chamber (C2) through the hole (44).

  When the drive shaft (33) makes one revolution and again enters the state of FIG. 3 (F), 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) through the discharge opening (18a) to the high-pressure space (19) in the casing (10).

  In the outer cylinder chamber (C1), refrigerant discharge is started approximately at the timing shown in FIG. 3E, and in the inner cylinder chamber (C2), discharge is started approximately at the timing shown in FIG. That is, the discharge timing differs by approximately 180 ° between the outer cylinder chamber (C1) and the inner cylinder chamber (C2). The high-pressure refrigerant compressed in the outer cylinder chamber (C1) and the inner cylinder chamber (C2) and flowing into the high-pressure space (19) in the casing (10) is discharged from the discharge pipe (15) and is condensed in the refrigerant circuit. After passing through the expansion stroke and the evaporation stroke, it is sucked into the compressor (1) again.

-Comparative example (fixed bush method)-
The compressor of the comparative example shown in FIGS. 4 to 6 will be briefly described.

  The compression mechanism of the compressor of this comparative example is a fixed type with the annular piston (22) on the fixed side, whereas the example of FIGS. Bush method. In the following, differences from the example of FIGS. 1 to 3 will be mainly described.

  The compression mechanism (20) is configured between a front head (16) and a rear head (17) fixed to the casing (10), as in the example of FIGS. 1 to 3, and includes an annular cylinder chamber (C1, A cylinder (21) having C2), an annular piston (22) disposed in the cylinder chamber (C1, C2), and a high pressure chamber (compression chamber) (the compression chamber) which is the first chamber as the cylinder chamber (C1, C2) ( C1-Hp, C2-Hp) and a low pressure chamber (suction chamber) (C1-Lp, C2-Lp), which is the second chamber, has a blade (23). The cylinder (21) is configured to perform an eccentric rotational motion with respect to the annular piston (22). That is, in this example, the cylinder (21) having the cylinder chambers (C1, C2) is the movable side, and the annular piston (22) disposed in the cylinder chambers (C1, C2) is the fixed side.

  The cylinder (21) includes an outer cylinder part (21a) and an inner cylinder part (21b). The outer cylinder part (21a) and the inner cylinder part (21b) are integrated by connecting the lower end part with a cylinder side end plate (21c). The inner cylinder part (21b) is slidably fitted into the eccentric part (33a) of the drive shaft (33). On the other hand, the said annular piston (22) is comprised by the front head (16), and it has the structure where the annular piston main-body part (22b) was integrally formed with the piston side end plate (22c) by the upper end part. .

  An outer cylinder chamber (C1) is formed between the cylinder side end plate (21c), piston side end plate (22c), outer cylinder part (21a), and annular piston body part (22b). The inner cylinder chamber (C2) is formed between the side end plate (22c), the inner cylinder part (21b), and the annular piston main body part (22b), which is the same as the example of FIGS. On the other hand, in this example, the rear head (17) is provided with an operation space (26) for allowing the eccentric rotation operation of the outer cylinder portion (21a). This working space (26) is a low pressure space communicating with the suction pipe (14), and the outer cylinder portion (21a) and the inner cylinder portion (21b) suck low pressure gas from the low pressure working space (26). For this purpose, through holes (44a, 44b) are formed.

  In this comparative example, the swing bushes (27A, 27B) are configured so 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). It is configured. The swing bushes (27A, 27B) are configured such that the blade (23) swings with respect to the annular piston (22). Therefore, the swing bush (27) can swing the blade (23) with respect to the annular piston (22) 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 the above configuration, when the drive shaft (33) is rotated, the outer cylinder portion (21a) and the inner cylinder portion (21b) are arranged such that the blade (23) advances and retracts in the blade groove (28) while the swing bush (27 ) Swing around the center point of). By this swinging operation, the contact point between the annular piston (22) and the cylinder (21) moves in order from FIG. 6 (A) to FIG. FIG. 6 is a diagram showing the operating state of the fixed bush type compression mechanism (20), and the cylinder (21) is rotated clockwise at 45 ° intervals from FIG. 6 (A) to FIG. 6 (H). It shows how it is moving. At this time, the outer cylinder portion (21a) and the inner cylinder portion (21b) revolve while swinging around the drive shaft (33), but do not rotate.

  A seal ring (29) is provided on the cylinder side end plate (21c). The seal ring (29) is loaded in the annular groove (21d) of the cylinder side end plate (21c) and is in pressure contact with the rear head (17). And the axial clearance between the upper end surface of the outer cylinder part (21a) and the inner cylinder part (21b) and the lower surface of the piston side end plate (22c), and the lower end surface of the annular piston (22b) and the cylinder side end plate (21c) ) To reduce the axial clearance between the upper surface and the upper surface.

  Other configurations are the same as those in the example of FIGS.

  When the compression mechanism (20) operates, in the outer cylinder chamber (C1), the volume of the low pressure chamber (C1-Lp) is almost minimum in the state of FIG. When the volume of the low pressure chamber (C1-Lp) increases as it rotates clockwise in the figure and changes to the state shown in FIGS. 6 (G) to 6 (E), the refrigerant flows into the suction pipe ( 14), is sucked into the low pressure chamber (C1-Lp) through the operation space (26) and the through hole (44a).

  When the drive shaft (33) makes one revolution and enters the state of FIG. 6 (F) 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) through the discharge opening (18a) to the high-pressure space (19) in the casing (10).

  In the inner cylinder chamber (C2), the volume of the low-pressure chamber (C2-Lp) is almost the minimum in the state of FIG. 6 (B), and from here the drive shaft (33) rotates clockwise in FIG. When the volume of the low pressure chamber (C2-Lp) increases with the change to the state of (C) to FIG. 6 (A), the refrigerant becomes the suction pipe (14), the operation space (26), the through hole. (44a), the low pressure chamber (C1-Lp) of the outer cylinder chamber (C1) and the through hole (44b) are sucked into the low pressure chamber (C2-Lp).

  When the drive shaft (33) makes one revolution and enters the state of FIG. 6 (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) through the discharge opening (18a) to the high-pressure space (19) in the casing (10).

  In the outer cylinder chamber (C1), refrigerant discharge is started approximately at the timing shown in FIG. 6A, and in the inner cylinder chamber (C2), discharge is started approximately at the timing shown in FIG. 6E. That is, the discharge timing differs by approximately 180 ° between the outer cylinder chamber (C1) and the inner cylinder chamber (C2). The high-pressure refrigerant compressed in the outer cylinder chamber (C1) and the inner cylinder chamber (C2) and flowing into the high-pressure space (19) in the casing (10) is discharged from the discharge pipe (15) and is condensed in the refrigerant circuit. After passing through the expansion stroke and the evaporation stroke, it is sucked into the compressor (1) again.

-Explanation of compression torque pulsation-
First, during low-speed operation where torque pulsation is particularly problematic, the discharge valve (47, 48) opens quickly because the compression ratio is small, and the discharge pressure is maximized at that time. In the fixed bushing system, the discharge valve (47) in the outer cylinder chamber (C1) opens at the timing of 0 ° in FIG. 6 (A), and the discharge valve (48) in the inner cylinder chamber (C2) approximately in FIG. ) At 180 ° timing. In the movable bush system, the discharge valve (47) in the outer cylinder chamber (C1) opens at about 180 ° in FIG. 3 (E), and the discharge valve (48) in the inner cylinder chamber (C2) is substantially in FIG. Open at 0 ° timing of (A).

  Assuming that the opening timing of the discharge valve (47) in the fixed bush type outer cylinder chamber (C1) is exactly as shown in FIG. 6 (A), the drive shaft (33) is at a minute angle Δt before and after that. A change in volume when rotated by θ will be discussed with reference to FIG. As shown in FIG. 7, when the rotation angle changes in order of (A) 0 ° −θ, (B) 0 °, and (C) 0 ° + θ, the seal point on the outer wall (outer cylinder part (21a)) side Are point A1, point A2, and point A3, and seal points on the inner wall (annular piston body (22b)) side are point B1, point B2, and point B3. At this time, when the movement distance of the outer wall (the arc length from the point A1 to the point A2 and the arc length from the point A2 to the point A3) is expressed in angle, it increases by θ corresponding to the swing angle of the cylinder (21). Therefore, θ + α. On the other hand, if the movement distance of the inner wall (the arc length from the point B1 to the point B2 and the arc length from the point B2 to the point B3) is expressed as an angle, the swing angle of the cylinder (21) does not affect θ and Become.

  On the other hand, assuming that the opening timing of the discharge valve (47) is exactly the time of FIG. 3 (E) for the movable bush type outer cylinder chamber (C1), the drive shaft (33) is at Δt time before and after that. A change in volume when rotated by a minute angle θ will be discussed with reference to FIG. As shown in FIG. 8, when the rotation angle changes in order of (A) 180 ° −θ, (B) 180 °, and (C) 180 ° + θ, the seal point on the outer wall (outer cylinder part (21a)) side. Are point A1, point A2, and point A3, and seal points on the inner wall (annular piston body (22b)) side are point B1, point B2, and point B3. At this time, if the moving distance of the outer wall (the arc length from the point A1 to the point A2 and the arc length from the point A2 to the point A3) is expressed by an angle, the swing angle of the cylinder (21) does not affect and is θ. . On the other hand, when the movement distance of the inner wall (the arc length from the point B1 to the point B2 and the arc length from the point B2 to the point B3) is expressed as an angle, it corresponds to the swing angle of the cylinder (21) with respect to θ. Since it becomes smaller, θ−α.

  From the above, in the fixed bush method, the volume of the compression chamber changes (becomes smaller) before and after the state shown in FIG. In contrast, in the movable bush method, the seal point on the inner wall side moves slower by the swing angle α before and after the state shown in FIG. It can be seen that the compression torque decreases as the volume changes (becomes smaller).

  Next, with respect to the inner cylinder chamber (C2) of the fixed bush system, it is assumed that the opening timing of the discharge valve (48) is just at the time of FIG. Next, a change in volume when rotated by a minute angle θ will be discussed with reference to FIG. As shown in FIG. 9, the seal on the outer wall (annular piston body (22b)) side when the rotation angle changes in order of (A) 180 ° −θ, (B) 180 °, and (C) 180 ° + θ. The points are point A1, point A2, and point A3, and the seal points on the inner wall (inner cylinder part (21b)) side are point B1, point B2, and point B3. At this time, if the moving distance of the outer wall (the arc length from the point A1 to the point A2 and the arc length from the point A2 to the point A3) is expressed by an angle, the swing angle of the cylinder (21) does not affect and is θ. . On the other hand, when the movement distance of the inner wall (the arc length from the point B1 to the point B2 and the arc length from the point B2 to the point B3) is expressed as an angle, it corresponds to the swing angle of the cylinder (21) with respect to θ. Since it becomes smaller, θ−α.

  On the other hand, for the movable bush type inner cylinder chamber (C2), assuming that the opening timing of the discharge valve (48) is exactly the time of FIG. A change in volume when rotated by a minute angle θ will be discussed with reference to FIG. As shown in FIG. 10, when the rotation angle changes in order of (A) 0 ° −θ, (B) 0 °, and (C) 0 ° + θ, the seal on the outer wall (annular piston body (22b)) side is sealed. The points are point A1, point A2, and point A3, and the seal points on the inner wall (inner cylinder part (21b)) side are point B1, point B2, and point B3. At this time, when the movement distance of the outer wall (the arc length from the point A1 to the point A2 and the arc length from the point A2 to the point A3) is expressed in angle, it increases by θ corresponding to the swing angle of the cylinder (21). Therefore, θ + α. On the other hand, if the movement distance of the inner wall (the arc length from the point B1 to the point B2 and the arc length from the point B2 to the point B3) is expressed in angle, the swing angle of the cylinder (21) has no effect, It becomes.

  From the above, in the fixed bushing system, the volume of the compression chamber changes (becomes smaller) before and after the state shown in FIG. 6E, because the seal point on the inner wall side moves slower by the swing angle α. In contrast, in the movable bush method, the seal point on the outer wall side moves faster by the swing angle α before and after the state shown in FIG. The volume changes (becomes smaller) faster and the compression torque increases.

  The graphs of FIGS. 11 and 12 show the volume change in the fixed bush system. Actually, the diagram showing the volume change rate of the outer cylinder chamber (C1) (outer compression chamber) and the inner cylinder chamber (C2) (inner compression chamber) is 180 degrees out of phase. In order to make it easier to compare the volume change rates of the outer cylinder chamber (C1) and the inner cylinder chamber (C2), the diagrams are shown in a phased state. As shown in FIGS. 11 and 12, the outer cylinder chamber (C1) has a larger volume change rate gradient around 180 ° than the inner cylinder chamber (C2), indicating that the volume change is fast.

  Therefore, in the fixed bush system, the compression torque of the outer cylinder chamber (C1) with a large cylinder volume increases, whereas the compression torque of the inner cylinder chamber (C2) with a small cylinder volume decreases, resulting in a large torque pulsation. Become.

  On the other hand, the graphs of FIGS. 13 and 14 show the volume change in the movable bush system. In this case as well, the diagram showing the volume change rate of the outer cylinder chamber (C1) (outer compression chamber) and the inner cylinder chamber (C2) (inner compression chamber) is actually out of phase by 180 °. In this figure, in order to make it easier to compare the volume change rates of the outer cylinder chamber (C1) and the inner cylinder chamber (C2), they are shown in a state where the phases of the diagrams are matched. As shown in FIGS. 13 and 14, the outer cylinder chamber (C1) has a smaller volume change rate gradient around 180 ° than the inner cylinder chamber (C2), indicating that the volume change is slow.

  Therefore, in the movable bush method, the compression torque of the outer cylinder chamber (C1) with a large cylinder volume is reduced, while the compression torque of the inner cylinder chamber (C2) with a small cylinder volume is increased, so that the torque pulsation is small. Become.

  An example in which the torque pulsations of the fixed bush type and the movable bush type are compared is shown in the graph of FIG. In the movable bush system with small torque pulsation, the maximum torque is reduced while the minimum torque is increased compared to the fixed bush system. In the example shown in the figure, the fluctuation range (the magnitude of torque pulsation) of the compression torque of the fixed bush type is a value represented by B, whereas the fluctuation range of the compression torque of the movable bush type is smaller than B. The value is A.

-Effect of Embodiment 1-
As described above, in the fixed bushing method, the compression torque of the outer cylinder chamber (C1) with a large cylinder volume increases, whereas the compression torque of the inner cylinder chamber (C2) with a small cylinder volume decreases. Although the torque pulsation increases, in the movable bush system of the present invention, the compression torque of the outer cylinder chamber (C1) having a large cylinder volume is reduced, whereas the compression torque of the inner cylinder chamber (C2) having a small cylinder volume is reduced. Since it increases, torque pulsation can be reduced.

  Also, for example, when considering a compression mechanism that does not use a swing bush between the annular piston and the blade, the annular piston can be made thinner in this method, so the volume difference between the outer cylinder chamber and the inner cylinder chamber is reduced, Even if the cylinder is fixed (fixed bushing), it is possible to design to suppress torque pulsation. However, when the swinging bush (27) is used, the annular piston (22) becomes thicker and the outer cylinder chamber (C1) and inner cylinder Since the volume difference of the chamber (C2) becomes large, it is extremely effective to suppress the torque pulsation by adopting the movable bush system of the present invention.

  Further, when the axial positions of the bearing portion (22a) and the annular piston main body portion (22b) are shifted, a force (overturning moment) for tilting the annular piston is generated. According to the above, since the annular piston body (22b) is positioned around the bearing (22a), the reaction force of the gas compression (lateral load) in the cylinder chamber (C1, C2) There is also an effect that it is possible to prevent the occurrence of the rollover moment.

  Further, in the configuration in which the high-pressure lubricating oil in the casing (10) is supplied to the bearing portion (22a) of the annular piston, the bearing portion of the cylinder-side end plate (21c), the piston-side end plate (22c), and the annular piston (22) ( If the operating space (25) formed between 22a) and the inner cylinder (21b) is a low pressure space, the lubricating oil will flow into the low pressure space and the oil will flow to other sliding locations. Although there is a risk of poor lubrication without being supplied, according to the present embodiment, since the movable space (25) is a high-pressure space, the lubricating oil flows into the movable space (25) more and more. Can be suppressed. Therefore, poor lubrication at other sliding locations can be prevented.

<< Other Embodiments >>
About the said embodiment, it is good also as the following structures.

  For example, the drive mechanism (30) does not necessarily have to be housed in the casing (10), and the compression mechanism (eccentric rotary piston mechanism) (20) may be driven from the outside of the casing (10). .

  Furthermore, although only the torque pulsation during low-speed operation has been described in the above embodiment, the present invention is not limited to during low-speed operation.

  In the above embodiment, the blade (23) is arranged so as to be positioned on the radial line of the cylinder chamber (C1, C2). However, the blade (23) is arranged in the radial direction of the cylinder chamber (C1, C2). The arrangement may be inclined with respect to the line segment.

  Furthermore, in the above embodiment, the low pressure gas is directly sucked into the compression mechanism (20) from the suction pipe (14) and compressed, and the high pressure gas is filled in the casing (10) and then discharged from the discharge pipe (15). The structure (so-called high-pressure dome structure) is adopted. In the present invention, the low-pressure gas is filled into the casing (10) from the suction pipe (14) and then sucked into the compression mechanism (20) for compression. Even a compressor having a structure (so-called low-pressure dome structure) that discharges gas directly from the compression mechanism (20) through the discharge pipe (15) is applicable.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, according to the present invention, the cylinder chamber (C1, C2) is arranged in the annular cylinder chamber (C1, C2) of the cylinder (21), the outer cylinder chamber (C1) and the inner cylinder chamber (C2). An annular piston (22) that is divided into a cylinder (21) and a blade (23) that divides the outer cylinder chamber (C1) and the inner cylinder chamber (C2) into a high pressure chamber and a low pressure chamber, The present invention is useful for a rotary compressor having a compression mechanism (20) configured to perform an eccentric rotational motion relative to an annular piston (22).

It is a longitudinal section of a compressor concerning an embodiment of the present invention. It is a cross-sectional view which shows the structure of the compression mechanism of the compressor of FIG. It is an operation state figure of the compression mechanism of the compressor of Drawing 1. It is a longitudinal cross-sectional view of the compressor which concerns on a comparative example. It is a longitudinal cross-sectional view which shows the structure of the compression mechanism of the compressor of FIG. It is an operation state figure of the compression mechanism of the compressor of Drawing 4. It is a figure which shows the volume change of the outer cylinder chamber of the compression mechanism which concerns on embodiment. It is a figure which shows the volume change of the outer side cylinder chamber of the compression mechanism which concerns on a comparative example. It is a figure which shows the volume change of the inner side cylinder chamber of the compression mechanism which concerns on embodiment. It is a figure which shows the volume change of the inner side cylinder chamber of the compression mechanism which concerns on a comparative example. It is a graph which shows the volume change rate of the compression mechanism which concerns on embodiment. It is a graph which shows the inclination of the volume change rate of the compression mechanism which concerns on embodiment. It is a graph which shows the volume change rate of the compression mechanism which concerns on a comparative example. It is a graph which shows the inclination of the volume change rate of the compression mechanism which concerns on a comparative example. It is a graph which shows the torque pulsation of the compressor of embodiment and a comparative example. It is a longitudinal cross-sectional view of the compressor which concerns on a prior art. It is a cross-sectional view which shows the structure of the compression mechanism of the compressor of FIG. It is a longitudinal cross-sectional view of the compressor which concerns on another prior art. It is a cross-sectional view which shows the structure and operation | movement of a compression mechanism of the compressor of FIG.

10 Casing (10)
14 Suction pipe (14)
15 Discharge pipe (15)
20 Compression mechanism (20)
21 cylinder (21)
21a Outer cylinder part (21a)
21b Inner cylinder (21b)
21c End plate on cylinder side (21c)
22 Annular piston (22)
22a Bearing (22a)
22b Annular piston body (22b)
22c Piston side end plate (22c)
23 blades (23)
27 Swing bush (27)
30 Electric motor (drive mechanism)
33 Drive shaft (33)
33a Eccentric part (33a)
45 Outer outlet (45)
46 Inner outlet (46)
C1 Outer cylinder chamber (C1)
C2 Inner cylinder chamber (C2)
C1-Hp High pressure chamber
C2-Hp High pressure chamber
C1-Lp Low pressure chamber
C2-Lp Low pressure chamber

Claims (1)

A cylinder (21) having an annular cylinder chamber (C1, C2) and an eccentricity with respect to the cylinder (21) are accommodated in the cylinder chamber (C1, C2). The cylinder chamber (C1, C2) is placed in the outer cylinder chamber ( C1) and the inner piston chamber (C2) are divided into an annular piston (22) and the cylinder chambers (C1, C2). Each cylinder chamber (C1, C2) is placed in a high-pressure chamber (C1-Hp, C2- Hp) and a low pressure chamber (C1-Lp, C2-Lp) with a blade (23) partitioned into a cylinder (21) and an annular piston (22) with a relatively eccentric rotational motion ( 20)
A drive mechanism (30) for driving the compression mechanism (20);
A casing (10) for accommodating the compression mechanism (20),
The compression mechanism (20) is provided with an outer discharge port (45) for discharging gas from the outer cylinder chamber (C1) and an inner discharge port (46) for discharging gas from the inner cylinder chamber (C2). A compressor,
While the cylinder (21) is fixed to the casing (10), the annular piston (22) is connected to the drive mechanism (30),
The annular piston (22) is formed in a C shape in which a part of the annular ring is divided,
The blade (23) is inserted into the cylinder (21) so as 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). Provided,
A swing bush (27) for connecting the annular piston (22) to the blade (23) so as to be swingable at a portion where the annular piston (22) is split ;
The drive mechanism (30) includes an electric motor (30) and a drive shaft (33) connected to the electric motor (30), and is housed in the casing (10).
The drive shaft (33) includes an eccentric portion (33a) that is eccentric from the center of rotation, and an annular piston (22) is coupled to the eccentric portion (33a),
The annular piston (22) is positioned concentrically with the bearing portion (22a) on the outer peripheral side of the bearing portion (22a), and the bearing portion (22a) fitted to the eccentric portion (33a) of the drive shaft (33). An annular piston main body (22b), a bearing part (22a) and an annular piston main body (22b) are provided with a piston side end plate (22c) connecting the one end side in the axial direction of the compression mechanism (20),
The cylinder (21) includes an inner cylinder portion (21b) positioned concentrically with the drive shaft (33) between the bearing portion (22a) and the annular piston body portion (22b), and an annular piston body portion (22b). The other end side in the axial direction of the compression mechanism (20) includes the outer cylinder portion (21a) positioned concentrically with the inner cylinder portion (21b) on the outer peripheral side, and the inner cylinder portion (21b) and the outer cylinder portion (21a). With cylinder end plate (21c) connected at
An outer cylinder chamber (C1) is formed between the cylinder side end plate (21c), piston side end plate (22c), outer cylinder part (21a), and annular piston body part (22b). An inner cylinder chamber (C2) is formed between the side end plate (22c), the inner cylinder part (21b), and the annular piston body part (22b).
The casing (10) includes a suction pipe (14) communicating with the suction side of the compression mechanism (20), and a discharge pipe (15) through which high-pressure gas discharged from the compression mechanism (20) into the casing (10) flows out. And
The space formed between the cylinder side end plate (21c), the piston side end plate (22c), the bearing portion (22a) of the annular piston (22), and the inner cylinder portion (21b) is a high-pressure space. Rotary compressor.

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